Causes of five major failures of hardware molds and solutions

In the stamping production of hardware molds, specific analysis is made for the stamping defects, and effective countermeasures are adopted to fundamentally solve the problems that occur, reduce production costs, and achieve smooth production. The following is an analysis of the common stamping defects in production, their causes and solutions, for the reference of mold maintenance personnel. 1. Material belt sickle bend (1) Reasons: a, punching burrs (especially on the carrier); b. material burrs, no trimming of the mold; c. improper punch depth (too deep or too shallow); d. crushing of stamping parts There are chips in the mold; e. The local pressing is too deep or the pressing part is locally damaged; f. The mold design. (2) Countermeasures: a. Study the cutting edge; b. Change the material and add a trimming device to the mold; c. Re-adjust the punch depth; d. Clean the mold to solve the problem of chip jumping and crushing; e. Check and adjust everyone The height of the unloading and die inserts is correct, and the damage position is researched; f. The adjustment of the whole bending mechanism is adopted. 2. Punch fracture and chipping (1) Reasons: a, chip jumping, chip blocking, jamming, etc.; b. improper feeding, cut half of the material; c. insufficient punch strength; d. large and small punches are too close to each other and punch The material is pulled during cutting, causing the small punch to break; e. The punch and the die are partially too sharp; f. The blanking gap is too small; g. There is no punching oil or the used punching oil is more volatile; h, punching Uneven gap, offset, interference between convex and concave molds; i. Poor precision or wear of the unloading insert, and loss of precision guiding function; j. Inaccurate mold guidance and wear; k. Improper selection of convex and concave mold materials and hardness Improper; i. The guide material (pin) is worn out; m. The gasket is improperly installed. (2) Countermeasures: a. Solve the problems of chip jumping, chip blockage, jamming, etc.; b. Pay attention to feeding, trim the material belt in time, and clean the mold in time; c. Modify the design to increase the overall strength of the punch and shorten the die Straight blade size, pay attention to the slope or arc on the end of the punch blade, and cut back the small part; d. The length of the small punch is shorter than that of the large punch, which is more than one material thickness; e. Modify the design; f. Control the convex and concave Die processing accuracy or modify the design gap, and the small part of the punching gap should be appropriately increased; g. Adjust the amount of stamping oil drops or change the oil type; h. Check the accuracy of each forming part, and adjust or replace it to control the processing accuracy; i , Training or replacement; j. Replace the guide post and guide sleeve, pay attention to daily maintenance; k, replace the material used, use suitable hardness; i, replace the guide material; m, modify, the number of shims should be as few as possible, and the use of steel pads , The gasket under the die needs to be cushioned under the cushion block. 3. Bending deformation size variation (1) Reasons: a. The guide pin is worn and the pin diameter is insufficient; b. The bending guide part has poor accuracy and wear; c. Bending convex and concave die wear (pressure loss); d. Die Insufficient clearance; e. Material slippage, bending convex and concave molds have no guiding function, and no pre-compression is applied during bending; f. The mold structure and design dimensions are not good; g. The punching parts are burrs, causing poor bending; h. There are more gaskets in the convex and concave molds at the bending position, resulting in unstable dimensions; i. Material thickness variation; j. Material mechanical shape energy variation. (2) Countermeasures: a. Replace the guide pin; b. Re-grind or replace; c. Check and modify; d. Modify the design and add guide and pre-compression functions; e. Modify the design size, decompose the bending, and increase the bending Bending and shaping, etc.; f. Studying the cutting edge of the material position; g. Adjusting, using integral steel pads; h. Changing the material to control the quality of the feed; 4. Punching height PIN (when there are multiple parts in one mold) (1) Reasons: a. The punching part has burrs; b. The punching part is crushed, and there are chips in the mold; c. The convex and concave molds (bending position) are damaged by pressure or Damage; d. Turning the material during punching and shearing; e. Wear and pressure loss of the relevant pressing parts; f. Inconsistent tearing dimensions of the relevant tearing and cutting positions and wear of the knife edge; g. Or chipping; h. The convex and concave molds in the relevant convex parts have chipping or severe wear; i. Defects in mold design. (2) Countermeasures: a. Study the cutting edge; b. Clean the mold to solve the problem of chip floating; c. Re-train or replace with new parts; d. Study the punching edge and adjust or add a strong pressure function; e. Check, Carry out maintenance or replacement; f. Repair or replace to ensure that the tearing condition is consistent; g. Check the condition of the pre-cut convex and concave molds, and implement maintenance or replacement; h. Check the convex and concave mold conditions, and implement maintenance or replacement; i. Modify Design, add height adjustment or add plastic station. 5. Improper maintenance (1) Reasons: a. The mold has no fool-proof function, and negligence in the assembly of the mold caused the reverse direction and misalignment (referring to different stations), etc.; b. The insert that has shifted through the gap has not been restored to its original state. (2) Countermeasures: a. Modify the mold to increase the foolproof function; b. Use methods such as marking on the mold, and make necessary inspections and confirmations against the material tape after the mold is assembled, and make a written record for inquiries. In the metal mold stamping production, the daily maintenance of the mold is very important, that is, daily attention to check whether the stamping machine and the mold are in a normal state, such as the refueling of the stamping oil supply guide. The inspection before the mold is put on the machine, the inspection of the blade, the confirmation of the locking of each part, etc., can avoid many unexpected accidents. When repairing a model, we must first think before doing it, and earnestly record and accumulate experience.