Unit Two

Unit Two
Mold Processes
图2 -1 旋转模弯曲过程
Unit Two
Mold Processes
2
Passage Two Fine
Blanking
Fine blanking is a technique used for production of blanks perfectly flat and with a cut edge which is comparable to a machined finish. This quick and easy process is worthy of serious thought when the number of parts justifies the cost of a blanking tool especially when consideration is given to the fact that operations such as shaving are eliminated. Two methods of fine blanking are practiced according to the type of work undertaken as follows: （1） The punch has a round edge and a small clearance and this is best used for blanks， but appears to give less satisfactory results when used for producing holes①.
Unit Two Notes:
Mold Processes
① Using this form of built -in cam action also provides an
uncommon degree of bending accuracy and consistency. 利
用内置凸轮的这种运动形式还能保证弯曲变形的精确性和 一致性达到非同寻常的程度。 句中“Using this form of built -in cam action”短语作为主语。 ② But in those situations where rotary bending is appropriate，
Unit Two
Mold Prary bending process
Unit Two
Mold Processes
Rotary bending will not completely replace the need for either vee bending or wipe bending for all applications. But in those situations where rotary bending is appropriate， the cost savings and overall efficiency of virtually any bending operation can be markedly increased②.
Unit Two
Mold Processes
New Words and Expressions ：
rotary bending旋转模弯曲 vee bending V形槽模弯曲 wipe bending折弯弯曲 tonnage［ t nid］ n.吨位 built -in cam内置凸轮 consistency［k n sist nsi］ n.一致性
Unit Two
Mold Processes
旋转模弯曲加工由瑞迪模具有限公司研制并取得专 利。它是一种能实现多种弯曲的高效率的加工方法。对 不同材料，弯曲冲模的精度和精确的弯曲度为0.008～ 0.500英寸，而弯曲吨位不到其他弯曲方法的 50%～80%。 如图2 -1所示，垂直压力传递给弯曲杆旋转运动，实 现高效的金属弯曲。利用内置凸轮的这种运动形式还能 保证弯曲变形的精确性和一致性达到非同寻常的程度。 先前的许多弯曲加工都要有一系列的步骤才能达到 要求精度，而旋转模弯曲通常允许在压缩冲程中执行的 操作。 旋转模加工并不能完全代替V形槽模弯曲和折弯弯 曲的所有应用。但是在适合运用旋转模弯曲的任何情况 下基本上都能节省费用，并且能显著地增加弯曲成型的 整体效率。
the cost savings and overall efficiency of virtually any bending operation can be markedly increased. 但是在适合运用旋转模
弯曲的任何情况下基本上都能节省费用，并且能显著地增 加弯曲成型的整体效率。 句中“But”为转折词，引出下面的语句;“overall”可译为“全 部的，全面的”。
Mold Processes Passage One Rotary
1
Bending
Press -working operations have increased dramatically over the last few years， but like many other manufacturing operations， the existing technology has sometimes failed to keep pace with the changing applications. One area where this is especially true is die bending. So， although there is a substantial increase in the applications for bending， the most common forms of bending methods— vee bending and wipe bending— represent tech- nologies that are sometimes quite outdated for today's high volume production runs and precision requirements.
Unit Two
Mold Processes
Die bending operations often present the tool designer with a variety of problem areas， especially when high volume production is a factor. From producing proper bend angles minimizing part distortion to reducing the required tonnage and keeping the material in place during the bend， the older vee bending and wipe bending methods can easily create many problems. But a newer alternative， rotary bending， may just be the solution to the problems caused by the other bending methods. The rotary bending process， developed and patented by Ready Tools， Inc.， Dayton， OH， is a highly efficient method of producing a wide range of different bends. This
Unit Two
Mold Processes
form of bending die can make precise and accurate bends in materials ranging from 0.008 in. to 0.500 in. at bending tonnages that are 50 to 80 percent less than those required for the other bending methods. As shown in Fig.2 -1，transferring the vertical motion of the press into a rotary motion of the bender，permits a highly efficient and effective method of bending metal. Using this form of built -in cam action also provides an uncommon degree of bending accuracy and consistency①. Where many bending operations were previously performed in a series of steps to maintain the required accuracy， rotary bending generally permits the operations to be performed in press stroke.
Unit Two
Mold Processes
Exercises： Exercises：
What are the advantages of rotary bending compared with other bending methods?
Is it true that rotary bending Tools， process was invented by Ready Tools， Inc. Dayton?
Unit Two