FLUID CONTROL SYSTEM AND FLUID CONTROL METHOD

• US 20130255793A1
• Filed: 02/04/2013
• Published: 10/03/2013
• Est. Priority Date: 03/29/2012
• Status: Active Grant

• Current Assignee: CKD Corporation
• Original Assignee: CKD Corporation
• Inventors: WATANABE, Masayuki, YAMADA, Yoshiyuki, UMEZAWA, Shunsuke
• Granted Patent: US 8,794,261 B2
• Time in Patent Office: Days
• US Class Current: 137/14
• CPC Class Codes: F17D 3/00 Arrangements for supervising or controlling working operations
• CPC Class Codes: G05D 7/0647 the plurality of throttling means being arranged in series
• CPC Class Codes: Y10T 137/0396 Involving pressure control
• CPC Class Codes: Y10T 137/7759 Responsive to change in rate of fluid flow
• CPC Class Codes: Y10T 137/7761 Electrically actuated valve
• CPC Class Codes: Y10T 137/86485 Line condition change responsive release of valve

Abstract

A fluid control system includes a vacuum chamber, a gas supply source to supply gas as a fluid, an exhaust pipe to discharge the fluid from the vacuum chamber, a gas supply pipe to connect the vacuum chamber to the gas supply source, and a pressure sensor to detect an internal pressure of the vacuum chamber. This system further includes a flowmeter placed between the gas supply source and the vacuum chamber, a proportional valve placed between the flowmeter and the vacuum chamber, a pressure controller to control the proportional valve based on output of the pressure sensor, a metering valve placed on the exhaust pipe, and a flow controller to control the metering valve based on an output of the flowmeter.

Claims

1. A fluid control system comprising:

a gas supply source to supply gas which is a fluid to the vacuum chamber;

an exhaust pipe to discharge the fluid from the vacuum chamber;

a gas supply pipe to connect the vacuum chamber and the gas supply source;

a pressure sensor to detect an internal pressure of the vacuum chamber;

a flowmeter placed on the gas supply pipe between the gas supply source and the vacuum chamber;

a proportional valve placed on the gas supply pipe between the flowmeter and the vacuum chamber;

a pressure controller to control the proportional valve in response to an output of the pressure sensor;

a metering valve placed on the exhaust pipe; and

a flow controller to control the metering valve in response to an output of the flowmeter.

2. The fluid control system according to claim 1, wherein

a flow-rate set value is set in the flow controller,

the flow controller controls the metering valve so that a flow rate of gas flowing in the gas supply pipe coincides with the flow-rate set value,

a pressure set value is set in the pressure controller, and

the pressure controller controls the proportional valve so that the internal pressure of the vacuum chamber coincides with the pressure set value.

3. The fluid control system according to claim 1, wherein the system includes:

a first mode in which the flow controller controls the metering valve and the pressure controller controls the proportional valve, and

a second mode in which the flow controller controls the proportional valve and the pressure controller controls the metering valve,

the first mode and the second mode being selectable.

4. The fluid control system according to claim 2, wherein the system includes:

a first mode in which the flow controller controls the metering valve and the pressure controller controls the proportional valve, and

a second mode in which the flow controller controls the proportional valve and the pressure controller controls the metering valve,

the first mode and the second mode being selectable.

5. The fluid control system according to claim 1, wherein a plurality of sets of gas supply units are provided, each set including the gas supply source, the flowmeter, and the proportional valve, the flowmeter and the proportional valve being placed on the gas supply pipe corresponding to the gas supply source,

the sets of gas supply units are arranged in parallel with respect to the vacuum chamber.

6. The fluid control system according to claim 2, wherein a plurality of sets of gas supply units are provided, each set including the gas supply source, the flowmeter, and the proportional valve, the flowmeter and the proportional valve being placed on the gas supply pipe corresponding to the gas supply source,

the sets of gas supply units are arranged in parallel with respect to the vacuum chamber.

7. The fluid control system according to claim 2, wherein control of the metering valve and control of the proportional valve are sequentially performed.

8. The fluid control system according to claim 2, wherein the pressure set value is determined based on a pressure curve or a pressure linear pattern.

9. A fluid control method of controlling a fluid control system comprising:

a gas supply source to supply gas which is a fluid to the vacuum chamber;

an exhaust pipe to discharge the fluid from the vacuum chamber;

a gas supply pipe to connect the vacuum chamber and the gas supply source;

a pressure sensor to detect an internal pressure of the vacuum chamber;

a flowmeter placed between the gas supply source and the vacuum chamber;

a proportional valve placed between the flowmeter and the vacuum chamber;

a pressure controller to control the proportional valve in response to an output of the pressure sensor;

a metering valve placed on the exhaust pipe; and

a flow controller to control the metering valve in response to an output of the flowmeter,

wherein the metering valve is controlled to regulate a flow rate of the gas to a flow-rate set value.