Internal combustion engine with ignition plug and pre-combustion chamber ignition plug

Abstract

The present invention relates to an internal combustion engine comprising: at least one cylinder (10); two scavenging openings (4) for each cylinder (10), wherein a first scavenging opening (4) is an inlet opening (41), and wherein a second scavenging opening (4) is an outlet opening (42); and an ignition plug (2) and a pre-combustion chamber ignition plug (3) for each cylinder (10).

Description

Technical Field

[0001] This invention relates to an internal combustion engine having an ignition plug and a pre-combustion chamber ignition plug, and a method for operating the internal combustion engine. Background Technology

[0002] Internal combustion engines with pre-combustion chamber ignition plugs are known from the prior art. As is known for conventional ignition plugs, a pre-combustion chamber ignition plug includes an intermediate electrode and a ground electrode disposed in a housing, which define an ignition gap to ignite an air-fuel mixture. The ignited air-fuel mixture is then introduced into the combustion chamber of the internal combustion engine through an opening in a plug cap located at the combustion chamber side end of the pre-combustion chamber ignition plug, where actual combustion of the air-fuel mixture for the piston stroke occurs. For example, DE 10 2019 205 478 A1 shows such a pre-combustion chamber ignition plug. Summary of the Invention

[0003] The internal combustion engine according to the invention is characterized by an improved operating mode that allows for particularly high efficiency under low knocking tendency and reliable operation under any operating conditions. According to the invention, this is achieved by an internal combustion engine comprising at least one cylinder, and for each cylinder including an ignition plug and a pre-combustion chamber ignition plug. Furthermore, for each cylinder, the internal combustion engine includes two scavenging openings. Here, the first scavenging opening is an inlet opening, and the second scavenging opening is an outlet opening.

[0004] Here, "ignition plug" refers to a conventional ignition plug, particularly one with exposed electrodes, configured to ignite a fuel-air mixture by means of an electric spark between at least two electrodes. Particularly preferably, the ignition plug has a straight intermediate electrode and at least one hook-shaped end or top electrode. In particular, such an ignition plug can also be alternatively referred to as a "spark ignition plug." Alternatively, a laser device can also be used as an "ignition plug," configured to ignite a fuel-air mixture by means of laser radiation.

[0005] A "pre-combustion chamber igniter" is considered to be a structure having a pre-combustion chamber constructed within a ignition cap, which is fluidly connected to the combustion chamber of an internal combustion engine via a through opening in the ignition cap. This allows gas to pass from the pre-combustion chamber through the ignition cap into the combustion chamber, and vice versa. Preferably, viewed axially, the ignition cap is positioned on the combustion chamber side of the pre-combustion chamber igniter housing. Here, the ignition cap, housing, and pre-combustion chamber form an integral component of the pre-combustion chamber igniter. In particular, the pre-combustion chamber is therefore located within the pre-combustion chamber igniter. Here, the fuel-air mixture located within the pre-combustion chamber is ignited by electrodes, wherein a flame jet passes through the through opening in the ignition cap and ignites the fuel-air mixture in the combustion chamber. That is, the actual ignition of the fuel-air mixture in the combustion chamber is achieved by the flame jet generated by the pre-combustion chamber igniter. Preferably, the pre-combustion chamber igniter can be considered as an integral component that can be securely fastened to the cylinder head of the internal combustion engine. Preferably, the fastening is achieved such that the through opening in the plug cap is oriented in a predefined manner in the final position to generate a particularly targeted jet of flame during operation. For example, the pre-combustion chamber ignition plug can be configured such that it can be screwed into a standard thread in the cylinder head that accepts common ignition plugs.

[0006] Here, the combination of a common ignition plug and a pre-combustion chamber ignition plug offers the advantages of a particularly flexible, efficient, and reliable operating mode for internal combustion engines. Thus, under any operating condition (e.g., cold start, catalytic converter heating phase, partial load, full load, etc.), the fuel-air mixture in the combustion chamber can always be optimally and reliably ignited. Preferably, the operation of the internal combustion engine can be designed so that the pre-combustion chamber ignition plug can be used as a standalone ignition source within the maximum possible operating range, in order to achieve effective knock reduction and low fuel consumption, especially under high loads. Here, the ignition plug can operate additionally or independently in operating ranges where the operation of the pre-combustion chamber ignition plug is unfavorable or impossible (e.g., during cold start), in order to achieve reliable ignition even in these ranges. Another advantage is that the pre-combustion chamber ignition plug can be specifically optimized for the most efficient operation possible, for example, for a specific operating point of the internal combustion engine, where efficiency degradation at other operating points can be ignored or accepted because, for example, ignition can be performed independently or additionally at these operating points. Furthermore, by ensuring optimal ignition for different operating ranges, damage to the internal combustion engine (such as damage caused by knocking, ignition interruption, or poor combustion) can be avoided, thus enabling an exceptionally long service life for the internal combustion engine.

[0007] Preferably, the ignition plug and / or pre-combustion chamber ignition plug are arranged on the top of the combustion chamber of the cylinder. In particular, the top of the combustion chamber forms the upper end of the combustion chamber along the piston stroke direction. Preferably, the top of the combustion chamber is part of the cylinder head of the internal combustion engine. Preferably, the pre-combustion chamber ignition plug and the ignition plug extend into the combustion chamber. Preferably, the plug cap of the pre-combustion chamber ignition plug and the electrode of the ignition plug extend into the combustion chamber. Alternatively, the combustion chamber side ends of the pre-combustion chamber ignition plug and the ignition plug can also be arranged in corresponding plug holes, in which the corresponding pre-combustion chamber ignition plug or ignition plug is arranged.

[0008] Particularly preferably, the scavenging openings are arranged in the top of the combustion chamber. The top of the combustion chamber is divided into two top regions by a first cutting plane located at the center point of the two scavenging openings, and particularly parallel to the piston direction. Here, the ignition plug and the pre-combustion chamber ignition plug are arranged in the same top region. Thus, the mixture formation in the combustion chamber can be specifically and locally matched to the top regions where the ignition plug and pre-combustion chamber ignition plug are located to achieve optimal ignition. Alternatively, the ignition plug and the pre-combustion chamber ignition plug are arranged in different top regions. This allows for particularly advantageous utilization of the free space in the top region, and it can be used, for example, for other components, such as injectors.

[0009] Preferably, the top of the combustion chamber is divided by a second cutting plane perpendicular to the first cutting plane, wherein the second cutting plane is arranged such that the inlet and outlet openings are located on different sides of the second cutting plane. Particularly preferably, the second cutting plane is perpendicular to the line connecting the center points of the two ventilation openings and preferably lies between the respective outer edges of the ventilation openings. Here, the ignition plug and / or the pre-combustion chamber ignition plug (especially substantially) is arranged on the second cutting plane. This orientation allows the ignition plug and / or the pre-combustion chamber ignition plug to be arranged particularly close to the center point of the top of the combustion chamber, which has a favorable effect on optimal ignition and uniform ignition within the combustion chamber.

[0010] Particularly preferably, the pre-combustion chamber igniter is positioned closer to the inlet opening than the igniter itself, to enable a particularly good and direct supply of fresh air, especially to the pre-combustion chamber of the pre-combustion chamber igniter. Alternatively, the pre-combustion chamber igniter is positioned closer to the outlet opening than the igniter, meaning (in other words) the igniter is positioned closer to the inlet opening than the pre-combustion chamber igniter. In this case, a particularly efficient supply of fresh air to the igniter is achieved, ensuring optimal ignition during its operation.

[0011] Preferably, the pre-combustion chamber ignition plug is arranged closer to the cylinder sidewall than the main ignition plug. In particular, the pre-combustion chamber ignition plug is laterally arranged on the top of the combustion chamber. This provides more space for the ignition plug and other components in the central region of the combustion chamber. Preferably, the pre-combustion chamber ignition plug is configured in this case such that the flame jet generated during ignition is oriented towards the center of the combustion chamber. Alternatively, the main ignition plug is arranged closer to the cylinder sidewall than the pre-combustion chamber ignition plug. In this case, more space is available for the pre-combustion chamber ignition plug in the central region of the top of the combustion chamber, allowing for higher efficiency in its operation. Here, the sidewall is considered as the substantially cylindrical side surface of the cylinder, which can also be referred to as the piston's working surface.

[0012] Further preferably, the pre-combustion chamber igniter is positioned closer to the center point of the combustion chamber top than the igniter. This allows for a particularly uniform passage through the combustion chamber via the generated flame jet, facilitating uniform ignition of the fuel-air mixture. Alternatively, it is preferable that the igniter is positioned closer to the center point of the combustion chamber top than the pre-combustion chamber igniter, to achieve particularly efficient and uniform ignition during igniter operation.

[0013] Preferably, the ignition plug and / or pre-combustion chamber ignition plug are arranged in the center region of the top of the combustion chamber. Here, the center region is defined as a circular area with a predefined radius around the center point of the top of the combustion chamber. Preferably, this predefined radius is a maximum of 50% of the cylinder radius. Particularly preferably, the ignition plug and / or pre-combustion chamber ignition plug are arranged as close as possible to the center point of the top of the combustion chamber according to the orientation of the scavenging opening, thereby enabling the most homogeneous ignition from the center region of the combustion chamber.

[0014] Preferably, the internal combustion engine also includes a combustion chamber fuel injector configured to inject fuel, particularly liquid or gaseous fuel, directly into the combustion chamber of the internal combustion engine.

[0015] Preferably, the combustion chamber fuel injector is arranged on top of the combustion chamber of the cylinder. In particular, the combustion chamber fuel injector is therefore located near the pre-combustion chamber ignition plug and / or ignition plug in order to produce a uniform fuel-air mixture that is optimally matched to the orientation of the pre-combustion chamber ignition plug and / or ignition plug for uniform ignition.

[0016] Preferably, the scavenging openings are arranged in the top of the combustion chamber, wherein the top of the combustion chamber is divided into two top regions by a first cutting plane, such that the first cutting plane is located at the center point of the two scavenging openings, and wherein the combustion chamber fuel injector and the ignition plug are arranged in the same top region. This enables spatial proximity between the combustion chamber fuel injector and the ignition plug to provide high efficiency during ignition plug operation. Alternatively or additionally, the combustion chamber fuel injector and the pre-combustion chamber ignition plug are arranged in the same top region. In this case, the pre-combustion chamber ignition plug and the combustion chamber fuel injector can be arranged particularly close to each other on the top of the combustion chamber to achieve particularly high efficiency during pre-combustion chamber ignition plug operation.

[0017] Particularly preferably, the top of the combustion chamber is divided by a second cutting plane perpendicular to the first cutting plane, such that the inlet and outlet openings are located on opposite sides of the second cutting plane. Preferably, the second cutting plane is arranged tangentially with respect to each of the two scavenging openings. The combustion chamber fuel injector is arranged on the second cutting plane. Thus, the combustion chamber fuel injector can be arranged particularly close to the center point of the top of the combustion chamber to achieve the most uniform fuel distribution in the combustion chamber and thus uniform and efficient combustion.

[0018] Preferably, the combustion chamber fuel injector is arranged within a central point region having a predefined maximum radius around the center point of the top of the combustion chamber. Particularly preferably, the maximum radius of the central point region is 50% of the cylinder radius. By arranging the combustion chamber fuel injector as centrally as possible, uniform fuel distribution and uniform and efficient combustion can be achieved in the combustion chamber.

[0019] Preferably, the distance between the combustion chamber fuel injector and the cylinder sidewall is a maximum of 30% of the cylinder radius, and particularly preferably a maximum of 15%. In other words, the combustion chamber fuel injector is arranged close to the sidewall, i.e., not centrally, but laterally on the top of the combustion chamber. Preferably, the combustion chamber fuel injector is oriented at an angle in this case, such that the injection direction of the fuel to be injected is oriented towards the center of the combustion chamber. This lateral arrangement of the combustion chamber fuel injector allows for a particularly space-saving arrangement on the top of the combustion chamber, thereby providing more space, especially in the central region of the top of the combustion chamber, for arranging the ignition plug and / or pre-combustion chamber ignition plug.

[0020] Particularly preferably, the pre-combustion chamber igniter is arranged closer to the combustion chamber fuel injector than the main igniter. This arrangement of the combustion chamber fuel injector and the pre-combustion chamber igniter being close to each other has a particularly advantageous effect on the efficient and reliable operation of the pre-combustion chamber igniter. The proximity between the combustion chamber fuel injector and the pre-combustion chamber igniter enables improved scavenging air and mixture supply to the pre-combustion chamber of the pre-combustion chamber igniter.

[0021] Alternatively, the ignition plug is preferably positioned closer to the combustion chamber fuel injector than the pre-combustion chamber ignition plug. In this case, a particularly good mixture supply can be provided in the region of the ignition plug. This arrangement, where the combustion chamber fuel injector and ignition plug are adjacent to each other, allows the internal combustion engine to operate particularly robustly, for example, during catalytic converter heating.

[0022] Preferably, the combustion chamber fuel injector and the pre-combustion chamber igniter are arranged at a distance of up to 50% of the cylinder radius, particularly up to 30%, and preferably up to 10%.

[0023] Further preferably, the combustion chamber fuel injector and ignition plug are arranged at a spacing of up to 50% of the cylinder radius, particularly up to 30%, and preferably up to 10%.

[0024] Particularly preferably, the injection direction of the combustion chamber fuel injector (i.e., the fuel is substantially along its injection direction) is oriented toward the pre-combustion chamber ignition plug, especially toward the plug cap of the pre-combustion chamber ignition plug. This enables particularly good scavenging and mixture supply to the pre-combustion chamber of the pre-combustion chamber ignition plug. Alternatively, it is preferable that the injection direction is substantially oriented toward the ignition plug.

[0025] Preferably, the internal combustion engine also includes an intake manifold fuel injector configured to inject fuel into the engine's intake manifold. Specifically, the intake manifold extends into the combustion chamber via an inlet opening. Advantageously, instead of a combustion chamber fuel injector disposed on the combustion chamber for direct injection, an intake manifold fuel injector is provided. This results in a greater amount of space on the top of the combustion chamber, and particularly in the cylinder head, available for the ignition plugs and pre-combustion chamber ignition plugs, allowing for their optimal arrangement and orientation.

[0026] Furthermore, the present invention relates to a method for operating an internal combustion engine having at least one cylinder and, for each cylinder, two scavenging ports, an ignition plug, and a pre-combustion chamber ignition plug. Here, the ignition plug and / or the pre-combustion chamber ignition plug are operated to ignite the fuel-air mixture in the combustion chamber of the cylinder. That is, during operation of the internal combustion engine, it is possible to achieve simultaneous operation of both the pre-combustion chamber ignition plug and the ignition plug, or alternatively, to operate either the ignition plug or the pre-combustion chamber ignition plug individually to ignite the fuel-air mixture in the combustion chamber of the cylinder. This enables particularly flexible and efficient operation of the internal combustion engine.

[0027] Preferably, the pre-combustion chamber ignition plug is operated alone during high-load operation of the internal combustion engine, especially while the ignition plug is deactivated. Preferably, high load is considered to be operation at a torque of at least 20%, preferably at least 50%, and particularly preferably at least 80% of the rated torque of the internal combustion engine. Preferably, this torque threshold may depend on the engine speed or other characteristic factors, such as the λ value, valve control time, engine temperature, etc. By operating the pre-combustion chamber ignition plug alone under high load, particularly efficient operation and effective reduction of the engine's knock tendency can be achieved.

[0028] Further preferably, during operation of the internal combustion engine under low load, especially while the pre-combustion chamber ignition plug is disabled, the ignition plug is operated alone. Preferably, low load is considered to be operation with a torque less than 80% of the rated torque of the internal combustion engine, more preferably less than 50% of the rated torque, and particularly preferably less than 20% of the rated torque. Thus, reliable ignition can be achieved by means of the ignition plug even under low load.

[0029] Particularly preferably, the ignition plugs are operated during the catalytic converter heating phase, especially after a cold start of the internal combustion engine. Preferably, the ignition plugs are operated independently during the catalytic converter heating phase, particularly while the pre-combustion chamber ignition plugs are deactivated. This ensures reliable and optimal ignition of the fuel-air mixture via the ignition plugs after a cold start (e.g., when optimal conditions for operating the pre-combustion chamber ignition plugs do not yet exist).

[0030] Preferably, the ignition plug operates alone at low engine temperatures, for example, at a maximum engine temperature of 323 K, particularly 303 K, and especially preferably 293 K. The engine temperature can be determined, for example, by taking the temperature of the engine coolant, for a particularly simple determination. Alternatively, at such low temperatures, combined operation of the ignition plug and the pre-combustion chamber ignition plug can also be achieved simultaneously.

[0031] Preferably, and particularly within a single working cycle of the internal combustion engine, the ignition plugs and pre-combustion chamber ignition plugs operate at different, and especially independent, ignition timings. For example, preferably under high loads, the ignition plugs can operate only during the exhaust stroke, wherein preferably only the pre-combustion chamber ignition plug is used to ignite the fuel-air mixture. Thus, depending on the operating conditions of the internal combustion engine, optimal, complete, and efficient combustion can be achieved separately.

[0032] Particularly preferably, the internal combustion engine operates within at least a portion of its operating range having a λ value of at least 1. Particularly preferably, the pre-combustion chamber igniter operates within this portion of its operating range. Preferably, the igniter can be deactivated within this portion of its operating range. However, alternatively, combined operation of the igniter and the pre-combustion chamber igniter is also possible. In another alternative configuration, the igniter can operate alone within this portion of its operating range, i.e., while the pre-combustion chamber igniter is deactivated. Particularly preferably, the λ value is at least 1.05 within at least one portion of the internal combustion engine's operating range. That is, in this case, the internal combustion engine operates with a lean fuel-air mixture within this portion of its operating range. Preferably, during lean operation, the pre-combustion chamber igniter and / or the igniter operate. This enables particularly fuel-efficient operation, wherein, especially through the pre-combustion chamber igniter, reliable ignition of the fuel-air mixture is achieved with low knock tendency. Attached Figure Description

[0033] Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. The drawings show: Figure 1 A cross-sectional view of an internal combustion engine according to a first embodiment of the present invention. Figure 2 Figure 1 Simplified schematic detailed views of different preferred configurations of an internal combustion engine. Figure 3 Figure 1 A simplified schematic detailed view of another preferred configuration of the internal combustion engine. Figure 4 A cross-sectional view of an internal combustion engine according to a second embodiment of the present invention, and Figure 5 Figure 4 Simplified schematic detailed views of different preferred configurations of an internal combustion engine. Detailed Implementation

[0034] Figure 1 A simplified cross-sectional view of an internal combustion engine 1 according to a first embodiment of the present invention is shown. The internal combustion engine 1 includes a plurality of cylinders 10, wherein, in Figure 1 Only one of the cylinders 10 is shown. Cylinder 10 has a combustion chamber 5, which is bounded at its upper end by a combustion chamber top 50. The combustion chamber top 50 is formed by the cylinder head 15 of the internal combustion engine 1. The combustion chamber top 50 is preferably conical or configured to taper upwards, wherein the tip is formed, in particular, at the center point 54 of the combustion chamber top 50 (see [reference]). Figure 2 The center point 54 is located at the center of the cylinder 10, particularly on the central axis 13 of the preferred circular cylinder 10.

[0035] The internal combustion engine 1 includes two scavenging openings 4 for each cylinder 10. The first scavenging opening 4 forms an inlet opening 41 through which fresh air can enter from the intake manifold 70 (see [link]). Figure 4 The exhaust gas flows into the combustion chamber 5, and the second venting opening 4 is the exhaust opening 42, through which the exhaust gas can flow from the combustion chamber 5 to the exhaust pipe 18 after combustion (see...). Figure 4 )middle.

[0036] Furthermore, the internal combustion engine 1 includes a combustion chamber fuel injector 6 for each cylinder 10, which is configured to inject liquid or gaseous fuel directly into the combustion chamber 5. The combustion chamber fuel injector extends slightly into the combustion chamber 5. Alternatively, the combustion chamber fuel injector 6 may be retracted and arranged inside an injector orifice 60.

[0037] In addition, the internal combustion engine includes an ignition plug 2 and a pre-combustion chamber ignition plug 3 for each cylinder 10.

[0038] The ignition plug 2 is a common type of ignition plug, designed to ignite the fuel-air mixture located in the combustion chamber 5 using an electric spark. For this purpose, the ignition plug 2 can have a central electrode 21 and a lateral, hook-shaped end electrode 22, which specifically forms a ground electrode. An ignition spark can be generated between the two electrodes 21 and 22. The ignition plug 2 can be as follows: Figure 1 The cylinder head 15 is arranged with drilled holes 20 as shown, wherein the drilled holes 20 lead to the combustion chamber 5. Alternatively, the ignition plug 2 can also extend into the combustion chamber 5.

[0039] The pre-combustion chamber igniter 3 has a cap 32 disposed on the axial end of the housing 32b of the pre-combustion chamber igniter 3. Here, the cap 32 forms a pre-combustion chamber 32a within the pre-combustion chamber igniter 3, wherein the pre-combustion chamber 32a is connected to the combustion chamber 5 via a through opening (not shown) that passes through the cap 32. With the aid of the electrode 31, the fuel-air mixture can be ignited within the pre-combustion chamber 32a, resulting in multiple, preferably four (especially in flame form) jets of flame (see...). Figure 2 , Figure 3 or Figure 5 (Schematably shown as a rod-shaped jet emitted from the pre-combustion chamber ignition plug 3) propagates through the through opening into the combustion chamber 5 to ignite the fuel-air mixture there. The pre-combustion chamber ignition plug 3 is screwed into a drilled hole 33 in the cylinder head 15. Here, the pre-combustion chamber ignition plug 3 is screwed in such that the plug cap 32 extends into the combustion chamber 5.

[0040] The pre-combustion chamber igniter 3 is optimized for operation of the internal combustion engine 1 under high loads, while the internal combustion engine 1 operates with a stoichiometric or lean fuel-air mixture. Through the specific ignition method of the pre-combustion chamber igniter 3, the fuel-air mixture can be reliably ignited and the internal combustion engine 1 can be ignited with low knock tendency. This enables particularly fuel-efficient operation of the internal combustion engine 1 without the risk of damage due to knocking.

[0041] Ignition plug 2 is designed to reliably ignite the fuel-air mixture in combustion chamber 5, especially after a cold start, during catalytic converter heating operation, and under low load.

[0042] exist Figure 2 and Figure 3 The diagram illustrates, in a simplified and schematic manner, several preferred variations of the arrangement of the combustion chamber fuel injector 6, ignition plug 2, and pre-combustion chamber ignition plug 3 on the combustion chamber top 50, which will be described below. Here, a top view of the combustion chamber top 50 along the piston direction, along which the (not shown) piston of the internal combustion engine 1 can move, is shown. The piston direction is parallel to the central axis 12 of the cylinder 10.

[0043] As in Figure 2 and Figure 3 As can be seen, the inlet opening 41 has a larger cross-section than the outlet opening 42. Alternatively, the inlet opening 41 and the outlet opening 42 may have the same cross-section, or further alternatively, the outlet opening 42 may have a larger cross-section than the inlet opening 41. The inlet opening 41 and the outlet opening 42 are each configured to be circular and are internally connected to the top 50 of the combustion chamber, thereby providing the maximum total cross-section for scavenging. Alternatively, the scavenging opening 42 may be smaller.

[0044] To simplify the description of the orientation of the components on the combustion chamber top 50, two perpendicular cutting planes 51 and 52 parallel to the piston direction are drawn. The first cutting plane 51 is arranged to divide the combustion chamber top 50 into two top regions 55 and 56, with the first cutting plane 51 located at the corresponding center point 45 of the scavenging openings 4. In particular, the first cutting plane 51 can also be considered as a plane of symmetry of the combustion chamber top 50. The second cutting plane 52 is arranged such that one of the two scavenging openings 4 is located on one side of the second cutting plane 52. Specifically, the second cutting plane 52 is arranged tangentially to and between the two scavenging openings 4.

[0045] Figure 2A variant arrangement of the component in the combustion chamber top 50 is shown, wherein the combustion chamber fuel injector 6 is centrally located. Here, the central location is considered to be within a central point region 53, which is circularly constructed around the center point 54 of the combustion chamber top 50 with a radius 53a equal to 50% of the cylinder radius 12. The central location of the combustion chamber fuel injector 6 enables a particularly uniform distribution of the injected fuel spray within the combustion chamber 5.

[0046] exist Figure 2 In all the variants shown, the combustion chamber fuel injector 6 is located in the first top region 55.

[0047] Figure 2 (a) shows the arrangement of the ignition plug 2 in the first top region 55 and the pre-combustion chamber ignition plug 3 in the second top region 56. This minimizes the distance 26 between the ignition plug 2 and the combustion chamber fuel injector 6. Here, the distance 66 between the combustion chamber fuel injector 6 and the center point 54 of the combustion chamber top 50 is greater than the distance 25 between the ignition plug 2 and the center point 54. This allows for ignition of the fuel-air mixture as centrally as possible with the ignition plug 2, resulting in particularly uniform ignition in the combustion chamber 5. Here, the pre-combustion chamber ignition plug 3 is arranged at a distance 35 from the center point 54, which is greater than the distance 25 between the ignition plug 2 and the center point 54. Furthermore, the pre-combustion chamber ignition plug 3 is arranged close to the side wall 11 of the cylinder 10, wherein the minimum distance 37 between the pre-combustion chamber ignition plug 3 and the side wall 11 is less than the distance 35 from the center point 54. The pre-combustion chamber ignition plug 3 is constructed and arranged such that the jet of flame 30 generated during its operation is substantially oriented toward the first top region 55. Figure 2 The arrangement of (a) provides a particularly efficient operating mode for the internal combustion engine 1 when the ignition plug 2 is running, due to the proximity of the combustion chamber fuel injector 6 and the ignition plug 2, because the resulting spray can be ignited by the ignition plug 2 in a particularly targeted and reliable manner.

[0048] Figure 2 (b) shows an arrangement in which, in addition to the pre-combustion chamber ignition plug 3, the ignition plug 2 is also arranged in the second top region 56. Here, the distance 34 between the ignition plug 2 and the inlet opening 41 is greater than the distance 24 between the pre-combustion chamber ignition plug 3 and the inlet opening 41. In this configuration, there is particularly much space in the first top region 55 available for the optimal arrangement of the combustion chamber fuel injector 6.

[0049] Figure 2 (c) shows something similar to Figure 2(a) The arrangement in which the ignition plug 2 and the pre-combustion chamber ignition plug 3 are arranged interchangeably, that is, the pre-combustion chamber ignition plug 3 is arranged at a minimum distance 36 from the combustion chamber fuel injector 6. This results in the advantage that better scavenging and mixture supply to the pre-combustion chamber ignition plug 3 can be achieved by being close to the combustion chamber fuel injector 6. In this case, it is particularly advantageous that the injection direction of the combustion chamber fuel injector is directly oriented towards the pre-combustion chamber ignition plug 3. Furthermore, the pre-combustion chamber ignition plug 3 is arranged as centrally as possible with a minimum distance 35 from the center point 54 of the combustion chamber top 50, thereby enabling the flame jet 30 to pass through the combustion chamber 5 as uniformly as possible and thus achieving particularly uniform ignition.

[0050] Figure 3 A variant is shown in which the combustion chamber fuel injector 6 is located in the second top region 56. Here, the combustion chamber fuel injector 6 is arranged laterally at a small spacing 61 from the sidewall 11. This lateral arrangement of the combustion chamber fuel injector 6 provides more space in the central region of the combustion chamber top 50 near the center point 54 for the ignition plug 2 and the pre-combustion chamber ignition plug 3, allowing both to be positioned as centrally as possible for improved uniform ignition.

[0051] exist Figure 3 In (a), a variant is shown in which the pre-combustion chamber igniter 3 is arranged at a particularly small distance 36 from the combustion chamber fuel injector 6. The igniter 2 is arranged in the opposite first top region 55 and at a distance 27 from the combustion chamber fuel injector 6 that is significantly larger than the distance 36.

[0052] Figure 3 (b) shows a variant in which the ignition plug 2 is also arranged in the second top region. Thus, the ignition plug 2 and the pre-combustion chamber ignition plug 3 can also be arranged particularly close to the injector, thereby achieving reliable and robust ignition during the operation of both the ignition plug 2 and the pre-combustion chamber ignition plug 3. Here, the ignition plug 2 is arranged at a distance 26 from the combustion chamber fuel injector 6, which is smaller than the distance 36 between the pre-combustion chamber ignition plug 3 and the combustion chamber fuel injector. Alternatively, the ignition plug 2 and the pre-combustion chamber ignition plug 3 can preferably also be arranged interchangeably.

[0053] Figure 3 (c) shows something similar to Figure 3 A variation of (a) in which the ignition plug 2 and the pre-combustion chamber ignition plug 3 are arranged interchangeably. That is, the ignition plug 2 is closer to the injector, while the pre-combustion chamber ignition plug 3 is farther from the injector. The distance 35 between the pre-combustion chamber ignition plug 3 and the center point 54 of the combustion chamber top 50 is here less than the distance 25 between the ignition plug 2 and the center point 54.

[0054] Figure 3(d) shows a variant in which the ignition plug 2 and the pre-combustion chamber ignition plug 3 are arranged in the first top region 55 and thus away from the injector. The pre-combustion chamber ignition plug 3 is arranged here at a distance of 35 from the center point 54 of the top of the combustion chamber 50, which is less than the distance between the ignition plug 2 and the center point 54.

[0055] exist Figure 4 A cross-sectional view of an internal combustion engine 1 according to a second embodiment of the present invention is shown. The second embodiment substantially corresponds to... Figures 1 to 3 In the first embodiment, the difference lies in that, instead of the combustion chamber fuel injector 6 arranged in the top 50 of the combustion chamber for direct injection, an intake manifold fuel injector 7 is provided. The intake manifold fuel injector 7 is arranged in the cylinder head 15 and at the intake manifold 70 and is configured to inject liquid or gaseous fuel into the intake manifold 70. Here, the intake manifold 7 leads into the combustion chamber 5 at the inlet opening 41 and thus guides the fuel-air mixture into the combustion chamber 5.

[0056] Figure 5 The ignition plug 2 and the pre-combustion chamber ignition plug 3 are shown in Figure 4 The second embodiment is a variation of the arrangement on the combustion chamber top 50 of the internal combustion engine 1. Since no fuel injector is arranged on the combustion chamber top 50 in the second embodiment, more space is advantageously available for the ignition plug 2 and the pre-combustion chamber ignition plug 3, allowing both to be centered for optimal uniform ignition (e.g., especially in…). Figure 5 (as in the variations of (a) and (b)) and arranged in a particularly flexible manner.

[0057] Figure 5 (a) A variant is shown here in which the ignition plug 2 is arranged in the first top region 55, while the pre-combustion chamber ignition plug 3 is arranged in the second top region 56. Here, the distance 25 between the ignition plug 2 and the center point 54 of the combustion chamber top 50 is smaller than the distance 35 between the pre-combustion chamber ignition plug 3 and the center point of the combustion chamber top. The ignition plug 2 and the pre-combustion chamber ignition plug 3 can be arranged particularly close to the inlet opening 41, thereby enabling optimal ignition of the fuel-air mixture flowing into the combustion chamber 5 therein.

[0058] Figure 5 The variant of (b) shows an inverted arrangement of the ignition plug 2 and the pre-combustion chamber ignition plug 3, that is, the pre-combustion chamber ignition plug 3 is arranged closer to the center point 54 of the top 50 of the combustion chamber.

[0059] Figure 5 (c) shows a variant in which the ignition plug 2 and the pre-combustion chamber ignition plug 3 are arranged in the second top region 56. Here, the distance 35 between the pre-combustion chamber ignition plug 3 and the center point 54 is smaller than the distance 25 between the ignition plug 2 and the center point 54.

[0060] Figure 5 (d) shows a variant in which the ignition plug 2 and the pre-combustion chamber ignition plug 3 are located in the first top region, wherein the distances 25 and 35 from the center point 54 are respectively as shown in... Figure 5 Constructed proportionally as in (c).

[0061] It should be noted that all the spacings cited should be considered as minimum spacings. That is, for example, the "spacing between the ignition plug and the center point of the combustion chamber top" is considered as the minimum distance from the outer periphery of the ignition plug (especially in the plane of the combustion chamber top) to the center point of the combustion chamber top.

Claims

1. An internal combustion engine, comprising: - At least one cylinder (10); - For each cylinder (10), there are two scavenging openings (4), wherein the first scavenging opening (4) is an inlet opening (41), and the second scavenging opening (4) is an outlet opening (42); and - Each cylinder (10) has one ignition plug (2) and one pre-combustion chamber ignition plug (3). - Wherein, the air exchange opening (4) is arranged in the top (50) of the combustion chamber (5) of the cylinder (10), - The top of the combustion chamber (50) is divided into two top regions (55, 56) by a first cutting plane (51), such that the cutting plane (51) is located at the center point (45) of the two air exchange openings (4). The combustion chamber top (50) is divided by a second cutting plane (52) perpendicular to the first cutting plane (51), such that the inlet opening (41) and the outlet opening (42) are located on different sides of the second cutting plane (52). The ignition plug (2) and the pre-combustion chamber ignition plug (3) are arranged on the second cutting plane (52).

2. The internal combustion engine according to claim 1, wherein, The ignition plug (2) and / or the pre-combustion chamber ignition plug (3) are arranged on the top (50) of the combustion chamber (5) of the cylinder (10).

3. The internal combustion engine according to claim 1 or 2, - in, The ignition plug (2) and the pre-combustion chamber ignition plug (3) are arranged in the same top area (55, 56), or - Wherein, the ignition plug (2) and the pre-combustion chamber ignition plug (3) are arranged in different top regions (55, 56).

4. The internal combustion engine according to claim 1 or 2, wherein, The pre-combustion chamber ignition plug (3) is positioned closer to the inlet opening (41) or closer to the outlet opening (42) than the ignition plug (2).

5. The internal combustion engine according to claim 1 or 2, wherein, The pre-combustion chamber ignition plug (3) is positioned closer to the side wall (11) of the cylinder (10) than the ignition plug (2), or The ignition plug (2) is positioned closer to the side wall (11) of the cylinder (10) than the pre-combustion chamber ignition plug (3).

6. The internal combustion engine according to claim 2, wherein, The pre-combustion chamber ignition plug (3) is positioned closer to the center point (54) of the top (50) of the combustion chamber than the ignition plug (2), or The ignition plug (2) is positioned closer to the center point (54) of the top (50) of the combustion chamber than the pre-combustion chamber ignition plug (3).

7. The internal combustion engine according to claim 2, wherein, The ignition plug (2) and / or the pre-combustion chamber ignition plug (3) are arranged in the center point region (53) of the top of the combustion chamber (50), the center point region having a predetermined radius (53a) around the center point (54) of the top of the combustion chamber (50).

8. The internal combustion engine according to claim 1 or 2, the internal combustion engine further comprising a combustion chamber fuel injector (6) configured to inject fuel directly into the combustion chamber (5).

9. The internal combustion engine according to claim 8, wherein, The combustion chamber fuel injector (6) is arranged on the top (50) of the combustion chamber.

10. The internal combustion engine according to claim 9, - Wherein, the air exchange opening (4) is arranged in the top (50) of the combustion chamber, - in, The top of the combustion chamber (50) is divided into two top regions (55, 56) by a first cutting plane (51), such that the cutting plane (51) is located at the center point (45) of the two ventilation openings (4), and - Wherein, the combustion chamber fuel injector (6) and the ignition plug (2) and / or the combustion chamber fuel injector (6) and the pre-combustion chamber ignition plug (3) are arranged in the same top area (55, 56).

11. The internal combustion engine according to claim 10, in, The top of the combustion chamber (50) is divided by a second cutting plane (52) perpendicular to the first cutting plane (51), such that the inlet opening (41) and the outlet opening (42) are located on different sides of the second cutting plane (52), and The combustion chamber fuel injector (6) is arranged on the second cutting plane (52).

12. The internal combustion engine according to any one of claims 9 to 11, wherein, The combustion chamber fuel injector (6) is arranged in a center point region (53) having a predefined maximum radius around the center point (54) of the top of the combustion chamber (50).

13. The internal combustion engine according to claim 8, wherein, The pre-combustion chamber ignition plug (3) is positioned closer to the combustion chamber fuel injector (6) than the ignition plug (2), or, The ignition plug (2) is positioned closer to the combustion chamber fuel injector (6) than the pre-combustion chamber ignition plug (3).

14. The internal combustion engine according to claim 8, wherein, The injection direction (65) of the combustion chamber fuel injector (6) is oriented toward the ignition plug (2) or the pre-combustion chamber ignition plug (3).

15. The internal combustion engine according to claim 1 or 2, the internal combustion engine further comprising an intake manifold fuel injector (7) configured to inject fuel into the intake manifold (70) of the internal combustion engine (1).

16. The internal combustion engine according to claim 7, wherein, The predefined radius is 60% of the maximum cylinder radius (12) of the cylinder (10).

17. The internal combustion engine according to claim 12, wherein, The maximum radius is 50% of the cylinder radius (12) of the cylinder (10).

18. A method for operating an internal combustion engine (1) having at least one cylinder (10), wherein, The internal combustion engine (1) is an internal combustion engine according to any one of claims 1 to 17, wherein the ignition plug (2) and / or the pre-combustion chamber ignition plug (3) are operated to ignite the fuel-air mixture in the combustion chamber (5) of the cylinder (10).

19. The method according to claim 18, wherein, During the operation of the internal combustion engine (1) under high load, the pre-combustion chamber ignition plug (3) is operated alone.

20. The method according to claim 18 or 19, wherein, During operation of the internal combustion engine (1) under low load, the ignition plug (2) is operated alone.

21. The method according to claim 18 or 19, wherein, The ignition plug (2) is operated during the catalytic converter heating phase and / or at low engine temperatures.

22. The method according to claim 18 or 19, wherein, The ignition plug (2) and the pre-combustion chamber ignition plug (3) are operated at different ignition times.

23. The method according to claim 18 or 19, wherein, The internal combustion engine (1) operates at least within a portion of its operating range having a λ value of at least 1.

24. The method of claim 20, wherein, The pre-combustion chamber ignition plug (3) operates alone when the torque is at least 20% of the rated torque of the internal combustion engine (1), and the ignition plug (2) operates alone when the torque is less than 20% of the rated torque of the internal combustion engine (1).

25. The method according to claim 20, wherein, When the torque is at least 50% of the rated torque of the internal combustion engine (1), the pre-combustion chamber ignition plug (3) operates alone; when the torque is less than 50% of the rated torque of the internal combustion engine (1), the ignition plug (2) operates alone.

26. The method of claim 20, wherein, The pre-combustion chamber ignition plug (3) operates alone when the torque is at least 80% of the rated torque of the internal combustion engine (1), and the ignition plug (2) operates alone when the torque is less than 80% of the rated torque of the internal combustion engine (1).

27. The method according to claim 21, wherein, After the internal combustion engine (1) is cold-started, the ignition plug (2) is activated.

28. The method according to claim 22, wherein, The ignition plug (2) and the pre-combustion chamber ignition plug (3) are operated at independent ignition times.

29. The method according to claim 23, wherein, During operation of the ignition plug (2) and / or the pre-combustion chamber ignition plug (3), the internal combustion engine (1) operates at least within a portion of the operating range having a λ value of at least 1.

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