EP0856655A2
Expired / Lapsed
EP
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Direct fuel injection engine
Assignee: Mazda Motor Corp
•
Filing: 1998-01-28
•
Granted: —
•
Expires: 2018-01-28
Abstract
Abstract A direct injection engine including, an ignition plug projected into a combustion chamber, an injector for injecting a fuel directly into the combustion chamber, a catalyst provided in an exhaust gas passage for cleaning an exhaust gas, a temperature sensor for detecting a coolant temperature condition of the catalyst, a control unit, for receiving signals from the sensor to determine that the catalyst is lower than an activation temperature when the engine coolant temperature is lower than a predetermined value, for calculating a fuel injection timing and fuel injection amount from the injector to form a fuel rich combustion gas mixture around the ignition plug equivalent to or richer than a combustion gas mixture having a theoretical air fuel ratio and a fuel lean combustion gas mixture leaner than the combustion gas mixture having the theoretical air fuel ratio in an area surrounding said area of the fuel rich combustion gas mixture when it is determined that the temperature of the catalyst is lower than an activation temperature, and, for producing signals to the injector to inject the fuel at the fuel injection timing. The emission performance of the exhaust gas is improved. The warming up of the catalyst as well as the engine is facilitated.
Inventors
- 👤 Hirofumi Nishimura
- 👤 Hiroyuki Yamashita
- 👤 Youichi Kuji
- 👤 Noriyuki Ota
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 12:10
CPC Classifications
F; F02; F02P; F02P5/00; F02P5/04; F02P5/145; F02P5/15; F02P5/1502; F02P5/1506; F02M; F02M69/00; F02D; F02D41/00; F02D41/02; F02D41/021; F02D41/0235; F02D41/024; F02D41/30; F02D41/3011; F02D41/3017; F02D41/3023; F02D41/38; F02D41/40; F02D41/402; F02B; F02B75/00; F02B75/12; F02B2075/125; F02D2041/389; F02D41/3029; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12; Y02T10/40
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
140 words
A direct injection engine comprising; an ignition plug projected into a combustion chamber, an injector for injecting a fuel directly into the combustion chamer, a catalyst provided in an exhaust gas passage for cleaning an exahust gas, a temperature condition judging means for judging a temperature condition of the
catalyst, a fuel supply means for forming a fuel rich combution gas mixture around the
ignition plug equivalent to or richer than a combustion gas mixture having a
theoretical air fuel ratio and a fuel lean combustion gas mixture leaner than the
combustion gas mixture having the theoretical air fuel ratio in an area surrounding said
area of the fuel rich combustion gas mixture by means of the injector when the
temperature of the catalyst is lower than an activation temperature based on the
judgment of the temperature condition judging means.
Claim 2
Dependent Claim
114 words
A direct injection engine as recited in claim 1 wherein the fuel supply means is
actuated to form the fuel rich combustion gas mixture around the ignition plug
equivalent to or richer than the combustion gas mixture having the theoretical air fuel
ratio by injecting the fuel from the injector in a compression stroke when the
temperature of the catalyst is lower than an activation temperature based on the
judgment of the temperature condition judging means and to form a fuel lean
combustion gas mixture leaner than said combustion gas mixture of the theoretical air
fuel ratio in said area surrounding said area of the fuel rich combustion gas mixture by
another fuel supply.
Claim 3
Dependent Claim
35 words
A direct injection engine as recited in claim 2 wherein the air fuel ratio of the
combustion gas mixture in the combustion chamber is maintained at substantially the
theoretical air fuel ratio as a whole.
Claim 4
Dependent Claim
41 words
A direct injection engine as recited in claim 2 wherein the fuel supply means executes
a separate injection in which the fuel is injected from the injector directly into the
combustion chamber in both an intake stroke and combustion stroke respectively.
Claim 5
Dependent Claim
34 words
A direct injection engine as recited in claim 4 wherein a fuel injection rate is
determined such that an injection fuel amount in the intake stroke is greater than that
in the compression stroke.
Claim 6
Dependent Claim
31 words
A direct injection engine as recited in claim 4 wherein the fuel injection rate of the fuel
injection amount in the intake stroke is increased as an engine load is increased.
Claim 7
Dependent Claim
54 words
A direct injection engine as recited in claim 4 further comprising an ignition timing
control means for retarding the ignition timing from a base ignition timing when the
separate injection is executed in the case where the catalyst is in a cold condition in
which the catalyst temperature is lower than the activation temperature.
Claim 8
Dependent Claim
60 words
A direct injection engine as recited in claim 7 wherein the ignition timing is retarded
in a very low engine load condition and in the cold condition of the catalyst , and
wherein the separate injection is executed with an increased supply of an amount of air
and fuel which is greater than those corresponding to an engine operating condition.
Claim 9
Dependent Claim
46 words
A direct injection engine as recited in claim 8 wherein the retardation of the ignition
timing and the increased supply of the air and fuel is canceled when the engine load is
increased from the very low engine load condition to a predetermined engine load
condition.
Claim 10
Dependent Claim
24 words
A direct injection engine as recited in claim 7 wherein the retardation of the ignition
timing is reduced when a running condition is established.
Claim 11
Dependent Claim
48 words
A direct injection engine as recited in claim 4 wherein the separate injection is
executed where the catalyst is in a cold condition where the catalyst temperature is lower
than the activation temperature, and wherein only an intake stroke injection is executed
after the catalyst is warmed up.
Claim 12
Dependent Claim
23 words
A direct injection engine as recited in claim 11 wherein only a compression stroke
injection is executed after the engine is warmed up.
Claim 13
Dependent Claim
48 words
A direct injection engine as recited in claim 4 wherein the separate injection is
executed where the catalyst is in a cold condition where the catalyst temperature is lower
than the activation temperature, and wherein only a compression stroke injection is
executed after the catalyst is warmed up.
Claim 14
Dependent Claim
24 words
A direct injection engine as recited in claim 4 wherein the compression stroke
injection is executed in a range of BTDC 50°- 60° CA.
Claim 15
Dependent Claim
24 words
A direct injection engine as recited in claim 4 wherein the intake stroke injection is
executed in a range of ATDC 70° 20° CA.
Claim 16
Dependent Claim
53 words
A direct injection engine as recited in claim 2 wherein a cavity of a concave
configuration is formed on a top portion of a piston which partly define the combustion
chamber so that an injected fuel through the compression stroke injection is reflected on
the cavity surface to stay around the ignition plug.
Claim 17
Dependent Claim
52 words
A direct injection engine as recited in claim 1 wherein the temperature condition
judging means infers the temperature of the catalyst based on an engine coolant
temperature to determine that the temperature of the catalyst is lower than the activation
temperature when the engine coolant temperature is lower than a predetermined value.
Claim 18
Dependent Claim
54 words
A direct injection engine as recited claim 1 wherein the fuel supply means is
actuated to form the fuel rich combustion gas mixture around the ignition plug and
a fuel lean combustion gas mixture in the area surrounding said area of the fuel rich
combustion gas mixture after an engine starting operation is completed.
Claim 19
Dependent Claim
126 words
A direct injection engine comprising; an ignition plug projected into a combustion chamber, an injector for injecting a fuel directly into the combustion chamber, a catalyst provided in an exhaust gas passage for cleaning an exhaust gas, a temperature condition judging means for judging a temperature condition of the
catalyst, a fuel supply means for forming a fuel rich combustion gas mixture around the
ignition plug equivalent to or richer than a combustion gas mixture having a
theoretical air fuel ratio and a fuel lean combustion gas mixture leaner than the
combustion gas mixture having the theoretical air fuel ratio in an area surrounding said
area of the fuel rich combustion gas mixture by means of the injector when the engine
is in a cold condition.
Claim 20
Dependent Claim
114 words
A direct injection engine as recited in claim 19 wherein the fuel supply means is
actuated to form the fuel rich combustion gas mixture around the ignition plug
equivalent to or richer than the combustion gas mixture having the theoretical air fuel
ratio by injecting the fuel from the injector in a compression stroke when the
temperature of the catalyst is lower than an activation temperature based on the
judgment of the temperature condition judging means and to form a fuel lean
combustion gas mixture leaner than said combustion gas mixture of the theoretical air
fuel ratio in said area surrounding said area of the fuel rich combustion gas mixture by
another fuel supply.
Claim 21
Dependent Claim
35 words
A direct injection engine as recited in claim 20 wherein the air fuel ratio of the
combustion gas mixture in the combustion chamber is maintained at substantially the
theoretical air fuel ratio as a whole.
Claim 22
Dependent Claim
41 words
A direct injection engine as recited in claim 20 wherein the fuel supply means
executes a separate injection in which the fuel is injected from the injector directly into
the combustion chamber in both an intake stroke and combustion stroke respectively.
Claim 23
Dependent Claim
32 words
A direct injection engine as recited in claim 20 wherein it is determined that the
engine is in the cold condition when an engine coolant temperature is lower than a
predetermined value.
Claim 24
Dependent Claim
54 words
A direct injection engine as recited claim 19 wherein the fuel supply means is
actuated to form the fuel rich combustion gas mixture around the ignition plug and
a fuel lean combustion gas mixture in the area surrounding said area of the fuel rich
combustion gas mixture after an engine starting operation is completed.
Claim 25
Dependent Claim
269 words
A direct injection engine comprising; an ignition plug projected into a combustion chamber, an injector for injecting a fuel directly into the combustion chamber, a catalyst provided in an exhaust gas passage for cleaning an exhaust gas, a temperature condition judging means for judging a temperature condition of the
catalyst, a fuel supply means for forming a fuel rich combustion gas mixture around the
ignition plug equivalent to or richer than a combustion gas mixture having a
theoretical air fuel ratio and a fuel lean combustion gas mixture leaner than the
combustion gas mixture having the theoretical air fuel ratio in an area surrounding said
area of the fuel rich combustion gas mixture by means of the injector when the
temperature of the catalyst is lower than an activation temperature based on the
judgment of the temperature condition judging means, the fuel supply means being actuated to form the fuel rich combustion gas
mixture around the ignition plug equivalent to or richer than the combustion gas
mixture having the theoretical air fuel ratio by injecting the fuel from the injector in a
compression stroke when the temperature of the catalyst is lower than an activation
temperature based on the judgment of the temperature condition judging means and to
form a fuel lean combustion gas mixture leaner than said combustion gas mixture of the
theoretical air fuel ratio in said area surrounding said area of the fuel rich combustion
gas mixture by another fuel supply, and, a fuel injection rate being determined such that an injection fuel amount in
the intake stroke is greater than that in the compression stroke.
Claim 26
Dependent Claim
54 words
A direct injection engine as recited claim 25 wherein the fuel supply means is
actuated to form the fuel rich combustion gas mixture around the ignition plug and
a fuel lean combustion gas mixture in the area surrounding said area of the fuel rich
combustion gas mixture after an engine starting operation is completed.
Claim 27
Dependent Claim
30 words
A direct injection engine as recited claim 25 wherein the fuel being injected from
the injector directly into the combustion chamber in both an intake stroke and
combustion stroke respectively.
Claim 28
Dependent Claim
289 words
A direct injection engine comprising; an ignition plug projected into a combustion chamber, an injector for injecting a fuel directly into the combustion chamber, a catalyst provided in an exhaust gas passage for cleaning an exhaust gas, a temperature condition judging means for judging a temperature condition of the
catalyst, a fuel supply means for forming a fuel rich combustion gas mixture around the
ignition plug equivalent to or richer than a combustion gas mixture having a
theoretical air fuel ratio and a fuel lean combustion gas mixture leaner than the
combustion gas mixture having the theoretical air fuel ratio in an area surrounding said
area of the fuel rich combustion gas mixture by means of the injector when the
temperature of the catalyst is lower than an activation temperature based on the
judgment of the temperature condition judging means, the fuel supply means being actuated to form the fuel rich combustion gas
mixture around the ignition plug equivalent to or richer than the combustion gas
mixture having the theoretical air fuel ratio by injecting the fuel from the injector in a
compression stroke when the temperature of the catalyst is lower than an activation
temperature based on the judgment of the temperature condition judging means and to
form a fuel lean combustion gas mixture leaner than said combustion gas mixture of the
theoretical air fuel ratio in said area surrounding said area of the fuel rich combustion
gas mixture by another fuel supply, a fuel injection rate being determined such that an injection fuel amount in
the intake stroke is greater than that in the compression stroke, and, the injection rate of the fuel injection amount in the intake stroke is increased
as an engine load is increased.
Claim 29
Dependent Claim
54 words
A direct injection engine as recited claim 28 wherein the fuel supply means is
actuated to form the fuel rich combustion gas mixture around the ignition plug and
a fuel lean combustion gas mixture in the area surrounding said area of the fuel rich
combustion gas mixture after an engine starting operation is completed.
Claim 30
Dependent Claim
190 words
A direct injection engine comprising; an ignition plug projected into a combustion chamber, an injector for injecting a fuel directly into the combustion chamber, a catalyst provided in an exhaust gas passage for cleaning an exhaust gas, a temperature condition judging means for judging a temperature condition of the
catalyst, a fuel supply means for forming a fuel rich combustion gas mixture around the
ignition plug equivalent to or richer than a combustion gas mixture having a
theoretical air fuel ratio including an excessive fuel not to be combusted at an initial
combustion stage in the combustion chamber and a fuel lean combustion gas mixture
leaner than the combustion gas mixture having the theoretical air fuel ratio in an area
surrounding said area of the fuel rich combustion gas mixture so as to reduce the
combustion speed at a main combustion stage following the initial combustion stage by
means of the injector when the temperature of the catalyst is lower than an activation
temperature based on the judgment of the temperature condition judging means, whereby the excessive fuel is combusted in a late combustion stage
following the main combustion stage.
Claim 31
Dependent Claim
114 words
A direct injection engine as recited in claim 30 wherein the fuel supply means is
actuated to form the fuel rich combustion gas mixture around the ignition plug
equivalent to or richer than the combustion gas mixture having the theoretical air fuel
ratio by injecting the fuel from the injector in a compression stroke when the
temperature of the catalyst is lower than an activation temperature based on the
judgment of the temperature condition judging means and to form a fuel lean
combustion gas mixture leaner than said combustion gas mixture of the theoretical air
fuel ratio in said area surrounding said area of the fuel rich combustion gas mixture by
another fuel supply.
Claim 32
Dependent Claim
35 words
A direct injection engine as recited in claim 31 wherein the air fuel ratio of the
combustion gas mixture in the combustion chamber is maintained at substantially the
theoretical air fuel ratio as a whole.
Claim 33
Dependent Claim
41 words
A direct injection engine as recited in claim 31 wherein the fuel supply means
executes a separate injection in which the fuel is injected from the injector directly into
the combustion chamber in both an intake stroke and combustion stroke respectively.
Claim 34
Dependent Claim
52 words
A direct injection engine as recited in claim 30 wherein the temperature condition
judging means infers the temperature of the catalyst based on an engine coolant
temperature to determine that the temperature of the catalyst is lower than the
activation temperature when the engine coolant temperature is lower than a
predetermined value.
Claim 35
Dependent Claim
54 words
A direct injection engine as recited claim 30 wherein the fuel supply means is
actuated to form the fuel rich combustion gas mixture around the ignition plug and
a fuel lean combustion gas mixture in the area surrounding said area of the fuel rich
combustion gas mixture after an engine starting operation is completed.
Claim 36
Dependent Claim
184 words
A direct injection engine comprising; an ignition plug projected into a combustion chamber, an injector for injecting a fuel directly into the combustion chamber, a catalyst provided in an exhaust gas passage for cleaning an exhaust gas, a temperature sensor for detecting a coolant temperature condition of the
catalyst, a control unit; for receiving signals from the sensor to determine that the catalyst is lower
than an activation temperature when the engine coolant temperature is lower than a
predetermined value, for calculating a fuel injection timing and fuel injection amount from the
injector to form a fuel rich combustion gas mixture around the ignition plug
equivalent to or richer than a combustion gas mixture having a theoretical air fuel
ratio and a fuel lean combustion gas mixture leaner than the combustion gas mixture
having the theoretical air fuel ratio in an area surrounding said area of the fuel rich
combustion gas mixture when it is determined that the temperature of the catalyst is
lower than an activation temperature, and, for producing signals to the injector to inject the fuel at the fuel injection
timing.
Claim 37
Dependent Claim
203 words
A direct injection engine comprising; an ignition plug projected into a combustion chamber, an injector for injecting a fuel directly into the combustion chamber, a catalyst provided in an exhaust gas passage for cleaning an exhaust gas, a temperature sensor for detecting a coolant temperature condition of the
catalyst, a control unit; for receiving signals from the sensor to determine that the catalyst is lower
than an activation temperature when the engine coolant temperature is lower than a
predetermined value, for calculating a first fuel injection timing and first fuel injection amount
from the injector to form a fuel rich combustion gas mixture around the ignition plug
equivalent to or richer than a combustion gas mixture having a theoretical air fuel
ratio and calculating a second fuel injection timing and second fuel injection amount
from the injector to form a fuel lean combustion gas mixture leaner than the
combustion gas mixture having the theoretical air fuel ratio in an area surrounding said
area of the fuel rich combustion gas mixture when it is determined that the temperature
of the catalyst is lower than an activation temperature, and, for producing signals to the injector to inject the fuel at the fuel injection
timings respectively.
Claim 38
Dependent Claim
33 words
A direct injection engine as recited in claim 37 wherein the first fuel injection timing
is set at a compression stroke and the second fuel injection timing is set at an intake
stroke.
Claim 39
Dependent Claim
38 words
A direct injection engine as recited in claim 37 wherein a total amount of the first
and second fuel injections provide a combustion gas mixture having the theoretical air
fuel ratio in the combustion chamber as a whole.
References Cited (Backward Citations)
JPH08193536A
Cited
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