How to solve the problem of rotating die skipping of CNC turret punch press?

1. Analysis of the causes of skipping In order to find out the specific influencing factors of the mold skipping, the use of random bed imported molds and self-made molds (Figure 3), as well as stamping waste, and part stamping openings were inspected at the production site. After inspection, it was found that: When the two kinds of molds showed scrap up, the parts processed were mostly stainless steel. The imported molds of the random bed used had been sharpened for many times due to the wear of the convex and concave cutting edges, and the lower end of the stamping parts fractured was rough and rough. It is obviously torn; the fracture of the self-made die stamping parts is along the length of 40mm, part of the end face is bright and smooth, and part is rough. After observing and analyzing the cross-section of die and stamping waste. Preliminarily judged that the jump of the scrap after stamping of the imported mold is mainly due to the short total length of the convex and concave molds after grinding, which causes the stamping depth to be too shallow, so that the lower end of the waste is almost broken, and the too shallow stamping depth also causes the waste to stay in The upper surface of the die orifice is easy to be adsorbed by the punch and jump up; the cross-sectional appearance of the parts stamped by the self-made die shows that the blanking gap of the die is uneven, and the uneven blanking gap appears, causing one side to be larger than the blanking gap. It is smaller than the blanking gap, so that after the blank enters the die, because of the large burrs, when the die is opened, the waste is easily taken out of the die. In addition, the punching punch has a simple shape, and the friction between the waste and the die hole is very small, and it is easy to be absorbed by the punch; the stamped stainless steel material has good toughness, and the waste is easy to adhere to the punch; the turret punch is used for punching The high speed makes the waste material susceptible to jump up due to vacuum adsorption, and these factors can easily lead to the generation of material jump. Second, the measures to solve According to the introduction of the data, the commonly used measures to prevent the occurrence of skipping mainly include: Making small grooves on the edge of the punch or making the edge of the punch into a spherical crown or making the punch into a bevel or shear shape. In addition, the punch is demagnetized, and ejector nails are set on the punch. In view of the above analysis of the causes of skipping, the following measures were taken for the two molds: The main factor for skipping due to imported molds is that the stamping depth is too shallow. So make the following changes to the mold: grind off the bottom surface of the guide sleeve by 2mm, and grind the cutting edge of the die into a small chamfer with a cemented carbide drill and grinding paste to increase the frictional resistance between the stamped waste and the die, so that The waste material can stay in the concave mold, and the waste material will not jump up. After inspecting the self-made mold, it was found that the uneven gap in the 40mm length direction of the mold was mainly due to the deviation between the positioning keyway in the upper and lower molds of the mold and the center line of the stamping parts, which led to the installation in the turret punch tower. The gap between the upper and lower molds in the 40mm length direction is uneven. Because it is difficult to re-process the mold, considering that the upper and lower mold positioning devices in the machine tool are two independent mechanisms, so before installing the mold, let The lower mold positioning device rotates one tooth idly to offset the upper and lower positioning keys of the machine tool, so that the gap after the mold is installed is adjusted. In addition, the self-made mold is improved as follows: vent holes are opened on the end of the punch to break the vacuum condition between the end of the punch and the punching sheet, and a small groove is made on the end of the guide sleeve to get air out of the punching surface. . In addition to the above-mentioned measures, the two molds also use cotton yarn to wipe the oil stains on the surface of the plate when processing the stainless steel plate, and use the emulsion to lubricate the surface of the concave die and the bottom surface of the plate appropriately to reduce the waste between the punch and the punch. Adsorption. Previous post: Three aspects should be considered in the selection of metal stamping materials