The invention relates to an injector used for an internal combustion engine, in which a favorable magnetic attraction force is obtained to reduce a controllable minimum injection amount of a fuel injection amount. In a fuel injection valve in which a fixed core (107) and a moving element (114) is contained inside a pipe-shaped member (101), and a coil (105) and a yoke (103) are provided on an outer side thereof, a space for placing the coil (105) is placed so that an inner circumference length in a vertical section of the space becomes smaller than an outside diameter of the yoke (103), or a height of the space in an axial direction of the fixed core (107) becomes smaller than a diameter of the fixed core (107).

Electromagnetic fuel injection valve

The invention concerns a valve assembly (11) for an injection valve (10), comprising a valve body (14) including a central longitudinal axis (L), the valve body (14) comprising a cavity (18) with a fluid inlet portion (42) and a fluid outlet portion (40), a valve needle (20) axially movable in the cavity (18), the valve needle (20) preventing a fluid flow through the fluid outlet portion (40) in a closing position and releasing the fluid flow through the fluid outlet portion (40) in at least one further position, an upper retainer (23) being arranged in the cavity (18) and being fixedly coupled to the valve needle (20), and an electro-magnetic actuator unit (36) being designed to actuate the valve needle (20), the electro-magnetic actuator unit (36) comprising an armature (21), which is arranged in the cavity (18) and which is axially movable relative to the valve needle (20), the armature (21) being designed to be coupled to the upper retainer (23) when the valve needle (20) is actuated to leave the closing position, wherein a permanent magnet (22) is arranged in the cavity (18) at a position adjacent to the position of the armature (21), when the valve needle (20) is in its closing position. The invention also concerns an injection valve comprising such a valve assembly.

Valve assembly for an injection valve and injection valve

A fuel-injection valve includes a fuel-injection hole, a valve element and a valve seat for opening and closing the fuel-injection hole, a force-applying member for applying force to the valve element in a direction of motion of the valve element, and a drive unit for applying force to the valve element in the direction opposite to that of the force applied by the force-applying member; wherein a secondary oscillation system, which interacts with a primary oscillation system including the valve element and the force-applying member, is added to the primary oscillation system, and the phase angle of force applied to the primary oscillation system by the secondary oscillation system is also staggered from that of force applied to the primary oscillation system, which is other than the force applied to the primary oscillation system by the secondary oscillation system, whereby the bouncing of the valve element during opening and closing of the valve is reduced, which in turn makes it possible to achieve very accurate fuel-injection control.

Fuel Injection Valve

A fuel injector injects high-pressure gaseous fuel directly into a cylinder of an engine. A small amount of liquid fuel is used in the injector to lubricate sliding portions of the fuel injector in addition to utilizing it as a medium for transmitting driving force. The fuel injector includes a nozzle member having injection holes at its elongated end and a needle slidably disposed in an elongated center hole of the nozzle member. The needle is driven by pressure of the liquid fuel introduced into a control chamber to open or close the injection holes. The pressure in the control chamber is controlled by a switching valve which is in turn driven by an actuator such as an electromagnetic or piezoelectric actuator. The liquid fuel is injected together with the high-pressure gaseous fuel after lubricating the sliding portions between the nozzle member and the needle.

Gaseous fuel injector using liquid fuel as lubricant and pressure-transmitting medium

Stable spray characteristics (particle size, directivity, divergence angle of spray, and penetration force) are provided for individual nozzle holes, flows of fuel toward the nozzle holes are not interfered with each other, and further spray characteristics can arbitrarily be altered at respective nozzle holes. A whirler 11 for providing a whirling force to fuel is provided, and a whirl flow is formed in a cavity 20 downstream of a seal portion of a needle valve 16 . A plurality of nozzle holes 13 are formed in an orifice plate 14 , and openings on the cavity 20 side of the nozzle holes 13 are formed on substantially the same diameter with respect to the central axis of a fuel injection valve 1 . Thus it becomes possible to cause fuel having inflow angle and high flow velocity to flow into the openings of the nozzle holes 13 . Furthermore, in the vicinity of the openings of the nozzle holes 13 , fuel having high flow velocity flows in only on one side with respect to the cross section of the nozzle holes, so that contraction flow is generated in the nozzle holes 13 , and atomization is achieved as well.

An injector for injecting fluid includes a valve needle axially moveable with respect to a valve body and operable to prevent a fluid injection in a closing position and to permit the fluid injection in an open position, an armature for moving the valve needle in a first direction from the closing position towards the open position, a needle retainer fixed to the valve needle, and an armature holder fixed to the armature, wherein the needle retainer and the armature holder are releasably coupleable such that when the armature moves in the first direction the needle is moved in the first direction by the movement of the armature holder and the needle retainer.

Injector for injecting fluid

A fluid injection valve (10) comprises a fluid inlet tube (12) with a recess (44) and a valve body (20) including a central longitudinal axis (L). The valve body (20) comprises a cavity (24) with a fluid outlet portion (28). Furthermore, the injection valve (10) comprises a valve needle (22) received in the recess (44) and in the cavity (24). The valve needle (22) is axially displaceable with respect to the fluid inlet tube (12) and the valve body (20) for preventing a fluid flow through the fluid outlet portion (28) in a closing position and releasing the fluid flow through the fluid outlet portion (28) in other positions. The injection valve (10) comprises a spring element (30) arranged in the recess (44) and operable to interact with the valve needle (22) for biasing the valve needle (22) in axial direction towards its closing position, wherein the spring element (30) is configured such that a spring stiffness of the spring element (30) depends on a pressure of fluid in the recess (44).

Fluid injection valve

A fluid injector includes a valve body, a valve needle and axially moveable in the valve body between a closing position that prevents a fluid injection and further positions that permit the fluid injection, an armature coupled to the valve needle for displacing the valve needle away from the closing position, and a solenoid assembly including at least a first and second coil and operable to magnetically actuate the armature via an electrical signal. A method for operating the fluid injector includes applying the electrical signal to the first coil to generate a magnetic field to move the armature for displacing the valve needle away from the closing position, evaluating a voltage across terminals of the first coil, and controlling the second coil with a further electrical signal to saturate a magnetic field in a portion of the valve body between the armature and solenoid assembly during evaluating the voltage.

Fluid injector and method for operating a fluid injector

The invention regards a valve assembly arrangement (2) for an injection valve (1), comprising a first valve assembly (3) and a second valve assembly (4), wherein the latter is axially arranged adjacent to and coupled to the first valve assembly (3), wherein the second valve assembly comprises a valve housing section (14) having an orifice (15) at an axial end area (16) of the valve housing (5), the second valve assembly comprises a cavity (17) in its valve housing section and the second valve assembly comprises a valve needle (18) being axially movable in said cavity between a closing position and other positions. The invention suggests that the second valve assembly (4) comprises a first magnetic member (20) being fixed to the valve needle (18) of the second valve assembly (4), that the second valve assembly (4) comprises a second magnetic member (21) being fixed to the valve housing section (14) of the second valve assembly (4), that at least one of the first magnetic member (20) and the second magnetic member (21) includes permanent-magnetic material or consists of permanent-magnetic material, and that the second valve assembly (4) is of the outward opening type and the first magnetic member (20) is disposed at a side (27) of the second magnetic member (21) wherein said side (27) is facing the axial end area (16).

Valerio Polidori

Papers

Valve assembly for an injection valve and injection valve

Injector for injecting fluid

Fluid injection valve

Fluid injector and method for operating a fluid injector

Valve assembly arrangement for an injection valve and injection valve