EP3564500A1 - Variable valve drive - Google Patents

Abstract

The invention relates to a variable valve train (10), in particular with a sliding cam system (14), for an internal combustion engine. The variable valve train (10) has a shaft (12), a cam carrier (22) which is rotatably and axially displaceable on the shaft (12) and has a first cam (28) and a second cam (29) on. The variable valve train (10) has an actuator device for axially displacing the cam carrier (22) and a carrying device (46) which at least partially surrounds a lever axis (42) of a force transmission device (16) and carries the actuator device (24, 26). The variable valve drive (10) can offer the advantage that a space-favorable arrangement of the actuator device (24, 26) in the region of the lever axis (42) is made possible. At the same time a support of the actuator device (24, 26) by means of the support device (46) on the lever axis (42) by the encompassing stiffen the flexurally soft lever axis (42).

Description

The invention relates to a variable valve train, in particular with a sliding cam system, for an internal combustion engine.

Valve-controlled internal combustion engines have one or more controllable intake and exhaust valves per cylinder. Variable valve trains allow flexible control of the valves to change the opening time, closing time and / or valve lift. As a result, the engine operation can be adapted, for example, to a specific load situation. For example, a variable valve train can be realized by a so-called sliding cam system.

From the DE 196 11 641 C1 is an example of such a sliding cam system is known, with which the operation of a gas exchange valve is made possible with several different lifting curves. For this purpose, a sliding cam with at least one, several cam tracks having cam portion rotatably but axially displaceably mounted on the camshaft having a Hubkontur, in which an actuator is introduced in the form of a pin from radially outside to produce an axial displacement of the sliding cam. Due to the axial displacement of the sliding cam, a different valve lift is set in the respective gas exchange valve. The sliding cam is thereby locked relative to the camshaft by the axial displacement thereof in its axial relative position on the camshaft.

The sliding cam system can take up a considerable amount of space. In particular, an arrangement of the actuators for moving a cam carrier (sliding cam) can be a challenge in tight spaces. Typically, the actuators are attached to a frame connected to the cylinder head or cylinder head cover.

From the DE 10 2011 050 484 A1 For example, an internal combustion engine having a plurality of cylinders, a cylinder head, and a cylinder head cover is known. For the actuation of gas exchange valves at least one rotatably mounted camshaft with at least one axially displaceable on the respective camshaft sliding cam is provided. The respective sliding cam has at least one slotted section with at least one groove. To effect an axial displacement of the respective sliding cam, an actuator is provided. The actuator is mounted in the cylinder head or in the cylinder head cover.

From the DE 10 2017 205 463 A1 Furthermore, a sliding cam system is known, in which extend actuators for moving a cam carrier partially by acting as lever axes Umschaltantriebswellen having corresponding thereto through holes.

Although an arrangement of actuators of a sliding cam system in or on lever axes can be advantageous in terms of space considerations, this can lead to unwanted bending of a flexurally soft lever axis due to occurring during operation of the actuators forces for moving the cam carrier. A passage opening in the lever axis, as in the prior art according to the DE 10 2017 205 463 A1 , the lever axis can even weaken even more and make flexible.

The invention is based on the object to provide an alternative and / or improved variable valve train, with which in particular the disadvantages of the prior art can be overcome.

The object is solved by the features of the independent claim. Advantageous developments are specified in the dependent claims and the description.

The invention provides a variable valve train, in particular with a sliding cam system, for an internal combustion engine. The variable valve train has a shaft and a cam carrier. The cam carrier is rotationally fixed and axially displaceable on the shaft (eg by means of axial profiling, in particular splined shaft connection or splined shaft connection). The cam carrier has a first cam and a second cam. The variable valve train has a power transmission device with a lever axis (eg, rocker arm axis or rocker arm axis) and a power transmission element, in particular a rocker arm or a rocker arm. The power transmission member is pivotable about the lever axis and selectively establishes an operative connection between the first cam and a gas exchange valve (eg, intake valve or exhaust valve of a cylinder) of the internal combustion engine or between the second cam and the gas exchange valve depending on an axial position of the cam carrier. The variable valve train has an actuator device for axially displacing the cam carrier and a carrying device which at least partially surrounds the lever axis and carries the actuator device (in particular on the lever axis).

The variable valve drive can offer the advantage that a space-favorable arrangement of the actuator device in the region of the lever axis is made possible. At the same time a support of the actuator device by means of the support device on the lever axis stiffen by the encompassing the flexible lever axis. As a result, a secure holding of the actuator device by means of the support device on the lever axis can be ensured.

Suitably, the actuator device may be an electrical (eg electromagnetic or electromotive), pneumatic and / or hydraulic actuator device.

In one embodiment, the actuator device, in particular a first actuator and a second actuator of the actuator device, at least partially received in the lever axis. Such an arrangement can be particularly space-saving.

For example, the first actuator in a first receiving hole, in particular a through hole, the lever axis may be at least partially received and / or the second actuator in a second receiving hole, in particular a through hole, the lever axis at least partially included. It is possible that the first receiving hole and / or the second receiving hole extend perpendicular to a longitudinal direction of the lever axis and / or are directed towards the cam carrier.

In a further embodiment, the actuator device, in particular a first actuator and a second actuator of the actuator device, is carried by the carrier device (eg completely) outside the lever axis.

In one embodiment, the carrying device is designed such that it stiffens the lever axis by gripping around and / or reduces bending softness of the lever axis and / or increases flexural rigidity of the lever axis. Alternatively or additionally, the support device has at least one mating with an outer peripheral surface of the lever axis, in particular circular cylindrical segment, contact surface (which in particular the outer peripheral surface of the lever axis contacted) for at least partially encompassing the lever axis stiffening the lever axis by the at least partially embracing and / or a Flexural softness of the lever axis reduced and / or increased flexural rigidity of the lever axis.

In a further embodiment, the carrying device is attached (eg, fastened) to the lever axis (eg, releasably) by means of a clamping connection, and / or the carrying device forms an annular clamp for the lever axis.

In one embodiment, the support device surrounds the lever axis in several parts (for example, two parts). Alternatively or additionally, the support device has a first support element and a second support element, which are fastened to one another (for example releasably) and each have a receiving tray, in particular a receiving half-shell, for forming a receptacle (for example a circular cylinder hole) for the lever axis.

For example, the first support member by means of several, in particular releasable, fasteners, for. As screws, be releasably secured to the second support member.

It is also possible that the first support element and the second support element are integrally formed integrally and / or the support device is integrally formed. For example. For example, the support device or the two support elements can be shrunk onto the lever axis (eg similar to a built-in camshaft).

One or more actuator receiving holes of the first support element and / or of the second support element may expediently open into the receiving shell of the first support element or of the second support element.

In a further embodiment, the support device is secured axially and / or against rotation on the lever axis; in particular by means of a pin, in particular by means of a single pin. Alternatively or additionally, the first support element and / or the second support element is secured axially and / or against rotation on the lever axis; in particular by means of a pin, in particular by means of a single pin.

In one embodiment, one or more actuators of the actuator device are received in the support device. Alternatively or additionally, one or more actuators of the actuator device are accommodated in the first support element and / or one or more actuators of the actuator device are received in the second support element.

For example, the first support element and / or the second support element may have one or more receiving holes, in particular through-holes, in which one or more actuators of the actuator device are accommodated. For example, the receiving holes of the first support member, the lever axis and / or the second support member may be aligned with each other.

In a further embodiment, the support device (for example, the first support element, which faces the cam carrier) one or more receiving holes to Recording one or more actuators of the actuator device. In addition, the one or more receiving holes have a shoulder (for example circumferential) on which the one or more actuators are supported for absorbing transverse forces. This can be prevented, for example, that lateral forces are introduced directly into the lever axis.

In one embodiment, the first support member and the second support member are attached (eg, fixed) to the lever shaft by means of a clamping connection. Alternatively or additionally, the first support element and the second support element form an annular clamp for the lever axis. Alternatively or additionally, the first support member and the second support member contact each other on one side of the lever axis and are spaced apart on an opposite side of the lever axis for clamping the lever axis. A clamping action may be adjusted in the region in which the first support element and the second support element are spaced from each other, for example by tightening one or more releasable fastening elements, for example screws, in this area.

In a further embodiment, the lever axis has a, in particular eccentric, fluid longitudinal channel, in particular for supplying lubricating fluid for lubricating a bearing point of the force transmission element, which at least partially intersects (cuts) a receiving hole of the lever axis for the actuator device. Alternatively or additionally, the support device is sealed to prevent leakage (eg from fluid from the fluid longitudinal passage).

For example, a seal, for. As an O-ring, be arranged in an actuator-receiving hole of the first support member and / or the second support member. It is possible that a seal, for example an O-ring, is arranged in a further actuator receiving hole (for example for a second actuator) of the first support element and / or of the second support element.

Suitably, the seal or the seals may be arranged in a circumferential groove of the respective actuator-receiving hole.

In one embodiment, the actuator device is attached (eg, fastened) by means of a flange plate (in particular on the outside) to the carrier device, in particular on a first carrier element of the carrier device (eg detachably).

In a development, the carrying device, in particular the first carrier element, has at least one recess on a surface facing the flange plate for increasing a bending elasticity of the carrier device. This can be prevented, for example, that arise in the second support member of the support device too large voltages when forces must be supported by the support device during operation of the actuator device.

In a further embodiment variant, the carrying device, in particular a second carrying element of the carrying device, has a holding region for holding supply lines, in particular electrical supply lines, for the actuator device, in particular on a side of the carrying device facing away from the cam carrier. Thus, the support device in addition to wearing the actuator device take over another function.

In one embodiment, the power transmission device to another power transmission element, in particular a drag lever or a rocker arm which is pivotable about the lever axis. Alternatively or additionally, the carrying device is arranged as a spacer between the force transmission element and the further force transmission element, in particular directly adjacent to the force transmission element and the further force transmission element (in particular on the lever axis). Thus, the support device in addition to wearing the actuator device take over another function.

The further force-transmitting element may expediently produce an operative connection between a third cam of the cam carrier and a further gas exchange valve (eg inlet valve or exhaust valve of a cylinder) of the internal combustion engine or between a fourth cam and the further gas exchange valve in dependence on an axial position of the cam carrier.

The actuator device can be designed in many ways. It is possible that the actuator device has one or more actuators, each having a movable pin or pin. The movable in particular in the radial direction of the shaft or the cam carrier pin or pin can intervene to move the cam carrier in an axial direction, for example in a helical engagement track or shift gate of the cam carrier. It is possible that a first actuator of the actuator device for displacing the cam carrier in a first axial direction by engaging (meshing) is formed in a first engagement track of the cam carrier. It is also possible for a second actuator to move the Cam carrier in a second axial direction, which is opposite to the first axial direction, is formed by engaging (meshing) in a second engagement track of the cam carrier.

Suitably, the cam carrier, the shaft and the actuator device can form a sliding cam system.

The invention also relates to a motor vehicle, in particular a commercial vehicle (eg lorry or bus) with a variable valve train as disclosed herein.

It is also possible to use the device as disclosed herein for passenger cars, large engines, off-highway vehicles, stationary engines, marine engines, etc.

Figur 1

eine isometrische Ansicht eines beispielhaften variablen Ventiltriebs gemäß der vorliegenden Offenbarung;

Figur 2

eine Draufsicht bzw. eine Ansicht von oben auf den beispielhaften variablen Ventiltrieb;

Figur 3

eine Schnittdarstellung des beispielhaften variablen Ventiltriebs entlang einer Linie A-A in Figur 2; und

Figur 4

eine Detaildarstellung eines Details B des beispielhaften variablen Ventiltriebs von Figur 3.

The preferred embodiments and features of the invention described above can be combined with one another as desired. Further details and advantages of the invention will be described below with reference to the accompanying drawings. Show it:

FIG. 1

an isometric view of an exemplary variable valve train according to the present disclosure;

FIG. 2

a top view and a view from above of the exemplary variable valve train;

FIG. 3

a sectional view of the exemplary variable valve train along a line AA in FIG. 2 ; and

FIG. 4

a detail view of a detail B of the exemplary variable valve train of FIG. 3 ,

The embodiments shown in the figures are at least partially identical, so that similar or identical parts are provided with the same reference numerals and to the explanation of which reference is also made to the description of the other embodiments or figures in order to avoid repetition.

The FIGS. 1 and 2 show a variable valve train 10. The variable valve train 10 has a shaft (camshaft) 12, a sliding cam system 14, a power transmission device 16, a first gas exchange valve 18 and a second gas exchange valve 20. The gas exchange valves 18, 20 may be, for example, intake valves or exhaust valves of a cylinder of an internal combustion engine.

The variable valve train 10 may be used to adjust the valve timing curves of the first and second gas exchange valves 18, 20. The variable valve train 10 is associated with an internal combustion engine (not shown). The internal combustion engine can be included, for example, in a commercial vehicle, for example a bus or a lorry. The internal combustion engine may have one or more cylinders.

The sliding cam system 14 has a cam carrier 22 and an actuator device 24, 26 with a first actuator 24 and a second actuator 26.

The cam carrier 22 is rotatably and axially displaceably arranged on the shaft 12, z. Example by means of an axial profiling of the outer circumference of the shaft 12 and the inner circumference of the cam carrier 22 (eg. Spline connection or spline connection). It is possible that a plurality of cam carrier 22 may be arranged on the shaft 12 in order to actuate, for example, gas exchange valves of a plurality of cylinders of the internal combustion engine. The cam carrier 22 has four cams 28-31, a first engagement track (shift gate) 32 and a second engagement track (shift gate) 34.

The cam carrier 22 together with the shaft 12 forms a camshaft. The shaft 12 with the cam carrier 22 is arranged as overhead camshaft (OHC). The shaft 12 with the cam carrier 22 may be part of a double camshaft (DOHC) system or may be provided as a single overhead camshaft (SOHC).

The four cams 28-31 may have different cam contours for generating different valve timing curves for the gas exchange valves 18, 20. The cams 28-31 may be at least partially designed as Nullhubnocken. The different cam contours of the cams 28-31 can be used, for example, to reduce consumption, for thermal management or for the realization of an engine brake.

The four cams 28-31 are arranged offset from one another along a longitudinal axis of the cam carrier 22. The first cam 28 is disposed adjacent to the second cam 29. The third cam 30 is disposed adjacent to the fourth cam 31. The first and second cams 28, 29 selectively serve to actuate the first gas exchange valve 18. The third and fourth cams 30, 31 are selectively for actuating the second gas exchange valve 20. The cams 28, 29 and 30, 31 are at opposite ends of the cam carrier 22nd arranged. In other embodiments, additional cams may have fewer cams and / or alternative arrangements of the cams may be provided, e.g. B. a central arrangement of the cam on the cam carrier.

The first engagement track 32 and the second engagement track 34 are provided centrally on the cam carrier 22. It is also possible that the engagement tracks are arranged eccentrically, for. B. end of the cam carrier. The first and second engagement tracks 32, 34 extend helically (helically) as depressions (grooves) in the cam carrier 22 about a longitudinal axis of the shaft 12.

For axially displacing the cam carrier 22, radially displaceable pins 12 (pins) of the actuators 24, 26 can engage radially in relation to the longitudinal axis of the shaft 12 (engaging in) into the engagement tracks 32, 34. In particular, the pin of the first actuator 24 may selectively engage the first engagement track 32 for shifting the cam carrier 22 from one axial position to another axial position. The pin of the second actuator 26 in turn can selectively engage in the second engagement track 34. Then, the cam carrier 22 is shifted back from the other axial position. Depending on the axial position of the cam carrier 22, the gas exchange valves 18, 20 are actuated either by the first cam 28 and the third cam 30 or by the second cam 29 and the fourth cam 31. For example, the second gas exchange valve 20 is actuated in the illustrated axial position of the cam carrier 22 by the fourth cam 31.

The axial displacement of the cam carrier 22 is triggered by the fact that the extended pin of the respective actuator 24, 26 with respect to an axial direction of the shaft 12 is stationary. Consequently, due to the helical shape of the engagement tracks 32, 34, the slidable cam carrier 22 is displaced in a longitudinal direction of the shaft 12 when one of the extended pins engages the respective engagement track 32, 34. At the end of the axial displacement operation, the extended pin of the respective actuator 24, 26 is guided by the respective engagement track 32, 34 via an ejection lamp opposite to the extension direction and thus retracted or ejected. The pin of the respective actuator 24, 26 is disengaged from the respective engagement track 32, 34th

The actuators 24, 26 may be actuated electrically (eg, by an electric motor, electromagnetically), pneumatically and / or hydraulically. In the illustrated embodiment, the actuators are electrically actuated (see electrical connections at their upper ends).

The sliding cam system 14 may additionally include a locking device (not shown). The locking device can be designed so that it axially secures the cam carrier 22 in the desired axial positions. For this purpose, the locking device, for example, have an elastically biased locking body. The blocking body can engage in a first axial position of the cam carrier 22 in a first recess of the cam carrier 22 and engage in a second axial position of the cam carrier 22 in a second recess of the cam carrier 22. The locking device may be provided for example in the shaft 12.

The power transmission device 16 has a first power transmission element 40, a second power transmission element 41, a lever axis 42 and a plurality of bearing blocks 43. The power transmission elements 40, 41 are rotatably arranged on the lever axis 42, so that they are pivotable about the lever axis 42. The lever axis 42 is mounted or held in the bearing blocks 43. The shaft 12 is rotatably mounted in the bearing blocks 43. For example, separate bearing blocks for the lever axis 42 and the shaft 12 may also be provided.

In the embodiment shown, the power transmission elements 40, 41 as a rocker arm and the lever axis 42 thus formed as a rocker shaft. However, it is also possible that the force transmission elements 40, 41, for example, as a drag lever and the lever axis 42 is thus formed as a drag lever axis.

In the illustrated embodiment, the first power transmission element 40 is used to actuate the first gas exchange valve 18 and the second power transmission element 41 for actuating the second gas exchange valve 20. However, it is also possible that, for example, several gas exchange valves are actuated by means of only one force transmission element, for example with the interposition of a valve bridge.

The power transmission elements 40, 41 each have a cam follower 44, 45, for example in the form of a rotatably mounted roller. The cam followers 44, 45 follow a cam contour of the cams 28-31 as a function of an axial position of the cam carrier 22.

In the first axial position of the cam carrier 22, the first force transmission element 40 via the cam follower 44 in operative connection between the first cam 28 and the first gas exchange valve 18. The second force transmission element 41 is connected via the cam follower 45 in operative connection between the third cam 30 and the second gas exchange valve 20th ,

The gas exchange valves 18 and 20 are operated according to the cam contours of the first and second cam 28, 30.

In the second axial position of the cam carrier 22, the first force transmission element 40 via the cam follower 44 in operative connection between the second cam 29 and the first gas exchange valve 18. The second force transmission element 41 is connected via the cam follower 45 in operative connection between the fourth cam 31 and the second gas exchange valve 20th The gas exchange valves 18 and 20 are operated according to the cam contours of the second and fourth cam 29, 31. This situation is in the FIGS. 1 and 2 shown.

The first actuator 24 and the second actuator 26 are partially received in the lever shaft 42 (integrated). This can be advantageous, in particular, from the point of view of optimum space utilization, since the actuators 24 and 26 thus require no or hardly any separate installation space. The actuators 24 and 26 are in this case supported by a support device 46, as described in detail below. However, it is also possible, for example, to carry the first actuator 24 and / or the second actuator 26 via a carrier device, which is attached to the lever axis 42, outside the lever axis 42 (not shown separately).

The FIG. 3 shows a cross section through the shaft 12, the cam carrier 22, and the support device 46 along the line AA of FIG. 2 , The FIG. 4 shows the detail B of FIG. 3 on an enlarged scale. As described below for the first actuator 24, the second actuator 26 may equally be carried by the support device 46. That is, the support device 46 may be designed to support the second actuator 26 as well as for supporting the first actuator 24. For example. For example, the support device 46 may be formed substantially mirror-symmetrically with respect to a median plane of the support device 46 which intersects perpendicularly a longitudinal axis of the lever axis 42. The second actuator 26 may be formed like the first actuator 24.

The support device 46 completely surrounds the lever axis 42. As a result, the flexurally soft lever axis 42, which is further weakened by receiving the first actuator 24, stiffened. In particular, a bending strength can be increased. The support device 46 may be constructed in one piece or, as shown, in several parts.

The support device 46 has a first support element 48 and a second support element 50. The support elements 48, 50 have receiving shells 52, 54 facing one another. The receiving shells 52, 54 may be formed as half-shells. The receiving cups 52, 54 Together, a receiving hole for receiving or surrounding (encompassing) of the lever axis 42. The receiving shells 52, 54 are shaped so that they mate with an outer peripheral shape of the lever axis 42, in particular this correspond. In particular, the receiving shells 52, 54 are circular-cylindrical segment-shaped.

The first support member 48 is releasably secured to the second support member 50 by a plurality of screws 56, 58, wherein the support members 48, 50 clamp the lever axis 42 between them. Here, the support elements 48, 50 in the region of the screw 56 in contact with each other while in the region of the screw 58, that is on an opposite side of the lever axis 42, with a small gap (for example, <1 mm) are spaced from each other. By tightening the screw 58, the clamping force of the support elements 48, 50 is increased to the lever axis 42. Previously, the screw 56 is tightened. The support elements 48, 50 thus form a multi-part, annular clamp for the lever axis 42. As an alternative to the screws, for example, other (eg detachable) fastening elements can be used.

The support elements 48, 50 can be secured against rotation and axially on the lever axis 42. For this purpose, for example, a single pin (not shown) may be provided, which projects beyond an outer circumference of the lever axis 42 and is received in corresponding receptacles of the support elements 48, 50.

By means of the screws (fastening elements) 56 and 58 and the first actuator 24 is releasably attached to the support device 46, in particular the first support member 48, fixed. Specifically, the first actuator 24 is attached via a flange plate 60 to a surface of the first support member 48 facing the cam carrier 22.

The first actuator 24 is accommodated in the first support element 48, the lever axis 42 and the second support element 50. For this purpose, the first actuator 24 extends through corresponding receiving holes 62, 64 and 66 in the first support member 48, in the lever axis 42 and the second support member 50. The receiving holes 62, 64 and 66 share a common longitudinal axis and are aligned. The receiving holes 62, 64 and 66 extend in particular perpendicular to a longitudinal axis of the lever axis 42.

The receiving hole 62 of the first support member 48 has a circumferential shoulder 68, which mates with a circumferential shoulder 70 on the first actuator 24. The paragraph 68 is is formed as a portion of the enlarged diameter receiving hole 62. The heel 70 is formed as a portion of the first actuator 24 of increased diameter. The shoulder 70 connects directly to the flange plate 60. About the paragraphs 68, 70, the first actuator 24 is supported in the transverse direction on the first support member 48 of the support device 46. In this way, transverse forces which arise during operation of the first actuator 24 during displacement of the cam carrier 22 can be introduced directly into the first carrier element 48, without having an effect on the lever axis 42. Via the first support element 48, the transverse forces are then introduced into the lever axis 42, which finally directs the transverse forces to the bearing blocks 43. This can be prevented that the transverse forces go over a body of the first actuator 24 and this deform, for example.

The lever axis 42 has a fluid longitudinal channel 72. The fluid longitudinal channel 72 extends eccentrically along a longitudinal axis of the lever axis 42 through the lever axis 42. The fluid longitudinal channel 72 may be used, for example, for guiding a lubricating fluid to lubricate the bearing points of the force transmission elements 40, 41 (see FIGS. 1 and 2 ) be used. The fluid longitudinal channel 72 intersects the receiving hole 64 in the lever axis 42. To prevent fluid leakage, seals 74, 76 are provided. The first seal 74 is seated in a circumferential groove in the receiving hole 62 of the first support member 48. The second seal 76 is seated in a circumferential groove in the receiving hole 66 of the second support member 50. The seals 74, 76 may be formed for example as O-rings.

The first support element 48 has a plurality of recesses 78 on a surface facing the flange plate 60. The recesses 78 are formed as pockets. The recesses 78 may increase a bending elasticity of the first support member 48. Thus, for example, excessive stresses in the second support element 50 upon introduction of forces by the first actuator 24 into the support device 46 can be reduced.

Referring again to the FIGS. 1 and 2 The second support element 50 has a holding region 80. The holding area 80 is arranged on one side of the carrying device opposite to the cam carrier 22. The holding portion 80 may be integrally-integral with the second support member 50 or may be attached to the second support member 50, for example. For example, electrical, pneumatic or hydraulic supply lines (not shown), in particular for the first actuator 24 and the second actuator 26, can be held on the holding region 80. For example, electrical supply lines can be kept if the actuators 24, 26 are designed as electrical actuators.

The support device 46 is also arranged as a spacer on the lever axis 42 between the power transmission elements 40, 41. The first power transmission element 40 and the second power transmission element 41 are in particular arranged on opposite end surfaces of the support device 46 fitting.

The invention is not limited to the preferred embodiments described above. Rather, a variety of variants and modifications is possible, which also make use of the inventive idea and therefore fall within the scope. In particular, the invention also claims protection of the subject matter and the features of the subclaims independently of the claims referred to. In particular, the features of independent claim 1 are independently disclosed. In addition, the features of the dependent claims are independent of all features of the independent claim 1 and, for example, regardless of the characteristics regarding the presence, the arrangement and / or the configuration of the shaft, the cam carrier, the power transmission device, the actuator device and the supporting device of independent claim 1 disclosed.

LIST OF REFERENCE NUMBERS

10

Variable valve train

12

wave

14

Sliding cam system

16

Power transmission device

18

First gas exchange valve

20

Second gas exchange valve

22

cam support

24

First actor

26

Second actor

28

First cam

29

Second cam

30

Third cam

31

Fourth cam

32

First intervention lane

34

Second intervention lane

40

First power transmission element

41

Second power transmission element

42

lever axis

43

bearing block

44

cam follower

45

cam follower

46

carrying device

48

First support element

50

Second support element

52

receiving dish

54

receiving dish

56

screw

58

screw

60

flange

62

receiving hole

64

receiving hole

66

receiving hole

68

paragraph

70

paragraph

72

Fluid longitudinal channel

74

poetry

76

poetry

78

recess

80

holding area

Claims (15)

Variable valve train (10), in particular with a sliding cam system (14), for an internal combustion engine, comprising: a shaft (12); a cam carrier (22) rotatably and axially slidable on the shaft (12) and having a first cam (28) and a second cam (29); a power transmission device (16) having a lever axis (42) and a force transmission element (40), in particular a drag lever or a rocker arm, which is pivotable about the lever axis (42) and depending on an axial position of the cam carrier (22) optionally an operative connection between the first cam (28) and a gas exchange valve (18, 20) of the internal combustion engine or between the second cam (29) and the gas exchange valve (18, 20) produces; an actuator device (24, 26) for axially displacing the cam carrier (22); and a support device (46) which at least partially surrounds the lever axis (42) and carries the actuator device (24, 26). A variable valve train (10) according to claim 1, wherein: the actuator device (24, 26), in particular a first actuator (24) and a second actuator (26) of the actuator device, at least partially received in the lever axis (42); or the actuator device (24, 26), in particular a first actuator (24) and a second actuator (26) of the actuator device, is carried by the carrier device (46) outside the lever axis (42). A variable valve train (10) according to claim 1 or claim 2, wherein: the support means (46) is adapted to stiffen the lever axis (42) by gripping and / or to reduce bending softness of the lever axis (42) and / or to increase flexural rigidity of the lever axis (42); and or the support device (46) has at least one mating with an outer peripheral surface of the lever axis (42), in particular circular cylinder segment, contact surface for at least partially encompassing the lever axis (42) stiffening the lever axis (42) by the at least partially embracing and / or a bending softness of Lever axis (42) reduces and / or increases bending stiffness of the lever axis (42). Variable valve train (10) according to one of the preceding claims, wherein: the support device (46) is attached to the lever shaft (42) by means of a clamping connection; and or the supporting device (46) forms an annular clamp for the lever axis (42). Variable valve train (10) according to one of the preceding claims, wherein: the support device (46) surrounds the lever axis (42) in several parts; and or the support device (46) has a first support element (48) and a second support element (50), which are fastened to each other and each have a receiving tray (52, 54), in particular a receiving half-shell, for forming a receptacle for the lever axis (42). Variable valve train (10) according to one of the preceding claims, wherein:
the support device (46), in particular a first support element (48) and / or a second support element (50) of the support device (46), is secured axially and / or non-rotatably on the lever axis (42); in particular by means of a pin, in particular by means of a single pin. Variable valve train (10) according to one of the preceding claims, wherein:
one or more actuators of the actuator device (24, 26) in the support device (46), in particular a first support member (48) and / or a second support member (50) of the support device (46) are received. Variable valve train (10) according to one of the preceding claims, wherein: the support device (46) has one or more receiving holes (62, 66) for receiving one or more actuators of the actuator device (24, 26); and the one or more receiving holes (62) has a shoulder on which the one or more actuators are supported for absorbing transverse forces. A variable valve train (10) according to any one of claims 5 to 8, wherein: the first support member (48) and the second support member (50) are attached to the lever shaft (42) by means of a clamping connection; and or the first support element (48) and the second support element (50) form an annular clamp for the lever axis (42), and / or the first support member (48) and the second support member (50) contact one another on one side of the lever axis (42) and are spaced apart on an opposite side of the lever axis (42) for clamping the lever axis (42). Variable valve train (10) according to one of the preceding claims, wherein: the lever axis (42) has a, in particular eccentric, fluid longitudinal channel (72), in particular for supplying lubricating fluid for lubricating a bearing point of the force transmission element (40), which has a receiving hole (64) of the lever axis (42) for the actuator device (24, 26 ) at least partially crosses; and the support device (46) is sealed to prevent leakage. Variable valve train (10) according to one of the preceding claims, wherein:
the actuator device (24, 26) by means of a flange plate (60) on the outside of the support device (46), in particular a first support member (48) of the support device (46) is mounted. The variable valve train (10) of claim 11, wherein:
the support device (46), in particular the first support element (48), at least one recess (78) on one of the flange plate (60) facing surface for increasing a bending elasticity of the support device (46). Variable valve train (10) according to one of the preceding claims, wherein:
the support device (46), in particular a second support element (50) of the support device (46), a holding region (80) for holding supply lines, in particular electrical supply lines, for the actuator device (24, 26), in particular on a cam carrier (22 ) facing away from the support device (46). Variable valve train (10) according to one of the preceding claims, wherein: the power transmission device (16) comprises a further force transmission element (41), in particular a drag lever or a rocker arm, which is pivotable about the lever axis (42); and the support device (46) is arranged as a spacer between the force transmission element (40) and the further force transmission element (41), in particular directly adjacent to the force transmission element (40) and the further force transmission element (41). Motor vehicle, in particular utility vehicle, with a variable valve train (10) according to one of the preceding claims.

Images