Fluid pressure control valve for dual braking system

摘要

A braking fluid pressure control apparatus for a dual circuit type vehicle brake system. The control apparatus is provided with a pair of pressure reducing or pressure limiting valve plungers disposed in a housing parallelly one another, with respective rear ends being protruded out of the housing, and a biasing device for commonly biasing both rear ends into the housing. The biasing device includes a guide rod pivoted to the housing at an intermediate position of the pair of valve plungers oscillatably in a parallel direction to a plane including the axes of both plungers. On the guide rod a transmitting member having an operating portion abuttable to the rear ends of both plungers is slidably fitted and biased by a spring toward the rear ends of the plungers. The guide rod limits the oscillation in a minute angle range, with a result that when a pressure failure has occurred in one circuit the valve plunger influenced by the pressure of the other circuit is obliged to singly resist the biasing force of the spring so as to start pressure reducing or limiting operation at a higher pressure level than in normal condition.