JPH0134701Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a fuel tank for a portable engine in which the air passage of the air vent can be opened and closed simultaneously with the operation of the fuel tank.

[Problems to be solved by conventional technology and ideas] Fuel tanks for portable engines are prone to problems such as fuel leakage due to gas expansion in the internal space, or insufficient fuel supply to the engine due to low pressure in the internal space. To prevent problems, it is necessary to constantly communicate with the atmosphere, and for this purpose a ventilation device is provided. Conventionally, for example, in the case of a fuel tank with a handle, the venting device was provided in the tank cap. In this case, if the tank cap was installed in the center of the tank, the handle would be difficult to grip, reducing operability, so the tank cap had to be installed eccentrically to the side from the handle. Then, if the tank cap is tilted upward, the air passage will not be blocked by the oil level and there is no problem, but if the tank cap is tilted downward, the oil level will block the ventilation passage, as mentioned above. Problems such as these occur, and as a result, the tilt resistance characteristics are affected by the position of the tank cap.
Furthermore, when the engine is operated in the rain, there is a risk that rainwater may enter the fuel tank through the tank cap's ventilation passage.

Therefore, a venting device for a fuel tank has been proposed to prevent such problems. for example,
Japanese Utility Model Publication No. 55-39797 discloses a prior art related to a ventilation device for a fuel tank for a portable engine. In the case of this conventional technology, a hollow handle is provided on the top surface of the fuel tank, a vent pipe is connected to vent holes provided near both ends of the handle, and the vent pipe is housed in the hollow part of the handle, and the other end of the handle is It is characterized by being extended to open.

With this conventional technology, when the engine is stopped and left unattended, or when the engine is mounted in a car or the like and transported, the fuel in the tank vaporizes and the pressure rises, causing vaporized gas to flow out of the fuel tank. This not only causes leakage fuel odor, but also causes problems such as air pollution and fuel wastage.

To deal with this, for example,
As disclosed in the above publication, the above-mentioned vaporization can be achieved by installing an interlocking mechanism that can simultaneously open and close the fuel supply path and the ventilation path that opens above the liquid level in the closed tank and penetrates the closed tank. This makes it possible to prevent gas from leaking out of the fuel tank.

However, in these prior examples, in order to prevent fuel oil from leaking from the tank, air-tight and liquid-tight means were used between the stud and the tank periphery, and air-tight and liquid-tight means between the air supply pipe as a ventilation path and the closed tank. All of these methods require special welding, etc., require a large number of manufacturing steps, are not suitable for mass production, and inevitably lead to an increase in costs.

Furthermore, in all of the preceding examples, the ventilation pipe (air supply pipe) is supported at one point, so it is vulnerable to shocks.
In addition, there is a problem in that vibrations during engine operation cause resonance, resulting in so-called chatter noise.

[Purpose of the invention] This invention was made in view of the above circumstances.
It has a simple structure that reliably prevents fuel oil from leaking from the fuel tank and allows ventilation, and even when the engine is stopped, the ventilation path is blocked to prevent vaporized gas in the fuel tank from leaking out, causing fuel odor and odor. The purpose of the present invention is to provide a fuel tank for a portable engine that prevents air pollution and fuel wastage, ensures impact resistance and strength, and does not cause chatter noise due to vibration.

[Means and effects for solving the problem] In order to achieve the above object, the present invention provides a hollow handle that is fixedly installed on the upper surface of the fuel tank of the engine, and that the hollow part of the handle communicates with the upper space inside the fuel tank. In a fuel tank for a portable engine, which houses a ventilation pipe and is equipped with an interlocking knob that simultaneously opens and closes a fuel supply path communicating from the fuel tank to the carburetor and a ventilation path, openings are provided at both ends of the handle of the fuel tank. a first vent pipe that interconnects the vents of the handle, the first vent pipe being disposed within the hollow part of the handle, and having one end communicating with the first vent pipe within the hollow part of the handle;
A second vent pipe is provided whose other end communicates with the vent outlet of the interlocking pot, and the second vent pipe is configured to penetrate through one end of the handle and be fixed to the outside of the fuel tank. .

That is, when the interlocking cock is opened, fuel is supplied from the fuel supply path to the carburetor, and at the same time, the second vent pipe communicates with the atmosphere, and the second vent pipe communicates with the atmosphere through the first vent pipe that communicates with the second vent pipe. The upper space within the fuel tank is communicated with the atmosphere. Further, when the interlocking cock is closed, the supply of fuel from the fuel supply path to the carburetor is stopped, and at the same time, the second vent pipe is cut off from the atmosphere. As a result, the first vent pipe is closed, and the upper space within the fuel tank is isolated from the atmosphere.

[Embodiments of the invention] The invention will be specifically described below with reference to the drawings.

1 to 4 relate to an embodiment of the present invention,
Figure 1 is an explanatory diagram showing the structure of the fuel tank, Figure 2 is an enlarged cross-sectional view of the attachment part of the handle in Figure 1, Figure 3 is a piping system diagram, and Figure 4 is a diagram of the ventilation pipe in the center of the handle. It is a sectional view showing a connection part.

In these figures, reference numeral 1 denotes a fuel tank for a portable engine, etc., and a hollow handle 2 is attached to the upper surface thereof with a stud 3. The fuel tank 1
The upper surface of the main body 4 is formed into a substantially rectangular shape, and both ends of the fuel tank main body 4 in the longitudinal direction are formed in a substantially rectangular shape.
A mounting portion 5 is formed to protrude somewhat from the top surface.

The handle 2 is molded from resin or the like, and a handle core 6 is provided inside for reinforcement on the lower side of the handle 2. Also, in order to attach the handle 2, a part of the handle core 6 extends out to attach the handle. A portion 7 is formed. The handle attachment part 7 and the attachment part 5 of the fuel tank body 4 are connected by a stud 3 inserted into a hole penetrating each through an air-liquid sealing means, for example, an O-ring 8, between them.
The mounting portion 5 is screwed and tightened into a nut 9 which is brazed or the like on the inner surface of the fuel tank body 4.

The stud 3 is provided with a ventilation passage 12 that communicates the upper space 10 of the fuel tank body 4 with the hollow part 11 of the handle 2, and the openings at both ends of the ventilation passage 12 serve as ventilation holes 13a and 13b. ing. A vent hole 13b on the hollow part 11 side of the handle 2
One end side of the first ventilation pipe 14 made of a material such as rubber is connected to the hollow part 11 of the handle 2, and the other end side is connected to the hollow part 11 of the handle 2.
A first ventilation pipe 14 and a Y-shaped joint 14' are housed in the interior and extend toward the other mounting part, and are similarly connected to the other mounting part at approximately the center of the handle 2.
One end of the vent pipe 15 is connected to the Y-shaped joint 14', and the other end extends to one side of the mounting portion again.

Further, on the side surface side of the fuel tank body 4 on the side where the vent pipe 15 is extended, a vent pipe 16 made of a metal material is provided at one end of the hollow part 1 of the attachment part of the handle 2.
The fuel tank body 4 protrudes into the fuel tank body 4 and is connected to the vent pipe 15 so as to communicate therewith, and its other end extends downward and is attached to the upper side of the fuel tank body 4 by welding.

On the other hand, an interlocking knob 17 is provided on the outer bottom surface of the fuel tank body 4. This interlocking knob 17 has a knob that opens and closes the fuel supply path that supplies fuel oil to the carburetor 18 and a knob that opens and closes simultaneously in conjunction with this opening and closing, and a single knob 19.
It can be operated with. The interlocking kettle 17
The supply passage inlet part 20 of the fuel supply passage side is connected to the bottom of the fuel tank body 4 so as to communicate with the inside of the tank body 4, and the supply passage outlet part 21
is connected to the vaporizer 18 via a connecting pipe (not shown).

Further, another pot that opens and closes in conjunction with the interlocking pot 17 is provided with an air passage inlet portion 22 and an air passage outlet portion 23 for opening and closing the air passage. One end side of a ventilation pipe 24 made of a material such as rubber is connected to the ventilation passage entrance part 22, and the other end side of the ventilation pipe 24 is open. One end side of a ventilation pipe 25 similar to the ventilation pipe 24 is connected, and the other end side of the ventilation pipe 25 is connected to the downwardly extending end of the ventilation pipe 16 made of the metal material. 16,2
5 constitutes a second ventilation pipe. That is, by operating the interlocking knob 17, the fuel supply passage and the ventilation passage can be opened and closed at the same time.

In the portable engine fuel tank configured in this way, first, when starting the engine, the knob 19 of the interlocking knob 17 is operated to open the fuel supply path. Thus, fuel oil is supplied from the fuel tank 1 to the carburetor 18 via the supply path inlet 20 → supply path outlet 21 → connection pipe as shown by the dotted line flow in FIG. As shown in the solid line flow in FIG.
5, 16, 15, 14 → ventilation path 12 of stud 3
It communicates with the upper space 10 of the fuel tank 1 through. Therefore, while the engine is running, the interlocking cock 17 can supply fuel oil and at the same time vent the fuel tank 1.

Further, the first vent pipe 14 disposed in the hollow portion 11 of the handle 2 is made of a material such as rubber, and the vent pipe 16 constituting the second vent pipe is located above the fuel tank body 4. Because it is fixed by welding on the side, it is resistant to shock and does not generate chattering noises due to vibrations during engine operation.

Further, even if the first ventilation pipe 14 is made of, for example, a metal material, it is supported at two points at both ends of the handle 2, so that it does not generate chattering noise due to vibration.

Next, when stopping the engine, the knob 19 of the interlocking knob 17 is operated to close the fuel supply path. Therefore, the ventilation path is cut off at the same time as the supply of fuel oil is cut off, and the vaporized gas in the fuel tank 1 does not leak outside, thereby preventing gasoline odor, air pollution, and fuel waste. In addition, since the ventilation passage is established through an air-liquid tight means such as an O-ring at the attachment part of the handle 1, leakage of fuel oil can be more easily prevented than in the case where the inner surface of the tank is brazed, etc. The structure is simple because this is mainly carried out by a vent pipe outside the fuel tank body 4.

Note that the interlocking knob 17 in the embodiment described above is not limited in its shape as long as it can open and close two passages by operating a single knob 19. Further, the interlocking cock 17 may not be provided at the bottom of the fuel tank body 4. Furthermore, the ventilation pipe 1 constituting the first ventilation pipe 14 and the second ventilation pipe
5, 16, 25, etc. are vents 1 at the top of fuel tank 1
3b and the air passage outlet 23 of the interlocking pot 17 may be connected so as to communicate with each other, and is not limited to the embodiment.

[Effects of the invention] As explained above, according to the invention, a first vent pipe that communicates with each other vents opening at both ends of the handle of the fuel tank is arranged in the hollow part of the handle, and one end is A second vent pipe is fixed to the outside of the fuel tank, the second vent pipe communicating with the first vent pipe within the hollow part of the handle and the other end communicating with the vent outlet of the interlocking pot, and a pot for opening and closing the fuel supply path. Since the second vent pipe is communicated with the interlocking cock which simultaneously opens and closes the vent passage by the operation of , the leakage of fuel oil can be reliably prevented and vented with a simple structure.
In addition, when the engine is stopped, the ventilation passage is blocked and vaporized gas in the fuel tank leaks outside, thereby preventing gasoline odor, air pollution, and fuel waste.

In addition, since no piping is required inside the fuel tank, no special welding is required for airtightness or liquidtightness, and the manufacturing process is easy and mass production is possible, resulting in cost reduction. Furthermore, it has high impact resistance and has excellent effects such as being able to prevent chatter noise caused by vibrations caused by engine operation.

[Brief explanation of the drawing]

1 to 4 relate to an embodiment of the present invention,
Figure 1 is an explanatory diagram showing the structure of the fuel tank, Figure 2 is an enlarged cross-sectional view of the attachment part of the handle in Figure 1, Figure 3 is a piping system diagram, and Figure 4 is a diagram of the ventilation pipe in the center of the handle. It is a sectional view showing a connection part. DESCRIPTION OF SYMBOLS 1... Fuel tank, 2... Handle, 3... Stud, 4... Fuel tank body, 11... Hollow part, 1
2...Vent passage, 13a, 13b...Vent hole, 1
4, 15, 16, 24, 25... Ventilation pipe, 17...
...Interlocking cock, 18... Carburizer, 22... Ventilation passage inlet, 23... Ventilation passage outlet.

Claims (1)

[Scope of Claim for Utility Model Registration] A hollow handle is fixedly installed on the top surface of the fuel tank of the engine, and a ventilation pipe communicating with the upper space inside the fuel tank is housed in the hollow part of the handle, and a ventilation pipe is connected from the fuel tank to the carburetor. In a fuel tank for a portable engine equipped with an interlocking mechanism that simultaneously opens and closes a communicating fuel supply path and a ventilation path, a first ventilation pipe that communicates with each other vents that open at both ends of the handle of the fuel tank, A second ventilation pipe is disposed within the hollow part of the handle, one end of which communicates with the first ventilation pipe within the hollow part of the handle, and the other end of which communicates with the ventilation part outlet of the interlocking pot; A fuel tank for a portable engine, characterized in that the second vent pipe is configured to penetrate through one end of the handle and to be fixedly installed outside the fuel tank.