Research On Grinding Force Control Method For Concave Cam Grinding

At present,the cam with concave surface structure has been widely used in the camshaft of oil supply system.Based on the analysis of the grinding process theory of concave camshaft,some researchers have produced some camshaft grinding machine equipments which can grind concave surface,and most of them are grinding workpieces with large and small grinding wheels.The efficiency of using this method to grind concave camshaft is not high,and the unstable grinding force is easy to occur when using small grinding wheel to grind concave camshaft,which obviously directly affects the processing efficiency and accuracy of the workpiece.In order to solve the above problems,the grinding process of concave surface is optimized by grinding wheel based on critical radius,which improves the efficiency of mass production of workpiece.At the same time,the fuzzy PID control technology is introduced into the grinding force control system,and the good grinding force control is realized by simulation.The main research contents are as follows:(1)The relationship between the rotational speed of the workpiece and the cam angle is deduced.Taking the intake cam of an automobile engine as an example,the speed and acceleration maps of X-axis and C-axis are simulated in Matlab.By analyzing the characteristics of concave cam contour,the original data are smoothed by midpoint springback method.A new grinding process of concave Camshaft Based on the optimization of critical grinding wheel radius is proposed by interpolating and fitting with cubic spline function,so as to improve the efficiency of workpiece grinding.(2)Research on the cam grinder system.Firstly,the hardware of open CNC system with PC+ NC structure is introduced.Then,using C# language and Visual Studio 2015 as the development platform,the processing parameters interface is developed.(3)Through the simplification and equivalence of the transmission structure,the mechanical structure is analyzed,and the grinding force model of grinding wheel grinding process is established.The principle of fuzzy-PID control and the control structure and rules of the fuzzy-PID controller are analyzed,which lays a foundation for the simulation analysis of grinding force control system.(4)The simulation models of the grinding force PID control system and the grinding force fuzzy PID control system are built in Matlab/Simulink respectively.The simulationresults show that:When the grinding force is input to 80 N,the effect of fuzzy PID control on grinding force is obviously better than that of PID control.