Pressure sensor including leakage detection part for detecting leakage of liquid

Patent metadata

Field	Value
Publication number	US-9766147-B2
Application number	US-201514641767-A
Country	US
Kind code	B2
Filing date	Mar 9, 2015
Priority date	Mar 14, 2014
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

Provided is a pressure sensor for detecting the pressure of liquid flowing in a main flow path, including: an introduction flow path to which liquid is introduced from the main flow path; a pressure detection element having a pressure receiving surface and for detecting the pressure of liquid received by the pressure receiving surface in the introduction flow path; a diaphragm provided in a downstream-side end part of the introduction flow path and for transferring the pressure of the liquid to the pressure receiving surface while isolating a contact between the liquid in the introduction flow path and the pressure receiving surface; and a leak sensor for detecting a leakage of liquid into an internal space in communication with the pressure receiving surface.

First claim

The invention claimed is:

1. A pressure sensor for detecting pressure of liquid flowing in a main flow path, the pressure sensor comprising:
an introduction flow path into which the liquid is introduced from the main flow path;
a pressure detection part having a pressure receiving surface and for detecting the pressure of liquid received by the pressure receiving surface in the introduction flow path;
a diaphragm provided in a downstream-side end part of the introduction flow path and for transferring the pressure of the liquid to the pressure receiving surface while isolating a contact between the liquid in the introduction flow path and the pressure receiving surface; and
a leakage detection part for detecting a leakage of liquid into a space in communication with the pressure receiving surface, wherein the pressure receiving surface of the pressure detection part is disposed in the space.

2. The pressure sensor according to claim 1 , wherein the introduction flow path and the diaphragm are integrally formed from a single material.

3. The pressure sensor according to claim 1 , further comprising a communication flow path for bringing the space and the outside of the pressure sensor into communication with each other.

4. The pressure sensor according to claim 1 , wherein:
the diaphragm has an annular shape in plan view; and
the pressure sensor further comprises a protruding part, which is connected to an inner peripheral edge part of the diaphragm, and protrudes further toward the pressure receiving surface with respect to a plane where the diaphragm is disposed,
wherein the diaphragm transfers the pressure of liquid to the pressure receiving surface via the protruding part.

5. The pressure sensor according to claim 1 , wherein:
the diaphragm has a circular shape in plan view; and
the diaphragm is deformed depending on the pressure of liquid which is introduced into the introduction flow path, thereby transferring the pressure of the liquid to the pressure receiving surface.

6. The pressure sensor according to claim 1 , wherein the diaphragm has a corrugated shape in sectional view.

7. The pressure sensor according to claim 1 , further comprising:
a housing for accommodating the pressure detection part, wherein the pressure receiving surface has a substantially circular shape in plan view; and
an O-ring for shutting off inflow of liquid from the space to the pressure detection part is provided in a contact part where an outer peripheral edge part of the pressure receiving surface and the housing are in contact with each other.

8. The pressure sensor according to claim 1 , wherein the leakage detection part is a reflection type detector which detects leakage of liquid into the space by detecting reflected light, which comes from the space, of irradiation light radiated toward the space from a light source.

9. The pressure sensor according to claim 1 , wherein:
portions of the housing and the leakage detection part, which are in abutment with the space, are each formed of fluororesin; and
a portion of the pressure receiving surface, which is in abutment with the space, is formed of sapphire.

10. The pressure sensor according to claim 1 , further comprising:
a housing for accommodating the pressure detection part, wherein:
an annular recess is formed on the housing, the annular recess being disposed on an outer peripheral side at downstream-side end part of the introduction flow path; and
the leakage detection part detects leakage of liquid into a bottom part of the annular recess.

Assignees

• Surpass Ind Co Ltd

Inventors

• Hasunuma Masahiro

Classifications

• G01L9/06

  of piezo-resistive devices · CPC title

• G01L19/0092 Primary

  Pressure sensor associated with other sensors, e.g. for measuring acceleration or temperature (G01L9/025, G01L9/045, G01L9/065, G01L9/085, G01L9/105, G01L9/125, G01L19/02, G01L19/04 take precedence; measuring two or more variable G01D21/02; temperature sensors with pressure compensation G01K1/26) · CPC title

• G01M3/38 Primary

  by using light (G01M3/02 takes precedence) · CPC title

• G01L19/0672

  Leakage or rupture protection or detection · CPC title

• G01L27/007

  Malfunction diagnosis, i.e. diagnosing a sensor defect · CPC title