An outlet valve includes an outlet valve housing with an outlet valve bore including an outlet valve seating surface. The outlet valve also includes an outlet valve member which moves within the outlet valve bore second portion between a closed position and an open position. A surface of the outlet valve bore guides the outlet valve member during movement between the closed position and the open position. The surface of the outlet valve bore and the outlet valve seating surface are provided on a continuous piece of material of the outlet valve housing. An outlet valve spring biases the outlet valve member toward the closed position and a retainer is fixed to the outlet valve housing which grounds the outlet valve spring to the outlet valve housing.

A direct-injection, supercharged internal combustion engine having at least one cylinder, in which each cylinder is equipped with a direct injection apparatus, a fuel supply system comprising a high-pressure side and a low-pressure side, and a high-pressure piston pump comprising a piston displaceable in translational fashion between a bottom dead center and a top dead center of a pressure chamber of variable volume. The displaceable piston jointly delimits the pressure chamber with variable volume in such a way that a displacement of the piston causes a change in the volume of the pressure chamber via actuation of least one movable actuation element.

A fuel pump includes a fuel pump housing with a pumping chamber and an inlet valve bore which extends along an inlet valve bore axis. The inlet valve bore is stepped such that the inlet valve bore includes a shoulder which is traverse to the inlet valve bore axis. A pumping plunger reciprocates within a plunger bore along a plunger bore axis such that an intake stroke of the pumping plunger increases volume of the pumping chamber and a compression stroke of the pumping plunger decreases volume of the pumping chamber. An inlet valve assembly includes a valve seat with a valve seat flow passage extending therethrough, the valve seat abuts the shoulder and is urged toward the shoulder by pressure within the pumping chamber during the compression stroke. The inlet valve assembly also includes a valve member which is moveable between an unseated position and a seated position.

A high-pressure fuel supply pump including an electromagnetically driven intake valve is configured such that a pressure equalizing hole is provided in the valve stopper positioned between the valve and a pressurizing chamber. The pressure equalization hole connects a spring storage space, provided between a valve and a valve stopper, with a surrounding fluid passage. The high-pressure fuel supply pump is further configured such that an opening of the pressure equalizing hole at the spring storage chamber side is open at a position at the inner side of a diameter of the spring. Since the pressure in the pressurizing chamber can be introduced into the inner side of the spring without traversing the spring, the unstable behavior of the spring or the valve due to the introduced pressure eliminated. Since the force applied to the valve when the valve closes is stabilized, the closing timing of the valve is stable.

A pump unit for feeding fuel, preferably diesel fuel, to an internal combustion engine, the pump unit comprising: a head (2) inside which a cylinder (3) is formed along an axis (A) for housing a sliding pumping piston (4); an intake valve (8) positioned inside an intake hole (7) between an intake chamber (9) and a compression chamber (10) upstream and downstream of the intake hole, respectively; a plug (11) sealingly connected to the head (2) so as to close the intake chamber; wherein the sealed connection is formed by means of forced surface-to-surface engagement between a portion of an inner surface of an annular wall of the head and a portion of an outer surface of an annular wall of the plug.

A fuel pump includes a fuel pump housing with a pumping chamber; a pumping plunger which reciprocates within a plunger bore; and an inlet valve assembly. The inlet valve assembly includes a check valve member which is moveable between an unseated position which provides fluid communication between the pumping chamber and a fuel supply passage and a seated position which prevents fluid communication between the pumping chamber and the fuel supply passage; and a solenoid assembly which includes a wire winding; a pole piece; an armature which is moveable between a first position when the wire winding is not energized and a second position when the wire winding is energized; a return spring which biases the armature away from the pole piece; and a control rod which is moveable along the inlet valve axis independently of the armature.

A fuel pump includes a fuel pump housing with a pumping chamber; a pumping plunger which reciprocates within a plunger bore; and an inlet valve assembly. The inlet valve assembly includes a check valve member which is moveable between an unseated position which provides fluid communication between the pumping chamber and a fuel supply passage and a seated position which prevents fluid communication between the pumping chamber and the fuel supply passage; and a solenoid assembly which includes a wire winding; a pole piece; an armature which is moveable between a first position when the wire winding is not energized and a second position when the wire winding is energized; a return spring which biases the armature away from the pole piece; and a control rod which is moveable along the inlet valve axis independently of the armature.

An object of the present invention is to obtain a high pressure fuel supply pump capable of reducing pressure pulsation that occurs in a low pressure pipe, preventing damage to the low pressure pipe, or reducing noise due to vibrations of the low pressure pipe. The present invention provides a high pressure fuel supply pump of a type in which, from a fuel suction port connected to a low pressure pipe provided upstream of a fuel, a low pressure passage, an electromagnetic suction valve driven by an electromagnetic force, a pressurizing chamber in which the volume thereof is increased or reduced by a plunger that is reciprocatingly moved by being guided by a cylinder, and a discharge valve provided at an outlet of the pressurizing chamber are sequentially arranged, a fuel is sucked to the pressurizing chamber through the electromagnetic suction valve, the amount of a part of the fuel, which is sucked to the pressurizing chamber, to be returned to the low pressure passage side is adjusted so that the amount of the fuel to be discharged through the discharge valve is controlled, and the high pressure fuel supply pump includes a backflow suppression mechanism for suppressing backflow of fuel from the fuel from the fuel suction portion to the low pressure pipe side.

A high-pressure fuel pump is disclosed. The high-pressure fuel pump comprises a housing, and a barrel that is positioned within the housing. A plunger is positioned in a pumping chamber that is defined within the barrel. The plunger is adapted to reciprocate within the pumping chamber that is defined within the barrel to facilitate delivering pressurized fuel from the pumping chamber to a fuel injector. A T-shaped valve and an inverse T-shaped valve are each positioned within a fuel inlet port that is defined in the barrel of the high-pressure fuel pump, the T-shaped valve and the inverse T-shaped valve adapted to regulate a flow of fuel between the pumping chamber and a fuel gallery of the high-pressure fuel pump is also disclosed.

A fuel pump includes a mechanical regulating valve arranged in a pump body which modulates the pressure in a high pressure space so that the pressure matches the engine demand. Modulation by the regulating valve requires adjustment of the inlet fuel quantity, adjustment of the volume of the high pressure space, and control of a return fluid communication enabling fuel to exit the high pressure reservoir.