| 摘要 |
PURPOSE:To make the opening of a valve modifiable according to feed pressure, by installing a magnetic resistance control body in position between a cover member being set up so as to surround the outer circumference of a solenoid and a yoke installed in the inner circumference of the solenoid, while shifting this control body to some extent according to hydraulic pressure at the high pressure side. CONSTITUTION:In case where this valve is applied to a speed responsive type power steering device, when a control current commensurate to a car speed is impressed on a solenoid 29, such magnetic flux as passing through a cover 30, a valve body 21, a spool 27, a yoke 26, a magnetic resistance control body 35 and an air gap 38 is formed up. With this constitution, the spool 27 is displaced to some extent against a spring 33 by dint of magnetic attraction whereby a slit 27a is opened to a port 22b and a bypass passage is formed between ports 20a and 20b. At this time, when a steering wheel is suddenly operated, with this operation, pressure in the hydraulic fluid given by way of a through hole 27b goes up, causing the magnetic resistance control body 35 to be raised against a spring 37, and magnetic resistance in the air gap 38 grows large, thus the spool 27 is made to go down. |
