The Study On Mathmatical Models For The Chinese Multi-facet Drill Based On The GrindSmart 620XS Tool Grinding Machine

The new type Chinese multi-facet drill(CMFD) developed from the common twist drill by rationally regrinding in order to solve problems existing with the twist drill has an excellent performance when cutting. However, its cutting edge, face and flank are very complex, and there are too many surfaces to be ground, so all along it is chiefly ground by handwork or developing special grinder. The manual method needs much more work and higher require in skill, so the precision is difficult to be ensured; and that the special grinder is too expensive is hard to be received for some companies. So trying to grind the CMFD automatically with a common grinder plays a significant role in applying and popularizing the CMFD in manufacture.The key to the problem of grinding the CMFD automatically is to establish its mathematical models correctly according to the grinding machine, and to find the relationship between design and grinding parameters. Choosing the GrindSmart 620XS tool grinder greatly used in manufacture as the CMFD grinder, through analyzing structure and design parameters of the basic type CMFD and considering the motion characteristic of each axis of the grinder, mathematic models for the CMFD with helicoid flanks based on the grinder are established in this paper according to the principle of coordinates transform, equation groups showing the relationship between design and grinding parameters are ratiocinated and grinding parameters of CMFD with an 8mm diameter are solved. To confirm the correctness of mathematical models, a 3D model is created using SolidWorks, and then structure and design parameters are measured. The result that almost all errors of the parameters are very small certifies the correctness of the mathematical models. At last, a simulation for the CMFD with conical flanks is carried out by utilizing VirtualGrind, and the result confirms the feasibility to grind the CMFD with this grinder.The study not only provides the foundation for writing CMFD grinding program,developing software for simulating the grinding process and finally grinding the drill automatically with this grinder, but also can be used for reference in the research on other CMFD grinding methods.