An inner side wall surface of a gap forming member, which is opposed to a flange outer wall surface of a flange of a needle, is slidable relative to the flange outer wall surface. Also, an outer side wall surface of the gap forming member, which is opposed to a stationary core inner wall surface of a stationary core, is slidable relative to the stationary core inner wall surface. The flange outer wall surface and the outer side wall surface are curved to project in a radially outer direction of a housing in a cross section thereof taken along an imaginary plane, which includes an axis of the housing.

A mobile valve member designed to be arranged in the nozzle body of a fuel injector, extends along a main axis and includes a piston formed of a first male cylinder of effective diameter forming the top end of the mobile member and of a second cylinder provided with an internal cylindrical bore of the effective diameter and a shutoff member including a male cylindrical shaft of the effective diameter that fits slidingly in the internal bore, and of a member extending as far as a pointed end provided with a mobile seat and forming the bottom end of the mobile member. The mobile member is hydraulically balanced and the length between the top end and the bottom end thereof is variable as a result of the sliding of the cylindrical shaft in the internal bore of the piston.

The present disclosure relates to internal combustion engines. Various embodiments may include a fuel injection system for delivering fuel to an internal combustion engine. For example, fuel injector may include a valve body having a cavity; a valve needle with a retainer moving in the cavity; an actuator assembly comprising: a spring element next to the valve needle; an electro-magnetic coil; an armature element movable in the cavity; and an anti-bounce device. The armature element may be between the retainer portion of the valve needle and the anti-bounce device. The anti-bounce device may impose a spring force and a hydraulic force for dampening a movement of the armature element. The anti-bounce device may comprise a spring portion exerting the spring force to close the valve needle and a hydraulic damper portion integrally connected to the spring portion.

An inlet valve assembly of a fluid pump comprises an inlet valve member movable between a closed position and an open position. In the closed position the inlet valve member is arranged to block a pump chamber inlet to prevent fluid from entering or exiting a pump chamber of the fluid pump through the pump chamber inlet. In the open position the inlet valve member is arranged to allow fluid to enter or exit the pump chamber through the pump chamber inlet. The inlet valve assembly further comprises a first biasing means configured to bias the inlet valve member in a first direction, d.sub.1, towards the open position, when the inlet valve member is in the closed position; and a second biasing means configured to reduce the speed of the inlet valve member when the inlet valve member is moving in the first direction, d.sub.1, towards the open position.

The invention relates to an electromagnetically actuable intake valve for a high-pressure pump of a fuel injection system, in particular of a common-rail injection system, comprising a reciprocating valve closure element (2) that engages with a valve seat (1) and is loaded in the closing direction by the spring force of a valve spring (3) which is supported on a spring plate (4) connected to the valve closure element (2), further comprising a reciprocating armature (6) that engages with an electromagnet (5) and is loaded in the direction of the valve closure element (2) by the spring force of an armature spring (7) which is larger than that of the valve spring (3). According to the invention, the spring plate (4) has a first abutment face (9) for limiting the opening travel of the valve closure element (2) and a second abutment face (10) for mechanically coupling to the armature (6). The invention also relates to a high-pressure pump having such an intake valve.

To reduce collision noise created by the operation of an electromagnetic suction valve provided on a high pressure fuel supply pump. In the present invention, in order to achieve the above object, the mass of a member which collides by magnetic attractive force is reduced to reduce the noise to be generated. The thus configured present invention provides the following advantageous effects. The noise generated when a core and an anchor collide with each other by magnetic attractive force depends on the magnitude of the kinetic energy of a moving element. The kinetic energy to be consumed in the collision is only the kinetic energy of the anchor. The kinetic energy of a rod, being absorbed by a spring, does not contribute to the noise; thus, the energy when the anchor and the core collide with each other can be reduced, whereby the noise to be created can be reduced.

An inlet valve assembly for a high-pressure fuel pump is disclosed. The inlet valve assembly comprises an inlet valve member moveable between open and closed positions to control the fuel flow from a source of low-pressure fuel to a pumping chamber of the fuel pump, a first biasing spring arranged to apply a first force to the valve member in an opening direction, a second biasing spring arranged to apply a second force to the valve member in a closing direction, and an actuator arrangement operable to remove the first force from the valve member, thereby to allow the valve member to move into its closed position.

To reduce collision noise created by the operation of an electromagnetic suction valve provided on a high pressure fuel supply pump. In the present invention, in order to achieve the above object, the mass of a member which collides by magnetic attractive force is reduced to reduce the noise to be generated. The thus configured present invention provides the following advantageous effects. The noise generated when a core and an anchor collide with each other by magnetic attractive force depends on the magnitude of the kinetic energy of a moving element. The kinetic energy to be consumed in the collision is only the kinetic energy of the anchor. The kinetic energy of a rod, being absorbed by a spring, does not contribute to the noise; thus, the energy when the anchor and the core collide with each other can be reduced, whereby the noise to be created can be reduced.

A fuel injector control valve assembly is provided that comprises a valve actuating mechanism, a cage member that is operatively connected to the valve actuating mechanism, a poppet valve member that is operatively connected to the cage member and that defines a perimeter and a longitudinal axis, a valve sleeve member that is disposed about the poppet valve member, a shim that includes an upper surface that at least partially makes uninterrupted contact with the cage member and a lower surface that at least partially makes uninterrupted contact with the sleeve member, thereby providing a fluid seal about the perimeter of the poppet valve member, and a bounce limiting mechanism that is adjacent the shim and that is interposed between the cage member and at least one of either the poppet valve member and the valve sleeve member.

A solenoid-based fuel injector is described. The fuel injector comprises a tubular body (48) comprising a magnetic material and an armature (16) disposed inside the tubular body. The tubular body has an integrally-formed, inwardly-projecting shelf (52) configured to provide a pole piece.