Abstract:The response speed of piezoelectric valve in piezoelectric injector determines the performance and accuracy of fuel injection control in internal combustion engines.In order to improve the response speed of piezoelectric valve,a joint simulation model of piezoelectric valve and its drive circuit based on pulse width modulation (PWM) control method was established by MATLAB/Simulink,and a test bench was built to test the performance of piezoelectric valve,and the effect of PWM pulse width and pulse number of injection control signal on the response time of piezoelectric valve was investigated by combining simulation and test.The results show that for the self-researched drive circuit,the PWM pulse width of the injection control signal has an optimal value,and the optimal pulse width is from 0.3 ms to 0.42 ms.Under the multi-pulse control strategy,the response times of piezoelectric valve opening and closing are 0.525 ms and 0.725 ms respectively; under the single-pulse control strategy,the response times of piezoelectric valve opening and closing are 0.5 ms and 0.6 ms respectively,which meet the control requirements for achieving multiple injections in one cycle of an internal combustion engine.Compared with the multi-pulse control strategy,the opening response time of the single-pulse control strategy is shortened by 4.762%,and the closing response time is shortened by 17.2%.