A good sheet metal must have smooth surface and good quality. How can we do this? Here's a detailed example of how to deal with burrs.
1, the amount of grinding die and the standard grinding quantity of mould
The standard die carrier (A station and E station) punching punch is only 2mm, because the standard die can not be worn due to the limitation of its structure.
The mold grinding of die standard is only under the pressure of 1mm, because the lower die edge depth is not linear, in order to facilitate the blanking, the edge of the vertical height of only 1mm thick, and the rest part of the cone, so the mold grinding 1mm, if continued grinding, the edge size increase.
2. Standard spines
The state of the die directly affects the punching state of the material, and directly affects the quality of the parts after molding. Therefore, the quality of the parts is the basis for judging the wear of the upper and lower die. This is the base of the burr. We can't determine the amount of grinding time according to the stamping die. That is to say, even in the same thickness of sheet metal, the wear of blades should be different according to different materials and wear. Therefore, according to different materials, even in dealing with the same thickness, the die grinding cycle is different. Therefore, the wear of the blade is multifaceted. The effect of re grinding die material and mold lubrication degree is the result. Of course, it is necessary to check the defects at the front of the tool, the dissolution of the cutting edge, the cracking and the runout of the lower die, because these factors can also lead to the increase of burr height.
3, the burr determines whether the mold needs the ground.
General sheet metal processing, we can not measure the height of burrs with measuring tools, but by visual and fingerprint method to judge. The usual standard is that the allowed burr height is invisible to the naked eye. If the eyes are visible, the edges of the material have a larger burr. Touch the hole of the edge of the material gently with your finger. If you feel that the hand and the burr are clearly scratched over the surface of the material, or the gloves are gently passing through the edge of the hole, the yarn of the glove is hung by the burr, and the burr is larger. It is not enough to check the burr, because it also says that the impact of the punch, the cracking of the lower die and the beating of the material will also affect the height of the burr, so the mold must be checked. If sharp corners of the upper and lower edges are worn to small fillet, the upper and lower die must be further rubbed.
4, grinding method
The basis of grinding is parallel vertical right angle. If these can not be guaranteed, it will cause burrs, moulds and so on.
(1) use the wet flat grinding wheel as much as possible. (if wet grinding is not used, the accumulation of mold, sand, sand, etc.) will occur.
(2) the grinding feed will be reduced as much as possible. Please grind it with cooling water. (if the amount of grinding feed is too large, it may cause mold burn), and the maximum feed speed is 0.03mm.
(3) grinding direction should be based on longer sides.
(4) the final feed rate is zero and the 2~3 idling improves the surface finish.
(5) please use the appropriate grindstone first (according to the material of the mold).
(6) the edge of the blade will have slight grindings after grinding. Please use the oil stone to remove it. If burrs are not removed, premature wear can be reduced and die life will be reduced. The upper and lower dies should be cleaned together.
(7) for the lower die shoulder R angle tip in the lower die mill, and the sharp part should be round grindstone, otherwise the material will be cut off by the sharp part of the outer part of the lower die.
(8) if it is the ordinary water mill after grinding, the mold will have a certain magnetism, therefore, if it is used, it is easy to jump and speed up the wear of the mold. Therefore, the mold must be removed after grinding.
(9) the grindstone should be cleaned regularly.
(10) if there is a stripper plate for removing the material at the upper end of the punch, the stripper plate is pulled out, then ground, and then installed after grinding.