The invention relates to an injection nozzle for injecting fuel under high pressure, comprising a nozzle body (2) in which a pressure chamber (9), which can be filled with fuel under high pressure, is formed and in which a conical body seat (25) is formed which opens into a blind hole (32), forming a transition edge (35), from which blind hole a plurality of injection holes (30) originate and the total of the flow cross-sections of all injection holes forms a total injection hole cross-section (A.sub.SL). A nozzle needle (14) is arranged in the pressure chamber (9) so as to be longitudinally movable, said nozzle needle interacting, by means of a conical sealing surface (27), with the body seat (25) in order to open and close a flow cross-section, wherein the nozzle needle (14) has, on the end thereof facing the body seat (25), a needle tip (28) which protrudes into the blind hole (32) when the sealing surface (27) contacts the body seat (25). A seat cross-section area (A.sub.S) is formed between the sealing surface (27) and the transition edge (35) when the nozzle needle (14) is raised from the body seat (25), through which seat cross-section area fuel can flow from the pressure chamber (9) into the blind hole (32). The needle tip (28) is conical and has an opening angle (13) that is smaller than the opening angle (a) of the conical sealing surface (27), and the blind hole (32) has a conical portion (132) having an opening angle (a) that is formed between the transition edge (35) and an intermediate edge (36), wherein the needle tip (28) is arranged in a partial stroke of the nozzle needle (14) at the height of the conical portion (132) of the blind hole (32).

The invention relates to a fuel injector (10) for internal combustion engines, comprising a nozzle body (12), in which there is formed a blind bore (14), from which at least one injection opening (22) starts, and comprising a nozzle needle (26; 26a to 26g) which is arranged so as to be movable longitudinally in the nozzle body (12), with a sealing face (28) formed on the side facing towards the blind bore (14), by means of which sealing face the nozzle needle (26; 26a to 26g) interacts with a seat face (17) of the nozzle body (12) in order to control a flow of fuel to the at least one injection opening (22), and comprising a needle tip (34), which has a first edge (41) miming radially around a longitudinal axis (15) and having a first diameter (D.sub.1), which first edge is adjoined in the direction of the base of the blind bore (20) by a second edge (42) miming radially around the longitudinal axis (15) and having a second diameter (D.sub.2).

The invention relates to a fuel injector for internal combustion engines for injecting fuel at high pressure, comprising a pressure chamber formed in an injector body, in which pressure chamber a nozzle needle is arranged in a longitudinally movable manner, which nozzle needle has a cone region tapered in a combustion chamber direction and a pin region having a constant diameter d23 at a combustion-chamber end of the nozzle needle. The injector body has a substantially conical nozzle needle seat, from which a first injection opening extends, and a blind hole, which adjoins the nozzle needle seat on the combustion chamber side. The blind hole has a cylindrical segment, which has the diameter d31, and a hole base, from which a second injection opening extends. The cone region of the nozzle needle interacts with the nozzle needle seat and thereby opens and closes the first injection opening and the second injection opening with respect to the pressure chamber. During a partial stroke of the nozzle needle, the first injection opening and the second injection opening are connected to each other by means of a throttle gap, which is formed in the blind hole between the pin region and the wall of the blind hole, and the throttle gap remains constant at least over the partial stroke of the nozzle needle.

A fuel injector 100 includes a nozzle member 60 having a fuel passage 60a leading to an injection port 60b; a valve main body 51 adapted to reciprocate for opening and closing the fuel passage 60a; an elastic portion 56 elastically deformable in closing the fuel passage 60a by movement of the valve main body 51 in a closing direction, the elastic member being attached to one of the nozzle member 60 and the valve main body 51 and adapted to be abutted against the other of the nozzle member 60 and the valve main body 51 to close the fuel passage 60a by moving the valve main body 51 in the closing direction; and a stopper 70 adapted to restrict movement of the valve main body 51 in the closing direction by being abutted against the valve main body 51, the stopper 70 being formed of material different from the nozzle member 60.

A needle includes a first seal portion, which is formed at an end portion of the needle located on a side where an injection hole is placed, and a second seal portion, which is formed on a side of the first seal portion where a stationary core is placed. When a boundary between a first outer wall of the first seal portion and a second outer wall of the second seal portion is lifted away from or is seated against an inner wall, the injection hole is opened or closed. Thereby, a seat diameter of the boundary and the inner wall is stabilized, and a change in a fuel injection quantity caused by aging can be reduced. Furthermore, the first outer wall of the first seal portion is shaped into a form of a spherical surface.

A valve is provided, in particular an injection valve, having a valve seat and a valve needle which extends along a closing direction for the most part, the valve seat having a valve-seat surface, and a valve-closing element is mounted on an end of the valve needle facing the valve seat, the valve-closing element being able to be moved between an open position and a closed position, and the valve-closing element together with the valve-seat surface forming a sealing seat in the closed position, the valve-closing element having a greater core hardness and/or surface hardness than the valve-seat surface.

A fuel injector for internal combustion engines is provided, which has a valve seat member, bordering a valve chamber, having a valve seat and spray orifices and a central blind-end bore as well as a valve member that is able to be driven to cause a lift motion having a closing head, which, together with a valve seat, forms a sealing seat lying upstream of the spray orifices. In order to prevent an underpressure developing in the blind-end bore in the closing phase of the sealing seat, and a partial return flow of the fuel connected with it, the closing head of the valve member is provided, at its end face facing towards the valve seat member, with a plunger sticking out from closing head, which has a shape adjusted to the contour of the blind-end bore, and dips into the blind-end bore when the sealing seat is closed.

An object of the present invention is to promote the stabilization of the fuel injection amount in a fuel injection device in which a valve body and a movable iron core are configured to be relatively displaceable. In a control unit 120 of a fuel injection device 100 which includes a control part that controls the energization time of a current flowing through a coil 108 based on the pulse width of a drive command pulse, the control part is configured to be able to execute control to split a required fuel injection amount for one combustion cycle into portions and inject the portions in a plurality of times. In addition, in injections including a sequence of a preceding drive command pulse Pi1 and a subsequent drive command pulse Pi2, the control part acquires a preceding drive command pulse width Ti1 of the preceding drive command pulse Pi1 and a pulse interval Tint that is the time between the end time te1 of the preceding drive command pulse Pi1 and the start time ts2 of the subsequent drive command pulse Pi2, and corrects the subsequent drive command pulse width Ti2 of the subsequent drive command pulse Pi2 by using the preceding drive command pulse width Ti1 and the pulse interval Tint.

An object of the present invention is to promote the stabilization of the fuel injection amount in a fuel injection device in which a valve body and a movable iron core are configured to be relatively displaceable. In a control unit 120 of a fuel injection device 100 which includes a control part that controls the energization time of a current flowing through a coil 108 based on the pulse width of a drive command pulse, the control part is configured to be able to execute control to split a required fuel injection amount for one combustion cycle into portions and inject the portions in a plurality of times. In addition, in injections including a sequence of a preceding drive command pulse Pi1 and a subsequent drive command pulse Pi2, the control part acquires a preceding drive command pulse width Ti1 of the preceding drive command pulse Pi1 and a pulse interval Tint that is the time between the end time te1 of the preceding drive command pulse Pi1 and the start time ts2 of the subsequent drive command pulse Pi2, and corrects the subsequent drive command pulse width Ti2 of the subsequent drive command pulse Pi2 by using the preceding drive command pulse width Ti1 and the pulse interval Tint.

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.