摘要:
A device with a piezoelectric actuator (1) comprises two faces (2, 3) and two electroconductive contact paths (4, 5), each traversing the actuator (1) starting from at least one face (3). The actuator is clamped between two metallic plates (6, 7), each arranged against a face (2, 3). The piezoelectric actuator further comprises an electroinsulating layer (8) arranged between each face 92, 3) and the corresponding metallic plate (6, 7).
摘要:
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.
摘要:
In a method for pretreating a piezoelectric ceramic (1) and a method for adjusting an injection valve (7), the piezoelectric ceramic (1) is exposed to environmental conditions, leading to a reduction of polarization and also a reduction of the length of the ceramic (1). The obtained length exhibits a greater long-term stability due to said adjusting phase. Consequently, the injection valve (7) can be re-adjusted before use. As a result, renewed adjustment thereof is required only after a long period in service.
摘要:
A method is described for improving the long-term stability of a piezoelectric actuator encased in a potting compound containing or forming hydrogen atoms. Oxygen is contained in the piezoelectric actuator's piezoelectric ceramic. Appropriate means are employed so that unsaturated bonds of the hydrogen in the potting compound will release less oxygen from the piezoelectric ceramic. One means consists in reducing the concentration of hydrogen in the potting compound, with appropriate thermal processes as a result of which the concentration of hydrogen will be reduced to below a predefined threshold being applied after the piezoelectric actuator has been encased in the potting compound. Means that form bonds with the hydrogen in the potting compound or duct oxygen thereto are provided in further embodiments.
摘要:
In a method for pretreating a piezoelectric ceramic (1) and a method for adjusting an injection valve (7), the piezoelectric ceramic (1) is exposed to environmental conditions, leading to a reduction of polarisation and also a reduction of the length of the ceramic (1). The obtained length exhibits a greater long-term stability due to said adjusting phase. Consequently, the injection valve (7) can be re-adjusted before use. As a result, renewed adjustment thereof is required only after a long period in service.
摘要:
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.
摘要:
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.
摘要:
An actuator for actuating a fuel injection valve has a piezoactuator, enclosed in an actuator housing unit (14, 16). The housing unit has a cylindrical actuator housing (14) which is elongate in its axial direction (A) and at least partially encased by an extruded plastic coat. The actuator housing unit (14, 16), in its encased area, is provided with a ventilation aperture (20) in which a ventilation element (22) produced from a microporous material is disposed.
摘要:
An actuator for actuating a fuel injection valve has a piezoactuator, enclosed in an actuator housing unit (14, 16). The housing unit has a cylindrical actuator housing (14) which is elongate in its axial direction (A) and at least partially encased by an extruded plastic coat. The actuator housing unit (14, 16), in its encased area, is provided with a ventilation aperture (20) in which a ventilation element (22) produced from a microporous material is disposed.
摘要:
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).