DE102023101222A1 - Rocker arm for a valve train of an internal combustion engine - Google Patents

Abstract

Proposed is a rocker arm (1) for a valve train of an internal combustion engine, with two side walls (3) connected by a cross beam (2), which rocker arm (1) has an inverted U-profile in cross-section, wherein on an underside (4) of the cross beam (2) bordered by the side walls (3) there is a calotte (7) for a support element at one end (6) and on another end (8) there is a contact (10) for a valve stem that is only laterally delimited by inner wall pieces (9) of the side walls (3), and wherein the rocker arm (1) has a cam counter-running surface (12) running between the ends (6, 8) on an upper side (11) of the cross beam (2). The rocker arm (1) has two guide plates (13) running in its longitudinal direction for engagement of an alignment and/or o. holding tool during its assembly on the internal combustion engine, which guide plates (13) are located at the other end (8) and protrude freely from the top side (11) of the crossbeam (2).

Description

The invention relates to a rocker arm for a valve train of an internal combustion engine, with two side walls connected by a crossbar, which rocker arm has an inverted U-profile in cross section, wherein on an underside of the crossbar enclosed by the side walls there is at one end a calotte for pivotably mounting the rocker arm on a support element and at another end a system for a valve stem that is laterally limited only by inner wall pieces of the side walls, and wherein the rocker arm has a cam counter-running surface running between the ends on an upper side of the crossbar.

A generic rocker arm is provided from the DE 195 43 657 A1 , 1 , 2 It can be seen that the "upper" crossbar in the longitudinal section of the system for the valve stem has smooth walls on the upper side.

Another rocker arm with an inverted U-profile in cross section is in the EN 10 2015 200 102 A1 , 1 Its crossbar has a slight indentation on its top side at the valve-side end to represent a minimally bulged contact area underneath for the valve stem. The height of the bulge is a few 1/10 mm.

The DE 198 11 658 B4 reveals a rocker arm with an upright U-profile in cross-section.

The task is to create a rocker arm with an inverted U-profile in cross-section, which can be easily assembled and/or aligned “from above” on a support element and gas exchange valve of the internal combustion engine.

According to the invention, this object is achieved in that the rocker arm has two guide plates running in its longitudinal direction for engagement of an alignment and/or.

holding tool during its assembly on the internal combustion engine, which guide plates are located at the other end and protrude freely from the top of the crossbeam.

This means that the rocker arm, which otherwise has at least largely smooth walls on its top side at the other end, has a simple means for engagement of a handling and/or alignment tool during its final assembly. For example, it can be provided to insert a gripper or similar between the guide plates and, if necessary, to spread them open in order to transport the rocker arm and, for example, to finally place it on the cylinder head. Alternatively, a cone or similar can be inserted between the support plates, via which the rocker arm undergoes fine alignment during/after the rocker arm is finally placed on the support element and the valve stem. With both of the aforementioned measures, another tool such as the above-mentioned calotte of the support element can also be included on the side of one end.

The rocker arm is preferably made of sheet steel and is produced by stamping and bending. Alternatively, it can also be an extruded, forged or cast part.

The plan is to have the two guide plates protrude from the rocker arm in one piece. In the case of a sheet metal design, these can, for example, consist of wall material that is cut out and erected like a tab.

However, it is particularly preferred to apply a separate, box-like retaining clip made of thin-walled sheet steel to the top of the system for the valve stem, from whose longitudinal webs the guide plates protrude and from whose transverse webs retaining claws protrude, which are locked/snapped to the front ends of the crossbar. If necessary, the retaining clip can also be designed as a closed plate in its main section on the top of the crossbar. The retaining clip can be removed before the internal combustion engine is put into operation, which has a positive effect on the moving valve train masses.

In the case of the cam counter-running surface being designed as a roller, the crossbar has a respective recess into which the roller projects in sections and on whose cross face facing the other end the corresponding retaining claw rests, the latter, preferably in the same way as the further retaining claw on the end face at the other end, engaging under the crossbar via bent projections.

The term "rocker arm" refers in particular to a valve train lever which can be pivoted on a support element at one end. However, it also includes other types of levers such as rocker arms or swing arms with an inverted U-profile in the cross section.

• • 1 zeigt eine räumliche Ansicht des Schlepphebels mit Halteklammer, längs aufgebrochen und
• • 2 zeigt die Halteklammer als Einzelheit.

About the drawing:

• • 1 shows a spatial view of the rocker arm with retaining clip, broken open lengthwise and
• • 2 shows the retaining clip as a detail.

1 shows a rocker arm 1 made of sheet steel for a valve train of an internal combustion engine. The rocker arm 1 has two side walls 3 connected by an "overhead" crossbar 2, whereby only the "rear" side wall 3 is visible due to the sectional view. In cross section, the rocker arm 1 has an inverted U-profile.

The crossbeam 2 has a calotte 7 on its underside 4 at an end 6 shown here on the left. This serves, which does not need to be explained in more detail, for a pivotable mounting of the rocker arm 1 on a support element. At another end 8, the crossbeam 2 has a system 10 for a valve stem of a gas exchange valve, which is only laterally limited by inner wall sections 9 of the side walls 3. The system 10 is slightly curved for a "clean", edge-support-free system of the valve stem. This shape is achieved by a minimal impression 25 applied to the top 11 of the crossbeam 2. The latter has a depth of a few 1/10 mm, for example 0.5 mm.

Between the ends 6, 8 of the rocker arm 1, the crossbar 2 has a recess 23, approximately in the section of a lever's longitudinal center. The section of the lever's longitudinal center is shown in relief. A roller 12 projects into the recess 23 as a cam counter-running surface. The roller 12 runs on a roller bearing on a bolt 5 accommodated in the side walls 3.

The section of the crossbar 2 located above the valve stem system 10, which is limited on the inside by a crossbar 22 of the recess 23 and on the outside by an end face 21 of the crossbar 2 / rocker arm 1, is provided with a retaining clip 14 made of sheet steel. The latter has two longitudinal webs 15, 16, which are connected at the longitudinal end by a crossbar 17, 18 each. In plan view, the retaining clip 14 thus has a box-like geometry (see also 2 ).

A retaining claw 19, 20 is bent at each crosspiece 17, 18 of the retaining clip 14. The outer retaining claw 20 is locked/snapped to the end face 21 of the crossbeam 2 at the other end 8 and the inner retaining claw 19 is locked/snapped to the crossbeam 22 of the recess 23 in the crossbeam 2, so that the retaining clip 14 is firmly but detachably connected to the drag lever 1. Fingers 26, 27 projecting orthogonally inwards from the retaining claws 19, 20 grip under the respective area of the crossbeam 2.

From the free upper ends 24 of the longitudinal webs 15, 16 of the retaining clip 14, 8 upright guide plates 13 protrude directly at the other end. These serve for the engagement of a tool "from above" for the final alignment of the rocker arm 1 on the cylinder head of the internal combustion engine, more precisely its fine alignment on the gas exchange valve. At the same time, another tool can grasp the rocker arm at one end 6, for example on its cap 7. A conical pin, for example, can be used as a tool. The rocker arm 1 can also be transported between the guide plates 13 by the engagement of a corresponding "clamping" tool from above.

List of reference numbers

1

Rocker arm

2

Crossbeam

3

Side wall

4

bottom

5

bolt

6

End

7

Calotte

8th

End

9

Interior wall section

10

Attachment

11

Top

12

Cam counterface, roller

13

Guide plates

14

Retaining clip

15

Longitudinal web

16

Longitudinal web

17

Crossbar

18

Crossbar

19

Retaining claw

20

Retaining claw

21

End forehead

22

Transverse forehead

23

Recess

24

Upper forehead

25

Imprinting

26

finger

27

finger

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was 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 accepts no liability for any errors or omissions.

Cited patent literature

• DE 19543657 A1 [0002]
• DE 102015200102 A1 [0003]
• DE 19811658 B4 [0004]

Claims (5)

Rocker arm (1) for a valve train of an internal combustion engine, with two side walls (3) connected by a crossbar (2), which rocker arm (1) has an inverted U-profile in cross-section, wherein on an underside (4) of the crossbar (2) bordered by the side walls (3) there is at one end (6) a calotte (7) for pivotably mounting the rocker arm (1) on a support element and at another end (8) a support (10) for a valve stem which is laterally delimited only by inner wall pieces (9) of the side walls (3), and wherein the rocker arm (1) has at an upper side (11) of the crossbar (2) a cam counter-running surface (12) running between the ends (6, 8), characterized in that the rocker arm (1) has two guide plates (13) running in its longitudinal direction for engagement of an alignment and/or o. holding tool during its assembly on the internal combustion engine, which guide plates (13) are located at the other end (8) and protrude freely from the top side (11) of the crossbeam (2). Rocker arm after Claim 1 , characterized in that the guide plates (13) are part of a retaining clip (14) joined to the rocker arm (1) on the upper side (11) of its cross beam (2). Rocker arm after Claim 2 , characterized in that the retaining clip (14) consists of sheet steel and has two longitudinal webs (15, 16) which are connected at the longitudinal end by a transverse web (17, 18), wherein a retaining claw (19, 20) is bent at each transverse web (17, 18), of which one retaining claw (19) is locked to an end face (21) of the crossbar (2) at the other end (8) and the other retaining claw (20) is locked to a transverse face (22) of a recess (23) in the crossbar (2), and wherein the guide plates (13) protrude from free upper faces (24) of the longitudinal webs (15, 16). Rocker arm according to one of the preceding claims, characterized in that the rocker arm (1) either consists of sheet steel or is an extruded part. Rocker arm according to one of the preceding claims, characterized in that a roller is provided as the cam counter-running surface (12), which projects through a recess (23) in the crossbeam (2) and runs on a bolt (5) received in the side walls (3).

Images