JP3818100B2 - Fuel injection control device for in-cylinder direct injection internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel injection control device for a direct injection type internal combustion engine, and more particularly, to a fuel injection technique for increasing the temperature of a catalyst.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a direct injection type internal combustion engine, in order to release poisoning of the catalyst due to sulfur or the like, the fuel is injected between the expansion stroke and the exhaust stroke, and the injected fuel is burned by the catalyst. Are known (see Japanese Patent Laid-Open Nos. 2000-130236 and 2000-054900).
[0003]
[Problems to be solved by the invention]
By the way, as described above, when fuel injection is performed between the expansion stroke and the exhaust stroke, combustion inside the catalyst is abruptly performed, a temperature difference is generated in the catalyst, and a semi-cell carrier having a particularly thin cell thickness is used. With the catalyst used, there was a possibility of cracking of the ceramic support.
[0004]
Therefore, as a method of avoiding sudden combustion inside the catalyst, the fuel injection amount between the expansion stroke and the exhaust stroke is set to a small value immediately after the start, and then gradually increased to gradually increase the temperature to the required temperature. It was investigated.
However, in general, since the injection amount between the expansion stroke and the exhaust stroke is small, in order to avoid rapid combustion, it is required to set the fuel injection amount below the minimum fuel amount that can be injected in the fuel injection valve. As a result, it was practically impossible to control the temperature rise by changing the injection amount.
[0005]
The present invention has been made in view of the above problems, and provides a fuel injection control device for a direct injection type internal combustion engine that can gradually raise the temperature of a catalyst by fuel injection between an expansion stroke and an exhaust stroke. The purpose is to provide.
[0006]
[Means for Solving the Problems]
Therefore, according to the first aspect of the present invention, in the internal combustion engine having a fuel injection valve that directly injects fuel into the cylinder, the catalyst interposed in the exhaust passage is raised by fuel injection between the expansion stroke and the exhaust stroke. The fuel injection control device for heating is configured to thin out the fuel injection between the expansion stroke and the exhaust stroke, and gradually reduce the number of thinning injections .
[0007]
According to such a configuration, the temperature of the catalyst is increased by burning the fuel injected between the expansion stroke and the exhaust stroke with the catalyst, but the fuel is not injected every time between the expansion stroke and the exhaust stroke of each cylinder. The amount of fuel supplied to the catalyst is controlled to be reduced by thinning out without performing some injections, and the number of injections to be thinned out is gradually reduced to gradually reduce the amount of fuel supplied to the catalyst. Increase.
[0008]
The invention according to claim 2 is configured such that the number of thinned injections increases as the engine speed increases. According to such a configuration, generally the higher the engine speed in the catalyst temperature is high Ino, the higher the engine speed, to increase the number of injections of thinning.
[0009]
The invention according to claim 3 is configured to increase the number of thinned injections as the engine load increases. According to such a configuration, the catalyst temperature is generally higher as the engine load is larger, and the engine load is higher when a certain proportion of the injection amount corresponding to the intake air amount is injected between the expansion stroke and the exhaust stroke. As the absolute amount of the injection amount in the expansion stroke increases, the number of injections to be thinned out increases as the engine load increases .
[0010]
In the invention according to claim 4, the initial value, the final value, and the decrease rate of the number of injections to be thinned out are set according to the engine speed and the engine load. According to such a configuration, the initial value of the injection frequency thinning in accordance with the engine speed and the engine load, gradually reduce the number of injections to thin out at a reduced rate corresponding to the rotation and the load, and finally according to the rotation-load Decrease to final value.
[0011]
The invention according to claim 5 is configured such that the fuel injection amount between the expansion stroke and the exhaust stroke is changed according to the number of injections to be thinned out . According to such a configuration, there is a case where the fuel injection amount between the expansion stroke and the exhaust stroke is changed according to the number of injections thinned out in the fuel injection between the expansion stroke and the exhaust stroke, and the thinning is not performed. Control the total injection amount as a reference.
[0012]
In the present invention, the fuel injection amount in the intake stroke or the compression stroke is changed according to the number of injections to be thinned out , and the remaining fuel is injected between the expansion stroke and the exhaust stroke. According to this configuration, the fuel is injected separately into the injection in the intake stroke or the compression stroke and the injection between the expansion stroke and the exhaust stroke, and the amount of fuel injected in the intake stroke or the compression stroke is The number of injections to be thinned out , in other words, the amount of oxygen in the combustion exhaust gas by the injection in the intake stroke or the compression stroke is controlled in accordance with the required temperature rise.
[0013]
【The invention's effect】
According to the first aspect of the present invention, it is possible to avoid rapid combustion in the catalyst by thinning out the injection from the expansion stroke to the exhaust stroke, and to gradually reduce the number of injections to be thinned out, thereby increasing the necessary temperature increase allowance. There is an effect that can be secured. According to the invention of claim 2, by increasing the number of injections to be thinned out as the engine rotational speed is higher, it is possible to control to a constant temperature increase rate even if the rotational speed is different, and the engine rotational speed is high and the required temperature rise is increased. When the allowance is small, there is an effect that an excessive temperature rise is avoided.
[0014]
According to the invention described in claim 3, when the engine load is large and the required temperature rise is small, the number of injections to be thinned out is set large , and the injection amount increases between the expansion stroke and the exhaust stroke as the engine load increases. In this case, since the number of injections to be thinned out is set to be large, it is possible to avoid an excessive temperature rise. According to the fourth aspect of the present invention, it is possible to set the change width of the number of thinnings according to the required temperature increase allowance, and to control to a constant temperature increase rate, while avoiding rapid combustion in the catalyst, and constant There is an effect that the temperature can be increased to a necessary temperature at an increase rate of.
[0015]
According to the fifth aspect of the present invention, for example, it is possible to control to an air-fuel ratio state necessary for releasing poisoning by changing the injection amount between the expansion stroke and the exhaust stroke according to the number of injections to be thinned out. There is an effect. According to the sixth aspect of the present invention, when the required temperature rise is large and it is necessary to increase the amount of oxygen in the combustion exhaust by injection in the intake stroke or compression stroke, the amount of oxygen can be controlled according to such a request. There is an effect that the amount of oxygen necessary for fuel combustion in the catalyst is secured, and a temperature increase commensurate with the injection between the expansion stroke and the exhaust stroke can be reliably obtained.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a system configuration diagram showing a direct injection type internal combustion engine to which a fuel injection control device according to the present invention is applied.
A cylinder head 2 of the internal combustion engine 1 shown in FIG. 1 is provided with a fuel injection valve 3 for directly injecting fuel into a cylinder, and an ignition plug 4 for spark-igniting an air-fuel mixture.
[0017]
The cylinder head 2 is provided with an intake port 5 for each cylinder, and the air whose flow rate is adjusted by the throttle valve 6 is distributed to the intake ports 5 of the respective cylinders by the intake manifold 7. A combustion mixture is formed by the air introduced into the fuel and the fuel injected from the fuel injection valve 3.
The cylinder head 2 has an exhaust port 8 for each cylinder. The exhaust manifold 9 connected to the exhaust port 8 collects exhaust from each cylinder and purifies it by the front catalyst 10 and the rear catalyst 11. And then released into the atmosphere.
[0018]
An exhaust gas recirculation passage 13 that connects the exhaust manifold 9 and the intake air collector portion 12 is provided, and a part of the exhaust gas is recirculated to the intake side through the exhaust gas recirculation passage 13 due to a pressure difference. Is controlled by an exhaust gas recirculation control valve 14 interposed in the exhaust gas recirculation passage 13.
When high pressure fuel is supplied from the fuel pump 15 to the fuel injection valve 3 and the fuel injection valve 3 is opened by an injection pulse signal from the control unit 16, an amount of high pressure fuel proportional to the valve opening time is in-cylinder. Is injected into.
[0019]
The control unit 16 includes an air flow meter 17 for detecting the intake air amount of the engine 1, a throttle sensor 18 for detecting the opening degree of the throttle valve 6, a water temperature sensor 19 for detecting the cooling water temperature of the engine 1, and an upstream of the front catalyst 10. An air-fuel ratio sensor 20 for detecting the air-fuel ratio based on the oxygen concentration in the exhaust gas, a catalyst temperature sensor 21 for detecting the temperature of the rear catalyst 11, and a rotation sensor 22 for extracting a rotation signal of the engine 1 from a crankshaft (not shown). Is provided.
[0020]
The control unit 16 includes a microcomputer, and controls the fuel injection by outputting an injection pulse signal to the fuel injection valve 3 based on detection signals from the various sensors. The exhaust gas recirculation amount is controlled by controlling the opening degree of the exhaust gas recirculation control valve 14.
The flowchart in FIG. 2 shows a routine for calculating the fuel injection amount (pulse width of the injection pulse signal). In step S201, the fuel injection pulse width TI is
TI = TP × COEF × ALPHA
Calculate as
[0021]
The TP is a basic injection pulse width corresponding to the theoretical air-fuel ratio calculated from the intake air amount and the engine speed, the COEF is an air-fuel ratio correction coefficient, and the ALPHA is an actual air-fuel ratio detected by the air-fuel ratio sensor 20. This is an air-fuel ratio feedback correction coefficient for matching with the target air-fuel ratio.
Usually, fuel injection with the fuel injection pulse width TI is performed in the intake stroke or compression stroke of each cylinder to form an air-fuel mixture in the cylinder, but for the purpose of releasing poisoning of the catalyst 10 due to sulfur or the like, Fuel injection is also performed during the expansion stroke.
[0022]
In the present embodiment, the fuel is injected in the expansion stroke, but any injection timing may be used as long as the injected fuel flows out to the exhaust side as it is between the expansion stroke and the exhaust stroke.
The fuel injected in the expansion stroke burns in the catalyst 10, thereby increasing the temperature of the catalyst.
When the catalyst 10 includes a NOx absorbent that absorbs NOx in the exhaust when the exhaust air-fuel ratio is leaner than the stoichiometric air-fuel ratio and releases the absorbed NOx when the oxygen concentration in the exhaust decreases. In addition, sulfur is absorbed together with NOx in the NOx absorbent, and this sulfur is not released even when the air-fuel ratio is enriched, but it decomposes by heating the NOx absorbent in a reducing atmosphere (exhaust air-fuel ratio rich state). Released from the NOx absorbent.
[0023]
The fuel injection control in the expansion stroke for releasing the poisoning will be described with reference to the flowchart of FIG.
The routine shown in the flowchart of FIG. 3 is executed for each injection.
In step S301, it is determined whether or not poisoning release control is being performed.
Note that the poisoning release control is performed, for example, when the estimated value of the poisoning amount becomes a predetermined value or more, or for every fixed operation time / travel distance.
[0024]
If it is determined in step S301 that the poisoning release control is not in progress, the process proceeds to step S311 to perform normal fuel injection for performing fuel injection in the intake stroke or compression stroke based on the fuel injection pulse width TI.
On the other hand, if it is determined in step S301 that the poisoning release control is being performed, the process proceeds to step S302, where it is determined whether the air-fuel ratio correction coefficient COEF is equal to or greater than a predetermined value lambdaSOx, thereby enabling the richer possible poisoning release. It is determined whether or not the air-fuel ratio control state is set.
[0025]
If COEF ≧ lambdaSOx, it is possible to obtain a reducing atmosphere in which poisoning can be released with the current fuel injection pulse width TI, so the process bypasses step S303 and proceeds to step S304.
On the other hand, when COEF <lambdaSOx, the reducing atmosphere necessary for releasing the poisoning cannot be obtained, so the process proceeds to step S303, and the predetermined value lambdaSOx is set to the air-fuel ratio correction coefficient COEF.
[0026]
In step S304, it is determined whether or not the number of thinning-out count1 of expansion stroke injection has reached the specified number of countinj.
That is, instead of injecting fuel for each expansion stroke of each cylinder, if fuel injection is performed once in the expansion stroke, the injection is stopped for the specified number of countinj, and after the injection is thinned for the specified number of countinj, the expansion is performed. The injection in the stroke is repeated (see FIG. 6).
[0027]
If it is determined in step S304 that the number of thinnings count1 has not reached the specified number of countinj (count1 <countinj), the injection in the current expansion stroke is stopped, and the process proceeds to step S308, where the intake stroke or compression is performed. The injection pulse width TI1st in the stroke is set as TI1st = TI × part. In the next step S309, the injection pulse width TI2nd in the expansion stroke is set to 0, and in the next step S310, the thinning-out count count1 is counted up. To do.
[0028]
On the other hand, when it is determined in step S304 that the number of thinnings count1 has reached the specified number of countinj (count1 ≧ countinj), injection is performed in the current expansion stroke, so the process proceeds to step S305, and the intake stroke or compression stroke is performed. In step S306, the injection pulse width TI2nd in the expansion stroke is set as TI2nd = (TI−TI × part) × (mincount + 1), and further, in step S306, the injection pulse width TI1st is set as TI1st = TI × part. In the next step S307, the thinning count count1 is cleared.
[0029]
The predetermined number of thinnings countinj is set to be gradually decreased from the initial value and changed to the final value mincount as described later, whereby the number of thinning injections is gradually decreased (see FIG. 6). . The coefficient part used for the calculation of the injection pulse width TI1st is a value slightly smaller than 1.0, so that the fuel injected during the intake stroke or the compression stroke is lean when combustion is performed, and the injection in the expansion stroke is performed in the catalyst 10. Ensuring oxygen for burning in.
[0030]
Further, when the required temperature rise is large and more fuel is injected during the expansion stroke and more fuel needs to be burned in the catalyst 10, the leaner the fuel injected during the intake stroke or the compression stroke, the leaner the combustion is. It is necessary to.
The required temperature increase allowance can be determined from the final value mincount of the specified number of thinnings countinj, and the smaller the final value mincount, the greater the required temperature increase allowance, so the smaller the final value mincount, the more the coefficient part It is set to a small value.
[0031]
However, if the final value mincount is a fixed value, the coefficient part is also a fixed value.
Further, the injection pulse width TI2nd in the expansion stroke is based on the remainder obtained by subtracting the injection pulse width TI1st = TI × part in the intake stroke or compression stroke from the normal injection pulse width TI, and is set to the basic value. It is set by multiplying the final value mincount of 1 by the value obtained by adding 1.
[0032]
TI2nd = (TI−TI × part) × (mincount + 1)
For example, if the final decimation value mincount is 1, twice the basic value will be injected, and the same amount of fuel will be injected as if the decimation was not performed as a total, reaching the final decimation value mincount. When the temperature necessary for releasing the poison is reached, the rich exhaust air-fuel ratio required for releasing the poison can be made as a total.
[0033]
As a simplified control, during the poisoning release control, the air-fuel ratio correction coefficient COEF is set to 1, the injection pulse width TI1st in the intake or compression stroke is set to TI1st = TI, and the injection pulse width TI2nd in the expansion stroke is set to TI2nd. = TI × afterinj (afterinj is a constant). As described above, if the configuration is such that the injection in the expansion stroke is performed by thinning while gradually reducing the number of thinning injections , as shown in FIG. 7, the temperature at the center of the catalyst is lower than when no thinning is performed. Since it gradually rises, it is possible to avoid cracking of the carrier due to heat shock.
[0034]
The flowchart of FIG. 4 shows the first embodiment of the setting control of the predetermined number of thinning-out countinj, and is executed at regular intervals.
In step S401, it is determined whether or not the poisoning release control is being performed. If the poisoning release control is not being performed, the processing is ended as it is.
On the other hand, if it is determined in step S401 that the poisoning release control is being performed, the process proceeds to step S402, where it is determined whether or not it is immediately after the start of the poisoning release control.
[0035]
If it is immediately after the start of the poisoning release control, the initial value countstart stored in advance is set in the specified number of countinj.
If it is determined in step S402 that it is not immediately after the start of the poisoning release control, the process proceeds to step S404, and it is determined whether or not the specified number of countinj is equal to or less than the final value mincount stored in advance.
[0036]
If countinj> mincount, the process proceeds to step S406, and the setting is made to decrease the specified number of countinj by a previously stored decrease correction value (decrease rate) decount.
If it is determined in step S404 that countinj ≦ mincount as a result of the decrease control in step S406, the process proceeds from step S404 to step S405, and the final value mincount is set to the specified number of countinj.
[0037]
By the above processing, the specified number of countinj is reduced from the initial value countstart to the final value mincount at a constant speed.
In the flowchart of FIG. 4, the injection in the expansion stroke is thinned out based on a fixed number of thinnings regardless of the operating conditions of the engine 1, but the number of thinnings can be changed according to the operating conditions. More preferably, a second embodiment in which setting control of the predetermined number of thinning-out countinj according to the operating conditions will be described with reference to the flowchart of FIG.
[0038]
In step S501, the engine load and the engine speed are read.
The engine load can be represented by the basic injection pulse width TP.
In the next step S502, it is determined whether or not the poisoning release control is being performed. If the poisoning release control is not being performed, the processing is ended as it is.
On the other hand, when the poisoning release control is being performed, the process proceeds to step S503, where the basic value mincountrev of the final value of the number of thinnings is set according to the engine speed.
[0039]
As shown in FIG. 8, the basic value mincountrev is set to a larger value as the engine speed is higher. When the engine rotational speed is high, as shown in FIG. 9, the catalyst temperature is generally high, and the higher the engine rotational speed , the lower the necessity for injection in the expansion stroke. The value mincountrev is set to a large value .
[0040]
In the next step S504, the load correction value minloadhosei as the final value of the number of thinnings is set according to the engine load at that time. As shown in FIG. 10, the load correction value minloadhosei is set to a larger value as the engine load is higher. When the engine load is high, as shown in FIG. 11, the catalyst temperature is generally high, and when the engine load is high, the injection amount absolute value in the expansion stroke becomes large, and the injection 1 in the expansion stroke Since the temperature rise per turn increases, the load correction value minloadhosei is set to a larger value as the engine load is higher.
[0041]
In step S505, the final value mincount of the number of thinnings is
mincount = mincountrev × minloadhosei
Calculate as
In step S506, it is determined whether or not it is immediately after the start of the poisoning release control.
If it is immediately after the start, the process proceeds to step S507, and the basic value stcountrev of the initial value of the number of thinnings is set according to the engine speed.
[0042]
The basic value stcountrev of the initial value is larger than the basic value mincountrev of the final value, but is set to a larger value as the engine speed increases in the same manner as the basic value mincountrev of the final value (see FIG. 8). ). In the next step S508, the load correction value stloadhosei, which is the initial value of the number of thinnings, is set according to the engine load at that time.
[0043]
Load correction value stloadhosei of the initial value is greater than the load correction value minloadhosei of the final value, in the same manner as the load correction value minloadhosei of the final value, the engine load is set to a higher value greater (FIG. 10 reference). In step S509, the initial setting is performed by setting stcountrev × stloadhosei to the predetermined number of thinning-out countinj.
[0044]
If it is determined in step S506 that it is not immediately after the start, the process proceeds to step S510, and it is determined whether or not the predetermined number of thinning countinj is equal to or less than the final value mincount.
When countinj ≦ mincount, the process proceeds to step S511, and the final value mincount is set as the predetermined number of thinning-out countinj.
[0045]
On the other hand, if countinj> mincount, the process proceeds to step S512, and the reduction rate basic value decountrev of the number of injections to be thinned out is set according to the engine speed. As shown in FIG. 12, the reduction rate basic value decountrev is set to a smaller value as the engine speed increases. When the engine speed is high, the required temperature rise of the catalyst is small. Therefore, a necessary and sufficient temperature rise can be obtained by gradually decreasing the number of thinnings while keeping the number of thinnings large.
[0046]
On the other hand, when the engine rotational speed is low, it is necessary to quickly reduce the number of injections to be thinned out in order to secure a large necessary temperature rise allowance while keeping the initial rapid temperature rise with a large number of thinning outs. Therefore, a large value is required as the decrease rate basic value decreterev. In the next step S513, the reduction rate load correction value deloadhosei of the number of injections to be thinned out is set according to the engine load.
[0047]
The decrease rate load correction value deloadhosei is set to a smaller value as the engine load is higher, as shown in FIG. When the engine load is high, the required temperature rise of the catalyst is small, so that a necessary and sufficient temperature rise can be obtained by gradually changing the number of injections to be thinned out while keeping it small. On the other hand, when the engine load is low, it is necessary to quickly reduce the number of injections to be thinned out in order to secure a large required temperature increase allowance in the catalyst while suppressing the initial rapid temperature rise with a large number of thinning outs. A large value is required as the reduction rate load correction value deloadhosei.
[0048]
In step S514, the decimation rate decount is set to
decount = decountrev × deloadhosei
Calculate as
In step S515, the prescribed number of thinning-out countinj is reduced by the thinning-out reduction rate decount.
[0049]
As described above, if the initial value , final value, and decrease rate of the specified number of thinnings countinj (thinning number of injections) are set according to the engine speed and engine load, heat shock will occur due to sudden combustion Thus, a necessary temperature rise allowance can be obtained, and an excessive temperature rise can be avoided. In the above-described embodiment, when the injection is performed once in the expansion stroke, the injection is thinned out by the prescribed number of countinj, and after the thinning out, the expansion stroke injection is performed only once, and the prescribed number of thinning-out countinj is gradually performed. However, it is configured to change the number of thinnings per predetermined number of injections. For example, at the start, the injection is continuously stopped 8 times after 2 continuous injections, and then the number of continuous injections is gradually increased. Correspondingly, the number of thinning is gradually reduced, and finally the number of continuous injections and the number of thinnings are relatively increased or decreased, such that the injection is thinned out only twice after eight continuous injections. It can be set as the structure made to do.
[0050]
In the above embodiment, the temperature of the catalyst is raised only by fuel injection in the expansion stroke (exhaust stroke). However, it can be combined with the retard control of the ignition timing or the exhaust recirculation stop control. .
[Brief description of the drawings]
FIG. 1 is a system configuration diagram of an internal combustion engine in an embodiment.
FIG. 2 is a flowchart showing calculation of a fuel injection amount in the embodiment.
FIG. 3 is a flowchart showing injection control for releasing poisoning in the embodiment.
FIG. 4 is a flowchart showing a first embodiment of setting the number of times of thinning.
FIG. 5 is a flowchart showing a second embodiment for setting the number of times of thinning.
FIG. 6 is a time chart showing the correlation between the intake stroke injection and the expansion stroke injection in the embodiment.
FIG. 7 is a time chart for explaining effects in the embodiment.
FIG. 8 is a diagram showing the correlation between the engine speed and the initial and final values of the number of thinnings in the embodiment.
FIG. 9 is a diagram showing the correlation between the engine speed and the catalyst temperature.
FIG. 10 is a diagram showing a correlation between the engine load and the initial value and the final value of the number of thinnings in the embodiment.
FIG. 11 is a diagram showing the correlation between engine load and catalyst temperature.
FIG. 12 is a diagram showing the correlation between the engine speed and the reduction rate of the number of thinnings in the embodiment.
FIG. 13 is a diagram showing a correlation between an engine load and a reduction rate of the number of thinnings in the embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 2 ... Cylinder head 3 ... Fuel injection valve 4 ... Spark plug 5 ... Intake port 6 ... Throttle valve 7 ... Intake manifold 8 ... Exhaust manifold 10 ... Front catalyst 11 ... Rear catalyst 16 ... Control unit 17 ... Air flow meter 18 ... Throttle sensor 19 ... Water temperature sensor 20 ... Air-fuel ratio sensor

Claims (6)

In an internal combustion engine having a fuel injection valve that directly injects fuel into a cylinder, a fuel injection control device that raises the temperature of a catalyst interposed in an exhaust passage by fuel injection between an expansion stroke and an exhaust stroke,
A fuel injection control device for a direct injection type internal combustion engine, wherein the fuel injection between the expansion stroke and the exhaust stroke is thinned out and the number of thinning injections is gradually reduced . 2. The fuel injection control device for a direct injection type internal combustion engine according to claim 1, wherein the number of thinned injections is increased as the engine rotational speed is higher. The fuel injection control device for a direct injection type internal combustion engine according to claim 1 or 2, wherein the number of injections to be thinned out increases as the engine load increases. 2. The fuel injection control device for a direct injection type internal combustion engine according to claim 1, wherein an initial value, a final value, and a reduction rate of the number of injections to be thinned out are set according to an engine speed and an engine load. 5. The direct injection type internal combustion engine according to claim 1, wherein a fuel injection amount between the expansion stroke and the exhaust stroke is changed in accordance with the number of injections to be thinned out . Fuel injection control device. 6. The fuel injection amount in the intake stroke or the compression stroke is changed according to the number of injections to be thinned out , and the remaining fuel is injected between the expansion stroke and the exhaust stroke. A fuel injection control device for an in-cylinder direct injection internal combustion engine according to one.

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