Gas detector

Patent metadata

Field	Value
Publication number	US-9709517-B2
Application number	US-201514608605-A
Country	US
Kind code	B2
Filing date	Jan 29, 2015
Priority date	Feb 7, 2014
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

A gas detector includes a detecting element, a circuit board, a housing case having a gas introduction hole, and a metal member which covers the gas introduction hole. The detecting element is disposed under the metal member. The gas detector further includes a detecting element wiring fusing prevention member which is electrically conductive and is electrically connected to a grounding line of the circuit board. The detecting element wiring fusing prevention member is disposed at a position such that the shortest distance between the metal member and the detecting element wiring fusing prevention member is smaller than that between the metal member and the detecting element.

First claim

The invention claimed is:

1. A gas detector comprising: a detecting element that detects flammable gas; a circuit board electrically connected to the detecting element; a housing case having a gas introduction hole, and housing the detecting element and the circuit board; and a metal member disposed in the gas introduction hole and having a plurality of gas flow passages; and a detecting element wiring fusing prevention member, has gas passages there through, and is electrically conductive and electrically connected to a grounding line of the circuit board, wherein the detecting element is disposed under the metal member, and the detecting element wiring fusing prevention member is disposed at a position such that shortest distance between the metal member and the detecting element wiring fusing prevention member is smaller than a shortest distance between the metal member and the detecting element.

2. The gas detector according to claim 1 , wherein the gas passage of the detecting element wiring fusing prevention member allows for the flammable gas to pass and is disposed in such a manner as to cover the detecting element.

3. The gas detector according to claim 1 , wherein
the detecting element is disposed on a base fixed on the circuit board, and
the detecting element wiring fusing prevention member is fixed to the base.

4. The gas detector according to claim 3 , wherein
the base is electrically insulative and has a grounding electrode pad formed thereon and electrically connected to the grounding line of the circuit board, and
the detecting element wiring fusing prevention member is electrically connected to the grounding electrode pad.

5. The gas detector according to claim 1 , wherein
the metal member assumes a form of a plate and is externally exposed, and
the detecting element is disposed under a main surface of the metal member in the form of a plate.

6. The gas detector according to claim 2 , wherein
the detecting element is disposed on a base fixed on the circuit board, and
the detecting element wiring fusing prevention member is fixed to the base.

7. The gas detector according to claim 2 , wherein
the metal member assumes a form of a plate and is externally exposed, and
the detecting element is disposed under a main surface of the metal member in the form of a plate.

8. The gas detector according to claim 3 , wherein
the metal member assumes a form of a plate and is externally exposed, and
the detecting element is disposed under a main surface of the metal member in the form of a plate.

9. The gas detector according to claim 4 , wherein
the metal member assumes a form of a plate and is externally exposed, and
the detecting element is disposed under a main surface of the metal member in the form of a plate.

10. The gas detector according to claim 6 , wherein
the metal member assumes a form of a plate and is externally exposed, and
the detecting element is disposed under a main surface of the metal member in the form of a plate.

11. The gas detector according to claim 1 , wherein
the detecting element has a heat-generating resistor and a thin film section deposited on a top surface thereof, and
the heat-generating resistor is deposited in the thin film section and is thermally insulated from a surrounding environment.

12. The gas detector according to claim 11 , wherein the gas passage of the detecting element wiring fusing prevention member allows for the flammable gas to pass, and no thin film section is deposited directly below the gas passage of the detecting element wiring fusing prevention member.

Assignees

• Ngk Spark Plug Co

Inventors

• Watanabe Masaya
• Kitanoya Shoji
• Ichikawa Daisuke
• Yamashita Masahiro
• Matsukura Yusuke
• Hisada Kaoru

Classifications

• G01N33/0027

  concerning the detector · CPC title

• G01N33/0016

  by regulating a physical variable, e.g. pressure or temperature · CPC title

• G01N27/406

  Cells and probes with solid electrolytes · CPC title

• G01N27/18 Primary

  caused by changes in the thermal conductivity of a surrounding material to be tested (G01N27/20 takes precedence) · CPC title

• G01N27/403

  Cells and electrode assemblies · CPC title