Internal combustion engine with a gas exchange valve

Abstract

The invention relates to an internal combustion engine (1) with a combustion chamber (8) which is fluidically connected to a flow channel (10) via a gas exchange valve (12), and with a valve train (13) which has a camshaft with at least one valve actuating cam (15) for actuating the gas exchange valve (12), wherein the gas exchange valve (12) has a valve stem (19) and a valve disc (21), and wherein the valve disc (21) provides a first flow cross-section in a first valve disc position and a second flow cross-section different from the first flow cross-section through a valve seat in a second valve disc position, wherein the valve disc (21) is pivotably mounted in such a way thatthat the valve disc (21) is arranged in a first pivot angle position when the valve stem (19) is in a first pivot angle position and in a second pivot angle position when the valve stem (19) is in a second pivot angle position different from the first pivot angle position, wherein the valve disc (21) is rotatably mounted on the valve stem (19) by means of a pivot joint (23) about an axis of rotation and pivotably mounted on a cylinder head (7) receiving the flow channel (10) by means of a pivot joint (25), wherein the pivot joint (25) comprises a first pivot joint (27) and a second pivot joint (28).

Description

[0001] The invention relates to an internal combustion engine with a combustion chamber which is fluidically connected to a flow channel via a gas exchange valve, and with a valve train which has a camshaft with at least one valve actuating cam for actuating the gas exchange valve, wherein the gas exchange valve has a valve stem and a valve disc, and wherein the valve disc, in a first valve disc position, provides a first flow cross-section and, in a second valve disc position, a second flow cross-section different from the first flow cross-section through a valve seat, wherein the valve disc is pivotably mounted in such a way thatthat the valve disc is arranged in a first pivot angle position when the valve stem is in a first position and in a second position when the valve stem is in a second pivot angle position different from the first position, wherein the valve disc is rotatably mounted on the valve stem about an axis of rotation by means of a pivot joint and pivotably mounted on a cylinder head receiving the flow channel by means of a pivot joint, wherein the pivot joint comprises a first pivot joint and a second pivot joint, wherein the valve disc is rotatably mounted on a connecting element about a first axis of rotation via the first pivot joint and the connecting element is rotatably mounted on the cylinder head about a second axis of rotation via the second pivot joint.

[0002] For example, German patent application DE 103 21 636 A1 is known from the prior art. This document describes a switching valve, particularly for switchable exhaust gas heat exchangers, with a valve housing, wherein a valve inlet or a plurality of valve openings are configured for the switching valve, and at least one valve outlet or a plurality of valve outlets are configured to direct a fluid flow through the switching valve from the valve housing. It is provided that a poppet valve, guided in the valve housing, is used as the valve actuator, wherein the poppet valve consists of a valve stem and a valve disc, with an angle between the surface normal of the valve disc and the direction of extension of the valve stem.

[0003] Furthermore, the publication WO 2018 / 188776 A1 discloses an adjustment device for an exhaust gas routing section of an exhaust gas turbocharger, wherein the adjustment device is provided for adjusting a characteristic of a fluid flowing onto the turbine wheel in the exhaust gas inlet routing section.

[0004] Furthermore, a device is known from the publication DE 35 07 919 A1, which is characterized in that, in the case of translationally moved valves, at least one angle between the surface normal standing on the geometric sealing surface and the translational direction of movement is less than 90° and greater than 0°.

[0005] German patent application DE 10 2013 213 820 A1 discloses a gas exchange valve for an internal combustion engine, which is arranged on the cylinder head of a combustion cylinder, with a valve stem and a flow device which is actuated by a camshaft rotating during the operation of the internal combustion engine via an actuating device and which periodically opens and closes a combustion chamber-side valve cross-section of a gas exchange channel, wherein the flow device comprises at least one flap which closes the valve cross-section in a closed position and opens the valve cross-section in a release position, whereby a precise and reproducible positioning of the at least one flap is achieved and at the same time the constriction of the air in the area of ​​the inlet or outlet cross-section is avoided and the largest possible cross-section is provided. For this purpose, the actuating device includes a linkage mechanism.

[0006] Furthermore, the prior art documents DE 196 13 589 A1, DE 10 2018 002 171 A1 and DE 21 33 880 A are known.

[0007] The object of the invention is to propose an internal combustion engine which has advantages over known internal combustion engines, in particular improving the inflow of fresh gas into the combustion chamber and / or the outflow of exhaust gas from the combustion chamber by increasing the available flow cross-section of the gas exchange valve.

[0008] According to the invention, this is achieved with an internal combustion engine having the features of claim 1. It is provided that the axis of rotation intersects a longitudinal center axis of the valve stem and the valve stem is mounted so as to be linearly displaceable along a displacement axis relative to the cylinder head.

[0009] Advantageous embodiments with expedient further developments of the invention are specified in the dependent claims. It should be noted that the exemplary embodiments described in the description are not limiting; rather, any variations of the features disclosed in the description, the claims, and the figures are possible.

[0010] The internal combustion engine serves to provide drive torque, which is used, for example, to propel a motor vehicle. Preferably, the internal combustion engine is an integral part of the motor vehicle, but it can, of course, also exist separately, particularly until the engine is mounted on and / or in the motor vehicle. The internal combustion engine is, for example, a gasoline engine or a diesel engine. During its operation, it is supplied with fuel and fresh air, at least intermittently, with the fresh air containing fresh air at least intermittently. Additionally, the fresh air may contain exhaust gas if exhaust gas recirculation is implemented, in which the exhaust gas produced by the internal combustion engine is at least partially returned to the engine as a component of the fresh air.The fuel and fresh gas supplied to the internal combustion engine form a fuel-fresh gas mixture with a specific composition, which is then reacted in the drive unit.

[0011] During the operation of an internal combustion engine, exhaust gas is produced due to the chemical reaction of fuel and fresh air / gas. This exhaust gas is discharged towards the outside environment of the engine or vehicle. Since the exhaust gas produced by the internal combustion engine contains pollutants, it is preferably first subjected to an exhaust aftertreatment system before being released into the environment. In the exhaust aftertreatment system, the pollutants are at least partially converted into less harmful products. Only after passing through the exhaust aftertreatment system is the exhaust gas discharged into the environment, in particular through a tailpipe of the engine's exhaust system.

[0012] The chemical reaction takes place in the combustion chamber, to which the fuel and fresh gas are supplied for this purpose, preferably either separately or already in the form of the fuel-fresh gas mixture. The combustion chamber is part of a cylinder of the internal combustion engine and is preferably bounded radially outwards along a longitudinal axis of the cylinder by a cylinder wall and axially by a cylinder head on one side and a piston of the internal combustion engine on the other. The cylinder wall is, for example, part of a cylinder crankcase in which the cylinder is manufactured, at least partially. The cylinder head is located, in particular, on a cylinder head that is arranged or attached to the cylinder head housing. Preferably, the internal combustion engine has several combustion chambers, each configured according to this description and located in a separate cylinder.

[0013] The combustion chamber is fluidically connected to a flow channel via the gas exchange valve. The flow channel can be either a fresh gas channel or an exhaust gas channel. Fresh gas is supplied to the combustion chamber through the fresh gas channel, and exhaust gas is discharged from the combustion chamber through the exhaust gas channel. In the case of a fresh gas channel, the gas exchange valve is in the form of an inlet valve, and in the case of an exhaust gas channel, it is an outlet valve. The fluid flowing through the gas exchange valve from the flow channel into the combustion chamber, or vice versa, is referred to as gas in this description. The gas flowing from the flow channel into the combustion chamber is fresh gas, while the gas flowing from the combustion chamber into the flow channel is exhaust gas. The flowing gas therefore forms a gas stream into or out of the combustion chamber.

[0014] Preferably, the combustion chamber is fluidically connected to several flow channels, each via a gas exchange valve. At least one of the gas exchange valves serves as an inlet valve, and at least one other serves as an exhaust valve. Where this description refers only to the gas exchange valve, it can be used as either an inlet or an exhaust valve. If several gas exchange valves are present, for example, in the form of at least one inlet valve and at least one exhaust valve, the descriptions of the gas exchange valve are preferably applicable to several or all of the gas exchange valves.

[0015] The gas exchange valve consists of a valve stem and a valve disc. The valve disc can be positioned in different orientations and interacts with the valve seat to create different flow cross-sections through the valve seat. In the first valve disc position, the first flow cross-section through the valve seat is present, and in the second valve disc position, the second flow cross-section is present. The two flow cross-sections are of different sizes; for example, the first flow cross-section is smaller than the second.

[0016] It may be provided that, for example, the first flow cross-section is zero. The first valve disc position can thus also be referred to as the closed position of the valve disc, and the second valve disc position as the open position. In any case, the respective flow cross-section is located between the valve disc and the valve seat; the fluid or gas flows between the flow channel and the combustion chamber, or vice versa, through a gap jointly defined by the valve seat and the valve disc, in particular by the valve seat radially outwards and by the valve disc radially inwards. The gap is therefore preferably annular, especially circular.

[0017] The valve head is moved between its positions via the valve stem. For this purpose, the gas exchange valve is designed such that a movement of the valve stem also causes a movement of the valve head. The valve head is connected to the valve stem for this purpose. For example, the valve head is connected to the valve train of the internal combustion engine via the valve stem. The valve train has a camshaft with at least one valve actuation cam, which deflects the valve stem and thus the valve head, for example, once per revolution of the camshaft. A drive connection between the valve actuation cam and the valve stem is preferably established via a rocker arm or a finger rocker arm, in particular via a roller rocker arm.

[0018] The valve stem is typically mounted so that it can move linearly along its longitudinal axis, particularly in the cylinder head of the internal combustion engine. If the valve head is rigidly connected to the valve stem, especially if it is manufactured as an integral part of it, then the movement of the valve stem causes a movement of the valve head, resulting in a uniform change in the flow cross-section of the gas exchange valve. Specifically, the flow cross-section changes uniformly, or at the same rate, on opposite sides of the valve head. The gas can then flow through the valve seat and around the valve head to either exit the flow channel into the combustion chamber or vice versa. In any case, however, the gas flows towards the valve head, thus creating a flow resistance for the gas.Accordingly, the valve plate influences the gas exchange rate of the internal combustion engine and, in particular, the filling of the combustion chamber with fresh gas.

[0019] To improve the charge exchange of the internal combustion engine, the valve head should be pivoted at least partially out of the gas flow. For this purpose, it is pivotally mounted such that it is in different pivot angle positions depending on the valve stem position, particularly with respect to the valve seat and / or the valve stem and / or the cylinder head. Preferably, the first valve head position corresponds to the first valve head position, and the second valve head position corresponds to the second valve head position. The valve head is connected to the valve stem in such a way that the displacement of the valve stem between the valve stem positions causes the pivoting movement of the valve head between the pivot angle positions.

[0020] Accordingly, in the case of the first valve stem position, the first flow cross-section is set, and in the case of the second valve stem position, the second flow cross-section is set between the valve head and the valve seat. However, the valve head is not moved exclusively linearly, as is the case in known internal combustion engines, but rather, when moving from the first valve head position to the second valve head position, or vice versa, it describes a rotary pivoting motion. Optionally, it also describes a translational motion. Thus, it is possible for the valve head to move exclusively rotaryally; however, preferably, its movement involves both a rotary and a translational motion.

[0021] For example, when the valve stem is in its first position, the valve head completely closes the valve seat and is in its first pivoting position relative to the valve seat. If the valve head is moved from this first position towards the second position, it is displaced from the valve seat and pivots in the process, rotating from the first position towards the second. In the second position, the valve head is at a different angle relative to the valve seat than in the first position. The valve head is mounted in such a way that a larger flow cross-section is available in the second position than with a purely translational movement of the valve head. This optimizes the charge exchange of the internal combustion engine.

[0022] The invention provides that the valve head is rotatably mounted on the valve stem by means of a pivot joint about an axis of rotation and pivotably mounted on a cylinder head accommodating the flow channel by means of a swivel joint about an axis of rotation. The oscillatory movement of the valve head relative to the valve stem is achieved by means of the pivot joint. The pivot joint is mechanically located between the valve head and the valve stem; in other words, the valve head is connected to the valve stem via the pivot joint. In particular, the pivot joint engages directly with the valve head on one side and directly with the valve stem on the other.

[0023] To achieve controlled rotational movement of the valve head, it is additionally mounted to the cylinder head using a pivot joint. This pivot joint engages both the valve head and the cylinder head, thus mounting the valve head to the cylinder head via the pivot joint. The cylinder head also houses the flow channel, and in particular, the valve seat is formed by the cylinder head. This described design of the internal combustion engine enables targeted and controlled pivoting of the valve head to achieve the aforementioned advantages.

[0024] The invention provides that the axis of rotation intersects a longitudinal center axis of the valve stem, and in particular is perpendicular to it. The longitudinal center axis passes through the valve stem centrally in cross-section and extends in the direction of the greatest extent of the valve stem. In particular, the longitudinal center axis of the valve stem runs centrally, or at least approximately centrally, through the valve stem in at least one valve head position. The axis of rotation, about which the valve head is rotatably mounted on the valve stem by means of the pivot joint, runs through the longitudinal center axis of the valve stem, thus intersecting it. This means that the axis of rotation and the longitudinal center axis form an angle with each other that is greater than 0° and less than 180°. Preferably, the axis of rotation is perpendicular to the longitudinal center axis. This design again serves to realize the advantages already explained.

[0025] A further development of the invention provides that the pivot joint is configured as a further rotary joint, and the valve head is rotatably mounted about a further axis of rotation by means of this further rotary joint, wherein the further axis of rotation is fixed relative to the cylinder head. The further rotary joint engages the valve head on one side and the cylinder head on the other. The further rotary joint has the further axis of rotation about which the valve head is rotatably mounted relative to the cylinder head. The further rotary joint is designed such that its further axis of rotation is fixed, meaning that the valve head describes a pure rotational movement about the further axis of rotation when moving between the valve head positions. Preferably, the further axis of rotation is perpendicular to an imaginary plane that completely encompasses the longitudinal center axis of the valve stem.In particular, the additional axis of rotation is arranged parallel to and spaced apart from the axis of rotation of the pivot joint. This represents a structurally simple design of the internal combustion engine, which nevertheless achieves improved charge exchange.

[0026] The invention provides that the pivot joint comprises a first pivot joint and a second pivot joint, wherein the valve head is rotatably mounted on a connecting element about a first axis of rotation via the first pivot joint, and the connecting element is rotatably mounted on the cylinder head about a second axis of rotation via the second pivot joint. The pivot joint is therefore not a single pivot joint, but rather comprises several pivot joints, namely the first pivot joint and the second pivot joint. The first pivot joint connects the valve head to the connecting element, and the second pivot joint connects the connecting element to the cylinder head. Accordingly, the valve head is pivotally mounted on the cylinder head via the first pivot joint, the connecting element, and the second pivot joint, in the aforementioned order.

[0027] The connecting element is preferably rigid, for example, in the form of a rod or the like. Preferably, the first and second axes of rotation are arranged parallel to and spaced apart from each other; in particular, they are perpendicular to an imaginary plane that contains the longitudinal center axis of the valve stem. Particularly preferably, the first and second axes of rotation are each arranged parallel to the axis of rotation of the pivot joint. The design of the pivot joint with two pivots and the connecting element linking the pivots enables particularly effective pivoting of the valve disc and a particularly flow-optimized release of the valve seat.

[0028] A further development of the invention provides that the additional pivot joint, the first pivot joint, and / or the second pivot joint are each configured as a fixed bearing or a floating bearing. A fixed bearing is understood to be a bearing that permits only rotational movement about an axis of rotation, but no translational movement. In the case of a fixed bearing, the axis of rotation is thus fixed in position relative to the two elements connected to each other via the fixed bearing.

[0029] The floating bearing, on the other hand, allows both rotational movement about the axis of rotation and translational movement, in particular linear translational movement. This means that the axis of rotation of the floating bearing is movable, specifically, it is parallel displaceable in an imaginary plane. The further pivot joint, the first pivot joint, or the second pivot joint, is preferably designed as a fixed bearing. However, it can also be in the form of the floating bearing, especially if this is necessary to allow linear displacement of the valve stem. In any case, the simplest possible design of the internal combustion engine is achieved.

[0030] The invention provides that the valve stem is mounted so as to be linearly displaceable along a displacement axis relative to the cylinder head. Such a design has already been mentioned. The displacement axis corresponds, for example, to the longitudinal center axis of the valve stem or runs parallel to it at a distance. Preferably, the valve stem is displaceable exclusively linearly, namely in the axial direction with respect to the displacement axis. This enables efficient actuation of the gas exchange valve, for example, by means of the valve train.

[0031] A further development of the invention provides that, in one of the pivot angle positions, the valve disc and the valve seat define a flow cross-section, and that a first part of the flow cross-section located in a first angular range about a central axis of the valve seat differs from a second part of the flow cross-section located in a second angular range about the central axis of the valve seat, offset from the first angular range but of the same size. In the pivot angle position, the gas exchange valve is preferably at least partially or fully open. For example, the second pivot angle position is used as the pivot angle position. In the pivot angle position, the valve disc and the valve seat define the flow cross-section through which gas can flow between the combustion chamber and the flow channel.

[0032] The flow cross-section is, in particular, annular and completely and continuously surrounds the valve head in the circumferential direction with respect to a longitudinal center axis of the valve head and / or a longitudinal center axis of the valve seat. The first part of the flow cross-section lies within the first angular region, and the second part within the second angular region. The two angular regions are offset from each other; in particular, they are diametrically opposed with respect to the longitudinal center axis of the valve seat. However, they are of the same size in the circumferential direction, thus enclosing the same angle. Nevertheless, the two parts of the flow cross-section are of different sizes. It follows that the valve head asymmetrically exposes the valve seat due to the different pivot angle positions. This results in particularly good combustion chamber filling and optimal charge exchange.

[0033] A further development of the invention provides that the first angular region is located on a side of the valve seat facing a longitudinal center axis of the combustion chamber, and the second angular region is located on a side of the valve seat facing away from the longitudinal center axis of the combustion chamber, and that the first part of the flow cross-section is larger than the second part. In other words, the second angular region is closer to a cylinder wall bounding the combustion chamber than the first angular region. Since the first part of the flow cross-section is larger than the second part, the gas flow towards and away from a longitudinal center axis of the combustion chamber is improved. This results in particularly good combustion chamber filling.

[0034] A further development of the invention provides that the gas exchange valve is a first gas exchange valve, the valve seat is a first valve seat and the flow channel is a first flow channel, wherein the combustion chamber is fluidically connected to a second flow channel via a second gas exchange valve, wherein the second gas exchange valve has a second valve stem and a second valve disc, wherein the second valve disc provides a first flow cross-section in a first valve disc position and a second flow cross-section different from the first flow cross-section in a second valve seat.

[0035] In addition to the first flow channel, the first valve seat, and the first gas exchange valve, there is also a second flow channel, a second valve seat, and a second gas exchange valve. For example, the first gas exchange valve serves as an inlet valve and the second gas exchange valve as an outlet valve, or vice versa. Preferably, the two gas exchange valves are designed analogously, such that for both the first and second gas exchange valves, the respective valve disc is pivotably mounted such that, in a first valve stem position, the disc is in a first pivot angle position, and in a second valve stem position, the disc is in a second pivot angle position different from the first.

[0036] Furthermore, it is preferably provided that each of the valve heads of the two gas exchange valves is rotatably mounted on the respective valve stem by means of a pivot joint about an axis of rotation and pivotably mounted on the cylinder head receiving the flow channel by means of a swivel joint about an axis of rotation. For example, both swivel joints are in the form of the second swivel joint, or both swivel joints each have the first and second swivel joints. However, it can also be provided that the swivel joint for the first gas exchange valve is the second swivel joint, whereas for the second gas exchange valve, the swivel joint comprises the first and second swivel joints, which are connected to each other via the connecting element. This achieves a particularly optimal charge exchange in the internal combustion engine.

[0037] The features and combinations of features described in the description, in particular those described in the following figure description and / or shown in the figures, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention. Thus, embodiments that are not explicitly shown or explained in the description and / or the figures, but which emerge from or can be derived from the explained embodiments, are also to be considered as encompassed by the invention.

[0038] The invention is explained in more detail below with reference to the exemplary embodiments shown in the drawing, without limiting the invention. The only embodiment shown is... Fig. 1 A schematic sectional view of a section of an internal combustion engine, in particular for a motor vehicle.

[0039] The Fig. Figure 1 shows a schematic sectional view of a section of an internal combustion engine 1, specifically in the area of ​​a cylinder 2 in which a piston 3 is movably mounted. The piston 3, together with a cylinder wall 4 formed by a cylinder crankcase 5 and a cylinder roof 6 formed by a cylinder head 7, defines a combustion chamber 8. A first flow channel 9 and a second flow channel 10 are fluidically connected to the combustion chamber 8. Here, flow channel 9 is, for example, in the form of an intake port and flow channel 10 in the form of an exhaust port. Flow channel 9 is fluidically connected to the combustion chamber 8 via a first gas exchange valve 11, and the second flow channel 10 via a second gas exchange valve 12. The first gas exchange valve 11 can therefore also be referred to as an intake valve and the second gas exchange valve 12 as an exhaust valve.

[0040] Both gas exchange valves 11 and 12 are actuated by a valve train 13, of which only two cams 14 and 15 are shown schematically here. Cam 14 is located, for example, on an intake camshaft and cam 15 on an exhaust camshaft. Both gas exchange valves 11 and 12 are each actuated by a valve spring 16 or 17, which forces them into a closed position. Each of the gas exchange valves 11 and 12 has a valve stem 18 or 19 and a valve head 20 or 21. The valve heads 20 and 21 are each rotatably mounted on the respective valve stem 18 or 19 by means of a pivot joint 20 or 23. In addition, the valve heads 20 and 21 are each rotatably mounted on the cylinder head 7 by means of a pivot joint 24 or 25.

[0041] In the case of the first non-inventive gas exchange valve 11, the pivot joint 24 has a further pivot joint 26. For the second gas exchange valve 12 according to the invention, the pivot joint 25, however, has a first pivot joint 27, a second pivot joint 28, and a connecting element 29. The connecting element 29 is articulated to the first valve disc 20 via the first pivot joint 27 and to the cylinder head 7 via the second pivot joint 28. Regardless of the configuration of the pivot joint 24 or 25, the connection of the valve discs 20 and 21 shown allows them to tilt relative to the valve stem. Different valve stem positions of the valve stem 18 and 19 correspond to different pivot angle positions of the valve discs 20 and 21. Such a configuration of the internal combustion engine 1 enables particularly good cylinder filling or optimal charge exchange.A spark plug 30 is also indicated, which is exemplified by the cylinder roof 6 and thus located between the gas exchange valves 11 and 12. REFERENCE MARK LIST: 1 internal combustion engine 2 cylinders 3 pistons 4 cylinder wall 5-cylinder crankcase 6-cylinder roof 7 cylinder head 8 Combustion chamber 9 1. Flow channel 10 2. Flow channel 11 1. Gas exchange valve 12 2. Gas exchange valve 13 Valve train 14 cams 15 cams 16 Valve spring 17 Valve spring 18 1. Valve stem 19 2. Valve stem 20 1. Valve plate 21 2. Valve plate 22 Swivel joint 23 Swivel joint 24 Swivel joint 25 Swivel joint 26 Swivel joint 27 1. Swivel joint 28 2. Swivel joint 29 Connecting element 30 Spark plug

Claims

[1] Internal combustion engine (1) with a combustion chamber (8) which is fluidically connected to a flow channel (10) via a gas exchange valve (12), and with a valve train (13) which has a camshaft with at least one valve actuating cam (15) for actuating the gas exchange valve (12), wherein the gas exchange valve (12) has a valve stem (19) and a valve disc (21), and wherein the valve disc (21) provides a first flow cross-section in a first valve disc position and a second flow cross-section different from the first flow cross-section through a valve seat in a second valve disc position, wherein the valve disc (21) is pivotably mounted,that the valve disc (21) is arranged in a first pivot angle position when the valve stem (19) is in a first pivot angle position and in a second pivot angle position when the valve stem (19) is in a second pivot angle position different from the first pivot angle position, wherein the valve disc (21) is rotatably mounted on the valve stem (19) by means of a pivot joint (23) about an axis of rotation and pivotably mounted on a cylinder head (7) receiving the flow channel (10) by means of a pivot joint (25), wherein the pivot joint (25) comprises a first pivot joint (27) and a second pivot joint (28), wherein the valve disc (21) is rotatably mounted on a connecting element (29) about a first axis of rotation via the first pivot joint (27) and the connecting element (29) is rotatably mounted on the cylinder head (7) about a second axis of rotation via the second pivot joint (28), , characterized by, that the axis of rotation intersects a longitudinal center axis of the valve stem (19) and the valve stem (19) is mounted to be linearly displaceable along a displacement axis relative to the cylinder head (7). [2] Internal combustion engine according to claim 1, characterized by , that the first pivot joint (27) and / or the second pivot joint (28) are each designed as a fixed bearing or as a floating bearing. [3] Internal combustion engine according to any one of the preceding claims, characterized by , that in one of the pivot angle positions of the valve disc (21) with the valve seat limits a flow cross-section, and a first part of the flow cross-section present in a first angular range about a central axis of the valve seat is different from a second part of the flow cross-section present in a second angular range offset from the first angular range, but of the same size, about the central axis of the valve seat. [4] Internal combustion engine according to claim 3, characterized by , that the first angular region is located on a side of the valve seat facing a longitudinal central axis of the combustion chamber (8) and the second angular region is located on a side of the valve seat facing away from the longitudinal central axis of the combustion chamber (8) and that the first part of the flow cross-section is larger than the second part of the flow cross-section. [5] Internal combustion engine according to any one of the preceding claims, characterized by, that the gas exchange valve (12) is a first gas exchange valve, the valve seat is a first valve seat and the flow channel (10) is a first flow channel, wherein the combustion chamber (8) is fluidically connected to a second flow channel (9) via a second gas exchange valve (11), wherein the second gas exchange valve (11) has a second valve stem (18) and a second valve disc (20), wherein the second valve disc (20) provides a first flow cross-section in a first valve disc position and a second flow cross-section different from the first flow cross-section through a second valve seat in a second valve disc position.

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