Simulation and Analysis on Stationary Combination Valve of Heavy-Duty Vehicle Automatic Transmission

A mathematical model and dynamic characteristics simulation model were established based on working principle of stationary combination valve in order to study shift quality of heavy-duty vehicle automatic transmission. Various parameters on buffer characteristics influence and outer diameter of the clutch hydraulic cylinder, the spring stiffness and preload influenced on the buffer time, starting pressure and termination pressure were gained with using batch function. The results show that the smaller the orifice diameter, spring stiffness and preload is, the longer the buffer time is, and the curve of buffer characteristic is downward translation. The larger the outer diameter of the clutch hydraulic cylinder, spring stiffness and preload is, the shorter the buffer time is, while the initial pressure and the termination pressure are relatively lower.