Research On Point-Grinding Temperature Field And The Mechanism Of The Axial Heat Transfer

Quick-Point grinding is the incorporation of high-speed grinding and super abrasive grinding, which has both the characters of high material removal rate and high surface quality of point grinding. Because of wide width of grinding wheel surrounding area of traditional external cylindrical grinding is large, so as the caloriffic value, and side contact area is small, caloriffic value is also small,can not be considered. Although point grinding process is a way of external cylindrical grinding, but because of thin grinding wheel and the existence of grinding variables point Angle, surrounding contact area is small, the calorific value is also small, little impact on surface integrity, and the side contact area is large, calorific value is big, so the research of the side temperature field and axial heat transfer mechanism has important significance. Based on the analysis above, the main contents of this paper have the following several aspects:(1) Summrize concepts, characteristics, environm ental protection of quick-point grinding. Application of point grinding technology and study on temperature field at home and abroad.(2) Introduce principles of point grinding. Establish side and surrounding contacting area model. Calculate contact arc length, contact width, contact area, grinding forces.(3) Analysis mechanism of heat transfer of point grinding. Calculating heat the chip taking away. Setting up heat distribution model between side and surrounding contacting area setting up heat distribution model between wheel and work-piece.(4) Finite element model of side and surrounding contact areas were established. Finishing parabolic heat source implement on contact areas. Using ANSYS software presents the point grinding contact zone temperature. Draw the temperature changes with contacting arc length and with different grinding depths, Using MATLAB to draw temperature change of different load step and contacting arc length under different grinding depths.(5) Making point grinding surface integrity experiment.45# steel is used as the specimen material. Using wire cutting way to remove the specimen from the workpiece machined by the point grinding machine,then use vickers hardness tester to measure hardness of the specimens.With the simulation of temperature field, analysing the experimental results.Research results show that the calorific value of point grinding surrounding contact zone is small, calorific value of side contact region is big, but most of heat taken away by chip along the axial direction, with experiment that processing workpiece surface hardness increases slightly, the surface quality is good, so calorific value of side contact region have little impact on surrounding contact region.