The fuel injection valve has a hydraulic control device for controlling the axial movement of the injection valve member. The stem of the intermediate valve member of mushroom-shaped configuration of the intermediate valve is guided in the guide recess of the intermediate part. In the open position, the intermediate valve member opens up a second connection between a high-pressure fuel inlet and a valve chamber and, in the closed position, the intermediate valve member shuts off the second connection between the high-pressure fuel inlet and the valve chamber. In the closed position of the intermediate valve member, the head of the intermediate valve member lies with a side facing toward the intermediate part against the intermediate valve seat via a first sealing surface, which runs around the stem or the guide recess at a first radial spacing so as to form a first annular sealing surface which is continuous in the circumferential direction.

An injector apparatus (210) for injecting fluid under pressure into an associated chamber (232) is provided. The injector apparatus (210) includes a first piston (214) defining a first working area facing an associated chamber, and a high pressure piston (218) defining a high pressure working area facing a high pressure chamber. The first working area is greater than the high pressure working area and the first piston is moveable in a body of the injector apparatus (210) to compress fluid in the high pressure chamber using the high pressure piston. The injector apparatus (210) further includes an accumulator (270) operable to supply fluid under pressure through an injector orifice (276) into an associated chamber (232), the high pressure chamber being operable to pressurise the accumulator (270) with fluid.

A flow control system for a fuel injector of an internal combustion engine includes: an inlet channel, an outlet channel, a return channel for returning pressurized fuel to a low-pressure system having a lower pressure than the inlet channel, a fuel outlet chamber, a moveable nozzle control member in the fuel outlet chamber for selectively allowing the pressurized fuel to flow into the outlet channel, a biasing member biasing the nozzle control member towards a closed position, a moveable member defining, with the nozzle control member, a fuel control chamber configured to bias the nozzle control member towards its closed position, a moveable valve member for selectively opening and closing a flow passage and a fuel connection between the inlet channel and the fuel control chamber for pressurizing the fuel control chamber.

A flow control system for a fuel injector of an internal combustion engine includes: an inlet channel, an outlet channel, a return channel for returning pressurized fuel to a low-pressure system having a lower pressure than the inlet channel, a fuel outlet chamber, a moveable nozzle control member in the fuel outlet chamber for selectively allowing the pressurized fuel to flow into the outlet channel, a biasing member biasing the nozzle control member towards a closed position, a moveable member defining, with the nozzle control member, a fuel control chamber configured to bias the nozzle control member towards its closed position, a moveable valve member for selectively opening and closing a flow passage and a fuel connection between the inlet channel and the fuel control chamber for pressurizing the fuel control chamber.

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 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.

An injector is designed to provide continuously variable injection rate shaping. With a hydro-mechanical internal feedback mechanism, injector needle position can be determined by controlling a feedback valve's on/off timing. According to the needle position, an injection needle valve opening can be controlled, and then the injection flow rate can be delivered proportionally. Also in accordance with the present invention a CRDI systems are provided including injectors of the present invention, wherein results demonstrate that injector designs of the present invention not only achieve rate shaping capability but also solve the above-noted problems of the current CRDI system. Finally, an iterative learning controller has also been developed to track the desired injection rate, and an injection rate estimator is designed to realize a cycle to cycle feedback control.

The invention relates to a fuel injection valve, comprising a nozzle body (1) and a pressure chamber (3) formed therein, wherein the pressure chamber (3) can be filled with fuel under high pressure and wherein a piston-shaped nozzle needle (5) is arranged in the pressure chamber so as to be movable longitudinally, which nozzle needle interacts with a nozzle seat (7) formed in the nozzle body (1) by means of a sealing surface (6) formed at the end of the nozzle needle on the combustion chamber side and thereby controls the flow of fuel from the pressure chamber (3) to at least one injection opening (8). A sleeve (12) accommodates the end of the nozzle needle (5) facing away from the nozzle seat and bounds a control chamber (20). By means of the pressure of the control chamber, a hydraulic force is applied to the nozzle needle (5) in the direction of the nozzle seat (7). A closing spring (16) is arranged in the control chamber (20). The closing spring is arranged between the sleeve (12) and the nozzle needle (5) under compressive preload.

The invention relates to a fuel injection valve for the intermittent injection of fuel into the combustion chamber of an internal combustion engine having a housing which has a high pressure chamber and a low pressure chamber. In addition, the fuel injection valve has a control chamber which is divided by means of a control valve into a first and a second control chamber. The control valve in turn has a valve guide and a valve insert, wherein an outflow throttle which connects the first control chamber to the second control chamber is arranged in the valve guide. According to the invention, the connection which is formed by way of the outflow throttle between the first control chamber and the second control chamber can be interrupted temporarily in a targeted manner.

The fuel injection valve includes a valve body having an injection hole at an end of the valve body facing in a first direction, and a needle valve provided inside the valve body and movable in an axial direction which includes the first direction and a second direction opposite to the first direction. A first control valve and a second control valve control the internal pressure of a back pressure chamber provided inside the valve body, a first actuator controls the first control valve, and a second actuator controls the second control valve. The second control valve is longer than the first control valve in the axial direction. The second actuator is located away in the second direction from the first actuator. A part of the second actuator overlaps at least a part of the first actuator when viewed in a plan view along the axial direction.