EP0984142A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Exhaust emission control system for internal combustion engines
Assignee: Toyota Motor Corp
•
Filing: 1998-04-21
•
Granted: —
•
Expires: 2018-04-21
Abstract
Abstract A particulate filter (18) is arranged in the exhaust passage of an engine. Only the inner wall surface of downstream end open cells (61d) of the particulate filter (18) is covered with a NO x adsorbent (62a), and the inner wall surface of the upstream end open cells (61u) is covered with a HC adsorbent (63a). The particulates in the exhaust gas are trapped in the HC adsorbent (63a) or the cell walls (60) of the particulate filter (18) and prevented from reaching the NO x adsorbent (62a). When the catalyst temperature is low, NO x in the inflowing exhaust gas is adsorbed in the NO x adsorbent (62a), and hydrocarbon (HC) is adsorbed in the HC adsorbent (63a). With the increase in the catalyst temperature, the adsorbed NO x is desorbed from the NO x adsorbent (62a), and the adsorbed HC is desorbed from the HC adsorbent (63a). This HC reduces the NO x desorbed from the NO x adsorbent (62a).
Inventors
- 👤 Shinya Hirota
- 👤 Toshiaki Tanaka
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 12:20
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/30; F02D41/38; F02D41/40; F02D41/402; F02D41/405; B; B01; B01D; B01D53/00; B01D53/34; B01D53/92; B01D53/94; B01D53/9445; B01D53/9481; B01D53/9495; F01; F01N; F01N13/00; F01N13/009; F01N13/0097; F01N3/00; F01N3/02; F01N3/021; F01N3/022; F01N3/0222; F01N3/023; F01N3/0233; F01N3/08; F01N3/0807; F01N3/0821; F01N3/0828; F01N3/0835; F01N3/0842; F01N3/085; F01N3/0871; F01N3/0878; F01N3/0885; F01N3/10; F01N3/24; F01N3/30; F01N3/306; F02D41/02; F02D41/021; F02D41/0235; F02D41/027; F02D41/0275; F01N2240/00; F01N2240/16; F01N2410/00; F01N2410/12; F01N2510/00; F01N2510/06; F01N2560/00; F01N2560/02; F01N2560/026; F01N2610/00; F01N2610/03; F01N3/18; F01N3/22; F02B; F02B1/00; F02B1/02; F02B1/04; F02D41/028; F02D41/029; Y; Y02; Y02A; Y02A50/00; Y02A50/20; Y02T; Y02T10/00; Y02T10/10; Y02T10/12; Y02T10/40; Y10; Y10S; Y10S55/00; Y10S55/30
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
60 words
An exhaust gas purification device for an
internal combustion engine having an exhaust passage,
comprising: a filter arranged in said exhaust passage
for trapping the particulates in the inflowing exhaust
gas; and a NO x storing member arranged only on the
exhaust gas downstream side surface of the filter for
temporarily storing NO x in the inflowing exhaust gas
therein.
Claim 2
Dependent Claim
32 words
An exhaust gas purification device according to
claim 1, wherein said NO x storing member is comprised of
a NO x adsorbent for adsorbing NO x in the inflowing
exhaust gas therein.
Claim 3
Dependent Claim
32 words
An exhaust gas purification device according to
claim 2, further comprising NO x desorbing means for
desorbing NO x adsorbed in the NO x adsorbent therefrom by
heating said NO x adsorbent.
Claim 4
Dependent Claim
65 words
An exhaust gas purification device according to
claim 3, wherein said NO x desorbing means comprises means
for supplying a secondary air to the NO x adsorbent when
NO x is to be desorbed from said NO x adsorbent and means
for heating said secondary air, said NO x adsorbent being
heated by causing the heated secondary air to flow
through said NO x adsorbent.
Claim 5
Dependent Claim
62 words
An exhaust gas purification device according to
claim 4, wherein the secondary air is supplied to the
filter in such a manner that said secondary air flows
from the exhaust gas downstream end toward the exhaust
gas upstream end of said filter, and NO x desorbed from
said NO x adsorbent is reduced by reacting with the
particulates trapped in said filter.
Claim 6
Dependent Claim
69 words
An exhaust gas purification device according to
claim 5, wherein said NO x desorbing means comprises means
for preventing the exhaust gas discharged from the engine
from flowing into said filter when said NO x desorbing
means desorbs NO x from said NO x adsorbent, and said NO x desorbing means desorbs NO x from said NO x adsorbent when
the engine load is lower than a preset load.
Claim 7
Dependent Claim
44 words
An exhaust gas purification device according to
claim 3, further comprising reducing agent supplying
means for supplying a reducing agent to said NO x adsorbent when NO x is desorbed from said NO x adsorbent,
wherein NO x is reduced by said reducing agent.
Claim 8
Dependent Claim
78 words
An exhaust gas purification device according to
claim 7, wherein said reducing agent supply means
comprises a HC adsorbent arranged on the side surface of
said filter upstream of said NO x adsorbent with respect
to the exhaust gas flow for adsorbing the hydrocarbon in
the inflowing exhaust gas, and the hydrocarbon adsorbed
in said HC adsorbent is desorbed therefrom to be supplied
to said NO x adsorbent when NO x is desorbed from said NO x adsorbent.
Claim 9
Dependent Claim
56 words
An exhaust gas purification device according to
claim 8, wherein said reducing agent supplying means
comprises a fuel injector for injecting fuel directly
into a cylinder, and hydrocarbon is supplied to said HC
adsorbent by injecting a secondary fuel from said fuel
injector when the engine is in the expansion stroke or in
the exhaust stroke.
Claim 10
Dependent Claim
54 words
An exhaust gas purification device according to
claim 3, further comprising means for increasing the
temperature of the exhaust gas flowing into said NO x adsorbent when desorbing NO x from said NO x adsorbent,
wherein said NO x adsorbent is heated by causing said
exhaust gas to flow through said NO x adsorbent.
Claim 11
Dependent Claim
39 words
An exhaust gas purification device according to
claim 2, wherein said NO x adsorbent is composed of at
least one selected from: a precious metal including
palladium, platinum and rhodium; a transition metal
including copper and iron; and lithium.
Claim 12
Dependent Claim
57 words
An exhaust gas purification device according to
claim 1, wherein said NO x storing member is comprised of
a NO x absorbent for absorbing NO x therein when the air-fuel
ratio of the inflowing exhaust gas is lean and
releasing and reducing the absorbed NO x when the oxygen
concentration in the inflowing exhaust gas becomes lower.
Claim 13
Dependent Claim
41 words
An exhaust gas purification device according to
claim 12, further comprising NO x releasing means for
releasing NO x from said NO x absorbent by temporarily
making the air-fuel ratio of the exhaust gas flowing into
said NO x absorbent rich.
Claim 14
Dependent Claim
123 words
An exhaust gas purification device according to
claim 13, further comprising a SO x absorbent arranged on
the side surface of said filter upstream of said NO x adsorbent with respect to the exhaust gas flow, said SO x absorbent absorbing SO x in the inflowing exhaust gas
therein when the air-fuel ratio of the inflowing exhaust
gas is lean, and releasing the absorbed SO x therefrom
when the oxygen concentration in the inflowing exhaust
gas becomes lower while the temperature of the SO x absorbent is higher than a SO x release temperature,
wherein the temperature of the SO x absorbent is prevented
from being higher than said SO x release temperature when
NO x is released from said NO x absorbent.
Claim 15
Dependent Claim
65 words
An exhaust gas purification device according to
claim 13, wherein said NO x releasing means comprises a
fuel injector for injecting fuel directly into a
cylinder, and the air-fuel ratio of the exhaust gas
flowing into said NO x absorbent is made rich by injecting
a secondary fuel from said fuel injector when the engine
is in the expansion stroke or in the exhaust stroke.
Claim 16
Dependent Claim
57 words
An exhaust gas purification device according to
claim 12, wherein said NO x absorbent is comprised of: at
least one selected from an alkali metal including
potassium, sodium, lithium and cesium, an alkali earth
metal including barium and calcium and a rare earth metal
including lanthanum and yttrium; and a precious metal
including palladium, platinum and rhodium.
Claim 17
Dependent Claim
53 words
An exhaust gas purification device according to
claim 1, further comprising means for estimating the
amount of NO x absorbed in said NO x storing member,
wherein NO x stored in said NO x storing member is released
when said estimated amount of NO x is larger than a preset
NO x amount.
Claim 18
Dependent Claim
49 words
An exhaust gas purification device according to
claim 1, further comprising poisoning material removing
means arranged on the side surface of said filter
upstream of said NO x storing member with respect to the
exhaust gas flow for preventing a poisoning material from
reaching said NO x storing member.
Claim 19
Dependent Claim
30 words
An exhaust gas purification device according to
claim 18, wherein said poisoning material removing member
is comprised of a HC adsorbent for adsorbing hydrocarbon
in the inflowing exhaust gas therein.
Claim 20
Dependent Claim
37 words
An exhaust gas purification device according to
claim 19, wherein the stored NO x is released from said
NO x storing member and caused to react with hydrocarbon
when said hydrocarbon is desorbed from said HC adsorbent.
Claim 21
Dependent Claim
43 words
An exhaust gas purification device according to
claim 19, wherein said HC adsorbent is comprised of at
least one selected from a precious metal including
platinum and palladium and a transition metal including
copper and iron, carried on a carrier composed of
zeolite.
Claim 22
Dependent Claim
80 words
An exhaust gas purification device according to
claim 18, wherein said poisoning material removing member
is comprised of a SO x absorbent, said SO x absorbent
absorbing SO x in the inflowing exhaust gas therein when
the air-fuel ratio of the inflowing exhaust gas is lean,
and desorbing the absorbed SO x therefrom when the oxygen
concentration in the influent exhaust gas becomes lower
while the temperature of the SO x absorbent is higher than
a SO x release temperature.
Claim 23
Dependent Claim
25 words
An exhaust gas purification device according to
claim 22, wherein said filter is regenerated immediately
after SO x is released from said SO x absorbent.
Claim 24
Dependent Claim
43 words
An exhaust gas purification device according to
claim 22, wherein the temperature of the SO x absorbent is
increased by increasing the temperature of the exhaust
gas flowing into the SO x absorbent when SO x is released
from said SO x absorbent.
Claim 25
Dependent Claim
61 words
An exhaust gas purification device according to
claim 24, further comprising a fuel injector for
injecting fuel directly into a cylinder, wherein the
temperature of the exhaust gas flowing into said SO x absorbent is increased by injecting a secondary fuel from
said fuel injector and burning the secondary fuel when
the engine is in expansion stroke or in exhaust stroke.
Claim 26
Dependent Claim
33 words
An exhaust gas purification device according to
claim 22, wherein said SO x absorbent is comprised of at
least one selected from: a transition metal including
iron, manganese, nickel and tin; and lithium.
Claim 27
Dependent Claim
56 words
An exhaust gas purification device according to
claim 18, further comprising means for estimating the
amount of the poisoning material stored in said poisoning
material removing member and means for releasing the
poisoning material from said poisoning material removing
member when the estimated amount of said poisoning
material is larger than a preset poisoning material
amount.
Claim 28
Dependent Claim
44 words
An exhaust gas purification device according to
claim 18, wherein the NO x releasing from said NO x storing
member, the releasing of the poisoning material from said
poisoning material removing member, and the regeneration
of said filter are performed at the same time.
Claim 29
Dependent Claim
34 words
An exhaust gas purification device according to
claim 1, further comprising filter regenerating means for
burning the particulates by heating said filter while
placing the filter in an oxidazing atmosphere to
regenerate said filter.
Claim 30
Dependent Claim
49 words
An exhaust gas purification device according to
claim 29, further comprising means for estimating the
amount of the particulates trapped in said filter,
wherein said filter regenerating means regenerates said
filter when the estimated amount of the particulates
trapped in said filter is larger than a preset
particulate amount.
Claim 31
Dependent Claim
32 words
An exhaust gas purification device according to
claim 29, wherein the NO x releasing from said NO x storing
member and the regeneration of said filter are performed
at the same time.
Claim 32
Dependent Claim
112 words
An exhaust gas purification device according to
claim 1, wherein said filter comprises a plurality of
cells defined by a porous cell wall extending
substantially in parallel to an axis of the exhaust
passage, said cells including upstream end open cells
with an exhaust upstream ends thereof being opened and
exhaust downstream ends thereof being closed, and
downstream end open cells with exhaust upstream ends
thereof being closed and exhaust downstream ends thereof
being opened, said upstream end open cells and said
downstream end open cells being arranged alternately in
repetitive fashion, and wherein said NO x storing member
is arranged only on inner wall surfaces of said
downstream end open cells.
References Cited (Backward Citations)
No citation records indexed.
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