Flow rate controlling valve of power steering apparatus

Abstract

Abstract PURPOSE: To enable the pump power to be decreased in accordance with the decrease in the steering power, by varying the passage area of a flow rate controlling valve for controlling the by-pass flow rate of a working fluid in accordance with the steering power of a steering actuator. CONSTITUTION: If a steering wheel 9 is at a neutral position, the working fluid discharged from a pump 1 is flowed from a supply path 5 via a control valve 2, a drain path 7 and a tank 6 to the pump 1 again, and the pressures in two fluid chambers 16, 17 of the actuator 8 are equalized. Accordingly, a spool valve 49 of the flow rate controlling valve 40 is positioned at the center of the chamber 48, the by-pass 21 becomes the open state, and at the same time the passage area of the throttle section of the drain path 7 is enlarged to decrease the fluid resistance of the working fluid. In other words, most of the working fluid by-passes through the by-pass 21, the piping resistance as a whole is decreased, and the load for driving the pump 1 can be lessened. COPYRIGHT: (C)1982,JPO&Japio

Inventors

• 👤 Masafumi Nakayama
• 👤 Setsuyoshi Yanai
• 👤 Masato Fukino

Bibliographic Details