초록 ▼

There are provided a flow control valve and a flow control device suitable for allowing flow control of a fluid with high accuracy. Diaphragms 8 and 9 are mounted to upper and lower openings, respectively, of an air chamber 6. The upper diaphragm 8 and the lower diaphragm 9 are connected by a conne

There are provided a flow control valve and a flow control device suitable for allowing flow control of a fluid with high accuracy. Diaphragms 8 and 9 are mounted to upper and lower openings, respectively, of an air chamber 6. The upper diaphragm 8 and the lower diaphragm 9 are connected by a connecting shaft 10 and have pressurized surfaces with different areas that receive pressure of the air chamber 6. This causes a difference between forces applied to the two diaphragms 8 and 9, and the difference causes the connecting shaft 10 and a valve body 2 mounted to an outer surface of the lower diaphragm 9 to slide and be separated from a valve seat 23.

대표청구항 ▼

What is claimed is: 1. A flow control valve comprising: an air chamber having two openings opposite each other; two diaphragms mounted to the openings of said air chamber and having pressurized surfaces with different areas that receive pressure of the air chamber; a connecting shaft that connects

What is claimed is: 1. A flow control valve comprising: an air chamber having two openings opposite each other; two diaphragms mounted to the openings of said air chamber and having pressurized surfaces with different areas that receive pressure of the air chamber; a connecting shaft that connects said two diaphragms; support means that supports said connecting shaft slidably in an axial direction; an internal channel that is provided outside said air chamber and through which a fluid flows; a valve body that slides in conjunction with the sliding operation of said connecting shaft to increase or decrease a flow rate of the fluid flowing through said internal channel; and an air supply passage that supplies air whose pressure or flow rate is controlled into said air chamber, wherein said air supply passage is divided at one end thereof into two branch duct lines, one of the two branch duct lines opens at an outlet thereof so as to face the pressurized surface of one of said diaphragms in close proximity, and the other of the branch duct lines opens at an outlet thereof so as to face the pressurized surface of the other of said diaphragms in close proximity. 2. The flow control valve according to claim 1, wherein said connecting shaft and said support means are placed in said air chamber. 3. The flow control valve according to claim 1, wherein said valve body is mounted to an outer surface of one of said two diaphragms, and said internal channel is adapted to pass through the outer surface of said one diaphragm to which said valve body is mounted. 4. The flow control valve according to claim 3, wherein the outer surface of said one diaphragm is protected by corrosion-resistant means such as fluorocarbon polymer. 5. A flow control valve comprising: an air chamber having upper and lower openings; upper and lower diaphragms mounted to the upper and lower openings of said air chamber and having pressurized surfaces with different areas that receive pressure of the air chamber; a connecting shaft that connects said upper and lower diaphragms; support means that supports said connecting shaft slidably in an axial direction; an internal channel that is provided outside said air chamber and through which a fluid flows; a valve body that slides in conjunction with the sliding operation of said connecting shaft to increase or decrease a flow rate of the fluid flowing through said internal channel; and an air supply passage that supplies air whose pressure or flow rate is controlled into said air chamber, wherein said air supply passage is divided at one end thereof into two branch duct lines, one of the two branch duct lines opens at an outlet thereof so as to face the pressurized surface of said upper diaphragm in close proximity, and the other of the branch duct lines opens at an outlet thereof so as to face the pressurized surface of said lower diaphragm in close proximity. 6. The flow control valve according to claim 5, wherein said connecting shaft and said support means are placed in said air chamber. 7. The flow control valve according to claim 5, wherein said valve body is mounted to an outer surface of one of said two diaphragms, and said internal channel is adapted to pass through the outer surface of said one diaphragm to which said valve body is mounted. 8. The flow control valve according to claim 6, wherein the outer surface of said one diaphragm is protected by corrosion-resistant means such as fluorocarbon polymer. 9. A flow control device comprising: a duct line that supplies a fluid; a flow control valve placed in the middle of said duct line; a flowmeter that measures a flow rate of the fluid passing through said duct line; and a control unit that controls said flow control valve based on a flow measurement value measured by said flowmeter and a flow set value to adjust the flow rate of the fluid flowing through said duct line so as to match said flow set value, wherein said flow control valve comprises: an air chamber having two openings opposite each other; two diaphragms mounted to the openings of said air chamber and having pressurized surfaces with different areas that receive pressure of the air chamber; a connecting shaft that connects said two diaphragms; support means that supports said connecting shaft slidably in an axial direction; an internal channel that is provided outside said air chamber and communicates with said duct line and through which the fluid flowing through said duct line flows; a valve body that slides in conjunction with the sliding operation of said connecting shaft to increase or decrease a flow rate of the fluid flowing through the internal channel; and an air supply passage that supplies air whose pressure or flow rate is controlled into said air chamber, wherein said air supply passage is divided at one end thereof into two branch duct lines, one of the two branch duct lines opens at an outlet thereof so as to face the pressurized surface of one of said diaphragms in close proximity, and the other of the branch duct lines opens at an outlet thereof so as to face the pressurized surface of the other of said diaphragms in close proximity. 10. The flow control device according to claim 9, wherein said flowmeter is an ultrasonic flowmeter and placed downstream of said flow control valve. 11. The flow control device according to claim 9, wherein said connecting shaft and said support means are placed in said air chamber. 12. The flow control device according to claim 9, wherein said valve body is mounted to an outer surface of one of said two diaphragms, and said internal channel is adapted to pass through the outer surface of said one diaphragm to which said valve body is mounted. 13. The flow control device according to claim 12, wherein the outer surface of said one diaphragm is protected by corrosion-resistant means such as fluorocarbon polymer. 14. A flow control device comprising: a duct line that supplies a fluid; a flow control valve placed in the middle of said duct line; a flowmeter that measures a flow rate of the fluid passing through said duct line; and a control unit that controls said flow control valve based on a flow measurement value measured by said flowmeter and a flow set value to adjust the flow rate of the fluid flowing through said duct line so as to match said flow set value, wherein said flow control valve comprises: an air chamber having upper and lower openings; upper and lower diaphragms mounted to the upper and lower openings of said air chamber and having pressurized surfaces with different areas that receive pressure of the air chamber; a connecting shaft that connects said upper and lower diaphragms; support means that supports said connecting shaft slidably in an axial direction; an internal channel that is provided outside said air chamber and communicates with said duct line and through which the fluid flowing through said duct line flows; a valve body that slides in conjunction with the sliding operation of said connecting shaft to increase or decrease a flow rate of the fluid flowing through said internal channel; and an air supply passage that supplies air whose pressure or flow rate is controlled into said air chamber, wherein said air supply passage is divided at one end thereof into two branch duct lines, one of the two branch duct lines opens at an outlet thereof so as to face the pressurized surface of said upper diaphragm in close proximity, and the other of the branch duct lines opens at an outlet thereof so as to face the pressurized surface of said lower diaphragm in close proximity. 15. The flow control device according to claim 14, wherein said flowmeter is an ultrasonic flowmeter and placed downstream of said flow control valve. 16. The flow control device according to claim 14, wherein said connecting shaft and said support means are placed in said air chamber. 17. The flow control device according to claim 14, wherein said valve body is mounted to an outer surface of one of said two diaphragms, and said internal channel is adapted to pass through the outer surface of said one diaphragm to which said valve body is mounted. 18. The flow control device according to claim 17, wherein the outer surface of said one diaphragm is protected by corrosion-resistant means such as fluorocarbon polymer.