Abstract: A fuel injection valve for internal combustion engines, having a valve body with a bore defined on its end toward the combustion chamber by a conical valve seat, with a valve needle disposed longitudinally displaceably in the bore and a sealing face with two sealing portions on its end toward the combustion chamber with the second conical face being disposed on the combustion chamber side of the first conical face. An annular groove extending between the conical faces has an end facing away from the combustion chamber which acts as a sealing edge upon contact of the valve sealing face with the valve seat. Recesses embodied in the valve seat and/or on the valve sealing face hydraulically connect the annular groove with a portion of the second conical face located on the combustion chamber side of the annular groove.

Abstract: An actuator unit which is suitable for actuating a fuel injection valve of an injection system for internal combustion engines includes a piezoelectric actuator and a hollow body embodied as a spring. The service life of the actuator unit can be improved by designing the hollow body to eliminate or minimize bending stresses on the piezoelectric actuator.

Abstract: A common rail injector having an injector housing with a fuel inlet connected to a central high-pressure fuel source outside the injector housing and to a pressure chamber inside the injector housing from which pressure chamber depending on the pressure in a control chamber fuel is injected when a nozzle needle lifts away from its seat and in which the pressure in the control chamber is controlled in a direct, inverse fashion by an actuator in particular a piezoelectric actuator. The combustion chamber end of the actuator or an actuator head provided on the actuator is guided in actuator guide section of a coupler sleeve, which has a larger inner diameter than a nozzle needle guide section of the coupler sleeve in which the end of the nozzle needle oriented away from the combustion chamber is guided.

Abstract: A fuel injection device includes at least two valve elements, disposed in a housing and coaxial with one another, with at least one fuel outlet opening associated with each valve element. On the outer valve element, radially outward from the at least one fuel outlet opening associated with it, there is a first sealing edge which cooperates with a valve seat on the housing and can separate the at least one fuel outlet opening from a high-pressure connection. An additional sealing edge is provided on the outer valve element, between the at least one fuel outlet opening associated with it and the inner valve element.

Abstract: A fuel injector for injecting fuel that is at high pressure into a combustion chamber of an internal combustion engine has an injection valve member triggered by an actuator and a coupler chamber; the actuator acts on the injection valve member and the injection valve member opens or closes at least one injection opening. The coupler chamber is located on the side of the actuator diametrically opposite the injection valve member; and the coupler chamber is filled with fuel that is at system pressure when the injection opening is closed.

Abstract: A fuel injection system having an injection valve, a line supplying fuel at high pressure to the injection valve a control valve controlling the pressure in a control chamber communicating with the line. The control valve has a movable valve part is actuatable by an actuator via a hydraulic coupler having two pistons cooperating with a booster chamber of the coupler. A seat of the movable valve part has an inside cross-sectional area f3, with means for filling the booster chamber via guide gaps of the pistons with fuel under pressure. The pistons are located parallel to and inside one another and a booster chamber is located on the ends of the pistons toward the actuator. In the interior of the outer piston defines a filling chamber which communicates with the line and one of the pistons has a cross-sectional area f4 is mechanically coupled to the actuator via a rod having a cross-sectional area f5.

Abstract: A piezoelectric actuator has a multilayered structure of piezoelectric layers with inner electrodes interspersed between them and a contacting of the inner electrodes on alternating sides by means of outer electrodes that can supply an electrical voltage. The respective outer electrodes are attached in a net-like, mesh-like, or screen-like fashion and contacts the respective inner electrodes at least at points in the corner region of the piezoelectric actuator, wherein the outer electrode is guided around the respective corner in a predetermined region extends in the direction of the multilayered structure of piezoelectric layers, and is provided with a terminal there.

Abstract: A fuel injection device has an injection valve, a line that supplies highly pressurized fuel to the injection valve during operation, a control valve that controls the pressure in a control chamber of the injection valve, which chamber is connected to the line, and whose moving valve element is actuatable by an actuator via a hydraulic coupler having two pistons cooperating with a coupler volume of the coupler, the seat of the moving valve element having an inner cross-sectional surface area f3 and a conduit for filling the coupler volume with pressurized fuel via guidance gaps of the pistons.

Abstract: A fuel injection system of an internal combustion engine includes at least one fuel injector which communicates via a fuel inlet with a fuel supply line that communicates with a source of fuel that is at high pressure; the fuel injector includes a valve control unit and a nozzle unit, and a fuel conduit communicating with the fuel supply line leads to the nozzle unit. A check valve which blocks a fuel flow in the direction of the fuel supply line is disposed in the fuel conduit.

Abstract: A common rail injector having an injector housing that has a fuel inlet, which communicates with a central high-pressure fuel source outside the injector housing and with a pressure chamber inside the injector housing, from the latter of which, depending on the pressure in a control chamber, highly pressurized fuel is injected into a combustion chamber of an internal combustion engine when a nozzle needle lifts away from its seat, and in which the pressure in the control chamber is directly controlled by a piezoelectric actuator. The end of the nozzle needle oriented away from the combustion chamber accommodates a control chamber delimiting sleeve that can move back and forth and reduce the size of the control chamber-pressurized end surface of the nozzle needle oriented away from the combustion chamber.

Abstract: A piezoelectric actuator for actuating a mechanical component, having a multilayered structure of piezoelectric layers with inner electrodes disposed between them and contacting outer electrodes on alternating sides and the piezoelectric actuator has chamfered corners or edges. In the region of the corners or edges, on the sides of the piezoelectric actuator on which the inner electrodes with alternating polarities are routed to the respective outer electrodes, the inner electrodes have a contour that makes it possible to achieve a lower field intensity between the inner electrodes of alternating polarities in the structure of piezoelectric layers. This is achieved by virtue of the fact that on the side that does not contact the outer electrodes, the edge has an obtuse angle (?) or is rounded.

Abstract: A fuel injection device for an internal combustion engine has a housing that contains a recess, which in turn contains two valve elements that are disposed coaxial to each other and each cooperating with a corresponding valve seat and are each associated with corresponding fuel outlet openings. In order for the fuel injection device to be as compact as possible, a shared valve device provided, which has at least three switched positions and influences the position of the valve elements.

Abstract: A fuel injector for a common rail injection system for injecting fuel into a combustion chamber of an internal combustion engine includes an injector body and a nozzle body with an injection valve member embodied in multiple parts received in the nozzle body. A hydraulic booster assembly connected downstream of a piezoelectric actuator. Control chambers are associated with the multi-part injection valve member for actuating it. The hydraulic booster assembly actuated by the piezoelectric actuator has booster chambers, which are each directly connected hydraulically with control chambers that actuate the needle parts of the injection valve member.

Abstract: A common rail injector for an internal combustion engines has control means including a piezoelectric actuator deposed in an injector body and via at least one booster piston actuates a control valve received in a valve plate. Also provided are a nozzle body having a nozzle outlet on its free end toward the combustion chamber; a nozzle needle located axially movably and actuatably in a longitudinal recess of the nozzle body; a throttle disk, closing off the rear end (remote from the nozzle outlet) of the longitudinal recess and located between the nozzle body and the control valve, which throttle disk forms an opening stop for the nozzle needle and cooperates with the rear end face of the nozzle needle and thus limits the opening stroke of the nozzle needle; and a control chamber between the rear nozzle needle end face and the throttle disk, which chamber is in hydraulic communication with a pressure connection serving to deliver fuel.

Abstract: A fuel injector having a piezoelectric actuator directly actuating an injection valve member, which piezoelectric actuator acts on a booster piston, and a face end of the booster piston acts on a hydraulic coupling chamber for actuating the injection valve member, and the piezoelectric actuator is received in a hollow chamber in the injector housing, which hollow chamber is filled with a fuel volume that is under high pressure. The diameter of a sealing edge in the actuator base region corresponds to the diameter of the booster piston.

Abstract: A fuel injector for injecting fuel into a combustion chamber of an internal combustion engine, the injector having body and a nozzle holder in which an injection valve member is movably received, which injection valve member has a seat that opens or closes injection openings, and the injection valve member is actuatable via a piezoelectric actuator. The piezoelectric actuator actuates a first booster piston, in which a second booster piston, connected to the injection valve member is guided.

Abstract: The invention relates to a fuel injector for internal combustion engines, having a high-pressure fuel reservoir, which includes a pressure booster and an injection valve member that has at least one booster portion and one needle portion that closes at least one injection opening. The pressure booster is received in a booster housing and is braced on a spring element which surrounds the booster housing. As a result, the booster housing is fixed on a nozzle housing part that encloses the injection valve member.

Abstract: A fuel injection device includes at least two valve elements, disposed in a housing and coaxial with one another, with at least one fuel outlet opening associated with each valve element. On the outer valve element, radially outward from the at least one fuel outlet opening associated with it, there is a first sealing edge which cooperates with a valve seat on the housing and can separate the at least one fuel outlet opening from a high-pressure connection. An additional sealing edge is provided on the outer valve element, between the at least one fuel outlet opening associated with it and the inner valve element.

Abstract: A fuel injection system having an injection valve, a line supplying fuel at high pressure to the injection valve a control valve controlling the pressure in a control chamber communicating with the line. The control valve has a movable valve part is actuatable by an actuator via a hydraulic coupler having two pistons cooperating with a coupler volume of the coupler. A seat of the movable valve part has an inside cross-sectional area f3, with means for filling the coupler volume via guide gaps of the pistons with fuel under pressure. The pistons are located parallel to and inside one another and a booster chamber is located on the ends of the pistons toward the actuator. In the interior of the outer piston defines a filling chamber which communicates with the line and one of the pistons has a cross-sectional area f4 is mechanically coupled to the actuator via a rod having a cross-sectional area f5.

Abstract: An injection nozzle for an internal combustion engine, having a nozzle body with a first nozzle needle for controlling at least one first injection opening and a second nozzle needle for controlling at least one second injection opening. A first drive piston is coupled to the first nozzle needle and is equipped with a first booster surface hydraulically coupled to a control surface of a control piston by a first hydraulic pressure transmission path, a second drive piston coupled to the second nozzle needle has a second booster surface that an activatable and deactivatable second hydraulic pressure transmission path is able to hydraulically couple to a control surface of the control piston; the activation and deactivation of the second hydraulic pressure transmission path is controlled as a function of the control piston stroke.