Study On Self-excited Vibration Of Clutch Hydraulic Control Valve And Optimization Design Of Key Parameters

The clutch control valve integrated in the hydraulic valve body of a CVT continuously variable transmission has the characteristics of being able to work under the environment of large changes in oil temperature and fluid gas content,and is affected by the actuator machine-hydraulic coupling effect,the clutch control valve is prone to self-excited vibration due to improper parameter matching.The continuous vibration of the clutch control valve spool will not only cause the clutch to shake,but also cause the increase of dynamic load or even damage to the gear,chain and bearing components.Therefore,the study of the dynamics of the clutch valve control hydraulic system,and the corresponding design means to suppress the vibration,to solve the current problem of self-excited vibration in the transmission clutch hydraulic control system has real engineering value and theoretical guidance significance.In order to fundamentally solve the stability problem of the clutch hydraulic control valve system,this paper focuses on the establishment of the nonlinear dynamics model of the clutch hydraulic control valve system,vibration simulation analysis,revealing the mechanism of self-excited vibration,clarifying the sensitive parameters,exploring the stability domain of the sensitive parameters,optimizing the sensitive structural parameters of the system and testing and verifying the valve module system before and after optimization,based on the general design idea of this paper.the following research work.(1)A nonlinear system dynamics model of the clutch valve-controlled hydraulic system was established.The model covers the vibration equation of the spool,the equation of motion of the piston,the flow equation of each chamber in the valve and cylinder,the flow equation through each valve port and damping hole,and the leakage of the spring chamber and the output chamber are taken into account in the model building process to make the model closer to the reality.(2)Simulation analysis of the vibration of the spool of the clutch hydraulic control valve and determination of the vibration form.Based on the system simulation model established by AME Sim,the control current signals of two common operating conditions of the corresponding solenoid valve are given,and the stable periodic equal-amplitude vibration of the spool is simulated,and the main frequency of oscillation is derived from the fast Fourier transform of the vibration phase curve,and finally the vibration form of the spool is judged to be periodic self-excited vibration according to the characteristics of various vibration forms,and the mechanism of self-excited vibration is revealed.(3)The search for sensitive parameters and sensitive parameters stability domain.Using batch processing,orthogonal test method and DOE virtual test method to find and exclude the interference of three non-sensitive parameters,the sensitivity of seven sensitive parameters is ranked,and the spatial stability domain of the system parameters is explored based on Hopf bifurcation theory and response surface analysis.(4)Optimization of system key sensitive parameters and testing and verification of the optimized valve body module system.Based on the genetic algorithm to optimize the key sensitive parameters of the system,the simulation analysis shows that the parameter optimization has achieved certain effect;and after the optimization,the test results show that the clutch output pressure is smoother and the fluctuation is improved compared with the previous situation,which also indicates that the clutch liquid control valve spool self-excited vibration has been moderated and the system is more stable.