JPH0521770B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a fuel tank for vehicles, in particular for motor vehicles.

Prior Art Vehicles driven by internal combustion engines are usually equipped with a fuel tank, and when the fuel in the fuel tank becomes low, the cap attached to the fuel inlet of the fuel tank is removed and the fuel nozzle is inserted into the fuel inlet. , the fuel is injected into the fuel tank from the fuel supply nozzle. However, when the fuel in the fuel tank becomes low, the upper space above the fuel level in the fuel tank is filled with a large amount of pressurized fuel vapor, so when the cap is removed, the fuel tank becomes full. This causes a problem in that fuel vapor blows out from the fuel injection port into the outside air, polluting the atmosphere. Also, when fuel is injected into the fuel tank by the fuel refueling nozzle, the fuel ejected from the fuel refilling nozzle violently collides with the fuel in the fuel tank, causing the fuel in the fuel tank to bubble, which is generated at this time. A problem arises in that fuel vapor leaks out of the fuel injection port into the outside air and pollutes the atmosphere.

Purpose of the Invention The present invention is a vehicle fuel that prevents evaporated fuel in a fuel tank from flowing out into the outside air when the cap of a fuel injection port is removed, thereby suppressing air pollution caused by evaporated fuel. The purpose is to provide a tank.

Structure of the Invention The structure of the present invention is a fuel tank equipped with a fuel injection pipe and a removable cap attached to the fuel injection port of the fuel injection pipe, and a valve port in the fuel injection pipe that communicates the inside of the fuel tank with the canister. The fuel injection pipe is provided with an opening/closing control valve that engages with the cap to close the valve port when the cap is fastened to the fuel injection port and opens the valve port when the cap is removed. There is a particular thing.

Embodiment Referring to FIG. 1, 1 is a fuel tank, 2 is a fuel injection pipe, and 3 is a cap detachably attached to a fuel injection port 4 of the fuel injection pipe 2, respectively. 1st
Referring to the figure and FIG. 2, a hollow cylindrical nozzle guide 5 is fixed inside the fuel injection pipe 2.
This nozzle guide 5 includes a hollow cylindrical portion 5a of approximately uniform cross section, a flap-shaped inlet end portion 5b that expands toward the cap 3, and an annular end plate 5c that is perpendicular to the axis of the fuel injection tube 2. configured. A valve chamber 6 is formed between the nozzle guide 5 and the fuel injection pipe 2. An annular groove 7 is formed in the center of the hollow cylindrical portion 5a, and a sealing member 8 such as an O-ring is fitted into the annular groove 7. The hollow cylindrical portion 5a has a nozzle insertion passage 9 having a substantially uniform cross section formed therein, and the fuel supply nozzle 1 is inserted into the nozzle insertion passage 9 as shown by the chain line in FIG. 2 during fuel injection.
0 is inserted. The inner diameter of the sealing member 8 is formed to a size such that the sealing member 8 sealingly engages the outer peripheral surface of the fueling nozzle 10 when the fueling nozzle 10 is inserted into the nozzle insertion passage 9. A valve port 11 is formed on the annular end plate 5c of the nozzle guide 5, and an opening/closing control valve 12 for controlling opening/closing of the valve port 11 is arranged in the valve chamber 6. Open/close control valve 1
2 is a hollow cylindrical portion 12a that is slidable along the inner peripheral surface of the fuel injection pipe 2 as shown in FIGS. 2 and 3.
, an annular lower end portion 12b that serves as a valve body for controlling the opening and closing of the valve port 11, a bent upper end portion 12c for holding a spring, and a curved upper end portion 12c that protrudes upward beyond the flap-shaped inlet end portion 5b of the nozzle guide 5. tongue-like part 12
d. A compression spring 13 is provided between the bent upper end 12c of the opening/closing control valve 12 and the nozzle guide 5.
is inserted, and the opening/closing control valve 12 is operated by this compression spring 13.
It is constantly urged upward by the spring force of. Valve chamber 6
An evaporated fuel outlet 14 is formed at the top end of the
This vaporized fuel outlet 14 is connected to a canister 15 as shown in FIG.

As shown in FIG. 2, an internal thread 16 is screwed onto the inner peripheral surface of the fuel injection port 4 of the fuel injection pipe 2.
An outer thread 17 that can be screwed into the inner thread 16 is screwed onto the outer peripheral surface of the cap 3. A contact plate 18 that can engage with the tip of the tongue 12d of the on-off control valve 12 is slidably attached to the inner end surface of the cap 3, and a contact plate 18 is provided between the contact plate 18 and the cap 3. 18
A compression spring 19 is inserted that constantly biases the spring downward. This compression spring 19 has a stronger spring force than the compression spring 13.

As shown in FIGS. 1 and 2, the fuel inlet 4
When the opening/closing control valve 12 is closed by the cap 3, the contact plate 18 comes into contact with the tongue-shaped portion 12d of the opening/closing control valve 12 and pushes down the opening/closing control valve 12, so that the annular lower end 12b of the opening/closing control valve 12 is connected to the valve port. 11 are closed. At this time, the evaporated fuel in the fuel tank 1 cannot escape to the canister 15, and thus the fuel tank 1 is filled with evaporated fuel. Next, when the cap 3 is slightly loosened to supply fuel, the cap 3 rises, so that the on-off control valve 12 rises, and the annular lower end 12b of the on-off control valve 12 opens the valve port 11. As a result, the evaporated fuel in the fuel tank 1 is transferred to the valve port 1.
1. The fuel vapor is sent into the canister 15 via the valve chamber 6 and the vaporized fuel outlet 14. Then cap 3
Loosen the cap 3 further and remove the cap 3 from the fuel inlet 4. At this time, since the evaporated fuel in the fuel tank 1 has already been fed into the canister 15, only a small amount of evaporated fuel flows out from the fuel inlet 4. Next, as shown by the chain line in FIG. 2, the fuel nozzle 10 is inserted into the nozzle insertion passage 9, and fuel is supplied from the fuel nozzle 10.
The fuel flowing out from the fuel supply nozzle 10 collides with the fuel in the fuel tank 1, causing the fuel to bubble and generate fuel vapor. However, at this time, the valve port 11 is open and the interior of the fuel tank 1 is isolated from the outside air by the seal member 8, so the generated fuel vapor is sent into the canister 15 via the valve port 11. Next, the fuel supply nozzle 10 is pulled out and the cap 3 is screwed onto the fuel inlet 4. The evaporated fuel sent into the canister 15 is adsorbed by activated carbon within the canister 15.
The fuel vapor adsorbed on the activated carbon is sucked into the engine intake passage through a conduit (not shown) during predetermined engine operating conditions.

In the embodiment shown in FIG. 4, a fuel vapor outlet 20 is formed on the upper wall surface of the fuel tank 1, and this fuel vapor outlet 20 is connected to a canister 15. Therefore, the vaporized fuel generated within the fuel tank 1 is sent to the canister 15. Further, a portion 21a of the bottom wall surface 21 of the fuel tank 1 is bulged downward, and a small chamber 23 surrounded by a rising wall 22 is formed within the bulge portion 21a. The fuel injection pipe 2 extends downward within the fuel tank 1 into the small chamber 23, and the fuel outlet 24 of the fuel injection pipe 2 opens into the small chamber 23. In this embodiment, the evaporated fuel in the fuel tank 1 is constantly fed into the canister 15, and when the cap 3 is loosened, a small amount of evaporated fuel in the fuel injection pipe 2 flows into the canister 15 through the valve chamber 6. Since the canister 15 is only fed, the capacity of the canister 15 can be reduced.
can be downsized. Furthermore, when the cap 3 is opened, only a portion of the evaporated fuel in the fuel injection pipe 2 that has not been sent into the canister 15 flows out into the outside air, so the amount of evaporated fuel that flows out into the outside air is extremely small. Become. Furthermore, since the fuel that bubbles when fuel is injected from the fuel injection pipe 2 is only the fuel in the small chamber 23, the amount of fuel that evaporates due to the bubbling action is small.
(Fig. 2), the amount of evaporated fuel that flows out into the outside air is extremely small.

Effects of the Invention When the cap is loosened to refuel, the valve port that communicates the inside of the fuel tank with the canister is automatically opened, and the evaporated fuel in the fuel tank is sent into the canister, making it easier to open the cap. The amount of evaporated fuel that flows out from the fuel injection port when the fuel injection port is removed is extremely small, and thus it is possible to suppress atmospheric pollution caused by evaporated fuel.

[Brief explanation of drawings]

FIG. 1 is a side cross-sectional view of a fuel tank according to the present invention, FIG. 2 is a partially enlarged view of FIG. 1, FIG. 3 is a cross-sectional perspective view of an on-off control valve, and FIG. 4 is another embodiment of a fuel tank. FIG. 1...Fuel tank, 2...Fuel injection pipe, 3...
Cap, 5... Nozzle guide, 6... Valve chamber, 1
1...Valve port, 12...Opening/closing control valve, 15...
Canista.

Claims (1)

[Claims] 1. In a fuel tank equipped with a fuel injection pipe and a removable cap attached to the fuel injection port of the fuel injection pipe, a valve port is formed in the fuel injection pipe to communicate the inside of the fuel tank with the canister, and the cap is A fuel tank for a vehicle having an opening/closing control valve in a fuel injection pipe that engages with a cap to close the valve port when the fuel injection port is tightened and opens the valve port when the cap is removed. .