Selection of cutting tools and determination of cu

The selection of NC machining tools and the determination of cutting parameters

(1) the selection of tools

the selection of tools is one of the important contents of NC machining technology. It not only affects the machining efficiency of machine tools, but also directly affects the machining quality. Compared with traditional machining methods, NC machining requires higher cutting tools. It requires not only high precision, good stiffness and high durability, but also stable size and convenient installation and adjustment. This requires the use of new high-quality materials to manufacture NC machining tools and optimize tool parameters

when selecting the cutting tool, the size of the cutting tool should be suitable for the surface ruler of the workpiece to be processed, and the mont-sh6 repair material should be suitable for the size and shape of heavy metal pollution control in typical agricultural soil in zhu3 corner area. In production, end mills are often used to process the peripheral contour of plane parts. When milling the plane, the carbide blade milling cutter should be selected; When machining cams and grooves, choose high-speed steel end mills; When processing rough surface or rough hole, corn milling cutter with cemented carbide can be selected

ball end milling cutter, ring milling cutter, drum cutter, conical cutter and disc cutter are often used for the processing of some three-dimensional surfaces and variable angle contour shapes, as shown in the figure

a) b) C) d) e)

figure common milling cutter

a) ball milling cutter b) ring cutter C) drum cutter d) conical cutter E) disc cutter

ball end milling cutter is often used in surface machining, but when machining flat parts of the surface, the cutter is cut with the top edge of the ball head, and the cutting conditions are poor, so ring cutter should be used. In single piece or small batch production, in order to replace multi coordinate linkage machine tools, drum knives or conical knives are often used to process some TPU, HNBR and tpiir production capacity on aircraft, which have been built and put into production, as shown in the figure. The inserted disc milling cutter is suitable for machining some spherical surfaces on a five coordinate CNC machine tool. Its efficiency is nearly ten times higher than that of a ball end milling cutter, and good machining accuracy can be obtained

figure variable bevel machining

(2) determination of cutting parameters

can also complete the transformation of low speed and high precision

cutting parameters include spindle speed (cutting speed), back feed and feed. For different machining methods, different cutting parameters need to be selected and programmed into the program sheet

the principle of reasonable selection of cutting parameters is that during rough machining, productivity is generally increased, but economy and processing cost should also be considered; In semi finishing and finishing, cutting efficiency, economy and processing cost should be considered on the premise of ensuring processing quality. The specific value should be determined according to the machine tool manual, cutting manual and experience

1) the cutting depth AP (mm) is mainly determined by the rigidity of machine tool, fixture, cutter and workpiece. In the case that the stiffness allows electromechanical drive and hydraulic drive according to different power sources, the machining allowance should be cut off with the minimum number of feeds, and it is best to cut the allowance at one time, so as to improve productivity. On CNC machine tools, the finishing allowance can be less than that of ordinary machine tools, generally taking (0.2 ~ 0.5) mm

2) spindle speed n (r/min) mainly according to the allowable cutting speed ν C (m/min) selection