JP2004019578A - Fuel injection control device of in-cylinder injection type internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection control device of an in-cylinder injection type internal combustion engine for suitably suppressing degradation of a combustion state caused by the cleaning of an engine valve while cleaning the engine valve with injected fuel. <P>SOLUTION: A fuel injection valve 35 of a gasoline engine 1 is disposed so as to collide a fuel against an umbrella part of an intake valve 12 by injecting the fuel in a predetermined fuel collision period. An ECU 50 sets a fuel injection timing by using an operation map M1 for regular injection except when the engine is cold, and an operation map M2 for cold injection when the engine is cold, respectively. The operation map M1 for regular injection sets the fuel injection period to permit the fuel injection in the fuel collision period, and the operation map M2 for cold injection sets the fuel injection period so as to avoid the fuel collision period. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fuel injection control device for an in-cylinder injection internal combustion engine in which fuel is directly injected into a cylinder, and more particularly to an improvement in a device for simultaneously cleaning an engine valve with fuel injected from a fuel injection valve.
[0002]
[Prior art]
2. Description of the Related Art Various types of exhaust gas purification devices such as an exhaust gas recirculation device and a blow-by gas recirculation device are provided in a recent internal combustion engine, especially an on-vehicle internal combustion engine. Has been reduced. For example, an exhaust gas recirculation device that introduces exhaust gas into an intake passage is provided in an internal combustion engine to lower the combustion temperature of the air-fuel mixture and reduce the amount of nitrogen oxides (NOx) generated. . On the other hand, in an internal combustion engine, during a compression stroke and an expansion stroke, a mixture of air and fuel, a combustion gas, or the like enters a crankcase from a combustion chamber and generates a large amount of hydrocarbons (HC) and lubrication. A blow-by gas containing a vaporized component of oil is generated. By providing a blow-by gas recirculation device for introducing the blow-by gas into the intake passage in the internal combustion engine, the blow-by gas is burned in the combustion chamber for processing.
[0003]
By the way, in an internal combustion engine equipped with such an exhaust gas purifying device, since exhaust gas and blow-by gas are introduced into the intake passage, deposits caused by HC, oil, and the like gradually accumulate on the intake valve, especially on its head. Would. If the amount of deposits increases, the flow of intake air along the intake valve will be disturbed, causing problems such as deterioration of the combustion state of the air-fuel mixture.
[0004]
In a port injection type internal combustion engine in which fuel is injected toward an intake port or an intake valve, the intake valve is exposed to an air-fuel mixture. The valve is cleaned. Therefore, in the port injection type internal combustion engine, the above-described problem is less likely to occur.
[0005]
On the other hand, in an in-cylinder injection type internal combustion engine, fuel is directly injected into the cylinder, so that the intake valve cannot be washed with the air-fuel mixture as described above, and deposits tend to accumulate on the intake valve.
[0006]
Thus, for example, in a direct injection internal combustion engine described in Japanese Patent Application Laid-Open No. 9-256867, the fuel injection valve is operated so that the fuel injected from the fuel injection valve collides with the head of the intake valve when the intake valve is lifted. By arranging, the intake valve is cleaned.
[0007]
[Problems to be solved by the invention]
If the fuel is caused to collide with the head of the intake valve in this way, it is possible to remove the deposit attached to the intake valve. However, in such a case, there is a problem that the combustion state at the time of cold engine is deteriorated as described below.
[0008]
If the fuel is injected so as to collide with the head of the intake valve as described above, a part of the fuel will adhere to the intake valve. At this time, if the internal combustion engine is sufficiently warmed up, the temperature of the intake valve is also rising, and the attached fuel is quickly vaporized.
[0009]
However, when the engine is cold, the temperature of the intake valve is low, so that the fuel attached to the intake valve does not evaporate and remains on the spot. As a result, the amount of fuel actually supplied into the cylinder becomes smaller than the amount of fuel injected from the fuel injection valve, so that the controllability of the fuel injection amount is deteriorated and the combustion state becomes poor. It leads to stabilization.
[0010]
Also, if fuel remains in the state of being attached to the intake valve, a part of the attached fuel is separated by the air flowing from the intake port, and is introduced into the combustion chamber as coarse particles. Become. As a result, fuel having a large particle diameter, that is, fuel that has not been atomized, is introduced into the cylinder, which also causes unstable combustion.
[0011]
As described above, when the engine valve is also washed with the fuel injected from the fuel injection valve, it is inevitable that the combustion state becomes unstable when the engine is cold or the like.
[0012]
SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a cylinder capable of suitably suppressing deterioration of a combustion state due to such cleaning while cleaning an engine valve with injected fuel. An object of the present invention is to provide a fuel injection control device for an internal injection type internal combustion engine.
[0013]
[Means for Solving the Problems]
The means for achieving the above object and the effects thereof will be described below.
According to a first aspect of the present invention, there is provided a fuel injection control apparatus for a cylinder injection type internal combustion engine in which fuel is injected within a predetermined fuel collision period to cause the injected fuel to collide with an engine valve. In some cases, the gist is to include an injection period setting means for setting a fuel injection period so as to avoid the fuel collision period.
[0014]
In the above configuration, by injecting the fuel during the fuel collision period, the injected fuel collides with the engine valve, and the deposits and the like deposited on the engine valve can be cleaned.
[0015]
On the other hand, when the engine is cold, in which fuel adhering to the engine valve is not easily vaporized, the fuel injection period is set so as to avoid the fuel collision period, so that the fuel is not directly blown to the engine valve. Therefore, the amount of fuel remaining in the state in which the fuel adheres to the engine valve can be reduced, and the deterioration of the combustion state due to such remaining fuel can be suppressed. Therefore, according to the above configuration, while the engine valve is being washed with the injected fuel, the deterioration of the combustion state accompanying the execution of such washing can be suitably suppressed.
[0016]
According to a second aspect of the present invention, in the fuel injection control device for a direct injection internal combustion engine according to the first aspect, the injection period setting means gives priority to the period before the start of the fuel collision period. The gist is to set the fuel injection period during the cold period.
[0017]
In order to avoid the fuel collision period, the fuel injection period is set to one or both of the period before the start of the fuel collision period and the period after the end of the fuel collision period. Of the two periods, the period before the start of the fuel collision period can secure a longer time from the injection of the fuel to the ignition, and can better vaporize the fuel and agitate the fuel in the cylinder. It is a more favorable period due to improvement. In this regard, in the above configuration, the period before the start of the fuel collision period is preferentially set as the fuel injection period during the cold engine, so that the combustion state during the cold engine can be more favorably maintained. .
[0018]
According to a third aspect of the present invention, in the fuel injection control device for a direct injection internal combustion engine according to the first aspect, the injection period setting means starts the fuel collision period when the fuel injection amount is less than a predetermined value. The fuel injection period at the time of engine cold is set so that fuel is injected only before, and when the fuel injection amount is equal to or more than a predetermined value, the fuel injection period is divided into a period before the start of the fuel collision period and a period after the end. The gist of the present invention is to set the fuel injection period when the engine is cold so that the fuel is injected.
[0019]
As described above, in order to ensure a good combustion state, it is desirable to set the fuel injection period during cold engine to a period before the start of the fuel collision period rather than a period after the end of the fuel collision period. Therefore, in the above configuration, when the fuel injection amount is less than the predetermined value, the fuel injection period at the time of engine cold is set so that fuel is injected only before the start of the fuel collision period.
[0020]
However, if the fuel is injected only during the period before the start of the fuel collision period, the start timing of the fuel injection must be advanced according to the increase in the fuel injection amount. However, if the fuel injection start timing is too early, the fuel injection period overlaps with the exhaust valve opening period, causing fuel to flow through the exhaust passage, and the combustion state deteriorates. There is a possibility that.
[0021]
In this regard, in the above configuration, when the fuel injection amount becomes equal to or more than the predetermined value, the fuel during the cold engine is so divided that the fuel is injected into a period before the start of the fuel collision period and a period after the end of the fuel collision period. An injection period is set. Therefore, a necessary fuel injection amount can be secured while avoiding excessively early injection start timing. Therefore, according to the above configuration, the combustion state when the engine is cold can be more favorably maintained.
[0022]
According to a fourth aspect of the present invention, in the fuel injection control device for a direct injection internal combustion engine according to the first or second aspect, the injection period setting means sets the fuel injection period during the engine cold period to the fuel injection period. The gist is to divide and set the period before the start of the collision period and the period after the end of the collision period.
[0023]
As described above, there is a limit to earlier fuel injection start timing. In addition, if the fuel injection end timing is too late, the time from fuel injection to ignition becomes short, and the time required for fuel vaporization and stirring in the cylinder becomes insufficient.
[0024]
On the other hand, in order to avoid the fuel collision period, when the fuel injection timing is shifted either before the start of the fuel collision period or after the end thereof, if the fuel injection amount increases, the injection start timing is advanced, or One of the delays of the injection end timing is unavoidable.
[0025]
In that regard, in the above configuration, the fuel injection period during the cold engine period is set to be divided into a period before the start of the fuel collision period and a period after the end thereof, so that even if the fuel injection amount increases, The increase can be distributed to both divided periods. Therefore, even if the fuel injection amount is increased to some extent, the injection start timing is not excessively advanced and the injection end timing is not excessively delayed. Therefore, according to the above configuration, the combustion state when the engine is cold can be more favorably maintained.
[0026]
According to a fifth aspect of the present invention, in the fuel injection control device for a direct injection internal combustion engine according to any one of the first to fourth aspects, the injection period setting means is configured to execute the fuel injection control during a period before the start of the fuel collision period. When the fuel is injected, the gist of the present invention is to set the fuel injection period when the engine is cold so that the injection of the fuel is terminated immediately before the start of the fuel collision period.
[0027]
If the fuel injection period is shifted to avoid the fuel collision period, the set fuel injection period deviates from the originally desired fuel injection period. In this regard, in the above configuration, in the case of the fuel injection in the period before the start of the fuel collision period during the cold period of the engine, the fuel is injected until immediately before the start of the fuel collision period. Therefore, the difference between the originally desired fuel injection period and the set fuel injection period can be reduced. Therefore, according to the above configuration, the combustion state when the engine is cold can be more favorably maintained.
[0028]
According to a sixth aspect of the present invention, in the fuel injection control device for a direct injection type internal combustion engine according to any one of the first to fifth aspects, the injection period setting means is configured to execute the fuel injection control during a period after the end of the fuel collision period. When the fuel is injected, the gist of the present invention is to set the fuel injection period when the engine is cold so that the injection of the fuel is started immediately after the end of the fuel collision period.
[0029]
With the above configuration, in the case of the fuel injection in the period after the end of the fuel collision period during the cold period of the engine, the fuel injection is started immediately after the end of the fuel collision period. Therefore, also in the same configuration, the difference between the originally desired fuel injection period and the set fuel injection period can be reduced. Therefore, according to the above configuration, the combustion state when the engine is cold can be more favorably maintained.
[0030]
According to a seventh aspect of the present invention, in the fuel injection control device for a direct injection internal combustion engine according to any one of the first to sixth aspects, the injection period setting means is configured to execute the fuel collision when the engine is not cold. The gist is to set the fuel injection period so as to overlap at least a part of the period.
[0031]
According to the above configuration, when the engine is not in the cold state, the fuel injected from the fuel injection valve always collides with the intake valve. Therefore, the deposit accumulated on the intake valve can be reliably reduced.
[0032]
The invention according to claim 8 is the fuel injection control device for a direct injection internal combustion engine in which fuel is injected within a predetermined fuel collision period to cause the injected fuel to collide with an engine valve. The first operation map for setting the fuel injection period so as to overlap at least a part of the period, and the second calculation map for setting the fuel injection period so as to avoid the fuel collision period are used for the engine operation condition. The gist of the present invention is to provide an injection period setting means for setting the fuel injection period in the intake stroke injection by switching according to the fuel injection period.
[0033]
In the above configuration, the fuel injection period in the intake stroke injection is set by switching between the first calculation map and the second calculation map according to the engine operating condition. Here, if the fuel injection period is set using the first calculation map, the fuel is injected at a time that overlaps at least a part of the fuel collision period. Therefore, the engine valve is also washed with the injected fuel. Can be made. On the other hand, if the fuel injection period is set using the second calculation map, the fuel injection period is set avoiding the fuel injection period, so that the injected fuel can be prevented from colliding with the engine valve. For this reason, it is possible to switch whether to perform cleaning of the engine valve according to the engine operating state. For example, the engine valves should normally be cleaned with injected fuel, but should not be performed in situations where such cleaning would adversely affect combustion, such as when the engine is cold. Can be. Therefore, while cleaning the engine valve with the injected fuel, it is possible to preferably suppress the deterioration of the combustion state accompanying the execution of such cleaning.
[0034]
According to a ninth aspect of the present invention, in the fuel injection control apparatus for a direct injection internal combustion engine according to the eighth aspect, the second arithmetic map is configured such that when the fuel injection amount is less than a predetermined value, The fuel injection period is set so that fuel is injected only before the start, and when the fuel injection amount is equal to or more than a predetermined value, fuel is divided into a period before the start of the fuel collision period and a period after the end of the fuel collision period. The gist is that the fuel injection period is set such that the fuel injection period is set.
[0035]
With the above configuration, when the second arithmetic map is used, when the fuel injection amount is less than the predetermined value, the fuel is injected only before the start of the fuel collision period. When the fuel injection amount becomes equal to or more than a predetermined value when the second calculation map is used, the fuel is divided into a period before the start of the fuel collision period and a period after the end of the fuel collision period. Therefore, the time from injection to ignition is long, and the period before the start of the fuel collision period, which is advantageous for fuel vaporization and stirring in the cylinder, is preferentially set as the fuel injection period. Can be avoided. Therefore, according to the above configuration, the combustion state when the fuel injection period is set using the second calculation map can be further improved.
[0036]
According to a tenth aspect of the present invention, in the fuel injection control apparatus for a direct injection internal combustion engine according to the eighth or ninth aspect, the injection period setting means uses the second arithmetic map when the engine is cold. The gist of the present invention is to set the fuel injection period, and to set the fuel injection period using the first calculation map except when the engine is cold.
[0037]
According to the above configuration, it is possible to preferably suppress the deterioration of the combustion state due to the execution of the cleaning when the engine is cold.
According to an eleventh aspect of the present invention, in the fuel injection control device for a direct injection internal combustion engine according to any one of the first to seventh aspects, when the engine is not cold, the fuel injection pressure is higher than when the engine is cold. The gist of the present invention is to further include an injection pressure control means for reducing the pressure.
[0038]
In the above configuration, when the engine is not cold, that is, when the collision of the fuel with the engine valve is permitted, the fuel injection is performed at a lower fuel injection pressure than when the engine is cold in which such a collision of the fuel is prohibited. Will be implemented. When the fuel collides with the engine valve, the impact at the time of the collision breaks up the liquid droplets of the fuel and promotes the atomization of the fuel. Therefore, even at a relatively low fuel injection pressure, sufficient atomization of the fuel is achieved. . Therefore, the load on a fuel supply system such as a fuel pump that pressurizes the fuel to the fuel injection valve and feeds the fuel can be reduced while ensuring atomization of the fuel. As a result, the reliability of the fuel supply system can be improved.
[0039]
According to a twelfth aspect of the present invention, in the fuel injection control device for a direct injection type internal combustion engine according to any one of the first to tenth aspects, the fuel injection control unit is configured to perform the fuel injection during the fuel collision period as compared with other times. The gist of the present invention is to further include injection pressure control means for reducing the injection pressure.
[0040]
In the above configuration, during the fuel injection period, the fuel is injected at a lower fuel injection pressure than at other times. The fuel injected during the fuel injection period collides with the engine valve, and the impact splits the liquid particles. Therefore, sufficient atomization can be achieved even at a relatively low fuel injection pressure. Therefore, according to the above configuration, it is possible to reduce the load on the fuel supply system such as the fuel pump that pressurizes the fuel to the fuel injection valve and feeds the fuel, while ensuring atomization of the fuel. As a result, the reliability of the fuel supply system can be improved.
[0041]
According to a thirteenth aspect of the present invention, in the fuel injection control device for a direct injection internal combustion engine according to any one of the first to tenth aspects, the fuel injection period is set so as to overlap at least a part of the fuel collision period. If so, the gist of the invention is to further include an injection pressure control means for lowering the fuel injection pressure compared to when the fuel injection period is set so as to avoid the fuel collision period.
[0042]
With the above configuration, when the fuel injection period is set so as to overlap at least a part of the fuel injection period, the fuel injection period is set at other times, that is, when the fuel injection period is set so as to avoid the fuel collision period. Is injected at a low fuel injection pressure. At least a portion of the fuel injected at this time collides with the engine valve, and the impact breaks up liquid particles. Therefore, sufficient atomization can be achieved even at a relatively low fuel injection pressure. Therefore, according to the above configuration, it is possible to reduce the load on the fuel supply system such as the fuel pump that pressurizes the fuel to the fuel injection valve and feeds the fuel, while ensuring atomization of the fuel. As a result, the reliability of the fuel supply system can be improved.
[0043]
According to a fourteenth aspect of the present invention, in the fuel injection control device for a direct injection internal combustion engine according to any one of the first to thirteenth aspects, the fuel collision period is a time when the lift amount of the engine valve is maximized. The gist is that the period is in the vicinity of.
[0044]
According to the above configuration, cleaning of the engine valve with the injected fuel can be performed more easily and accurately.
[0045]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, one embodiment of a fuel injection control device for a direct injection internal combustion engine according to the present invention will be described in detail with reference to FIGS.
[0046]
FIG. 1 is a schematic configuration diagram showing a fuel injection control device according to the present embodiment, a direct injection gasoline engine 1 to which the fuel injection control device is applied, and peripheral components thereof.
The gasoline engine 1 has a plurality of cylinders, and a plurality of cylinders 4 are provided in a cylinder block 2 of the gasoline engine 1 (only one is shown in FIG. 1). A piston 5 is provided in the cylinder 4, and the piston 5 is connected to a crankshaft 7 via a connecting rod 6.
[0047]
A crankcase 21 is attached to a lower portion of the cylinder block 2, and the crankshaft 7 is rotatably supported by the crankcase 21.
[0048]
On the other hand, a cylinder head 3 is mounted on an upper portion of the cylinder block 2. A space defined by the upper end of the piston 5, the cylinder head 3 and the cylinder 4 in the cylinder 4 is a combustion chamber 8. The cylinder head 3 is provided with a fuel injection valve 35 for directly injecting fuel into the combustion chamber 8 and a spark plug 11 for igniting an air-fuel mixture in the combustion chamber 8 for each cylinder. The cylinder head 3 is provided with two intake ports 9 as intake passages to the combustion chamber 8 for each cylinder (only one is shown in FIG. 1). On the other hand, two exhaust ports 10 each serving as an exhaust passage from the combustion chamber 8 are provided for each cylinder (only one is shown in FIG. 1).
[0049]
The above-described intake port 9 and exhaust port 10 are connected to an intake passage 20 and an exhaust passage 30, respectively. A throttle valve 23 whose opening is adjusted by an actuator 22 driven based on an operation of an accelerator pedal (not shown) is provided in the intake passage 20. By changing the opening of the throttle valve 23, the amount of air taken into the combustion chamber 8 is adjusted.
[0050]
On the other hand, the crankshaft 7 is drivingly connected to an intake-side timing pulley 15 and an exhaust-side timing pulley 16 via a timing belt 14. An intake camshaft 17 is attached to the intake timing pulley 15. An exhaust-side camshaft 18 is attached to the exhaust-side timing pulley 16.
[0051]
An intake valve 12 and an exhaust valve 13 provided corresponding to the combustion chamber 8 open and close the intake port 9 and the exhaust port 10, respectively. The intake valve 12 and the exhaust valve 13 are opened and closed by cams (not shown) provided on the intake camshaft 17 and the exhaust camshaft 18, respectively. Further, when the crankshaft 7 makes two rotations, the intake-side timing pulley 15 and the exhaust-side timing pulley 16 each make one rotation. Therefore, the intake valve 12 and the exhaust valve 13 are opened and closed at a predetermined timing in synchronization with the rotation of the crankshaft 7, that is, in response to the reciprocating movement of each piston 5.
[0052]
In addition, the gasoline engine 1 is provided with an exhaust gas recirculation device (hereinafter, referred to as an EGR device) 60. The EGR device 60 is a device that reduces the amount of NOx generated in the combustion stroke by introducing a part of the exhaust gas into the intake air to lower the combustion temperature in the cylinder. The EGR device 60 includes an EGR passage 61 that connects the intake passage 20 and the exhaust passage 30, and an EGR valve 62 provided in the EGR passage 61. By adjusting the opening degree of the EGR valve 62, the amount of exhaust gas (EGR amount) introduced from the exhaust passage 30 to the intake passage 20 is adjusted.
[0053]
Further, the gasoline engine 1 is provided with a blow-by gas recirculation device 70. The blow-by gas recirculation device 70 is a device that introduces blow-by gas entering the crankcase 21 from the combustion chamber 8 into the intake air during the compression stroke and the expansion stroke of the gasoline engine 1 and burns the gas in the combustion chamber 8. The blow-by gas recirculation device 70 includes a gas recirculation passage 72, a fresh air passage 73, and a control valve 71. Further, the internal space of the crankcase 21 communicates with the internal space of the cylinder head 3 so that the blow-by gas in the crankcase 21 can flow into the internal space of the cylinder head 3. The fresh air passage 73 communicates the intake passage 20 upstream of the throttle valve 23 with the internal space of the cylinder head 3. The gas recirculation passage 72 communicates the internal space of the cylinder head 3 with the intake passage 20 downstream of the throttle valve 23 via a control valve 71. The control valve 71 allows only the flow of the blow-by gas from the internal space of the cylinder head 3 to the intake passage 20.
[0054]
In such a blow-by gas recirculation device 70, when the engine load is low, the blow-by gas is introduced into the intake air through the gas recirculation passage 72, burns in the combustion chamber 8, and flows in through the fresh air passage 73. Thereby, the inside of the crankcase 21 is scavenged. On the other hand, when the engine load is high, a large amount of blow-by gas is introduced into the intake air via the gas recirculation passage 72 and the fresh air passage 73, and is processed by combustion in the combustion chamber 8.
[0055]
Further, the gasoline engine 1 is provided with various sensors for detecting an engine operating state such as a crank angle sensor 41, a cam angle sensor 42, a throttle opening sensor 44, an air flow meter 45, a water temperature sensor 46, and the like.
[0056]
The crank angle sensor 41 is provided near the crankshaft 7 and detects the rotation phase of the crankshaft 7. From the detection result, the engine speed NE of the gasoline engine 1 (crankshaft 7) is also detected.
[0057]
The cam angle sensor 42 is provided close to the intake camshaft 17 and outputs a reference signal based on the rotation of the intake camshaft 17. By referring to the output signal of the cam angle sensor 42 and the output signal of the crank angle sensor 41 together, the rotational phase (cam angle) of the intake camshaft 17 is detected.
[0058]
The throttle opening sensor 44 is provided near the throttle valve 23 and detects the opening of the throttle valve 23 (throttle opening).
The air flow meter 45 is provided upstream of the throttle valve 23 and detects the amount of intake air flowing through the intake passage 20. Further, a water temperature sensor 46 is provided in the cylinder block 2 and detects the temperature of the cooling water.
[0059]
Various controls such as the ignition timing control and the fuel injection control of the gasoline engine 1 are performed by a control device (hereinafter, referred to as an ECU) 50.
The ECU 50 mainly includes a microcomputer having a central processing unit (CPU), and includes a read-only memory (ROM), a random access memory (RAM), a backup RAM, an input interface, an output interface, and the like.
[0060]
Various programs, maps, and the like are stored in the ROM in advance. In the present embodiment, as the maps stored in the ROM, there are provided two operation maps used for setting the fuel injection period, that is, an operation map M1 for normal injection and an operation map M2 for cold injection. ing.
[0061]
The random access memory (RAM) is configured to temporarily store the calculation results of the CPU and the like. The backup RAM is composed of a non-volatile memory, and is used for storing and holding the calculation results, pre-stored data, and the like even after the engine is stopped.
[0062]
Output signals from the crank angle sensor 41, the cam angle sensor 42, the throttle opening sensor 44, the air flow meter 45, the water temperature sensor 46, and the like are input to the input interface. The operating state of the gasoline engine 1 is detected by the sensors 41, 42, 44 to 46, and the like.
[0063]
On the other hand, the output interface is connected to the fuel injection valve 35, the EGR valve 62, the ignition coil for applying a high voltage to the ignition plug 11, the actuator 22 of the throttle valve 23, and the like via the corresponding drive circuits and the like. The ECU 50 controls the valves, the ignition coil, the actuator, and the like according to the control program and the initial data stored in the ROM based on the signals from the sensors 41, 42, 44 to 46, and the like.
[0064]
In particular, control of the fuel injection valve 35 by the ECU 50 is performed as follows.
First, a period of fuel injection by the fuel injection valve 35 is set in order to supply the required amount of fuel into the cylinder according to the engine operating state. Then, the actuator provided in the fuel injection valve 35 is drive-controlled to open the fuel injection valve 35, and fuel is injected within the required fuel injection period. Further, the ECU 50 controls a fuel pump that supplies fuel to the fuel injection valve 35 and a pressure control valve provided in the middle of the fuel supply pipe, and controls the injection pressure of the fuel injected from the fuel injection valve 35 into the engine operating state. The pressure is adjusted according to.
[0065]
As described above, the gasoline engine 1 of the present embodiment is configured as an in-cylinder injection type internal combustion engine that directly injects fuel into a cylinder, and includes an exhaust gas purification device such as an EGR device 60 or a blow-by gas recirculation device 70. Have. Therefore, in the gasoline engine 1, as described above, deposits tend to be deposited on the intake valve 12 depending on the operation time. Therefore, in the present embodiment, the deposits deposited on the intake valve 12 are cleaned by providing the following configuration.
[0066]
Next, details of the configuration related to the cleaning of the intake valve 12 in the present embodiment will be described with reference to FIGS.
First, in the present embodiment, as shown in FIG. 2, when the intake valve 12 is located near the maximum lift position, the fuel injected from the fuel injection valve 35 is applied to the head 12a of the intake valve 12. They are going to collide. This is realized by devising the arrangement of the intake valve 12, the fuel injection valve 35, and the like.
[0067]
Therefore, in the present embodiment, as shown in FIG. 3, when the intake valve 12 injects fuel from the fuel injection valve 35 during the fuel collision period Ta near the maximum lift position, the fuel is The portion 12a comes into collision. Then, the deposits deposited on the head portion 12a of the intake valve 12 are cleaned by the collision fuel.
[0068]
In the gasoline engine 1 of the present embodiment, the intake valve 12 is supported so as to be rotatable in the circumferential direction of the shaft 12b. A plurality of ribs 12c as shown in FIG. 4 are provided on the upper surface of the umbrella portion 12a on the shaft 12b side of the intake valve 12. FIG. 1A shows a plan structure of such an intake valve 12 and the like, and FIG. 1B shows a side structure of the intake valve 12.
[0069]
The rib 12 c is provided radially from the shaft 12 b of the intake valve 12, and has a curved shape that is concave with respect to the direction of fuel injection from the fuel injection valve 35. Therefore, the fuel injected from the fuel injection valve 35 collides with the umbrella portion 12a, so that a rotational force is applied to the intake valve 12. By rotating the intake valve 12 in this manner, the entire peripheral surface of the umbrella portion 12a is cleaned with fuel.
[0070]
As described above, in the present embodiment, the umbrella portion 12a of the intake valve 12 is cleaned with the fuel injected from the fuel injection valve 35. However, if the cleaning of the intake valve 12 in such a mode is performed even when the engine is cold, combustion may be unstable as described above.
[0071]
Therefore, in the fuel injection control device according to the present embodiment, the occurrence of such a problem is suppressed through the following fuel injection control.
That is, in this embodiment, when the engine is cold, the mode of fuel injection is switched from when it is not. Specifically, when the engine is cold, the mode of fuel injection is switched so that fuel is injected only at a time when fuel does not collide with the head 12a of the intake valve 12.
[0072]
Such switching of the fuel injection mode is realized by providing the following configuration.
That is, in the present embodiment, the following two calculation maps are stored in advance in the ROM of the ECU 50 as calculation maps for setting the fuel injection timing. One of them is a "normal injection calculation map M1" used for setting the fuel injection timing when the engine is not cold, and the other is the setting of the fuel injection timing when the engine is cold. Is used as the "calculation map M2 for cold injection".
[0073]
In the present embodiment, when the fuel injection period is set, the operation maps M1 and M2 are switched and used depending on whether or not the engine is cold. Thus, except when the engine is cold, fuel injection, that is, “normal injection” is performed in the mode shown in FIG. 6A, and when the engine is cold, fuel injection is performed in the mode shown in FIG. 6B. That is, "cold injection" is performed.
[0074]
Hereinafter, the details of the processing for switching the fuel injection mode will be described based on the flowchart shown in FIG. This switching process is an interrupt process that is repeatedly executed by the ECU 50 every predetermined time. Note that the ECU 50 that performs the present process and sets the fuel injection period constitutes the injection period setting means.
[0075]
When this process is started, first, it is determined whether or not the warm-up of the gasoline engine 1 has been completed (step S110). This determination may be made, for example, based on the cooling water temperature detected by the water temperature sensor 46. In the present embodiment, if the warm-up is not completed, it is determined that the engine is cold.
[0076]
If the warm-up of the gasoline engine 1 has been completed (YES in step S110), the fuel injection control corresponding to the "normal injection" is executed (step S120), and the process ends.
[0077]
In the "normal fuel", based on the engine load and the engine speed calculated from the throttle opening, the intake air amount, and the like, refer to the "calculation map M1 for normal injection" stored in the ROM of the ECU 50. The fuel injection period QT is set. The calculation map M1 for normal injection is set as follows.
[0078]
First, when the engine load is low, the fuel injection period QT is set so that fuel injection is performed in the compression stroke, as shown by the area B in FIG. On the other hand, when the engine load is high, the fuel injection period QT is set so that the fuel injection is performed in the intake stroke as shown by the area A in FIG.
[0079]
Further, when the fuel injection is performed in the intake stroke, the fuel injection period QT is set so that the fuel injection period QT and the above-described fuel collision period Ta at least partially overlap.
[0080]
Therefore, when the warm-up of the gasoline engine 1 is completed and fuel is injected in the intake stroke, the fuel injected from the fuel injection valve 35 surely collides with the head 12a of the intake valve 12. The deposit deposited on the umbrella section 12a is cleaned. Further, since the above-described ribs 12c are provided on the intake valve 12 in the present embodiment, each time fuel collides with such an umbrella portion 12a, the intake valve 12 is rotated, and the entire circumferential surface of the intake valve 12 is rotated. Can be washed.
[0081]
On the other hand, when the warm-up of the gasoline engine 1 is not completed (NO in step S110), that is, when the engine is cold, the fuel injection control by the above-mentioned "cold injection" is executed (step S130), and this processing is performed. finish.
[0082]
In the "cold injection", based on the engine load and the engine speed calculated from the throttle opening, the intake air amount, and the like, refer to the "cold injection calculation map M2" stored in the ROM of the ECU 50. Then, the fuel injection period QT is set. The calculation map M2 for cold injection is set as follows.
[0083]
First, if fuel injection is performed during the compression stroke when the engine is cold, the combustion state becomes unstable. Therefore, when the engine is cold, the fuel injection period QT is set so that fuel injection is performed in the intake stroke regardless of the level of the engine load.
[0084]
Further, in order to prevent the fuel from being injected during the fuel collision period Ta, the fuel injection period QT is set so as to avoid the fuel collision period Ta.
Further, in the present embodiment, as shown by the area A1 in FIG. 6B, when the engine load is low, the fuel injection period QT is set so that fuel injection is performed before the start of the fuel collision period Ta. Have been. Thereby, the time from the fuel injection end timing to the ignition timing at which the air-fuel mixture is ignited by the ignition plug 11 is ensured, and the time for vaporizing the fuel injected into the cylinder and the time for the air-fuel mixture to diffuse into the cylinder are ensured. Will be done.
[0085]
Further, in the present embodiment, the fuel injection period QT is set so that the fuel injection ends immediately before the start of the fuel collision period Ta when the fuel injection is started before the start of the fuel collision period Ta. As a result, the lift amount of the intake valve 12 becomes larger, fuel is injected until just before the start of a fuel collision period Ta in which a larger amount of air can be taken into the cylinder, and the fuel is appropriately stirred by the intake air. It has become to be.
[0086]
By the way, the period in which the fuel can be suitably injected has the following restrictions. For example, if the start time of the fuel injection is earlier than a certain time, the fuel injection period QT and the valve opening period of the exhaust valve 13 may overlap with each other, which may cause fuel blow-through. In the gasoline engine 1, the period before the injection start limit a shown in FIG. 6B is a period inappropriate for fuel injection for such a reason.
[0087]
There is also a similar restriction on the end timing of fuel injection. For example, if the end time of the fuel injection is later than a certain time, the time between the end time of the fuel injection and the ignition timing becomes short, and the time for fuel vaporization and the time for the mixture to diffuse into the cylinder become insufficient. . In the gasoline engine 1, the period after the injection end limit b shown in FIG. 6B is inappropriate for fuel injection for such a reason.
[0088]
On the other hand, as described above, in order to secure the time from fuel injection to ignition and to promote agitation of the fuel, the fuel injection period QT is such that the fuel is injected before the start of the fuel collision period Ta and the fuel is injected immediately before the start. Is desirably set so that the injection of the fuel is terminated. Thus, in the present embodiment, when the engine load is low, such a fuel injection period QT is set.
[0089]
However, when the engine load increases and the fuel injection amount becomes equal to or more than a predetermined value, it becomes difficult to inject all of the fuel only in the period between the injection start limit a and the start time of the fuel collision period Ta. . Therefore, in this embodiment, in such a case, as shown by regions A2 and A3 in FIG. 6B, the fuel injection period QT is divided into a period QT1 before the start of the fuel collision period Ta and a period after the end of the fuel collision period Ta. The “split injection” is performed in which the fuel is divided into two periods QT2 and the fuel is injected twice. When this split injection is performed, the sum of the period QT1 secured before the start of the fuel collision period Ta and the period QT2 secured after the end of the fuel collision period Ta becomes the fuel injection period QT according to the engine operating state. .
[0090]
Further, in the split injection, priority is given to the fuel injection in a period before the start of the fuel collision period Ta in which a longer period from the injection to the ignition can be secured.
Here, the fuel injection in the period QT1 is set to be completed immediately before the start of the fuel collision period Ta, and the fuel injection in the period QT2 is started immediately after the end of the fuel collision period Ta. Is set. Thus, while avoiding the fuel collision period Ta, the fuel injection is performed at a time when the lift amount of the intake valve 12 is larger and the amount of intake air to the cylinder is larger.
[0091]
Note that due to the structure of the fuel injection valve 35 and the like, the controllable minimum amount is determined for the amount of fuel that can be injected at one time. That is, the fuel injection period cannot be set shorter than a certain period (minimum injection period). Therefore, the period QT2 immediately after the transition from the region A1 to the region A2 in FIG. 6B with the increase in the engine load is set to the minimum injection period. In the transition from the region A1 to the region A2, the period QT1 immediately after the transition is shorter than the fuel injection period QT immediately before the transition so that the total amount of fuel injection changes without generating a step. The period is set to be shorter by the minimum injection period.
[0092]
The above is the details of the switching process of the fuel injection mode in the present embodiment. In this embodiment, when the engine is cold, the fuel injection period QT is set so as to avoid the fuel collision period Ta in which the fuel collides with the head portion 12a of the intake valve 12. Therefore, while the fuel is normally allowed to collide with the umbrella portion 12a of the intake valve 12 to clean the deposit, it is possible to avoid such fuel collision when the engine is cold. Therefore, it is possible to suppress deterioration of controllability of the fuel injection amount and coarsening of the fuel caused by the fuel adhering to the head portion 12a of the intake valve 12 having a low temperature.
[0093]
As described above, according to the fuel injection control device of the present embodiment, the following effects can be obtained.
(1) In the in-cylinder injection type gasoline engine 1 according to the present embodiment, by injecting fuel within the fuel collision period Ta, the injected fuel collides with the intake valve 12, and Cleaning is performed. In such a gasoline engine 1, the ECU 50 sets the fuel injection period QT so as to avoid the fuel collision period Ta when the engine is cold. Therefore, when the engine is cold, in which the attached fuel is unlikely to evaporate, the fuel does not directly collide with the intake valve 12, and the amount of fuel remaining in the intake valve 12 can be reduced. Accordingly, it is possible to suppress deterioration of controllability of the fuel injection amount and coarsening of the fuel caused by such adhesion of the fuel to the intake valve 12, and to maintain favorable combustion even when the engine is cold. become.
[0094]
(2) In the present embodiment, when the fuel injection amount becomes equal to or more than the predetermined value, the ECU 50 sets the fuel injection period QT during the cold engine period to a period QT1 before the start of the fuel collision period Ta and a period after the end thereof. The period is set separately for the period QT2. As described above, there is a limit to the period during which fuel can be injected satisfactorily. If the injection start timing is too early or the injection end timing is too late, a good combustion state cannot be maintained. . In this regard, as described above, if the fuel injection period QT when the engine is cold is divided into a period QT1 before the start of the fuel collision period Ta and a period QT2 after the end, the intake air is increased even if the fuel injection amount increases. While avoiding collision of fuel with the valve 12, fuel injection can be performed within the period in which the fuel can be well injected.
[0095]
(3) Further, in the present embodiment, when the fuel injection amount is less than the predetermined value, the ECU 50 sets the fuel injection period QT when the engine is cold so that fuel is injected only before the start of the fuel collision period Ta. are doing. That is, if all the necessary fuel can be injected only before the start of the fuel collision period Ta, the fuel is injected there. In this way, by setting the period before the start of the fuel collision period Ta preferentially as the fuel injection period QT when the engine is cold, the injection necessary for vaporizing the injected fuel and diffusing the air-fuel mixture in the cylinder is made. It is easier to secure the time from the end to the ignition, and the combustion state when the engine is cold can be better maintained.
[0096]
(4) In the present embodiment, the ECU 50 sets the period QT1 to terminate the fuel injection immediately before the start of the fuel collision period Ta during the fuel injection in the period QT1 before the start of the fuel collision period Ta. ing. As a result, when the engine is cold, fuel is injected during a period in which the lift amount of the intake valve 12 is large as long as it is allowed, while avoiding the fuel collision period Ta. As a result, deterioration of fuel agitation due to intake air according to the setting of the fuel injection period QT is suppressed, and the combustion state when the engine is cold can be more favorably maintained.
[0097]
(5) Further, in the present embodiment, the ECU 50 sets the period QT2 for the fuel injection in the period QT2 after the end of the fuel collision period Ta such that the fuel injection is started immediately after the end of the fuel collision period Ta. You have set. In this manner, similarly to the above, deterioration of fuel agitation due to intake air according to the setting of the fuel injection period QT is suppressed, and the combustion state when the engine is cold can be more favorably maintained.
[0098]
(6) When the gasoline engine 1 is warmed up and the fuel injection is performed during the intake stroke, the fuel injection period QT and the fuel collision period Ta at least partially overlap. Therefore, when fuel injection is performed while the gasoline engine 1 is warmed up, the fuel injected from the fuel injection valve 35 surely collides with the head 12a of the intake valve 12. Therefore, the amount of deposit deposited on the head 12a of the intake valve 12 can be reliably reduced.
[0099]
(7) A plurality of ribs 12c are provided on the umbrella portion 12a of the intake valve 12. In particular, when the fuel injected from the fuel injection valve 35 collides with the umbrella portion 12a, the rotational force is applied to the intake valve 12. In order to provide them, the ribs 12c are provided so as to be curved so as to be concave with respect to the fuel injection direction. Therefore, when fuel collides with the head portion 12a of the intake valve 12, the intake valve 12 rotates and the entire surface of the head portion 12a can be cleaned.
[0100]
(Other embodiments)
Next, another embodiment that embodies the present invention will be described focusing on differences from the above embodiment.
[0101]
If the fuel collides with the intake valve 12 for cleaning the deposits deposited as described above, the liquid droplets of the fuel are split by the impact at the time of the collision, and the atomization of the fuel is promoted. Therefore, while the fuel is colliding with the intake valve 12, sufficient atomization of the fuel can be achieved without increasing the injection pressure of the fuel from the fuel injection valve 35 too much. That is, while the fuel is colliding with the intake valve 12, the fuel injection pressure can be set lower.
[0102]
On the other hand, if the fuel injection pressure is reduced, the load on the fuel supply system such as a fuel pump that pressurizes the fuel to the fuel injection valve 35 and feeds the fuel can be reduced, and the reliability of the fuel supply system can be improved. it can.
[0103]
Therefore, if the following fuel injection pressure control is performed in addition to the fuel injection control in the above embodiment, the load on the fuel supply system can be reduced while sufficiently atomizing the fuel.
[0104]
That is, during the fuel collision period Ta, the ECU 50 performs the fuel injection pressure control so as to decrease the fuel injection pressure as compared with the other times. Such adjustment of the injection pressure can be performed through control of a fuel pump that supplies fuel to the fuel injection valve 35 or a pressure control valve provided in the fuel supply pipe. The ECU 50 that performs such control is the above-described fuel injection pressure control means.
[0105]
At times other than when the engine is cold, that is, at the time of the normal injection, the fuel injection period QT may be set to be entirely within the fuel collision period Ta. In such a case, the fuel injection pressure is set to a lower value during the fuel injection during the fuel collision period Ta. Therefore, during the fuel collision period Ta in which the effect of atomizing the fuel by the collision with the intake valve 12 can be enjoyed, the fuel injection pressure is kept low, and the load on the fuel supply system can be reduced. On the other hand, during times other than the fuel collision period Ta in which the atomization effect due to such collision cannot be enjoyed, the fuel injection pressure is set high, thereby reducing the particle size of the fuel spray. Accordingly, unnecessary fuel injection system load can be omitted while sufficiently atomizing the fuel. Incidentally, when the fuel injection period QT is set so as to straddle the fuel collision period Ta and other periods, the fuel injection pressure is set to a higher value before the start of the fuel collision period Ta, It is reduced to a lower value at the start of the fuel collision period Ta. Then, at the end of the fuel collision period Ta, the fuel injection pressure returns to a higher value.
[0106]
On the other hand, when the engine is cold, since the fuel injection period QT is set so as to avoid the fuel collision period Ta as described above, the fuel injection pressure is always set to a higher value.
[0107]
Further, the above-described fuel injection pressure control may be performed with the following changes.
(A) When the fuel injection period QT is set so as to overlap at least a part of the fuel collision period Ta, the fuel injection is performed as compared with when the fuel injection period QT is set so as to avoid the fuel collision period Ta. The fuel injection pressure control is performed so as to reduce the pressure.
[0108]
In this case, in the region A of FIG. 6A, the fuel is injected at a lower fuel injection pressure than in the other cases, that is, when the engine is cold when the fuel injection period QT is set so as to avoid the fuel collision period Ta. It will be injected. Thereby, the load on the fuel supply system in the region A can be reduced. In the region A, since at least a part of the fuel injection period QT is within the fuel collision period Ta, the fuel can be atomized by the collision with the intake valve 12.
[0109]
However, in this case, when the fuel injection period QT is set so as to straddle the fuel collision period Ta and other periods, the fuel may be injected at a lower injection pressure other than during the fuel collision period Ta. In addition, the effect of promoting atomization is limited as compared with the above-described fuel injection pressure control. However, according to such fuel injection pressure control, it is not necessary to change the fuel injection pressure during fuel injection, and an advanced fuel injection pressure adjustment device that allows such a change is not required, and can be realized with a simpler configuration. is there. Also, the control of the fuel injection pressure is easier.
[0110]
(B) When the engine is not cold, the fuel injection pressure control is performed so as to reduce the fuel injection pressure as compared to when the engine is cold.
In this case, the fuel injection period QT is set so as to avoid the fuel collision period Ta as described above, and when the engine is cold during which the atomization of fuel due to the collision cannot be enjoyed at all, the fuel is injected at a higher fuel injection pressure. Will be injected. On the other hand, at the time of normal injection in which the fuel can be atomized by collision, fuel is injected at a lower fuel injection pressure. Therefore, also in this case, it is possible to realize fuel injection pressure control that can reduce the load on the fuel supply system with a simpler configuration. In this case, since the fuel injection pressure is changed depending on whether the engine is cold or not, the control is further facilitated.
[0111]
Furthermore, each embodiment described above can be modified and implemented as follows.
In the above embodiment, the rib 12c is provided on the head portion 12a of the intake valve 12. However, according to the fuel injection control device according to the above embodiment, even if the intake valve is not provided with the rib 12c, It is possible to avoid the above-described problem when the engine 1 is cold.
[0112]
In the above embodiment, the fuel injection before the fuel collision period Ta is prioritized. However, the present invention is not limited to this, and the fuel injection after the fuel collision period Ta is prioritized, The fuel injection may be performed substantially equally before and after the collision period Ta. Also in this case, it is possible to avoid occurrence of the above-described problem when the gasoline engine 1 is cold.
[0113]
In the above-described embodiment, the configuration in which the fuel collides with the intake valve 12 and the cleaning is performed has been described. It is, of course, possible to apply the control in a similar or similar manner.
[0114]
In the above embodiment, the fuel injection control device according to the present invention is applied to the gasoline engine 1. However, the internal combustion engine to be applied is not limited to the gasoline engine 1 at all, and the fuel injection control device according to the embodiment can be applied to other in-cylinder injection type internal combustion engines, for example, a diesel engine. . Also in this case, it is possible to obtain the operation and effect according to the above embodiment.
[0115]
In addition, technical ideas that can be grasped from each of the above embodiments or modifications thereof will be described below together with their effects.
(A) In the fuel injection control device for a direct injection internal combustion engine according to any one of claims 1 to 14, a plurality of ribs radially formed from a coaxial portion are formed on an umbrella portion on a shaft portion side of the intake valve. The fuel injection control device for a direct injection internal combustion engine, wherein the rib is provided so as to be concave with respect to the injection direction of the fuel injected from the fuel injection valve.
[0116]
According to this configuration, when fuel collides with the head of the intake valve, the intake valve is easily rotated, and the entire head can be cleaned with the fuel.
(B) In the fuel injection control apparatus for a direct injection internal combustion engine according to any one of claims 1 to 14, the injection period setting means sets a fuel injection period in an intake stroke injection. A fuel injection control device for a direct injection internal combustion engine.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a gasoline engine to which a fuel injection control device is applied according to an embodiment of the present invention, and a peripheral configuration thereof.
FIG. 2 is a sectional view showing a partial sectional structure of the gasoline engine.
FIG. 3 is a graph showing a relationship between a change in a lift amount of an intake valve and a fuel collision period Ta.
FIG. 4 is a diagram showing both a planar structure and a side structure of the intake valve according to the embodiment.
FIG. 5 is a flowchart of a switching process of an injection mode according to the embodiment.
FIG. 6 is a diagram illustrating a control example of a switching process of the injection mode.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Gasoline engine, 2 ... Cylinder block, 3 ... Cylinder head, 4 ... Cylinder, 5 ... Piston, 6 ... Connecting rod, 7 ... Crankshaft, 8 ... Combustion chamber, 9 ... Intake port, 10 ... Exhaust port, 11 ... Ignition Plug, 12 ... intake valve, 12a ... head, 12b ... shaft, 12c ... rib, 13 ... exhaust valve, 14 ... timing belt, 15 ... intake side timing pulley, 16 ... exhaust side timing pulley, 17 ... intake side camshaft 18 exhaust camshaft, 20 intake passage, 21 crankcase, 22 actuator, 23 throttle valve, 30 exhaust passage, 35 fuel injection valve, 41 crank angle sensor, 42 cam angle sensor, 44: throttle opening sensor, 45: air flow meter, 46: water temperature sensor, 50: control unit (ECU), 60: exhaust gas Ring device (EGR device), 61 EGR passage, 62 EGR valve, 70 blow-by gas recirculation device, 71 control valve, 72 gas recirculation passage, 73 fresh air passage, M1 calculation map for normal injection, M2 … Calculation map for cold injection.

Claims (14)

By injecting fuel within a predetermined fuel collision period, in a fuel injection control device for a direct injection internal combustion engine that causes the injected fuel to collide with an engine valve,
A fuel injection control device for a direct injection internal combustion engine, comprising: injection period setting means for setting a fuel injection period so as to avoid the fuel collision period when the engine is cold. 2. The fuel injection control device for a direct injection internal combustion engine according to claim 1, wherein the injection period setting means preferentially sets a period before the start of the fuel collision period as the fuel injection period when the engine is cold. The injection period setting means sets the fuel injection period when the engine is cold so that fuel is injected only before the start of the fuel collision period when the fuel injection amount is less than a predetermined value, and the fuel injection amount is set to a predetermined value. The in-cylinder according to claim 1, wherein when the value is equal to or more than the value, the fuel injection period at the time of engine cold is set so that fuel is injected separately into a period before the start of the fuel collision period and a period after the end of the fuel collision period. A fuel injection control device for an injection type internal combustion engine. 3. The in-cylinder according to claim 1, wherein the injection period setting unit sets the fuel injection period when the engine is cold, divided into a period before the start of the fuel collision period and a period after the end of the fuel collision period. 4. A fuel injection control device for an injection type internal combustion engine. When injecting fuel during a period before the start of the fuel collision period, the injection period setting means sets the fuel injection period at the time of engine cold so as to end the injection of the fuel immediately before the start of the fuel collision period. The fuel injection control device for a direct injection internal combustion engine according to claim 1, wherein the fuel injection control device is set. When injecting fuel during a period after the end of the fuel collision period, the injection period setting means sets the fuel injection period at the time of engine cold so as to start injection of the fuel immediately after the end of the fuel collision period. A fuel injection control device for a direct injection internal combustion engine according to any one of claims 1 to 5, which is set. The cylinder injection type internal combustion engine according to any one of claims 1 to 6, wherein the injection period setting means sets the fuel injection period so as to overlap at least a part of the fuel collision period when the engine is not cold. Fuel injection control device. By injecting fuel within a predetermined fuel collision period, in a fuel injection control device for a direct injection internal combustion engine that causes the injected fuel to collide with an engine valve,
A first calculation map for setting a fuel injection period so as to overlap at least a part of the fuel collision period, and a second calculation map for setting a fuel injection period so as to avoid the fuel collision period. A fuel injection control device for a direct injection internal combustion engine, comprising: an injection period setting means for setting a fuel injection period in an intake stroke injection by switching according to an engine operating condition. The second operation map is configured such that the fuel injection period is set so that fuel is injected only before the start of the fuel collision period when the fuel injection amount is less than a predetermined value, and when the fuel injection amount is equal to or more than a predetermined value, 9. The direct injection internal combustion engine according to claim 8, wherein the fuel injection period is set so that fuel is injected separately into a period before the start of the fuel collision period and a period after the end of the fuel collision period. Fuel injection control device. The injection period setting means sets the fuel injection period using the second operation map when the engine is cold, and uses the first operation map other than when the engine is cold for the fuel injection period. The fuel injection control device for a direct injection internal combustion engine according to claim 8 or 9, wherein: The fuel injection control device for a direct injection internal combustion engine according to any one of claims 1 to 7,
A fuel injection control device for a direct injection internal combustion engine, further comprising an injection pressure control means for reducing the fuel injection pressure when the engine is not cold compared to when the engine is cold. The fuel injection control device for a direct injection internal combustion engine according to any one of claims 1 to 10,
A fuel injection control device for a direct injection internal combustion engine, further comprising an injection pressure control means for reducing the fuel injection pressure during the fuel collision period as compared to other times. The fuel injection control device for a direct injection internal combustion engine according to any one of claims 1 to 10,
When the fuel injection period is set so as to overlap at least a part of the fuel collision period, the injection for reducing the fuel injection pressure as compared with when the fuel injection period is set so as to avoid the fuel collision period. A fuel injection control device for a direct injection internal combustion engine, further comprising pressure control means. 14. The fuel injection control device for a direct injection internal combustion engine according to claim 1, wherein the fuel collision period is a period near a time when a lift amount of the engine valve is maximized.

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