JPS6030201Y2 - fuel tank cap - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a fuel tank cap for a motorcycle.

In this type of cap, a breather passage is provided in the cap to respond to changes in the internal pressure inside the tank.
Gasoline tends to leak from the passage when the vehicle suddenly stops, collides, or falls over, and in order to prevent this, the structure becomes increasingly complicated.

The present invention is aimed at improving the above disadvantages, and is a flange portion 1a that blocks the mouth edge of the inlet 3 of the fuel tank 2.
and a body part 1b that is inserted into the inlet 3. A breather inlet 6 is provided on the lower surface of the flange part 1a, and a breather passage 8 connected to the inlet 6 is connected to the body part 1b. A first check valve 7 is provided in the passage 8, and a breather chamber 9 is formed in the lower part of the body part 1b by communicating with the lower end of the passage 8. 9, a second check valve 10 that opens when the pressure inside the tank is reduced.
It is characterized by having the following.

To explain this with reference to the illustrated embodiment, reference numeral 1 indicates a fuel tank cap, and the cap 1 includes a flange portion 1a that blocks the mouth edge of an inlet 3 of a tank 2, and a body portion that is fitted into the inlet 3. 1b, the seal rubber 4 provided on the lower surface of the flange portion 1a is brought into contact with the mouth edge of the injection port 3 via the guide 5 provided on the outer periphery of the body portion 1b and pressed. A lock bar of a cylinder lock (not shown) provided at 1b is engaged with the inner edge of the injection port 3, thereby sealing the injection port 3.

A breather inlet hole 6 is opened on the lower surface of the flange portion 1a and is connected to the inside of the tank 2 through a gap formed between the seal rubber 4 and the guide 5.
b includes a vertical breather passage 8 having a ball-shaped first check valve 7, and a lower first breather passage 8 that blocks the lower end of the passage 8.
A breather chamber 9 is provided, and the first breather chamber 9 includes:
A second check valve 10 that opens when the pressure inside the tank 2 is reduced is provided on the bottom wall of the tank 2, and a small hole 11 is provided on the top wall of the second check valve 10, and a second breather chamber 12 is connected to the first breather chamber 9 through the small hole 11. The breather chamber 12 is shaped like an arc with one end of the opening of the small hole 11 extending from the middle of the body part 1b to the flange part 1a. A breather discharge hole 13 is provided in the flange portion 1a at the center of the arc surface, and the hole 13 is provided at right angles to the traveling direction of the vehicle.

In the figure, 14 indicates a filter located directly below the breather passage 8 and provided in the first breather chamber 9. The filter 14 prevents the scattering of the breather and reduces the wave motion of the raw gas accumulated in the first breather chamber 9. This prevents the internal pressure within the chamber 9 from increasing.

15 is a resilient spring for the guide 5; 16 is a first check valve 7;
The return spring is shown.

Next, to explain its operation, during normal driving, the wave motion of gasoline in the tank 2 and the temperature rise due to the outside temperature increase the internal pressure in the tank 2 to a sufficient extent to close the second check valve 10. The raw gas generated in the tank 2 passes through the gap formed between the seal rubber 4 and the guide 5 and flows into the first breather chamber 9 from the breather inlet 6 by opening the first check valve 7. The raw gas filling the chamber 9 further flows into the second breather chamber 12 through the small hole 11, and the excess gas is discharged to the outside air from the breather discharge hole 13 provided in the flange portion 1a. The breather discharge hole 13 is the second
Since the breather chamber 12 is located approximately in the center of the upper arc of the vertical arc-shaped chamber and is formed perpendicular to the direction of travel of the vehicle, the raw gas accumulated in the chamber 12 will be absorbed by the sudden movement of the vehicle. It does not easily leak to the outside even during sudden braking.

When the consumption of gasoline in the tank 2 progresses and the pressure inside the tank 2 is reduced, the second check valve 10 is opened to allow outside air and the raw gas in the first breather chamber 9 to flow into the tank 2.

In this way, according to the present invention, the inlet 3 of the fuel tank 2
In a fuel tank cap consisting of a flange portion 1a that blocks the mouth edge of the fuel tank cap and a body portion 1b that is fitted into the inlet 3, a breather inlet 6 is provided on the lower surface of the flange portion 1a, and a breather inlet 6 is provided on the lower surface of the flange portion 1a. A continuous breather passage 8 is formed in the axial direction of the body part 1b, a first check valve 7 is provided in the passage 8, and a breather chamber 9 is formed in the lower part of the body part 1b by communicating with the lower end of the passage. As a result, the chamber 9 is provided with a second check valve 10 that opens when the pressure inside the tank is reduced, so when the internal pressure of the tank 2 increases and the first check valve 7 is opened, the raw gas inside the tank is This prevents the raw gas from flowing into the breather chamber 9 and increasing the internal pressure inside the tank, and when the pressure inside the tank is reduced, the second check valve 10 is opened to release the raw gas inside the breather chamber 9 into the tank. This has the effect of preventing unnecessary leakage of gas.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a view taken along the line A-A in FIG. 2, FIG. 2 is a vertical sectional view taken along the line B-B in FIG. 1, and FIG. FIG. 2 is a cross-sectional view taken along the line C-C in FIG. 1; 1a...Flange part, 1b...Body part, 2...Fuel tank, 3...Inlet, 6...Blizzer flow Entrance, 7...1st
Check valve, 8... Breather passage, 9...
... Breather chamber, 10... Second check valve.

Claims (1)

[Scope of utility model registration request] In a fuel tank cap consisting of a flange portion 1a that blocks the mouth edge of an inlet 3 of a fuel tank 2, and a body portion 1b that is fitted into the inlet 3, a breather inlet 6 is provided on the lower surface of the flange portion 1a. A breather passage 8 connected to the inlet 6 is shaped in the axial direction of the body part 1b, and the passage 8
A first check valve 7 is provided in the tank, and a breather chamber 9 is formed in the lower part of the body part lb by communicating with the lower end of the passage 8, and a second check valve 10 is provided in the chamber 9, which opens when the pressure in the tank is reduced. A fuel tank cap characterized by the provision of a fuel tank cap.