Simulation Study On Deformation Mechanism Of Parallel Grinding Slender Shaft With Horizontal Opposed Double Grinding Wheels

Slender shaft parts are widely used in mechanical products.With the need of industrial development,cemented carbide materials with high hardness and high wear resistance are gradually used to process long and thin shaft parts.The slender shaft of conventional materials is mainly machined by turning.For the slender shaft made of cemented carbide,the traditional turning method is not applicable,and the grinding method is usually used for machining.In this paper,the deformation mechanism of parallel grinding cemented carbide slender shaft with double grinding wheels is simulated.The main research contents are as follows:(1)The axial feed plane grinding force experiments of cemented carbide and40 Cr were carried out.The influence of grinding process parameters(grinding depth,linear speed of grinding wheel,axial feed speed)on the grinding force under rough and fine grinding conditions were studied respectively.The results show that the grinding normal force is the main cutting force for both cemented carbide and 40 Cr under rough grinding condition;The grinding force increases with the increase of grinding depth;The grinding force decreases with the increase of the linear speed of the grinding wheel;When the feed speed increases,the grinding force is basically unchanged.Under the condition of fine grinding,whether it is cemented carbide or40 Cr,the grinding normal force is the main cutting force;With the increase of the linear speed of the grinding wheel,the grinding force of cemented carbide increases in three directions,the normal force and tangential force decrease in 40 Cr,and the axial force increases slightly;When the feed speed increases,the grinding force is basically unchanged.The empirical formulas of grinding force of cemented carbide and 40 Cr under two working conditions are established respectively.(2)The axial feed plane grinding temperature experiment of cemented carbide and 40 Cr was carried out.The grinding temperatures under rough grinding and fine grinding were measured by thermocouple wire clamping method.The influence of grinding process parameters(grinding depth,linear speed of grinding wheel,axial feed speed)on the grinding temperature was analyzed.The results show that the grinding depth increases and the grinding temperature increases under rough grinding conditions,whether it is cemented carbide or 40Cr;The grinding temperature decreases with the increase of the linear speed of the grinding wheel;When the feed speed increases,the grinding temperature remains basically unchanged.Under the condition of fine grinding,whether it is cemented carbide or 40 Cr,the grinding temperature increases with the increase of the linear speed of the grinding wheel;With the increase of feed speed,the grinding temperature of cemented carbide increases,and that of 40 Cr is basically unchanged.Empirical formulas for grinding temperature of cemented carbide and 40 Cr under two working conditions are established respectively.(3)The deformation simulation calculation of cemented carbide slender shaft with force load,heat flow load and superposition of force load and heat flow load under the action of a single grinding wheel is carried out.The simulation results show that under the action of a single force,the model mainly produces radial bending and axial elongation deformation,in which radial bending is the main deformation;Under a single heat flow load,the model mainly has radial expansion and axial elongation deformation,and the axial elongation deformation is the main deformation;Under the superposition of force load and heat flow load,the model mainly produces radial comprehensive deformation and axial elongation deformation,in which axial elongation is the main deformation,which indicates that grinding heat has a significant impact on workpiece deformation.(4)The deformation simulation calculation of cemented carbide slender shaft with force load,heat flow load and superposition of force load and heat flow load under the action of double grinding wheels is carried out.The deformation results of the model under two extreme working conditions are compared and analyzed.The results show that the radial deformation of double grinding wheel condition 1 is not reduced compared with that of single grinding wheel,and the radial deformation and axial deformation of double grinding wheel condition 2 are greatly reduced compared with that of single grinding wheel and condition 1.This shows that double wheel grinding can not reduce the deformation when the magnitude difference of force loads on both sides is large.On the contrary,the temperature rise is large and the thermal deformation is aggravated due to double wheel grinding;When the force loads on both sides are close to the order of magnitude,the double grinding wheel grinding has smaller radial bending deformation and axial elongation deformation.Therefore,reasonable process parameters can reduce deformation and improve accuracy.