Study On Plane Grinding Process Of Low-rigidity Thin Plates

With the rapid development of the machinery manufacturing industry,due to the requirements of miniaturization and light weight,the demand for low-rigidity components has continuously increased,at the same time,manufacturing accuracy requirements have been continuously improved.This type of part is difficult to obtain high surface precision surface due to factors such as its diameter-to-thickness ratio exceeding 20 and extremely low rigidity,which are affected by factors such as clamping deformation,thermal deformation,stress deformation due to machining damage,and deformation due to initial internal stress release during processing.At present,mainly based on some qualitative laws and experience of engineers through continuous testing to improve the precision of flat grinding of thin plate workpieces,long test cycle,low processing efficiency,poor process stability.Therefore,revealing the deformation regularity and mechanism of the low-rigidity sheet metal processing process and improving its processing precision and efficiency have very important significance for the development of manufacturing technology.Based on the application background,this paper presents a new and more complete processing method based on the traditional process of grinding 45 steel sheet workpieces through in-depth study on the deformation caused by residual stress and clamping deformation.Through finite element simulation analysis and experimental verification,it is possible to reduce the flatness of parts more efficiently while optimizing the process parameters,reducing the dependence on the experience of engineering technicians.(1)Based on the differences in sheet deformation caused by different surface residual stresses,the residual stress variation of 45 steel sheet under different grinding conditions was investigated by means of inverse solution,and the adjustment of the process parameters to balance the compressive stress produced by the plastic deformation of the grinding process and the tensile stress produced by the thermal deformation to achieve the minimization of the surface stress lamination stress,thereby reducing the overall deformation of the thin plate grinding residual stress control principles and methods.(2)In order to solve the problem of clamping deformation of sheet workpieces,a finite element model of the workpiece deformation analysis using ordinary clamping method,elastic pad method,and viscoelastic cushion method was established.The effect of clamping methods on the accuracy of the workpiece surface was analyzed and studied.The influence of mechanical and geometrical characteristics of different elastic cushions on the clamping deformation of the workpiece reveals the basic rules of the clamping deformation of the thin component.(3)A method for grinding high-precision ferromagnetic thin components on plane grinding machine was proposed.The deformation caused by the residual stress of surface processing was reduced through the optimization of process parameters.The thin component clamping deformation was reduced by the development of a new viscoelastic pad.As a result a 118×110×5 mm 45 steel sheet with high surface accuracy is ground and the accuracy of the surface is PV 5.5 μm.Compared to the elastic pad method,the surface accuracy was improved by 50%.