(1) The punch wears too fast. The main reasons are: ① The gap between the molds is too small. Generally, the total gap between the molds is 20% to 25% of the material thickness. ② The alignment of the convex and concave molds is not good, including the lack of precision of the mold base, mold guide components, and turret inserts, which causes the molds to be poorly aligned. ③ 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. ④ Improper mold grinding method causes mold annealing and increased wear. ⑤ When punching on one side of the part, such as step punching, punching angles, or shearing, the lateral force of the aluminum alloy door and window accessories will cause the punch to deviate to one side, and the gap on that side will decrease, causing serious wear of the mold. If the installation accuracy of the machine tool mold is not high, the punch will seriously deviate from the upper mold, causing damage to the convex and concave molds. The top ten problems of mold testing, all of which are classic!
(2) The problem of mold carrying material. The mold carrying material will cause waste rebound. The related factors are: ① The sharpness of the mold edge. The larger the radius of the blade, the easier it is to cause waste rebound. ② The die input amount of the mold. The die input amount of each upper position of the machine tool is certain. If the die modulus is small, it is easy to cause waste rebound. Mold expert WeChat: mujudaren③ The gap of the mold is reasonable. If the mold gap is not appropriate, it is easy to cause waste rebound. ④ Whether there is a lot of oil on the surface of the processed plate. ⑤ Spring fatigue damage. Methods to prevent mold carry: ① Use a special anti-carrying die. Aluminum alloy door and window accessories ② The mold is often sharpened to keep it sharp and demagnetized. ③ Increase the gap between the die. ④ Use an oblique blade die instead of a flat blade die. ⑤ Install a material stripper on the mold. ⑥ Reasonably increase the die input amount. ⑦ Check the fatigue strength of the mold spring or unloading sleeve. (3) Mold alignment problem When the mold is used, it is easy for the wear of the punches on each side to be different. Some parts have larger scratches and wear faster. This situation is particularly obvious on narrow rectangular molds. The main reasons for this problem are: ① The design or processing accuracy of the machine tool turret is insufficient. The main reason is that the alignment of the upper and lower turntables and the mold mounting seat is not good. ② The design or precision of the mold cannot meet the requirements. ③ The guide sleeve of the mold punch is not accurate enough. ④ The mold gap is not selected properly. ⑤ The mold mounting seat or mold guide sleeve is not well centered due to long-term wear. To prevent inconsistent mold wear, you should: ① Regularly use the centering core rod to check and adjust the centering of the machine tool turret and the mounting seat. ② Replace the mold guide sleeve in time and select a convex and concave mold with a suitable gap. ③ Use a full-lead mold. ④ Strengthen the sense of responsibility of the operator, find the cause in time after discovery, and avoid causing greater losses. (4) Use of special forming molds To meet production needs, forming molds or special molds are often needed, mainly bridge molds, shutter molds, countersunk molds, tapping molds, boss molds, stretching molds, combined molds, etc. The use of special or forming molds can improve production efficiency, but the price of forming molds is relatively high, usually 4-5 times that of ordinary molds. Mold expert WeChat: mujudaren To avoid mistakes, you should pay attention to and follow the following principles: ① Check the direction when installing the mold to ensure that the installation direction of the mold convex and concave is consistent. ②According to the requirements, the stamping depth of the die should be adjusted correctly. Each adjustment should preferably not exceed 0.15mm. ③Use a lower punching speed. ④The sheet should be flat without deformation or warping. ⑤The forming process should be placed as far away from the clamp as possible. ⑥Avoid downward forming operations when using the forming die: ⑦When stamping, first stamp with the ordinary die and then use the forming die. (5) Fatigue damage of the die spring is a problem that is easily overlooked in the use of punching die. Aluminum alloy door and window accessories are sufficient for the service life of the die spring. The die spring also needs to be maintained or replaced regularly. However, many domestic users can maintain the equipment and molds, but often ignore the maintenance of the die spring. Some users have not replaced the spring for many years. The same workstation or mold is often damaged or stamped with material, but the cause cannot be found. Later, after replacing the die spring, the problem was completely solved. For different punching equipment and molds, the type of die spring is also different. If improperly maintained, it is easy to produce mold material and may damage the mold or guide sleeve, causing unnecessary losses.
