Micro flow control valve
AssigneeJgc Corporation
InventorsJun-ichi Nishizawa, Shinzo Kasai, Tetsuo Okada, Mitsuhiko Dohzono
Life of this patent
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Abstract
Disclosed is a micro gas flow rate control valve which is used in semi-conductor producing system operated under a high vacuum or various apparatus for analysis. The valve uses combination of a flat surface valve tip and a flat surface valve seat of cylindrical shape, and is capable of controlling minute flow and durable even used under severe conditions of high pressure differences and large temperature changes to have stable performance. Also enclosed is a metal-ceramics sealing mechanism suitable for the above valve. The sealing mechanism uses, in addition to a sealing member made of a soft metal, a seal assisting member, and durable under the conditions of repeated temperature changes.
Claims7
A micro flow control valve comprising a valve tip installed at one end of a stem, a cylindrical valve seat installed at the bottom of a gas chamber, the valve tip and the cylindrical valve seat each having a flat surface, the flat surfaces being arranged to provide a gap therebetween for a gas to flow into a passageway in the center of the valve seat;
- a driving system for controlling the gap within a range of elastic deformation of the valve tip and valve seat and without permanent deformation thereof, the driving system including pressing means for pressing the valve against the valve seat, and reverse forcing means for providing a controllable force against the pressing of the valve against the valve seat and for opening the gap;
- the reverse forcing means including a pneumatic system having an air chamber, a diaphragm connected to the stem, and means for controlling the air pressure within the air chamber and on the diaphragm;
- and
- the pressing means and reverse force means being arranged so than an amount of opening of the gap can be controlled independently of the pressure of gas flowing through the gap.
Dependencies are inferred from the claim text.