EP1036256B1 - Valve operating lever - Google Patents

Description

The present invention relates to a valve operating lever for transmitting the Movement of a cam arranged on a camshaft onto a gas exchange valve an internal combustion engine.

The object of the invention and its solution are described below using the example of a Roller rocker arm described. It should be noted that this description is not to be construed as limiting the application of the invention, it is rather, the invention is also possible with valve actuation levers of a different design, such as B. with rocker arms or with non-roller-operated valve actuation levers perform.

A roller rocker arm of the type in question is by DE 195 43 657 A1 became known.

The known valve actuation lever has a U-shaped base body on, at one end a pan-like depression is provided with which the lever supports in the installed state via a support element on the cylinder head. At the other end there is the valve contact area through which the gas exchange valve the internal combustion engine depending on the position of the cam of the camshaft is operated.

The cam is in a cam contact area with the valve actuation lever Contact, one in this cam contact area with a roller rocker arm roller is rotatably mounted by rolling elements.

The base body of the valve actuation lever is formed without cutting and points to the End at which the valve contact area is provided, inwardly bent tabs which form lateral boundary surfaces.

Although this known valve actuation lever works very satisfactorily fulfilled, there is still a need to further increase the technical functionality, by the weight and therefore the moment of inertia of the lever around its Axis of rotation is reduced without affecting the rigidity. There is also the desire to further reduce manufacturing costs.

The present invention is therefore based on the object of a valve actuation lever and in particular a roller rocker arm and a method for the same To provide production at which the moment of inertia the lever around the axis of rotation is reduced. Another aspect of this task is it to design the valve actuation lever so that the rigidity against the State of the art increased and low manufacturing costs can be achieved.

This object is achieved by the subject matter of claim 1.

The method according to the invention is the subject of claims 13 and 14.

Preferred developments of the invention are the subject of the dependent claims.

The valve actuation lever according to the invention has a substantially non-cutting shaped elongated body, preferably with a U-shaped profile. The The basic body is essentially symmetrical to itself in its longitudinal direction extending longitudinal plane of symmetry. On both sides of this plane of longitudinal symmetry tabs are arranged in the valve contact area, each one have the side surface facing the longitudinal plane of symmetry. The tabs are on molded onto an end edge of this base body and towards the valve contact area bent.

At least one of these tabs points away from this plane of longitudinal symmetry away extending transition area, in which the distance between them Side surfaces enlarged and at least one parallel area in which this Side surfaces run essentially parallel to this longitudinal plane of symmetry.

The two tabs are at a clear distance at the end edge of the body arranged, which is less than the clear distance of the side surfaces in the parallel area, this distance in each case in a direction perpendicular to the longitudinal plane of symmetry is determined.

The design according to the invention has a number of essential advantages.

The distance between the tabs on the end edge of the elongated body is constructive Size, which is the width of the elongated body in the valve contact area certainly. By reducing this distance, the width of the elongated one becomes simultaneously Base body at least in the valve contact area and thereby also its Weight decreased. Because the valve contact area is radial from the axis of rotation of the valve operating lever is spaced, this results in a significant reduction the moment of inertia around the axis of rotation of the lever. With that, the forces required to operate the lever are reduced at the same speed, and it becomes the permissible for the valve train with regard to the actuation forces Speed limit raised.

Since it is possible to reduce the width of the lever with the same dimensions, the bending lengths of the lever are also transverse to its longitudinal direction reduced, which can increase the rigidity.

Furthermore, the material costs are reduced by reducing the lever width, thereby reducing manufacturing costs. Compared to other manufacturing processes has the non-cutting shape, in which the tabs are also through one simple punching and bending process can be produced, significant cost advantages anyway.

Reducing the width of the lever also has the advantage that the valve train overall can build narrower. Because the engine designers due to the requirements are forced to space economy and weight optimization, engines Developing with the shortest possible overall length is not only particularly then of importance if due to the specifications for power, consumption and Exhaust levels three or more valves per cylinder are to be used.

In a first, preferred embodiment, the tabs are on the base body the bending process molded in such a way that they are parallel to the plane of longitudinal symmetry extend, d. H. run straight. The bending then takes place in such a way that one or both tabs to form the transition area from the longitudinal plane of symmetry be bent away. At the end of the transition area are the tabs then bent in such a way that the inner plane facing the plane of symmetry Side surface of the tab runs parallel to this.

Depending on the design requirements, this parallel area can then be used connect yet another constriction area in which one or both tabs are facing the longitudinal plane of symmetry again.

In a second, preferred embodiment of the invention, the tabs are such punched that the transition area and the parallel area already with the deformed tabs are present. The tabs then only have to be bent through 180 ° and then in the bent state, without further bending, the desired contour in the valve contact area.

The first and the second embodiment can also be combined with one another. In this case, the flaps are stamped into an initial shape followed by a 180 ° bend and an additional bend brought to the longitudinal symmetry plane or away from it into the final shape.

It is also possible to treat the tabs differently, so that e.g. a Tab is only subjected to a bend of approximately 180 °, while the other tab both this bend and a further bend, in particular to the plane of longitudinal symmetry there or away from it. The initial form of Tabs be the same, e.g. the shape of an elongated cuboid parallel to the plane of longitudinal symmetry corresponding longitudinal edges or different from each other his.

Figur 1

eine Untersicht eines ersten Ausführungsbeispiels der Erfindung, welches als Rollenschlepphebel ausgebildet ist;

Figur 2

einen Längsschnitt des Ausführungsbeispiels gemäß Fig. 1;

Figur 3

einen Schnitt durch die Darstellung gemäß Fig. 2 entlang der Linien III-III gesehen;

Figur 4

eine Aufsicht auf das Ausführungsbeispiel gemäß Fig. 1;

Figur 5

eine Ansicht des Rollenschlepphebels des Ausführungsbeispiels gemäß Fig. 1 während der Fertigung, von unten gesehen;

Figur 6

eine Darstellung entsprechend der Fig. 5 in einem weiteren Stadium der Fertigung;

Figur 7

ein zweites Ausführungsbeispiel des erfindungsgemäßen Rollenschlepphebels in einem vorhergehenden Stadium der Fertigung, von unten gesehen;

Figur 8

den Rollenschlepphebel gemäß Fig. 7 in einer Ansicht von unten gesehen;

Further advantages, features and possible uses of the present invention result from the following description of exemplary embodiments in connection with the figures. In it show:

Figure 1

a bottom view of a first embodiment of the invention, which is designed as a roller rocker arm;

Figure 2

a longitudinal section of the embodiment of FIG. 1;

Figure 3

seen a section through the representation of Figure 2 along the lines III-III.

Figure 4

a plan of the embodiment of FIG. 1;

Figure 5

a view of the roller rocker arm of the embodiment of Figure 1 during manufacture, seen from below.

Figure 6

a representation corresponding to Figure 5 in a further stage of manufacture.

Figure 7

a second embodiment of the roller finger follower according to the invention in a previous stage of manufacture, seen from below;

Figure 8

seen in a view from below.

A first embodiment of the invention will now be described with reference to FIGS. 1 to 6 described.

Fig. 1 shows a first embodiment of the roller finger follower according to the invention.

The roller rocker arm has a base body designated 1 overall, which extends essentially symmetrically along a longitudinal plane of symmetry 2. The term plane of symmetry is not to be understood here in a purely geometrical sense, it simply means that essential areas of the valve actuation lever are designed symmetrically to this plane of symmetry. The plane of symmetry 2 1 runs perpendicular to the plane of the drawing and forms in the 2 the sectional plane.

The elongated body is, as can be seen from the illustration in FIG. 3, in designed essentially U-shaped and has a symmetrical to the plane of symmetry 2 extending recess 4 in which a roller 7 mounted on rolling elements 6th is arranged. When installed, the roller 7 stands with the cam of a camshaft in contact.

In the right part of the illustration according to FIG. 1 there is a depression 10 for receiving a Support element (not shown) is provided. When installed this element in turn is supported within the cylinder head (not shown) from. The design of this recess 10 is known in the prior art and therefore need not be discussed further here.

On the left side of the base body in the illustration according to FIG. 1 there is a valve contact area 20 provided. The valve contact area has a surface 21, which is designed to be slightly convex in the exemplary embodiment, but can also do other things Have curvature shapes or just be designed.

The valve contact area is through two, the longitudinal symmetry plane 2 facing limited lateral surfaces 23, 24, which are part of the tabs 25, 26.

The tabs 25, 26 are formed on an end edge 30 of the elongate base body 1, the end edge 30 being substantially perpendicular to the plane of symmetry 2. The distance between the tabs 25 and 26 corresponds to this end edge of the base body the length a in Fig. 5 between the arrows 31 and 32 or, in other words, the Tabs 25 and 26 are on the end edge 30 of a web 30a, which has the width c (see Fig. 5) between the arrows 33 and 34, integrally formed.

1, both tabs 25, 26 have a transition region 35, 36 on, in which the tabs away from the plane of symmetry 2 extend. A parallel area 37 adjoins this transition area 35, 36 38 in which both tabs run parallel to the plane of symmetry 2. At the tab 26 is followed by a constriction area 40, in which the tab rests on the Plane of symmetry 2 runs.

The term transition area is therefore defined by the fact that here the angular Alignment of the tab or the side surfaces with respect to the longitudinal plane of symmetry changes.

In the parallel area 37, 38, the distance between the two tabs corresponds to the distance b, as shown between arrows 42, 43. This distance b is larger than the distance a. The difference between the two routes essentially corresponds to the width savings of the base body compared to the prior art discussed above.

In the embodiment shown, the two tabs 25, 26 are located, in particular the representation according to Figure 2 shows, flush, d. H. without space on which curved surface of the valve contact area 20.

Deviating from this, the tabs can also in this embodiment be designed in the next embodiment so that between the tabs and a gap is provided on the surface of the valve contact area, the tabs are then shaped so that their end area rests on the valve contact area. Around the end region, in the illustration according to FIG. B. at the tab 26 of the Constriction area 40, with respect to the valve contact area, can be fixed in the first alternative, d. H. with flush-fitting tabs, as well as with the second alternative, d. H. in the case of tabs that are partially at a distance from the valve contact area have at the end of an additional connection, preferably by a spot weld is made.

A method of making this embodiment of the invention is now described in with reference to FIGS. 5 and 6 explained.

The roller rocker arm shown in the embodiment is a total of one Metal sheet punched out and then preferably cold-formed to the in Fig. 1 to 4 to achieve the final design shown. The tabs 25 and 26 are at Punching as an essentially straight extension of the base body 1 educated. Then, as shown in Fig. 6, they are down (in the illustration seen the drawing) reshaped, the distance between the tabs continues corresponds to the distance a. Then the tabs from the plane of symmetry 2 bent away to form the transition region 35, 36. This bending process is carried out so that the tabs are initially at a first bending angle are bent outwards so that the outwards from the plane of symmetry 2nd forms the first part of the transition region 35, 36 and that adjoins it the tabs bent back in the direction of the plane of symmetry 2 be that the further part of the tabs runs parallel to the line of symmetry 2. Only one or both ends of the tabs, as indicated by 40 in Fig. 1, is again with an inward bending angle, formed on the plane of symmetry 2.

As the representation according to FIGS. 1 to 6 shows, this design makes it possible run the valve operating lever with a small width. This becomes significant of material saved, thereby reducing the moment of inertia around the axis of rotation reduced and, with otherwise the same dimensions, the rigidity is increased.

Another embodiment of the invention will now be described with reference to FIGS. 7 and 8 explained.

In this exemplary embodiment, this essentially corresponds to that shown in FIG. 8 End product, namely the roller finger follower, essentially as shown Fig. 1. Corresponding reference numerals are therefore also used there.

However, there is a difference in the design of the tabs 51 and 52.

As the illustration in FIG. 7 shows, the tabs are here during a punching process immediately formed so that the desired transition area is already during the punching process and not, as in the exemplary embodiment according to FIGS. 1 to 6, results in bending.

The tab 51 is on the substantially perpendicular to the plane of symmetry 2 End edge 30 of the base body 1 is formed. The tab 51 has a first Area in which the tab is designated 53 even in the undeformed state forms an acute angle to this end edge 30, whereby one of the longitudinal symmetry plane 2 pointing transition area 54 forms. The transition area 54 is followed by a parallel region 55, which is designed parallel to the plane of longitudinal symmetry and there is an area 56 in which the side surface is at an acute angle to the longitudinal plane of symmetry is directed towards.

In the case of the tab 52, a parallel region 57 is initially provided, which is parallel to the Longitudinal plane of symmetry 2 runs, to which the transition region 58 then adjoins, in which the tab extends outward from the longitudinal plane of symmetry 2. This is followed by a further parallel area 59, which is parallel to the longitudinal plane of symmetry 2 extends and which forms the side surface 60.

The process for producing this valve actuation lever is similar to that in the above-described embodiment. The tabs are also approx. Bent 180 °, which is a design of the rocker arm according to the Fig. 8 results. The directed towards or away from the longitudinal plane of symmetry Bending is omitted here. The punching tool is somewhat more complex overall designed as in the embodiment of FIGS. 1 to 6. But there is the advantage compared to that the bending process is easier.

LIST OF REFERENCE NUMBERS

1

body

2

Longitudinal plane of symmetry

4

recess

6

rolling

7

role

10

deepening

20

Valve contact area

21

Area of 20

23, 24

Lateral surface

25, 26

flap

30

end edge

30a

web

31, 32

arrow

33, 34

arrow

35, 36

Transition area

37, 38

parallel area

40

throat area

42, 43

arrow

51, 52

flap

53

acute angle

54

Transition area

55

parallel area

56

throat area

58

Transition area

59

parallel area

60

side surface

a

Distance perpendicular to the plane of longitudinal symmetry

b

Distance perpendicular to the plane of longitudinal symmetry

c

Width between arrows 33 and 34

Claims (15)

1. Valve actuating lever for transmitting movement of a cam arranged on a camshaft to a gas changing valve of an internal combustion engine comprising:

   an essentially non-cut formed oblong base body (1) configured essentially symmetrical to its longitudinal symmetry plane (2) extending longitudinally therefrom,

   a valve contact area (20) arranged at a first end of said base body,

   two tabs (25, 26; 51, 52) arranged at both sides of said longitudinal symmetry plane in said valve contact area, each respectively having a lateral surface (23, 24; 60, 61) aligned facing said longitudinal symmetry plane, whereby said tabs are formed on said base body and are bent over toward said valve contact area,

   characterized in that
   said tabs are arranged spaced at a clearance (a) at an end edge (30) of said base body, said clearance (a) being less than the clearance (b) of said lateral surfaces in said valve contact area, whereby said clearance is respectively measured perpendicular to said longitudinal symmetry plane (2), and
   at least one of said tabs has at least one connecting portion (35, 36; 54, 58) extending from said longitudinal symmetry plane in which the clearance between said lateral surfaces enlarges as well as at least one parallel portion (37, 38; 55, 59) in which said lateral surfaces extend essentially parallel to said longitudinal symmetry plane (2).
2. Valve actuating lever according to claim 1, characterized in that
   said connecting portion (35, 36) is created through means of plastic deformation.
3. Valve actuating lever according to claim 1, characterized in that
   said connecting portion (54, 58) is created through means of a material removal process.
4. Valve actuating lever according to at least one of the preceding claims, characterized in that
   at least one of said tabs comprises a narrowed portion (40, 56) adjoining said parallel portion in which said tab is formed toward said longitudinal symmetry plane (2).
5. Valve actuating lever according to at least one of the preceding claims, characterized in that
   said base body is configured of essentially U-shape in a section plane which lies perpendicular to said longitudinal symmetry plane.
6. Valve actuating lever according to at least one of the preceding claims, characterized in that
   said tabs are of rectangular configuration in cross-section and preferably of square configuration in cross-section.
7. Valve actuating lever according to at least one of the preceding claims, characterized in that
   said surface (21) formed by said valve contact area (20) extends in curved configuration and that said tabs are bent in such a manner so as to abut up against said surface to follow said curvature.
8. Valve actuating lever according to at least one of claims 1 - 6, characterized in that
   said surface (21) formed by said valve contact area (20) extends in curved configuration and that said tabs are bent in such a manner that they have a clearance from said surface in a partial section and only abut up against said surface at their end sections.
9. Valve actuating lever according to claim 7 or 8, characterized in that
   said curvature is at least partially a convex curvature.
10. Valve actuating lever according to at least one of the preceding claims, characterized in that
    said valve lever is configured as a drag lever.
11. Valve actuating lever according to claim 10, characterized in that
    said valve actuating lever is configured as a roller drag lever.
12. Valve actuating lever according to claim 11, characterized in that
    said roller drag lever comprises a roller (7) rotatably mounted via roller elements (6).
13. Valve actuating lever according to claim 1, characterized in that
    said base body (1) is of U-shaped form in cross-section and that said tabs are formed on one end edge (30) of said base body, in particular on a trestle (30a) of narrower width (c) of said U-shaped base body (1).
14. Method for manufacturing a valve actuating lever and especially a valve actuating lever in accordance with one of claims 1 - 13 including the following procedural steps:

    stamping out of an oblong base body (1) configured essentially symmetrical to a longitudinal symmetry plane (2) extending longitudinally therefrom having two tabs (25, 26) arranged at both sides of said longitudinal symmetry plane (2) on an end edge, each respectively having a lateral surface (23, 24) aligned facing said longitudinal symmetry plane (2), whereby said tabs (25, 26) are formed on said base body (1) and extend parallel to said longitudinal symmetry plane (2),

    bending of said tabs (25, 26) at an angle of approximately 180°,

    bending of at least one of said tabs (25, 26) to form a connecting portion (35, 36) extending from said longitudinal symmetry plane (2) in which the clearance between said lateral surfaces (23, 24) enlarges, as well as at least one parallel portion (37, 38) in which said lateral surfaces (23, 24) extend essentially parallel to said longitudinal symmetry plane (2).
15. Method for manufacturing a valve actuating lever and especially a valve actuating lever in accordance with one of claims 3 - 13, including the following procedural steps:

    stamping out of an oblong base body (1) configured essentially symmetrical to a longitudinal symmetry plane (2) extending longitudinally therefrom having two tabs (51, 52) arranged at both sides of said longitudinal symmetry plane, each respectively having a lateral surface (60, 61) aligned facing said longitudinal symmetry plane, whereby said tabs (51, 52) are formed on said base body and whereby at least one of said tabs (51, 52) comprises at least one connecting portion (54, 58) extending from said longitudinal symmetry plane (2) in which the clearance between said lateral surfaces enlarges as well as at least one parallel portion (55, 59) in which said lateral surfaces extend essentially parallel to said longitudinal symmetry plane (2),

    bending of said tabs at an angle of approximately 180°.

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