EP3221567B1 - Valve train for an internal combustion engine and corresponding internal combustion engine - Google Patents

Valve train for an internal combustion engine and corresponding internal combustion engine Download PDF

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Publication number
EP3221567B1
EP3221567B1 EP15795113.8A EP15795113A EP3221567B1 EP 3221567 B1 EP3221567 B1 EP 3221567B1 EP 15795113 A EP15795113 A EP 15795113A EP 3221567 B1 EP3221567 B1 EP 3221567B1
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EP
European Patent Office
Prior art keywords
axial
gate
tracks
track
cam carrier
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EP15795113.8A
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German (de)
French (fr)
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EP3221567A1 (en
Inventor
Matthias Ortmann
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Audi AG
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Audi AG
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L13/00—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations
    • F01L13/0015—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque
    • F01L13/0036—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque the valves being driven by two or more cams with different shape, size or timing or a single cam profiled in axial and radial direction
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L13/00—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations
    • F01L13/0015—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque
    • F01L13/0036—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque the valves being driven by two or more cams with different shape, size or timing or a single cam profiled in axial and radial direction
    • F01L2013/0052—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque the valves being driven by two or more cams with different shape, size or timing or a single cam profiled in axial and radial direction with cams provided on an axially slidable sleeve

Definitions

  • the invention relates to a valve drive for an internal combustion engine and a corresponding internal combustion engine.
  • the valve drive is designed for use with the internal combustion engine, in particular it is part of the internal combustion engine.
  • the valve train is used for an internal combustion engine in which the working cycle of gas exchange valves of individual cylinders of the internal combustion engine can be influenced to improve the thermodynamic properties.
  • the at least one cam carrier which can also be referred to as a cam piece, is arranged non-rotatably and axially displaceably or displaceably on the base camshaft.
  • the cam carrier is usually assigned several, that is to say at least two, valve actuation cams.
  • Each of these valve-actuating cams has an eccentricity which is used to actuate one of the gas exchange valves of the internal combustion engine at a specific angle of rotation of the basic camshaft.
  • the valve actuating cams accordingly rotate together with the basic camshaft, so that the respective gas exchange valve of the internal combustion engine is actuated at least once per revolution of the basic camshaft by the associated valve actuating cam or its eccentricity.
  • the valve actuating cam preferably interacts with a roller rocker arm of the gas exchange valve in that it comes into abutment contact with the latter.
  • valve actuation cams are preferably provided which can be assigned to different cam groups.
  • the valve actuation cams of a cam group now differ, for example, with regard to the angular position of their eccentricity and / or the extent of the same in the radial direction (height) and / or in the circumferential direction (length), each with respect to an axis of rotation of the basic camshaft.
  • By axially displacing the cam carrier it can be brought into at least two axial positions, for example into a first and a second axial position.
  • the gas exchange valve In the first axial position the gas exchange valve is actuated by a first of the valve actuation cams and in the second axial position by a second of the valve actuation cams which are assigned to the same group of cams.
  • the opening time, the opening duration and / or the lift of the gas exchange valve can thus be selected and set, in particular as a function of an operating state of the internal combustion engine.
  • the shifting or shifting of the cam carrier in the axial direction takes place with the aid of an actuating device which comprises the shift gate on the cam carrier and the stationary actuator, usually in a cylinder head of the internal combustion engine.
  • the actuator has an extendable driver which can be brought into engagement with a, for example, screw-shaped or spiral-shaped link path of the shift gate.
  • the slide track or slide tracks are provided on the shift gate which is assigned to the cam carrier.
  • the shift gate is formed on the cam carrier or is operatively connected to it for axial displacement.
  • the slide tracks are each located along a course of a preferably, but not necessarily continuous, curved track and have a certain width, which is preferably matched to the width of the driver of the actuator.
  • the slide track is slightly wider than the driver, so that the driver can pass through the slide track without problems.
  • the slide tracks are, for example, in the form of radial grooves which extend through the circumference of the shift gate, that is to say are designed with open edges in it.
  • the curved path is, for example, in the center of the slide path and is a line in the mathematical sense. This line can consist of several line segments. When a point on the slide track is referred to below, a point on the curved track on which the slide track is based is always meant.
  • the slide tracks run in opposite directions at least in some areas in the axial direction and merge into one another at the point of opening.
  • the slide tracks are partially spaced from one another, so do not directly merge into one another.
  • the slide tracks are arranged essentially in a Y-shape, whereby - viewed in the circumferential direction with respect to the axis of rotation of the base camshaft - the slide tracks are spaced apart from one another starting from the opening point in a first direction, but also starting from the opening point in a second direction opposite to the first direction run in the form of a common backdrop track.
  • the cam piece should be provided with a flexible guide element, which serves to form inner guide walls of the axial link that are axially movable relative to the outer guide walls and which switches between them like a switch in the area of the intersection of the link tracks, so that one of the link tracks is released for the actuating pin and the other slide track is blocked.
  • the publication also describes DE 10 2008 054 254 A1 a camshaft for a variable-lift valve drive of an internal combustion engine, with a carrier shaft and a cam piece arranged thereon in a rotationally fixed and axially displaceable manner, which is composed of a cam carrier and a sleeve, the cam carrier having a group of immediately adjacent cams with different cam lifts and a pin on which the Sleeve is attached, and wherein the sleeve has a link in the form of a groove extending over the circumference of the sleeve, which serves to specify an axial link path for a confirmation pin that moves the cam piece on the support shaft.
  • the backdrop should be produced by non-cutting shaping of sheet metal to form the sleeve.
  • the publication also describes DE 10 2013 111 476 A1 a valve drive of an internal combustion engine with a base camshaft and a cam carrier which is mounted in a rotationally fixed and axially displaceable manner and which has at least two cams for the alternative actuation of a valve.
  • At least one actuator is required to move the cam carrier provided, to which two switching curves are assigned.
  • the respective switching curve has a meshing area for the actuator, a shifting area for shifting the cam carrier by means of the actuator and an ejecting area.
  • the two switching curves intersect in their shift ranges. In this crossing area, the actuator is out of contact with the switching curves.
  • a locking mechanism is provided for locking the cam carrier in its switching positions.
  • a spring-loaded locking member of the locking mechanism is effective in a shifting position of the cam carrier in which the actuator is located in the intersection area of the switching cams that a switching force for moving the cam carrier is introduced via this locking member.
  • the document also describes DE 10 2011 114 300 A1 a valve drive of an internal combustion engine, with at least one basic camshaft, on which at least one cam carrier having valve actuation cams is provided in a rotationally fixed manner and axially displaceable between at least two axial positions, the cam carrier being assigned a shift gate for axial displacement by means of an actuator, which on its circumference over two in axial Direction of opposing, intersecting slide tracks, each having a reversal point. It is provided that the reversal points are offset from one another in the circumferential direction.
  • a valve lift adjustment device is known.
  • a slide block has a first protrusion protruding outward from a radially outer surface of the slide block at a position in a radial direction opposite to a rotational direction with respect to a first inclined surface, and a second protrusion protruding from the radially outer surface in the radial direction at a position opposite to the direction of rotation with respect to a second inclined surface protrudes outward.
  • the first protrusion or the second protrusion is adapted to push the operating component further outward in the radial direction.
  • the document also discloses DE 10 2007 010 149 A1 a valve drive for gas exchange valves of an internal combustion engine with at least one camshaft which is rotatably mounted in a housing of the internal combustion engine, at least one non-rotatable and axially displaceable cam carrier guided on the camshaft, and devices for axially moving the at least one cam carrier on the camshaft in opposite directions.
  • These devices comprise at least two engagement elements which can be brought into engagement with a right-hand or left-hand groove. To enable a reduction in the axial installation space and the number of parts to be assembled, the right-hand groove and the left-hand groove should be arranged directly next to one another and merge with one another or merge.
  • the object of the invention is to propose a valve drive for an internal combustion engine which has advantages over the known prior art, in particular has a greater displacement path for the actuator or the driver in the axial direction, but at the same time is easy to manufacture.
  • valve drive has at least one basic camshaft on which at least one cam carrier having valve actuation cams is provided in a rotationally fixed manner and axially displaceable between at least two axial positions, the cam carrier being assigned a shift gate for axial displacement by means of an actuator, which has two in has slide tracks running in opposite directions in the axial direction, partially spaced apart from one another at an opening point, both slide tracks each having an axial projection in the direction of a slide track wall delimiting the other of the slide tracks in the axial direction. It is also provided that the axial projections of the slide tracks are arranged offset from one another in the circumferential direction.
  • both slide tracks each have an axial projection in the direction of a slide track wall that delimits the other of the slide tracks in the axial direction.
  • the displacement path of the at least one slide track is increased with the aid of the axial projection.
  • the slide track wall of the slide track projects in the axial direction of the slide track wall delimiting the other of the slide tracks.
  • the axial projection is understood to mean in particular a projection which, at a circumferential position with respect to the axis of rotation of the base camshaft, has a maximum extent in the axial direction and is configured on both sides of this circumferential position with an extent in the axial direction that is smaller than that maximum extension.
  • the axial projection is in the form of a bulged elevation in the axial direction, for example.
  • One reason for an incomplete shift can be, for example, increased friction between the cam carrier and the basic camshaft, in particular between an external toothing of the basic camshaft and an internal toothing of the cam carrier engaging in this. Increased friction can also occur as a result of the roller finger follower resting against the valve actuation cam.
  • the described configuration of the slide track is particularly useful when a latching device is assigned to the cam carrier or the shift gate, which latches the cam carrier in one of several axial positions.
  • the latching device holds the cam carrier in each of the plurality of axial positions. For example, at least two, in particular exactly two, different axial positions are provided.
  • a certain force must be applied. This is achieved with the help of the actuator.
  • the impulse caused by the actuator is insufficient, the cam carrier does not reach the desired axial position, which results in the incomplete displacement described above.
  • both slide tracks each have an axial projection in the direction of the slide track wall delimiting the other of the slide tracks in the axial direction.
  • the problem of the incomplete Shifting is effectively eliminated not only for one of the slide tracks, but rather for both slide tracks.
  • the axial projections preferably have the same dimensions, in particular the same axial extent, in particular therefore the same maximum axial extent, and / or the same extent in the circumferential direction.
  • the width of the slide tracks is reduced or, given a given width of the slide tracks of the cam carriers, widened.
  • the latter is fundamentally undesirable due to the given installation space.
  • the former means that the valve train is difficult to manufacture because under certain circumstances the slide tracks, especially in the area in which they form the common slide track, are too narrow to be made with the same milling tool that is used for the other areas of the slide tracks .
  • the axial projections of the slide tracks are arranged offset from one another in the circumferential direction.
  • This preferably means that the circumferential positions at which the axial projections each have their greatest extent in the axial direction are offset from one another in the circumferential direction. If the axial projections are arranged opposite one another, however, the problem arises again that the slide tracks are under certain circumstances too narrow for the milling tool used. For this reason, it is particularly advantageous if the axial projections are arranged offset from one another, that is to say do not lie opposite one another in the circumferential direction.
  • a further development of the invention provides that the offset of the axial projections is selected such that the smallest distance between the axial projections corresponds to at least one width of the slide tracks.
  • the smallest distance between the axial projections is preferably defined as the length of that straight line which connects the axial projections or those circumferential positions at which the axial projections have their respective greatest extension in the axial direction. This smallest distance should correspond at least to the width of the slide tracks, the slide tracks usually having the same width. Of course, the smallest distance between the axial projections can also be greater than the width of the slide tracks.
  • the slide tracks run separately from each other in front of the opening and after the opening in the form of a common slide track, an extension ramp being formed in the common slide track.
  • the slide tracks meet or merge for the first time.
  • the slide tracks run together so that they form the common slide track.
  • the extension ramp is provided, which is characterized in particular by a decreasing depth of the slide tracks in the direction facing away from the opening or an increasing distance from a base of the slide tracks.
  • the axial projections are present in the common slide track.
  • at least that circumferential position at which the axial projection or the axial projections have their greatest extent in the axial direction is - seen in the circumferential direction - in the common slide track or in the opening point.
  • a further embodiment of the invention provides that the axial extensions of the axial projections are selected such that the respective axial projection at the point of its maximum axial extension is spaced apart in the axial direction by a distance from a longitudinal center path of the common slide path which is at least half of the axial extension corresponds to a driver of the actuator.
  • the longitudinal center path corresponds, for example, to the curved path already explained above, which always runs in the middle of the respective slide path.
  • the longitudinal center track of each slide track runs in the axial direction in the middle of the slide track and on its base.
  • the distance of the axial projection from the longitudinal center axis preferably corresponds to exactly half the axial extension of the driver.
  • the driver is deflected by the axial projection as it traverses the slide track in such a way that after the axial projection - viewed in the axial direction - it is approximately centrally, preferably exactly in the middle, in the slide track or the common slide track.
  • both are axial projections or their axial extensions are selected accordingly, so that the driver is present in the circumferential direction close to the axial projection in the center of the slide track regardless of which slide track it traverses.
  • the groove depths of the link tracks are the same at the same circumferential positions.
  • the groove depth is preferably to be understood as the distance between a base of the respective gate track and an outer circumference of the shift gate. The smaller the groove depth, the greater the distance between the axis of rotation of the base camshaft and the base of the slide track in the radial direction.
  • the same groove depths of the slide tracks at the same circumferential positions have the advantage that the base of one of the slide tracks merges into the base of the other slide track without a shoulder in the radial direction, so that the base or the bottom of the common slide track is formed continuously or without a jump in the radial direction .
  • the groove depth decreases from a point of the greatest axial extent of that axial projection to form the extension ramp which is at the front in the circumferential direction.
  • the extension ramp ensures that the driver is pushed out in the radial direction out of the slide track or the slide tracks.
  • the groove depth should decrease, preferably decrease continuously, in the area of the extension ramp.
  • the extension ramp and consequently the decrease in the groove depth, viewed in the circumferential direction already begins from the circumferential position at which the greatest axial extent of the axial projection is present.
  • the groove depth can be reduced from the axial projection at the front in the circumferential direction, i.e. the axial projection facing away from the common slide track.
  • the invention further relates to an internal combustion engine with a valve drive, in particular according to the above statements, the valve drive having at least one basic camshaft on which at least one cam carrier having valve actuation cams is provided in a rotationally fixed manner and axially displaceable between at least two axial positions, the cam carrier being axially displaced by means of a Actuator is assigned a shift gate, which on its circumference has two axially opposite, partially spaced from each other, at an opening point into each other slotted link tracks, wherein both gate tracks each have an axial projection in the direction of the other of the gate tracks in the axial direction delimiting gate track wall. It is provided that the axial projections of the slide tracks are offset from one another in the circumferential direction.
  • the Figure 1 shows a region of an internal combustion engine 1, in particular a valve drive 2.
  • a shift gate 3 is shown, which is arranged on a base camshaft 4 of the valve drive 2 so as to be displaceable in the axial direction.
  • the shift gate 3 has an internal toothing for this purpose, which engages in an external toothing of the basic camshaft 4.
  • the shift gate 3 is assigned at least one cam carrier, not shown here, on which at least one valve actuating cam is provided.
  • the valve actuation cam is used to actuate at least one gas exchange valve of the internal combustion engine 1.
  • valve actuation cams are preferably provided on the cam carrier, with different valve actuation cams serving to actuate the gas exchange valve in different axial positions of the cam carrier.
  • the cam carrier can be displaced in the axial direction by means of the shift gate 3.
  • the valve drive 2 has an actuator 5 with a driver 6.
  • the actuator 5 is designed such that the driver 6 can be displaced in the radial direction with respect to an axis of rotation 7 of the base camshaft 4. It is shown once with solid lines in a starting position and with dashed lines in an extended position.
  • the shift gate 3 has a first gate track 8 and a second gate track 9.
  • Each of the gate tracks 8 and 9 is defined by a longitudinal center track 10 and 11, which runs centrally in the respective gate track 8 and 9, viewed in the axial direction.
  • the slide tracks 8 and 9 merge into one another at an opening point 12.
  • the opening point 12 can be defined by that point 13 at which the longitudinal center tracks 10 and 11 merge into one another.
  • the opening point 12 can also be understood to mean that circumferential position at which a partition 14 present between the slide tracks 8 and 9 is omitted for the first time.
  • slide tracks 8 and 9 are spaced apart from one another in front of the opening point 12, in particular the partition 14 is present between them. However, because they are designed to run in opposite directions in the axial direction, they run towards one another so that they merge into one another at the opening point 12. After the opening point 12, they continue to run in the form of a common slide track 15. This, too, is again characterized by the course of the longitudinal center tracks 10 and 11, which now overlap. In the outward axial direction, the slide tracks 8 and 9 are each delimited by a slide track wall 16 and 17, respectively.
  • the actuator 5 is activated in such a way that the driver 6 is extended in the radial direction, that is to say is displaced in the direction of the base camshaft 4. Accordingly, it engages in one of the slide tracks 8 and 9 (here: the first slide track 8). Because the shift gate 3 is driven in the circumferential direction by the basic camshaft 3, the driver 6 runs through the gate track 8 in the direction of the common slide track 15. It rests at least partially on the slide track wall 16, whereby the shift gate 3 and consequently also the cam carrier is displaced in the axial direction.
  • both slide tracks 8 and 9 have an axial projection 18 and 19, respectively. This protrudes in the direction of the respective other of the slide tracks 9 or 8 in the axial direction limiting slide track wall 17 or 16 16 is initially always larger until a maximum axial extension is reached. In the circumferential direction after that circumferential position at which this maximum axial extension is present, the axial extension decreases again.
  • the axial projections 18 and 19 are arranged opposite one another in the circumferential direction. This is preferably to be understood as meaning that the circumferential positions at which they have their maximum axial extent coincide.
  • the common gate track 15 is narrow in the axial direction, so that a production of the common Slide track 15 may not be able to use the same milling tool as the production of slide tracks 8 and 9 in the circumferential direction in front of the opening point 12. For this reason, it is particularly preferred if the axial projections 18 and 19 are arranged offset from one another in the circumferential direction.
  • the circumferential position of the maximum axial extent of the second link path 9 is at a circumferential position at which the axial projection 18 is no longer present.
  • the circumferential position of the maximum axial extent can also be arranged after the axial projection 18 in the circumferential direction.
  • the axial projections 18 and 19 are configured or their offset in the circumferential direction is selected such that the smallest distance 20 between the axial projections 18 and 19 corresponds to at least a width 21 of the slide tracks 8 and 9. These preferably have the same width.
  • the smallest distance 22 in the axial direction between the axial projections 18 and 19 is dimensioned in such a way that it corresponds to at least one axial extension 23 of the driver 6.
  • the distance 22 is exactly as large as the extension 23 or at most slightly larger.
  • the common slide track 15 can be formed with the same milling tool as the slide tracks 8 and 9.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Valve Device For Special Equipments (AREA)
  • Valve-Gear Or Valve Arrangements (AREA)

Description

Die Erfindung betrifft einen Ventiltrieb für eine Brennkraftmaschine sowie eine entsprechende Brennkraftmaschine.The invention relates to a valve drive for an internal combustion engine and a corresponding internal combustion engine.

Der Ventiltrieb ist für den Einsatz mit der Brennkraftmaschine ausgelegt, insbesondere ist er Bestandteil der Brennkraftmaschine. Der Ventiltrieb wird für eine Brennkraftmaschine eingesetzt, bei welcher das Arbeitsspiel von Gaswechselventilen einzelner Zylinder der Brennkraftmaschine zur Verbesserung der thermodynamischen Eigenschaften beeinflusst werden kann. Der mindestens eine Nockenträger, welcher auch als Nockenstück bezeichnet werden kann, ist drehfest und axial verschiebbar beziehungsweise verlagerbar auf der Grundnockenwelle angeordnet.The valve drive is designed for use with the internal combustion engine, in particular it is part of the internal combustion engine. The valve train is used for an internal combustion engine in which the working cycle of gas exchange valves of individual cylinders of the internal combustion engine can be influenced to improve the thermodynamic properties. The at least one cam carrier, which can also be referred to as a cam piece, is arranged non-rotatably and axially displaceably or displaceably on the base camshaft.

Dem Nockenträger sind üblicherweise mehrere, also zumindest zwei, Ventilbetätigungsnocken zugeordnet. Jeder dieser Ventilbetätigungsnocken weist eine Exzentrizität auf, welche der Betätigung eines der Gaswechselventile der Brennkraftmaschine bei einem bestimmten Drehwinkel der Grundnockenwelle dient. Die Ventilbetätigungsnocken laufen demnach gemeinsam mit der Grundnockenwelle um, sodass das jeweilige Gaswechselventil der Brennkraftmaschine zumindest einmal pro Umdrehung der Grundnockenwelle von dem zugeordneten Ventilbetätigungsnocken beziehungsweise dessen Exzentrizität betätigt wird. Der Ventilbetätigungsnocken wirkt dabei vorzugsweise mit einem Rollenschlepphebel des Gaswechselventils zusammen, indem er mit diesem in Anlagekontakt tritt.The cam carrier is usually assigned several, that is to say at least two, valve actuation cams. Each of these valve-actuating cams has an eccentricity which is used to actuate one of the gas exchange valves of the internal combustion engine at a specific angle of rotation of the basic camshaft. The valve actuating cams accordingly rotate together with the basic camshaft, so that the respective gas exchange valve of the internal combustion engine is actuated at least once per revolution of the basic camshaft by the associated valve actuating cam or its eccentricity. The valve actuating cam preferably interacts with a roller rocker arm of the gas exchange valve in that it comes into abutment contact with the latter.

Vorzugsweise sind mehrere Ventilbetätigungsnocken vorgesehen, welche unterschiedlichen Nockengruppen zugeordnet sein können. Die Ventilbetätigungsnocken einer Nockengruppe unterscheiden sich nun beispielsweise hinsichtlich der Winkellage ihrer Exzentrizität und/oder der Erstreckung derselben in radialer Richtung (Höhe) und/oder in Umfangsrichtung (Länge), jeweils bezüglich einer Drehachse der Grundnockenwelle. Durch das axiale Verlagern des Nockenträgers kann dieser in wenigstens zwei Axialpositionen, beispielsweise in eine erste und eine zweite Axialposition, gebracht werden. In der ersten Axialposition wird das Gaswechselventil von einem ersten der Ventilbetätigungsnocken und in der zweiten Axialposition von einem zweiten der Ventilbetätigungsnocken betätigt, welche derselben Nockengruppe zugeordnet sind. Durch die Verlagerung des Nockenträgers können somit insbesondere der Öffnungszeitpunkt, die Öffnungsdauer und/oder der Hub des Gaswechselventils, insbesondere in Abhängigkeit von einem Betriebszustand der Brennkraftmaschine, ausgewählt und eingestellt werden.A plurality of valve actuation cams are preferably provided which can be assigned to different cam groups. The valve actuation cams of a cam group now differ, for example, with regard to the angular position of their eccentricity and / or the extent of the same in the radial direction (height) and / or in the circumferential direction (length), each with respect to an axis of rotation of the basic camshaft. By axially displacing the cam carrier, it can be brought into at least two axial positions, for example into a first and a second axial position. In the first axial position the gas exchange valve is actuated by a first of the valve actuation cams and in the second axial position by a second of the valve actuation cams which are assigned to the same group of cams. As a result of the displacement of the cam carrier, the opening time, the opening duration and / or the lift of the gas exchange valve can thus be selected and set, in particular as a function of an operating state of the internal combustion engine.

Das Verschieben beziehungsweise Verlagern des Nockenträgers in axialer Richtung erfolgt mithilfe einer Stelleinrichtung, die die Schaltkulisse auf dem Nockenträger und den ortsfest angeordneten Aktuator, üblicherweise in einem Zylinderkopf der Brennkraftmaschine, umfasst. Der Aktuator verfügt über einen ausfahrbaren Mitnehmer, der sich mit einer beispielsweise schrauben- oder spiralförmigen Kulissenbahn der Schaltkulisse in Eingriff bringen lässt. Die Kulissenbahn beziehungsweise die Kulissenbahnen sind an der Schaltkulisse vorgesehen, welche dem Nockenträger zugeordnet ist. Beispielsweise ist die Schaltkulisse an dem Nockenträger ausgebildet oder mit diesem zum axialen Verlagern wirkverbunden.The shifting or shifting of the cam carrier in the axial direction takes place with the aid of an actuating device which comprises the shift gate on the cam carrier and the stationary actuator, usually in a cylinder head of the internal combustion engine. The actuator has an extendable driver which can be brought into engagement with a, for example, screw-shaped or spiral-shaped link path of the shift gate. The slide track or slide tracks are provided on the shift gate which is assigned to the cam carrier. For example, the shift gate is formed on the cam carrier or is operatively connected to it for axial displacement.

Die Kulissenbahnen liegen jeweils entlang eines Verlaufs einer vorzugsweise, jedoch nicht notwendigerweise stetigen Kurvenbahn vor und weisen eine bestimmte Breite auf, welche vorzugsweise auf die Breite des Mitnehmers des Aktuators abgestimmt ist. Üblicherweise ist die Kulissenbahn geringfügig breiter als der Mitnehmer, sodass ein problemloses Durchlaufen der Kulissenbahn durch den Mitnehmer möglich ist. Die Kulissenbahnen liegen beispielsweise als Radialnuten vor, welche den Umfang der Schaltkulisse durchgreifen, also randoffen in dieser ausgebildet sind. Die Kurvenbahn liegt beispielsweise zentral in der Kulissenbahn vor und ist eine Linie im mathematischen Sinn. Diese Linie kann sich aus mehreren Linienabschnitten zusammensetzen. Wenn im Folgenden von einem Punkt der Kulissenbahn die Rede ist, so ist stets ein Punkt auf der der Kulissenbahn zugrunde liegenden Kurvenbahn gemeint.The slide tracks are each located along a course of a preferably, but not necessarily continuous, curved track and have a certain width, which is preferably matched to the width of the driver of the actuator. Usually, the slide track is slightly wider than the driver, so that the driver can pass through the slide track without problems. The slide tracks are, for example, in the form of radial grooves which extend through the circumference of the shift gate, that is to say are designed with open edges in it. The curved path is, for example, in the center of the slide path and is a line in the mathematical sense. This line can consist of several line segments. When a point on the slide track is referred to below, a point on the curved track on which the slide track is based is always meant.

Die Kulissenbahnen verlaufen wenigstens bereichsweise in axialer Richtung gegenläufig und münden an der Mündungsstelle ineinander ein. Die Kulissenbahnen sind teilweise voneinander beabstandet, gehen also nicht unmittelbar ineinander über. Beispielsweise sind die Kulissenbahnen im Wesentlichen Y-förmig angeordnet, wobei - in Umfangsrichtung bezüglich der Drehachse der Grundnockenwelle gesehen - die Kulissenbahnen ausgehend von der Mündungsstelle in eine erste Richtung voneinander beabstandet sind, ebenfalls ausgehend von der Mündungsstelle in eine der ersten Richtung entgegengesetzte zweite Richtung jedoch in Form einer gemeinsamen Kulissenbahn verlaufen.The slide tracks run in opposite directions at least in some areas in the axial direction and merge into one another at the point of opening. The slide tracks are partially spaced from one another, so do not directly merge into one another. For example, the slide tracks are arranged essentially in a Y-shape, whereby - viewed in the circumferential direction with respect to the axis of rotation of the base camshaft - the slide tracks are spaced apart from one another starting from the opening point in a first direction, but also starting from the opening point in a second direction opposite to the first direction run in the form of a common backdrop track.

Aus dem Stand der Technik ist beispielsweise die Druckschrift DE 10 2008 024 911 A1 bekannt. Diese betrifft einen Ventiltrieb einer Brennkraftmaschine mit einer Nockenwelle, die eine Trägerwelle und ein darauf drehfest und axial verschiebbar angeordnetes Nockenstück umfasst, das zumindest eine Nockengruppe unmittelbar benachbarter Nocken mit unterschiedlichen Erhebungen zur variablen Betätigung eines Gaswechselventils und eine Axialkulisse mit äußeren Führungswänden zur Vorgabe zweier sich kreuzender Kulissenbahnen aufweist, und mit einem in die Axialkulisse radial zur Nockenwelle einkuppelbaren Betätigungsstift zum Verlagern des Nockenstücks in Richtung beider Kulissenbahnen. Dabei soll das Nockenstück mit einem flexiblen Führungselement versehen sein, das zur Bildung relativ zu den äußeren Führungswänden axial beweglicher innerer Führungswände der Axialkulisse dient und das nach Art einer Weiche im Kreuzungsbereich der Kulissenbahnen zwischen diesen umschaltet, sodass für den Betätigungsstift eine der Kulissenbahnen freigegeben und die andere Kulissenbahn gesperrt ist.From the prior art, for example, is the document DE 10 2008 024 911 A1 known. This relates to a valve drive of an internal combustion engine with a camshaft, which comprises a carrier shaft and a cam piece arranged thereon in a rotationally fixed and axially displaceable manner, which has at least one cam group of directly adjacent cams with different Has elevations for the variable actuation of a gas exchange valve and an axial link with outer guide walls for specifying two intersecting slide tracks, and with an actuating pin that can be coupled into the axial link radially to the camshaft for moving the cam piece in the direction of both slide tracks. The cam piece should be provided with a flexible guide element, which serves to form inner guide walls of the axial link that are axially movable relative to the outer guide walls and which switches between them like a switch in the area of the intersection of the link tracks, so that one of the link tracks is released for the actuating pin and the other slide track is blocked.

Weiterhin beschreibt die Druckschrift DE 10 2008 054 254 A1 eine Nockenwelle für einen hubvariablen Ventiltrieb einer Brennkraftmaschine, mit einer Trägerwelle und einem darauf drehfest und axialverschiebbar angeordneten Nockenstück, das aus einem Nockenträger und einer Hülse zusammengesetzt ist, wobei der Nockenträger eine Nockengruppe unmittelbar benachbarter Nocken mit unterschiedlichen Nockenhüben und einen Zapfen aufweist, auf dem die Hülse befestigt ist, und wobei die Hülse eine Kulisse in Form einer sich über den Umfang der Hülse erstreckenden Nut aufweist, die zur Vorgabe einer axialen Kulissenbahn für einen das Nockenstück auf der Trägerwelle verschiebenden Bestätigungsstift dient. Die Kulisse soll durch spanloses Umformen von Blechwerkstoff zu der Hülse hergestellt sein.The publication also describes DE 10 2008 054 254 A1 a camshaft for a variable-lift valve drive of an internal combustion engine, with a carrier shaft and a cam piece arranged thereon in a rotationally fixed and axially displaceable manner, which is composed of a cam carrier and a sleeve, the cam carrier having a group of immediately adjacent cams with different cam lifts and a pin on which the Sleeve is attached, and wherein the sleeve has a link in the form of a groove extending over the circumference of the sleeve, which serves to specify an axial link path for a confirmation pin that moves the cam piece on the support shaft. The backdrop should be produced by non-cutting shaping of sheet metal to form the sleeve.

Weiterhin beschreibt die Druckschrift DE 10 2013 111 476 A1 einen Ventiltrieb einer Brennkraftmaschine mit einer Grundnockenwelle und einem in dieser drehfest und axial verschiebbar gelagerten Nockenträger, der mindestens zwei Nocken zum alternativen Betätigen eines Ventils aufweist. Zum Verschieben des Nockenträgers ist mindestens ein Aktuator vorgesehen, dem zwei Schaltkurven zugeordnet sind. Die jeweilige Schaltkurve weist einen Einspurbereich für den Aktuator, einen Verschiebebereich zum Verschieben des Nockenträgers mittels des Aktuators und einen Auswerferbereich auf. Die beiden Schaltkurven kreuzen sich in deren Verschiebebereichen. In diesem Kreuzungsbereich ist der Aktuator außer Kontakt mit den Schaltkurven. Zusätzlich ist ein Arretiermechanismus zum Arretieren des Nockenträgers in dessen Schaltstellungen vorgesehen. Ein federbelastetes Arretierglied des Arretiermechanismus ist in einer Verschiebeposition des Nockenträgers, in der sich der Aktuator im Kreuzungsbereich der Schaltkurven befindet, derart wirksam, dass über dieses Arretierglied eine Schaltkraft zum Verschieben des Nockenträgers in diesen eingeleitet wird.The publication also describes DE 10 2013 111 476 A1 a valve drive of an internal combustion engine with a base camshaft and a cam carrier which is mounted in a rotationally fixed and axially displaceable manner and which has at least two cams for the alternative actuation of a valve. At least one actuator is required to move the cam carrier provided, to which two switching curves are assigned. The respective switching curve has a meshing area for the actuator, a shifting area for shifting the cam carrier by means of the actuator and an ejecting area. The two switching curves intersect in their shift ranges. In this crossing area, the actuator is out of contact with the switching curves. In addition, a locking mechanism is provided for locking the cam carrier in its switching positions. A spring-loaded locking member of the locking mechanism is effective in a shifting position of the cam carrier in which the actuator is located in the intersection area of the switching cams that a switching force for moving the cam carrier is introduced via this locking member.

Zudem beschreibt die Druckschrift DE 10 2011 114 300 A1 einen Ventiltrieb einer Brennkraftmaschine, mit wenigstens einer Grundnockenwelle, auf der drehfest und zwischen wenigstens zwei Axialpositionen axial verschiebbar wenigstens ein Ventilbetätigungsnocken aufweisender Nockenträger vorgesehen ist, wobei dem Nockenträger zum axialen Verschieben mittels eines Aktuators eine Schaltkulisse zugeordnet ist, welche an ihrem Umfang über zwei in axialer Richtung gegenläufige, sich kreuzende Kulissenbahnen verfügt, die jeweils einen Umkehrpunkt aufweisen. Dabei ist vorgesehen, dass die Umkehrpunkte in Umfangsrichtung versetzt zueinander vorliegen.The document also describes DE 10 2011 114 300 A1 a valve drive of an internal combustion engine, with at least one basic camshaft, on which at least one cam carrier having valve actuation cams is provided in a rotationally fixed manner and axially displaceable between at least two axial positions, the cam carrier being assigned a shift gate for axial displacement by means of an actuator, which on its circumference over two in axial Direction of opposing, intersecting slide tracks, each having a reversal point. It is provided that the reversal points are offset from one another in the circumferential direction.

Aus der Druckschrift DE 10 2013 208 364 A1 ist eine Ventilhubanpassungsvorrichtung bekannt. Bei dieser weist ein Gleitblock einen ersten Vorsprung auf, der von einer radial äußeren Fläche des Gleitblocks an einer Position in einer Radialrichtung entgegen einer Drehrichtung bezüglich einer ersten geneigten Fläche nach außen vorsteht, und einen zweiten Vorsprung, der von der radial äußeren Fläche in der Radialrichtung an einer Position entgegen der Drehrichtung bezüglich einer zweiten geneigten Fläche nach außen vorsteht. Wenn eine Betätigungskomponente in der Radialrichtung durch die erste geneigte Fläche oder die zweite geneigte Fläche nach außen gedrückt wird, ist der erste Vorsprung oder der zweite Vorsprung dazu angepasst, die Betätigungskomponente in der Radialrichtung weiter nach außen zu drücken.From the pamphlet DE 10 2013 208 364 A1 a valve lift adjustment device is known. In this, a slide block has a first protrusion protruding outward from a radially outer surface of the slide block at a position in a radial direction opposite to a rotational direction with respect to a first inclined surface, and a second protrusion protruding from the radially outer surface in the radial direction at a position opposite to the direction of rotation with respect to a second inclined surface protrudes outward. When an operating component is pushed outward in the radial direction by the first inclined surface or the second inclined surface, the first protrusion or the second protrusion is adapted to push the operating component further outward in the radial direction.

Weiter offenbart die Druckschrift DE 10 2007 010 149 A1 einen Ventiltrieb für Gaswechselventile einer Brennkraftmaschine mit mindestens einer Nockenwelle, die in einem Gehäuse der Brennkraftmaschine drehbar gelagert ist, mindestens einem drehfest und axial verschiebbar auf der Nockenwelle geführten Nockenträger, sowie Einrichtungen zum axialen Verschieben des mindestens einen Nockenträgers auf der Nockenwelle in entgegengesetzte Richtungen. Diese Einrichtungen umfassen mindestens zwei Eingriffselemente, die sich mit einer rechtsgängigen beziehungsweise linkgängigen Nut in Eingriff bringen lassen. Um eine Verkleinerung des axialen Bauraums und der Anzahl der zu montierenden Teile zu ermöglichen, sollen die rechtsgängige Nut und die linksgängige Nut unmittelbar nebeneinander angeordnet sein und ineinander übergehen beziehungsweise sich vereinigen.The document also discloses DE 10 2007 010 149 A1 a valve drive for gas exchange valves of an internal combustion engine with at least one camshaft which is rotatably mounted in a housing of the internal combustion engine, at least one non-rotatable and axially displaceable cam carrier guided on the camshaft, and devices for axially moving the at least one cam carrier on the camshaft in opposite directions. These devices comprise at least two engagement elements which can be brought into engagement with a right-hand or left-hand groove. To enable a reduction in the axial installation space and the number of parts to be assembled, the right-hand groove and the left-hand groove should be arranged directly next to one another and merge with one another or merge.

Weitere Ventiltriebe sind aus den Druckschriften US 2010/0126448 A1 und DE 101 48 177 A1 bekannt.Further valve trains can be found in the publications US 2010/0126448 A1 and DE 101 48 177 A1 known.

Es ist Aufgabe der Erfindung, einen Ventiltrieb für eine Brennkraftmaschine vorzuschlagen, welcher gegenüber dem bekannten Stand der Technik Vorteile aufweist, insbesondere einen größeren Verschiebeweg für den Aktuator beziehungsweise den Mitnehmer in axialer Richtung aufweist, gleichzeitig jedoch einfach herzustellen ist.The object of the invention is to propose a valve drive for an internal combustion engine which has advantages over the known prior art, in particular has a greater displacement path for the actuator or the driver in the axial direction, but at the same time is easy to manufacture.

Dies wird erfindungsgemäß mit einem Ventiltrieb mit den Merkmalen des Anspruchs 1 erreicht. Dabei ist vorgesehen, dass der Ventiltrieb wenigstens eine Grundnockenwelle aufweist, auf der drehfest und zwischen wenigstens zwei Axialpositionen axial verlagerbar mindestens ein Ventilbetätigungsnocken aufweisender Nockenträger vorgesehen ist, wobei dem Nockenträger zum axialen Verlagern mittels eines Aktuators eine Schaltkulisse zugeordnet ist, welche an ihrem Umfang zwei in axialer Richtung gegenläufige, teilweise voneinander beabstandete, an einer Mündungsstelle ineinander einmündende Kulissenbahnen aufweist, wobei beide Kulissenbahnen jeweils einen Axialvorsprung in Richtung einer die jeweils andere der Kulissenbahnen in axialer Richtung begrenzende Kulissenbahnwand aufweisen. Weiterhin ist vorgesehen, dass die Axialvorsprünge der Kulissenbahnen in Umfangsrichtung gegeneinander versetzt angeordnet sind. Grundsätzlich ist also vorgesehen, dass beide Kulissenbahnen jeweils einen Axialvorsprung in Richtung einer die jeweils andere der Kulissenbahnen in axialer Richtung begrenzende Kulissenbahnwand aufweisen. Mithilfe des Axialvorsprungs wird der Verschiebeweg der wenigstens einen Kulissenbahn vergrößert. Das bedeutet, dass die Kulissenbahnwand der Kulissenbahn in axialer Richtung der die jeweils andere der Kulissenbahnen begrenzende Kulissenbahnwand vorspringt. Dies bewirkt, dass der Aktuator beziehungsweise dessen Mitnehmer durch den Axialvorsprung weiter in axialer Richtung ausgelenkt wird als dies bei bisherigen Ausführungsformen des Ventiltriebs der Fall ist.This is achieved according to the invention with a valve drive with the features of claim 1. It is provided that the valve drive has at least one basic camshaft on which at least one cam carrier having valve actuation cams is provided in a rotationally fixed manner and axially displaceable between at least two axial positions, the cam carrier being assigned a shift gate for axial displacement by means of an actuator, which has two in has slide tracks running in opposite directions in the axial direction, partially spaced apart from one another at an opening point, both slide tracks each having an axial projection in the direction of a slide track wall delimiting the other of the slide tracks in the axial direction. It is also provided that the axial projections of the slide tracks are arranged offset from one another in the circumferential direction. In principle, it is therefore provided that both slide tracks each have an axial projection in the direction of a slide track wall that delimits the other of the slide tracks in the axial direction. The displacement path of the at least one slide track is increased with the aid of the axial projection. This means that the slide track wall of the slide track projects in the axial direction of the slide track wall delimiting the other of the slide tracks. This has the effect that the actuator or its driver is deflected further in the axial direction by the axial projection than is the case with previous embodiments of the valve drive.

Unter dem Axialvorsprung wird im Rahmen dieser Beschreibung insbesondere ein Vorsprung verstanden, der an einer Umfangsposition bezüglich der Drehachse der Grundnockenwelle eine maximale Erstreckung in axialer Richtung aufweist und beidseitig dieser Umfangsposition mit einer Erstreckung in axialer Richtung ausgestaltet ist, die kleiner ist als die maximale Erstreckung. Der Axialvorsprung liegt insoweit beispielsweise in Form einer bauchigen Erhebung in axialer Richtung vor.
Mit einer solchen Ausgestaltung der Kulissenbahn wird eine unvollständige Verschiebung des Nockenträgers wirkungsvoll vermieden. Bei einem derartigen unvollständigen Verlagern kann es zu Kantenträgern beziehungsweise zu schräg gestellten Rollenschlepphebeln kommen, wobei die Gefahr des Umfallens beziehungsweise einer unzulässig hohen Flächenpressung besteht. Ein Grund für eine unvollständige Verschiebung kann beispielsweise erhöhte Reibung zwischen dem Nockenträger und der Grundnockenwelle, insbesondere zwischen einer Außenverzahnung der Grundnockenwelle und einer in diese eingreifende Innenverzahnung des Nockenträgers sein. Auch durch das Anliegen des Rollenschlepphebels an dem Ventilbetätigungsnocken kann erhöhte Reibung auftreten.In the context of this description, the axial projection is understood to mean in particular a projection which, at a circumferential position with respect to the axis of rotation of the base camshaft, has a maximum extent in the axial direction and is configured on both sides of this circumferential position with an extent in the axial direction that is smaller than that maximum extension. In this respect, the axial projection is in the form of a bulged elevation in the axial direction, for example.
With such a configuration of the link path, incomplete displacement of the cam carrier is effectively avoided. Such incomplete displacement can lead to edge supports or to inclined roller rocker arms, with the risk of falling over or an impermissibly high surface pressure. One reason for an incomplete shift can be, for example, increased friction between the cam carrier and the basic camshaft, in particular between an external toothing of the basic camshaft and an internal toothing of the cam carrier engaging in this. Increased friction can also occur as a result of the roller finger follower resting against the valve actuation cam.

Die beschriebene Ausgestaltung der Kulissenbahn ist insbesondere sinnvoll, wenn dem Nockenträger beziehungsweise der Schaltkulisse eine Rastvorrichtung zugeordnet ist, die den Nockenträger in jeweils einer von mehreren Axialpositionen rastend hält. Insbesondere hält die Rastvorrichtung den Nockenträger in jeder der mehreren Axialpositionen. Beispielsweise sind wenigstens zwei, insbesondere genau zwei voneinander verschiedene Axialpositionen vorgesehen. Zum Überwinden der Rastkraft der Rastvorrichtung zum Wechseln der Axialposition muss eine bestimmte Kraft aufgebracht werden. Dies wird mit Hilfe des Aktuators erzielt. Reicht jedoch der mittels des Aktuators bewirkte Impuls nicht aus, so erreicht der Nockenträger nicht die gewünschte Axialposition, was in dem vorstehend beschriebenen unvollständigen Verlagern resultiert.The described configuration of the slide track is particularly useful when a latching device is assigned to the cam carrier or the shift gate, which latches the cam carrier in one of several axial positions. In particular, the latching device holds the cam carrier in each of the plurality of axial positions. For example, at least two, in particular exactly two, different axial positions are provided. To overcome the locking force of the locking device to change the axial position, a certain force must be applied. This is achieved with the help of the actuator. However, if the impulse caused by the actuator is insufficient, the cam carrier does not reach the desired axial position, which results in the incomplete displacement described above.

Es ist vorgesehen, dass beide Kulissenbahnen jeweils einen Axialvorsprung in Richtung der die jeweils andere der Kulissenbahnen in axialer Richtung begrenzende Kulissenbahnwand aufweist. Das Problem des unvollständigen Verlagerns wird insoweit nicht lediglich für eine der Kulissenbahnen, sondern vielmehr für beide Kulissenbahnen effektiv beseitigt. Bevorzugt weisen die Axialvorsprünge dabei dieselben Abmessungen auf, insbesondere dieselbe Axialerstreckung, insbesondere also dieselbe maximale Axialerstreckung, und/oder dieselbe Erstreckung in Umfangsrichtung.It is provided that both slide tracks each have an axial projection in the direction of the slide track wall delimiting the other of the slide tracks in the axial direction. The problem of the incomplete Shifting is effectively eliminated not only for one of the slide tracks, but rather for both slide tracks. In this case, the axial projections preferably have the same dimensions, in particular the same axial extent, in particular therefore the same maximum axial extent, and / or the same extent in the circumferential direction.

Durch den Axialvorsprung beziehungsweise die beiden Axialvorsprünge wird jedoch die Breite der Kulissenbahnen verringert beziehungsweise bei vorgegebener Breite der Kulissenbahnen der Nockenträger verbreitert. Letzteres ist grundsätzlich aufgrund des vorgegebenen Bauraums unerwünscht. Ersteres führt dazu, dass der Ventiltrieb schwierig herzustellen ist, weil unter Umständen die Kulissenbahnen, insbesondere in demjenigen Bereich, in welchem sie die gemeinsame Kulissenbahn ausbilden, zu schmal sind, um sie mit demselben Fräswerkzeug herzustellen, welcher für die weiteren Bereiche der Kulissenbahnen verwendet wird.Due to the axial projection or the two axial projections, however, the width of the slide tracks is reduced or, given a given width of the slide tracks of the cam carriers, widened. The latter is fundamentally undesirable due to the given installation space. The former means that the valve train is difficult to manufacture because under certain circumstances the slide tracks, especially in the area in which they form the common slide track, are too narrow to be made with the same milling tool that is used for the other areas of the slide tracks .

Schließlich ist vorgesehen, dass die Axialvorsprünge der Kulissenbahnen in Umfangsrichtung gegeneinander versetzt angeordnet sind. Das bedeutet vorzugsweise, dass die Umfangspositionen, an welchen die Axialvorsprünge jeweils ihre größte Erstreckung in axialer Richtung aufweisen, in Umfangsrichtung gegeneinander versetzt sind. Bei einer gegenüberliegenden Anordnung der Axialvorsprünge tritt jedoch erneut das Problem zutage, dass die Kulissenbahnen unter Umständen zu schmal für das verwendete Fräswerkzeug sind. Aus diesem Grund ist es besonders vorteilhaft, wenn die Axialvorsprünge gegeneinander versetzt angeordnet sind, also einander in Umfangsrichtung nicht gegenüberliegen.Finally, it is provided that the axial projections of the slide tracks are arranged offset from one another in the circumferential direction. This preferably means that the circumferential positions at which the axial projections each have their greatest extent in the axial direction are offset from one another in the circumferential direction. If the axial projections are arranged opposite one another, however, the problem arises again that the slide tracks are under certain circumstances too narrow for the milling tool used. For this reason, it is particularly advantageous if the axial projections are arranged offset from one another, that is to say do not lie opposite one another in the circumferential direction.

Eine Weiterbildung der Erfindung sieht vor, dass der Versatz der Axialvorsprünge derart gewählt ist, dass die kleinste Entfernung zwischen den Axialvorsprüngen zumindest eine Breite der Kulissenbahnen entspricht. Die kleinste Entfernung zwischen den Axialvorsprüngen ist vorzugsweise definiert als die Länge derjenigen geraden Linie, welche die Axialvorsprünge beziehungsweise diejenigen Umfangspositionen, an welchen die Axialvorsprünge ihre jeweils größte Erstreckung in axialer Richtung aufweisen, miteinander verbindet. Diese kleinste Entfernung soll wenigstens der Breite der Kulissenbahnen entsprechen, wobei die Kulissenbahnen üblicherweise dieselbe Breite aufweisen. Selbstverständlich kann die kleineste Entfernung zwischen den Axialvorsprüngen jedoch auch größer sein als die Breite der Kulissenbahnen.A further development of the invention provides that the offset of the axial projections is selected such that the smallest distance between the axial projections corresponds to at least one width of the slide tracks. The smallest distance between the axial projections is preferably defined as the length of that straight line which connects the axial projections or those circumferential positions at which the axial projections have their respective greatest extension in the axial direction. This smallest distance should correspond at least to the width of the slide tracks, the slide tracks usually having the same width. Of course, the smallest distance between the axial projections can also be greater than the width of the slide tracks.

In einer weiteren bevorzugten Ausgestaltung der Erfindung ist vorgesehen, dass die Kulissenbahnen vor der Mündungsstelle separat voneinander und nach der Mündungsstelle in Form einer gemeinsamen Kulissenbahn verlaufen, wobei in der gemeinsamen Kulissenbahn eine Ausschubrampe ausgebildet ist. Auf eine derartige Ausgestaltung wurde vorstehend bereits hingewiesen. In Umfangsrichtung gesehen vor der Mündungsstelle liegen die Kulissenbahnen beabstandet voneinander vor, das bedeutet, dass die sie ausbildenden Vertiefungen an derselben Umfangsposition nicht ineinander übergehen.In a further preferred embodiment of the invention, it is provided that the slide tracks run separately from each other in front of the opening and after the opening in the form of a common slide track, an extension ramp being formed in the common slide track. Such a configuration has already been pointed out above. Viewed in the circumferential direction in front of the opening point, the slide tracks are spaced apart from one another, which means that the depressions that form them do not merge into one another at the same circumferential position.

An der Mündungsstelle treffen die Kulissenbahnen erstmals aufeinander beziehungsweise gehen ineinander über. In Umfangsrichtung nach der Mündungsstelle verlaufen die Kulissenbahnen gemeinsam, sodass sie die gemeinsame Kulissenbahn ausbilden. In letztere ist die Ausschubrampe vorgesehen, welche sich insbesondere durch einen in die von der Mündungsstelle abgewandte Richtung abnehmende Tiefe der Kulissenbahnen beziehungsweise eine wachsende Entfernung eines Grunds der Kulissenbahnen auszeichnet. Für ein Verlagern des Nockenträgers greift der Mitnehmer vor der Mündungsstelle in eine der Kulissenbahnen ein und durchläuft diese bis zu der Mündungsstelle. Nachfolgend durchläuft er die gemeinsame Kulissenbahn und wird durch die Ausschubrampe in radialer Richtung nach außen gedrängt, sodass er nach dem Durchlaufen der gemeinsamen Kulissenbahn vorzugsweise wieder in seiner Ausgangsposition vorliegt.At the point where they meet, the slide tracks meet or merge for the first time. In the circumferential direction after the opening point, the slide tracks run together so that they form the common slide track. In the latter, the extension ramp is provided, which is characterized in particular by a decreasing depth of the slide tracks in the direction facing away from the opening or an increasing distance from a base of the slide tracks. For a displacement of the cam carrier, the driver engages in one of the slide tracks in front of the muzzle and runs through it up to the muzzle. Then he goes through the common slide track and is pushed outward in the radial direction by the extension ramp, so that it is preferably back in its starting position after passing through the common slide track.

In einer weiteren bevorzugten Ausgestaltung der Erfindung ist vorgesehen, dass die Axialvorsprünge in der gemeinsamen Kulissenbahn vorliegen. Bevorzugt liegt zumindest diejenige Umfangsposition, an welcher der Axialvorsprung beziehungsweise die Axialvorsprünge ihre größte Erstreckung in axialer Richtung aufweisen, - in Umfangsrichtung gesehen - in der gemeinsamen Kulissenbahn oder in der Mündungsstelle.In a further preferred embodiment of the invention it is provided that the axial projections are present in the common slide track. Preferably, at least that circumferential position at which the axial projection or the axial projections have their greatest extent in the axial direction is - seen in the circumferential direction - in the common slide track or in the opening point.

Eine weitere Ausgestaltung der Erfindung sieht vor, dass die Axialerstreckungen der Axialvorsprünge derart gewählt sind, dass der jeweilige Axialvorsprung an der Stelle seiner maximalen axialen Erstreckung in axialer Richtung um eine Entfernung von einer Längsmittelbahn der gemeinsamen Kulissenbahn beabstandet ist, die mindestens der Hälfte der axialen Erstreckung eines Mitnehmers des Aktuators entspricht. Die Längsmittelbahn entspricht beispielsweise der vorstehend bereits erläuterten Kurvenbahn, welche stets in der Mitte der jeweiligen Kulissenbahn verläuft. Beispielsweise verläuft die Längsmittelbahn jeder Kulissenbahn in axialer Richtung mittig in der Kulissenbahn und auf deren Grund.A further embodiment of the invention provides that the axial extensions of the axial projections are selected such that the respective axial projection at the point of its maximum axial extension is spaced apart in the axial direction by a distance from a longitudinal center path of the common slide path which is at least half of the axial extension corresponds to a driver of the actuator. The longitudinal center path corresponds, for example, to the curved path already explained above, which always runs in the middle of the respective slide path. For example, the longitudinal center track of each slide track runs in the axial direction in the middle of the slide track and on its base.

Vorzugsweise entspricht die Entfernung des Axialvorsprungs von der Längsmittelachse genau der Hälfte der axialen Erstreckung des Mitnehmers. Das bedeutet, dass der Mitnehmer bei dem Durchlaufen der Kulissenbahn von dem Axialvorsprung derart ausgelenkt wird, dass er nach dem Axialvorsprung - in axialer Richtung gesehen - in etwa mittig, vorzugsweise genau mittig, in der Kulissenbahn, beziehungsweise der gemeinsamen Kulissenbahn angeordnet ist. Insbesondere sind beide Axialvorsprünge beziehungsweise deren Axialerstreckungen entsprechend gewählt, sodass der Mitnehmer unabhängig davon, welche Kulissenbahn er durchläuft, in Umfangsrichtung nah dem Axialvorsprung in axialer Richtung mittig in der Kulissenbahn vorliegt.The distance of the axial projection from the longitudinal center axis preferably corresponds to exactly half the axial extension of the driver. This means that the driver is deflected by the axial projection as it traverses the slide track in such a way that after the axial projection - viewed in the axial direction - it is approximately centrally, preferably exactly in the middle, in the slide track or the common slide track. In particular, both are axial projections or their axial extensions are selected accordingly, so that the driver is present in the circumferential direction close to the axial projection in the center of the slide track regardless of which slide track it traverses.

In einer weiteren Ausgestaltung der Erfindung ist vorgesehen, dass Nuttiefen der Kulissenbahnen an gleichen Umfangspositionen gleich sind. Unter der Nuttiefe ist vorzugsweise der Abstand zwischen einem Grund der jeweiligen Kulissenbahn und einem Außenumfang der Schaltkulisse zu verstehen. Je geringer also die Nuttiefe ist, umso größer ist der Abstand zwischen der Drehachse der Grundnockenwelle und dem Grund der Kulissenbahn in radialer Richtung. Die gleichen Nuttiefen der Kulissenbahnen an gleichen Umfangspositionen haben den Vorteil, dass der Grund einer der Kulissenbahnen ohne Absatz in radialer Richtung in den Grund der anderen Kulissenbahn übergeht, sodass also der Grund beziehungsweise der Boden der gemeinsamen Kulissenbahn stetig beziehungsweise ohne Sprung in radialer Richtung ausgebildet ist.In a further embodiment of the invention it is provided that the groove depths of the link tracks are the same at the same circumferential positions. The groove depth is preferably to be understood as the distance between a base of the respective gate track and an outer circumference of the shift gate. The smaller the groove depth, the greater the distance between the axis of rotation of the base camshaft and the base of the slide track in the radial direction. The same groove depths of the slide tracks at the same circumferential positions have the advantage that the base of one of the slide tracks merges into the base of the other slide track without a shoulder in the radial direction, so that the base or the bottom of the common slide track is formed continuously or without a jump in the radial direction .

Schließlich kann in einer weiteren Ausgestaltung der Erfindung vorgesehen sein, dass die Nuttiefe ab einer Stelle der größten Axialerstreckung desjenigen Axialvorsprungs zur Bildung der Ausschubrampe abnimmt, der in Umfangsrichtung vorne liegt. Wie bereits erläutert, sorgt die Ausschubrampe für ein Ausschieben des Mitnehmers in radialer Richtung aus der Kulissenbahn beziehungsweise den Kulissenbahnen. Zu diesem Zweck soll die Nuttiefe im Bereich der Ausschubrampe abnehmen, vorzugsweise stetig abnehmen. Insbesondere beginnt die Ausschubrampe und mithin das Abnehmen der Nuttiefe in Umfangsrichtung gesehen bereits ab derjenigen Umfangsposition, an welcher die größte Axialerstreckung des Axialvorsprungs vorliegt.Finally, in a further embodiment of the invention it can be provided that the groove depth decreases from a point of the greatest axial extent of that axial projection to form the extension ramp which is at the front in the circumferential direction. As already explained, the extension ramp ensures that the driver is pushed out in the radial direction out of the slide track or the slide tracks. For this purpose, the groove depth should decrease, preferably decrease continuously, in the area of the extension ramp. In particular, the extension ramp and consequently the decrease in the groove depth, viewed in the circumferential direction, already begins from the circumferential position at which the greatest axial extent of the axial projection is present.

Sind mehrere Axialvorsprünge vorhanden, welche zudem in Umfangsrichtung gegeneinander versetzt angeordnet sind, so kann das Abnehmen der Nuttiefe bereits ab dem in Umfangsrichtung vorne liegenden Axialvorsprung vorgesehen sein, also demjenigen Axialvorsprung, welcher der gemeinsamen Kulissenbahn abgewandt ist. Selbstverständlich ist alternativ auch ein Beginn der Abnahme der Nuttiefe ab demjenigen Axialvorsprung realisierbar, welcher in Umfangsrichtung hinten liegt.If there are several axial projections which are also offset from one another in the circumferential direction, the groove depth can be reduced from the axial projection at the front in the circumferential direction, i.e. the axial projection facing away from the common slide track. As an alternative, of course, it is also possible to start the decrease in the groove depth from that axial projection which is at the rear in the circumferential direction.

Die Erfindung betrifft weiterhin eine Brennkraftmaschine mit einem Ventiltrieb, insbesondere gemäß den vorstehenden Ausführungen, wobei der Ventiltrieb wenigstens eine Grundnockenwelle aufweist, auf der drehfest und zwischen wenigstens zwei Axialpositionen axial verlagerbar mindestens ein Ventilbetätigungsnocken aufweisender Nockenträger vorgesehen ist, wobei dem Nockenträger zum axialen Verlagern mittels eines Aktuators eine Schaltkulisse zugeordnet ist, welche an ihrem Umfang zwei in axialer Richtung gegenläufige, teilweise voneinander beabstandete, an einer Mündungsstelle ineinander einmündende Kulissenbahnen aufweist, wobei beide Kulissenbahnen jeweils einen Axialvorsprung in Richtung einer die jeweils andere der Kulissenbahnen in axialer Richtung begrenzenden Kulissenbahnwand aufweisen. Dabei ist vorgesehen, dass die Axialvorsprünge der Kulissenbahnen in Umfangsrichtung gegeneinander versetzt angeordnet sind.The invention further relates to an internal combustion engine with a valve drive, in particular according to the above statements, the valve drive having at least one basic camshaft on which at least one cam carrier having valve actuation cams is provided in a rotationally fixed manner and axially displaceable between at least two axial positions, the cam carrier being axially displaced by means of a Actuator is assigned a shift gate, which on its circumference has two axially opposite, partially spaced from each other, at an opening point into each other slotted link tracks, wherein both gate tracks each have an axial projection in the direction of the other of the gate tracks in the axial direction delimiting gate track wall. It is provided that the axial projections of the slide tracks are offset from one another in the circumferential direction.

Auf die Vorteile einer derartigen Ausgestaltung der Brennkraftmaschine beziehungsweise des Ventiltriebs wurde bereits hingewiesen. Sowohl die Brennkraftmaschine als auch der Ventiltrieb können gemäß den vorstehenden Ausführungen weitergebildet sein, sodass insoweit auf diese verwiesen wird.The advantages of such a configuration of the internal combustion engine or of the valve drive have already been pointed out. Both the internal combustion engine and the valve drive can be developed in accordance with the above explanations, so that reference is made to them in this respect.

Die Erfindung wird nachfolgend anhand der in der Zeichnung dargestellten Ausführungsbeispiele näher erläutert, ohne dass eine Beschränkung der Erfindung erfolgt. Dabei zeigt:

Figur 1
einen Bereich einer Brennkraftmaschine, nämlich eine Schaltkulisse eines Ventiltriebs, und
Figur 2
eine schematische Darstellung der Verläufe von Kulissenbahnen der Schaltkulisse.
The invention is explained in more detail below with reference to the exemplary embodiments shown in the drawing, without restricting the invention. It shows:
Figure 1
an area of an internal combustion engine, namely a shift gate of a valve drive, and
Figure 2
a schematic representation of the courses of slide tracks of the shift gate.

Die Figur 1 zeigt einen Bereich einer Brennkraftmaschine 1, insbesondere eines Ventiltriebs 2. Konkret ist eine Schaltkulisse 3 gezeigt, die auf einer Grundnockenwelle 4 des Ventiltriebs 2 in axialer Richtung verlagerbar angeordnet ist. Beispielsweise weist die Schaltkulisse 3 zu diesem Zweck eine Innenverzahnung auf, welche in eine Außenverzahnung der Grundnockenwelle 4 eingreift. Der Schaltkulisse 3 ist wenigstens ein hier nicht dargestellter Nockenträger zugeordnet, an welchem wenigstens ein Ventilbetätigungsnocken vorgesehen ist. Der Ventilbetätigungsnocken dient zur Betätigung wenigstens eines Gaswechselventils der Brennkraftmaschine 1.The Figure 1 shows a region of an internal combustion engine 1, in particular a valve drive 2. Specifically, a shift gate 3 is shown, which is arranged on a base camshaft 4 of the valve drive 2 so as to be displaceable in the axial direction. For example, the shift gate 3 has an internal toothing for this purpose, which engages in an external toothing of the basic camshaft 4. The shift gate 3 is assigned at least one cam carrier, not shown here, on which at least one valve actuating cam is provided. The valve actuation cam is used to actuate at least one gas exchange valve of the internal combustion engine 1.

Vorzugsweise sind an dem Nockenträger mehrere Ventilbetätigungsnocken vorgesehen, wobei in unterschiedlichen axialen Positionen des Nockenträgers unterschiedliche Ventilbetätigungsnocken zur Betätigung des Gaswechselventils dienen. Der Nockenträger ist mittels der Schaltkulisse 3 in axialer Richtung verlagerbar. Zu diesem Zweck verfügt der Ventiltrieb 2 über einen Aktuator 5 mit einem Mitnehmer 6. Der Aktuator 5 ist derart ausgebildet, dass der Mitnehmer 6 in radialer Richtung bezüglich einer Drehachse 7 der Grundnockenwelle 4 verlagerbar ist. Dargestellt ist er einmal mit durchgezogenen Linien in einer Ausgangsposition sowie mit gestrichelten Linien in einer ausgefahrenen Position.A plurality of valve actuation cams are preferably provided on the cam carrier, with different valve actuation cams serving to actuate the gas exchange valve in different axial positions of the cam carrier. The cam carrier can be displaced in the axial direction by means of the shift gate 3. For this purpose, the valve drive 2 has an actuator 5 with a driver 6. The actuator 5 is designed such that the driver 6 can be displaced in the radial direction with respect to an axis of rotation 7 of the base camshaft 4. It is shown once with solid lines in a starting position and with dashed lines in an extended position.

Die Schaltkulisse 3 verfügt über eine erste Kulissenbahn 8 sowie eine zweite Kulissenbahn 9. Jede der Kulissenbahnen 8 und 9 wird von einer Längsmittelbahn 10 beziehungsweise 11 definiert, welche in axialer Richtung gesehen mittig in der jeweiligen Kulissenbahn 8 beziehungsweise 9 verläuft. Die Kulissenbahnen 8 und 9 gehen an einer Mündungsstelle 12 ineinander über. Die Mündungsstelle 12 kann durch denjenigen Punkt 13 definiert sein, an welchem die Längsmittelbahnen 10 und 11 ineinander übergehen. Alternativ kann unter der Mündungsstelle 12 auch diejenige Umfangsposition verstanden werden, an welcher erstmalig eine zwischen den Kulissenbahnen 8 und 9 vorliegende Trennwand 14 entfällt.The shift gate 3 has a first gate track 8 and a second gate track 9. Each of the gate tracks 8 and 9 is defined by a longitudinal center track 10 and 11, which runs centrally in the respective gate track 8 and 9, viewed in the axial direction. The slide tracks 8 and 9 merge into one another at an opening point 12. The opening point 12 can be defined by that point 13 at which the longitudinal center tracks 10 and 11 merge into one another. Alternatively, the opening point 12 can also be understood to mean that circumferential position at which a partition 14 present between the slide tracks 8 and 9 is omitted for the first time.

Es wird deutlich, dass die Kulissenbahnen 8 und 9 vor der Mündungsstelle 12 voneinander beabstandet sind, insbesondere liegt zwischen ihnen die Trennwand 14 vor. Weil sie jedoch in axialer Richtung gegenläufig ausgestaltet sind, laufen sie aufeinander zu, sodass sie an der Mündungsstelle 12 ineinander einmünden. Nach der Mündungsstelle 12 laufen sie in Form einer gemeinsamen Kulissenbahn 15 weiter. Auch diese ist wiederum charakterisiert durch den Verlauf der Längsmittelbahnen 10 und 11, welche nunmehr überdeckend verlaufen. In axialer Richtung nach außen sind die Kulissenbahnen 8 und 9 jeweils durch eine Kulissenbahnwand 16 beziehungsweise 17 begrenzt.It becomes clear that the slide tracks 8 and 9 are spaced apart from one another in front of the opening point 12, in particular the partition 14 is present between them. However, because they are designed to run in opposite directions in the axial direction, they run towards one another so that they merge into one another at the opening point 12. After the opening point 12, they continue to run in the form of a common slide track 15. This, too, is again characterized by the course of the longitudinal center tracks 10 and 11, which now overlap. In the outward axial direction, the slide tracks 8 and 9 are each delimited by a slide track wall 16 and 17, respectively.

Soll die Schaltkulisse 3 und mithin der wenigstens eine Nockenträger in axialer Richtung verlagert werden, so wird der Aktuator 5 derart angesteuert, dass der Mitnehmer 6 in radialer Richtung ausgefahren, also in Richtung der Grundnockenwelle 4 verlagert wird. Entsprechend greift er in eine der Kulissenbahnen 8 und 9 (hier: die erste Kulissenbahn 8) ein. Weil die Schaltkulisse 3 von der Grundnockenwelle 3 in Umfangsrichtung angetrieben wird, durchläuft der Mitnehmer 6 die Kulissenbahn 8 in Richtung der gemeinsamen Kulissenbahn 15. Dabei liegt er zumindest teilweise an der Kulissenbahnwand 16 an, wodurch die Schaltkulisse 3 und mithin auch der Nockenträger in axialer Richtung verlagert wird.
Es ist nun vorgesehen, dass zumindest eine der Kulissenbahnen 8 und 9, in dem hier dargestellten Ausführungsbeispiel beide Kulissenbahnen 8 und 9, einen Axialvorsprung 18 beziehungsweise 19 aufweisen. Dieser ragt in Richtung der die jeweils andere der Kulissenbahnen 9 beziehungsweise 8 in axialer Richtung begrenzenden Kulissenbahnwand 17 beziehungsweise 16. Der Axialvorsprung 18 beziehungsweise 19 ist dabei derart ausgestaltet, dass seine Erstreckung in axialer Richtung der die jeweils andere Kulissenbahn 9 beziehungsweise 8 begrenzende Kulissenbahnwand 17 beziehungsweise 16 zunächst stets größer wird, bis eine maximale Axialerstreckung erreicht ist. In Umfangsrichtung nach derjenigen Umfangsposition, an welcher diese maximale Axialerstreckung vorliegt, nimmt die Axialerstreckung wieder ab.If the shift gate 3 and therefore the at least one cam carrier are to be displaced in the axial direction, the actuator 5 is activated in such a way that the driver 6 is extended in the radial direction, that is to say is displaced in the direction of the base camshaft 4. Accordingly, it engages in one of the slide tracks 8 and 9 (here: the first slide track 8). Because the shift gate 3 is driven in the circumferential direction by the basic camshaft 3, the driver 6 runs through the gate track 8 in the direction of the common slide track 15. It rests at least partially on the slide track wall 16, whereby the shift gate 3 and consequently also the cam carrier is displaced in the axial direction.
It is now provided that at least one of the slide tracks 8 and 9, in the embodiment shown here both slide tracks 8 and 9, have an axial projection 18 and 19, respectively. This protrudes in the direction of the respective other of the slide tracks 9 or 8 in the axial direction limiting slide track wall 17 or 16 16 is initially always larger until a maximum axial extension is reached. In the circumferential direction after that circumferential position at which this maximum axial extension is present, the axial extension decreases again.

Das bedeutet im Falle des hier dargestellten Ausführungsbeispiels, dass die Breite der Kulissenbahnen 8 und 9 beziehungsweise der gemeinsamen Kulissenbahn 15 nach der Umfangsposition, an welcher die maximale Axialerstreckung vorliegt, zunimmt beziehungsweise die Axialerstreckung des Axialvorsprungs 18 beziehungsweise 19 wieder abnimmt. In dem hier dargestellten Ausführungsbeispiel sind die Axialvorsprünge 18 und 19 in Umfangsrichtung gegenüberliegend angeordnet. Darunter ist vorzugsweise zu verstehen, dass die Umfangspositionen, an welchen sie ihre maximale Axialerstreckung aufweisen, übereinstimmen.In the case of the exemplary embodiment shown here, this means that the width of the slide tracks 8 and 9 or the common slide track 15 increases or the axial extension of the axial projection 18 or 19 decreases again after the circumferential position at which the maximum axial extent is present. In the embodiment shown here, the axial projections 18 and 19 are arranged opposite one another in the circumferential direction. This is preferably to be understood as meaning that the circumferential positions at which they have their maximum axial extent coincide.

Eine derartige Ausgestaltung stellt zwar einen vergrößerten Verlagerungsweg der Schaltkulisse 3 sicher. Im Vergleich zu anderen Ausführungen der Schaltkulisse 3 ist die gemeinsame Kulissenbahn 15 in axialer Richtung jedoch schmal, sodass eine Herstellung der gemeinsamen Kulissenbahn 15 unter Umständen nicht mit demselben Fräswerkzeug erfolgen kann, wie die Herstellung der Kulissenbahnen 8 und 9 in Umfangsrichtung vor der Mündungsstelle 12. Aus diesem Grund ist es besonders bevorzugt, wenn die Axialvorsprünge 18 und 19 in Umfangsrichtung gegeneinander versetzt angeordnet sind.Such a configuration ensures an increased displacement path of the shift gate 3. In comparison to other designs of the shift gate 3, the common gate track 15 is narrow in the axial direction, so that a production of the common Slide track 15 may not be able to use the same milling tool as the production of slide tracks 8 and 9 in the circumferential direction in front of the opening point 12. For this reason, it is particularly preferred if the axial projections 18 and 19 are arranged offset from one another in the circumferential direction.

Dies wird anhand der Figur 2 verdeutlicht. Dort sind schematisch Verläufe der Kulissenbahnen 8 und 9 dargestellt, wobei zudem rein beispielhaft mehrere Positionen des Mitnehmers 6 angedeutet sind. In der hier dargestellten Ausführungsform liegt die Umfangsposition der maximalen Axialerstreckung der zweiten Kulissenbahn 9 an einer Umfangsposition, an welcher der Axialvorsprung 18 gerade nicht mehr vorliegt. Selbstverständlich kann die Umfangsposition der maximalen Axialerstreckung auch in Umfangsrichtung nach dem Axialvorsprung 18 angeordnet sein.This is done using the Figure 2 clarified. There the courses of the slide tracks 8 and 9 are shown schematically, with several positions of the driver 6 being indicated purely by way of example. In the embodiment shown here, the circumferential position of the maximum axial extent of the second link path 9 is at a circumferential position at which the axial projection 18 is no longer present. Of course, the circumferential position of the maximum axial extent can also be arranged after the axial projection 18 in the circumferential direction.

Die Axialvorsprünge 18 und 19 sind derart ausgestaltet beziehungsweise ist ihr Versatz in Umfangsrichtung derart gewählt, dass die kleinste Entfernung 20 zwischen den Axialvorsprüngen 18 und 19 zumindest einer Breite 21 der Kulissenbahnen 8 und 9 entspricht. Vorzugsweise weisen diese dieselbe Breite auf. Zusätzlich kann es vorgesehen sein, dass der kleinste Abstand 22 in axialer Richtung zwischen den Axialvorsprüngen 18 und 19 derart bemessen ist, dass er zumindest einer Axialerstreckung 23 des Mitnehmers 6 entspricht. Insbesondere ist der Abstand 22 genau so groß wie die Erstreckung 23 oder allenfalls geringfügig größer.The axial projections 18 and 19 are configured or their offset in the circumferential direction is selected such that the smallest distance 20 between the axial projections 18 and 19 corresponds to at least a width 21 of the slide tracks 8 and 9. These preferably have the same width. In addition, it can be provided that the smallest distance 22 in the axial direction between the axial projections 18 and 19 is dimensioned in such a way that it corresponds to at least one axial extension 23 of the driver 6. In particular, the distance 22 is exactly as large as the extension 23 or at most slightly larger.

Bedingt durch die Wahl der Entfernung 20, welche zumindest der Breite 21 der Kulissenbahnen 8 und 9 entsprechen soll, ist eine einfache Fertigung der Kulissenbahnen 8 und 9 möglich. Dabei kann die gemeinsame Kulissenbahn 15 mit demselben Fräswerkzeug ausgebildet werden wie die Kulissenbahnen 8 und 9.Due to the selection of the distance 20, which should correspond at least to the width 21 of the slide tracks 8 and 9, the slide tracks 8 and 9 can be manufactured easily. The common slide track 15 can be formed with the same milling tool as the slide tracks 8 and 9.

Claims (8)

  1. Valve train (2) for an internal combustion engine (1), comprising at least one main camshaft (4), on which at least one cam carrier having valve-actuating cams is provided, said cam carrier being rotationally fixed and capable of axial movement between at least two axial positions, wherein a shifting gate (3) is associated with the cam carrier for axial movement by means of an actuator (5), which shifting gate has two gate tracks (8, 9) on the perimeter of the shifting gate, which extend oppositely in the axial direction, are partially spaced apart from each other and lead into each other at a mouth point (12), wherein both of the gate tracks (8, 9) respectively have an axial projection (18, 19) toward a gate track wall (16, 17) bounding the other of the gate tracks (9, 8) in the axial direction, wherein the axial projections (18, 19) of the gate tracks (8, 9) are arranged offset from one another in the peripheral direction.
  2. Valve train according to claim 1, characterised in that the offset of the axial projections (18, 19) is selected such that the smallest distance (20) between the axial projections (18, 19) corresponds to at least one width (21) of the gate tracks (8, 9).
  3. Valve train according to any one of the preceding claims, characterised in that the gate tracks (8, 9) run separately from one another before the mouth point (12) and after the mouth point (12) run in the form of a common gate track (15), wherein an extension ramp is formed in the common gate track (15).
  4. Valve train according to claim 3, characterised in that the axial projections (18, 19) are present in the common gate track (15).
  5. Valve train according to claim 3 or 4, characterised in that the axial extensions of the axial projections (18, 19) are selected such that the respective axial projection (18, 19), at the point of its maximum axial extension, is spaced apart in the axial direction by a distance from a longitudinal central track (10, 11) of the common gate track (15), which distance corresponds to at least half the axial extension (23) of a driver (6) of the actuator (5).
  6. Valve train according to any one of the preceding claims, characterised in that groove depths of the gate tracks (8, 9) are the same at the same peripheral positions.
  7. Valve train according to any one of claims 3 to 6, characterised in that the groove depth decreases from a point of the greatest axial extension of that axial projection (18, 19) for forming the extension ramp which lies in front in the peripheral direction.
  8. Internal combustion engine (1) with a valve train (2), comprising at least one main camshaft (4), on which at least one cam carrier having valve-actuating cams is provided, said cam carrier being rotationally fixed and capable of axial movement between at least two axial positions, wherein a shifting gate (3) is associated with the cam carrier for axial movement by means of an actuator (5), which shifting gate has two gate tracks (8, 9) on the perimeter of the shifting gate, which extend oppositely in the axial direction, are partially spaced apart from each other and lead into each other at a mouth point (12), wherein both of the gate tracks (8, 9) respectively have an axial projection (18, 19) toward a gate track wall (16, 17) bounding the other of the gate tracks (9, 8) in the axial direction, wherein the axial projections (18, 19) of the gate tracks (8, 9) are arranged offset from one another in the peripheral direction.
EP15795113.8A 2014-11-18 2015-11-10 Valve train for an internal combustion engine and corresponding internal combustion engine Active EP3221567B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102014017036.5A DE102014017036B3 (en) 2014-11-18 2014-11-18 Valve train for an internal combustion engine and corresponding internal combustion engine
PCT/EP2015/002247 WO2016078751A1 (en) 2014-11-18 2015-11-10 Valve train for an internal combustion engine and corresponding internal combustion engine

Publications (2)

Publication Number Publication Date
EP3221567A1 EP3221567A1 (en) 2017-09-27
EP3221567B1 true EP3221567B1 (en) 2020-10-07

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EP (1) EP3221567B1 (en)
JP (1) JP6462129B2 (en)
DE (1) DE102014017036B3 (en)
WO (1) WO2016078751A1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6400040B2 (en) * 2016-03-31 2018-10-03 本田技研工業株式会社 Variable valve gear
DE102019125100A1 (en) 2019-09-18 2021-03-18 Thyssenkrupp Ag Shift gate, sliding cam system and camshaft
DE102021210649A1 (en) * 2021-09-23 2023-03-23 Thyssenkrupp Ag Shift gate, sliding cam system and camshaft

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10148177B4 (en) * 2001-09-28 2015-05-13 Schaeffler Technologies AG & Co. KG Valve train with valve lift switching for the gas exchange valves of a 4-stroke internal combustion engine
DE102007010149A1 (en) * 2007-03-02 2008-09-04 Audi Ag Automotive piston engine gas valve timer has right- and left-handed grooves are located immediately alongside and translating into each other
DE102007037232A1 (en) * 2007-08-07 2009-02-12 Eto Magnetic Gmbh Device for adjusting the camshaft of an internal combustion engine
DE102008024911A1 (en) * 2008-05-23 2009-11-26 Schaeffler Kg Valve gear for internal-combustion engine, has cam shaft, which has carrier shaft and cam part, where cam part is provided with guiding element
DE102008054254A1 (en) * 2008-10-31 2010-05-06 Schaeffler Kg Camshaft for a variable-stroke valve drive of an internal combustion engine
DE102008060170A1 (en) * 2008-11-27 2010-06-02 Dr.Ing.H.C.F.Porsche Aktiengesellschaft Valve gear of an internal combustion engine
DE102011114300B4 (en) * 2011-09-23 2016-02-25 Audi Ag Valve gear of an internal combustion engine and internal combustion engine
JP5598497B2 (en) * 2012-05-08 2014-10-01 株式会社デンソー Valve lift adjustment device
DE102013111476B4 (en) * 2013-10-17 2021-09-09 Dr. Ing. H.C. F. Porsche Aktiengesellschaft Valve drive of an internal combustion engine

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

Also Published As

Publication number Publication date
DE102014017036B3 (en) 2016-03-24
WO2016078751A1 (en) 2016-05-26
JP6462129B2 (en) 2019-01-30
JP2018500492A (en) 2018-01-11
EP3221567A1 (en) 2017-09-27

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