Solenoid valve
AssigneeHitachi, Ltd.
InventorsYoshio Okamoto, Kazumi Iwai, Hiroshi Inoue, Yoshifumi Kunugi, Tadashi Shinozaki
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Abstract
A solenoid valve in which a pulse signal is applied to an electromagnet thereof to eliminate an electric hysteresis. The solenoid valve includes a piston-like valve slidably supported in a cylinder, and at least one aperture, for communicating with a fluid inlet and a fluid outlet, provided in at least one of the valve and cylinder, whereby the flow rate of a fluid may be continuously controlled and the collision between the valve and a valve seat may be avoided.
Claims11
A solenoid valve including a fluid inlet, a fluid outlet, a plunger adapted to be reciprocated by an electromagnetic force and a force of a spring so as to selectively open or close one of said fluid inlet and said fluid outlet, a piston valve engageable with said plunger, a cylinder slidably accommodating said piston valve, aperture means provided in one of said piston valve and said cylinder for communicating said fluid inlet with said fluid outlet, said spring is interposed between an upper part of said plunger and a mangetic head mounted on a plunger casing, another spring is interposed between a lower part of said piston valve and a body of said solenoid valve whereby a balance condition is achieved between the electromagnetic force and said spring so as to enable a reciprocation of the plunger, said plunger and piston valve being supported solely by a balance of said two springs without contact of the piston valve with an inner wall of said cylinder, and wherein a pulse signal is applied to an electromagnet of said solenoid valve, with at least a pulse repetition period of said pulse signal being varied in a predetermined manner so as to cause a flow rate of the solenoid valve to change continuously so as to obtain a desired value of the flow rate.
Dependencies are inferred from the claim text.