JPS55132354A - Fluid-pressure control valve for double system piping - Google Patents

Abstract

PURPOSE: To raise the critical fluid-pressure in a control valve of one system twice or more as high as the normal one when another system is lost by using not only a common spring to control the critical fluid-pressure of a fluid-pressure control valve for double system piping but also a spring in a control valve of the lost system for operating the control valve of the normal system.

CONSTITUTION: When two systems are both normal, the fluid-pressure in a master cylinder is given through inlets 4 and 6 and fluid passages 40 and 41 to small pistons 38 and 39, which are shifted to the right and compress springs 34 and 35 via spring- operating elements so that forces of these springs may not be given to a spring seat main body 22. Consequently, critical fluid-pressures in control valves 8 and 9 are usually controlled by the force of a spring 26. For example, when the system of a front wheel 28 is lost, the small piston 38 does not work and the force of the spring 34 is given to the spring seat main body 22 to incline a spring seat 27. Thus, since the whole force of the spring 26 and the force of the spring 34 are added to the control valve 9, the critical fluid-pressure of the control valve 9 is raised twice or more as high as the normal one.

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