Large-scale CNC lathe processing is a high-precision, high-efficiency automatic machine tool that uses digital information to control the displacement of parts and tools. Since the processing of large CNC lathes is one clamping, and all turning processes are completed automatically in continuous processing, the following matters should be paid attention to when processing large CNC lathes.
1. Pay attention to the choice of cutting amount
The three elements of cutting conditions of large CNC lathes: cutting speed, feed and depth of cut will directly cause tool damage. As the cutting speed increases, the temperature of the tool tip will increase, which will cause mechanical, chemical, and physical related wear. A 20% increase in cutting speed reduces tool life by 1/2. The influence of the feed rate on the wear of the tool is smaller than that of the cutting speed, but the larger the feed rate, the higher the cutting temperature, the greater the wear of the tool. Although the effect of the depth of cut on the tool is not as large as the cutting speed and feed, when cutting with a small depth of cut, the material to be cut will produce a hardened layer, which will also affect the life of the tool.
2. Pay attention to the choice of tools
(1) When rough turning, a tool with high strength and good durability should be selected, so as to meet the requirements of large amount of knife and large feed during rough turning.
(2) When finishing turning, tools with high precision and good durability should be selected to ensure the requirements of machining accuracy.
(3) In order to reduce tool change time and facilitate tool setting, machine-clamped knives and machine-clamped blades should be used as much as possible.
3. Pay attention to the selection of fixtures
(1) Try to use general fixtures to clamp the workpiece, and avoid using special fixtures;
(2) The positioning datum of the parts is coincident to reduce the positioning error.
4. Pay attention to the determination of the processing route
The processing route refers to the movement trajectory and direction of the tool relative to the part during the processing of the large CNC lathe.
(1) It should be able to ensure the machining accuracy and surface roughness requirements;
(2) The processing route should be shortened as much as possible to reduce the idle travel time of the tool.