Research And Development Of Pump-controlled Hydraulic Press For Transmission Shaft

As a key equipment for accurate press-fitting of transmission shaft,bearing,bushing and other componets in the the transmission assembly section,it has direct impact on the assembly quality of trasmission.With the increase in requirements for high-precision,high-integration,intelligent,high-efficiency,and low-energy consumption of hydraulic equipment,the existing shaft press-fitting equipment of 5T18 automobile transmission assembly line has the disadvantages of low press-fitting accuracy and energy consumption,large noise,and large vibration do not meet the requirements of advanced production concepts.In this paper,the shaft press machine based on the pump control system,Compared with the traditional valve-controlled hydraulic system,has the advantages of low energy consumption,low noise,simple and easy to maintenance,small size,wide speed adjustment range,high flexibility,highly automated.The main work of this paper are:(1)Select the tonnage of the press according to the assembly requirements of the part.Redesign and study the hydraulic system based on valve-less hydraulic system.The hydraulic circuit diagram was drawn up,and the important components in the hydraulic system were selected according to the hydraulic tonnage.the composition,configuration and function of the electrical control process and system are introduced.(2)The transfer function of the pump control cylinder of the pump control press is detailedly deduced,the mathematical model of the electrohydraulic position control system is established and the relevant important characteristics are analyzed.(3)According to the advantages of fractional order PID controller,it is proposed that FOPID should be applied to pump-controlled servo system instead of the traditional PID control and fuzzy PID control,and the controller parameters are tunning by phase margin method.(4)Simulink tool and fuzzy toolbox are used to build the simulation model of position electro-hydraulic servo system under three type controllers.The simulation results show that the FOPID controller shows higher control accuracy and stronger anti-interference ability.The credibility of the mathematical model and the rationality of the mathematical model based research is verified by AMESim/Simulink co-simulation.Taking the press-fitting of the countershaft and the bearing as an example,the displacement functions of the upper and lower cylinder are set.The simulation results show that the fractional PID controller can track the displacement signal of the nut effectively and work better.