# US 8,973,430 B2 · Diesel particulate filter system

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- Number: US 8,973,430 B2
- Document ID: US8973430B2
- Status: Granted
- Kind: B2
- Application number: 13/994,356
- Filed: 2011-12-07
- Published: 2013-10-17
- Granted: 2015-03-10
- Earliest claimed: 2010-12-16
- Assignees: Isuzu Motors Limited
- Applicants: Daiji Nagaoka; Teruo Nakada; Hiroyuki Yuza
- Inventors: Daiji Nagaoka; Teruo Nakada; Hiroyuki Yuza
- Web page: https://patentgrep.com/patent/US8973430B2

## CPC

- F01N 11/002: {the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus}
- B01D 46/448: {by temperature measuring}
- B01D 46/84: by heating only
- F01N 3/0253: {adding fuel to exhaust gases}
- B01D 2279/30: for treatment of exhaust gases from IC Engines
- F01N 2550/05: Systems for adding substances into exhaust
- F01N 2560/06: the means being a temperature sensor
- F01N 2610/03: the substance being hydrocarbons, e.g. engine fuel
- F01N 2900/0418: using integration or an accumulated value within an elapsed period
- F01N 2900/06: Parameters used for exhaust control or diagnosing
- F01N 2900/1404: Exhaust gas temperature
- F01N 2900/1821: Injector parameters
- Y02T 10/40: Engine management systems
- 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)
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A diesel particulate filter (“DPF”) system is provided with temperature sensors at an entrance side and an exit side of a diesel oxidation catalyst, an SV ratio determining device that determines an exhaust gas SV ratio by measuring flow rate of exhaust gas during the DPF forcible regeneration, and an injector diagnosing device including a heat-generation region determining unit to which detection values of the temperature sensors and a determination value of the SV ratio determining device are input to determine whether or not these values are within a theoretical heat-generation region, and an actual injection amount diagnosing unit that diagnoses a decrease amount in an actual injection amount of an exhaust pipe injector, when the detection values of the temperature sensors and the determination value of the SV ratio determining device are within the theoretical heat-generation region.

## Claims

### Claim 1

A diesel particulate filter system for performing a diesel particulate filter forcible regeneration that combusts and removes particulate matter deposited in a diesel particulate filter by injecting fuel from an exhaust pipe injector and oxidizing and combusting the injected fuel with a diesel oxidation catalyst, the diesel particulate filter system comprising:
temperature sensors on an entrance side and an exit side of the diesel oxidation catalyst to detect a diesel oxidation catalyst entrance temperature and a diesel oxidation catalyst exit temperature, respectively, during the diesel particulate filter forcible regeneration;
a space velocity ratio determining device that determines an exhaust gas space velocity ratio by measuring a flow rate of exhaust gas during the diesel particulate filter forcible regeneration; and
an injector diagnosing device including:
a heat-generation region determining unit to which detection values of the temperature sensors and a determination value of the space velocity ratio determining device are input to determine whether or not these values are within a theoretical heat-generation region; and
an actual injection amount diagnosing unit that diagnoses a decrease amount in an actual injection amount of the exhaust pipe injector, when the detection values of the temperature sensors and the determination value of the space velocity ratio determining device are within the theoretical heat-generation region, but not when these values are outside this region.

### Claim 2 (depends on 1)

The diesel particulate filter system according to claim 1, wherein the actual injection amount diagnosing unit performs an integration by calculating an actual heat-generation amount of the diesel oxidation catalyst from a temperature difference between the entrance and the exit of the diesel oxidation catalyst and the flow rate of the exhaust gas, and performs an integration by calculating a theoretical heat-generation amount of the diesel oxidation catalyst from an indication-injection amount of the exhaust pipe injector to diagnose the decrease amount in the actual injection amount of the exhaust pipe injector from integration values of the actual heat-generation amount and the theoretical heat-generation amount.

### Claim 3 (depends on 2)

The diesel particulate filter system according to claim 2, wherein the injector diagnosing device corrects the indication-injection amount of the exhaust pipe injector based on the decrease amount in the diagnosed actual injection amount.

### Claim 4 (depends on 3)

The diesel particulate filter system according to claim 3, wherein the injector diagnosing device sets a correction coefficient for correcting the indication-injection amount of the exhaust pipe injector based on the decrease amount in the diagnosed actual injection amount and detects a failure of the exhaust pipe injector when the correction coefficient exceeds a failure determining threshold value which is previously set.