Pressure sensor
AssigneeNagano Keiki Co., Ltd.
InventorsKouzou Yamagishi, Toshiaki Okumura, Kunihiro Yamaura, Takayuki Yokoyama, Kenji Kobayashi
Life of this patent
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Abstract
A pipe having a through-hole of smaller diameter than a pressure port is disposed in the pressure port. Therefore, a volume of the pressure port can be reduced by the thickness of the pipe, thereby improving response of a pressure sensor. Furthermore, there is no need for the pressure port having smaller diameter to be provided by drill processing, so that a volume in the pressure port can be easily adjusted. Accordingly, the volume in the pressure port can be reduced with a simple structure to improve response of the pressure sensor.
Claims20
A pressure sensor for detecting a fluid pressure, comprising:
- a fitting provided with a pressure port for introducing the fluid pressure;
- a pressure detecting module attached to the fitting and shutting an end of the pressure port;
- and
- a volume adjusting member having a penetrating channel of a smaller cross section than the pressure port and disposed inside the pressure port of the fitting, the volume adjusting member positioned to protrude into openings of both the fitting and the pressure detecting module,
- wherein the pressure detecting module is abutted and welded to the fitting, and wherein the position of the volume adjusting member corresponds to a welded part of the fitting and the pressure detecting module.
A pressure sensor for detecting a fluid pressure, comprising:
- a fitting including a pressure port located at a central axis thereof for introducing the fluid pressure, the pressure port having a first fluid pressure intake end, a central portion and a second end, the second end including a fitted portion having a diameter greater than the diameter at the central portion of the pressure port;
- a pressure detecting module having a mounting end secured to the fitting and shutting the second end of the pressure port, the pressure detecting module including a diaphragm and a strain gauge at a sensing end for sensing the fluid pressure;
- and
- a volume adjusting member disposed in the fitted portion at the second end of the pressure port of the fitting and having a through hole of a smaller cross section than a cross section of the pressure port at the first intake end of the fitting.
A method of making a fluid pressure sensor, the fluid pressure sensor comprising (1) a metal fitting including a pressure port located at a central axis thereof for introducing the fluid pressure, the pressure port having a first fluid pressure intake end, a central portion and a second end, the second end including a fitted portion having a diameter greater than the diameter at the central portion of the pressure port;
- (2) a pressure detecting module including a first end and a cavity extending from the first end toward a second sensing end, the first end of the pressure detecting module being mounted to the second end of the fitting, the pressure detecting module comprising a diaphragm and a strain gauge on the sensing end for sensing the fluid pressure;
- and (3) a volume adjusting member including a through hole of a smaller cross section than the cross section at the first intake end of the pressure port, the method comprising the steps of:
- disposing the volume adjusting member in the fitted portion of the fitting and in the cavity of the pressure detecting module;
- and
- securing a module surface at the first end of the pressure detecting module to a fitting surface at the second end of the fitting to close the second end of the pressure port, thereby enclosing the volume adjusting member.
Dependencies are inferred from the claim text.