Design And Test Research Of Digital Proportional Relief Valve For Shifting On Vehicle

As the development of automobile technology, the convenience and comfort are highly desired by people, so more and more automatic transmissions are installed to cars. Automatic transmission shifts up and down through the joint and withdrawing of the unite components. In order to limit the torque disturbance on the transmission output shaft, get a good shift quality and improve the comfort in the process of shifting changes, the oil pressure is reasonably controlled. The digital proportional relief valve is the ideal component for pressure controlling in the process of shifting changes.In this thesis, the digital proportional relief valve was designed, the geometry of the main valve and static properties were calculated, the PWM signal generation circuit and high speed valve drive circuit were designed, and the simulation model of the digital proportional relief valve was established. By virtual of numberical simulation, the conclusions were drawn that the fluid resistance mainly affected the pressure regulating scope of the valve and had an appreciable effect on the response time, the import volume of main valve affected the step response of the digital proportional relief valve, the chamber before safety valve mainly affected the speed of the pressure adjustment, and the frequency of control signals major impact on the oscillation amplitude of the pressure. The test-bed design was established, on which the characteristics experiments of the digital proportional relief valve were completed. The results showed that the frequency signal obtained an effective duty cycle range and met the performance requirements of the frequency response, when the frequency signal was 50Hz. And the pressure range met the design requirements, when the diameter of damping hole was 1mm . The results of experiments were the same as the simulations'. It was proved that the established model of the digital proportional relief valve for shifting on vehicle was correct and feasible.This research shows that the digital proportional relief valve have a reasonable control of the oil pressure and meet the requirements of the oil pressure in the process of shifting changes.