Research On Force Control System Of Hydraulic Power Chuck Of Numerical Control Machine Tool Based On DDVC

Modern manufacturing technology is developing towards high speed,high efficiency,high precision and high flexibility.Hydraulic power chuck is an important functional part of CNC lathe,CNC grinder and turn-milling compound machining center.It has the advantages of compact structure and high rotational speed.In the cutting process,the reasonable clamping of the workpiece can avoid vibration and improve the stability of the cutting force and the surface quality of the workpiece,so it is very important to control the clamping force of the hydraulic power chuck in the process of machining.In this paper,the key technology of precise control and adjustment of clamping force of hydraulic power chuck is studied,and the direct drive electro-hydraulic servo system is put forward.The application of service technology in the force control of chuck provides a new energy saving idea for the force control of hydraulic power chuck and solves the problem of unadjustable clamping force in the existing workpiece processing scheme.The main contents of this paper are as follows:The working principle of the direct drive hydraulic power chuck force control system is analyzed,the mathematical model of the pump controlled cylinder power system is established,and the relevant parameters are obtained by experiment.Combined with the mathematical model of servo speed regulation module and pressure detection module,the transfer function of the system is deduced.Finally,the stability of the system is analyzed.An adaptive fuzzy PID clamping force controller for hydraulic power chuck is designed.In Simulink,the pressure keeping performance of the system under the action of PID controller and adaptive fuzzy PID controller is simulated and analyzed,and the joint simulation model of system commutation is established by AMESim and Simulink.The commutation performance of the system is simulated and analyzed under the action of PID controller and adaptive fuzzy PID controller respectively.The results show that the system can realize the chuck force control.The adaptive fuzzy PID controller has better dynamic characteristics and robustness than the PID controller.Overshoot,no pressure impact during the commutation process,fully meet the precision and stability requirements of clamping force in the process of workpiece processing.The experiment system is built and the adaptive fuzzy PID controller is developed on the programmable controller.The performance of the system under the action of PID controller and adaptive fuzzy PID controller is compared experimentally.The experimental results are in agreement with the simulation results,and the correctness of the established mathematical model is verified.