High-frequency on-off valve

#[1] Field of the Invention

#The present invention relates to high-frequency on-off valves that frequently open and close output orifices by bringing valve members, which have a small opening-closing stroke, into and out of contact with valve seats.

#[2] Description of the Related Art

#FIG. 1 is a perspective view of a high-frequency on-off valve according to a first embodiment of the present invention.

#FIG. 2 is an enlarged vertical sectional view of FIG. 1.

#FIG. 3 is a vertical sectional view taken along a center line in FIG. 2.

#FIGS. 1 to 6 illustrate a high-frequency on-off valve according to a first embodiment of the present invention. This valve has a valve structure serving as a poppet-type two-port electromagnetic valve, and includes an electromagnetic operating section 1 and a main valve section 2 that are connected to each other via a spacer 3, a valve chamber 4 formed between the electromagnetic operating section 1 and the main valve section 2, and a valve member 5 accommodated within the valve chamber 4. In plan view, the valve has a slender rectangular shape having a longitudinal direction and a lateral direction. Therefore, in plan view, the valve chamber 4 similarly has a slender rectangular shape having a longitudinal direction and a lateral direction.

#As shown in FIGS. 2 and 3, the electromagnetic operating section 1 includes a nonmagnetic bobbin 7 having a substantially rectangular cross-sectional shape extending slenderly in the longitudinal direction of the valve, an exciting coil 8 wound around the bobbin 7, a stationary core 9 having a substantially slender rectangular cross-sectional shape and accommodated within a center hole 7a of the bobbin 7, and a substantially U-shaped magnetic frame 10 that covers the upper surface and opposite side surfaces, in the longitudinal direction, of the bobbin 7. The bobbin 7, the exciting coil 8, the stationary core 9, and the magnetic frame 10 constitute an electromagnetic valve assembly. The upper surface and side surfaces of this electromagnetic valve assembly are entirely coated with a sealing member 11 composed of synthetic resin. The sealing member 11 has a flat upper surface 11a from which a pair of coil terminals 12 that conduct electricity to the exciting coil 8 protrude. The coil terminals 12 are connected to lead wires 13. A cover 14 is disposed on the upper surface 11a of the sealing member 11 so as to cover the connection area between the coil terminals 12 and the lead wires 13. The cover 14 is attached to the sealing member 11 by means of screws 15. Reference numeral 14a in FIG. 4 denotes screw through-holes formed in the cover 14, and reference numeral 11b denotes screw holes formed in the sealing member 11.

#An end surface, that is, a lower end surface, of the stationary core 9 serves as a pole face 9a to which the valve member 5 is attached. A central area of the pole face 9a in the longitudinal direction thereof is provided with a fluid introduction chamber 16 formed by cutting out a portion of the stationary core 9 into a U-shape. In a state where the valve member 5 is attached to the pole face 9a by applying electricity to the exciting coil 8, when the electricity is cut off, the fluid introduction chamber 16 accelerates separation of the valve member 5 from the pole face 9a by utilizing an effect of a pressure fluid, such as air, introduced into the fluid introduction chamber 16.