JPS6033283Y2 - Valve stem cap pop-out prevention device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a cap popping-out prevention device that prevents a cap placed on the head of a valve stem of an intake/exhaust valve of an internal combustion engine from falling off.

Conventionally, when a stem cap is placed on the valve stem of an internal combustion engine, when the height h of the head 1a of the stem 1 is small, as shown in Fig. 1, the depth of the cap 2 is not sufficient. Also, in horizontal engines, the valve shaft is horizontal, so the vibration of the valve could cause the cap 2 to fly off the valve stem.

To solve this problem, increase the h dimension,
For example, it is possible to increase the height of the rocker shaft bracket to increase the h dimension, but this is often difficult in terms of design, and in existing engines, making this bracket taller would require changes in the design of related parts. Not only is this disadvantageous in terms of compatibility, but additional drawbacks arise, such as the valve becoming heavier and the dynamic characteristics of the valve deteriorating.

For example, Japanese Utility Model Application Publication No. 50-145908 discloses a cap holding member that is fastened to a retainer with bolts, and a cap groove that is engaged with a clip or knock pin.

However, in this known technique, since the cap is pressed down relatively strongly, the cap cannot be rotated.
Therefore, the end of the rocker arm collides with only one part of the cap, resulting in abnormal wear on the cap and shortening the life of the cap.

In addition, tightening bolts or cutting grooves into the cap impairs assembly and workability. Therefore, the purpose of this invention is to improve assembly, workability, and workability, and to make the cap rotatable. To provide an attachable valve stem cap pop-out prevention device.

According to the present invention, it is cut out from the holding member of the cap that is placed on the head of the valve stem. , consisting of an engaging element that has a large diameter hole and a smaller diameter hole than the flange of the cap, has a clearance in the flange of the cap, and engages with the flange of the cap, and a locking element that elastically engages with the retainer of the valve. has been done.

Therefore, since the flange of the cap engages with the engaging element formed around the hole of the holding member, it is possible to prevent the cap from popping out.

Further, since there is always a clearance between the flange and the engagement element, there is no problem in rotating the cap.

Since the holding member is elastically locked to the retainer by the locking element, the holding member can be easily assembled.

Since the holding member itself is not subjected to much acting force, it is sufficient to hold it by the step action of the locking element.

The locking element can also be made sufficiently light so that jumping and balancing of the valve can be reduced.

When carrying out the present invention, it is preferable that the planar shape of the presser member is substantially rectangular, and that the locking element is formed by bending the short side end of the rectangle inwardly into an arc shape.

By doing so, the above-mentioned effects can be further exhibited.

Embodiments of the present invention will be described below with reference to FIGS. 2 to 5.

The embodiment shown in FIG. 2 is similar to the conventional example shown in FIG. 1 in that a cap 2 is placed over the head 1a of the stem 1.

However, in the embodiment shown in FIG. 2, a holding member 10 for the cap 2 is provided, and this holding member 10 is formed from a plate into a circular or substantially rectangular planar shape by pressing or drawing, and has a cross section of approximately 80 mm. A hole having a diameter larger than that of the cap 2 is formed in the substantially central part thereof, and an engaging element 11 that engages with the flange 21 of the cap 2 is formed therein.

Further, the hem portion 12 of the presser member 10p is secured to the retainer 30 by an elastic ring 40 having a hook-shaped cross section.

Therefore, the elastic ring 40 constitutes a locking element that elastically locks the holding member 10 to the retainer of the valve.

In the illustrated embodiment, a groove 31 is formed on the outer periphery of the retainer 30 in order to prevent the elastic ring 40 from falling off, and a portion of the ring fits into this groove.

A clearance 1 is formed between the flange 31 and the engagement element 11, and the cap 2 is rotatable.

3 and 4 show another embodiment of the present invention. In this embodiment, the presser member 10 is formed from a single elastic plate, and its planar shape is rectangular. The vertical cross-section is shaped like a figure eight.

The engaging element 11 that engages with the flange 21 of the cap 2 is formed with a hole that is larger than the cap diameter but smaller than the outer diameter of the flange, similar to that shown in FIG.

The hem portion 12 on the short side of the holding member 10 extends across the outer periphery of the retainer 30, hangs down from there to form a hanging portion 16, and is further bent slightly inward to form an inclined portion 17. It is well-formed.

These hem portion 12, hanging portion 16, and inclined portion 17 constitute a locking element that locks with the retainer.

This embodiment also has a clearance 1 for making the cap 2 rotatable.

The embodiment shown in FIG. 5 is a modification of the one shown in FIG.
It is made of an elastic material with a U-shaped cross section, sandwiching the two sides.

As described above, the valve stem cap pop-out prevention device according to the present invention has a flange 21 formed on the cap 2, and a holding member 10 having an engaging element that engages with the flange 21, and a locking element on the retainer 30. Assembling is extremely simple as all you have to do is lock it in place.

Therefore, even when improving the prior art, it is only necessary to prepare a cap with a flange, a pressing member, and a locking element, and the improvement is easy.

Further, the cap 2 can be easily assembled by pressing down the engaging element 11 of the holding member 10 and covering the stem with the cap 2.

As explained above, according to the present invention, the cap is lightweight and securely held on the stem, so there is no fear of the cap popping out even when the exhaust brake is activated.

The entire device is extremely simple and can be manufactured at low cost, and has little effect on the valve system.

If a cap with a flange is used, it can be easily applied to an existing valve, and since the holding member is simple and lightweight, the dynamic characteristics of the valve will not deteriorate.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a conventional valve stem and cap, Fig. 2 is a longitudinal sectional view showing one embodiment of the present invention, Fig. 3 is a longitudinal sectional view showing another embodiment, and Fig. 4 is a longitudinal sectional view of a conventional valve stem and cap. Plan view of figure 3, 5th
The figure is a longitudinal sectional view showing still another embodiment. 1... Stem, 1a... Stem head,
2...Cap, 21...Brim part, 10
... Pressing member, 11 ... Engagement element that engages with the collar, 12 ... Hem part.

Claims (2)

[Scope of utility model registration request] (1) It is cut out from the holding member of the cap that is placed on the head of the valve stem. A hole with a smaller diameter than the flange of the cap is formed, and the cap is composed of a retaining element that engages with the flange of the cap and a clearance, and a locking element that elastically engages with the retainer of the valve. Valve stem carb pop-out prevention device featuring: (2) The holding member has a substantially rectangular planar shape, and the locking element is formed by bending the short edge of the rectangle inward into an arc shape. Valve stem cap pop-out prevention device as described in section.