A fuel pump includes a pump housing with a pumping chamber an inlet valve bore. An inlet valve selectively provides and prevents fluid communication between an inlet of the fuel pump and the pumping chamber. The inlet valve includes an inner housing received within the inlet valve bore such that an outer periphery of the inner housing is sealed to an inner periphery of the inlet valve bore. An outer housing circumferentially surrounds the inner housing. An annular chamber is defined radially between the inner housing and the outer housing and axially between the outer housing and the pump housing. A sealing ring is located within the annular chamber such that the sealing ring is compressed axially against the pump housing and the outer housing.

A fuel pump includes a pump housing with a pumping chamber an inlet valve bore. An inlet valve selectively provides and prevents fluid communication between an inlet of the fuel pump and the pumping chamber. The inlet valve includes an inner housing received within the inlet valve bore such that an outer periphery of the inner housing is sealed to an inner periphery of the inlet valve bore. An outer housing circumferentially surrounds the inner housing. An annular chamber is defined radially between the inner housing and the outer housing and axially between the outer housing and the pump housing. A sealing ring is located within the annular chamber such that the sealing ring is compressed axially against the pump housing and the outer housing.

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 high-pressure pump includes: a low-pressure chamber, into which low-pressure fuel discharged from a low-pressure pump flows; a pressurizing chamber, which pressurizes the low-low-pressure fuel; and a leak chamber, into which leaked fuel from the pressurizing chamber flows. The leaked fuel of the leak chamber is suctioned into and is pressurized in the pressurizing chamber together with the low-pressure fuel of the low-pressure chamber, so that the leaked fuel is discharged to an outside of the high-pressure pump as high-pressure fuel. Furthermore, a suction check valve, which is placed between the low-pressure chamber and the leak chamber, limits backflow of the leaked fuel of the leak chamber to the low-pressure chamber when the high-pressure pump does not supply the high-pressure fuel.

Responsiveness is improved in valve opening and valve closing of an electromagnetically driven intake valve unit in which a valve is provided on a pressurizing chamber side of a valve seat. The valve includes an annular abutting surface that abuts the valve seat to shut off a fuel intake passage and a bottomed cylindrical part provided at an inner peripheral part of the annular abutting surface. The bottomed cylindrical part is inserted into a fuel introduction hole formed in the valve housing inside the valve seat, and the outer surface of an end part of the bottomed cylindrical part is exposed to fuel in a low pressure fuel chamber provided upstream of the fuel introduction hole.

An engine fuel delivery system includes a fuel pump having a pumping chamber to increase fuel pressure and a closeable inlet valve, and a fuel rail to communicate pressurized fuel received from the fuel pump to at least one engine cylinder. The engine fuel delivery system also includes a controller programmed to issue a control signal to periodically close the inlet valve to generate a setpoint fuel pressure within the pumping chamber. The controller is also programmed to adjust a control signal gain value in response to deviation in an outlet fuel pressure relative to the setpoint fuel pressure. The controller is further programmed to issue a warning message in response to the control signal gain being adjusted by more than a predetermined threshold from a calibrated gain value.

A quantity control valve comprises a valve needle configured to move in an axial direction, a damping chamber having a wall, and a valve element delimiting the damping chamber. The valve needle is configured to move the valve element in an opening direction. A gap is defined between the wall of the damping chamber and the valve element. The gap has at least one recess and connects the damping chamber to a flow duct.

Systems and methods are provided herein for tracking degradation of a high-pressure fuel pump. In one example, a fuel system controller is configured to receive an output pressure signal from a pressure sensor, transform the output pressure signal to the frequency domain to generate frequency content of the output pressure signal, and diagnose a condition of a fuel pump based at least in part on the frequency content of the output pressure signal, the fuel pump fluidly coupled to a fuel injector via a common fuel rail, and the fuel injector is operable to inject fuel to a cylinder of an engine.

Embodiments relate to a valve arrangement for a fuel injection system, including a valve disc that has a valve opening. A deformable valve sheet that is movable in a movement direction is provided to open and close the valve opening, and a valve shaft of a movement-activation arrangement, provided to activate the movement of the valve sheet, is secured to the valve sheet. The embodiments also relate to a high-pressure pump which includes the valve arrangement.

The present invention relates to a high pressure fuel pump comprising an inlet channel in connection with a first chamber, through which inlet channel fuel is led to the first chamber, a second chamber arranged in connection with the first chamber, an outlet valve arranged in connection with the second chamber and an inlet valve comprising a piston, with a first end section and a second end section. The piston is moveably arranged with the first end section in a third chamber, and the second end section is moveably arranged between the first chamber and the second chamber. A press element is arranged to act on the piston with a mechanic force, so that the piston strives to be positioned with the second end section closing the connection between the first chamber and the second chamber. The inlet valve is in a closed state and may be controlled via an electromagnetic unit.