JP2562037Y2 - Reservoir cap with breather - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cap mounted on an oil supply port of a reservoir for storing hydraulic oil of a hydraulic device such as a master cylinder, and more particularly, to an outer cap and a cap provided inside the outer cap. The present invention relates to a cap with a breather, which comprises an inner cap defining an expansion chamber therebetween and communicates the inside of the reservoir with the atmosphere via the expansion chamber.

[0002]

2. Description of the Related Art In this type of conventional cap with a breather,
As disclosed in Japanese Utility Model Laid-Open No. 3-55362,
A small hole communicating between the expansion chamber and the inside of the reservoir is provided in the inner cap for the purpose of preventing the hydraulic oil from entering the expansion chamber from inside the reservoir while allowing the breathing inside the reservoir.

[0003]

Incidentally, the small holes need to be as small as possible in order to reliably achieve the above object, and if they are small, they tend to be clogged. Although it is necessary to provide them, it is difficult to meet these requirements in terms of processing.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and a breather of the reservoir capable of easily forming a myriad of maze-like fine passages between the expansion chamber and the inside of the reservoir to satisfy the above-mentioned requirements. It is intended to provide an attached cap.

[0005]

In order to achieve the above-mentioned object, the present invention provides a funnel-shaped portion facing an expansion chamber in an inner cap, and a vent hole communicating the deepest portion of the funnel-shaped portion into a reservoir. A barrier that covers the vent and abuts the funnel is disposed in the expansion chamber, and a number of labyrinthine fine passages are defined between the funnel and the abutment surface of the barrier in order to define a myriad of fine passages. At least one of the contact surfaces is formed in a matte rough surface.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, a reservoir 1 is for storing hydraulic oil for a hydraulic device such as a master cylinder (not shown). An oil supply port cylinder 2 is provided on an upper surface thereof, and an oil feed pipe 3 is provided on a lower surface thereof. Provided.

[0008] A cap 4 is usually mounted on the fuel filler cylinder 2. The cap 4 abuts and fits with an outer cap 5 that is bayonet-coupled to the outer periphery of the fuel filler tube 2 and the upper end surface and the inner peripheral surface of the fuel filler tube 2 inside the outer cap 5 via a seal member 7. And an inner cap 6. These are all made of synthetic resin.

The inner cap 6 has a cylindrical portion 8 into which the sealing member 7 is fitted, a pair of flanges 12 and 13 formed at upper and lower ends of the cylindrical portion 8 to clamp the sealing member 7,
A funnel-shaped portion 14 connected to the inner peripheral edge of the upper end portion of the cylindrical body portion 8;
5, and the ventilation pipe 15 has a ventilation hole 15a vertically penetrating therethrough. The upper flange 12
Is formed to have a larger diameter than the lower flange 13, and its outer peripheral portion is sandwiched between the annular step 16 on the inner wall of the outer cap 5 and the locking claw 17.

The funnel 14 defines an expansion chamber 19 between itself and the ceiling wall 18 of the outer cap 5. A labyrinth 20 for communicating the expansion chamber 19 with the atmosphere is provided by the upper flange 12 and the outer cap 5. It is formed between the facing surfaces.

On the ceiling wall 18 of the outer cap 5, a funnel-like portion 14 is formed in an annular area A (FIG. 2) surrounding the vent hole 15a.
A barrier 21 having a spherical end 21a that abuts on the upper surface and covers the ventilation hole 15a is integrally formed.

Thus, at least the annular region A on the upper surface of the funnel-shaped portion 14 is formed on a matte rough surface 22, while the surface of the spherical end portion 21a abutting on the rough surface 22 is formed on a mirror surface. By doing so, the funnel-shaped part 14 and the abutment 2
Between the abutment surfaces 1, a myriad of fine labyrinths 23 communicating between the inside and outside of the annular area A are defined innumerably.

The rough surface 22 is formed by shot peening or sand blasting after the inner cap 6 is formed, or is formed by a previously formed rough surface on the inner surface of a mold when the inner cap 6 is formed. This rough surface 2
The preferred roughness of 2 is 12.5 to 25Z. Rough surface 2
If 2 is less than 12.5Z, the air permeability of the fine passage 23 will deteriorate, and if it exceeds 25Z, the oil in the reservoir 1 will easily pass through the fine passage 23.

Next, the operation of this embodiment will be described.
The interior of the reservoir 1 is provided with a vent 15a,
3. Since hydraulic fluid is constantly communicated with the atmosphere through the expansion chamber 19 and the labyrinth 20, when hydraulic oil is transferred between the reservoir 1 and a hydraulic device such as a master cylinder (not shown) through the oil supply pipe 3, the reservoir 1 The inside of the reservoir 1 can breathe smoothly according to the elevation of the oil level inside. Moreover, since there are countless fine passages 23, even if a part of the passages is clogged with dust or the like, the respiratory action is not hindered.

On the other hand, due to the vibration applied to the reservoir 1, the oil level inside the reservoir 1 vibrates violently, and a part of the oil vigorously rises through the vent hole 15a. Is attenuated, and the remaining oil tends to pass through the maze-like fine passage 23, but is blocked by the large restriction resistance of the passage 23. Therefore, even if the fine passage 2
If there is any oil that enters the expansion chamber 19 through the passage 3, the amount of the oil is very small, and the oil goes down the fine passage 23 along the slope of the funnel-shaped portion 14 with the passage of time and passes through the vent hole 1.
Returning to the reservoir 1 from 5a, even if the expansion chamber 19 has a relatively small volume, it does not reach the point where the oil that enters the expansion chamber 19 is full, and the oil leaks out through the labyrinth 20. Never.

FIG. 3 shows another embodiment of the present invention.
The barrier 21 is made of a steel ball, and has the same configuration as that of the previous embodiment except that a protrusion 18a for pressing the upper surface is formed on the ceiling wall 18 of the outer cap 5 in order to prevent the barrier 21 from jumping. In the figure, in the part corresponding to the previous embodiment,
The same reference numerals are given.

Various modifications can be made to the above embodiments without departing from the gist of the present invention. For example, the surface of the barrier 21 may be formed in a pear-shaped rough surface, and the upper surface of the funnel-shaped portion 14 may be made a mirror surface, or both may be made rough surfaces. However, it is advantageous to make one rough surface and the other a mirror surface in order to prevent abrasion of the rough surface.

[0018]

As described above, according to the present invention, the inner cap is provided with a funnel-shaped portion facing the expansion chamber, and a vent hole communicating the deepest portion of the funnel-shaped portion into the reservoir. A barrier that covers and abuts the funnel is disposed in the inflation chamber, and at least one of the abutment surfaces is defined between the abutment surfaces of the funnel and the barrier so as to define a myriad of microscopic passages. Since it is formed on a matte rough surface, the breathing inside the reservoir can be performed smoothly through the fine passages, and since there are countless fine passages, the clogging of a part of them may interfere with the above breathing Absent. In addition, the oil in the reservoir is effectively prevented from entering the expansion chamber due to the large restriction resistance of the fine passage, and even if it does, the oil is very small and the slope of the funnel-shaped part with the passage of time Can be returned into the reservoir along. Therefore, the expansion chamber needs to have a relatively small volume, which can contribute to downsizing of the cap. Moreover, since the rough surface can be easily obtained by shot peening or the like, there is no difficulty in processing.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part of a reservoir equipped with a cap with a breather according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of FIG.

FIG. 3 is an enlarged view corresponding to FIG. 2, showing a second embodiment of the present invention;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reservoir 2 Refueling port cylinder 4 Cap 5 Outer cap 6 Inner cap 14 Funnel-shaped part 15a Vent hole 19 Expansion chamber 21 Barrier 22 Rough surface 23 Fine passage

Claims (1)

(57) [Scope of request for utility model registration] 1. A cap (4) mounted on a fuel filler cylinder (2) of a reservoir (1) is provided between an outer cap (5) and an inner cap (5), and is expanded between the cap and the outer cap. An inner cap (6) defining a chamber (19), wherein the interior of the reservoir (1) communicates with the atmosphere via the expansion chamber (19). A funnel-shaped part (14) facing the expansion chamber (19) and a vent (15a) communicating the deepest part of the funnel-shaped part (14) into the reservoir (1). ), And a barrier (21) that contacts the funnel is disposed in the expansion chamber (19), and a maze-like fine passage is provided between the funnel (14) and the contact surface of the barrier (21). In order to define innumerable (23), at least one of the contact surfaces Characterized by being formed in the land-like rough surface (22), the breather cap with the reservoir.