JP2003090239A - Internal combustion engine of cylinder direct injection type - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve fuel consumption and emission, by spreading an operating region of compression self ignition combustion while avoiding knocking and unstable combustion. SOLUTION: This internal combustion engine of cylinder direct injection type, performing compression self ignition combustion, when it is performed, mixes fuel injected from a fuel injection valve 16 into a mixture chamber 17 provided in a two-fluid injection valve 14 with air supplied from an air pipe 19, increases aldehyde to reform the fuel into fuel enhancing ignitability by igniting the concerned mixture by a spark plug 20, and spreads an operating region of the compression self ignition combustion by injecting the concerned reformed fuel into a cylinder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-cylinder direct injection internal combustion engine in which fuel is directly injected into a cylinder from a fuel injection valve.

[0002]

A cylinder direct injection internal combustion engine (hereinafter referred to as compression self-ignition internal combustion engine) that performs compression self-ignition (hereinafter also simply referred to as self-ignition) combustion is disclosed in Japanese Patent Laid-Open No. 10-196.
There is one described in Japanese Patent No. 424. This is equipped with a control piston as auxiliary compression means in addition to the piston in the cylinder.By further adding compression by the control piston to the air-fuel mixture compressed to a high temperature on the verge of self-ignition, It is designed to self-ignite all at once.

A compression self-ignition type internal combustion engine equipped with a spark plug is disclosed in Japanese Laid-Open Patent Publication No. 11-210539. In the present invention, in particular, by determining whether the gas temperature in the cylinder at the end of the compression stroke is a target temperature that causes self-ignition of the entire air-fuel mixture when ignited, and controlling the opening timing of the intake valve, The gas temperature in the cylinder at the end of the stroke is controlled to be maintained at the target temperature.

[0004]

Unlike the combustion by flame propagation, self-ignition combustion has a low local combustion temperature and N
There is an advantage that Ox is generated only in a very small amount. On the other hand, in a homogeneous air-fuel mixture field, the entire region of the cylinder is ignited all at once, so if the mixture is made richer as the load increases, the rate of pressure increase in the cylinder becomes too large, and vibration and noise increase. There is a problem of becoming.

Therefore, in order to increase the load limit of the self-ignition combustion, the ignition timing is set near the top dead center or later, and most of the combustion is generated in the period after the top dead center. Therefore, it is necessary to reduce the rate of pressure increase in the cylinder. However, the combustion when the ignition timing is delayed is essentially unstable because the initial combustion progresses as the pressure decreases due to the lowering of the piston.

That is, in order to increase the load limit of self-ignition combustion, it is necessary to delay the ignition timing and control so that stable ignition can be obtained. On the other hand, when the technique described in Japanese Patent Laid-Open No. 11-210539 is applied in a homogeneous air-fuel mixture field, the ignition timing is stabilized by the assistance of the spark plug. However, this method cannot delay the ignition position even if self-ignition combustion occurs near or after top dead center, and as a result, it is not effective for increasing the load limit of self-ignition combustion. It has been confirmed by experiments conducted by the inventors of the present application that there is none.

Further, there is a method of locally forming a rich air-fuel mixture field during self-ignition combustion, causing self-ignition or spark ignition from there, and self-igniting surrounding fuel by combustion from the rich air-fuel mixture field. 11-210539, the local formation of a rich air-fuel mixture is performed by injecting from the side of the combustion chamber on the intake valve arrangement side to the piston crown surface. It is impossible to keep a specific rich mixture in a certain place,
Further, in order to maintain a rich air-fuel mixture field and stably supply it to the spark plug arranged in the center of the cylinder head, the amount of injected fuel increases. That is, even if it can be delayed near the top dead center or thereafter, there is a large amount of rich air-fuel mixture, so it is difficult to reduce the pressure increase rate, and NOx cannot be reduced.

The present invention has been made by paying attention to such a conventional problem, and it is possible to expand the load range of stable self-ignition combustion by improving the fuel property, thereby improving the fuel consumption and the emission, and the in-cylinder direct injection is improved. An object of the present invention is to provide an internal combustion engine.

[0009]

Therefore, according to the first aspect of the present invention, in a cylinder direct injection internal combustion engine in which fuel is directly injected into a cylinder from a fuel injection valve, the fuel is modified so as to improve ignitability. Characterized by injecting the reformed fuel.

According to the first aspect of the present invention, by injecting the fuel having the improved ignitability into the cylinder, the ignition delay time of the fuel becomes extremely short, and during the self-ignition combustion, the fuel injection to the ignition occur. Since it is possible to shorten the time until, and it is possible to maintain a high degree of stratification, it is possible to suppress the amount of HC emission. Further, since the ignitability is good even during the spark ignition operation, the HC emission amount can be suppressed.

As a result, the operating range in which self-ignition combustion is possible is expanded, and fuel consumption and emissions are improved. The invention according to claim 2 is characterized in that the fuel is reformed by increasing the amount of aldehyde. According to the invention of claim 2, the ignitability can be enhanced by increasing the aldehyde amount of the fuel, and the fuel having the high ignitability can be easily injected without having two types of fuel.

Further, the invention according to claim 3 is a mixture chamber with a spark plug for mixing the fuel injected from the second fuel injection valve and the air upstream of the fuel pipe connected to the fuel injection valve. The reformed fuel obtained by spark ignition of the air-fuel mixture in the air-fuel mixture chamber with a spark plug is injected into the cylinder from the fuel injection valve on the downstream side.

According to the third aspect of the present invention, the fuel in the air-fuel mixture chamber is ignited by spark ignition, so that the fuel can be reformed and the amount of aldehyde can be increased, and the ignitability of the fuel can be enhanced. The invention according to claim 4 is characterized in that the fuel injection valve is provided with an air-fuel mixture chamber with an ignition plug for mixing the fuel injected from the second fuel injection valve and the air, and the mixture in the air-fuel mixture chamber is provided. It is characterized in that reformed fuel obtained by spark ignition of air with a spark plug is injected into a cylinder.

According to the fourth aspect of the present invention, the fuel in the air-fuel mixture chamber is ignited by spark ignition, so that the fuel can be reformed and the amount of aldehyde can be increased, and the ignitability of the fuel can be enhanced. Further, by providing the air-fuel mixture chamber in the fuel injection valve for in-cylinder injection, the size can be reduced. Also,
According to the invention of claim 5, by adding ozone,
It is characterized in that the fuel is reformed.

According to the fifth aspect of the invention, by adding ozone to the mixture, it is possible to enhance the ignitability, and it is possible to easily inject a highly ignitable fuel without having two types of fuel. Becomes Further, the invention according to claim 6 is characterized in that a second pipe is provided upstream of the fuel pipe connected to the fuel injection valve.
An air-fuel mixture chamber that mixes the fuel injected from the fuel injection valve and the air to which ozone is added, and the air-fuel mixture in the air-fuel mixture chamber is used as reformed fuel, and the fuel is injected from the downstream side fuel injection valve into the cylinder. It is characterized by injecting into.

According to the sixth aspect of the invention, by adding ozone to the fuel in the air-fuel mixture chamber, the fuel can be reformed into a fuel having an improved ignitability. In the invention according to claim 7, a fuel-air mixture chamber for mixing the fuel injected from the second fuel-injection valve and the air to which ozone is added is provided in the fuel injection valve, and the mixture in the air-fuel mixture chamber is provided. It is characterized in that air is injected into the cylinder as reformed fuel.

According to the invention of claim 7, it becomes possible to enhance the ignitability of the fuel by adding ozone to the fuel in the air-fuel mixture chamber. Further, the air-fuel mixture chamber is arranged in the two-fluid injection valve so as to be integrated with the two-fluid injection valve, whereby the device is made compact. Further, the invention according to claim 8 switches between spark ignition operation and compression self-ignition operation depending on the operation region, and during the compression self-ignition operation, the fuel is injected into the cylinder by dividing into two times, and
It is characterized in that fuel reformed so as to enhance ignitability is injected at the time of the fuel injection for the first time.

According to the eighth aspect of the present invention, during the compression self-ignition operation, the fuel is supplied into the cylinder in two steps, and the first-time supply fuel is used as the main combustion of the self-ignition combustion, and the second supply is performed. The fuel is used to cause compression self-ignition by its combustion. By modifying the fuel supplied for the second time so as to improve the ignitability, the injection timing of the fuel supplied for the second time can be set immediately before ignition, so that high stratification can be maintained. As a result, the amount of fuel supplied for the second time can be suppressed to the minimum amount of fuel required to reach main combustion, and NOx can be sufficiently reduced.

The invention according to claim 9 is characterized in that the second injected fuel amount ratio is increased as the engine speed is increased. According to the invention of claim 9, in addition to the effect of claim 8, during the compression self-ignition operation, as the engine speed increases, the
By increasing the fuel supply amount of the reformed fuel so as to improve the ignition performance of the second time, it is possible to suppress the deterioration of the ignition performance of the main combustion due to the reduction of the actual time.
Not only can the amount of emissions be suppressed, but the compression self-ignition combustion region can be expanded to the high rotation side, and fuel efficiency can be further improved.

The invention according to claim 10 is characterized in that the second injected fuel amount ratio is increased as the load is increased. According to the invention of claim 10, as the load increases during the compression self-ignition operation, it is necessary to retard the main combustion start timing due to compression self-ignition from top dead center in order to avoid knocking. Delaying the combustion from the top dead center leads to deterioration of the ignitability of the main combustion. Therefore, by increasing the fuel supply amount of the fuel reformed so as to enhance the ignitability of the second time, it becomes possible to avoid the deterioration of the ignitability of the main combustion, and it is possible to suppress the HC emission amount. Not only that, but the compression self-ignition combustion region can be expanded to the high load side, and fuel consumption can be further improved.

The invention according to claim 11 is characterized in that the injection timing of the first fuel injection is delayed as the engine rotation speed increases. According to the invention of claim 11, by delaying the injection timing of the first fuel injection with the increase of the engine rotation speed, the mixing relating to the self-ignition combustion is performed at an appropriate combustion timing that does not cause a rapid pressure increase. It is possible to suppress leaning due to air diffusion, and prevent deterioration of stability of self-ignition combustion and increase of combustion period due to insufficient pre-reaction time of fuel accompanying increase in rotation speed.

The invention according to claim 12 is characterized in that the injection timing of the first fuel injection is advanced as the load increases. According to the invention of claim 12, by advancing the injection timing of the first fuel injection with the increase of the load, the fuel is diffused in the cylinder, and the fuel-air mixture related to the self-ignition combustion with the increase of the fuel injection amount It is possible to suppress enrichment and prevent a sudden increase in pressure.

The invention according to claim 13 is characterized in that the ignition timing of the fuel injected into the cylinder is delayed as the engine speed increases. According to the thirteenth aspect of the present invention, by delaying the ignition timing as the engine speed increases, it is possible to delay the self-ignition combustion timing subsequent to the spark ignition combustion and prevent a sudden increase in pressure during combustion.

The invention according to claim 14 is characterized in that the ignition timing of the fuel injected into the cylinder is delayed as the load increases. According to the invention of claim 14, by delaying the ignition timing as the load increases,
It is possible to delay the self-ignition combustion timing subsequent to the spark ignition combustion, and prevent a sudden increase in pressure.

The invention according to claim 15 is characterized in that the injection timing of the second fuel injection is delayed as the engine speed increases. According to the fifteenth aspect of the present invention, by delaying the injection timing of the second fuel injection in accordance with the ignition timing that is delayed as the engine speed increases, leaning is achieved by diffusion of the air-fuel mixture involved in spark ignition combustion. By suppressing and preventing the ignition stability from deteriorating, the control of the self-ignition combustion start timing is accurately performed.

The invention according to claim 16 is characterized in that the injection timing of the second fuel injection is delayed as the load increases. According to the invention of claim 16, by delaying the injection timing of the second fuel injection in accordance with the ignition timing delayed as the load increases,
By suppressing leaning due to diffusion of the air-fuel mixture related to spark ignition combustion and preventing deterioration of ignition stability, the self-ignition combustion start timing is accurately controlled.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of a first embodiment in which a combustion control device for an internal combustion engine according to the present invention is applied to a gasoline engine. In the present embodiment, self-ignition combustion is performed under specific operating conditions of medium and low load and medium revolutions or less, and spark ignition combustion is performed in a high load or high revolution range, such as self-ignition combustion and spark ignition combustion. Can be switched (see FIG. 2).

The engine body includes a piston 1, a combustion chamber 2,
The fuel injection valve 3, the intake port 4, the intake valve 5, the exhaust port 6, the exhaust valve 7, and the spark plug 8 are provided. An electronic control unit (hereinafter abbreviated as ECU) 10 for controlling the engine body determines a combustion pattern determination unit 11 that determines whether to perform operation by self-ignition combustion or spark ignition combustion according to operating conditions. A spark ignition combustion control unit 12 that controls combustion parameters during spark ignition combustion operation; a self-ignition combustion control unit 13 that controls combustion control parameters during self-ignition combustion operation; an injection fuel control unit 14; and an injection timing. The controller 15 and the ignition timing controller 31 are provided. The self-ignition combustion control unit 13 injects the reformed fuel when the load is low, and injects the non-reformed fuel during the first injection when the load is medium or high.
The injection fuel control unit 14 is controlled so as to inject the reformed fuel at the time of the second injection, and the injection timing control unit 15 is controlled so that the injection timing at the low load and the first injection time at the medium and high loads are controlled. The injection timing and the second injection timing are controlled.

Although the combustion pattern determination unit 11, the spark ignition combustion control unit 12, and the self-ignition combustion control unit 13 among the constituent elements of the ECU 1 can be configured by a hard-wired logic circuit, in the present embodiment, , Is realized as a program of a microcomputer. FIG. 3 shows a range in which self-ignition combustion at the ignition timing for the same load is established.

The knocking strength increases as the ignition timing is set earlier. In addition, delaying the ignition timing increases stability in a deteriorating direction. Due to the knock limit and the stability limit, as can be seen from FIG. 3, in the conventional technique, the allowable ignition timing range in the compression self-ignition combustion operation is extremely narrow. FIG. 4 shows combustion waveforms of in-cylinder pressure and heat generation when the ignition timing is changed. The broken line waveform is a waveform according to the ignition timing immediately after the compression top dead center, and the solid line waveform is a waveform when the ignition timing is retarded from the compression top dead center. When the ignition timing is advanced, the cylinder pressure changes sharply. Since the in-cylinder temperature is affected by the residual EGR gas, once the ignition timing advances, the in-cylinder temperature rises, so that the ignition timing tends to advance further in the subsequent combustion cycle. Therefore, in the present invention, a high-concentration air-fuel mixture arranged in the center of the cylinder is ignited by spark ignition to control the ignition timing so that a low-concentration air-fuel mixture is self-ignited.

The control flow will be described with reference to the flow chart of FIG.
First, in S31, the engine speed and load are detected. Next, in S32, the combustion mode is determined. That is, it is determined whether the spark ignition combustion or the self-ignition combustion is performed from the detected values of the engine rotation speed and the load by using the map of FIG.

When the spark ignition combustion is performed, the control of the spark ignition combustion is started in S33, and when the self ignition combustion is performed, the control of the self ignition combustion is started in S34. In the first embodiment, the flat cylinder head is shown, but
The same effect can be obtained in an engine having a vent roof type cylinder head. FIG. 6 shows a time chart in the low load operation region during self-ignition combustion.

During low load operation, the rate of pressure increase in the cylinder does not become excessively large, so that self-ignition may occur before the compression top dead center. That is, SI-CI control that causes spark ignition combustion (SI) to trigger self-ignition combustion (CI) is not necessary. When the load is small (the fuel injection amount is small), if the injected fuel is evenly distributed in the combustion chamber, the air-fuel ratio of the air-fuel mixture becomes too large, and good self-ignition cannot be obtained. Therefore, during low load operation, fuel injection is performed during the compression stroke, and a small amount of fuel is distributed in a limited region to obtain good ignitability.

The fuel injected into the combustion chamber is concentrated in the spray region, but with the passage of time, diffusion to the surroundings progresses, and the fuel distribution is flattened. Therefore, the longer the time from injection to ignition, the larger the air-fuel mixture region with an excessive air-fuel ratio. The fuel in this region has a high probability of being discharged without being ignited, which becomes a factor to increase the amount of HC emission.

Therefore, when the pre-reformed fuel is injected,
Since the time from injection to ignition is shortened, the fuel reaches self-ignition while being concentrated in the spray region. Therefore, H
The amount of C emission can be suppressed. FIG. 7 shows a time chart in the medium / high load operation region during self-ignition combustion. During medium / high load operation, it is necessary to burn the fuel after the compression top dead center, so SI-CI control is performed.

That is, in addition to the fuel injection for self-ignition combustion, a small amount of the second injection is performed immediately before the ignition is performed.
Spark ignition to a relatively rich mixture formed by the second injection,
The fuel in the rich air-fuel mixture region is burned by spark ignition. Even when performing spark ignition, it is necessary to wait for a certain time from injection to ignition, and there is a time lag between the ignition and the actual ignition of the fuel.

During this time, the injected fuel is diffused and the fuel distribution is flattened, so that the longer the time from injection to ignition, the larger the air-fuel mixture region in which flame does not propagate. To ensure self-ignition combustion by spark ignition combustion,
It is necessary to inject fuel for spark ignition combustion (increase the fuel injection amount for spark ignition combustion) in anticipation of the occurrence of a region where flame propagation does not occur.

When the pre-reformed fuel is injected,
The time to be secured from injection to ignition is shortened, and the time lag from ignition to ignition is shortened. Therefore, it becomes possible to propagate the flame to the peripheral portion of the rich air-fuel mixture region while the fuel is concentrated in the spray region.
The fuel injection amount for spark ignition combustion can be minimized.

In self-ignition, as shown in FIG. 8, there is a correlation between the pressure increase rate and the knocking strength, and it has been clarified that the knocking strength increases as the pressure increase rate increases. Further, as shown in FIG. 9, it is clear that as the combustion period increases, the piston descends during the combustion period, resulting in incomplete combustion and reduced combustion efficiency. That is, when the combustion is completed within a certain crank angle so as not to reduce the combustion efficiency, the actual time when the combustion is performed decreases and the pressure increase rate per unit time increases. It is difficult to expand the ignition operation area.

FIG. 10 shows the engine speed N and the load T.
And the relationship of the pressure rise rate with respect to the combustion timing θ50. θ50 is the crank angle when 50% of the fuel injected into the cylinder burns, and is one parameter indicating the combustion timing. The pressure increase rate decreases as the combustion timing is retarded from the top dead center at the same rotation speed or the same load. This is because the combustion is performed when the piston descends, and the pressure decrease due to the piston descending suppresses the pressure increase during combustion.

In the present embodiment, the combustion timing represented by the crank angle (hereinafter, abbreviated as θ50) at which 50% of the fuel injected into the cylinder is burned is after the top dead center, and the engine rotation is performed as shown in FIG. Knocking is prevented by controlling the speed to be further delayed as the speed increases or the load increases. As a result, the compression self-ignition operation range can be expanded. Therefore, according to the operating conditions of the engine, the first fuel injection timing, the second fuel injection timing, the ignition timing for starting the first-stage combustion, and the first fuel injection are performed so that an appropriate combustion timing can be obtained. The injection amount ratio of the second fuel injection is controlled as follows.

FIG. 12 shows the first fuel injection timing IT1 with respect to the engine speed N and the load T. IT1 as shown
By delaying the engine speed as the engine speed increases, at an appropriate combustion timing that does not cause a sudden pressure increase,
It is possible to suppress leaning due to diffusion of the air-fuel mixture related to self-ignition combustion, and prevent deterioration of stability of self-ignition combustion and increase of combustion period due to insufficient pre-reaction time of fuel accompanying increase in rotation speed. Further, the fuel is diffused in the cylinder by advancing IT1 as the engine load increases, and the enrichment of the air-fuel mixture associated with the self-ignition combustion accompanying the increase in the fuel injection amount is suppressed,
It is possible to prevent a sudden increase in pressure.

FIG. 13 shows the ignition timing IGT with respect to the engine speed N and the load T. By delaying the IGT as the engine speed increases as shown in the figure, it is possible to delay the self-ignition combustion timing subsequent to the spark ignition combustion and prevent a rapid pressure increase during combustion. Further, by delaying the IGT as the engine load increases, it is possible to delay the self-ignition combustion timing subsequent to the spark ignition combustion and prevent a sudden increase in pressure.

FIG. 14 shows the second fuel injection timing IT2 with respect to the engine speed N and the load T. By delaying IT2 with IGT, that is, with increase in engine speed and load, by suppressing leaning due to diffusion of air-fuel mixture related to spark ignition combustion at ignition timing, and preventing deterioration of ignition stability, The self-ignition combustion start timing is accurately controlled.

FIG. 15 shows the ratio of the second fuel injection amount to the total injection amount due to the engine speed N and the load T. As described above, the ignition timing IGT is controlled by delaying it as the engine speed and the load increase. In that case, it is possible to increase the heat generation amount of the spark ignition combustion by increasing the second fuel injection ratio with respect to the total injection amount as shown in the figure, and to reliably perform the subsequent self-ignition combustion.

FIG. 16 shows a first structural view of a two-fluid injection valve as a fuel injection valve. The air-fuel mixture chamber 1 in the two-fluid injection valve 14
7, a fuel injection valve (second fuel injection valve) 16 and a spark plug 20 are provided in the mixture chamber 17. Fuel is supplied to the fuel injection valve 18 via a fuel pipe 18, and air is supplied to the air-fuel mixture chamber 17 via an air pipe 19.
A high-concentration air-fuel mixture is generated in the air-fuel mixture chamber 17, and the spark plug 20 is ignited to increase the amount of aldehyde. By increasing the amount of aldehyde in the reformed fuel 15 injected from the two-fluid injection valve 14, ignitability is enhanced and reforming is performed.

FIG. 17 shows a second structural view of a two-fluid injection valve as a fuel injection valve. The air-fuel mixture chamber 1 in the two-fluid injection valve 14
7 and has a fuel injection valve 16 in a mixture chamber 17.
By adding ozone to the air pipe 21 for the two-fluid injection valve, the air-fuel mixture generated in the air-fuel mixture chamber 17 has an improved ignitability and is reformed. FIG. 18 shows a fuel injection valve 2
The 3rd block diagram of a fluid injection valve is shown. The mixture chamber 17 is provided upstream of the two-fluid injection valve 14, and the mixture chamber 17 has a fuel injection valve 16 and an ignition plug 20. A high-concentration air-fuel mixture is generated in the air-fuel mixture chamber 17, and the spark plug 20 is ignited to increase the amount of aldehyde. As the amount of aldehyde in the reformed fuel 15 increases, the ignitability is increased and reforming is performed.

FIG. 19 shows a fourth structural view of a two-fluid injection valve as a fuel injection valve. An air-fuel mixture chamber 17 is provided upstream of the two-fluid injection valve 14, and a fuel injection valve 16 is provided in the air-fuel mixture chamber 17. By adding ozone to the air pipe 21 for the two-fluid injection valve, the air-fuel mixture generated in the air-fuel mixture chamber 17 has an improved ignitability and is reformed.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment of an internal combustion engine according to the present invention.

FIG. 2 is a diagram illustrating a self-ignition establishment range.

FIG. 3 is a diagram for explaining self-ignition timing, knock strength, and stability.

FIG. 4 is a diagram illustrating a combustion waveform with respect to a combustion timing.

FIG. 5 is a diagram illustrating a control flow according to the first embodiment.

FIG. 6 is a time chart in low load operation during compression self-ignition operation.

FIG. 7 is a time chart from compression self-ignition operation to high load operation.

FIG. 8 is a diagram illustrating a relationship between a pressure increase rate and knocking strength.

FIG. 9 is a diagram showing a relationship between a combustion period and combustion efficiency.

FIG. 10 is a diagram illustrating a relationship between a load and an engine speed, and a pressure increase rate with respect to knocking strength.

FIG. 11 is a diagram for explaining the relationship between engine speed and combustion period with respect to load.

FIG. 12 is a diagram illustrating the relationship between the engine speed and the load of the first fuel injection timing IT1.

FIG. 13: Ignition timing IGT with respect to engine speed and load
FIG.

FIG. 14 is a diagram for explaining the relationship between the engine speed and the load of the second injection timing IT2.

FIG. 15 is a diagram illustrating a relationship between a second injection amount ratio with respect to a total injection amount with respect to an engine rotation speed and a load.

FIG. 16 is a diagram illustrating a first configuration diagram of a two-fluid injection valve.

FIG. 17 is a diagram illustrating a second configuration diagram of a two-fluid injection valve.

FIG. 18 is a diagram illustrating a third configuration diagram of a two-fluid injection valve.

FIG. 19 is a diagram illustrating a fourth configuration diagram of a two-fluid injection valve.

[Explanation of symbols]

1 piston 2 combustion chamber 3 Fuel injection valve 4 intake ports 5 intake valve 6 exhaust port 7 exhaust valve 8 spark plugs 10 ECU 11 Combustion pattern determination unit 12 Spark ignition combustion control unit 13 Self-ignition combustion control unit 14 Two-fluid injection valve 15 reformed fuel 16 2 Injection valve for fluid injection valve 17 Mixture chamber for two-fluid injection valve 18 Fuel piping 19 2 Air pipe for fluid injection valve 20 2 Fluid injection valve spark plug 21 Two-fluid injection valve air piping

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02D 41/02 351 F02D 41/02 351 41/34 41/34 H 45/00 312 45/00 312H 312Z 364 364N F02M 25/00 F02M 25/00 H 27/02 27/02 A C F term (reference) 3G084 AA04 AA05 BA03 BA13 CA04 CA09 DA02 DA10 EB08 FA18 FA33 3G092 AA01 AA06 AA09 AB01 AB02 AB06 AB11 AB12 AB13 AB15 AB16 BA03 BB01 BA06 BB01 BB11 BB12 BB13 BB20 DE01S DE03S DE04S DE11S DE17S DF03 DG07 DG09 EA01 EA11 EC09 FA18 FA24 GA03 GA06 GA16 GA18 HA11Z HB01X HB01Z HE01Z 3G301 HA01 HA04 HA16 HA01 HA01 HA25 HA16 HA21 HA02 HA16 HA21 HA02 HA16 HA21 HA02 HA16 HA21 HA02 HA16 HA25

Claims (16)

[Claims] 1. An in-cylinder direct injection internal combustion engine in which fuel is directly injected from a fuel injection valve into a cylinder, the fuel is reformed so as to improve ignitability, and the reformed fuel is injected. In-cylinder direct injection internal combustion engine. 2. The in-cylinder direct injection internal combustion engine according to claim 1, wherein the fuel is reformed by increasing the amount of aldehyde. 3. An air-fuel mixture chamber with a spark plug for mixing fuel and air injected from a second fuel injection valve is provided upstream of a fuel pipe connected to the fuel injection valve, and the air-fuel mixture is provided. The in-cylinder direct injection internal combustion engine according to claim 2, wherein the reformed fuel obtained by spark ignition of the air-fuel mixture in the room is injected from the downstream fuel injection valve into the in-cylinder. organ. 4. An air-fuel mixture chamber with an ignition plug for mixing fuel and air injected from a second fuel injection valve is provided in the fuel injection valve, and the air-fuel mixture in the air-fuel mixture chamber is discharged by the ignition plug. The in-cylinder direct injection internal combustion engine according to claim 2, wherein the reformed fuel obtained by spark ignition is injected into the cylinder. 5. The in-cylinder direct injection internal combustion engine according to claim 1, wherein the fuel is reformed by adding ozone. 6. An air-fuel mixture chamber for mixing fuel injected from a second fuel injection valve and ozone-added air is provided upstream of a fuel pipe connected to the fuel injection valve, and the air-fuel mixture is mixed. The in-cylinder direct injection internal combustion engine according to claim 5, wherein the air-fuel mixture in the chamber is used as reformed fuel and is injected into the cylinder from the fuel injection valve on the downstream side. 7. A fuel-air mixture chamber for mixing the fuel injected from the second fuel-injection valve and ozone-added air is provided in the fuel injection valve, and the air-fuel mixture in the air-fuel mixture chamber is reformed fuel. The in-cylinder direct injection internal combustion engine according to claim 5, characterized in that the fuel is injected into the cylinder. 8. A spark ignition operation and a compression self-ignition operation are switched depending on the operation region, and during the compression self-ignition operation, the fuel is injected into the cylinder in two divisions, and the ignitability is obtained at the second fuel injection. The in-cylinder direct injection internal combustion engine according to any one of claims 1 to 6, wherein the reformed fuel is injected so as to increase the fuel consumption. 9. As the engine speed increases, 2
The in-cylinder direct injection internal combustion engine according to claim 8, wherein the fuel injection rate of the second injection is increased. 10. The second injected fuel amount ratio is increased as the load is increased.
Alternatively, the in-cylinder direct injection internal combustion engine according to claim 9. 11. As the engine speed increases,
The cylinder direct injection internal combustion engine according to any one of claims 8 to 10, characterized in that the injection timing of the first fuel injection is delayed. 12. The in-cylinder direct injection internal combustion engine according to claim 8, wherein the injection timing of the first fuel injection is advanced as the load increases. . 13. As the engine speed increases,
The cylinder direct injection internal combustion engine according to any one of claims 8 to 12, characterized in that the ignition timing of the fuel injected into the cylinder is delayed. 14. The in-cylinder direct injection internal combustion engine according to claim 8, wherein the ignition timing of the fuel injected into the cylinder is delayed as the load increases. organ. 15. As the engine speed increases,
The in-cylinder direct injection internal combustion engine according to claim 13, wherein the injection timing of the second fuel injection is delayed. 16. The in-cylinder direct injection internal combustion engine according to claim 14, wherein the injection timing of the second fuel injection is delayed as the load increases.