Intermediate lever for a variable-stroke valve train of an internal combustion engine

Abstract

Intermediate lever (1) for a variable-stroke valve train of an internal combustion engine, with two side walls (2) which emerge in one piece from a base-like lower part (3) which connects them in the manner of a crossbar and which end in an upper part (4) like a finger, which side walls (2) in the upper part (4) either have at least one support roller (5) between them or each have a bearing eye, wherein the intermediate lever (1) can be acted upon by a cam on its front side (6) and the side walls (2) have a cam counter-running surface (7) for this purpose in their longitudinal center region, wherein the lower part (3) supports the intermediate lever (1) via its front side and / or upper side.widened outwards at the rear side (6, 9) by means of a foot piece (10, 11) and has on the outside a continuously closed guide track (12) for contact with a valve actuator, wherein longitudinal ends (13) of the side walls (2) on the rear side (9) in the lower part (3) are bridged by a tab (14) which is provided for the contact of a transversely running end leg of a cam return spring on the upper end (15) thereof, characterized in that the tab (14) describes an H-like profile in plan view, wherein the central web (8) thereof lies longitudinally centrally between the side walls (2) and two support feet (18) extend from each side end (16) of the central web (8), which support feet are arranged at each of its longitudinal ends (17), which respective support foot (18) runs in a claw-like manner onto the longitudinal end (13) of the respective side wall (2).

Description

[0001] The invention relates to an intermediate lever for a variable-stroke valve train of an internal combustion engine, with two side walls which emerge in one piece from a base-like lower part which connects them in the manner of a crossbar and which run out like fingers into an upper part, which side walls in the upper part have either at least one support roller between them or each have a bearing eye, wherein the intermediate lever can be acted upon by a cam on its front side and the side walls for this purpose have a cam counter-running surface in their longitudinal center region, wherein the lower part supports the intermediate lever via its front and / or upper side.Widened at the rear with a foot piece and has a continuously closed guide track on the outside for contact with a valve actuator, wherein the longitudinal ends of the side walls on the rear at the lower part are bridged by a tab which is provided for the attachment of a transversely running end leg of a cam return spring to its upper end.

[0002] DE 202024 104 558 U1 shows a sheet metal intermediate lever whose tab rests on the side walls via two feet located transversely opposite each other directly at the lower part. Only one of the two feet is integrally connected to its respective side wall. A central section of the tab protrudes freely lengthwise over the cam contact surface, which is designed as a roller.

[0003] The task is to create an intermediate lever whose tab is improved in terms of absorbing the force of the torsion spring.

[0004] According to the invention, this object is achieved in that the tab describes an H-like profile in plan view, wherein its central web lies longitudinally centrally between the side walls and two support feet extend from each side end of the central web, which are arranged at each of its longitudinal ends, each support foot being bent like a claw and running onto the longitudinal end of the respective side wall.

[0005] This four-point support of the tab on the side walls allows for excellent absorption of the restoring forces introduced by the end leg of the torsion spring without causing undesirable deformation of the tab during operation. At the same time, the inventive design is easy to implement in terms of manufacturing technology.

[0006] The tab can, for example, be connected in one piece to the respective side wall via just one support foot and, in the case of a sheet metal construction of the intermediate lever, this tab is punched out of the plate, bent with its remaining support feet and simply placed on the side walls or welded to them.

[0007] It is clear here that the intermediate lever can also be an MIM, extrusion, forging or casting component and / or that 2 - 4 support feet can also emerge from the side walls in one piece.

[0008] According to a specific embodiment of the invention, the cam counter-running surface of the intermediate lever can be a roller bearing mounted on a roller, so that little friction can be expected during contact. Alternatively, a sliding surface can be used, for example, a roof-like bridge over the side walls on the rear side of the intermediate lever.

[0009] It is also proposed to design the tab so long that it extends at least partially beyond the cam counter-running surface toward the upper part. This provides a comparatively long "track" for the end leg of the torsion spring as a cam return spring, facilitating its assembly. The track can optionally be coated with a wear-resistant layer.

[0010] A further development of the invention provides for the tab to have a concave shape, viewed in the longitudinal direction of the lever. This design can, under certain circumstances, prevent the end leg of the torsion spring from popping off during operation. Its convex shape may increase the rigidity of the structure.

[0011] About the drawing: • The only figure shows a three-dimensional view of the intermediate lever.

[0012] Shown is an intermediate lever 1 for a variable-stroke valve train of an internal combustion engine. The intermediate lever 1 is made of sheet steel and has two spaced-apart side walls 2. These extend in one piece from a base-like lower part 3 connecting them with a crossbar and extend finger-like into an upper part 4, where they are connected via a stiffening crossbar 19. Installed between the side walls 2 in the upper part 4 is a set of support rollers 5 for counter-rotating a cam disc thereon and for engaging the set against a guide slot.

[0013] Approximately in a longitudinal center region, the intermediate lever 1 has a roller bearing mounted roller as a cam counter-running surface 7 between its side walls 2. When the intermediate lever 1 is installed, this is acted upon by a cam at a front side 6 of the intermediate lever 1.

[0014] It can also be seen that the intermediate lever 1 on the lower part 3 is extended beyond its front and rear sides 6, 9 by means of a foot piece 10, 11 in the lever pivoting direction, wherein the lower part 3 has a continuously closed guide track 12 on the outside for contact with a valve actuator such as a rocker arm.

[0015] Longitudinal ends 13 of the side walls 2 are bridged at the rear 9 of the lower part 3, shown here at the top, by a tab 14 with an H-like profile. The tab 14 serves to attach a transversely running end leg of a cam return spring in the form of a torsion spring to its upper end 15. If necessary, a longitudinal or oblique run of this end leg or a run of a different type of spring, such as a helical compression spring or leaf spring, is also possible. A central web 8 of the tab 14 lies longitudinally centrally between the side walls 2. It can be seen that from each side end 16 and at each longitudinal end 17 of the central web 8, a claw-like support foot 18 extends, which runs in a bent manner onto the longitudinal end 13 of the respective side wall 2. In this case, only the front support foot 18, which can be seen in the drawing at the longitudinal end 17 at the cam counter-running surface 7, is formed monolithically with the respective side wall 2.The remaining support feet 18 rest only on the longitudinal ends 13 of the side walls 2. As can be seen, the tab 14 has a bulged shape in the longitudinal direction of the lever. List of reference numbers 1 intermediate lever 2 side wall 3 Lower part 4 Top 5 support roller 6 Front 7 Cam counterface 8 Central bridge 9 Back 10 foot piece 11 Foot piece 12 slide track 13 Longitudinal forehead 14 tab 15 Upper forehead 16 Side forehead 17 Longitudinal end 18 Support foot 19 crossbars QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This 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

[0000] DE 202024 104 558 U1

[0002]

Claims

[1] Intermediate lever (1) for a variable-stroke valve train of an internal combustion engine, with two side walls (2) which emerge in one piece from a base-like lower part (3) which connects them in the manner of a crossbar and which end in an upper part (4) like a finger, which side walls (2) in the upper part (4) either have at least one support roller (5) between them or each have a bearing eye, wherein the intermediate lever (1) can be acted upon by a cam on its front side (6) and the side walls (2) have a cam counter-running surface (7) for this purpose in their longitudinal center region, wherein the lower part (3) supports the intermediate lever (1) via its front and / or upper side.Rear side (6, 9) is widened out with a foot piece (10, 11) and has on the outside a continuously closed guide track (12) for contact with a valve actuator, wherein longitudinal ends (13) of the side walls (2) on the rear side (9) in the lower part (3) are bridged by a tab (14) which is provided for the application of a transversely running end leg of a cam return spring to the upper end (15) thereof, . characterized by that the tab (14) describes an H-like profile in plan view, wherein its central web (8) lies longitudinally centrally between the side walls (2) and two support feet (18) extend from each side end (16) of the central web (8), which are arranged at each of its longitudinal ends (17), each support foot (18) being bent like a claw and running onto the longitudinal end (13) of the respective side wall (2). [2] Intermediate lever according to claim 1, characterized bythat the tab (14) either a) via exactly one support foot (18) or b) via two support feet (18) lying opposite one another at the same longitudinal end (17) or at the same side end (16) or c) via all support feet (18) monolithically emerges from the side wall (2) / the side walls (2). [3] Intermediate lever according to claim 2, characterized by that in case a) or b) the support feet (18) which are not connected in one piece either simply stand on the longitudinal ends (13) of the side walls (2) without any further joining connection or are welded to them. [4] Intermediate lever according to one of claims 1 to 3, characterized by that the intermediate lever (1) is made of sheet steel. [5] Intermediate lever according to claim 1, characterized by that the cam counter-running surface (7) is a roller bearing mounted roller. [6] Intermediate lever according to claim 1 or 5, characterized bythat the tab (14) covers the cam counter-running surface (7) at least in sections, viewed in the longitudinal direction of the intermediate lever (1) towards its upper part (4). [7] Intermediate lever according to claim 1, characterized by that the tab (14) has a concave shape at least in its contact area for the end leg of the cam return spring on its upper end face (15) when viewed in the longitudinal direction.

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