机械工程毕业设计外文翻译
机械工程外文翻译(适用于毕业论文外文翻译+中英文对照)
Mechanical engineering1.The porfile of mechanical engineeringEngingeering is a branch of mechanical engineerig,itstudies mechanical and power generation especially power and movement.2.The history of mechanical engineering18th century later periods,the steam engine invention hasprovided a main power fountainhead for the industrialrevolution,enormously impelled each kind of mechznicalbiting.Thus,an important branch of a newEngineering –separated from the civil engineering tools andmachines on the branch-developed together with Birmingham andthe establishment of the Associantion of Mechanical Engineersin 1847 had been officially recognized.The mechanicalengineering already mainly used in by trial and error methodmechanic application technological development into professional engineer the scientific method of which in theresearch,the design and the realm of production used .From themost broad perspective,thedemend continuously to enhance theefficiencey of mechanical engineers improve the quality of work,and asked him to accept the history of the high degreeof education and training.Machine operation to stress not only economic but also infrastructure costs to an absolute minimun.3.The field of mechanical engineeringThe commodity machinery development in the develop country,in the high level material life very great degree is decided each kind of which can realize in the mechanical engineering.Mechanical engineers unceasingly will invent the machine next life to produce the commodity,unceasingly will develop the accuracy and the complexity more and more high machine tools produces the machine.The main clues of the mechanical development is:In order to enhance the excellent in quality and reasonable in price produce to increase the precision as well as to reduce the production cost.This three requirements promoted the complex control system development.The most successful machine manufacture is its machine and the control system close fusion,whether such control system is essentially mechanical or electronic.The modernized car engin production transmission line(conveyer belt)is a series of complex productions craft mechanization very good example.The people are in the process of development in order to enable further automation of the production machinery ,the use of a computer to store and handle largevolumes of data,the data is a multifunctional machine tools necessary for the production of spare parts.One of the objectives is to fully automated production workshop,threerotation,but only one officer per day to operate.The development of production for mechanical machinery must have adequate power supply.Steam engine first provided the heat to generate power using practical methods in the old human,wind and hydropower,an increase of engin .New mechanical engineering industry is one of the challenges faced by the initial increase thermal effciency and power,which is as big steam turbine and the development of joint steam boilers basically achieved.20th century,turbine generators to provide impetus has been sustained and rapid growth,while thermal efficiency is steady growth,and large power plants per kW capital consumption is also declining.Finally,mechanical engineers have nuclear energy.This requires the application of nuclear energy particularly high reliability and security, which requires solving many new rge power plants and the nuclear power plant control systems have become highly complex electroonics,fluid,electricity,water and mechanical parts networks All in all areas related to the mechanical engineers.Small internal combustion engine,both to the type(petrol and diesel machines)or rotary-type(gas turbines and Mong Kerr machine),as well as their broad application in the field of transport should also due to mechanical enginerrs.Throughout the transport,both in the air and space,or in the terrestrial and marine,mechanial engineers created a variety of equipment and power devices to their increasing cooperation with electrical engineers,especially in the development of appropration control systems.Mechanical engineers in the development of military weapons technology and civil war ,needs a similar,though its purpose is to enhance rather than destroy their productivity.However.War needs a lot of resources to make the area of techonlogy,many have a far-reaching development in peacetime efficiency.Jet aircraft and nuclear reactors are well known examples.The Biological engineering,mechanical engineering biotechnology is a relatively new and different areas,it provides for the replacement of the machine or increase the body functions as well as for medical equipment.Artficial limbs have been developed and have such a strong movement and touch response function of the human body.In the development of artificial organ transplant is rapid,complex cardiac machines and similar equipment to enable increasingly complexsurgery,and injuries and ill patients life functions can be sustained.Someenviromental control mechanical engineers through the initial efforts to drainage or irrigation pumping to the land and to mine and ventilation to control the human environment.Modern refrigeration and air-conditioning plant commonaly used reverse heat engine,where the heat from the engine from cold places to more external heat.Many mechanical engineering products,as well as other leading technology development city have side effects on the environment,producingnoise,water and air pollution caused,destroyed land and landscape.Improve productivity and diver too fast in the commodity,that the renewable natural forces keep pace.For mechanical engineers and others,environmental control is rapidly developing area,which includes a possible development and production of small quantities of pollutants machine sequnce,and the development of new equipment and teachnology has been to reduce and eliminate pollution.4.The role of mechanical engineeringThere are four generic mechanical engineers in common to the above all domains function.The 1st function is the understanding and the research mechanical sciencefoundation.It includes the power and movement of the relationship dynamics For example,in the vibration and movement of the relationship;Automaticcontrol;Study of the various forms of heart,energy,power relations between the thermodynamic;Fluidflows; Heat transfer; Lubricant;And material properties.The 2nd function will be conducts the research,thedesing and the development,this function in turn attempts to carry on the essential change to satisfy current and the future needs.This not only calls for a clear understanding of mechanical science,and have to break down into basic elements of a complex system capacity.But also the need for synthetic and innovative inventions.The 3rd function is produces the product and the power,includeplan,operation and maintenance.Its goal lies in the maintenance either enhances the enterprise or the organization longer-tern and survivabilaty prestige at the same time,produces the greatest value by the least investments and the consumption.The 4th function is mechanical engineer’s coordinated function,including the management,theconsultation,as well as carries on the market marking in certain situation.In all these function,one kind unceasingly to use thescience for a long time the method,but is not traditional or the intuition method tendency,this is a mechanical engineering skill aspect which unceasingly grows.These new rationalization means typical names include:The operations research,the engineering economics,the logical law problem analysis(is called PABLA) However,creativity is not rationalization.As in other areas,in mechanicalengineering, to take unexpected and important way to bring about a new capacity,still has a personal,markedcharacteristice.5.The design of mechanical engineeringThe design of mechanical is the design has the mechanical property the thing or the system,suchas:the instrument and the measuring appliance in very many situations,the machine design must use the knowledge of discipline the and so on mathematics,materials science and mechanics.Mechanical engineering desginincludeing all mechanical desgin,but it was a study,because it also includes all the branches of mechsnicalengineering,such as thermodynamics all hydrodynamics in the basic disciplines needed,in the mechanical engineering design of the initial stude or mechanical design.Designstages.The entire desgin process from start to finish,in the process,a demand that is designed forit and decided to do the start.After a lot of repetition,the final meet this demand by the end of the design procees and the plan.Designconsiderations.Sometimes in a system is to decide which parts needs intensity parts of geometric shapes and size an important factor in this context that we must consider that the intensity is an important factor in the design.When we use expression design considerations,we design parts that may affect the entire system design features.In the circumstances specified in the design,usually for a series of such functions must be taken into account.Howeever,to correct purposes,we should recognize that,in many cases the design of important design considerations are not calculated or test can determine the components or systems.Especiallystudents,wheen in need to make important decisions in the design and conduct of any operation that can not be the case,they are often confused.These are not special,they occur every day,imagine,forexample,a medical laboratory in the mechanical design,from marketing perspective,people have high expectations from the strength and relevance of impression.Thick,and heavy parts installed together:to produce a solid impression machines.And sometimes machinery and spare parts from the design style is the point and not theother point of view.Our purpose is to make those you do not be misled to believe that every design decision will need reasonable mathematical methods.Manufacturing refers to the raw meterials into finished products in the enterprise.Create three distinct phases.Theyare:input,processingexprot.The first phase includes the production of all products in line with market needs essential.First there must be the demand for the product,the necessary materials,while also needs such as energy,time,human knowledge and technology resourcess . Finall,the need for funds to obtain all the other resources. Lose one stage after the second phase of the resources of the processes to be distributed.Processing of raw materials into finished products of these processes.To complete the design,based on the design,and then develop plans.Plan implemented through various production processes.Management of resources and processes to ensure efficiency and productivity.Forexample,we must carefully manage resources to ensure proper use of funds.Finally,people are talking about the product market was cast.Stage is the final stage of exporting finished or stage.Once finished just purchased,it must be delivered to the users.According to productperformance,installation and may have to conduct further debugging in addition,someproducts,especially those very complex products User training is necessary.6.The processes of materials and maunfacturingHere said engineering materials into two main categories:metals and non-ferrous,high-performance alloys and power metals.Non-metallic futher divided into plastice,syntheticrubber,composite materials and ceramics.It said the production proccess is divided into several major process,includingshape,forging,casting/founding,heattreatment,fixed/connections ,measurement/ quality control and materalcutting.These processes can be further divide into each other’s craft.Various stages of the development of the manufacturing industry Over the years,the manufacturing process has four distinct stages of development, despite the overlap.These stages are:The first phase is artisanal,the second Phase is mechanization.The third phase is automation the forth Phase is integrated.When mankind initial processing of raw materials into finished products will be,they use manual processes.Each with their hands and what are the tools manusllyproduced.This is totally integrated production take shape.A person needsindentification,collectionmaterials,the design of a product to meet that demand,the production of such products and use it.From beginning to end,everything is focused on doing the work of the human ter in the industrial revolution introduced mechanized production process,people began to use machines to complete the work accomplished previously manual. This led to the specialization.Specialization in turn reduce the manufacture of integrated factors.In this stage of development,manufacturing workers can see their production as a whole represent a specific piece of the part of the production process.Onecan not say that their work is how to cope with the entire production process,or how they were loaded onto a production of parts finished.Development of manufacting processes is the next phase of the selection process automation.This is a computer-controlled machinery and processes.At this stage,automation island began to emerge in the workshop lane.Each island represents a clear production process or a group of processes.Although these automated isolated island within the island did raise the productivity of indivdualprocesses,but the overall productivity are often not change.This is because the island is not caught in other automated production process middle,but not synchronous withthem .The ultimate result is the efficient working fast parked through automated processes,but is part of the stagnation in wages down,causingbottlenecks.To better understand this problem,you can imagine the traffic in the peak driving a red light from the red Service Department to the next scene. Occasionally you will find a lot less cars,more than being slow-moving vehicles,but the results can be found by the next red light Brance.In short you real effect was to accelerate the speed of a red Department obstruction offset.If you and other drivers can change your speed and red light simultaneously.Will advance faster.Then,all cars will be consistent,sommthoperation,the final everyone forward faster.In the workshop where the demand for stable synchronization of streamlined production,and promoted integration of manufacturing development.This is a still evolving technology.Fully integrated in the circumstances,is a computer-controllrd machinery and processing.integrated is completed through computer.For example in the preceding paragraph simulation problems,the computer will allow all road vehicles compatible with the change in red.So that everyone can steady traffic.Scientific analysis of movement,timing and mechanics ofthe disciplines is that it is composed of two pater:statics and dynamics.Statics analyzed static system that is in the system,the time is not taken into account,research and analysis over time and dynamics of the system change.Dynameics from the two componets.Euler in 1775 will be the first time two different branches: Rigid body movement studies can conveniently divided into two parts:geometric and mechanics.The first part is without taking into account the reasons for the downward movement study rigid body from a designated location to another point of the movement,and must use the formula to reflect the actual,the formula would determine the rigid body every point position. Therefore,this study only on the geometry and,morespecifically,on the entities from excision.Obviously,the first part of the school and was part of a mechanical separation from the principles of dynamics to study movement,which is more than the two parts together into a lot easier.Dynamics of the two parts are subsequently divided into two separate disciplines,kinematic and dynamics,a study of movement and the movement strength.Therefore,the primary issue is the design of mechanical systems understand its kinematic.Kinematic studies movement,rather than a study ofits impact.In a more precise kinematic studies position,displacement,rotation, speed,velocity and acceleration of disciplines,foresample,or planets orbiting research campaing is a paradigm.In the above quotation content should be pay attention that the content of the Euler dynamics into kinematic and rigid body dynamics is based on the assumption that they are based on research.In this very important basis to allow for the treatment of two separate disciplines.For soft body,soft body shape and even their own soft objects in the campaign depends on the role of power in their possession.In such cases,should also study the power and movement,and therefore to a large extent the analysis of the increased complexity.Fortunately, despite the real machine parts may be involved are more or less the design of machines,usually with heavy material designed to bend down to the lowest parts.Therefore,when the kinematic analysis of the performance of machines,it is often assumed that bend is negligible,spare parts are hard,but when the load is known,in the end analysis engine,re-engineering parts to confirm this assnmption.机械工程1.机械工程简介机械工程是工程学的一个分支，它研究机械和动力的产，尤其是力和动力。
机械设计毕业设计翻译
机械设计毕业设计翻译Introduction to Mechanical EngineeringMechanical engineering is the branch of engineering that deals with machines and the production of power. It is particularly concerned with forces and motion.History of Mechanical EngineeringThe invention of the steam engine in the latter part of the 18th century, providing a key source of power for the Industrial Revolution, gave an enormous impetus to the development of machinery of all types. As a result a new major classification of engineering, separate from civil engineering and dealing with tools and machines, developed, receiving formal recognition in 1847 in the founding of the Institution of Mechanical Engineers in Birmingham, England.Mechanical engineering has evolved from the practice by the mechanic of an art based largely on trial and error to the application by the professional engineer of the scientific method in research, design, and production.The demand for increased efficiency, in the widest sense, is continually raising the quality of work expected from a mechanical engineer and requiring of him a higher degree of education and training. Not only must machines run more economically but capital Costs also must be minimized.Fields of Mechanical EngineeringDevelopment of machines for the production of goods the high material standard of living in the developed countries owes much to the machinery made possible by mechanical engineering. The mechanical engineer continually invents machines to produce goods and develops machine tools of increasing accuracy and complexity to build the machines.The principal lines of development of machinery have been an increase in the speed of operation to obtain high rates of production, improvement in accuracy to obtain quality and economy in the product, and minimization of operating costs. These three requirements have led to the evolution of complex control systems.The most successful production machinery is that in which the mechanical design of the machine is closely integrated with the control system, whether the latter is mechanical or electrical in nature. A modern transfer line (conveyor) for the manufacture of automobile engines is a good example of the mechanization of a complex series of manufacturing processes. Developments are in hand to automate production machinery further, using computers to store and process the vast amount of data required for manufacturing a variety of components with a small number of versatile machine tools. One aim is a completely automated machine shop for batch production, operating on a three shift basis but attended by a staff for only one shift per day.Development of machines for the production of power Production machinery presuppose an ample supply of power. The steam engine provided the first practical means of generating power from heat to augment the old sources of power from muscle, wind, and waterOne of the first challenges to the new profession of mechanical engineering was to increase thermal efficiencies and power; this was done principally by the development of the steam turbine and associated large steam boilers. The 20th century has witnessed a continued rapid growth in the power output of turbines for driving electric generators, together with a steady increase in thermal efficiency and reduction in capital cost per kilowatt of large power stations. Finally, mechanical engineers acquired the resource of nuclear energy, whose application has demanded an exceptional standard of reliability and safety involving the solution of entirely new problems- The control systems of large power plank and complete nuclear power stations have become highly sophisticated networks of electronic, fluidic. Electric, hydraulic, and mechanical components, ail of these involving me province of the mechanical engineer.The mechanical engineer is also responsible for the much smaller internal combustion engines, both reciprocating (gasoline and diesel) and rotary (gas-turbine and Wankel) engines, with their widespread transport applications- In the transportation field generally, in air and space as well as on land and sea. the mechanical engineer has created the equipment and the power plant, collaborating increasingly with the electrical engineer, especially in the development of suitable control systems.Development of military weapons The skills applied to war by the mechanical engineer are similar to those required in civilian applications, though the purpose is to enhance destructive power rather than to raise creative efficiency. The demands of war have channeled huge resources into technical fields, however, and led to developments that have profound benefits in peace. Jet aircraft and nuclear reactors are notable examples.Biaengineering Bioengineering is a relatively new and distinct field of mechanical engineering that includes the provision of machines to replace or augment the functions of the human body and of equipment for use in medical treatment. Artificial limbs have been developed incorporating such lifelike functions as powered motion and touch feedback. Development is rapid in the direction of artificial spare-part surgery. Sophisticated heart-lung machines and similar equipment permit operations of increasing complexity and permit the vital functions in seriously injured or diseased patients to be maintained.Environmental control Some of the earliest efforts of mechanical engineers were aimed at controlling man's environment by pumping water to drain or irrigate land and by ventilating mines. The ubiquitous refrigerating and air-conditioning plants of the modem age are based on a reversed heat engine, where the supply of power "pumps" heat from the cold region to the warmer exterior.Many of the products of mechanical engineering, together with technological developments in other fields, have side effects on the environment and give rise to noise, the pollution of water and air, and the dereliction of land and scenery. The rate of production, both of goods and power, is rising so rapidly that regeneration by natural forces can no longer keep pace. A rapidly growing field for mechanical engineers and others is environmental control, comprising the development of machines and processes that will produce fewer pollutants and of new equipment and techniques that can reduce or remove the pollution already generated.Functions of Mechanical EngineeringFour functions of the mechanical engineering, common to all the fields mentioned, arecited. The first is the understanding of and dealing with the bases of mechanical science. These include dynamics, concerning the relation between forces and motion, such as in vibration; automatic control; thermodynamics, dealing with the relations among the various forms of heat, energy, and power; fluid flow; heat transfer; lubrication; and properties of materials.Second is the sequence of research, design, and development. This function attempts to bring about the changes necessary to meet present and future needs. Such work requires not only a dear understanding of mechanical science and an ability to analyze a complex system into its basic factors, but also the originality to synthesize and invent.Third is production of products and power, which embraces planning, operation, and maintenance. The goal is to produce the maximum value with the minimum investment and cost while maintaining or enhancing longer term viability and reputation of the enterprise or the institution.Fourth is the coordinating functioning of the mechanical engineering, including management, consulting, and, in some cases, marketing.In all of these functions there is a long continuing trend toward the use of scientific instead of traditional or intuitive methods, an aspect of the ever-growing professionalism of mechanical engineering. Operations research, value engineering, and PABLA (problem analysis by logical approach) are typical titles of such new rationalized approaches. Creativity, however, cannot be rationalized. The ability to take the important and unexpected step that opens up new solutions remains in mechanical engineering, as elsewhere, largely a personal and spontaneous characteristic.The Future of Mechanical EngineeringThe number of mechanical engineers continues to grow as rapidly as ever, while the duration and quality of their training increases. There is a growing: awareness, however, among engineers and in the community at large that the exponential increase in population and living standards is raising formidable problems in pollution of the environment and the exhaustion of natural resources; this clearly heightens the need for all of the technical professions to consider the long-term social effects of discoveries and developments. -There will be an increasing demand for mechanical engineering skills to provide for man's needs while reducing to a minimum the consumption of scarce raw materials and maintaining a satisfactory environment.Introduction to DesignThe Meaning of DesignTo design is to formulate a plan for the satisfaction of a human need. The particular need to be satisfied may be quite well defined from the beginning. Here are two examples in which needs are well defined:1. How can we obtain large quantities of power cleanly, safely, and economical/ without using fossil fuels and without damaging the surface of the earth?2. This gear shaft is giving trouble; there have been eight failures in the last six weeks. Dosomething about it.On the other hand, the statement of a particular need to be satisfied may be so nebulous and ill defined that a considerable amount of thought and effort is necessary in ( order to state it dearly as a problem requiring a solution. Here are two examples.-1. Lots of people are killed in airplane accidents.2. In big cities there are too many automobiles on the streets and highways.This second type of design situation is characterized by the fact that neither the need nor the problem to be solved has been identified. Note, too, that the situation may contain not one problem but many.We can classify design, too. For instance, we speak of:1. Clothing design 7. Bridge design2. Interior design 8. Computer-aided design3. Highway design 9. Heating system design.4. Landscape design 10. Machine design5. Building design 11. Engineering design6. Ship design 12. Process designIn fact, there are an endless number, since we can classify design according to the particular article or product or according to the professional field,In contrast to scientific or mathematical problems, design problems have no unique answers; it is absurd, for example, to request the "correct answer" to a design problem, because there is none. In fact, a "good" answer today may well turn out to be a "poor" answer tomorrow, if there is a growth of knowledge during the period or if there are other structural or societal changes.Almost everyone is Involved with design in one way or another, even in dally living, because problems are posed and situations arise which must be solved. A design problem is not a hypothetical problem at all. Design has an authentic purpose—the creation of an end result by taking definite action, or the creation of something having physical reality. In engineering, the word design conveys different meanings to different persons. Some think of a designer as one who employs the drawing board to draft the details of a gear, clutch, or other machine member. Others think of design as the creation of a complex system, such as a communications network. In some areas of engineering the word design has been replaced by other terms such as systems engineering or applied decision theory. But no matter what words are used to describe the design function, in engineering it is still the process in which scientific principles and the tools of engineering—mathematics, computers, graphics, and English—are used to produce a plan which, when carried out, will satisfy a human need.Mechanical Engineering DesignMechanical design means die design of things and systems of a mechanical nature machines, products, structures, devices, and instruments. For the most part, mechanical design utilizes mathematics, the materials sciences, and the engineering-mechanics sciences.Mechanical engineering design includes all mechanical design, but it is a broader study, because it includes all the disciplines of mechanical engineering, such as the thermal and fluids sciences, too. Aside from the fundamental sciences that are required, the first studies in mechanical engineering design are in mechanical design.The Phases of DesignThe complete process, from start to finish. The process W begins with a recognition of a need and a decision to do something about it. After much iteration, the process ends with the presentation of the plans for satisfying the need.Design ConsiderationsSometimes the strength required of an element in a system is an important factor in the determination of the geometry and the dimensions of the element. In such a situation we say that strength is an important design consideration. When we use the expression design consideration, we are referring to some characteristic which influences the design of the element or, perhaps, the entire system. Usually quite a number of such characteristics must be considered in a given design situation. Many of the important ones are as follows:1. Strength2. Reliability3. Thermal properties4. Corrosion5. Wear6. Friction7. Processing8. Utility9. Cost10. Safety11. Weight12. Life 13. Noise14. Styling15. Shape16. Size17. Flexibility18. Control19. Stiffness20. Surface finish21. Lubrication22. Maintenance23. V olume24. LiabilitySome of these have to do directly with the dimensions, the material, the processing, and the joining of the elements of the system. Other considerations affect the configuration of the total system.To keep the correct perspective, however, it should be observed that in many design situations the important design considerations are such that no calculations or experiments are necessary in order to define an element or system. Students, especially, are often confounded when they run into situations in which it is virtually impossible to make a single calculation and yet an important design decision must be made. These are not extraordinary occurrences at all; they happen every day. Suppose that it is desirable from a sales standpoint—for example, in medical laboratory machinery—to create an impression of great strength and durability. Thicker parts assembled with larger-than-usual oversize bolts can be used to create a rugged-looking machine. Sometimes machines and their parts are designed purely from the standpoint of styling and nothing else. These points are made here so that you will not be misled into believing that there is a rational mathematical approach to every design decision.ManufacturingManufacturing is that enterprise concerned with converting raw material into finished products. There are three distinct phases in manufacturing. These phases are as follows: input, processing, and output.The first phase includes all of the elements necessary to create a marketable product. First, there must be a demand or need for the product. The necessary materials must be (available. Also needed are such resources as energy, time, human knowledge, and human skills. Finally, it takes capital to obtain all of the other resources.Input resources are channeled through the various processes in Phase Two. These are the processes used to convert raw materials into finished products. A design is developed. Based on the design, various types of planning are accomplished. Plans are put into action through various production processes. The various resources and processes are managed to ensure efficiency and productivity. For example, capital resources must be carefully managed to ensure they are used prudently. Finally, the product in question is marketed.The final phase is the output or finished product. Once the finished product has been purchased it must be transported to users. Depending on the nature of the product, installation and ongoing field support may be required. In addition, with some products, particularly those of a highly complex nature, training is necessary.Materials and Processes in ManufacturingEngineering materials covered herein are divided into two broad categories:metals and nonmetals. Metals are subdivided into ferrous metals, nonferrous metals, high-performance alloys, and powdered metals. Nonmetals are subdivided into plastics, elastomers, composites, and ceramics. Production processes covered herein are divided into several broad categories including forming, forging, casting/molding, .heat treatment^ .fastening joining metrology/quality control, and material removal. Each of these is subdivided into several other processes.Stages in the Development of ManufacturingOver the years, manufacturing processes have- gone through four distinct, -although overlapping, stages of development. These stages are as follows: Stage 1 ManualStage 2 MechanizedStage 3 AutomatedStage 4 IntegratedWhen people first began converting raw materials into finished products, they used manual processes. Everything was accomplished using human hands and manually operated tools. This was a very rudimentary form of fully integrated manufacturing. A person identified the need, collected materials, designed a product to meet the need, produced the product, and used it. Everything from start to finish was integrated within the mind of the person who did all the work.Then during the industrial revolution mechanized processes were introduced and humans began using machines to accomplish work previously accomplished manually. This led to work specialization which, in turn, eliminated the integrated aspect of manufacturing. In this stage of development, manufacturing workers might see only that part of an overall manufacturing operation represented by that specific piece on which they worked. There was no way to tell how their efforts fit into the larger picture or their workpiece into the finished product.The next stage in the development of manufacturing processes involved the automation of selected processes. This amounted to computer control of machines and processes. During this phase, islands of automation began to spring up on the shop floor. Each island represented a distinct process or group of processes used in the production of a product. Although these islands of automation did tend to enhance the productivity of the individual processes within the islands, overall productivity often was unchanged. This was because the islands were sandwiched in among other processes that were not automated and were not synchronized with them.The net result was that workpieces would move quickly and efficiently through the automated processes only to back up at manual stations and create bottlenecks. To understand this problem, think of yourself driving from stoplight to stoplight in rush hour traffic Occasionally you find an opening and an: able to rush ahead of the other cars that are creeping along, only to find yourself backed up at the next light. The net effect of your brief moment of speeding ahead is canceled out by the bottleneck at the next stoplight. Better progress would be made if you and the other drivers could synchronize your speed to the changing of the stoplights. Then all cars would move steadily and consistently along and everyone would make better progress in the long run.This need for steady, consistent flow on the shop floor led to the development of integrated manufacturing, a process that is still emerging. In fully integrated settings, machines and processes are computer controlled and integration is accomplished through computers. In the analogy used in the previous paragraph, computers would synchronize the rate of movement of all cars with the changing of the stoplights so that everyone moved steadily and consistently along.The Science of MechanicsThat branch of scientific analysis which deals with motions, time, and forces is called mechanics and is made up of two parts, static’s and dynamics. Static’s deals with the analysis of stationary systems, i. e., those in which time is not a factor, and dynamics deals with systems which change with time.Dynamics is also made up. of tyro major disciplines, first recognized as separate entities by Euler in 1775.The investigation of the motion of a rigid body may be conveniently separated into two parts, the one geometrical, the other mechanical. In the first part, the transference of the body from a given position to any other position must be investigated without respect to the cause of the motion, and must be represented by analytical formulae, which will define the position of each point of the body. This investigation will therefore be referable solely to geometry, or rather to stereotomy.It is clear that by the separation of this part of the question from the other, which belongs properly to Mechanics, the determination of the motion from dynamical principles will be made much easier than if the two parts were undertaken conjointly.These two aspects of dynamics were later recognized as the distinct sciences of kinematics and kinetics, and deal with motion and the forces producing it respectively.The initial problem in the design of a mechanical system therefore understands its kinematics. Kinematics is the study of motion, quite apart from the forces which produce that motion. More particularly, kinematics is the study of position,displacement rotation, speed, velocity, and acceleration. The study, say of planetary or orbital motion is also a problem in kinematics.It should be carefully noted in the above quotation that Euler based his separation of dynamics into kinematics and kinetics on the assumption that they should deal with rigid bodies. It is this very important assumption that allows the two to be treated separately. For flexible bodies, the shapes of the bodies themselves, and therefore their motions, depend on the forces exerted on them. In this situation, the study of force and motion must take place simultaneously, thus significantly increasing the complexity of the analysis.Fortunately, although all real machine parts are flexible to some degree, machines are usually designed from relatively rigid materials, keeping part deflections to a minimum. Therefore, it is common practice to assume that deflections are negligible and parts are rigid when analyzing a machine's kinematics performance, and then, after the dynamic analysis when loads are known, to design the parts so that this assumption is justified.。
机械类毕业设计外文翻译范文
机械类毕业设计外文翻译、毕业设计（论文）外译文题目：轴承的摩擦与润滑10 月 15 日外文文献原文：Friction , Lubrication of BearingIn many of the problem thus far , the student has been asked to disregard or neglect friction . Actually , friction is present to some degree whenever two parts are in contact and move on each other. The term friction refers to the resistance of two or more parts to movement.Friction is harmful or valuable depending upon where it occurs. friction is necessary for fastening devices such as screws and rivets which depend upon friction to hold the fastener andthe parts together. Belt drivers, brakes, and tires are additional applications where friction is necessary.The friction of moving parts in a machine is harmful because it reduces the mechanical advantage of the device. The heat produced by friction is lost energy because no work takes place. Also , greater power is required to overcome the increased friction. Heat is destructive in that it causes expansion. Expansion may cause a bearing or sliding surface to fit tighter. If a great enough pressure builds up because made from low temperature materials may melt.There are three types of friction which must be overcome in moving parts: (1)starting, (2)sliding, and(3)rolling. Starting friction is the friction between two solids that tend to resist movement. When two parts are at a state of rest, the surface irregularities of both parts tend to interlock and form a wedging action. T o produce motion in these parts, the wedge-shaped peaks and valleys of the stationary surfaces must be made to slide out and over each other. The rougher the two surfaces, the greater is starting friction resulting from their movement .Since there is usually no fixed pattern between the peaks and valleys of two mating parts, the irregularities do not interlock once the parts are in motion but slide over each other. The friction of the two surfaces is known as sliding friction. As shown in figure ,starting friction is always greater than sliding friction .Rolling friction occurs when roller devces are subjected to tremendous stress which cause the parts to change shape or deform. Under these conditions, the material in front of a roller tends to pile up and forces the object to roll slightly uphill. This changing of shape , known as deformation, causes a movement of molecules. As a result ,heat is produced from the addedenergy required to keep the parts turning and overcome friction.The friction caused by the wedging action of surface irregularities can be overcome partly by the precision machining of the surfaces. However, even these smooth surfaces may require the use of a substance between them to reduce the friction still more. This substance is usually a lubricant which provides a fine, thin oil film. The film keeps the surfaces apart and prevents the cohesive forces of the surfaces from coming in close contact and producing heat .Another way to reduce friction is to use different materials for the bearing surfaces and rotating parts. This explains why bronze bearings, soft alloys, and copper and tin iolite bearings are used with both soft and hardened steel shaft. The iolite bearing is porous. Thus, when the bearing is dipped in oil, capillary action carries the oil through the spaces of the bearing. This type of bearing carries its own lubricant to the points where the pressures are the greatest.Moving parts are lubricated to reduce friction, wear, and heat. The most commonly used lubricants are oils, greases, and graphite compounds. Each lubricant serves a different purpose. The conditions under which two moving surfaces are to work determine the type of lubricant to be used and the system selected for distributing the lubricant.On slow moving parts with a minimum of pressure, an oil groove is usually sufficient to distribute the required quantity of lubricant to the surfaces moving on each other .A second common method of lubrication is the splash system in which parts moving in a reservoir of lubricant pick up sufficient oil which is then distributed to all moving parts during each cycle. This system is used in the crankcase of lawn-mower engines to lubricate the crankshaft, connecting rod ,and parts of the piston.A lubrication system commonly used in industrial plants is the pressure system. In this system, a pump on a machine carries the lubricant to all of the bearing surfaces at a constant rate and quantity.There are numerous other systems of lubrication and a considerable number of lubricants available for any given set of operating conditions. Modern industry pays greater attention to the use of the proper lubricants than at previous time because of the increased speeds, pressures, and operating demands placed on equipment and devices.Although one of the main purposes of lubrication is reduce friction, any substance-liquid , solid , or gaseous-capable of controlling friction and wear between sliding surfaces can be classed as a lubricant.V arieties of lubricationUnlubricated sliding. Metals that have been carefully treated to remove all foreign materials seize and weld to one another when slid together. In the absence of such a high degree of cleanliness, adsorbed gases, water vapor ,oxides, and contaminants reduce frictio9n and the tendency to seize but usually result in severe wear; this is called “unlubricated ”or dry sliding.Fluid-film lubrication. Interposing a fluid film that completely separates the sliding surfaces results in fluid-film lubrication. The fluid may be introduced intentionally as the oil in the main bearing of an automobile, or unintentionally, as in the case of water between a smooth tuber tire and a wet pavement. Although the fluid is usually a liquid such as oil, water, and a wide。
(完整版)机械毕业设计外文翻译7243268
Introduciton of MachiningHave a shape as a processing method, all machining process for the production of the most commonly used and most important method. Machining process is a process generated shape, in this process, Drivers device on the workpiece material to be in the form of chip removal. Although in some occasions, the workpiece under no circumstances, the use of mobile equipment to the processing, However, the majority of the machining is not only supporting the workpiece also supporting tools and equipment to complete.Machining know the process . For casting, forging and machining pressure, every production of a specific shape of the workpiece, even a spare parts, almost the shape of the structure, to a large extent, depend on effective in the form of raw materials. In general, through the use of expensive equipment and without special processing conditions, can be almost any type of raw materials, mechanical processing to convert the raw materials processed into the arbitrary shape of the structure, as long as the external dimensions large enough, it is possible. Because of a production of spare parts, even when the parts and structure of the production batch sizes are suitable for the original casting, Forging or pressure processing to produce, but usually prefer machining.Strict precision and good surface finish, Machining the second purpose is the establishment of the and surface finish possible on the basis of. Many parts, if any other means of production belonging to the large-scale production, Well Machining is a low-tolerance and can meet the requirements of small batch production. Besides, many parts on the production and processing of coarse process to improve its generalshape of the surface. It is only necessary precision and choose only the surface machining. For instance, thread, in addition to mechanical processing, almost no other processing method for processing. Another example is the blacksmith pieces keyhole processing, as well as training to be conducted immediately after the mechanical completion of the processing.Primary Cutting ParametersCutting the work piece and tool based on the basic relationship between the following four elements to fully describe : the tool geometry, cutting speed, feed rate, depth and penetration of a cutting tool.Cutting Tools must be of a suitable material to manufacture, it must be strong, tough, order to effectively processing, and cutting speed must adapt to the level of specific parts -- with knives. Generally, the more the work piece or tool for reciprocating movement and feed rate on each trip through the measurement of inches. Generally, in other conditions, feed rate and cutting speed is inversely proportional to。
机械类毕业设计外文翻译_New
机械类毕业设计外文翻译外文原文Options for micro-holemakingAs in the macroscale-machining world, holemaking is one of the most— if not the most—frequently performed operations for micromachining. Many options exist for how those holes are created. Each has its advantages and limitations, depending on the required hole diameter and depth, workpiece material and equipment requirements. This article covers holemaking with through-coolant drills and those without coolant holes, plunge milling, microdrilling using sinker EDMs and laser drilling.Helpful HolesGetting coolant to the drill tip while the tool is cutting helps reduce the amount of heat at the tool/workpiece interface and evacuate chips regardless of hole diameter. But through-coolant capability is especially helpful when deep-hole microdrilling because the tools are delicate and prone to failure when experiencing recutting of chips, chip packing and too much exposure to carbide’s worst enemy—heat.When applying flood coolant, the drill itself blocks access to the cutting action. “Somewhere about 3 to 5 diam eters deep, the coolant has trouble getting down to the tip,” said Jeff Davis, vice president of engineering for Harvey Tool Co., Rowley, Mass. “It becomes wise to use a coolant-fed drill at that point.”In addition, flood coolant can cause more harm than good when microholemaking. “The pressure from the flood coolant can sometimes snap fragile drills as they enter the part,” Davis said.The toolmaker offers a line of through-coolant drills with diameters from 0.039" to 0.125" that are able to produce holes up to 12 diameters deep, as well as microdrills without coolant holes from 0.002" to 0.020".Having through-coolant capacity isn’t enough, though. Coolant needs to flow at a rate that enables it to clear the chips out of the hole. Davis recommends, at a minimum, 600 to 800 psi of coolant pressure. “It works much better if you have higher pressure than that,” he added.To prevent those tiny coolant holes from becoming clogged with debris, Davis also recommends a 5μm or finer coolant filter.Another recommendation is to machine a pilot, or guide, hole to prevent the tool from wandering on top of the workpiece and aid in producing a straight hole. When applying a pilot drill, it’s important to select one with an included angle on its point that’s equal t o or larger than the included angle on the through-coolant drill that follows.The pilot drill’s diameter should also be slightly larger. For example, if the pilot drill has a 120° included angle and a smaller diameter than a through-coolant drill with a 140°included angle, “then you’re catching the coolant-fed drill’s corners and knocking those corners off,” Davis said, which damages the drill.Although not mandatory, pecking is a good practice when microdrilling deep holes. Davis suggests a pecking cycle that is 30 to 50 percent of the diameter per peck depth, depending on the workpiece material. This clears the chips, preventing them from packing in the flute valleys.Lubricious ChillTo further aid chip evacuation, Davis recommends applying an oil-based metalworking fluid instead of a waterbased coolant because oil provides greater lubricity. But if a shop prefers using coolant, the fluid should include EP (extreme pressure) additives to increase lubricity and minimize foaming. “If you’ve got a lot of foam,” Davis noted, “the chips aren’t being pulled out the way they are supposed to be.”He added that another way to enhance a tool’s slipperiness while extending its life is with a coating, such as titanium aluminum nitride. TiAlN has a high hardness and is an effective coating for reducing heat’s impact when drilling difficult-to-machine materials, like stainless steel.David Burton, general manager of Performance Micro Tool, Janesville, Wis., disagrees with the idea of coating microtools on the smaller end of the spectrum. “Coatings on tools below 0.020" typically have a negative effect on every machining aspect, from the quality of the initial cut to tool life,” he said. That’s becaus e coatings are not thin enough and negatively alter the rake and relief angles when applied to tiny tools.However, work continues on the development of thinner coatings, and Burton indicated that Performance Micro Tool, which produces microendmills and microrouters and resells microdrills, is working on a project with others to create a submicron-thickness coating. “We’re probably 6 months to 1 year from testing it in the market,” Burton said.The microdrills Performance offers are basically circuit-board drills, which are also effective for cutting metal. All the tools are without through-coolant capability. “I had a customer drill a 0.004"-dia. hole in stainless steel, and he was amazed he could do it with a circuit-board drill,” Burton noted, adding th at pecking and running at a high spindle speed increase the drill’s effectiveness.The requirements for how fast microtools should rotate depend on the type ofCNCcharged EDM wire. The fine-hole option includes a W-axis attachment, which holds a die that guides the electrode, as well as a middle guide that prevents the electrode from bending or wobbling as it spins. With the option, the machine is appropriate for drilling hole diameters less than 0.005".Another sinker EDM for micro-holemaking is the Mitsubishi VA10 with afine-hole jig attachment to chuck and guide the fine wire applied to erode the material. “It’s a standard EDM, but with that attachment fixed to the machine, we can do microhole drilling,” said Dennis Powderly, sinker EDM product manager for MC Machinery Systems Inc., Wood Dale, Ill. He added that the EDM is also able to create holes down to 0.0004" using a wire that rotates at up to 2,000 rpm.Turn to TungstenEDMing is typically a slow process, and that holds true when it is used for microdrilling. “It’s very slow, and the finer the details, the slower it is,” said , president and owner of Optimation Inc. The Midvale, Utah, company builds Profile 24 Piezo EDMs for micromachining and also performs microEDMing on a contract-machining basis.Optimation produces tungsten electrodes using a reverse-polarity process and machines and ring-laps them to as small as 10μm in diameter with 0.000020" roundness. Applying a 10μm-dia. electrode produces a hole about 10.5μm to 11μm in diameter, and blind-holes are possible with th e company’s EDM. The workpiece thickness for the smallest holes is up to 0.002", and the thickness can be up to 0.04" for 50μm holes.After working with lasers and then with a former EDM builder to find a better way to produce precise microholes, Jorgense n decided the best approach was DIY. “We literally started with a clean sheet of paper and did all the electronics, all the software and the whole machine from scratch,” he said. Including the software, the machine costs in the neighborhood of $180,000 to $200,000.Much of the company’s contract work, which is provided at a shop rate of $100 per hour, involves microEDMing exotic metals, such as gold and platinum for X-ray apertures, stainless steel for optical applications and tantalum and tungsten for the electron-beam industry. Jorgensen said the process is also appropriate for EDMing partially electrically conductive materials, such as PCD.“The customer normally doesn’t care too much about the cost,” he said. “We’ve done parts where there’s $20,000 [in time and material] involved, and you can put the whole job underneath a fingernail. We do everything under a microscope.”Light CuttingBesides carbide and tungsten, light is an appropriate “tool material” formicro-holemaking. Although most laser drilling is performed in the infrared spectrum, the SuperPulse technology from The Ex One Co., Irwin, Pa., uses a green laser beam, said Randy Gilmore, the company’s director of laser technologies. Unlike the femtosecond variety, Super- Pulse is a nanosecond laser, and its green light operates at the 532-nanometer wavelength. The technology provides laser pulses of 4 to 5 nanoseconds in duration, and those pulses are sent in pairs with a delay of 50 to 100 nanoseconds between individual pulses. The benefits of this approach are twofold. “It greatly enhances material removal compared to other nanosecond lasers,” Gilmore said, “and greatly reduces the amount of thermal damage done to the workpiece material” because of the pulses’ short duration.The minimum diameter produced with the SuperPulse laser is 45 microns, but one of the most common applications is for producing 90μm to 110μm holes in diesel injector nozzles made of 1mm-thick H series steel. Gilmore noted that those holes will need to be in the 50μm to 70μm ra nge as emission standards tighten because smaller holes in injector nozzles atomize diesel fuel better for more efficient burning.In addition, the technology can produce negatively tapered holes, with a smaller entrance than exit diameter, to promote better fuel flow.Another common application is drilling holes in aircraft turbine blades for cooling. Although the turbine material might only be 1.5mm to 2mm thick, Gilmore explained that the holes are drilled at a 25° entry angle so the air, as it comes out of the holes, hugs the airfoil surface and drags the heat away. That means the hole traverses up to 5mm of material. “Temperature is everything in a turbine” he said, “because in an aircraft engine, the hotter you can run the turbine, the better the fuel economy and the more thrust you get.”To further enhance the technology’s competitiveness, Ex One developed apatent-pending material that is injected into a hollow-body component to block the laser beam and prevent back-wall strikes after it creates the needed hole. After laser machining, the end user removes the material without leaving remnants.“One of the bugaboos in getting lasers accepted in the diesel injector community is that light has a nasty habit of continuing to travel until it meets anothe r object,” Gilmore said. “In a diesel injector nozzle, that damages the interior surface of the opposite wall.”Although the $650,000 to $800,000 price for a Super- Pulse laser is higher than a micro-holemaking EDM, Gilmore noted that laser drilling doesn’t require electrodes. “A laser system is using light to make holes,” he said, “so it doesn’t have a consumable.”Depending on the application, mechanical drilling and plunge milling, EDMing and laser machining all have their place in the expanding microm achining universe. “People want more packed into smaller spaces,” said Makino’s Kiszonas.中文翻译微孔的加工方法正如宏观加工一样，在微观加工中孔的加工也许也是最常用的加工之一。
机械类毕业设计外文翻译 (2)
外文原文Options for micro-holemakingAs in the macroscale-machining world, holemaking is one of the most— if not the most—frequently performed operations for micromachining. Many options exist for how those holes are created. Each has its advantages and limitations, depending on the required hole diameter and depth, workpiece material and equipment requirements. This article covers holemaking with through-coolant drills and those without coolant holes, plunge milling, microdrilling using sinker EDMs and laser drilling.Helpful HolesGetting coolant to the drill tip while the tool is cutting helps reduce the amount of heat at the tool/workpiece interface and evacuate chips regardless of hole diameter. Butthrough-coolant capability is especially helpful when deep-hole microdrilling because the tools are delicate and prone to failure when experiencing recutting of chips, chip packing and too much exposure to carbide’s worst enemy—heat.When applying flood coolant, the drill itself blocks access to the cutting action. “Somewhere about 3 to 5 diameters deep, the coolant has trouble getting down to the tip,” said Jeff Davis, vice president of engineering for Harvey Tool Co., Rowley, Mass. “It becomes wise to use a coolant-fed drill at that point.”In addition, flood coolant can cause more harm than good when microholemaking. “The pressure from the flood coolant can sometimes snap fragile drills as they enter the part,” Davis said.The toolmaker offers a line of through-coolant drills with diameters from 0.039" to 0.125" that are able to produce holes up to 12 diameters deep, as well as microdrills without coolant holes from 0.002" to 0.020".Having through-coolant capacity isn’t enough, though. Coolant needs to flow at a rate that enables it to clear the chips out of the hole. Davis recommends, at a minimum, 600 to 800 psi of coolant pressure. “It works much better if you have higher pressure than that,” he added.To prevent those tiny coolant holes from becoming clogged with debris, Davis also recommends a 5μm or finer coolant filter.Another recommendation is to machine a pilot, or guide, hole to prevent the tool from wandering on top of the workpiece and aid in producing a straight hole. When applying a pilot drill, it’s important to select one with an included angle on its point that’s equal to or larger than the included angle on the through-coolant drill that follows. The pilot drill’sdiameter should also be slightly larger. For example, if the pilot drill has a 120° included angle and a smaller diameter than a through-coolant drill with a 140° included angle, “then you’re catching the coolant-fed drill’s corners and knocking those corners off,” Davis said, which damages the drill.Although not mandatory, pecking is a good practice when microdrilling deep holes. Davis suggests a pecking cycle that is 30 to 50 percent of the diameter per peck depth, depending on the workpiece material. This clears the chips, preventing them from packing in the flute valleys.Lubricious ChillTo further aid chip evacuation, Davis recommends applying an oil-based metalworking fluid instead of a waterbased coolant because oil provides greater lubricity. But if a shop prefers using coolant, the fluid should include EP (extreme pressure) additives to increase lubricity and minimize foaming. “If you’ve got a lot of foam,” Davis noted, “the chips aren’t being pulled out the way they are supposed to be.”He added that another way to enhance a tool’s slipperiness while extending its life is with a coating, such as titanium aluminum nitride. TiAlN has a high hardness and is an effective coating for reducing heat’s impact when drilling difficult-to-machine materials, like stainless steel.David Burton, general manager of Performance Micro Tool, Janesville, Wis., disagrees with the idea of coating microtools on the smaller end of the spectrum. “Coatings on tools below 0.020" typically have a negative effect on every machining aspect, from the quality of the initial cut to tool life,” he said. That’s because coatings are not thin enough and negatively alter the rake and relief angles when applied to tiny tools.However, work continues on the development of thinner coatings, and Burton indicated that Performance Micro Tool, which produces microendmills and microrouters and resells microdrills, is working on a project with others to create a submicron-thickness coating. “We’re probably 6 months to1 year from testing it in the market,” Burton said.The microdrills Performance offers are basically circuit-board drills, which are also effective for cutting metal. All the tools are without through-coolant capability. “I had a customer drill a 0.004"-dia. hole in stainless steel, and he was amazed he could do it with a circuit-board drill,” Burton noted, adding that pecking and running at a high spindle speed increase the drill’s effectiveness.The requirements for how fast microtools should rotate depend on the type of CNC machines a shop uses and the tool diameter, with higher speeds needed as the diameter decreases. (Note: The equation for cutting speed is sfm = tool diameter × 0.26 × spindlespeed.)Although relatively low, 5,000 rpm has been used successfully by Burton’s customers. “We recommend that our customers find the highest rpm at the lowest possible vibration—the sweet spot,” he said.In addition to minimizing vibration, a constant and adequate chip load is required to penetrate the workpiece while exerting low cutting forces and to allow the rake to remove the appropriate amount of material. If the drill takes too light of a chip load, the rake face wears quickly, becoming negative, and tool life suffers. This approach is often tempting when drilling with delicate tools.“If the customer decides he wants to baby the tool, he takes a lighter chip load,” Burton said, “and, typically, the cutting edge wears much quicker and creates a radius where the land of that radius is wider than the chip being cut. He ends up using it as a grinding tool, trying to bump material away.” For tools larger than 0.001", Burton considers a chip load under0.0001" to be “babying.” If the drill doesn’t snap, premature wear can result in abysmal tool life.Too much runout can also be destructive, but how much is debatable. Burton pointed out that Performance purposely designed a machine to have 0.0003" TIR to conduct in-house, worst-case milling scenarios, adding that the company is still able to mill a 0.004"-wide slot “day in and day out.”He added: “You would think with 0.0003" runout and a chip load a third that, say,0.0001" to 0.00015", the tool would break immediately because one flute would be taking the entire load and then the back end of the flute would be rubbing.When drilling, he indicated that up to 0.0003" TIR should be acceptable because once the drill is inside the hole, the cutting edges on the end of the drill continue cutting while the noncutting lands on the OD guide the tool in the same direction. Minimizing run out becomes more critical as the depth-to-diameter ratio increases. This is because the flutes are not able to absorb as much deflection as they become more engaged in the workpiece. Ultimately, too much runout causes the tool shank to orbit around the tool’s center while the tool tip is held steady, creating a stress point where the tool will eventually break.Taking a PlungeAlthough standard microdrills aren’t generally available below 0.002", microendmills that can be used to “plunge” a hole are. “When people want to drill smaller than that, they use our endmills and are pretty successful,” Burton said. However, the holes ca n’t be very deep because the tools don’t have long aspect, or depth-to-diameter, ratios. Therefore, a 0.001"-dia. endmill might be able to only make a hole up to 0.020" deep whereas a drill of the same sizecan go deeper because it’s designed to place the load on its tip when drilling. This transfers the pressure into the shank, which absorbs it.Performance offers endmills as small as 5 microns (0.0002") but isn’t keen on increasing that line’s sales. “When people try to buy them, I very seriously try to talk them out of it because we don’t like making them,” Burton said. Part of the problem with tools that small is the carbide grains not only need to be submicron in size but the size also needs to be consistent, in part because such a tool is comprised of fewer grains. “The 5-micron endmill probably has 10 grains holding the core together,” Burton noted.He added that he has seen carbide powder containing 0.2-micron grains, which is about half the size of what’s commercially available, but it also contain ed grains measuring 0.5 and 0.6 microns. “It just doesn’t help to have small grains if they’re not uniform.”MicrovaporizationElectrical discharge machining using a sinker EDM is another micro-holemaking option. Unlike , which create small holes for threading wire through the workpiece when wire EDMing, EDMs for producing microholes are considerably more sophisticated, accurate and, of course, expensive.For producing deep microholes, a tube is applied as the electrode. For EDMing smaller but shallower ho les, a solid electrode wire, or rod, is needed. “We try to use tubes as much as possible,” said Jeff Kiszonas, EDM product manager for Makino Inc., Auburn Hills, Mich. “But at some point, nobody can make a tube below a certain diameter.” He added that some suppliers offer tubes down to 0.003" in diameter for making holes as small as 0.0038". The tube’s flushing hole enables creating a hole with a high depth-to-diameter ratio and helps to evacuate debris from the bottom of the hole during machining.One such sinker EDM for producing holes as small as 0.00044" (11μm) is Makino’s Edge2 sinker EDM with fine-hole option. In Japan, the machine tool builder recently produced eight such holes in 2 minutes and 40 seconds through 0.0010"-thick tungsten carbide at the hole locations. The electrode was a silver-tungsten rod 0.00020" smaller than the hole being produced, to account for spark activity in the gap.When producing holes of that size, the rod, while rotating, is dressed with a charged EDM wire. The fine-hole option includes a W-axis attachment, which holds a die that guides the electrode, as well as a middle guide that prevents the electrode from bending or wobbling as it spins. With the option, the machine is appropriate for drilling hole diameters less than 0.005".Another sinker EDM for micro-holemaking is the Mitsubishi VA10 with a fine-holejig attachment to chuck and guide the fine wire applied to erode the material. “It’s a standardEDM, but with that attachment fixed to the machine, we can do m icrohole drilling,” said Dennis Powderly, sinker EDM product manager for MC Machinery Systems Inc., Wood Dale,Ill. He added that the EDM is also able to create holes down to 0.0004" using a wire that rotates at up to 2,000 rpm.Turn to TungstenEDMing is typically a slow process, and that holds true when it is used for microdrilling. “It’s very slow, and the finer the details, the slower it is,” said , president and owner of Optimation Inc. The Midvale, Utah, company builds Profile 24 Piezo EDMs for micromachining and also performs microEDMing on a contract-machining basis.Optimation produces tungsten electrodes using a reverse-polarity process and machines and ring-laps them to as small as 10μm in diameter with 0.000020" roundness. Applying a10μm-dia. electrode produces a hole about 10.5μm to 11μm in diameter, and blind-holes are possible with the company’s EDM. The workpiece thickness for the smallest holes is up to 0.002", and the thickness can be up to 0.04" for 50μm holes.After working with lasers and then with a former EDM builder to find a better way to produce precise microholes, Jorgensen decided the best approach was DIY. “We literally started with a clean sheet of paper and did all the electronics, all the software and the whole machine from scratch,” he said. Including the software, the machine costs in the neighborhood of $180,000 to $200,000.Much of the company’s contract work, which is provided at a shop rate of $100 per hour, involves microEDMing exotic metals, such as gold and platinum for X-ray apertures, stainless steel for optical applications and tantalum and tungsten for the electron-beam industry. Jorgensen said the process is also appropriate for EDMing partially electricallyconductive materials, such as PCD.“The customer normally doesn’t care too much about the cost,” he said. “We’ve done parts where there’s $20,000 [in time and material] involved, and you can put the whole job underneath a fingernail. We do everything under a microscope.”Light CuttingBesides carbide and tungsten, light is an appropriate “tool material” formicro-holemaking. Although most laser drilling is performed in the infrared spectrum, the SuperPulse technology from The Ex One Co., Irwin, Pa., uses a green laser beam, said Randy G ilmore, the company’s director of laser technologies. Unlike the femtosecond variety, Super- Pulse is a nanosecond laser, and its green light operates at the 532-nanometer wavelength. The technology provides laser pulses of 4 to 5 nanoseconds in duration, and those pulses are sent in pairs with a delay of 50 to 100 nanoseconds between individual pulses. The benefits of this approach are twofold. “It greatly enhances material removal compared to other nanosecond lasers,” Gilmore said, “and greatly reduces th e amount of thermal damage。
机械设计制造及其自动化毕业论文中英文资料外文翻译
机械设计创造及其自动化毕业论文外文文献翻译INTEGRATION OF MACHINERY译文题目专业机械设计创造及其自动化外文资料翻译INTEGRATION OF MACHINERY（From ELECTRICAL AND MACHINERY INDUSTRY）ABSTRACTMachinery was the modern science and technology development inevitable result, this article has summarized the integration of machinery technology basic outline and the development background .Summarized the domestic and foreign integration of machinery technology present situation, has analyzed the integration of machinery technology trend of development.Key word： integration of machinery ，technology， present situation ，product t，echnique of manufacture ，trend of development0. Introduction modern science and technology unceasing development, impelled different discipline intersecting enormously with the seepage, has caused the project domain technological revolution and the transformation .In mechanical engineering domain, because the microelectronic technology and the computer technology rapid development and forms to the mechanical industry seepage the integration of machinery, caused the mechanical industry the technical structure, the product organization, the function and the constitution, the production method and the management systemof by machinery for the characteristic integration ofdevelopment phase.1. Integration of machinery outline integration of machinery is refers in the organization new owner function, the power function, in the information processing function and the control function introduces the electronic technology, unifies the system the mechanism and the computerization design and the software which constitutes always to call. The integration of machinery development also has become one to have until now own system new discipline, not only develops along with the science and technology, but also entrusts with the new content .But its basic characteristic may summarize is: The integration of machinery is embarks from the system viewpoint, synthesis community technologies and so on utilization mechanical technology, microelectronic technology, automatic control technology, computer technology, information technology, sensing observation and control technology, electric power electronic technology, connection technology, information conversion technology as well as software programming technology, according to the system function goal and the optimized organization goal, reasonable disposition and the layout various functions unit, in multi-purpose, high grade, redundant reliable, in the low energy consumption significance realize the specific function value, and causes the overall system optimization the systems engineering technology .From this produces functional system, then becomes an integration of machinery systematic or the integration of machinery product. Therefore, of coveringtechnology is based on the above community technology organic fusion one kind of comprehensive technology, but is not mechanical technical, the microelectronic technology as well as other new technical simple combination, pieces together .This is the integration of machinery and the machinery adds the machinery electrification which the electricity forms in the concept basic difference .The mechanical engineering technology has the merely technical to develop the machinery electrification, still was the traditional machinery, its main function still was replaces with the enlargement physical strength .But after develops the integration of machinery, micro electron installment besides may substitute for certain mechanical parts the original function, but also can entrust with many new functions,like the automatic detection, the automatic reduction information, demonstrate the record, the automatic control and the control automatic diagnosis and the protection automatically and so on .Not only namely the integration of machinery product is human's hand and body extending, human's sense organ and the brains look, has the intellectualized characteristic is the integration of machinery and the machinery electrification distinguishes in the function essence.2. Integration of machinery development condition integration of machinery development may divide into 3 stages roughly.20th century 60's before for the first stage, this stage is called the initial stage .In this time, the people determination not on own initiative uses the electronic technology the preliminary achievement to consummate the mechanical product the performance .Specially in Second World War period, the war has stimulated the mechanical product and the electronic technology union, these mechanical and electrical union military technology, postwar transfers civilly, to postwar economical restoration positive function .Developed and the development at that time generally speaking also is at the spontaneouscondition .Because at that time the electronic technology development not yet achieved certain level, mechanical technical and electronic technology union also not impossible widespread and thorough development, already developed the product was also unable to promote massively. The 20th century 70~80 ages for the second stage, may be called the vigorous development stage .This time, the computer technology, the control technology, the communication development, has laid the technology base for the integration of machinery development . Large-scale, ultra large scale integrated circuit and microcomputer swift and violent development, has provided the full material base for the integration of machinery development .This time characteristic is :①A mechatronics word first generally is accepted in Japan, probably obtains the quite widespread acknowledgment to 1980s last stages in the worldwide scale ;②The integration of machinery technology and the product obtained the enormous development ;③The various countries start to the integration of machinery technology and the product give the very big attention and the support. 1990s later periods, started the integration of machinery technology the new stagewhich makes great strides forward to the intellectualized direction, the integration of machinery enters the thorough development time .At the same time, optics, the communication and so on entered the integration of machinery, processes the technology also zhan to appear tiny in the integration of machinery the foot, appeared the light integration of machinery and the micro integration of machinery and so on the new branch; On the other hand to the integration of machinery system modeling design, the analysis and the integrated method, the integration of machinery discipline system and the trend of development has all conducted the thorough research .At the same time, because the hugeprogress which domains and so on artificial intelligence technology, neural network technology and optical fiber technology obtain, opened the development vast world for the integration of machinery technology .These research, will urge the integration of machinery further to establish the integrity the foundation and forms the integrity gradually the scientific system. Our country is only then starts from the beginning of 1980s in this aspect to study with the application .The State Councilsummary had considered fully on international the influence which and possibly brought from this about the integration of machinery technology developmenttrend .Many universities, colleges and institutes, the development facility and some large and middle scale enterprises have done the massive work to this technical development and the application, does not yield certain result, but and so on the advanced countries compared with Japan still has the suitable disparity.3. Integration of machinery trend of development integrations of machinery are the collection machinery, the electron, optics, the control, the computer, the information and so on the multi-disciplinary overlapping syntheses, its development and the progress rely on and promote the correlation technology development and the progress .Therefore, the integration of machinery main development direction is as follows:3.1 Intellectualized intellectualizations are 21st century integration of machinery technological development important development directions .Theartificial intelligence obtains day by day in the integration of machinery constructor's research takes, the robot and the numerical control engine bedis to the machine behavior description, is in the control theory foundation, the absorption artificial intelligence, the operations research, the computer science, the fuzzy mathematics, the psychology, the physiology and the chaos dynamics and so on the new thought, the new method, simulate the human intelligence, enable it to have abilities and so on judgment inference, logical thinking, independent decision-making, obtains the higher control goal in order to .Indeed, enable the integration of machinery product to have with the human identical intelligence, is not impossible, also is nonessential .But, the high performance, the high speed microprocessor enable the integration of machinery product to have preliminary intelligent or human's partial intelligences, then is completely possible and essential.In the modern manufacture process, the information has become the control manufacture industry the determining factor, moreover is the most active actuation factor .Enhances the manufacture system information-handling capacity to become the modern manufacture science development a key point .As a result of the manufacture system information organization and structure multi-level, makes the information the gain, the integration and the fusion presents draws up the character, information measure multi-dimensional, as well as information organization's multi-level .In the manufacture information structural model, manufacture information uniform restraint, dissemination processing and magnanimous data aspects and so on manufacture knowledge library management, all also wait for further break through.Each kind of artificial intelligence tool and the computation intelligence method promoted the manufacture intelligence development in the manufacture widespread application .A kind based on the biological evolution algorithm computation intelligent agent, in includes thescheduling problem in the combination optimization solution area of technology, receives the more and more universal attention, hopefully completes the combination optimization question when the manufacture the solution speed and the solution precision aspect breaks through the question scale in pairs the restriction .The manufacture intelligence also displays in: The intelligent dispatch, the intelligent design, the intelligent processing, the robot study, the intelligent control, the intelligent craft plan, the intelligent diagnosis and so on are various These question key breakthrough, may form the product innovation the basic research system. Between 2 modern mechanical engineering front science different science overlapping fusion will have the new science accumulation, the economical development and society's progress has had the new request and the expectation to the science and technology, thus will form the front science .The front science also has solved and between the solution scientific question border area .The front science has the obvious time domain, the domain and the dynamic characteristic .The project front science distinguished in the general basic science important characteristic is it has covered the key science and technology question which the project actual appeared.Manufacture system is a complex large-scale system, for satisfies the manufacture system agility, the fast response and fast reorganization ability, must profit from the information science, the life sciences and the social sciences and so on the multi-disciplinary research results, the exploration manufacture system new architecture, the manufacture pattern and the manufacture system effective operational mechanism .Makes the system optimization the organizational structure and the good movement condition is makes the system modeling , the simulation and the optimized essential target .Not only the manufacture system new architecture to makes the enterprise the agility and may reorganize ability to the demand response ability to have the vital significance, moreover to made the enterprise first floor production equipment the flexibility and may dynamic reorganization ability set a higher request .The biological manufacture view more and more many is introduced the manufacture system, satisfies the manufacture system new request.The study organizes and circulates method and technique of complicated system from the biological phenomenon, is a valid exit which will solve many hard nut to cracks that manufacturing industry face from now on currently .Imitating to living what manufacturing point is mimicry living creature organ of from the organization, from match more, from growth with from evolution etc. function structure and circulate mode of a kind of manufacturing system and manufacturing process.The manufacturing drives in the mechanism under, continuously by one's own perfect raise on organizing structure and circulating mode and thus to adapt the process of[with] ability for the environment .For from descend but the last product proceed together a design and make a craft rules the auto of the distance born, produce system of dynamic state reorganization and product and manufacturing the system tend automatically excellent provided theories foundation and carry out acondition .Imitate to living a manufacturing to belong to manufacturing science and life science of"the far good luck is miscellaneous to hand over", it will produce to the manufacturing industry for 21 centuries huge of influence .机电一体化摘要机电一体化是现代科学技术发展的必然结果,本文简述了机电一体化技术的基本概要和发展背景。
机械毕业设计外文翻译原文（万能!!!）
机械毕业设计外⽂翻译原⽂（万能）CA6140 lathe CNC turret design transformationL i YunchaoNortheast China Electric Power University 132012 China466595838@/doc/c69df869a5e9856a561260f4.htmlAbstract: The transformation of ordinary machine tools are CNC machining of small and medium enterprises to improve the accuracy of a way to reduce the auxiliary processing time is now shorter processing time is a major means of automatic rotary tool holder so the transformationis the main part of NC.Keywords: CNC turret rotation transformation of the Hall element1 IntroductionMachine is the basis of equipment manufacturing industry, which directly affects the level of technology manufacturing industry. Currently, the processing center as the representative of the NC machine tool commonly used by developed countries has become a modern industrial manufacturing plant processing unit. From the development of general machine tools to CNC machine tools, machine tool structure in the transmission and a leap forward with this adaptation, CNC machine tools in its structural design will surely require new design methods and theories to guide.China as a developing country, the CNC machine tools are expensive, some SMEs unableto acquire CNC machine, so the general transformation of NC machine tools is a better and more economical way, a CK6140 needs funds 115,000, while the CA6140 CNC Lathe 2.7 million renovation needs.Machine tool holder is one of the main components, but also one of the objects need to transform NC. Turret accuracy, rigidity and reliability of a direct impact on machine performance, in the deadly machine analysis, the deadly turret is the highest degree, digital control system to issue commands, the turret does not turn position, knife switch bit errors, misplaced turret, turret alarm, turret tool change and a seriesof failures can not be normal so that the machine will not work properly. This paper briefly describes the economic CA6140 Machine Tool CNC turret part of the transformation of the transformation of design.The need for reform knife, according to the modified object to determine the main processing machine. If using a knife to complete the processing on this machine, there is no need to transform the knife. For multi-knife, such as lathe modified take three or four knives to complete all the sewing process, we must transform the turret components. That removed the original manual turret, fitted with electric or hydraulic drive controlled by the numerical control device of automatic knife.Turret lathe is mainly used for holding the cutting tool used, so a direct impact on the structure function of the cutting lathe and cutting efficiency, according to the type of machine tool holder, properties and use the occasion of the comprehensive comparison, the specific use by the Changzhou Wang of CNC equipment factory production L D4-CK6140 four-station automatic rotary tool holder. The turret has shifted fast, high positioning accuracy, the advantages of tangential torque, sending translocation by the Hall element, long life. Rotating turret with automatic replacement of ordinary knife, remove the original turret and small slide plate, put LD4-CK6140 electric knife.2, the turret control design2.1 The process of tool changeRotating turret tool change, the first cutter release (lift), cutter knife near translocation arrived at the designated position, the last cutter reset (drop) clamping. When the control2011 Second International Conference on Digital Manufacturing & Automationinstruction issued by ATC, through the interface circuit to the motor is transferred, by the structure of transmission and drive down knife tooth plate on the knife and have a "elevation" action. Then turret body translocation, when the tool holder indexable cutter to need, the Hall switch feedback signal to the motor reversal, the tool rest stops, so that it falls in that location, after the knife to achieve precise positioning, Turret clamping motor to reverse, when the two teeth to a certain clamping force plate, the numerical control device issued a directive to stop the motor reversal, reverse and prevent the motoroverload stop the destruction to complete a tool change process. 2.2 Implementation of ATC functionsTurret tool change process to achieve through the auxiliary control PL C. Set up a Hall sensor position detection tool, knife switch signal as a PLC input signals. PLC on the turret of all the I / O signal processing logic and judge, to achieve turret tool change the order of the process control and automatic tool selection, tool change to allow the signals sent by the CNC system.Switch signal is defined as X (ie the interface of the I signal) PLC output to the tool holder of the switch signal is defined as Y (ie the interface of the O signal) by setting the system parameters in the PL C hardware configuration coefficient and system parameters .Figure 1 controls the turret main circuit operationFigure 2, the Hall element letter trayFigure 1 is to control the operation of the main circuit turret, turret motor controlled by the KM1 Forward looking forward to achieve knife knife,knife motor reversal by the KM2 control to achieve reverse lock knife; Figure 2 letter tray the Hall element, the tool rest on every knife is a fixed cutter, the cutter by the Hall switch in place testing, tool change program instruction specified by the target tool number, tool change system operation to the instruction. ATC will be issued to allow the PLC signal, turret motor clockwise rotation, Hall switch blade position detection, if detected, the cutter location and procedures consistent with the target knife position, the knife to stop the clockwise rotation of the inverse clockwise rotation, tool holder locking reverse positioning. If the requirement can not be completed within the time monitoring the forward and reverse locking tool selection, tool change process is automatically ended, the election monitoring tool time and time lock set by the PLCtimer.3, ConclusionIn the NC lathe, the methods described in this paper is easy to implement, especially in the economic transformation of the NC can be widely used. Practice has proved that after transformation, using three-phase asynchronous machine motor, worm gear, the transmission ratio can be larger, stable tool change, reliability, and to overcome the traditional machine tool supporting the shortcomings of long processing time, tool change time is short, high efficiency .References1?CNC Technology Machinery Industry Press, second edition Zhu Xiaochun2?Guangxi School Metal Cutting Machine Tools Machinery Industry Beijing: China Machine Press. 1979,23?Department of Beijing Institute of Aeronautics CNC machining the structure and transmission. Beijing: National Defence Industry Press .2005,1。
机械类毕业设计外文及其翻译
译文原文题目：State of the art in robotic assembly 译文题目：用机械手装配的发展水平学院：机电工程学院专业班级： 09级机械工程及自动化01班学生姓名：学号：From: of the art in robotic assemblyRobotic assembly systems offer good perspectives for the rationalization of assembly activities. Various bottlenecks are still encountered, however, in the widespread application of robotic assembly systems. This article focuses on the external developments, bottlenecks and development tendencies in robotic assembly.External developmentsThe current market trends are:Increasing international competition, shorter product life cycle, increasing product diversity, decreasing product quantity, shorter delivery times, higher delivery reliability, higher quality requirements and increasing labour costs. Next to these market developments, technological developments also play a role, offering new opportunities to optimize price, quality and delivery time in their mutual relationships. The technological developments are among other things: information technology, new design strategies, new processing techniques, and the availability of flexible production systems, such as industrial robots. Companies will have to adjust their policy to these market and technology developments (market pull and technology push, respectively). This policy is determined by the company objectives and the company strategy which lie at its basis. Under the influence of the external developments mentioned, the company objectives can, in general, be divided into: high flexibility, high productivity, constant and high product quality, short throughput times, and low production costs. Optimizing these competition factors normally results in the generation of more money, and thus (greater) profits. To realize this objective, most companies choose the following strategies: reduction of complexity, application of advanced production technologies, integral approach, quality control, and improvement of the working conditions. Figure 1 shows the company policy in relation to the external developments to which the company policy should be adjusted.Figure 1. External developments and company policyWith regard to the product and production development, a subdivision canbe made into the following strategies which involve[1]:The product: design for manufacturing/assembly, a short development time, a more frequent development of new products, function integration to minimize the number of parts, miniaturization and standardization.The process: improved controllability, shorter cycle times and minimal stocks. There is a trend increasingly to carry out processes in discrete production in flow form.The production system: the use of universal, modular, and reliable system components, high system flexibility (in relation to decreasing batch sizes, and increasing product variants), and the integration of product systemsin the entire production.State of the artParts manufacturing and assembly together form coherent sub-processes within the production process. In parts manufacturing, the raw material is processed or transformed into product parts in the course of which the form, sizes and/or properties of the material are changed. In assembly the product parts are put together into subassemblies or into final products. Figure 2 shows the relationships between these functional processes and the most important control processes within an industrial enterprise. This shows that assembly by means of material or product flows is linked to parts manufacturing, and that by means of information flows it is integrated with marketing, product planning, product development, process planning and production control.Figure 2. Assembly as part of the production processAssembly forms an important link in the whole manufacturing process, because this operational activity is responsible for an important part of the total production costs and the throughput time. It is one of the most labour-intensive sectors in which the share of the costs of the assembly can amount from 25 to 75 per cent of the total production costs[1]. Research shows that the share of the labour costs in the assembly in relation to the total manufacturing costs is approximately 45 per cent for lorry engines, approximately 55 per cent for machine tools, and approximately 65 per cent for electrical apparatus[1]. The centre of the cost items moves more and more fromthe parts manufacturing to the assembly, as automation of the parts manufacturing has been introduced on a larger scale and more consistently than for the assembly. This is mainly due to the complexity of the assembly process and is also a result of assembly unfriendly product designs. As a result, there are high assembly costs. Furthermore, it appears that assembly accounts for approximately 20 to 50per cent of the total throughput time[1].On the one hand, rationalization and automation of the assembly offer good opportunities to minimize the production costs and the throughput time. However, success depends on numerous factors, such as an integral perception of assembly in conjunction with marketing, product planning, product development, process planning, production control and parts manufacturing (see Figure 2). For this purpose, an assembly-friendly product and process design are of essential importance. Research shows that the design costs of a product amount to only approximately 5 per cent of the manufacturing costs on average, and that the product design influences approximately 70 per cent of these costs. Examples are alternative material choice, differently shaped parts, and/or having one part fulfil various functions. On the other hand, rationalization and automation of the assembly provide the opportunity of taking advantage of external developments, such as increasing product diversity, shorter delivery times, and a shorter product life cycle (see Figure 1).Except for the complexity of the product and process design, the performance of robotic assembly systems is also determined by the degree of synchronization between the assembly system and the parts manufacturing, the flexibility of the end-effectors and of the peripheral equipment, as well as by the system configuration. In Japan, most robotic assembly systems have a line configuration in contrast with the systems in the USA and Europe. Apart from Europe and the USA, preference is increasingly given to robotic assembly systems in Japan, instead of manual and mechanized systems. The largest area of application of robotic assembly systems in Japan is the electromechanical industry (40 per cent), followed by the car industry (approximately 27 per cent).Increasingly, robot applications are envisaged for the assembly of complex final products, in several varieties and in low to medium-high production volumes. Research has shown that robotic assembly offers good perspectives insmall to medium-size batch production with annual production volumes between 100,000 and 600,000 product compositions per shift. The production volumes for robotic assembly cells lie between approximately 200 and 620 products per hour, and for robotic assembly lines between approximately 220 and 750 products per hour[1].BottlenecksExperience has shown that various bottlenecks still thwart the widespread application of robotic assembly systems. These bottlenecks include: a high complexity of the product and process design, a low quality level of the product parts, as well as product dependence of the peripheral equipment. From a study in Germany into the automation of the assembly process in 355 companies, it appeared that 40 per cent of the companies had an unsuitable product design, 30 per cent had too complex processing of the parts, and 25 per cent had too complex assembly operations[5]. This study confirms the importance of design for assembly(DFA).The second area in which difficulties occur concerns the limited accuracy ofthe product parts which makes the assembly process unnecessarily complex. This problem can be solved by optimizing the machining processes in the parts manufacturing, and a proper synchronization between the parts manufacturing and the assembly process. The integration of parts manufacture into assembly is also an option.The third area in which difficulties occur involves the robot and the peripheral equipment. The bottlenecks here are:1 Limited acceleration an deceleration of robots: resulting in reduced speed.2 Insufficient means of integrating complex sensors: on the one hand because of the low reliability of these sensors, and on the other hand because of the closeness of robot controllers; a universal language for robotic assembly systems and a standard interface for robot controllers are, unfortunately, not yet available.3 Limited flexibility of grippers and other assembly tools: owing to the product-dependence of these assembly means, end-effector change is in general required, for which on average 30 per cent of the cycle time will be needed[1].4 Limited flexibility of the peripheral equipment: this is generally seen as the main bottleneck. The peripheral equipment is often product-dependent,which affects the system flexibility negatively. In this manner, no justice is done to the high flexibility of the robot.5 Limited reliability of the peripheral equipment and the low accessibility of individual system components: these aspects are greatly influenced by the product complexity and the system configuration[1].These bottlenecks often result in a higher capital consumption, and a longer cycle time of the assembly system. Insufficient coherence and synchronization between product, process and system design often lie at the basis of this. Development tendenciesIn the past years, numerous DFA methods have been developed to optimize product design, reducing the complexity of the assembly process and assembly costs[4,6]. These are based on two principles, namely: avoiding assembly operations and simplifying assembly operations[ 1,4,6]. Avoiding assembly operations can be realized, among other things, by modular product design, and eliminating parts as a result of function integration. Assembly operations can be simplified, for example, by taking numerous design rules into account, such as one assembly direction (preferably from top to bottom), the simple feeding, handling and composing of parts, as well as a good accessibility of the assembly location. Figure 3 shows an application for the robotic assembly of gearboxes, with the execution of top to bottom assembly operations.Figure 3. Robotic assembly of gearboxes (ABB)In the field of the assembly process, there are also new developments occurring. Especially for the assembly friendly composition of parts, new joining methods are being applied, such as:1 adhesive bonding;2 snap fittings. In this manner, a form-closed and force-closed connection can be obtained with small effort;3 insert and outsert techniques. In this respect, metal or plastic parts are moulded together during the injection moulding process.Except for developments in the area of product and process design, new developments in the area of robotic assembly systems have emerged under pressure of the bottlenecks mentioned, and under influence of the external developments (see Figure 1). These can be classified as developments which involve the robot,and developments in the area of the peripheral equipment. The developments regarding the robot are:1 Kinematic and drive: new configurations, lighter constructions, and new drive systems whichguarantee higher speeds and more accuracy.2 Control: increasingly better controlling and programming facilities, as well as the development of standard interfaces for interactions with the environment, and for communication with control systems higher in the hierarchy. CAD and simulation systems are also increasingly applied for off-line programming of robotic assembly systems[7].3 Sensors: new developments in the area of optical and tactile sensors offer good opportunities to increase the controllability of the assembly process.4 End-effectors: new developments in the area of assembly tools and grippers. Especially the integration of optical and tactile sensors, as well as developments in the area of mechanical interfaces, offer in coherence with flexible peripheral equipment the opportunity to assemble various product families in one system.New developments in the area of the peripheral equipment are:1 Development of programmable feeding systems and magazines, which can be used for more than one type of part.2 Integration of sensors in the peripheral equipment for arranging parts and for quality check.3 Increasing miniaturization, universality, and modularity of system components.4 The application of automated guided vehicles (AGVs) as transport system.These developments are particularly initiated by robot manufacturers and technological research institutions, whereas from the viewpoint of industrial engineering, there is mainly interest in new strategies for the development of efficient system layouts, enabling various product variants to be assembled cost efficiently in small batches and in low production volumes. The bottlenecks listed and the development tendencies are summarized in Figure 4.Figure 4. Bottlenecks and developments tendencies in robotic assembly References1. Rampersad, ., Integrated and Simultaneous Design for Robotic Assembly, John Wiley, Chichester, November 1994.2. Rampersad, ., “A concentric design process”, Advanced Summer Institute in Co-operative Intelligent Manufacturing Systems, Proceedings of the ASI 94, Patras, Greece, June 1994, pp. 158-65.3. Rampersad, ., “Integral an d simultaneous design of robotic assembly systems”, paper presented at the Third International Conference on Automation, Robotics and Computer Vision, Singapore, November 1994.4. Boothroyd, G. and Dewhurst, P., Design for Robot Assembly, University of Massachusetts, Armherst, 1985.5. Schraft, . and Baessler, R., “Possibilities to realize assembly-oriented product design”, Proceedings of the 5th International Conference on Assembly Automation, IFS, Paris, 1984.6. Rampersad, ., “The DFA house”, Assembly A utomation, Vol. 13 No. 4, December 1993, pp. 29-36.7. Drimmelen, ., Rampersad, . and Somers, ., “Simulating robotic assembly cells: a general model using coloured petri nets”, Proceedings of the International conference on Data and Knowledge Systems for Manufacturing and Engineering, Hong Kong, May 1994, pp. 368-82.用机械装配的发展水平机器人装配系统为装配活动提供了合理化良好的发展前景。
机械设计毕业设计翻译样本
Mechanical EngineeringIntroduction to Mechanical EngineeringMechanica.engineerin.i.th.branc.o.engineerin.tha.deal.wit.machine.an.th.productio.o.power.I.i.particularl.concerne.wit.force.an.motion.History of Mechanical Engineeringtte.par.o.th.18t.century,providin..ke.sourc.o.powe.fo.th.Industria.Revolution,gav.a.enormou.impetu.t.th.developmen.o.machiner.o.al.types.A..resul..ne.majo.classificatio.o.engineering, separat.fro.civi.engineerin.an.dealin.wit.tool.an.machines, developed, receivin.forma.recognitio.i.184.i.th.foundin.o.th.Institutio.o.Mechanica.Engineer.i.Birmingha m, England.Mechanical engineering has evolved from the practice by the mechanic of an art based largely on trial and error to the application by the professional engineer of the scientific method in research, design, and production.Th.deman.fo.increase.efficiency，i.th.wides.sense，i.continuall.raisin.th.qualit.o.wor.expecte.fro..mechanica.enginee.an.requirin.o.hi..highe.degre.o. 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operatin.o..thre.shif.basi.bu.attende.b..staf.fo.onl.on.shif.pe.day.Developmen.o.machine.fo.th.productio.o.powe..Productio.machiner.presuppos.a.ampl.supp l.o.power.Th.stea.engin.provide.th.firs.practica.mean.o.generatin.powe.fro.hea.t.augmen.th.ol.so urce.o.powe.fro.muscle, wind, an.wate.On.o.th.firs.challenge.t.th.ne.professio.o.mechanica.engineerin.wa.t.increas.therma.effi ciencie.an.power；rg.stea.boilers.Th.20t.centu r.ha.witnesse..continue.rapi.growt.i.th.powe.outpu.o.turbine.fo.drivin.electri.generators, rg.powe.stati ons.Finally, mechanica.engineer.acquire.th.resourc.o.nuclea.energy, whos.applicatio.ha.demande.a.exceptiona.standar.o.reliabilit.an.safet.involvin.th.solutio.o.entire plet.nuclea.powe.station.hav.becom.hig work.o.electronic, fluidic.Electric, hydraulic, ponents, ai.o.thes.involvin.m.provinc.o.th.mechanica.engineer.bustio.engines,bot.reciprocatin.(gasolin.an.diesel.an.rotar.(gas-turbin.an.Wankel.engines,wit.thei.widesprea.transpor.applications.I.th.transportatio.fiel.generally,n.an.sea.th.mechanica.enginee.ha.create.th.equipmen.an.th.powe.plant, collaboratin.increasingl.wit.th.electrica.engineer,especiall.i.th.developmen.o.suitabl.contro.systems.itar.weapon..Th.skill.applie.t.wa.b.th.mechanica.enginee.ar.simila.t.thos.r equire.i.civilia.applications,thoug.th.purpos.i.t.enhanc.destructiv.powe.rathe.tha.t.rais.creativ.efficiency.Th.demand.o.wa.ha v.channele.hug.resource.int.technica.fields, however, an.le.t.development.tha.hav.profoun.benefit.i.peace.Je.aircraf.an.nuclea.reactor.ar.notabl.exampl es.Biaengineerin..Bioengineerin.i..relativel.ne.an.distinc.fiel.o.mechanica.engineerin.tha.inclu .i.me dica.treatment.Artificia.limb.hav.bee.develope.incorporatin.suc.lifelik.function.a.powere.motio. plexit.an.permi.th.vita.functio n.i.seriousl.injure.o.disease.patient.t.b.maintained.Environmenta.contro..Som.o.th.earlies.effort.o.mechanica.engineer.wer.aime.a.controllin.m an'n.an.b.ventilatin.mines.Th.ubiquitou.refrigeratin .an.air-conditionin.plant.o.th.mode.ag.ar.base.o..reverse.hea.engine,wher.th.suppl.o.powe."pumps.hea.fro.th.col.regio.t.th.warme.exterior.Man.o.th.product.o.mechanica.engineering，togethe.wit.technologica.development.i.othe.fields，hav.sid.effect.o.th.environmen.an.giv.ris.t.noise，th.pollutio.o.wate.an.air，n.an.scenery.Th.rat.o.production，bot.o.good.an.power，i.risin.s.rapidl.tha.regeneratio.b.natura.force.ca.n.longe.kee.pace..rapidl.growin.fiel.fo.mechanic a.engineer.an.other.i.environmenta.control，comprisin.th.developmen.o.machine.an.processe.tha.wil.produc.fewe.pollutant.an.o.ne.equipme n.an.technique.tha.ca.reduc.o.remov.th.pollutio.alread.generated.Functions of Mechanical EngineeringFou.function.o.th.mechanica.engineering, commo.t.al.th.field.mentioned, ar.cited.Th.firs.i.th.understandin.o.an.dealin.wit.th.base.o.mechanica.science.Thes.includ.dynam ics, concernin.th.relatio.betwee.force.an.motion, suc.a.i.vibration；automati.control；thermodynamics, dealin.wit.th.relation.amon.th.variou.form.o.heat, energy, an.power；flui.flow；hea.transfer；lubrication；an.propertie.o.materials.Secon.i.th.sequenc.o.research, design, an.development.Thi.functio.attempt.t.brin.abou.th.change.necessar.t.mee.presen.an.futur.need ple.sy ste.int.it.basi.factors, bu.als.th.originalit.t.synthesiz.an.invent.Thir.i.productio.o.product.an.power，whic.embrace.planning，operation，an.maintenance.Th.goa.i.t.produc.th.maximu.valu.wit.th.minimu.investmen.an.cos.whil.maint ainin.o.enhancin.longe.ter.viabilit.an.reputatio.o.th.enterpris.o.th.institution.Fourth is the coordinating functioning of the mechanical engineering, including management, consulting, and, in some cases, marketing..o.scientifi.instea.o.traditiona.o.intui tiv.methods，a.aspec.o.th.ever-growin.professionalis.o.mechanica.engineering.Operation.research，valu.engineering，an.PABL.(proble.analysi.b.logica.approach.ar.typica.title.o.suc.ne.rationalize.approaches.Creati vity，however，canno.b.rationalized.Th.abilit.t.tak.th.importan.an.unexpecte.ste.tha.open.u.ne.solution.remain.i. mechanica.engineering，a.elsewhere，largel..persona.an.spontaneou.characteristic.The Future of Mechanical EngineeringTh.numbe.o.mechanica.engineer.continue.t.gro.a.rapidl.a.ever,whil.th.duratio.an.qualit.o.thei.trainin.increases. Ther.i..growing: awareness, however, rg.tha.th.exponentia.increas.i.populatio.an.livin.standard.i.raisin.formidabl.problem.i. pollutio. o.th.environmen.an.th.exhaustio.o.natura.resources；thi.clearl.heighten.th.nee.fo.al.o.th.technica.profession.t.conside.th.long-ter.socia.effect.o.discov erie.an.developments.-Ther.wil.b.a.increasin.deman.fo.mechanica.engineerin.skill.t.provid.fo.m an'.need.whil.reducin.t..minimu.th.consumptio.o.scarc.ra.material.an.maintainin..satisfactor.envi ronment.Introduction to DesignThe Meaning of DesignT.desig.i.t.formulat..pla.fo.th.satisfactio.o..huma.need.Th.particula.nee.t.b.satisfie.ma.b.qui t.wel.define.fro.th.beginning.Her.ar.tw.example.i.whic.need.ar.wel.defined:1. rg.quantitie.o.powe.cleanly, safely, in.fossi.fuel.an.withou.damagin.th.surfac.o.th.earth?2.Thi.gea.shaf.i.givin.trouble；s.si.weeks.D.somethin.abou.it.O.th.othe.hand,th.statemen.o..particula.nee.t.b.satisfie.ma.b.s.nebulou.an.il.define.tha..considerabl.amoun.o.tho ugh.an.effor.i.necessar.i..orde.t.stat.i.dearl.a..proble.requirin..solution.Her.ar.tw.examples.-1. Lot.o.peopl.ar.kille.i.airplan.accidents.2.I.bi.citie.ther.ar.to.man.automobile.o.th.street.an.highways.Thi.secon.typ.o.desig.situatio.i.characterize.b.th.fac.tha.neithe.th.nee.no.th.proble.t.b.solve. ha.bee.identified.Note, too, tha.th.situatio.ma.contai.no.on.proble.bu.many.W.ca.classif.design, too.Fo.instance, w.spea.of:1.Clothin.design.. 7.Bridg.design2.Interio.desig... puter-aide.design3.Highwa.design.9.Heatin.syste.design.ndscap.desig..10.Machin.design5.Buildin.desig...11.Engineerin.design6.Shi.design...12.Proces.designIn fact, there are an endless number, since we can classify design according to the particular article or product or according to the professional field,I.contras.t.scientifi.o.mathematica.problems, desig.problem.hav.n.uniqu.answers；i.i.absurd, fo.example, t.reques.th."correc.answer.t..desig.problem, becaus.ther.i.none.I.fact, ."good.answe.toda.ma.wel.tur.ou.t.b.."poor.answe.tomorrow, i.ther.i..growt.o.knowledg.durin.th.perio.o.i.ther.ar.othe.structura.o.societa.changes.Almos.everyon.i.Involve.wit.desig.i.on.wa.o.another，eve.i.dall.living，becaus.problem.ar.pose.an.situation.aris.whic.mus.b.solved..desig.proble.i.no..hypothetica.probl e.a.all.Desig.ha.a.authenti.purpose—th.creatio.o.a.en.resul.b.takin.definit.action，o.th.creatio.o.somethin.havin.physica.reality.I.engineering，th.wor.desig.convey.differen.meaning.t.differen.persons.Som.thin.o..designe.a.on.wh.employ.th. drawin.boar.t.draf.th.detail.o..gear，clutch，ple.system，work.I.som.area.o.engineerin.th.wor.desig.ha.bee.replace.b.othe.term.s e.t.describ.th.desig.fun ction，i.engineerin.i.i.stil.th.proces.i.whic.scientifi.principle.an.th.tool.o.engineering—mathematics，computers，graphics，an.English—e.t.produc..pla.which，whe.carrie.out，wil.satisf..huma.need.Mechanical Engineering DesignMechanica.desig.mean.di.desig.o.thing.an.system.o..mechanica.natur.machines, products, structures, devices, an.instruments.Fo.th.mos.part, mechanica.desig.utilize.mathematics,th.material.sciences, an.th.engineering-mechanic.sciences.Mechanica.engineerin.desig.include.al.mechanica.design，bu.i.i..broade.study，becaus.i.include.al.th.discipline.o.mechanica.engineering，suc.a.th.therma.an.fluid.sciences，too.Asid.fro.th.fundamenta.science.tha.ar.required，th.firs.studie.i.mechanica.engineerin.desig.ar.i.mechanica.design.The Phases of Designplet.process,fro.star.t.finish.Th.proces..begin.wit..recognitio.o..nee.an..decisio.t.d.somethin.abou.it.Afte.muc. iteration, th.proces.end.wit.th.presentatio.o.th.plan.fo.satisfyin.th.need.Design ConsiderationsSometime.th.strengt.require.o.a.elemen.i..syste.i.a.importan.facto.i.th.determinatio.o.th.geo metr.an.th.dimension.o.th.element.I.suc..situatio.w.sa.tha.strengt.i.a.importan.desig.consideratio .th.expressio.desig.consideration,w.ar.referrin.t.som.characteristi.whic.influence.th.desig.o.th.elemen.or, perhaps, uall.quit..numbe.o.suc.characteristic.mus.b.considere.i..give.desig.situation.M an.o.th.importan.one.ar.a.follows:1.Strength2.Reliabilit............3.Therma.properties4.Corrosio................5.Wea................6.Friction7.Processin...............8.Utilit............... 9.Cost10.Safet..................11.Weigh.............12.Lif.............13.Nois...................14.Stylin..............15.Shape16.Size17.Flexibilit.............18.Control19.Stiffness20.Surfac.finis........21.Lubrication22.Maintenance23.V olum.............24.LiabilitySom.o.thes.hav.t.d.directl.wit.th.dimensions, th.material, th.processing, an.th.joinin.o.th.element.o.th.system.Othe.consideration.affec.th.config-uratio.o.th.tota.system.T.kee.th.correc.perspective，however，i.shoul.b.observe.tha.i.man.desig.situation.th.importan.desig.consideration.ar.suc.tha.n .calculation.o.experiment.ar.necessar.i.orde.t.defin.a.elemen.o.system.Students，especially，ar.ofte.confounde.whe.the.ru.int.situation.i.whic.i.i.virtuall.impossibl.t.mak..singl.calc ulatio.an.ye.a.importan.desig.decisio.mus.b.made.Thes.ar.no.extraordinar.occurrence.a .all；the.happe.ever.day.Suppos.tha.i.i.desirabl.fro..sale.standpoint—fo.example，borator.machinery—rger-than-us e.t.creat..rugged-lookin.machine.Sometime.machine.an.thei.part .ar.designe.purel.fro.th.standpoin.o.stylin.an.nothin.else.Thes.point.ar.mad.her.s.tha.yo .wil.no.b.misle.int.believin.tha.ther.i..rationa.mathematica.approac.t.ever.desig.decisio n.ManufacturingManufacturin.i.tha.enterpris.concerne.wit.convertin.ra.materia.int.finishe.product s. Ther.ar.thre.distinc.phase.i.manufacturing.Thes.phase.ar.a.follows: input, processing, an.output.Th.firs.phas.include.al.o.th.element.necessar.t.creat..marketabl.product.First, ther.mus.b..deman.o.nee.fo.th.product.Th.necessar.material.mus.b.(available.Als.need e.ar.suc.resource.a.energy, time, huma.knowledge, an.huma.skills.Finally,i.take.capita.t.obtai.al.o.th.othe.resources.Inpu.resource.ar.channele.throug.th.variou.processe.i.Phas.Two.Thes.ar.th.process e.t.conver.ra.material.int.finishe.products..desig.i.developed.Base.o.th.design, variou.type.o.plannin.ar.accomplished.Plan.ar.pu.int.actio.throug.variou.productio.pro cesses.Th.variou.resource.an.processe.ar.manage.t.ensur.efficienc.an.productivity.Fo.e xample, e.prudently.Finally, th.produc.i.questio.i.marketed.Th.fina.phas.i.th.outpu.o.finishe.product.Onc.th.finishe.produc.ha.bee.purchase.i. ers.Dependin.o.th.natur.o.th.product，installatio.an.ongoin.fiel.suppor.ma.b.required.I.addition，wit.som.products，ple.nature，trainin.i.necessary.Materials and Processes in ManufacturingEngineerin.material.covere.herei.ar.divide.int.tw.broa.categories:metal.an.nonmetals.Metal.ar.subdivide.int.ferrou.metals, nonferrou.metals, high-performanc.alloys, an.powdere.metals.Nonmetal.ar.subdivide.int.plastics, elastomers, composites, an.ceramics.Productio..processe.covere.herei.ar.divide.int.severa.broa.categorie.includ in.forming, forging, casting/molding, .hea.treatment..fastenin.joinin.metrology/qualit.control, an.materia.removal.Eac.o.thes.i.subdivide.int.severa.othe.processes.Stages in the Development of ManufacturingOve.th.years,manufacturin.processe.have.gon.throug.fou.distinct,-althoug.overlapping,stage.o.development.Thes.stage.ar.a.follows:Stage 1 ManualStage 2 MechanizedStage 3 AutomatedStage 4 IntegratedWhe.peopl.firs.bega.convertin.ra.material.int.finishe.products,in.huma.hand.an.manuall.opera te.tools.Thi.wa..ver.rudimentar.for.o.full.integrate.manufacturing..perso.identifie.th.ne ed, collecte.materials, designe..produc.t.mee.th.need, produce.th.product, e.it.Everythin.fro.star.t.finis.wa.integrate.withi.th.min.o.th.perso.wh.di.al.th.work .The.durin.th.industria.revolutio.mechanize.processe.wer.introduce.an.human.beg in.machine.t.accomplis.wor.previousl.accomplishe.manually.Thi.le.t.wor.specializ atio.which, i.turn, eliminate.th.integrate.aspec.o.manu-facturing.I.thi.stag.o.development,manufacturin.worker.migh.se.onl.tha.par.o.a.overal.manufacturin.operatio.represente.b.tha.specifi.piec.o.whic.the.workerge.pict ur.o.thei.workpiec.int.th.finishe.product.Th.nex.stag.i.th.developmen.o.manufacturin.processe.involve.th.auto-pute.contro.o.machine.an.pro-cesses.Durin.thi.phase,island.o.automatio.bega.t.sprin.u.o.th.sho.floor.Eac.islan.represente..distinc.proces.o.g e.i.th.productio.o..product.Althoug.thes.island.o.automatio.di.ten.t.en hanc.th.productivit.o.th.individua.processe.withi.th.islands,overal.productivit.ofte.wa.unchanged.Thi.wa.becaus.th.island.wer.sandwiche.i.amon.o the.processe.tha.wer.no.automate.an.wer.no.synchronize.wit.them.Th.ne.resul.wa.tha.workpiece.woul.mov.quickl.an.efficientl.throug.th.automate.pr ocesse.onl.t.bac.u.a.manua.station.an.creat.bottlenecks.T.understan.thi.problem, thin.o.yoursel.drivin.fro.stopligh.t.stopligh.i.rus.hou.traffi.Occasionall.yo.fin.a.openin. an.an：abl.t.rus.ahea.o.th.othe.car.tha.ar.creepin.along, onl.t.fin.yoursel.backe.u.a.th.nex.light.Th.ne.effec.o.you.brie.momen.o.speedin.ahea.i. cancele.ou.b.th.bottlenec.a.th.nex.stoplight.Bette.progres.woul.b.mad.i.yo.an.th.othe.d river.coul.synchroniz.you.spee.t.th.changin.o.th.stoplights.The.al.car.woul.mov.steadil .an.consistentl.alon.an.everyon.woul.mak.bette.progres.i.th.lon.run.Thi.nee.fo.steady，consisten.flo.o.th.sho.floo.le.t.th.developmen.o.integrate.manufacturing，.proces.tha.i .stil.emerging.I.full.integrate.settings，pute e.i.th.previou.paragraph，computer.woul.synchroniz.th.rat.o.movemen.o.al.car.wit.th.changin.o.th.stoplight.s.th a.everyon.move.steadil.an.consistentl.along.The Science of MechanicsTha.branc.o.scientifi.analysi.whic.deal.wit.motions, time,an.force.i.calle.mechanic.an.i.mad.u.o.tw.parts,static’.an.dynamics.Static’.deal.wit.th.analysi.o.stationar.systems, i.e., thos.i.whic.tim.i.no..factor, an.dynamic.deal.wit.system.whic.chang.wit.time.Dynamic.i.als.mad.up.o.tyr.majo.disciplines.firs.recognize.a.separat.entitie.b.Eule .i.1775.Th.investigatio.o.th.motio.o..rigi.bod.ma.b.convenientl.separate.int.tw.parts，th.on.geometrical，th.othe.mechanical.I.th.firs.part，th.transferenc.o.th.bod.fro..give.positio.t.an.othe.positio.mus.b.investigate.withou.resp ec.t.th.caus.o.th.motion，an.mus.b.represente.b.analytica.formulae，whic.wil.defin.th.positio.o.eac.poin.o.th.body.Thi.investigatio.wil.therefor.b.referabl.s olel.t.geometry，o.rathe.t.stereotomy.It is clear that by the separation of this part of the question from the other, which belongs properly to Mechanics, the determination of the motion from dynamical principles will be made much easier than if the two parts were undertaken conjointly.These two aspects of dynamics were later recognized as the distinct sciences of kinematics and kinetics, and deal with motion and the forces producing it respectively.Th.initia.proble.i.th.desig.o..mechanica.syste.therefor.understand.it.kinematics.Kinem atic.i.th.stud.o.motion, quit.apar.fro.th.force.whic.produc.tha.motion.Mor.particularly, kinematic.i.th.stud.o.position, displacemen.rotation, speed, velocity, an.acceleration.Th.study, sa.o.planetar.o.orbita.motio.i.als..proble.i.kinematics.I.shoul.b.carefull.note.i.th.abov.quotatio.tha.Eule.base.hi.separatio.o.dynamic.int.kine matic.an.kinetic.o.th.assumptio.tha.the.shoul.dea.wit.rigi.bodies.I.i.thi.ver.importan.as sumptio.tha.allow.th.tw.t.b.treate.separately.Fo.flexibl.bodies,th.shape.o.th.bodie.themselves, an.therefor.thei.motions, depen.o.th.force.exerte.o.them.I.thi.situation,th.stud.o.forc.an.motio.mus.tak.plac.simultaneously,plexit.o.th.analysis.Fortunately，althoug.al.rea.machin.part.ar.flexibl.t.som.degree，uall.designe.fro.relativel.rigi.materials，keepin.par.deflection.t..minimum.Therefore，mo.practic.t.assum.tha.deflection.ar.negligibl.an.part.ar.rigi.whe.analyzin..mac hine'.kinematic.performance，an.then，afte.th.dynami.analysi.whe.load.ar.known，t.desig.th.part.s.tha.thi.assumptio.i.justified.。
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毕业设计论文外文资料原文及译文学院：机电工程学院专业：机械设计制造及其自动化班级：学号：姓名：Mechanical engineering1.The porfile of mechanical engineeringEngingeering is a branch of mechanical engineerig,it studies mechanical and power generation especially power and movement.2.The history of mechanical engineering18th century later periods,the steam engine invention has provided a main power fountainhead for the industrial revolution,enormously impelled each kind of mechznical biting.Thus,an important branch of a new Engineering – separated from the civil engineering tools and machines on the branch-developed together with Birmingham and the establishment of the Associantion of Mechanical Engineers in 1847 had been officially recognized.The mechanical engineering already mainly used in by trial and error method mechanic application technological development into professional engineer the scientific method of which in the research,the design and the realm of production used .From the most broad perspective,the demend continuously to enhance the efficiencey of mechanical engineers improve the quality ofwork,and asked him to accept the history of the high degree of education and training.Machine operation to stress not only economic but also infrastructure costs to an absolute minimun.3.The field of mechanical engineeringThe commodity machinery development in the develop country,in the high level material life very great degree is decided each kind of which can realize in the mechanical engineering.Mechanical engineers unceasingly will invent the machine next life to produce the commodity,unceasingly will develop the accuracy and the complexity more and more high machine tools produces the machine.The main clues of the mechanical development is:In order to enhance the excellent in quality and reasonable in price produce to increase the precision as well as to reduce the production cost.This three requirements promoted the complex control system development.The most successful machine manufacture is its machine and the control system close fusion,whether such control system is essentially mechanical or electronic.The modernized car engin production transmission line(conveyer belt)is a series of complex productions craft mechanizationvery good example.The people are in the process of development in order to enable further automation of the production machinery ,the use of a computer to store and handle large volumes of data,the data is a multifunctional machine tools necessary for the production of spare parts.One of the objectives is to fully automated production workshop,three rotation,but only one officer per day to operate.The development of production for mechanical machinery must have adequate power supply.Steam engine first provided the heat to generate power using practical methods in the old human,wind and hydropower,an increase of engin .New mechanical engineering industry is one of the challenges faced by the initial increase thermal effciency and power,which is as big steam turbine and the development of joint steam boilers basically achieved.20th century,turbine generators to provide impetus has been sustained and rapid growth,while thermal efficiency is steady growth,and large power plants per kW capital consumption is also declining.Finally,mechanical engineers have nuclear energy.This requires the application of nuclear energy particularly high reliability and security,which requires solving many new rge power plants and the nuclear power plant control systems have become highly complex electroonics,fluid,electricity,water and mechanical parts networks All in all areas related to the mechanical engineers.Small internal combustion engine,both to the type (petrol and diesel machines)or rotary-type(gas turbines and Mong Kerr machine),as well as their broad application in the field of transport should also due to mechanical enginerrs.Throughout the transport,both in the air and space,or in the terrestrial and marine,mechanial engineers created a variety of equipment and power devices to their increasing cooperation with electrical engineers,especially in the development of appropration control systems.Mechanical engineers in the development of military weapons technology and civil war ,needs a similar,though its purpose is to enhance rather than destroy their productivity.However.War needs a lot of resources to make the area of techonlogy,many have a far-reaching development in peacetime efficiency.Jet aircraft and nuclear reactors are well known examples.The Biological engineering,mechanical engineering biotechnology is a relatively new and different areas,it provides for the replacement of the machine or increase thebody functions as well as for medical equipment.Artficial limbs have been developed and have such a strong movement and touch response function of the human body.In the development of artificial organ transplant is rapid,complex cardiac machines and similar equipment to enable increasingly complex surgery,and injuries and ill patients life functions can be sustained.Some enviromental control mechanical engineers through the initial efforts to drainage or irrigation pumping to the land and to mine and ventilation to control the human environment.Modern refrigeration and air-conditioning plant commonaly used reverse heat engine,where the heat from the engine from cold places to more external heat.Many mechanical engineering products,as well as other leading technology development city have side effects on the environment,producing noise,water and air pollution caused,destroyed land and landscape.Improve productivity and diver too fast in the commodity,that the renewable naturalforces keep pace.For mechanical engineers and others,environmental control is rapidly developing area,which includes a possible development and production of small quantities of pollutants machine sequnce,and the development of new equipment and teachnology has been to reduce and eliminate pollution.4.The role of mechanical engineeringThere are four generic mechanical engineers in common to the above all domains function.The 1st function is the understanding and the research mechanical science foundation.It includes the power and movement of the relationship dynamics For example,in the vibration and movement of the relationship;Automatic control;Study of the various forms of heart,energy,power relations between the thermodynamic;Fluidflows; Heat transfer; Lubricant;And material properties.The 2nd function will be conducts the research,the desing and the development,this function in turn attempts to carry on the essential change to satisfy current and the future needs.This not only calls for a clear understanding of mechanical science,and have to breakdown into basic elements of a complex system capacity.But also the need for synthetic and innovative inventions.The 3rd function is produces the product and the power,include plan,operation and maintenance.Its goal lies in the maintenance eitherenhances the enterprise or the organization longer-tern and survivabilaty prestige at the same time,produces the greatest value by the least investments and the consumption.The 4th function is mechanical engineer’s coordinated function,including the management,the consultation,as well as carries on the market marking in certain situation.In all these function,one kind unceasingly to use the science for a long time the method,but is not traditional or the intuition method tendency,this is a mechanical engineering skill aspect which unceasingly grows.These new rationalization means typical names include:The operations research,the engineering economics,the logical law problem analysis(is called PABLA) However,creativity is not rationalization.As in other areas,in mechanical engineering,to take unexpected and important way to bring about a new capacity,still has a personal,marked characteristice.5.The design of mechanical engineeringThe design of mechanical is the design has the mechanical property the thing or the system,such as:the instrument and the measuring appliance in very many situations,the machine design must use the knowledge of discipline the and so on mathematics,materials science and mechanics.Mechanical engineering desgin includeing all mechanical desgin,but it was a study,because it also includes all the branches of mechsnical engineering,such as thermodynamics all hydrodynamics in the basic disciplines needed,in the mechanical engineering design of the initial stude or mechanical design.Design stages.The entire desgin process from start to finish,in the process,a demand that is designed for it and decided to do the start.After a lot of repetition,the final meet this demand by the end of the design procees and the plan.Design considerations.Sometimes in a system is to decide which parts needs intensity parts of geometric shapesand size an important factor in this context that we must consider that the intensity is an important factor in the design.When we use expression design considerations,we design parts that may affect the entire system design features.In the circumstances specified in the design,usually for a series of such functions must be taken into account.Howeever,to correct purposes,we should recognize that,in many cases thedesign of important design considerations are not calculated or test can determine the components or systems.Especially students,wheen in need to make important decisions in the design and conduct of any operation that can not be the case,they are often confused.These are not special,they occur every day,imagine,for example,a medical laboratory in the mechanical design,from marketing perspective,people have high expectations from the strength and relevance of impression.Thick,and heavy parts installed together:to produce a solid impression machines.And sometimes machinery and spare parts from the design style is the point and not the other point of view.Our purpose is to make those you do not be misled to believe that every design decision will needreasonable mathematical methods.Manufacturing refers to the raw meterials into finished products in the enterprise.Create three distinct phases.They are:input,processing exprot.The first phase includes the production of all products in line with market needs essential.First there must be the demand for the product,the necessary materials,while also needs such as energy,time,human knowledge and technology resourcess .Finall,the need for funds to obtain all the other resources. Lose one stage after the second phase of the resources of the processes to be distributed.Processing of raw materials into finished products of these processes.To complete the design,based on the design,and then develop plans.Plan implemented through various production processes.Management of resources and processes to ensure efficiency and productivity.For example,we must carefully manage resources to ensure proper use of funds.Finally,people are talking about the product market was cast.Stage is the final stage of exporting finished or stage.Once finished just purchased,it must be delivered to the users.According to product performance,installation and may have to conduct further debugging in addition,some products,especially those very complex products User training is necessary.6.The processes of materials and maunfacturingHere said engineering materials into two main categories:metals and non-ferrous,high-performance alloys and power metals.Non-metallic futher divided into plastice,synthetic rubber,composite materials and ceramics.It said the productionproccess is divided into several major process,includingshape,forging,casting/ founding,heat treatment,fixed/connections ,measurement/ quality control and materal cutting.These processes can be further divide into each other’s craft.Various stages of the development of the manufacturing industry Over the years,the manufacturing process has four distinct stages of development, despite the overlap.These stages are:The first phase is artisanal,the second Phase is mechanization.The third phase is automation the forth Phase is integrated.When mankind initial processing of raw materials into finished products will be,they use manual processes.Each with their hands and what are the tools manuslly produced.This is totally integrated production take shape.A person needs indentification,collection materials,the design of a product to meet that demand,the production of such products and use it.From beginning to end,everything is focused on doing the work of the human ter in the industrial revolution introduced mechanized production process,people began to use machines to complete the work accomplished previously manual. This led to the specialization.Specialization in turn reduce the manufacture of integrated factors.In this stage of development,manufacturing workers can see their production as a whole represent a specific piece of the part of the production process.One can not say that their work is how to cope with the entire production process,or how they were loaded onto a production of parts finished.Development of manufacting processes is the next phase of the selection process automation.This is a computer-controlled machinery and processes.At this stage,automation island began to emerge in the workshop lane.Each island represents a clear production process or a group of processes.Although these automated isolated island within the island did raise the productivity of indivdual processes,but the overall productivity are often not change.This is because the island is not caught in other automated production process middle,but not synchronous with them .The ultimate result is the efficient working fast parked through automated processes,but is part of the stagnation in wages down,causing bottlenecks.To better understand this problem,you can imagine the traffic in the peak driving a red light from the red Service Department to the next scene. Occasionally you will find a lot less cars,more than being slow-moving vehicles,but the results can be found by thenext red light Brance.In short you real effect was to accelerate the speed of a red Department obstruction offset.If you and other drivers can change your speed and red light simultaneously.Will advance faster.Then,all cars will be consistent,sommth operation,the final everyone forward faster.In the workshop where the demand for stable synchronization of streamlined production,and promoted integration of manufacturing development.This is a still evolving technology.Fully integrated in the circumstances,is a computer-controllrd machinery and processing.integrated is completed through computer.For example in the preceding paragraph simulation problems,the computer will allow all road vehicles compatible with the change in red.So that everyone can steady traffic.Scientific analysis of movement,timing and mechanics of the disciplines is that it is composed of two pater:statics and dynamics.Statics analyzed static system that is in the system,the time is not taken into account,research and analysis over time and dynamics of the system change.Dynameics from the two componets.Euler in 1775 will be the first time two different branches: Rigid body movement studies can conveniently divided into two parts:geometric and mechanics.The first part is without taking into account the reasons for the downward movement study rigid body from a designated location to another point of the movement,and must use the formula to reflect the actual,the formula would determine the rigid body every point position. Therefore,this study only on the geometry and,more specifically,on the entities from excision.Obviously,the first part of the school and was part of a mechanical separation from the principles of dynamics to study movement,which is more than the two parts together into a lot easier.Dynamics of the two parts are subsequently divided into two separate disciplines,kinematic and dynamics,a study of movement and the movement strength.Therefore,the primary issue is the design of mechanical systems understand its kinematic.Kinematic studies movement,rather than a study of its impact.In a more precise kinematic studies position,displacement,rotation, speed,velocity and acceleration of disciplines,for esample,or planets orbiting research campaing is a paradigm.In the above quotation content should be pay attention that the content of the Euler dynamics into kinematic and rigid body dynamics is based on the assumptionthat they are based on research.In this very important basis to allow for the treatment of two separate disciplines.For soft body,soft body shape and even their own soft objects in the campaign depends on the role of power in their possession.In such cases,should also study the power and movement,and therefore to a large extent the analysis of the increased complexity.Fortunately, despite the real machine parts may be involved are more or less the design of machines,usually with heavy material designed to bend down to the lowest parts.Therefore,when the kinematic analysis of the performance of machines,it is often assumed that bend is negligible,spare parts are hard,but when the load is known,in the end analysis engine,re-engineering parts to confirm this assnmption.机械工程1.机械工程简介机械工程是工程学的一个分支，它研究机械和动力的产，尤其是力和动力。