Compensation element for the compensation of temperature-conditioned

Abstract

The compensation element is compensating for temperature-conditioned length changes of an object. An injection valve that is fully functional in the entire range of the operating temperatures of a motor requires a device that compensates thermally conditioned length changes of the mechanical components (piezo-electric actuator, valve lifter, housing, etc.). This device should be capable of absorbing great forces and allow a stiff bearing of the actuator. The compensation element (3) has an oil-filled chamber (21) is composed of an actuator-side upper part (18), of a lower part (19) supported on a stiff bearing (valve housing 17), and of a structure (annular seal element 20) sealing the chamber (21) and yielding in an axial direction. Since the compensation element (3) is fitted into an annular holder (4) with little lateral play, every temperature-conditioned change of the oil or, respectively, chamber volume results in a displacement of the upper housing part (18) in an axial direction that is proportional to the volume change. As a result of a corresponding dimensioning of the chamber height, temperature-conditioned length changes of the valve housing (4) and of the piezo-electric actuator (2) can be compensated using the extremely compactly constructed and comparatively rigid compensation element (3).