JPH045376Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a fuel tank used mainly for automobiles, and more specifically, to prevent fuel from leaking into the outside air when fuel is injected into this type of fuel tank. This relates to the fuel tank inlet for the fuel tank.

Conventional technology Vehicles powered by internal combustion engines such as gasoline engines are usually equipped with a fuel tank, and when the fuel in the tank becomes low, the cap attached to the fuel inlet of the fuel tank is removed and the fuel is injected. A fuel supply nozzle is inserted into the mouth, and fuel is injected into the fuel tank through this 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 A problem arises in that the fuel vapor that fills the inside blows out from the fuel injection port into the outside air, polluting the atmosphere. Also, when fuel is injected into the 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, and this foamed fuel A problem arises in that the fuel leaks out from the fuel injection port into the outside air and pollutes the atmosphere.

In order to prevent the fuel in the fuel tank from leaking into the outside air and polluting the atmosphere, a truncated conical or cylindrical shape that tightly fits around the outer circumference of the fuel supply nozzle is installed at the fuel injection port of the fuel tank. A fuel injection port equipped with an elastic body has been proposed (Utility Model Act 1973-
(See Publication No. 21610 and Publication No. 58-36586).

Problems to be Solved by the Invention Although the fuel inlet of the fuel tank proposed above prevents the fuel from flowing out into the outside air by the attached elastic body, if refueling is repeated many times, the fuel inlet nozzle As a result, the elastic body is easily damaged,
In turn, this will be damaged and the sealing performance will deteriorate.
There is a problem with the durability of the elastic body. The present invention has been made to solve the problems of the prior art.

Means for Solving the Problems According to the present invention, in order to solve the above problems, an upper nozzle guide whose lower end is reduced in diameter into a cylindrical shape and a certain interval between the upper nozzle guide and the upper nozzle guide are provided in the fuel injection pipe of the fuel tank. and a lower nozzle guide located below the lower nozzle guide whose upper end has a reduced diameter into a cylindrical shape, and a cylindrical elastic seal is provided between the upper and lower ends of the upper and lower nozzle guides with the above-mentioned interval. A fuel inlet for a fuel tank is provided, in which a tube is attached, and a thick walled portion protruding inward is formed in a middle portion of the elastic seal tube at a portion spaced apart from the upper and lower nozzle guides.

Embodiment An embodiment of the present invention will be described with reference to the drawings.

Referring to FIG. 3, reference numeral 1 denotes a fuel tank, with a fuel injection pipe 2 protruding diagonally above the tank, and a cap 3 detachably attached to a fuel injection port 4 at the upper end of the fuel injection pipe 2. ing. 5 is a fuel vapor outlet provided on the upper wall surface of the fuel tank 1;
It is connected to a canister 6 containing a fuel adsorbent such as activated carbon. Fuel vapor filling the upper space of the fuel tank 1 flows out into the canister 6 through the fuel vapor outlet 5 and is once adsorbed by activated carbon within the canister 6. The fuel vapor adsorbed by the activated carbon is sucked into the engine intake passage through a fuel introduction pipe (not shown) when the engine is in a predetermined operating state.

Next, details of the vicinity of the fuel filler port of the fuel injection pipe 2 will be explained with reference to FIG.

An upper nozzle guide 7 is attached near the upper end of the fuel injection pipe 2 . This upper nozzle guide 7
is provided with a cylindrical nozzle insertion passage 8 which is biased to one side and has a reduced diameter in its lower part, and has a cylindrical nozzle insertion passage 8 which is offset to one side and whose diameter is reduced, and its upper part 9.
has a flap-like shape, and is fixed to the inner wall of the fuel injection pipe 2 by this upper flap-shaped portion 9. A lower nozzle guide 10 is attached below the nozzle insertion passage 8 at a certain distance therebetween. This lower nozzle guide 10 has a cylindrical nozzle insertion passage 11 at its upper end that is reduced in diameter and has approximately the same diameter as the nozzle insertion passage 8, and its lower part is enlarged in diameter and this enlarged diameter part 12 forms an inner wall of the fuel injection pipe 2. is fixed. These upper and lower nozzle guides 7 and 10
A cylindrical seal tube 13 made of an elastic material such as rubber is installed between the lower end nozzle insertion passage 8 and the upper end nozzle insertion passage 11. The upper and lower ends of the seal cylinder 13 are closely fitted to the outer peripheries of the nozzle insertion passages 8 and 11, respectively, and the clamp 1
4 and 14. In addition, a thick wall portion 15 that protrudes inward is formed in the intermediate portion of the nozzle insertion passages 8 and 11, and the inner diameter of the thick wall portion 15 is made slightly smaller than the outer diameter of the fuel supply nozzle. .

FIG. 2 shows a state in which the fuel supply nozzle is inserted into the fuel injection pipe 2 constructed as described above. When the fuel supply nozzle 16 is inserted into the nozzle insertion passages 8 and 11, the thick portion 15 of the seal cylinder 13 comes into contact with the outer peripheral surface of the fuel supply nozzle 16 and is slightly expanded outward. is elastically and sealingly engaged with the fuel supply nozzle 16, and the interior of the fuel tank 1 is completely isolated from the outside air.

The upper space within the fuel tank 1 is filled with fuel vapor under pressure, and when the cap 3 is removed, a portion of the evaporated fuel flows out from the fuel inlet 4 into the outside air. However, when the fuel supply nozzle 16 is subsequently inserted into the nozzle insertion passages 8 and 11, the seal cylinder 13 sealingly engages with the outer circumferential surface of the fuel supply nozzle 16 as described above. is isolated from the outside air, preventing fuel from flowing into the outside air. Next, the fuel supply nozzle 16
When fuel is supplied from the fuel tank 1, this fuel violently collides with the fuel in the fuel tank 1, causing the fuel to bubble and generate fuel vapor. However, since the inside of the fuel tank 1 is isolated from the outside air, this fuel vapor is sent to the canister 6 and adsorbed therein without flowing out to the outside.

When the fuel supply is completed, the fuel supply nozzle 16 is pulled out and the cap 3 is fitted again.

Note that when the cap 3 is removed from the fuel injection port 4, the fuel supply nozzle 16 is inserted into the nozzle insertion passage 8,
If it is not inserted into fuel tank 1
Although some of the fuel vapor inside the cap 3 leaks out into the outside air, most of the time during which the cap 3 is disengaged is occupied by the time when the fuel supply nozzle 16 is inserted. As a whole, the amount of evaporated fuel that leaks into the atmosphere is extremely small. Furthermore, since the lower nozzle guide 10 is provided apart from the upper nozzle guide 7, the lower nozzle guide 10 restricts the movement of the fuel supply nozzle 16 and improves the close contact between the nozzle 16 and the seal cylinder 13. In other words, if there is only the upper nozzle guide 7, when the tip of the nozzle 16 swings vertically and horizontally around the upper nozzle guide 7, a gap will be created between the nozzle 16 and the seal cylinder 13, or the sealing force will be weakened. If the nozzle guides 7 and 10 are provided on the upper and lower sides as in the example, the movement of the nozzle 16 can be restricted to a minimum, and the sealing force between the nozzle 16 and the seal cylinder 13 can be made uniform. Further, the seal cylinder 13 has its upper and lower ends connected to nozzle insertion passages 8 and 11, respectively.
When the fuel supply nozzle 16 is inserted, only the middle portion of the seal cylinder 13 is expanded, so that the seal cylinder 13 is less likely to be damaged by the fuel supply nozzle 16. Sealing performance is maintained for a long time.

Further, since the seal cylinder 13 has a thick wall portion formed in the middle thereof, the sealing performance against the nozzle 16 is improved, and the strength of the seal cylinder 13 itself is increased, resulting in improved durability.

Effects of the invention In this invention, when fuel is injected, the cylindrical seal tube comes into close contact with the fuel refueling nozzle, completely sealing off the inside of the fuel tank from the outside air.Therefore, it is possible to prevent evaporated fuel from flowing out when fuel is injected. can.

Moreover, the upper and lower ends of the cylindrical seal tube are
Since it is supported by both the upper and lower nozzle guides and has a thick part formed in the middle, it prevents this from being significantly deformed when inserting the fuel supply nozzle, thereby avoiding damage and maintaining good performance over a long period of time. The sealing performance is maintained, the sealing force is increased, and the strength of the seal cylinder itself is increased, so that its durability can be improved.

Furthermore, since the nozzle guides are provided vertically and spaced apart from each other, the movement of the fuel supply nozzle can be restricted to a minimum compared to the case where only the upper nozzle guide is used, and the tightness between the nozzle and the seal cylinder is improved. It is possible to increase the sealing force and make the sealing force uniform.

[Brief explanation of the drawing]

Fig. 1 is an enlarged sectional view of the fuel injection port according to the embodiment of the present invention, Fig. 2 is a sectional view of the fuel injection port of Fig. 1 when the fuel supply nozzle is inserted, and Fig. 3 is the enlarged sectional view of the fuel injection port according to the embodiment of the present invention. FIG. 3 is a side sectional view showing the overall configuration. 1...Fuel tank, 2...Fuel injection pipe, 3...
Cap, 4... Fuel injection port, 7... Upper nozzle guide, 8... Nozzle insertion passage, 10... Lower nozzle guide, 11... Nozzle insertion passage, 13...
Cylindrical seal tube, 15...thick wall portion, 16...fuel supply nozzle.

Claims (1)

[Scope of utility model registration request] In the fuel injection pipe of the fuel tank, an upper nozzle guide whose lower end is reduced in diameter to a cylindrical shape, and a lower nozzle guide located below the nozzle guide at a certain distance and whose upper end is reduced in diameter to a cylindrical shape are provided, respectively. A cylindrical elastic seal cylinder is installed between the upper and lower ends of the upper and lower nozzle guides at the interval, and a cylindrical elastic seal cylinder is installed at a portion of the middle part of the elastic seal cylinder that is spaced apart from the upper and lower nozzle guides. , a fuel inlet for a fuel tank characterized by forming a thick wall portion projecting inward.