JPH11247733A - Fuel cut off valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the flow rate of the vapor passing through a gas introduction hole and an excellent valve closing property. SOLUTION: A protrusion wall section 28, which overhangs outward from the surface of a housing 16 at least on the upper side of the gas introduction hole formed in the housing of a fuel cut off valve 14. The tip face of this protrusion wall section 28 is positioned outside more than the internal wall face of the notch 26 formed in a packing 20. The packing 20 is liable to swell and extend toward the gas introduction hole 22 due to dipping in fuel, but the packing 20 is prevented from extending toward the gas introduction hole 22 by the extrusion wall section 28, resulting in the prevention of the clogging of the gas introduction hole 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cutoff valve for guiding fuel gas generated in a fuel tank of an automobile or the like to the outside.

[0002]

2. Description of the Related Art In a fuel tank of an automobile or the like, a fuel vapor generated in the fuel tank is guided to the outside of a canister or the like, and the fuel is prevented from flowing out of the canister to the canister when the automobile or the like falls. The fuel cutoff valve is provided. FIGS. 4 and 5 show a state in which the fuel cutoff valve is attached to the fuel tank. A hole 12 is formed in the upper surface of the fuel tank 10.
4 is inserted into the hole 12. Housing 1 for fuel cutoff valve 14
An annular flange 18 is formed on the side wall of 6, and this annular flange 18 indirectly contacts the upper surface of the fuel tank 10 with the annular annular packing 20. This prevents the fuel cutoff valve 14 from being inserted through the hole 12 of the fuel tank 10 and ensures the airtightness of the hole 12 of the fuel tank 10.

[0003] A gas introduction hole 2 for introducing fuel vapor generated in the fuel tank 10 into the fuel shut-off valve 10 is provided on a side wall of the housing 16 immediately below the flange 18.
2 are formed. It is desirable that the position of the gas introduction hole 22 be located at the uppermost position in the fuel tank 10 when the fuel cutoff valve 14 is attached to the fuel tank 10. Conventionally, the height of the gas introduction hole 22 is set to
In many cases, the cutout 24 is formed by partially cutting off the inner wall side of the packing 20 in order to take in fuel vapor into the gas introduction hole 22 (FIG. 5). . The depth h of the notch 24 is, for example, about 1.75 mm. However, since the accuracy of mounting the fuel cutoff valve 14 to the fuel tank 10 varies, the notch 2
4 reaches the seal position, and the fuel vapor leaks from the position of the notch 24 to the outside.

[0004]

In order to solve this problem, the depth h of the notch 24 of the packing 20 is reduced (the depth h of the notch 24 is reduced to about 0.5 mm, which is less than one third of the conventional depth). To do). However, when the depth h of the notch 24 of the packing 20 is reduced, fuel
In this case, the packing 20 swells, and the swelled packing 20 closes the gas introduction hole 22 of the fuel shut-off valve 14, resulting in a problem that the flow rate of the fuel vapor to the canister or the like is poor. In order to solve this problem, it has been considered to lower the gas introduction hole 22 of the fuel cutoff valve 14 downward. However, if the gas introduction hole 22 of the fuel cutoff valve 14 is lowered too low, the float (not shown) of the fuel cutoff valve 14 becomes easy to close with a gentle inclination and a slightly low oil level, so that poor valve closing characteristics easily occur. The drawback was that it became.

[0005] The present invention has been made in view of the above points, and has as its object to provide a fuel cutoff valve which ensures a sufficient flow rate of steam passing through a gas introduction hole and good valve closing characteristics. Things.

[0006]

In order to achieve the above object, a fuel shut-off valve according to the present invention is fixed to a fuel tank via a packing, and has a fuel inlet formed with a gas introduction hole communicating with the inside and outside of a housing. In the shut-off valve, a protruding wall protruding outward from a surface of the housing is formed at least above the gas introduction hole.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings. FIG. 1 is an enlarged longitudinal sectional view of a main part of a fuel cutoff valve according to the present invention, and FIG. 2 is a sectional view taken along line AA of FIG. 1 and 2
4, the same reference numerals as those in FIGS. 4 and 5 denote the same parts. A disk-shaped packing 20 is interposed between the fuel tank 10 and the flange 18 of the fuel cutoff valve 14. A notch 26 is formed in the packing 20 at a position corresponding to the gas introduction hole 22. Assuming that the depth of the notch 26 is H, the depth H is set to, for example, about 0.5 mm to eliminate the possibility that fuel vapor leaks from the position of the notch 26 to the outside. Thereby, the airtightness of the mounting position of the fuel cutoff valve 14 in the fuel tank 10 is ensured.

[0008] Gas introduction hole 2 formed in housing 16
The position 2 is located slightly below the height of the packing 20. For example, the upper end of the gas introduction hole 22 is lower than the lower surface of the packing 20 by about 1 mm. In the present invention, as shown in FIGS. 1 and 2, a projecting wall portion 28 that projects outward from the surface of the housing 16 like an eave is formed at least above the gas introduction hole 22. This protruding wall portion 28
As shown in FIG. 2, not only above the gas introduction hole 22,
It is desirable that it extends to the side. In some cases, it may be formed around the gas introduction hole 22. When the fuel cutoff valve 14 is attached to the fuel tank 10 as shown in FIG.
6 is desirably located outside the inner wall surface.

When the gasket 20 is immersed in fuel from the state shown in FIG. 1 due to a fall or inclination of the vehicle, the gasket 20 swells (FIG. 3). Although the swollen packing 20 tends to extend toward the gas introduction hole 22, the presence of the protruding wall portion 28 prevents the packing 20 from extending to the gas introduction hole 22. As a result, the gas introduction hole 22 is not closed and the steam flow rate of the fuel cutoff valve 14 is ensured. Further, since the gas inlet hole 22 can be prevented from being blocked by the swelling of the packing 20 by the protruding wall portion 28, the gas inlet hole 22 can be prevented.
Can be provided at a high position in the fuel tank 10 (the fuel cutoff valve 14), and there is no occurrence of poor valve closing characteristics.

[0010]

As described above, according to the fuel shut-off valve according to the present invention, the fuel is immersed in the packing by providing the protruding wall projecting outward from the main body surface at least above the gas introduction hole. Even if the gas swells, the protruding wall prevents the gas introduction hole from being blocked by the swelling packing, and the flow rate of the fuel vapor can be secured.
In addition, since the blocking of the gas introduction hole can be prevented by the protruding wall portion, the depth of the notch can be reduced, and leakage of fuel vapor can be prevented. In addition, the gas introduction hole can be provided at a high position of the fuel cutoff valve, and good valve closing characteristics can be secured.

[Brief description of the drawings]

FIG. 1 is an enlarged vertical sectional view of a main part of a fuel cutoff valve according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a cross-sectional view of a main part showing a packing after swelling.

FIG. 4 is a sectional view showing a state in which a conventional fuel cutoff valve is attached to a fuel tank.

FIG. 5 is a sectional view of a main part of FIG.

[Description of sign]

 DESCRIPTION OF SYMBOLS 10 Fuel tank 14 Fuel cutoff valve 16 Housing 20 Packing 22 Gas introduction hole 26 Notch 28 Projection wall

Claims (2)

[Claims] 1. A fuel cut-off valve which is fixed to a fuel tank via a packing and has a gas introduction hole communicating with the inside and outside of a housing, wherein at least an upper side of the gas introduction hole extends outward from a surface of the housing. A fuel cut-off valve having a protruding protruding wall portion. 2. A notch is formed in an inner wall surface of the packing,
The fuel cutoff valve according to claim 1, wherein a tip end surface of the protruding wall portion is located outside a surface of the housing with respect to the notch.