Time delay characteristics analysis of pressure dynamic response on electro-hydraulic pressure regulating valve

The electro-hydraulic pressure regulating valve (EHPRV) is a key component for wet clutch actuator system, of which time delay characteristic will delay shifting process and increase the sliding friction time of friction plate, resulting affect shifting quality. In this paper, the time delay characteristics of a two-stage EHPRV is studied, using a high-speed solenoid valve as the pilot and a spool valve as the power amplification. Through theoretical analysis, six parameters that affect the system's time delay characteristics are determined. The analysis results show that four of these parameters have obvious effects on time delay characteristics. First, the delay in the pilot solenoid valve is the greatest impact on the time delay of system. The faster the solenoid valve response speed, the smaller the system time delay. The second is that the smaller the volume of control cavity, the faster the decompression rate of system, but the overshoot of the oil pressure response increases. The third is the larger the size of feedback cavity orifice, the lower the time delay of system. The fourth is the working cavity. The smaller the volume, the lower the time delay of system, and the lower the overshoot of the oil pressure response. This article reveals the influence of key parameters on time-delay characteristics for EHPRV, which can provide a basis for the optimal design of shifting system.