Control valve and four-wheel steering system including control valve

摘要

A control valve includes a first valve having a cylinder and a piston arranged in the cylinder. The piston defines in the cylinder a pressure receiving chamber and first and second output pressure chambers, and is moved by pilot pressure applied to the pressure receiving chamber to change volumes of the first and second output pressure chambers. The output pressure chambers are connected to each other through a throttle control valve which generates pressure difference corresponding to a rate of change in volumes of the output pressure chambers, between the output pressure chambers. A main valve is connected to the throttle control valve and includes an inlet port, output ports, and a valve member located between the input and output ports. The valve member is moved in accordance with the pressure difference between the first and second output pressure chambers to control hydraulic pressure output from the output ports.