Abstract: The cutting edge usually has uniform chamfer in order to improve the strength of the cutting edge and extend the service life of cutting tools, but a structure with uniform chamfer can make the chip accumulated and increase the cutting resistance and the temperature of cutting zone. To improve chip removal and cooling as well as reduce cutting resistance, a structure with variable chamfer for PCBN tool is proposed. The mathematical model of the cutting edge is established, and a numerical simulation is performed base on the mathematical model. According to the characteristics of the PCBN tool with variable chamfer edge, combined with the grinding method of the end face and the idea of regression, an approximation type grinding trajectory planning is proposed. The number of grinding are optimized through a trajectory simulation, and a precision grinding of the tool with variable chamfer edge is achieved. The detection method for the edge chipping, width and angle of the chamfering of the cutting edge of the PCBN tool with variable chamfer edge is proposed, and the quantitative evaluation of the grinding accuracy is done. The results of grinding accuracy detection show that the actual grinding values of edge radius and width and angle of chamfer are consistent with the design values, which accords with the requirements of precision grinding and hard cutting. Finally, the cutting performance of the design tool is verified by the contrast test.

Key words: accuracy detection, grinding, PCBN tool, tool design, variable chamfer