Valve control device

Patent metadata

Field	Value
Publication number	US-10599166-B2
Application number	US-201815863883-A
Country	US
Kind code	B2
Filing date	Jan 6, 2018
Priority date	Jan 12, 2017
Publication date	Mar 24, 2020
Grant date	Mar 24, 2020

Abstract

A valve control device configured such that a pressure measurement value of a chamber, a target pressure value of the chamber, and an opening degree measurement value of the vacuum valve are input to the valve control device and configured to control an opening degree of the vacuum valve based on a deviation between the pressure measurement value and the target pressure value, comprises: a storage storing a correlation between the opening degree of the vacuum valve and a conductance of a system including the vacuum valve; and a correction gain setting section obtaining, based on the correlation, a change rate of the conductance in association with an opening degree change at the input opening degree measurement value, thereby setting an inverse of the change rate as a correction gain. The opening degree of the vacuum valve is controlled based on the deviation and the correction gain.

First claim

What is claimed is:

1. A valve control device configured such that a pressure measurement value of a chamber connected to a vacuum valve, a target pressure value of the chamber, and an opening degree measurement value of the vacuum valve are input to the valve control device and configured to control an opening degree of the vacuum valve based on a deviation between the pressure measurement value and the target pressure value, comprising:
a storage configured to store a correlation between the opening degree of the vacuum valve and a conductance of a system including the vacuum valve; and
a correction gain setting section configured to obtain, based on the correlation, a change rate of the conductance in association with an opening degree change at the opening degree measurement value, thereby setting an inverse of the change rate as a correction gain,
wherein the opening degree of the vacuum valve is controlled based on the deviation and the correction gain.

2. The valve control device according to claim 1 , wherein
the conductance is a conductance of a system including the vacuum valve, the chamber attached to the vacuum valve, and a vacuum pump attached to the vacuum valve.

3. The valve control device according to claim 1 , wherein
the storage stores multiple correlations for different gas flow rates, and
the correction gain setting section selects, based on a gas flow rate of the system, one correlation from the multiple correlations stored in the storage, thereby setting the correction gain based on the selected correlation.

4. A valve control device configured such that a pressure measurement value of a chamber connected to a vacuum valve, a target pressure value of the chamber, and an opening degree measurement value of the vacuum valve are input to the valve control device and configured to control an opening degree of the vacuum valve based on a deviation between the pressure measurement value and the target pressure value, comprising:
a storage configured to store a correlation between the opening degree of the vacuum valve and a conductance of a system including the vacuum valve; and
a correction gain setting section configured to obtain, based on the correlation, a change rate of the conductance in association with an opening degree change at the opening degree measurement value, thereby setting, as a correction gain, a product of an inverse of the change rate, an inverse of the pressure measurement value, and the conductance at the opening degree measurement value,
wherein the opening degree of the vacuum valve is controlled based on the deviation and the correction gain.

5. The valve control device according to claim 4 , wherein
the correction gain setting section
sets the correction gain within a predetermined opening degree range,
replaces a product of the inverse of the change rate in the correction gain and the conductance with a first constant at an opening degree exceeding an upper limit of the opening degree range, and
replaces the product of the inverse of the change rate in the correction gain and the conductance with a second constant at an opening degree falling below a lower limit of the opening degree range.

6. The valve control device according to claim 4 , wherein
the conductance is a conductance of a system including the vacuum valve, the chamber attached to the vacuum valve, and a vacuum pump attached to the vacuum valve.

7. The valve control device according to claim 4 , wherein
the storage stores multiple correlations for different gas flow rates, and
the correction gain setting section selects, based on a gas flow rate of the system, one correlation from the multiple correlations stored in the storage, thereby setting the correction gain based on the selected correlation.

Assignees

• Shimadzu Corp

Inventors

• Hirata Nobuyuki
• Kozaki Junichiro
• Nakatani Atsuo
• Nakamura Masaya

Classifications

• F16K3/0227

  Packings · CPC title

• F16K51/02

  specially adapted for high-vacuum installations · CPC title

• F16K3/04

  with pivoted closure members · CPC title

• F16K3/10

  with special arrangements for separating the sealing faces or for pressing them together · CPC title

• G05D16/202 Primary

  actuated by an electric motor · CPC title