JPS6260314B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fuel tank cap for a motorcycle.

2. Description of the Related Art Some conventional fuel tanks for motorcycles have a fuel filler port deviated outward from the center line of the tank.

As a cap attached to the fuel filler port, a cap body is known in which a breather passage and a relief passage are provided in the main body of the cap to communicate the upper space within the fuel tank with the atmosphere.

The breather passage applies atmospheric pressure within the tank so that the fuel within the tank is delivered to the carburetor.

In addition, the relief passage is designed to prevent fuel from leaking from undesirable places such as the fuel tank of the tank or the carburetor near the engine due to an increase in tank internal pressure due to deformation of the tank when the motorcycle falls over. This system actively releases the internal pressure of the tank at a remote location.

However, when the breather passage is provided offset from the center of the cap body toward the outside of the tank, the opening position of the passage in the tank approaches the fuel oil level, and when the vehicle is tilted, the passage is located below the oil level. This causes a problem in that fuel leaks out of the tank.

The present invention has been made in view of the above circumstances, and its object is to provide a cap that prevents fuel from leaking from the breather passage and the relief passage when the vehicle is tilted.

An example of carrying out the present invention will be explained with reference to the drawings. Fig. 1 shows the front half of a motorcycle, in which 1 is a steering handle, 2 is a tank rail, 3 is a fuel tank,
4 is a sheet.

The tank 3 is provided with a fuel filler port 5 on its upper surface, and the fuel filler port 5 is provided so as to be offset outward from the center line l of the tank 3.

A cap 6 closes the fuel filler port 5, and is attached to the upper surface of the tank 3 so as to be openable and closable. The mounting structure of this cap 6 is shown enlarged in FIGS. 2 and 3.

The cap 6 has a main body 6a made of synthetic resin, and a metal plate 6 on the outer surface of the main body 6a.
b is applied.

Reference numeral 7 denotes a hinge member attached to the tank 3, and by rotatably connecting the rear end of the cap body 6a to the hinge member 7, the cap 6 is attached to the tank 3 so as to be openable and closable.

Reference numeral 8 denotes a cylinder lock provided at the center of the cap body 6a, and two lock pieces 9 are moved to protrude and retract from the outer periphery of the lower end of the cap body 6a by rotating a key (not shown). There is.

The lock piece 9 is engaged with the upper opening edge 10a of the cylindrical body 10 welded to the fuel filler port 5, thereby locking the cap 6 in the closed state.

10b is an air bleed hole drilled in the cylinder 10.

A casing 11 is attached to the outer periphery of the cylindrical portion 6a ₁ of the cap body 6a and is constantly urged downward by a spring (not shown), and is removably fitted into the cylindrical body 10 when the cap 6 is closed. It's becoming like that.

Reference numeral 12 denotes a gasket attached to the upper end of the casing 11, and when the gasket 12 comes into close contact with the upper end of the cylindrical body 10, the fuel filler port 5 is sealed.

13 is a breather passage, and 14 is a relief passage. These passages 13 and 14 communicate the upper space inside the tank 3 with the atmosphere, and the cylinder lock 8 is inserted into the cylindrical part _6a1 of the cap body 6a. They are each formed separately.

That is, by forming both passages 13 and 14 separately, a locking mechanism can be provided in the cap body 6a without any problem.

The breather passage 13 is arranged closer to the center of the fuel tank than the relief passage 14, and is also arranged offset from the center of the cap body 6a toward the center line l of the tank 3, and is equipped with a valve body having a steel ball 17. 15
It is designed to be opened and closed by.

The valve 15 houses a valve body of a steel ball 17 in a chamber 16 connected to the passage 13, and the steel ball 17 is displaced toward the passage 13 side when the tank 3 falls sideways due to the overturning of the vehicle. so that it is occluded.

Reference numeral 18 denotes a through hole that communicates the chamber 16 with the inside of the tank 3. On the other hand, the relief passage 14 is provided at a position symmetrical to the breather passage 13 and is closed by a resistance member 19.

The resistance member 19 is made of a material having breathability and liquid absorption properties, such as felt or ceramic, and is made of a supporting metal fitting 2 having an opening in a chamber 20 connected to the passage 14.
It is housed and fixed by 1.

22 is a through hole that communicates the chamber 20 with the inside of the tank 3.

The passages 13 and 14 are respectively connected to an annular groove 23 formed at the upper end of the cap body 6a, and from there are connected via a passage 24 to a space 25 communicating with the atmosphere. Suppose, therefore, that the motorcycle is temporarily tilted by a predetermined angle θ to one side, for example to the right, when the motorcycle is running or stopped.
Tank 3 also tilts accordingly (Figure 4).

At this time, the fuel oil level in the tank 3 becomes horizontal, so the breather passage 13 approaches the oil level.
However, the breather passage 13 is located at the center line l of the tank 3.
Since the breather passage 13 is provided offset to the side, even if the angle θ is made considerably large, the breather passage 13 is maintained above the oil level, and fuel will not leak out of the tank 3 through this passage.

On the other hand, the relief passage 14 is located below the oil level, but before the fuel reaches this passage 14, the resistance member 19
Due to this regulation, there is a time delay in fuel leakage, and fuel leakage does not occur.

Next, when the vehicle falls, the tank 3 also falls sideways. (Figure 5).

In this case, the breather passage 13 is located below the oil level, but since the passage 13 is closed by the valve body of the steel ball 17 of the valve 15, fuel leakage therefrom is prevented.

On the other hand, although the relief passage 14 is also submerged below the oil level, the resistance member 19 suppresses fuel leakage therefrom to a very small amount, and if the vehicle is immediately raised, there will be almost no fuel leakage. Further, when the tank 3 is deformed during the fall, the internal pressure of the tank 3 increases, but this internal pressure is released through the relief passage 14.

That is, due to the breathability of the resistance member 19, the tank 3
Inside air passes through the member 19 and the relief passage 14
is released into the atmosphere. At this time, relief passage 1
4 is located completely below the oil level, there is a risk that some fuel may leak from the passage 14 the moment the internal pressure is released, but since the passage 14 is open to the top of the fuel tank 3 on the opposite side from the engine. No problem.

Therefore, it is possible to reliably prevent fuel leakage from places close to the engine, such as the fuel tank seal and the carburetor.

In the present invention, as described above, the breather passage is located closer to the center of the fuel tank than the relief passage, and is also offset from the center of the cap body toward the center line of the tank. can be maintained above the oil level to prevent fuel leakage from there. Therefore, in the case where the cap is attached to the fuel filler port which is deviated towards the outside of the tank, and the breather passage and the relief passage are provided in the cap body, there is an effect that the inclination angle of the vehicle can be made as large as the conventional one. .

Furthermore, even if the relief passage is submerged below the oil level during a large inclination, the resistance member restricts the outflow of fuel, so no fuel leakage occurs.

Thus, the intended purpose can be achieved.

[Brief explanation of the drawing]

Figure 1 is a plan view showing the front half of the motorcycle, Figure 2 is an enlarged sectional view taken along the line - in Figure 1, Figure 3 is a sectional view taken along the line - in Figure 2, and Figure 4 shows the tank. FIG. 5 is a cross-sectional view showing the tank in a tilted state. FIG. In the figure, 3...Fuel tank, 6...Cap, 6a
...cap body, 13...breather passage, 5...fuel filler port, 14...relief passage, 17...steel ball, 19...resistance member, l...center line of fuel tank.

Claims (1)

[Claims] 1. In a motorcycle fuel tank cap that is attached to a fuel filler port that is provided outwardly from the center line of the fuel tank, a breather passage and a relief are provided in the cap body to communicate the upper space inside the fuel tank with the atmosphere. The breather passage is provided with a valve body made of a steel ball, is arranged closer to the center of the fuel tank than the relief passage, and is offset from the center of the cap body toward the center of the fuel tank, and the relief passage A structure with a resistance member inside that has breathability and liquid absorption properties.