Exhaust emission purifier of internal combustion engine

Patent metadata

Field	Value
Publication number	US-9523300-B2
Application number	US-45134908-A
Country	US
Kind code	B2
Filing date	May 2, 2008
Priority date	May 15, 2007
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

Abstract

An electronic control unit estimates the amount of sulfur accumulated in a filter for purifying PM and NOx based on the operating state of an engine. When an estimated value is equal to or greater than a predetermined determination value, a first regeneration procedure is executed, in which sulfur is released from the filter by raising the temperature of the filter up to a first predetermined temperature and lowering the exhaust air-fuel ratio. When predetermined conditions are met the second regeneration procedure is executed separately from the first regeneration procedure. In the second regeneration procedure, sulfur is completely released from the filter by raising the temperature of the filter up to a temperature higher than the first temperature and lowering the exhaust air-fuel ratio. The estimated value is reset upon completion of the second regeneration procedure.

First claim

The invention claimed is:

1. An exhaust emission purifier of an internal combustion engine, comprising a catalyst that is provided in an exhaust system of the internal combustion engine to purify exhaust gas, and an electronic control unit,
wherein the electronic control unit is configured to estimate an amount of accumulated poisoning material in the catalyst based on an operating state of the engine, and the electronic control unit is configured to execute a first regeneration procedure by raising a temperature of the catalyst up to a first predetermined temperature and lowering an exhaust air-fuel ratio on condition that an estimated value of the amount of accumulated poisoning material is equal to or greater than a predetermined determination value,
the electronic control unit is configured to determine whether a degree of a deviation between the estimated value of the amount of accumulated poisoning material in the catalyst and an actual amount of accumulated poisoning material in the catalyst reaches a predetermined degree, and
when the degree of the deviation reaches the predetermined degree, the electronic control unit is configured to execute a second regeneration procedure separately from the first regeneration procedure by raising the temperature of the catalyst up to a temperature higher than the first predetermined temperature and lowering the exhaust air-fuel ratio, so that the deviation is eliminated upon completion of the second regeneration procedure.

2. The exhaust emission purifier according to claim 1 , wherein the internal combustion engine is mounted in a vehicle, and, when the logical OR of the following conditions (1) to (4) is true, the electronic control unit is configured to determine that the degree of the deviation reaches the predetermined degree and to execute the second regeneration procedure:
(1) the number of execution times of the first regeneration procedure after execution of the second regeneration procedure is equal to or greater than a determination number of times,
(2) the traveled distance of the vehicle after the execution of the second regeneration procedure is equal to or longer than a determination distance,
(3) the engine operation time after the execution of the second regeneration procedure is equal to or longer than determination period, and
(4) the accumulated value of a fuel injection amount after the execution of the second regeneration procedure is equal to or greater than a predetermined amount.

3. The exhaust emission purifier according claim 1 , wherein the internal combustion engine is mounted in a vehicle, and, when the logical AND of the following conditions (1) to (4) is true, the electronic control unit is configured to determine that the degree of the deviation reaches the predetermined degree and to execute the second regeneration procedure,
(1) the number of execution times of the first regeneration procedure after execution of the second regeneration procedure is equal to or greater than a determination number of times,
(2) the traveled distance of the vehicle after the execution of the second regeneration procedure is equal to or longer than a determination distance,
(3) the engine operation time after the execution of the second regeneration procedure is equal to or longer than determination period, and
(4) the accumulated value of a fuel injection amount after the execution of the second regeneration procedure is equal to or greater than a predetermined amount.

4. The exhaust emission purifier according to claim 1 , wherein the poisoning material is sulfur.

5. An exhaust emission purifier of an internal combustion engine, comprising a catalyst that is provided in an exhaust system of the internal combustion engine to purify exhaust gas, and an electronic control unit,
wherein the electronic control unit is configured to estimate an amount of accumulated poisoning material in the catalyst based on an operating state of the engine, and the electronic control unit is configured to execute a first regeneration procedure by raising a temperature of the catalyst for a first predetermined period and lowering an exhaust air-fuel ratio on condition that an estimated value of the amount of accumulated poisoning material is equal to or greater than a predetermined determination value,
the electronic control unit is configured to determine whether a degree of a deviation between the estimated value of the amount of accumulated poisoning material in the catalyst and an actual amount of accumulated poisoning material in the catalyst reaches a predetermined degree, and
when the degree of the deviation reaches the predetermined degree, the electronic control unit is configured to execute a second regeneration procedure separately from the first regeneration procedure by raising the temperature of the catalyst for a period longer than the first predetermined period and lowering the exhaust air-fuel ratio,
so that the deviation is eliminated upon completion of the second regeneration procedure.

6. The exhaust emission purifier according to claim 5 , wherein the internal combustion engine is mounted in a vehicle, and, when the logical OR of the following conditions (1) to (4) is true, the electronic control unit is configured to determine that the degree of the deviation reaches the predetermined degree and to execute the second regeneration procedure:
(1) the number of execution times of the first regeneration procedure after execution of the second regeneration procedure is equal to or greater than a determination number of times,
(2) the traveled distance of the vehicle after the execution of the second regeneration procedure is equal to or longer than a determination distance,
(3) the engine operation time after the execution of the second regeneration procedure is equal to or longer than determination period, and
(4) the accumulated value of a fuel injection amount after the execution of the second regeneration procedure is equal to or greater than a predetermined amount.

7. The exhaust emission purifier according to claim 5 , wherein the internal combustion engine is mounted in a vehicle, and, when the logical AND of the following conditions (1) to (4) is true, the electronic control unit is configured to determine that the degree of the deviation reaches the predetermined degree and to execute the second regeneration procedure,
(1) the number of execution times of the first regeneration procedure after execution of the second regeneration procedure is equal to or greater than a determination number of times,
(2) the traveled distance of the vehicle after the execution of the second regeneration procedure is equal to or longer than a determination distance,
(3) the engine operation time after the execution of the second regeneration procedure is equal to or longer than determination period, and
(4) the accumulated value of a fuel injection amount after the execution of the second regeneration procedure is equal to or greater than a predetermined amount.

8. The exhaust emission purifier according to claim 5 , wherein the poisoning material is sulfur.

9. An exhaust emission purifier of an internal combustion engine, comprising a catalyst that is provided in an exhaust system of the internal combustion engine to purify exhaust gas, and an electronic control unit,
wherein the electronic control unit is configured to estimate an amount of accumulated poisoning material in the catalyst based on an operating state of the engine, and the electronic control unit is configured to execute a first regeneration procedure by raising a temperature of the catalyst up to a first predetermined temperature for a first predetermined period and lowering an exhaust air-fuel ratio on con

Assignees

• Handa Hideyuki
• Toyota Motor Co Ltd

Inventors

• Handa Hideyuki

Classifications

• B01D53/944

  Simultaneously removing carbon monoxide, hydrocarbons or carbon making use of oxidation catalysts (three-way-catalysts [TWC] B01D53/9445) · CPC title

• F01N9/002

  of filter regeneration · CPC title

• F01N3/035 Primary

  with catalytic reactors · CPC title

• Y02T10/47

  Cross-Sectional Technologies · mapped topic

• B01D2257/404

  Nitrogen oxides other than dinitrogen oxide · CPC title