Piezo-type valve

摘要

A piezo-type valve with piezo-elements as a valve actuator. The piezo-elements are interposed by two freely movable pistons. A pressure chamber is formed on the outer side of one of the pistons to limit its outward movement. Thus, the substantial part of the expansion of the piezo-elements is transmitted to the other piston. The other piston is connected to a valve element. At least one flow port and a relief port are formed in the valve body. When voltage is applied to the piezo-elements, the at least one flow port and the relief port are communicated.