Tools can be divided into five categories according to the form of workpiece surface: tools for machining various external surfaces include turning tools, planers, milling cutters, external broaches and files; Hole processing tools include drill, reamer, boring cutter, reamer and internal surface broach, etc; Thread processing tools include tap, die, automatic thread cutting head, thread turning tool and thread milling cutter, etc; Gear cutting tools include hobs, gear shapers, gear shavers, bevel gears, broaches, etc; Non standard parts customization company pointed out that cutting tools include insert circular saw blade, band saw, hacksaw, cutting turning tool and saw blade milling cutter, etc. In addition, there are combined tools. According to the cutting motion mode and corresponding blade shape, tools can be divided into three categories: general tools such as turning tools, planers, milling cutters (excluding formed turning tools, formed planers and formed milling cutters), boring cutters, drills, reamers, reamers and saws; The cutting edges of such tools have the same or nearly the same shape as the section of the workpiece to be processed, such as formed turning tools, formed planers, formed milling cutters, broaches, taper reamers and various thread processing tools; Special tools are used to process some special workpieces, such as gears, splines, etc. For example, gear shaper, shaving cutter, bevel gear planer and bevel gear milling cutter head.
Methods to improve the cutting ability of tools:
① Reasonable selection of tool geometric parameters:
Front angle: under the condition of maintaining the strength of the cutting edge, the front angle should be appropriately selected to be larger. On the one hand, it can grind a sharp edge, on the other hand, it can reduce cutting deformation, make chip removal smooth, and then reduce cutting force and cutting temperature. Never use negative rake angle tools. (x: i $Y; a, G+m V 4 i. Y D "i&W4 y Rear angle: the size of the rear angle has a direct impact on the wear of the rear tool face and the quality of the machined surface.
The cutting thickness is an important condition for selecting the back angle. During rough milling, due to the large feed rate, heavy cutting load and large heat generation, good heat dissipation condition of the tool is required, so the back angle should be smaller. During precision milling, the cutting edge is required to be sharp to reduce the friction between the rear cutting surface and the processing surface and reduce the elastic deformation. CNC parts processing points out that, therefore, the rear angle should be larger.; V; J0 W) G9 O: c7 S:.
② Improved tool structure:
Reduce the number of milling cutter teeth and increase the chip space. Due to the large plasticity of aluminum materials and the large cutting deformation during processing, a large chip space is required. Therefore, it is better to have a larger radius at the bottom of the chip groove and fewer milling cutter teeth. Shanghai Batch Aluminum NC Machining Company pointed out that to avoid deformation of thin-walled aluminum parts caused by chip blockage+ W, ?* c5 H4 O! K% [, q $Q 'j! S. K' K, w: T) v $p5 b; h Finish grinding of cutter teeth: the roughness value of the cutting edge of the cutter teeth should be less than Ra=0.4um. Before using a new cutter, a fine oilstone should be used to gently grind the cutter teeth in front of and behind the cutter teeth, so as to eliminate the residual burrs and slight saw tooth lines when grinding the cutter teeth.
Strictly control the tool wear standard: after tool wear, the workpiece surface roughness value increases, the cutting temperature rises, and the workpiece deformation increases. Therefore, in addition to selecting tool materials with good wear resistance, the tool wear standard should not be greater than 0.2mm, otherwise chip accretion is likely to occur. During cutting, the temperature of the workpiece shall not exceed 100 ℃ to prevent deformation.
