DE102017218080A1 - Cylinder head cover with a circumferentially interrupted radial plain bearing - Google Patents

Abstract

The invention relates to a cylinder head cover (12) for an internal combustion engine (10), comprising a radial sliding bearing (20) for holding a camshaft (16) of the internal combustion engine (10). In this case, the radial sliding bearing (20) has a circumferential range (22), which comprises an angle (a) of at most 180 °. Next, the cylinder head cover (12) is integrally formed.

Description

The invention relates to a cylinder head cover for an internal combustion engine according to the preamble of patent claim 1.

Current cylinder head covers have a bearing frame construction. When assembling the cylinder head covers cam pieces are inserted into the body of the cylinder head cover and fixed with a bearing frame. The fixation between the main body of the cylinder head cover and the bearing frame creates a 360 ° circumferential radial plain bearing for holding the cam pieces and thus also the camshaft. The radial bearing is supplied with oil via the bearing frame. Due to the bearing frame construction, the cost of assembling the currently used cylinder head covers is high.

For example, the show DE 198 07 675 A1 and the DE 197 47 244 A1 in each case a cylinder head cover with a 360 ° sliding bearing of the camshaft, which is formed by half shells. The cylinder head covers described have several individual separate components.

The invention has for its object to provide a cylinder head cover, in which a cumbersome assembly can be omitted. It is also an object of the invention to provide an internal combustion engine with such a cylinder head cover.

This object is achieved by a cylinder head cover according to claim 1. Advantageous embodiments of the invention are described in further claims.

Accordingly, a cylinder head cover for an internal combustion engine is provided. The cylinder head cover comprises a radial sliding bearing for holding a camshaft of the internal combustion engine. In this case, the radial slide bearing on a circumferential range, which includes an angle of at most 180 °. Next, the cylinder head cover is integrally formed.

The fact that the radial sliding bearing has a circumferential range, which includes an angle of at most 180 °, it is possible to form the cylinder head cover in one piece. The camshaft with the cam pieces can then be easily fitted into the radial slide bearing and held by this. A bearing frame and screws for attaching the bearing frame to the base of the cylinder head cover can be omitted. This simplifies the manufacture and assembly of the cylinder head cover. This results in a significant cost advantage.

The valve actuation forces occurring during operation are introduced into the cylinder head cover via the cam pieces, i. The cam pieces are pressed against the radial slide bearing. A radial plain bearing with a completely 360 ° circumferential range is therefore not required. The cylinder head cover according to the invention therefore has a radially interrupted radial bearing. Thus, the cylinder head cover can be integrally formed, the angle of the circumferential range is at most 180 °, so that the cam pieces can be pressed against the radial slide bearing.

The cylinder head cover according to the invention is a monolithic component. In this case, the cylinder head cover may be a casting mold and / or be milled from a block.

The omission of a bearing frame also improves the space situation within the cylinder head cover.

The radial sliding bearing may have a sliding surface, which is formed in the form of a portion of an inner circular cylinder jacket surface. The radial plain bearing can directly hold the camshaft. Alternatively, the radial slide bearing can also hold the camshaft indirectly via at least one cam piece.

By "holding a camshaft" is meant that the movement of the camshaft through the radial slide bearing is limited in a certain angular range (at most 180 °) in the radial direction with respect to the longitudinal axis of the camshaft.

By the expression "the radial sliding bearing has a circumferential range, which comprises an angle of at most 180 °" is meant that the radial slide bearing is interrupted in the circumference. The radial slide bearing therefore does not form a closed surface around the camshaft. The part of the circumference, which constitutes the circumferential range, is defined by an angle of at most 180 °. In this case, the angle is defined by two radially extending straight lines in a plane perpendicular to the longitudinal axis of the radial sliding bearing with the common starting point on the longitudinal axis of the radial sliding bearing.

According to an embodiment of the cylinder head cover, the angle is in a range from 80 ° to 180 °, preferably from 120 ° to 180 ° and more preferably from 160 ° to 180 °. The larger the angle, the better the guidance of the camshaft. However, the angle is definitely not greater than 180 °, since the cylinder head cover otherwise can not be formed in one piece.

According to a further embodiment of the cylinder head cover at least one Druckbeölungsbohrung is provided in the cylinder head cover for supplying the radial sliding bearing with oil. Advantageously, a 360 ° circumferential radial plain bearing is not necessary to build up a sufficient hydrodynamic oil lubricating film. Characterized in that the at least one Druckbeölungsbohrung is provided in the cylinder head cover, a bearing frame can be omitted, since it is no longer required for oil supply to the radial sliding bearing.

Preferably, a portion of the circumferential span located between the at least one pressure oiling well and a load maximum of the radial plain bearing has an angle in a range of 60 ° to 90 °, preferably 70 ° to 90 ° and more preferably 80 ° to 90 ° , In this case, the load maximum is that point on the circumferential range at which the maximum load occurs, i. E. the location where the largest valve actuation forces occur. The pressure lubrication is provided as needed in the radial plain bearing. The oil is introduced into the claimed frictional contact between the radial slide bearing and the cam piece or camshaft. In this case, little loss oil is generated, since the bearing gap between the radial slide bearing and the cam piece or the camshaft in the direction of the maximum load is always lower. As a result, the oil consumption is reduced.

The oil supply to the radial slide bearing can be further simplified by the cylinder head cover having a central oil gallery for conducting oil to the at least one pressure oiling well, the central oil gallery extending within a body of the cylinder head cover. In this case, only the cylinder head cover at a central oil inlet opening, where the central oil gallery is supplied with oil, needs to be sealed. A seal at several oil supply points of a bearing frame is eliminated. Accordingly, the entire cylinder head gasket is simplified.

The central oil gallery can run parallel to a longitudinal axis of the radial plain bearing. This can be very well supplied with oil from the central oil gallery several Druckbeölungsbohrungen. The central oil gallery may be formed as a bore for conducting oil.

According to another embodiment of the cylinder head cover between two and twelve, two and eight or two and four Druckbeölungsbohrungen provided for connecting the central oil gallery with the radial sliding bearing. In particular, at least one Druckbeölungsbohrung per cam piece is provided.

Further, an internal combustion engine having a cylinder head cover as described is provided.

The embodiments and features described for the proposed cylinder head cover apply accordingly to the proposed internal combustion engine and vice versa.

Further possible implementations of the invention also include not explicitly mentioned combinations of features described above or below. The skilled person will also add individual aspects as improvements or additions to the respective basic form of the invention.

• 1 eine teilweise Schnittansicht einer Brennkraftmaschine mit einer Zylinderkopfhaube, und
• 2 eine teilweise Schnittansicht der Brennkraftmaschine mit der Zylinderkopfhaube entlang der Linie II-II der 1.

The invention will be explained in more detail below with reference to the drawings. These show in

• 1 a partial sectional view of an internal combustion engine with a cylinder head cover, and
• 2 a partial sectional view of the internal combustion engine with the cylinder head cover along the line II-II of the 1 ,

In the figures, identical or functionally identical elements have been given the same reference numerals. It should also be noted that the illustrations in the figures are not necessarily to scale.

1 shows a partial sectional view of an internal combustion engine 10 with a cylinder head cover 12 , From the internal combustion engine 10 only a few elements are shown. The internal combustion engine 10 has a housing 14 , two camshafts 16 and several cam pieces 18 on. In the case 14 it concerns components, which with the cylinder head cover 12 mechanically connected.

The cylinder head cover 12 is integrally formed. Accordingly, it is in the cylinder head cover 12 around a monolithic component. Next, in the 1 illustrated cylinder head cover 12 two radial plain bearings 20 on which in 1 are shown as dashed line. Each radial slide bearing 20 serves to hold a camshaft 16 , The respective radial plain bearing 20 has a circumferential range 22 on which an angle α of 180 °.

The circumferential range 22 extends from a first endpoint 24 of the radial plain bearing 20 along the radial slide bearing 20 to a second endpoint 26 of the radial plain bearing 20 , It encompasses the all-encompassing scope 22 an angle α , The angle α is the angle between two straight lines which are in a plane perpendicular to the longitudinal axis 28 of the radial plain bearing 20 are arranged. A straight line leads from the first endpoint 24 to the intersection 30 the longitudinal axis 28 with the said plane. The other straight leads from the second endpoint 26 to the intersection 30 the longitudinal axis 28 with the said plane.

Alternatively, the angle α also be less than 180 °. The angle α is, however, at most 180 °. Because the angle α is not more than 180 °, it is possible that the cam piece 18 , which is the camshaft 16 surrounds, in the radial plain bearing 20 is fitted and the cylinder head cover 12 is integrally formed. In particular, the angle is α in a range of 80 ° -180 °, preferably in a range of 120 ° -180 °, and more preferably in a range of 160 ° -180 °.

As 1 shows, the respective radial plain bearing 20 via a pressure oiling hole 32 in the cylinder head cover 12 supplied with oil. In addition, next to the radial sliding bearing 20 a central oil gallery 34 intended. The central oil gallery 34 is parallel to the longitudinal axis 28 of the radial plain bearing 20 arranged. Alternatively, the central oil gallery 34 also not parallel to the longitudinal axis 28 of the radial plain bearing 20 run. This serves the central oil gallery 34 to, oil to the pressure oiling hole 32 to lead. Both the central oil gallery 34 as well as the pressure oiling hole 32 can be considered as holes within a body of the cylinder head cover 12 be educated.

The pressure oil feed via the central oil gallery 34 simplifies the construction of the gasket of the cylinder head cover 12 , as only a central oil inlet opening on the cylinder head cover 12 is to seal. As a result, leakage losses can be reduced.

Every central oil gallery 34 can several pressure oiling holes 32 supply with oil. In particular, the cylinder head cover 12 , within the area where there is a cam piece 18 is located, one, two, three or four pressure oiling wells 32 exhibit. It can per camshaft 16 one, two, three or four cam pieces 18 be provided.

The respective pressure oiling hole 32 is related to the radial sliding bearing 20 arranged so that they are before the load maximum 36 lies. It means "before" in the direction of rotation of the camshaft 16 and the cam piece 18 before the load maximum 36 , Here is the load maximum 36 the point of the radial plain bearing 20 with the greatest load, ie on the largest pressure through the cam piece 18 is exercised. The largest forces occurring are exerted by the valve actuation forces. A valve or transition from the cam piece 18 to the valve are in 1 not shown. The valve actuation forces act so that the load maximum 36 in 1 at the top of the radial plain bearing 20 lies.

An optimal supply of the radial plain bearing 20 with oil results when a section 38 the circumferential range 22 which is between the pressure oiling hole 32 and the load maximum 36 is arranged an angle β which is in a range of 60 ° to 90 °, preferably in a range of 70 ° to 90 °, and more preferably in a range of 80 ° to 90 °. As a result, the oil can optimally bring into the claimed frictional contact and it is produced little loss of oil, since the bearing gap between the cam piece 18 and radial plain bearings 20 in the direction of the load maximum 36 gets smaller and smaller.

The section 38 the circumferential range 22 extends from the point where the Druckbeölungsbohrung 32 in the radial plain bearing 20 flows along the radial plain bearing 20 to the load maximum 36 , The section encloses 38 the circumferential range 22 the angle β , The angle β is the angle between two straight lines which are in a plane perpendicular to the longitudinal axis 28 of the radial plain bearing 20 are arranged. In this case, a straight line leads from the point at which the Druckbeölungsbohrung 32 in the radial plain bearing 20 flows to the point of intersection 30 the longitudinal axis 28 with the said level. The other straight leads from the load maximum 36 to the intersection 30 the longitudinal axis 28 with the said level.

2 shows a partial sectional view of the internal combustion engine 10 with the cylinder head cover 12 along the line II-II of the 1 , Shown are the cylinder head cover 12 , a drive wheel 40 , the camshaft 16 and two cam pieces 18 , The cam pieces 18 each have cams 42 for actuating valves. How to get the 2 can take, is the radial slide bearing 20 interrupted in scope.

In 2 not shown, however, are the housing 14 , Valves and the connecting elements between the valves and the cam pieces 18 ,

Each cam piece 18 comes in contact with a tread 44 of the radial plain bearing 20 , Next, every camshaft 16 in particular one, two, three or four cam pieces 18 exhibit.

The cam pieces 18 can in the treads 44 be inserted, since the radial sliding bearing 20 is broken in the scope and an angle α of not more than 180 °. The valve actuation forces are in 2 up into the cylinder head cover 12 initiated. A 360 ° radial bearing is therefore not necessary. In addition, a 360 ° comprehensive radial bearing is not necessary to a build up sufficient oil lubrication film. Characterized in that the compressed oil supply via at least one Druckbeölungsbohrung 32 in the cylinder head cover 12 takes place, the bearing frame including screw for a 360 ° radial bearing can be omitted. Accordingly, a monolithic cylinder head cover 12 without bearing frame allows.

LIST OF REFERENCE NUMBERS

10

Internal combustion engine

12

Cylinder head cover

14

casing

16

camshaft

18

cam piece

20

radial bearings

22

circumferential range

24

first end point of the radial plain bearing

26

second end point of the radial plain bearing

28

Longitudinal axis of the radial plain bearing

30

intersection

32

Druckbeölungsbohrung

34

central oil gallery

36

load maximum

38

Section of the circumferential range

40

drive wheel

42

cam

44

tread

α

angle

β

angle

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 [0003]
• DE 19747244 A1 [0003]

Claims (8)

Cylinder head cover (12) for an internal combustion engine (10), with a radial sliding bearing (20) for holding a camshaft (16) of the internal combustion engine (10), characterized in that the radial sliding bearing (20) has a circumferential reach (22) which forms an angle (A) of at most 180 °, and in that the cylinder head cover (12) is integrally formed. Cylinder head cover after Claim 1 , characterized in that the angle (a) is in a range of 80 ° to 180 °, preferably 120 ° to 180 ° and more preferably 160 ° to 180 °. Cylinder head cover after Claim 1 or 2 , characterized in that at least one Druckbeölungsbohrung (32) in the cylinder head cover (12) for supplying the radial sliding bearing (20) is provided with oil. Cylinder head cover after Claim 3 characterized in that a portion (38) of circumferential span (22) disposed between the at least one pressure oiling bore (32) and a load maximum (36) of the radial sliding bearing (20) forms an angle (β) in a range of 60 ° to 90 °, preferably from 70 ° to 90 ° and more preferably from 80 ° to 90 °. Cylinder head cover after Claim 3 or 4 characterized in that the cylinder head cover (12) has a central oil gallery (34) for directing oil to the at least one pressure oiling well (32), the central oil gallery (34) extending within a body of the cylinder head cover (12). Cylinder head cover after Claim 5 , characterized in that the central oil gallery (34) extends parallel to a longitudinal axis (28) of the radial sliding bearing (20). Cylinder head cover after Claim 5 or 6 , characterized in that between two and twelve, two and eight or two and four Druckbeölungsbohrungen (32) for connecting the central oil gallery (34) with the radial sliding bearing (20) are provided. Internal combustion engine (10) with a cylinder head cover (12) according to at least one of the preceding claims.

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