JPH024059Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a cap device for a fuel tank for two-wheeled motor vehicles and other fuel tanks.
The present invention relates to a cap device in which a cylinder lock for locking the cap body to the injection port is inserted.

Conventional fuel tanks have a breather passage separate from the cap, which has an intermediate gas-liquid separation chamber that communicates the inside of the tank with the outside air, so that the interior can have a breathing effect without discharging evaporated fuel to the outside. Generally speaking, it is desirable to form this breather passage in the cap, considering the amount of processing required for the tank.

However, in the case of a cap in which a cylinder lock is inserted, in order to form a breather passage in the cap main body, the problem is how to arrange the gas-liquid separation chamber in the main body space restricted by the cylinder lock.

The purpose of the present invention is to provide a cap device with a breather passage that solves this problem. A cylinder lock 4 for hooking the main body 3 to the injection port 2 is inserted, and a breather passage 5 for communicating the inside of the fuel tank 1 with outside air is formed in the peripheral wall of the cap main body 3 surrounding the cylinder lock 4. In a tank cap device, a concave hole 15 in the front part is fitted with an exhaust valve 14 that opens the breather passage 5 by increasing the internal pressure, and extends in the axial direction adjacent to the cylinder lock 4; It is characterized in that the gas-liquid separation chamber 6 is formed in an intermediate gas-liquid separation chamber 6 extending to the recessed hole 15 through a communication hole 16 along its peripheral wall surface.

In the illustrated cap main body 3, a gasket 10 is provided on the lower surface of a flange 7 at the upper end thereof, and is urged downwardly by a spring 8 via a guide frame 9. Left and right 1 are airtightly joined via 10 and interlocked with the cylinder lock 4.
The pair of latching pieces 4a, 4a are adapted to be latched to the lower surface of the mouth edge of the inlet 2.

Furthermore, in the illustrated case, as clearly shown in FIG. 2, a groove 11 is formed in the peripheral wall of the cap body 3 surrounding the cylinder lock 4, extending approximately all the way around the cylinder with a gap on one side in the circumferential direction. The groove 11 is covered with a seal rubber 12 on the upper surface, and a guide integrated with the seal rubber 12 is provided inside the groove 11, which slopes downward from one end of the groove 11 to the other end, as shown in FIG. wall 1
3 to form the gas-liquid separation chamber 6 in the space below, and an exhaust valve that opens when the internal pressure of the fuel tank 1 rises in the circumferential gap between one end and the other end of the groove 11. a recessed hole 15 into which the gas-liquid separation chamber 6 is inserted; and a communication hole 1 that communicates the inside of the recessed hole 15 with the upper end of the gas-liquid separation chamber 6.
6, further forming a breather hole 17 in the seal rubber 12 on the upper surface of the other end of the gas-liquid separation chamber 6,
The inside of the fuel tank 1 is connected to the exhaust valve 14 through the communication hole 16.
The breather passage 5 is configured to communicate with the outside air via the gas-liquid separation chamber 6 and the breather hole 17.

In the drawing, reference numeral 18 indicates a liquid chamber formed at the lower end of the cap main body 3, and the liquid chamber 18 is connected to the gas-liquid separation chamber 6 through a through hole 19 at the bottom of the other end, and is connected to a drain at the lower side. It is connected to the inside of the fuel tank 1 via a liquid valve 20. In the drawings, reference numeral 21 indicates a lid member that covers the cylinder lock 4 and can be opened and closed.

Next, to explain its operation, when the internal pressure of the fuel tank 1 rises, the exhaust from the tank 1 consisting of a mixture of evaporated fuel and air is discharged from the communication hole 16 via the exhaust valve 14 to the gas-liquid separation chamber. The fuel is introduced into one end of the chamber 6, and then swirls and flows inside the chamber 6 toward the other end. According to this, the fuel comes into contact with the peripheral wall surface of the chamber 6 due to the centrifugal force caused by the swirl, and is condensed. Furthermore, when the guide wall 13 is provided as described above, the gas and liquid are separated by contact condensation on this wall, and the separated air is discharged to the outside from the breather hole 17 at the other end, and the liquid fuel is permeated. The liquid is returned to the tank 1 through the hole 19 via the liquid chamber 18 and the drain valve 20.

As described above, according to the present invention, the breather passage 5 of the cap body 4 having the cylinder lock 4 is fitted with the exhaust valve 14 which is opened when the internal pressure increases, and the breather passage 5 of the cap main body 4 having the cylinder lock 4 has a front portion adjacent to the cylinder lock 4 extending in the axial direction. Recessed hole 15
and an intermediate gas-liquid separation chamber 6 surrounding the cylinder lock 4 and extending in the circumferential direction, the gas-liquid separation chamber 6 can be formed as long as possible within the limited cap body 4. Moreover, since the separation chamber 6 is communicated with the recessed hole 15 through the communication hole 16 along the peripheral wall surface thereof, the exhaust flow passing through the communication hole 16 flows from one end of the separation chamber 6 to the other. The flow becomes a swirling flow toward the end, which has the effect of significantly improving the gas-liquid separation performance within the separation chamber 6.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional side view of one example of the present device, FIG. 2 is a cross-sectional view taken along the line -- in FIG. 1, and FIG. 3 is a developed view taken along the line -- in FIG. 1... Fuel tank, 2... Inlet, 3... Cap body, 4... Cylinder lock, 5... Breather passage, 6... Gas-liquid separation chamber.

Claims (1)

[Scope of utility model registration request] A cylinder lock 4 for latching the cap body 3 to the inlet 2 is inserted into the approximate center of the cap body 3 that is fitted into the inlet 2 of the fuel tank 1, and the cap body surrounds the cylinder lock 4. In a fuel tank cap device, a breather passage 5 for communicating the inside of the fuel tank 1 with the outside air is formed in the peripheral wall of the fuel tank 3, in which an exhaust valve 14 that opens the breather passage 5 by an increase in internal pressure is inserted and is adjacent to the cylinder lock 4. A concave hole 15 is formed in the front part extending in the axial direction, and an intermediate gas-liquid separation chamber 6 surrounds the cylinder lock 4 and extends in the circumferential direction. A cap device for a fuel tank, characterized in that the cap device communicates with the recessed hole 15 through a hollow communication hole 16.