Gas sensor

Patent metadata

Field	Value
Publication number	US-9733207-B2
Application number	US-201314074861-A
Country	US
Kind code	B2
Filing date	Nov 8, 2013
Priority date	May 11, 2012
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A protector includes an inside protector having an inside peripheral wall and a front end wall in a front end side thereof and a tubular outside protector which surrounds the inside protector. In an outside peripheral wall of the outside protector, a plurality of outside introducing ports through which an external part of the outside protector communicates with a gas separating chamber are formed at equal intervals along a circumferential direction. The outside introducing ports are formed at positions nearer to the front end side than positions where inside introducing ports of the inside protector are formed. The outside introducing ports extend in the circumferential direction of the outside peripheral wall and formed in shapes of lateral holes in which opening lengths in the circumferential direction are larger than opening lengths in the direction perpendicular to the circumferential direction.

First claim

What is claimed is:

1. A gas sensor comprising:
a sensing element which extends in an axial direction and has in a front end side a detecting part configured to detect a specific gas component in gas to be detected;
a metal shell which surrounds and holds a periphery of the sensing element in a radial direction under a state that the detecting part is allowed to protrude from a front end part of the metal shell;
an inside protector which includes an inside peripheral wall, a front end wall provided at a front end side of the inside protector, and inside introducing ports formed on the inside peripheral wall to introduce the gas to an inner part of the inside protector and an opening end part provided at a base end side of the inside protector, the opening end part being fixed to the front end part of the metal shell under a state that the detecting part is accommodated in an inner part of the inside protector; and
an outside protector which is configured in a cylindrical form so as to surround at least the inside peripheral wall with a cavity provided between the inside protector and the outside protector and includes an outside peripheral wall and a plurality of outside introducing ports formed on the outside peripheral wall to introduce the gas into the cavity,
wherein the plurality of outside introducing ports are provided at other positions than positions opposed to the inside introducing ports, arranged in a circumferential direction of the outside peripheral wall and are formed in shapes of lateral holes in which opening lengths in the circumferential direction are larger than opening lengths in a direction perpendicular to the circumferential direction.

2. The gas sensor according to claim 1 , wherein when L1 represents a length of an outer periphery of the outside peripheral wall, and L2 represents a total of lengths of the introducing ports in the circumferential direction when the outside peripheral wall is projected on a plane vertical to the axial direction, L2/L1 is 0.3 or more.

3. The gas sensor according to claim 2 , wherein that L2/L1 is 0.52 or more.

4. The gas sensor according to claim 1 , wherein when L3 represents a length of the introducing port in the circumferential direction of the peripheral wall of the outside protector and L4 represents a length of the introducing port in the direction perpendicular to L3, L3/L4 is 3 or more.

5. The gas sensor according to claim 1 , wherein when a circular section of the outside protector viewed at a plane which is perpendicular to the axial direction and passes the outside introducing ports is divided into a plurality of parts by a straight line passing through a center of the circular section, at least one introducing port is present in each of the divided areas.

6. The gas sensor according to claim 5 , wherein the outside introducing ports are provided nearer to the front end side in the axial direction than the inside introducing port located nearest to the base end side in the outside peripheral wall.

7. The gas sensor according to claim 5 , wherein the plurality of outside introducing ports are provided in the axial direction in the outside peripheral wall.

Assignees

• Ngk Spark Plug Co

Inventors

• Fujii Tomoki
• Yoshikawa Takaya

Classifications

• G01N27/4077 Primary

  Means for protecting the electrolyte or the electrodes · CPC title

• G01N27/4075

  Composition or fabrication of the electrodes and coatings thereon, e.g. catalysts · CPC title

• G01N27/4073

  Composition or fabrication of the solid electrolyte · CPC title