GAS SENSOR FITTING STRUCTURE

• US 20100064663A1
• Filed: 09/25/2008
• Published: 03/18/2010
• Est. Priority Date: 09/27/2007
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Goya, Yoichiro
• Granted Patent: US 8,210,061 B2
• Time in Patent Office: Days
• US Class Current: 60/276
• CPC Class Codes: F01N 11/00 Monitoring or diagnostic devices for exhaust-gas treatment apparatus , e.g. for catalytic activity safety, indicating or supervising devices for internal combustion engines F02B77/08; testing of machines G01M13/00
• CPC Class Codes: F01N 13/008 Mounting or arrangement of exhaust sensors in or on exhaust apparatus sensor arrangements for engine control F02D41/1439
• CPC Class Codes: F01N 2560/00 Exhaust systems with means for detecting or measuring exhaust gas components or characteristics
• CPC Class Codes: G01N 33/006 avoiding interference of water vapour with the gas to be measured
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A gas sensor is fitted to an exhaust pipe such that an end face in which a vent-hole is formed is not visible from any position of inlet portions of the exhaust pipe. Thus, it is possible to suppress entry of condensed water through the vent hole formed in the end face of the gas sensor. As a result, it is possible to minimize occurrence of a crack in the gas sensor.

Claims

1. A gas sensor fitting structure for fitting a gas sensor to an exhaust pipe of an internal combustion engine, comprising:

a gas sensor including a sensor element and a cover which covers the sensor element, and has a vent-hole at an end portion of the cover, wherein;

the exhaust pipe has multiple inlet portions; and

the gas sensor is fitted to the exhaust pipe at a predetermined fitting angle so that the end portion is not visible from any position of the multiple inlet portions.

3. The gas sensor fitting structure according to claim 1, wherein;

the exhaust pipe has a bent portion; and

the gas sensor is fitted to the exhaust pipe at the predetermined fitting angle so that the end portion is not visible via the bent portion from any position of the inlet portions of the exhaust pipe.

4. The gas sensor fitting structure according to claim 1, wherein the gas sensor is fitted to the exhaust pipe at the predetermined fitting angle so that the end portion is not visible from any position on a virtual plane that is surrounded by the inlet portion.

5. The gas sensor fitting structure according to claim 4, wherein the virtual plane includes an end face of the inlet portion of the exhaust pipe.

6. The gas sensor fitting structure according to claim 1, wherein the predetermined fitting angle θ

satisfies the following formula;

θ

0≦

90°

−

arctan{(h−

t)/1} where h is a diameter of the exhaust pipe, t is a distance from an inner wall face of the exhaust pipe to the end portion, and 1 is a distance from the inlet portion of the exhaust pipe to the gas sensor.

7. The gas sensor fitting structure according to claim 6, wherein:

the distance from the inlet portion of the exhaust pipe to the gas sensor is a length of a line segment in parallel with an axis of the exhaust pipe while extending from the inlet portion of the exhaust pipe to the end portion; and

the predetermined fitting angle of the gas sensor with respect to the exhaust pipe is an angle between the axis of the exhaust pipe and an axis of the gas sensor.

8. The gas sensor fitting structure according to claim 6, wherein:

the inlet portion of the exhaust pipe is connected to an exhaust port of the internal combustion engine; and

the predetermined fitting angle of the gas sensor with respect to the exhaust pipe is decreased as the distance between the inlet portion and the gas sensor decreases.

9. The gas sensor fitting structure according to claim 1, wherein the gas sensor is an air-fuel ratio sensor that linearly detects an air-fuel ratio based on an oxygen concentration in exhaust gas that is discharged from the internal combustion engine.

2. A gas sensor fitting structure for fitting a gas sensor to an exhaust pipe of an internal combustion engine, comprising:

a gas sensor including a sensor element and a cover which covers the sensor element, and has a vent-hole at an end portion of the cover, wherein;

the exhaust pipe has a bent portion; and

the gas sensor is fitted to the exhaust pipe at a predetermined fitting angle so that the end portion is not visible via the bent portion from any position of an inlet portion of the exhaust pipe.

10. The gas sensor fitting structure according to claim 2, wherein the gas sensor is fitted to the exhaust pipe at the predetermined fitting angle so that the end portion is not visible from any position on a virtual plane that is surrounded by the inlet portion.

11. The gas sensor fitting structure according to claim 10, wherein the

virtual plane includes an end face of the inlet portion of the exhaust pipe.

12. The gas sensor fitting structure according to claim 2, wherein the predetermined fitting angle 0 satisfies the following formula;

θ

≦

90°

−

arctan{(h−

t)/1} where h is a diameter of the exhaust pipe, t is a distance from an inner wall face of the exhaust pipe to the end portion, and 1 is a distance from the inlet portion of the exhaust pipe to the gas sensor.

13. The gas sensor fitting structure according to claim 12, wherein:

the distance from the inlet portion of the exhaust pipe to the gas sensor is a length of a line segment in parallel with an axis of the exhaust pipe while extending from the inlet portion of the exhaust pipe to the end portion; and

the predetermined fitting angle of the gas sensor with respect to the exhaust pipe is an angle between the axis of the exhaust pipe and an axis of the gas sensor.

14. The gas sensor fitting structure according to claim 12, wherein:

the inlet portion of the exhaust pipe is connected to an exhaust port of the internal combustion engine; and

the predetermined fitting angle of the gas sensor with respect to the exhaust pipe is decreased as the distance between the inlet portion and the gas sensor decreases.

15. The gas sensor fitting structure according to claim 2, wherein the gas sensor is an air-fuel ratio sensor that linearly detects an air-fuel ratio based on an oxygen concentration in exhaust gas that is discharged from the internal combustion engine.