Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
  • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
  • F01L1/02—Valve drive
  • F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
  • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
  • F01L1/02—Valve drive
  • F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
  • F01L1/047—Camshafts
  • F01L1/053—Camshafts overhead type
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
  • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
  • F01L1/02—Valve drive
  • F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
  • F01L1/047—Camshafts
  • F01L2001/0476—Camshaft bearings
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
  • F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
  • F01L1/02—Valve drive
  • F01L1/04—Valve drive by means of cams, camshafts, cam discs, eccentrics or the like
  • F01L1/047—Camshafts
  • F01L1/053—Camshafts overhead type
  • F01L2001/0537—Double overhead camshafts [DOHC]
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
  • F02F7/00—Casings, e.g. crankcases or frames
  • F02F7/006—Camshaft or pushrod housings

Definitions

• the invention relates to a cylinder head cover of an internal combustion engine of a motor vehicle with camshaft bearings integrated into the cylinder head cover and the cylinder head.
• the invention relates more particularly to a cylinder head cover for an internal combustion engine comprising at least one camshaft mounted to rotate in a series of bearings which are arranged long itud inally along the axis of rotation of the shaft with cams and each of which has an upper half of the bearing, also called a half-bearing, a cylinder head cover in which the series of half-bearings is formed in one piece with the body of the cylinder head cover.
• the cylinder head cover is mounted on the cylinder head which is delimited by a horizontal upper face in which are formed lower halves of the bearings each of which is associated with an upper half associated with the cylinder head cover.
• the cylinder head cover is fixed to the cylinder head by series of screws or fixing studs whose axes are orthogonal to the plane of the upper face of the cylinder head.
• the cylinder head cover comprises a plurality of screws for fixing the cylinder head cover which are distributed in a first series and a second series of substantially long aligned screws which are arranged on either side. other from the camshaft housing,
• each bearing cap has two opposite lower support legs which are aligned transversely, in a plane orthogonal to the axis of rotation of the camshaft, and which are connected to one another by a bridge of arcuate material in which is formed a concave bearing surface open in a lower face of the cylinder head cover.
• each bearing cap is mounted tight on the cylinder head by means of a pair of fixing screws, each of which extends vertically through a corresponding hole in a support leg of the bearing cap.
• the bearing cap is mounted clamped vertically with the underside of the support foot i resting on a portion of surface facing the upper face of the cylinder head.
• each bearing is adjacent to a cylindrical housing of generally vertical orientation and which extends at least partly in a transverse plane passing through the two support legs. of the landing.
• Such a housing can receive a section of a fuel injector (as illustrated in the document mentioned above), or a coil body of a spark plug.
• the coil housing can be located on the same axis of the fixing screws making it impossible to have a fixing architecture as mentioned in the previous document.
• the invention aims to propose a new design for a cylinder head cover to meet these design requirements.
• the invention provides a cylinder head cover of the type mentioned above, characterized in that the support leg i, adjacent to the associated housing, of at least one half-bearing is devoid of an associated screw for its attachment to a lower half of additional bearing.
• At least half a bearing is devoid of associated screws for fixing it on a lower half of a complementary bearing.
• the removal of at least one through hole or else of the two through holes for the fixing screws makes it possible to place space and material to modify the positioning and / or the orientation of the housing.
• the cylinder head cover comprises, on its upper face, at least one rib of rig idification of the cylinder head cover which extends generally transversely and which is adjacent to the half-bearing without at least one screw associated for its fixation.
• At least one rig id ification rib of the cylinder head cover of a first type, which i extends generally transversely between the axes of two screws for fastening the cylinder head cover, each belonging to one of the two sets of screws and which are adjacent to said at least half a bearing;
• This rig id rib extends generally transversely between the axis of a fixing screw belonging to the first series of screws and the axis of a fixing screw belonging to the second series of screws and which is adjacent to a cylindrical housing;
• the axis of said fixing screw belonging to the first series of screws is located in the transverse plane passing through the two opposite feet dud it at least half a bearing;
• Said rig idification rib comprises a first section which i extends in a vertical plane parallel to it transverse plane passing through the two opposite feet dud it at least half a bearing, and a second section which extends in a vertical plane forming an angle with respect to said transverse plane passing through the two opposite feet of said at least half a bearing;
• the cylinder head cover comprises, on an upper face, at least one rib of rig id ification of the cylinder head cover, of a second type, which extends generally transversely between an axis of a screw for fixing the cylinder head cover belonging to the first series of screws and a transversely opposite cylindrical housing;
• This rigid identification rib extends in the transverse plane passing through the two opposite feet dud it at least half a bearing
• At least half a bearing is associated with at least one rigid identification rib, of the first type and at least one other rigid stiffening rib of the second type.
• At least several adjacent half-bearings are each devoid of at least one associated screw for its fixing on a lower half of complementary bearing;
• Each of said several adjacent half-bearings lacking at least one associated screw for its fixing is associated with at least one adjacent stiffening rib.
• FIG. 1 is a top view of an exemplary embodiment of a cylinder head cover according to the invention for a four-cylinder engine with two overhead camshafts;
• FIG. 2 is a detail view in section along the plane 2- 2 of Figure 1;
• FIG. 3 is a detailed perspective view from above of the area in which is arranged the half-bearing illustrated in Figure 2;
• FIG. 4 is a detail view on a larger scale of the area shown in perspective in Figure 3;
• Figure 5 is a view similar to that of Figure 4, but which illustrates an example of design according to the invention using pairs of screws for tightening bearing caps;
• FIG. 6 is a bottom view of the cylinder head cover shown in Figure 1. DESCRIPTION OF THE DETAILS OF THE FIGURES
• the horizontal plane is parallel to the joint plane between the underside of the cylinder head cover and the upper face of the cylinder head.
• the long itudinal axis is horizontal and parallel to the parallel axes of the two camshafts guided in rotation by the half-bearings of the cylinder head cover.
• FIG. 1 shows a cylinder head cover 10 according to the invention which is in the form of a rectangular contour plate.
• the cylinder head cover 1 0 is designed to be fixed on the upper face of the cylinder head (not shown in the figures) to form here a cylinder head with its cylinder head cover of a combustion engine with four cyl rims al igneous long itud inally to two overhead camshafts, each rim cylinder being supplied with fuel by a direct injection injector and provided with an ignition plug, these two components carried by the cylinder head not being shown in the figures.
• the central part 1 2 of the cylinder head cover 1 0 is hollowed out to delimit two parallel main parts 14A and 14B of long long ital extension which, at their front ends are connected by a transverse part 16 which is intended to be arranged on the side of the chain or of the distribution belt which rotates the two rod shafts, not shown, each of which is covered and guided in rotation by an associated main part of the cylinder head cover.
• the central part can also be full to ensure the stiffness of the part by connecting the two parallel main parts.
• the cylinder head cover 1 0 is made in one piece by molding, for example in light alloy.
• Each main part 14A, 14B is in the form of a generally semi-tubular body, the convex semi-cylindrical upper face 15A, 15B is oriented vertically upwards.
• each main part defines a housing which in part receives an associated camshaft.
• the first main part 14A is designed to accommodate a first camshaft which i is mounted rotating or swiveling in the cylinder head around a first longitudinal axis of rotation AA, while the second main part 14B is designed to house a second camshaft which is mounted rotating or journalling in the cylinder head around a second longitudinal inal axis of rotation AB.
• the first main part 14A is delimited laterally by two long transverse opposite edges 18A and 20A, while the second main part 14B is delimited laterally by two long transverse opposite edges 18B and 20B
• each camshaft is here guided in rotation in four consecutive axially aligned bearings, each of which is produced in two halves, namely an upper concave semicylindrical half carried by the cylinder head cover 1 0 and a complementary lower concave indric semi-cyl half formed in the upper face of the cylinder head.
• each upper half of the bearing is a semi-real ized material made by molding in one piece with the cylinder head cover 10.
• the first main part 14A comprises four half-bearings 22A
• the second main part 14B comprises four half-bearings 22B.
• the four half-bearings 22A are here transversely aligned with the four half-bearings 22B.
• Each half-bearing is in the general form of a bridge of transverse orientation material which i connect between them two support feet transversely opposite.
• each half-bearing 22A of the first main part 14A is associated with a through housing 24 which is here designed to receive the coil body (not shown) of an associated spark plug.
• Each housing 24 is here a cylindrical cylindrical housing whose axis AL extends substantially in a transverse and vertical plane med ian PTVM of the half-bearing 22A.
• each half-bearing 22A comprises a bridge of central material 26 in the form of a cylindrical arc which extends over a half circumference.
• the central material bridge 26 extends transversely between two support legs 28 and 30, one of which is close to the inal longitudinal edge 1 8 while the other is adjacent to the housing 24.
• Each support leg 28.30 is delimited vertically downwards by the flat horizontal lower face 32 of the half-bearing 22A which belongs to the flat horizontal lower face of the cylinder head cover 10.
• the upper half of the bearing 34 in cooperation with the lower half of the complementary bearing of the cylinder head (not shown), forms a concave cylindrical cylindrical guide for guiding the rotation of an associated journal of the shaft. with cams.
• the half-bearing 22A in particular undergoes a force F of radial orientation which urges it generally vertically upwards, tending to "lift” it relative to the portion opposite the cylinder head.
• the means of fixing and assembling the two upper and lower parts of the cylinder head must be such that they guarantee perfect support and sufficient tightening of the lower face 32 of the support legs 28 and 30 in particular in order to avoid any risk of "opening" of the bearing at the level of the two generally opposite connection lines 33 and 35 between the two halves of the bearing to avoid any risk, in particular of rupture of the film of the lubricating oil formed between the surface concave of the bearing in two parts and the associated convex cylindrical cylindrical surface of the camshaft journal.
• each half-bearing 22A has a pair of fixing screws VFC1 and VFC2 each of which extends along a vertical axis V1, V2 respectively and whose body passes through an associated vertical bore that i extends through the support leg 28.30 respectively.
• the two fixing screws VFCI and VFC2 are mounted screwed into corresponding threaded holes formed in the horizontal upper face of the cylinder head.
• the arrangement of the fixing screws VFC1, VFC2 of each half-bearing 22A harms the compactness of the half-bearing 22A and the surrounding area of the cylinder head cover 1 0.
• the VFC2 fixing screw adjacent to the housing 24 does not allow to modify the transverse position and / or the inclination of the axis AL of the housing 24 given the risk of interference between the housing 24 and the drilling of the support leg 30 for the passage of the fixing screw VFC2.
• each half-bearing 22A associated with an adjacent housing 24 to remove at least the fixing screw (VFC2) associated with the support leg 30 adjacent to the housing 24 according to the design state of the art.
• each half-bearing 22A it is possible to remove the two fixing screws (VFC1, VFC2) associated with each half-bearing 22A in the design according to the state of the art.
• each of the three rear half-bearings 22A is devoid of any associated fixing screw, while the fourth front half-bearing 22A next to the transverse part 1 6 illustrating a design according to the state of the art only comprises the only fixing screw VFC1 adjacent to the long itudinal edge 1 8A.
• the four half-bearings can be produced according to the invention.
• the absence of any specific fixing screw, or at least of the fixing screw VFC2, of the half-bearing 22A makes it possible, thanks to the elimination of the hole or holes for the passage of such fixing screws to have spaces and materials in particular for the positioning and orientation of the housing 24.
• each half-bearing 22A The mounting and tightening of the main part 14A of the cylinder head cover 1 0, in particular at right angles to or in the vicinity of each half-bearing 22A are ensured by means of two sets of fixing screws (not shown) each of which extends vertically through an associated bore which extends vertically and which is arranged transversely along a long itudinal edge 18A, 20A.
• Figure 1 a first series of three holes 36 whose vertical axes AV1 are aligned long itud inally along a line L1 adjacent to the longitudinal inal edge 18A.
• each vertical axis AV1 of a bore 36 extends here in the median plane PTVM of the associated half-bearing 22A.
• FIG. 1 shows a second series of three bores 38 whose vertical axes AV2 are aligned long itud inally along a line L2 adjacent to the long itudinal edge 20A.
• each vertical axis AV2 of a bore 38 is offset long itudinally forwards with respect to the median plane PTVM of the associated half-bearing 22A and the bore 38 is adjacent to the housing 24.
• each half-bearing 22A in order to rigidify the main part 14A of the cylinder head cover 1 0 to the right of each half-bearing 22A or at least to the right of each half-bearing 22A according to the invention devoid of 'at least its fixing screw VFC2, there is provided one or more stiffening ribs which are formed in rel ief on the upper face 1 5A of the main part 14A and which are advantageously made integrally by molding with the cover cylinder head 10.
• first stiffening rib 40 which i extends generally transversely between the longitudinal longitudinal edges 18A and 20A and which is adjacent to the half-bearing 22A.
• the rigid identification rib 40 extends generally between the holes 36 and 38 for the bolts for fixing the cylinder head cover 10 adjacent to the half-bearing 22A considered.
• the rig id ification rib 40 comprises a first section 39 which extends in a vertical plane PV1 parallel to the median vertical transverse plane PTVM of half - bearing 22A passing through the support legs 28 and 30.
• the identification rib 40 has a second section 41 which extends in a vertical plane PV2 which i form an angle with respect to the median transverse plane PTVM and which passes substantially through the axis AV2 of the bore 38 for the fixing screw. associated with the cylinder head cover 1 0 adjacent to the housing 24.
• the stiffening rib connecting the support feet for a half-bearing comprises a section which extends obliquely with respect to the vertical plane PTVM orthogonal to the axis of rotation AA of the shaft with cams.
• a second stiffening rib 42 is provided here which extends transversely in a substantially rectilinear manner and in the median vertical plane PTVM.
• the second stiffening rib 42 extends generally transversely between the axis AV1 of the bore 36 and the axis AL of the bore 24.
• the second stiffening rib 42 thus extends in the median transverse plane of the support legs 28 and 30 which, in the design according to the state of the technique illustrated in Figure 5, is the plane in which the axes are located V1 and V2 of the fixing screws of the half bearing 22.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Cylinder Crankcases Of Internal Combustion Engines (AREA)
• Valve-Gear Or Valve Arrangements (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=65244199

Family Applications (1)

Country Status (3)

Families Citing this family (1)

Family Cites Families (3)

• 2018
  • 2018-10-09 FR FR1859341A patent/FR3086975B1/fr active Active
• 2019
  • 2019-09-16 EP EP19766049.1A patent/EP3864277A1/de not_active Withdrawn
  • 2019-09-16 WO PCT/EP2019/074727 patent/WO2020074216A1/fr unknown

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