JPS603285Y2 - Tappet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tappet that serves as a cam follower of a cam rotated by a camshaft, and more particularly to a tappet for use in an intake/exhaust overhead valve type engine.

Various such tappets are known in the art. For example, as shown in FIG. 1, a tappet a, which is a cam follower, has a bottomed ear shape or a cylindrical shape, and has a hemispherical recess formed in its inner bottom.

The lower end of the bushing rod C is formed into a hemispherical surface d, and the upper end is formed with a hemispherical recess e.

The hemispherical surface d of the bushing rod C is engaged with a hemispherical recess in the tappet a, and the hemispherical recess e at the upper end of the bushing rod C receives an adjusting screw of a rocker (not shown).

The cam g rotated by the cam shaft f comes into contact with the bottom of the tappet a and functions as a cam mechanism.

When the cam g pushes up the tappet a, the bushing rod C is pushed up and the exhaust valve is opened via the rocker.

Therefore, a large frictional force acts on the contact surface between the bottom of the tappet a and the cam g, causing wear.

For this purpose, the bottom of the tappet must be lubricated,
Therefore, various techniques have been proposed to improve lubricity.

In order to make the bottom part more susceptible to oil splashes, it is preferable that the area of the bottom part be wide, but the tappet itself becomes large, resulting in an increase in weight and inertial force, which is not desirable as a movable member.

Therefore, an object of the present invention is to provide a tappet that is not heavy and has good lubricity.

According to the present invention, the tappet is provided with a lower end portion having a contact portion with the cam, and an annular oil pan separate from the tappet is fixed to a portion of the outer periphery of the lower end portion of the tappet that is not in contact with the cam and the tappet, The annular oil pan is constructed of lightweight material.

Therefore, the part that comes into contact with the cam is the same as the conventional product, but the annular oil holder made of lightweight material provided on the outer periphery of the lower end can sufficiently capture oil droplets and flow them to the bottom of the tappet, thereby providing lubrication. Improves sex.

Since this annular oil pan does not come into contact with the cam, a lightweight material such as soft material such as aluminum or synthetic resin can be used.

Embodiments of the present invention will be described below with reference to the drawings from FIG. 2 onwards.

In FIG. 2, a tappet or cam follower 1 has a cylindrical shape with a bottom and a hemispherical recess 2 formed in the inner bottom.

The lower end of the bushing rod 3 is formed into a hemispherical surface 4, and the upper end is formed with a hemispherical recess 5.

The hemispherical surface 4 of the bushing rod 3 is engaged in the hemispherical recess 2 of the tappet 1, and the hemispherical recess 5 of the upper end of the bushing rod 3
accepts an adjustment screw for a rocker (not shown).

A cam 7 rotated by a camshaft 6 is in contact with the bottom 8 of the tappet 1 and acts as a cam mechanism.

The bushing rod 3, in which the cam 7 pushes up the tappet 1, is pushed up and opens the exhaust valve via the rocker.

Reference numeral 9 denotes an annular oil receiver, and the oil receiver 9 is provided on the outer periphery of the lower end portion of the tappet 1 in a range that does not come into contact with the cam 7.

The cam 7 is located in the crank chamber, and there are many droplets of lubricating oil floating in the crank chamber, so the oil pan 9 captures the droplets and entrains the captured oil droplets with the airflow generated by the rotation of the cam 7. This can be fed to the contact surface between the cam and the bottom of the tappet to improve lubricity.

By providing the oil pan 9, the present invention increases the area of the bottom of the tappet and increases the amount of oil droplets captured, thereby improving lubricity.

In order to keep the weight increase of the valve train as low as possible, the oil pan 9 is made of lightweight material, such as brass, aluminum, synthetic resin, etc.

FIG. 3 shows a second embodiment of the present invention, in which a screw 11 is screwed on the outer peripheral surface of the lower end of the tappet 10, and a female screw 13 is screwed on the inner peripheral surface of the oil pan 12, so that the two are screwed together. This is what I did.

FIG. 4 shows a third embodiment of the present invention, in which an annular oil receiver 15 is press-fitted into the outer peripheral surface of the lower end of the tappet 14.

FIG. 5 is a view of the tappet viewed from the bottom.

Reference numeral 16 indicates the lower surface of the annular oil pan 15, and a rectangular portion surrounded by side 11 and side 1° indicates a portion where the cam and the bottom surface of the tappet come into contact.

If this contact portion is located inside the lower surface 16 of the oil pan 15, the bottom of the tappet and the lower surface 16 of the oil pan may be in the same plane.

However, if the contact portion is a rectangular portion surrounded by sides 13 and 1□, excessive force will be applied to the oil pan 15 due to contact with the lower surface 16 of the oil pan at the portions S□ and S2.
To prevent this, it is preferable to provide a relief.

FIG. 6 is an enlarged view of part A in FIG. 4, and is an example in which the lower surface 17 of the oil pan 15 is tapered with respect to the horizontal plane, and is made into a conical surface 17 having an angle θ with respect to the horizontal plane, thereby providing a relief. It is.

FIG. 7 shows a fourth embodiment of the present invention, in which an oil receiver 18 having an angular cross section is press-fitted into the outer peripheral surface of the lower end of a tappet 19.

FIG. 8 shows a fifth embodiment of the present invention, in which an annular oil receiver 21 having an angular cross-section is press-fitted into the outer surface of the lower end of a cylindrical tappet 20.

FIG. 9 shows a sixth embodiment of the present invention, in which an annular oil receiver 23 is cast into the outer peripheral surface of the lower end of the tappet 22.

The effects of any of the above embodiments are substantially the same as those of the first embodiment.

As described above, according to the present invention, a separate annular oil pan made of lightweight material is provided on the outer periphery of the lower end portion of the tappet, so that lubricity can be improved without increasing the weight of the tappet.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a conventional device, Fig. 2 is a cross-sectional view showing a first embodiment of the present invention, Fig. 3 is a cross-sectional view showing a second embodiment of the present invention, and Fig. 4 is a cross-sectional view showing a second embodiment of the present invention. Cross-sectional view showing the third embodiment, fifth
The figure is a view of the tappet from the bottom, and Figure 6 is Figure 4A.
FIG. 7 is a sectional view showing the fourth embodiment of the invention, FIG. 8 is a sectional view showing the fifth embodiment of the invention, and FIG. 9 is a sectional view showing the sixth embodiment of the invention. FIG. 1... Tappet, 3... Bush rod, 6... Camshaft, 7... Cam, 8...
...Tappet bottom, 9...Oil pan, 10.
14. 19.20.22... Tappet, 1
2, 15, 18, 21, 23... Oil pan.

Claims (1)

[Claims for Utility Model Registration] 1. A tappet that serves as a cam follower of a cam rotated by a camshaft, the tappet having a lower end portion having a contact portion with the cam, and a cam and a cam on the outer periphery of the lower end portion of the tappet. A tappet characterized in that an annular oil holder separate from the tappet is fixed to a non-contact part with the tappet, and the annular oil holder is made of a lightweight material. 2. The tappet as set forth in claim 1 of the utility model registration claim, in which an annular oil receiver is screwed onto the outer periphery of the lower end portion of the tappet. 3. The tappet as set forth in claim 1 of the utility model registration claim, in which an annular oil receiver is press-fitted into the outer periphery of the lower end portion of the tappet. 4. The tappet according to claim 1, which is a utility model, in which an annular oil holder having an angular cross-section is press-fitted into the outer periphery of the lower end portion of the tappet. 5. The tappet as set forth in claim 1 of the utility model registration claim, in which an annular oil receiver is cast into the outer periphery of the lower end portion of the tappet.