JPH0221621Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a front fork that prevents oil mixed in the air chamber from scattering when the air chamber is opened to the atmosphere.

(Conventional Front Fork) In the conventional front fork shown in FIG. A lower spacer 4 is provided.

The upper spacer 3 is connected to the first air chamber 6 between the upper spacer 3 and the cap 5 at the upper end of the inner tube 2.
is formed. Further, the lower spacer 4 is
An oil level 7 is located therein, and a second air chamber 8 is formed above the oil level 7.

Furthermore, there is a third spacer between these two spacers 3 and 4.
An air chamber 9 is provided, and a spring 10 is provided in this third air chamber 9.

In this front fork, an orifice 11 is formed in the upper spacer, and the mist of oil is
The air is prevented from flowing into the first air chamber 6.

The biggest drawback of such a conventional front fork is that the total volume of the second and third air chambers 8, 9 cannot be made large enough.

This is because the upper spacer 3 protrudes into the third air chamber 9, and the total volume becomes smaller accordingly.

When the total volume of the second and third air chambers becomes smaller, pressure changes within these air chambers increase when the inner tube 2 moves up and down, resulting in poor riding comfort.

Therefore, if an attempt is made to increase the total volume, a problem arises in that the overall length of the front fork becomes longer.

For this reason, in the conventional front fork, it has been impossible to overcome the drawback of poor riding comfort.

(Purpose of this invention) This invention makes the volume of the air chamber sufficiently large,
Moreover, the purpose is to provide a front fork that prevents oil flowing into the air chamber from turning into mist.

(Embodiment of the present invention) In the first embodiment shown in FIG. 2, an inner tube 22 is slidably inserted into an outer tube 21, and the upper end of the inner tube 22 is closed with a cap 23. There is.

A cylindrical body a is provided on the upper side of the inner tube 22, and the configuration of this cylindrical body a is as follows.

That is, the upper holder 24 and the intermediate holder 2
5, an upper cylinder member 26 is interposed therebetween.
That is, both the holders 24 and 25 are formed with protrusions 27 and 28 that protrude in directions facing each other, and the upper cylinder member 26 is fitted into these protrusions 27 and 28.

The upper cylindrical member 26 interposed between the holders 24 and 25 in this way has an outer diameter smaller than the inner diameter of the inner tube 22 and forms an annular chamber 29 between it and the inner tube 22. ing.

Further, a lower cylindrical member 31 is interposed between the intermediate holder 25 and a lower holder 30 provided below the intermediate holder 25.

The outer diameter of the lower cylindrical member 31 is made slightly smaller than the inner diameter of the inner tube 22 to maintain a gap between it and the inner surface of the inner tube.

And, on the lower side of the lower holder 30,
A protrusion 32 is provided, and the upper end of the spring 33 is placed along the circumference of the protrusion 32.

The inside of the cylinder a as described above and the upper part of the oil level 36 in the inner tube 22 together constitute the air chamber A of this invention.

Note that an oil passage hole 34 is formed in a portion of the inner tube 22 that corresponds to the annular chamber 29, and through this oil passage hole 34 and valve 35,
The annular chamber 29 can be opened to the atmosphere.

When the inner tube 22 moves up and down, the oil in the air chamber A becomes mist due to the expansion and contraction of the spring 33.

And this mist-like oil-laden air is
It flows into the annular chamber 29 through the gap formed between the lower cylindrical member 31 and the inner tube 22 .

However, when the air containing the mist of oil passes through the gap, the oil returns from the mist state to the liquid state.

Therefore, the valve 35 is opened and the annular chamber 2
Even if the air inside 9 is released to the atmosphere, mist oil will not spout out and stain the clothes of the workers.

Furthermore, since the annular chamber 29 is formed around the upper cylindrical member 26 as described above, the air chamber A can extend up to the upper end of the inner tube, and the substantial volume of the air chamber A can be You can make it bigger.

The second embodiment shown in FIG. 3 differs from the first embodiment only in the structure of the cylinder a.

In other words, the cylinder a in this second embodiment is 1
An upper holder 38 and a lower holder 39 are provided above and below the two cylindrical members 37.

The upper portion 37a of the cylinder member 37 is
The diameter is smaller than that of the lower part 37b, and an annular chamber 40 is formed between the upper part 37a and the inner tube 22. In addition, the lower portion 37b and the inner tube 22
As in the first embodiment, a very small gap is maintained between the two.

Therefore, also in this second embodiment, the annular chamber 40
Oil does not become mist inside.

Further, the air chamber A can be made sufficiently large as in the first embodiment.

In both the first and second embodiments, an orifice may be used to communicate the air chamber A with the annular chamber 29 or 40.

That is, in the first embodiment, an orifice may be formed in the upper cylindrical member 26, and the air chamber A and the annular chamber 29 may be communicated through this orifice. Also,
In the second embodiment, an orifice may be formed in the upper portion 37a.

(Structure of the present invention) The structure of the present invention is that a front fork is provided with an air chamber in the upper part of the inner tube and is opened to the atmosphere via a valve, etc., and a spring is attached to the lower end of the front fork. A cylindrical body provided with a receiving portion is provided in the air chamber, and an annular chamber is formed between a required portion around the cylindrical body and the inner tube, and the annular chamber and the air chamber are separated by a gap or an orifice. communicate through the
A further feature is that the annular chamber is opened to the atmosphere via the valve or the like.

Therefore, the entire interior of the cylindrical body can be used as an air chamber, and the oil flowing into the annular chamber is not in the form of mist but in complete liquid form.

(Effects of the present invention) With the above configuration, the air chamber above the inner tube can be made sufficiently large.
The change in pressure within the air chamber is also reduced, and the riding comfort is improved accordingly.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional main part, FIG. 2 is a sectional view of a main part of a first embodiment of this invention, and FIG. 3 is a sectional view of a main part of a second embodiment. 22... Inner tube, a... Cylindrical body, 2
9, 40... annular chamber, 33... spring, A...
...air chamber, 35...valve.

Claims (1)

[Scope of utility model registration request] In the front fork, an air chamber is provided in the upper part of the inner tube, and the air chamber is opened to the atmosphere via a valve, etc., and a cylindrical body is provided with a spring receiving part at the lower end.
An annular chamber is provided in the air chamber, and an annular chamber is formed between a required portion around the cylinder and the inner tube, and the annular chamber and the air chamber are communicated through a gap or an orifice. A front fork configured to open the chamber to the atmosphere via the above-mentioned valve.