When CNC machine tools process parts, the cutting parameters are pre-programmed into the program, and the manual does not change under normal circumstances. Only in the case of test cutting or abnormal conditions, the speed adjustment knob or handwheel is adjusted to adjust the cutting amount. Therefore, the cutting parameters selected in the program should be the best and reasonable. In this way, the processing accuracy, tool life and productivity of CNC machine tools can be improved, and the processing cost can be reduced.
The factors that affect the cutting amount of CNC machining are:
1, machine tool: the selection of cutting parameters must be in the machine tool main transmission power, feed transmission power, spindle speed range and feed speed range. The rigidity of the machine-tool-workpiece system is an important factor limiting the amount of cutting. The selection of the cutting amount makes the machine-tool-workpiece system without large tremors. Numerical control machine tools with good thermal stability, small thermal deformation and good rigidity can increase the feed amount appropriately.
2, tool: tool material is another important factor affecting the cutting amount. Commonly used tool materials are high-speed steel, carbide, ceramics and diamond. Diamond blades have the best performance, allowing for high cutting speeds, good wear resistance, high hardness, and small changes in hardness with temperature. The cutting tools used in CNC machine tools are mostly non-sharpened replaceable blades (machine clamp blades). The material, shape and size of the clamping blade must be adapted to the cutting speed and feed in the program and stored in the tool parameters. Specifications of standard blades refer to the relevant manuals and product samples.
3, the workpiece: the material of the workpiece is different, the tool material and blade type are different. To pay attention to machinability, the sign of excellent machinability is: under high-speed cutting, effective formation of chips, small tool wear, good surface machining quality. Better surface roughness can be obtained by using higher cutting speed, smaller back cutting amount and feed amount. With reasonable constant cutting speed, small back cutting amount and feed amount, higher machining accuracy can be obtained. In addition to the comprehensive inspection of the first piece, the important dimensions of the workpiece should be inspected at a certain interval, and the tool wear should be controlled in time for tool compensation or blade replacement.
4, coolant: coolant has two functions of cooling and lubrication. The coolant can take away the heat generated by the cutting process, reduce the temperature rise of the workpiece, the tool, the fixture and the machine tool, reduce the friction and wear between the tool and the workpiece, and improve the tool life and the workpiece surface processing quality. The use of coolant can also increase the cutting amount. The coolant must be replaced regularly to prevent aging and corrosion of machine guide rails or other parts.
