Research On Steam Cooling Mechanism Of Internal Cooling Grinding Wheel In Molding Mill Based On Bionic Principle

Forming grinding is a commonly used technology in gear processing.Due to the existence of closed grinding are zone and "gas barrier",the grinding fluid can not directly act on the processing surface smoothly,thus it can not play an effective role of lubrication and cooling.Grinding heat can not be released from the grinding zone in time,resulting in the accumulation of grinding heat on the tooth surface,resulting in the formation of residual stress on the surface of the workpiece,affecting the processing accuracy of the workpiece.In this paper,an internal cooling grooved grinding wheel used in Forming mill.The superalloy is used as the workpiece.Through the grinding wheel structure design,Fluent finite volume method simulation and grinding experiments,the surface temperature,roughness and surface morphology of the workpiece during the grinding process of the internal cooling grooved grinding wheel are qualitatively studied.The following are:(1)A new type of internal cooling grooved grinding wheel was designed and manufactured.45 steel was selected as the material of grinding wheel matrix,and the abrasive grain was CBN abrasive.At the same time,based on the principle of field synergy and bionics self-similarity,the structure design and optimization of grinding wheel microchannel are carried out.The are-shaped bifurcation microchannel structure with the same bifurcation mode as the forewing vein of Lepidoptera insects is selected.The flow field of the runner was analyzed by Fluent software,and the structure size of the grinding wheel microchannel was determined.(2)The simulation model of grinding temperature field for forming gear is constructed.The temperature and thermal stress distribution in the grinding zone of traditional external casting method and internal cooling method were compared,and the influence of various grinding factors on the grinding temperature was analyzed.The analysis shows that the internal cooling method can effectively reduce the grinding temperature,reduce the thermal stress on the surface of the workpiece and the grinding wheel body,and reduce the thermal deformation of the workpiece and the grinding wheel body compared with the traditional external casting method.With the increase of grinding wheel speed,grinding temperature and grinding feed will increase,which will also increase the grinding temperature,and the increase of grinding feed speed will lead to the decrease of grinding temperature.(3)The experimental scheme of grinding V-shaped workpiece with single factor internal cooling grinding wheel was designed.The temperature of the grinding zone and the surface quality of the machined workpiece during dry grinding,conventional external pouring cooling and internal cooling were studied under different grinding parameters.The influence of new internal cooling slotted grinding wheel on surface temperature and surface quality of V-shaped workpiece was investigated.The experimental results show that the internal cooling method can effectively reduce the temperature of the grinding arc zone,improve the surface morphology of the workpiece and improve the quality of the workpiece.In this paper,the simulation and experimental research prove that the new type of internal cooling slotted grinding wheel can effectively solve the problem of forming grinding.In the process of forming grinding,the phenomenon of high grinding temperature is caused by the closed arc sealing and "gas barrier" phenomenon,which provides a new cooling method for gear forming grinding.