Compound die refers to a die structure in which a press machine completes blanking, punching and other processes in one stroke.
Compound Die Classification
(1)Blanking compound die set: such as blanking and punching or cutting and punching etc.
(2)Forming compound die: such as bending, extrusion etc.
(3)Blanking and forming compound die: such as blanking and deep drawing; punching and flanging; deep drawing and trimming; blanking, deep drawing, punching and flanging etc.
Compound Die Set Features
1. Production efficiency is highly increased.
2. Quality of stamping parts improved
3. Concentricity error of compound die is within +/-0.02 ~ +/-0.04mm.
4. High requirements for die manufacturing accuracy
Because the compound die needs to complete several stamping processes in one die, the die structure is generally more complex than single station die. And the components require no interference, accuracy, and reliability during operation which requires a high manufacturing precision. Therefore, the manufacturing cost of the compound die is also increased, the manufacturing cycle is relatively extended, and the maintenance is not as simple as the single process.
Principles of Selecting Compound Dies
2.High-volume is more suitable for using compound die.
3.Precision of stamping part
4.When the precision and concentricity of the stamping parts are highly required; the shape is complex, and repositioning the stamping part may produce large errors, the compound die should be considered.
5.The number of compound processes
Generally, the number of compounding processes for the compound die is less than four. More processes will cause die structures overly complex. At the same time, the strength, rigidity, and reliability of the die will also decrease, making it more difficult to manufacture and maintain.
Discharge and Knock off Device
In the compound die, since there are more actions to be completed in one stroke of the press, in order to simplify the mold structure, some auxiliary actions, such as discharging and knocking off are usually performed by using elastic devices. At the same time, the elastic device can also allow the stamped work piece to be pressed throughout the stamping process, so that the stamped work piece has better flatness.
Mold Base selection
Because the precision of the compound mold is higher, its mold base should also be selected with higher accuracy. The ball type mold base has the advantages of high precision and long service life compared with the slide type mold base, so the ball type is often used.
The mold seat in the mold base is often made of steel plate by replacing the ordinary cast iron
For complex compound dies that require high precision, spherical floating die shanks can be used to reduce the adverse effects of stamping equipment or die mounting errors on the die. It should be noted that when the floating shanks are used, the guide posts cannot leave the guide bush, otherwise severe machine and personal accidents may occur.