Internal combustion engine

Abstract

To provide an internal combustion engine which enables a flame injection mode to be set from an auxiliary combustion chamber to a main combustion chamber.SOLUTION: An internal combustion engine 1 includes: a main combustion chamber 41; and an auxiliary combustion chamber 43 provided at an upper center part in the main combustion chamber 41; and an ignition plug 35 for igniting an air-fuel mixture in the auxiliary combustion chamber 43. The auxiliary combustion chamber 43 includes: a plurality of communication holes 44a, 44b which inject a flame generated by ignition by the ignition plug 35; and a division wall 71 which passes through a space between the communication holes 44a, 44b and divides an internal space of the auxiliary combustion chamber into a first auxiliary combustion chamber 43a and a second auxiliary combustion chamber 43b.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an internal combustion engine having a sub-combustion chamber in a main combustion chamber.

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 a 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, an air-fuel mixture having a relatively high fuel concentration is supplied into the sub-combustion chamber, and the air-fuel mixture in the sub-combustion chamber is ignited by an ignition device, so that flames are ejected (spouted) from the sub-combustion chamber into the main combustion chamber to burn the air-fuel mixture in the main combustion chamber. Thereby, the ignitability of the air-fuel 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 consumption.

[0003] Furthermore, Patent Document 1 discloses an internal combustion engine that forms a space covered by a ground terminal below an ignition plug and uses the space as a sub-combustion chamber.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] [[ID=四十]] [[ID=四十一]]In an internal combustion engine having a sub-combustion chamber as described above, in order to further suppress knocking and protect the inside of the cylinder, it is desirable to appropriately eject flames from the sub-combustion chamber into the main combustion chamber to suppress uneven temperature rise in the main combustion chamber. The present invention was made to solve these problems, and aims to provide an internal combustion engine having a sub-combustion chamber in the main combustion chamber, in which the air-fuel mixture is ignited in the sub-combustion chamber and a flame is injected from the sub-combustion chamber into the main combustion chamber to burn the air-fuel mixture in the main combustion chamber, by making it possible to set the manner in which the flame is injected from the sub-combustion chamber to the main combustion chamber, and thereby enabling proper combustion in the main combustion chamber. [Means for solving the problem]

[0006] To achieve the above objective, the internal combustion engine of the present invention is an internal combustion engine having a main combustion chamber, a sub-combustion chamber provided in the main combustion chamber, and a spark plug for igniting the air-fuel mixture in the sub-combustion chamber, wherein the sub-combustion chamber has a plurality of injection holes for injecting the flame generated by ignition by the spark plug, and the air passing between the plurality of injection holes into the sub-combustion chamber Extending upward from the surface of the piston-side end A dividing wall that divides the interior space, and The aforementioned sub-combustion chamber and divided wall are formed by a part of the spark plug. Characterized by As a result, flames are injected into the main combustion chamber from each of the divided internal spaces of the sub-combustion chamber through the injection holes. Therefore, by appropriately setting the size of the internal space, the size and position of the injection holes, it becomes possible to arbitrarily set the intensity and direction of the flames directed towards the main combustion chamber. Furthermore, by integrating the spark plug and the pre-combustion chamber, the internal combustion engine with a pre-combustion chamber can be simplified. Preferably, the internal space of the sub-combustion chamber is divided radially by the dividing wall into a first sub-combustion chamber on one side and a second sub-combustion chamber on the other side, and a gap is provided between the ignition device and the upper end of the dividing wall, and the area of ​​the gap is smaller than the total area of ​​the injection holes provided in the first sub-combustion chamber and the total area of ​​the injection holes provided in the second sub-combustion chamber. Preferably, the dividing wall has a substantially semicircular notch, and the ignition device is positioned above the notch.

[0007] Preferably, the dividing wall divides the internal space of the sub-combustion chamber into an intake side and an exhaust side. That's good. This allows for the injection of flames of different strengths into the intake and exhaust portions of the main combustion chamber. Preferably, the dividing wall is provided such that the internal space of the sub-combustion chamber is larger on the exhaust side than on the intake side.

[0008] This allows a stronger flame to be injected from the sub-combustion chamber to the exhaust side of the main combustion chamber, causing the exhaust side of the main combustion chamber to burn earlier and reducing knocking. 。

[0009] Preferably, the dividing wall is formed by a ground electrode. This allows the ignition position to be arbitrarily set by appropriately configuring the partition walls of the sub-combustion chamber. Therefore, the flame generated in the sub-combustion chamber can be efficiently ejected from the injection port, reducing the energy loss of the flame. Preferably, the dividing wall is inclined from the intake side to the exhaust side.

[0010] This makes it easier for the air-fuel mixture that has flowed into and filled the internal space on the intake side of the sub-combustion chamber to flow into the exhaust side, thus enabling efficient supply of the air-fuel mixture to the internal space on the exhaust side as well. Preferably, the injection holes provided on the exhaust side are formed to be smaller than the injection holes provided on the intake side. This increases the force of the flame injected from the exhaust-side injection port, allowing for earlier combustion in the exhaust-side portion of the main combustion chamber, thereby suppressing temperature rise and reducing knocking. [Effects of the Invention]

[0011] According to the internal combustion engine of the present invention, the injection characteristics, such as the strength of the flame injected from multiple injection holes in the sub-combustion chamber, can be arbitrarily set, thereby enabling proper combustion in the main combustion chamber. This suppresses knocking, reduces heat loss, and protects the walls inside the cylinder. Furthermore, by integrating the spark plug and the pre-combustion chamber, the internal combustion engine with a pre-combustion chamber can be simplified. [Brief explanation of the drawing]

[0012] [Figure 1] This is a diagram showing the configuration of the intake and exhaust system of an internal combustion engine according to one embodiment of the present invention. [Figure 2] This is a top view showing the positions of the intake and exhaust ports and spark plug in the internal combustion engine of the first embodiment. [Figure 3] This is a perspective view showing the structure of the grounding terminal of the spark plug according to the first embodiment. [Figure 4]It is a cross-sectional view showing the structure of the ground terminal of the spark plug according to the first embodiment. [Figure 5] It is a longitudinal sectional view showing the structure of the ground terminal of the spark plug according to the first embodiment. [Figure 6] It is a cross-sectional view showing the structure of the ground terminal of the spark plug according to the second embodiment. [Figure 7] It is a longitudinal sectional view showing the structure of the ground terminal of the spark plug according to the third embodiment. [Figure 8] It is a longitudinal sectional view showing the structure of the ground terminal of the spark plug according to the fourth embodiment. 3>

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described based on the drawings. FIG. 1 is a configuration diagram of the intake and exhaust system of an internal combustion engine 1 according to an embodiment of the present invention. As shown in FIG. 1, the internal combustion engine 1 of the present embodiment is a port injection type gasoline engine having an injector 3 that injects gasoline as fuel into an intake port 2. In the intake passage 5 of the internal combustion engine 1 of the present embodiment, an air cleaner 6, an intercooler 7, and a throttle valve 8 are provided along the flow of intake air toward the intake port 2. In the exhaust passage 11 of the internal combustion engine 1, an upstream exhaust purification catalyst 12 and a downstream exhaust purification catalyst 13 are provided along the flow of exhaust from the exhaust port 31.

[0014] The internal combustion engine 1 is also provided with a supercharger (turbocharger) 15 and an EGR system 16. 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 passage area of the EGR passage 20, and an EGR cooler 22 that cools the exhaust 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.

[0015] <00001~07>Figure 2 is a top view showing the positions of the intake and exhaust ports 2 and 31 and the spark plug 35 (ignition device) in the internal combustion engine 1 of the first embodiment. 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.

[0016] Each intake port 2 has one injector 3, meaning there are two injectors for each cylinder 30. 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, and two exhaust ports 31 are arranged side by side on the other side.

[0017] 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 surrounding the central electrode 35a of the spark plug 35. Inside the cylinder 30 is a main combustion chamber 41, which is a roughly cylindrical space surrounded by the cylinder, cylinder head 34, and piston 37 formed in the cylinder block. 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 (injection holes) 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 via the communication holes 44.

[0018] 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, etc.

[0019] Figure 3 is a perspective view showing the structure of the grounding terminal of the spark plug 35 in the first embodiment. Figure 4 is a top view showing the structure of the grounding terminal of the spark plug 35 in the first embodiment. Note that in Figure 3, the upper wall surface 70 is omitted in order to show the inside of the partition wall 42. The upper wall surface 70 may be formed integrally with the partition wall 42 or may be formed as part of the cylinder head 34. In Figure 4, the position of the center electrode 35a of the spark plug 35 is also shown. Figure 5 is a longitudinal cross-sectional view showing the structure of the grounding terminal of the spark plug 35 in the first embodiment.

[0020] In the first embodiment, the spark plug 35 has a ground electrode that forms a partition wall 42 that constitutes a sub-combustion chamber 43 inside. As shown in Figures 2-5, the compartment wall 42 has a roughly hemispherical internal space and is further provided with a dividing wall 71 that extends vertically from the lower surface (the surface at the piston end) of the compartment wall 42, dividing the internal space into an intake side and an exhaust side. A roughly semicircular notch 72 is provided in the center of the upper end of the dividing wall 71. The center electrode 35a of the spark plug 35 is located above the notch 72. A gap 73 of approximately a few millimeters is provided between the center electrode 35a of the spark plug 35 and the upper end of the dividing wall 71. Of the sub-combustion chambers 43, the first sub-combustion chamber 43a on one side of the dividing wall 71 and the second sub-combustion chamber 43b on the other side are in communication through the gap 73 between the center electrode 35a and the upper end of the dividing wall 71.

[0021] The partition wall 42, including the dividing wall 71, is formed of a conductive material and also serves as the ground electrode for the spark plug 35. The partition wall 42 may be covered with an insulating material in all parts except the upper surface of the gap 73 in the dividing wall 71 (the surface facing the center electrode 35a). The center electrode 35a of the spark plug 35 and the partition wall 42 are closest to each other in the gap 73 between the center electrode 35a and the upper end of the dividing wall 71. Therefore, a spark is generated by the spark plug 35 in the gap 73 between the center electrode 35a and the upper end of the dividing wall 71.

[0022] The dividing wall 71 is positioned to intersect the line connecting the intake valve 32 and the exhaust valve 33, that is, the intake and exhaust direction which is the direction of gas (intake and exhaust) movement within the main combustion chamber 41, and divides the inside of the sub-combustion chamber 43 into a first sub-combustion chamber 43a and a second sub-combustion chamber 43b. The first sub-combustion chamber 43a is located on the intake valve 32 side (intake side), and the second sub-combustion chamber 43b is located on the exhaust valve 33 side (exhaust side).

[0023] The communication holes 44 provided in the partition wall 42 include a first communication hole 44a (first injection hole) facing the first sub-combustion chamber 43a and a second communication hole 44b (second injection hole) facing the second sub-combustion chamber 43b. In this embodiment, there are multiple first communication holes 44a and multiple second communication holes 44b. The first communication holes 44a open toward the intake side space of the main combustion chamber 41, and the second communication holes 44b open toward the exhaust side space of the main combustion chamber 41. That is, the dividing wall 71 is provided between the first communication hole 44a facing the intake valve 32 side (intake side) and the second communication hole 44b facing the exhaust valve 33 side (exhaust side). In this embodiment, the dividing wall 71 is provided perpendicular to the intake and exhaust directions as shown in Figures 2 and 4, but it may also be provided inclined with respect to the direction perpendicular to the intake and exhaust directions.

[0024] The area of ​​the gap 73 between the central electrode 35a and the upper end of the dividing wall 71 is set to be smaller than the total area of ​​the first communication hole 44a and smaller than the total area of ​​the second communication hole 44b. In the first embodiment, the volumes of the first sub-combustion chamber 43a and the second sub-combustion chamber 43b are set to be the same. Also, the second communication hole 44b on the exhaust side is formed to be smaller than the first communication hole 44a provided on the intake side.

[0025] As described above, the internal combustion engine 1 of the first 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.

[0026] Furthermore, the sub-combustion chamber 43 is divided into a first sub-combustion chamber 43a and a second sub-combustion chamber 43b by a dividing wall. As a result, when a spark is generated by the spark plug 35, flames are generated individually in the first sub-combustion chamber 43a and the second sub-combustion chamber 43b. The flame generated in the first sub-combustion chamber 43a is injected towards the main combustion chamber 41 from the first communication hole 44a, and the flame generated in the second sub-combustion chamber 43b is injected towards the main combustion chamber 41 from the second communication hole 44b.

[0027] Therefore, by appropriately setting the position, size, and number of each communication hole 44a, 44b, the direction, strength, and number of multiple flames injected from the sub-combustion chambers 43a, 43b toward the main combustion chamber 41 can be set to be different. This makes it possible to appropriately set the combustion within the main combustion chamber 41. For example, by injecting a strong flame into a part of the main combustion chamber 41, the combustion speed can be increased, and the occurrence of knocking can be suppressed. In addition, it is possible to protect the inside of the cylinder 30 by preventing the flame from strongly hitting the cylinder wall facing the main combustion chamber 41 or the top surface of the piston. Furthermore, even if the size and number of each communication hole 44a, 44b are set without providing the dividing wall 71, it is difficult to accurately adjust the flame intensity. However, by providing the dividing wall 71 to partition the sub-combustion chamber 43 into a first sub-combustion chamber 43a and a second sub-combustion chamber 43b, and by providing a first communication hole 44a in the first sub-combustion chamber 43a and a second communication hole 44b in the second sub-combustion chamber 43b, and setting the size and number of each communication hole 44a, the flame intensity can be controlled for each combustion chamber 43a, 43b, thus allowing for more accurate adjustment of the flame intensity from each communication hole 44a, 44b.

[0028] In this embodiment, the dividing wall 71 that divides the sub-combustion chamber 43 is arranged to intersect with the intake and exhaust directions in the cylinder 30, dividing the sub-combustion chamber 43 into a first sub-combustion chamber 43a on the intake side and a second sub-combustion chamber 43b on the exhaust side. Since the intake side and exhaust side of the main combustion chamber 41 have different temperatures, it is preferable to vary the flame intensity accordingly. According to this embodiment, flames of different intensities can be injected into the intake side and the exhaust side of the main combustion chamber 41.

[0029] In particular, the second communication hole 44b facing the second sub-combustion chamber 43b on the exhaust side is set to be smaller than the first communication hole 44a facing the first sub-combustion chamber 43a on the intake side. This makes it possible to make the flame injected from the second communication hole 44b on the exhaust side stronger than the flame injected from the first communication hole 44a. In the main combustion chamber 41 of the internal combustion engine 1, the temperature is generally higher on the exhaust side than on the intake side, and the air-fuel mixture tends to accumulate there. Therefore, there is a higher possibility of knocking occurring in the exhaust side than on the intake side, where the air-fuel mixture burns unintentionally. In this embodiment, by injecting a strong flame into the exhaust side of the main combustion chamber 41 from the second communication hole 44b, the air-fuel mixture can be burned earlier on the exhaust side, effectively suppressing the occurrence of knocking.

[0030] Furthermore, in this embodiment, the partition wall 42 that forms the sub-combustion chamber 43 is shared with the grounding terminal of the spark plug 35. This simplifies the internal structure of the internal combustion engine 1, particularly the structure forming the sub-combustion chamber 43, making it more efficient. Furthermore, the dividing wall 71 extends its ground electrode upward from the lower surface of the partition wall 42, and is configured to face the central electrode 35a at the upper part of the sub-combustion chamber 43. For example, if the central electrode 35a were extended downward and faced the central electrode 35a at the lower part of the sub-combustion chamber 43, the flame generated in the sub-combustion chamber 43 would have a thermal effect on the side of the central electrode 35a. In contrast, in this embodiment, the effect of the flame generated in the sub-combustion chamber 43 on the central electrode 35a is suppressed, thereby protecting the spark plug 35. Furthermore, if, for example, the central electrode 35a is extended downward and faces the central electrode 35a at the lower part of the sub-combustion chamber 43, the flame generated in the sub-combustion chamber 43 will spread upward before being ejected from each communication hole 44a, 44b. However, if, as in this embodiment, the ground electrode is extended upward and faces the central electrode 35a at the upper part of the sub-combustion chamber 43, the flame generated in the sub-combustion chamber 43 will spread downward while the flame is ejected from each communication hole 44a, 44b, thereby reducing the energy loss of the flame.

[0031] Figure 6 is a cross-sectional view showing the structure of the grounding terminal of the spark plug 35 according to the second embodiment of the present invention. As shown in Figure 6, in the second embodiment, in the partition wall 42 forming the ground terminal of the spark plug 35, i.e., the sub-combustion chamber 43, the dividing wall 71 is provided such that the volume of the first sub-combustion chamber 43a on the intake side is smaller than the volume of the second sub-combustion chamber 43b on the exhaust side. The size of the first communication hole 44a and the second communication hole 44b are the same.

[0032] This makes it possible to suppress the flame intensity in the first sub-combustion chamber 43a and increase the flame intensity in the second sub-combustion chamber 43b. Therefore, even if the size of the first communication hole 44a and the second communication hole 44b are the same, similar to the first embodiment, the flame injected from the second communication hole 44b to the exhaust side of the main combustion chamber 41 can be made stronger than the flame injected from the first communication hole 44a to the intake side of the main combustion chamber 41, thereby burning the mixture remaining on the exhaust side earlier and suppressing the occurrence of knocking.

[0033] In the above embodiment, the sub-combustion chamber 43 is positioned above the center of the main combustion chamber 41. However, if, for example, the sub-combustion chamber 43 is positioned offset from the center of the main combustion chamber 41, or if the sizes of the first sub-combustion chamber 43a and the second sub-combustion chamber 43b, and the sizes of the first communication hole 44a and the second communication hole 44b are appropriately set in accordance with the shape of the main combustion chamber 41, flames can be appropriately injected from the sub-combustion chamber 43 into the main combustion chamber 41, thereby suppressing knocking and protecting the inside of the cylinder.

[0034] Figure 7 is a top view showing the structure of a third embodiment of the present invention. In a third embodiment of the present invention, the interior of the partition wall 42 is divided vertically by an upper and lower dividing wall 75 (in the direction of movement of the piston 37). The upper and lower dividing wall 75 divides the sub-combustion chamber 43 vertically. Therefore, in this embodiment, the sub-combustion chamber 43 has a third sub-combustion chamber 43c in the upper part and a fourth sub-combustion chamber 43d in the lower part. In this embodiment, a conical grounding terminal extends upward from the lower surface of the dividing wall 42. The third sub-combustion chamber 43c and the lower fourth sub-combustion chamber 43d are in communication, for example, through a hole provided in the upper and lower dividing wall 75 to allow the grounding terminal to pass through, and a small gap of a few millimeters between the hole and the grounding terminal 76.

[0035] Furthermore, each sub-combustion chamber 43 (43c to 43d) in the compartment wall 42 is provided with a communication hole 44 (44c to 44d) that communicates with the main combustion chamber 41 outside, corresponding to each sub-combustion chamber 43 (43c to 43d). The third communication hole 44c, facing the third sub-combustion chamber 43c, opens laterally and diagonally downward toward the upper part of the main combustion chamber 41. The fourth communication hole 44d, facing the fourth sub-combustion chamber 43d, opens laterally and diagonally downward toward the lower part of the compartment wall 42. The diagonal downward inclination angle of the fourth sub-combustion chamber 43d is greater than that of the third sub-combustion chamber 43c. In other words, the upper and lower dividing wall 75 is provided between the third communication hole 44c and the fourth sub-combustion chamber 43d.

[0036] The third sub-combustion chamber 43c may be formed with a larger volume than the fourth sub-combustion chamber 43d. Alternatively, the third communication hole 44c may be formed smaller than the fourth communication hole 44d. In the third embodiment, by setting the sizes of the third sub-combustion chamber 43c and the fourth sub-combustion chamber 43d, and the sizes of the third communication hole 44c and the fourth communication hole 44d, the flame can be injected with different strengths in the vertical direction, and the strength of the flame in the main combustion chamber 41 can be finely controlled. For example, by making the volume of the fourth sub-combustion chamber 43d smaller than that of the third sub-combustion chamber 43c, or by making the third communication hole 44c larger than that of the fourth communication hole 44d, the strength of the flame directed downwards into the main combustion chamber 41 can be set lower, thereby protecting the upper surface of the piston. In this embodiment, in addition to the upper and lower dividing wall 75, a dividing wall 71 as in the first and second embodiments may be provided to divide the sub-combustion chamber 43 into four parts: the upper intake side, the lower intake side, the upper exhaust side, and the lower exhaust side.

[0037] Figure 8 is a longitudinal cross-sectional view showing the structure of the grounding terminal of the spark plug 35 in the fourth embodiment. In the fourth embodiment of the present invention, the intake-side wall surface 71a of the divided wall 71 is formed to be inclined toward the exhaust side toward the central electrode 35a (upward), compared to the structure of the sub-combustion chamber 43 in the second embodiment. When intake air is introduced into the main combustion chamber 41, the intake air flows into the first sub-combustion chamber 43a and the second sub-combustion chamber 43b, but it is more difficult for intake air to flow into the second sub-combustion chamber 43b, which is on the exhaust side, than into the first sub-combustion chamber 43a, which is on the intake side. As in the fourth embodiment, by inclining the intake-side wall surface 71a of the dividing wall 71 toward the exhaust side toward the gap 73, the intake air that has flowed into the first sub-combustion chamber 43a can easily pass through the gap 73 and flow into the second sub-combustion chamber 43b. As a result, sufficient intake air (air-fuel mixture) can flow into the exhaust-side second sub-combustion chamber 43b, promoting the generation of a flame in the second sub-combustion chamber 43b.

[0038] The present invention is not limited to the embodiments described above. For example, in each of the embodiments described above, there is one or two dividing walls 71, but the number of dividing walls 71 is not limited thereto. For example, when viewed from the piston 37 side, the compartment wall 42 may have four communication holes 44 arranged in the circumferential direction of the compartment wall 42, and four dividing walls 71 may be formed so that the inside of the sub-combustion chamber 43 is divided for each communication hole 44, and the four dividing walls 71 may be connected at the center of the sub-combustion chamber 43.

[0039] Furthermore, in the above embodiment, each cylinder 30 is provided with two intake ports 2 and two exhaust ports 31, but the number of ports may be other than two. Also, auxiliary equipment such as an internal combustion engine without a supercharger may be modified as appropriate. The detailed structure of each injector and the inside of the cylinder of the internal combustion engine may be modified as appropriate. Furthermore, the internal combustion engine of the present invention can be applied to various types of internal combustion engines, such as those used for driving automobiles. [Explanation of symbols]

[0040] 1. Internal combustion engine 35. Spark plug (ignition system) 41 Main combustion chamber 43. Sub-combustion chamber 43a First auxiliary combustion chamber 43b Second auxiliary combustion chamber 44 Communication hole (injection hole) 44a 1st communication hole (injection hole) 44b 2nd communication hole (injection hole) 71 Dividing wall (ground electrode)

Claims

1. The main combustion chamber, A sub-combustion chamber is provided within the main combustion chamber, An internal combustion engine having an ignition device for igniting the air-fuel mixture in the pre-combustion chamber, The aforementioned sub-combustion chamber has a plurality of injection holes for ejecting the flame generated by the ignition of the ignition device, A dividing wall that passes between a plurality of injection holes and extends upward from the surface of the piston-side end of the sub-combustion chamber, dividing the internal space, is provided, The aforementioned sub-combustion chamber and divided wall are formed by a part of the spark plug. An internal combustion engine characterized by the following features.

2. The internal space of the sub-combustion chamber is divided radially by the dividing wall into a first sub-combustion chamber on one side and a second sub-combustion chamber on the other side. A gap is provided between the ignition device and the upper end of the dividing wall, and the area of ​​the gap is smaller than the total area of ​​the injection holes provided in the first sub-combustion chamber and the total area of ​​the injection holes provided in the second sub-combustion chamber. The internal combustion engine according to Feature 1.

3. The dividing wall is provided with a substantially semicircular notch, The ignition device is located above the notch. Internal combustion engine as described in Feature 1

4. The dividing wall divides the internal space of the sub-combustion chamber into an intake side and an exhaust side. The internal combustion engine according to feature 1.

5. The dividing wall is provided such that the internal space of the sub-combustion chamber is larger on the exhaust side than on the intake side. The internal combustion engine according to feature 4.

6. The dividing wall is formed by the ground electrode. The internal combustion engine according to feature 1.

7. The aforementioned dividing wall is inclined from the intake side to the exhaust side. The internal combustion engine according to claim 4 or 5, characterized by the features described above.

8. The injection holes located on the exhaust side are formed to be smaller than the injection holes located on the intake side. An internal combustion engine according to any one of claims 1 to 5, characterized by the following:

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