# US 8,539,757 B2 · Exhaust purification apparatus for internal combustion engine

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- Number: US 8,539,757 B2
- Document ID: US8539757B2
- Status: Granted
- Kind: B2
- Application number: 12/990,816
- Filed: 2010-01-14
- Published: 2011-10-27
- Granted: 2013-09-24
- Earliest claimed: 2009-01-16
- Assignees: Toyota Jidosha Kabushiki Kaisha
- Applicants: Shinya Hirota; Toru Sasatani; Sakutaro Hoshi; Hiroshi Fujimoto
- Inventors: Shinya Hirota; Toru Sasatani; Sakutaro Hoshi; Hiroshi Fujimoto
- Web page: https://patentgrep.com/patent/US8539757B2

## CPC

- F01N 3/28: Construction of catalytic reactors
- F01N 3/0256: {the fuel being ignited by electrical means}
- F01N 3/2013: {using electric or magnetic heating means}
- F01N 3/2033: {using a fuel burner or introducing fuel into exhaust duct}
- F01N 3/2066: {Selective catalytic reduction [SCR]}
- F01N 11/002: {the diagnostic devices measuring or estimating temperature or pressure in, or downstream of the exhaust apparatus}
- F01N 11/005: {the temperature or pressure being estimated, e.g. by means of a theoretical model}
- F01N 13/009: {having two or more separate purifying devices arranged in series}
- F01N 13/0093: {the purifying devices are of the same type}
- F01N 13/0097: {the purifying devices are arranged in a single housing}
- F01N 13/017: {the purifying devices are arranged in a single housing}
- F01N 3/0253: {adding fuel to exhaust gases}
- F01N 2240/20: a flow director or deflector
- F01N 2340/00: Dimensional characteristics of the exhaust system, e.g. length, diameter or volume of the exhaust apparatus; Spatial arrangements of exhaust apparatuses
- F01N 2340/02: Distance of the exhaust apparatus to the engine or between two exhaust apparatuses
- F01N 2550/02: Catalytic activity of catalytic converters
- F01N 2560/06: the means being a temperature sensor
- F01N 2560/07: the means being an exhaust gas flow rate or velocity meter or sensor, intake flow meters only when exclusively used to determine exhaust gas parameters
- F01N 2610/02: the substance being ammonia or urea
- F01N 2900/0418: using integration or an accumulated value within an elapsed period
- F01N 2900/1404: Exhaust gas temperature
- F01N 2900/1602: Temperature of exhaust gas apparatus
- F01N 2900/1631: Heat amount provided to exhaust apparatus
- Y02T 10/12: Improving ICE efficiencies
- 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)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

An exhaust purification apparatus for an internal combustion engine according to the present invention includes a heated gas generation apparatus configured to generate heated gas utilizing exhaust gas flowing through an exhaust passage. The heated gas generation apparatus includes a catalyst configured to provide an oxidation function, a fuel supply nozzle, and a heater. An exhaust purification unit is provided downstream of the heated gas generation apparatus. An incoming gas temperature of the exhaust purification unit is detected and estimated. An actual incoming gas temperature being a detected value and an estimated incoming gas temperature both acquired when at least the fuel supply nozzle is actuated are compared with each other. Based on the result of the comparison, the apparatus detects one of poisoning of the catalyst with HC and degradation of the catalyst. Thus, the heated gas generation apparatus is prevented from discharging HC.

## Claims

### Claim 1

An exhaust purification apparatus for an internal combustion engine comprising:
a heated gas generation apparatus configured to generate heated gas utilizing part of exhaust gas flowing through an exhaust passage in the internal combustion engine, the heated gas generation apparatus including a catalyst configured to provide an oxidation function, a fuel supply nozzle configured to supply fuel to the catalyst, and a heater;
an exhaust purification unit provided downstream of the heated gas generation apparatus so as to be heated by the heated gas;
an incoming gas temperature sensor configured to detect an actual incoming gas temperature of the exhaust purification unit;
an incoming gas temperature estimation unit configured to estimate the incoming gas temperature of the exhaust purification unit; and
a diagnosis unit configured to acquire the actual incoming gas temperature detected by the incoming gas temperature sensor and the estimated incoming gas temperature estimated by the incoming gas temperature estimation unit, when at least the fuel supply nozzle of the heated gas generation apparatus is actuated, and detecting one of poisoning of the catalyst with HC and degradation of the catalyst in the heated gas generation apparatus based on a result of comparison of the actual incoming gas temperature and the estimated incoming gas temperature acquired,
wherein the diagnosis unit first detects that one of the poisoning of the catalyst with HC and the degradation of the catalyst is occurring and then carries out a predetermined poisoning recovery process for recovering the catalyst from being poisoned with HC, and thereafter determines which of the poisoning with HC and the degradation is occurring, and
wherein the diagnosis unit detects that one of the poisoning of the catalyst with HC and the degradation of the catalyst is occurring if a difference between the actual incoming gas temperature and the estimated incoming gas temperature both acquired at a first timing when at least the fuel supply nozzle of the heated gas generation apparatus is actuated is greater than a predetermined value, and then the diagnosis unit carries out the poisoning recovery process by stopping the fuel supply nozzle while actuating the heater, and thereafter the diagnosis unit actuates at least the fuel supply nozzle again and detects degradation of the catalyst if the difference between the actual incoming gas temperature and the estimated incoming gas temperature both acquired at a second timing when the fuel supply nozzle is actuated is greater than a predetermined value.

### Claim 2 (depends on 1)

The exhaust purification apparatus for the internal combustion engine according to claim 1, wherein the exhaust purification unit comprises a selective reduction NOx catalyst.

### Claim 3 (depends on 1)

The exhaust purification apparatus for the internal combustion engine according to claim 1, wherein the exhaust purification unit comprises an oxidation catalyst or a particulate filter.

### Claim 4 (depends on 1)

The exhaust purification apparatus for the internal combustion engine according to claim 1, wherein the diagnosis unit sets a time for the poisoning recovery process based on the difference between the actual incoming gas temperature and the estimated incoming gas temperature both acquired at the first timing.

### Claim 5 (depends on 1)

The exhaust purification apparatus for the internal combustion engine according to claim 1, wherein the incoming gas temperature estimation unit calculates a heat storage quantity of the catalyst based on an integrated value of a difference between quantities of heat input to and output from the catalyst, and estimates the incoming gas temperature based on the heat storage quantity of the catalyst and flow rates of gas flowing into and out from the catalyst.