Considerations in the design of non-standard tool processing

With the development of industrial technology, the use of non-standard tools has been expanding. Non-standard tools can be used without tool adjustment, simple operation and safe processing; rough drilling, reaming and hole processing can be realized in one. The clamping part of the non-standard tool has two types: with hole and with shank. Many non-standard tools with shanks have shanks made of low alloy steel, while the working part is made of high-speed steel to weld the two parts together. The following issues need to be noted in the design of non-standard tool machining.

1, after heat treatment, higher strength and hardness, the general tool material can not be cutting processing, or sticky knife of the powerful, which is, it is necessary to put forward special requirements for the material of the tool. The general solution is to use high-grade tool materials, such as high-speed cobalt-containing just tools have a higher hardness to cut tempered workpiece materials, with high-quality carbide material tools can be processed high hard materials, and even milling instead of grinding.

2, non-standard tool material is relatively brittle, especially carbide this material, which makes the processing once encountered in the vibration or processing torque is large, the tool will break, which in the use of conventional tool processing, often does not cause great damage, because the tool is broken can be replaced.

3, the geometry of the tool is more complex, in the heat treatment, the tool is prone to bending, deformation, or local stress concentration, which should be in the design of the attention to avoid the parts prone to stress concentration, the parts of the diameter change, plus the bevel transition or step design, etc.

4, if the surface roughness problem, can be achieved by changing the geometric angle of the edge, such as increasing the number of degrees of the front and rear angle will significantly improve the surface roughness of the workpiece. However, if the user's machine tool rigidity is not enough, the edge may be inverted blunt instead of improving the surface roughness, this aspect is very complex, need to analyze the processing site to come to a conclusion.

5, non-standard tool size difference can not be too large, generally do not exceed 2mm, because the size difference is too large, it will cause the tool groove shape changes, directly affecting the chip space and geometric angle.