NON-RETURN FUEL SYSTEM WITH FUEL PRESSURE VACUUM RESPONSE

摘要

A fuel pressure regulator valve (16) for a fuel rail (12) requires only a single conduit between the tank-mounted fuel pump and the fuel rail, thereby eliminating the need for a separate, and additional, return conduit for returning excess fuel to the tank. It does this by a spring-biased check valve (74) in the inlet (92) to the fuel chamber (52) of the regulator. The check valve (74) is biased to prevent flow from the pump into the fuel chamber of the regulator, but when the pressure in the rail drops below a certain level, a post on the diaphragm (40) that separates the fuel chamber (52) of the regulator from a control chamber (54) of the regulator, unseats a spherical valve element (74) in the check valve to allow pumped fuel to enter the fuel chamber of the regulator and pass into the fuel rail to the fuel injectors. When the pressure has built up beyond a certain pressure the sphere again closes. Excess pressure is relieved by the pressure acting on the sphere (74) causing the sphere to unseat, thereby allowing the excess fuel to pass out through the pressure regulator inlet.