JPH07243363A - Breather - Google Patents

Abstract

PURPOSE:To certainly prevent leakage of gasoline from a gasoline tank by providing a check valve to open and close flowing of an orifice. CONSTITUTION:A breather 4 installed on an opening part 21 of a gasoline tank 1 has a holding plate 5 having a through hole 10 and a partition plate 6 having an orifice 9. A function film 14 hating gas permeability and having a characteristic to obstruct passing of fluid is provided on the holding plate 5 and a check valve 18 is provided on the partition plate 6 respectively. Gasoline leakage from the gasoline tank 1 is prevented by existence of the function film 14 and the check valve 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a breather, and more particularly to a breather suitable for use in a gasoline tank in a portable general-purpose engine used in a brush cutter such as a mower.

[0002]

2. Description of the Related Art FIG. 2 shows an engine of a general brush cutter. The engine has an engine section 50 and a gasoline tank 51 which is a fuel tank. A breather used for the gasoline tank 51 of such an engine is shown in FIG.

That is, the breather 54 shown in FIG. 3 is composed of a rubber-like elastic body, a partition case 55 having an orifice 55a, and a sponge filter 59 held by the partition case 55. The partition case 55 is a fuel filler port 51a of the gasoline tank 51.
The cap 53 is attached to the cap 53 that can be screwed in a state of being fitted to the partition 53, and the partition case 55 is attached in a state in which the inside of the cap 53 is partitioned.

The cap 53 has an orifice 53a.
However, each of the partition cases 55 has an orifice 55a formed therein, and the orifice 53 of the cap 53 is formed.
In the middle of the flow path from a to the orifice 55a of the partition case 55, the partition case 5 is closed with the flow path closed.
A sponge filter 59, which is held at 5, is provided.

Then, as shown in FIG. 6, the breather 54
When the cap 53 integrally attached to the fuel tank 51 is screwed into the fuel filler port 51a of the gasoline tank 51, the inside of the gasoline tank 51 becomes the orifice 55a of the partition case 55, the sponge filter 59, and the orifice 53 of the cap 53.
The internal pressure of the gasoline tank 51 is adjusted by communicating with the outside via a.

However, in the breather 54 described above, when the gasoline tank 51 is tilted as shown in FIG. 7, the gasoline 52 contained therein leaks to the outside through the orifices 55a and 53a. There was something that happened.

Another conventional example is shown in FIG. That is, FIG.
The breather 74 shown in is formed of a partition member 75 having a unidirectional valve portion 76. In FIG. 4, the cap 53 can be screwed in a state in which the cap 53 is fitted into the fuel filler port 51a of the gasoline tank 51 shown in FIG. A partition member 75, which is a rubber-like elastic body and partitions the interior of the cap 53, is attached to the cap 53 in an engaged state. At this time, the partition member 75 is used for the fuel filler port 5 of the gasoline tank 51.
It is formed in a shape that covers 1a.

A valve portion 76 having an orifice 76a is formed at the center of the partition member 75. As shown in FIG. 5, the valve portion 76 is formed in a valley portion that opens upward, and an orifice 76a is formed on the side surface of the valley portion. Then, the valley portion of the valve portion 76 opens and closes the orifice 76a when both side surfaces f, f are brought into close contact with each other and separated from each other.
It can communicate with the orifice 53a formed in the cap 53. Note that FIG. 5 is a diagram showing a state where the valley portion of the valve portion 76 is open, and a state where the valley portion is closed is as shown in FIG.

Then, as shown in FIG. 6, a breather 74
When the cap 53 integrally attached to the fuel tank 51 is screwed into the filler opening 51a of the gasoline tank 51,
The inside of the above will communicate with the outside through the valve portion 76 of the partition member 75. As a result, the gasoline tank 5
The internal pressure of 1 is adjusted to be constant by opening and closing the valve portion 76 according to its size.

However, in the breather 74, when the gasoline tank 51 is tilted, the gasoline 52 contained inside may leak to the outside.

Generally, the gasoline tank 51 is preferably used in a horizontal state, and in that case, the function of adjusting the internal pressure as a breather is exhibited. However, in the case of a portable engine, how to use it and how to place it are not specified, so the gasoline tank 5
1 may be placed in an inclined state for a long time as shown in FIG. At this time, the gasoline 52 comes into direct contact with the breather 74, so that the function as the breather is not exerted. In particular, after the engine is stopped, the temperature of the gasoline 52 often rises due to the heat from the engine, and the internal pressure of the gasoline tank 51 often rises, which may cause the gasoline 52 to leak to the outside.

It is an object of the present invention to solve the above problems and provide a breather capable of reliably preventing fuel leakage from a fuel tank.

[0013]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention partitions a fuel tank opening into a holding plate having a through hole and is attached to the holding plate to connect the through hole and the outside. In the fuel tank that passes through the orifice of the partition plate, and a filter member that partitions the space and through which gas passes but does not pass the liquid, partitions the opening inside of the holding plate and has an orifice The breather comprises a check valve which opens and closes the flow of the orifice in response to a positive pressure.

[0014]

The present invention, by adopting the above means,
A check valve and a filter member prevent fuel from leaking from the fuel tank.

Since the filter member has gas permeability and liquid impermeability, water can be prevented from entering from the outside, and the fuel can be prevented by the check valve. When the positive pressure in the tank rises, the pressure can open the check valve and further permeate and open the filter member.

[0016]

Embodiments of the present invention shown in the drawings will be described below. FIG. 1 is a diagram showing an embodiment of a breather according to the present invention. That is, the breather 4 shown in FIG.
Holding plate 5 having 0 and partition plate 6 having orifice 9
And the partition plate 6 is provided with a functional film 14 as a filter member, and the gasoline partition plate 7 as a fuel partition plate having an orifice 8 is provided with a check valve 1
8 are provided.

In FIG. 1, the cap 3 can be screwed in a state in which it is fitted in the fuel filler port 1a of the gasoline tank 1 which is a fuel tank. A resin holding plate 5 that partitions the interior of the cap 3 and forms the third chamber C is attached to the cap 3. The holding plate 5 is formed so as to be able to close the fuel filler port 1a of the gasoline tank 1, and has a through hole 10 formed in the center thereof. This through hole 10 is the third
It communicates with the orifice 3a formed in the cap 3 through the chamber C.

The functional film 14 is held on the holding plate 5 and is located in the flow path from the through hole 10 to the orifice 3a of the cap 3. The functional film 14 has a pore diameter of 1 μm.
It is made of a porous material of about m and has a disk shape.
It has the property of allowing the passage of gas, but blocking the passage of liquids such as water, gasoline and oil. Functional film 14
As an example, for example, a PTFE (polytetrafluoroethylene) film is used to improve gasoline / oil resistance,
An oil-repellent or water-repellent treatment is applied, and a product having a predetermined gasoline pressure resistance is used.

The functional film 14 is sandwiched between buffer rings 12 and 13 located on the upper and lower surfaces of the peripheral edge thereof, and is pressed by the presser cover 11 to be fixed to the holding plate 5. As shown in the drawing, the pressing cover 11 may be fitted in an annular engaging portion 5a formed on the holding plate 5 in an engaged state, or may be directly welded to the holding plate 5. In addition,
The buffer rings 12 and 13 are made of a rubber-like elastic body having gasoline resistance.

A partition plate 6 is provided below the holding plate 5 to form a second chamber B between the partition plate 6 and the holding plate 5. The partition plate 6 is formed in a size and shape capable of closing the fuel filler port 1a of the gasoline tank 1, and a mounting hole 19 is formed in the center thereof. The mounting hole 19 has a rubber-like elastic body having gasoline resistance. Alternatively, a check valve 18 made of elastic plastic is attached.

The check valve 18 has a cylindrical valve body 15 having an upward opening, an annular lip 16 formed in the opening, and a slit 17 formed in the closed end surface of the valve body 15. It has a lip 16
Is attached in a state in which the peripheral edge portion of is in contact with the upper surface of the partition plate 6. An orifice 9 is formed in the part of the partition plate 6 covered by the lip 16, and the orifice 9 is opened and closed by elastic deformation of the lip 16.

A gasoline partition plate 7 which forms a first chamber A between the partition plate 6 and the lower part of the partition plate 6 is provided. The gasoline partition plate 7 is formed in a size and shape capable of closing the fuel filler port 1a of the gasoline tank 1, and an orifice 8 is formed in the center thereof. The gasoline partition plate 7 covers the check valve 18 from below. The holding plate 5, the partition plate 6, and the gasoline partition plate 7 having heat resistance and gasoline resistance are used.

When the holding plate 5, the partition plate 6 and the gasoline partition plate 7 are attached to the cap 3, the plates 5, 6, 7 are stacked and then the plates 5, 6, 7 are stacked. The annular gasket 20 made of a rubber-like elastic material having gasoline resistance is positioned in the peripheral portion and pushed into the inside of the cap 3. Then, the gaskets 20 are interposed between the plates 5, 6, 7 and the cap 3 to be integrated. At this time, in order to improve the sealing performance between the plates 5, 6, 7 and the cap 3, the outer diameters of the plates 5, 6, 7 and the inner diameter of the gasket 20 are provided with a tightening margin. Is desirable.

In order to mount the thus-configured one on the gasoline tank 1, the cap 3 to which the breather 4 is integrally attached via the gasket 20 is screwed into the fuel inlet 1a of the gasoline tank 1. This allows gasket 2
0 seals the open end of the fuel filler port 1a of the gasoline tank 1, and is installed so as to partition the mouth 21 of the fuel tank 1. Then, inside the gasoline tank 1, the orifice 8 of the gasoline partition plate 7, the check valve 18 of the partition plate 6, the through hole 10 of the holding plate 5, the air-permeable functional film 14, and the orifice 3a of the cap 3 are provided. The pressure is released by communicating with the outside through the. Thereby, the internal pressure (vapor pressure) of the gasoline tank 1 is adjusted.

When the inside of the gasoline tank 1 has a negative pressure, the check valve 18 opens the slit 17 by the action of the negative pressure to introduce the pressure, and the gasoline tank 1 is sucked. Further, when the inside of the gasoline tank 1 has a positive pressure, the lip 16 is elastically deformed by the action of the positive pressure, the orifice 9 is opened, and the pressure in the gasoline tank 1 is released. In any case, since the functional film 14 has an air permeability even though it blocks the passage of liquid, the gasoline in the gasoline tank 1 does not move through the functional film 14, Only gas is inhaled and released.

The breather 4 has a check valve 18 provided on the partition plate 6 and a functional film 14 for preventing the passage of liquid, and is double-checked against leakage of gasoline 2. Due to the structure, even if the gasoline tank 1 is tilted, the gasoline 2 is prevented from passing through the functional film 14 and proceeding to the outside.

Moreover, since the check valve 18 is covered with the gasoline partition plate 7, the check valve 18 is not directly applied when the gasoline 2 contained in the gasoline tank 1 swells. Also, if
Even if the gasoline 2 penetrates through the orifice 8 of the gasoline partition plate 7 and enters the first chamber A, the gasoline 2 does not hit the check valve 18 violently. Therefore, the leakage of the gasoline 2 from the check valve 18 will be significantly suppressed.

Further, the gasoline 2 does not pass through the check valve 18 and the functional film 14, but in the unlikely event that it passes, the passing amount is very small.
Is contained in the second chamber B or the third chamber C, and is vaporized at that location to be released to the outside. Therefore, the leakage of the gasoline 2 is surely prevented. Furthermore, since the functional film 14 also blocks the passage of water,
It is designed to prevent rainwater and the like from entering the gasoline tank 1 from the outside.

In the breather 4 described above, since the check valve 18 and the functional film 14 are assured of air permeability, even if the inside of the gasoline tank 1 becomes a negative pressure by consuming the gasoline 2, for example. , Is immediately inhaled to maintain a predetermined internal pressure. Therefore, there is no problem that the gasoline 2 sent to the carburetor side (not shown) is reduced.

[0030]

Since the breather according to the present invention has the check valve, it is possible to effectively prevent the fuel from leaking to the outside. Then, when the pressure in the fuel tank rises, the gas body opens the check valve and tries to flow out, but the fuel molecules contained in the gas body are captured by the filter member, and only air flows out.

Further, when the pressure in the fuel tank becomes negative and the air from the outside flows in, the moisture in the air is captured by the filter member, and only the air with a small moisture can flow in. Therefore, there is an effect that it is possible to prevent the intrusion of water into the fuel tank and surely prevent the fuel leakage from the fuel tank.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a breather according to the present invention.

FIG. 2 is a diagram showing a general-purpose engine.

FIG. 3 is a diagram showing a conventional example.

FIG. 4 is a diagram showing another conventional example.

FIG. 5 is an enlarged view of the valve portion in FIG.

FIG. 6 is a first diagram illustrating an operation of a conventional example.

FIG. 7 is a second diagram illustrating the operation of the conventional example.

[Explanation of symbols]

 1, 51 ... Gasoline tank (fuel tank) 1a, 51a ... Refueling port 2, 52 ... Gasoline (fuel) 3, 53 ... Cap 3a, 8, 9, 53a, 55a, 76a ... Orifice 4, 54 , 74 ... Breather 5 ... Holding plate 5a ... Engaging part 6 ... Partition plate 7 ... Gasoline partition plate (fuel partition plate) 10 ... Through hole 11 ... Presser cover 12, 13 ... Buffer ring 14 …… Functional film 15 …… Valve body 16 …… Lip 17 …… Slit 18 …… Check valve 19 …… Mounting hole 20 …… Gasket 21 …… Port 50 …… Engine part 55 …… Partition case 59 …… Sponge Filter 75 ... Partition member 76 ... Valve A, B, C ... Chamber

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[Procedure amendment]

[Submission date] December 9, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

[0016]

Embodiments of the present invention shown in the drawings will be described below. FIG. 1 is a diagram showing an embodiment of a breather according to the present invention. That is, the breather 4 shown in FIG.
Holding plate 5 having 0 and partition plate 6 having orifice 9
And a gasoline partition which is a fuel partition plate having an orifice 8.
The holding plate 5 has a cutting plate and a functional film as a filter member.
14 is provided, and a check valve 18 is provided on the partition plate 6.
It has been burned.

Claims (1)

[Claims] 1. A holding plate (5) for partitioning an opening (21) of a fuel tank (1) and having a through hole (10), and the holding plate (5) attached to the holding plate (5) and the outside. And a partition plate (6) having a orifice (9) for partitioning the filter member (14) that allows gas to pass but does not allow liquid to pass, and the opening (21) that is inside the holding plate (5). ), And a check valve (18) for opening and closing the flow of the orifice (9) in response to the positive pressure in the fuel tank (1) passing through the orifice (9) of the partition plate (6). Breather characterized by.