JP4730147B2 - In-cylinder fuel injection internal combustion engine - Google Patents

Description

The present invention relates to a cylinder fuel injection internal combustion engine .

  2. Description of the Related Art In recent years, a spark ignition type gasoline engine (hereinafter simply referred to as a direct injection gasoline engine) that injects fuel into a cylinder has been put into practical use for the purpose of greatly improving fuel efficiency. For direct injection gasoline engines, various fuel injection valve arrangements and fuel injection directions in the arrangements are disclosed in order to realize suitable stratified combustion and homogeneous combustion (for example, Patent Documents 1, 2, 3, and 4). reference).

Japanese Patent Laying-Open No. 2003-322022 (FIGS. 1 and 2) JP-A-10-176628 (FIGS. 2 and 3) JP 2004-162577 A (FIG. 1) JP 2002-371852 A (FIGS. 5 and 6)

  If the flame propagation speed (combustion speed) during combustion is slow, the combustion period becomes long. If the ignition timing and the opening timing of the exhaust valve are the same, the longer the combustion period, the worse the fuel consumption and the greater the emissions such as unburned HC. In this regard, among the above-described patent documents, for example, as in the technique proposed in Patent Document 1 or 2, if a plurality of fuel injection valves are provided per cylinder and fuel is injected in an appropriate direction, Although the mixing speed is improved and the combustion speed is improved by increasing the turbulence of the air-fuel mixture, there is still room for improvement in the combustion speed. Further, in a direct injection gasoline engine, there is a possibility that the injection hole of the fuel injection valve exposed in the cylinder may be blocked by the deposit. However, when the injection hole is blocked by the deposit, the injection amount decreases or the spray A change in shape or the like causes deterioration of the combustion state. Furthermore, in a direct injection gasoline engine, when the atomization of the injected fuel deteriorates, such as when it is cold, it is necessary to inject more fuel as much as it contributes to combustion. Emissions such as deterioration and unburned HC will increase.

Accordingly, the present invention has been made in view of the above problems, and provides an in- cylinder fuel injection type internal combustion engine capable of realizing more suitable combustion when a plurality of fuel injection valves are provided per cylinder. For the purpose.

In order to solve the above-described problems, the present invention provides an intake-side fuel injection valve disposed on the intake port side from a first plane that includes a cylinder center axis and is substantially parallel to the crank axis, and an exhaust from the first plane. An in-cylinder fuel injection type internal combustion engine having an exhaust side fuel injection valve disposed on a port side, wherein a first spark ignition means and a second spark ignition means for igniting a spark in an air-fuel mixture in a combustion chamber And a swirl airflow generating means for generating a swirl airflow that is a tumble flow by the intake air flowing into the combustion chamber, wherein the intake-side fuel injection valve and the exhaust-side fuel injection valve are respectively the swirl airflow. And the center axis of each of the intake side fuel injection valve and the exhaust side fuel injection valve includes the cylinder center axis and is substantially orthogonal to the crank axis. Second to It is arranged so as to be included in the surface, the first spark ignition means is disposed above the combustion chamber than the intake-side fuel injection valve to a said intake port side than the first plane are disposed in correspondence with the whirling airflow towards the exhaust-side fuel injection valve in Rukoto, is and is arranged such that the central axis of the first spark ignition means is included in said second plane, the second The spark ignition means is disposed on the exhaust port side of the first plane and above the combustion chamber of the exhaust side fuel injection valve so that the swirl airflow toward the intake side fuel injection valve is generated. And the second spark ignition means is arranged so that the center axis of the second spark ignition means is included in the second plane, and the swirling airflow is generated by the first spark ignition means, the intake side fuel injection, Valve, exhaust-side fuel injection valve, and second spark Characterized by pivoting so as to pass through the fire unit in this order.

According to the present invention, since the fuel is injected so as to improve the strength of the swirling airflow, it is possible to reduce the intake resistance. Furthermore, according to the present invention, the injection holes of each of the intake side and exhaust side fuel injection valves can be cleaned with each flame propagating from the upstream side of these injection holes in the direction of flow of the swirling airflow, so that the deposit adheres. Can be suppressed. Therefore, according to the present invention, suitable combustion can be realized.

According to the present invention, it is possible to provide an in- cylinder fuel injection type internal combustion engine capable of realizing more suitable combustion when a plurality of fuel injection valves are provided per cylinder.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing an in-cylinder fuel injection internal combustion engine (hereinafter simply referred to as an internal combustion engine) 100A according to the present embodiment, together with another configuration highly related to the internal combustion engine 100A in the present embodiment. The internal combustion engine 100A is a direct injection gasoline engine having an in-line four-cylinder cylinder arrangement structure. However, the invention is not limited to this, and the internal combustion engine 100A may be a direct injection gasoline engine having another appropriate cylinder arrangement structure and the number of cylinders. The intake system 10 of the internal combustion engine 100A includes an air cleaner 11, an intake pipe 12, a surge tank 13, and the like. The intake air is supplied from the atmosphere to each cylinder of the internal combustion engine 100A via the intake system 10. The internal combustion engine 100A has spark plugs (spark ignition means) 1 and 2 that are configured to ignite the air-fuel mixture for each cylinder, and intake-side fuel injection that is configured to inject fuel directly into the cylinder. A valve 21 (hereinafter simply referred to as a fuel injection valve 21a) a and an exhaust side fuel injection valve 22 (hereinafter also referred to simply as a fuel injection valve 22b) a are provided. In addition, the fuel injection valve 21a and the fuel injection valve 22a provided two per cylinder are different in arrangement, and the fuel injection directions are different from each other. Further, for convenience of explanation, the two spark plugs 1 and 2 provided per cylinder are denoted by different reference numerals, but in this embodiment, the spark plugs 1 and 2 are different in arrangement in the internal combustion engine 100A. , Has become the same thing.

  Each of the fuel injection valves 21 a and 22 a is connected to the reservoir tank 26 via each branch pipe 31. In addition, about the connection with the reservoir tank 26 of the exhaust side fuel injection valve 22a, illustration is simplified. The reservoir tank 26 is connected via a high-pressure conduit 32 to a high-pressure fuel pump 23 that can control the discharge pressure. The high-pressure fuel pump 23 is configured to pump high-pressure fuel to the reservoir tank 26, and is connected to the low-pressure fuel pump 24 via a conduit 33. The low-pressure fuel pump 24 is configured to supply fuel from the fuel tank 25 to the high-pressure fuel pump 23. The discharge side of the low-pressure fuel pump 24 is further connected to a piezoelectric element cooling introduction pipe 34 for cooling the piezoelectric piezoelectric elements of the fuel injection valves 21a and 22a. The fuel flowing through the piezoelectric element cooling introduction pipe 34 is collected in the fuel tank 25 via the piezoelectric element cooling return pipe 35.

  The ECU (Electronic Control Unit) 40 </ b> A is mainly configured to control the internal combustion engine 100 </ b> A, and has a CPU (Central Processing Unit) 41 connected to each other by a bidirectional bus 49. A ROM (Read Only Memory) 42 and a RAM (Random Access Memory) 43 are provided. The ROM 42 stores a program describing processing executed by the CPU 41 when controlling the internal combustion engine 100A including fuel injection control. The ROM 42 stores map data for switching between stratified combustion and homogeneous combustion based on the load and the rotational speed of the internal combustion engine 100A. In this embodiment, the load generates an output pulse proportional to the rotation speed based on an output signal of an accelerator opening sensor 52 that is a configuration for detecting the opening of an accelerator pedal (not shown). Each is detected based on an output signal from the crank angle sensor 54.

  The ECU 40A further includes an input port 44 and an output port 45, A / D converters 46a, 46b and 46c, and drive circuits 47a, 47b, 47c and 47d. The input port 44 includes a pressure sensor 51 configured to detect the pressure in the reservoir tank 26 via an A / D converter 46a, and an accelerator opening sensor 52 via an A / D converter 46b. A water temperature sensor 53, which is a configuration for detecting the temperature of each, is connected via the A / D converter 46c. In addition to the crank angle sensor 54 connected to the input port 44, various sensors such as an air flow meter (not shown), which is a configuration for detecting the intake air flow rate, are also connected. On the other hand, in the output port 45, each intake-side fuel injection valve 21a passes through the drive circuit 47a, the spark plugs 1 and 2 pass through the drive circuit 47b, and each exhaust-side fuel injection valve 22a passes through the drive circuit 47c. The high-pressure fuel pump 23 is connected to each other via a drive circuit 47d. Although the illustration is simplified in FIG. 1, each of the drive circuits 47a, 47b, and 47c individually corresponds to each intake-side fuel injection valve 21a, each ignition plug 1 and 2, and each exhaust-side fuel injection valve 22a. It consists of a plurality of drive circuits.

  FIG. 2 is a view showing the main part of the internal combustion engine 100A with respect to the cylinder 7 among the cylinders. Specifically, FIG. 2 (a) is a diagram conceptually showing the main part of the internal combustion engine 100A with respect to the cylinder 7 in a top view, and FIG. 2 (b) is the main part of the internal combustion engine 100A with respect to the cylinder 7. It is a figure conceptually shown by the side view. In FIG. 2, the main part of the internal combustion engine 100A is shown for the cylinder 7 as a representative of each cylinder. However, in this embodiment, the other cylinders have the same structure. The internal combustion engine 100A includes a cylinder block 3A, a cylinder head 4A, a piston 5, and the like. A substantially cylindrical cylinder 7 is formed in the cylinder block 3A. A piston 5 is accommodated in the cylinder 7. A cylinder head 4A is fixed to the upper surface of the cylinder block 3A. The combustion chamber 6 is formed as a space surrounded by the cylinder block 3 </ b> A, the cylinder head 4 </ b> A, and the cylinder 7. The cylinder head 4A is formed with exhaust ports 9a and 9b for exhausting the combusted gas from the combustion chamber 6 in addition to intake ports 8a and 8b for guiding intake air to the combustion chamber 6, and these intake and exhaust ports 8 In addition, an intake / exhaust valve (not shown) for opening and closing the passages 9 and 9 is provided. The intake port 8 is provided with an air flow control valve (swirl air flow generating means) (not shown). When an actuator (not shown) changes the opening degree of the air flow control valve under the control of the ECU 40A, the air flow control valve is opened. As the degree changes, the flow rate and flow velocity of the intake air change. The intake air is drifted in the intake port 8 from the time when the airflow control valve is fully closed to the time when it is half-opened, and is generated in the swirl flow S having high strength in the combustion chamber 6 in this embodiment. A cavity may be formed on the top surface of the piston 5.

  Each of the fuel injection valves 21a and 22a is disposed so as to include a plane that includes the central axis P1 of the cylinder 7 and that is substantially orthogonal to the crank axis (not shown). More specifically, the intake-side and exhaust-side fuel injection valves 21a and 22a are disposed so that the central axis of the main body is included in the above-described plane and is substantially orthogonal to the central axis P1. The crank axis extends substantially parallel to the center line P2. Further, each of the fuel injection valves 21a and 22a includes an injection hole (not shown) for injecting fuel in a direction along the swirl flow S. These injection holes protrude into the combustion chamber 6, and the injected fuel forms a spray F. The spark plug 1 is disposed in correspondence with the swirl flow S toward the exhaust-side fuel injection valve 22a with the electrode protruding into the combustion chamber 6. Similarly, the spark plug 2 is disposed corresponding to the swirl flow S toward the intake side fuel injection valve 21a. These spark plugs 1 and 2 have a central axis of each main body including the central axis P1 and are included in a plane substantially parallel to the crank axis, and to the combustion chamber 6 so as to be substantially parallel to the central axis P1. Evenly arranged.

  Next, the combustion performed in the combustion chamber 6 with the above configuration will be described in detail. In the intake process, intake air is supplied and a swirl flow S is generated in the combustion chamber 6. When stratified combustion is performed in the internal combustion engine 100A, the fuel injection valves 21a and 22a perform the first stage fuel injection in the intake process to generate a lean air-fuel mixture under the control of the ECU 40A and can be ignited. The second stage fuel injection for producing a rich mixture is performed in the compression process. When homogeneous combustion is performed in the internal combustion engine 100A, the fuel injection valves 21a and 22a perform fuel injection for generating a homogeneous air-fuel mixture in the intake process under the control of the ECU 40A. However, the mode of fuel injection control is not limited to these. For example, in a suitable mode such as injecting fuel step by step over a plurality of times, and further changing the fuel injection pressure in each step at that time. It may be. At this time, since the fuel is injected along the swirl flow S, the strength of the swirl flow S is increased. Further, in the internal combustion engine 100A according to the present embodiment, the intake resistance caused by the airflow control valve is reduced by reducing the degree of intake air drift by the amount that the strength of the swirl flow S is increased by fuel injection. As a result, even when the swirl flow S having the same strength is generated, the intake flow rate is further increased, so that the lean combustion region is expanded in the small and medium load operation region where stratified combustion is performed, and further in the medium and high load operation region where homogeneous combustion is performed. The mixing property of the air-fuel mixture is improved and the disturbance is increased.

  On the other hand, the fuel injected in the intake process is generated into a highly mixed gas mixture until the piston 5 reaches near the top dead center in the compression process. Further, at the ignition timing, the spark plugs 1 and 2 ignite the air-fuel mixture under the control of the ECU 40A. In this embodiment, since the air-fuel mixture is ignited by the spark plugs 1 and 2 that are evenly arranged, the propagation distance of each flame becomes the shortest, and rapid combustion occurs at a higher combustion speed. In the present embodiment, each flame easily propagates along with the flow of the swirl flow S, so that the injection holes of the fuel injection valves 21a and 22a are cleaned by each flame. As a result, fuel consumption can be further improved and emissions can be reduced, and deposits can be suitably suppressed. As described above, when two fuel injection valves 21a and 22a are provided per cylinder, it is possible to realize the internal combustion engine 100A capable of realizing more suitable combustion.

  FIG. 3 is a view showing a main part of the internal combustion engine 100B with respect to the cylinder 7 among the cylinders. Specifically, FIG. 3A is a diagram conceptually showing the main part of the internal combustion engine 100B with respect to the cylinder 7 in a top view, and FIG. 3B is the main part of the internal combustion engine 100B with respect to the cylinder 7. It is a figure conceptually shown by the side view. The internal combustion engine 100B according to the present embodiment differs from the internal combustion engine 100A according to the first embodiment in the arrangement of the spark plugs 1 and 2. Further, the internal combustion engine 100B includes fuel injection valves 21b and 22b having fuel injection directions different from those of the internal combustion engine 100A instead of the fuel injection valves 21a and 22a. The cylinder block 3B is the same as the internal combustion engine 100A except that the cylinder head 4A is changed to the cylinder head 4B. For convenience of explanation, the ECU 40B is referred to, but in this embodiment, the ECU 40B is the same as the ECU 40A shown in the first embodiment.

  Each of the fuel injection valves 21b and 22b is disposed so as to sandwich a plane that includes the central axis P1 of the cylinder 7 and that is substantially orthogonal to the crank axis. More specifically, each of the intake side and exhaust side fuel injection valves 21b and 22b has a central axis line at a position where the central axis line of the main body is offset toward the opposite side at equal intervals in a direction substantially orthogonal to the plane described above. It is arranged so as to be substantially orthogonal to a plane including P1 and substantially parallel to the crank axis. In the present embodiment, each of the fuel injection valves 21b and 22b includes an injection hole for injecting fuel in the direction along the swirl flow S in the above-described arrangement. On the other hand, the spark plug 1 is disposed in correspondence with the swirl flow S toward the injection hole of the exhaust-side fuel injection valve 22b with the electrode protruding into the combustion chamber 6. Similarly, the spark plug 2 is disposed in correspondence with the swirl flow S toward the injection hole of the intake side fuel injection valve 21b. These spark plugs 1 and 2 include the combustion chamber 6 so that the center axis of each main body includes the center axis P1 and is included in a plane substantially orthogonal to the crank axis, and is approximately orthogonal to the pent roof wall above the combustion chamber 6. Are evenly arranged.

  Next, the combustion performed in the combustion chamber 6 with the above configuration will be described in detail. Also in the present embodiment, as in the first embodiment, the lean combustion region is expanded in the small and medium load operation region in which the stratified combustion is performed based on the fuel injection from the fuel injection valves 21b and 22b performed under the control of the ECU 40B. Further, in the middle and high load operation region where homogeneous combustion is performed, the mixing property of the air-fuel mixture is improved and the turbulence is increased. Also in the present embodiment, under the control of the ECU 40B, the air-fuel mixture is ignited by the spark plugs 1 and 2 that are evenly arranged at the ignition timing, so that the propagation distance of each flame is the shortest and higher combustion is achieved. Burns rapidly at speed. Also in the present embodiment, since each flame easily propagates along with the flow of the swirl flow S, the injection holes of the fuel injection valves 21b and 22b are cleaned with each flame. As a result, fuel consumption can be further improved and emissions can be reduced, and deposits can be suitably suppressed.

  The internal combustion engine 100B is different from the internal combustion engine 100A according to the first embodiment because the protruding positions of the spark plugs 1 and 2 are different from those of the internal combustion engine 100A according to the first embodiment due to, for example, a pent roof shape. A little different. Therefore, the internal combustion engine 100B according to the present embodiment is effective when a higher degree of effect is obtained in combination with other specifications of the internal combustion engine such as the strength of the generated swirl flow S and the shape of the combustion chamber 6. In the case where a more advantageous structure can be obtained in combination with other components as a whole, the internal combustion engine 100A can be selectively employed. Similarly, the internal combustion engines 100A and 100B, for example, each of the internal combustion engines provided with one ignition plug substantially at the center above the combustion chamber 6 instead of including the ignition plugs 1 and 2, respectively. An internal combustion engine can be selectively employed. As described above, when the two fuel injection valves 21b and 22b are provided per cylinder, the internal combustion engine 100B capable of realizing more suitable combustion can be realized.

  FIG. 4 is a view showing the main part of the internal combustion engine 100C with respect to the cylinder 7 among the cylinders. Specifically, FIG. 4 (a) is a diagram conceptually showing the main part of the internal combustion engine 100C with respect to the cylinder 7 in a top view, and FIG. 4 (b) is the main part of the internal combustion engine 100C with respect to the cylinder 7. It is a figure conceptually shown by the side view. The internal combustion engine 100C according to the present embodiment includes fuel injection valves 21c and 22c having different fuel injection directions instead of the fuel injection valves 21a and 21b, and generates a tumble flow T instead of generating a swirl flow S. The same as the internal combustion engine 100A according to the first embodiment except that the cylinder head 4A is changed to the cylinder head 4C because the air flow control valve to be generated is provided and the arrangement of the spark plugs 1 and 2 is different. It has become. For convenience of explanation, the cylinder block 3C is referred to, but in this embodiment, the cylinder block 3C is the same as the cylinder block 3A shown in the first embodiment. Similarly, although referred to as ECU 40C, in this embodiment, the ECU 40C is the same as the ECU 40A shown in the first embodiment.

  Similarly to the first embodiment, the fuel injection valves 21c and 22c include a central axis of the main body that includes the central axis P1 of the cylinder 7, is included in a plane that is substantially orthogonal to the crank axis, and is substantially orthogonal to the central axis P1. However, in this embodiment, each of the fuel injection valves 21c and 22c has an injection hole for injecting fuel in a direction along the tumble flow T. In the present embodiment, the spark plug 1 is disposed in correspondence with the tumble flow T toward the injection hole of the exhaust side fuel injection valve 22c with the electrode protruding into the combustion chamber 6. The tumble flow T is structurally passed through the injection hole of the intake side fuel injection valve 21c before reaching the injection hole of the exhaust side fuel injection valve 22c. Therefore, in this embodiment, the flame propagating based on the spark from the spark plug 1 cleans not only the injection hole of the fuel injection valve 22c but also the injection hole of the fuel injection valve 21c. Similarly to the spark plug 1, the spark plug 2 is also disposed in correspondence with the tumble flow T toward the injection hole of the intake side fuel injection valve 21c. These spark plugs 1 and 2 are combusted so that the center axis of each main body includes the center axis P1 and is included in a plane substantially orthogonal to the crank axis, and substantially orthogonal to the pent roof wall above the combustion chamber 6. The chambers 6 are evenly arranged.

  Next, the combustion performed in the combustion chamber 6 with the above configuration will be described in detail. Also in the present embodiment, as in the first embodiment, the lean combustion region is expanded in the small and medium load operation region in which the stratified combustion is performed based on the fuel injection from the fuel injection valves 21c and 22c performed under the control of the ECU 40C. Further, in the middle and high load operation region where homogeneous combustion is performed, the mixing property of the air-fuel mixture is improved and the turbulence is increased. Also in this embodiment, under the control of the ECU 40C, the air-fuel mixture is ignited by the spark plugs 1 and 2 that are evenly arranged at the ignition timing, so that the propagation distance of each flame becomes the shortest and the higher combustion Burns rapidly at speed. Also in the present embodiment, each flame easily propagates along with the flow of the tumble flow T, so that the injection holes of the fuel injection valves 21c and 22c are cleaned with each flame. That is, even when the tumble flow T is generated in the combustion chamber 6, according to the internal combustion engine 100C according to the present embodiment, it is possible to further improve fuel efficiency and reduce emissions, and to suppress deposit adhesion. is there. As described above, when the two fuel injection valves 21c and 22c are provided per cylinder, it is possible to realize the internal combustion engine 100C capable of realizing more suitable combustion.

  In the present embodiment, the control performed by the ECU 40D as a control device for the in-cylinder fuel injection type internal combustion engine will be described in detail. The ECU 40D according to the present embodiment is the same as the ECU 40A shown in the first embodiment except that the ROM 42 further stores a fuel injection valve selection program in which the processing shown in the flowcharts of FIGS. It has become a thing. Note that this program may be combined with other programs. In this embodiment, the control target of the ECU 40D is the internal combustion engine 100A. However, the control target of the ECU 40D may be the internal combustion engine 100B or 100C shown in the second or third embodiment, and is not limited to this. The control target may be an in-cylinder fuel injection internal combustion engine including the fuel injection valve 21 on the intake port 8 side and the fuel injection valve 22 on the exhaust port 9 side.

  FIG. 5 is a flowchart illustrating a process performed by the CPU 41 in order to inject fuel with only the fuel injection valve 22 during warm-up in the ECU 40D according to the present embodiment. Based on the fuel injection valve selection program stored in the ROM 42, the CPU 41 repeatedly executes the processing shown in the flowchart in an extremely short time, so that the ECU 40D injects fuel with only the fuel injection valve 22 during warm-up. The injection valves 21 and 22 are controlled. The CPU 41 executes processing for determining whether or not the internal combustion engine 100A is warming up (step 11). More specifically, in this embodiment, the CPU 41 executes a process for determining whether or not the water temperature of the internal combustion engine 100A detected based on the output signal from the water temperature sensor 53 is equal to or lower than a predetermined value. It is determined whether or not internal combustion engine 100A is warming up. In this embodiment, the predetermined value is set to an appropriate temperature (for example, 70 ° C.), and when the water temperature is equal to or lower than the predetermined value, the internal combustion engine 100A is warming up. If the determination in step 11 is affirmative, the CPU 41 executes a process for prohibiting the use of the fuel injection valve 21a (step 12). On the other hand, if the determination in step 11 is negative, the CPU 41 executes a process for permitting use of both the fuel injection valves 21a and 22a (step 13). Thereby, at the time of cold before the warm-up is completed, the fuel can be injected only by the fuel injection valve 22a to which the fuel that receives heat from the exhaust gas is supplied in the conduit 31, and as a result, more fine particles can be injected. Combustion is performed with the fuel that has been promoted to improve fuel efficiency, and emission can be reduced.

  FIG. 6 is a flowchart illustrating a process performed by the CPU 41 in order to inject fuel by only the fuel injection valve 21a under the severe thermal condition in the ECU 40D according to the present embodiment. Based on the fuel injection valve selection program stored in the ROM 42, the CPU 41 repeatedly executes the processing shown in the flowchart in an extremely short time, so that the ECU 40D supplies fuel only with the fuel injection valve 21a under a severely severe condition. The fuel injection valves 21a and 22a are controlled to inject. The CPU 41 executes a process for determining whether or not the internal combustion engine 100A is under a severe heat condition (step 21). More specifically, in this embodiment, the CPU 41 executes a process for determining whether or not the water temperature of the internal combustion engine 100A detected based on the output signal from the water temperature sensor 53 is equal to or lower than a predetermined value. It is determined whether or not the internal combustion engine 100A is under a severe heat condition. In this embodiment, the predetermined value is set to 105 ° C., and when the water temperature is higher than the predetermined value, the internal combustion engine 100A is under a severe heat condition. If the determination in step 21 is affirmative, the CPU 41 executes a process for prohibiting use of the fuel injection valve 22a (step 22). On the other hand, if the determination in step 21 is negative, the CPU 41 executes a process for permitting use of both the fuel injection valves 21a and 22a (step 23). As a result, even when the fuel supplied to the exhaust-side fuel injection valve 22a receives heat from the exhaust gas in the conduit 31 and causes percolation under severely thermal conditions, the fuel injection valve 21a alone is used. By injecting the fuel, it is possible to avoid an unstable combustion state, thereby improving fuel consumption and reducing emissions. As described above, for example, when two fuel injection valves 21a and 22a are provided per cylinder as in the internal combustion engine 100A, it is possible to realize the ECU 40D that can realize more suitable combustion.

  The embodiment described above is a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.

It is a figure which shows internal combustion engine 100A which concerns on Example 1 with the other structure highly relevant to internal combustion engine 100A in Example 1. FIG. FIG. 2 is a view showing a main part of an internal combustion engine 100A with respect to a cylinder 7. FIG. 3 is a view showing a main part of an internal combustion engine 100B with respect to a cylinder 7. FIG. 3 is a view showing a main part of an internal combustion engine 100C with respect to a cylinder 7. It is a figure which shows the process which CPU41 performs in order for ECU40D to inject a fuel only by the fuel injection valve 22 during warming-up. It is a figure which shows the process which CPU41 performs in order for ECU40D to inject a fuel only with the fuel injection valve 21 on conditions with a severe heat | fever.

Explanation of symbols

1, 2 Spark plug 10 Intake system 21 Intake side fuel injection valve 22 Exhaust side fuel injection valve 40 ECU
100 In-cylinder fuel injection internal combustion engine

Claims (1)

An intake side fuel injection valve disposed on the intake port side from a first plane that includes the cylinder center axis and is substantially parallel to the crank axis, and an exhaust side fuel injection valve disposed on the exhaust port side from the first plane An in-cylinder fuel injection type internal combustion engine,
First spark igniting means and second spark igniting means for igniting sparks in the air-fuel mixture in the combustion chamber;
A swirl airflow generating means for generating a swirl airflow that is a tumble flow by the intake air flowing into the combustion chamber;
The intake-side fuel injection valve and the exhaust-side fuel injection valve each have an injection hole for injecting fuel in a direction along the swirling airflow, and each of the intake-side fuel injection valve and the exhaust-side fuel injection valve A central axis is disposed so as to be included in a second plane that includes the cylinder central axis and is substantially orthogonal to the crank axis;
The first spark ignition means is disposed on the intake port side with respect to the first plane and above the combustion chamber with respect to the intake side fuel injection valve. Arranged corresponding to the swirling airflow, and arranged so that the central axis of the first spark ignition means is included in the second plane,
The second spark ignition means is disposed on the exhaust port side from the first plane and above the exhaust chamber fuel injection valve and toward the intake side fuel injection valve. Arranged corresponding to the swirling airflow, and arranged so that the central axis of the second spark ignition means is included in the second plane ,
The swirl airflow swirls so as to pass through the first spark ignition means, the intake side fuel injection valve, the exhaust side fuel injection valve, and the second spark ignition means in this order . Fuel injection internal combustion engine.

Images