The main components of the guide post and guide sleeve unit of the mold(1)

1. Standard parts and specifications
The selection method of standard specifications for molds is best to consider the following items:

(A). When the specifications used are not restricted, it is best to use the highest level.

(B). In principle, standard numbers are used.

(C). When the standard part of the mold does not have this size, the closest one will be used for processing.

2. The design of the punch
Punches can be roughly divided into three parts according to their functions:

(A). The tip of the cutting edge of the processed material (the cutting edge has irregular, square, round shapes, etc.).

(B). The contact part with the fixed plate of the punch (fixed part or shank, the cross-sectional shape of which is irregular, square, round, etc.).

(C). The connecting part of the blade and the handle (middle part).

The design basis of each part of the punch is briefly described from

(A). Length of the cutting edge,

(B). Grinding direction of the cutting edge,

(C). The fixing method of the punch and the shape of the handle.

3. The design of the punch fixing plate

The thickness of the punch fixing plate is related to the size of the die and the load. Generally, it is 30-40% of the length of the punch, and the length of the punch guide should be 1.5 times higher than the diameter of the punch.

4. Design of guide pin (punch)

The gap between the diameter of the guiding part of the guide pin (punch) and the material guide hole, the size and the amount of the protruding pressure plate are designed according to the thickness of the material, and the tip shape of the guide pin can be roughly divided into two types: A. Cannonball Shape, B. Conical (push-pull shape).

(1). The shell shape is the most common form, and there are also standard parts on the market.

(2). The cone has a certain angle, which is very suitable for high-speed stamping of small parts. The determinants of the push-pull angle are the stamping stroke, the material of the processed part, the size of the guide hole, and the processing speed. When the push-pull angle is large, it is easier to correct the position of the processed material, but the length of the push-pull part will become longer. The connection between the push-pull part and the cylinder part should be smooth.

5. Design of the concave mold

(1). Design of punching die

The key items that should be considered in the shape design of the punching die are: A. The life of the die and the shape of the escape angle, B. The shear angle of the die, and C. The division of the die.

(A). Mold life and shape of escape angle: This design is a very important matter. If the design is not correct, it will cause punch damage, blockage or floating of punching chips, and occurrence of burrs.

(B). Shear angle of the die: In order to reduce the punching force when the shape is punched, the die can be designed with a shear angle. When the shear angle is large, the punching force will be reduced greatly, but it is easy to cause the product to bend and deform .

(C). Dividing of the concave mold: The concave mold must be subjected to finishing processing such as forming and grinding. Because of its concave shape, the grinding tool is not easy to enter, so it must be divided.

(2). Design of bending die

The design of the concave mold for bending is to prevent springback and excessive bending. The shape of the concave mold for U-shaped bending is a combination of double R and straight part (30 degrees inclination), preferably approximately R shape. The shape of R part should be polished after forming grinding or NC electric discharge machining.

(3). Design of drawing die

The corner shape of the drawing die and the shape of the escape angle are very important design items. The shapes and characteristics of the corner and escape corner are as follows: When the R angle value of the drawing die is large, it is easier to draw and process, but it also produces the surface of the drawn product. Wrinkles occur, and the thickness of the side wall of the drawn product is greater than the thickness of the plate. When drawing thick plates and difficult ejection, the R value of the die should be small, about 1-2 times the thickness of the plate. Generally, most of the extension parts of the drawing die of the cylinder and the square tube are made straight, in order to prevent For purposes such as burning, destroying the lubricating oil film and reducing the ejection force, it is advisable to have an escape part (stage shape or push-pull shape) design under the straight section. Especially in the case of shrinking processing, this straight section must be as small as possible.