At present, the processing parameters of high-speed automobile molds in individual companies have used a step of 0.1mm and a speed of 30,000 revolutions. But for automobile molds, high-speed machining is only suitable for flat outer plate processing, because the higher the speed, the linear speed of the tool changes. The larger the range, the allowable cutting speed range of the tool is much smaller than this value. The way to solve this problem is to separate the flat areas for separate processing. In order to avoid the shortcomings of the tool center line speed being zero, it can be processed at an appropriate angle.
The outer plate parts such as the drawing die of the engine hood, the automobile mold part is flat, and can be processed at a high speed. The process supplement part is not suitable for high-speed processing. The inner plate part can hardly find a flat surface except for the pressing surface. The flat surface is mentioned here. It must be large. If it is too small, the tool will be lifted more due to too many fragments. The tool path is very short and frequent turns are not conducive to high-speed machining. Even some of the outer panels cannot be distinguished much. For example, the front wall has fewer exposed surfaces and fewer flat areas. The drawing die punch can separate less than 20% of the high-speed processing area, and this 20% can be improved. If the rate is 30%, then the lifting rate of the entire punch is above 5%, and parts such as engine hoods and doors are even higher and can reach more than 20%. If a part can only be divided into a small piece for high-speed processing, the overall rate may not be increased.
The commonly used milling methods in automobile mold processing mainly include the following:
1. High-feed milling method (features: small depth of cut ap, high fz, high Vc)
2. High-speed milling method (features: small cutting width ae, large cutting depth ap, more wear-resistant material tools, low cutting heat, dry cutting)
3. Plunge milling method (feature: high metal removal rate, solve the problem of large margin and long overhang)
4. "Slice skin" milling method (features: small cutting width ae, large cutting depth ap, high Vc, spiral cutting edge design). In addition, the "cycloid" milling method is also a processing method similar to the "slice" milling method.