Abstract: A piezoelectric actuator module having a piezoelectric actuator, fastened between an actuator head and an actuator foot, and having a sheath, surrounding the piezoelectric actuator, for electrical passivation, is proposed in which the sheath is an insulation guard layer that is joined by nonpositive and/or positive engagement, by means of a mechanical attachment, to attachment components in the region of the end faces of the piezoelectric actuator or of the actuator head and/or of the actuator foot.

Abstract: A fuel injector with a direct needle control for an internal combustion engine, having an actuator, a hydraulic booster, and a nozzle needle guided in a nozzle body and acting on a nozzle needle sealing seat. The hydraulic booster includes a booster piston connected to the actuator and a nozzle needle booster piston connected to the nozzle needle; a booster chamber in the form of an actuator coupler chamber is associated with a pressure surface of the actuator booster piston; and depending on the pressure in the actuator coupler chamber, the nozzle needle is lifted away from the nozzle needle sealing seat, thus initiating an injection. In addition to the actuator booster piston, a control element is provided that is able to execute a stroke motion, is hydraulically coupled to the actuator coupler chamber by means of a first control surface, and is associated with a control chamber by means of a second control surface.

Abstract: A fuel injector for injecting fuel into an internal combustion engine has an at least two-stage pressure boosting or a variable pressure boosting and an actuator able to actuate an injection valve member. A prestroke element travels a prestroke distance hv during the opening movement of the injection valve member until it reaches a changeover point of the pressure boosting. The injection valve member or a second piston is associated with a prestressing spring element, which can be a disk spring, a tubular spring, a helical spring, or a spring element integrated into the second piston. During the passage through the prestroke distance hv, the prestressing spring element continuously builds up the force required to switch the pressure boosting from a first opening pressure po,1 to a second opening pressure Po,2.

Abstract: A fuel injector with a direct needle control for an internal combustion engine, having an actuator, a hydraulic booster, and a nozzle needle guided in a nozzle body and acting on a nozzle needle sealing seat. The hydraulic booster includes a booster piston connected to the actuator and a nozzle needle booster piston connected to the nozzle needle; a booster chamber in the form of an actuator coupler chamber is associated with a pressure surface of the actuator booster piston; and depending on the pressure in the actuator coupler chamber, the nozzle needle is lifted away from the nozzle needle sealing seat, thus initiating an injection. In addition to the actuator booster piston, a control element is provided that is able to execute a stroke motion, is hydraulically coupled to the actuator coupler chamber by means of a first control surface, and is associated with a control chamber by means of a second control surface.

Abstract: The invention relates to a piezoelectric actuator, in particular for actuating control valves or injection valves of internal combustion engines in motor vehicles, having a circular, cylindrical piezoelectric actuator body in the form of a multilayered laminate made up of stacked layers of piezoelectric material with intervening metallic or electrically conductive, alternating first and second electrode layers that function as electrodes, wherein these first and second electrode layers alternatingly contact a first and second electrically conductive common electrode connection.

Abstract: The invention relates to a piezoelectric actuator, especially for actuating control valves or injection valves in motor vehicles, having an actuator body (1) in the form of a multilayer laminate of layered plies of piezoelectric material and intervening metal or electrically conductive layers (2a, 2b), acting as electrodes, which are contacted in alternation by metal outer electrodes (3, 5), facing one another on the jacket side in the longitudinal direction of the actuator body (1), that are at least in the form of laminar electrode strips (3), and the outer electrodes (3, 5) are in contact with electric terminal leads (7) for connecting the piezoelectric actuator to an electrical voltage. The piezoelectric actuator is characterized in that the outer electrodes (3, 5) also have additional electrodes (5) that are in contact at a plurality of points, via narrow elastic feet (6), with the laminar electrode strips (3).

Abstract: A piezoelectric actuator in which a piezoelectric element is present for subjecting an actuating element to a tensile or compressive stress. A sleeve is secured to a foot part, to which the piezoelectric element is secured and by way of which the piezoelectric element is kept centered in a housing under mechanical prestressing, and this sleeve surrounds the piezoelectric element in such a way as to stabilize it mechanically, at least in partial regions that are electrically insulated from the piezoelectric element. Between the sleeve and the piezoelectric element, a heat-conducting elastomer is placed, and the sleeve comprises a heat-conducting material that is deformable within predetermined limits.

Abstract: A piezoelectric actuator having a plurality of plates of a piezoelectric material whose polarization direction runs perpendicularly to the plate plane, and which are stacked one over another in their polarization direction. The piezoelectric actuator includes a control voltage source having two contacts, two groups of at least two outer electrodes, respectively, and a plurality of internal electrodes which, in each case, are arranged between the piezoelectric plates. In this context, the outer electrodes of the first group are electrically connected to a first contact of control voltage source, and the outer electrodes of the second group to the second contact of control voltage source. Internal electrodes alternately contact outer electrodes in such a way that, in each case, an internal electrode is electrically connected to one contact of control voltage source, and the internal electrode that is next in the stacking direction is electrically connected to the other contact of control voltage source.

Abstract: A piezoelectric component, including a ceramic actuator having a coating made of an elastomer. The elastomer is a heat conductive elastomer including a filler which is manufactured based upon aluminum dioxide, titanium dioxide, boron nitride, aluminum nitride, silicon carbide and/or preferably silicon dioxide.

Abstract: The invention relates to a piezoelectric actuator, in particular for actuating control valves or injection valves in motor vehicles, having an actuator body in the form of a multilayered laminate made up of stacked layers of piezoelectric material with intervening metallic or electrically conductive layers that function as electrodes, and the end faces of this actuator body are respectively contacted by a top plate oriented toward the valve having an axially protruding valve tappet and a bottom plate at the opposite end, wherein the actuator rests in an axial bore of a valve housing and is prestressed at the ends in the axial direction between the top plate and the bottom plate by means of a spring element.

Abstract: A piezoelectric actuator (1) is proposed, in which a piezoelectric element (2) is present for subjecting an actuating element to a tensile or compressive stress. A sleeve (4; 20) is secured to a foot part (3), to which the piezoelectric element (2) is secured and by way of which the piezoelectric element (2) is kept centered in a housing (8) under mechanical prestressing, and this sleeve surrounds the piezoelectric element (2) in such a way as to stabilize it mechanically, at least in partial regions that are electrically insulated from the piezoelectric element. Between the sleeve (4; 20) and the piezoelectric element (2), a heat-conducting elastomer (6) is placed, and the sleeve (4; 20) comprises a heat-conducting material that is deformable within predetermined limits.

Abstract: A piezoelectric actuator has a plurality of disks made of piezoelectric material, arranged to form a stack in a stack direction, a plurality of flat inside electrodes arranged in alternation with the disks made of piezoelectric material, and at least two outside electrodes applied to the outside of the stack along the stack direction, the inside electrodes each being connected in alternation to one of the outside electrodes by a contact zone. The outside electrodes are applied to the outside of the stack in the form of a coating of an elastic, electrically conductive polymer material.

Abstract: The invention relates to a piezoelectric actuator, in particular for actuating control valves or injection valves in internal combustion engines in motor vehicles, having a piezoelectric actuator body, in particular in the form of a multilayer laminate of layered plies of piezoelectric material and intervening metal or electrically conductive layers acting as electrodes, in which one of the face ends of the actuator body is fixed on an actuator base, and the actuator body is surrounded by a module wall so as to define an interstice there between, and the interstice is filled with an elastic or plastic electrically insulating material of good thermal conductivity, which is solid at least in the temperature range below the operating temperature of the actuator.

Abstract: A valve for controlling fluids is described, wherein a valve closing member (13) divides a low-pressure region (16) in the valve (1) from a high-pressure region (17), and a filling device (19) is provided to compensate for a leakage quantity from the low-pressure region (16) by withdrawal of hydraulic fluid from the high-pressure region (17). The filling device (19) is embodied in a valve body (9) with a conduitlike hollow chamber (18) in which a solid body (26) is disposed in such a way that a gap (28) is formed between the solid body (26) and the valve body (9). The material of the solid body (26) has a coefficient of thermal expansion that is so much greater than that of the material of the valve body (9) that with increasing temperature, a viscosity-dictated increase in the volumetric flow around the solid body (26) is at least partly limited (FIG. 1).

Abstract: A piezoelectric actuator, for example for actuating a mechanical component, is proposed, which has a multilayered structure of piezoelectric layers and internal electrodes (2, 3) disposed between them. As a conductive surface, a first external electrode (6) is affixed to a respective side surface and is contacted by the respective internal electrodes (2, 3), and a second net-like or woven cloth-like external electrode (7) is disposed on the first external electrode (6). In the regions of the piezoelectric layers, which have respective internal electrodes (2, 3) that are respectively contacted on opposite sides from one another, there is a passive zone (10) without an internal electrode layer. The ceramic piezoelectric material—at least in the passive zone (10)—and the material of the second external electrode (7) have almost the same thermal expansion coefficient, by means of which the influence of mechanical stresses in the piezoelectric actuator can be reduced.

Abstract: A piezoelectric actuator is described, for example for actuating a mechanical component, in which a piezoelectric element that produces tensile or compressive force acting on an actuation element is provided. The piezoelectric element has a multi-layer structure of piezoelectric layers with internal electrodes (2, 3) disposed between them. The contacting of the internal electrodes (2, 3) on alternate sides takes place by means of external electrodes (10, 11). External electrical connections (12) for the lateral contacting are affixed to an inactive end region (4, 5, 6, 7; 13, 14) in the multi-layer structure, which has a heat-conducting core (5; 14) with a favorable heat conductivity.

Abstract: The invention relates to a piezoelectric actuator, in particular for actuating control valves or injection valves in motor vehicles, having an actuator body in the form of a multilayered laminate made up of stacked layers of piezoelectric material with intervening metallic or electrically conductive layers that function as electrodes, and the end faces of this actuator body are respectively contacted by a top plate oriented toward the valve having an axially protruding valve tappet and a bottom plate at the opposite end, wherein the actuator rests in an axial bore of a valve housing and is prestressed at the ends in the axial direction between the top plate and the bottom plate by means of a spring element. According to the invention, the actuator-at least including the top plate -is enclosed by an electrically insulating elastomer sleeve so that when installed, the actuator with the elastomer sleeve rests snugly against the inner wall of the axial bore of the valve housing in the vicinity of the actuator.

Abstract: A piezoelectric actuator, for instance for actuating a mechanical component, is proposed that has a multilayer structure of piezoelectric layers and disposed between them inner electrodes (2, 3) and an alternate-side lateral contacting of the inner electrodes (2, 3) via outer electrodes (4, 5). The outer electrodes (4, 5) are applied in network- or fabric-like fashion, each distributed over one side face, and are contacted at least at some points to the respective inner electrodes (2, 3). The outer electrodes (4, 5) are lengthened past the multilayer structure of piezoelectric layers in such a way that the delivery of the electrical voltage takes place at the extensions (8, 9).

Abstract: A piezoelectric actuator for actuating control valves or injection valves in internal combustion engines in motor vehicles. The piezoelectric actuator body is in the form of a multilayer laminate of layered plies of piezoelectric material and intervening metal, for instance electrically conductive layers acting as electrodes. The electrode layers are contacted by electrically conductive common electrode leads, and the actuator body is surrounded by a metal module wall which encircles an interstice that contains the common electrode leads. The common electrode leads are designed in the form of a three-dimensionally structured surface or a three-dimensionally structured body, and a portion thereof contacting the actuator body has a lengthened portion or enlargement, that protrudes into the interstice, for dissipating heat from the actuator body, and an elastomer filling with heat-conducting additive particles in the interstice.

Abstract: A piezoelectric actuator for actuating control valves or injection valves in motor vehicles. The actuator includes an actuator body in the form of a multilayer laminate of stacked layers of piezoelectric material and intervening metallic or electrically conductive layers acting as electrodes. One bottom plate toward the valve and an opposed top plate are mounted on each of the end faces of the actuator body. The piezoelectric actuator is characterized in that the actuator body on each of its end faces has one piezoelectrically inactive cover layer and that the connection faces of the bottom plate and the top plate which adjoin the end faces of the actuator body have fixation elements that grip the cover layers, for at least nonpositive fixation of the cover layers of the actuator body.