机械设计双语版第4章

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(机械设计理论)双语版

Machine design theory（机械设计理论）——中英文对照The machine design is through designs the new product or improves the old product to meet the human need the application technical science. It involves the project technology each domain, mainly studies the product the size, the shape and the detailed structure basic idea, but also must study the product the personnel which in aspect the and so on manufacture, sale and use question.Carries on each kind of machine design work to be usually called designs the personnel or machine design engineer. The machine design is a creative work. Project engineer not only must have the creativity in the work, but also must in aspect and so on mechanical drawing, kinematics, engineerig material, materials mechanics and machine manufacture technology has the deep elementary knowledge.If front sues, the machine design goal is the production can meet the human need the product. The invention, the discovery and technical knowledge itself certainly not necessarily can bring the advantage to the humanity, only has when they are applied can produce on the product the benefit. Thus, should realize to carries on before the design in a specific product, must first determine whether the people do need this kind of productMust regard as the machine design is the machine design personnel carries on using creative ability the product design, the system analysis and a formulation product manufacture technology good opportunity. Grasps the project elementary knowledge to have to memorize some data and the formula is more important than. The merely service data and the formula is insufficient to the completely decision which makes in a good design needs. On the other hand, should be earnest precisely carries on all operations. For example, even if places wrong a decimal point position, also can cause the correct design to turn wrongly.A good design personnel should dare to propose the new idea, moreover is willing to undertake the certain risk, when the new method is not suitable, use original method. Therefore, designs the personnel to have to have to have the patience, because spends the time and the endeavor certainly cannot guarantee brings successfully. A brand-new design, the request screen abandons obsoletely many, knows very well the method for the people. Because many person of conservativeness, doesthis certainly is not an easy matter. A mechanical designer should unceasingly explore the improvement existing product the method, should earnestly choose originally, the process confirmation principle of design in this process, with has not unified it after the confirmation new idea.Newly designs itself can have the question occurrence which many flaws and has not been able to expect, only has after these flaws and the question are solved, can manifest new goods come into the market the product superiority. Therefore, a performance superior product is born at the same time, also is following a higher risk. Should emphas ize, if designs itself does not request to use the brand-new method, is not unnecessary merely for the goal which transform to use the new method.In the design preliminary stage, should allow to design the personnel fully to display the creativity, not each kind of restraint. Even if has had many impractical ideas, also can in the design early time, namely in front of the plan blueprint is corrected. Only then, only then does not send to stops up the innovation the mentality. Usually, must propose several sets of design proposals, then perform the comparison. Has the possibility very much in the plan which finally designated, has used certain not in plan some ideas which accepts.How does the psychologist frequently discuss causes the machine which the people adapts them to operate. Designs personnel''s basic responsibility is diligently causes the machine to adapt the people. This certainly is not an easy work, because certainly does not have to all people to say in fact all is the most superior operating area and the operating process.Another important question, project engineer must be able to carry on the exchange and the consultation with other concerned personnel. In the initial stage, designs the personnel to have to carry on the exchange and the consultation on the preliminary design with the administrative personnel, and is approved. This generally is through the oral discussion, the schematic diagram and the writing material carries on. In order to carry on the effective exchange, needs to solve the following problem:(1) designs whether this product truly does need for the people? Whether there is competitive ability(2) does this product compare with other companies'' existing similar products?(3) produces this kind of product is whether economical?(4) product service is whether convenient?(5) product whether there is sale? Whether may gain?Only has the time to be able to produce the correct answer to above question. But, the product design, the manufacture and the sale only can in carry on to the above question preliminary affirmation answer foundation in. Project engineer also should through the detail drawing and the assembly drawing, carries on the consultation together with the branch of manufacture to the finally design proposal.Usually, can have some problem in the manufacture process. Possibly can request to some components size or the common difference makes some changes, causes the components the production to change easily. But, in the project change must have to pass through designs the personnel to authorize, guaranteed cannot damage the product the function. Sometimes, when in front of product assembly or in the packing foreign shipment experiment only then discovers in the design some kind of flaw. These instances exactly showed the design is a dynamic process. Always has a better method to complete the design work, designs the personnel to be supposed unceasingly diligentlyRecent year, the engineerig material choice already appeared importantly. In addition, the choice process should be to the material continuously the unceasing again appraisal process. The new material unceasingly appears, but some original materials can obtain the quantity possibly can reduce. The environmental pollution, material recycling aspect and so on use, worker''s health and security frequently can attach the new limiting condition to the choice of material. In order to reduce the weight or saves the energy, possibly can request the use different material. Comes from domestic and international competition, to product service maintenance convenience request enhancement and customer''s aspect the and so on feedback pressure, can urge the people to carry on to the material reappraises. Because the material does not select when created the product responsibility lawsuit, has already had the profound influence. In addition, the material and between the material processing interdependence is already known by the people clearly.Therefore, in order to can and guarantees the quality in the reasonable cost under the premise to obtain satisfaction the result, project engineer makes engineers all to have earnestly carefully to choose, the determination and the use material.Makes any product the first step of work all is designs. Designs usually may divide into several explicit stages: (a) preliminary design; (b) functional design;(c) production design. In the preliminary design stage, the designer emphatically considered the product should have function. Usually must conceive and consider several plans, then decided this kind of thought is whether feasible; If is feasible, then should makes the further improvement to or several plans. In this stage, the question which only must consider about the choice of material is: Whether has the performance to conform to the request material to be possible to supply the choice; If no, whether has a bigger assurance all permits in the cost and the time in the limit develops one kind of new material.In the functional design and the engineering design stage, needs to make a practical feasible design. Must draw up the quite complete blueprint in this stage, chooses and determines each kind of components the material. Usually must make the prototype or the working model, and carries on the experiment to it, the appraisal product function, the reliability, the outward appearance and the service maintenance and so on. Although this kind of experiment possibly can indicate, enters in the product to the production base in front of, should replace certain materials, but, absolutely cannot this point take not earnestly chooses the material the excuse. Should unify the product the function, earnestly carefully considers the product the outward appearance, the cost and the reliability. Has the achievement very much the company when manufacture all prototypes, selects the material should the material which uses with its production in be same, and uses the similar manufacture technology as far as possible. Like this has the advantage very much to the company. The function complete prototype if cannot act according to the anticipated sales volume economically to make, or is prototypical and the official production installment has in the quality and the reliable aspect is very greatly different, then this kind of prototype does not have the great value. Project engineer is best can completely complete the material in this stage the analysis, the choice and the determination work, but is not remains it to the production design stage does. Because, is carries on in the production design stage materialreplacement by other people, these people are inferior to project engineer to the product all functions understanding. In the production design stage, is should completely determine with the material related main question the material, causes them to adapt with the existing equipment, can use the existing equipment economically to carry on the processing, moreover the material quantity can quite be easy to guarantee the supply.In the manufacture process, inevitably can appear to uses the material to make some changes the situation. The experience indicated that, may use certain cheap materials to take the substitute. However, in the majority situation, in will carry on the production later to change the material to have in to start before the production to change the price which the material will spend to have to be higher than. Completes the choice of material work in the design stage, may avoid the most such situations. Started after the production manufacture to appear has been possible to supply the use the new material is replaces the material the most common reason. Certainly, these new materials possibly reduce the cost, the improvement product performance. But, must carry on the earnest appraisal to the new material, guarantees its all performance all to answer the purpose. Must remember that, the new material performance and the reliable very few pictures materials on hand such understood for the people. The majority of products expiration and the product accident caused by negligence case is because in selects the new material to take in front of substitution material, not truly understood their long-term operational performance causes.The product responsibility lawsuit forces designs the personnel and the company when the choice material, uses the best procedure. In the material process, five most common questions are: (a) did not understand or cannot use about the material application aspect most newly the best information paper; (b) has not been able to foresee and to consider the dusk year possible reasonable use (for example to have the possibility, designs the personnel also to be supposed further to forecast and the consideration because product application method not when creates consequence.In r ecent years many products responsibilities lawsuit case, because wrongly uses the plaintiff which the product receives the injury to accuse produces the factory, and wins the decision); (c) uses the material data not entire perhaps some data areindefinite, works as its long-term performance data is the like this time in particular; (d) the quality control method is not suitable and not after the confirmation; (e) the personnel which completely is not competent for the post by some chooses the material.Through to the above five questions analysis, may obtain these questions is does not have the sufficient reason existence the conclusion. May for avoid these questions to these questions research analyses the appearance indicating the direction. Although uses the best choice of material method not to be able to avoid having the product responsibility lawsuit, designs the personnel and the industry carries on the choice of material according to the suitable procedure, may greatly reduce the lawsuit the quantity.May see from the above discussion, the choice material people should to the material nature, the characteristic and the processing method have comprehensive and the basic understanding.机械设计理论机械设计是一门通过设计新产品或者改进老产品来满足人类需求的应用技术科学。

机械工程专业英语Unit 4

Fig 4.2 Forging Grain Flow
锻造晶粒流动
A forged metal can result in the following:
1. Increase length, decrease cross-section, called drawing out the metal.
2. Decrease length, increase cross-section, called upsetting the metal.
greater strength and more uniform structure to large components. 3. On account of the high pressure and squeezing action, it operates with less noise and vibration than a drop-forge. 4. manual operation is impossible and it is essential that all the manipulation of the ingot is done mechanically.
虽然这种液压锻机比落锤锻造要昂贵得多，但它除了能给予大零件较高的强度和更均匀的组织外还有其他优点。由于较高的压力和挤压作用，它比落锤锻造噪声及振动都小得多。人工操作是不可能的，钢坯的所有操作都必须是机械化的。
Fig 4.1 forging progression
锻造进程
Forging Grain Flow
❖ Advantage：can produce components of greater complexity and accuracy, with a better surface finish, than the more traditional methods not using closed dies. 优点：闭式模锻能生产高度复杂和精确的零件，而且表面光洁度要比不用闭式锻模的更传统方法好。

机械设计基础课件第4章

机械设计的基本原则
• 技术性能准则：技术性能包括产品功能、制造和运行状况在内的一切性能，既包含静态性能，也包含动态性能。例如，产品所能传递的功率、效率、使用寿命、强度、刚度、抗摩擦、磨损性能、振动稳定性、热特性等。技术性能原则要求机械设计过程中的所有技术问题都必须得到圆满的解决。
• 经济性准则：经济准则是指以最低的成本获得最好的产品。经济准则要求机械设计的成本尽可能的低，同时又能保证产品的必要功能和质量。
提高疲劳强度的措施
降低应力集中
采用高强度材料
通过改进零件结构形状，避免截面尺寸突变，以及提高表面光洁度等措施，可以降低应力集中，提高疲劳强度。
选用高强度材料，可以提高零件的承载能力，从而提高疲劳强度。
表面强化处理
控制载荷
对零件表面进行喷丸、碾压等强化处理，可以提高表面硬度，增加残余压应力，从而提高疲劳强度。
• 可靠性准则：可靠性准则是指所设计的产品应能满足规定的可靠性要求。可靠性原则要求机械设计的产品在规定的使用条件下，在规定的期限内，应具有完成规定功能的能力。
• 安全性准则：安全性准则是指所设计的产品应能确保人的生命安全。安全性原则要求机械设计的产品必须具有足够的强度、刚度、稳定性、耐磨性，在规定的寿命期内能安全可靠地工作，能抵御各种有害因素的影响，有一定的安全裕度，以防万一出现的危险情况。
预防性维护
建立预防性维护制度，定期对机械零件进行检查、保养和维修，确保其处于良好状态。
06
机械设计中的创新思维与方法
创新思维的定义与特点
定义
创新思维是指在解决问题或创造新事物时，突破传统思维模式，运用独特、新颖的思考方式和方
法。
独特性
创新思维不满足于常规解法，追求独特、新颖的解决方案。

机械设计制造及其自动化-专业外语-Chapter Four Lesson 2 The Design Process

Chapter Four Manufacturing 第四章制造技术 Lesson 2 The Design Process 第二课设计过程
The design process for a product first requires a clear understanding of the functions and the performance expected of that product (Fig.4.3) .The product may be new, or it may be a revised version of an existing product. You undoubtedly have observed, for example, how the design and style of radios, toasters, watches, automobiles, and washing machines have changed. The market for a product and its anticipated uses must be defined clearly, with the assistance of sales personnel, market analysts, and others in the organization.
Hale Waihona Puke 产品的设计过程首先需要对产品所期望的功能和性能有一个清楚的理解。产品可能是新的，或者是已有产品的更新。毫无疑问，你可以看到诸如收音机，烤面包机，手表，汽车，洗衣机设计和样式的改变。借助于销售人员，市场分析师和企业其他人员的帮助，一个产品和他预期的使用市场必须清楚的确定。

机械设计制造及其自动化专业英语课文翻译-Unit1-9

U 1The use of metals has always a key factor in the development of the social systems of man. Of the roughly ['rʌfl ɪ] 100 basic elements of which all matter is composed, about half are classified as metals.金属的开发利用在人类社会系统的发展中扮演了了重要的角色，世界的物质大概由100种基本元素构成，其中一半是金属元素。

The distinction[dɪ'stɪŋkʃən] between a metal and a nonmetal is not always clear cut. The most basic definition centers around the type of bonding existing between the atoms of the element, and around the characteristics [,kærəkt ə'ristiks] of certain of the electrons[ɪ'lɛk,trɑn] associated with these atoms.金属与非金属的区分不是十分的清晰，最重要（基本）的在于元素原子之间的连接形式以及和原子相关联的电子的确定特性。

in a more practical['præktikəl] way, however, a metal can be defined as an element which has a particular package of properties.然而，在更多的实践当中，金属定义为具有一种整体特性的元素。

机械制造技术基础双语第4章

河南科技大学机电工程学院 2
2018/9/4
4.1 Introduction to machine tools’ fixture

4.1.3 Functions and Elements of the Fixture
1. Functions of fixture Take a jig and a milling machine fixture for example

To ensure the machining accuracy reliably, reducing
the influence of humaห้องสมุดไป่ตู้ interference on machining To shorten the set-up assisting time of workpiece, and increase the productivity, further reducing the production cost To enlarge the machining range of machine tools To improve the working condition and decrease the labor intensity
2018/9/4
河南科技大学机电工程学院
5
4.1 Introduction to machine tools’ fixture

2. Components of fixture
◆ Other components or devices. Which are used to meet the loading and unloading workpiece or others needs during machining. Such as auxiliary support, loading/ unloading device, and indexing device etc. ◆ Fixture body Which is a base of the whole fixture and is used to connect all other parts as mentioned above into an integral fixture.

机械设计大纲(双语版)要点

《机械设计》课程教学大纲《Mechanical design》Course syllabus制订人（Author）:涂杰（Tu Jie）总学时数（ total class time）：56（45min/time）理论教学时数(Theory Teaching time)：52 ；实验教学时数（experimental teaching time）:4；学分(credit)：4适用专业（suitable major）: NC Technology一．课程的性质和作用（The task of the course）本课程是机械类专业的一门必修的专业基础课。

通过本课程的学习，为学生在今后的工作中解决机械设计问题打下一定基础,同时也为学生学习后继课程和新的科学技术提供必需的预备知识。

The course is a required professional basic course for mechanical engineering majors,through the course can lay a good foundation for the students to solve the problems of mechanical design.it can also provide the necessary preliminaries for the the successor curriculum.二．课程的基本内容（Basic content of the course）第1章绪论Chapter 1 introduction（1）机械设计研究对象、内容及在国民经济发展中的作用。

（1）research object、contents of the mechanical design.（2）机械、机器、机构及构件的概念。

(2)the conception of Mechanics and mechanism .第2章机械设计概论Chapter 2 Introduction to mechanical design（1）机械设计的基本要求。

机械工程英语叶邦彦第二单元到第四单元课文+翻译

Unit 2 Numerical Control of Production EquipmentUnit 2 生产设备的数字控制Numerical Control (NC) is a form of programmable automation in which the processing equipment is controlled by means of numbers, letters, and other symbols. The numbers, letters, and symbols are coded in an appropriate format to define a program of instructions for a particular work-part or job. 数控是程序控制的自动化，在数字控制系统中，设备通过数字，字母和符号来编码，以一种合适的格式为每一个特定的零件或工件定义一个程序指令集。

When the job changes, the program of instructions is changed. The capability to change the program is what makes NC suitable for low-and medium-volume production. It is much easier to write new programs than to make major alterations of the processing equipment.当工件变化时，程序也变化，改变程序的能力亦适合中小批量生产。

写一个新程序比改变大量生产设备要容易的多。

Basic Components of NC数控基本结构A numerical control system consists of the following three basic components:数控系统由下面三部分组成：• Program of instructions控制程序• Machine control unit机器控制单元• Processing equipment加工设备The general relationship among the three components is illustrated in Fig. 2.1. The program is fed into the control unit, which directs the processing equipment accordingly.三部分的基本关系，由图 2.1 所示。

2024版机械设计基础课件第4章

机械设计基础课件第4章•机械设计概述•机械设计的基本原理•机械零件的设计•机械传动的设计目•液压与气压传动的设计•机械设计实践与应用录机械设计概述机械设计的定义与分类定义分类机械设计的重要性机械设计努力的目标是在各种限定的条件（如材料、加工能力、理论知识和计算手段等）下设计出最好的机械，即做出优化设计。

优化设计需要综合地考虑许多要求，一般有最好工作性能、最低制造成本、最小尺寸和重量、使用中最可靠性、最低的消耗和最少的环境污染。

机械设计的发展趋势绿色化智能化模块化网络化机械设计的基本原理经济性设计应考虑到制造成本、使用成本和维护成本，力求以最低的成本实现所需的功能。

实现预定功能设计应确保机械系统或设备能够实现预定的功能，满足使用要求。

可靠性机械系统或设备应具有足够的可靠性，能在规定的条件下和规定的时间内完成规定的功能。

安全性机械系统或设备应具有足够的安全性，能防止人员伤亡和财产损失。

环保性设计应考虑到环境保护的要求，减少对环境的污染和资源的浪费。

机械设计的基本要求明确设计任务了解用户需求，明确设计目标、限制条件和设市场调研与资料收集方案设计与评价详细设计制造与试验设计修改与完善机械设计的一般步骤机械设计中的创新思维01020304突破传统思维模式借鉴跨领域知识利用现代科技手段关注用户需求变化机械零件的设计机械零件的分类与功能根据结构和功能分类01根据运动形式分类02根据材料分类03机械零件的设计准则保证零件在机器中的使用性能，如传递动力、支撑载荷、保持运动精度等。

零件的结构形状应便于加工制造和测量，尽量采用标准件和通用件。

在满足使用要求的前提下，尽量降低制造成本和节约原材料。

保证零件在规定的使用条件下和规定的时间内，完成规定功能的能力。

满足使用要求工艺性良好经济性合理可靠性高机械零件的强度与刚度设计强度设计刚度设计根据零件的受力情况和材料的弹性力学性能，进行零件的截面尺寸和形状设计，以保证零件在正常工作条件下不会发生过大的弹性变形。

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第16页页
4.3 ★Characteristics Analysis of Four-bar Linkages
4.3.1 Conditions for having a crank a+b≤c+d d<c+b-a c<d+b-a (1)+(2) (1)+(3) (2)+(3) a+d≤c+b a+c≤b+d a≤c a≤b a≤d (1) (2) (3)
第17页页
The types of revolute four-bar-linkage: Do not satisfy the Grashof Criterion
lmax + lmin > lb + lc
Do satisfy the Grashof Criterion
——Double-rocker mecha
(1)
15 30 10 40
10 + 40 ≤ 15 + 30 /
Whichever link is the frame, the mechanism is double-rocker mechanism . If Link CD is the frame.
Pump
第13页页
These mechanisms contain two sliding pairs.
Sine mechanism
Double rotating block
Elliptic trammel
第14页页
Oldham coupling
(3)Enlarging a revolute pair Enlarging a revolute pair in no way changes the motion relationship between any links.
A 1
4
D 3
B
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Crane
Ackerman steering linkage
第8页页
4.2.2 Variation of Revolute Four-bar Mechanisms (1)Replacing a revolute pair with a sliding pair
Offset slider-crank mechanism
第9页页
Centric slider-crank mechanism
Slider-crank mechanisms are used in puncher, internal-combustion engine, air compressor , crank press and so on。。
Disadvantages:
1.It is difficult to perform precision motion 2.Low speed 3.Difficult to balance So,the linkage is preferred for low speed and heavy load situation.
If the link adjacent to the ——Crank-rocker shortest Link is the frame. mechanism
第18页页
lmax + lmin = lb + lc
The centre lines of the four links can become collinear. At these positions, the output behavior may become indeterminate. These positionsAB1C1D are called change-points. AB2C2D Parallel-crank mechanism AB2C’2D AntiParallel-crank mechanism The change-points are handled by inertia of flywheel fixed with the B' driven crank or providing the duplicatelinkage 90° out of phase. °
B1 b B 2 C1 3 a 1 A B2 d 4 D c C C2
1. The crank must be shortest link. 2. Grashof Criterion: The sum of the shortest and the longest links must be less than the sum of the remaining two links. .
Rotating guide-bar Oscillating guide-bar mechanism mechanism
lBC>lAB
lBC<lAB
Crank and oscillating block mechanism
Selftipping vehicle
Translating sliding-rod mechanism
Crank 1 --
Eccentric
When the power transmitted by the linkage mechanism is quite large, the radii of revolutes should be increased.
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(4)Interchanging guide-bar and sliding block Any link in a sliding pair can be drawn as a guide-bar, and the other link as a sliding block. The centre line of any sliding pair can be translated without changing any relative motion.
Puncher
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(2)Replacing two revolute pairs with sliding pairs
Sinusoid Generator
Tangent generator
S = lAB sin φ
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y = l tan ϕ
(2)Taking different links as frame -----inversions Inversion of a mechanism in no way changes the type of revolute and the relative motion between its links. Inversions of the crank-rocker mechanism:
Emphases★： ★ Types, basic Knowledge and design of planar linkage mechanisms Difficulties▲: ▲ Design of planar linkage mechanisms
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4.1 Characteristics of Planar Linkage Mechanisms 4.2 ★The Types of Four-bar Linkages 4.3 ★ Characteristics Analysis of Four-bar Linkages 4.4 ★ ▲Dimensional Synthesis of Four-bar Linkages
Fully rotating revolute: A & B Partially rotating revolute : C & D
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Inversions of the slider-crank mechanism:
Slider-crank mechanism
Guide-bar mechanism
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(a) Crank-rocker mechanism One side links is rocker. The other one is crank.
Foot operated sewing machine
Pitching Mechanism for Radar Antenna
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4.2 ★The Types of Four-bar Linkages
4.2.1 The Basic Form of Four-bar Mechanism Revolute Four-bar Mechanism(铰链四杆机构铰链四杆机构) 铰链四杆机构 side links(连架杆 1 &3 连架杆) 连架杆 crank（曲柄）1 （曲柄） rocker（摇杆）3 （摇杆） coupler（连杆）2 （连杆） According to the types of the two side links, the types of the revolute four-bar mechanisms can be divide into: 1)Crank-rocker mechanism 2)Double-crank mechanism 3)Double-rocker mechanism
If the link opposite to the ——Double-Rocker shortest Link is the frame. mechanism The shortest link is the lmax + lmin ≤ lb + lc frame. ——Double-crank mechanism