DE102011003900A1 - intermediate lever - Google Patents

Abstract

An intermediate lever (1) for a variable valve train of an internal combustion engine is proposed, with two support rollers (4) running on one end (2) on an axis (3) for counter-rotation on a sliding track, which support rollers (4) have a contact surface (5). for a cam disc, two counter-rollers (8) for a lifting cam positioned on a further axis (7) being arranged in a central section (6) of the intermediate lever (1), a surface (10) for a further end face (9) variable transmission of a stroke of the lifting cam sits on a tap of a follower, with one counter-rotating and one supporting roller (8, 4) each running on an outer wall (11) of the intermediate lever (1) and the intermediate lever (1) from its outer contour viewed as an at least substantially closed block.

Description

The invention relates to an intermediate lever for a variable valve train of an internal combustion engine, with two running at one end on a shaft support rollers, which support rollers include a contact surface, wherein in a center portion of the intermediate lever at least one positioned on a further axis counter-roller for a lift cam is arranged and , at a further end face a surface for variable transmission of a stroke of the lifting cam sits on a tap of a follower member.

Such an intermediate lever goes out of the 5 . 6 of the DE 10 2006 018 512 A1 out. This has two bar-shaped side walls. At one end, the side walls include a total of three roller bearings, of which two rollers act as support rollers for a counter-rotation on a slide track and the roller lying between them as a starting roller for a cam. In a middle section of the intermediate lever has another roller bearing roller for a cam start. At a further end face, the side walls converge toward one another to form a hub transmission surface connecting them.

A disadvantage is the relatively complicated structure in the aforementioned embodiment. The intermediate lever is made of sheet metal in a complex, consisting of too many processing steps and thus in mass production still too expensive punch-bending process. Since the side walls comprise the rollers on the outside, the intermediate lever may build too wide.

The invention is therefore based on the object to provide an intermediate lever of the aforementioned type, in which the indicated disadvantages are eliminated.

In particular, a very inexpensive producible and simply constructed intermediate lever to be created.

According to the invention, this object is achieved in that two counter-rotating rollers are provided for the lifting cam, wherein each run a Gegenlauf- and depending on a support roller on an outer wall of the intermediate lever and wherein the intermediate lever viewed from the outer contour thereof is present as at least substantially closed block.

Thus, an intermediate lever without the aforementioned disadvantages is created. The intermediate lever, for example, simply from a sheet metal blank, whose thickness preferably has the width of the intermediate lever punched or made in a forging process. Alternatively, it can also be machined (milling o. The like.) Or at least machined or represented by casting / sintering. An MIM training is also thought. The intermediate lever is thus available as a simple block or as a solid part. The aforementioned bending processes are eliminated. Due to the outer layer of the rollers, the intermediate lever also builds comparatively narrow. Mounting the axles and rollers is extremely easy.

The intermediate lever can be used in a fully variable valve train for throttle-free load control application, as it is installed by the Bavarian engine works under the name "Valvetronic".

It is expedient to represent either the contact surface for the cam or for the slide track centrally directly at the one end as bulge material. Thus, a complex role tap is dispensed with. In the case of the central arrangement of the contact surface for the cam is done on the outside roles a good, non-tilting leadership of the intermediate lever on the slide track.

An axial line of the bulge runs according to a further development of the invention coaxially to the axial line of the support rollers at one end.

According to a further concretization of the invention, a storage of the axes in the intermediate lever via a roller bearing such as a needle bearing. The rollers themselves are simply pressed onto the projecting axle stumps, for example. However, there are also alternative forms of attachment such as end-side caulking, welding or tongue and groove connections in question. Alternatively, thought of a sliding bearing. Also, the support rollers on the projecting axle stubs rolling or sliding be.

The surface for variably transmitting the cam lift at the other end consists of a zero stroke and a stroke range. It is connected in one piece to the intermediate lever and runs on undersides of bilaterally Hebelverschwenkrichtung bow-like protruding extensions. Possibly. In this area, a variant is also conceivable or a configuration in which only one extension protrudes.

Preferably, tabs for guiding a force acting on the intermediate lever cam return spring should project in one piece from an upper side or end face of one of the extensions. These tabs can be represented, for example, by embossing, bending or cutting.

Preferably, the mating rollers for the lifting cam protrude beyond the contour of the intermediate lever out. Thus, the lift cam does not need to be split and can counter full width.

The protection of the invention also relates to intermediate lever, in which only a total of a support or counter-rotating roller is applied.

The invention will be explained with reference to the drawing.

Show it:

1 a spatial view of a first variant of an intermediate lever and

2 a central longitudinal section through a second variant of an intermediate lever.

Is shown in 1 a present as a closed block intermediate lever 1 for a fully variable valve train of an internal combustion engine for throttle-free load control. The intermediate lever 1 is punched out of a sheet metal plate or a sheet metal strip.

The intermediate lever 1 to 1 has two on one front end 2 on an axis 3 running support rollers 4 for a reverse course on a slide track (sa 6 of the DE 10 2006 018 512 A1 ). The axis 3 is in the intermediate lever 1 via a roller bearing 13 added. On their protruding stumps are the support rollers 4 pressed.

The support rollers 4 close a tarpaulin 5 for a cam. The contact surface 5 is as a cylinder segment-like bulge of the material of the intermediate lever 1 on the one front end 2 formed, wherein the bulge over an outer sheath 12 the support rollers 4 protrudes radially.

In a middle section 6 of the intermediate lever 1 two are flanking these and on another axis 7 positioned counter rolls 8th arranged for a lift cam. The axis 7 again passes over a rolling bearing 14 in the intermediate lever 1 , wherein the two-sided counter-rotating rollers 8th on the axis 7 are pressed on.

At another front end 9 are on both sides in Hebelverschwenkrichtung one-piece protruding extensions 15 . 16 applied. Their common bottom 20 forms an area 10 for the variable transmission of the cam lift. This area 10 has a Nullhubabschnitt in a known manner 21 on which a lift section 22 connected. In the installation position, this surface communicates 10 with a valve opener like a rocker arm.

From a final mind 17 the extension shown here on the left 15 stand two one-piece tailed tabs 18 from. Between these is an end of the intermediate lever 1 In the installation acting on cam return spring feasible (here counterclockwise).

According to 2 serve the external support rollers 4 a start-up of a cam (sa 4 of the DE 10 2008 018 512 A1 ). They close a contact surface 5 for a contact of a slide track. The latter, central contact surface 5 is again as a cylinder segment-like bulge of the material of the intermediate lever 1 on the one front end 2 formed, with this bulge of the support rollers 4 is towered over.

LIST OF REFERENCE NUMBERS

1

intermediate lever

2

a front end

3

axis

4

supporting role

5

approach surface

6

mid section

7

axis

8th

Reverse roller

9

another front end

10

area

11

outer wall

12

outer sheath

13

roller bearing

14

roller bearing

15

renewal

16

renewal

17

Endstirn

18

flap

19

outside

20

bottom

21

Nullhubabschnitt

22

stroke section

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 102006018512 A1 [0002, 0021]
• DE 102008018512 A1 [0026]

Claims (10)

Intermediate lever ( 1 ) for a variable valve train of an internal combustion engine, with two at one end ( 2 ) on one axis ( 3 ) running support rollers ( 4 ) and with a contact surface ( 5 ), whereby in a middle section ( 6 ) of the intermediate lever ( 1 ) at least one on another axis ( 7 ) positioned counter-rotating roller ( 8th ) is arranged for a lifting cam and wherein at another front end ( 9 ) an area ( 10 ) sits for variable transmission of a stroke of the lifting cam on a tap of a follower member, characterized in that two mating rollers ( 8th ) are provided for the lifting cam, with one each mating and one support roller ( 8th . 4 ) on an outer wall ( 11 ) of the intermediate lever ( 1 ) and wherein the intermediate lever ( 1 ) viewed from the outer contour thereof is present as at least substantially closed block. Intermediate lever according to claim 1, characterized in that the external support rollers ( 4 ) are provided for a counter-rotation on a slide track, wherein the contact surface ( 5 ) is in contact with a cam ( 1 ). Intermediate lever according to claim 1, characterized in that the external support rollers ( 4 ) are provided for a counter run on a cam, wherein the contact surface ( 5 ) serves a contact with a slide track. ( 2 ). Intermediate lever according to claim 2 or 3, characterized in that the central contact surface ( 5 ) as a cylinder segment-like bulge of the material of the intermediate lever ( 1 ) at the one end ( 2 ), which bulge over an outer shell ( 12 ) of the support rollers ( 4 ) protrudes radially. Intermediate lever according to claim 2 or 3, characterized in that the central contact surface ( 5 ) as a cylinder segment-like bulge of the material of the intermediate lever ( 1 ) at the one end ( 2 ), which bulge of the support rollers ( 4 ) is surmounted. Intermediate lever according to claim 2 or 3, characterized in that an axial line of the bulge as the material of the intermediate lever ( 1 ) trained contact surface ( 5 ) with the axial line of the axis ( 3 ) for the support rollers ( 4 ) coincides. Intermediate lever according to claim 1, characterized in that the intermediate lever ( 1 ) by a chipless process such as stamping / forging / casting / sintering / metal powder injection molding (MIM) or by a chip method such as milling. Intermediate lever according to claim 1, characterized in that either the axes ( 3 . 7 ) via a rolling or plain bearing ( 13 . 14 ) in the intermediate lever ( 1 ), wherein the corresponding support or counter-rotating rollers ( 8th . 4 ) via a non-rotatable connection such as a pressing / caulking / welding / gluing / screwing on the respective axis ( 3 . 7 ) or that the corresponding support or counter-rotating rollers ( 8th . 4 ) via a rolling or sliding bearing on the axles ( 3 . 7 ). Intermediate lever according to claim 1, characterized in that, for the formation of the surface ( 10 ) for variable transmission, the cam lift at the further front end ( 9 ), the front end ( 9 ) on both sides, in Hebelverschwenkrichtung protruding extensions ( 15 . 16 ) has, at their common bottom ( 20 ) the area ( 10 ) is present, wherein at an end-face ( 17 ) or top of one of the extensions ( 15 . 16 ) two integrally connected tabs ( 18 ), between which one end of the intermediate lever ( 1 ) acted upon cam return spring is feasible. Intermediate lever according to claim 9, characterized in that outer sides ( 19 ) of the two tabs ( 18 ) the outer walls ( 11 ) of the intermediate lever ( 1 ) extend in alignment or slightly in or out.

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