Tension spring for piezo-multilayer actuator e.g., of high pressure fuel injection valve, uses wave spring having amplitude sized to within wall thickness, or less

摘要

A tensioning spring for tensioning piezoelectric actuator between two closure elements (2,3) and has at least two wave-springs (6) each fixed to the closure elements (2,3) and joining them together. The wave springs (6) have a wave amplitude lying in the order of their wall thickness or less, and the length of the wave-train amounts to a multiple of the wave amplitude.