JP2015021389A - Fuel injection control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel injection control device for stabilizing combustion while suppressing the occurrence of smoke.SOLUTION: The fuel injection control device for a spark ignition type direct-injection engine 1 having an ignition plug 36 arranged at the center of a combustion chamber 31 and a direct-injection injector 67 for injecting fuel directly into the combustion chamber executes first fuel injection for injecting 80-90% of a total fuel injection amount in a period from an intake stroke to the first half of a compression stroke to form substantially uniform and lean air-fuel mixture, and second fuel injection for injecting 10-20% of the total fuel injection amount in the second half of the compression stroke to form locally rich air-fuel mixture around the ignition plug, when the operating condition of the spark ignition type direct-injection engine is a predetermined or higher load condition.

Description

  The present invention relates to a fuel injection control device that controls the fuel injection amount, injection timing, and the like of a spark ignition direct injection engine, and relates to one that stabilizes combustion and suppresses the generation of smoke.

In a spark ignition direct injection engine such as a gasoline engine, direct injection (in-cylinder injection) is performed in which fuel is directly injected into a combustion chamber (inside a cylinder) in place of or in combination with conventional port injection. It is popular.
By such direct injection, the effect of cooling fresh air with the latent heat of vaporization of the fuel is enhanced, and knocking can be suppressed, and the output and torque can be improved by improving the charging efficiency.

In the case of such a direct injection engine, various techniques for forming a desired air-fuel mixture by performing fuel injection a plurality of times from the intake stroke to the compression stroke have been proposed.
For example, in Patent Document 1, when the catalyst is warmed up, the air-fuel ratio is made leaner than the combustion limit air-fuel ratio in the intake stroke, and the total air-fuel ratio in the intake stroke and the compression stroke is stoichiometric (theoretical air-fuel ratio). ) Is described as lean.
Patent Document 2 describes a split injection method in which fuel is injected once each in the second half of the intake stroke and the first half of the compression stroke in a high load region.
Patent Document 3 describes a split injection method in which injection is performed once during an intake stroke and twice during a compression stroke.
Patent Document 4 describes that the air-fuel ratio is made rich with respect to the stoichiometric mixture by split injection during medium / high load operation, and that only the intake stroke is injected when the load becomes higher. ing.

JP 2000-38945 A JP 2011-17285 A JP 2005-256630 A JP 2001-248482 A

In a direct injection gasoline engine, when the fuel injection amount increases in a high load state, the amount of smoke (i.e.) generated increases. This is because, for example, the mixing time is insufficient due to an increase in the fuel injection amount, the adhesion of the fuel to the wall surface increases, and the uneven distribution of the spray results in a non-uniform mixture.
On the other hand, it is known that a certain smoke suppression effect can be obtained by injecting fuel divided into a plurality of times. This is because the amount of fuel adhering to the wall surface is reduced and the air-fuel mixture distribution is improved.
However, in this case, a sufficient smoke reduction effect can be obtained because the mixing time of the fuel injected in the latter period is insufficient, or the air-fuel mixture becomes non-uniform due to the mutual interference between the initial spray and the subsequent spray. Often not.
On the other hand, when lean combustion is performed with the equivalent ratio of the entire combustion chamber as lean. Although it has been found that smoke can be suppressed, there are problems such as reduced combustion stability and output, and reduced purification efficiency of a three-way catalyst, which is a general exhaust gas aftertreatment device for gasoline engines. is there.
In view of the above-described problems, an object of the present invention is to provide a fuel injection control device that stabilizes combustion and suppresses the generation of smoke.

The present invention solves the above-described problems by the following means.
The invention according to claim 1 is a fuel injection control device for a spark ignition type direct injection engine having an ignition plug disposed in the center of the combustion chamber and a direct injection injector for directly injecting fuel into the combustion chamber, wherein the spark ignition When the operating state of the direct injection engine is a high load state that exceeds a predetermined level, 80 to 90% of the total fuel injection amount is injected from the intake stroke to the first half of the compression stroke to obtain a substantially uniform and lean air-fuel mixture. And a second fuel injection that injects 10 to 20% of the total fuel injection amount in the latter stage of the compression stroke to form a locally rich mixture around the spark plug; This is a fuel injection control device characterized in that
According to this, the ignition stability can be improved and the combustion can be stabilized by forming a rich air-fuel mixture around the spark plug by the second fuel injection.
In addition, the fuel that remains unburned in the rich region can be substantially completely burned by excess air (oxygen) present in the surrounding lean air-fuel mixture region, and the occurrence of smoke can be suppressed. it can.

The invention according to claim 2 is set such that an average equivalence ratio of an air-fuel mixture formed by the first fuel injection and the second fuel injection is set within a predetermined active range of the three-way catalyst. The fuel injection control device according to claim 1, wherein the fuel injection control device is a fuel injection control device.
According to this, by making it possible to use a three-way catalyst, it is possible to perform exhaust gas aftertreatment by a relatively simple and inexpensive exhaust gas treatment device applied to an existing general gasoline engine.

The invention according to claim 3 is the fuel injection control device according to claim 1 or 2, wherein the equivalence ratio of the air-fuel mixture around the spark plug immediately before ignition is set to 2 or less.
According to this, it is possible to prevent the air-fuel mixture around the spark plug from becoming excessively rich and increasing the generation of smoke.

The invention according to claim 4 is characterized in that the excess air ratio of the air-fuel mixture formed by the first fuel injection is 1.1 to 1.2. The fuel injection control device according to item 1.
According to this, the fuel remaining unburned in the region where the air-fuel mixture around the spark plug is rich can be surely substantially completely burned by the excess air remaining in the surrounding area.
In addition, if the excess air ratio is at this level, the flame can be sufficiently propagated by itself, and combustion can be completed before the exhaust valve is opened to prevent afterburning.

According to a fifth aspect of the invention, the spark ignition direct injection engine has a swirl flow forming means for forming a swirl flow in the combustion chamber, and the first fuel injection includes a plurality of fuel injections. The fuel injection control device according to claim 1, wherein the fuel injection control device is a fuel injection control device.
According to this, fuel injection is performed a plurality of times while a swirl flow such as tumble or swirl swirls inside the combustion chamber, thereby improving the mixture of the lean air-fuel mixture and enhancing the uniformity.

According to a sixth aspect of the present invention, the spark ignition direct injection engine has a port injection injector disposed in an intake port for introducing fresh air into the combustion chamber, and the first fuel injection is performed on the port injection injector. 6. The fuel injection control device according to claim 1, wherein the second fuel injection is performed using the direct injection injector.
According to this, by using the first fuel injection as the port injection, it is possible to sufficiently secure the fuel vaporization time and the mixing time and improve the vaporization state and uniformity of the lean air-fuel mixture.

  As described above, according to the present invention, it is possible to provide a fuel injection control device that stabilizes combustion and suppresses the generation of smoke.

It is a schematic diagram showing a configuration of an engine having an embodiment of a fuel injection control device to which the present invention is applied. It is a figure which shows the combustion chamber shape of the engine of FIG. 2 is a timing chart showing a fuel injection timing, an ignition timing, and the like at a high load after the end of warming in the engine of FIG. FIG. 2 is a diagram schematically showing an air-fuel mixture formation state immediately before ignition in the engine of FIG. 1. It is a graph which shows the correlation with the ratio of the 1st injection in the engine of FIG. 1, and the amount of smoke generation. It is a graph which shows the correlation with the ratio of the 1st injection in the engine of Drawing 1, and the amount of hydrocarbons (THC) generation. 2 is a graph showing a correlation between an equivalence ratio around a spark plug and a stratified volume in the engine of FIG. 1.

  An object of the present invention is to provide a fuel injection control device that stabilizes combustion and suppresses the generation of smoke, and injects 80 to 90% of the total injection amount per cycle in the first injection performed in the intake stroke. A uniform and lean air-fuel mixture, and in the second injection performed in the compression stroke, 10 to 20% of the total injection amount is injected to form a rich air-fuel mixture around the spark plug, and the total air-fuel ratio is reduced. It was solved by making it substantially stoichiometric (within the active range of the three-way catalyst).

Embodiments of a fuel injection control apparatus to which the present invention is applied will be described below.
The fuel injection control device of the embodiment is an engine control that comprehensively controls, for example, fuel injection timing, fuel injection amount, ignition timing, throttle valve opening, valve timing, etc. of a gasoline direct injection engine mounted on an automobile such as a passenger car. A unit (ECU).
FIG. 1 is a schematic diagram showing a configuration of an engine having a fuel injection control device of an embodiment.
The engine 1 includes a cylinder 10, a piston 20, a cylinder head 30, an intake device 40, an exhaust device 50, a fuel supply device 60, and the like.

The cylinder 10 includes a sleeve into which the piston 20 is inserted.
The cylinder 10 is formed in a cylinder block formed integrally with a crankcase (not shown).

The piston 20 is a member that is inserted into the sleeve of the cylinder 10 and reciprocates.
The piston 20 is connected to a crankshaft (not shown) via a connecting rod 21.
The crown surface 22 of the piston 20 forms a combustion chamber of the engine 1 in cooperation with the cylinder head 30.

The cylinder head 30 is provided at the end of the cylinder 10 opposite to the crankshaft side.
The cylinder head 30 includes a combustion chamber 31, an intake port 32, an exhaust port 33, an intake valve 34, an exhaust valve 35, a spark plug 36, and the like.
The combustion chamber 31 is a recess formed facing the crown surface 22 of the piston 20 and is formed in, for example, a pent roof type.
The combustion chamber shape will be described in detail later.
The intake port 32 is a flow path for introducing combustion air (fresh air) into the combustion chamber 31.
The exhaust port 33 is a flow path for discharging burned gas (exhaust gas) from the combustion chamber 31.
For example, two intake ports 32 and two exhaust ports 33 are formed per cylinder.
The intake valve 34 and the exhaust valve 35 open and close the intake port 32 and the exhaust port 33 at predetermined valve timings, respectively.
The intake valve 34 and the exhaust valve 35 are driven by a valve drive system such as a camshaft and a rocker arm.
The spark plug 36 generates a spark (spark) at a predetermined ignition timing in accordance with an ignition signal generated by the engine control unit, and ignites the air-fuel mixture.
The spark plug 36 is disposed substantially at the center of the combustion chamber 31 (near the center axis of the cylinder 10).

The intake device 40 introduces combustion air into the engine 1.
The intake device 40 includes an intake duct 41, an air cleaner 42, a throttle 43, an intake manifold 44, and the like.
The intake duct 41 is a conduit that introduces air from the atmosphere and supplies the air to the engine 1.
The air cleaner 42 is provided in the vicinity of the inlet of the intake duct 41 and filters and purifies dust in the air.
The throttle 43 is provided downstream of the air cleaner 42 in the intake duct 41 and adjusts the output of the engine 1 by reducing the amount of intake air.
The throttle 43 includes a valve element such as a butterfly valve and an electric actuator that drives the valve element.
The electric actuator is driven according to a control signal from the engine control unit.
The intake manifold 44 is provided on the downstream side of the throttle 43 and has a surge tank formed in a container shape and a branch pipe that is connected to the intake port 32 of each cylinder and introduces fresh air.

The exhaust device 50 discharges exhaust gas from the engine 1.
The exhaust device 50 includes an exhaust pipe 51, a catalytic converter 52, and the like.
The exhaust pipe 51 is a conduit for exhausting exhaust gas that has exited from the exhaust port 33.
The catalytic converter 52 is provided at an intermediate portion of the exhaust pipe 51.
The catalytic converter 52 is configured by supporting a noble metal such as platinum or rhodium on a honeycomb-like alumina carrier, and includes a three-way catalyst that purifies HC, NOx, CO, and the like.

The fuel supply device 60 includes a fuel tank 61, a feed pump 62, a fuel transfer pipe 63, a high-pressure pump 64, a fuel pipe 65, a delivery pipe 66, an injector 67, and the like.
The fuel tank 61 is a container for storing fuel (gasoline), and is mounted, for example, under the floor at the rear of the vehicle body.
The feed pump (low pressure pump) 62 pumps the fuel in the fuel tank 61 to the high pressure pump 64 via the fuel transfer pipe 63.
The high-pressure pump 64 boosts the fuel supplied from the feed pump 62 to a high pressure and supplies the fuel to a delivery pipe 66 that also serves as a pressure accumulation chamber via a fuel pipe 65.
The high-pressure pump 64 is driven by a cam shaft 64 a that is provided in the cylinder head 30 and drives the intake valve 34.
The injector 67 includes a needle valve that is driven by an actuator having, for example, a solenoid or a piezo element. This is the amount to be injected.
The injector 67 has a function of performing fuel injection a plurality of times per cycle.
As shown in FIG. 1 and the like, the nozzle of the injector 67 is inserted into the cylinder from the intake valve 34 side of the combustion chamber 31 (on the cylinder bore side).

Next, the shape of the combustion chamber of the engine 1 will be described.
FIG. 2 is a diagram showing a combustion chamber shape of the engine of the embodiment.
FIG. 2A is a view taken along a plane perpendicular to the center axis direction of the crankshaft and passing through the center of the cylinder, and FIG. 2B is a view taken along the line bb in FIG. FIG.
The combustion chamber 31 of the cylinder head 30 is configured to have a pent roof portion 31a formed substantially in a so-called pent roof type (triangular roof type) and a squish area 31b provided around the pent roof portion 31a.
The main roof portion of the pent roof portion 31a is provided with valve body portions of the intake valve 34 and the exhaust valve 35, respectively.
The electrode part of the spark plug 36 is arrange | positioned at the top part of the pent roof part 31a.

A cavity 23, an exhaust valve recess 24, and the like are provided on the crown surface 22 of the piston 20.
The cavity 23 forms a layered mixture around the spark plug 36 by winding up the air-fuel mixture formed by the fuel injected in the second injection, which will be described later, to the spark plug 36 side using tumble. It is a concave portion to be
For example, the cavity 23 is formed in a substantially elliptical shape when viewed from the central axis direction of the cylinder 10 and is offset to the intake valve 34 side (injector 67 side) with respect to the center of the piston 20. Has been placed.
The end position on the exhaust valve 35 side where the air-fuel mixture is wound up from the cavity 23 (the right end in FIG. 2B) is slightly inhaled with respect to the top of the pent roof portion 31a where the spark plug 36 is provided. It is arranged offset to the side (left side in FIG. 2 (b)).
The exhaust valve recess 24 is a recess provided to prevent the exhaust valve 35 from interfering with the piston 20 when the valve drive mechanism is out of order.

The injector 67 has six nozzle holes, for example.
In the embodiment, the points P at which the spray injected from the injector 67 in the latter half of the compression stroke collides with the crown surface 22 of the piston 20 are distributed so that five of the six points are in the cavity 23.
The spray injected into the cavity 23 is blown up from the cavity 23 to the vicinity of the ignition plug 36 of the combustion chamber 31 while being vaporized in fresh air at 100 ° C. or higher to form a mixed air flow, and around the ignition plug 36. A rich air-fuel mixture is formed in a layered manner with respect to the peripheral region.

FIG. 3 is a timing chart showing the fuel injection timing, ignition timing, etc. at the time of high load after the warm-up of the engine 1 is completed.
As shown in FIG. 3, the engine 1 is an Otto cycle four-stroke engine that sequentially repeats an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke.
The intake valve 34 is opened immediately before the end of the exhaust stroke and immediately after the start of the compression stroke, and is closed during other periods.
The exhaust valve 35 is opened immediately before the end of the expansion stroke and immediately after the start of the intake stroke, and is closed during other periods.
The spark plug 36 generates a spark at a predetermined ignition timing immediately before the compression top dead center at the end of the compression stroke, and ignites the air-fuel mixture.

Hereinafter, fuel injection and air-fuel mixture formation in a high load state in the engine 1 of the embodiment will be described.
The engine control unit determines the load state of the engine 1 from the required torque from the driver, the throttle opening, the intake pipe pressure, the fuel injection amount, and the like. In order to stabilize, the divided injection including the first injection and the second injection described below is performed.
The injector 67 performs the first injection in the intake stroke, and forms a substantially uniform air-fuel mixture over the entire combustion chamber 31.
The equivalence ratio (air-fuel ratio) of the substantially uniform air-fuel mixture is set to be lean with respect to the stoichiometric (theoretical equivalence ratio), and the excess air ratio λ is, for example, 1.1 to 1.1, which allows flame propagation alone. It is set to about 1.2.
This first injection may be a single injection, but may be divided into a plurality of injections.
For example, when the engine has a tumble flow generating means (swirl flow forming means) such as an intake port having a shape capable of generating a tumble flow, the tumble flow is substantially equal during the period of one round in the combustion chamber. By performing the injection a plurality of times at intervals, the homogeneity of the air-fuel mixture can be improved.
As an example, when the tumble ratio in the combustion chamber is 2, the tumble flow makes one round in the combustion chamber at a crank angle of 180 °. In this case, injection is performed three times at intervals of 60 ° crank angle from the intake stroke to the compression stroke.
The fuel injection amount of the first injection is set to 80 to 90% of the total injection amount including the fuel injection amount of the second injection.

The injector 67 performs the second injection at the latter stage of the compression stroke to form a relatively rich mixture around the spark plug 36 in a layered manner.
FIG. 4 is a diagram schematically showing an air-fuel mixture formation state immediately before ignition in the engine of FIG.
As shown in FIG. 4, immediately before ignition, a region R1 of a fuel-rich mixture with respect to stoichiometry is formed around the spark plug 36 by the second injection.
The equivalent ratio φ in the region R1 around the spark plug 36 is set to be 2 or less.
The fuel injection amount of the second injection is set to 10 to 20% of the total injection amount including the fuel injection amount of the first injection (the remaining amount obtained by subtracting the injection amount of the first injection from the total injection amount).
Further, the average equivalence ratio of the entire combustion chamber obtained by totaling the fuel injection amounts of the first injection and the second injection is substantially 1 (stoichi), and is within the active range of the three-way catalyst.

Around the region R1, there is formed a substantially uniform air-fuel mixture region R2 formed by the first injection and lean to the stoichiometry.
When the spark plug 36 generates a spark in this state, it ignites in the rich region R1 and then propagates in the lean region R2.
At this time, since the region R1 is rich, good ignition stability can be obtained, and combustion can be stabilized.
Further, since the surrounding region R2 is lean with respect to the stoichiometry and the air is excessive, the fuel that remains unburned in the region R1 is substantially completely burned by the remaining air in the region R2.
In addition, although the inside of R2 is lean, it has an excess air ratio that allows flame propagation alone, so that it is possible to complete the fuel before the exhaust valve 35 is opened and to prevent the occurrence of afterburning. .

Hereinafter, a description will be given of the ratio of the injected fuel amount between the first injection and the second injection (injection division ratio) and the grounds for setting the air-fuel ratio in each region.
FIG. 5 is a graph showing the correlation between the ratio of the first injection and the amount of smoke generated in the engine of FIG.
In FIG. 5, the horizontal axis indicates the ratio of the first injection to the total fuel injection amount, and the vertical axis indicates the smoke generation amount.
As shown in FIG. 5, the amount of smoke generated decreases as the ratio of the first injection increases, and smoke is generated in the region where the ratio of the first injection is 0.8 or more as in this embodiment. Is at a level that does not substantially matter.

FIG. 6 is a graph showing the correlation between the ratio of the first injection and the amount of generated hydrocarbon (THC) in the engine of FIG.
In FIG. 6, the horizontal axis indicates the ratio of the first injection to the total fuel injection amount, and the vertical axis indicates the THC generation amount.
As shown in FIG. 6, the ratio of the first injection has little effect on the THC generation amount, and the THC generation amount is substantially reduced in the region where the ratio of the first injection is 0.8 or more as in this embodiment. At a level that does not matter.

FIG. 7 is a graph showing the correlation between the equivalent ratio around the spark plug and the stratified volume in the engine of FIG.
The horizontal axis indicates the ratio (%) of the stratification volume around the spark plug, and the vertical axis indicates the equivalent ratio (φ) in the stratification region (region R1) around the spark plug.
Also, when the ratio of the fuel injection amount between the first injection and the second injection (injection ratio) is 6: 4, the data is a solid line, the data when it is 7: 3 is the broken line, and the data is 8: 2. These data are shown by a one-dot chain line.
Note that when the injection ratios are 6: 4, 7: 3, and 8: 2, the equivalent ratio (φ) of the peripheral portion (region R2) other than the stratification region of the combustion chamber 31 is substantially 0. It becomes around 6, 0.7, 0.8.

In order to improve the ignitability around the spark plug 36, the equivalent ratio (φ) around the spark plug is required to be 1.7 or more.
On the other hand, if the equivalent ratio (φ) around the spark plug exceeds 2.0, the PN deteriorates rapidly, so this equivalent ratio is required to be 2.0 or less.
Further, if the region R2 is excessively lean and the flame propagation alone becomes unstable, it becomes difficult to complete the combustion until the exhaust valve 35 is opened.
In consideration of the above conditions, in this embodiment, the ratio of the injection amount of the second injection to the total injection amount is set to be 10 to 20%.

According to the present embodiment described above, by forming the region R1 in which the air-fuel mixture is locally rich around the spark plug 36 by the second injection, the ignition stability can be improved and the combustion can be stabilized. it can.
Further, by setting the equivalent ratio in the region R1 to 2 or less, it is possible to prevent the air-fuel mixture from becoming excessively rich and increasing the generation of smoke.
Further, a substantially uniform and lean region R2 is formed around the rich air-fuel mixture by the first injection, and the excess air ratio here is set to 1.1 to 1.2, thereby burning in the rich region. The remaining fuel can be completely burned by excess air.
In addition, if the excess air ratio is at this level, the flame can be sufficiently propagated by itself, and combustion can be completed before the exhaust valve is opened to prevent afterburning.
Furthermore, by making the equivalence ratio of the first injection and the second injection total substantially stoichiometric, it becomes possible to use a three-way catalyst, and exhaust gas aftertreatment can be performed by a simple and low-cost exhaust gas treatment device. .

(Modification)
The present invention is not limited to the embodiments described above, and various modifications and changes are possible, and these are also within the technical scope of the present invention.
(1) The engine of the embodiment is, for example, a naturally aspirated gasoline engine. However, the present invention can also be applied to a supercharged engine or a spark ignition type internal combustion engine using a fuel other than gasoline. .
(2) The structure of each member which comprises an engine is not limited to the Example mentioned above, It can change suitably.
For example, the shape of the combustion chamber, the shape of the crown of the piston, the spray formation pattern of the injector, and the like can be changed as appropriate.
(3) In the embodiment, fuel is directly injected into the combustion chamber (cylinder) in both the first injection and the second injection. However, in the case of an engine having an injector in the intake port, one of the first injections is performed. You may inject part or all by port injection.
As a result, the fuel vaporization time and the mixing time can be secured long, and the vaporization state of the lean air-fuel mixture and the uniformity of the mixing can be improved.
(4) In the embodiment, the first injection is performed in the intake stroke. However, when the first injection is performed in a plurality of times, the first injection is performed from the intake stroke to the first half of the compression stroke. May be.

DESCRIPTION OF SYMBOLS 1 Engine 10 Cylinder 20 Piston 21 Connecting rod 22 Crown 23 Cavity 24 Exhaust valve recess 30 Cylinder head 31 Combustion chamber 32 Intake port 33 Exhaust port 34 Intake valve 35 Exhaust valve 36 Spark plug 40 Intake device 41 Intake duct 42 Air cleaner 43 Throttle 44 Intake manifold DESCRIPTION OF SYMBOLS 50 Exhaust apparatus 51 Exhaust manifold 52 Catalytic converter 60 Fuel supply apparatus 61 Fuel tank 62 Feed pump 63 Fuel conveyance pipe 64 High pressure pump 64a Cam shaft 65 Fuel piping 66 Delivery pipe 67 Injector

Claims (6)

A fuel injection control device for a spark ignition type direct injection engine having an ignition plug disposed in the center of the combustion chamber and a direct injection injector for directly injecting fuel into the combustion chamber,
When the operating state of the spark ignition direct injection engine is a high load state of a predetermined or higher,
A first fuel injection that injects 80 to 90% of the total fuel injection amount from the intake stroke to the first half of the compression stroke to form a substantially uniform and lean mixture;
A second fuel injection for injecting 10 to 20% of the total fuel injection amount in a later stage of the compression stroke to form a locally rich mixture around the spark plug; Control device. The average equivalence ratio of the air-fuel mixture formed by the first fuel injection and the second fuel injection is set so as to be within a predetermined active range of the three-way catalyst. Fuel injection control device. The fuel injection control device according to claim 1 or 2, wherein the equivalence ratio of the air-fuel mixture around the spark plug immediately before ignition is set to 2 or less. The fuel injection control according to any one of claims 1 to 3, wherein an excess air ratio of an air-fuel mixture formed by the first fuel injection is 1.1 to 1.2. apparatus. The spark ignition direct injection engine has a swirl flow forming means for forming a swirl flow inside the combustion chamber;
The fuel injection control device according to any one of claims 1 to 4, wherein the first fuel injection includes a plurality of fuel injections. The spark ignition direct injection engine has a port injection injector disposed in an intake port for introducing fresh air into the combustion chamber;
The said 1st fuel injection is performed using the said port injection injector, The said 2nd fuel injection is performed using the said direct injection injector. Any one of Claim 1-5 characterized by the above-mentioned. The fuel injection control device described.

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