JPH11287107A - Locker arm - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a locker arm which can promote the improvement of productive efficiency and the reduction of cost, and has a highly accurate valve stem guide groove. SOLUTION: This locker arm is equipped with a pair of both side walls 22 and one end connected wall 30 which connects between the one end parts of both the side walls 22 and is composed so that the tip of the valve stem may abut on the side of a lower face, and a frame-shaped piece 40 having a rectangular hole 41 at the center is provided in series at the longitudinal end edge of the locker arm on the one end connected wall 30, and the frame- shaped piece 40 is folded back so as to overlap on the lower face side of the one end connected wall 30. Thus a valve stem guide groove 45 using the frame parts 42 on both sides of the frame-shaped piece 40 as a guide wall is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rocker arm for opening and closing a valve provided on a cylinder head with rotation of a cam in a valve operating mechanism of an internal combustion engine of a vehicle, for example.

[0002]

2. Description of the Related Art FIG. 12 is a sectional view showing a valve train in an internal combustion engine of a vehicle. As shown in the figure, the valve operating mechanism includes a cam (3) that rotates in conjunction with a crankshaft (2) and a cam (3) that rotates by a valve (4) such as an intake valve or an exhaust valve.
A rocker arm (1) for converting the reciprocating linear motion of the valve stem (5) in the first embodiment is provided.

As shown in FIGS. 12 and 13, the rocker arm (1) has a pair of side walls (11) arranged in parallel, and one end between the two side walls (11) and the other end. It has one end connecting wall (12) and the other end connecting wall (13) to be connected. A support shaft (8) of a roller (7) is fixed to a shaft fixing hole provided in a longitudinally intermediate region of both side walls (11), and the roller (7) and the cam (3) are fixed. It is configured to be able to make rolling contact. A pivot engagement recess (13a) is formed on the lower surface side of the other end connecting wall (13) of the rocker arm (1), and the pivot portion (6) fixed to the cylinder head is formed in the recess (13a). ) Is arranged in the engaged state, and the tip of the valve stem (5) is arranged in a contact state on the lower surface of the one end connecting wall (12). In addition, the lower surface side of the one end connecting wall (12) is provided with a valve stem guide groove (1).
2a) is formed, the tip of the valve stem (5) is housed in the guide groove (12a), and the tip of the valve stem is engaged with the groove wall (the lower edge of both side walls 11) to thereby locker. The arm (1) is prevented from being displaced in the horizontal direction with the pivot (6) side as a fulcrum.

[0004]

The rocker arm (1) as described above has a complicated shape, for example, a guide groove (12a) for accommodating the tip of the valve stem is provided in one end connecting wall (12). In general, it is generally manufactured by forging or precision casting (lost wax).

[0005] However, the rocker arm (1) is
When manufactured by low-efficiency machining such as forging or precision casting, there is a problem that production efficiency is reduced and costs are increased.

On the other hand, in recent years, with the increase in speed and output of an internal combustion engine, it has been desired to reduce the weight of the rocker arm in order to reduce the inertial weight. Many have been proposed.

However, since the rocker arm has a complicated shape such as the guide groove (12a), the number of steps is increased in conventional press working, and it is difficult to form the guide groove (12a) with sufficient accuracy. Thus, there is a problem that the production efficiency decreases and the cost increases.

An object of the present invention is to provide a rocker arm having a high-precision valve stem guide groove, which can solve the above-mentioned problems of the prior art, improve the production efficiency and reduce the cost.

[0009]

In order to achieve the above object, a rocker arm according to the present invention comprises a pair of side walls extending in the longitudinal direction of a rocker arm, one end of each of the side walls being connected to each other, and a lower surface side. And a frame-like piece having a rectangular hole at the center is continuously provided at an end edge of the rocker arm in the longitudinal direction of the one-side connection wall. By folding the shape piece into a mode overlapping the lower surface side of the one end connecting wall,
The gist of the present invention is that a valve stem guide groove is formed with the frame portions on both side frame portions as guide walls.

In the rocker arm according to the present invention, the frame-like piece connected to the edge of the one-side connecting wall is folded back so as to overlap the lower surface of the one-side connecting wall, and both side frame portions of the frame-like piece are used as the guide wall. Since the valve stem guide groove is formed, for example, punching processing for forming a rectangular hole of the frame-shaped piece, and press processing such as bending processing for overlapping the frame-shaped piece on one end connecting wall only are performed. A valve stem guide groove can be formed.

Further, since the frame-like piece is formed in a highly rigid frame shape, sufficient rigidity can be secured in both side frame portions as guide walls, and stable dimensional accuracy can be obtained.

In the present invention, it is preferable to adopt a configuration in which the frame-shaped piece is fixed to the one end connecting wall.

That is, when this configuration is employed, it is possible to reliably prevent the frame-shaped piece, that is, the guide wall from being displaced or separated from each other.

Further, in the present invention, it is preferable to adopt a configuration in which the frame-shaped piece is continuously provided on one end side edge of the one end connecting wall.

That is, when this configuration is adopted, the frame-shaped piece can be easily manufactured without any particular restrictions.

Further, in the present invention, it is preferable to adopt a configuration in which the frame-shaped piece is continuously provided on the other end side edge of the one end connecting wall.

That is, in the case of adopting this configuration, the area where the roller accommodating opening is formed can be used as it is as a frame-shaped piece. The material for the arm can be used effectively.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a rocker arm according to an embodiment of the present invention will be described in detail with reference to the drawings. In the following drawings, the rocker arm (including the intermediate processed product) is shown in a state during the manufacturing process, that is, in a state where the rocker arm is turned upside down with respect to the actual use state, but in the following description, According to the actual use condition, "upper side" of the drawing
Is described as “lower side”.

<First Embodiment> As shown in FIG. 4, a rocker arm (20) according to a first embodiment of the present invention comprises:
One end connecting wall (30) connecting between a pair of opposite side walls (22) and one end lower end of the both side walls (22).
And a second end connecting wall (23) connecting the lower ends of the other ends. Further, a frame-shaped piece (40) having a rectangular hole (41) at the center is continuously provided at one end side edge of the one-end connection wall (30), and the frame-shaped piece (40) is connected to the one end connection wall (30). By being folded back so as to overlap the lower surface side, both side frame portions (42) (42) of the frame-shaped piece (40) are used as guide walls,
Further, a valve stem guide groove (45) having the lower surface (32) of the one end connecting wall (30) as a bottom surface (a valve stem contact surface) is formed. A pivot engagement recess (24) is formed in the center of the lower surface side of the other end connecting wall (23).
Shaft fixing holes (21) whose axial centers coincide with each other are formed at longitudinally intermediate portions of both side walls (22).

In order to manufacture the rocker arm (20), first, as shown in FIG. 1, a predetermined region of a steel plate is punched to obtain a punched plate having a predetermined shape, and the punched plate is perforated. A blank product (20a) is obtained.

This blank processed product (20a) has arc-shaped convex portions on both side edges, a drum-shaped hole in the center, and a center of one end edge corresponding to the longitudinal direction of the rocker arm. Extend in one direction along the direction,
A frame-shaped piece (40) having a rectangular hole (41) at the center is continuously provided.

Next, in the area corresponding to the center of the lower surface of the other end connecting wall (23) in the blank processed product (20a),
An overhanging process is performed to form a hemispherical pivot engaging concave portion (24), and then, as shown in FIG. 2, the blank product (20a) is bent.

As a result, the lower end at one end and the lower end at the other end of both side walls (22) are connected by one end connecting wall (30) and the other end connecting wall (23), and between the pair of side walls (22). A U-shaped bent product (20b) having an opening for accommodating and viewing the roller is provided between the one end connecting wall (30) and the other end connecting wall (23). Needless to say, the pivot engaging recess (23) is arranged on the lower surface side of the other end connecting wall (23).

Subsequently, as shown in FIG. 3, one end connecting wall (3
The frame-shaped piece (40) connected to (0) is bent, and the frame-shaped piece (40) is folded downward with the one edge of the one end connecting wall (30) as a bending line, and the one end is bent. Connecting wall (3
0).

Thus, both sides of the rectangular hole (41) in the frame-shaped piece (40), that is, both side frame portions (42) (4)
2) is a guide wall, and the lower surface (3) of one end connecting wall (30).
A valve stem guide groove (45) having 2) as a valve stem contact surface is formed.

Next, the frame-shaped piece (40) is connected to one end connecting wall (30).
Stick to For example, as shown in FIG.
0) The side is set on the die (50), and the frame-shaped piece (40) is set.
A die punch (60) is driven into the front end frame portion (43) by an amount corresponding to the thickness of the frame-shaped piece (40). As a result, the punched area of the frame-shaped piece (40) is pressed and deformed and bites into one end connecting wall (30), and the frame-shaped piece (40) is firmly fixed to the one end connecting wall (30).

In the present invention, as a fixing means other than the above, for example, as shown in FIGS. 6 and 7, the front end frame portion (43) of the frame-shaped piece (40) is press-formed as shown in FIGS. Means for bending and fixing so as to be wound around the other edge of the above) can also be adopted.

However, in the present invention, the frame-shaped piece (40)
The fixing means between the end connecting wall (30) and the one end connecting wall (30) is not limited to the fixing means by press caulking such as the pressing in FIG. 5 or the bending in FIG. 6 and FIG. Various welding and joining means may be used.

In this way, the frame-shaped piece (40) is connected to the connecting wall (3) at one end.
4), a punch is punched from both sides into a longitudinally intermediate portion of both side walls (22) as shown in FIG. Form a shaft fixing hole (21). In the same figure, (55) is a frame-shaped piece (40) and one end connecting wall (30).
7 shows traces of the fixing process when fixing is performed by the above-described pressing deformation.

Thus, the manufacture of the rocker arm (20) of the present embodiment is completed.

According to the manufacturing method of this embodiment, since the rocker arm (20) is manufactured only by pressing such as outer diameter punching, bending, pressing, punching, and the like, for example, Further, it is possible to improve production efficiency and reduce costs without requiring low-efficiency machining such as forging and precision casting.

In this embodiment, the frame-shaped piece (40)
Has a rectangular frame shape in which both side frame portions (43) are connected to each other, so that the guide wall formed by the both side frame portions (43) can secure sufficient rigidity,
The dimension between both side frame portions (43) is also stable, and high dimensional accuracy can be obtained.

In this embodiment, the frame-like piece (4
0) is fixed to the connecting wall (30) at one end, so that it is possible to reliably prevent the frame-shaped piece (40), that is, the guide wall from being displaced or separated, and to provide a high-quality rocker arm ( 20) can be produced efficiently.

Particularly in the present embodiment, the frame-shaped piece (40)
When the above-mentioned press caulking is used as a means for fixing the one end connecting wall (30), the rocker arm (20) is constantly and efficiently subjected to high-efficiency pressing.
Can be manufactured, so that the production efficiency can be further improved.

<Second Embodiment> As shown in FIG. 11, a rocker arm (120) according to a second embodiment of the present invention comprises:
A frame-shaped piece (140) is attached to the other edge of the one end connecting wall (30).
Are different from the rocker arm (120) of the first embodiment in that the rocker arms (120) are continuously provided, and other configurations are substantially the same as those of the rocker arm (20) of the first embodiment. It is.

The rocker arm (12) of the second embodiment
8), first, as shown in FIG. 8, a predetermined region of a steel plate is punched to obtain a punched plate having a predetermined shape, and the punched plate is perforated to form a blank processed product (1).
20a) is obtained.

This blank processed product (120a) has arc-shaped projections on both side edges and a rectangular hole at the center, which will later become a rectangular hole (141) of the frame-shaped piece (140). ing.

Next, a region corresponding to the center of the lower surface of the other end connecting wall (23) of the blank processed product (120a) is subjected to overhanging processing to form a hemispherical pivot engaging concave portion (24). .

Thereafter, as shown in FIG. 9, the blank processed product (120a) is bent to form a U-shaped bent view having a pair of side walls (22) arranged opposite to each other. A product (120b) is obtained.

In FIG. 9, the frame-shaped piece (14
The cut-and-raised area which becomes 0) is shown by an imaginary line.

Next, as shown in FIG. 10, both side walls (22)
The peripheral area of the rectangular hole (141) is cut and raised between them.
At this time, in the bent product (120b), a frame-shaped piece (140) is formed by the cut and raised area,
The opening formed by cutting and raising the frame-like piece (140) forms an opening for accommodating the roller, and further includes a region located at one end and the other end of the opening at one end connecting wall (30). And the other end connecting wall (23).

The cut and raised bottom wall forming piece (1)
40) is bent to one end side and overlapped on the lower surface side of one end connecting wall (30).

Thus, both side frames (142) (142) of the rectangular hole (141) in the frame-shaped piece (140) are used as guide walls, and the lower surface (32) of the one end connecting wall (30) is used as a valve stem contact surface. A valve stem guide groove (45) is formed.

Next, after the frame-like piece (140) is fixed to the connecting wall (30) by the same means as in the first embodiment, the length of the side walls (22) is reduced as shown in FIG. A shaft fixing hole (21) is formed in the middle part in the direction.

Thus, the manufacture of the rocker arm (120) of the present embodiment is completed.

According to this embodiment, similarly to the above, the rocker arm (120) can be manufactured only by press working, so that the production efficiency can be improved and the cost can be reduced.

Further, since the frame-like piece (140) is formed in a highly rigid rectangular frame shape, sufficient dimensional accuracy can be obtained while maintaining high rigidity. Further frame-shaped pieces (140)
Is fixed to the connecting wall (30) at one end, so that the frame-shaped piece (1
In this case, it is possible to surely prevent the problems described in (40), such as displacement and separation.

Further, in this embodiment, the area in which the roller accommodating opening is formed is cut and raised to form the frame-shaped piece (14).
Since it is used as 0), the material can be more effectively used and the product yield can be improved as compared with a case where the opening forming region is punched and discarded, for example.

By the way, in the rocker arm (120) of this embodiment, both side walls (22) protrude greatly upward as compared with a normal rocker arm, and the shaft fixing hole (21) is displaced upward. It is formed in the position where it did. This is for the following reason. That is, when the rocker arm is manufactured, generally, the roller accommodating opening of the blank material is punched into a drum shape, and after the bending process, the protruding portion having a downwardly projecting shape is formed on the edge of the roller accommodating opening on both sides. Is formed to secure an area for forming the shaft fixing hole. On the other hand, in the present embodiment, the bent product (120) is determined in relation to the width of the frame-shaped piece (140).
b) the roller accommodating opening is formed in a rectangular shape;
The edges of the side walls (22) on the side of the roller accommodating opening are formed linearly, and do not have downwardly projecting projections. In other words, in the present embodiment, since the protrusion is not formed on the side edge of the roller accommodating opening of both side walls (22), the vertical dimension of both side walls (22) is reduced, and the area for forming the shaft fixing hole is reduced. It will be difficult to secure. Therefore, in the present embodiment, by increasing the amount of protrusion of the both side walls (22) upward and shifting the formation position of the shaft fixing hole (21) upward, the shaft fixing hole forming area is formed in the both side walls (22). Is ensured.

However, in this embodiment, the frame-shaped piece (1
In the case where 40) is formed to be considerably smaller than the width dimension of the rocker arm (120), similarly to a general rocker arm, the both side walls (22) have a downwardly projecting edge on the edge of the roller housing opening side. It is possible to form the shaft fixing hole at the same position by making the amount of upward protrusion of both side walls (22) the same as that of a general rocker arm.

[0051]

As described above, according to the rocker arm of the present invention, a frame-like piece having a rectangular hole is continuously provided on the edge of one end connecting wall, and the frame-like piece is provided on the lower surface side of the one end connecting wall. By being folded back in an overlapping manner, since the valve stem guide groove with the both side frame portions of the frame-shaped piece as a guide wall is formed, for example, a punching process for forming a rectangular hole of the frame-shaped piece, In addition, the valve stem guide groove can be formed only by pressing such as bending to overlap the frame-shaped piece on one end connecting wall, and the guide groove is formed using low-efficiency machining such as forging or precision casting. Compared to the case of forming, it is possible to efficiently produce and reduce the cost. Furthermore, since the frame-shaped piece is formed in a highly rigid frame shape, sufficient rigidity can be secured in both side frame portions as guide walls, and dimensions are stabilized, so that a valve stem guide groove with high dimensional accuracy is formed. There is an effect that can be.

In the present invention, when the frame-shaped piece is fixed to the connecting wall at one end, it is possible to reliably prevent the frame-shaped piece, that is, the guide wall, from being displaced or separated, and to improve the quality. There is an advantage that it can be achieved.

Further, in the present invention, when the frame-shaped piece is continuously connected to one end edge of the one end connecting wall, the frame-shaped piece can be manufactured without any particular limitation without any difficulty, and the production efficiency can be further improved. There is an advantage that improvement and cost reduction can be achieved.

Further, in the present invention, when the frame-shaped piece is continuously provided to the other end of the connecting wall, the area where the roller accommodating opening is formed can be used as the frame-shaped piece. Therefore, as compared with the case where the opening forming region is punched out and discarded, for example, there is an advantage that the material can be used more effectively and the cost can be further reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a blank processed product as an intermediate processed product when manufacturing a rocker arm according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a bent product as an intermediate product in the first embodiment.

FIG. 3 is a perspective view showing a bent product after a frame-shaped piece bending process in the first embodiment.

FIG. 4 is a perspective view showing a rocker arm according to the first embodiment.

FIG. 5 is a cross-sectional view showing frame-shaped piece fixing means for fixing the frame-shaped piece to one end connecting wall in the first embodiment.

FIG. 6 is a perspective view showing a bent product employing another frame-shaped piece fixing means.

FIG. 7 is a sectional view showing a bent product in which the other frame-shaped piece fixing means is employed.

FIG. 8 is a perspective view showing a blank product as an intermediate product when manufacturing a rocker arm according to a second embodiment of the present invention.

FIG. 9 is a perspective view showing a bent product as an intermediate product in the second embodiment.

FIG. 10 is a perspective view showing a bent product after a frame-shaped piece bending process in the second embodiment.

FIG. 11 is a perspective view illustrating a rocker arm according to a second embodiment.

FIG. 12 is a cross-sectional view showing a valve mechanism of an internal combustion engine in a conventional vehicle.

FIG. 13 is a sectional view showing a rocker arm applied to a conventional valve train.

[Explanation of symbols]

 Reference numerals 20, 120: Rocker arm 22: Both side walls 30: One end connecting wall 32: Lower surface 40, 140: Frame-shaped piece 41, 141 ... Rectangular holes 42, 142: Both side frame portions 45: Valve stem guide groove

Claims (4)

[Claims] 1. A pair of side walls extending in the longitudinal direction of a rocker arm, and one end connecting wall configured to connect one end of the both side walls and to be in contact with the tip of a valve stem on a lower surface side. A frame-like piece having a rectangular hole in the center is continuously provided at an edge of the one end connecting wall in the rocker arm longitudinal direction, and the frame-like piece is folded back so as to overlap the lower surface side of the one end connecting wall. A rocker arm, wherein a valve stem guide groove is formed with both side frame portions of the frame-shaped piece as guide walls. 2. The rocker arm according to claim 1, wherein said frame-shaped piece is fixed to said one end connecting wall. 3. The rocker arm according to claim 1, wherein the frame-shaped piece is connected to one edge of the one end connecting wall. 4. The rocker arm according to claim 1, wherein the frame-shaped piece is connected to the other end of the one end connecting wall.