What is the selection principle of CNC turning cutting amount?

(1) Selection principle of cutting amount: When rough turning, try to ensure a high metal removal rate and necessary tool durability. When selecting the cutting amount, first select the largest possible amount of back engagement ap, then select the largest possible feed f according to the constraints of machine power and rigidity, and finally determine the appropriate cutting speed vc according to the requirements of tool durability . Increasing the amount of back engagement ap can reduce the number of passes, and increasing the feed f is conducive to chip breaking. When finishing, the machining accuracy and surface roughness are required to be high, and the machining allowance is small and uniform. When choosing the cutting amount of fine turning, we should focus on how to ensure the processing quality, and try to improve the productivity on this foundation soil. Therefore, a small (but not too small) back-cut amount and feed should be selected during finishing, and high-performance tool materials and reasonable geometric parameters should be selected to increase the cutting speed as much as possible. (2) Selection method of cutting amount ①The choice of the amount of knife to eat on the back. When roughing, in addition to leaving a finishing allowance, remove as much of the allowance as possible in one pass. It can also be divided into multiple passes. The machining allowance for finishing is generally small and can be removed at one time. ②Determine the feed rate (feed amount). During rough machining, since there is no high requirement for the surface quality of the workpiece, it is mainly based on the strength and rigidity of the machine tool feed mechanism, the strength and rigidity of the tool bar, the tool material, the size of the tool bar and the workpiece, and the selected backing. The feed rate is selected according to factors such as the amount of cutting. When finishing, the feed rate is selected according to the surface roughness requirements, tool and workpiece material and other factors. ③ Determination of cutting speed. The cutting speed vc can be selected according to the selected amount of back cut, feed and tool durability. In the actual processing process, it can also be selected according to the practical experience of production and the method of looking up the table.