For high efficiency metal cutting, the processed materials, cutting tools and cutting conditions are the three major elements. It determines the processing time, tool life and processing quality. The economic and effective machining method must be reasonable selection of cutting conditions.
The three elements of cutting conditions: cutting speed, feed and cutting depth directly cause tool damage. With the increase of cutting speed, the temperature of tool tip will rise, which will produce mechanical, chemical and thermal wear. If the cutting speed is increased by 20%, the tool life will be reduced by 1 / 2.
The relationship between the feed condition and the tool wear is very small. But when the feed rate is large, the cutting temperature rises, and the back wear is large. It has less influence on the tool than the cutting speed. Although the influence of cutting depth on the tool is not as big as cutting speed and feed rate, the hardened layer of the material to be cut will also affect the life of the tool.
- Reasonable selection of cutting tools
① In rough turning, the cutting tools with high strength and good durability should be selected, so as to meet the requirements of large back feed and large feed.
② When finishing turning, the cutting tools with high precision and good durability should be selected to meet the requirements of machining accuracy.
③ In order to reduce the tool changing time and facilitate tool setting, the machine clamping tool and machine clamping blade should be used as far as possible.
- Reasonable selection of fixture
① Try to use general fixture to clamp workpiece, avoid using special fixture;
② In order to reduce the positioning error, the positioning datum of parts coincides.
- Determine the processing route, which refers to the movement path and direction of the cutter relative to the part in the process of NC machine tool processing.
① It should be able to meet the requirements of machining accuracy and surface roughness;
② The processing route should be shortened as far as possible to reduce the tool idle travel time.
