CYLINDER HEAD COVER

Abstract

A cylinder head cover for covering a cylinder head of an internal combustion engine having at least one first sealing surface via which the cylinder head cover can be tightly connected to an associated second sealing surface on the cylinder head, the cylinder head cover may include at least one first reference surface configured for unambiguous position-fixing on an associated second reference surface of the cylinder head. The at least one first reference surface and the at least one first sealing surface may be formed separately from one another.

Claims

1. A cylinder head cover for covering a cylinder head of an internal combustion engine having at least one first sealing surface via which the cylinder head cover can be tightly connected to an associated second sealing surface on the cylinder head, the cylinder head cover, comprising: at least one first reference surface configured for unambiguous position-fixing on an associated second reference surface of the cylinder head; wherein the at least one first reference surface and the at least one first sealing surface are formed separately from one another.

2. The cylinder head cover according to claim 1, wherein: the at least one first reference surface is smaller than the at least one first sealing surface; and/or a sum of all first reference surfaces is smaller than a sum of all first sealing surfaces.

3. The cylinder head cover according to claim 1, wherein on the cylinder head cover at least two bearings for a camshaft are provided, and wherein on at least one bearing a first reference surface is arranged.

4. The cylinder head cover according to claim 3, wherein the at least two bearings are part of a bearing frame that is connected to the cylinder head cover or formed integrally with the same.

5. The cylinder head cover according to claim 1, wherein: the at least one first sealing surface is arranged parallel and spaced apart from the at least one first reference surface; and/or the at least one first sealing surface is flat or comprises a sealing groove for receiving a seal.

6. The cylinder head cover according to claim 1, wherein: the cylinder head cover is formed as a metallic die-casting; and/or the cylinder head cover includes at least one opening configured for installing a function component, the function component comprising one among a position sensor, a pump or an oil mist separator or for filling-in oil.

7. The cylinder head cover according to claim 3, wherein the cylinder head cover is formed as a plastic injection-moulding, and wherein the at least two bearings comprise bearing rings which are injection-moulded into the plastic of the cylinder head cover.

8. The cylinder head cover according to claim 1, wherein: the cylinder head cover comprises at least two first reference surfaces that are inclined towards one another; and/or at least one first reference surface is designed curved.

9. A cylinder head of an internal combustion engine, comprising: at least one second sealing surface; at least one associated first sealing surface of a cylinder head cover; wherein on the cylinder head, at least one second reference surface configured for unambiguous position-fixing on an associated first reference surface of the cylinder head cover is provided; and wherein the at least one second reference surface and the at least one second sealing surface are formed separately from one another.

10. The cylinder head according to claim 9, wherein: the at least one second reference surface is smaller than the at least one second sealing surface; and/or a sum of all second reference surfaces is smaller than a sum of all second sealing surfaces.

11. The cylinder head according to claim 9, wherein the at least one second sealing surface is arranged parallel and spaced apart from the at least one second reference surface.

12. The cylinder head according to claim 9, wherein the cylinder head comprises at least two second reference surfaces that are inclined towards one another; and/or at least one second reference surface is designed curved.

13. An internal combustion engine, comprising: a cylinder head according to claim 9; and a cylinder head cover connected to the cylinder head according to claim 1.

14. The internal combustion engine according to claim 13, wherein: the at least one first reference surface on the cylinder head cover is screwed, glued, riveted and/or connected by way of dowels to an associated second reference surface on the cylinder head; and/or between the at least one first sealing surface and the associated at least one second sealing surface an elastomer seal, a paper gasket, a liquid seal or a metal gasket is arranged.

15. The internal combustion engine according to claim 13, wherein: the cylinder head cover comprises at least two first reference surfaces that are inclined towards one another; on the cylinder head, at least two inclined second reference surfaces formed complementarily to the inclined first reference surfaces arranged on the cylinder head cover are arranged; the cylinder head cover and the cylinder head are positively connected to one another via the at least two first and second reference surfaces.

16. The cylinder head cover according to claim 1, wherein the cylinder head cover is formed of aluminium.

17. The cylinder head cover according to claim 1, wherein the cylinder head cover is formed of a plastic injection-moulding.

18. The cylinder head cover according to claim 7, wherein the at least two bearings comprise aluminium and are injection-moulded into the plastic of the cylinder head cover.

19. The cylinder head cover according to claim 1, wherein the at least one first reference surface is smaller than the at least one first sealing surface.

20. The cylinder head cover according to claim 1, wherein a sum of all first reference surfaces is smaller than a sum of all first sealing surfaces.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] It shows, in each case schematically,

[0025] FIG. 1 a sectional representation through an internal combustion engine having a cylinder head cover and a cylinder head according to the prior art,

[0026] FIG. 2 a sectional representation through a cylinder head cover according to the invention and a cylinder head according to the invention,

[0027] FIG. 3 a lateral view of the cylinder head cover according to the invention,

[0028] FIG. 4 a sectional representation through an internal combustion engine according to the invention in the region of a cylinder head cover and of a cylinder head.

DETAILED DESCRIPTION

[0029] According to FIG. 1, a conventional internal combustion engine 1′ comprises a cylinder head 2′ and a cylinder head cover 3′, wherein on the cylinder head cover 3′ a camshaft 5′ is mounted via a bearing 4′. Here, first sealing surfaces 6′ with a seal 7′ are provided on the cylinder head cover 3′, wherein on the cylinder head 2′ associated second sealing surfaces 11′ are arranged, which with the cylinder head cover 3′ mounted on the cylinder head 2′, seal a camshaft space 8′ to the surroundings via the seal 7′. In order to be able to achieve here an exact alignment of the cylinder head cover 3′ relative to the cylinder head 2′, the first sealing surfaces 6′ on the cylinder head cover 3′ are simultaneously formed as first reference surfaces 9′, while the second sealing surfaces 11′ arranged on the cylinder head 2′ simultaneously serve as second reference surfaces 10′.

[0030] Since on the cylinder head cover 3′ the camshaft 5′ is also mounted via the bearings 4′, an exact alignment of a camshaft axis relative to a cam-follower axis on the cylinder head 2′ which is not designated in more detail is required in order to be able to achieve in particular a low-friction operation of a valve drive and thus a reduced noise emission and a reduced fuel consumption. Here, the first and second reference surfaces 9′, 10′ serve for the exact alignment of the cylinder head cover 3′ relative to the cylinder head 2′ which therefore have to be formed extremely exactly, in particular also reworked. Since with the internal combustion engine 1′ known from the prior art the first and second reference surfaces 9′, 10′ also serve as sealing surfaces 6′, 11′ at the same time, a particularly high dimensional accuracy is required in order to be able to ensure on the one hand the tightness and on the other hand the exact alignment. Through the low tolerable dimensional inaccuracies in the region of the sealing surfaces 6′, 11′ serving as reference surfaces 9′, 10′, the production both of the cylinder head 2′ and also of the cylinder head cover 3′ is comparatively involved and expensive.

[0031] The solution according to the invention is now described in the following, wherein same reference numbers relate to same components but which, in the solution according to the invention, are designated without apostrophe.

[0032] According to FIGS. 2 to 4, likewise at least one first sealing surface 6 is provided on the cylinder head cover 3 according to the invention shown there for covering a cylinder head 2 of an internal combustion engine 1, via which sealing surface 6 the cylinder head cover 3 can be tightly connected to an associated second sealing surface 11 on the cylinder head 2. At least one first reference surface 9 for the unambiguous position-fixing and thus alignment relative to the cylinder head 2 is additionally provided on the cylinder head cover 3 or on at least one associated second reference surface 10 of the cylinder head 2. According to the invention, the at least one first reference surface 9 and the at least one first sealing surface 6 is now formed on the cylinder head cover 3 separately from one another, as a result of which an alignment function and a sealing function can likewise be decoupled from one another.

[0033] In the same manner, a second reference surface 10 for the unambiguous position-fixing on the associated first reference surface 9 of the cylinder head cover 3 is now formed on the cylinder head 2 separately from the at least one second sealing surface 11 also with the cylinder head 2 (see FIG. 4) according to the invention. By way of this a working with greater tolerances or complete omission of a working of the first and/or second sealing surface 6, 11 is possible since these sealing surfaces 6, 11 are now no longer decisive for the exact alignment of the cylinder head cover 3 relative to the cylinder head 2 and thus for the exact alignment of the camshaft 5 or of the camshaft axis of the same relative to a cam-follower axis on the cylinder head 2.

[0034] Looking at the cylinder head cover 3 according to FIGS. 2 and 3 further, it is noticeable that in the region of the first reference surface 9 screws 12 are provided, so that a fixing of the cylinder head cover 3 on the cylinder head 2 takes place via screws 12 directly arranged on the first reference surfaces 9 and thus close to the bearing, which is a major advantage in particular for absorbing greater engine forces.

[0035] Looking at the first reference surfaces 9 compared with the first sealing surface 6 on the cylinder head cover 3 and also at the second reference surfaces 10 with reference to the second sealing surface 11 on the cylinder head 2 it is noticeable that the at least one first reference surface 9 is smaller than the at least one first sealing surface 6 and to the same extent the at least one second reference surface 10 is also smaller than the at least one second sealing surface 11. By way of this it can be achieved that a large-area working of the sealing surfaces 6 and 11 required to date can be omitted and merely the reference surfaces 9, 10 that are significantly smaller relative to this still have to be worked if required, which saves both working time and also working expenditure. Here, a sum of all first reference surfaces 9 can also be smaller than a sum of all first sealing surfaces 6. Likewise, a sum of all second reference surfaces 10 can also be smaller than a sum of all second sealing surfaces 11.

[0036] Looking at the cylinder head cover 3 further it is noticeable that on the same at least two bearings 4 for a camshaft 5, here even two camshafts 5 are provided, wherein on at least one of these bearings 4 an associated first reference surface 9 is arranged. Here, the at least two bearings 4 can be part of a bearing frame connected to the cylinder head cover 3 or formed integrally with the same, as a result of which it becomes possible to form the bearing frame out of a material, for example metal, in particular aluminium, distinct from the cylinder head cover 3, which can then be formed for example as a plastic injection-moulding. Here, the bearings 4 can be designed as split-bearing or as one-piece bearing.

[0037] Generally it is also conceivable that the cylinder head cover 3 is formed as a plastic injection-moulding, wherein in this case the at least two bearings 4 comprise bearing rings for a or bearings shells, in particular of aluminium, which are injection-moulded into the plastic of the cylinder head cover 3.

[0038] According to FIGS. 2 and 4, the first sealing surface 6 is arranged parallel or orthogonally to the surface spaced apart from the at least one reference surface 9, so that the first sealing surface 6 according to FIGS. 2 to 4 is situated higher than the first reference surfaces 9. In the shown embodiments, the first sealing surface 6 is additionally formed flat, wherein the same can obviously comprise alternatively also a sealing groove for receiving a seal which is not shown. On the same manner, the second sealing surface 11 arranged on the cylinder head 2 can also be designed flat or with a sealing groove for receiving a seal. Generally, curved first reference surfaces 9 and associated curved second reference surfaces 10 formed complementarily are also conceivable, which make possible a positive interlocking and thus an exact alignment of the cylinder head cover 3 relative to the cylinder head 2.

[0039] Generally, the cylinder head cover 3 can be formed as a metallic die-casting for example of aluminium or as an injection-moulding, wherein on the cylinder head cover 3 at least one opening for installing a function part, such as for example a position sensor, a pump or an oil mist separator or for filling-in oil can be additionally arranged.

[0040] In a particularly advantageous embodiment of the solution according to the invention, at least two first reference surfaces 9 inclined towards one another can also be arranged on the cylinder head cover 3, wherein in the same manner second reference surfaces 10 inclined towards one another and formed complementarily thereto can also be arranged on the cylinder head 2. By way of this, a particularly simple exact since positive-locking alignment and mounting of the cylinder head cover 3 on the cylinder head 2 is possible.

[0041] On its at least one first reference surface 9, the cylinder head cover 3 can be screwed, glued, riveted or connected by way of dowels to an associated second reference surface 10 of the cylinder head 2. Such dowels can enforce a further comparatively easy predefined position of the cylinder head cover 3 relative to the cylinder head 2 and thereby simplify the mounting.

[0042] Between the first sealing surface 6 and the second sealing surface 11, an elastomer seal, a paper gasket, a liquid seal or a metal gasket can be arranged for example, wherein the two sealing surfaces 6, 11, because of the reference surfaces 9, 10 decoupled from these, need not be reworked or less intensively so since for example by way of an elastomer seal higher dimensional tolerances can compensated for without problems.

With the internal combustion engine 1 according to the invention having the cylinder head 2 according to the invention and the cylinder head cover 3 according to the invention a decoupling of reference surfaces 9, 10 aligning the cylinder head cover 3 relative to the cylinder head 2, from the associated sealing surfaces 6, 11 is possible for the first time, as a result of which a simpler and more cost-effective as well as also an extremely exact production of the internal combustion engine 1 is possible. Because of the circumstance that the reference surfaces 9, 10 compared with the associated sealing surfaces 6, 11 are significantly smaller and the latter do not have to be reworked or only marginally so, a reworking in the most favourable of cases can remain limited to the reference surfaces 9, 10 as a result of which a significantly reduced reworking effort materialises.