JP2003222005A - Rocker arm - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rocker arm, in which the strength around a mounting hole in an adjusting part is ensured by a simple work, and an offset amount is easily ensured, and which is manufactured compactly in the longitudinal direction, inexpensively in light weight, and in the smaller number of man-hours. <P>SOLUTION: A rocker arm 1 has an arm main-body 2 formed of a single sheet by press-work, and is formed of a pair of parallel side-walls 5, and a joint sheet wall 6. A hole 7 for rocking support is made nearly in the center in the longitudinal direction of both opposed side-walls 5. A supporting shaft for a roller 10 for engagement with the cam is attached to an end 1a of both opposing side-walls 5. The other end 1b of the joint sheet wall 6 constitutes a folded part 13 of a tip-end folded piece 12 extending integrally from the side edge. The folded part 13 is formed into an adjusting part 16 having a mounting hole 15 for mounting a valve action member 14 so as to be adjustable for come-in/out movement. The rocker arm 1 may be of an end pivot-type, and in this case, a pivot member is attached to the adjusting part 16. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rocker arm of a center pivot type or an end pivot type which is mounted on an internal combustion engine and is rockably driven by a cam to open and close a valve of a cylinder head, and more particularly to a metal plate such as a steel plate. A rocker arm made of processed material.

[0002]

2. Description of the Related Art Conventionally, since a rocker arm incorporated in a valve train of an internal combustion engine is formed by casting, it is heavy in weight, requires a large number of processing steps, and has a high cost. There is much room for improvement. On the other hand, a rocker arm made of a sheet metal, which is formed by sheet metal pressing from a relatively thin sheet material, is being widely used because of its light weight, small number of processing steps, and low cost. Rocker arms are roughly classified into a center pivot type that swingably supports in the center of the arm body and an end pivot type that supports by attaching pivot parts to the end of the arm body. In the above, the above-mentioned sheet metal rocker arm is adopted.

In the center pivot type, a valve action member is attached to a screw hole of an adjusting portion formed in an arm body so as to be adjustable in and out, and adjustment is performed between a cam, a valve and a rocker arm. In the end pivot type, a pivot member is attached to a screw hole of an adjusting portion formed in an arm body so that the pivot member can be moved in and out, and adjustment is performed between a cam, a valve, and a rocker arm. Both types of rocker arms differ depending on whether the part to be mounted is a valve action member or a pivot part, but both have an adjusting part, and when using a relatively thin sheet metal, mounting the adjusting part It is difficult to secure the depth of the hole and there is a problem in securing the strength around the mounting hole.

For example, FIG. 10 shows an example of a conventional center pivot type (Japanese Patent Laid-Open No. 2001-41011). In the rocker arm 51 of this example, an arm main body 52 pressed from a single plate material has an inverted U-shape composed of a pair of parallel opposing side walls 53 and a connecting plate wall 54 connecting the upper edges of these opposing side walls 53. It has a cross-sectional shape. A mounting hole 55 with a female screw is provided at an end of the connecting plate wall 54 which serves as an adjusting part so that a valve acting member (not shown) can be adjusted in and out, and the mounting hole 55 is formed with a cylindrical bulging portion 56. Is reinforced so as to firmly hold the valve action member. Also, the rocker arm 51
If the offset structure is such that the centers of the adjusting portion and the roller supporting portion are displaced in the axial direction, the cylindrical bulging portion 56 interferes with the opposing side wall 53 as it is, so that the opening window 57 is offset from the offset side so that it does not interfere. Are provided on the opposing side wall 53.

In the conventional example shown in the figure, a cylindrical bulge portion 56 is provided in the mounting hole 55 of the adjusting portion of the connecting plate wall 54 to secure the depth of the mounting hole 55. Due to the processing, it takes time to form the mounting hole 55. Further, in the case of the offset structure, the opening window 57 is provided so that the cylindrical bulging portion 56 does not interfere, but the escape amount by the opening window 57 has a limit to the offset amount.

FIG. 11 shows a conventional example of an end pivot type, which is shown in Japanese Patent Laid-Open No. 2001-132414.
In the rocker arm 81 of this example, a tip overlapping piece 83 extending in the arm length direction is provided at one end of an arm body 82 having an inverted U-shaped cross section, and an adjusting portion having an overlapping structure is formed by folding back the tip overlapping piece 83. There is. A mounting hole 85 is provided in the adjusting portion of this overlapping structure, and a pivot member (not shown) is mounted so as to be adjustable in and out. In the case of this example, since the adjusting portion has an overlapping structure, it is possible to secure the strength around the mounting hole 85. However, in order to fold back the tip overlapping piece 83 to form the mounting hole 85, as shown in FIG.
It is necessary to form the distance L from the mounting hole 85 to the folded edge to be somewhat long. That is, since the tip stacking piece 83 is bent into a folded state, the tip stacking piece 83 and the connecting plate wall 84 are deteriorated in the material in the vicinity of the folded edge, which is not suitable as a place for forming the mounting hole 85. In particular,
If the mounting hole 85 is a screw hole, a problem may occur. Therefore, it is necessary to take a margin dimension in consideration of this material deterioration and the like. As described above, the tip portion of the arm main body 82 is lengthened due to the above-mentioned allowance, so that the overall length dimension is increased, which hinders the compactness of the rocker arm 81. When the adjusting portion having the overlapping structure in the tip overlapping piece 83 is applied to the example of the center pivot type shown in FIG. 9, the same problem of length dimension as described above occurs.

FIG. 12 shows a proposal example of a center pivot type shown in Japanese Patent Laid-Open No. 10-299430. The rocker arm 61 is bent at the center in the longitudinal direction of the strip-shaped long plate as a fulcrum, so that the two opposite side walls 63 and 64 are folded in two at one end. This bent end 61b is
It is an adjusting part for attaching a valve action member (not shown) so that it can be adjusted in and out. In the case of this conventional example, the mounting hole 75 of the adjusting portion can be deeply formed, but since the arm body is formed by only the pair of opposing side walls 63, 64, means for regulating the width dimension between the pair of opposing side walls 63, 64. Is required. The pair of opposed side walls 63 and 64 are reinforced by providing a cylindrical bulging portion 70 around the swing fulcrum hole 69 so that strength can be ensured even if a thin metal plate is used. However, it takes time to process the cylindrical bulging portion 70.

The object of the present invention is to make it possible to secure the strength around the mounting hole of the adjusting portion by simple processing, to make it lightweight, to reduce the number of processing steps, to reduce the cost, and to make it compact in the length direction. Is to provide. Another object of the present invention is to change the width of the arm body without changing the width.
The purpose is to change only the width dimension of the adjusting portion so that the offset amount can be set arbitrarily. Still another object of the present invention is to ensure the strength around the swinging fulcrum portion of the opposing side wall by simple processing.

[0009]

A first rocker arm and a second rocker arm according to the present invention are a rocker arm that is rockably driven by a cam to operate a valve of an internal combustion engine. It has an arm body which is press-formed from a single plate material and is composed of a connecting plate wall that connects opposing side walls. Among them, the rocker arm of the first invention is applied to the center pivot type and has the following configuration. The arm main body has a swing fulcrum portion in the middle in the longitudinal direction, a roller that is in rolling contact with the cam is attached to one end, and the other end serves as an adjust portion having the following configuration. That is, the portion of the connecting plate wall at the other end of the arm body is an overlapping portion formed by folding the tip overlapping piece integrally extending from the side edge of the connecting plate wall, and this overlapping portion allows the valve action member to move in and out. A mounting hole to be mounted is formed so as to penetrate therethrough to form an adjusting portion. With this configuration, since the adjusting portion is an overlapping portion in which the tip overlapping piece is folded on the connecting plate wall, the depth of the mounting hole penetrating the adjusting portion can be ensured, and the periphery of the mounting hole of the adjusting portion can be secured. The strength of can be secured. In this case, since it suffices to provide the tip overlapping piece and fold it, the processing for reinforcement is easy. In addition, since the adjusting part of this overlapping structure is such that the tip overlapping piece extends from the side edge of the connecting plate wall, the margin dimension required to avoid the altered part near the bending edge is taken in the width direction of the arm body. Will be done. Therefore, the total length of the arm body does not become long due to the folding. In the width direction of the arm body, there is a margin with respect to the inner diameter of the mounting hole in order to secure the width dimension of the roller to be brought into rolling contact with the cam, and it is not necessary to particularly widen the width of the arm body. Further, since this rocker arm is formed by pressing one plate material, it is lightweight, has a small number of processing steps, and can be manufactured at low cost.

The mounting holes may be offset from the center of the connecting plate wall in the width direction. When the offset structure is thus biased, the offset amount can be easily ensured because there is no attached portion such as the conventional cylindrical bulging portion around the mounting hole.

The width of the overlapping portion in the width direction of the connecting plate wall may be wider than that of the connecting plate wall. It is not necessary to widen the width of the overlapping part that will be the adjusting part from the margin of folding back, but when the width is widened in this way, the adjusting part and the roller support can be supported without changing the width of the general part of the arm body. It is possible to set the offset amount with respect to the section without limitation. Therefore, it is possible to obtain a large offset amount without significantly increasing the weight of the rocker arm.

The rocker arm of the second invention of the present invention is applied to an end pivot type,
It has the following configuration. This rocker arm has an arm body that is press-formed from a single plate material that is composed of a pair of opposing side walls and a connecting plate wall that connects the opposing side walls. The arm body is transferred to the cam in the middle in the longitudinal direction. A roller in contact is attached, a valve action portion that acts on the valve is formed at one end, and the portion of the connecting plate wall at the other end is
A tip overlapping part that extends integrally from the side edge of the connecting plate wall becomes a folded overlapping part, and this overlapping part is an adjusting part formed by penetrating a mounting hole through which a pivot part can be adjusted in and out. Is. In the case of this configuration, the member attached to the adjusting portion is a pivot part, which is different from the first invention, but the same effects as the first invention are obtained as follows. In other words, since the adjusting part is an overlapping part in which the tip stacking piece is folded over the connecting plate wall, the depth of the mounting hole penetrating the adjusting part can be secured, and the strength around the mounting hole of the adjusting part can be secured. Can be done. In this case, since it suffices to provide the tip overlapping piece and fold it, the processing for reinforcement is easy. Further, in the adjusting portion of this overlapping structure, since the tip overlapping piece extends from the side edge of the connecting plate wall,
The extra dimension required to avoid the altered portion near the bending edge is taken in the width direction of the arm body. Therefore, the total length of the arm body does not become long due to the folding. In the width direction of the arm body, there is a margin with respect to the inner diameter of the mounting hole in order to secure the width dimension of the roller to be brought into rolling contact with the cam, and it is not necessary to particularly widen the width of the arm body. Further, since this rocker arm is formed by pressing one plate material, it is lightweight, has a small number of processing steps, and can be manufactured at low cost.

In either of the first and second aspects of the present invention, a plurality of the tip overlapping pieces may be provided and overlapped with each other, and the overlapping portion may have an overlapping structure of three or more layers. Thereby, the thickness of the overlapping portion can be increased, and the strength of the overlapping portion serving as the adjusting portion is further improved. Further, the overlapping surfaces of the tip overlapping piece with the connecting plate wall may be joined to each other, or the tip of the tip overlapping piece may be fitted into an engagement opening provided in the opposing side wall.
This also improves the strength of the overlapping portion that serves as the adjusting portion.

The mounting hole provided in the adjusting portion may be a screw hole. In the case of using screw holes, the peripheral strength is more necessary to secure the strength of the thread groove, and it is necessary to take a larger margin from the bending edge. Since it extends from the edge, there is no problem of dimensional increase such as the length of the arm body.

Furthermore, at least a part of both or one of the opposite side walls of the arm body may have an overlapping structure in which a part of the plate material is folded. In this way, when at least a part of the opposing side walls have an overlapping structure, a portion requiring strength can be selectively reinforced, and strength can be ensured even if a thin plate material is used. In particular, in the case of the first invention, that is, the center pivot type, by forming an overlapping structure in which a part of the plate material is folded over at least in the vicinity of the swing fulcrum portion on the opposing side wall, the swing fulcrum required to have strength. The strength in the vicinity of the portion can be secured without increasing the plate thickness. Since it only needs to have an overlapping structure, processing for improving strength is easy.

[0016]

1 is a block diagram of a first embodiment of the present invention.
And it demonstrates with FIG. As shown in FIG. 1, this rocker arm 1 is mounted on an engine and has a cam 2 at one end 1a.
It is a center pivot type in which the valve 3 of the cylinder head is opened and closed at the other end 1b by being swung by. This rocker arm 1 includes a pair of parallel opposite side walls 5
And the connecting plate wall 6 connecting the upper edges of the opposing side walls 5 to each other, the arm body 4 is press-worked from one plate material in an inverted U-shaped cross-sectional shape. The plate material is a metal plate such as a steel plate. The side shape of the arm body 4 may be a straight line shape or a V-shape bent shape, but in this embodiment, it is a V-shape bent shape. Opposing side walls 5 on both sides
Are symmetrical to each other except for the other end 1b. The connecting plate wall 6 is provided from the vicinity of the one end 1a to the other end 1b.

The opposite side walls 5 have a swing fulcrum hole 7 which serves as a swing fulcrum portion substantially at the center in the longitudinal direction, and a swing fulcrum shaft 9 is provided in the swing fulcrum hole 7 via a bush 8. Fit together.
The rocker arm 1 is supported around the swing fulcrum shaft 9 so as to be rotatable forward and backward. The bush 8 is attached to the swing fulcrum hole 7 in a press-fitted state, for example. The opposite ends 1a of the opposite side walls 5 have roller support holes 11 for mounting the support shafts 10a of the rollers 10 for engagement with the cams 2 (FIG. 1). The roller 10 is rotatably supported by the shaft 10a. The roller supporting portion 17 is configured by the one ends 1a of the opposite side walls 5 to which the support shaft 10a is attached. For example, as shown in FIG. 2A, the roller 10 has a double structure of an inner roller 10A and an outer roller 10B, and a contact surface between the inner diameter surface of the inner roller 10A and the support shaft 10a and the inner roller 10A. Sliding contact surfaces between the outer diameter surface and the inner diameter surface of the outer roller 10B are bearing surfaces that are in sliding contact with each other. Alternatively, the roller 10 may be an outer ring of a rolling bearing as shown in FIG. 2 (B). In the example shown in the figure, the inner diameter surface of the roller 10 and the support shaft 10a are
And the rolling element 10b made of rollers is interposed between the roller bearing and the roller bearing. 2A shows a double structure and FIG. 2B shows a roller bearing, but in the case of sliding contact, a single roller type may be used as shown in FIG. 2C.

As shown in FIG. 3, the other end 1b of the connecting plate wall 6 is formed.
Serves as an overlapping portion 13 in which a tip overlapping piece 12 integrally extending from the other end 1b is folded. This overlapping part 13
Is an adjusting portion 16 formed by penetrating a mounting hole 15 for mounting the valve action member 14 so as to be adjustable in and out. The valve acting member 14 has a male screw portion 14 a, and the mounting hole 15 of the adjusting portion 16 has a male screw portion 1 a.
4a is formed in a screw hole into which the screw 4a is screwed. Tip stacking piece 1
2 integrally extends from one side edge at the other end of the connecting plate wall 6, and is bent at the side edge as a bent base end 12a.
The tip of the tip overlapping piece 12 is in contact with or close to the inside of the opposing side wall 5 opposite to the bending base end 12a.

An example of the material of the arm body 4 is a case hardening steel (for example, SCM415) or the like, which is tempered after carburizing and quenching. The effective hardened layer depth is, for example, 0.4 to 1.5 mm, preferably 0.9 to 1.5 mm
Is.

According to the rocker arm 1 having this structure, the adjusting portion 16 is formed by the overlapping portion 13 in which the tip overlapping piece 12 is folded and overlapped on the connecting plate wall 6, so that a mounting hole penetrating the adjusting portion 16 is provided. The depth of 15 can be secured, and the strength around the mounting hole 15 of the adjusting portion 16 can be secured. In this case, since it suffices to provide a portion to be the tip stacking piece 12 and fold it, processing for reinforcement is easy. Also, the adjusting portion 16 of this overlapping structure
Since the tip overlapping piece 12 extends from the side edge of the connecting plate wall 6, a marginal dimension required to avoid the altered portion near the bending edge is generated in the width direction of the arm body 4. Therefore, the total length of the arm body 4 does not become long due to the folding. With respect to the width direction of the arm body 4, there is a margin with respect to the inner diameter of the mounting hole 15 in order to secure the width dimension of the roller 10 to be in rolling contact with the cam 2, and the width of the arm body 4 does not have to be particularly widened. . Mounting hole 15
May be disposed at the center of the connecting plate wall 6 in the width direction or may be deviated from the center of the width. Due to this deviation, the center of the adjusting portion 16 and the center of the roller supporting portion 17 of the arm body 4 can be offset in the direction of the rocking center axis of the rocker arm 1. When this offset structure is used, the conventional cylindrical bulging portion 56 is provided around the mounting hole 15.
Since there is no attached part such as (FIG. 10), it is easy to secure the offset amount. Further, since this rocker arm 1 is formed by pressing one plate material, it is lightweight, has a small number of processing steps, and can be manufactured at low cost.

The overlapping surfaces of the tip overlapping pieces 12 of the adjusting portion 16 with the connecting plate wall 6 may be joined to each other by welding or the like. With this joining, the strength of the adjusting portion 16 can be improved.

As shown in FIG. 4 (A), the tip stacking piece 12 may have its tip 12b engaged with an engagement opening 19 provided in the opposing side wall 5. The engagement opening 19 is formed in a groove shape at the lower edge of the other end 1b of the opposing side wall 5. As described above, the strength of the adjusting portion 16 can be improved also by forming the tip overlapping piece 12 into the fitting structure.
The fitting structure and the joining by welding or the like may be used together.

Further, as shown in FIG. 4B, a plurality of tip overlapping pieces 12 may be provided and overlapped with each other, and the overlapping portion 13 may have a triple overlapping structure. In the example of the same figure, the tip overlapping pieces 12 are integrally extended from both side edges of the connecting plate wall 6, and are alternately folded. As described above, when the overlapping portion 13 is tripled, the thickness of the adjusting portion 16 becomes thicker, the mounting hole 15 can be made deeper, and the strength of the adjusting portion 16 can be further strengthened. Tip stacking piece 12
For example, one that further extends from the other end 1b of the connecting plate wall 6 to the tip side may be provided, and this may be folded and overlapped so that the overlapping portion 13 has a quadruple structure. When the overlapping portion 13 has three or more layers, the plate portions of the respective layers forming the overlapping portion 13 may be joined by welding or the like at the overlapping surface. When the overlapping portion 13 has three layers, as shown in FIG.
The second tip 12b may be fitted into the engagement opening 19A provided in the opposing side wall 5. In this case, the engagement opening 19A becomes a hole.

In the first embodiment shown in FIGS. 1 and 2, as shown in FIG. 5 (A), the overlapping portion 13 is projected from the connecting plate wall 6 to one side, and the connecting plate wall width of the overlapping portion 13 is increased. The width W in the direction may be wider than that of the connecting plate wall 6. In this case, the mounting hole 15 is biased toward the protruding side of the overlapping portion 13. In this way, by widening the width W of the overlapping portion 13 serving as the adjusting portion 16, the offset amount between the adjusting portion 16 and the roller supporting portion 17 can be set without limitation without changing the width dimension of the general portion of the arm body 4. can do. Therefore, it is possible to obtain a large offset amount without significantly increasing the weight of the rocker arm 1.

In the embodiment shown in FIGS. 1 and 2, the connecting plate wall 6 of the rocker arm 1 can be arbitrarily formed within the range where the roller 10 does not interfere with it. For example, as shown in FIG. Adjust part 16 from the center of the direction
The connecting plate wall 6 may be provided only up to. By reducing the formation range of the connecting plate wall 6 in this way, weight reduction can be achieved. However, if the molding range of the connecting plate wall 6 is reduced,
Since the strength decreases, the amount should be reduced within the range where the required strength is secured.

6A to 6D and 7A to 7D.
Each of the examples shown in (D) is the first shown in FIGS. 1 and 2.
In the above embodiment, the opposing side wall 5 has an overlapping structure. In the example of FIG. 6A, an example is provided in which the side wall overlapping piece 21 integrally extending from the side wall 5 is provided, and the side wall overlapping piece 21 is folded on the side wall 5 to form the side wall 5 having the overlapping structure. Is. The side overlapping piece 21 has a width that overlaps a range near the swing fulcrum hole 7 in the opposing side wall 5, extends integrally downward from the opposing side wall 5, and is folded back to the outer surface side. Further, the opposing side walls 5 on both sides have an overlapping structure by the side overlapping pieces 21.

The example of FIG. 6 (B) is obtained by folding back the side overlapped piece 21 to the outer surface side of the opposed side wall 5 in the example of FIG. 6 (A), and folding it back to the inner surface side. Figure 6
Examples of (C) and (D) are shown in FIGS. 6 (A) and 6 (B), respectively.
In each of the above examples, the opposite side walls 5 on both sides are replaced with the overlapping structure, and only the opposite side wall 5 on one side is formed with the overlapping structure.

In the example of FIG. 7A, the overlapping portion 13 of the adjusting portion 16 is projected to one side from the connecting plate wall 6 as in the example of FIG. 5A, and the overlapping portion 13 in the connecting plate wall width direction is formed. In the embodiment in which the width is wider than that of the connecting plate wall 6, the side wall overlapping piece 21 is provided and the opposing side wall 5 has a double structure as in the example of FIG. 6A.

In the embodiment shown in FIG. 7B, as in the example shown in FIG. 5B, in the embodiment in which the connecting plate wall 6 is provided only between the vicinity of the longitudinal center of the arm body 4 and the adjusting portion 16, Similar to the example of FIG. 6A, this is an example in which the side overlapping piece 21 is provided and the opposing side wall 5 has a double structure. Like the example of FIG. 7B, the example of FIG. 7C has an overlapping structure in the embodiment in which the connecting plate wall 6 is only between the vicinity of the longitudinal center of the arm body 4 and the adjusting portion 16. Opposing side wall 5
Is an example in which the first side wall constituting plate portion 5A and the second side wall constituting plate portion 5B, which constitute the portion near the swing fulcrum hole 7 following the connecting plate wall 6, are constituted. The second side wall constituting plate portion 5B is
It extends integrally from the first side wall constituting plate portion 5A, is folded and folded on the first side wall constituting plate portion 5A, and has a roller supporting hole 11 at the tip thereof.

In the example of FIG. 7D, in the example of FIG. 7C, the first side wall constituting plate portion 5A and the second side wall constituting plate portion 5B are separated from each other in the swing axis direction to adjust the adjusting portion. In this example, the center of the roller 16 and the center of the roller supporting portion 17 are offset from each other in the swing axis direction. In any of the configurations shown in FIGS. 6 and 7, since the opposing side wall 5 has the overlapping structure, the strength of the opposing side wall 5 can be improved.

8 and 9 show an embodiment corresponding to the second invention of the present invention. The rocker arm 1A is of the end pivot type, is mounted on an internal combustion engine, and is rockably driven by a cam 2 to operate a valve 3 of a cylinder head. Also in this rocker arm 1A, the arm body 4A is pressed from a single plate material into an inverted U-shaped cross-sectional shape consisting of a pair of opposed side walls 5 and a connecting plate wall 6 connecting the upper edges of the opposed side walls 5. ing. The plate material is a metal plate such as a steel plate, and is, for example, the same material and heat-treated as in the first embodiment. The side surface shape of the arm body 4A may be a straight line shape or a V-shaped bent shape, but is substantially linear in this embodiment. The opposite side walls 5 on both sides are symmetrical with each other except for the other end 1Ab.

A roller 10 rollingly contacting the cam 2 is attached to the arm body 4A at an intermediate portion in the longitudinal direction, and one end 1Aa is provided.
A valve action portion 34 that acts on the valve 3 is formed on the other end, and the other end 1Ab is an adjustment portion 16A to which the pivot part 30 is attached. The valve action portion 34 is formed of a part of the connecting plate wall 6, and has a curved plate shape that is convex toward the valve 3 side in a cross section along the length direction of the arm body 4A. The connecting plate wall 6 of the arm body 4A is provided in the remaining range of the substantially entire length in the length direction excluding the intermediate portion, and the intermediate portion is formed in the window 32 through which a part of the roller 10 projects. The portion on the one end 1Aa side of the window 32 serves as the valve acting portion 34. As shown in FIG. 2A in the first embodiment, the roller 10 has a double structure of an inner roller 10A and an outer roller 10B, and a contact surface between the inner diameter surface of the inner roller 10A and the support shaft 10a. , And the sliding contact surface of the outer diameter surface of the inner roller 10A and the inner diameter surface of the outer roller 10A are bearing surfaces that are in sliding contact with each other. Alternatively, the roller 10 may be an outer ring of a rolling bearing as shown in FIG. 2 (B). In the example of the figure, a roller bearing is provided in which a rolling element 10b made of rollers is interposed between the inner diameter surface of the roller 10 and the support shaft 10a. Further, the roller 10 may be a single roller type.

8 and 9, the adjusting portion 16A
Is a part of the connecting plate wall 6 at the other end 1Ab of the arm body 4A, which is an overlapping part 13A obtained by folding a tip overlapping piece 12A integrally extending from a side edge of the connecting plate wall 6, and the pivot part 30 is attached to the overlapping part 13A. Is formed by penetrating a mounting hole 15A for mounting so as to be adjustable in and out. The tip of the tip overlapping piece 12A is in contact with or close to the inside of the opposing side wall 5 opposite to the bending base end. The mounting hole 15A is formed as a screw hole. The pivot part 30 has a male screw portion 31 and a spherical pivot portion 30a formed at the tip thereof, and the male screw portion 31 is screwed into the mounting hole 15A formed by the screw hole of the adjusting portion 16A. The pivot part 30
The pivot portion 30a is swingably supported by the pivot receiving member 33. The swing center of the pivot portion 30a, that is, the ball center is the swing center O of the arm body 4A. Other configurations in this embodiment are the same as those in the first embodiment.

In the case of this configuration, the member attached to the adjusting portion 16A is the pivot part 30, which is different from the first embodiment, but the same effects as those of the first embodiment can be obtained as follows. . That is, according to this rocker arm 1A, the adjusting portion 16A has the overlapping portion 13A in which the tip overlapping piece 12A is folded and overlapped with the connecting plate wall 6.
As a result, the depth of the mounting hole 15A penetrating the adjusting portion 16A can be secured, and the strength around the mounting hole 15A of the adjusting portion 16A can be secured. In this case, since it suffices to provide a portion to be the tip overlapping piece 12A and fold it, the processing for reinforcement is easy.
Further, since the adjusting portion 16A of this overlapping structure has the tip overlapping piece 12A extending from the side edge of the connecting plate wall 6, the margin dimension required to avoid the altered portion near the bending edge is larger than that of the arm body 4A. It will be taken in the width direction. Therefore, the total length of the arm body 4A does not become long due to the folding. With respect to the width direction of the arm body 4A, there is a margin with respect to the inner diameter of the mounting hole 15A in order to secure the width dimension of the roller 10 to be in rolling contact with the cam 2.
It is not necessary to particularly widen the width of the arm body 4A. For the overlapping portion 13A, it is possible to adopt various modifications (FIGS. 4 and 5) as in the first embodiment.

In each of the above embodiments, the arm body has an inverted U-shape, but the arm body may have a U-shaped cross section.

[0036]

The rocker arm of the present invention has an arm body which is pressed from a single plate material into an inverted U-shaped cross-sectional shape, and the valve action member or the pivot part is formed in and out of the arm body. Since the adjustably mounted adjust part is an overlap part where the tip overlapping pieces are folded, the strength around the adjust part mounting hole can be secured by simple processing, and the weight is light and the number of processing steps is small, and the cost can be reduced. . In particular, since the tip overlapping piece is assumed to extend from the side edge of the connecting plate wall that serves as the ceiling portion of the inverted U-shaped arm body, the margin dimension necessary for avoiding the altered portion near the bending edge is larger than that of the arm body. Since it is taken in the width direction, the arm body can be made compact in the length direction. When the width of the overlapping portion in the width direction of the connecting plate wall is wider than that of the connecting plate wall, the offset amount can be arbitrarily set by changing only the width dimension of the adjusting portion without changing the width of the arm body. it can.

[Brief description of drawings]

FIG. 1 is a cutaway side view showing a rocker arm according to a first embodiment of the present invention together with a peripheral mechanism of an engine.

FIGS. 2A to 2C are cross-sectional views of an example of a roller support portion and a modification thereof of the rocker arm, respectively.

FIG. 3 is an exploded perspective view of the rocker arm and its accessories.

4A to 4C are perspective views showing a rocker arm according to another embodiment of the present invention.

5A and 5B are perspective views showing a rocker arm according to still another embodiment of the present invention.

6 (A) to (D) are perspective views showing a rocker arm according to still another embodiment of the present invention.

7A to 7D are perspective views showing rocker arms according to still another embodiment of the present invention.

FIG. 8 is a cutaway side view showing a rocker arm according to an embodiment corresponding to a second invention of the present invention.

9A is a plan view of the rocker arm, and FIG. 9B is a perspective view of a part thereof.

FIG. 10 is a perspective view of a conventional example.

FIG. 11 is a perspective view of another conventional example.

FIG. 12 is a perspective view of still another conventional example.

[Explanation of symbols]

1, 1A ... Rocker arm 1a, 1Aa ... One end 1b, 1Ab ... the other end 2 ... cam 3 ... Valve 4, 4A ... Arm body 5 ... Opposing side wall 5A ... 1st side wall constituent board part 5B: Second side wall forming plate portion 6 ... Connecting plate wall 7 ... rocking fulcrum hole 10 ... Laura 12, 12A ... Tip stacking piece 13, 13A ... Overlap 14 ... Valve acting member 15,15A ... Mounting hole 15a ... screw groove 16, 16A ... Adjustment part 17 ... Roller support 21 ... Side overlapping piece 30 ... Pivot parts

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Claims (9)

[Claims] 1. A rocker arm for oscillatingly driven by a cam to operate a valve of an internal combustion engine, wherein an arm body made of a single plate material, which comprises a pair of opposed side walls and a connecting plate wall connecting the opposed side walls. The arm main body has a swing fulcrum portion in the middle in the longitudinal direction, and a roller rolling on the cam is attached to one end of the arm main body.
The portion of the connecting plate wall at the other end serves as an overlapping portion formed by folding the tip overlapping piece extending integrally from the side edge of the connecting plate wall, and the overlapping portion penetrates through the mounting hole for mounting the valve action member in an adjustable manner. A rocker arm that is used as an adjusting portion formed by. 2. The rocker arm according to claim 1, wherein the mounting hole is offset from the center of the connecting plate wall in the width direction. 3. The rocker arm according to claim 1, wherein a width of the overlapping portion in the width direction of the connecting plate wall is wider than that of the connecting plate wall. 4. A rocker arm for oscillatingly driven by a cam to operate a valve of an internal combustion engine, wherein an arm body made of a single plate material, which comprises a pair of opposing side walls and a connecting plate wall connecting the opposing side walls. The arm main body has a roller attached to the cam in the middle in the longitudinal direction, a valve acting portion acting on the valve is formed at one end, and a portion of the connecting plate wall at the other end is formed by the connecting portion. A rocker arm which is an adjusting part formed by folding a tip overlapping piece integrally extending from a side edge of a plate wall, and the overlapping part is formed by penetrating a mounting hole through which a pivot part can be adjusted in and out. 5. The rocker arm according to claim 1, wherein a plurality of the tip overlapping pieces are provided and overlapped with each other, and the overlapping portion has an overlapping structure of three or more layers. 6. The rocker arm according to any one of claims 1 to 5, wherein the overlapping surfaces of the tip overlapping piece and the wall of the connecting plate are joined to each other. 7. The rocker arm according to claim 1, wherein the tip of the tip overlapping piece is fitted into an engagement opening provided in the opposing side wall. 8. The rocker arm according to claim 1, wherein the mounting hole is a screw hole. 9. The rocker arm according to claim 1, wherein at least a part of both or one of the opposite side walls of the arm body has an overlapping structure in which a part of the plate material is folded and overlapped.