Abstract: The positioning of the actuating drive in a fuel injector with a piezoactuator (2) that is screwed into the housing (1) of the fuel injector is performed by applying a voltage (U) to the piezoactuator (2) that corresponds to a given idle stroke (h), and the surface grinding of the housing (3) and base plate (4) of the piezoactuator (2) when voltage is applied. Between the housing (1) of the fuel injector and the housing (3) of the piezoactuator (2), there is also provided a compensation collar (9) of a suitable thickness.

Abstract: A nozzle clamping nut for an injection valve comprises two sections in the longitudinal direction, having different-sized free inner diameters (D1, D2). A shoulder forms a bearing surface (9) in a transition region between the first and second sections, extending in a circular manner perpendicularly to the longitudinal direction. The nozzle clamping nut has a large bearing surface with low stress concentration. The nozzle clamping nut consists of an inner tube (3) and an outer tube (1) which have different-sized inner diameters (D1, D2), which fit inside each other and which are connected to each other in a fixed manner, and the bearing surface (9) is formed by the annular front surface of the inner tube (3).

Abstract: The invention relates to, in particular, a fuel injection valve and to a method for injecting fuel into a combustion chamber of an internal combustion engine. According to the invention, a mechanical positive-control valve gear is provided for a nozzle needle of the fuel injection valve in order to carry out an injection of fuel.

Abstract: The positioning of the actuating drive in a fuel injector with a piezoactor (2) that is screwed into the housing (1) of the fuel injector is performed by applying a voltage (U) to the piezoactor (2) that corresponds to a given idle stroke (h), and the surface grinding of the housing (3) and base plate (4) of the piezoactor (2) when voltage is applied. Between the housing (1) of the fuel injector and the housing (3) of the piezoactor (2), there is also provided a compensation collar (9) of a suitable thickness.

Abstract: The positioning of the actuating drive in a fuel injector with a piezoactor (2) that is screwed into the housing (1) of the fuel injector is performed by applying a voltage (U) to the piezoactor (2) that corresponds to a given idle stroke (h), and the surface grinding of the housing (3) and base plate (4) of the piezoactor (2) when voltage is applied. Between the housing (1) of the fuel injector and the housing (3) of the piezoactor (2), there is also provided a compensation collar (9) of a suitable thickness.

Abstract: A method for producing a tubular spring (12) in the form of a cylindrical hollow body, especially for pre-tensioning a piezoelectric actuator element (2) of an actuator unit (1) of a fuel injector comprises the step of providing a thin-walled, solid-drawn steel tube with a plurality of regularly arranged longish recesses (14) by means of laser cutting. Thus, an actuator unit (1) comprises a piezoelectric actuator element (2) which is arranged in a thin-walled cylindrical hollow body, wherein the hollow body being elastically embodied and pre-tensioning the actuator element (2). Furthermore, the hollow body is a solid-drawn steel tube which is provided with a plurality of longish recesses (14).

Abstract: A fuel-injection nozzle for an internal combustion engine is disclosed. The nozzle comprises a nozzle body (2), in which a nozzle needle (10) with a stop (34) is positioned so that it can be displaced, and a nozzle holder (6), in which a pressure pin (16) is displaceably mounted. A disc-shaped stop element (26) is provided in a zone between the nozzle body (2) and the nozzle holder (6). The nozzle body (2) and the nozzle holder (6) are axially braced against one another in such a way that the stop element (26) forms a first sealing surface (30), which lies adjacent to one section (23) of the nozzle holder and a second sealing surface (31), which lies adjacent to one section (24) of the nozzle body. Both the first and second sealing surfaces (30, 31) respectively have at least one cavity (36), which is punched, drilled and/or stamped.

Abstract: The invention relates to an injection valve (1) comprising a booster piston (23), said piston delimiting a pump chamber (22) and a booster chamber (29). A valve (14) is provided in the inlet to the chamber (22). The valve is configured as a 3/2-way valve and controls the pressure in the pump chamber (22). The pressure in the pump chamber (22) is converted into a correspondingly increased pressure in the booster chamber (29) and in an injection chamber (34) containing an injection needle (6), by means of the booster piston (23). The use of the valve (14) allows a precise control of the injection times.

Abstract: A piezoelectric assembly, a method for producing a structural unit with a prestressed piezoelectric actuator and a method for producing a hollow body for prestressing the piezoelectric actuator include an actuator pushed into a spring sleeve and force-lockingly and/or form-lockingly connected under prestress to two ends of the spring sleeve. This provides a structural unit in which the prestressing force of the piezoelectric actuator is permanently fixed by the production process.

Abstract: An actuator unit has an elastically configured hollow body in which a piezoelectric actuator is biased, the hollow body being provided with holes which are of a dumb-bell shape and run transversely of the hollow body's axis.

Abstract: The injection valve has a housing, a nozzle body and a clamping nut connected to the housing that contacts the nozzle body with first contact surface (9) acting on a second contact surface (10), whereby the clamping nut clamps the nozzle body against the housing. The first or second contact surface has a curvature (24) towards the second or first contact surface and the both contact surfaces are in contact in the area of the curvature.

Abstract: The positioning of the actuating drive in a fuel injector with a piezoactor (2) that is screwed into the housing (1) of the fuel injector is performed by applying a voltage (U) to the piezoactor (2) that corresponds to a given idle stroke (h), and the surface grinding of the housing (3) and base plate (4) of the piezoactor (2) when voltage is applied. Between the housing (1) of the fuel injector and the housing (3) of the piezoactor (2), there is also provided a compensation collar (9) of a suitable thickness.

Abstract: The injection valve has a housing, a nozzle body and a clamping nut connected to the housing that contacts the nozzle body with first contact surface (9) acting on a second contact surface (10), whereby the clamping nut clamps the nozzle body against the housing. The first or second contact surface has a curvature (24) towards the second or first contact surface and the both contact surfaces are in contact in the area of the curvature.

Abstract: The fuel injector has a housing that is formed from at least one nozzle tension nut, a first injector module and a second injector module. The first injector module and the second injector module adjoin one another and are disposed in the nozzle tension nut. A fuel high-pressure bore is led through the first injector module and the second injector module. A fuel return bore is disposed in the housing. Contact surfaces between the injector modules form a first gap that adjoins the high-pressure bore. Contact surfaces between the nozzle tension nut and the injector modules form a second gap that is connected to the first gap. The return line adjoins the second gap for the discharge of fuel that has entered the second gap from the high-pressure bore via the first gap. The fuel injector is such that the second gap is sealed off relative to the surroundings of the fuel injector.

Abstract: The positioning of the actuating drive in a fuel injector with a piezoactor (2) that is screwed into the housing (1) of the fuel injector is performed by applying a voltage (U) to the piezoactor (2) that corresponds to a given idle stroke (h), and the surface grinding of the housing (3) and base plate (4) of the piezoactor (2) when voltage is applied. Between the housing (1) of the fuel injector and the housing (3) of the piezoactor (2), there is also provided a compensation collar (9) of a suitable thickness.

Abstract: A method for producing a structural unit with a prestressed piezoelectric actuator includes the steps of inserting a front end of the actuator into a hollow body, form-lockingly or force-lockingly connecting the inserted front end of the actuator to the hollow body, pressing the actuator into the hollow body with a defined force establishing a prestress of the actuator, and force-lockingly or form-lockingly connecting the actuator to the hollow body in the vicinity of a rear end of the actuator, for fixing the prestress of the actuator.

Abstract: A device for transferring a thrust, a fuel injection valve with such a device, and a method for manufacturing such a thrust transferring device. To transfer the thrust of an actuator, especially in an injection valve, mechanical tappets are used, which have substantially the shape of a cylinder whose defining surfaces are substantially triangular, with the corners rounded. By the great width of the tappet, broad contact areas are created so that friction during the transfer is reduced.

Abstract: Located between the frustoconical needle tip and the cylindrical needle shank of a nozzle needle of a fuel injection valve is a frustoconical needle portion, into which is introduced a peripheral groove. Through this kind of arrangement damping is capable of being set, depending on the position of the groove, during the axial movement of the nozzle needle.

Abstract: The nozzle body (5) of a fuel injection valve has a central bore (54) in which a nozzle needle (1) is guided. The tip (52) of the nozzle body (5) has a tapered valve seat (55) which forms together with the sealing edge (27) of the nozzle needle (1) a valve (27, 55) which controls the flow of fuel to the injection holes (9) in the nozzle tip (52). Underneath the sealing edge (27) a circumferential groove (33) is disposed in the truncatoconical needle tip (30, 35, 40, 45) at the level of which the injection holes (9) are disposed, so that when the valve (27, 55) opens the nozzle needle (1) is axially stabilized and the shaping of the injected jet is improved.

Abstract: A servo drive includes a piezoelectric actuator contained in a drive housing. The actuator has an actuator stack surrounded by a hollow cylindrical spring element and an actuator casing disposed in the spring element. The spring element is clamped, together with the actuator stack, between an actuator cap and an actuator base. An elastic compound fills gaps between the drive housing and the spring element as well as between the spring element and the actuator casing, and damps an actuator motion. A piezoelectric actuator for the servo drive and a method of producing the piezoelectric actuator are also provided.