DE102016208391A1 - Valve train roller cam - Google Patents

Abstract

A roller rocker arm for the valve train of an internal combustion engine, which is made as a cross-sectionally U-shaped component with side cheeks (2) has in its central region in an aligned holes (3) of the side cheeks (2) arranged bolt (9) on which a cam roller (8) is rotatably mounted. According to the invention the roller rocker arm (1) in the region of the cam roller (8) with an open top (7), wherein the bores (3) of the side cheeks (2) are designed to be radially open on one side and in the bores (3) as a bearing for the Bolt (9) acting half shells (4) are arranged, which are pressed into the side cheeks (2). Instead of the half-shells (4) and sleeves can be used.

Description

Valve train roller cam

The invention relates to a roller rocker arm for the valve train of a reciprocating internal combustion engine, which is made as a cross-sectionally U-shaped component with side cheeks and in its central region has an aligned holes in the side cheeks bolts on which a cam roller is rotatably mounted.

Background of the invention

Such a roller rocker is from the document DE 42 34 868 C2 known. This shows a arranged in the cylinder head of an internal combustion engine valve train with a roller rocker arm, acting on the cam roller of the cam of a camshaft, not shown. One end portion of the roller rocker arm is provided for acting on the valve stem of a gas exchange valve, while the other end portion rests on a support member.

Roller rocker arms in sliding cam systems with large Abschalthüben each have a large footprint in terms of the distance of the camshaft from the top of the rocker arm. Roller cam followers are currently being developed for this purpose, which have an open top pull. A problem with the roller toggle levers with open top is that they have high tensile stresses in the region of their beam due to the lower rigidity of their design in the internal combustion engine under load.

Summary of the invention

The invention has for its object to provide a roller cam follower in which in operation under load, the tensile stresses occurring in the region of the beam are reduced.

This object is achieved according to a first proposal according to the invention that the roller cam follower has an open top in the region of the cam roller, the holes of the side cheeks are designed to be radially open on one side and arranged in the bores as bearings for the bolt half shells, which in the Side cheeks are pressed.

According to another proposal, the object is achieved in a corresponding manner according to the invention that instead of the half-shells in the holes of the side cheeks acting as a bearing for the bolt sleeves are arranged, which are pressed into the side cheeks.

In order to reduce the tensile stresses during operation, so half shells or sleeves are pressed within the holes for receiving the bolt in the side cheeks. As a result, a part of the tensile stresses present under load and introduced compressive stresses are balanced against each other. The half-shells or sleeves have the decisive advantage that you can each mount a bolt that can rotate during operation and thereby provides a larger wear zone, as a firmly pressed in the side bolsters bolt. In comparison with the half-shells, the sleeves have the disadvantage that the possible Abschalthub turns out smaller, since the roller cam follower builds altogether higher. However, there is the advantage in the smaller dimension of the sleeve relative to the half-shell, since the latter deforms under load with the same wall thickness.

In order to secure the half shell against twisting, the upper pull is partially and selectively deformed. To facilitate assembly, the sleeve or the half-shell can be performed with a step as a stop.

Short description of the drawing

Two embodiments of the invention are illustrated in the drawings and will be described in more detail below. Show it

1 a roller rocker arm with side cheeks, in the open holes half shells are pressed as a bearing for a bolt;

2 according to the roller rocker arm 1 before mounting the half-shells and the bolt;

3 a roller rocker arm with side cheeks, in the open holes sleeves are pressed as a bearing for a bolt.

Detailed description of the drawing

One in the 1 and 2 illustrated roller rocker arm 1 is as Blechbiegebauteil with two parallel side walls 2 executed. These point in the middle area of the roller rocker arm 1 two aligned, radially one-sided open holes 3 on. In every hole 3 is a likewise radially open half shell 4 axially so far in the corresponding side cheek 2 pressed until a stop step 5 the half shell 4 on the outer surface of the Rollenschlepphebels 1 is applied. Opposite the closed beam 6 of the roller cam follower 1 is its top train 7 in the area of the pressed half shells 4 each open, so that a cam roller 8th from above into the roller rocker arm 1 can be used. Part of the inserted cam roller 8th juts over the top train 7 out the roller rocker arm 1 out. As bearing for the cam roller 8th is in the rocker arm 1 a bolt 9 used and in the half shells 4 stored. In this way, the bolt can 9 rotate during operation, so it is in the side walls 2 not firmly pressed.

Opposite this roller cam follower 1 is different in 3 shown roller cam follower only in that instead of the half shells 4 in the side cheeks 2 sleeves 10 with the facilitating stop levels 11 are pressed.

LIST OF REFERENCE NUMBERS

1

 Roller cam

2

 side cheek

3

 open hole

4

 half shell

5

 stop step

6

 Beam

7

 top pull

8th

 cam roller

9

 bolt

10

 shell

11

 stop step

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 4234868 C2 [0002]

Claims (4)

Roller rocker arm for the valve train of a reciprocating internal combustion engine, which as a cross-sectionally U-shaped component with side cheeks ( 2 ) and in its central region in an aligned holes ( 3 ) of the side cheeks ( 2 ) arranged bolts ( 9 ), on which a cam roller ( 8th ) is rotatably mounted, characterized in that the roller rocker arm ( 1 ) in the area of the cam roller ( 8th ) an open top train ( 7 ), wherein the bores ( 3 ) of the side cheeks ( 2 ) are radially open on one side open and in the holes ( 3 ) as a bearing for the bolt ( 9 ) acting half shells ( 4 ) are arranged in the side cheeks ( 2 ) are pressed. Roller rocker arm for the valve train of a reciprocating internal combustion engine, which as a cross-sectionally U-shaped component with side cheeks ( 2 ) and in its central region in an aligned holes ( 3 ) of the side cheeks ( 2 ) arranged bolts ( 9 ), on which a cam roller ( 8th ) is rotatably mounted, characterized in that the roller rocker arm ( 1 ) in the area of the cam roller ( 8th ) an open top train ( 7 ), wherein the bores ( 3 ) of the side cheeks ( 2 ) are radially open on one side open and in the holes ( 3 ) as a bearing for the bolt ( 9 ) acting sleeves ( 10 ) are arranged in the side cheeks ( 2 ) are pressed. Roller rocker arm according to claim 1, characterized in that the half-shell ( 4 ) in each case by a deformation in the upper 7 ) is secured against twisting. Roller rocker arm according to claim 1 or 2, characterized in that the half-shell ( 4 ) or the sleeve ( 10 ) each with a their assembly in the roller rocker arm ( 1 ) facilitating stop step ( 5 respectively. 11 ) is executed.

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