| Considering the decreasing resource and the importance of environment protection, people use new tools to enhance the cutting efficiency and reduce the waste of raw materials. The development of tool material and coating improve the cutting efficiency, advanced tool structure design displays advantages of material and coating sufficiently. Wiper tool is a new geometry structure of cutting tool. In order to improve its application in the cutting, the cutting performances of Wiper tool are investigated in detail in this thesis.The tool geometry, the edge geometry, the main angle of turning tool are firstly analyzed. Design theory of CNMG type Wiper tool is presented. Wiper tool uses short large arc or straight line to link the nose radius and auxiliary cutting edge. Thus, the auxiliary lead angle of Wiper tool can be decreased, and the machined surface finish can be improved. The application guidance of Wiper tool is also presented in this thesis.Surface finish generated in turning of 45# steel parts using conventional and Wiper inserts are secondly researched by theoretical and experimental approaches, respectively. The surface roughness models with conventional and Wiper inserts are established on the basis of the tool geometry. With the surface roughness formula at different feedrates, the theoretical surface roughness can be obtained for Wiper and conventional inserts. The experimental results are consistent with theoretical analysis. It is found that Wiper inserts could improve surface quality very well at the same feeds, and if the requirement of surface quality is the same, the machining efficient of Wiper insets can be double by using double feedrates.Research on cutting force in turning of 45# steel parts using conventional and Wiper inserts by theoretical and experimental approaches are thirdly conducted. On the basis of the tool geometry, the cutting force models for conventional and Wiper inserts are established, the chip area and width are calculated at different feedrates, and the cutting force formula can be used to predict the tangential cutting force, radial cutting force, and feed force components. With experimental result and theoretical analysis, the cutting force in three directions for Wiper inserts are all greater than conventional ones.Systematic research is lastly conducted on turning tool wear. With experiments of turning of 45# steel parts using conventional and Wiper inserts, it is found that the tool wear tyoes are nose wear,flank wear, chipping exfoliation for conventional and Wiper inserts, the wear land is different for two inserts. The friction, mechanical stress and thermal stress results in tool wear.This thesis is supported by National Natural Science Foundation of China (50675122), Excellent Postdoctoral Foundation of Shandong Province (200602008), and the Program for New Century Excellent Talents in University (NCET-04-0629). |
