JPH0134702Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to an air vent device for a portable engine that allows the air vent passages of the fuel tank and carburetor to be opened and closed simultaneously with the operation of the fuel tank. It is.

[Prior Art] Generally, in a fuel tank for a portable engine, it is necessary to constantly communicate the upper space with the atmosphere in order to avoid gas expansion in the upper space or to supplement air when the fuel level decreases. For this purpose, an air vent device is provided.

By the way, when such an air vent device is used with the engine stopped and left unattended, or when the engine is mounted on a car or the like and transported, the fuel in the tank vaporizes and the pressure rises, causing vaporized gas to be released. Because gasoline leaks out of the tank and causes gasoline odor, the air passage of the air vent device can be opened and closed.

The vent passage can be opened and closed, for example, by manually turning a knob provided on the tank cap, or by connecting the vent passage to the fuel strainer body and opening and closing the fuel tank. They were opening and closing the ventilation passages.

By the way, in addition to the air vent device for the fuel tank, the portable engine is also provided with an air vent device for the carburetor, and it is also necessary to open and close the ventilation path of the air vent device for the carburetor.

[Problems to be Solved by the Invention] An example of an air vent device for a fuel tank is disclosed in Japanese Utility Model Publication No. 55-39797.

In this prior art, a hollow handle is provided on the top surface of the fuel tank, vent pipes are connected to vent holes provided near both ends of the handle, both vent pipes are housed in the hollow part of the handle, and the other end is connected to the vent hole provided near both ends of the handle. They extend toward the other end and are open.

Therefore, there is a problem in that vaporized fuel leaks from the vent pipe when the engine is stopped and not only pollutes the atmosphere by emitting gasoline odor, but also wastes fuel.

As a countermeasure, for example, as disclosed in Japanese Utility Model Publication No. 40-14721, interlocking joints are installed in the ventilation pipe and fuel supply passage, and when the engine is stopped,
Although the interlocking knob may be operated to close the vent pipe and the fuel supply passage, there is still a problem in that vaporized fuel is still discharged from the air vent of the carburetor.

For example, as disclosed in Japanese Utility Model Application Publication No. 50-4120, the air vent passage of the fuel tank and the upper space of the carburetor are connected, and a plug is attached to the air vent of the carburetor, so that when the engine is stopped, It is possible to prevent leakage of vaporized fuel from both the fuel tank and the carburetor by closing this hole, but in general, in the case of such a structure, the air vent passage of the fuel tank is connected to the inside of the fuel tank. Since the fuel tank must be connected to the carburetor by passing through the bottom thereof, sealing between the bottom of the fuel tank and the air vent passage becomes a problem.

[Purpose of the invention] This invention was made in view of the above circumstances.
The air vent passages for the fuel tank and carburetor can be opened and closed simultaneously with the opening and closing of the fuel supply passage, improving operability, and the simple structure ensures that fuel oil or vaporized gas leaks are prevented. To provide an air vent device for a portable engine that not only prevents gasoline odor and air pollution from occurring, but also ensures sufficient structural sealing performance of the fuel tank.

[Means and effects for solving the problem] In order to achieve the above object, the present invention fixes a hollow handle on the upper surface of the fuel tank, and attaches a hollow handle to the upper space inside the fuel tank in the hollow part of the handle. A first vent pipe that communicates with the atmosphere is housed, and a second vent pipe that communicates with the atmosphere is connected to the first vent pipe, while the bottom of the fuel tank and the carburetor are communicated via a fuel supply passage. Further, there is a connection between the fuel supply passage and the second vent pipe midway between the fuel supply passage and the second vent pipe.
In the air vent device for a portable engine equipped with an interlocking cock that simultaneously opens and closes a vent pipe, both ends of the first vent pipe are opened from an attachment portion of the handle to the fuel tank to an upper space of the fuel tank. , and the second vent pipe is located midway through the first vent pipe.
Connect one end of the ventilation pipe to the second
The other end of the vent pipe is arranged from the side of the fuel tank to the interlocking cock side, and one end of the second vent pipe is connected to the middle of the first vent pipe. The other end of the vent pipe is arranged from the outer surface of the fuel tank to the interlocking pot side, and the second vent pipe between the interlocking pot and the first vent pipe is provided with a carburetor air vent. The first valve is connected to the carburetor vent pipe, and when the interlocking valve is closed, the first pipe is connected to the upper space inside the fuel tank.
A second vent pipe communicating with the vent pipe, a carburetor vent pipe for the carburetor air vent, and a fuel supply path communicating the bottom of the fuel tank and the carburetor are closed together.

[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-A in Figure 1. It is a line enlarged sectional view.

In these figures, reference numeral 1 is a fuel tank for a portable engine, and a hollow handle 2 is attached to the upper surface of the tank with studs 3, 3.

The upper surface of the main body 4 of the fuel tank 1 is formed into a substantially rectangular shape, and both end portions in the longitudinal direction are
Attachment portions 5, 5 are formed to project somewhat from the upper surface of the fuel tank body 4.

The handle 2 is made of 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 portion 7 and the attachment portion 5 of the fuel tank body 4 are provided with air-liquid sealing means, such as an O-ring 8, between them.
A stud 3 is inserted through a hole passing through each of the holes, and is screwed into a nut 9 which is brazed or the like on the inner surface of the fuel tank body 4 of the mounting portion 5.

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 are vents 13a and 13b. It's summery.
In addition, the vent 13b on the hollow part 11 side of the handle 2
One end side of a first ventilation pipe 14 made of a material such as rubber is connected to the , and the other end side of the first ventilation pipe 14 is housed in the hollow part 11 of the handle 2, and a similar opening is made at approximately the center. It is connected to the ventilation pipe 14 connected to the other mounting part side via a Y-shaped hose joint 14', and the Y-shaped hose joint 14'
One end of the ventilation pipe 15 is connected to the vent pipe 15, and the other end extends again to one side of the mounting portion.

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 ventilation pipe 15, and its other end extends downward and is attached by welding to the upper side of the fuel tank body 4.

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 pot 17 is connected so that a supply passage inlet 20 of the cot on the fuel supply passage side communicates with the inside of the tank body 4 at the bottom surface of the fuel tank body 4, and a supply passage outlet 21 is connected to a connecting pipe (not shown). It is connected to the fuel supply port of the carburetor 18 via.
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 portion 22.
4 is open at the other end, and a ventilation pipe 2 similar to the ventilation pipe 24 is provided at the ventilation passage outlet portion 23.
5 is connected to one end side, and the other end side of the ventilation pipe 25 is connected to a Y type hose joint 26 and further to the Y type hose joint 2.
6, and connected to the downwardly extending end of the vent pipe 16 made of the metal material via a vent pipe 27 disposed along the outer surface of the fuel tank 4. has been done.

On the other hand, one end side of a carburetor vent pipe 28 for air venting is connected to the carburetor 18, and the other end side is connected to the other end of the Y-shaped hose joint 26. That is, fuel tank vent pipe 1 for air vent
4, 15 and the vaporizer vent pipe 28 are connected to each other.
The fuel supply passage and the ventilation passage can be opened and closed at the same time by operating the interlocking knob 17.

In addition, the above-mentioned ventilation pipes 15, 16, 24, 25, 2
7 constitutes a second vent pipe.

In the air vent device for a portable engine 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, the fuel oil is supplied from the fuel tank 1 to the carburetor 18 via the supply path inlet 20 -> supply path outlet 21 -> connecting pipe, as shown by the dotted line flow in FIG.

The interlocking cock 17 opens the fuel supply path.
At the same time as the operation, as shown by the solid line flow in Figure 3, the ventilation passage on the fuel tank 1 side is opened from the atmosphere to the ventilation pipe 24→
Ventilation passage inlet part 22 → ventilation passage outlet part 23 → ventilation pipe 2
5 → Y type hose joint 26 → Ventilation pipes 27, 16 → Fuel tank ventilation pipes 15, 14 → Connects to the upper space 10 of the fuel tank 1 via the ventilation passage 12 of the stud 3, and also the ventilation passage on the side of the carburetor 18 is from the atmosphere to the ventilation pipe 2
4 → Ventilation passage inlet 22 → Ventilation passage outlet 23 → Ventilation pipe 25 → Y-type hose joint 26 → Carburetor ventilation pipe 28
It communicates with the air vent of the carburetor 18 through. Therefore, while the engine is running, the interlocking gear 17
The fuel tank 1 and the carburetor 18 can be vented at the same time as fuel oil is supplied.

Next, when stopping the engine, the knob 19 of the interlocking knob 17 is operated to close the fuel supply path. Therefore, at the same time as the supply of fuel oil is cut off, the ventilation path on the fuel tank 1 and carburetor 18 side is cut off, and the vaporized gas in the fuel tank 1 and carburetor 18 is not leaked outside, causing gasoline odor. Not.

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 2, 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.

The shape of the interlocking knob 17 in the embodiment is not limited as long as the two channels can be opened and closed by a single operation of the knob 19. Furthermore, the interlocking cock 17 may not be provided at the bottom of the fuel tank body 4. Further, the vent pipe and the Y-type hose joint 26 may be connected to the vent passage outlet 23 of the interlocking cock 17 so as to communicate with the fuel tank vent pipes 14 and 15 for air venting and the carburetor vent pipe 28. Not limited to examples.

[Effects of the invention] As explained above, according to the invention, a hollow handle is fixed to the upper surface of the fuel tank, and a first passage communicating with the upper space inside the fuel tank is provided in the hollow part of the handle. A second vent pipe communicating with the atmosphere is connected to the first vent pipe, and the bottom of the fuel tank and the carburetor are communicated via a fuel supply passage, and the fuel supply pipe is connected to the first vent pipe. This fuel supply passage and the second vent pipe are located halfway between the passage and the second vent pipe.
An interlocking cock that simultaneously opens and closes the ventilation pipes is interposed, and a carburetor vent pipe for the carburetor air vent is connected to the second ventilation pipe between the interlocking cock and the first ventilation pipe. The air vent passages for the fuel tank and carburetor can be opened and closed simultaneously with the opening and closing of the fuel supply passage, improving operability, and the simple structure ensures that fuel oil or vaporized gas leaks are prevented. It is possible to achieve the effect of preventing gasoline odor.

Further, both ends of the first vent pipe are opened from the attachment portion of the handle to the fuel tank to the upper space of the fuel tank, and one end of the second vent pipe is opened midway through the first vent pipe. At the same time, the other end of the second vent pipe was arranged from the outer surface of the fuel tank to the interlocking cock side.
No piping is required in the fuel tank, the sealing performance of the fuel tank can be maintained, and the second
The vent pipe and the vaporizer vent pipe for the above-mentioned vaporizer air vent are easy to pipe, and are excellent in mass production.

[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-A in Figure 1. It is a line enlarged sectional view. DESCRIPTION OF SYMBOLS 1... Fuel tank, 2... Handle, 3... Stud, 4... Fuel tank body, 5... Handle part, 10
... upper space part, 11 ... hollow part, 12 ... ventilation path, 13a, 13b ... ventilation port, 14 ... first ventilation pipe, 15, 16, 24, 25, 27 ... second
Ventilation pipe, 17... Interlocking cock, 18... Carburetor, 22... Ventilation passage inlet, 23... Ventilation passage outlet, 28... Carburetor ventilation pipe.

Claims (1)

[Claims for Utility Model Registration] A hollow handle is fixed to the upper surface of the fuel tank, a first ventilation pipe communicating with the upper space inside the fuel tank is housed in the hollow part of the handle, and A second vent pipe communicating with the atmosphere is connected to the first vent pipe.
The bottom of the fuel tank and the carburetor are connected to each other via a fuel supply passage, and the fuel supply passage and the second vent pipe are connected to each other midway between the fuel supply passage and the second ventilation pipe. In a portable engine air vent device equipped with an interlocking cock that simultaneously opens and closes a second vent pipe, both ends of the first vent pipe are connected from the attachment portion of the handle to the fuel tank to the upper space of the fuel tank. one end of the second vent pipe is connected to the middle of the first vent pipe, and the other end of the second vent pipe is arranged from the outer surface of the fuel tank to the interlocking tank side. An air vent device for a portable engine, further comprising: a carburetor vent pipe for a carburetor air vent connected to the second vent pipe between the interlocking cock and the first vent pipe.