JPH0336422Y2 - - 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 structure of 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, the fuel tank is connected to first and second canisters that adsorb evaporated fuel, and the fuel inlet of the fuel tank is connected to the first and second canisters that adsorb evaporated fuel. By inserting a fuel supply nozzle near the first and second
A switching valve is provided to communicate one of the inlets of each canister with the fuel inlet, and normally the fuel inlet is communicated with the first canister, and when the fuel supply nozzle is inserted, the switching valve is switched to connect the fuel inlet. A fuel vapor recovery device has been proposed in which an inlet is communicated with the second canister (Jitsukai Sho et al.
55-62848).

Problems to be solved by the invention The fuel vapor recovery device proposed above attempts to adsorb evaporated fuel into a separately provided second canister only when supplying fuel to a fuel tank. When you remove the entrance cap,
Unless a fuel supply nozzle is inserted, the evaporated fuel generated in the fuel tank will inevitably flow out into the outside air, and therefore, there is a problem in that it is difficult to take all possible measures to prevent air pollution caused by the evaporated fuel.

Means for Solving the Problems In order to solve the above problems, the present invention has a structure in which even if the cap of the fuel inlet of the fuel tank is removed, the fuel inlet is isolated from the outside air, and the fuel inlet is not connected to the fuel tank. During supply, the vaporized fuel generated in the fuel tank is adsorbed onto the canister. Its structural features include a nozzle guide for inserting the fuel supply nozzle into the fuel injection pipe of the fuel tank; An on-off valve is attached to the tip of the nozzle guide and is closed at all times and is opened when the fuel supply nozzle is inserted, and a canister is connected to the fuel tank via an evaporative fuel passage to prevent the evaporation. The present invention is characterized in that a switching control valve is provided in the fuel passage, which communicates the inside of the fuel tank with the canister in conjunction with opening of the on-off valve.

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.

The details of the vicinity of the fuel injection port 4 will be described with reference to FIG. 1. An upper nozzle guide 5 is attached to the fuel injection port 4. This upper nozzle guide 5 has a cylindrical nozzle insertion passage 6 which is biased to one side and has a reduced diameter in its lower part, and its upper part 7 has a truss-like shape.
It is fixed to the inner wall of the fuel injection pipe 2 by. A lower nozzle guide 8 is attached below the nozzle insertion passage 6 at a certain distance therebetween.
This lower nozzle guide 8 is the nozzle insertion passage 6
It has a cylindrical nozzle insertion passage 9 having approximately the same diameter as the fuel injection pipe 2 and is fixed to the inner wall of the fuel injection pipe 2 by a flange portion 10. A cylindrical seal tube 11 made of an elastic material such as rubber is installed between the nozzle insertion passages 6 and 9 of the upper and lower nozzle guides 5 and 8. The upper and lower ends of the seal cylinder 11 are closely fitted to the outer peripheries of the nozzle insertion passages 6 and 9, respectively, and are fixed by clamps 12, 12.
Also, the nozzle insertion passages 6, 9 in the middle part thereof.
A thick portion 13 that protrudes inward at a portion spaced apart from
The inner diameter of this thick portion 13 is made slightly smaller than the outer diameter of the fuel supply nozzle.

An on-off valve 14 is attached to the tip (lower end) of the lower nozzle guide 8, which is pushed and opened when a fuel supply nozzle is inserted.
This on-off valve 14 is normally operated by a spring 15 when the cap 3 is fitted into the nozzle insertion passage 9.
It is becoming more and more obstructed.

A switching control valve 16 is provided near the on-off valve 14 and whose opening and closing are controlled in conjunction with the opening and closing of the on-off valve 14. This switching control valve 1
Normally, a spring 17 pushes down the valve rod 18 and a valve seal 19 blocks communication between the passage 20 to the fuel tank 1 and the passage 21 to the canister. Further, the on-off valve 14 has an arm 2.
2 is attached and the on-off valve 14 is rotated around a pivot 23, this arm 22 engages with the valve rod 18.

Referring again to FIG. 3, a fuel vapor outlet 24 is provided in the upper wall of the fuel tank 1, and the outlet 24 connects the aforementioned passages 20 and 21 to a canister 25 containing a fuel adsorbent such as activated carbon. connected via. The canister 25 adsorbs evaporated fuel only when supplying fuel into the fuel tank 1, and the canister 25 adsorbs evaporated fuel in the fuel tank 1 during normal times.
It is provided separately.

FIG. 2 shows a state in which the fuel supply nozzle is inserted into the fuel injection pipe 2 constructed as described above. Cap 3 is removed and fuel supply nozzle 2
6 is inserted into the nozzle insertion passages 6 and 9,
The thick part 13 of the seal cylinder 11 contacts the outer circumferential surface of the fuel supply nozzle 26 and is pushed outward slightly, so that the seal cylinder 11 engages with the fuel supply nozzle 26 in an elastic and sealing manner, and the inside of the fuel tank 1 is sealed. is completely isolated from the outside air.

Further, when the fuel supply nozzle 26 is inserted all the way, the opening/closing valve 14 is pushed by its tip.
4 rotates around the pivot 23 as shown in the figure to open the nozzle passage 9 of the lower nozzle guide 8 and communicate the fuel inlet 4 with the inside of the fuel tank 1. Therefore, fuel is supplied into the fuel tank 1 from the fuel supply nozzle 26. Due to the rotation of the on-off valve 14, the arm 22 also rotates, and its tip engages the valve rod 18 of the switching control valve 16, pulling the valve rod 18 up against the spring 17, and connecting it to the passage 20 as shown in the figure. It communicates with the passage 21. Therefore, the evaporated fuel in the fuel tank 1 and the fuel vapor generated by the collision between the injected fuel and the fuel in the fuel tank pass through the passages 20 and 21 and are adsorbed by the activated carbon in the canister 25. In this way, fuel is prevented from escaping into the outside air during fuel supply.

The fuel vapor adsorbed on the activated carbon in the canister 25 is sucked into the intake passage of the engine through an inlet pipe (not shown) during a predetermined engine operating state.

In this way, even if the cap 3 of the fuel inlet 4 is removed, the nozzle insertion passage 9 is closed by the on-off valve 14, so the fuel tank 1 will not communicate with the outside air, and the fuel supply nozzle 26 will not be inserted. When this happens, the on-off valve 14 is opened and at the same time the fuel tank 1 is communicated with the canister 25, so that the evaporated fuel generated therein is adsorbed in the canister 25 and is prevented from flowing out to the outside air.

Figures 4, 5 and 6 show other embodiments of the present invention.

This embodiment is different from the embodiments shown in FIGS. 1, 2, and 3 in that the on-off control valve 16 is different from the on-off valve 14.
The point is that it is located upstream from the Incidentally, each part common to the embodiment shown in FIGS. 1, 2, and 3 is given the same reference numeral.

Referring to FIG. 5, an on-off valve 14 is provided at the tip of the lower nozzle guide 8 and is opened when a fuel supply nozzle 26 is inserted. This on-off valve 14
is normally closed by a spring 15. The on-off control valve 16 is provided on the upstream side of the on-off valve 14, and the valve rod 1 is supported by a spring 17.
8 upward to open the passage 20 to the fuel tank 1.
The communication between the passage 21 and the canister 25 is cut off.

As shown in FIG. 6, when the fuel supply nozzle 26 is inserted into the fuel injection port 4, the fuel supply nozzle 26
The outer periphery of the valve is in close contact with the cylindrical seal tube 11, and communication between the outside air and the inside of the fuel tank 1 is cut off.
will be released. As the on-off valve 14 is opened, the lever 22 engages with the valve rod 18 and pulls it down against the spring 17. Therefore, the switching control valve 16 is opened, the passages 20 and 21 are communicated, and the evaporated fuel in the fuel tank 1 flows into the canister 25 and is adsorbed by the activated carbon contained therein.

Effects of the invention As described above, the present invention has an on-off valve that is normally closed at the tip of the nozzle guide for inserting the fuel refilling nozzle provided in the fuel injection port, so that the cap fitted into the fuel injection port can be closed. Even if the fuel tank is removed, the inside of the fuel tank will not communicate with the outside air, and when the fuel supply nozzle is inserted and the on-off valve is opened, the inside of the fuel tank will be in communication with the canister at the same time, so evaporated fuel will be transferred to the canister. is adsorbed to the air, preventing it from escaping into the outside air. In this way, when supplying fuel to the fuel tank,
In both cases when the cap is removed and when the fuel supply nozzle is attached, the vaporized fuel is prevented from flowing out into the outside air, and the effect of preventing air pollution is further improved.

[Brief explanation of drawings]

Fig. 1 is an enlarged sectional view of the main parts of the first embodiment of the present invention, Fig. 2 is a sectional view similar to Fig. 1 showing the state when the fuel supply nozzle is inserted in the same embodiment, and Fig. 3. 4 is an overall view of the second embodiment of the present invention, FIG. 5 is an enlarged sectional view of the main parts of the same embodiment, and FIG. 6 is a diagram showing the fuel supply nozzle in the same embodiment. The first one shows the state when inserted.
It is a sectional view similar to the figure. 1...Fuel tank, 2...Fuel injection pipe, 4...
Fuel injection port, 5... Upper nozzle guide, 6... Nozzle insertion passage, 8... Lower nozzle guide, 9...
Nozzle insertion passage, 11...Cylindrical seal tube, 14
... Opening/closing valve, 16... Switching control valve, 18... Valve rod, 20... Fuel tank passage, 21... Canister passage, 22... Opening/closing valve arm, 25... Canister.

Claims (1)

[Scope of utility model registration request] A nozzle guide for inserting the fuel supply nozzle is provided in the fuel injection pipe of the fuel tank, and an on-off valve that is opened only when the fuel supply nozzle is inserted is attached to the tip of the nozzle guide, and the fuel tank is evaporated. A fuel tank, which is connected to a canister through a fuel passage, and further includes a switching control valve in the evaporated fuel passage, which communicates the inside of the fuel tank with the canister in conjunction with opening of the on-off valve. .