The correct use method and maintenance tips of CNC punching die

The service life of CNC punching dies depends on factors such as reasonable die structure, high manufacturing precision, good heat treatment effect and correct selection of punching machines and die installation accuracy of punching machines. The correct use, maintenance and maintenance of dies cannot be ignored. , the following points should be noted:

(1) Before the mold is installed and used, it should be strictly inspected to remove dirt and check whether the guide sleeve of the mold and the mold are well lubricated.

(2) Regularly check the turntable of the punch press and the mold installation base to ensure the coaxial accuracy of the upper and lower turntables.

(3) Install the convex and concave molds on the turntable according to the mold installation procedure to ensure that the direction of the convex and concave molds is consistent, especially for molds with direction requirements (non-circular and square) to prevent wrong installation and reverse installation.

(4) After the mold is installed, check whether the fastening screws of the mold installation base are locked correctly.

(5) When the cutting edge of the punch and die of the punch die is worn, stop using it and sharpen it in time, otherwise the wear degree of the die cutting edge will be rapidly expanded, the wear of the die will be accelerated, and the quality of the punching part and the life of the die will be reduced.

(6) For the general molds used in mass production, there should be backups for rotation production to ensure production needs.

(7) Stamping personnel should use soft metal (such as copper, aluminum, etc.) to make operating tools to install the mold to prevent damage to the mold during knocking and smashing during installation.

(8) During the transportation of the mold, it should be handled with care, and it is never allowed to throw and touch it, so as not to damage the cutting edge and guide of the mold.

(9) After the mold is used, it should be returned to the designated position in time, and treated with oil and antirust.

(10) To ensure the service life of the mold, the spring of the mold should be replaced regularly to prevent spring fatigue damage from affecting the use of the mold. Common problems in the use of punch dies

(1) The punch wears too fast

The main reasons: ①The mold gap is too small. ② 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 neutrality. ③The 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 sharpening method, resulting in mold annealing and increased wear. ⑤ Partial unilateral punching, such as nibbling, punching angle or shearing, the lateral force will make the punch deflect to one side, and the gap on this side will be reduced, resulting in serious mold wear. If the machine tool mold installation accuracy is not high, serious If it is, the punch will deflect over the lower 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: ① The sharpness of the cutting edge of the mold, the larger the fillet of the cutting edge, the easier it is to cause waste to rebound. ② The modulus of the mold, the modulus of each station of the machine tool is fixed, the modulus of the mold is small, it is easy to cause the waste to rebound. ③Whether the clearance of the mold is reasonable, if the clearance of the mold is not suitable, it is easy to cause the waste to rebound. ④Whether there is more oil on the surface of the processed plate. ⑤ Spring fatigue damage.

Methods to prevent the mold from carrying material: ① Use a special anti-carrying die. ②The mold should be sharpened frequently to keep it sharp and demagnetized. ③ Die clearance. ④ Use oblique edge mold instead of flat edge mold. ⑤The mold is equipped with a stripper. ⑥Reasonable mold input modulus. ⑦ Check the fatigue strength of the mold spring or discharge sleeve.

(3) Mold alignment problem

During the use of the mold, the amount of wear on each side of the punch is prone to be different, and some parts have large scratches and wear quickly. This situation is especially obvious on the thin and narrow rectangular mold. The main reasons for this problem are as follows: ①The machine tool turret design or machining accuracy is insufficient, mainly due to the poor alignment of the mold mounting seats of the upper and lower turntables. ②The design or processing accuracy of the mold cannot meet the requirements. ③The precision of the guide sleeve of the mold punch is not enough. ④ Die gap selection is not appropriate. ⑤ The mold mounting seat or mold guide sleeve is not well aligned due to long-term wear and tear.

In order to prevent inconsistent mold wear, it should be: ① Regularly use the centering mandrel to check and adjust the neutrality of the machine tool turret and mounting seat. ②Replace the mold guide sleeve in time and select a convex-concave mold with a suitable gap. ③Adopt full-lead mold. ④ Strengthen the sense of responsibility of the operators, find out the reasons in time after discovery, and avoid causing greater losses.

(4) Use of special forming dies

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 holes and tapping dies, boss dies, stretch dies, combined dies, etc., using special or Forming molds can greatly improve production efficiency, but the price of forming molds is relatively high, usually 4 to 5 times that of ordinary molds. In order to avoid mistakes, the following principles should be noted and followed:

① Check the direction when the mold is installed to ensure that the installation direction of the convex and concave molds of the mold is consistent.

② Correctly adjust the stamping depth of the mold according to the requirements, and each adjustment must not exceed 0.15mm.

③Use a lower punching speed.

④The board should be flat without deformation or warping.

⑤The forming processing position should be as far away from the clamp as possible.

⑥The downward forming operation should be avoided when the forming die is used.

⑦ When stamping, press the ordinary mold first, and use the forming mold first.