DE102011011803A1 - Actuation module for at least one gas exchange valve of an internal combustion engine - Google Patents

Abstract

The invention relates to an actuation module for at least one gas exchange valve of an internal combustion engine having a cylinder head cover (10) and at least one camshaft (14) with at least one cam piece (16, 17) arranged on the camshaft (14), in particular toothed shaft, wherein the cylinder head cover (10 ) for supporting the camshaft (14) at least one split bearing bridge (12) having a bearing base (28) and a bearing cap (30), each forming a bearing opening with radially inner bearing surface (32). In this case, at least one cam piece (16, 17) has a bearing element (26) which is arranged in a bearing bridge (12) radially between the camshaft (14) and the bearing surface (32).

Description

The invention relates to an actuation module for at least one gas exchange valve of an internal combustion engine having a cylinder head cover and at least one camshaft, which has a drive shaft, in particular toothed shaft, and at least one axially displaceable cam piece as built camshaft, wherein the cylinder head cover for supporting the camshaft has at least one divided bearing bridge, The invention further relates to a method for assembling an actuation module for at least one gas exchange valve of an internal combustion engine according to the preamble of patent claim 8.

From the DE 198 07 675 A1 is a cylinder head for an internal combustion engine with at least one camshaft known. For the lowest possible bearing of the camshaft, a drive wheel for the camshaft immediately adjacent bearing in the region of an outer web as a rolling bearing, such as ball bearings, formed and the other bearings are made as plain bearings. Optionally, the bearing which is furthest away from the drive wheel is also produced as a roller bearing, for example ball bearings.

From the DE 103 31 089 A1 is a cylinder head cover for an internal combustion engine with at least one camshaft known, wherein the camshaft protrudes through at least one bearing bridge along a bearing lane for the camshaft in the cylinder head cover. The bearing bridges each have an opening which completely surrounds the camshaft. The bearing bridges are undivided, wherein the bearing can have a roller bearing, for example a ball bearing, for mounting the camshaft. For assembly, the camshaft is cooled below a temperature of the cylinder head cover and fitted in the holes of the bearing bridges and in prefabricated cams. An assembly aid ensures correct alignment of the cams, in particular for the correct distance and the predetermined rotation of the same. The cams are arranged between the undivided bearing bridges.

The invention has for its object to improve an actuating module and a method of the type mentioned above in that a simple and inexpensive installation is achieved and a variation of the cam lift is possible.

This object is achieved by an actuation module of the type mentioned above with the features characterized in claim 1 and by a method of the type mentioned above in claim 8 method steps. Advantageous embodiments of the invention are described in the further claims.

For this purpose, it is provided according to the invention in an actuator module of the type mentioned above, that at least one cam piece has a bearing element, which is arranged in a bearing bridge radially between the camshaft and the bearing surface.

This has the advantage that the bearing of the camshaft and the cam pieces is independent and at the same time must not be formed divided by the division of the bearing bridges regardless of a housing of the cylinder head cover this case, so that a simple sealing of the cylinder head cover is possible.

A particularly simple manufacture and assembly is achieved in that at least one bearing element and a cam piece are integrally formed with each other.

For additional storage of the camshaft or toothed shaft, the cylinder head cover has at least one undivided bearing point.

A reduction of frictional forces within an undivided bearing of the camshaft or toothed shaft is achieved in that a rolling bearing, in particular a ball bearing, is arranged in at least one undivided bearing point.

A particularly reliable and functionally reliable design of the actuating module is achieved in that the camshaft has a toothed drive shaft, wherein this is mounted in an undivided bearing point.

A valve switching system is achieved in that at least one cam piece is designed and arranged in such a way that it is axially displaceable on the cam or toothed shaft.

A simple assembly is achieved by the fact that the bearing base is formed integrally with the cylinder head cover.

• (a) Einlegen aller Nockenstücke mit Lagerelementen in eine jeweilige geteilte Lagerbrücke;
• (b) Einschieben der Nocken- bzw. Zahnwelle durch die Lagerelemente.

Furthermore, according to the invention, the following steps are provided in a method of the abovementioned type,

• (a) placing all cam pieces with bearing elements in a respective split bearing bridge;
• (B) insertion of the cam or toothed shaft by the bearing elements.

This has the advantage that in a simple and cost-effective manner, a switchable valve train can be mounted in a cylinder head cover, both Split bearing bridges and undivided bearings has.

A correct position mounting of the cam pieces is achieved by aligning the cam pieces during or after step (a).

For mechanical retention of the cam pieces in the split bearing bridges and to complete the bearings in the bearing bridges at least one bearing cap is mounted on a respective bearing base before or after step (b).

A low-friction bearing of the camshaft on at least one undivided bearing point is achieved in that prior to step (a) at least one roller bearing, in particular a ball bearing, is pressed onto at least one camshaft at a location after step (b) arranged in the undivided bearing area is.

A simple assembly of a built camshaft with at least one axially displaceable on the camshaft cam piece is achieved in that after step (a) and before step (b) an actuating mechanism for a camshaft axially displaceable cam piece is mounted.

A fixed mounting of the cam pieces for axial insertion of the camshaft is achieved in that in step (a) the cam pieces are each inserted into a bearing base.

A special form of this built camshaft is achieved in that after step (b) at least one cam piece rotatably connected to the camshaft, in particular pinned, is.

The invention will be explained in more detail below with reference to the drawing. This shows in

1 an exemplary embodiment of an actuating module according to the invention in a perspective view and

2 a sectional view of the actuating module according to 1 in a plane intersecting a camshaft.

In the 1 and 2 illustrated, preferred embodiment of an actuating module according to the invention comprises a cylinder head cover 10 with shared bearing bridges 12 and two camshafts 14 , the first and second cam pieces respectively 16 . 17 exhibit. The cylinder head cover 10 Further, for each of the camshafts 14 both sides each have an undivided depository 18 on, being in one of two storage locations 18 for a camshaft 14 a rolling bearing 20 , in particular ball bearings, is arranged. The rolling bearing 20 simultaneously provides axial fixation of the camshaft or toothed shaft 14 to disposal.

The first cam pieces 16 are non-rotating and axially fixed on the camshaft 14 arranged. The second cam pieces 17 are non-rotatable with the camshaft 14 connected, but in addition by a predetermined path axially displaceable relative to the camshaft, as with double arrows 24 indicated, so that optionally different cam contours for actuation of a respective gas exchange valve (not shown) can be adjusted. In this way, a valve switching mechanism is available. Corresponding switching devices 22 for axially displacing the second cam pieces 17 are on the cylinder head cover 10 arranged.

Each cam piece 16 . 17 has in one piece a bearing element 26 on and the cam pieces 16 . 17 are in the shared camp bridges 12 arranged so that the cam pieces 16 . 17 or their respective bearing element 26 each between the respective bearing bridge 12 and the camshaft 14 are arranged. The camp bridges 12 each include a storage base 28 , which are integral with the cylinder head cover 10 is formed, and a bearing cap 30 ( 2 ). In the presentation of 1 the bearing caps are not yet on the respective storage bases 28 fastened so that from the shared bearing bridges 12 only the storage bases 28 you can see. One storage base each 28 and a bearing cap 30 form a bearing opening through which engages a camshaft and one of the camshaft 14 facing storage area 32 trains ( 2 ). The cam pieces 16 . 17 or their bearing elements 26 are in the respective bearing bridge 12 between the camshaft 14 and the storage area 32 arranged.

Through the shared bearing bridges 12 can be a housing of the cylinder head cover 10 be undivided trained. This is the cylinder head cover 10 easier to seal than a cylinder head cover 10 with split housing, wherein the housing parts have the two complementary parts (base and cover) of the split bearing bridge.

For mounting the actuation module according to the invention, the following procedure is used as an example:
First, the cam pieces 16 . 17 into the camp bases 28 shared storage bridges 12 inserted in such a way that the bearing elements 26 the cam pieces 16 . 17 at the respective of the storage base 28 trained storage area 32 issue. The cam pieces 16 . 17 are then aligned correctly. On the not yet mounted cam or gear shafts 14 In each case, a rolling bearing, for example, ball bearings, in particular a deep groove ball bearing, pressed at a point after assembly the camshaft 14 in a respective storage lane of the cylinder head cover 10 in the area of the undivided depository 18 lies. Actuators for the axially displaceable second cam pieces 17 be pre-assembled. These actuators include, for example, spring and ball when inserting the camshaft 14 lock. Subsequently, the camshaft 14 through the undivided bearings 18 and the cam pieces 16 . 17 in the camp bridges 12 inserted axially. The camshaft 14 is characterized by the undivided bearings 18 directly and through the shared storage bridges 12 indirectly via the cam pieces 16 . 17 stored. The rolling bearing 20 becomes the undivided depository 18 pressed. Next, the assembly of a first end piece 34 with pump cam and the installation of a second end piece 36 with water pump drive. Finally, the first cam pieces 16 mechanically fixed to the camshaft 14 , for example by means of pinning, so that these first cam pieces 16 rotationally fixed and axially fixed with the camshaft 14 are connected. Then it is still on the side of the bearings 20 a shaft seal is pressed in and at the opposite end of the camshafts 14 a lid 38 assembled.

• – Der Zylinderkopf eines Motors mit konventioneller Nockenwelle und eines Motors mit variablem Ventiltrieb sind identisch. Alle Umfänge, die sich zwischen den Motorenvarianten ändern, sind innerhalb der Zylinderkopfhaube untergebracht. So kann ein Haubenmodul mit konventioneller Nockenwelle und ein Haubenmodul mit einem schaltbaren Ventiltrieb, der eine Abschaltung der Ventile von 2 Zylindern realisiert, für einen ansonsten konstruktiv unveränderten Motor vorgesehen werden. Beide Varianten sind realisierbar ohne den Basismotor zu ändern. Bei bisher bekannten Konstruktionen sind hierfür zwei unterschiedliche Zylinderköpfe notwendig.
• – Die Nockenstücke werden in die geteilten Lager innerhalb der Zylinderkopfhaube eingelegt und die verzahnte Antriebswelle anschließend in die Zylinderkopfhaube eingesteckt. So sind das erste und das letzte Lager der Nockenwelle ungeteilt. Dies reduziert die Reibung dieser Lager und ermöglicht eine nach außen abgeschlossene Zylinderkopfhaube. Es ist nicht notwendig, die Zylinderkopfhaube auf Höhe der Nockenwellen komplett zu trennen, um die vorher montierte Nockenwelle einzulegen. Somit ist auch keine Abdichtung der außen liegenden Trennfuge notwendig. Alle Trennfugen der Lagerung liegen innerhalb der Haube und müssen somit nicht öldicht abgedichtet werden.
• – Als Axiallager wird ein Kugellager eingesetzt. Wenn man diese Kugellager axial in ein geschlossenes Lager einpresst und so fixiert, wird es annähernd rotationssymmetrisch verpresst. Wenn man ein Kugellager in ein geteiltes Lager einlegt und mit einer Lagerbrücke versieht, wird es in eine ovale Form gedrückt. Alternativ ist es allerdings möglich ein konventionelles Gleitlager vorzusehen, welches wiederum über eine ungeteilte Lauffläche und damit Reibleistungsvorteile besitzt.

Overall, the invention provides the following advantages:

• - The cylinder head of a conventional camshaft engine and a variable valve train engine are identical. All circumferences that change between the engine variants are housed within the cylinder head cover. Thus, a hood module with conventional camshaft and a hood module with a switchable valve train, which realizes a shutdown of the valves of 2 cylinders, are provided for an otherwise structurally unchanged engine. Both variants can be realized without changing the base engine. In previously known constructions two different cylinder heads are necessary for this purpose.
• - The cam pieces are inserted into the split bearings inside the cylinder head cover and the toothed drive shaft is then inserted into the cylinder head cover. Thus, the first and the last bearing of the camshaft are undivided. This reduces the friction of these bearings and allows an outwardly closed cylinder head cover. It is not necessary to completely separate the cylinder head cover at the level of the camshafts to insert the previously assembled camshaft. Thus, no sealing of the outer parting line is necessary. All joints of the storage are within the hood and therefore need not be sealed oil-tight.
• - A ball bearing is used as the thrust bearing. If you press these ball bearings axially into a closed bearing and so fixed, it is pressed approximately rotationally symmetrical. If you insert a ball bearing in a split bearing and provide it with a bearing bridge, it is pressed into an oval shape. Alternatively, however, it is possible to provide a conventional plain bearing, which in turn has an undivided tread and thus friction performance advantages.

LIST OF REFERENCE NUMBERS

10

Cylinder head cover

12

divided bearing bridge

14

camshaft

16

first cam piece, fixed

17

second cam piece, axially displaceable

18

undivided depository

20

ball-bearing

22

switching device

24

double arrow

26

bearing element

28

bearing base

30

bearing cap

32

storage area

34

first tail with pump cam

36

second end piece with water pump drive

38

cover

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19807675 A1 [0002]
• DE 10331089 A1 [0003]

Claims (15)

Actuation module for at least one gas exchange valve of an internal combustion engine with a cylinder head cover ( 10 ) and at least one camshaft ( 14 ), in particular toothed shaft, with at least one on the camshaft ( 14 ) arranged cam piece ( 16 . 17 ), wherein the cylinder head cover ( 10 ) for supporting the camshaft ( 14 ) at least one split bearing bridge ( 12 ) having a storage base ( 28 ) and a bearing cap ( 30 ), each having a bearing opening with radially inner bearing surface ( 32 ), characterized in that at least one cam piece ( 16 . 17 ) a bearing element ( 26 ), which in a bearing bridge ( 12 ) radially between the camshaft ( 14 ) and the storage area ( 32 ) is arranged. Actuating module according to claim 1, characterized in that at least one bearing element ( 26 ) and a cam piece ( 16 . 17 ) are integrally formed with each other. Actuating module according to at least one of the preceding claims, characterized in that the cylinder head cover ( 10 ) at least one undivided depository ( 18 ) having. Actuation module according to claim 3, characterized in that in at least one undivided bearing ( 18 ) a rolling bearing ( 20 ), in particular a ball bearing, is arranged. Actuating module according to claim 2 or 3, characterized in that the camshaft ( 14 ) has a toothed drive shaft, wherein these in an undivided bearing ( 18 ) is stored. Actuating module according to at least one of the preceding claims, characterized in that at least one cam piece ( 17 ) is designed and arranged such that this on the camshaft ( 14 ) is axially displaceable. Actuating module according to at least one of the preceding claims, characterized in that the bearing base ( 28 ) in one piece with the cylinder head cover ( 10 ) is trained. Method for assembling an actuation module for at least one gas exchange valve of an internal combustion engine, wherein the actuation module is designed according to at least one of the preceding claims and has at least one undivided bearing, characterized by the following steps, (a) inserting at least one or all cam pieces with bearing elements into a respective split bearing bridge; (B) insertion of the camshaft by the bearing elements. A method according to claim 8, characterized in that during or after step (a) the cam pieces are aligned. A method according to claim 8 or 9, characterized in that before or after step (b) at least one bearing cap is mounted on a respective bearing base. Method according to at least one of claims 8 to 10, characterized in that before step (a) at least one roller bearing, in particular a ball bearing, is pressed onto at least one camshaft at a location which is arranged after step (b) in the undivided bearing area , A method according to claim 11, characterized in that after step (b) the rolling bearing fixed in the undivided bearing point, in particular pressed into the undivided bearing point, is. Method according to at least one of claims 8 to 12, characterized in that after step (a) and before step (b) an actuating mechanism for a camshaft axially displaceable cam piece is mounted. Method according to at least one of claims 8 to 13, characterized in that in step (a) the cam pieces are each inserted into a bearing base. Method according to at least one of claims 8 to 14, characterized in that after step (b) at least one cam piece rotatably connected to the camshaft, in particular pinned, is.

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