Diaphragm valve and mass flow controller using the same
AssigneeHitachi Metals, Ltd.
InventorTakao Goto
Life of this patent
Estimating the term…
Abstract
In a diaphragm valve comprising a tubular valve seat, a primary side passage located outside the valve seat, a secondary side passage located inside the valve seat, and pressing member which presses the diaphragm to a seating surface to change a valve opening, a supporting member which contacts with the diaphragm in a valve opening range that is at least one part of an entire opening range from a fully opened state to a fully closed state to obstruct deformation of the diaphragm to the secondary side passage side is disposed in a region between the seating surface and a center of the seating surface. Thereby, even when a pressure difference between both sides of the diaphragm is large, a reduction of a gap at the seating surface can be prevented, and gas can be flowed at a large flow rate.
Claims36
A diaphragm valve which comprises,
- a circular diaphragm,
- a valve seat constituted by a tubular member disposed coaxially with said diaphragm and having a seating surface formed on an end surface on the diaphragm side of said tubular member, and said seating surface being a plane having an annular shape on which said diaphragm is seated,
- a primary side passage that is a space located outside said valve seat,
- a secondary side passage that is a space located inside said valve seat, and
- a pressing member configured so as to press said diaphragm to bring said diaphragm closer to said seating surface, and
- a periphery part of said diaphragm is fixed at a reference position a predetermined distance apart from a seating plane that is a plane including said seating surface, and
- said pressing member is configured so as to press said diaphragm and thereby change the distance between said diaphragm and said seating surface to change a valve opening of said diaphragm valve,
- wherein:
- said diaphragm valve further comprises a supporting member configured so as to contact with said diaphragm in a first opening range that is at least one part of a range of the valve opening within an entire opening range that is a range of the valve opening of said diaphragm valve from a fully opened state to a fully closed state to obstruct deformation of said diaphragm to the side of said secondary side passage, and
- said supporting member is configured such that a supporting surface that is a surface of said supporting member, which contacts with said diaphragm in said first opening range, is located in a region between a seating center that is a center of the annular shape of said seating surface and said seating surface, in a normal projection to said seating plane.
A mass flow controller comprising:
- a flow sensor, and
- a diaphragm valve comprising:
- a circular diaphragm,
- a valve seat constituted by a tubular member disposed coaxially with said diaphragm and having a seating surface formed on an end surface on the diaphragm side of said tubular member, and said seating surface being a plane having an annular shape on which said diaphragm is seated,
- a primary side passage that is a space located outside said valve seat,
- a secondary side passage that is a space located inside said valve seat, and
- a pressing member configured so as to press said diaphragm to bring said diaphragm closer to said seating surface, and
- a periphery part of said diaphragm is fixed at a reference position a predetermined distance apart from a seating plane that is a plane including said seating surface, and
- said pressing member is configured so as to press said diaphragm and thereby change the distance between said diaphragm and said seating surface to change a valve opening of said diaphragm valve,
- wherein:
- said diaphragm valve further comprises a supporting member configured so as to contact with said diaphragm in a first opening range that is at least one part of a range of the valve opening within an entire opening range that is a range of the valve opening of said diaphragm valve from a fully opened state to a fully closed state to obstruct deformation of said diaphragm to the side of said secondary side passage, and
- said supporting member is configured such that a supporting surface that is a surface of said supporting member, which contacts with said diaphragm in said first opening range, is located in a region between a seating center that is a center of the annular shape of said seating surface and said seating surface, in a normal projection to said seating plane.
Dependencies are inferred from the claim text.