Maintenance of main parts of multi-station progressive die

1. Maintenance of convex and concave molds 　　 Punch and concave molds are the most frequently maintained parts in progressive molds. Two methods can be used to repair it: when the punched parts have burrs exceeding the regulations, and when the edges of the concave and convex molds are abnormally worn, dulled, or chipped, they must be sharpened or replaced; when the number of punched parts reaches the specified durability (Such as Cr12MoV steel: 30,000 to 50,000 times / once per sharpening; steel-bonded cemented carbide: 300,000 to 600,000 times / once per sharpening; cemented carbide: 500,000 to 1 million times / once per sharpening), no matter The cutting edge must be sharpened if the punched parts are qualified. The amount of sharpening has different requirements for different mold steels: the amount of sharpening of alloy steel molds does not exceed 0.2mm each time; the amount of sharpening of cemented carbide molds does not exceed .1mm each time. After grinding, the length of the convex and concave molds becomes shorter, and a gasket of corresponding thickness can be placed thereafter to ensure the synchronization of the convex and concave molds at each stamping station. The convex and concave molds for bending, stretching and partial forming should be specially prevented from falling into foreign objects, which will seriously damage the forming surface. Carefully check the forming surface before pressing and clean the forming surface with compressed air. If the forming surface is excessively deformed, worn, or even burned, it should be replaced immediately, and attention should be paid to the lubrication of the forming surface.　　2, the maintenance of the discharge plate　　The discharge plate is a key part of the progressive die, and it is responsible for guiding and protecting the punch. The matching clearance between the various holes on the discharge plate and the punch is only 1/3-1/4 of the clearance between the punch and the concave mold. Its rigidity, strength and wear resistance will seriously affect the guiding accuracy of the punch, so it must be regular Strengthen the lubrication of the sliding parts on the unloading plate; when sharpening and replacing the punch, if the size of the punch is small and the number is large, it is necessary to avoid removing the punch unloading plate from the top during the day, otherwise it will be difficult to reassemble and guide accuracy It is also difficult to reach the initial state; the key to dismantling, assembling and unloading the material board is to maintain stability, otherwise the punch will break.　　3, the maintenance of the guide pin guide bush 　 　 Precision multi-station progressive molds generally use ball or roller guide pin guide bushing, which is an important part to maintain the high precision of the mold. The lubrication is generally paid more attention to, but the abnormal wear of the guide pin due to eccentric load is often ignored. Especially in the high-speed stamping process, the heat generated by the friction between the guide pin and the ball or roller is too late to dissipate, leading to the guide pin. The thermal expansion of the column aggravates the wear and even burns of the guide column, which seriously affects the guiding accuracy and mold life. Therefore, the size and surface of the guide column should be checked regularly and replaced in time. For the small guide posts and small guide sleeves on the unloading plate, ensure that the fit clearance does not exceed 1/2 of the gap between the punch and the unloading plate.　　4. Maintenance of springs　　 There are many springs used in the mold, and some of them work in an invisible state. Once a problem occurs, the damage will be great. Therefore, the management and maintenance of the spring is very important. The maintenance of the spring is difficult to judge from the appearance, and the replacement cycle can be determined according to the number of parts processed and the life of the spring. If the punch is sharpened many times and the closing height of the mold is reduced, attention must be paid to the replacement of the spring; smooth work and as small as possible compression is the key to choosing the spring; if it is a nitrogen gas spring, the punching process must be coordinated with the spring characteristic curve , The elastic pressure of each spring must be balanced, work must be stable, and shock and vibration must be avoided. 5. Maintenance of other parts. After long-term use of the unloading screw, the thread will wear out due to the force, and the locking force will be reduced, resulting in an unstable unloading plate, so it should be replaced regularly; the guide pin is the key to precise control of the feeding step. For the parts, pay close attention to the degree of wear of the guide parts; for the safety detection of the guide nails, always check the sensitivity of their movement flexibility when they are stopped; for the floater, ensure that the floating height is consistent and there is no hysteresis, and it is replaced regularly Spring; For the mechanism with lateral punching, ensure that the oblique wedge is fixed reliably and the working surface is smooth (Ra<0.2a). For the sliding block, ensure that the movement is stable and there is no obvious lateral swing; for the backlash mechanism, pay attention to the backlash convex The reliability of the mold guide, whether the lever is deformed, and whether the reset is timely; for the parts that prevent the scrap from rebounding, pay attention to the reliability of their movement and maintain them at any time; the small screws that fix the pieces are deformed due to the large screw force. It directly affects the locking force and should be replaced on time.