HYDRAULISCHE STEUERANLAGE FUER EIN MEHRGANGGETRIEBE

摘要

A hydraulic control for an automatic transmission has a plurality of shift control valves for controlling the interchange of drive ratios within the transmission. The shift control valves each have a control chamber subjected to substantially constant pressure and a shift control chamber having an area proportional to the respective control chamber which is subjected to a variable control pressure. The variable control pressure is controlled at discrete levels by a single pulse width modulator (PWM) solenoid. The respective area ratios of the shift control chambers to the controlled chambers determines the distinct shift point of each shift valve.