Characteristics Research And Experimentation Of Digital Proportional Relief Cone Valve For Shifting On Vehicle

With the development of automotive electronic technology and improvement ofautomatic transmission loading rate, a higher demand on convenience and comfort ofvehicle handling is proposed. The shifting process is achieved through separation andcombination of wet clutch in the automatic transmission, and the oil pressure variation inthe hydraulic cylinder of wet clutch needs to be reasonably controlled in this process,which can effectively limit the torque disturbance on transmission output shaft, to get agood shift quality.In view of the need of hydraulic buffer control of wet clutch in shifting process, adigital proportional cone valve is independently designed in this paper. The main contentincludes: (1) The digital proportional cone valve is designed, and the main geometry sizeparameters and static characteristics parameters are calculated. (2) Based on the operatingprinciple of the digital proportional cone valve, switching characteristic and drivingperformance of high-speed on-off valve is analyzed in details, and PWM control signal isobtained by software programming and its driver circuit is designed. (3) The mathematicalof the digital proportional cone valve are established, and the influence of the structuralparameters and flow characteristics on valve pressure is analyzed. (4) Experimentalresearch on the digital proportional cone valve is carried out, and its steady property andflow rate are tested. Through comparing the characteristics of pressure regulation betweenslide-valve and cone-valve, the results show that the digital proportional cone valve has awide duty-cycle pressure regulating range and meets the design requirements of wet clutchin shifting process.