DE102018206901A1 - Cylinder head cover with opening for the implementation and storage of a camshaft of an internal combustion engine and arrangement of a camshaft on such a cylinder head cover - Google Patents

Abstract

A cylinder head cover of an internal combustion engine according to the invention has a main body (12) and at least one opening (14) formed in the main body (12) for passing and supporting a camshaft (26) relative to the main body (12) and at least one in the main body (12) Oil passage (16) on. In this case, at least one separate insert element (18) is arranged in the base body (12), which has an inner side (28) oriented in the direction of the camshaft (26) and is designed and arranged in the base body (12) such that a flow path of at least one Insert element inlet opening (22) to at least one insert element outlet opening (24) is provided to promote oil from an in the base body (12) formed in the oil passage outlet opening (20) through the insert element (18) directly in the direction of the camshaft (26) can.

Description

The invention relates to a cylinder head cover with at least one opening for carrying and supporting a camshaft of an internal combustion engine and the arrangement of a camshaft on such a cylinder head cover. In particular, the invention relates to a cylinder head cover and an arrangement of such a cylinder head cover of an internal combustion engine, which serves primarily as a drive element of a vehicle, preferably as a drive element of a motor vehicle. For the sake of completeness, reference is also made to internal combustion engines and motor vehicles with corresponding cylinder head covers or with corresponding arrangements.

Out EP 1 550 793 A1 is a camshaft adjuster with partially interrupted pressure oil supply known. In connection with this camshaft adjuster reference is made to the use of a sliding bearing with a segment-like annular groove. This refers to the EP 1 550 793 A1 exclusively to a system having a camshaft receptacle for supplying a device for the camshaft adjustment of an internal combustion engine with pressurized oil. On the formation of a cylinder head cover with at least one - formed on a base body of the cylinder head cover - opening for the implementation and storage of a camshaft is not taken.

Out DE 196 22 676 A1 is known as a secondary drive of an internal combustion engine chain drive known. In connection with this chain drive a lubricating oil supply of a sliding bearing is described, which takes place from a pressure chamber via a transverse bore in a bearing journal and an embossed in a bearing surface of a bearing bushing annular groove. On the formation of a cylinder head cover with at least one - formed on a base body of the cylinder head cover - opening for the implementation and storage of a camshaft is also in DE 196 22 676 A1 not referenced.

The invention has for its object to provide a cylinder head cover with at least one opening for the implementation and storage of a camshaft of an internal combustion engine and the arrangement of a camshaft on such a cylinder head cover available in a simple and cost-effective manner efficient and only with low oil consumption allow accompanying camshaft slide bearing.

The object is achieved according to the invention with the features of the independent claims. Further practical embodiments and advantages of the invention are described in connection with the dependent claims.

A cylinder head cover of an internal combustion engine according to the invention has a main body and at least one opening formed in the main body for the passage and storage of a camshaft relative to the main body. Furthermore, at least one oil channel is formed in the base body, in particular an oil channel leading in the direction of the at least one opening for supplying oil to a camshaft bearing. Preferably, at least one such oil passage is provided in the region of each opening for the passage and storage of a camshaft. In addition, at least one separate insert element is arranged in the base body, which has an inner side oriented in the direction of the camshaft and is arranged and arranged in the base body such that a flow path from at least one insert element inlet opening to at least one insert element outlet opening is provided in order to remove oil be able to promote by a formed in the body oil passage outlet opening by the insert element directly in the direction of the camshaft. In other words, in a cylinder head cover according to the invention, the use of an insert element is provided as a camshaft slide bearing to provide a simple and cost-effective manner a flow path from an insert inlet opening to at least one insert-outlet opening, in particular, with the aid of Insertion element to bridge over a portion of the circumference extending flow path and thus to allow at least partially over a part of the circumference extending flow of oil and so compensate for an angular offset between the insert element inlet opening and insert outlet opening. Thus, the angular position of the oil supply can be optimized in camshaft bearings in a simple and low-cost manufacturing manner without costly design changes existing internal combustion engines. This is particularly advantageous if in existing cylinder head covers or cylinder head covers with over a portion of the surrounding circumference of the circumference with only small wall thicknesses oil to be promoted in oil passages poorly or only with high production costs accessible areas. This may be the case, in particular depending on the bearing load direction, since it has emerged from research and development work that the oil consumption in camshaft plain bearings can be significantly reduced by selecting a suitable oil feed position.

For the sake of completeness, it should be noted that the oil passage is preferably a passage pressurized with oil, that is, oil having a higher pressure than the ambient pressure. This pressure is often in a range during engine operation between ambient pressure and 5 bar, depending on the application, only between ambient pressure and 4 bar or between ambient pressure and 3 bar.
A cylinder head cover according to the invention has the additional advantage that the material of the insert element is largely independent of the material of the cylinder head cover selectable. For example, as the material for the insert element, the same material can be used as for the camshaft mounted by the insert element, for example a steel material, although the base body of the cylinder head cover is made of aluminum for reducing the weight of the internal combustion engine. This in turn has the advantage that a dimensioned between insert element and camshaft gap regardless of the temperature of the insert element and camshaft maintains approximately the same degree, if it is assumed that the temperature of insert element and camshaft due to the immediately adjacent arrangement and thereby resulting contact changed approximately evenly. It is advantageous to the extent that the same or in relation to the relevant temperature range with respect to material expansion and material compression similarly behaving material is selected for the insert element as for the camshaft. Initial tests have shown that oil consumption can be reduced by well over 10 percent, in some cases even more than 20 percent or even around 30 percent. This also results in a reduced CO ₂ emissions. Ensuring a uniform gap between the insert element and the camshaft, regardless of the actual operating temperature, also makes it possible to use oils with a low viscosity class according to SAE classification, for example 0W15, 0W12, 0W10 or even 0W8, without significant additional consumption being expected as a result ,

In a practical embodiment of a cylinder head cover according to the invention, the insert element is designed in the manner of a bearing bush, the inside of which is designed as a bearing surface surrounding the cam shaft on the outside. In this case, the bearing bush is provided for a direct contact with the camshaft and designed so that the bearing bush is in direct contact with the camshaft in an arrangement according to the invention.

In a further practical embodiment of a cylinder head cover according to the invention, a circumferentially extending, arcuately extending channel section is formed on the bearing bush as an insert element inlet opening radially on the outside in order to guide oil at least partially in the circumferential direction of the bearing bush. Such a channel portion may be formed in a particularly easy to manufacture embodiment, in particular as a circumferential groove or as a segment groove. It is preferred to produce such a circumferential groove or segment groove in a - in relation to the axial direction of the camshaft - middle portion of the outer peripheral surface of a bearing bush as a recess, which together with a portion of the base body which surrounds the insert element on the outside, in the case of Circumferential groove forms over the entire outer circumference of the insert element extending annular channel. As already mentioned, the formation of a circumferentially extending, arcuate channel section, which may extend completely or only partially over the circumference, has the advantage that with the aid of the insert element a simple and cost-effective flow guidance of intended for the storage of the camshaft Oil can be realized.

Both manufacturing technology and functional, it is advantageous if the bearing bush as an insert element outlet opening is provided in the radial direction up to the inside extending outlet channel. Such an outlet channel may in particular be formed as a bore or other channel-like opening which extends only over a limited angular range. In terms of manufacturing technology and function, it is advantageous if, viewed in the radial direction, the outlet channel has a constant diameter over its entire length or a constant geometry and opening width. Then, in the case of an outlet opening with a circular cross-section, such an outlet opening can be produced in particular as a bore or as an opening formed by casting. For the sake of completeness, it should be pointed out that the outlet opening can alternatively also have a cross-sectional width increasing in the radial direction or an increasing diameter or a decreasing diameter. Such geometries can also be produced in a simple and cost-effective manner in terms of production technology, both within the scope of casting processes and as part of a subsequent mechanical processing.

In a further practical embodiment of a cylinder head cover according to the invention, the insert element is produced as a sintered part or from bronze. As a result, the bearing properties can be further improved and the sliding friction of the camshaft can be reduced.

The invention also relates to an arrangement of a camshaft on a cylinder head cover, in particular a cylinder head cover as described above, wherein the camshaft is in a base body with "closed", ie not openable and in particular integrally formed, openings camshaft. To the cams on a cylindrical shaft portion in desired position in the body can be joined in particular thermally or positively with the camshaft. Corresponding thermal and positive joining methods are known from the prior art. When cylinder head covers with such closed openings, a different assembly than a positive and / or thermal joining of the camshaft in the body is not possible.

For thermal joining, the camshaft is usually cooled, whereas the cams are heated so that the outer diameter of the camshaft decreases and the inner diameter of the cams increases, so that the camshaft can be guided through cams arranged in its desired position in the cylinder head cover. After adjusting the temperature of the camshaft and cam then creates a non-positive, non-rotatable press connection between the cam and the camshaft. If a thermal and / or positive joining of the cams on the cylindrical shaft portion of the camshaft within the body is mandatory in order to arrange the camshaft in the openings of the body, resulting in an integrated - in particular thermally and / or positively - joined unit from Camshaft and body.

The insert elements described above can be advantageously used in conjunction with the integrated units of camshaft and base body described above.

It is also referred to an assembly method of a camshaft slide bearing, according to which cams are arranged in a desired position within a cylinder head cover, as camshaft slide bearing provided insert elements are used in openings in the cylinder head cover and then the camshaft is sketched as outlined above thermally to establish a rotationally fixed connection between the cam and the camshaft and to guide the camshaft through the provided as a camshaft bearing insert elements in a desired position. The insertion of the insert elements can take place either prematurely by inserting or pressing in or during the passage of the camshaft through the openings in the cylinder head cover. Preliminary pressing of the insert elements makes it easier to take into account an individual orientation of insert element outlet openings relative to the cylinder head cover, in particular a determined bearing load direction in the region of a camshaft slide bearing. In that regard, it may be preferable to press the insert elements in a first step with a desired orientation of insert element outlet openings into corresponding openings of a cylinder head cover. Alternatively, a desired orientation of an insert element relative to the cylinder head cover can also be achieved and ensured in another way, for example by a positive, non-positive and / or material-locking fixation of the insert elements with respect to the cylinder head cover. In this regard, reference is made in particular to the possibility of providing an insert element with one or more radially outwardly projecting positioning lugs, which correlate with corresponding, formed in the cylinder head cover recesses and so clearly set the desired position of the insert element relative to the opening of the cylinder head cover , So assembly errors with respect to the relative alignment of insert elements relative to the cylinder head cover can be safely avoided.

In a further practical embodiment of an arrangement according to the invention, a multiplicity of openings are formed in the base body and corresponding insert elements are arranged which respectively serve for storage and oil supply of the camshaft, for example eight openings and corresponding insert elements, each on both sides by one or more cams of a camshaft are arranged.

In a further practical arrangement, which can be realized alternatively or in addition, the outlet channel is arranged oriented starting from the bearing load direction of the outlet channel associated camshaft bearing at an angle of 75 ° to 105 ° counter to the direction of rotation of the camshaft. In this regard, the angle range between 80 ° and 100 °, more preferably the angle range between 85 ° and 95 °, and particularly preferably the angle range 90 ° +/- 3 °, 90 ° +/- 2 ° or 90 ° +/- 1 °.

• 1 eine Zylinderkopfhaube in einer erfindungsgemäßen Anordnung mit einer Nockenwelle in einer Explosionsdarstellung,
• 2 nur die Zylinderkopfhaube aus 1 mit darin eingesetzten Einsatzelementen in einer Längsschnittdarstellung durch eine Reihe von Einsatzelementen und Öffnungen,
• 3 die Zylinderkopfhaube aus den 1 und 2 mit eingesetzter Nockenwelle und weiteren drehfest mit der Nockenwelle verbundenen Elementen,
• 4 eine vergrößerte Darstellung eines Einsatzelements in einer isometrischen Darstellung,
• 5 eine Öffnung der Zylinderkopfhaube aus den 1 bis 3 mit einem darin eingesetzten Einsatzelement in einer vergrößerten isometrischen Darstellung und
• 6 die Zylinderkopfhaube aus den 1 bis 3 mit zwei eingesetzten Einsatzelementen in einer Querschnittsdarstellung, wobei die Schnittebene durch zwei Öffnungen und darin eingesetzte Einsatzelemente führt.

Further practical embodiments of the invention are described below in conjunction with the drawings. Show it:

• 1 a cylinder head cover in an arrangement according to the invention with a camshaft in an exploded view,
• 2 only the cylinder head cover off 1 with insert elements inserted therein in a longitudinal section through a series of insert elements and openings,
• 3 the cylinder head cover from the 1 and 2 with inserted camshaft and other non-rotatably connected to the camshaft elements,
• 4 an enlarged view of an insert element in an isometric view,
• 5 an opening of the cylinder head cover from the 1 to 3 with an insert element inserted therein in an enlarged isometric view and
• 6 the cylinder head cover from the 1 to 3 with two inserted insert elements in a cross-sectional view, wherein the cutting plane through two openings and insert elements inserted therein.

1 shows an exploded view of a non-limiting embodiment of the invention, a cylinder head cover according to the invention 10 with a basic body 12 , In this embodiment, in the main body 12 a total of eight openings 14 for the implementation and storage of two parallel camshafts 26 opposite the main body 12 intended. There are four openings each 14 arranged in alignment with each other and for the implementation and storage of a corresponding camshaft 26 determined (cf. 2 ).

As in 6 is clearly recognizable, is in the main body 12 in the area of the respective openings 14 for the implementation and storage of the camshaft 26 in each case at least one oil channel 16 designed so that oil to a guided through the opening camshaft 26 is eligible. As if from a synopsis of 1 to 6 is clearly visible, it must first in the inventive arrangement according to the embodiment, the oil in the oil passage 18 up to an oil passage exit opening 20 flow to an insert entry port 22 an insert element 18 to arrive, as a camshaft plain bearings 40 serves. The oil can then pass through the insert element 18 through to an insert outlet opening 24 and from there directly to a radially inner side of the insert element 18 arranged camshaft 26 reach.

As in 4 is clearly recognizable, is the insert element 18 in the embodiment shown in the manner of a bearing bush 30 formed, whose inside 44 as one the camshaft 26 Outside enclosing storage area 32 is trained.

As an insert element inlet opening 22 is radially outside of the insert element 18 a circumferentially extending arcuate channel section 34 educated. Here is the channel section 34 in the embodiment as an over the entire circumference of the insert element extending circumferential groove 36 educated. About the oil channel 16 to the oil channel outlet opening 20 thus reaching oil is conveyed in the circumferential direction completely along an annular channel, which through the circumferential groove 26 and this circumferential groove 26 Radial outer side enclosing body is formed. For the sake of completeness, it is once again pointed out here that a channel section 34 instead of one in the embodiment according to 4 can also have any other geometries shown, for example, a helical or otherwise shaped like geometry. Such a channel section may alternatively extend, for example, both partially in the circumferential direction, partially in the axial direction of the camshaft and / or partially in the radial direction.

The inner diameter d of the insert element 18 is preferably in a range between 18 mm and 30 mm, more preferably in a range between 20 mm and 28 mm and particularly preferably at 22 mm to 26 mm, in particular at about 24 mm.

The material thickness s is preferably between 4 mm and 10 mm, in particular between 5 mm and 8 mm. The material thickness s in the embodiment shown is about 6 mm, wherein the circumferential groove 36 has a depth of about 3 mm.

The insert element 18 has in the embodiment shown a extending in the axial direction of the camshaft bearing width of about 10 mm. As in 1 can be seen, the storage width but space-constrained can be varied relatively generous, with storage widths between 5 mm and 20 mm are preferred.

As in 1 Ansatzweise can be seen, in the embodiment shown in each case six cams 42 provided, rotatably each with a corresponding camshaft 26 to be connected. This is done by heating the cams 42 and cooling the camshaft 26 so far that the cams 42 with the camshaft 26 can be joined and after re-adjusting the temperature of the cams 42 and the camshaft 26 a non-positive, non-rotatable connection between the camshaft 26 and the corresponding cam 42 results.

Based on 6 let the operation of a cylinder head cover according to the invention 10 or an arrangement according to the invention easily recognize and explain. Oil for lubrication of the camshaft plain bearing 40 the in 6 not shown camshaft 26 becomes according to the arrows I through the oil channel 16 in the direction of the insert element 18 promoted. The oil then passes through the oil passage exit opening 20 in the as an insert element inlet opening 22 serving circumferential groove 36 and can be in the direction of the arrows II in the circumferential direction up to the insert element outlet opening 24 reach. Through the insert element outlet opening 24 The oil then passes in the radial direction inwardly to the camshaft, not shown 26 to do that through the insert element 18 Lubricate formed camshaft bearing.

In 3 is clearly visible that in the embodiment shown in each case two cams 42 the camshaft 26 between two insert elements 18 are stored. At the cylinder head cover 10 According to the embodiment, it is the cylinder head cover of a 3-cylinder internal combustion engine, each with two cams 42 actuated intake valves and two via cams 42 actuated exhaust valves. For the sake of completeness, it is again pointed out that the number of intake and exhaust valves as well as the arrangement and the number of cylinders and other parameters can be modified as desired. However, it is preferred if at least all cams associated with a cylinder 42 on both sides of an insert element 18 are surrounded, so that at least per cylinder and each camshaft 26 a mating of insert elements 42 for storage of the corresponding camshaft 26 is provided.

In the in the 1 to 6 shown embodiment is with the arrows L in each case the bearing load direction of the corresponding opening 14 characterized. The respective direction of rotation of the camshaft 26 is with the arrows D characterized. In the embodiment shown, the angle α is provided at about 90 °, that is, the oil is through the selected arrangement of the insert element outlet opening 24 About 90 ° before the bearing load direction in the camshaft plain bearing 40 brought in. It is understood that this angle for each opening 14 is individually adjustable by the respective insert element 18 with the respective insert outlet opening 20 is arranged appropriately.

In order to achieve a low oil consumption, it is advantageous to choose the angle α in a range between 75 ° and 105 °, more preferably between 80 ° and 100 ° and particularly preferably between 85 ° and 95 °, in each case opposite to the direction of rotation D of camshaft 26 before the bearing load direction.

In 6 left is an outlet side, serving as a camshaft plain bearing opening 14 for the in 6 not shown camshaft shown, right an inlet side, serving as a camshaft slide bearing opening 14 , The bearing load direction L is oriented on the outlet side at an angle of about 345 °, inlet side at an angle of about 375 ° or 15 °.

The features of the invention disclosed in the present description, in the drawings and in the claims may be essential both individually and in any desired combinations for the realization of the invention in its various embodiments. The invention may be varied within the scope of the claims and in consideration of the knowledge of the person skilled in the art.

LIST OF REFERENCE NUMBERS

10

Cylinder head cover

12

body

14

opening

16

oil passage

18

insert element

20

Oil channel outlet opening

22

Insert element inlet opening

24

Insert element exit port

26

camshaft

28

inside

30

bearing bush

32

storage area

34

channel section

36

Circumferential groove (recess)

38

outlet channel

40

Camshaft bearings

42

cam

44

inside

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

• EP 1550793 A1 [0002]
• DE 19622676 A1 [0003]

Claims (10)

Cylinder head cover of an internal combustion engine having a base body (12) and at least one opening (14) formed in the base body (12) for passing and supporting a camshaft (26) relative to the base body (12) and at least one oil channel formed in the base body (12) ( 16), characterized in that in the base body (12) at least one separate insert element (18) as a camshaft sliding bearing (40) is arranged, which in the direction of the camshaft (26) oriented inside (28) and formed in such and Base body (12) is arranged, that a flow path of at least one insert element inlet opening (22) is provided to at least one insert element outlet opening (24) to oil from an in the base body (12) formed in the oil passage outlet opening (20) through the Insert element (18) directly in the direction of camshaft (26) to promote. Cylinder head cover according to the preceding claim, characterized in that the insert element (18) in the manner of a bearing bush (30) is formed, whose inside is formed as a camshaft (26) on the outside enclosing bearing surface (32). Cylinder head cover according to the preceding claim, characterized in that on the bearing bush (30) as a insert element inlet opening (22) radially outwardly a circumferentially extending, arcuate channel portion (34) is formed to at least partially in the circumferential direction of the bearing bush (30 ). Cylinder head cover according to the preceding claim, characterized in that the channel section (34) is designed as a circumferential groove (36) or as a segment groove. Cylinder head cover according to one of the two preceding claims, characterized in that on the bearing bush (30) as an insert element outlet opening (24) in the radial direction to the inside (28) extending outlet channel (38) is provided. Cylinder head cover according to one of the preceding claims, characterized in that the insert element (18) is made as a sintered part or of bronze. Arrangement of a camshaft (26) on a cylinder head cover (10) according to one of the preceding claims, characterized in that the camshaft (26) is a camshaft (26) joined in a base body with closed openings. Arrangement according to the preceding claim, characterized in that the insert element (18) is positively, positively and / or materially fixed relative to the base body (12). Arrangement according to one of the two preceding claims, characterized in that in the base body (12) a plurality of insert elements are arranged, each of which serves for storage and oil supply of the camshaft (26). Arrangement according to one of the three preceding claims, characterized in that the outlet channel (38), starting from the bearing load direction of the outlet channel (38) associated camshaft slide bearing (40) at an angle of 75 ° to 105 ° counter to the direction of rotation (D) Camshaft (26) oriented is arranged.

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