JP2000240833A - Fuel shut-off valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel shut-off valve which improves assembly workability for the tank upper wall of a fuel tank and reducing the number of part items. SOLUTION: A fuel shut-off valve 20 is provided with a case main body 30, a float 40, and a lid body 50. The case main body 30 is inserted into a mounting hole FTc o a fuel tank FT and is mounted on a tank upper wall FTa by a flange part. The lid body 50 is assembled to the case main body 30 by welding it with an annular weld 52a to the tank upper wall FTa. A projection 52b is formed on the lid body 50, and by pressing a ceiling walling part 32 of the case main body 30, a sealing part is formed between a bottom face of the flange part and an opening rim part of the mounting hole FTc of the tank upper wall FTa.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is directed to a fuel tank for a vehicle, which is disposed above a fuel tank for discharging fuel vapor from the fuel tank at the time of refueling and restricting the fuel flow when the fuel reaches a predetermined liquid level. Fuel shut-off valve.

[0002]

2. Description of the Related Art Conventionally, as this kind of fuel cutoff valve, U.S. Pat. No. 5,404,907 and the like are known and have a configuration as shown in FIG. In FIG. 7, the fuel cutoff valve 1
Reference numeral 00 denotes a device that is mounted on the tank upper wall FTa of the fuel tank FT, and includes a case main body 102, a lid 110, a float 120, a spring (not shown), and an O-ring 140. The case body 102 includes the upper wall 1
03, a side wall portion 104 integrally formed on the outer peripheral portion of the upper wall portion 103, and a bottom plate 105 attached to a lower end of the side wall portion 104.
02S. A mounting hole 103a is formed in an outer peripheral portion of the upper wall portion 103 of the case main body 102, and an upper projecting portion 103b is formed in a central portion thereof. An annular recess 103c for accommodating the O-ring 140 is formed on the outer peripheral side wall of the upper protruding portion 103b, and a connection passage 103d connected to the float chamber 102S is formed at the axis thereof.

[0003] The float chamber 102S houses a float 120 having a valve portion 120a at an upper portion thereof. The valve portion 120a opens and closes the connection passage 103d. The float 120 is supported by a spring placed on the bottom plate 105.

[0004] On the other hand, the lid 110 is composed of a lid main body 112 assembled to the case main body 102 and a lid passage forming portion 114.
And a flange portion 115, which are integrally formed. A mounting recess 114a is formed in the lid body 112, and the upper protruding portion 103b of the upper wall portion 103 of the case body 102 is fitted into the mounting recess 114a. Further, the flange portion 115 is thermally fused to the tank upper wall FTa of the fuel tank FT at the joint end surface 115a.

[0005] In the fuel cutoff valve 100 having the above structure, when fuel is supplied to the fuel tank FT, the fuel vapor in the fuel tank FT passes through the through hole 1 formed in the bottom plate 105 of the case body 102.
05a, the float chamber 102S, the connection passage 103d, and the outside (canister) through the passage 114a of the lid 110. Then, when the fuel in the fuel tank FT reaches the predetermined liquid level F
When the fuel reaches L1, the fuel flows into the float chamber 102S through the through-hole 105a, and gives buoyancy to float the float 120. The float 12 is raised by the float 120 being raised.
The valve portion 120a formed in the upper portion of the cylinder 0 blocks the connection passage 103d, thereby preventing the fuel from flowing out of the fuel tank FT.

In order to mount the fuel cutoff valve 100 on the tank upper wall FTa of the fuel tank FT, first, a float 120 and a spring are assembled in the case main body 102 and closed by the bottom plate 105. Then, the case body 102 is
Assemble to 10. That is, after attaching the O-ring 140 to the annular recess 103c of the upper protruding portion 103b of the case main body 102, the upper protruding portion 103b is fitted into the mounting recess 114a of the lid 110. Further, the joining end face 115a of the flange portion 115 is heated by a heat sealing plate (not shown), and the peripheral edge of the tank mounting hole FTc of the fuel tank FT is also heated by the heat welding plate (not shown). Then, the two parts are heat-welded by combining the melted parts.

[0007]

However, the case body 1
02, the lid 110 and the O-ring 140, the fuel cutoff valve 100 has been required to further reduce the number of parts. That is, the use of the O-ring 140 not only makes the mounting workability not good, but also
The number of parts has increased, which has been a factor of cost increase.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a fuel shut-off valve which is excellent in workability of assembling a fuel tank to a tank upper wall and has a reduced number of parts. I do.

[0009]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is provided in a mounting hole formed in a tank upper wall of a fuel tank, so that the inside and outside of the fuel tank can be connected to each other. In a fuel cutoff valve that opens and closes a connection passage to connect and shut off communication between the fuel tank and the outside, a cylindrical side wall inserted into the mounting hole, a ceiling wall integrally formed with the side wall, A flange portion formed on the outer peripheral portion of the ceiling wall portion and placed on the upper wall portion on the outer peripheral side of the mounting hole to form a float chamber surrounded by the side wall portion and the ceiling wall portion in a cup shape. A case body, a float that is housed in the float chamber, lifts and lowers by increasing or decreasing the buoyancy according to the fuel level of the fuel tank to open and close the connection passage, a lid body that covers the ceiling wall, and a lid. Connection passage formed integrally with the body A lid passage forming portion having a lid side passage communicating with the outside, and an annular welded portion provided on an outer peripheral portion of the lid main body and welded to an upper wall portion, and is made of the same resin material as the tank upper wall. And a lid that is in close contact with the other of the lid body or the ceiling wall on one of the lid body or the ceiling wall, and the projection connects the annular welded portion to the fuel tank. A seal portion is formed on a contact surface between the case main body and the mounting hole when welded to the tank upper wall.

[0010] The fuel cutoff valve according to the present invention is mounted on the upper wall of the fuel tank, and when the fuel level rises due to refueling of the fuel tank, the fuel vapor in the fuel tank flows into the float chamber, the connection passage, It flows out through the lid-side passage of the lid. When the fuel reaches a predetermined liquid level in the fuel tank, the float rises by increasing buoyancy to close the connection passage, thereby preventing the fuel from flowing out of the fuel tank.

[0011] The case main body constituting the fuel cutoff valve includes:
It is formed in a cup shape by the side wall part and the ceiling wall part,
A flange provided on the outer peripheral side of the ceiling wall is placed on the tank upper wall with the side wall inserted into the mounting hole. Then, when assembling the lid to the case main body, when the annular welded portion of the lid and the tank upper wall of the fuel tank are welded, the projection formed on one of the lid main body or the tank upper wall presses the other, A seal portion is formed on a contact surface between the case body and the mounting hole to seal the inside and the outside of the fuel tank.

As described above, when the annular welded portion of the lid is welded to the upper wall of the fuel tank in order to assemble the lid to the case main body, the contact surface between the case main body and the mounting hole is simultaneously sealed. That is, another sealing member such as an O-ring is not required, and the number of components can be reduced.

Further, since the lid is formed of the same material as the upper wall of the fuel tank, the flange portion and the upper wall of the tank can be easily welded to each other, and a high sealing property is secured also in this portion. can do.

In a preferred embodiment of the present invention, the protrusion is formed on a sealing ridge for sealing between the ceiling wall or the lid body, so that the number of sealing points is two, and the sealing property is further improved. Can be increased.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to further clarify the configuration and operation of the present invention described above, a preferred embodiment of the present invention will be described below.

FIG. 1 is a sectional view showing a fuel cutoff valve 20 mounted on an upper portion of a fuel tank FT of an automobile according to an embodiment of the present invention. In FIG. 1, the fuel tank F
T is formed of a multi-layered resin material having a polyethylene layer on the surface and including a nylon layer, and has a mounting hole FT formed as a step FTb in the tank upper wall FTa.
The fuel cutoff valve 20 is mounted in the mounting hole FTc. The fuel cutoff valve 20 regulates the outflow to the outside (canister) when the fuel in the fuel tank FT rises to a predetermined liquid level FL1 during refueling.

FIG. 2 is an exploded sectional view of the fuel cutoff valve 20. The fuel cutoff valve 20 includes a case body 30 and a bottom plate 35.
, A float 40, a spring 46, and a lid 50 as main components. Case body 30, bottom plate 3
5 and the float 40 are formed of a synthetic resin polyacetal or nylon having fuel oil resistance. The lid 50 is formed of a composite material mainly composed of polyethylene.

The case body 30 includes a ceiling wall 32,
A cup-shaped float chamber 30S is provided, which is provided with a side wall portion 33 extending downwardly from the ceiling wall portion 32 in a cylindrical shape, and surrounded by the ceiling wall portion 32 and the side wall portion 33. 30a.

The outer peripheral portion of the ceiling wall portion 32 is
And a disk-shaped flange portion 32a larger than the outer diameter of the flange portion 32a. The flange portion 32a is placed on the step FTb of the mounting hole FTc of the fuel tank FT. A communication pipe 3 having a connection passage 32b is provided at the center of the ceiling wall 32.
2c is formed. The connection passage 32b communicates with the outside through the float chamber 30S and the lid 50. The communication pipe portion 32c has a conical seat portion 32d on the float chamber 30S side.

In the lower portion of the side wall portion 33, an engagement hole 33 is provided.
a is formed. The engagement hole 33a is for attaching the bottom plate 35 as described later. further,
A float 4 extending in the vertical direction is provided on the inner peripheral portion of the side wall portion 33.
A guide ridge 33b for guiding 0 is formed.

The bottom plate 35 is a member that closes the lower opening 30a of the case main body 30, and the engagement portion 35a formed on the outer periphery thereof engages with the engagement hole 33a.
The case body 30 is mounted so as to close the lower opening 30a. The bottom plate 35 is formed with a communication hole 35b for communicating the float chamber 30S with the inside of the fuel tank FT. Therefore, the inside of the fuel tank FT communicates with the float chamber 30S through the communication hole 35b. A spring support 35c is formed in the upper center of the lid 50. The spring support portion 35c supports the spring 46 between itself and the lower surface of the float 40.

The float 40 accommodated in the float chamber 30S is formed in a container shape having an upper wall 41 and a cylindrical side wall 42 formed below the outer periphery of the upper wall 41. The inside space is a buoyancy chamber 40S for generating buoyancy.

On the other hand, the lid 50 is formed of a lid main body 52 and a lid passage forming portion 54 projecting from the center of the lid main body 52 in an L-shape. An annular welded portion 52 welded to the tank upper wall FTa of the fuel tank FT is provided on an outer peripheral portion of the lid main body 52.
a is formed. In the lid passage forming section 54, a lid-side passage 54a is formed. One end of the lid side passage 54a is a communication port 54b communicating with the float chamber 30S side, and the other end is configured to be connected to the canister side. A projection 5 is provided on the inner peripheral side of the lid body 52.
2b is formed. The projection 52b is a projection for generating a sealing pressure between the lower surface of the flange 32a and the step FTb of the mounting hole FTc by pressing the ceiling wall 32 of the case body 30.

Next, the operation of the fuel cutoff valve 20 will be described. When fuel is supplied into the fuel tank FT by refueling, the fuel vapor accumulated in the upper part of the fuel tank FT as the fuel level in the fuel tank FT rises is released to the canister through the passage.

When the fuel level in the fuel tank FT reaches a predetermined level FL1, the fuel flows into the float chamber 30S through the communication hole 35b of the bottom plate 35. As a result, the float 40 generates buoyancy and rises, closing the connection passage 32b with the valve portion 41a to prevent fuel from flowing out to the canister side. Therefore, when fuel is supplied to the fuel tank FT, the fuel vapor can be released from the fuel tank FT and the fuel can be prevented from flowing out of the fuel tank FT.

Next, the operation of attaching the fuel cutoff valve 20 to the tank upper wall FTa of the fuel tank FT will be described.
2, the float 40 and the spring 46 are housed in the float chamber 30S of the case body 30, and the lower end of the spring 46 is aligned with the spring supporting portion 35c of the bottom plate 35, and the engaging portion 35a of the bottom plate 35 Is engaged with the engagement hole 33 a of the side wall 33, and the bottom plate 35 is attached to the case body 30.

Subsequently, as shown in FIG.
The case body 3 is attached to the mounting hole FTc of the tank upper wall FTa of the T.
Then, the flange portion 32a of the ceiling wall portion 32 is placed on the step portion FTb of the tank upper wall FTa. At this time, the flange portion 32a of the case body 30
It is placed in a state where it is positioned on the step FTb of the tank upper wall FTa.

Thereafter, the lower end of the annular welded portion 52a of the lid 50 is melted by the hot plate Hp1, and is melted by the hot plate Hp2 along the periphery of the mounting hole FTc of the fuel tank FT to form a welded portion FTd. Then, the lid 50 is aligned with the case body 30, and the annular welded portion 52a is pressed against the welded portion FTd. When the annular welded portion 52a and the welded portion FTd are solidified by cooling, they are welded to each other. At this time, the projection 52b is pressed by the ceiling wall portion 32 of the case body 30, and a first seal portion is formed between the lower surface of the flange portion 32a and the opening edge of the mounting hole FTc. By this pressing,
Since the ceiling wall portion 32 is elastically deformed, the sealing pressure is maintained for a long time due to its restoring force.

Therefore, if the lid 50 is mounted on the tank upper wall FTa of the fuel tank FT, the projection 52b provided integrally with the lid 50 can simultaneously seal the fuel tank FT and the outside. The projection 52b is formed integrally with the lid 50, and is formed as described in the related art.
Since no ring is required, the number of parts can be reduced.

Further, since the lid 50 is formed of the same resin material as the tank upper wall FTa of the fuel tank FT, they can be welded to each other reliably and easily, and high sealing performance is secured in this portion. be able to.

The present invention is not limited to the above embodiment, but can be implemented in various modes without departing from the gist of the present invention. For example, the following modifications are possible.

(1) FIG. 4 is a sectional view showing a joint portion between a case body 30 and a lid 50A according to another embodiment. A projection 52 is provided on the lower surface of the lid body 52A of the lid 50A.
Ab is formed. The projection 52Ab is a flexible projection, which bends when pressed by the ceiling wall portion 32 of the case main body 30, and maintains the sealing property of the first seal portion for a long period of time by the restoring force. Can be.

(2) FIG. 5 is a sectional view showing a joint portion between a case body 30B and a lid 50B according to still another embodiment. That is, in the embodiment of FIG. 1, the projection 52b is formed on the lid 50, but in the embodiment shown in FIG. 5, the projection 52B is formed on the side of the ceiling wall 32B of the case body 30B.
This is an example in which b is provided, and the same operation and effect as in FIG. 1 can be obtained.

(3) FIG. 6 is a sectional view showing a joint portion between a case body 30C and a lid 50C according to another embodiment. That is, the flange portion 32a of the ceiling wall portion 32C
A first seal protrusion 32Ca is formed on the lower surface of the cover 50C to form a first seal portion, and the protrusion 52Cb of the lid 50C is formed as a ring-shaped protrusion as a second seal portion, and two seal portions are provided. . According to this embodiment, the lid 50
The space between C and the case body 30C is sealed by the projection 52Cb, and the first seal ridge 32Ca is strongly pressed against the contact surface of the step portion FTb of the tank upper wall FTa, so that the sealing performance can be further enhanced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a fuel cutoff valve 20 mounted on an upper part of a fuel tank FT of an automobile according to one embodiment of the present invention.

FIG. 2 is an exploded sectional view of the fuel cutoff valve 20.

FIG. 3 shows a mounting hole F in a tank upper wall FTa of the fuel tank FT.
FIG. 4 is an explanatory diagram illustrating an operation of attaching a fuel cutoff valve 20 to Tc.

FIG. 4 is a cross-sectional view showing the vicinity of a welded portion between a lid body 50A and a case body 30 according to another embodiment.

FIG. 5 is a cross-sectional view showing the vicinity of a welded portion between a lid body 50B and a case body 30B according to still another embodiment.

FIG. 6 is a cross-sectional view showing the vicinity of a welded portion between a lid 50C and a case main body 30C according to another embodiment.

FIG. 7 is a sectional view showing a conventional fuel cutoff valve 100.

[Explanation of symbols]

 Reference Signs List 20 fuel cut-off valve 30 case body 30S float chamber 30a lower opening 32 ceiling wall 32a flange 32b connection passage 32c communication pipe 32d seat 33 33 side wall 33a engaging hole 33b Guide ridge 35 ... Bottom plate 35a ... Engagement part 35b ... Communication hole 35c ... Spring support part 40 ... Float 40S ... Buoyancy chamber 41 ... Upper wall part 41a ... Valve part 42 ... Side wall part 46 ... Spring 50 ... Lid 52 ... Lid Main body 52a ... Annular welded part 52b ... Projection 54 ... Lid passage forming part 54a ... Lid side passage 54b ... Communication port FT ... Fuel tank FTa ... Tank upper wall FTb ... Stepped part FTc ... Mounting hole FTd ... Welded part Hp1 ... Hot plate Hp2 … Hot plate

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tomohide Aoki 1 Ochiai Nagahata, Kasuga-machi, Nishikasugai-gun, Aichi Prefecture Inside Toyoda Gosei Co., Ltd. F-term (reference) in Toyoda Gosei Co., Ltd. 3H055 AA01 CC02 CC17 DD27 FF15 GG26 JJ03

Claims (2)

[Claims] 1. A fuel cutoff valve which is mounted in a mounting hole formed in a tank upper wall of a fuel tank and opens and closes a connection passage for connecting the inside of the fuel tank and the outside, thereby shutting off the communication between the fuel tank and the outside. A cylindrical side wall to be inserted into the mounting hole, a ceiling wall integrally formed with the side wall, and an upper wall formed on an outer peripheral portion of the ceiling wall and outer peripheral side of the mounting hole. A case body comprising a flange portion to be placed, the case body forming a float chamber surrounded by the side wall portion and the ceiling wall portion in a cup shape, and buoyancy stored in the float chamber and according to a fuel level of a fuel tank. A float for opening and closing the connection passage by raising and lowering the connection passage, a lid body for covering the ceiling wall portion, and a lid passage formed integrally with the lid body and having a lid-side passage that communicates the connection passage with the outside. Part, provided on the outer peripheral part of the lid body A lid formed of the same resin material as the tank upper wall, and a lid formed of the same resin material as the tank upper wall. A projection is formed which is in close contact with the other of the main body or the ceiling wall, and the projection is formed on the contact surface between the case main body and the mounting hole when the annular welded portion is welded to the tank upper wall of the fuel tank. And a fuel cutoff valve. 2. The fuel cutoff valve according to claim 1, wherein the projection is formed as a sealing ridge that seals between the ceiling wall and the lid body.