Reciprocating piston internal combustion engine including a sensor system on a gas exchange valve

Abstract

A reciprocating piston internal combustion engine includes: a sensor system on a gas exchange valve which has a valve head situated at a first end of a valve stem; a lever element which engages at a second end of the valve stem and which is designed to actuate the gas exchange valve by displacing the valve head; a detection element which, upon actuation of the gas exchange valve, is displaced along a displacement path; and a sensor device configured to ascertain a position of the detection element. The sensor device is situated in such a way that the detection element, during a displacement along a portion of the displacement path, moves predominantly in a movement toward the sensor device or away from the same, thereby providing a measurement of valve timing of the gas exchange valve.

Claims

1. A reciprocating piston internal combustion engine, comprising: a gas exchange valve having a valve head which is situated at a first end of a valve stem; a lever element which engages at a second end of the valve stem and which is configured to actuate the gas exchange valve by displacing the valve head; a detection element which, upon actuation of the gas exchange valve, is displaced along a displacement path; and a sensor device configured to ascertain a position of the detection element, wherein the sensor device is situated so that the detection element, during a displacement along a portion of the displacement path in which the detection element is situated closer to the sensor device than in other portions of the displacement path, moves predominantly in one path component of two path components in a movement one of toward the sensor device or away from the sensor device; wherein the detection element samples data in a circumferential direction based on a pivoting or rotational movement of the lever element along the displacement path, and wherein at least one portion of a valve disk is used as the detection element.

2. The reciprocating piston internal combustion engine as recited in claim 1, wherein the lever element includes one of: (i) a flattened area, so that an outer surface of the lever element extends in parallel to an outer surface of the sensor device, at least in a starting position of the lever element; (ii) the lever element includes a roller cam follower.

3. The reciprocating piston internal combustion engine as recited in claim 1, wherein the detection element is configured integrally with the lever element.

4. The reciprocating piston internal combustion engine as recited in claim 1, wherein the detection element is situated at one end of the lever element located opposite of a rotational axis of the lever element in the longitudinal extension direction of the lever element.

5. A reciprocating piston internal combustion engine, comprising: a gas exchange valve having a valve head which is situated at a first end of a valve stem; a lever element which engages at a second end of the valve stem and which is configured to actuate the gas exchange valve by displacing the valve head; a detection element which, upon actuation of the gas exchange valve, is displaced along a displacement path; and a sensor device configured to ascertain a position of the detection element, wherein the sensor device is situated so that the detection element, during a displacement along a portion of the displacement path in which the detection element is situated closer to the sensor device than in other portions of the displacement path, moves predominantly in one path component of two path components in a movement one of toward the sensor device or away from the sensor device; wherein the detection element samples data in a circumferential direction based on a pivoting or rotational movement of the lever element along the displacement path, wherein the detection element is situated at one end of the lever element located opposite of a rotational axis of the lever element in the longitudinal extension direction of the lever element, and wherein the detection element is situated on the valve stem.

6. The reciprocating piston internal combustion engine as recited in claim 5, wherein the detection element is configured integrally with a valve disk situated on the valve stem.

7. The reciprocating piston internal combustion engine as recited in claim 5, wherein the sensor device is configured to contactlessly ascertain the position of the detection element.

8. The reciprocating piston internal combustion engine as recited in claim 7, wherein the sensor device includes a Hall-effect sensor for ascertaining the position of the detection element.

9. The reciprocating piston internal combustion engine as recited in claim 7, wherein the sensor device includes a Hall-effect sensor having an integrated circuit, and at least one of an analog interface for outputting an analog sensor signal and a digital interface for outputting a digital sensor signal.

10. The reciprocating piston internal combustion engine as recited in claim 9, wherein the sensor device is configured to output the digital sensor signal at a valve lift of the valve head of the gas exchange valve of more than 2%.

11. The reciprocating piston internal combustion engine as recited in claim 9, wherein the sensor device is configured to output the digital sensor signal at a valve lift of the valve head of the gas exchange valve of more than 0.3 mm.

12. A reciprocating piston internal combustion engine, comprising: a gas exchange valve having a valve head which is situated at a first end of a valve stem; a lever element which engages at a second end of the valve stem and which is designed to actuate the gas exchange valve by displacing the valve head; a detection element which, upon actuation of the gas exchange valve, is displaced along a displacement path; and a sensor device to ascertain a position of the detection element, the sensor device being situated so that the detection element, during a displacement along a first portion of the displacement path in which the detection element is situated closer to the sensor device than in other portions of the displacement path, moves predominantly in a movement toward the sensor device or away from the same, the detection element being situated on one end of the lever element; wherein the one end is situated opposite of a rotational axis of the lever element in the longitudinal extension direction of the lever element, the detection element being displaced from a starting point to an end point along the first portion of the displacement path when the lever element is pivoted and the motion of detection element being representable by a motion vector, the motion vector including a first movement component and a second movement component which is orthogonal to the first movement component, relative to an outer surface of the sensor device facing the end of the lever element at the starting point of the lever element, the first movement component being directed in parallel to a normal vector of the outer surface and the second movement component being directed orthogonally to the normal vector of the outer surface, and, during a displacement of the detection element along the first portion of the displacement path, the first movement component being greater, in terms of absolute value, than the second movement component.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a reciprocating piston internal combusting engine according to one specific embodiment of the present invention.

(2) FIG. 2A shows a part of a sensor system of a reciprocating piston internal combustion engine known from the related art.

(3) FIG. 2B illustrates a displacement of a permanent magnet of the sensor system of FIG. 2A.

(4) FIG. 3A shows a part of a sensor system of a reciprocating piston internal combustion engine according to one specific embodiment of the present invention.

(5) FIG. 3B illustrates a displacement of a detection element of the sensor system of FIG. 3A.

(6) FIG. 4 shows a part of a lever element and of a sensor device for a reciprocating piston internal combustion engine according to one specific embodiment of the present invention.

(7) FIG. 5 shows a part of a lever element, of a gas exchange valve and of a sensor device for a reciprocating piston internal combustion engine according to one specific embodiment of the present invention.

(8) FIG. 6 shows an analog and a digital sensor signal of a sensor device and a valve lift of a gas exchange valve in each case as a function of a position of a camshaft for a reciprocating piston internal combustion engine according to one specific embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(9) The figures are only schematic representations and are not true to scale. Identical reference numerals denote identical or identically-acting features in the figures.

(10) FIG. 1 shows a reciprocating piston internal combusting engine 10 according to one specific embodiment of the present invention.

(11) Reciprocating piston internal combustion engine 10 includes a cylinder 12 having a piston 14 situated displaceably therein. Reciprocating piston internal combustion engine 10 may include multiple such cylinders 12, each having a piston 14. Piston 14 may be operatively connected to a crankshaft and be displaced together with the same.

(12) Reciprocating piston internal combustion engine 10 furthermore includes a gas exchange valve 16. For example, gas exchange valve 16 may be an intake valve for introducing an air/fuel mixture into cylinder 12, or an exhaust valve for discharging exhaust gas from cylinder 12. Reciprocating piston internal combustion engine 10 may include multiple such gas exchange valves 16, for example, two gas exchange valves 16, such as one intake valve and one exhaust valve, may be provided per cylinder 12.

(13) Reciprocating piston internal combustion engine 10 furthermore includes a sensor device 18, which is designed to ascertain an actuating degree and/or an opening angle and/or a position of at least a part of gas exchange valve 16, as is described in detail above and below. For this purpose, sensor device 18 includes a sensor element 20 designed as a Hall-effect sensor. Sensor device 18 and/or sensor element 20 furthermore include(s) an integrated circuit 22 for processing a measured variable detected by sensor element 20, such as a detected magnetic field strength and/or a magnetic field change and/or a magnetic flux. For this purpose, integrated circuit 22 may include a microcontroller and/or a memory device for storing measuring data, for example. Moreover, sensor device 18 includes an analog interface 24 for outputting an analog sensor signal and/or a digital interface 26 for outputting a digital sensor signal. The analog sensor signal and/or the digital sensor signal may be transferred and/or transmitted, for example via corresponding electrical lines, to a control unit 28, such as an engine control unit, for further processing and/or for processing of the sensor signals.

(14) Sensor device 18 may also only have one digital interface 26 for outputting the digital sensor signal, which may be used for engine control, for example. In this case, a processing of the analog sensor signal may take place in integrated circuit 22, for example. In this way, sensor device 18 may have a simpler and more cost-effective design.

(15) FIG. 2A shows a part of a sensor system of a reciprocating piston internal combustion engine 10 known from the related art.

(16) Reciprocating piston internal combustion engine 10 includes a gas exchange valve 16 having a valve head 30, which is situated at a first end 32 of a rod-shaped valve stem 34.

(17) Moreover, reciprocating piston internal combustion engine 10 includes a lever element 36, which rests against a second end 38 of valve stem 34 situated opposite of first end 32 of valve stem 34 in the longitudinal extension direction of valve stem 34. Lever element 36 is designed as a cam follower. Lever element 36 is mounted rotatably and/or pivotably on a rotational axis 39 at a first end 37 of lever element 36. At a second end 40 of lever element 36 situated opposite of first end 37 of lever element 36 in the longitudinal extension direction of lever element 36, a permanent magnet 42 is situated as a signal generator for determining a position and/or a location of lever element 36.

(18) Adjoining and/or resting against second end 40 of lever element 36, a camshaft 44 which has at least one cam element 46 or a cam lobe for displacing lever element 36 is situated opposite of second end 38 of valve stem 34.

(19) Reciprocating piston internal combustion engine 10 furthermore includes a sensor device 18 for ascertaining a position and/or a location of permanent magnet 42, and thus for indirectly ascertaining a location and/or a position of lever element 36 and/or of gas exchange valve 16. For example, sensor device 18 includes a sensor element 20 designed as a Hall-effect sensor or as a GMR sensor.

(20) During rotation of camshaft 44, cam element 46 pushes onto second end 40 of lever element 36, whereby lever element 36 is pivoted out of a starting position 48 about rotational axis 39 into an end position 50. During pivoting of lever element 36, in turn, second end 40 of lever element 36 pushes against second end 38 of valve stem 34, whereby valve stem 34 and valve head 30 are displaced in the longitudinal extension direction of valve stem 34. For example, gas exchange valve 16 may be closed in the starting position of lever element 36, and may be open in end position 50, or vice versa. If camshaft 44 rotates further until cam element 46 releases second end 40 of lever element 36, lever element 36 again pivots out of end position 50 into starting position 48. For this purpose, lever element 36 and/or valve stem 34 may be preloaded in the direction of starting position 48, for example with the aid of a suitable spring device.

(21) When lever element 36 is pivoted between starting position 48 and end position 50, permanent magnet 42 is displaced along a displacement path 52, the displacement of permanent magnet 42 being detected with the aid of sensor device 18 and/or sensor element 20 via a change in the magnetic field, so that a position and/or location of permanent magnet 42 and indirectly a position and/or location and/or an opening angle of gas exchange valve 16 may be ascertained.

(22) FIG. 2B illustrates the displacement of permanent magnet 42 along displacement path 52 of the sensor system of FIG. 2A. When lever element 36 is pivoted out of starting position 48 into end position 52, permanent magnet 42 is displaced from a starting point 54 to an end point 56 along displacement path 52. The movement of permanent magnet 42 may be represented by a motion vector 58. The movement or motion vector 58 of permanent magnet 42 may be broken down into a first movement component 60 and a second movement component 62 which is orthogonal to first movement component 60. Based on a reference point 17 of sensor device 18 and/or based on an outer surface 19 of sensor device 18 which faces lever element 36 at least in its starting position 48, first movement component 60 is directed away from sensor device 18 and/or reference point 17 and/or outer surface 19, or first movement component 60 is directed in parallel to a normal vector of outer surface 19. In contrast, second movement component 62 extends orthogonally to the normal vector of outer surface 19.

(23) Reference point 17 may denote a central point of outer surface 19 of sensor device 18, for example, such as a geometric center of outer surface 19. Reference point 17 may also denote a geometric center of sensor element 20 and/or a center of gravity of sensor element 20. For example, reference point 17 may be situated along a central center line through sensor device 18, which may extend in parallel to a longitudinal extension direction of sensor device 18, for example at one end of sensor device 18.

(24) During a displacement of permanent magnet 42 out of end position 50 into starting position 48, motion vector 58, first movement component 60 and second movement component 62 are each directed in the opposite direction.

(25) In the embodiment known from the related art and shown in FIGS. 2A and 2B, first movement component 60 is always smaller, in absolute terms, than second movement component 62 during a displacement of permanent magnet 42 along displacement path 52. Accordingly, permanent magnet 42 moves farther along second movement component 62 orthogonally to the normal vector of outer surface 19 past sensor device 18 and/or reference point 17 and/or outer surface 19 than it moves along first movement component 60 in parallel or antiparallel to the normal vector of outer surface 19 toward, or away from, sensor device 18 and/or reference point 17 and/or outer surface 19. This means that permanent magnet 42 moves along displacement path 52 predominantly past sensor device 18, than it moves toward, or away from, the same.

(26) The arrangement of sensor device 18 relative to lever element 36, known from the related art, may be referred to as radial sampling based on a pivoting or rotational movement of the lever element along displacement path 52. A sensing direction, i.e., a direction in which sensor element 20 of sensor device 18 essentially detects and/or ascertains the magnetic field generated by permanent magnet 42, extends in parallel to a longitudinal extension direction of lever element 36, at least in starting position 48 of lever element 36.

(27) FIG. 3A shows a part of a sensor system of a reciprocating piston internal combustion engine 10 according to one specific embodiment of the present invention. Unless described otherwise, the part of the sensor system of reciprocating piston internal combustion engine 10 shown in FIG. 3A has the same elements and features as the part shown in FIG. 2A.

(28) Analogously to FIG. 2A, lever element 36, which is designed as a roller cam follower, is pivoted and/or displaced out of a starting position 48 by cam element 46 during rotation of camshaft 44, a detection element 64 situated at second end 40 of lever element 36 being displaced along displacement path 52. The movement or displacement of detection element 64 along displacement path 52 is again picked up and/or ascertained and/or detected with the aid of sensor device 18 having an integrated magnetic element and a sensor element 20 designed as a Hall-effect sensor, so that a position and/or a location and/or an opening angle of gas exchange valve 16 and/or of valve head 30 is/are indirectly ascertainable. Detection element 64 shown in FIG. 3A is designed integrally with lever element 36 at least as a part and/or an area of second end 40 of lever element 36.

(29) Detection element 64 may denote, for example, an edge, an outer surface, a tip and/or another area of second end 40 of lever element 36. To allow detection element 64 to be precisely detected by sensor device 18, lever element 36 may be made from ferromagnetic material, for example, and/or detection element 64 may be designed as a magnetic element which is integrated into lever element 36. Outer surface 19 of sensor device 18 which faces lever element 36 and/or detection element 64 may be spaced apart from detection element 64 and/or from an outer surface of lever element 36 which faces outer surface 19 by at least 0.2 mm, for example by at least 0.5 mm, and preferably by at least 1.0 mm.

(30) FIG. 3B illustrates the displacement of detection element 64 along displacement path 52 of the sensor system of FIG. 3A. When lever element 36 is pivoted out of starting position 48 into end position 52, detection element 64 is displaced from a starting point 54 to an end point 56 along displacement path 52. The movement of detection element 64 may be represented by a motion vector 58. The movement or motion vector 58 of detection element 64 may be broken down into a first movement component 60 and a second movement component 62 which is orthogonal to first movement component 60. Based on a reference point 17 of sensor device 18 and/or based on an outer surface 19 of sensor device 18 which faces lever element 36 and/or its second end 40 and/or detection element 64 at least in starting position 48 of lever element 36, first movement component 60 is directed away from sensor device 18 and/or reference point 17 and/or outer surface 19, or first movement component 60 is directed in parallel to a normal vector of outer surface 19. In contrast, second movement component 62 extends orthogonally to the normal vector of outer surface 19. Reference point 17 of FIG. 3A may be selected analogously to reference point 17 of FIG. 2A.

(31) During a displacement of detection element 64 out of end position 50 into starting position 48, motion vector 58, first movement component 60 and second movement component 62 are each directed in the opposite direction.

(32) In the embodiment according to the present invention and shown in FIGS. 3A and 3B, first movement component 60 is greater, in absolute terms, than second movement component 62 during a displacement of detection element 64 along displacement path 52. This condition applies at least during a displacement of detection element 64 along a portion 53a of displacement path 52, in which detection element 64 is situated closer to sensor device 18 than in another portion 53b of displacement path 52, in particular in a portion of displacement path 52 in which detection element 64 is located closest to sensor device 18 compared to other portions. Portion 53a of displacement path 52 may denote an area in which lever element 36 may be moved within design boundaries, and portion 53b may denote a hypothetical extension of portion 53a, in which it is in fact not possible to pivot lever element 36 for mechanical design reasons. Within portion 53a, detection element 64 moves farther along first movement component 60 in parallel or antiparallel to the normal vector of outer surface 19 toward, or away, from sensor device 18 and/or reference point 17 and/or outer surface 19 than it moves along second movement component 62 orthogonally to the normal vector of outer surface 19 past sensor device 18 and/or reference point 17 and/or outer surface 19. This means that detection element 64 moves along displacement path 52 predominantly toward or away from sensor device 18.

(33) The arrangement according to the present invention of sensor device 18 relative to lever element 36 may be referred to as sampling in the circumferential direction based on a pivoting or rotational movement of lever element 36 along displacement path 52. A sensing direction, i.e., a direction in which sensor element 20 of sensor device 18 essentially detects and/or ascertains detection element 64, extends transversely to a longitudinal extension direction of lever element 36, at least in starting position 48 of lever element 36. As a result of such an arrangement of sensor device 18 and such a sampling of detection element 64 in the circumferential direction, a precision of the ascertainment of the position of detection element 64 and/or of lever element 36 may advantageously be achieved. Furthermore, compared to a radial sampling, a larger change of a measuring signal, per displacement path, ascertained by sensor device 18 may advantageously be achieved, so that it is possible to determine a position and/or a location of detection element 64 and/or of the lever element, and thus a position and/or a location and/or an opening angle of gas exchange valve 16, more precisely.

(34) Furthermore, a sampling in the circumferential direction may be easier to implement in terms of the design than a radial sampling, since a collision risk of sensor device 18 with other components of gas exchange valve 16 may exist in the case of a radial sampling. Attachment tolerances or installation tolerances of the sensor device may also influence a signal accuracy in the case of radial sampling, so that a sampling in the circumferential direction may be considerably less sensitive to attachment or installation tolerances.

(35) One aspect of the present invention may be summarized as follows. The movement and/or the displacement of detection element 64 along portion 53a of displacement path 52 may denote a vector or motion vector 58 between starting point 54 and the end point of the displacement of detection element 64 along displacement path 52, or the movement may be represented by vector 58. The movement may thus similarly denote a net movement of detection element 64 from starting point 54 to end point 56. If starting point 54 is located farther away from sensor device 18 than end point 56, detection element 64 is moved toward sensor device 18, which may result in a closing of gas exchange valve 16, for example. In contrast, if starting point 54 is located closer to sensor device 18 than end point 56, detection element 64 is moved away from sensor device 18, which may result in an opening of gas exchange valve 16, for example. The movement or the displacement of detection element 64 along displacement path 52 may include first movement component 60 in the direction of sensor device 18, or in the opposite direction, and second movement component 60 orthogonal to first movement component 60 and/or be broken down into first and second movement components 60, 62. For example, the direction of first movement component 60 may be in parallel or antiparallel to the normal vector of outer surface 19 of sensor device 18 which faces lever element 36. If detection element 64 is displaced from starting point 54 to end point 56, first movement component 60 in the direction of sensor device 18 and/or of outer surface 19 of sensor device 18 (or in the opposite direction) is greater, in absolute terms, than second movement component 62 in the arrangement according to the present invention of sensor device 18 relative to detection element 64 and/or to lever element 36. Accordingly and/or equivalently, detection element 64, during its displacement, is predominantly moved toward, or away from, sensor device 18.

(36) FIG. 4 shows a part of a lever element 36, which is designed as a roller cam follower, and of a sensor device 18 for a reciprocating piston internal combustion engine 10 according to one specific embodiment of the present invention. Unless described otherwise, lever element 36 shown in FIG. 4 and sensor device 18 may have the same features and elements as the corresponding components shown in FIGS. 2A through 3B.

(37) Sensor device 18 and/or sensor element 20 designed as a Hall-effect sensor are able to detect a distance from an edge of lever element 36 via a magnetic flux, for example. In the case of a lateral offset of sensor element 20 relative to lever element 36, the magnetic flux may change accordingly strongly, which in turn may influence signal quality. To increase the signal quality, second end 40 of lever element 36 may thus have a flattened design and/or have a flattened area, which may serve as detection element 64. In the flattened area, an outer surface of lever element 36 may extend in parallel to the outer surface of the sensor device, for example, at least in starting position 48 of lever element 36. Detection element 64 may also be designed as a flattened tip of lever element 36. In this way, a lateral offset of sensor element 20 and/or of sensor device 18 relative to lever element 36 may have only little influence on the signal quality, or a reliability and/or precision of the ascertainment of the position of detection element 64 may be increased.

(38) FIG. 5 shows a part of a lever element 36 of a gas exchange valve 16 and of a sensor device 18 for a reciprocating piston internal combustion engine 10 according to one specific embodiment of the present invention. Lever element 36 is designed as a roller cam follower. Unless described otherwise, the components shown in FIG. 5 may have the same features and elements as the corresponding components shown in FIGS. 2A through 4.

(39) As shown in FIG. 5, it is also possible, as an alternative or in addition to the embodiments of FIGS. 3A through 4, to use at least one portion of a valve disk 66 as detection element 64. For example, valve disk 66 may be designed for locking a valve spring and surround valve stem 34 in an annular manner in the area of second end 38 of valve stem 34 along an outer circumference of valve stem 34. For example, an edge area of valve disk 66 may serve as detection element 64. Valve disk 66 may be made from ferromagnetic material for this purpose.

(40) It is also conceivable to situate a detection element 64 as a separate component made from ferromagnetic material on valve disk 66, valve stem 34 and/or lever element 36, whose displacement along displacement path 52 may be detected by sensor device 18. For example, detection element 64 may be designed as a projection.

(41) FIG. 6 shows an analog sensor signal 68 and a digital sensor signal 70 of a sensor device 18 and a valve lift 72 of a gas exchange valve 16 in each case as a function of a position of a camshaft 44 for a reciprocating piston internal combustion engine 10 according to one specific embodiment of the present invention. FIG. 6 may thus be considered to be a representation of the timing of gas exchange valve 16. Analog sensor signal 68 and valve lift 72 are indicated in % on the y axis on the left of FIG. 6, each standardized to a maximum value. Digital sensor signal 70 is indicated as a voltage in volt on the y axis on the right of FIG. 6, and the position of camshaft 44 is plotted in units of angular degrees of camshaft 44 or in degrees of camshaft angle on the x axis. All values indicated in FIG. 6 are purely of an exemplary nature and shall not be considered to be limiting.

(42) A rest position or starting position 48 of lever element 36, and correspondingly a rest position of gas exchange valve 16, may correspond to a closed gas exchange valve 16 and/or a position of the camshaft at 0 and/or 150. In the rest position of gas exchange valve 16, sensor device 18, or outer surface 19 of sensor device 18 which faces lever element 36 in starting position 48 of lever element 36, may be spaced apart from detection element 64 by approximately 1.0 mm, for example. In other words, the sensor device may be installed with a nominal air gap of approximately 1.0 mm from detection element 64.

(43) An area of analog sensor signal 68 having a maximum slope may be at approximately 0.5 mm to 1.0 mm of the mechanical valve lift of gas exchange valve 16, or of the distance of outer surface 19 of sensor device 18 from detection element 64 and/or from lever element 36. The area having the maximum slope of analog sensor signal 68 may be deliberately selected as the area of a switching threshold of digital sensor signal 70 to be able to reach a maximum accuracy. This is primarily due to the fact that, in the area of the maximum slope of analog sensor signal 68, a small change in the position of camshaft 44 causes a large change in analog sensor signal 68, so that the position and/or location and/or the opening angle of gas exchange valve 16 may be determinable with high accuracy. The switching threshold of digital sensor signal 70 may, for example, be in a range between 90% and 30% of analog sensor signal 68. The switching threshold is preferably around 70% of analog sensor signal 68, both in the case of a falling edge, which may correspond to an event gas exchange valve 16 opens, and in the case of a rising edge, which may correspond to an event gas exchange valve 16 closes. Digital sensor signal 70 of sensor device 18 may be transmitted via digital interface 26, for example, to a control unit, for example an engine control unit, and be processed by the same. The switching threshold of digital sensor signal 70 may advantageously be set at approximately 0.5 mm of the mechanical valve lift of gas exchange valve 16 or of the valve lift of valve head 30 of gas exchange valve 16 since, starting at this valve lift, an opening cross section and/or opening angle of gas exchange valve 16 corresponding to this valve lift may be sufficiently large for a flow which is relevant for a charge cycle of cylinder 12 to begin or set in.

(44) In closing, it shall be pointed out that terms such as including, having etc. do not exclude other elements or steps, and that terms such as a or an do not exclude a plurality. It shall moreover be pointed out that features which were described with reference to one of the above-mentioned exemplary embodiments may also be used in combination with other features of other above-described exemplary embodiments. Reference numerals in the claims shall not be regarded as limiting.