# US 2009/0260447 A1 · Diaphragm attaching structure of electrostatic capacity type pressure gage

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- Number: US 2009/0260447 A1
- Document ID: US20090260447A1
- Status: Published application
- Kind: A1
- Application number: 11/995,234
- Filed: 2006-08-02
- Published: 2009-10-22
- Earliest claimed: 2005-08-10
- Assignees: HORIBA STEC, Co., Ltd.
- Inventors: Toru Ikeda
- Web page: https://patentgrep.com/patent/US20090260447A1

## CPC

- G01L 9/0072: {using variations in capacitance}
- G01L 9/0048: {Details about the mounting of the diaphragm to its support or about the diaphragm edges, e.g. notches, round shapes for stress relief}
- G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G)

## Abstract

The present invention provides a diaphragm attaching structure of an electrostatic capacity type pressure gauge which can achieve an improvement of a measuring precision by inhibiting a poor weld and a heat strain from being generated while restricting an increase of a cost with an easy manufacturing. The present invention is a diaphragm attaching structure of an electrostatic capacity type pressure gauge in which a diaphragm for receiving a fluid pressure is provided in a tensional manner on one end of a tubular case, and a fixed side electrode for picking up a deflection displacement of the diaphragm as a change of an electric capacity is provided within the tubular case on a side opposite to a pressure receiving surface of the diaphragm, wherein an outer peripheral edge portion of the diaphragm is formed thicker than a center portion thereof, and the thick outer peripheral edge portion is thermally molten to be welded and firmly attached to an end surface portion around the opening on the one end of the tubular case.

## Claims

### Claim 1

A diaphragm attaching structure of an electrostatic capacity type pressure gauge, in which a diaphragm for receiving a fluid pressure is provided in a tensional manner on one end of a tubular case, and a fixed side electrode for picking up a deflection displacement of the diaphragm as a change of an electric capacity is provided within the tubular case on a side opposite to a pressure receiving surface of the diaphragm, wherein an outer peripheral edge portion of the diaphragm is formed thicker than a center portion thereof, and the thick outer peripheral edge portion is thermally molten to be welded and firmly attached to an end surface portion around the opening on the one end of the tubular case.

### Claim 2 (depends on 1)

The diaphragm attaching structure of an electrostatic capacity type pressure gauge according to claim 1, wherein the thick outer peripheral edge portion of the diaphragm is formed in a symmetrical shape back to front while setting a center of thickness of the diaphragm to a center of symmetry.

### Claim 3 (depends on 1)

The diaphragm attaching structure of an electrostatic capacity type pressure gauge according to claim 1, wherein the outer peripheral edge portion of the diaphragm is formed with a thickness having a volume which is equal to or approximately equal to a volume of the portion on the one end side rather than a recess provided in an outer peripheral surface portion around the opening on the one end of the tubular case to be welded.

### Claim 4 (depends on 2)

The diaphragm attaching structure of an electrostatic capacity type pressure gauge according to claim 2, wherein the outer peripheral edge portion of the diaphragm is formed with a thickness having a volume which is equal to or approximately equal to a volume of the portion on the one end side rather than a recess provided in an outer peripheral surface portion around the opening on the one end of the tubular case to be welded.