Five major problems of stamping dies and their solutions

(1) The punch wears too fast. The main reasons are:

The mold gap is too small. Generally, the total gap of Jianhan mold is 20% or 25% of the material plate thickness.
The centering of the convex and concave molds is not good, including the lack of precision of the mold base, mold guide components and turret inserts, etc., resulting in poor mold alignment.
The temperature of the punch is too high, mainly due to the overheating of the punch caused by continuous long-term stamping of the same mold.
Improper mold sharpening method causes mold annealing and increased wear.
Partial unilateral punching, such as nibbling, punching angle or shearing, the lateral force of the aluminum alloy door and window accessories will make the punch deflect to one side, and the gap on this side will be reduced, resulting in serious wear of the mold. High, serious will make the punch over the upper die, causing damage to the punch and die.

(2) Mold belt material problem

Mold belt material will cause waste to rebound, and its related factors:

The sharpness of the cutting edge of the mold, the larger the rounded corner of the cutting edge, the easier it is to cause the waste to rebound.
The modulus of the mold and the modulus of each upper position of the machine tool are fixed, and the modulus of the mold is small, which is easy to cause waste to rebound.
The gap of the mold is reasonable, if the gap of the mold is not suitable, it is easy to cause the waste to rebound.
Whether there is more oil on the surface of the processed plate.
Spring fatigue damage.

Ways to prevent the mold from carrying material:

Use a special anti-carrying die. Aluminum alloy door and window accessories
Dies are often sharpened to keep them sharp and demagnetized.
Increase die clearance.
The oblique edge n die is used instead of the flat edge die.
Mold mount ejector.
Reasonably increase the mold input modulus.
Check the fatigue strength of the die spring or stripper sleeve.

(3) Mold alignment problem

When the mold is in use, the amount of wear on each side of the punch is different, and some parts have large scratches and wear quickly. This situation is especially obvious on thin and narrow rectangular molds. The main reason for this problem:
Machine tool turret design or insufficient machining accuracy. The main reason is that the alignment of the upper and lower turntables and mold mounting seats is not good.
The design of the mold or the added precision cannot meet the requirements.
The precision of the guide sleeve of the mold punch is not enough.
Die clearance selection is not appropriate.
The mold mounting seat or mold guide sleeve is not well aligned due to long-term wear and tear.

To prevent inconsistent die wear, you should:

Regularly use the centering mandrel to check and adjust the neutrality of the machine tool turret and mounting seat.
Replace the mold guide sleeve in time and choose a convex-concave mold with a suitable gap.
Adopt full lead mold.
Strengthen the sense of responsibility of the operator, find out the reason in time after discovery, and avoid causing greater losses.

(4) Use of special forming molds

In order to meet the production needs, it is often necessary to use forming dies or special dies, mainly including bridge dies, louver dies, countersunk dies, turning hole tapping dies, boss dies, stretch dies, combined dies, etc., using special or Forming molds are used to improve production efficiency, but the price of forming molds is relatively high, usually 4-5 times that of ordinary molds. In order to avoid mistakes, the following principles should be noted and followed:

Check the direction when the mold is installed to ensure that the convex and concave molds of the mold are installed in the same direction.
Correctly adjust the stamping depth of the mold according to the requirements, and each adjustment should preferably not exceed 0.15mm.
Use a lower punching speed.
The board should be flat without deformation or warping.
The forming process should be placed as far away from the clamp as possible.
The downward forming operation should be avoided when the forming die is used:
When stamping, press with a common die first, and finally use a forming die.

(5) Die spring fatigue damage

A problem that is easily overlooked in the use of punching dies is that the aluminum alloy door and window accessories are sufficient for the service life of the die spring, and the die spring also needs to be maintained or replaced regularly. However, many domestic users can maintain the equipment and dies, but they often ignore the die spring. Even some users have not replaced the spring for many years. The same station or mold often has damage or stamping strips, but the cause cannot be found. After the mold spring is replaced, the problem is completely solved. For different punching equipment and dies, the types of die springs are also different. If it is not maintained properly, it is easy to produce mold banding and may damage the mold or guide sleeve, resulting in unnecessary losses.