Intermediate lever made of sheet metal for a stroke-variable valve drive of an internal combustion engine

Abstract

The invention proposes an intermediate lever made of sheet metal for a stroke-variable valve drive of an internal combustion engine. Side walls run from a bracket-like lower part connecting the side walls in a transverse arc and end in an open upper part, in which the side walls have a support roller, the side walls carrying a roller in their longitudinal center region, the lower part extending out in each case on both sides with a foot in the pivoting direction of the intermediate lever, there being a slide rail on the outside for contact with a valve opener, one foot having two fork-like open arms, a tongue projecting upright in front of the outer end of the side wall in the direction of the upper part from the base of the arms as an abutment for a cam return spring, the tongue being so long that it projects upright at least sectionally in the longitudinal center region of the side wall in overlapping relation to the contour of the roller (7) to the extent that a step section exists between the transition regions of the arms of one foot to the side wall, the longitudinal sides of the tongue being secured via a clamping part between the transition regions.

Description

TECHNICAL FIELD

[0001] The invention relates to an intermediate lever made of sheet metal for a stroke-variable valve drive of an internal combustion engine, which has two side walls which are connected by a bracket-like lower part which is arched transversely and which ends in an open upper part, the side walls having in the upper part either at least one support roller for the cam disk abutment running or having a swing surface for bearing on a shaft which is fixed relative to the cylinder head, wherein the side walls carry in their longitudinal central region rollers which serve for at least indirect abutment running of the cam, wherein the lower part extends on both sides respectively with a foot in the pivoting direction of the intermediate lever and has on the outside a sliding slot track for contact with the valve opener, and wherein one foot has two fork-like open arms which project upright in front of the outer end of the side wall in the direction of the upper part with a tongue which serves as an abutment for a cam return spring. BACKGROUND

[0002] The overall design of the sheet metal intermediate lever is described in EP 1 573 174 B1, which is provided for a fully variable valve drive for throttleless load control.

[0003] DE 10 2011 003 898 A1 shows a further intermediate lever, in which from Figure 2 A bent short tongue marked with "21" is known, which does not or hardly projects beyond the bracket-like base body. The tongue serves for abutment on the leg of a torsion spring of a cam return spring which extends along the intermediate lever on the end side.

[0004] From CN 206889038 U it is also known that an intermediate lever is provided, which here serves for the swingable bearing on a shaft via its upper part. SUMMARY

[0005] The task of the invention is to provide an intermediate lever whose tongue is suitable for a comparatively large displacement of the leg of a cam return spring or for a comparatively "high" application of force of the cam return spring and which is at the same time particularly robust.

[0006] According to the invention, the task is solved in that the tongue is so long that it projects upright at least section-wise beyond the contour of the roller up to the longitudinal central region of the side wall, wherein the transition region of the arms from one foot to the side wall is present as a step section, the longitudinal sides of the tongue being fixed between these transition regions via a clamping part in such a way that the longitudinal sides are only grasped with a partial region of their thickness.

[0007] There are intermediate levers whose tongues are significantly longer than those implemented to date. The intermediate lever is therefore very suitable for laterally bracing the end legs of a cam return spring present as a torsion spring, where of course also longitudinal abutment or other spring types for return are considered.

[0008] By the lateral transition region also being designed in a stepped shape according to the application, on the one hand the tongue is laterally abutted and reinforced in its lower section. On the other hand the tongue is additionally held / clamped in this lower section, so that its lever arm is shortened when the spring is loaded. This brings advantages in the case of a hardening process at the end of the manufacturing process of the intermediate lever, since less deformation, etc. can be expected.

[0009] For the fixing of the tongue it is envisaged to apply a pressing process laterally to the transition region, for example in a die. In other words, an embossing, a snap connection or a crimping can also be carried out, as can a riveting. In some cases a welding can also be used.

[0010] According to the application the tongue protrudes slightly from its "rim" at the transition region. Thus, spring contact can almost occur over the entire length of the tongue, without lateral wall contact occurring when the spring end leg is bent.

[0011] The novel intermediate lever has a support roller / support roller set in its upper part for abutment running on a cam track. Alternatively, it can also have two holes in this section, via which the intermediate lever can be supported pivotably on a shaft of a cylinder head.

[0012] Further dependent claims relate to suitable design variants of the side wall region of the intermediate lever. It is proposed that the intermediate lever has a minimum clear width in its foot region, is correspondingly widened in its longitudinal central region and has a maximum clear width in the section of the upper part.

[0013] Due to the box-like geometry of the further foot proposed in the embodiment (U-shaped cross section), a further contribution to a particularly robust intermediate lever is made.

[0014] As is also proposed in the design variant, the two arms of the tongue flanks of one foot should only have a bar-like shaping. This saves material and provides construction space.

[0015] A lever-like cam follower, such as a rocker or a swing lever, is particularly suitable as a valve opener loaded by the intermediate lever. However, abutment running on a roller of a tappet is also conceivable and provided. BRIEF DESCRIPTION OF DRAWINGS

[0016] · Figure 1 A spatial side view of the intermediate lever is shown, and

[0017] Figure 2 "from behind" shows a side view of an intermediate lever according to Figure 1 the application. DETAILED DESCRIPTION

[0018] An intermediate lever 1 for a stroke-variable valve drive of an internal combustion engine is shown in the drawings. The base body of the intermediate lever 1 is composed of a steel sheet. The intermediate lever has two side walls 2. These side walls emerge integrally from a foot-like lower part 3, and form on the free outer side of the side walls a slide track 10 for contact with a rocker lever.

[0019] The side walls 2 end in an open upper part 4, and carry in this section a support roller set 5 for abutment running on a cam track. At the same time, the side walls 2 are reinforced at the upper part 4 by a transverse arch 20. The side walls 2 carry in their longitudinal central region 6 a roller 7 for abutment running on a cam, which is arranged "left" according to Figure 1 the application.

[0020] From the lower part 3, the side walls 2 are stepped in width. The lower part 3 has here the smallest net width. Correspondingly, the longitudinal central region 6 is expanded. The upper part 4 has the greatest net width.

[0021] The above-mentioned lower part 3 expands the intermediate lever 1 on both sides, seen in the pivoting direction, by a foot 8, 9, respectively. Here, one foot 8 drawn to the left in the drawings has two fork-like open arms 11. From the base of these arms 11, a tongue 13 projects upright in front of the outer end 14 of the side wall 2 in the direction of the upper part 4. The relatively long tongue 13 is used to abut against the transverse leg of a torsion spring as a cam return spring for the intermediate lever 1. The tongue 13 projects, as can best be seen from Figure 1 the drawings, into the longitudinal central region 6 of the side wall 2 with the roller 7. Figure 1 As can be seen from the two drawings, the tongue 13 is additionally clamped in its lower section. For this purpose, the transition area 15 from the arm 11 of one foot 8 to the side wall 2 is configured as a stepped section, so that this edge area is not "grooved". The clamping / fixing takes place by means of a pressing tool, which exerts a force on the transition area 15 from the outside, so that the longitudinal side 16 of the tongue 13 is "clamped". It can be clearly seen from

[0022] the drawings that the longitudinal side 16 of the tongue 13 is not grasped over its entire thickness. Figure 2 In order to additionally reinforce the structure, the intermediate lever 1 has a box-like geometry (U-shaped cross section) on the side of the other foot 9. Here, the side face 18 of the other foot 9 rises wedge-like from its outer end 19. Here, as can best be seen from

[0023] the drawings, the side face 18 of the other foot 9 is configured as a stepped section, so that this edge area is not "grooved". The clamping / fixing takes place by means of a pressing tool, which exerts a force on the transition area 15 from the outside, so that the longitudinal side 16 of the tongue 13 is "clamped". It can be clearly seen from Figure 1 ​As can be seen, the two arms 11 of the opposite foot 8 have a largely rod-like, flattened course.

[0024] List of reference signs

[0025] 1) middle bar

[0026] 2) side wall

[0027] 3) lower part

[0028] 4) upper part

[0029] 5) support roller

[0030] 6) longitudinal central region

[0031] 7) roller

[0032] 8) one foot

[0033] 9) the other foot

[0034] 10) sliding slot track

[0035] 11) arm

[0036] 12) base

[0037] 13) tongue

[0038] 14) outer end

[0039] 15) transition region

[0040] 16) longitudinal side

[0041] 17) clamping portion

[0042] 18) side face

[0043] 19) outer end

[0044] 20) transverse bow

Claims

1. An intermediate lever (1) made of sheet metal for a stroke-variable valve drive of an internal combustion engine, having two side walls (2) which run from a lower part (3) in the form of a strut which connects the side walls in an arcuate manner transversely and end in an open upper part (4), the side walls (2) in the upper part (4) either having at least one support roller (5) for cam disk abutment running or having a swing surface for bearing on a shaft fixed with respect to the cylinder head, wherein The side wall (2) carries in its longitudinal center region (6) a roller (7) which serves for at least indirect abutment of the cam in operation, wherein the lower part (3) extends the intermediate lever (1) on both sides with a foot (8, 9) in the pivoting direction of the intermediate lever and has on the outside a slide track (10) for contact with a valve opener, and wherein one foot (8) has two forked open arms (11) which rise up from the base (12) of the arms in front of the outer end (14) of the side wall (2) in the direction of the upper part (4) with a tongue (13) which serves as an abutment for a cam return spring, characterized in that the tongue (13) has a length which at least section-wise overlaps the contour of the roller (7) rising up into the longitudinal center region (6) of the side wall (2), wherein the transition area (15) from the arms (11) of one foot (8) to the side wall (2) is present as a step section, the longitudinal sides (16) of the tongue (13) being fixed between the transition areas via a clamping (17) in such a way that the longitudinal sides (16) are only grasped with a partial area of their thickness.

2. The intermediate pole according to claim 1, characterized in that The clamping (17) is present by the transition area (15) at the longitudinal sides (16) of the tongue (13) via a press, a snap connection or a press fit applied on the outside.

3. The intermediate pole according to claim 1, characterized in that The side wall (2) has in the lower part (3) a course which retracts the width between the two side walls relative to the longitudinal center region (6).

4. An intermediate rod according to claim 1 or 3, characterized in that The side wall (2) has in its longitudinal center region (6) a course which retracts the width between the two side walls relative to the upper part (4).

5. The intermediate pole according to claim 1, characterized in that, The intermediate lever (1) has on the side of the other foot (9) a box-like geometry, wherein the flank (18) of this foot (9) transitions into the side wall (2) in a wedge-like rising manner from its outer end (19).

6. The intermediate pole according to claim 1, characterized in that The two arms (11) of the one foot (8) have a largely rod-like flat course.

7. Intermediate rod according to any of the preceding claims 1-3, 5, 6, characterized in that The tongue (13) is designed for transverse abutment of an end leg of a cam return spring which is configured as a torsion spring.

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