Characteristic Analysis Of Single CBN Grit Honing Based On Finite Element Method

Gear honing as gear surface entire processing has a direct influence on the quality of gear tooth's and service life. But gear honing always has many shortcomings, such as the tooth profile low, honing efficiency low, error correction ability weak and so on, therefore the study of top gear is very necessary. Gear honing mainly rely on grits of the surface of gear honing wheels to squeezing and honing gears. So the honing process of single CBN (cubic boron nitride) grit has a direct influence on gear's quality and performance. And with high quality, high efficiency, high precision, more demands of materials and performance of cutting tools and work-pieces, the research of honing process is more important in modern machining. This paper has a research on honing character of single CBN grit on the surface of gear honing wheels. Concrete content as follows:1) Using the non-linear dynamics theory of large-scale finite element analysis software ANSYS/LS-DYNA, using single CBN grit the simulations of 45 steel honing processes are carried out. The unit uses three-dimensional entity's linear function Solidl64 units which have 8 nodes, and honing model of three-dimensional explicit dynamic finite element analysis is based on one-point integral Lagrange formulation. The model uses the Johnson-Cook plastic model. Reasonable grid division of single CBN grit and the work-piece not only reduces the CPU time, but also avoids mesh distortion questions produced because of unreasonable grid division. Appropriate restraint and the additional load must be carried on the single CBN grit and the work-piece, and inappropriate restrain will make the work-piece material have big distortion and affect honing process even to stop. The honing way of single CBN grit is decided by exerting load, so exerting load is also quite important to honing process. Through reasonable honing model and computation parameter,this paper realized the simulation of 45 steel three-dimensional big distortion honing process in different speeds. The result of numerical analysis clearly realized the simulation of material scrap shape in plastic deformation stage, cutting slipping stage, scrap forms stage and different honing velocity. And the analysis of effective stress, effective plastic deformation and temperature field theory in different velocity finally obtained the relation of honing velocity and scrap shape in other same situation. Reasonable choosing honing velocity may not only control the scrap shape, may but also take appropriate chip measures promptly, preventing scrap from flying randomly or influencing honing process because of too long, so it is helpful to optimize honing process.2) Using ANSYS/LS-DYNA and Solidl64 unit respectively establish three-dimensional honing large distortion coupled thermal analytical model of honing angles of-10°,-15°,-20°,-25°,-30°,-35°. Work-piece material uses elastic-viscoplastic model with thermal analysis capabilities, reasonable contact and separation criterion to simulate chip shape of different rake angles and temperature distribution. Simulation results showing chip shape and stress in the same honing speed but different rake angles, temperature field theory analyzed and researched finally worked out the relationship of rake angles, chip shape and maximum honing temperature. An appropriate tool rake angle not only reduces the honing forces, honing temperature, but also can reduce chip deformation and thickness, so an appropriate tool rake angle, is very important to optimize honing process and honing parameters.