Abstract: The present disclosure relates to internal combustion engines. Various embodiments thereof may include a piezo injector for fuel injection. For example, an injector may include: a nozzle unit with a nozzle needle; a piezoelectric actuator unit; and a hydraulic coupler unit coupling the nozzle unit to the actuator unit. The coupler unit includes a coupler piston, a coupler cylinder, and a coupler spring. The coupler piston has a top side facing toward the coupler cylinder and a bottom side. The coupler spring pushes the coupler piston against a face side of the nozzle needle oriented toward the bottom side of the coupler piston and has a contact area with the nozzle needle. The coupler piston includes a passage opening providing a flow connection from the bottom side of the coupler piston to the top side of the coupler piston, arranged within the contact area.

Abstract: An injection valve may have a nozzle body with a longitudinal axis, in which a nozzle body aperture and at least one injection opening are arranged, wherein the nozzle body aperture can be coupled hydraulically to a high-pressure circuit for a fluid, at least one nozzle needle arranged in an axially movable manner in the nozzle body aperture, wherein the nozzle needle prevents fluid flow through the at least one injection opening in a closing position and allows fluid flow through the at least one injection opening outside the closing position, an actuator housing, which is designed to accommodate an actuator designed to act on the nozzle needle, and at least one fluid line, which is designed for hydraulic coupling to the high-pressure circuit for the fluid and is constructed and arranged separately from the actuator housing, and is directly coupled hydraulically to the nozzle body aperture.

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: An injection valve may have a nozzle body with a longitudinal axis, in which a nozzle body aperture and at least one injection opening are arranged, wherein the nozzle body aperture can be coupled hydraulically to a high-pressure circuit for a fluid, at least one nozzle needle arranged in an axially movable manner in the nozzle body aperture, wherein the nozzle needle prevents fluid flow through the at least one injection opening in a closing position and allows fluid flow through the at least one injection opening outside the closing position, an actuator housing, which is designed to accommodate an actuator designed to act on the nozzle needle, and at least one fluid line, which is designed for hydraulic coupling to the high-pressure circuit for the fluid and is constructed and arranged separately from the actuator housing, and is directly coupled hydraulically to the nozzle body aperture.

Abstract: The invention relates to an injection valve, comprising a control chamber (15) with a control piston (16) that is functionally linked with a nozzle needle (35). The control chamber (15) is linked, via an inlet throttle (13), with pressurized fuel, and with an outlet throttle (14) with a valve chamber (9). A servo valve (5) is disposed in the valve chamber (9), said servo valve opening a connection between the valve chamber (9) and a return element (40) depending on its position. The inventive injection valve further comprises a bypass throttle (12) that is interposed between the fuel feed line and the valve chamber.

Abstract: A seal (10) for a piezo-actuator of a fuel injector with terminal posts (12) projecting out of the piezo-actuator and a head arrangement (14) mounted on the piezo-actuator with openings (16) for passage of the terminal posts (12) is particularly suitable even for comparatively thin head plates. A sealing unit (18) mounted on the head arrangement (14) and provided with openings for passage of the terminal posts (12) is provided, having a support (22), on which a sealing material (26) is arranged, which is in contact in a sealing manner with the peripheral surfaces of the terminal posts (12) and a peripheral region of the head arrangement (14) and in which an element (20) made of microporous material is integrated to create gas permeability.

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 hole in a body, especially an injection hole in a fuel injector is disclosed. The hole (L) is first produced by a percussion boring process or a trepanation boring process using a laser. The percussion boring process lasts less than 3 seconds. The trepanation boring process lasts less than 10 seconds. After percussion boring or trepanation boring a smoothing step is carried out by forcing a medium that is mixed with abrasive particles under pressure through the hole until any roughnesses of surfaces (F) of the body that form the hole (L) are substantially removed.

Abstract: A seal (10) for a piezo-actuator of a fuel injector with terminal posts (12) projecting out of the piezo-actuator and a head arrangement (14) mounted on the piezo-actuator with openings (16) for passage of the terminal posts (12) is particularly suitable even for comparatively thin head plates. A sealing unit (18) mounted on the head arrangement (14) and provided with openings for passage of the terminal posts (12) is provided, having a support (22), on which a sealing material (26) is arranged, which is in contact in a sealing manner with the peripheral surfaces of the terminal posts (12) and a peripheral region of the head arrangement (14) and in which an element (20) made of microporous material is integrated to create gas permeability.

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 invention relates to an injection valve, comprising a control chamber (15) with a control piston (16) that is functionally linked with a nozzle needle (35). The control chamber (15) is linked, via an inlet throttle (13), with pressurized fuel, and with an outlet throttle (14) with a valve chamber (9). A servo valve (5) is disposed in the valve chamber (9), said servo valve opening a connection between the valve chamber (9) and a return element (40) depending on its position. The inventive injection valve further comprises a bypass throttle (12) that is interposed between the fuel feed line and the valve chamber.

Abstract: The invention relates to an injection valve, comprising a control chamber (15) with a control piston (16) that is functionally linked with a nozzle needle (35). The control chamber (15) is linked, via an inlet throttle (13), with pressurized fuel, and with an outlet throttle (14) with a valve chamber (9). A servo valve (5) is disposed in the valve chamber (9), said servo valve opening a connection between the valve chamber (9) and a return element (40) depending on its position. The inventive injection valve further comprises a bypass throttle (12) that is interposed between the fuel feed line and the valve chamber.

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 hole in a body, especially an injection hole in a fuel injector is disclosed. The hole (L) is first produced by a percussion boring process or a trepanation boring process using a laser. The percussion boring process lasts less than 3 seconds. The trepanation boring process lasts less than 10 seconds. After percussion boring or trepanation boring a smoothing step is carried out by forcing a medium that is mixed with abrasive particles under pressure through the hole until any roughnesses of surfaces (F) of the body that form the hole (L) are substantially removed.

Abstract: The invention relates to an injection valve, comprising a control chamber (15) with a control piston (16) that is functionally linked with a nozzle needle (35). The control chamber (15) is linked, via an inlet throttle (13), with pressurized fuel, and with an outlet throttle (14) with a valve chamber (9). A servo valve (5) is disposed in the valve chamber (9), said servo valve opening a connection between the valve chamber (9) and a return element (40) depending on its position. The inventive injection valve further comprises a bypass throttle (12) that is interposed between the fuel feed line and the valve chamber.

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: An actuator is operatively connected to a closing member via a tappet. The closing member is introduced in a valve chamber and forms, with a conically tapering valve seat as part of a servovalve, a seal resistant to high pressure. The cross section of the closing member is configured to be mushroom-shaped, a closing head being in the form of a part-sphere and having a central flattening, with the result that the tappet has an enlarged bearing surface. A stem of the closing member is surrounded by a valve spring. The closing member is preferably shaped out of a solid sphere.

Abstract: A device for transmitting a deflection of a piezoelectric actuator to a movable tappet includes a pressure chamber between the piezoelectric actuator and the tappet. The pressure chamber is substantially formed by two mutually parallel diaphragms having effective radii of different lengths. The diaphragm with the longer radius is associated with the piezoelectric actuator and the diaphragm with the shorter radius is associated with the tappet. Therefore, upon a deflection of the first diaphragm by the piezoelectric actuator, the second diaphragm is deflected by a greater distance toward the tappet. A controller with an actuator having a controllable length is also provided.