US5437153A
Expired / Lapsed
US
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Exhaust purification device of internal combustion engine
Assignee: Toyota Motor Corp
•
Filing: 1993-06-10
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Granted: 1995-08-01
•
Expires: 2013-06-10
Abstract
Abstract A NO x absorbent (17) is disposed in an exhaust passage of an internal combustion engine. This NO x absorbent (17) absorbs the NO x when the air-fuel ratio of the exhaust gas flowing into the NO x absorbent (17) is lean and releases the absorbed NO x when the air-fuel ratio of the exhaust gas flowing into the NO x absorbent (17) becomes rich. It estimates the amount of NO x absorbed in the NO x absorbent (17) from the engine load and the engine rotational speed and when the amount of the estimated NO x becomes the maximum NO x absorption capacity of the NO x absorbent (17), makes the air-fuel ratio of the exhaust gas flowing into the NO x absorbent (17) rich.
Inventors
- 👤 Shinichi Takeshima
- 👤 Toshiaki Tanaka
- 👤 Satoshi Iguchi
- 👤 Yasushi Araki
- 👤 Shinya Hirota
- 👤 Tomohiro Oda
- 👤 Fumitada Murakami
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:51
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9481; B01D53/02; B01D53/04; B01D53/0454; B01D53/74; B01D53/86; B01D53/8696; B01D53/9445; B01D53/9495; F; F01; F01N; F01N13/00; F01N13/009; F01N3/00; F01N3/08; F01N3/0807; F01N3/0828; F01N3/0842; F01N3/0871; F01N9/00; F01N9/005; F02; F02D; F02D41/00; F02D41/02; F02D41/021; F02D41/0235; F02D41/027; F02D41/0275; F02D41/14; F02D41/1438; F02D41/1444; F02D41/146; F02D41/1461; F02D41/1462; F02D41/1473; F02D41/1475; F01N2240/00; F01N2240/18; F01N2250/00; F01N2250/12; F01N2390/00; F01N2390/02; F01N2550/00; F01N2550/03; F01N2570/00; F01N2570/12; F01N2610/00; F01N2610/03; F01N3/10; F01N3/18; F01N3/20; F02B; F02B1/00; F02B1/02; F02B1/04; F02D2200/00; F02D2200/02; F02D2200/08; F02D2200/0806; F02D2200/0811; F02D41/1446; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12; Y02T10/40
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
134 words
An exhaust purification device of an internal combustion engine which has in an engine exhaust passage a NO x absorbent which absorbs NO x when the air-fuel ratio of the inflowing exhaust gas is lean and which releases the absorbed NO x when the oxygen concentration in the inflowing exhaust gas is reduced and which is provided with a NO x estimating means for estimating the amount of the NO x absorbed by the NO x absorbent and a NO x releasing means for reducing the oxygen concentration in the exhaust gas flowing into the NO x absorbent and releasing NO x from the NO x absorbent when the amount of the NO x estimated to be absorbed in the NO x absorbent by the NO x estimating means exceeds a predetermined allowable value.
Claim 2
Dependent Claim
134 words
An exhaust purification device of an internal combustion engine which has in an engine exhaust passage a NO x absorbent which absorbs NO x when the air-fuel ratio of the inflowing exhaust gas is lean and which releases the absorbed NO x when the oxygen concentration in the inflowing exhaust gas is reduced and which is provided with a NO x estimating means for estimating the amount of the NO x absorbed by the NO x absorbent and a NO x releasing means for reducing the oxygen concentration in the exhaust gas flowing into the NO x absorbent and releasing NO x from the NO x absorbent when the amount of the NO x estimated to be absorbed in the NO x absorbent by the NO x estimating means exceeds a predetermined allowable value.
Claim 3
Dependent Claim
48 words
An exhaust purification device of an internal combustion engine according to claim 1, wherein said NO x estimating means estimates the NO x absorbed in the NO x absorbent on the basis of the amount of NO x discharged from the combustion chamber to the engine exhaust passage.
Claim 4
Dependent Claim
77 words
An exhaust purification device of an internal combustion engine according to claim 2, wherein said NO x estimating means is comprised of a NO x calculating means for calculating the amount of NO x discharged per unit time from the engine to the engine exhaust passage in accordance with the engine load and the engine rotational speed and an cumulative adding means for cumulatively adding the amounts of NO x calculated by the NO x calculating means.
Claim 5
Dependent Claim
86 words
An exhaust purification device of an internal combustion engine according to claim 3, wherein said NO x calculating means is provided with a memory in which is previously stored the amount of NO x discharged per unit time from the engine to the engine exhaust passage as a function of the engine load and the engine rotational speed and wherein the cumulative adding means cumulatively adds the amounts of NO x stored in the memory and determined from the engine load and the engine rotational speed.
Claim 6
Dependent Claim
54 words
An exhaust purification device of an internal combustion engine according to claim 3, wherein provision is made of a throttle valve disposed in the engine intake passage for controlling the engine load and the vacuum inside the engine intake passage downstream of the throttle valve is used as a value representing the engine load.
Claim 7
Dependent Claim
42 words
An exhaust purification device of an internal combustion engine according to claim 3, wherein an accelerator pedal is provided for controlling the engine load and the amount of depression of the accelerator pedal is used as a value representing the engine load.
Claim 8
Dependent Claim
28 words
An exhaust purification device of an internal combustion engine according to claim 1, wherein said allowance is the maximum NO x absorption capacity of the NO x absorbent.
Claim 9
Dependent Claim
35 words
An exhaust purification device of an internal combustion engine according to claim 1, wherein said allowance is a predetermined amount of absorption smaller than the maximum NO x absorption capacity of the NO x absorbent.
Claim 10
Dependent Claim
30 words
An exhaust purification device of an internal combustion engine according to claim 1, wherein said allowance is a function of a temperature representing the temperature of the NO x absorbent.
Claim 11
Dependent Claim
31 words
An exhaust purification device of an internal combustion engine according to claim 9, wherein the temperature representing the temperature of the NO x absorbent is the temperature of the exhaust gas.
Claim 12
Dependent Claim
58 words
An exhaust purification device of an internal combustion engine according to claim 1, wherein said NO x releasing means switches from lean to rich the air-fuel ratio of the exhaust gas flowing into the NO x absorbent in a predetermined time when the amount of the NO x estimated by the NO x estimating means exceeds the allowance.
Claim 13
Dependent Claim
56 words
An exhaust purification device of an internal combustion engine according to claim 11, wherein said NO x releasing means switches from lean to rich the air-fuel ratio of the air-fuel mixture fed to the combustion chamber for a predetermined time when the amount of NO x estimated by the NO x estimating means exceeds the allowance.
Claim 14
Dependent Claim
89 words
An exhaust purification device of an internal combustion engine according to claim 11, which is provided with a reducing agent feeding means for feeding a reducing agent into the engine exhaust passage upstream of the NO x absorbent and wherein said NO x releasing means causes the reducing agent to be fed from said reducing agent feeding means into the engine exhaust passage upstream of the NO x absorbent for a predetermined time when the amount of NO x estimated by the NO x estimating means exceeds the allowance.
Claim 15
Dependent Claim
22 words
An exhaust purification device of an internal combustion engine according to claim 13, wherein said reducing agent is comprised of a hydrocarbon.
Claim 16
Dependent Claim
33 words
An exhaust purification device of an internal combustion engine according to claim 14, wherein the hydrocarbon is at least one hydrocarbon selected from gasoline, isooctane, hexane, heptane, butane, propane, gas oil, and kerosine.
Claim 17
Dependent Claim
62 words
An exhaust purification device of an internal combustion engine according to claim 11, wherein said NO x releasing means switches from lean to rich the air-fuel ratio of the exhaust gas flowing into the NO x absorbent in a predetermined time during a deceleration operation when the amount of the NO x estimated by the NO x estimating means exceeds the allowance.
Claim 18
Dependent Claim
36 words
An exhaust purification device of an internal combustion engine according to claim 16, wherein an intake shutoff valve which is normally fully open and is closed during deceleration operation is disposed inside the engine exhaust passage.
Claim 19
Dependent Claim
58 words
An exhaust purification device of an internal combustion engine according to claim 11, wherein said NO x estimating means makes the amount of the NO x estimated to be absorbed in the NO x absorbent zero when the air-fuel ratio of the exhaust gas flowing into the NO x absorbent is made rich during the above predetermined time.
Claim 20
Dependent Claim
55 words
An exhaust purification device of an internal combustion engine according to claim 11, wherein said NO x estimating means estimates that NO x remains in the NO x absorbent when the air-fuel ratio of the exhaust gas flowing into the NO x absorbent is made rich for a time shorter than the above predetermined time.
Claim 21
Dependent Claim
46 words
An exhaust purification device of an internal combustion engine according to claim 19, wherein said NO x estimating means estimates the amount of the NO x absorbed in the NO x absorbent taking into consideration the amount of NO x remaining in the NO x absorbent.
Claim 22
Dependent Claim
59 words
An exhaust purification device of an internal combustion engine according to claim 19, wherein said NO x estimating means causes the amount of the NO x estimated to be remaining in the NO x absorbent to increase the shorter the time in which the air-fuel ratio of the exhaust gas flowing into the NO x absorbent is made rich.
Claim 23
Dependent Claim
99 words
An exhaust purification device of an internal combustion engine according to claim 21, wherein provision is made of a memory which stores in advance the relationship between the time during which the air-fuel ratio of the exhaust gas flowing into the NO x absorbent is made rich and the residual rate of the NO x estimated to be remaining in the NO x absorbent and wherein said NO x estimating means estimates the amount of the NO x remaining in the NO x absorbent on the basis of the residual rate of the NO x stored in the memory.
Claim 24
Dependent Claim
92 words
An exhaust purification device of an internal combustion engine according to claim 11, wherein a NO x concentration detecting means is provided for detecting the concentration of NO x in the exhaust gas flowing out from the NO x absorbent and a NO x release promoting means is provided for promoting the releasing action of the NO x from the NO x absorbent when the concentration of NO x is higher than a predetermined concentration when the amount of the NO x estimated by the NO x estimating means exceeds the allowance.
Claim 25
Dependent Claim
49 words
An exhaust purification device of an internal combustion engine according to claim 23, wherein said NO x release promoting means promotes the release action of NO x by prolonging the time during which the air-fuel ratio of the exhaust gas flowing into the NO x absorbent is made rich.
Claim 26
Dependent Claim
47 words
An exhaust purification device of an internal combustion engine according to claim 23, wherein said NO x release promoting means promotes the release action of NO x by raising the degree of richness of the air-fuel ratio of the exhaust gas flowing into the NO x absorbent.
Claim 27
Dependent Claim
87 words
An exhaust purification device of an internal combustion engine according to claim 23, which is provided with a deterioration judging means for judging the NO x absorbent is deteriorating when the concentration of NO x is higher than a predetermined concentration when the amount of the NO x estimated by said NO x estimating means exceeds the allowance even when the promoting action of the release of said NO x by the NO x release promoting means has been performed more than a predetermined number of times.
Claim 28
Dependent Claim
56 words
An exhaust purification device of an internal combustion engine according to claim 1, wherein said NO x estimating means estimates the amount of the NO x absorbed in the NO x absorbent taking into consideration the reduction in the NO x absorption capacity when the NO x absorption capacity of the NO x absorbent has fallen.
Claim 29
Dependent Claim
92 words
An exhaust purification device of an internal combustion engine according to claim 27, wherein provision is made of a memory for storing in advance the relationship between the time in which the air-fuel ratio of the exhaust gas flowing into the NO x absorbent 17 is made lean and the NO x absorption capacity of the NO x absorbent and wherein said NO x estimating means estimates the amount of the NO x absorbed in the NO x absorbent on the basis of the NO x absorption capacity stored in the memory.
Claim 30
Dependent Claim
63 words
An exhaust purification device of an internal combustion engine according to claim 1, wherein an air-fuel ratio control means is provided for making the air-fuel ratio of the air-fuel mixture fed to the combustion chamber rich in accordance with the operating state of the engine regardless of whether the amount of NO x estimated by the NO x estimating means exceeds the allowance.
Claim 31
Dependent Claim
43 words
An exhaust purification device of an internal combustion engine according to claim 29, wherein said air-fuel ratio control means makes the air-fuel ratio of the air-fuel mixture fed into the combustion chamber rich when the engine load is higher than a predetermined load.
Claim 32
Dependent Claim
38 words
An exhaust purification device of an internal combustion engine according to claim 29, wherein said air-fuel ratio control means makes the air-fuel ratio of the air-fuel mixture fed to the combustion chamber rich when shifting to idling operation.
Claim 33
Dependent Claim
48 words
An exhaust purification device of an internal combustion engine according to claim 29, wherein said air-fuel ratio control means makes the air-fuel ratio of the air-fuel mixture fed into the combustion chamber rich during an acceleration operation where the degree of acceleration is larger than a predetermined value.
Claim 34
Dependent Claim
41 words
An exhaust purification device of an internal combustion engine according to claim 29, wherein said air-fuel ratio control means makes the air-fuel ratio of the air-fuel mixture fed into the combustion chamber rich during a shift down action of the transmission.
Claim 35
Dependent Claim
52 words
An exhaust purification device of an internal combustion engine according to claim 29, wherein said NO x estimating means makes the amount of NO x estimated as being absorbed in the NO x absorbent zero when the air-fuel ratio of the air-fuel mixture is made rich for more than a predetermined time.
Claim 36
Dependent Claim
51 words
An exhaust purification device of an internal combustion engine according to claim 1, wherein the NO x absorbent includes at least one substance selected from alkali metals such as potassium, sodium, lithium, and cesium, alkali earths such as barium and calcium, and rare earths such as lanthanum and yttrium and platinum.
Claim 37
Dependent Claim
28 words
An exhaust purification device of an internal combustion engine according to claim 1, wherein the NO x absorbent is comprised of a compound oxide of barium and copper.
Claim 38
Dependent Claim
30 words
An exhaust purification device of an internal combustion engine according to claim 1, wherein a three-way catalyst is disposed in the engine exhaust passage downstream of the NO x absorbent.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-07-31 | 1999-01-30 | 1999-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-07-31 | 2003-01-30 | 2003-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-07-31 | 2007-01-30 | 2007-08-01 | $7700.00 | Window Closed / Lapsed |