DE102016109223A1 - Chain for a timing drive of a reciprocating internal combustion engine and control drive a reciprocating internal combustion engine with such a chain - Google Patents

Abstract

The invention relates to a chain for a control drive (10) of a reciprocating internal combustion engine having a plurality of link plates (66), wherein the link plates (66) at least partially a back plate (68a, 68b), which when circulating the chain (18, 22 ) at least partially in sliding contact with a slide rail (52, 58, 64, 90), wherein the tab back (68a, 68b) at least one link plate (66) - a particular - tread - (82a, 82b) having a width of at least 0th , 1 mm, which is smaller than the width of the link plate (66).

Description

The invention relates to a chain for a timing drive of a reciprocating internal combustion engine according to the preamble of claim 1 and a control drive a reciprocating internal combustion engine with such a chain.

Timing drives with enveloping drives in the form of chain drives in reciprocating internal combustion engines regularly have slide rails and / or slide rails in order to guide the chain and to counteract vibrations and noises of the chain. In the area of slide rails and slide rails, the link plates with their tab backs partly come into contact with them. This leads to friction losses and wear on the link plates and on the slide rails and slide rails.

From the DE 10 2012 016 153 A1 is known a tab chain for motor vehicles. The chain comprises a plurality of link plates, which have a tab back at least partially sliding contact with a designated as a guide rail slide rail. The back plate has a transverse to the longitudinal center line of the flap extending convex curvature. A similarly designed necklace is out DE 10 2013 201 462 A1 known. This also has a plurality of links with link plates, which have a convexly curved contour in the region of the tab back.

A disadvantage of the known from the above-mentioned publications chains that the link plates have only a very small linear contact with the slide, resulting in a high local load and heavy wear of slide rail and link plates. This leads to a partially very high wear on the chain and slide rail.

The invention has for its object to provide a chain for a timing drive of a reciprocating internal combustion engine and a timing drive with such a chain available in which the wear between the chain and a slide and / or clamping rail is reduced.

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 chain of a reciprocating internal combustion engine according to the invention comprises a plurality of link plates. The link plates have at least partially on a back plate, which is at least partially in sliding contact with a slide rail when the chain is running. In the context of this disclosure, a slide rail is also understood to mean slide rails which are designed to be movable in the direction of the chain, in particular in order to produce a (minimum) clamping force in the chain. The word slide rail therefore also includes the above-mentioned slide rails in the following. In a chain according to the invention, the tab back of at least one link plate has a running surface with a width of at least 0.1 mm, wherein the width of the tab back is smaller than the width of the link plate. The running surface is the contact region which extends in the width direction of the link plate and which is designed to be complementary to the contact region of the slide rail. Usually slide rails have a flat in the width direction contour. In this case, the tread is formed with a flat surface contour.

In the present case, the area of a link plate, which points in the direction of a slide rail during circulation of the chain, is referred to as back plate. The inventive design of the tab backing the wear on both the slide rail and the link plate can be reduced by the fact that the tread has a contact area extending over a certain width and thus distributed across the width of the chain straps acting on the slide rail forces in the Slide rail are initiated. The specified minimum width further ensures that the friction is further reduced by the fact that, due to the minimum width, a friction-reducing oil film can form between the running surface and the slide rail. In particular, in this case, a kind of "lubricating wedge" can form between the chain and the slide rail, which effects a very small but friction-reducing spacing of the chain from the slide rail.

For the sake of completeness, it is pointed out that link plates can also have two or more link backs, if there is sliding contact with different surfaces with slide rails during circulation. The invention also encompasses multiple chains, e.g. As so-called duplex chains or triplex chains, in which the chain links are executed several times.

Preferably, the plurality of link plates of a chain according to the invention with the technical features of the claims and / or formed with the features described in detail below, particularly preferably all link plates are formed.

It should also be noted that the invention has been made in particular for roller chains and sleeve chains which are used in control drives of motor vehicles. Accordingly, the invention was especially for such Chain types optimized. The width of the link plates of such chains is in most cases 0.8 mm to 2 mm, preferably 1.0 mm to 1.8 mm and particularly preferably 1.2 mm to 1.6 mm.

The friction between the slide rail and the at least one link plate can be further reduced if the plate back, in particular at least in the region of the running surface, has an R _z value of not more than 2 μm. The tab backs of a chain according to the invention preferably have an R _z value of not more than 1.6 μm, more preferably an R _z value of not more than 1.3 μm and particularly preferably an R _z value of not more than 1 μm. The R _z value is understood to be the average roughness depth of a surface. Tabbed backings and / or treads having the R _z values noted above can be made, inter alia, by superfinishing methods, stream finishing methods, band finishing methods and / or super band finishing methods. Due to the resulting smooth surface structure, the frictional wear is further reduced.

Alternatively or in addition to the design of link backs of link plates to a particular R _z value, the design can also be made to an R _a value. With an R _a value of about 0.16, similar results are achieved in this case as with an R _z value of 1 μm.

In a practical embodiment, the tread merges into at least one transition region extending in the direction of a side flank of the link plate. Preferably, such a continuous transition to both side edges is formed. In particular, the transitional areas are rounded by radii, d. H. they have a constant transition radius in such a way that one transition region adjoins the tread tangentially or that both transition regions adjoin one another tangentially to the tread.

The formation of a continuous transition, especially in the form of rounding radii that are easy to produce, has the advantage that no edges are created between the running surface and the respective transitional areas, which can be penetrated into the slide rail, in particular during temporary tilting of link plates, including link backs during operation , could cause increased wear.

It is particularly preferred if at least one transition region also merges continuously into the side flanks, so that the entire region from the tread to the side flanks is free of edges. This preferably applies to both transition regions. By an additional rounding between the transition areas and the side edges, residual fractions and associated surfaces with high R _z values, which occur in particular in a punched production of link plates, can be reliably removed. The formation of continuous transitions between the transition region and side edges therefore lead to a further improvement in the surface of the tab back, which may be connected in certain operating conditions of timing chains with a further reduction in friction.

As already mentioned, a certain width of the link plates - in particular for the formation of a friction-reducing oil film and to avoid locally high material tension - is required. Apart from that, but a rather narrow width of the link plates is preferred to keep the friction low. Preferably, a width ratio of the tread of a link plate to the overall width of the link plate of a maximum of 80%, more preferably a maximum of 70% and most preferably a maximum of 50%. In the context of calculations carried out in particular with very small widths, such. B. in the range between 20% to 50%, in particular 30% to 40%, achieved particularly low friction values.

Alternatively or in addition to the embodiments described above, the tread may be provided with a friction-reducing layer. As a friction-reducing layers all subsequently applied to a base body of the link plates layers are considered, which cause in comparison with the main body in frictional contact with the same slide reduced frictional forces, especially layers of a different material and / or with a different chemical structure than the material of the body. Optionally, a transition region, a plurality of transition regions, a side flank and / or a plurality of side flanks of a link plate or a plurality of link plates can be provided with such a layer. This is independent of the process by which such a layer is generated. The choice of the material of a friction-reducing layer depends, inter alia, on the material and the hardness of the slide rail. Diamond-like carbon layers, which are also referred to as diamond-like carbon layers (DLC layers), have proven to be particularly suitable friction-reducing layer. Also suitable as materials for friction-reducing layers, for example, various carbides, nitrides and / or Teflon. In connection with the application of friction-reducing layers, it is particularly advantageous if the friction-reducing layers after production lie within the above-defined limits for the R _z value. This may require the base material of a Laschenrückens a chain according to the invention previously provided by special processing with a particularly smooth surface, in particular with a surface having an even lower R _z value than the later to be applied, friction-reducing layer. This is especially true for the application of DLC layers.

Particularly good results in terms of wear, noise damping and service life are achieved with link plates whose tread, in particular in the form of a friction-reducing layer, have a Vickers hardness of at least 1500 HV 0.05. Particularly preferred is a Vickers hardness of at least 1800 HV 0.05.

The link plates of chains according to the invention can be produced inexpensively and simply by means of a stamping process. In a further practical embodiment, the link plates are subsequently reworked by means of grinding or milling, wherein it is particularly preferred to machine the link back of link plates after a punching process such that a flat running surface is formed when the slide rail has a flat bearing surface (or if Tread and slide rail are complementary to each other). By means of grinding and / or milling, transition regions can also be generated, in particular transition regions with continuous transitions to the tread.

Alternatively, or in addition to chain links can be made by laser cutting and / or post-processed.

Particularly suitable as a material for the link plates are metal materials, especially steel, mainly due to the material stiffness, wear resistance and relatively low compared to other metal materials material price.

The invention also relates to a timing drive having at least one chain as described above with a plurality of link plates and at least one slide rail, wherein the link plates of the chain are at least partially in sliding contact with the slide rail. The advantages already described in connection with the chain according to the invention are hereby referred to once again.

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

1 a control drive according to the invention of a reciprocating internal combustion engine, not shown,

2 the area marked II 1 in an enlarged schematic view with only one link plate rotated 90 degrees clockwise,

3 two links of a chain according to the invention in a plan view,

4 a link plate of a chain link 3 in a side view,

5 the link plate off 4 in a perspective view obliquely from the front,

6a the link plate off 4 in a view from the front and

6b the area marked VIb 6a in an enlarged view.

1 shows a multilevel control drive 10 a non-illustrated reciprocating internal combustion engine of a motor vehicle with a primary drive 12 and a secondary drive 14 , In the primary drive 12 is the first envelope drive structure 16 a first chain 18 used. At the secondary drive 14 is as a second envelope drive structure 20 a second chain 22 used. The first chain 18 is powered by a first rotor 24 , the first gearwheel 26 is trained. By means of the first chain 18 is through the primary drive 12 a second rotor 28 driven, which also serves as a second gear 30 is trained. The second rotor 28 is part of a one-piece intermediate wheel 32 next to the second rotor 28 a third rotor 34 which also serves as the third gear 36 is trained. Alternatively, the second rotor 28 and the third rotor 34 manufactured as separate components and rotatably connected together to form an assembly component. The third rotor 34 serves as the "drive element" of the secondary drive 14 , The secondary drive 14 further includes a fourth rotor 38 , the fourth gear 40 is formed, and a fifth rotor 42 , the fifth gear 44 is trained. The first rotor 24 is non-rotatable with a crankshaft 46 connected. The fourth rotor 38 and the fifth rotor 42 are in with 1 unrecognizable camshafts connected. In 1 the camshafts are covered by the first camshaft adjuster 48 and the second phaser 50 , The first camshaft adjuster 48 conceals an intake camshaft which controls the opening and closing times of the intake valves of the reciprocating internal combustion engine, not shown in detail. The second camshaft adjuster 50 conceals the exhaust camshaft which controls the opening and closing times of the exhaust valves of the reciprocating internal combustion engine.

In 1 is also one on the outside of the second chain 22 of the secondary drive 14 arranged first slide rail 52 recognizable, which about a rotation axis 54 is rotatably mounted and the second chain 22 of the secondary drive 14 supported from the outside. The first slide rail 52 is functionally connected to a clamping element 56 , can be used for the tension of the chain and is therefore also referred to as a tensioning rail. In the secondary drive 14 is a second slide rail 58 provided, which is the second chain 22 of the secondary drive 14 on the first slide rail 52 opposite side leads from the inside and in the upper area the distance to a gear 60 a high pressure fuel pump 62 keeps constant. Between the camshaft adjusters 48 . 50 is a third slide rail 64 arranged, which from the inside to the second chain 22 acts. Furthermore, in the primary drive 12 a fourth slide rail 90 arranged, which in sliding contact with the first chain 18 stands and as a guide for the first chain 18 serves. The fourth slide rail 90 is designed in the form of an assembly unit as a slide with chain tensioner and in 1 shown only schematically.

In a control drive according to the invention 10 becomes the respective chain 18 . 22 from the corresponding slide rails 52 . 58 . 64 . 90 guided and is in operation in sliding contact with the respective slide rails 52 . 58 . 64 . 90 ,

In the following, a chain according to the invention using the example of the second chain 22 and the first slide rail 52 explained. The features can, however, also analogously to the first chain 18 and one or more of the other slide rails 58 . 64 . 90 be realized.

2 shows by way of example only a link plate 66 with the first slide rail 52 in a schematic representation. As can be seen, one points to the first slide rail 52 directed flap back 68b the link plate 66 only partial sliding contact with the first slide rail 52 on, since the first slide rail 52 convex, here with a radius R _G , is formed during the back of the tab 68b has a rectilinear outer contour parallel to the direction of rotation U. Accordingly, there is sliding contact between the link plate 66 and the first slide rail 52 only with the tangential to the first slide rail 52 arranged running section of the link plate 66 ,

More geometric details of the second chain 22 and the link plates 66 are below in connection with the 3 - 5 described.

In 3 are two links 70a . 70b a second chain according to the invention 22 represented in the form of a roller chain in a plan view. Each chain link 70a includes two outer link plates 72 and two inner link plates 74 , which in the present case are designed as in 2 Chain link shown 66 , Two outer link plates each 72 are by means of a bolt 76 connected. In the area between two link plates 66 is on every bolt 76 a role 78 arranged. Between the roll 78 and the outer link plates 74 are in a known manner pods 92 arranged, in particular by the distance of the outer link plates 66 pretend in the width direction and as a bearing element for the rollers 78 ,

In 4 is to illustrate further geometric features of the link plates 66 an inner link plate 74 shown in detail. How out 4 combined with 3 it can be seen has the second chain 22 an upper flap back 68a and a lower flap back 68b on, while revolving the second chain 22 in sliding contact with the slide rails 52 . 58 (see. 1 ) stand. Furthermore, the link plate 66 two through holes 80a . 80b on, by which in the assembled state of the second chain 22 one bolt each 76 and a sleeve 92 for making the connection with corresponding outer link plates 72 are guided.

The design of the flap back 68a . 68b will be described below in connection with the 5 and 6 explained. The back of the tongue 68a . 68b each have a flat tread in the embodiment shown 82a . 82b on, which is the part of each flap back 68a . 68b form, which in the operation of the Steuertriebes 10 in contact with one of the slide rails 52 . 58 stands (cf. 1 ). The treads 82a . 82b in the present case have a width B _L of 0.5 mm. The entire width of the link plates B _K is 1.5 mm (see. 6b ).

The link plates 66 have in the embodiment shown on both sides (right and left side) transition areas 86a . 86b . 86c . 86d on that both to the treads 86a . 86b as well as to the side flanks 84a . 84b the link plate 66 have a steady transition. The transition areas 86a . 86b . 86c . 86d are each designed as a rounding with constant radii of curvature. In the embodiment shown was for all transition areas 86a . 86b . 86c . 86d used a radius R _Ü of 0.5 mm. The side flanks 84a . 84b and the treads 82a . 82b Accordingly, have a edge-free transition to the transition areas 86a . 86b . 86c . 86d on, as they tangentially follow. By this completely continuous trained outer contour of the back plate 68a . 68b in the width direction up to the side edges 84a . 84b (transverse to the direction of rotation U of the second chain 22 ), become edges in the contour and an associated cutting action of the link plates 66 completely avoided.

Present were the link plates 72 . 74 first produced by means of a stamping process. The surface of the flap back 68a . 68b with the treads 82a . 82b and the transition areas 86a . 86b . 86c . 86d were subsequently produced by fine grinding.

Subsequently, the treads were 82a . 82b and the transition areas 86a . 86b . 86c . 86d Smoothed by a superfinishing process to an R _z value of 1.0 microns.

Alternatively or in addition to this can strap back 68a . 68b also be provided with a sliding-reducing coating, in particular with a so-called diamond-like-carbon (DLC) coating to an R _z value of 1 micron. The adjoining in the direction of U U end faces 88a . 88b the link plates 66 which are not in sliding contact with the slide rails 52 . 58 . 64 . 90 were not post-processed in the present case.

LIST OF REFERENCE NUMBERS

10

Timing

12

primary drive

14

Secondary drive

16

first envelope drive structure

18

first chains

20

second envelope drive structure

22

second chain

24

first rotor

26

first gear

28

second rotor

30

second gear

32

idler

34

third rotor

36

third gear

38

fourth rotor

40

fourth gear

42

fifth rotor

44

fifth gear

46

crankshaft

48

first camshaft adjuster

50

second camshaft adjuster

52

first slide rail (in the form of a tension rail)

54

axis of rotation

56

clamping element

58

second slide rail

60

gear

62

High pressure fuel pump

64

third slide rail

66

link plate

68a, 68b

Lasch back

70a, 70b

link

72

outer link plate

74

inner link plate

76

bolt

78

role

80a, 80b

Through opening

82a, 82b

tread

84a, 84b

side flank

86a, 86b, 86c, 86d

Transition area

88a, 88b

front

90

fourth slide rail (in the form of a tension rail)

92

shell

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 102012016153 A1 [0003]
• DE 102013201462 A1 [0003]

Claims (10)

Chain for a timing drive ( 10 ) a reciprocating internal combustion engine having a plurality of link plates ( 66 ), with the link plates ( 66 ) at least partially a tab back ( 68a . 68b ), which when circulating the chain ( 18 . 22 ) at least partially in sliding contact with at least one slide rail ( 52 . 58 . 64 . 90 ), characterized in that the tab back ( 68a . 68b ) at least one link plate ( 66 ) a tread ( 82a . 82b ) having a width of at least 0.1 mm, which is smaller than the width of the link plate ( 66 ). Chain according to the preceding claim, characterized in that the tab back ( 68a . 68b ) has an R _z value of not more than 2 μm. Chain according to one of the preceding claims, characterized in that the tread ( 82a . 82b ) steadily in at least one towards the side flanks ( 84a . 84b ) of the link plate ( 66 ) extending transition area ( 86a . 86b . 86c . 86d ) passes over. Chain according to one of the preceding claims, characterized in that the width of the tread ( 82a . 82b ) maximum 80% of the width of the link plate ( 66 ) is. Chain according to one of the preceding claims, characterized in that the tread ( 82a . 82b ) is provided with a friction reducing layer. Chain according to the preceding claim, characterized in that the friction-reducing layer is a diamond-like carbon layer. Chain according to one of the preceding claims, characterized in that the tread ( 82a . 82b ) has a Vickers hardness of at least 1500 HV 0.05. Chain according to one of the preceding claims, characterized in that the at least one link plate ( 66 ) is produced by means of a stamping process. Chain according to one of the preceding claims, characterized in that the at least one link plate ( 66 ) is processed by grinding or milling. Timing drive of a reciprocating internal combustion engine with at least one chain ( 18 . 22 ) according to one of claims 1 to 9 with a plurality of link plates ( 66 ) and at least one slide rail ( 52 . 58 . 64 . 90 ), with the link plates ( 66 ) of the chain ( 18 . 22 ) at least partially in sliding contact with the slide rail ( 52 . 58 . 64 . 90 ) stand.

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