internal combustion engine for a motor vehicle as well as motor vehicle

Abstract

The invention relates to an internal combustion engine (10) for a motor vehicle, with at least one combustion chamber (12) in which a mixture comprising at least the fuel and air introduced into the combustion chamber (12) can be received by introducing air and fuel into the combustion chamber (12), with a first spark plug (44) associated with the combustion chamber (12) and designed as a pre-chamber spark plug, which has a pre-chamber (46) which is fluidically separated from the combustion chamber (12) except for at least one through-opening and is fluidically connected to the combustion chamber (12) via the at least one through-opening, from which at least a part of the mixture can be introduced into the pre-chamber (46) via the at least one through-opening, in which at least one ignition spark can be generated by means of the first spark plug (44) to ignite the part of the mixture introduced into the pre-chamber (46) via the at least one through-opening.and with a second spark plug (48) assigned to the combustion chamber (12).

Description

The invention relates to an internal combustion engine for a motor vehicle according to the preamble of claim 1 or 5. The invention also relates to a motor vehicle with such an internal combustion engine. US patent 8,006,666 B2 discloses an internal combustion engine with a combustion chamber to which a standard spark plug and a pre-chamber spark plug are assigned. Furthermore, German patent DE 10 2008 014 047 A1 discloses an ignition coil assembly for a single-cylinder internal combustion engine. DE 10 2021 103 022 A1 discloses systems and methods for ignition coil multiplexing in a pre-chamber system. Methods and systems for multiplexing ignition signals in an engine system based on engine operating conditions are provided, wherein each cylinder of the engine system includes a main chamber spark plug and a pre-chamber system. The object of the present invention is to create an internal combustion engine for a motor vehicle and a motor vehicle with such an internal combustion engine, so that a particularly advantageous operation of the internal combustion engine can be realized in a particularly advantageous way. This problem is solved by an internal combustion engine with the features of claim 1, by an internal combustion engine with the features of claim 5, and by a motor vehicle with the features of claim 10. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims. A first aspect of the invention relates to an internal combustion engine for a motor vehicle, also simply referred to as a vehicle. This means that the motor vehicle, preferably designed as a motor vehicle, in particular as a passenger car, in its fully manufactured state, has the internal combustion engine and can be driven by means of the internal combustion engine. The internal combustion engine, also referred to as an internal combustion engine or combustion engine, has at least one combustion chamber, which is, for example, partially formed, i.e., delimited, by a cylinder. In particular, the cylinder is a cylinder of a first housing part of the internal combustion engine, the first housing part of which can, for example, be a cylinder housing, in particular a cylinder crankcase. Furthermore, it is conceivable that the combustion chamber is partially formed, i.e., delimited, by a combustion chamber roof.The combustion chamber roof is formed, for example, by a second housing part of the internal combustion engine, which might be a cylinder head. The first and second housing parts are, for example, separate and connected. Furthermore, it is conceivable that the combustion chamber is partially delimited by a piston that is arranged to move translationally within the cylinder. The internal combustion engine can be operated in a fired mode. For example, in the method for operating the internal combustion engine, the internal combustion engine is operated in a fired mode. In the fired mode of the internal combustion engine, combustion processes take place in the combustion chamber, in particular such that within each operating cycle of the internal combustion engine, specifically, one of the combustion processes takes place. In each combustion process, a fuel-air mixture, also simply referred to as a mixture, is ignited and burned, resulting in exhaust gas from the internal combustion engine. The mixture comprises at least air and a fuel, in particular a liquid fuel. Preferably, the fuel is a gasoline, also known as Otto cycle fuel, so that the internal combustion engine is preferably designed as a Otto engine.The air required to form the respective mixture can be introduced or supplied to the combustion chamber. The fuel required to form the respective mixture can be introduced or supplied to the combustion chamber, in particular in such a way that the fuel can be injected or is injected directly into the combustion chamber. For this purpose, for example, an injector, also referred to as an injection valve or injection element, is assigned to the combustion chamber, by means of which the fuel can be injected or is injected directly into the combustion chamber, thereby introducing or supplying the fuel directly into the combustion chamber. It is evident that the combustion chamber, by introducing air and fuel, can accommodate or incorporates the respective mixture, comprising at least the fuel and air introduced into the combustion chamber, particularly within the respective operating cycle of the internal combustion engine. In particular, it can be provided that the respective mixture can be generated or is generated within the combustion chamber by introducing air and fuel, especially within the respective operating cycle. Thus, preferably, internal mixture formation is provided, in which the mixture is not formed outside the combustion chamber and then introduced into it, but rather the mixture is formed within the combustion chamber during the respective operating cycle, particularly by introducing air and fuel into the combustion chamber. A first spark plug, designed as a pre-chamber spark plug, is assigned to the combustion chamber. The pre-chamber spark plug has a pre-chamber which is fluidically separated from the combustion chamber, also referred to as the main combustion chamber, except for at least one or exactly one through-opening, and in particular for several through-openings. The pre-chamber is fluidically connected to the combustion chamber via the at least one through-opening, and in particular via the several through-openings. This allows at least a portion of the mixture from the combustion chamber to be introduced into the pre-chamber via the at least one through-opening. In the pre-chamber, at least one ignition spark can be generated by the first spark plug, and in particular by the first electrodes of the first spark plug, especially within the respective operating cycle, to ignite the portion of the mixture introduced into the pre-chamber via the at least one through-opening.The ignition of the portion of the mixture introduced into the pre-chamber ignites and combusts the mixture already present in the pre-chamber. This results in a so-called "burning torch," particularly at each pre-chamber through-hole. This torch flows through at least one through-hole, exiting the pre-chamber and entering the main combustion chamber, where it ignites the mixture remaining in the main combustion chamber. Thus, the ignition of the portion of the mixture introduced into the pre-chamber ignites the mixture remaining in the combustion chamber, or the entire mixture. As a result of this ignition, the mixture is combusted, which in turn drives the piston. Furthermore, the combustion chamber is equipped with a second spark plug in addition to the first, by means of which at least one ignition spark can be generated in the combustion chamber and outside the pre-chamber, particularly within the respective operating cycle of the internal combustion engine, to ignite the mixture taken up in the combustion chamber. Thus, the second spark plug is a standard spark plug, and therefore not a pre-chamber spark plug. In other words, it is preferably provided that the internal combustion engine is free of a pre-chamber in which an ignition spark can be generated by means of the second spark plug.The second spark plug is also referred to as an open spark plug, since, for example, at least parts of its electrodes are located in the main combustion chamber and outside the pre-chamber. These electrodes are used to generate the second spark, also known as the second ignition spark. Using pre-chamber spark plugs can compensate for any weaknesses or disadvantages of standard spark plugs. The first and second spark plugs form a so-called dual ignition system, also known as a twin-spark ignition system. The first spark plug is also called the primary spark plug, and the second spark plug is also called the secondary spark plug. To achieve a particularly advantageous operation of the internal combustion engine, the invention provides that the internal combustion engine has a common ignition coil for both the spark plugs. This coil is located in a first circuit, in which the first spark plug is located, and in a second circuit, in which the second spark plug is located. Furthermore, the internal combustion engine has a common voltage source for both the spark plugs and the ignition coil, which is configured to provide a first electrical voltage and thereby apply it to the ignition coil. This means that the ignition coil can be supplied with, or is supplied with, the first electrical voltage. The ignition coil has two output terminals, which are also simply referred to as terminals or first terminals. The ignition coil is connected to the respective circuit via these output terminals.For example, the ignition coil has two input terminals, which are also referred to as the second terminals. The ignition coil is electrically connected to the voltage source via these input terminals, allowing the ignition coil to be supplied with the first electrical voltage. In other words, the first electrical voltage can be applied to the ignition coil via the input terminals, thus supplying it with the first electrical voltage. The ignition coil is designed to convert the first electrical voltage into a second electrical voltage that is higher than the first. In other words, the ignition coil can convert, or transform, the first electrical voltage into the second electrical voltage, with the second voltage being higher than the first.For example, the first electrical voltage is a low voltage. For example, the second electrical voltage is a high voltage. In particular, the ignition coil can provide the second electrical voltage via its output terminals. Because the ignition coil is connected to the respective circuit via its output terminals, the second electrical voltage can be applied to the respective spark plug located in that circuit via the output terminals and the respective circuit. This spark plug then generates the ignition spark to ignite the fuel-air mixture. This means that the ignition coil can couple the second electrical voltage into the respective circuit via its output terminals, thus supplying the respective spark plug located in that circuit with the second electrical voltage. By supplying the respective spark plug with the second electrical voltage, that is, by applying the second electrical voltage to the respective spark plug, the spark plug can generate the ignition spark to ignite the fuel-air mixture. The voltage source is designed to reverse the electrical polarity of the first electrical voltage, that is, to switch or change it. In particular, it is designed so that reversing the electrical polarity of the first electrical voltage results in a reversal, that is, a change or change, of the electrical polarity of the second electrical voltage. Thus, for example, the voltage source and the ignition coil form an ignition system, also known as an ignition device, which is designed to reverse the electrical polarity of the second electrical voltage, that is, to switch or change it, in particular by reversing, that is, switching or changing, the electrical polarity of the first electrical voltage. The voltage source, and thus, for example, the ignition system, has a first state and a second state. This means, in particular, that the voltage source, and thus especially the ignition system, can be operated in either the first or the second state. In the first state, the second electrical voltage between the output terminals of the ignition coil is positive. In the second state, the second electrical voltage between the output terminals is negative. This means that in the first state, the second electrical voltage from one output terminal to the other is positive, and in the second state, the second electrical voltage from one output terminal to the other is negative. Furthermore, according to the invention, a diode is provided in at least one of the circuits between the ignition coil and the spark plug located in that circuit. The diode is also referred to as the first diode. Unless otherwise specified, references to the diode in the preceding and following text shall refer to the first diode. The diode is a semiconductor-based electronic component and has a forward and a reverse bias. In the forward bias, the diode allows the electric current flowing through the circuit, and in the reverse bias, the diode blocks the current, thus preventing the flow of electric current through the diode and consequently through the circuit. In particular, the diode is a semiconductor diode.The diode thus allows electric current to flow through the at least one circuit in one state, and in the other state, it prevents electric current from flowing through the at least one circuit. If the voltage source, also referred to as the power supply, and thus, for example, the ignition system, is operated in one state, a spark is generated by the spark plug connected to the at least one circuit to ignite the mixture, since the spark plug in the at least one circuit is supplied with the second voltage and thus with electric current, which flows through the at least one circuit, as permitted by the diode.However, if the voltage source, and thus in particular the ignition system, is operated in the other state, the diode blocks the flow of electric current through the at least one circuit, so that the spark plug arranged in the at least one circuit is not supplied with electric current and / or the spark plug arranged in the at least one circuit is prevented from generating a spark to ignite the mixture. The first aspect of the invention thus makes it possible, in a particularly simple way, to selectively generate a spark to ignite the mixture by means of the at least one spark plug arranged in the circuit, or to prevent or avoid such generation of a spark by the spark plug arranged in the at least one circuit.Since the ignition coil is a single coil shared by all spark plugs, each spark plug does not need its own dedicated coil. In other words, the single coil is sufficient to supply both spark plugs with the second electrical voltage, thus significantly reducing the number of parts, the required installation space, the weight, and the cost of the internal combustion engine. In particular, it is provided that in one state the diode is connected in forward bias, while in the other state the diode is connected in reverse bias. By using the diode, the spark plug arranged in the at least one circuit can be selectively supplied with the second electrical voltage, which is, for example, a high voltage and required to generate the ignition spark. This selective supply of the second electrical voltage to the spark plug arranged in the at least one circuit enables advantageous operation, since, for example, the mixture can be selectively ignited by the spark plug arranged in the at least one circuit, or ignition of the mixture by the spark plug arranged in the at least one circuit can be avoided. This allows for particularly advantageous operation of the internal combustion engine.Since one ignition coil is sufficient to operate both spark plugs advantageously, the number of parts, the weight, the cost and the installation space required for the internal combustion engine can be kept particularly low, thus enabling a particularly advantageous operation of the internal combustion engine in a particularly advantageous way. In order to achieve a particularly advantageous operation of the internal combustion engine, in one embodiment of the invention it is provided that the at least one circuit is the second circuit in which the diode is arranged, so that the spark plug arranged in the at least one circuit is the second spark plug. To achieve a particularly advantageous operation in a particularly advantageous manner, a further embodiment of the invention provides that the first circuit is diode-free. This allows the following to be realized: In one state, both spark plugs are supplied with the second electrical voltage. In other words, in one state, an electric current flows through both circuits, so that in one state, a spark can be generated, or is generated, by both the first and second spark plugs to ignite the mixture. In the other state, the second electrical voltage is applied only to the first spark plug.In other words, in the other state, with respect to the electrical circuits, an electric current flows exclusively through the first circuit, meaning that, with respect to the spark plugs, a spark to ignite the mixture can be generated, or is generated, exclusively by the first spark plug. This allows for a particularly efficient and advantageous operation of the internal combustion engine in a very simple manner. Another embodiment is characterized in that the diode is arranged as the first diode in the second circuit, with a second diode being arranged in the first circuit between the ignition coil and the first spark plug. In one state, the second diode prevents the flow of electric current through the first circuit, and in the other state, the second diode allows the flow of electric current through the first circuit. In particular, the preceding and following descriptions of the first diode can readily be applied to the second diode and vice versa. Thus, if the voltage source, and therefore in particular the ignition system, is operated in one state, the second electrical voltage is applied to the second spark plug, and the second electrical voltage is not applied to the first spark plug.In other words, an electric current flows through the second circuit, while the flow of electric current through the first circuit is prevented. This means that, with respect to the spark plugs, a spark to ignite the mixture can be generated, or is generated, exclusively by the second spark plug. If, however, the voltage source, and thus in particular the ignition system, is operated in the opposite state, the second electrical voltage is applied to the first spark plug, and no second electrical voltage is applied to the second spark plug. In other words, an electric current flows through the first circuit, while the flow of electric current through the second circuit is prevented, so that, with respect to the spark plugs, a spark to ignite the mixture can be generated, or is generated, exclusively by the first spark plug.By using the two diodes, a spark for igniting the mixture can be generated in a particularly simple way, and only by reversing the polarity of the first electrical voltage, either with respect to the spark plugs exclusively by means of the second spark plug or with respect to the spark plugs exclusively by means of the first spark plug, thereby enabling a particularly advantageous operation of the internal combustion engine. A second aspect of the invention relates to an internal combustion engine for a motor vehicle. The internal combustion engine according to the second aspect of the invention has at least one combustion chamber in which, by introducing air and fuel into the combustion chamber, a mixture comprising at least the fuel introduced into the combustion chamber and the air introduced into the combustion chamber can be received.In the second aspect of the invention, a first spark plug, designated as a pre-chamber spark plug, is associated with the combustion chamber. This first spark plug has a pre-chamber that is fluidically separated from the combustion chamber except for at least one through-opening and is fluidically connected to the combustion chamber via this at least one through-opening. At least a portion of the mixture can be introduced into the pre-chamber from the combustion chamber via this at least one through-opening. In the second aspect of the invention, a second spark plug is provided in addition to the first spark plug. This second spark plug can be used to generate at least one spark in the combustion chamber and outside the pre-chamber to ignite the mixture contained in the combustion chamber.The preceding and following statements regarding the first aspect of the invention can readily be applied to the second aspect of the invention, and vice versa. Advantages and advantageous embodiments of the first aspect of the invention are to be regarded as advantages and advantageous embodiments of the second aspect of the invention, and vice versa. In order to achieve a particularly advantageous operation in a particularly advantageous manner, the second aspect of the invention provides that the internal combustion engine has an ignition coil common to the spark plugs, which is arranged in a first circuit in which the first spark plug is located and in a second circuit in which the second spark plug is located. The second aspect of the invention also provides a voltage source, also referred to as a voltage supply, common to the spark plugs and the ignition coil, which is configured to provide a first electrical voltage and thereby apply it to the ignition coil.The ignition coil is designed to convert the first electrical voltage into a second, higher voltage, which is then applied via the circuit to the respective spark plug located in that circuit. This spark plug then generates the ignition spark to ignite the fuel-air mixture. In other words, by applying the second electrical voltage via the circuit to the respective spark plug, the spark plug can generate the ignition spark to ignite the fuel-air mixture. In the second aspect of the invention, it is provided that a semiconductor switching element is arranged in at least one of the circuits between the ignition coil and the spark plug arranged in the at least one circuit. This semiconductor switching element can be switched between at least or exactly two states, namely a first state and a second state, particularly by controlling and especially by electrically controlling the semiconductor switching element. The first state is also referred to as the first connection state, in which the ignition coil is electrically connected to the spark plug arranged in the at least one circuit via the semiconductor switching element.Thus, in the connected state, the second electrical voltage can be applied to the spark plug arranged in the at least one circuit, causing the spark plug in the at least one circuit to generate, and thus provide, the spark for igniting the mixture. In other words, in the connected state, the semiconductor switching element allows an electric current to flow through the at least one circuit, causing the spark plug in the at least one circuit to generate the spark for igniting the mixture. When the connected state is mentioned before and after, unless otherwise specified, this refers to the first connected state. The semiconductor switching element is also called the first semiconductor switching element.When the semiconductor switching element is mentioned before and below, this refers, unless otherwise specified, to the first semiconductor switching element. The second state, also referred to as the first blocking state, is in which the ignition coil is electrically disconnected from the spark plug in the at least one circuit by means of the semiconductor switching element. Thus, in this blocking state, the semiconductor switching element prevents the second electrical voltage from being applied to the spark plug in the at least one circuit, thereby preventing the spark plug from generating a spark to ignite the mixture. In other words, in this blocking state, the semiconductor switching element prevents the flow of electric current through the at least one circuit, thus preventing the spark plug from generating a spark to ignite the mixture.The second aspect of the invention also enables an advantageous, selective supply of the second electrical voltage to the spark plug arranged in the at least one circuit, so that both spark plugs can be supplied with the second electrical voltage by means of the single ignition coil common to the spark plugs, and so that either a spark is generated by the spark plug arranged in the at least one circuit, or the generation of a spark by the spark plug arranged in the at least one circuit is prevented and thus does not occur. This allows the number of parts, the costs, the installation space required, and the weight of the internal combustion engine to be kept particularly low, thereby enabling a particularly advantageous operation of the internal combustion engine. In order to switch the semiconductor switching element between the connected state and the blocked state as required, and thus to achieve a particularly advantageous operation of the internal combustion engine, an electronic computing device, also referred to as a control unit, is provided in one embodiment of the invention, which is designed to provide an electrical control signal by means of which the semiconductor switching element can be electrically controlled and thereby switched at least from one of the states to the other state. In order to keep the installation space requirement, costs and weight of the internal combustion engine particularly low, so that a particularly advantageous operation can be realized in a particularly advantageous way, it is provided in a further embodiment of the invention that the semiconductor switching element is designed as a triac. Another embodiment is characterized in that, in the second aspect of the invention, the at least one circuit is the second circuit in which the semiconductor switching element is arranged, such that the spark plug arranged in the at least one circuit is the second spark plug. This allows for a particularly advantageous operation. Finally, it has proven particularly advantageous if, in a first variant, the first circuit is free of a semiconductor switching element. This allows costs to be kept especially low. In a second variant, the semiconductor switching element is arranged as the first semiconductor switching element in the second circuit, wherein a second semiconductor switching element is arranged in the first circuit between the ignition coil and the first spark plug. This second semiconductor switching element is switchable between at least or exactly two further states, namely a third state and a fourth state. The third state is a second connection state in which the ignition coil is electrically connected to the first spark plug via the second semiconductor switching element. The fourth state is a second blocking state in which the ignition coil is electrically disconnected from the first spark plug by means of the second semiconductor switching element.This allows a spark to ignite the mixture either exclusively using the first spark plug or exclusively using the second spark plug, thus enabling a particularly demand-oriented and therefore advantageous operation of the internal combustion engine. The preceding and following explanations regarding the first semiconductor switching element can readily be applied to the second semiconductor switching element and vice versa. A third aspect of the invention relates to a motor vehicle which has an internal combustion engine according to the first aspect or according to the second aspect of the invention and which can be driven by means of the internal combustion engine. Advantages and advantageous embodiments of the first aspect and the second aspect of the invention are to be regarded as advantages and advantageous embodiments of the third aspect of the invention and vice versa. Further advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. The features and combinations of features mentioned above in the description, as well as those mentioned below in the figure description and / or shown in the figures alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention. The drawing shows in: Fig. 1 a schematic sectional view of a first embodiment of an internal combustion engine for a motor vehicle; Fig. 2 a partial schematic sectional view of a second embodiment of the internal combustion engine; and Fig. 3 a schematic sectional view of a third embodiment of the internal combustion engine. In the figures, identical or functionally equivalent elements are provided with the same reference symbols. Fig. 1 shows a schematic sectional view of a first embodiment of an internal combustion engine 10 for a motor vehicle. The internal combustion engine 10 is designed as a reciprocating piston engine, i.e., a piston-type engine. The internal combustion engine 10 has at least one combustion chamber 12, which is partially formed, i.e., delimited, by a cylinder 14, a piston 16, and a combustion chamber roof 18. The cylinder 14 is formed by a crankcase 20, also known as a cylinder crankcase or crankcase. The piston 16 is mounted in the cylinder 14 so as to be translationally movable and is articulated via a connecting rod 22 to an output shaft 24 of the internal combustion engine 10, which is designed as a crankshaft. A counterweight provided on the crankshaft is designated 26.An oil channel, particularly one regulated by pressure, through which oil flows for lubricating and / or cooling the internal combustion engine 10, and which is referred to as a secondary oil channel, is designated by 28. An oil syringe is designated by 30, wherein the aforementioned oil can be sprayed against the piston 16 by means of the oil syringe. A main oil channel is designated by 32 and through which the oil flows, particularly at high pressure. The crankcase 20 has at least one stiffening rib 34 to counteract transverse vibrations. The combustion chamber roof 18 is formed by a cylinder head 36 of the internal combustion engine 10. The cylinder head 36 and the crankcase 20 are designed separately from each other and connected to each other. The internal combustion engine 10 also has an exhaust gas turbocharger 38, which has a compressor 40 and a turbine 42, by which the compressor 40 can be driven. By introducing air and fuel into the combustion chamber 12, a mixture, also referred to as a fuel-air mixture, comprising at least the fuel and air introduced into the combustion chamber 12, can be received in the combustion chamber 12. A first spark plug 44, also referred to as the primary spark plug, is assigned to the combustion chamber 12 and is designed as a pre-chamber spark plug. The pre-chamber spark plug has a pre-chamber 46, which, except for several through-openings, is fluidically separated from the combustion chamber 12 (also referred to as the main combustion chamber) and fluidically connected to the combustion chamber 12 via these through-openings.This allows at least a portion of the mixture initially taken up in the combustion chamber 12 to be introduced into the pre-chamber 46 via the through-openings, where at least a first spark can be generated by the first spark plug 44 to ignite the portion of the mixture introduced into the pre-chamber 46 via the through-openings. A second spark plug 48, in addition to the primary spark plug, is assigned to the combustion chamber 12, by means of which at least a second spark can be generated in the combustion chamber 12 and outside the pre-chamber 46 to ignite the mixture taken up in the combustion chamber 12. In the first embodiment, the internal combustion engine 10 has an ignition coil 50 common to the spark plugs 44 and 48, which is arranged in a first circuit K1 and in a second circuit K2. The primary spark plug is also arranged in the first circuit K1. The second spark plug 48, which is also referred to as the secondary spark plug, is arranged in the second circuit K2. The internal combustion engine 10 also has a voltage source 52, also referred to as the voltage supply, which is common to the spark plugs 44 and 48 and the ignition coil 50. This voltage source is designed to provide a first electrical voltage and thereby apply it to the ignition coil 50. The ignition coil 50 is designed to convert the first electrical voltage into a second electrical voltage that is higher than the first electrical voltage. For example, the first electrical voltage is a low-voltage voltage (LV voltage), while the second electrical voltage is a high-voltage voltage (HV voltage). The ignition coil 50, for example, has two output terminals A1 and A2, shown schematically in Fig. 1, through which the ignition coil 50 is connected to the respective circuits K1 and K2. This allows the second electrical voltage provided or available from the ignition coil 50 to be applied to the respective spark plug 44 or 48 located in the respective circuit via the output terminals A1 and A2, and thus via the respective circuits K1 and K2. Applying this second electrical voltage to the respective spark plug 44 or 48 then generates the spark. Output terminal A1 is connected to a center electrode of the respective spark plug(s), and output terminal A2 is connected to the ground electrode(s) of the respective spark plug(s). The voltage source 52 is designed to reverse the electrical polarity of the first voltage and, consequently, the electrical polarity of the second voltage, since, for example, reversing the electrical polarity of the first voltage leads to a reversal of the electrical polarity of the second voltage. Thus, the voltage source 52 can be operated in a first state and a second state. In the first state, the second voltage between the output terminals A1 and A2 of the ignition coil 50 is positive, and in the second state, the second voltage between the output terminals A1 and A2 is negative.In other words, in the first state the electrical polarity of the second electrical voltage between the output terminals A1 and A2 is positive, and in the second state the electrical polarity of the second electrical voltage between the output terminals A1 and A2 is negative. Fig. 2 shows a partial schematic sectional view of a second embodiment of the internal combustion engine 10. In both the first and second embodiments, a diode 54 is arranged in the second circuit K2 between the ignition coil 50 and the second spark plug 48. In the first state, the diode allows electric current to flow through the second circuit K2, while in the second state, it prevents the flow of electric current through the second circuit K2. In the second embodiment, the first circuit K1 is free of a diode. In the first embodiment, a second diode 56 is arranged in the circuit K1 between the ignition coil 50 and the first spark plug 44. In the first state, this diode prevents electric current from flowing through the first circuit K1, while in the second state, it allows electric current to flow through the first circuit K1.The background to this is that spark-ignition internal combustion engines, particularly to achieve high specific power outputs, are equipped with pre-chamber and standard spark plugs. At low operating loads, especially in naturally aspirated operation of the internal combustion engine 10, a pre-chamber spark plug operates with increased pressure fluctuations, primarily due to impaired ignition of the mixture. Therefore, the combustion chamber 12 is assigned not only the pre-chamber spark plug but also the secondary spark plug. The ignition coil 50 can selectively supply the spark plugs 44 and 48 with the second electrical voltage required to generate the respective ignition spark by reversing the electrical polarity of the first voltage and, consequently, the electrical polarity of the second voltage.This eliminates the need for two ignition coils to operate spark plugs 44 and 48. For example, the internal combustion engine 10 is designed as a highly turbocharged internal combustion engine, such as a V8 engine. The ignition coil 50 is, for example, screwed onto the top of the cylinder head 36. The second electrical voltage can be applied to the respective spark plugs 44 and 48 via ignition cables 58. For example, a cable leading from the ignition coil 50 branches into strands leading to the spark plugs 44 and 48. The diode 54 is located in the strand leading to spark plug 48, and the diode 56 is located in the strand leading to spark plug 44. On the low-voltage side, the ignition coil 50 can be supplied with the first electrical voltage from the voltage source 52. The voltage source 52 is, or comprises, for example, an electronic computing device, also referred to as a control unit, whereby the control unit can reverse the polarity of the first electrical voltage and thereby the polarity of the second electrical voltage.The first electrical voltage is also referred to as the supply voltage. Under high engine loads, the voltage source 52, or the control unit, energizes the ignition coil 50 such that the second electrical voltage between output terminals A1 and A2 is negative, meaning it has a negative polarity. This results in only spark plug 44 generating a spark to ignite the mixture, relative to spark plugs 44 and 48. The mixture in the main combustion chamber is thus ignited by ignition jets, which result from the mixture being ignited and combusted in the pre-chamber 46. These ignition jets then flow through the passages and into the main combustion chamber.At low engine loads, the polarity of the first electrical voltage, and thus of the second electrical voltage, is reversed. This means that the voltage source 52, or the control unit, energizes the ignition coil 50 such that the second electrical voltage between output terminals A1 and A2 is positive, i.e., it has a positive polarity. Consequently, when the spark plugs 44 and 48 are engaged, only spark plug 48 generates a spark to ignite the mixture. This ignites the mixture in the combustion chamber 12 conventionally by means of the spark generated by spark plug 48 in the combustion chamber 12 and outside the pre-chamber 46. In the second embodiment, the voltage source 52, or the control unit, energizes the ignition coil 50 such that the second electrical voltage has a negative polarity, i.e., it is negative between output terminals A1 and A2.This results in spark plug 44 generating the ignition spark in the pre-chamber 46, while spark plug 48 fails to generate a spark in the combustion chamber 12 and outside the pre-chamber 46. At low engine loads, the polarity is reversed. This means that the voltage source 52, or the control unit, then energizes the ignition coil 50 such that the second electrical voltage between output terminals A1 and A2 is positive, i.e., it has a positive polarity. As a result, spark plug 44 generates the first ignition spark in the pre-chamber 46, and spark plug 48 generates the second ignition spark in the combustion chamber 12 and outside the pre-chamber 46. This ensures efficient combustion in the pre-chamber 46, thus preventing excessive emissions of carbon monoxide and unburned hydrocarbons. Fig. 3 shows a schematic sectional view of a third embodiment of the internal combustion engine 10. In this third embodiment, a first semiconductor switching element 60 is arranged in circuit K2 between the ignition coil 50 and the second spark plug 48 instead of the diode 54, and a second semiconductor switching element 62 is arranged in circuit K1 between the ignition coil 50 and the first spark plug 44. The semiconductor switching element 60 can be switched between a first connected state and a blocked state, particularly by electrically controlling the semiconductor switching element 60. In the first connected state, the ignition coil 50 is electrically connected to the spark plug 48 via the first semiconductor switching element 60. In the first blocked state, the ignition coil 50 is electrically disconnected from the spark plug 48 by means of the semiconductor switching element 60.The second semiconductor switching element 62 is switchable between a second connected state and a second blocked state, in particular by electrically controlling the semiconductor switching element 62. In the second connected state, the ignition coil 50 is electrically connected to the spark plug 44 via the second semiconductor switching element 62. In the second blocked state, the ignition coil 50 is electrically disconnected from the first spark plug 44 by means of the second semiconductor switching element 62. The respective semiconductor switching elements 60 and 62 are designed as triacs, in particular as high-voltage triacs. The control unit is connected to the semiconductor switching elements 60 and 62 via control lines 64, so that the control unit can control the semiconductor switching elements 60 and 62 via the control lines 64 and thereby switch between the respective connected state and the respective blocked state.In particular, the semiconductor switching elements 60 and 62 can be controlled independently of each other by the control unit designed as an ignition control unit. The control unit can thus, depending on the operating range of the internal combustion engine 10, control the semiconductor switching elements 60 and 62 in such a way that, for example, either only spark plug 44 generates the first spark to ignite the mixture, or only spark plug 48 generates the second spark to ignite the mixture, or both spark plugs 44 and 48 generate their respective sparks to ignite the mixture. This enables a particularly demand-oriented and therefore advantageous operation of the internal combustion engine 10. Reference symbol list 10 Internal combustion engine 12 Combustion chamber 14 Cylinder 16 Piston 18 Combustion chamber roof 20 Crankcase 22 Connecting rod 24 Output shaft 26 Counterweight 28 Oil channel 30 Oil syringe 32 Main oil channel 34 Stiffening rib 36 Cylinder head 38 Exhaust turbocharger 40 Compressor 42 Turbine 44 First spark plug 46 Prechamber 48 Second spark plug 50 Ignition coil 52 Voltage source 54 First diode 56 Second diode 58 Ignition cable 60 First semiconductor switching element 62 Second semiconductor switching element 64 Control lines A1 Output terminal A2 Output terminal K1 First circuit K2 Second circuit

Claims

Internal combustion engine (10) for a motor vehicle, comprising: - at least one combustion chamber (12) in which a mixture comprising at least the fuel and air introduced into the combustion chamber (12) can be received by introducing air and fuel into the combustion chamber (12); - a first spark plug (44) associated with the combustion chamber (12) and designed as a pre-chamber spark plug, which has a pre-chamber (46) which is fluidically separated from the combustion chamber (12) except for at least one through-opening and is fluidically connected to the combustion chamber (12) via the at least one through-opening, from which at least a part of the mixture can be introduced into the pre-chamber (46) via the at least one through-opening, in which at least one ignition spark can be generated by means of the first spark plug (44) to ignite the part of the mixture introduced into the pre-chamber (46) via the at least one through-opening;and- a second spark plug (48) associated with the combustion chamber (12), by means of which at least one ignition spark can be generated in the combustion chamber (12) and outside the pre-chamber (46) to ignite the mixture taken up in the combustion chamber (12); characterized in that:- an ignition coil (50) common to the spark plugs (44, 48) is provided, which is arranged in a first circuit (K1) in which the first spark plug (44) is arranged, and in a second circuit (K2) in which the second spark plug (48) is arranged;- a voltage source (52) common to the spark plugs (44, 48) is provided, which is designed to:◯ provide a first electrical voltage and thereby apply it to the ignition coil (50), which:▪ is designed to convert the first electrical voltage into a second electrical voltage that is higher than the first electrical voltage;▪ has two output terminals (A1, A2) via which the ignition coil (50) is connected to the respective circuit (K1, K2), whereby the second electrical voltage can be applied to the respective spark plug (44, 48) arranged in the respective circuit (K1, K2) via the output terminals (A1, A2) and the respective circuit (K1, K2), which thereby generates the ignition spark to ignite the mixture; and◯ to reverse the electrical polarity of the first electrical voltage, so that the second electrical voltage between the output terminals (A1, A2) of the ignition coil (50) is positive in a first state and negative in a second state;and- in at least one of the circuits (K1, K2) between the ignition coil (50) and the spark plug (44, 48) arranged in the at least one circuit (K1, K2) a diode (54) is arranged, which in one of the states allows an electric current to flow through the at least one circuit (K1, K2) and in the other state prevents an electric current from flowing through the at least one circuit (K1, K2). Internal combustion engine (10) according to claim 1 , characterized in that the at least one circuit (K1, K2) is the second circuit (K2) in which the diode (54) is arranged. Internal combustion engine (10) according to claim 2, characterized in that the first circuit (K1) is free of a diode. Internal combustion engine (10) according to claim 2, characterized in that the diode (54) is arranged as the first diode (54) in the second circuit (K2), wherein a second diode (56) is arranged in the first circuit (K1) between the ignition coil (50) and the first spark plug (44), which in one state prevents the flow of electric current through the first circuit (K1) and in the other state allows the flow of electric current through the first circuit (K1). Internal combustion engine (10) for a motor vehicle, comprising: - at least one combustion chamber (12) in which a mixture comprising at least the fuel and air introduced into the combustion chamber (12) can be received by introducing air and fuel into the combustion chamber (12); - a first spark plug (44) associated with the combustion chamber (12) and designed as a pre-chamber spark plug, which has a pre-chamber (46) that is fluidically separated from the combustion chamber (12) except for at least one through-opening and is fluidically connected to the combustion chamber (12) via the at least one through-opening, from which at least a part of the mixture can be introduced into the pre-chamber (46) via the at least one through-opening, in which at least one ignition spark can be generated by means of the first spark plug (44) to ignite the part of the mixture introduced into the pre-chamber (46) via the at least one through-opening;and- a second spark plug (48) associated with the combustion chamber (12), by means of which at least one ignition spark can be generated in the combustion chamber (12) and outside the pre-chamber (46) to ignite the mixture taken up in the combustion chamber (12); characterized in that:- an ignition coil (50) common to the spark plugs (44, 48) is provided, which is arranged in a first circuit (K1) in which the first spark plug (44) is arranged, and in a second circuit (K2) in which the second spark plug (48) is arranged;- a voltage source (52) common to the spark plugs (44, 48) is provided, which is designed to provide a first electrical voltage and thereby apply it to the ignition coil (50), which is designed to convert the first electrical voltage into a second electrical voltage that is larger than the first electrical voltage, which can be applied via the respective circuit (K1, K2) to the respective spark plug (44, 48) arranged in the respective circuit (K1, K2), which thereby generates the ignition spark to ignite the mixture;and- in at least one of the circuits (K1, K2) between the ignition coil (50) and the spark plug (44, 48) arranged in the at least one circuit (K1, K2) a semiconductor switching element (60) is arranged, which is switchable between: ◯ a connected state as the first state, in which the ignition coil (50) is electrically connected to the spark plug (44, 48) arranged in the at least one circuit (K1, K2) via the semiconductor switching element (60); and ◯ a blocked state as the second state, in which the ignition coil (50) is electrically disconnected from the spark plug (44, 48) arranged in the at least one circuit (K1, K2) by means of the semiconductor switching element (60). Internal combustion engine (10) according to claim 5, characterized by an electronic computing device which is configured to provide an electrical control signal by means of which the semiconductor switching element (60) switches at least from one of the states to the other state. Internal combustion engine (10) according to claim 5 or 6, characterized in that the semiconductor switching element (60) is designed as a triac. Internal combustion engine (10) according to one of claims 5 to 7, characterized in that the at least one circuit (K1, K2) is the second circuit (K2) in which the semiconductor switching element (60) is arranged. Internal combustion engine (10) according to claim 8, characterized in that: - the first circuit (K1) is free of a semiconductor switching element; or - the semiconductor switching element (60) is arranged as the first semiconductor switching element (60) in the second circuit (K2), wherein a second semiconductor switching element (62) is arranged in the first circuit (K1) between the ignition coil (50) and the first spark plug (44), which is switchable between: ◯ a second connection state in which the ignition coil (50) is electrically connected to the first spark plug (44) via the second semiconductor switching element (62); and ◯ a second blocking state in which the ignition coil (50) is electrically disconnected from the first spark plug (44) by means of the second semiconductor switching element (62). Motor vehicle, with an internal combustion engine (10) according to one of the preceding claims.

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