Internal combustion engine

Abstract

To provide an internal combustion engine with high combustion efficiency by properly performing combustion in a cylinder in a wide operation range.SOLUTION: An internal combustion engine 1 having: a main combustion chamber 41 formed in a cylinder 30; an auxiliary combustion chamber 43 disposed in the main combustion chamber 41; and a pair of intake ports 2a, 2b arranged side by side in a direction orthogonal to a moving direction of a piston and an air intake / exhaust direction, comprises: an intake port vane 71 for changing an angle formed between a pair of intake air flows flowing from the pair of intake ports 2, 2b into the main combustion chamber 41; a vane actuator 72 for operating the intake port vane 71; and a tumble flow control unit 75 for controlling the vane actuator 72 according to an operation state of the internal combustion engine 1. An inflow direction of the pair of intake air flows into the main combustion chamber 41 is changed according to the operation state of the internal combustion engine 1 to move a position of an axis of the tumble flow in the cylinder 30.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a technology for controlling an intake air flow into a cylinder of an internal combustion engine.

Background Art

[0002] Many internal combustion engines such as gasoline engines used in automobiles have an injector (fuel injection valve) that injects fuel into an intake passage or a combustion chamber, and an ignition device (ignition plug) disposed facing the combustion chamber in the cylinder. Furthermore, Patent Document 1 discloses an internal combustion engine provided with a sub-combustion chamber in a combustion chamber (main combustion chamber). In the internal combustion engine described in Patent Document 1, a mixture with a relatively high fuel concentration is supplied into the sub-combustion chamber, and the mixture in the sub-combustion chamber is ignited by an ignition device, so that flames are injected (ejected) from the sub-combustion chamber into the main combustion chamber to burn the mixture in the main combustion chamber. As a result, the ignition property of the mixture in the main combustion chamber can be improved to improve the output of the internal combustion engine, or the fuel concentration in the main combustion chamber can be lowered to improve the fuel efficiency.

[0003] On the other hand, in an internal combustion engine, it is known that generating a tumble flow by intake air in the cylinder is effective for improving the combustion efficiency of the mixture. For example, Patent Document 2 discloses an internal combustion engine provided with a device that causes intake air to pass through the intake passage while being biased upward by a movable valve body.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] As described in Patent Document 1, in an internal combustion engine having a sub-combustion chamber, the shape of the sub-combustion chamber, such as the size of the injection holes, cannot be changed. Therefore, the flame intensity from the sub-combustion chamber to the main combustion chamber cannot be changed according to the operating conditions of the internal combustion engine, such as the load. This makes it difficult to appropriately control the flame intensity, i.e., the combustion intensity of the air-fuel mixture in the main combustion chamber, over a wide operating range. Furthermore, while Patent Document 2 describes the possibility of controlling the intensity of the tumble flow in the cylinder according to the operating conditions of the internal combustion engine, excessively strong tumble flow leads to excessively high combustion intensity, which can cause fouling and damage to the internal combustion engine. On the other hand, if the tumble flow is too weak, the premixing of air and fuel in the main combustion chamber becomes insufficient. Therefore, it is difficult to achieve appropriate combustion intensity over a wide operating range of the internal combustion engine.

[0006] This invention was made to solve these problems and aims to provide an internal combustion engine with high combustion efficiency over a wide operating range by appropriately controlling the tumble flow. [Means for solving the problem]

[0007] To achieve the above objective, the internal combustion engine of the present invention comprises a main combustion chamber formed by surrounding a cylinder head, a cylinder, and a piston. ,before An internal combustion engine having a pair of intake ports arranged in a direction perpendicular to the direction of movement of the piston and the intake / exhaust direction, The intake port has a side wall that extends in the intake and exhaust directions perpendicular to the direction of piston movement, and a pair of valve bodies extending in the intake and exhaust directions are provided at intervals perpendicular to the direction of piston movement and the intake and exhaust directions. The valve bodies are provided at the upstream end of the valve body in the intake flow direction, extending in the direction of piston movement, and an actuator that rotates the valve body around the rotation support axis to change the angle of the valve body with respect to the side wall, and a control unit that controls the actuator. When the amount of fuel supplied to the internal combustion engine is large, the control unit controls the actuator to reduce the angle between the pair of valve bodies compared to when the amount of fuel supplied to the internal combustion engine is small, so that the center of the tumble flow moves closer to the exhaust valve side, and the collapse of the tumble flow is accelerated. It is characterized by the following:

[0008] This allows the internal combustion engine to operate according to its operating conditions. The control unit controls the actuator to change the angle of the valve body, thereby controlling the direction of intake air flow from a pair of intake ports into the cylinder. By shifting the axis of rotation of the intake tumble flow generated in the main combustion chamber, the collapse timing of the tumble flow can be altered. Therefore, depending on the operating range of the internal combustion engine, it is possible to achieve both improved combustion efficiency by promoting the mixing of fuel and intake air in the main combustion chamber and suppressing excessive combustion. Preferably, the system further comprises a supercharger, and the control unit ensures that the angles of the pair of intakes are parallel in the supercharging region of the supercharger. valve body Control the following so that the angles of the pair of intakes do not become parallel in the non-supercharged region of the supercharger. valve body It would be good to control that.

[0009] This allows the tumble flow axis to be positioned on the exhaust side of the main combustion chamber's center in the supercharged region, suppressing tumble flow and preventing excessive combustion. In the non-supercharged region, the tumble flow axis is positioned near the center of the main combustion chamber, making it easier to maintain tumble flow and assisting combustion. 。

[0010] good More precisely, the pair of intake ports are arranged so as they move away from each other toward the main combustion chamber, control unit The above valve body By aligning the intake port parallel to the wall surface in a direction perpendicular to the direction of movement of the piston, the rotation axis is positioned approximately at the center of the main combustion chamber, valve body It is preferable to raise the intake port from the wall surface in a direction perpendicular to the direction of movement of the piston so that the axis of rotation is offset in the intake and exhaust directions from approximately the center of the main combustion chamber.

[0011] As a result, valve body By aligning the intake port parallel to the wall surface perpendicular to the direction of piston movement, intake air is introduced so that it spreads from the intake port into the cylinder. This suppresses the amount of intake air moving in the center of the main combustion chamber, and allows the axis of rotation of the tumble flow to be positioned approximately at the center of the main combustion chamber. valve body By making it so that it rises from the wall surface perpendicular to the direction of piston movement of the intake port, the intake air is less likely to spread when introduced into the cylinder from the intake port. This increases the amount of intake air passing through the center of the main combustion chamber, and the axis of rotation of the tumble flow can be moved from approximately the center of the main combustion chamber towards the exhaust side.

[0012] Preferably, the internal combustion engine is controlled stoichiometrically to maintain a target air-fuel ratio. As a result, by the change means and the control unit, the tumble flow is positioned near the center in the main combustion chamber, so that the tumble flow can be maintained and the tumble flow can be maintained up to near the top dead center of the piston, and the output of the internal combustion engine with the target air-fuel ratio of the main combustion chamber set to stoichiometry can be increased.

Advantages of the Invention

[0016] According to the internal combustion engine of the present invention, the inflow direction of the intake air into the cylinder can be controlled to move and control the position of the rotation axis of the tumble flow in the cylinder. As a result, an internal combustion engine with high combustion efficiency according to the operating state in a wide operating range can be achieved.

Brief Description of the Drawings

[0017] [Figure 1] FIG. 1 is an example of a configuration diagram of the intake and exhaust system of an internal combustion engine 1 employing a tumble flow control device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a top view showing the positions of the intake and exhaust ports and the ignition plug in the internal combustion engine of the present embodiment. [Figure 3] FIG. 3 is a configuration diagram of the tumble flow control device of the internal combustion engine of the present embodiment. [Figure 4] FIG. 4 is an image diagram showing the generation state of the tumble flow by the tumble flow control device during high-load operation. [Figure 5] FIG. 5 is an image diagram showing the generation state of the tumble flow by the tumble flow control device during low-load operation. [Figure 6] FIG. 6 is a graph showing an example of the transition of the tumble ratio in the internal combustion engine of the present embodiment.

Embodiments for Carrying Out the Invention

[0018] Hereinafter, embodiments of the present invention will be described based on the drawings. FIG. 1 is an example of a configuration diagram of the intake and exhaust system of an internal combustion engine 1 employing a tumble flow control device according to an embodiment of the present invention. As shown in Figure 1, the internal combustion engine 1 of this embodiment is a port injection type gasoline engine having an injector 3 that injects gasoline, which is fuel, into the intake port 2.

[0019] In this embodiment, the intake passage 5 of the internal combustion engine 1 is equipped with an air cleaner 6, an intercooler 7, and a throttle valve 8, which are positioned along the intake airflow toward the intake port 2. The exhaust passage 11 of the internal combustion engine 1 is equipped with an upstream exhaust catalytic converter 12 and a downstream exhaust catalytic converter 13, which are positioned along the exhaust airflow toward the exhaust port 31. Furthermore, the internal combustion engine 1 is equipped with a supercharger (turbocharger) 15 and an EGR system 16.

[0020] The supercharger 15 includes a turbine (not shown) which is rotationally driven by the exhaust gas, and a compressor (not shown) which rotates in conjunction with the turbine and compresses the intake air in the intake passage. The turbine is located in the exhaust passage 11 between the exhaust port 31 and the upstream exhaust gas purification catalyst 12, and the compressor is located in the intake passage 5 between the air cleaner 6 and the intercooler 7. The EGR system 16 includes an EGR passage 20 that connects the exhaust passage 11 and the intake passage 5 of the internal combustion engine 1, an EGR valve 21 that changes the flow area of ​​the EGR passage 20, and an EGR cooler 22 that cools the exhaust gas passing through the EGR passage 20. The EGR passage 20 connects the exhaust passage 11 between the upstream exhaust purification catalyst 12 and the downstream exhaust purification catalyst 13, and the intake passage 5 between the air cleaner 6 and the compressor of the supercharger 15.

[0021] Furthermore, the exhaust passage 11 is equipped with a wastegate valve 25 that opens and closes a passage that bypasses the turbine of the supercharger 15. The intake passage 5 is equipped with a recirculation valve 26 that opens and closes a passage that bypasses the compressor of the supercharger 15. Figure 2 is a top view showing the positions of the intake and exhaust ports 2, 31 and the spark plug 35 in the internal combustion engine 1 of the first embodiment.

[0022] As shown in Figure 2, the internal combustion engine 1 is equipped with two intake ports 2 and two exhaust ports 31 for each cylinder 30. In addition, each of the two intake ports 2 is equipped with an intake valve 32, and each of the two exhaust ports 31 is equipped with an exhaust valve 33. Each intake port 2 has one injector 3, meaning there are two injectors for each cylinder 30.

[0023] In the upper part of cylinder 30 of the internal combustion engine 1 (cylinder head 34), two intake ports 2 are arranged side by side on one side of the central part, in a direction perpendicular to the direction of movement of the piston 37 and the intake / exhaust direction, and two exhaust ports 31 are arranged side by side on the other side. The arrangement of the two intake ports 2 in a direction perpendicular to the direction of movement of the piston 37 and the intake / exhaust direction means that the vicinity of the outlets of the two intake ports 2 (ends on the cylinder 30 side) are aligned in a direction perpendicular to the direction of movement of the piston 37 and the intake / exhaust direction, that is, the two intake ports 2 are not aligned in the direction of movement of the piston 37 or the intake / exhaust direction.

[0024] As shown in Figures 1 and 2, a spark plug 35 is provided in the center of the cylinder head 34. The cylinder head 34 is provided with a partition wall 42 that surrounds the central electrode of the spark plug 35. Within the cylinder 30, a main combustion chamber 41 is formed, which is a roughly cylindrical space surrounded by the cylinder head 34, the cylinder 36, and the piston 37, with its axis extending in the direction of movement of the piston 37. Furthermore, the space in the upper central part of the main combustion chamber 41 is provided as a sub-combustion chamber 43, surrounded by a partition wall 42. Multiple communication holes 44 are opened in the partition wall 42, and the main combustion chamber 41 and the sub-combustion chamber 43 are in communication with each other through the communication holes 44.

[0025] The internal combustion engine 1 is operated and controlled by a control unit 50 (control unit). The control unit 50 consists of an output device, a memory device (ROM, RAM, non-volatile RAM, etc.), a central processing unit (CPU), etc. The control unit 50 receives input such as crank angle, intake air temperature, exhaust air temperature, EGR gas temperature, etc., and operates and controls the injectors 3, spark plugs 35, throttle valves 8, EGR valves 21, wastegate valves 25, recirculation valves 26, etc. In this embodiment, the control unit 50 controls the injectors 3, throttle valves 8, etc. so that the main combustion chamber 41 is stoichiometric.

[0026] Figure 3 is a diagram showing the configuration of the tumble flow control device 70 of the internal combustion engine 1. Figure 4 is an illustrative diagram showing the state of tumble flow generation by the tumble flow control device 70 during high-load operation. Figure 5 is an illustrative diagram showing the state of tumble flow generation by the tumble flow control device 70 during low-load operation. The internal combustion engine 1 is equipped with a tumble flow control device 70 that controls the tumble flow of intake air generated in the main combustion chamber 41.

[0027] As shown in Figure 3, the tumble flow control device 70 includes an intake port vane 71 (valve body, plate-shaped member) that changes the direction of intake air movement at each intake port 2 (2a, 2b) of each cylinder 30, and a vane actuator 72 (actuator) that drives the intake port vane 71, as well as a tumble flow control unit 75 (control unit) that controls the operation of the vane actuator 72. Note that the intake port vane 71 and the vane actuator 72 correspond to modifications of the present invention.

[0028] The intake port vanes 71 are provided in a pair of intake ports 2, which are arranged perpendicular to the direction of movement of the piston 37 and the intake / exhaust direction, and are located near the intake valves 32. The intake / exhaust direction is the direction of intake and exhaust movement within the cylinder 30, and is the direction connecting the intake valves 32 and the exhaust valves 33. In this embodiment, since there are two intake valves 32 and two exhaust valves 33, the intake / exhaust direction is defined as the direction of the line connecting the center of the line connecting the centers of the pair of intake valves 32 and the center of the line connecting the centers of the pair of exhaust valves 33.

[0029] The intake port vane 71 is a plate-shaped member that is provided on the outer wall surface (side wall) of each intake port 2a, 2b, which is the side furthest from the center C inside the cylinder 30 (main combustion chamber 41) and perpendicular to the direction of movement of the piston 37, and is supported so as to be able to swing around a rotation support shaft 73 that extends in the vertical direction (direction of piston movement). The rotation support shaft 73 is provided at the upstream end of the intake port vane 71 in the intake and exhaust direction.

[0030] In this embodiment, the two intake ports 2a and 2b extend so as they move away from each other as they enter the cylinder 30. The intake port vanes 71 are movable between a first position (shown by a solid line in Figure 3) where they are along the outer walls of the intake ports 2a and 2b, i.e., extending away from each other toward the main combustion chamber 41, and a second position (shown by a dashed line in Figure 3) where the downstream ends of the intake port vanes 71 rise up from the outer walls of the intake ports 2a and 2b, i.e., the pair of intake port vanes 71 are parallel to each other.

[0031] The vane actuator 72 is, for example, a servo motor or a stepping motor, which moves the intake port vane 71 between a first position and a second position. The tumble flow control unit 75 is composed of input / output devices, memory devices (ROM, RAM, non-volatile RAM, etc.), a timer, and a central processing unit (CPU), and controls the operation of the vane actuator 72 by receiving the operating state (load and rotational speed) of the internal combustion engine 1 from the control unit 50, etc. The tumble flow control unit 75 may be provided within the control unit 50 that controls the operation of the internal combustion engine 1, or it may be provided separately from the control unit 50.

[0032] As shown in Figure 4, the tumble flow control unit 75 moves the intake port vane 71 to a first position, that is, moves the intake port vane 71 along the outer wall surface of the intake ports 2a and 2b, when the supercharger 15 is not supercharged and in the high-load operating region. As a result, the intake air flows into the main combustion chamber 41 from a pair of intake ports 2a and 2b, spreading outward from the center C of the main combustion chamber 41. That is, the angle formed by the pair of intake air flowing into the main combustion chamber 41 from the pair of intake ports 2a and 2b widens in a direction perpendicular to the direction of movement of the piston 37 and the intake and exhaust directions as it moves toward the exhaust direction. The angle formed by the pair of intake air is the angle formed by the main flow of intake air flowing through the pair of intake ports 2a and 2b. Consequently, the difference between the flow velocity on the side of the center C of the main combustion chamber 41 and the flow velocity on the outside becomes small, and the rotation axis Axt of the intake air tumble flow generated in the main combustion chamber 41 is positioned close to the center C of the main combustion chamber 41 and extends in a direction approximately perpendicular to the intake and exhaust directions.

[0033] As shown in Figure 5, the tumble flow control unit 75 sets the intake port vane 71 to a second position, that is, to make the intake port vane 71 parallel to the intake and exhaust directions, in the supercharging region of the supercharger 15. As a result, intake air flows into the main combustion chamber 41 from a pair of intake ports 2a and 2b, approximately parallel to the intake and exhaust directions. Consequently, the flow velocity on the side of the center C of the main combustion chamber 41 is greater than the flow velocity on the outer side in the direction perpendicular to the intake and exhaust directions. This causes the center of the rotation axis Axt of the intake tumble flow generated in the main combustion chamber 41 to move away from the center C of the main combustion chamber 41 and closer to the exhaust valve 33, resulting in the rotation axis Axt being bent in an arc shape.

[0034] Figure 6 is a graph showing an example of the change in the tumble ratio in the internal combustion engine 1 of this embodiment. In Figure 6, the solid line shows the case when the rotation axis Axt of the tumble flow is moved as in Figure 5, while the dashed line shows the case when the rotation axis Axt of the tumble flow is not moved as in Figure 4. As shown by the solid line in Figure 6, by shifting the rotation axis Axt of the tumble flow away from the center C of the main combustion chamber 41, the tumble ratio is maintained from the initial to mid-stage of intake air inflow, while the tumble flow becomes more likely to collapse near the top dead center of the piston.

[0035] As described above, the internal combustion engine 1 of this embodiment is equipped with a sub-combustion chamber 43 surrounded by a partition wall 42 in the upper central part of the main combustion chamber 41. The partition wall 42 is provided with a communication hole 44 that connects the main combustion chamber 41 and the sub-combustion chamber 43, and the spark plug 35 ignites the air-fuel mixture in the sub-combustion chamber 43. As a result, the flame generated by ignition in the sub-combustion chamber 43 passes through the communication hole 44 and diffuses into the main combustion chamber 41, efficiently burning the air-fuel mixture in the main combustion chamber 41.

[0036] The internal combustion engine 1 has a pair of intake ports 2a and 2b arranged in a direction perpendicular to the direction of movement of the piston 37. Furthermore, it is equipped with a tumble flow control device 70 that changes the angle (inflow angle) formed by a pair of intake air flowing from these intake ports 2a and 2b into the main combustion chamber 41. Therefore, by changing the inflow angle of the intake air with the tumble flow control device 70, the axis of rotation Axt of the intake air tumble flow generated in the main combustion chamber 41 can be shifted.

[0037] Furthermore, by moving the axis of rotation Axt of the intake tumble flow within the main combustion chamber 41 according to the operating state of the internal combustion engine 1, the collapse timing of the tumble flow can be changed. Therefore, by maintaining the tumble flow according to the operating range of the internal combustion engine 1, the mixing of fuel and intake air in the main combustion chamber 41 can be promoted, improving combustion efficiency, while by accelerating the collapse of the tumble flow, excessive combustion in the cylinder 30 can be suppressed.

[0038] Conventionally, while changes in intake volume could alter the flow velocity of intake air flowing through a pair of intake ports, the angle of intake air discharged from the pair of intake ports remained constant. Therefore, it was not possible to move the rotation axis Axt of the tumble flow, and thus not to control the collapse timing of the tumble flow. According to this embodiment, the tumble flow control device 70 can change the angle formed by the pair of intake air flowing in from the pair of intake ports 2a and 2b, thereby moving the rotation axis Axt of the tumble flow. This allows for control of the collapse timing of the tumble flow and adjustment of the combustion state within the cylinder 30.

[0039] When moving the rotation axis Axt of the tumble flow away from the center C of the main combustion chamber 41, it is preferable to move the rotation axis Axt towards the exhaust side. This allows the exhaust side of the cylinder 30, which tends to become hot, to be cooled by the tumble flow, thereby suppressing the occurrence of knocking. The internal combustion engine 1 of this embodiment is equipped with a supercharger 15, and the tumble flow control device 70 controls the intake port vanes 71 so that the angles of the pair of intakes are parallel in the supercharged region, and controls the intake port vanes 71 so that the angles of the pair of intakes are not parallel in the high-load region when not supercharged.

[0040] As a result, in the supercharging region, the rotation axis Axt of the tumble flow can be shifted away from the center C in the main combustion chamber 41, thereby accelerating the collapse of the tumble flow and suppressing excessive combustion. In particular, in the internal combustion engine 1 with a sub-combustion chamber 43, the flame injection from the sub-combustion chamber 43 becomes stronger as the fuel supply increases. Therefore, in the supercharging region where the fuel supply increases, the collapse of the tumble flow is accelerated, suppressing excessive combustion and protecting the cylinder 36, piston 37, and other components inside the cylinder 30.

[0041] In the non-supercharged region where fuel supply is reduced, the rotation axis Axt of the tumble flow can be positioned near the center C within the main combustion chamber 41, making it easier to maintain the tumble flow and assisting combustion. In particular, in the non-supercharged state and low-load region, where combustion tends to be unstable, maintaining the tumble flow at the center position within the main combustion chamber 41 promotes mixing of intake air and fuel, thereby assisting combustion and effectively maintaining stable combustion.

[0042] The tumble flow control device 70 has intake port vanes 71 provided on the outer walls of a pair of intake ports 2a and 2b in a direction perpendicular to the direction of movement of the piston 37, and controls the angle of the intake port vanes 71. This allows the direction of intake air inflow into the main combustion chamber 41 to be controlled with a simple structure, thereby changing the position of the rotation axis Axt of the tumble flow.

[0043] More specifically, the pair of intake ports 2a and 2b are arranged so as they move away from each other towards the main combustion chamber 41, and the tumble flow control device 70 aligns the intake port vanes 71 parallel to the outer walls of the intake ports 2a and 2b so that the rotation axis Axt of the tumble flow is located approximately at the center of the main combustion chamber 41. Furthermore, by raising the intake port vanes 71 inward from the outer walls of the intake ports 2a and 2b, the rotation axis Axt of the tumble flow is positioned offset from approximately the center of the main combustion chamber 41 in the intake and exhaust directions.

[0044] As a result, by aligning the intake port vane 71 parallel to the outer walls of the intake ports 2a and 2b, intake air is introduced so that it spreads from the intake ports 2a and 2b into the cylinder 30. This suppresses the amount of intake air passing through the center of the main combustion chamber 41, and allows the rotation axis Axt of the tumble flow to be located approximately in the center of the main combustion chamber 41. Furthermore, by positioning the intake port vanes 71 to rise inward from the outer walls of the intake ports 2a and 2b, the intake air is less likely to spread when introduced into the cylinder 30 from the intake ports 2a and 2b. This increases the amount of intake air passing through the center of the main combustion chamber 41, causing the rotation axis Axt of the tumble flow to curve and move from approximately the center of the main combustion chamber 41 towards the exhaust side.

[0045] Furthermore, the output of the internal combustion engine 1 can be increased by controlling the target air-fuel ratio in the main combustion chamber 41 to stoichiometric levels. Simply controlling the target air-fuel ratio to stoichiometric levels may cause combustion in the cylinder 30 to become too violent at high output levels (operating ranges where the fuel supply is large). However, according to the present invention, even in such cases, by moving the rotation axis Axt of the tumble flow, the tumble ratio can be maintained from the initial to the middle of the intake air inflow, ensuring premixing while suppressing excessive combustion.

[0046] The present invention is not limited to the embodiments described above. For example, although the above embodiment is an internal combustion engine 1 having a sub-combustion chamber 43 and a supercharger, the present invention can also be applied to an internal combustion engine that does not have a sub-combustion chamber or a supercharger. Even in an internal combustion engine having only a main combustion chamber 41 as a combustion chamber, by controlling the direction of intake air inflow into the main combustion chamber 41 with the tumble flow control device 70 as in the above embodiment, the position of the rotation axis Axt of the tumble flow can be changed and the tumble flow can be controlled, thereby achieving both the promotion of combustion and the suppression of excessive combustion according to the operating state of the internal combustion engine 1. For example, in the case of an internal combustion engine equipped with an EGR passage 20 and an EGR valve 21, if the amount of EGR introduced into the intake air increases, combustion becomes slower, and if the amount of EGR decreases, combustion is promoted. Therefore, when the amount of EGR is above a predetermined level, the intake port vane 71 should be controlled so that the rotation axis Axt of the tumble flow is approximately at the center of the main combustion chamber 41, and when the amount of EGR is below a predetermined level, the intake port vane 71 should be controlled so that the rotation axis Axt of the tumble flow is offset from approximately the center of the main combustion chamber 41.

[0047] Furthermore, although the above embodiment provides two intake ports 2 in one cylinder 30, the present invention can also be applied to internal combustion engines having three or more intake ports 2. Alternatively, even in an internal combustion engine having one intake port 2 in one cylinder 30, intake port vanes 71 can be provided on both side walls of the intake port 2 to change the degree of intake spread within the cylinder 30. Furthermore, various components such as the intake port vane 71, as well as the detailed structure of each injector and the inside of the cylinder of the internal combustion engine, may be modified as appropriate. In addition, the internal combustion engine of the present invention can be applied to various internal combustion engines, such as those used for driving automobiles. [Explanation of Symbols]

[0048] 1. Internal combustion engine 2 (2a, 2b) Intake port 15 Supercharger 34 Cylinder head 36 cylinders 37 Pistons 41 Main combustion chamber 43. Sub-combustion chamber 71 Intake port vane (valve body, plate-shaped member, modification means) 72. Vane actuator (actuator, modification mechanism) 73 Rotating support shaft 75. Tumble Flow Control Unit (Control Device) Axt Rotation axis

Claims

1. The main combustion chamber is formed by being surrounded by the cylinder head, the cylinder, and the piston. An internal combustion engine having a pair of intake ports arranged in a direction perpendicular to the direction of movement of the piston and the intake / exhaust direction, The intake port has a side wall that extends in the intake and exhaust directions perpendicular to the direction of piston movement, and a pair of valve bodies extending in the intake and exhaust directions are provided at intervals in directions perpendicular to the direction of piston movement and the intake and exhaust directions, and a rotating support shaft is provided at the upstream end of the valve body in the intake flow direction, extending in the direction of piston movement, and an actuator rotates the valve body around the rotating support shaft to change the angle of the valve body with respect to the side wall, and a control unit controls the actuator. When the amount of fuel supplied to the internal combustion engine is high, the control unit reduces the angle between the pair of valve bodies compared to when the amount of fuel supplied to the internal combustion engine is low, thereby bringing the center of the tumble flow closer to the exhaust valve side and controlling the actuator to accelerate the collapse of the tumble flow. An internal combustion engine characterized by the following features.

2. Equipped with an additional supercharger, The control unit controls the valve body so that the angles of the pair of intakes are parallel in the supercharged region of the supercharger, and controls the valve body so that the angles of the pair of intakes are not parallel in the non-supercharged region of the supercharger. The internal combustion engine according to feature 1.

3. The pair of intake ports are arranged so as they move away from each other toward the main combustion chamber, The control unit positions the valve body parallel to the wall surface of the intake port in a direction perpendicular to the direction of movement of the piston, so that the axis of rotation of the intake tumble flow generated in the main combustion chamber is located approximately at the center of the main combustion chamber, and raises the valve body from the wall surface of the intake port in a direction perpendicular to the direction of movement of the piston, so that the axis of rotation is located offset from approximately the center of the main combustion chamber in the intake and exhaust directions. The internal combustion engine according to feature 2.

4. The aforementioned internal combustion engine is controlled stoichiometrically to maintain a target air-fuel ratio. An internal combustion engine according to feature 1 or 2.

Images