The present invention provides a fuel pump capable of suppressing sticking of a plunger. The fuel pump of the present invention includes a plunger 2 that reciprocates, a cylinder 6 in which a guide hole 6a that guides the reciprocating motion of the plunger 2 extends in the axial direction, and a pump body 1 that holds the cylinder 6. The pump body 1 includes a cylinder insertion hole 1g into which the cylinder 6 is inserted, and a pressurizing chamber 11 that communicates with the cylinder insertion hole 1g and has a volume increased or decreased by the reciprocating motion of the plunger 2. The cylinder 6 includes a press-fitting portion 6b press-fitted into the inner peripheral surface of the cylinder insertion hole 1g, and a groove 6d formed at a position corresponding to the press-fitting portion 6b on the inner peripheral surface of the guide hole 6a.

A fuel pump for a direct injection system and having: a main body; a pumping chamber; a piston, which is mounted in a sliding manner on the inside of the pumping chamber; an intake duct, which ends in the pumping chamber; an intake valve, which is arranged along the intake duct; and a flow rate adjustment device provided with a control rod which is coupled to the intake valve and with an electromagnetic actuator which is configured to axially move the control rod. The flow rate adjustment device has a containing element, which houses the electromagnetic actuator, has an open end facing the intake valve, and ends with a “U”-shaped rim which has an outer ring which is arranged around the containing element at a given distance from a cylindrical wall of the containing element. An annular weld (22) is obtained between the main body and the outer ring of the “U”-shaped rim.

A valve arrangement for a high pressure pump includes a pump housing with a depression, and a valve housing configured to be inserted in the depression, and a clamping disc. The valve housing has at least one radial projection with a first axial boundary surface and a second axial boundary surface arranged opposite the first axial boundary surface, wherein the clamping disc extends radially over the radial projection of the valve housing and has a third axial boundary surface that corresponds with the second axial boundary surface of the valve housing. On the circumferential side, the clamping disc has a thread that can be screwed into a thread on the inner side of the depression to brace the valve housing onto the first boundary surface.

Provided is a high-pressure fuel pump that ensures oil tightness even at high fuel pressure and has a small and lightweight inexpensive discharge valve structure. Therefore, a high-pressure fuel pump according to the present invention includes: a discharge valve arranged on a discharge side of a pressurizing chamber; a discharge valve seat on which the discharge valve is seated; and a facing member configured independently as a separate member from the discharge valve seat and located on an opposite side of the discharge valve seat with the discharge valve interposed therebetween, in which a stroke direction regulating portion that regulates displacement of the discharge valve in a stroke direction is formed on a tapered surface of the facing member.

A high-pressure fuel supply pump for a fuel system that supplies a high-pressure fuel injection (GDI) apparatus and a low-pressure fuel injection (PFI) apparatus incorporates an inlet check valve to isolate a low-pressure fuel feed channel in the pump from pressure fluctuations at the inlet of an inlet control valve. Upstream of the inlet check valve, the low-pressure fuel feed channel is connected to a seal chamber surrounding the pumping plunger. Circulating fresh low-pressure fuel through the seal chamber ensures that the pumping plunger and the clearance between the plunger and the pump bore are cooled and lubricated with fuel, even when high pressure fuel is not produced by the high-pressure pump. The low-pressure fuel feed channel is connected to the low-pressure PFI outlet downstream of the seal chamber. This pump configuration provides stable source of low-pressure fuel for a PFI system.

A valve assembly for a fuel pump and having: a one-way outlet closing valve, which only allows fuel to flow out; a one-way pressure relief valve, which only allows fuel to flow in; a connector, which has a housing on the inside; and a valve disc, which engages the housing of the connector and has a plurality of through outlet holes and a through relief hole. A shutter of the outlet closing valve consists of a flexible sheet, which is fixed to the valve disc and has: a plurality of shutting portions arranged in the area of the outlet holes; a peripheral mounting portion with an annular shape; a plurality of outer connection portions, each connecting the peripheral mounting portion to a corresponding shutting portion; a central mounting portion; and a plurality of inner connection portions, each connecting the central mounting portion to a corresponding shutting portion.

A high pressure fuel pump includes a pressurizing assembly where a plunger arranged in a bore translates along a main axis. The pump also includes a fuel transfer assembly having an inlet valve assembly and an outlet valve assembly. The pressurizing assembly has a pressurizing body provided with the bore and the fuel transfer assembly has a fuel transfer body within which are arranged the inlet and the outlet valve assemblies. The pressurizing body and the fuel transfer body are distinct parts fixed to each other along a sealing area.

To increase a valve-opening pressure at which a pressure relief valve is opened in order to deal with a higher pressure of the fuel, a large pressure relief valve is installed in a high-pressure fuel supply pump. This upsizes the high-pressure fuel supply pump. A pressure relief valve is installed in a discharge joint. This can provide a high-pressure fuel supply pump that is not large too much and sufficiently performs a relief function by efficiently using the excessive space in the pump even when the fuel pressure is increased.

A high pressure fuel pump includes a pressurizing assembly where a plunger arranged in a bore translates along a main axis. The pump also includes a fuel transfer assembly having an inlet valve assembly and an outlet valve assembly. The pressurizing assembly has a pressurizing body provided with the bore and the fuel transfer assembly has a fuel transfer body within which are arranged the inlet and the outlet valve assemblies. The pressurizing body and the fuel transfer body are distinct parts fixed to each other along a sealing area.

A digital inlet valve is the complementary assembly of an armature module, a body module and an actuation module enabling direct control over an air gap between a magnetic armature and a pole piece body.