Piezo actuator for use in injector of injection device utilized for direct injection of liquid fuel into combustion chamber of internal-combustion engine of motor vehicle, has electrodes for detecting compression and lengthening of stack

摘要

The actuator has a piezo stack (10) extending along longitudinal direction and provided with two pairs of electrodes that are electrically coupled with a rectangular piezo layer (12). A compression of the piezo stack with force acting diagonally or vertically to the longitudinal extending direction toward the piezo stack is detectable by one pair of electrodes. A lengthening of the piezo stack due to the force is detected by another pair of electrodes, where the electrodes are distributed around the piezo layer. An independent claim is also included for a method for manufacturing a piezo actuator.