Diagnosis device

Patent metadata

Field	Value
Publication number	US-10060829-B2
Application number	US-201415025082-A
Country	US
Kind code	B2
Filing date	Sep 26, 2014
Priority date	Sep 27, 2013
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

A diagnosis device includes: a diesel particulate filter (DPF) collecting particulate matter (PM) in exhaust gas; a resistive type PM sensor provided downstream of the DPF, detecting an amount of PM from current flowing through PM deposited between electrodes. An actual regeneration interval calculator calculating an actual interval from completion of regeneration of the sensor to a start of the next regeneration; a PM slippage amount calculator estimating an amount of PM slippage in exhaust gas that slips through the DPF, assuming the DPF is normal; an estimated regeneration interval calculator calculating, on the basis of the PM slippage amount, an estimated interval from completion of the regeneration of the sensor to the start of the next regeneration; and a DPF failure-normal determination device determining whether the DPF has failed or is normal by comparing the actual interval to the estimated interval.

First claim

The invention claimed is:

1. A diagnosis device comprising:
a filter that collects a particulate matter in an exhaust gas emitted from an internal combustion engine;
a sensor provided at a downstream side of the filter that detects an amount of the particulate matter based on a current flowing through the particulate matter deposited between electrodes,
wherein regeneration that combusts and eliminates the particulate matter from the sensor is performed when the particulate matter deposited between the electrodes is detected as reaching a predetermined amount; and
an electronic controller configured to
calculate an actual interval from a completion of the regeneration of the sensor to a start of a next regeneration,
estimate an amount of a particulate matter slippage in the exhaust gas that is emitted from the internal combustion engine and that slips through the filter, assuming a collection capability of the filter being normal,
calculate an estimated interval from the completion of the regeneration of the sensor to the start of the next regeneration based on the particulate matter slippage amount, and
determine at least failure of the filter by comparing the actual interval to the estimated interval,
wherein the sensor is forcibly regenerated when the internal combustion engine is started.

2. The diagnosis device according to claim 1 , wherein the electronic controller determines that the filter is normal when the regeneration of the sensor is not started after a predetermined threshold time elapses from the completion of the calculation of the estimated interval.

3. The diagnosis device according to claim 1 , wherein the electronic controller determines that the filter is in failure when the calculation of the estimated interval is not completed after a predetermined threshold time elapses from the completion of the calculation of the actual interval.

4. The diagnosis device according to claim 1 , wherein the electronic controller determines that the filter is in failure when a difference between the actual interval and the estimated interval exceeds a predetermined maximum threshold.

5. The diagnosis device according to claim 1 , wherein the electronic controller determines that the filter is in failure when a ratio of the actual interval to the estimated interval exceeds a prescribed maximum threshold.

6. The diagnosis device according to claim 1 , wherein the electronic controller estimates the particulate matter slippage amount from a model formula having an input value containing an intake and exhaust state quantity that changes depending on an operational status of the internal combustion engine.

Assignees

• Isuzu Motors Ltd

Inventors

• Hanawa Satoshi
• Uchiyama Tadashi
• Fujie Hidekazu
• Nakada Teruo
• Murasawa Naoto

Classifications

• Y02T10/47

  Cross-Sectional Technologies · mapped topic

• F01N2900/0416

  using the state of a sensor, e.g. of an exhaust gas sensor · CPC title

• F01N11/00 Primary

  Monitoring or diagnostic devices for exhaust-gas treatment apparatus · CPC title

• F01N2900/0418

  using integration or an accumulated value within an elapsed period · CPC title

• G01M15/102 Primary

  by monitoring exhaust gases · CPC title