JPH024913Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a fuel tank cap device for motorcycles and other fuel tanks.

The applicant of this application previously applied for this type of device in 1983.
According to No. 152112, a cap body fitted into a fuel inlet of a fuel tank has a breather passage having an intermediate gas-liquid separation chamber communicating the tank with outside air;
A liquid chamber for receiving the fuel separated and recovered in the separation chamber is formed, as illustrated in FIG.
A valve seat part d around the drain hole c is formed on the lower surface of the bottom wall b, and a thin film is accommodated in the valve housing e below the bottom wall b and faces the valve seat part d. A drain valve f is provided, and the drain valve f is always brought into close contact with the valve seat part d by the tank internal pressure without using a spring or the like to prevent leakage of gas in the tank from the drain hole c. I proposed something like this. However, in this case, the valve seat part d is constituted by an annular protrusion protruding from the lower surface of the bottom wall b, and the drain valve f is in line contact with the annular protrusion. If the liquid valve f is tilted as shown by the dotted line in Figure 1 during the closing operation from the open state, and its peripheral edge catches on the valve seat part d, the liquid drain valve f will not close completely. , the drain valve f
A guide pin g inserted through the bottom wall b is attached to the bottom wall b to prevent its tilting, but this complicates the structure of the drain valve f and also prevents the pin g from tilting.
This causes the disadvantage that the weight of the drain valve f increases to some extent and the responsiveness of its closing operation deteriorates. In order to eliminate such inconveniences, the present invention provides a device that can provide a reliable closing operation even if the drain valve is tilted to some extent, and eliminates the need to attach a guide pin to the drain valve. As illustrated in FIG. 2 and below, a cap body 3 fitted into a fuel inlet 2 of a fuel tank 1 is provided with a breather passage 5 that communicates the inside of the tank 1 with outside air;
A liquid chamber 6 connected to the breather passage 5 is formed, and a liquid drain hole 7 connected to the inside of the tank is formed in the bottom wall 6a of the liquid chamber 6, and a valve seat part 8 is formed on the outer periphery of the lower end of the liquid drain hole 7. In the valve seat portion 8 which is opened and closed by a drain valve 10 operated by tank internal pressure, the drain valve 1
0 is formed of a flat thin film, and the drain valve 10
The valve seat part 8 that opens and closes is formed on a flat surface, and a bottom cover 24 provided at the lower part of the liquid chamber 6 for preventing the liquid drain valve 10 from falling has a through hole 25 connected to the inside of the tank 1 and a through hole 25 connected to the inside of the tank 1. It is characterized in that a plurality of protrusions 26 are provided surrounding the hole 25 and holding the drain valve 10 horizontally. In the illustrated cap body 3, a gasket 1 is attached to the lower surface of a flange 11 at the upper end of the cap body 3 and is biased downwardly via a guide frame 13 by a spring 12.
4 and a cylinder lock 15 at the center of the upper part, a pair of left and right locking pieces 15a, which are airtightly joined to the upper surface of the mouth edge of the inlet 2 via the gasket 14 and interlock with the cylinder lock 15; At 15a, it is latched to the lower end of the lip. Furthermore, in the illustrated case, as clearly shown in FIGS. 3 and 4, on the peripheral wall of the cap body 3 surrounding the cylinder lock 15,
A concave groove 16 that extends approximately all the way around the circumference with a gap on one side in the circumferential direction.
The groove 16 is covered with a seal rubber 17 on the upper surface to form the gas-liquid separation chamber 4 described above. Recessed hole 1 into which exhaust valve 18 is inserted
9 and a communication hole 20 that communicates the inside of the recessed hole 19 with one end of the gas-liquid separation chamber 4, further forming a breather hole 21 in the rubber 17 on the upper surface of the other end of the separation chamber 4, The inside of the tank 1 is connected to the exhaust valve 18 and the communication hole 20.
The above-mentioned breather passage 5 is configured to communicate with the outside via the separation chamber 4 and the breather hole 21.

The liquid chamber 6 is constructed by forming the lower end of the cap main body 3 into a cylindrical shape and fitting the lid body 22 onto the lower end from below. The liquid fuel separated and recovered in the separation chamber 6 is communicated with the through hole 23 formed as shown in FIG.
The liquid was allowed to flow into the liquid chamber 6 through the liquid chamber 6. The liquid drain hole 7 is provided in the center of the bottom wall 6a of the liquid chamber 6, which is constituted by the lid 22, and the flat valve seat portion 8 is provided on the lower surface of the bottom wall 6a, and the valve seat portion 8 is provided on the lower surface of the bottom wall 6a. A cylindrical valve housing 9 is formed extending below the outer periphery of the valve seat portion 8, and the drain valve 10 is accommodated in this.

As the drain valve 10, a thin film made of, for example, polyester and having a thickness of about 0.05 mm is used, which has elasticity, pressure resistance, and durability against gasoline as a fuel.

In the drawing, 24 indicates a bottom cover fitted to the valve housing 9;
As shown in FIG. 5, the bottom cover 24 is formed with a plurality of through holes 25 in its center, and has a gap in the circumferential direction on its upper surface so that when the drain valve 10 is opened, it is held in a horizontal position. A plurality of supporting protrusions 26 were formed. The bottom cover 24 also functions as a barrier to prevent the liquid level in the fuel tank 1 from acting directly on the drain valve 10 when the liquid level rises.

In the drawings, reference numeral 27 indicates a top cover that covers the cylinder lock 15 and can be opened and closed.

Next, to explain its operation, the drain valve 10 is as follows:
Because the internal pressure of the fuel tank 11 is such that it is always in a closed state in close contact with the valve seat 8, when the internal pressure increases, the exhaust from the tank 1 is discharged through the exhaust valve 18 into the gas-liquid separation chamber 4. The liquid fuel is introduced into one end, and while flowing through the chamber 4 from one end to the other, gas and liquid are separated, and only the air is discharged to the outside from the breather hole 21, and the separated liquid fuel is It flows into chamber 6 and is stored there. When the internal pressure of the tank 1 decreases due to this exhaust operation, the drain valve 10 is opened and the fuel in the liquid chamber 6 is returned to the tank 1, and the outside air is passed through the drain valve 10. When the liquid is suctioned and the internal pressure rises again, the drain valve 10 is brought into close contact with the valve seat 8 as described above and is closed. Although the above is not particularly different from the above-mentioned proposal, according to the present invention, the valve seat portion 8 is formed into a flat surface, and the drain valve 10 is brought into surface contact with the flat surface, so that the valve seat portion 8 can be closed. Even if the drain valve 10 is tilted during operation, the portion of the drain valve 10 that comes into contact with the valve seat 8 is
without interfering with its closing action by sliding on top.
Furthermore, the valve seat 8 leaks due to the discharge of fuel when the drain valve 10 is opened, and when the drain valve 10 is closed, this leaks and sticks to the valve seat 8, thus causing the drain valve to leak. Even if the movement of the drain valve 10 is not guided by a guide pin or the like as in the previous proposal, the drain valve 10 can be moved by the valve seat 8.
is firmly attached to the

In this way, according to the present invention, the liquid drain hole 7 of the liquid chamber 6
The drain valve 10 that opens and closes the valve seat 8 formed on the outer periphery of the lower end is formed of a flat thin film, so the drain valve 10 is lightweight and easily formed. The valve seat part 8 which opens and closes is formed on a flat surface, and a bottom cover 24 provided at the lower part of the liquid chamber 6 for preventing the liquid drain valve 10 from falling includes a through hole 25 connected to the tank and surrounding the through hole 25. Since the drain valve 10 is provided with a plurality of protrusions 26 that hold the drain valve 10 horizontally, the drain valve 10 can be easily moved to the valve seat part 8 by the internal pressure inside the tank 1.
The drain valve 10 can be opened and closed easily by the negative pressure inside the tank 1, and the plurality of protrusions 26 prevent the drain valve 10 from falling. This has the effect of reducing the bearing area and facilitating recovery due to tank internal pressure.

[Brief explanation of the drawing]

Fig. 1 is a cutaway side view of the main parts of the device according to the previous proposal, Fig. 2 is a cutaway side view of an example of the proposed device, and Fig. 3
The figure is a cross-sectional view taken along the - line of Fig. 2, Fig. 4 is a developed view taken along the - line of Fig. 3, and Fig. 5 is a - line cross-sectional view of Fig. 2.
FIG. 1... Fuel tank, 2... Fuel inlet, 3...
Cap body, 4... Gas-liquid separation chamber, 5... Breather passage, 6... Liquid chamber, 6a... Bottom wall, 7... Drain hole, 8... Valve seat, 9... Valve housing, 10 ...Drain valve.

Claims (1)

[Scope of utility model registration request] A cap body 3 fitted into a fuel inlet 2 of a fuel tank 1 is formed with a breather passage 5 that communicates the inside of the tank 1 with outside air, and a liquid chamber 6 connected to the breather passage 5. A drain hole 7 connected to the inside of the tank and a valve seat part 8 on the outer periphery of the lower end of the drain hole 7 are formed in the bottom wall 6a of the tank, and the valve seat part 8 is opened and closed by a drain valve 10 operated by the tank internal pressure. In this structure, the drain valve 10 is formed of a flat thin film, and the valve seat portion 8 on which the drain valve 10 opens and closes is formed as a flat surface, and the drain valve 10 is formed of a flat thin film to prevent the drain valve 10 from falling. A bottom cover 24 provided at the lower part of the liquid chamber 6 is provided with a through hole 25 that extends into the tank 1 and a plurality of protrusions 26 that surround the through hole 25 and hold the drain valve 10 horizontally. A fuel tank cap device featuring: