Patent ID: 6170473
Filing Date: 2001-01-09
Classification: F02D,F02M

Abstract:
A relief device for a high-pressure direct-injection pump for feeding petrol to a manifold of injectors of an automobile vehicle internal combustion engine, the high-pressure pump being connected by a feed pipe to a low-pressure electrical fuel pump which communicates with a fuel tank and the high pressure delivered being regulated by a pressure regulator, wherein the pressure regulator is a three-way regulator with three ports, a first port A connecting the high-pressure pump to the manifold of the injectors, a second port B connecting the high-pressure pump to the tank and a third port C connecting the fuel pump to the manifold of the injectors, the second port B being selectively open in normal operation, the first port A being closed when the third port C is open and vice versa in operation from an electrical power supply, the third port C being:normally open when the electrical fuel pump is not switched on, in which case the second port B is forced open,held open during the engine starting phase, the fuel pump being energised to supply petrol at a stable low pressure to the injectors, andclosed when the engine speed reaches a predetermined threshold corresponding to a rotation speed of the high-pressure pump adapted to supply petrol at a stable high pressure to the injectors.