1、毕 业 设 计（论 文）外 文 参 考 资 料 及 译 文译文题目： 油底壳的成型工艺与模具设计 学生姓名： 学 号： 专 业： 所在学院： 指导教师： 职 称： 20xx年 2月 27日外文原文: Stamping Die DesignThe wide variety of sheet metal parts for both the automobile and electronic industries is produced by numerous forming processes that fall into the generic category of sheet-metal
2、forming. Sheet-metal forming ( also called stamping or pressing )is often carried out in large facilities hundreds of yards long.Another factor that one sees standing next to such lines is the number of different sheet-forming operations that automobile panels go through. Blanks are created by simpl
3、e shearing, but from then on a wide variety of bending, drawing, stretching, cropping , and trimming takes place, each requiring a special, custom-made die.Despite this wide variety of sub-processes, in each case the desired shapes are achieved by the modes of deformation known as drawing, stretchin
4、g, and bending. The three modes can be illustrated by considering the deformation of small sheet elements subjected to various states of stress in the plane of the sheet. Figure 1 considers a simple forming process in which a cylindrical cup is produced from a circular blank.Figure 1 Sheet forming a
5、 simple cupDrawing is observed in the blank flange as it is being drawn horizontally through the die by the downward action of the punch. A sheet element in the flange is made to elongate in the radial direction and contract in the circumferential direction, the sheet thickness remaining approximate
6、ly constant Modes of sheet forming are shown in Figure 2.Figure2 Modes of sheet formingStretching is the term usually used to describe the deformation in which an element of sheet material is made to elongate in two perpendicular directions in the sheet plane. A special form of stretching, which is
7、encountered in most forming operations, is plane strain stretching. In this case, a sheet element is made to stretch in one direction only, with no change in dimension in the direction normal to the direction of elongation but a definite change in thickness, that is, thinning.Bending is the mode of
8、deformation observed when the sheet material is made to go over a die or punch radius, thus suffering a change in orientation. The deformation is an example of plane strain elongation and contractionA complete press tool for cutting a hole or multi-holes in sheet material at one stroke of the press
9、as classified and standardized by a large manufacturer as a single-station piercing die is shown in Figure3.Any complete press tool, consisting of a pair( or a combination of pars ) of mating member for producing pressworked (stmped）parts, including all supporting and actuating elements of the tool,
10、 is a die. Pressworking terminology commonly defines the female part of any complete press tool as a die.The guide pins, or posts, are mounted in the lower shoe. The upper shoe contains bushings which slide on the guide pins. The assembly of the lower and upper shoes with guide pins and bushings is
11、a die set. Die sets in many sizes and designs are commercially available. The guide pins are shown in Figure 3. Figure3 Typical single-station die for piercing hole1Lower shoe 2,5Guide bushings 3Cavity plate 4Guid pin 6Spring-loaded stripper 7Punch 8Support plate 9Punch bushing 10Fan-shaped block 11
12、Fixed plate 12Punch-holder plate 13Backing plate 14Spring 15Stepping bolts 16Upper shoe 17ShankA punch holder mounted to the upper shoe holds two round punches (male members of the die) which are guided by bushings inserted in the stripper. A sleeve, or quill, encloses one punch to prevent its buckl
13、ing under pressure from the ram of the press. After penetration of the work material, the two punches enter the die bushings for a slight distance.The female member, or die, consists of two die bushings inserted in the die block. Since this press tool punches holes to the diameters required, the dia
14、meters of the die bushings are larger than those of the punches by the amount of clearance.Since the work material stock or workpiece can cling to a punch on the upstroke, it may be necessary to strip the material from the punch. Spring-loaded strippers hold the work material against the die block u
15、ntil the punches are withdrawn from the punched holes. A workpiece to be pierced is commonly held and located in a nest (Figure 2-3) composed of flat plates shaped to encircle the outside part contours. Stock is positioned in dies by pins, blocks, or other types of stops for locating before the downstroke of the ram.Bending is one of the most common forming operations. We merely have to look at the components in an automobile or an appliance-or at a paper clip
