A fuel injector includes an injector body comprising an internal injector cavity, a flow passageway, and a drain conduit. The flow passageway is in fluid communication with at least one injector orifice. The fuel injector further includes a valve assembly comprising a valve seat and a valve member in fluid communication with the fuel circuit. The valve member is configured to move between an open position allowing fuel flow through the at least one injector orifice and a closed position inhibiting fuel flow through the at least one injector orifice. The fuel injector also includes a nozzle valve element fluidly coupled to the valve assembly, an actuator operably coupled to the valve assembly and the nozzle valve element, and a flexible member configured to elastically deform in response to pressure in the fuel injector. The flexible member is configured to inhibit flow to the drain circuit during an injection event.

The housing (18) of the fuel injection valve (10) of the device for intermittently injecting fuel into the combustion chamber of an internal combustion engine comprises a high-pressure inlet (34) with a conical sealing face (44). The high-pressure chamber (36) is disposed in the housing (18) from the high-pressure inlet (34). A cartridge-like, independent component (56) is inserted into the high-pressure chamber (36). Said component comprises the valve carrier (46), the non-return valve (48), the holding element (50), and preferably the filter body (52′). The valve carrier (46) is provided with a conical outer sealing face (69), by which the valve carrier rests against the conical sealing face (44). A fixing element (74) presses the supply line (16) against the valve carrier (46).

An electromagnetic valve drive device which supplies a hold current with a prescribed fluctuation range to an electromagnetic coil of an electromagnetic valve after a current peak when a supply of electricity starts has passed includes: a power supplier which intermittently applies a drive voltage to the electromagnetic coil; a detector which detects the hold current; a first comparator which compares a detected current by the detector with a first threshold value; a filter which performs integration processing on an output of the first comparator; a second comparator which compares an output of the filter with a second threshold value to generate an output signal used for generating a control signal for controlling the power supplier; and a control signal generator which generates the control signal for controlling the power supplier based on the output signal of the second comparator, wherein the filter is a count-up/down type digital filter.

A fuel injection valve (10) comprises an intermediate valve with a mushroom-shaped intermediate valve member (78). The shaft (76) of the intermediate valve member (78) is guided with a sliding fit in the guiding passage (74) of an intermediate component (66). An annular space (120) is defined between the shaft (76) and the head (80) of the intermediate valve member (78) and the intermediate component (66), and a high-pressure inlet (86) opens into the annular space, which is formed by an inner annular space (108) and by a split ring space (118). The split ring space (118) is defined between the head (80) and the intermediate component (66), and is also radially outwardly defined by a sealing bead (112). The adhesion force between the intermediate valve member (78) and the intermediate component (66), which acts against the opening motion of the injection valve member (56), is minimized.

A fuel injector includes an injector body comprising an internal injector cavity, a flow passageway, and a drain conduit. The flow passageway is in fluid communication with at least one injector orifice. The fuel injector further includes a valve assembly comprising a valve seat and a valve member in fluid communication with the fuel circuit. The valve member is configured to move between an open position allowing fuel flow through the at least one injector orifice and a closed position inhibiting fuel flow through the at least one injector orifice. The fuel injector also includes a nozzle valve element fluidly coupled to the valve assembly, an actuator operably coupled to the valve assembly and the nozzle valve element, and a flexible member configured to elastically deform in response to pressure in the fuel injector. The flexible member is configured to inhibit flow to the drain circuit during an injection event.

The invention relates to a fuel injection valve comprising a housing (1) in which pressure is applied to a nozzle needle (8), in a control chamber (28), at least indirectly with a closing force in the direction of a valve seat (10). The pressure in the control chamber (28) can be adjusted using a control valve (40) as said control chamber (28) is able to be connected to a low pressure chamber (46) via an outlet restrictor (31) and be filled with fuel at high pressure via an inlet restrictor (30). A longitudinally-displaceable control piston (29) is arranged in the control chamber (28) and divides said chamber (28) into a first control sub-chamber and a second control sub-chamber (228), the first control sub-chamber (128) being able to be connected to the low pressure chamber (46) by means of said outlet restrictor (31). A sealing surface (38) is formed on the control piston (29) and interacts with a sealing seat (39) in the control chamber (28) such that the inlet restrictor (30) is hydraulically disconnected from the second control sub-chamber (228) when the sealing surface (38) comes to rest against the sealing seat (39). Said first control sub-chamber (128) and second control sub-chamber (228) are constantly hydraulically interconnected by means of a restrictor connection (34).

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.

A fuel injection system of an internal combustion engine includes: an injector having a hydraulic control chamber controlling the delivery of fuel through the injector, an actively controlled first valve system controlling the pressure relief from the control chamber, movable between: a first position in which the first valve system closes the injector by deterring the pressure from being relieved from the control chamber through the first relief circuit, and a second position in which the first valve system opens the injector by allowing the pressure to be relieved from the control chamber through the first relief circuit. A second relief circuit allows the pressure to be relieved from the control chamber through the second relief circuit. The second relief circuit includes a second valve system passively controlled by the fuel pressure and movable between two positions deterring or allowing the pressure to be relieved from the control chamber through the second relief circuit.

A small-size injector having a built-in ignition device which can surely inject fuel and ignite the fuel with low electric power by the ignition device with a simple configuration is provided. The injector comprises a fuel injecting device 2 provided with a fuel injecting port 20 configured to inject the fuel, an ignition device 3 configured to ignite the injected fuel, and a casing 10 inside housing therein the fuel injecting device 2 and the ignition device 3 together. The ignition device 3 is constituted of a plasma generator 3 which integrally comprises a booster 5 having a resonation structure capacity-coupled with an electromagnetic wave oscillator MW configured to oscillate an electromagnetic wave, and a discharger 6 configured to cause a discharge of a high voltage generated by the booster 5.

An apparatus and method for operating a fuel injector of an internal combustion engine is disclosed. A first energizing electrical current is supplied to an injector solenoid, causing the opening of an injector control volume and a pressure reduction in said injector control volume, for a first energizing time. The first energizing time is predetermined to avoid that the pressure in the injector control volume approximates a value which would cause an injector needle to raise up and a fuel injection to start. After the predetermined time interval, a second energizing electrical current is supplied to the injector solenoid for a predetermined second energizing time, which is a function of a rail pressure (p.sub.rail) and a fuel injection quantity.