# US 8,751,185 B2 · Detection device for internal combustion engine

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- Number: US 8,751,185 B2
- Document ID: US8751185B2
- Status: Granted
- Kind: B2
- Application number: 13/201,795
- Filed: 2009-02-18
- Published: 2011-12-08
- Granted: 2014-06-10
- Earliest claimed: 2009-02-18
- Assignees: Toyota Jidosha Kabushiki Kaisha
- Applicants: Naofumi Magarida
- Inventors: Naofumi Magarida
- Web page: https://patentgrep.com/patent/US8751185B2

## CPC

- F02D 41/1495: {Detection of abnormalities in the air/fuel ratio feedback system}
- F01N 11/002: {the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus}
- F01N 11/007: {the diagnostic devices measuring oxygen or air concentration downstream of the exhaust apparatus}
- F02D 41/1494: {Control of sensor heater}
- F01N 2550/12: of particulate filters
- F02D 41/042: {for stopping the engine}
- F02D 41/1446: {the characteristics being exhaust temperatures}
- F02D 41/1454: {the characteristics being an oxygen content or concentration or the air-fuel ratio}
- Y02T 10/40: Engine management systems
- F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W)
- F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A detection device for an internal combustion engine is preferably applied to the internal combustion engine which includes a temperature varying member, which is provided in an exhaust system, and whose temperature varies due to gas flow in the exhaust system. A temperature correlation value detection unit detects a correlation value which correlates with the temperature of the temperature varying member. The term correlation value herein includes impedance of the temperature varying member, a signal output value such as current and voltage output sent from the temperature varying member, and/or the temperature varying member's own temperature. A variation calculating unit calculates a variation of the correlation value, in a time period when the gas flow arises, detected by the temperature correlation value detection unit.

## Claims

### Claim 1

A detection device for an internal combustion engine which is applied to the internal combustion engine including a sensor equipped with a cover for covering a temperature varying member, which is provided in an exhaust system, and whose temperature varies due to gas flow in the exhaust system, comprising:
a temperature correlation value detection unit which detects a correlation value which correlates with the temperature of the temperature varying member; and
a variation calculating unit which calculates a variation of the correlation value, in a time period when the gas flow arises, detected by the temperature correlation value detection unit,
wherein an exhaust temperature sensor which detects temperature of the gas is provided on a streamline which is approximately same as the streamline where the temperature varying member is provided in the exhaust system, and
wherein the variation calculating unit calculates a rate of the variation of the correlation value to a variation of an exhaust temperature detected by the exhaust temperature sensor and detects clogging or cracking in the cover based on the rate of the variation.

### Claim 2 (depends on 1)

The detection device for an internal combustion engine according to claim 1,
wherein the temperature varying member is an electric heater of a gas sensor, and
wherein the temperature correlation value detection unit detects impedance of the electric heater as the correlation value.

### Claim 3 (depends on 1)

The detection device for an internal combustion engine according to claim 1,
wherein the temperature varying member is a temperature sensor, and
wherein the temperature correlation value detection unit detects a signal output value supplied from the temperature sensor as the correlation value.

### Claim 4 (depends on 1)

The detection device for an internal combustion engine according to claim 1,
wherein a filter member is provided in the exhaust system, and
wherein the temperature varying member is provided at the downstream side of the filter member.

### Claim 5 (depends on 1)

The detection device for an internal combustion engine according to claim 1,
wherein a threshold of the variation is set according to an amount of inhibitors which adhere to the temperature varying member, and
further comprising a determining unit which determines whether or not the variation calculated by the variation calculating unit is smaller than the threshold.