JP3302395B2 - Roller tappet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roller tappet used for a head valve type valve opening / closing mechanism of an automobile engine or the like.

[0002]

2. Description of the Related Art As one means for improving the fuel efficiency of automobiles, the tappet portion of a head valve type valve opening / closing mechanism has been rolled, and a roller tappet has become widespread.

As shown in FIG. 5, a conventional roller tappet includes a tappet case 1 and a roller 2, and a tappet rod insertion hole 3 is formed at an upper end of the tappet case 1. Further, a roller mounting groove 4 is formed at the lower end of the tappet case 1, and a shaft 5 fixedly inserted through both side walls of the groove 4.
Thereby, the roller 2 fitted in the groove 4 is rotatably supported.

[0004]

The above tappet case 1 is manufactured by cold forging a raw material and then performing machining such as turning, milling, and polishing. And the cost increases.

Accordingly, an object of the present invention is to reduce the cost of a roller tappet by reducing the number of machining steps.

[0006]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides an automobile engine comprising a tappet case for receiving and supporting a lower end of a push rod, and a roller attached to the lower end of the tappet case. Etc. head valve
In a roller tappet used in a valve opening / closing mechanism, the tappet case includes a cup-shaped case member and a yoke member supporting the roller, and the yoke portion
The material is formed in a gate shape consisting of both side walls and an upper wall extending between its upper ends.
And make the both side walls outward so that the cross-sectional shape becomes an arc shape.
The case member and the yoke member are formed by drawing a metal plate, and the upper end of the yoke member is connected to the lower surface of the case member to integrate the two members. It is.

[0007]

In the roller tappet having the above structure, the push rod is inserted into the upper end opening of the case member and the roller is brought into contact with the cam on the cam shaft, whereby the rotation of the cam is transmitted to the rocker arm via the push rod. I do.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A roller tappet according to a first embodiment shown in FIGS.
2 and a yoke member 13. The case member 12 has an opening 1 at the upper end by drawing of a metal plate.
4 is formed in a cup shape, and a recess 16 for receiving the lower end of the push rod is formed on the inner bottom surface.

The yoke member 13 is a gate-shaped one comprising both side walls 17, 17 and an upper wall 18 extending between upper ends thereof.
This is also formed by drawing a metal plate. The upper wall 18 of the yoke member 13 has a recess 1 of the case member 12.
A shallow recess 19 conforming to the lower surface shape of 6 is formed. The central portion of each of the side walls 17 has an arc-shaped wall in cross section, thereby providing a required strength.

A roller 20 is inserted between the side walls 17, 17 of the yoke member 13, and the roller 20 is rotatably supported via a bearing 22 by a shaft 21 fixed through the side walls 17, 17. You.

The above-mentioned case member 12 and yoke member 13
The upper wall 18 of the yoke member 13 is provided on the lower surface of the case member 12.
Are integrated by spot welding.

Incidentally, either one of the case member 12 and the yoke member 13 may be cut out or formed by die casting.

In the case of the second embodiment shown in FIG. 3, an opening 23 is provided in the upper wall 18 of the yoke member 13, and the opening 2 is provided.
3, the bottom of the recess 16 of the case member 12 is fitted. When such an opening 23 is provided, it becomes easier to fit the lower surface of the yoke member 13 than when the shallow recess 19 is provided in the upper wall 18 as shown in FIG. Other configurations of the second embodiment are the same as those of the first embodiment.

A third embodiment shown in FIG.
2 and the upper wall 18 of the yoke member 13 are provided with rivet holes 24 and 24 ', respectively.
The case member 12 and the yoke member 13 are integrated by caulking the rivet 25 passed through 4 ′. In this case, a recess 26 is provided on the upper surface of the head of the rivet 25, and the lower end of the push rod is supported by the recess 26. Other configurations are the same as in the first embodiment.

The roller tappet of each embodiment is configured as described above. In each case, the opening 1 of the case member 12 is formed.
Insert the lower end of the push rod into the recess 16 or 26
, And the operation of the cam is transmitted to the rocker arm via the push rod by bringing the roller 20 into contact with the cam.

Since the load acting on the tappet case 11 is only the load in the compression direction, there is no functional problem even if it is composed of two members.

[0017]

As described above, according to the present invention, since the tappet case is constituted by the two members, the case member and the yoke member, each member can be easily manufactured by drawing. As a result, since the number of machining steps is reduced, there is an effect that the manufacturing cost of the roller tappet can be reduced. Further, the yoke member is connected to both side walls.
Of the upper wall extending between the upper ends of the
Bulged outward so that the cross-sectional shape becomes an arc.
Because the bulging part reinforces both side walls
Especially, the contact area of the rollers that contact the inner surfaces of both side walls is reduced.
Thus, the rollers can be smoothly rotated.

[Brief description of the drawings]

FIG. 1 is a sectional view of a first embodiment.

FIG. 2 is an exploded perspective view of the above.

FIG. 3 is a sectional view of a second embodiment.

FIG. 4 is a sectional view of a third embodiment.

FIG. 5 is a sectional view of a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 11 tappet case 12 case member 13 yoke member 14 opening 16 recess 17 side wall 18 upper wall 19 recess 20 roller 21 shaft 22 bearing 23 opening 24, 24 'rivet hole 25 rivet 26 recess

Claims (1)

(57) [Claims] 1. A head valve type valve for an automobile engine comprising a tappet case for receiving and supporting a lower end of a push rod and a roller attached to the lower end of the tappet case.
In roller tappet for use in opening and closing mechanism, and the case member of the cup-shaped said tappet casing, constituted by a yoke member supporting the rollers, said yoke member
Formed as a gate consisting of both walls and an upper wall extending between its upper ends
Then, the side walls are expanded outward so that the cross-sectional shape becomes an arc.
A roller tappet , wherein the case member and the yoke member are formed by drawing a metal plate, respectively, and both members are integrated by connecting an upper end of the yoke member to a lower surface of the case member.