Pressure detection device and pressure sensor

Patent metadata

Field	Value
Publication number	US-10422712-B2
Application number	US-201816054204-A
Country	US
Kind code	B2
Filing date	Aug 3, 2018
Priority date	Aug 18, 2017
Publication date	Sep 24, 2019
Grant date	Sep 24, 2019

Abstract

Provided is a pressure detection device, wherein a pressure detection unit includes: a pressure detecting diaphragm; a second connection portion; and four strain resistance portions. One of either a first connection portion or the second connection portion is formed of a magnet, and the other of either the first connection portion or the second connection portion is formed of a magnet or a magnetic body. The first connection portion and the second connection portion are arranged such that the first connection portion and the second connection portion are attracted by a magnetic force in a state where a flow passage unit is mounted on the pressure detection unit. The four strain resistance portions are attached to a region of a second surface of a pressure detecting diaphragm other than a center portion.

First claim

The invention claimed is:

1. A pressure detection device comprising:
a flow passage unit in which a flow passage for introducing a fluid is formed;
a pressure detection unit configured to detect a pressure of the fluid; and
a mounting mechanism by which the flow passage unit is detachably mounted on the pressure detection unit, wherein
the flow passage unit includes:
a pressure receiving diaphragm configured to be displaced upon receiving the pressure of the fluid flowing through the flow passage on a first surface of the pressure receiving diaphragm; and
a first connection portion attached to a second surface of the pressure receiving diaphragm,

the pressure detection unit includes:
a pressure detecting diaphragm having a first surface to which a pressure is to be transmitted from the first connection portion;
a second connection portion attached to a center portion of a second surface of the pressure detecting diaphragm; and
four strain resistance portions attached to the second surface of the pressure detecting diaphragm, the strain resistance portions being connected to each other so as to form a Wheatstone bridge circuit,

one of either the first connection portion or the second connection portion is formed of a magnet, and the other of either the first connection portion or the second connection portion is formed of a magnet or a magnetic body,
the first connection portion and the second connection portion are arranged such that the first connection portion and the second connection portion are attracted by a magnetic force in a state where the flow passage unit is mounted on the pressure detection unit by the mounting mechanism, and
the four strain resistance portions are attached to a region of the second surface of the pressure detecting diaphragm other than the center portion.

2. The pressure detection device according to claim 1 , wherein:
a pair of the strain resistance portions are disposed at positions of two opposite sides of four sides of the Wheatstone bridge circuit, and the pair of the strain resistance portions are disposed in a first region disposed adjacent to the center portion, and
a pair of the strain resistance portions are disposed at positions of the other two opposite sides of the four sides of the Wheatstone bridge circuit, and the pair of the strain resistance portions are disposed in a second region which is further separated from the center portion than the first region.

3. The pressure detection device according to claim 2 , wherein:
a third region is formed on the second surface of the pressure detecting diaphragm, the third region being further separated from the center portion than the first region, and being closer to the center portion than the second region, and
the third region includes a region which has a minimum amount of deformation in a radial direction in a state where a pressure is transmitted from the first connection portion.

4. The pressure detection device according to claim 1 , wherein:
each of the four strain resistance portions includes a plurality of strain resistance elements; and
the plurality of strain resistance elements are disposed at different positions in a circumferential direction about the center portion.

5. The pressure detection device according to claim 2 , wherein:
each of the four strain resistance portions includes a plurality of strain resistance elements; and
the plurality of strain resistance elements are disposed at different positions in a circumferential direction about the center portion.

6. The pressure detection device according to claim 1 , wherein:
the first connection portion is formed of a magnetic body; and
the second connection portion is formed of a magnet.

7. A pressure sensor comprising:
a pressure detecting diaphragm having a first surface to which a pressure is to be transmitted;
a connection portion attached to a center portion of a second surface of the pressure detecting diaphragm, the connection portion being formed of a magnet or a magnetic body; and
four strain resistance portions attached to the second surface of the pressure detecting diaphragm, the strain resistance portions being connected to each other so as to form a Wheatstone bridge circuit, wherein:
the four strain resistance portions are attached to a region of the second surface of the pressure detecting diaphragm other than the center portion.

Assignees

• Surpass Ind Co Ltd

Inventors

• Abo Kazuo
• Kobayashi Masamichi

Classifications

• G01L19/0023

  for flowthrough systems having a flexible pressure transmitting element · CPC title

• G01L9/0044

  Constructional details of non-semiconductive diaphragms · CPC title

• G01L9/0055

  bonded on a diaphragm · CPC title

• G01L19/003 Primary

  using a detachable interface or adapter between the process medium and the pressure gauge · CPC title

• G01L19/0046

  using isolation membranes (G01L13/026 and G01L19/0645 take precedence) · CPC title