EP0921285A2
Expired / Lapsed
EP
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Compression ignition type engine
Assignee: Toyota Motor Corp
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Filing: 1998-10-23
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Granted: —
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Expires: 2018-10-23
Abstract
Abstract A compression ignition type engine, wherein a first combustion where the amount of the inert gas in the combustion chamber is larger than the amount of inert gas where the amount of production of soot peaks and almost no soot is produced and a second combustion where the amount of inert gas in the combustion chamber is smaller than the amount of inert gas where the amount of production of soot peaks are selectively switched between. The second combustion is performed after the engine operation is started until a catalyst arranged in the engine exhaust passage has become activated and, the first combustion is performed after the catalyst has become activated.
Inventors
- 👤 Takekazu Ito
- 👤 Shizuo Sasaki
- 👤 Satoshi Iguchi
- 👤 Tsukasa Abe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 05:56
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/02; F02D41/04; F02D41/06; F02D41/062; F02B; F02B3/00; F02B3/06; F02D41/0025; F02D41/0047; F02D41/005; F02D41/0057; F02D41/021; F02D41/0235; F02D41/024; F02D41/30; F02D41/38; F02D41/40; F02D41/402; F02D41/405; F02B2275/00; F02B2275/14; F02D2041/389; F02D41/3011; F02D41/3076; F02M; F02M26/00; F02M26/13; F02M26/14; F02M26/15; F02M26/22; F02M26/23; F02M26/28; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12; Y02T10/40
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
191 words
A compression ignition type engine in which an
amount of production of soot gradually increases and then
peaks when an amount of inert gas in a combustion chamber
increases and in which a further increase of the amount
of inert gas in the combustion chamber results in a
temperature of fuel and surrounding gas at the time of
combustion in the combustion chamber becoming lower than
a temperature of production of soot and therefore almost
no production of soot any longer, said engine comprising: a catalyst arranged in an engine exhaust
passage and having an oxidation function and; switching means for selectively switching
between a first combustion where the amount of the inert
gas in the combustion chamber is larger than the amount
of inert gas where the amount of production of soot peaks
and almost no soot is produced and a second combustion
where the amount of inert gas in the combustion chamber
is smaller than the amount of inert gas where the amount
of production of soot peaks, said switching means first
performing the second combustion and then switching to
the first combustion when the engine operation is
started.
Claim 2
Dependent Claim
29 words
A compression ignition type engine as set forth
in claim 1, wherein said catalyst is comprised of at
least one of an oxidation catalyst, three-way catalyst,
and NOx absorbent.
Claim 3
Dependent Claim
44 words
A compression ignition type engine as set forth
in claim 1, wherein an exhaust gas recirculation device
is provided for recirculating exhaust gas, discharged
from the combustion chamber, into an engine intake
passage and wherein the inert gas is comprised by
recirculated exhaust gas.
Claim 4
Dependent Claim
28 words
A compression ignition type engine as set forth
in claim 3, wherein an exhaust gas recirculation rate in
the first combustion state is at least about 55 percent.
Claim 5
Dependent Claim
51 words
A compression ignition type engine as set forth
in claim 1, wherein the temperature of the fuel and the
gas surrounding it at the time of combustion in the first
combustion state is a temperature at which the amount of
NOx in the exhaust gas becomes around 10 ppm or less.
Claim 6
Dependent Claim
58 words
A compression ignition type engine as set forth
in claim 1, wherein, in the first combustion state,
unburnt hydrocarbons are exhausted from the combustion
chamber not in the form of soot but in the form of a soot
precursor or a form before that and the unburned
hydrocarbons exhausted from the combustion chamber are
oxidized by said catalyst.
Claim 7
Dependent Claim
33 words
A compression ignition type engine as set forth
in claim 1, wherein an engine idling speed is made higher
when second combustion, performed first when the engine
operation is started, is being performed.
Claim 8
Dependent Claim
33 words
A compression ignition type engine as set forth
in claim 1, wherein a fuel injection start timing is
retarded when second combustion, performed first when the
engine operation is started, is being performed.
Claim 9
Dependent Claim
35 words
A compression ignition type engine as set forth
in claim 1, wherein an opening timing of an exhaust valve
is advanced when second combustion, performed first when
the engine operation is started, is being performed.
Claim 10
Dependent Claim
46 words
A compression ignition type engine as set forth
in claim 9, wherein the opening timing of the exhaust
valve continues to be advanced for a fixed time even
after switching from the second combustion, performed
first when the engine operation is started, to the first
combustion.
Claim 11
Dependent Claim
48 words
A compression ignition type engine as set forth
in claim 1, wherein activation judging means is provided
for judging if the catalyst has become activated and,
said switching means switches from the second combustion
to the first combustion when it is judged that the
catalyst has become activated.
Claim 12
Dependent Claim
79 words
A compression ignition type engine as set forth
in claim 11, wherein an engine operating region is
divided into a low load side first operating region where
the first combustion can be performed and a high load
side second operating region where second combustion is
performed and, said switching means switches from the
second combustion to the first combustion if the engine
is operating in the first operating region when it is
judged that the catalyst has become activated.
Claim 13
Dependent Claim
45 words
A compression ignition type engine as set forth
in claim 11, wherein detecting means for detecting a
representative temperature representing a temperature of
the catalyst and, said activation judging means judges
that the catalyst has become activated when the
representative temperature exceeds a predetermined
temperature.
Claim 14
Dependent Claim
46 words
A compression ignition type engine as set forth
in claim 13, wherein said detecting means is comprised of
a temperature sensor arranged in the engine exhaust
passage downstream of said catalyst and, said
representative temperature is a temperature of the
exhaust gas passing through said catalyst.
Claim 15
Dependent Claim
74 words
A compression ignition type engine as set forth
in claim 11, wherein temperature sensors are arranged in
the engine exhaust passage upstream of the catalyst and
the engine exhaust passage downstream of the catalyst
and, said activation judging means judges that the
catalyst has become activated when a temperature of
exhaust gas downstream of the catalyst becomes higher by
at least a predetermined temperature than a temperature
of exhaust gas upstream of the catalyst.
Claim 16
Dependent Claim
127 words
A compression ignition type engine as set forth
in claim 1, wherein activation judging means is provided
for judging if the catalyst will become activated if
temporarily increasing amounts of unburned HC and CO in
the exhaust gas when the second combustion is being
performed and, unburned HC and CO increasing means is
provided for temporarily increasing the amounts of
unburned HC and CO in the exhaust gas when it is judged
that the catalyst will become activated if temporarily
increasing the amounts of unburned HC and CO in the
exhaust gas, said judging means switching from the second
combustion to the first combustion after the amounts of
unburned HC and CO in the exhaust gas are temporarily
increased by the unburned HC and CO increasing means.
Claim 17
Dependent Claim
64 words
A compression ignition type engine as set forth
in claim 16, wherein detecting means is provided for
detecting a representative temperature representing a
temperature of the catalyst and, said activation judging
means judges that the catalyst will become activated if
the amounts of unburned HC and CO in the exhaust gas are
made to temporarily increase when the representative
temperature exceeds a predetermined temperature.
Claim 18
Dependent Claim
46 words
A compression ignition type engine as set forth
in claim 17, wherein said detecting means is comprised of
a temperature sensor arranged in the engine exhaust
passage downstream of said catalyst and, said
representative temperature is a temperature of the
exhaust gas passing through said catalyst.
Claim 19
Dependent Claim
45 words
A compression ignition type engine as set forth
in claim 16, wherein said unburned HC and CO increasing
means increases the amounts of unburned HC and CO in the
exhaust gas by temporarily switching to the first
combustion when the second combustion is being performed.
Claim 20
Dependent Claim
48 words
A compression ignition type engine as set forth
in claim 16, wherein said unburned HC and CO increasing
means increases the amounts of unburned HC and CO in the
exhaust gas by performing VIGOM injection and making an
air-fuel ratio rich when the second combustion is being
performed.
Claim 21
Dependent Claim
82 words
A compression ignition type engine as set forth
in claim 16, wherein valve overlap time control means is
provided for controlling a valve overlap time where the
intake valve and exhaust valve are both open and, said
unburned HC and CO increasing means increases the amounts
of unburned HC and CO in the exhaust gas by making the
valve overlap time longer and injecting at least part of
the fuel during the valve overlap time when the second
combustion is being performed.
Claim 22
Dependent Claim
49 words
A compression ignition type engine as set forth
in claim 16, wherein said unburned HC and CO increasing
means increases the amounts of unburned HC and CO in the
exhaust gas by injecting additional fuel in an explosive
stroke or exhaust stroke when the second combustion is
being performed.
References Cited (Backward Citations)
JPH04334750A
Cited
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