Gas sensor with increased sealing performance

• US 20080022754A1
• Filed: 05/29/2007
• Published: 01/31/2008
• Est. Priority Date: 07/31/2006
• Status: Abandoned Application

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Nakagawa, Kazuya
• Application Number:
  US11/802,970
• Publication Number:
  US 20080022754A1
• Time in Patent Office: Days
• US Class Current: 73/31.05
• CPC Class Codes: G01N 27/4077 Means for protecting the electrolyte or the electrodes

Abstract

A gas sensor is disclosed as having a gas sensing element operative to detect a concentration of a specified gas in measuring gases, a cylindrical housing internally supporting the gas sensing element in fixed place, and a cylindrical measuring gas side cover fixedly secured to the housing at a leading end thereof so as to cover a leading end of the gas sensing element. The gas sensor has a response, ranging from 150 ms to 200 ms, which is a parameter representing a speed of detecting the concentration of the specified gas with respect to variation in a specified gas concentration in the measuring gases. The measuring gas side cover has fine holes each with an opening surface area ranging from 0.1 mm² to 1 mm².

Claims

1. A gas sensor comprising:

a gas sensing element operative to detect a concentration of a specified gas in measuring gases;

a cylindrical housing internally supporting the gas sensing element in fixed place; and

a cylindrical measuring gas side cover fixedly secured to the housing at a leading end thereof so as to cover a leading end of the gas sensing element;

wherein the gas sensor has a response, ranging from 150 ms to 200 ms, which is a parameter representing a speed of detecting the concentration of the specified gas with respect to variation in a specified gas concentration in the measuring gases; and

wherein the measuring gas side cover has fine holes each with an opening surface area ranging from 0.1 mm² to 1 mm².

2. The gas sensor according to claim 1, wherein:

the measuring gas side cover is made of a mesh-like member composed of wire components woven with a clearance equal to or less than 1 mm; and

the wire components are made of stainless steel wires each having a diameter equal to or greater than 0.5φ

.

3. The gas sensor according to claim 1, wherein:

the measuring gas side cover has a saclike configuration.

4. The gas sensor according to claim 1, wherein:

the measuring gas side cover has a cone-shaped configuration.

5. The gas sensor according to claim 1, wherein:

the measuring gas side cover has a cylindrical configuration with a leading end being shackled and closed.

6. The gas sensor according to claim 1, wherein:

the measuring gas side cover is formed in a cylindrical shape and includes a cylindrical metallic plate body and a mesh-like cylindrical body, composed of woven wire components, which is connected to one end of the metallic plate body.

8. The gas sensor according to claim 1, wherein:

the measuring gas side cover includes a multi-layer structure formed in a cylindrical shape having two kinds of an inner cover and an outer cover;

wherein the inner cover includes a mesh-like member formed by weaving wire components; and

wherein the outer cover is made of a metallic plate and has a gas ventilation bore.

9. The gas sensor according to claim 1, wherein:

the measuring gas side cover includes a multi-layer structure formed in a cylindrical shape having two kinds of an inner cover and an outer cover;

wherein the inner cover is made of a metallic plate and has a gas ventilation bore; and

wherein the outer cover includes a mesh-like member formed by weaving wire components.

7. The gas sensor according to claim 7, wherein:

the measuring gas side cover is formed in a cylindrical shape and includes an inner cover formed in a cylindrical shape and disposed in an inside area;

wherein the inner cover has a gas ventilation bore providing fluid communication between inside and outside areas; and

wherein the metallic plate, body acts as an outer cover that is radially spaced from the inner cover so as to cover the gas ventilation bore.

10. A gas sensor comprising:

a gas sensing element operative to detect a concentration of a specified gas in measuring gases;

a cylindrical housing internally supporting the gas sensing element in fixed place; and

a cylindrical measuring gas side cover fixedly secured to the housing at a leading end thereof so as to cover a leading end of the gas sensing element;

wherein the gas sensor has a response, ranging from 150 ms to 200 ms, which is a parameter representing a speed of detecting the concentration of the specified gas with respect to variation in a specified gas concentration in the measuring gases; and

wherein the measuring gas side cover has a multi-layer structure at least a part of which includes a mesh-like member formed with fine holes each having an opening surface area ranging from 0.1 mm² to 1 mm².

11. The gas sensor according to claim 10, wherein:

the mesh-like member is composed of wire components woven with a clearance equal to or less than 1 mm; and

the wire components are made of stainless steel wires each having a diameter equal to or greater than 0.5φ

.

12. The gas sensor according to claim 10, wherein:

the multi-layer structure has a saclike configuration. equal to or greater than 0.5φ

.

13. The gas sensor according to claim 10, wherein:

the multi-layer structure has a cone-shaped configuration.

14. The gas sensor according to claim 10, wherein:

the multi-layer structure has a cylindrical configuration with a leading end being shackled and closed.

15. A gas sensor comprising:

a gas sensing element operative to detect a concentration of a specified gas in measuring gases;

a cylindrical housing internally supporting the gas sensing element in fixed place; and

a cylindrical measuring gas side cover fixedly secured to the housing at a leading end thereof so as to cover a leading end of the gas sensing element;

wherein the gas sensor has a response, ranging from 150 ms to 200 ms, which is a parameter representing a speed of detecting the concentration of the specified gas with respect to variation in a specified gas concentration in the measuring gases; and

wherein the measuring gas side cover has a multi-layer structure including an outer cover and an inner cover, the outer cover including a cylindrical metallic plate body and a mesh-like cylindrical body formed with fine holes, each having an opening surface area ranging from 0.1 mm² to 1 mm², which is connected to one end of the metallic plate body.

17. The gas sensor according to claim 16, wherein:

the inner cover has a gas ventilation bore providing fluid communication between inside and outside areas; and

wherein the outer cover is radially spaced from the inner cover so as to cover the gas ventilation bore.

16. The gas sensor according to claim 15, wherein:

the mesh-like cylindrical body is composed of wire components woven with a clearance equal to or less than 1 mm; and

the wire components are made of stainless steel wires each having a diameter

18. A gas sensor comprising:

a gas sensing element operative to detect a concentration of a specified gas in measuring gases;

a cylindrical housing internally supporting the gas sensing element in fixed place; and

a cylindrical measuring gas side cover fixedly secured to the housing at a leading end thereof so as to cover a leading end of the gas sensing element;

wherein the gas sensor has a response, ranging from 150 ms to 200 ms, which is a parameter representing a speed of detecting the concentration of the specified gas with respect to variation in a specified gas concentration in the measuring gases; and

wherein the measuring gas side cover has a multi-layer structure including an outer cover and an inner cover, the outer cover including a cylindrical metallic plate body formed with a gas ventilation bore providing fluid communication between inside and outside areas, and the inner cover including a mesh-like cylindrical body formed with fine holes each having an opening surface area ranging from 0.1 mm² to 1 mm².

19. The gas sensor according to claim 18, wherein:

the mesh-like cylindrical body is composed of wire components woven with a clearance equal to or less than 1 mm; and

the wire components are made of stainless steel wires each having a diameter equal to or greater than 0.5φ

.

20. A gas sensor comprising:

a gas sensing element operative to detect a concentration of a specified gas in measuring gases;

a cylindrical housing internally supporting the gas sensing element in fixed place; and

a cylindrical measuring gas side cover fixedly secured to the housing at a leading end thereof so as to cover a leading end of the gas sensing element;

wherein the gas sensor has a response, ranging from 150 ms to 200 ms, which is a parameter representing a speed of detecting the concentration of the specified gas with respect to variation in a specified gas concentration in the measuring gases; and

wherein the measuring gas side cover has a multi-layer structure including an outer cover and an inner cover, the inner cover including a cylindrical metallic plate body formed with a gas ventilation bore providing fluid communication between inside and outside areas, and the outer cover including a mesh-like cylindrical body formed with fine holes each having an opening surface area ranging from 0.1 mm² to 1 mm².