A valve member is movable with first and second partition member and opens and closes a first pressure chamber with respect to a return passage. The first partition member partitions the first pressure chamber from a second pressure chamber. The second partition member partitions the second pressure chamber from a third pressure chamber. The first, second, and third pressure chambers cause fuel from a fuel flow passage to flow therethrough. A switching unit switches an opening and closing state of the second pressure chamber and the third pressure chamber with respect to the fuel flow passage and the return passage.

Provided is a high-pressure fuel supply pump capable of arranging a relief valve mechanism inside a pump body while suppressing an increase in size and an increase in manufacturing cost. Therefore, a high-pressure fuel supply pump of the present invention includes: a plunger that changes a volume of a pressurizing chamber by reciprocating an inside of a cylinder; a first hole formed from an outer circumferential surface of a pump body toward an inner circumferential side; a relief valve mechanism arranged in the first hole; and a second hole that returns fuel in a flow path on a discharge side of a discharge valve pressurized in the pressurizing chamber to a damper chamber or a plunger seal chamber communicating with the damper chamber when the relief valve mechanism opens in communication with the first hole. At least a part of the relief valve mechanism arranged in the first hole is arranged on the pressurizing chamber side with respect to the uppermost end portion on the pressurizing chamber side of the cylinder.

The present disclosure relates to pressure relief and pressure regulating valves. More particularly, the disclosure relates to a miniature in-line fuel pressure regulator having a regulator body that includes a housing member and an adjusting member, a pin axially disposed within the regulator body, the pin including an upper end having a circumferential groove, a lower end having a fluid inlet, one or more fluid discharge ports, and a fluid passageway connecting the fluid inlet to the one or more fluid discharge ports, an elastomeric O-ring conformingly positioned within the circumferential groove on the upper end of the pin so that the elastomeric O-ring contacts the raised annular valve seat when the fluid pressure regulator is closed, and a biasing member coupled to the pin and configured to maintain the elastomeric O-ring in contact with the raised annular valve seat to control an opening pressure of the fluid pressure regulator.

A high-pressure fuel pump for a fuel delivery system of an internal combustion engine includes a pressure limiting valve positioned between an outlet and an inlet of the pump. The valve includes a spring-loaded closing element and a closing body that radially holds the closing element in place, and that has a concave receiving portion configured to at least partially receive the closing element. The receiving portion has a radially outer first area with a first opening angle, and a radially inner second area with a second opening angle larger than the first opening angle. The first area and the second area are located outside of a contact region between the closing element and the closing body.

The present invention provides a fuel pump capable of preventing the occurrence of cavitation near a seat member in a valve mechanism. The fuel pump includes a plunger adapted to reciprocate, a pressurizing chamber adapted to increase and decrease its volumetric capacity through the reciprocation of the plunger, and a relief valve mechanism adapted to return a fuel to the pressurizing chamber. The relief valve mechanism includes a relief valve, and a seat member having a valve contact portion for seating the relief valve thereon. The relief valve is disposed closer to the plunger than the seat member. The seat member has an annular groove portion which forms a space communicating with the pressurizing chamber, between the annular groove portion and a second chamber (a fixing portion) surrounding the outer peripheral surface of the seat member. The space is provided at a position farther from the plunger than the valve contact portion.

A pressurized fuel system for an engine includes a fuel pump in a pump protection device structured to drain pressurized fuel from a common rail to provide fuel flow through the fuel pump that limits cavitation. The device includes a valve mechanism having a first valve and a second valve that are movable to an open position and a closed position respectively, in response to valve opening and valve closing rail pressures. The active pressure range of the device may be a medium pressure range.

Various methods and systems are provided for a pressure relief valve of a fuel system. In one example, a valve includes a first chamber in fluid communication with a first fuel line, a second chamber in fluid communication with a second fuel line and in fluid communication with a fuel storage tank, a piston separating the first chamber from the second chamber, and a needle coupled to the piston and controlling a flow passage between the second fuel line and the second chamber, where the piston and needle are sized such that a force applied on the piston by the first chamber parallel to an axis of movement of the piston maintains the needle in a closed position when the first fuel line flows fuel at a first pressure and the second fuel line flows fuel at a second pressure, the second pressure greater than the first pressure.

In a high-pressure pump, a relief valve main body has a rod shape. A relief valve seat portion is integrated with an end of a relief valve main body so as to be capable of contacting a relief valve seat. The relief valve main body is inserted into a guide hole portion of a support portion. The guide hole portion slidably supports an outer wall of the relief valve main body so as to guide a reciprocating movement of the relief valve main body in the axial direction. A fuel guide portion is provided at an end portion of the relief valve main body facing the pressurizing chamber and can guide a flow of the fuel in a direction radially outward of the relief valve main body on the way from the pressurizing chamber toward the valve seat portion.

The invention relates to a control method for controlling a fuel injection system (10) of an internal combustion engine, wherein, wherein, in a fault situation of the fuel injection system (10), a camshaft angle of a camshaft (34) which drives a pump piston (32) of a high-pressure fuel pump (14) of the fuel injection system (10) is adjusted such that an injection time (tI) of injector valve (42) which injects the fuel from the fuel injection system (10) into a combustion chamber of the internal combustion engine lies in a pressure trough (50) of a pressure oscillation in a high-pressure region (16).

The present disclosure relates to pressure relief and pressure regulating valves. More particularly, the disclosure relates to a miniature in-line fuel pressure regulator having a regulator body that includes a housing member and an adjusting member, a pin axially disposed within the regulator body, the pin including an upper end having a circumferential groove, a lower end having a fluid inlet, one or more fluid discharge ports, and a fluid passageway connecting the fluid inlet to the one or more fluid discharge ports, an elastomeric O-ring conformingly positioned within the circumferential groove on the upper end of the pin so that the elastomeric O-ring contacts the raised annular valve seat when the fluid pressure regulator is closed, and a biasing member coupled to the pin and configured to maintain the elastomeric O-ring in contact with the raised annular valve seat to control an opening pressure of the fluid pressure regulator.