Internal combustion engine

Abstract

To provide an internal combustion engine capable of more appropriately improving efficiency and combustion stability and protecting components by using a first ignition device disposed in a main combustion chamber and a second ignition device disposed in an auxiliary combustion chamber.SOLUTION: An internal combustion engine includes: an internal combustion engine body having a main combustion chamber 40, an auxiliary combustion chamber 42, a first ignition plug 61 disposed in the main combustion chamber 40 and a second ignition plug 62 disposed in the auxiliary combustion chamber 42; and a control device that controls the internal combustion engine body. The control device causes either one of the first ignition plug 61 or the second ignition plug 62 to ignite an air-fuel mixture in a predetermined low speed region, and causes both of the first ignition plug 61 and the second ignition plug 62 to ignite the air-fuel mixture in a predetermined high speed region that is higher speed than the predetermined low speed region.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an internal combustion engine having an ignition device disposed in a main combustion chamber and an ignition device disposed in an auxiliary combustion chamber. [Background technology]

[0002] Conventionally, there is known a technique relating to an internal combustion engine equipped with an ignition device arranged in a main combustion chamber and an ignition device arranged in an auxiliary combustion chamber. For example, Patent Document 1 describes an internal combustion engine in which, in a load region lower than a control switching line, an ignition plug (ignition device) in the main combustion chamber is ignited while intake is being performed so that a tumble vortex is easily formed in the main combustion chamber, and in a load region higher than the control switching line, an air-fuel mixture is taken into the main combustion chamber at a high flow rate so that a rich air-fuel mixture is filled in the auxiliary combustion chamber, and the ignition plug (ignition device) in the auxiliary combustion chamber is ignited. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-119297 Summary of the Invention [Problem to be solved by the invention]

[0004] The ignition control described in Patent Document 1 aims to achieve lean combustion in each combustion chamber by using one of the ignition devices depending on the load of the internal combustion engine. However, from the perspective of improving the efficiency and combustion stability of the internal combustion engine and protecting its components, it is necessary to switch the ignition method more precisely, taking into account the engine speed.

[0005] The present invention has been made in view of the above problems, and its purpose is to provide an internal combustion engine that can improve efficiency and combustion stability and more appropriately protect component parts by using a first ignition device arranged in the main combustion chamber and a second ignition device arranged in the auxiliary combustion chamber. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the internal combustion engine of the present invention comprises an internal combustion engine body including a main combustion chamber filled with a mixture of air and fuel, an auxiliary combustion chamber communicating with the main combustion chamber via a plurality of communication holes, a first ignition device arranged in the main combustion chamber and igniting the mixture in the main combustion chamber, and a second ignition device arranged in the auxiliary combustion chamber and igniting the mixture in the auxiliary combustion chamber, and a control device that controls the internal combustion engine body, wherein the control device ignites the mixture by either the first ignition device or the second ignition device in a predetermined low rotation range of the internal combustion engine body, and ignites the mixture by both the first ignition device and the second ignition device in a predetermined high rotation range having a higher rotation speed than the predetermined low rotation range. [Effects of the Invention]

[0007] According to the internal combustion engine of the present invention, it is possible to improve efficiency and combustion stability and more appropriately protect component parts by using a first ignition device arranged in the main combustion chamber and a second ignition device arranged in the auxiliary combustion chamber. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram of an internal combustion engine according to an embodiment. [Figure 2] FIG. 2 is an explanatory diagram schematically showing a cylinder. [Figure 3] 3 is an explanatory diagram showing an ignition method according to an embodiment according to the rotation speed and charging efficiency of an internal combustion engine. FIG. [Figure 4] 5A and 5B are schematic diagrams showing other examples of the positions of the first and second spark plugs. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0010] (Internal combustion engine) Fig. 1 is a schematic diagram of an internal combustion engine according to an embodiment. The internal combustion engine 1 is, for example, a gasoline engine mounted on a vehicle. The internal combustion engine 1 includes an internal combustion engine main body 10 (hereinafter referred to as "main body 10") and a control device 50. In an intake passage 5 of the main body 10, an air cleaner 6, an intercooler 7, and a throttle valve 8 are provided upstream of the intake port 2 of each cylinder 30 along the flow of intake air. Meanwhile, in an exhaust passage 11 of the main body 10, an upstream exhaust purification catalyst 12 and a downstream exhaust purification catalyst 13 are provided along the flow of exhaust from the exhaust port 3 of each cylinder 30.

[0011] The main body 10 is also provided with a turbocharger 15 and an EGR system 16. The turbocharger 15 rotates a turbine (not shown) using exhaust gas flowing through the exhaust passage 11, and supplies compressed air to the intake side by rotating a compressor (not shown) connected to the turbine. The EGR system 16 includes an EGR passage 20 that connects the exhaust passage 11 and the intake passage 5, 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.

[0012] 2 is an explanatory diagram that schematically shows a cylinder 30. The cylinder 30 is composed of a cylinder head 34, a cylinder block 36, and a piston 37 that is slidably disposed within the cylinder block 36 via a cylindrical cylinder liner (not shown). The cylinder head 34 is provided with an intake port 2 and an exhaust port 3 corresponding to each cylinder 30, and each intake port 2 is provided with an intake valve 32 that can be opened and closed, and each exhaust port 3 is provided with an exhaust valve 33 that can be opened and closed.

[0013] The cylinder 30 is provided with a main combustion chamber 40, which is a space surrounded by the cylinder head 34, cylinder block 36, and piston 37. In the main body 10 of this embodiment, an injector (not shown) serving as a fuel injection device is provided in the intake port 2, and an air-fuel mixture mixed with air in the intake port 2 is supplied into the main combustion chamber 40. Note that the main body 10 may also be provided with a direct injection type injector that injects fuel directly into the main combustion chamber. A first spark plug 61 (first ignition device) that ignites the air-fuel mixture in the main combustion chamber 40 is provided at the top of the main combustion chamber 40 (i.e., the cylinder head 34).

[0014] Also, within the main combustion chamber 40, there is provided an auxiliary combustion chamber 42, which is a space separated by a partition wall 44 attached to the cylinder block 36. A plurality of communication holes 46 are formed in the partition wall 44. As a result, the main combustion chamber 40 and the auxiliary combustion chamber 42 are in communication with each other via the plurality of communication holes 46, and the air-fuel mixture within the main combustion chamber 40 flows into the auxiliary combustion chamber 42. A second spark plug 62 (second ignition device) is disposed within the auxiliary combustion chamber 42, and ignites the air-fuel mixture that flows in from the main combustion chamber 40.

[0015] When the first spark plug 61 ignites the air-fuel mixture in the main combustion chamber 40 (hereinafter referred to as "SI ignition"), as shown by the dashed dotted line in the figure, the flame F1 propagates from the first spark plug 61 toward the exhaust port 3 due to the flow of the air-fuel mixture in the main combustion chamber 40. In this way, stable ignition can be achieved by directly igniting the air-fuel mixture filled in the main combustion chamber 40.

[0016] On the other hand, when the second spark plug 62 ignites the air-fuel mixture in the auxiliary combustion chamber 42 (hereinafter referred to as "JET ignition"), flame F2 is injected from the auxiliary combustion chamber 42 through the multiple communication holes 46 into the main combustion chamber 40, as shown by the dashed line in the figure. As a result, flame F2 can be quickly propagated within the main combustion chamber 40, accelerating combustion and ultimately improving the thermal efficiency of the main body 10. Furthermore, when both SI ignition and JET ignition are performed, flame F2 from JET ignition can burn unburned fuel that was not ignited by SI ignition. Furthermore, flame F2 from JET ignition can push flame F1 generated by SI ignition to the vicinity of the cylinder wall, thereby also burning unburned fuel that remained near the cylinder wall in the previous cycle. By promoting the combustion of unburned fuel in this way, knocking can be suppressed.

[0017] The auxiliary combustion chamber 42 and the plurality of communication holes 46 are positioned so that the injection direction of the flame F2 is generally along the extension direction of the face of the piston 37 facing the main combustion chamber 40 (a direction perpendicular to the sliding direction of the piston 37). This makes it possible to prevent the flame F2 from damaging the piston 37. The size and number of the plurality of communication holes 46 may be set according to the cylinder volume. In this embodiment, the plurality of communication holes 46 are formed side by side in the depth direction of FIG. 2.

[0018] The main body 10 configured as described above is controlled by a control device 50 (FIG. 1). The control device 50 is composed of an output device, memory devices (ROM, RAM, non-volatile RAM, etc.), a central processing unit (CPU), etc. The control device 50 acquires information such as the crank angle, intake air volume, exhaust temperature, and EGR gas volume from various sensors provided in the main body 10, and appropriately controls the throttle valve 8, EGR valve 21, turbocharger 15, the amount of fuel injected from an injector (not shown), intake valve 32, exhaust valve 33, first spark plug 61, second spark plug 62, etc. based on the acquired information.

[0019] (Ignition control) Next, ignition control using the first spark plug 61 and the second spark plug 62 will be described with reference to FIG. 3. FIG. 3 is an explanatory diagram showing an ignition method according to an embodiment corresponding to the rotation speed Ne and charging efficiency Ec of the main body 10. The charging efficiency Ec (%) is a value obtained by converting the amount of intake air into the main body 10 to a standard atmospheric condition, and is proportional to the load on the main body 10. Therefore, in the following description, a high charging efficiency Ec will be considered to indicate a high load. In addition, in the following description, "ignite," "perform SI ignition," and "perform JET ignition" mean that a signal indicating ignition processing is being output from the control device 50 to each spark plug ("ON" in FIG. 3).

[0020] The control device 50 divides the predetermined range of the operating region of the main body 10 into a plurality of regions as shown in the figure, and changes the ignition method for each divided region. The divided regions are a predetermined low rotation region A L (The patterned area in the diagram) and the specified high rotation range A H Furthermore, a predetermined low rotation range A L is the low rotation and low load region A LL and low rotation and low load region A LL Higher load than low rotation high load region A LH Also, in the specified high rotation range A H is the high speed, low load region A HL and high rotation low load region A HL High-load, high-speed range A HH Includes:

[0021] In this embodiment, a predetermined low load region where the charging efficiency is less than a predetermined value Ec1 is set as a non-operating region of the supercharger 15, and a predetermined high load region where the charging efficiency is equal to or greater than the predetermined value Ec1 is set as an operating region of the supercharger 15. L and the specified high rotation range A H The predetermined high rotation region A is a region that is divided into a low rotation side and a high rotation side when the predetermined low load region and the predetermined high load region are divided. H is the engine speed in a specified low load region. L (Low rotation, low load area A LL ) Higher RPM range (High RPM low load range AHL ) and in a predetermined high load range, a predetermined low rotation range A L (Low rotation, high load area A LH ) Higher rotation range (High rotation, high load range A HH )

[0022] (Low rotation, low load range) Low rotation and low load region A LL The low rotation and low load region A is the region with the lowest rotation and load among the four regions, and in this embodiment, it is the region including the idling operation of the main body 10. More specifically, the low rotation and low load region A LL is a region in which the rotation speed Ne of the main body 10 is less than the first predetermined rotation speed Ne1 as the upper limit rotation speed of the idling operation and the load is in the non-operating region of the supercharger 15. LL In this region, the amount of air and fuel supplied to the main combustion chamber 40 is relatively small compared to other regions, and the amount of air and fuel supplied to the auxiliary combustion chamber 42 is insufficient, which may cause a failure of jet ignition by the second ignition plug 62. Therefore, the control device 50 determines whether the main body 10 is in the low rotation / low load region A. LL When the engine is operated in the low speed, low load region A, SI ignition is performed by the first spark plug 61, and JET ignition is not performed by the second spark plug 62. LL This ensures that the air-fuel mixture is ignited, and misfires in the main body 10 can be suppressed.

[0023] (Low RPM, high load range) Low RPM, high load range A LH is a region in which the rotation speed Ne of the main body 10 is lower than a second predetermined rotation speed Ne2 that is higher than the first predetermined rotation speed Ne1 and the load is within the operating range of the supercharger 15. The second predetermined rotation speed Ne2 is a low rotation, high load region A LH and a high-speed, high-load region A, which aims to protect the components of the cylinder 30 and suppress noise, as will be described later. HH The threshold value for distinguishing between the two is set in advance based on experiments, analysis, etc.

[0024] Such a low rotation, high load region A LHIn the low rotation / low load region A, the pressure in the main combustion chamber 40 is sufficiently high, and the mixture is easily pushed into the auxiliary combustion chamber 42, so misfires may occur during jet ignition. LL Therefore, the control device 50 determines whether the main body 10 is in the low rotation / high load region A. LH When the engine is operated in this condition, JET ignition is performed by the second spark plug 62, and SI ignition is not performed by the first spark plug 61. This allows for high-speed combustion by JET ignition and suppression of knocking due to the combustion of unburned fuel, while also reducing wear and deterioration of the first spark plug 61 by not performing unnecessary SI ignition, thereby enabling energy savings in electric power.

[0025] (High RPM, low load range) High speed, low load range A HL is a region where the rotation speed Ne of the main body 10 is equal to or higher than the first predetermined rotation speed Ne1 and the load is in the non-operating region of the supercharger 15. HL When the engine is operated in this range, JET ignition is performed by the second spark plug 62, and then SI ignition is performed by the first spark plug 61. In this way, by mainly using JET ignition, the engine can be ignited in the high rotation / low load range A where the time is likely to be short. HL This allows high-speed combustion to accommodate one cycle of operation of the main body 10 in the engine, thereby stabilizing combustion. Furthermore, even if JET ignition fails because an insufficient mixture is supplied to the auxiliary combustion chamber 42 due to the relatively low load region, subsequent SI ignition can ensure ignition of the mixture in the main combustion chamber 40. Therefore, SI ignition here is performed as a support to suppress misfires, and it is sufficient that flame F1 is generated in the main combustion chamber 40 by SI ignition at least simultaneously with or after the injection of flame F2 by JET ignition.

[0026] (High rotation, high load range) High-speed, high-load range A HHis a region where the rotation speed Ne of the main body 10 is equal to or higher than the second predetermined rotation speed Ne2 and the load is within the operating range of the turbocharger 15. In such a high load region, high-speed combustion is aimed at by mainly using JET ignition as described above. However, when a large amount of air and fuel is contained in the main combustion chamber 40 due to high rotation speed and high load, the explosion caused by JET ignition is likely to increase the in-cylinder pressure in the main combustion chamber 40, which may cause damage to the components of the cylinder 30 such as the piston 37 or generate noise (jet shock).

[0027] Therefore, the control device 50 determines whether the main body 10 is in the high rotation and high load region A. HH When the engine is operated in this mode, SI ignition is performed by the first spark plug 61, and then JET ignition is performed by the second spark plug 62. This allows a portion of the air-fuel mixture in the main combustion chamber 40 to be pre-burned and consumed by SI ignition before JET ignition is performed, thereby preventing the in-cylinder pressure in the main combustion chamber 40 from increasing excessively due to JET ignition. Therefore, it is possible to protect the components of the cylinder 30 and suppress noise while achieving high-speed combustion by using JET ignition.

[0028] (Adjusting the ignition interval) In addition, in the high rotation and low load region A HL and high rotation and high load area A HH In the case where SI ignition and JET ignition are used together, the control device 50 sets a larger ignition interval Δt between SI ignition and JET ignition as the load on the main body 10 increases. This increases the interval between the explosion caused by SI ignition and the explosion caused by JET ignition, particularly in the case of a high load, and prevents the in-cylinder pressure in the main combustion chamber 40 from increasing excessively, making it possible to more appropriately protect the components of the cylinder 30 and suppress noise.

[0029] In the main body 10 of the embodiment, the high rotation and high load region A HHIn this case, the control device 50 executes exhaust system protection control, which lowers the exhaust gas temperature by enriching the mixture (increasing the amount of fuel supplied). In this case, the control device 50 sets the ignition interval Δt to be longer than when exhaust system protection control by enriching the mixture is not executed. This prevents the in-cylinder pressure from increasing excessively in the enriched main combustion chamber 40, making it possible to more appropriately protect the components of the cylinder 30 and suppress noise.

[0030] The control device 50 may also set the ignition interval Δt to be large when enrichment control is performed for reasons other than exhaust system protection, such as when increasing the fuel supply amount to purge oxygen from the upstream side exhaust purification catalyst 12 and the downstream side exhaust purification catalyst 13 when the main body 10 returns from fuel cut control. In addition, the ignition interval Δt may be changed in accordance with the estimated pushing amount of unburned fuel into the auxiliary combustion chamber 42, based on the in-cylinder pressure caused by SI ignition.

[0031] (Effects of the embodiment) As described above, the internal combustion engine 1 of the embodiment includes a main combustion chamber 40, an auxiliary combustion chamber 42, a first spark plug 61 (first ignition device) arranged in the main combustion chamber 40, and a second spark plug 62 (second ignition device) arranged in the auxiliary combustion chamber 42, and a control device 50 that controls the main combustion engine 10. The control device 50 controls the main combustion engine 10 to generate a predetermined low rotation speed range A. L In the predetermined low rotation range A, the mixture is ignited by either the first spark plug 61 or the second spark plug 62. L A specified high rotation speed range A H In this example, the air-fuel mixture is ignited by both the first spark plug 61 and the second spark plug 62.

[0032] This configuration allows the ignition method to be switched depending on the situation taking into consideration both the load and the rotation speed Ne. LIn this case, only one of SI ignition and JET ignition is used to stabilize and speed up combustion, while the other unnecessary ignition is not used, thereby reducing spark plug wear and power consumption. H In this case, the combined use of SI ignition and JET ignition makes it possible to achieve high-speed combustion, combustion of unburned fuel, prevention of misfires, and prevention of increases in cylinder pressure. Therefore, the internal combustion engine 1 of this embodiment makes it possible to improve efficiency and combustion stability and more appropriately protect component parts.

[0033] In addition, the control device 50 controls the engine speed in the low rotation and low load region A. LL In the low rotation, high load region A, the first spark plug 61 ignites the air-fuel mixture. LH In the low rotation / low load region A, the air-fuel mixture is ignited by the second spark plug 62. LL In the low rotation, high load range A, reliable ignition is achieved by SI ignition. LH This allows for high-speed combustion and consumption of unburned fuel through JET ignition, as well as reducing energy consumption through unnecessary SI ignition.

[0034] In addition, the control device 50 is configured to H In this example, the higher the load on the main body 10, the longer the ignition interval Δt between the first spark plug 61 and the second spark plug 62 is set. With this configuration, the interval between the explosions of SI ignition and JET ignition can be appropriately set according to the load, and the pressure inside the cylinder can be prevented from increasing too much, thereby protecting the components of the cylinder 30 and suppressing noise.

[0035] In addition, the control device 50 controls the high rotation and high load region A HH In this case, the first spark plug 61 is ignited before the second spark plug 62. With this configuration, the high rotation and high load range A HH In this case, by consuming a portion of the fuel by SI ignition before explosion by JET ignition, it is possible to prevent the pressure inside the cylinder from increasing too much, thereby protecting the components of the cylinder 30 and suppressing noise.

[0036] In addition, the control device 50 controls the high rotation / low load region A HLIn this case, the second spark plug 62 is ignited before the first spark plug 61. With this configuration, the high-speed combustion achieved by JET ignition is used to stabilize combustion in the main body 10 at high revolutions, while the occurrence of misfires when JET ignition fails can be suppressed by SI ignition.

[0037] Furthermore, the first spark plug 61 is provided in the cylinder head 34 of the main body 10, and the auxiliary combustion chamber 42 and the second spark plug 62 are provided in the cylinder block 36 of the main body 10. With this configuration, it is possible to adjust the flame F2 so that it is not injected in a direction toward the piston 37, thereby suppressing damage to the piston 37. Furthermore, the flame F1 of SI ignition is boosted by the flame F2 of JET ignition, thereby enabling combustion of unburned fuel near the cylinder wall.

[0038] However, the positions of the first spark plug 61 and the second spark plug 62 are not limited to this example. Fig. 4 is an explanatory diagram schematically showing another example of the positions of the first spark plug 61 and the second spark plug 62. In the cylinder 300 shown in Fig. 4, a pre-combustion chamber 42 separated by a partition wall 44 is provided at the top of the main combustion chamber 40 (i.e., the cylinder head 34), and the second spark plug 62 is disposed within the pre-combustion chamber 42. The first spark plug 61 is also provided in the cylinder block 36. Even with this arrangement of the first spark plug 61 and the second spark plug 62, the ignition control of the embodiment can achieve the above-described effects.

[0039] In the configuration shown in Fig. 4, the flame F1 caused by SI ignition is set to spread in the extension direction of the face of the piston 37. In this configuration, the flame F1 propagates a longer distance within the main combustion chamber 40 than in the example shown in Fig. 2, in which the flame F1 caused by SI ignition spreads from the center of the main combustion chamber 40. As a result, combustion can be slowed down in the same way as with ignition timing retardation used in catalyst temperature rise control, for example.

[0040] Although the description of the embodiment has been completed above, the aspects of the present invention are not limited to this embodiment.L In the specified high rotation range A, either SI ignition or JET ignition is used. H In this case, assuming that SI ignition and JET ignition are used in combination, an ignition method different from the method described in the above embodiment may be used in the transient state of the main body 10. For example, if the rotation speed Ne of the main body 10 is increasing (for example, while the vehicle is accelerating), JET ignition may be used with priority given to achieving high-speed combustion (JET ignition may be used primarily when used in combination with SI ignition). Also, if the rotation speed Ne of the main body 10 is decreasing (for example, while the vehicle is decelerating), SI ignition may be used to suppress misfires due to a decrease in fuel (when used in combination with JET ignition, it may be used as an auxiliary ignition).

[0041] Furthermore, when using both SI ignition and JET ignition, which one is executed first may be changed as appropriate depending on the purpose, such as combustion stability when the intake air amount or fuel supply amount changes transiently or improving the output of high-speed combustion.

[0042] In addition, only SI ignition may be performed when starting the main body 10, when idling before warming up, when catalyst temperature rise control is being performed, etc., or SI ignition and JET ignition may be used in combination when ignition performance is required, such as during high-load operation before warming up, when returning to normal operation after a fuel cut, or when restarting after an idle stop. [Explanation of symbols]

[0043] 1. Internal combustion engine 10 Internal combustion engine body 15. Turbocharger 30, 300 cylinders 40 Main combustion chamber 42 Auxiliary combustion chamber 46 Communication hole 50 Control device 61 First spark plug (first ignition device) 62 Second spark plug (second ignition device) A H Predetermined high rotation range A HH High rotation and high load range A HL High speed, low load range AL Prescribed low rotation range A LH Low RPM, high load range A LL Low rotation and low load range Δt Ignition interval

Claims

1. a main combustion chamber filled with an air-fuel mixture; an auxiliary combustion chamber communicating with the main combustion chamber via a plurality of communication holes; a first ignition device disposed in the main combustion chamber and configured to ignite the air-fuel mixture in the main combustion chamber; a second ignition device disposed in the auxiliary combustion chamber and configured to ignite the air-fuel mixture in the auxiliary combustion chamber; an internal combustion engine body including: a control device that controls the internal combustion engine body; Equipped with The control device ignites the mixture using either the first ignition device or the second ignition device in a predetermined low rotation range of the internal combustion engine body, and ignites the mixture using both the first ignition device and the second ignition device in a predetermined high rotation range having a rotation speed higher than the predetermined low rotation range.

2. the predetermined low rotation region includes a low rotation, low load region and a low rotation, high load region having a higher load than the low rotation, low load region, 2. The internal combustion engine according to claim 1, wherein the control device ignites the air-fuel mixture by the first ignition device in the low-speed, low-load region, and ignites the air-fuel mixture by the second ignition device in the low-speed, high-load region.

3. 2. The internal combustion engine according to claim 1, wherein the control device sets a longer ignition interval between the first ignition device and the second ignition device as the load on the internal combustion engine body increases in the predetermined high rotation speed range.

4. the predetermined high rotation region includes a high rotation, low load region and a high rotation, high load region having a higher load than the high rotation, low load region, 4. The internal combustion engine according to claim 3, wherein the control device causes the first ignition device to ignite before the second ignition device in the high-speed, high-load region.

5. the predetermined high rotation region includes a high rotation, low load region and a high rotation, high load region having a higher load than the high rotation, low load region, 4. The internal combustion engine according to claim 3, wherein the control device causes the second ignition device to ignite before the first ignition device in the high rotation speed, low load region.

6. the first ignition device is provided in a cylinder head of the internal combustion engine body, 6. The internal combustion engine according to claim 1, wherein the auxiliary combustion chamber and the second ignition device are provided in a cylinder block of the internal combustion engine body.

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