A study on the dynamic response characteristics of electro-hydraulic proportional valve for the shift of automatic transmission

To improve the shift quality of vehicle, an electro-hydraulic proportional valve for the gear shifting of automatic transmission is proposed with its working principle analyzed and a dynamic model set up for the flow control valve of proportional valve at opening and closing moments. A simulation is conducted on the dynamic characteristics of proportional valve with Matlab/Simulink, and the bench test verifies the correctness of the modeling and simulation techniques. The results of test also show that under the condition with a oil pressure of 12 bar and a solenoid supply voltage of 42 V, the response time of electro-hydraulic valve for pressure build up is about 70 ms while that for pressure release is around 50 ms, meeting the requirements of practical control.