Intermediate rocker arm for a variable-lift cam drive mechanism of an internal combustion engine

Abstract

The utility model provides a kind of intermediate rocker for internal combustion engine variable lift valve drive mechanism, with two side walls, respectively from the lower part of pedestal shape integral extension and terminate in the upper part of open type, side wall is equipped with at least one support roller for cam disc reverse operation in upper part, the longitudinal middle area of two side walls is supported with roller, cam thus can act on the front side of intermediate rocker, lower part is widened by the support leg that protrudes from the front side and / or rear side of intermediate rocker, lower part outside has continuous closed chute track, intermediate rocker is equipped with integrally connected tongue in the rear side of lower part, its outside is used to support cam return spring, tongue extends from the longitudinal end face of one side wall, and extends to the other side wall transversely, and the free end of tongue is connected with the contact area on the longitudinal end face of the other side wall.

Description

Technical Field

[0001] This utility model relates to an intermediate rocker arm for a variable lift valve drive mechanism of an internal combustion engine, which is made of sheet metal. The intermediate rocker arm has two sidewalls, each extending integrally from a base-like lower part and terminating in an open upper part. The upper sidewall is provided with at least one support roller for the reverse movement of the cam disc or a pivot surface for support on a cylinder head fixed shaft, wherein the cam can thus act on the front side of the intermediate rocker arm. The sidewall is supported by rollers or sliding surfaces in its longitudinal middle region. The lower part is widened by a foot protruding from the front and / or rear (or at least one) side of the intermediate rocker arm and has a continuously closed slide rail on the outer side for contact with a valve opener. The intermediate rocker arm is inherently provided with an integrally connected tongue on its rear lower part, the outer side of which is used to support a cam return spring. Background Technology

[0002] DE 10 2016 223 087 A1 discloses an intermediate rocker arm made of sheet metal. The tongue of the intermediate rocker arm, which supports the cam return spring, is located inside the lower foot and extends integrally from the upper surface of the foot wall, extending in a belt shape to the upper surface of the opposite foot wall.

[0003] DE 10 2021 120 356 A1 discloses an intermediate rocker arm whose tongue is formed by cutting and bending from the slide rail of the support leg. Utility Model Content

[0004] The technical problem to be solved by this invention is to provide a middle rocker arm with an optimized tongue.

[0005] The aforementioned technical problem is solved by the intermediate rocker arm designed according to this utility model. The intermediate rocker arm is made of sheet metal and is used in a variable lift valve drive mechanism for an internal combustion engine. The intermediate rocker arm has two sidewalls, each extending integrally from a base-like lower portion and terminating in an open upper portion. The lower portion connects the two sidewalls via a crossbridge. Each sidewall has at least one support roller on the upper portion for the reverse movement of the cam disc or a pivoting surface for support on a shaft fixed relative to the cylinder head. The intermediate rocker arm can be subjected to force by a cam on its front side, and the two sidewalls... A roller or sliding surface is supported in the longitudinal middle region of each side wall, wherein the lower part is widened by a support foot protruding from the front and / or rear side of the intermediate rocker arm, and has a continuously closed slide rail on the outer side of the lower part that directly contacts the rocker arm as a valve opener, wherein the intermediate rocker arm has an integrally connected tongue on its rear side on the lower part, the outer side of the tongue being used to support the cam return spring, the tongue extending from the longitudinal end face of one side wall and extending in a transverse bridge shape to the other side wall, wherein the free end of the tongue is connected to the contact area of ​​the longitudinal end face of the other side wall.

[0006] The tongue is integrally formed during the stamping of the intermediate rocker arm sheet metal, and is an extension of the longitudinal end face of one of the side walls to be bent in the sheet metal. Through the bridging structure design of the tongue, the force transmission of the cam return spring is made as symmetrical as possible. The cam return spring is preferably at least one torsion spring, and is hinged during assembly via a laterally positioned end arm. This process makes the tongue easy to implement and it is no longer part of the slide rail, therefore it does not affect the slide rail.

[0007] Regarding the connection between the free end of the tongue and the other sidewall, a welding connection such as spot welding can be considered. However, a weld extending longitudinally through the middle rocker arm can also be used for connection.

[0008] In addition to the above-described solutions, a form-fitting-plug connection can also be achieved between the free end of the tongue and the other sidewall. For example, one component may have a bag-shaped mounting groove, and the other component may be fitted into the mounting groove with a form-fitting protrusion (e.g., by light pressure fitting). More preferably, in this connection, the longitudinal ends of the mounting groove and the protrusion may be wedge-shaped bevels.

[0009] If necessary, interlocking or pressing connections can also be used in the connection area.

[0010] The tongue can have an inwardly curved arcuate segment on each sidewall, as described in the dependent claims. Between these two arcuate segments are longitudinal finger-like structures integrally connected to them and extending toward the cam contact roller. The outer side of the longitudinal finger-like structures serves to support the cam return spring. Such a tongue experiences lower stress and is easier to manufacture. The longitudinal finger-like structures at least partially cover the roller.

[0011] In a further preferred embodiment of this invention, the tongue can be designed to be spherical or cylindrically arched when viewed laterally in the contact area with the cam return spring (the end arm of the torsion spring). This allows for low-friction and well-defined point or line contact. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the middle rocker arm; Figure 2 for Figure 1 The rear view of the middle rocker arm shown; Figure 3 A magnified view of the lower part of the middle rocker arm with legs; Figure 4 This is a front view of the middle rocker arm. Detailed Implementation

[0013] Figure 1 and Figure 2 An intermediate rocker arm 1, made of sheet metal, is shown for use in a variable lift valve actuation mechanism in an internal combustion engine. This valve actuation mechanism is known for BMW's "Valvetronic" technology.

[0014] The metal plate substrate of the intermediate rocker arm 1 is made of steel plate through a stamping and bending process, and includes two longitudinally extending sidewalls 2a and 2b, as shown below. Figure 1 As shown on the left, these two sidewalls extend integrally from the base-shaped lower part 3, which connects the two sidewalls in a cross-bridge manner. Sidewalls 2a and 2b extend to the forked-open upper part 4. In this upper structure, a support roller 5 that moves relative to the cam is arranged between the sidewalls 2a and 2b. This support roller 5 is a graded assembly.

[0015] like Figure 1 On the front side 6 shown below, in the longitudinal middle region 7 of the middle rocker arm 1, the side wall 2 supports a roller 8 that rolls against the camshaft or eccentric wheel. Figure 1 In the middle, below the roller 8 (i.e., in the front direction), the reinforcing bridge 29 bridges the side walls 2a and 2b. The reinforcing bridge is divided into two sections, which extend from the side walls 2a and 2b respectively and abut against each other at their ends.

[0016] like Figure 1As shown, the lower part 3 is widened by support feet 10 and 11 protruding from the front side 6 and the rear side 9, and has a continuously enclosed slide rail 12 on the outer side of the bottom 3 that directly contacts the rocker arm that serves as a valve opener.

[0017] It should be noted that, viewed longitudinally from the upper part 4, the middle rocker arm 1 has an integrally connected tongue 13 on its rear side 9 directly in front of the lower part 3, which is used to support the cam return spring. The outer side 14 of the tongue 13 provides lateral support for the end arm of the torsion spring, which serves as the cam return spring.

[0018] The above tongue 13 from Figure 1 rear and Figure 2 The longitudinal end face 27 of the lower side wall 2b extends integrally and belt-like to the other side wall 2a. The free end 15 of the tongue 13 is spot-welded to the longitudinal end face 17 of the other side wall 2a via the contact area 16 (see...). Figure 1 (18) of the welded connection.

[0019] As an alternative to the above-mentioned welded connections, such as Figure 3 As shown, the tongue 13 can also be connected to the contact area 16 of the other sidewall 2a via a form-fitting plug-in connection 19. In this case, a bag-shaped mounting groove 20 is provided on the longitudinal end face 17 of the corresponding sidewall 2a to accommodate a protrusion 21 on the free end 15 of the tongue 13 that is complementary in shape. If necessary, additional reinforcement can be provided here by welding. Meanwhile, as... Figure 3 As shown, the longitudinal end faces 22 and 23 of the mounting groove 20 on the side wall 2a and the longitudinal end face of the protrusion 21 on the tongue 13 are all machined into wedge-shaped bevels to ensure convenient insertion and mating.

[0020] like Figure 4 As shown, the tongue 13 has an arcuate profile along the transverse direction of the intermediate rocker arm 1, and includes two arcuate segments 25 and 24 extending upward from the side walls 2a and 2b. Between these two arcuate segments, a similarly arcuate longitudinal finger-like structure 26 extending upward towards the upper part 4 is formed, the outer side 14 of which is used to directly support the cam return spring (e.g., Figure 1-3 (As shown).

[0021] List of reference numerals 1. Middle rocker arm 2a sidewall 2b sidewall 3 lower part 4 upper part 5 support rollers 6 front side 7. Vertical intermediate area 8 rollers 9 rear side 10 legs 11 legs 12-slide rail 13 Tongue 14 outer side 15 end 16 contact areas 17 Longitudinal end face 18 Welded Connections 19 Shape-fitting - Plug-in Connection 20 mounting slots 21 protrusions 22 Longitudinal end face 23 Longitudinal end face 24 arc segments 25 arc segments 26 longitudinal finger structures 27 Longitudinal end face 28 end 29 Reinforced Bridge

Claims

1. An intermediate rocker arm (1) made of sheet metal for a variable lift valve drive mechanism of an internal combustion engine, the intermediate rocker arm (1) having two sidewalls (2a, 2b) extending integrally from a base-shaped lower portion (3) and terminating at an open upper portion (4), the lower portion (3) connecting the two sidewalls (2a, 2b) in a cross-bridge manner, the two sidewalls (2) having at least one support roller (5) on the upper portion (4) for reversible cam disc operation or a pivoting surface for support on a shaft fixed relative to the cylinder head, wherein, The intermediate rocker arm (1) can be subjected to force by a cam on its front side (6), and rollers (8) or sliding surfaces are supported in the longitudinal middle region (7) of the two side walls (2). The lower part (3) is widened by legs (10, 11) protruding from the front side (6) and / or rear side (9) of the intermediate rocker arm (1), and has a continuously closed slide rail (12) on the outer side of the lower part (3) that directly contacts the rocker arm as a valve opener. The intermediate rocker arm (1) has an integrally connected tongue (13) on its rear side (9) on the lower part (3), and the outer side (14) of the tongue (13) is used to support the cam return spring. The tongue (13) extends from the longitudinal end face (27) of one of the two side walls (2b) and extends across the other side wall (2a), and the free end (15) of the tongue (13) is connected to the contact area (16) on the longitudinal end face (17) of the other side wall (2a).

2. The intermediate rocker arm (1) according to claim 1, characterized in that, The connection between the tongue (13) and the contact area (16) of the other sidewall (2a) is a welded connection (18).

3. The intermediate rocker arm (1) according to claim 1, characterized in that, The connection between the tongue (13) and the contact area (16) of the other sidewall (2a) is a form-fit-plug connection (19), wherein the longitudinal end face (17) of the other sidewall (2a) has a mounting groove (20), and the free end (15) of the tongue (13) has a protrusion (21) that is complementary in shape to the mounting groove (20), and the protrusion (21) is installed in the mounting groove (20).

4. The intermediate rocker arm (1) according to claim 3, characterized in that, The longitudinal end faces (22, 23) of the mounting groove (20) of the other sidewall (2a) and the protrusion (21) of the tongue (13) both have wedge-shaped bevels.

5. The intermediate rocker arm (1) according to claim 1, characterized in that, The tongue (13) has arc-shaped segments (24, 25) in the area directly and integrally connected to the longitudinal end face (27) of one of the side walls (2b) and in the area abutting against the other side wall (2a). Between the arc-shaped segments (24, 25) there is a longitudinal finger structure (26) extending toward the upper part (4), and the outer side (14) of the longitudinal finger structure is used to support the cam return spring.

6. The intermediate rocker arm (1) according to claim 5, characterized in that, The longitudinal finger structure (26) at least partially covers the roller (8).

7. The intermediate rocker arm (1) according to claim 1 or 5, characterized in that, The tongue (13) is spherical or arched when viewed from the lateral direction of the intermediate rocker arm (1).

8. The intermediate rocker arm (1) according to claim 1, characterized in that, The tongue (13) is used to laterally support the end arm of the cam return spring, which is designed as a torsion spring.

9. The intermediate rocker arm (1) according to claim 1, characterized in that, The two sidewalls (2a, 2b) of the intermediate rocker arm (1) are connected on the front side (6) or the rear side (9) by a reinforcing bridge (29), which is located in front of the free end (28) of the upper part (4).

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