EP3899215A1

EP3899215A1 - Switchable actuation device for a poppet valve in an internal combustion engine, internal combustion engine and motor vehicle

Info

Publication number: EP3899215A1
Application number: EP19827665.1A
Authority: EP
Inventors: Johannes Hollweck; Thorsten Bachmann
Original assignee: MAN Truck and Bus SE
Current assignee: MAN Truck and Bus SE
Priority date: 2018-12-19
Filing date: 2019-12-12
Publication date: 2021-10-27
Anticipated expiration: 2039-12-12
Also published as: EP3899215B1; US11371396B2; US20220074321A1; CN113015846A; DE102018132857A1; CN113015846B; WO2020126775A1; BR112021006313A2

Abstract

The present invention relates to a switchable actuation device (100) for a gas exchange valve. The switchable actuation device (100) comprises a two-piece rocker arm (10). Said rocker arm comprises a first rocker arm portion (1a), which is mounted pivotably about a rocker arm shaft (2) and to which a bearing sleeve (1a1) is fastened concentrically with the rocker arm shaft (2), and a second rocker arm portion (1b) mounted pivotably on the bearing sleeve (1a1). Furthermore, both the first and the second rocker arm portions (1a, 1b) each comprise a cut-out (3a, 3b), wherein a locking element (4a) of a coupling device (4) of the switchable actuation device (100) can optionally be brought into and out of engagement with the two cut-outs (3a, 3b). An actuation of the poppet valve, preferably a change between a closed position and an open position of the poppet valve, is interrupted if the locking element (4a) is not in engagement with the two cut-outs (3a, 3b). The invention also relates to an internal combustion engine (20) and a motor vehicle (30).

Description

Switchable actuating device for a lift valve of an internal combustion engine, internal combustion engine and motor vehicle

description

The present invention relates to a switchable actuating device for a lift valve egg ner internal combustion engine. In particular, the invention relates to a switchable actuating device for a charge exchange valve of an internal combustion engine, which is periodically movable between a closed and open position indirectly by a cam of a camshaft. Furthermore, the invention also relates to an internal combustion engine and a motor vehicle with such an actuating device.

In internal combustion engines, in situations in which the full drive torque of the internal combustion engine is not required, the fuel consumption of the internal combustion engine can be reduced by deactivating the injection of individual cylinders. If the gas exchange in the corresponding cylinders is also deactivated, the fuel consumption can be reduced even further, since then no gas exchange work has to be done. At the same time, by deactivating the gas exchange, cooling of the exhaust gas aftertreatment system, in particular in low-load operation, is reduced.

In order to enable such a targeted deactivation of the gas exchange of individual cylinders, various systems with rocker arm or rocker arm combinations are known in the prior art. A disadvantage of the known systems, however, is often that large loads occur on the bearings or the individual components and / or that many or large components have to be moved in order to activate or deactivate them.

It is therefore an object of the invention to provide an improved compared to the prior art solution for specifically deactivating the gas exchange of individual cylinders of an internal combustion engine. In particular, the invention has for its object to provide a (down) switchable actuating device for a lift valve of an internal combustion engine, which with few loads, ie. H. especially not burdened by moments, construction parts can be realized.

According to the invention, these objects are achieved by a switchable actuating device, an internal combustion engine and a motor vehicle with the features of the independent claims. Advantageous embodiments and applications of the invention are the subject of dependent claims and are explained in more detail in the following description with partial reference to the figures.

The switchable actuation device for a lift valve of an internal combustion engine comprises a two-part rocker arm for actuating the lift valve. This has a first rocker arm part pivotably mounted about a rocker arm axis, to which a, preferably hollow cylindrical, bearing sleeve is fastened concentrically to the rocker arm axis. Furthermore, the two-part rocker arm comprises a second rocker arm part pivotably mounted on the bearing sleeve. In other words, the bearing sleeve fastened with the first rocker arm part can thus serve as a sliding bearing for the second rocker arm part. Furthermore, both the first and the second rocker arm part each have a recess, preferably in the form of a groove extending parallel to the rocker arm axis. To make it easier to distinguish between the recesses, the recess in the first rocker arm part is referred to below as the “first” recess and the recess in the second rocker arm part as the “second” recess.

In addition to the two-part rocker arm, the switchable actuation device also has a coupling device for the detachable, rotationally fixed connection of the first and second rocker arms. For this purpose, the coupling device comprises a locking element - for. B. in the form of an insert - which can be brought into and out of engagement with the first and second recesses. The engagement between the locking element and the first or second recess is preferably a tongue and groove engagement and / or a positive and / or non-positive engagement. An actuation of the lift valve, preferably a change between a closed and open position of the lift valve, is interrupted if the locking element is not in engagement with the first or second recess. In other words, the two-part rocker arm can, on the one hand, be in a coupled state, in which the two rocker arm parts are connected in a rotationally fixed manner and act like a single two-sided overall rocker arm, in order to enable a gas change at the lift valve. On the other hand, the two-part rocker arm can be present in a decoupled state, in which the two rocker arm parts can be pivoted independently of one another and how two separate one-sided levers work, in order to interrupt a gas change at the lift valve. The change from the coupled to the uncoupled state and vice versa takes place through the movement of the locking element. Overall, this provides a (switchable) actuating device for a lift valve, in which the type of coupling and the mounting according to the invention result in the rocker arm guide being less loaded and therefore less wear-resistant, in which the occurrence of moments on the bearing and the Components can largely be avoided as far as possible.

Preferably, the stroke valve of the internal combustion engine is a charge exchange valve which can be moved periodically between a closed and open position indirectly by a cam of a camshaft. For example, the first rocker arm part can be operatively connected to a cam of the camshaft via a roller rotatably mounted on the first rocker arm part and the second rocker arm part can be coupled in terms of motion with the lift valve or load change valve. This assignment of the first or second rocker arm part to a cam or a valve can, however, also follow the other way around. In other words, the first rocker arm part pivoted about the rocker arm axis can be both a cam lever and a valve lever, in which case the second rocker arm part pivotably mounted on the bearing sleeve is accordingly corresponding to the other lever form (valve or Cam lever) should be trained.

According to a first aspect of the invention, the bearing sleeve can be integrally formed on the first tilt lever part. In other words, the bearing sleeve and the first rocker arm part are formed in one piece. This can advantageously facilitate the manufacture and assembly. In addition or alternatively, the bearing sleeve can also surround the rocker arm axis in a central manner. Or. in other words, the bearing sleeve can completely enclose the rocker arm axis around the catch side. The bearing sleeve is particularly preferably designed as a hollow cylinder, the inner radius of which essentially corresponds to the outer radius of the rocker arm salmon. Advantageously, a large contact surface between La gerhülse and rocker arm axis can be achieved, which increases the stability of the bearing. In order to further reduce the friction between the pivotally mounted first rocker arm part about the rocker arm part and the rocker arm axis, the first rocker arm part and the bearing sleeve can also be arranged on a common plain bearing bush around the rocker arm axis. Additionally or alternatively, the bearing sleeve can also comprise a groove, preferably a circumferential one, that is to say perpendicular to the rocker arm axis. A securing ring for axially securing the position of the second rocker arm part can then be inserted into this. In front of geous way, an axial movement of the second rocker arm part is prevented, thereby achieving a more stable rocker arm guide. It is preferably between the Circlip and the second rocker arm part additionally arranged a thrust washer surrounding the bearing sleeve to reduce friction.

According to a further aspect of the invention, the locking element can be brought into a release position S _e or into a locking position S _a by moving perpendicular to the rocker arm axis, preferably by essentially radial movement. For this purpose, the coupling device can be designed to move the locking element perpendicular to the rocker arm axis for releasably non-rotatably connecting the first and second rocker arm parts in order to bring the locking element either into a release position S _e or into a locking position S _a . The locking element should not be in engagement with the first and second recesses in the release position S _e . While the locking element in the animal position S _a should be in engagement with the first and second recesses. The expression “being in engagement” can generally refer to an intermeshing of the components and / or an insertion of the locking element in the first and second recesses. Preferably, if the locking element “engages” with the first and second recesses, a non-positive and / or positive connection is formed between the locking element and the first recess, as well as the locking element and the second recess. The locking element is particularly preferably non-positively connected to the first and second recesses in the radial and axial directions and positively in the circumferential direction. In this case and in the entire document, such directions (radial, axial, circumferential) should be understood in relation to the rocker arm axis. So z. For example, the expression "in the circumferential direction" can be interpreted as a short form for "in the circumferential direction to the rocker arm axis" or "in the circumferential direction in relation to the rocker arm axis". Characterized in that a locking or releasing the locking by moving the locking element perpendicular to the rocker arm axis he follows, loads on the bearings and components can be avoided in an advantageous manner, since this involves forces but no moments on the bearings and components occur.

According to a further aspect of the invention, the first and second recesses can each extend as a groove extending parallel to the rocker arm axis with a groove cross section tapering to the rocker arm axis, e.g. B. in the form of a trapezoidal groove. The expression “groove cross section” is intended to mean a section through the first or second recess perpendicular to the rocker arm axis. In other words, a circumferential extension of the groove lying radially on the outside with respect to the rocker arm axis can be larger than a circumferential extension of the groove lying radially further inside. Furthermore, the locking element can be wedge-shaped and / or wedge-shaped and / or at least partially complementary in shape first and / or second recess. Preferably, the contact surfaces between the locking element and the first and second recesses run parallel to the rocker arm axis. Advantageously, a positive connection between the locking element and the first and / or second recess can be achieved in the circumferential direction, whereby a stable locking of the two rocker arm parts is made possible. In addition, the insertion or insertion of the locking element into the first and second recess can thereby be facilitated.

In order to improve the locking still further in this context, according to a further development of this aspect, each of the groove cross sections can also be designed to self-lockingly clamp the locking element in the circumferential direction when the locking element engages in the first and second recesses. In other words, the seat of the Arretierele element in the first and second recess can be designed to prevent unwanted independent loosening of the connection between the locking element and the first and second recess ge compared movements in the circumferential direction. The person skilled in the art can determine the specific design of the groove cross section in which such a self-locking bracing of the locking element occurs through simple test series with different groove cross sections. The operating safety of the actuating device can be increased overall by the self-locking in an advantageous manner.

According to a further aspect of the invention, each of the groove cross-sections to the rocker arm salmon, ie in the direction of the rocker arm axis, can be bounded by a groove base and by two groove flanks to the side. Here, an angle of inclination a of the groove flanks can be smaller than the self-locking angle on the material pairing of the first rocker arm part locking element and / or that smaller than the self-locking angle on the material pairing of the second rocker arm part locking element. The angle of inclination a is intended to denote the angular deviation of the groove flanks from an ideal rectangular cross section (cf. also FIG. 5). Furthermore, both groove flanks can also have the same or different inclination angles a. Furthermore, the material-pair-dependent determination of the self-locking angle au can be carried out via the arctangent of the static friction coefficient m between the two components (ci _h <2-arctan (p)) or experimentally. In the preferred case here of a pair of materials made of oiled iron surfaces, the angle of inclination of the groove flanks should therefore be less than 11.4 °. Advantageously, fixation of the locking element in the circumferential direction can be achieved in a simple manner. According to a further aspect of the invention, the locking element can have the greatest expansion along the rocker arm axis. In other words, the locking element can thus have a greater length in the axial direction than in the radial direction or circumferential direction. For the largest possible contact area between the locking element and the first and second recesses, the locking element can - particularly preferably - have the same length in the axial direction as the first and second recesses. Additionally or alternatively, the locking element can also extend, preferably essentially, parallel to the rocker arm axis. For example, for this purpose the locking element can be made in the form of a rod and / or bar. These features advantageously enable a stable, rotationally fixed connection of the two rocker arm parts. In addition or alternatively, the locking element can also be movable only perpendicular to the rocker arm axis. I.e. in other words, the locking element, in order to bring it selectively into and out of engagement with the first and second recesses, can only be movable in the radial direction. This enables reliable and simple coupling or decoupling of the two rocker arm parts in an advantageous manner.

According to a further aspect of the invention, the coupling device can also comprise a bearing block for axially fixing the locking element. The bearing block can have two bearing cheeks spaced apart in the axial direction, on which the locking element can be pivotably mounted by means of two pins fastened to the locking element. The bearing cheeks preferably include bushings, particularly preferably bushings with elongated holes, for receiving the pins. Advantageously, can be achieved by a reliable position tion of the locking element.

In order to facilitate the insertion of the locking element into the first and second recesses, according to a further aspect of the invention, the pins of the locking element can each be guided in a circumferentially extending slot of the bearing cheeks of the bearing block. In other words, the bearing cheeks can each comprise bushings with elongated holes extending in the circumferential direction, in which the pins of the locking elements are movably mounted. Thus, in addition to a pivoting movement of the locking element around the pin, a movement of the locking element in the circumferential direction is also made possible, whereby jamming of the two rocker arm parts during the locking can be avoided. According to a further aspect of the invention, the bearing block can also comprise a guide roller rotatably mounted in the axial direction, which can be supported on the locking element in the radial direction for the radial fixing of the locking element. The rotatably mounted guide roller can preferably roll on an outer surface of the locking element. In this way, optimal radial force transmission for securing the locking element can be achieved in an advantageous manner at any time or for any pivoting state in the locked state.

In order to hold the bearing block itself, the coupling device according to a further aspect of the invention can also comprise at least one sliding pin arranged on the rocker arm axis, on which the bearing block is mounted so as to be displaceable radially to the rocker arm axis. In addition or alternatively, the coupling device can also comprise at least one slide rail arranged on the rocker arm axis, on which the bearing block is slidably mounted radially to the rocker arm axis. Both variants advantageously enable easy-to-implement radial guidance of the bearing block in order to achieve a reliable change between the release position S _e and the locking position S _a . Instead of the arrangement or attachment of the one or more slide pins and / or slide rails on the rocker arm salmon, these can also be attached at other locations. Thus, the coupling device can additionally or alternatively also comprise at least one slide pin arranged on a cylinder head or on a projection and / or a bracket of the cylinder head and / or on which the bearing block is displaceably mounted radially to the rocker arm axis. In addition or alternatively, the slide pin can also be designed as a slide rail.

In order to ensure adequate radial securing of the locking element, according to a further aspect of the invention, the coupling device can further comprise a clamping device, by means of which the bearing block can be clamped in the radial direction against the first and second recesses. For example, the tensioning device can comprise one or more spring elements (e.g. coil springs). Here, the clamping device can also be designed to salmon the bracket and thus the locking element stronger against the rocker arm and thus against the first and second recess, if the locking element does not lie or engage in the first and second recesses than when the locking element lies or engages in the first and second recesses. In other words, the clamping device can be formed, the clamping force on the bearing block and / or the locking element in dependence on the radial distance thereof to adjust the rocker arm axis. Advantageously, this enables secure radial fi xation of the locking element.

In order to also enable a quick and easy change between the locked and released state of the two-part rocker arm, the actuating device according to a further aspect of the invention can comprise a switching device by means of which the locking element can be actuated in order to selectively engage and disengage it with the first and bring second recess. In other words, the switching device can be designed to bring the locking element for non-rotatably connecting the first and second rocker arm parts into engagement with the first and second recesses and for releasing the rotationally fixed connection of the first and second rocker arm parts, the locking element out of engagement with the first and second recesses bring to. This switching device can be an electromagnetic and / or a pneumatic and / or a hydraulic switching device. For example, the switching device may comprise a permanent magnet material fastened to the bearing block and an electromagnet arranged adjacent to it, the permanent magnetic material interacting magnetically with the electromagnet for switching the locking element with the electromagnet. In addition or alternatively, the switching device can also comprise a piston-cylinder arrangement attached to the bearing block, the cylinder being acted upon by a hydraulic medium for switching the locking element. The switching device is preferably designed such that the locking element is in engagement with the first and second recesses in a deactivated state of the switching device and is out of engagement with the first and second recesses in an activated state of the switching device. In this way, the reliability can be increased in an advantageous manner, since in the event of a fault in the switching device, operation of the lift valve is still possible (fail-safe).

According to a further aspect of the invention, an internal combustion engine, preferably a diesel internal combustion engine, is also provided. The internal combustion engine comprises a globe valve with a switchable actuating device as described in this document. Furthermore, the internal combustion engine can also have multiple, i.e. H. comprise at least two, lift valves, each with a corresponding switchable actuating device. In an advantageous manner, an internal combustion engine is thus provided overall, in which - preferably in low-load operation - the gas exchange of individual globe valves is deactivated in a targeted manner who can.

Furthermore, the invention also relates to a motor vehicle, comprising an aforementioned internal combustion engine, ie an internal combustion engine having a lift valve with a switchable Actuator as described in this document. The motor vehicle is preferably a commercial vehicle. In other words, the motor vehicle can be a motor vehicle that is designed for its construction and device for the conveyance of people, for the transport of goods or for pulling trailer vehicles. For example, the motor vehicle may be a truck, a bus and or a tractor-trailer. In this context, however, it is immediately apparent to the person skilled in the art that the internal combustion engine according to the invention can also be used in other types of vehicles, so that protection is also claimed for other types of vehicles which comprise such an internal combustion engine with a switchable actuating device for a lift valve. In particular, a rail vehicle, preferably a traction vehicle, an aircraft, preferably an aircraft, and a ship are accordingly provided according to the invention. The features disclosed in connection with the motor vehicle should thus also be disclosed for the rail vehicle and the aircraft, and thus in particular can be claimed independently of the motor vehicle.

The previously described aspects and features of the invention can be combined with one another as desired. Further details and advantages of the invention are described below with reference to the accompanying drawings. Show it:

Figure 1 is a schematic representation of a switchable actuator for a

Lift valve of an internal combustion engine according to an embodiment of the invention;

Figure 2 is a schematic exploded view of a two-part rocker arm of the switchable actuating device according to an embodiment of the invention;

Figure 3 is a schematic exploded view of a coupling device of the switchable actuating device according to an embodiment of the invention;

Figure 4 is a schematic side view of the switchable actuator according to

Figure 1 in a locking position S _a and release position S _e ;

Figure 5 is an enlarged detail view of Figure 4 to illustrate the angle of inclination of the groove flanks; and

Figure 6: a motor vehicle comprising an internal combustion engine with a switchable actuation device according to an embodiment of the invention. io

The same or functionally equivalent elements are denoted in all figures with the same reference numerals and some are not described separately.

FIG. 1 shows a schematic illustration of a switchable actuation device 100 for a lift valve of an internal combustion engine 20 according to an embodiment of the invention. The actuating device 100 in this case comprises a two-part rocker arm 10 for actuating the lift valve (not shown in more detail). For this purpose, the two-part rocker arm 10 has a pivotable about a rocker arm axis 2, i. H. Rotatable first rocker arm part 1 a over a certain angular range about the rocker arm axis 2. On this first Kipphe belteil 1a, a, preferably hollow cylindrical, bearing sleeve 1a1 is fixed concentrically to the rocker arm axis 2, on which in turn a second rocker arm part 1 b is pivotally mounted. In the assembled state shown in FIG. 1, however, the bearing sleeve 1a1 is not visible (see FIG. 2 in this regard), so that here the two rocker arm parts 1a and 1b appear to be mounted adjacent to the rocker arm axis 2. The feature used in this context that the bearing sleeve 1a1 is attached “concentrically” to the rocker arm axis 2 here means that the bearing sleeve 1a1 and the rocker arm axis 2 are arranged around a common central axis (dashed line in FIG. 1) in such a way that the first rocker arm part 1a and the second rocker arm part 1b mounted on the bearing sleeve 1a1 are pivotable about a central axis common to them. In other words, the term "concentric" can also mean "coaxial" in this context. Concentrically, however, it is not the same meaning that the bearing sleeve 1a1 also necessarily completely surrounds the rocker arm axis 2, but this is possible.

The first rocker arm part 1a can - as shown - be in operative connection with a cam 11 of the camshaft 12 via a roller 1a3 which is rotatably mounted on the first rocker arm part 1a. I.e. in other words, the first rocker arm part 1 a can be moved by a periodic movement of the cam 11 when the camshaft 12 rotates, in particular in a pivoting movement about the rocker arm axis 2. This movement of the first rocker arm part 1a can then be transmitted to a second rocker arm part 1b or not by means of a coupling device 4 - described in more detail below. For this purpose, the coupling device 4 is set up to connect the two rocker arm parts 1 a, 1 b to one another in a detachable, non-rotatable manner. In other words, the first and second rocker arm parts 1 a and 1 b can be coupled in terms of movement technology by means of the coupling device 4. The second rocker arm part 1 b can be in operative connection with the lift valve, preferably with a charge exchange valve, so that in the coupled state of the two rocker arm parts 1a, 1b, the lift valve can be moved periodically between a closed and open position by means of a cam 11 of the camshaft 12. However, the aforementioned assignment of the first and second rocker arm parts 1 a, 1 b to a cam 11 or a valve can also be carried out in reverse.

Furthermore, it can be seen from FIG. 1 that the rocker arm axis 2 is not designed as a continuous cylinder in the present case, but instead has flattened regions 2a which are used for fastening a coupling device 4 for releasably non-rotatably connecting the first and second rocker arm parts 1a, 1b. Here, the coupling device 4 is designed as a bearing block 4b guided on two sliding pins 4d1, 4d2, which is clamped against the first and second rocker arm parts 1a, 1b by means of a tensioning device 4e - in the form of two spiral springs 4e1, 4e2. In the present embodiment, the coupling device 4 is arranged in the direction of gravity above the rocker arm axis 2. Alternatively, however, other positions of the coupling device 4 with respect to the rocker arm axis 2 are also possible. This, the precise design of the bearing block 4b and the mode of operation of the coupling mechanism according to the invention are discussed in more detail in connection with the following figures.

Figure 2 shows a schematic exploded view of a two-part rocker arm 10 of the switchable actuating device 100 according to an embodiment of the invention. As mentioned above, the two-part rocker arm 10 has a first rocker arm part 1a and a second rocker arm part 1b. The two rocker arm parts 1 a and 1 b can each be designed as a one-sided lever, d. That is, one end area can be formed for the pivotable mounting of the lever and another end area for power transmission. As shown in Figure 2, an existing hollow cylindrical bearing sleeve 1a1 is attached to the first rocker arm part 1a. If the bearing sleeve 1 a1 and the first rocker arm part 1a are formed in several parts, the fastenings, i. that is, permanent, non-rotatable connections are preferably made, for example by welding, soldering and / or pressing. Al ternatively, the bearing sleeve 1a1 and first rocker arm part 1a can also be formed in one piece, for. B. by the bearing sleeve 1 a1 is integrally formed on the first rocker arm part 1a.

On the hollow cylindrical bearing sleeve 1 a1, the second rocker arm part 1 b is pivotally mounted. In other words, the bearing sleeve 1 a1 fastened with the first rocker arm part 1a can thus serve as a sliding bearing for the second rocker arm part 1b. In order to fix the axial position of the second rocker arm part 1b on the bearing sleeve 1a1, the bearing sleeve 1a1 further include a groove 1 a2 running circumferentially, ie perpendicular to the rocker arm axis 2. In this case, a locking ring 5 for the axial position securing of the second Kipphe belteile 1 b can be used, with a thrust washer 6 can also be arranged in the axial direction between the second rocker arm part 1 b and the locking ring 5 to reduce friction. To further reduce friction, the two-part rocker arm 10 can further comprise a, preferably hollow cylindrical, slide bearing bush 7, by means of which the first rocker arm part 1 a and / or the bearing bush 1 a1 are / are mounted on the rocker arm axis 2. The plain bearing bush 7 is preferably designed to concentrically surround the rocker arm axis 2 or to completely surround it on the circumferential side. Instead of using an (optional) slide bearing bushing 7, the first rocker arm part 1a and / or the bearing bushing 1a1 can also be mounted directly on the rocker arm axis 2, in which case a sliding layer, for. B. M0S2, is applied to the rocker arm axis 2.

For releasably non-rotatably connecting the first and second rocker arm parts 1 a and 1 b, the first rocker arm part 1 a comprises a first recess 3a and the second rocker arm part 1 b has a second external effect 3 b. In the present case, these are designed in the form of a groove with a trapezoidal cross section, each extending parallel to the tilt axis 2. The recesses 3a and 3b are arranged and dimensioned in such a way that they can complement each other to form an overall groove, into which, for locking or coupling the two tilting lever parts 1a and 1b, a - which is described in more detail below and preferably has a complementary shape - Locking element 4a can engage or can be used. If this locking element 4a is engaged with the first and second recesses 3a, 3b (= locking position S _a ), then the two rocker arm parts 1 a and 1 b are connected in a rotationally fixed manner by the locking elements 4a bridging the two recesses 3a, 3b, so that a movement transmission between camshaft 12 and lift valve is made possible. However, if the locking element 4a is not in engagement with the first and second recesses 3a, 3b (= free position S _e ), then the two rocker arm parts 1 a and 1 b are not coupled in terms of movement technology, ie can be pivoted independently of one another, so that in this case none Movement transmission between camshaft 12 and lift valve can take place. In the present case, the locking element 4a engages in the first and second recesses 3a, 3b “from above”. Alternatively, by appropriately attaching the first and second recesses 3a, 3b and the coupling device 4, an intervention “from below” or any radial direction can also be realized. FIG. 3 shows a schematic exploded illustration of a coupling device 4 of the switchable actuating device 100 including a locking element 4a, in the present case designed as an insert, according to an embodiment of the invention. The Arretie relement 4a, which has its greatest extent along the rocker arm axis 2, is complementary to the first and second recesses 3a, 3b (see FIG. 2). As a result, the locking element 4a can cooperate as optimally as possible with the first and second recesses 3a, 3b in the form of a tongue and groove engagement in order to releasably connect the two rocker arm parts 1a and 1b in a rotationally fixed manner.

To hold and guide the locking element 4a and in particular to switch as reliably as possible between the locking position S _a and release position S _e , two pins 4a1, 4a2 are fastened to the locking element 4a, by means of which the locking element 4a is pivotally mounted in a bearing block 4b. The bearing block 4b is made portal-shaped and comprises two bearing cheeks 4b1, 4b2 spaced in the axial direction, each of which has elongated holes 4b3 (only one shown) extending in the circumferential direction, in which the locking element 4a is guided by means of the pins 4a1, 4a2. This elongated hole guide enables a restricted movement of the locking element 4a in the circumferential direction, as a result of which the insertion of the locking element 4a into the first and second recesses 3a, 3b and thus the change between the locking position S _a and release position S _{e is} facilitated. In order to additionally fix the locking element 4a in the radial direction, the bearing block 4b further comprises a guide roller 4c which is rotatably mounted in the axial direction and which is supported on the locking element 4a. Preferably, the rotatably mounted guide roller 4c can roll on an outer surface of the locking element 4a, as a result of which optimal radial force transmission for securing the locking element 4a can be achieved at any time or for any pivoting state.

Furthermore, the present embodiment of the bearing block 4b comprises two guide eyes 4f1 and 4f2, by means of which the bearing block 4b, preferably for movement in the radial direction, is guided on two sliding pins 4d1 and 4d2 (cf. FIG. 1). It is particularly advantageous if the coupling device 4 further comprises a clamping device by means of which the bearing block 4b can be clamped in the radial direction against the first and second recesses 3a, 3b. As shown in FIG. 1, this can be designed in the form of two spiral springs 4e1, 4e2 surrounding the sliding pins 4d1, 4d2, the spiral springs 4e1, 4e2 each at one of their ends on the respective guide eyelet 4f1 or 4f2 and at their opposite ends Support each end at a stop on the respective slide pin 4d1 or 4d2. FIG. 4 shows a schematic side view of the switchable actuating device 100 according to FIG. 1 in a locking position S _a (top) and a release position S _e (bottom). Here, in the locking position S _a shown above _, the locking element 4a is almost completely constantly in the first and second recesses 3a, 3b, whereby the first and second rocker arm parts 1 a and 1 b are coupled in terms of movement. In the release position S _e shown below, the locking element 4a is not in contact with the first and / or second recess 3a, 3b, as a result of which the first and second rocker arm parts 1a, 1b are movable independently of one another. The change between these two positions takes place by moving the locking element 4a in a plane perpendicular to the rocker arm axis 2, preferably by moving the locking element 4a radially. In the presently illustrated embodiment, the bearing block 4b guided on sliding pins 4d1, 4d2 can be raised or lowered radially to the rocker arm axis 2 by means of the switching device 13. The switching device 13 is in the form of an electromagnet, which interacts magnetically with a permanent magnet material attached to the bearing block 4b. In addition or alternatively, the switching device 13 can also comprise a piston-cylinder arrangement attached to the bearing block 4b, the cylinder being acted upon by a hydraulic medium and / or compressed air for switching the locking element 4a.

Figure 5 shows an enlarged detail view of the area of the first recess 3a of the release position S _e of Figure 4. In this, the shape or cross section of the recess 3a and the locking element 4a can be seen more clearly. Here, the first and second recesses 3a, 3b are each formed as a tra peznut extending parallel to the rocker arm axis 2. I.e. the first and second recesses 3a, 3b each have a groove cross section that tapers to the rocker arm axis 2. This is bounded to the rocker arm axis 2 by a groove base and laterally by two groove flanks, each of which is inclined by an inclination angle α in comparison to an ideal rectangular cross section. This inclination facilitates the insertion of the complementary locking element 4a into the first and second recesses 3a, 3b. Here, however, the angle of inclination a of the groove flanks is smaller than the self-locking angle O _{h of} the corresponding material pairing of the first rocker arm locking element and / or second rocker arm locking element (in the example 1 1, 4 °), so that the locking element 4a in the locking position S _a self-locking tension. In this way, reliable fixing of the locking element 4a in the circumferential direction can advantageously be achieved. FIG. 6 shows a motor vehicle 30 comprising an internal combustion engine 20 with a switchable actuating device 100 for a lift valve according to an embodiment of the invention. In the present case, the motor vehicle 30 is a commercial vehicle in the form of a truck. Alternatively, however, the motor vehicle 30 can also be an omnibus and / or a tractor-trailer. Advantageously, by means of the switchable actuating device 100 according to the invention in the schematically illustrated motor vehicle 30, a gas change of individual lift valves of the internal combustion engine 20 - preferably in low-load operation - can be specifically deactivated and the overall fuel consumption thereby reduced. Although the invention has been described with reference to certain embodiments, it will be apparent to those skilled in the art that various changes can be made and equivalents can be used as substitutes without departing from the scope of the invention. Accordingly, the invention is not to be limited to the disclosed embodiments, but is intended to encompass all exemplary embodiments which fall within the scope of the appended claims. In particular, the invention also claims protection for the subject matter and the features of the subclaims independently of the claims taken in reference.

Reference list

1a First rocker arm part

1a1 bearing sleeve

1a2 groove

1a3 role

1 b Second rocker arm part

2 rocker arm axis

2a Flattened area of the rocker arm axis

3a first recess

3b second recess

4 coupling device

4a locking element

4a1, a2 cones

4b bearing block

4b1, 4b2 bearing cheeks

4b3 slot

4c leadership role

4d1, 4d2 slide pin

4e clamping device

4e1, 4e2 coil springs

4f1, 4f2 guide eyes

5 circlip

6 thrust washer

7 plain bearing bush

10 two-piece rocker arm

11 cams

12 camshaft

13 switching device

20 internal combustion engine

30 motor vehicle

100 actuating device

S _a locking position

S _e release position

a angle of inclination Q _h self-locking angle

Claims

1. Switchable actuating device (100) for a stroke valve of an internal combustion engine (20), preferably a charge exchange valve, which can be moved periodically between a closed and an open position by a cam (11) of a camshaft (12), comprising:

a) having a two-part rocker arm (10) for actuating the lift valve

ai) a first rocker arm part (1a) pivotably mounted about a rocker arm axis (2), to which a bearing sleeve (1a1) is fixed concentrically to the rocker arm axis (2); and

a2) a second rocker arm part (1b) pivotally mounted on the bearing sleeve (1a1);

wherein the first rocker arm part (1a) comprises a first recess (3a) and the second rocker arm part (1b) comprises a second recess (3b); and

b) a coupling device (4) for releasably non-rotatably connecting the first and second rocker arm parts (1a, 1b), comprising a locking element (4a) which can optionally be brought into and out of engagement with the first and second recesses (3a, 3b) An actuation of the lift valve is interrupted if the locking element (4a) is not in engagement with the first or second recess (3a, 3b).

2. Actuator (100) according to claim 1, characterized in that the La gerhülse

a) is integrally formed on the first rocker arm part (1a); and or

b) concentrically surrounds the rocker arm axis (2); and or

c) comprises a groove (1a2) into which a locking ring (5) is inserted to secure the position of the second rocker arm part (1b) axially.

3. Actuating device (100) according to one of the preceding claims, characterized in that the locking element (4a) by moving perpendicular to the tilting salmon (2) optionally in

a) can be brought into a release position S _e , in which the locking element (4a) is not in engagement with the first and second recesses (3a, 3b), or

b) in a locking position S _a , in which the locking element (4a) with the first and two th recess (3a, 3b) is engaged, can be brought.

4. Actuating device (100) according to one of the preceding claims, characterized in that a) the first and second recess (3a, 3b) each as a parallel to the rocker arm salmon (2) extending groove with a tapering to the rocker arm axis (2) groove cross section are trained; and

b) the locking element (4a) is wedge-shaped and / or truncated-wedge-shaped and / or at least in sections is complementary to the first and / or second recess (3a, 3b).

5. Actuating device (100) according to claim 4, characterized in that each of the groove cross sections is designed to tension the locking element (4a) in the circumferential direction in a self-locking manner when the locking element (4a) engages in the first and second recesses (3a, 3b).

6. Actuating device (100) according to claim 4 or 5, characterized in that each of the groove cross sections to the rocker arm axis (2) is delimited by a groove base and laterally by two groove flanks, an inclination angle a of the groove flanks being smaller than the self-locking angle on the material pairing first- Rocker arm locking element and / or second rocker arm locking element.

7. Actuating device (100) according to one of the preceding claims, characterized in that the locking element (4a)

a) has the greatest extent along the rocker arm axis; and / or b) extends parallel to the rocker arm axis (1); and or

c) can only be moved perpendicular to the rocker arm axis (2).

8. Actuating device (100) according to one of the preceding claims, characterized in that the coupling device (4) comprises a bearing block (4b) for axially fixing the locking element (4a), the bearing block (4b) having two bearing cheeks spaced apart in the axial direction (4b1, 4b2), on which the locking element (4a) is pivotally mounted by means of two pins (4a1, 4a2) fastened to the locking element (4a).

9. Actuating device (100) according to claim 8, characterized in that the pins (4a1, 4a2) of the locking element (4a) each extend in a circumferentially extending slot (4b3) of the bearing cheeks (4b1, 4b2) of the bearing block (4b ) are performed.

10. Actuating device (100) according to claim 8 or 9, characterized in that the bearing block (4b) comprises an axially rotatably mounted guide roller (4c), which is for the radial fixing of the locking element (4a) in the radial direction on the locking element (4a) supports.

11. Actuating device (100) according to one of claims 8 to 10, characterized in that the coupling device (4) at least one on the rocker arm axis (2) on arranged sliding pin (4d1, 4d2) or one on the rocker arm axis (2) arranged slide rail comprises, on which the bearing block (4b) is mounted radially to the rocker arm axis (2) displaceable bar.

12. Actuating device (100) according to one of the preceding claims 8 to 11, characterized in that the coupling device (4) comprises a clamping device (4e) by means of which the bearing block (4b) in the radial direction against the first and second recess (3a , 3b) can be tensioned.

13. Actuating device (100) according to one of the preceding claims, characterized by an electro-magnetic and / or pneumatic and / or hydraulic Schaltvor direction (13), by means of which the locking element (4a) can be actuated to selectively engage and disengage it to bring the first and second recess (3a, 3b).

14. Internal combustion engine (20), preferably a diesel internal combustion engine, comprising a lifting valve with a switchable actuating device (100) according to one of the preceding claims.

15. Motor vehicle (30), preferably commercial vehicle, comprising an internal combustion engine (20) according to claim 14.