[미국특허]
Exhaust purification system of internal combustion engine
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
F01N-003/00
F01N-003/08
F01N-009/00
F02D-041/02
F01N-013/00
F02D-041/14
출원번호
US-0264230
(2011-02-10)
등록번호
US-9140162
(2015-09-22)
국제출원번호
PCT/JP2011/053429
(2011-02-10)
§371/§102 date
20111013
(20111013)
국제공개번호
WO2012/108063
(2012-08-16)
발명자
/ 주소
Bisaiji, Yuki
출원인 / 주소
Toyota Jidosha Kabushiki Kaisha
대리인 / 주소
Oliff PLC
인용정보
피인용 횟수 :
0인용 특허 :
42
초록▼
In an internal combustion engine, inside of an engine exhaust passage, a hydrocarbon feed valve (17), exhaust purification catalyst (13), and intermediate NOx adsorption catalyst (15) are arranged. The intermediate NOx adsorption catalyst (15) adsorbs nitrogen-containing intermediate and NOx which a
In an internal combustion engine, inside of an engine exhaust passage, a hydrocarbon feed valve (17), exhaust purification catalyst (13), and intermediate NOx adsorption catalyst (15) are arranged. The intermediate NOx adsorption catalyst (15) adsorbs nitrogen-containing intermediate and NOx which are exhausted from the exhaust purification catalyst (13). To make the nitrogen-containing intermediate or NOx which is adsorbed at the intermediate NOx adsorption catalyst (15) desorb from it, the concentration of hydrocarbons flowing into the exhaust purification catalyst (13) is made to vibrate within a predetermined range of amplitude of 200 ppm or more and within a predetermined range of period of 5 seconds or less, whereby NOx which is contained in exhaust gas is removed at the exhaust purification catalyst (13) while the heat of oxidation reaction of the hydrocarbons is used to make the intermediate NOx adsorption catalyst (15) rise in temperature.
대표청구항▼
1. An exhaust purification system of an internal combustion engine, the exhaust purification system comprising: an engine exhaust passage;an exhaust purification catalyst for reacting NOx contained in exhaust gas and reformed hydrocarbons arranged inside of the engine exhaust passage;a precious meta
1. An exhaust purification system of an internal combustion engine, the exhaust purification system comprising: an engine exhaust passage;an exhaust purification catalyst for reacting NOx contained in exhaust gas and reformed hydrocarbons arranged inside of the engine exhaust passage;a precious metal catalyst carried on an exhaust gas flow surface of the exhaust purification catalyst;a basic exhaust gas flow surface part formed around the precious metal catalyst;an intermediate NOx adsorption catalyst for adsorbing a nitrogen-containing intermediate or NOx that is produced in a NOx reduction process and exhausted from the exhaust purification catalyst arranged inside of the engine exhaust passage downstream of the exhaust purification catalyst; andan electronic control unit, wherein the electronic control unit is configured to control a vibration of a concentration of hydrocarbons flowing into the exhaust purification catalyst within a predetermined range of amplitude and within a predetermined range of period, and is configured to control the vibration period of the hydrocarbon concentration longer than the predetermined range of period, wherein when the electronic control unit controls the vibration of the concentration of hydrocarbons flowing into the exhaust purification catalyst within the predetermined range of amplitude and within the predetermined range of period, a reducing intermediate containing nitrogen and hydrocarbons is produced on the precious metal catalyst and held on the basic exhaust gas flow surface part, the NOx contained in the exhaust gas catalyst is chemically reduced by the reducing intermediate held on the basic exhaust gas flow surface part in the exhaust purification catalyst, the nitrogen-containing intermediate is derived from the reducing intermediate, and the exhaust purification catalyst has a property of chemically reducing the NOx that is contained in the exhaust gas without storing, or storing a fine amount of nitrates in the exhaust gas in the basic exhaust gas flow surface part,when the electronic control unit controls the vibration period of the hydrocarbon concentration longer than the predetermined range of period, the exhaust purification catalyst has a property of being increased in a storage amount of NOx that is contained in the exhaust gas, andthe electronic control unit is further configured to cause a desorbing of the nitrogen-containing intermediate or NOx that is adsorbed at the intermediate NOx adsorption catalyst by causing a temperature of the intermediate NOx adsorption catalyst to rise using a heat of an oxidation reaction of the hydrocarbons while vibrating the concentration of hydrocarbons flowing into the exhaust purification catalyst within the predetermined range of amplitude and within the predetermined range of period. 2. The exhaust purification system of an internal combustion engine as claimed in claim 1, wherein the electronic control unit is further configured to determine, based on an amount of hydrocarbons required for causing the temperature of the intermediate NOx adsorption catalyst rise to to a target temperature, the amplitude and the vibration period of the hydrocarbon concentration when causing the temperature of the intermediate NOx adsorption catalyst to rise in temperature within the predetermined range of period and amplitude. 3. The exhaust purification system of an internal combustion engine as claimed in claim 2, wherein the electronic control unit is further configured to calculate an amount of hydrocarbons fed per unit time required for causing the temperature of the intermediate NOx adsorption catalyst to rise to the target temperature, and is further configured to determine, based on a calculated amount of hydrocarbons fed per unit time, the amplitude and the vibration period of the hydrocarbon concentration when causing the temperature of the intermediate NOx adsorption catalyst to rise within the predetermined range of period and amplitude. 4. The exhaust purification system of an internal combustion engine as claimed in claim 1, further comprising: a reduction catalyst arranged inside of the engine exhaust passage downstream of the intermediate NOx adsorption catalyst, wherein when the electronic control unit has caused the temperature of the intermediate NOx adsorption catalyst to rise to the target temperature, the electronic control unit is further configured to cause an air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst to be made rich to reduce a desorbing nitrogen-containing intermediate or NOx. 5. The exhaust purification system of an internal combustion engine as claimed in claim 1, wherein when a NOx purification rate of the exhaust purification catalyst falls to a predetermined allowable purification rate or less, the electronic control unit is further configured to temporarily cause an air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst to be made rich to release NOx stored in the exhaust purification catalyst. 6. The exhaust purification system of an internal combustion engine as claimed in claim 1, wherein a metal with a lower oxidizing strength than a precious metal is carried on a catalyst carrier of the intermediate NOx adsorption catalyst. 7. The exhaust purification system of an internal combustion engine as claimed in claim 6, wherein the metal that is carried on the catalyst carrier of the intermediate NOx adsorption catalyst is at least one transition metal selected from silver (Ag), copper (Cu), iron (Fe), vanadium (V), molybdenum (Mo), cobalt (Co), nickel (Ni), and/or manganese (Mn). 8. The exhaust purification system of an internal combustion engine as claimed in claim 1, wherein the vibration period of the hydrocarbon concentration is a vibration period necessary for continued production of the reducing intermediate. 9. The exhaust purification system of an internal combustion engine as claimed in claim 8, wherein the vibration period of the hydrocarbon concentration is 0.3 second to 5 seconds. 10. The exhaust purification system of an internal combustion engine as claimed in claim 1, wherein the precious metal catalyst is comprised of platinum (Pt) and at least one of rhodium (Rh) and/or palladium (Pd). 11. The exhaust purification system of an internal combustion engine as claimed in claim 1, wherein a basic layer containing an alkali metal, an alkali earth metal, a rare earth, or a metal that can donate electrons to NOx is formed on the exhaust gas flow surface of the exhaust purification catalyst and wherein a surface of the basic layer forms the basic exhaust gas flow surface part.
Handa, Hideyuki; Koshida, Yasuto, Exhaust gas purification device for internal combustion engine and method of controlling the exhaust gas purification device.
Fukuda, Koichiro; Suyama, Kingo, Fuel supply control method applied to exhaust gas control apparatus for internal combustion engine and exhaust gas control apparatus to which the method is applied.
Bouchez Mathias,FRX ; Martin Brigitte,FRX ; Bourges Patrick,FRX, Process for controlled injection of hydrocarbons into an exhaust line of an internal-combustion engine.
Clerc James C. (Columbus IN) Gladden John R. (Germantown Hills IL) Miller Paul R. (Columbus IN), Unitary hybrid exhaust system and method for reducing particulate emmissions from internal combustion engines.
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