Pressure control device

Patent metadata

Field	Value
Publication number	US-10520958-B2
Application number	US-201715686981-A
Country	US
Kind code	B2
Filing date	Aug 25, 2017
Priority date	Feb 26, 2015
Publication date	Dec 31, 2019
Grant date	Dec 31, 2019

Abstract

A pressure control device maintains a pressure within a target of pressure control at a set pressure. The pressure control device includes a correction circuit that corrects a pressure signal, which represents the pressure within the target of pressure control that is detected by a pressure sensor, such that the pressure signal approaches a set pressure signal representing the set pressure; a comparison circuit that compares the corrected pressure signal with the set pressure signal; and a valve drive circuit that controls an opening and closing of a flow control valve based on a comparison result from the comparison circuit. The correction circuit is a filter circuit. The frequency characteristic of the filter circuit has a peak at a prescribed frequency, and corrects the pressure signal so as to raise a component of the prescribed frequency of the pressure signal.

First claim

What is claimed is:

1. A pressure control device which maintains a pressure within a target of pressure control at a set pressure, the pressure control device comprising:
a correction circuit that corrects a pressure signal, which represents the pressure within the target of pressure control that is detected by a pressure sensor, such that the pressure signal approaches a set pressure signal representing the set pressure;
a comparison circuit that compares the corrected pressure signal with the set pressure signal; and
a valve drive circuit that controls an opening and closing of a flow control valve based on a comparison result from the comparison circuit,
wherein the correction circuit is a filter circuit, the frequency characteristic of the filter circuit having a peak at a prescribed frequency, and correcting the pressure signal so as to raise a component of the prescribed frequency of the pressure signal,
wherein the prescribed frequency is determined based on a relationship between the flow rate of a gas flowing through a pipe and a volume of the target of the pressure control and/or based on a length of the pipe between the target of the pressure control and the pressure control device.

2. The pressure control device according to claim 1 , wherein when the pressure signal has a value greater than that of the set pressure signal and changes in a decreasing manner, the correction circuit corrects the pressure signal in such a manner that the value thereof becomes small.

3. The pressure control device according to claim 1 , wherein when the pressure signal has a value smaller than that of the set pressure signal and changes in an increasing manner, the correction circuit corrects the pressure signal in such a manner that the value thereof becomes large.

Assignees

• Fujikin Kk

Inventors

• Nozawa Takahiro
• Nakamura Takeshi

Classifications

• G05B11/011

  details of the correcting means · CPC title

• G05D16/20 Primary

  characterised by the use of electric means · CPC title

• G05B11/36 Primary

  with provision for obtaining particular characteristics, e.g. proportional, integral, differential · CPC title

• G05D16/2013 Primary

  using throttling means as controlling means · CPC title

• G05B1/03

  for comparing digital signals · CPC title