Siemens Aktiengesellschaft

Continental Automotive Gmbh

Klaus Plecher

Marcus Unruh

Claus Zumstrull

Andreas Voigt

Stefan Kohn

Michael Denzler

Tim Bohlmann

Emanuel Sanftleben

Martin Neumaier

Roland Niefanger

Yavuz Kurt

An actuator for actuating a fuel injection valve has a piezoactuator, enclosed in an actuator housing unit (). The housing unit has a cylindrical actuator housing () which is elongate in its axial direction (A) and at least partially encased by an extruded plastic coat. The actuator housing unit (), in its encased area, is provided with a ventilation aperture () in which a ventilation element () produced from a microporous material is disposed.

Actuator for actuating a fuel injection valve

A protective cover for an actuating drive, that can be used as universally as possible, for components () of a contacting and/or sealing arrangement of the actuating drive. The sealing arrangement is embodied in a liquid-tight but gas-permeable manner and ends in a cavity on the outer side, the cavity being covered by a cover () held on the actuating drive by means of a catch connection ().

Actuating drive for actuating a fuel injection valve

A sealing arrangement of a piezoelectric actuator comprises terminal posts () projecting from the piezoelectric actuator and a metallic top arrangement (), provided with openings () allowing the passage of the terminal posts () which is emplaced on the piezoelectric actuator. In order to facilitate reliable sealing in particular also for comparatively thin top plates (), the invention provides for emplacing on terminal post sections () projecting from the openings () a sealing element () which is formed from an electrically insulating and sealing material and which is positioned tight against, on the one hand, circumferential areas () of the terminal post sections () and, on the other hand, the top arrangement (), with an insulating disk () provided with openings allowing the passage of the terminal posts () and made of electrically insulating material being located between the sealing element () and the top arrangement ().

Sealing arrangement for a piezoelectric actuator for a fuel injection valve of an internal combustion engine

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.

Method for improving the long-term stability of a piezoelectric actuator and a piezoelectric actuator

In a method and arrangement for sealing a piezoactuator having terminal pins () protruding from the piezoactuator and a top plate () surmounting the piezoactuator, the top plate is provided with openings () to enable the terminal pins () to pass through. In order to ensure a reliable seal even for comparatively thin top plates () in particular, the invention proposes placing a sealing-ring () made from an elastic sealant material on each of the terminal pin sections () protruding from the openings (), so that the sealing ring fits tightly to a circumferential surface () of the terminal pin section (), as well as to the top plate (), forming a seal, and being pressure-injected into the top plate () by means of a plastic extrusion coating (arrows in FIG.).

Sealing apparatus assembly for sealing a piezoactuator and method for sealing a piezoactuator

In order to increase the lifetime for a piezoactuator of a fuel injector and to make possible a reliable seal of the piezoactor especially for comparatively thin head plates as well a gas exchange passage running through an actuator housing () is provided, where a sealing unit () placed on the head arrangement () is provided for sealing the piezoactor () which features a carrier () on which a sealing material () is arranged which forms a seal around the piezo contact pins () and the head arrangement () and on which a microporous gas exchanger () to create gas permeability of the sealing unit () is integrated such that any fluid which has penetrated through to the gas exchanger () can flow out of the gas exchanger () under the force of gravity.

Growing community of inventors

Zeitlarn, Germany

Klaus Plecher