JPS61191427A - Evaporative gas discharge inhibit device for fuel tank - Google Patents

Abstract

PURPOSE:To reduce the size of a canister and prevent fuel to flow outside by connecting the canister to a bent hose and providing the midway of the bent hose with a shut-of valve which is opened only when a fuel filler-lid is opened. CONSTITUTION:A bent hose 7 is connected at one end to the top of a fuel tank 1 and at the other end to a canister 8. An electromagnetically operated shut-off valve 9 is incorporated in the midway of the bent hose 7. The shut-off valve 9 comprises a valve disk 9a normally closed by the pressure in the fuel tank 1 and valve casing 9b in which the valve disk 9a is built. The valve disk 9a is opened by a coil 9c energized in response to a signal from a lid switch 10 for detecting that a fuel filler-lid 5 is opened. Thus, since the shut-off valve 9 is normally closed except in fuel supply and the canister 8 will suffice if it absorbs only a gas evaporated from fuel flowing in its supply, the volume of the canister 8 may be relatively small.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a fuel tank for an automobile, and more particularly to a device for suppressing the discharge of evaporative gas within the tank during refueling.

1. Prior Art 1. As is well known, the conventional general fuel tank T + 3M tank is clearly communicated in the same way as the book and the seven illusions. That is, reference numeral 1 in FIG. 3 indicates a fuel tank, to which an outlet tube 2 and a return pipe 3 are connected, and a fuel neck whose tip is led to a fuel filler lid 5 of a vehicle body panel 4. By connecting the part near the tip of the fuel tank 6 with the upper part of the fuel tank 1 with a vent hose 7, the air inside the tank during refueling is released into the atmosphere (see, for example, Japanese Utility Model Application No. 50-3119). ).

However, with such a structure of the fuel tank l, the air inside the tank contains a large amount of evaporated gas from the fuel, so during refueling, the evaporated gas is discharged into the atmosphere together with the air inside the tank through the vent hose 7. Since there is a risk of contamination, it has recently been considered to connect the vent hose 7 to the canister so that the evaporated gas discharged during refueling is temporarily absorbed into the canister. However, in such a canister combination structure, since evaporated gas is constantly processed, a large canister with a large capacity must be used, making it difficult to load the canister. Furthermore, there is a risk that fuel may flow out through the vent hose 7 due to a sudden turn or rollover of the vehicle.

A purpose of the present invention An object of the present invention is to make the canister as small as possible in consideration of the evaporative residue emission suppressing device as described above.
To obtain an evaporative gas emission suppressing device for a fuel tank that prevents fuel from flowing out to the outside even when an automobile makes a sudden turn or rolls over.

Structure of the Invention - In order to achieve this object, the present invention combines a Yayanista that temporarily adsorbs evaporative gas in the tank during refueling with the vent hose, and also connects the vent hose in the middle of the bed hose with a valve that responds to the opening/closing movement of the fuel filler lid. It is proposed to incorporate a shutoff valve to open the closed 1F valve only when the fuel filler 718 is opened.

-Example- Hereinafter, details of an example of the present invention will be explained with reference to FIGS. 1 and 2.

FIG. 1 shows a first embodiment of the present invention, and the same structural parts as those in FIG. 3 described above are designated by the same reference numerals. The feature of the first embodiment is that the opposite end of the vent hose 7 connected to the upper part of the fuel tank 1 is connected to the canister 8, and an electromagnetically actuated shutoff valve 9 is installed in the middle of the vent hose 7.
The point is that it incorporates. That is, the shutoff valve 9 has a valve body 9a built into a valve box 9b, which is always kept in the closed position by the pressure of the fuel tank 1. The coil 9C, which is excited by the signal from the RAD switch 10, is energized and opened. Of course, the outlet pipe 11 on the opposite side of the canister 8 is connected to the intake system of the engine, although not shown. In addition,
Reference numeral 12 in FIG. 1 is an evaporative tube connected to a small canister 13.

Since the evaporative gas emission suppression device of the first embodiment has the structure as described in 1- below, the shutoff valve 9 automatically opens in response to the opening of the fuel filler line 5 during refueling. The evaporative gas of the fuel discharged together with the air inside the tank passes through the vent hose 7 and flows into the canister 8 for treatment, thereby preventing direct release into the atmosphere. In addition, the shutoff valve 9 is always closed except when refueling, and the canister 8 only needs to absorb the fumes of the fuel flowing during refueling, so a compact one with a relatively small capacity can be used. . Closing the stop valve 9 at times other than when refueling prevents fuel from flowing out of the canister 8 when the vehicle makes a sharp turn or rolls over.

FIG. 2 shows a second embodiment in which a mechanically operated shutoff valve 9A is used, and this shutoff valve 9A has a needle valve type valve body 9e built in inside a valve box 9d. The wire 14 connects the fuel filler to the fuel filler 5. That is, since the valve body 9e is opened by moving forward when the seven-wheel fluoride 5 is opened, it is always closed except when refueling. Therefore, with this structure as well, as in the case of the first embodiment, it is possible to prevent the evaporative gas of the fuel from being released into the atmosphere during refueling, thereby preventing fuel leakage due to sharp turns or rollovers of the vehicle.

In each of the above embodiments, a shutoff valve that directly responds to the fuel filler lid has been exemplified, but in the present invention, it is only necessary to make the shutoff valve respond to the opening/closing operation of the fuel filler lid. The shutoff valve may be opened using an opener inch or the like.

Effects of the Invention As is clear from the above description, according to the present invention, a shutoff valve is incorporated into the vent hose to make it sensitive to the opening/closing operation of the fuel filler lid, so that evaporative gas from fuel during refueling can be treated. It is possible to obtain an evaporative gas emission suppressing device in which the canister can be made smaller and in which fuel does not flow out due to rollover of an automobile or the like.

[Brief explanation of drawings]

FIG. 1 is a conceptual diagram of an evaporative gas emission suppressing device according to a first embodiment of the present invention, FIG. 2 is a partially enlarged sectional view of an evaporative gas emission suppressing device according to a second embodiment of the present invention, and FIG. 3 is a conventional FIG. 3 is a sectional view of the fuel tank of FIG. 1... Fuel tank, 5... Fuel filler lid, 7... Vent hose, 9... Shutoff valve.

Claims (1)

[Claims] 1) A canister that temporarily absorbs evaporative gas in the tank during refueling is coupled to the vent hose, and a shutoff valve that is sensitive to the opening and closing movement of the fuel filler lid is installed in the middle of the vent hose, A device for suppressing evaporative gas emissions from a fuel tank, characterized in that the shutoff valve is opened only when the lid is opened.