1、外文资料翻译 Stamping and Punching Dies, Compound Die Design A compound die performs only cutting operations (usually blanking and piercing) which are completed during a single press stroke. A characteristic of compound dies is the inverted position of the blanking die and blanking punch which also functi
2、ons as the piercing die. The die is fastened to the upper shoe and the blanking punch having a tapered hole in it and in the lower shoe for slug disposal is mounted on the lower shoe. The guide pins, or posts, are mounted in the lower shoes. The upper shoes contains bushing which slide on the guide
3、pins. The assembly of the lower and upper shoes with guide pins and bushing is a die set. Die sets in many sizes and designs are commercially available. On the upstroke of the press slide, the knock out rod of the press strikes the ejector plate, forcing the ejector tie rod and shedder downward, thu
4、s pushing the finished work piece out of the blanking die. Four special shoulder screws (stripper bolts), commercially available, guide the stripper in its travel and retain it against the preload of its springs. The blanking die as well as the punch pad is screwed and doweled to the upper shoe. 1、
5、Bending Die Bending is the uniform straining of material, usually flat sheet or strip metal, around a straight axis which lies in the neutral plane and normal to the lengthwise direction of the sheet or strip. Metal flow takes place within the plastic range of the lengthwise direction of the bend re
6、tains a permanent set after removal of the applied stress. The inner surface of a bend is in compression； the outer surface is in tension. A pure bending action does not reproduce the exact shape of the punch and die in the metal； such a reproduction is one of forming. The neutral axis is the plane
7、area in bend metal where all strain is zero. 2、 Bending Methods Metal sheet or strip, supported by a V bending, produces a bend having an included angle which may be acute, obtuse, or of 90. Friction between a spring-loaded knurled pin in the Vee of a die and the part will prevent or reduce side cre
8、ep of the part during its bending. Other methods are Z-bending edge bending and U-bending etc. 3、 Drawing Die Drawing is a process of changing a flat, precut metal blank into a hollow vessel without excessive wrinkling, thinning, or fracturing. The various forms produced may be cylindrical or box-sh
9、aped with straight or tapered sides or sides or a combination of straight, tapered, or curved sides. The size of the parts may vary from 0.25mm diameter or smaller, to aircraft or automotive parts large enough to require the use of mechanical handing equipment. 4、 Single-action Die The simplest type
10、 of draw dies is one with only a punch and die. One type of drawing die use in a single-action press is shown in Fig.3-4. This die is plain single-action type where the punch pushes the metal blank into the die, using a spring-loaded pressure pad to control the metal flow. The punch has an air vent
11、to eliminate suction which would hold the cup on the punch and damage the cup when it is stripped from the punch by the pressure pad. The sketch shows the pressure pad fitting the stop pin, which acts as a spacer that an even and proper pressure is exerted on the blank at all times. If the spring pr
12、essure pad is used without the stop pin, the more the springs are depressed, the greater the pressure exerted on the blank, thereby limiting the depth of drawing. Because of limited pressures obtainable, this type of die should be used with light- gage stock and shallow depths. Mold Cavities and Cores
