An object of the present invention is to prevent generation of wear at a rod collision portion in an electromagnetic intake valve of a high-pressure fuel supply pump by reducing inclinations of the intake valve and a rod. A structure of the electromagnetic intake valve of the high-pressure fuel supply pump is configured as follows. A seat portion of an intake valve and a guide portion of a rod are configured as an integral part, and further, a rod guide is made to have a sufficiently long length so that it is possible to perform guide at one portion. Further, the intake valve seat portion and a surface where the rod collides with the intake valve are formed on the same plane.

Provided is a solution to a problem on a discharge valve mechanism disposed at an exit of a pressurizing chamber of a high-pressure fuel supply pump, that is, an occurrence of a backward flow of the fuel concentrates on a limited fuel passage, leading to a higher fuel flow rate, and this easily induces the occurrence of cavitation, and collapse of the generated cavitation might damage a seat surface, making it difficult to maintain valve functions. The present invention provides a valve mechanism including a seat member having a seat section, a valve body configured to attach to or detached from the seat section, and a housing member arranged on an outer peripheral side of the seat member. A first fluid flow-path is formed to connect an inner peripheral side and an outer peripheral side of the seat section in a case where the valve is detached from the seat section. A second fluid flow-path is formed to be connected with the first fluid flow-path, between an outer peripheral surface of the seat member and an inner peripheral surface of the housing member, or between an outer peripheral surface of the valve body and the inner peripheral surface of the housing member. The cross-sectional area along the axial direction of the valve mechanism of the second fluid flow-path is 0.18 mm square or above.

A high-pressure fuel supply pump includes a plunger, a valve member, a valve seat, a pressurizing chamber, and a fuel passage. The fuel passage includes a gap passage portion formed in a gap between the valve seat and the valve member. The fuel passage also includes a bent passage portion extending in a bent direction with respect to the gap passage portion, on the downstream side of the gap passage portion. The inner surface of the valve member, on a side thereof that faces the valve seat, has a convex shape in an area of the valve member that is between the bent passage portion and the gap passage portion.

A valve assembly for a pump includes an electrical actuator having a stator and an armature. The stator includes an annular outer stator portion and an annular inner stator portion, and an annular channel formed radially between the outer stator portion and the inner stator portion. A first radial channel extending through the annular outer stator portion between an outer surface of the outer stator portion and the annular channel, and at least one second opening in the annular outer stator portion results in magnetic symmetry of the stator . Upon activating the electrical actuator, the attraction of the armature towards the stator is uniform thus displacing fluid between the stator and armature in a uniform manner and to avoid high velocity, potentially damaging fluid flow.

The present invention relates to a fuel pump for pumping fuel, comprising a piston (2) and a diaphragm seal element (3), which seals on an inner annular seal seat (4) and an outer annular seal seat (5), wherein the following equation is satisfied: (Ra.sup.2−ra.sup.2)/(ri+L).sup.2=ra/ri, where ri is the inner radius of the inner seal seat (4), ra is the inner radius of the outer seal seat (5), Ra is the outer diameter of the piston (2) and L is a difference between an outer radius (Ria) of the inner seal seat (4) and the inner radius (ri) of the inner seal seat (4). The invention further relates to a method for operating a fuel pump.

The present disclosure relates to a nozzle for a fuel injector that comprises a pivotably symmetrical nozzle member having a hollow space for introducing a nozzle needle, a nozzle tip that is provided at a longitudinal end of the nozzle member, and at least one opening for discharging fuel, and a nozzle needle arranged in the hollow space for a selective blocking of a fuel inflow to the at least one opening, wherein the nozzle needle is designed as tubular in the region of the nozzle tip and is adapted to conduct fuel in the interior of the tubular region to the at least one opening.

A valve includes a valve body having a valve plunger barrel formed therein and configured to be mounted to a pump head of a fuel pump, a valve plunger arranged to perform reciprocal motion with respect to the valve plunger barrel, a drive assembly configured to cause the valve plunger to perform reciprocal motion, and a spacer configured to couple to the valve plunger to perform reciprocal motion together with the valve plunger and configured to interface with the pump head. The spacer has a spacer body with first and second opposing spacer surfaces and with a central aperture extending from the first to the second spacer surface and configured to receive the valve plunger therethrough. At least one of the first and second spacer surfaces includes one or more grooves recessed into the spacer body to reduce or inhibit cavitation of the interface of the spacer and pump head.

A valve assembly for a pump includes an electrical actuator having a stator and an armature. The stator includes an annular outer stator portion and an annular inner stator portion, and an annular channel formed radially between the outer stator portion and the inner stator portion. A first radial channel extending through the annular outer stator portion between an outer surface of the outer stator portion and the annular channel, and at least one second opening in the annular outer stator portion results in magnetic symmetry of the stator. Upon activating the electrical actuator, the attraction of the armature towards the stator is uniform thus displacing fluid between the stator and armature in a uniform manner and to avoid high velocity, potentially damaging fluid flow.

The present disclosure relates to methods and fuel compositions for reducing cavitation-induced damage in common-rail injection engines operated at high fuel pressures. The fuel compositions include a gasoline-like fuel and one or more cavitation inhibitor additives.

An object of the invention is to provide a fuel supply pump that can simultaneously prevent cavitation erosion in a relief valve seat portion at the time of increasing the pressure and reduce a maximum pressure when releasing an abnormally high pressure. Therefore, in the fuel supply pump, a relief valve mechanism includes a seat portion and a relief valve seated on the seat portion, and sets a set discharge pressure to 30 MPa or more. A seat angle of the seat portion is formed to be 40° to 50°, and a set valve opening pressure of the relief valve mechanism is set to 2 MPa or more than the set discharge pressure.