JP2008045447A - Fuel cutoff valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve productivity of a fuel cutoff valve 10, while enhancing molding accuracy of a float, and reducing a variation in a valve closing liquid level by a temperature change in a fuel tank. <P>SOLUTION: The fuel cutoff valve 10 has: a casing 20 forming a valve chest 30S; and the float 52 opening-closing a connecting passage 31b connected to an external part from the valve chest 30S, and opens and closes the connecting passage 31b by lifting of the float 52. The float 52 is composed of: a first float part 53 having a storage chamber 53S; and a second float part 55 stored in the storage chamber 53S. The second float part 55 has an upward extending part 55b penetrating through a through-hole 53e of the first float part 53, and is arranged up to the side of a sheet member 57. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel cutoff valve that is attached to an upper part of a fuel tank and that opens and closes a connection passage that connects the inside and outside of the fuel tank to cut off communication between the fuel tank and the outside.

  Conventionally, Patent Documents 1 and 2 are known as this type of fuel cutoff valve. The fuel shut-off valve is mounted on the upper part of the fuel tank, and is moved up and down by increasing / decreasing buoyancy in the valve chamber of the casing provided with a connection passage connected to the outside (canister) and the valve chamber of the casing. With a float. Then, the float rises due to an increase in buoyancy due to the rise in the fuel level in the fuel tank, thereby closing the connection passage and preventing the fuel from flowing out.

  The float of the conventional fuel cutoff valve is formed in a thin cup shape provided with a buoyancy chamber that opens downward, thereby preventing sink marks that are likely to occur during injection molding of the float and increasing the molding accuracy. In such a cup-shaped float, the buoyancy chamber is sealed when the fuel level rises above the lower end of the float. The air in the sealed buoyancy chamber expands and contracts as the temperature in the fuel tank changes, changing the buoyancy of the float. For this reason, the fuel shut-off valve has a problem that the valve closing liquid level varies due to a temperature change in the fuel tank. In order to solve this problem, when the buoyancy chamber is reduced, the float not only deteriorates the molding accuracy due to resin sink marks during injection molding, but also takes a long time to cool down, reducing productivity. There was a problem to do.

JP 2004-308838 A Japanese Utility Model Publication No.5-1547

  The present invention is based on solving the above-described problems of the prior art, and the fluctuation of the valve closing liquid level is small due to the temperature change in the fuel tank, the float molding accuracy can be increased, and the fuel shut-off excellent in productivity. The purpose is to provide a valve.

The present invention made to solve the problems
In a fuel cutoff valve that is mounted on the upper part of the fuel tank and that opens and closes a connection passage that connects the inside and outside of the fuel tank so as to cut off communication between the fuel tank and the outside.
A casing forming a valve chamber communicating the inside of the fuel tank and the connection passage;
A float that is housed in the valve chamber, and opens and closes the connection passage by raising and lowering the buoyancy according to the fuel level in the valve chamber; and
With
The float is
An upper wall portion, a side wall extending in a cylindrical shape from the outer peripheral portion of the upper wall portion, a storage chamber surrounded by the upper wall portion and the side wall and opened downward; and an upper portion of the upper wall portion A first float portion having a provided valve portion and a through hole formed through the upper wall portion;
A float body that is housed in the housing chamber; and an upwardly extending portion that is integrally formed at an upper portion of the float body and that is disposed on the outer peripheral side of the valve portion through the through hole. A second float part integrated with the part;
It is provided with.

  In the fuel cutoff valve according to the present invention, the float is raised by buoyancy when the vehicle is tilted or swings. When the float rises, the valve portion closes the connection passage, thereby blocking the fuel tank from the outside and preventing the fuel from flowing out from the fuel tank.

  By configuring the float with a plurality of members composed of the first float part and the second float part, that is, by taking a configuration in which the storage chamber of the cup-shaped first float part is filled with the float body of the second float part, The thickness of the first float portion can be reduced. Thereby, when forming a 1st float part by injection molding, sink marks can be reduced in the valve | bulb part of a 1st float part, or a sliding part with a casing, and a shaping | molding precision can be made high. In addition, since the first float portion is cup-shaped, the storage chamber opened below the float is filled below the second float portion, so that the capacity of the gas can be reduced. Fluctuations in the valve closing liquid level can be reduced.

  Further, when the float is molded by resin injection molding, the first float portion can have a large storage chamber, so that a cooling means can be provided in the mold forming the storage chamber, and the float of the second float portion can be provided. Since the main body needs only a small member to fill the storage chamber, both members do not require a long time for cooling. Therefore, the injection molding cycle can be shortened and the productivity is excellent.

  Further, the upwardly extending portion of the second float portion increases the buoyancy as a whole of the float when the float is submerged. This increase in buoyancy acts as a force to stay at the position where the connection passage is closed against the downward force when the fuel tank vibrates in the submerged state. Therefore, even if the slight vibration caused by the vibration of the vehicle reaches the fuel cutoff valve, the seat member is unlikely to be separated from the seal portion, and the sealing performance is not deteriorated.

  As a preferred aspect of the present invention, the second float part may be formed with a specific gravity smaller than that of the first float part, and for example, at least a part thereof may be formed of a foamed resin. With this configuration, the second float portion has a specific gravity smaller than that of the first float portion, and the second float portion can be lightened and the entire float can be lightened. There is no invitation.

  As a preferred aspect of the present invention, the float mechanism is formed in the ascending / descending direction by being interposed between the valve portion and the upper extending portion, which is formed on the casing and is formed below the inner wall facing the valve chamber. The structure provided with the guide part to guide can be taken. With this configuration, the guide portion is interposed between the valve portion and the upper extending portion of the second float portion, and guides the float mechanism in the up-and-down direction. The seat member is seated on the seal portion with a high sealing performance, and there is no problem with the deterioration of the sealing performance between them, that is, the problem that the fuel flows out from the gap through the connection passage.

  As a preferred aspect of the present invention, the first float portion and the second float portion can be integrated by welding, mechanical engagement means, or the like. By adopting a configuration in which the first float unit and the second float unit are assembled, the assembly work of the first float unit and the second float unit can be simplified.

  Moreover, as a preferable aspect of the present invention, the valve portion may be formed separately from the first float portion or may be formed separately. In the case where the valve portion is configured separately, the valve portion is a sheet member formed of a flexible material such as rubber, and the sealing performance can be improved by bending the valve portion with respect to the seal portion. As a configuration for supporting the seat member with the first float portion so as to bend in this way, the first float portion is provided with a valve support portion that protrudes from an upper portion of the first float portion and supports the seat member. The valve support portion has a bending space having an inner diameter larger than an outer diameter of the seal portion, and the bending space is elastically deformed when the seat member is seated on the seal portion. The structure formed so that it may accept | permit can be taken.

  As another preferred embodiment, the upper portion of the upper extending portion is configured to regulate the upper limit position of the float mechanism by hitting the inner wall of the casing when the float mechanism is in the raised position. be able to. With this configuration, the upper portion of the upper extending portion hits the inner wall of the casing, so that the vertical distance between the float mechanism and the ceiling wall portion is regulated within a predetermined range, and when seated on the seal portion of the seat member Since the amount of elastic deformation of the member is suppressed, the sheet member can maintain high sealing performance over a long period of time.

  In order to further clarify the configuration and operation of the present invention described above, preferred embodiments of the present invention will be described below.

(1) Schematic configuration of fuel cutoff valve 10 FIG. 1 is a side view showing a fuel cutoff valve 10 attached to an upper part of a fuel tank FT of an automobile according to an embodiment of the present invention, and FIG. 2 is a plan view of the fuel cutoff valve 10. 3 is a cross-sectional view taken along line 3-3 in FIG. In FIG. 1, the surface of the fuel tank FT is formed of a composite resin material containing polyethylene, and a mounting hole FTb is formed in the tank upper wall FTa. A fuel shut-off valve 10 is attached to the tank upper wall FTa in a state where the lower part thereof enters the attachment hole FTb. The fuel shut-off valve 10 regulates the fuel in the fuel tank FT from flowing out to the canister when the vehicle is tilted or swings.

(2) Configuration of Each Part of Fuel Shutoff Valve 10 In FIG. 3, the fuel cutoff valve 10 includes a casing 20, a float mechanism 50, and a spring 70 as main components. The casing 20 includes a casing main body 30, a bottom plate 35, and a lid body 40. A space surrounded by the casing main body 30 and the bottom plate 35 is a valve chamber 30S, and the valve chamber 30S is supported by a spring 70. The float mechanism 50 is accommodated.

  FIG. 4 is an exploded sectional view of the fuel cutoff valve 10. The casing body 30 has a cup shape surrounded by a ceiling wall portion 31 and a side wall portion 32, and a lower portion thereof is an opening 30a. A passage forming protrusion 31a is formed in the center of the ceiling wall 31 so as to project downward. A connection passage 31b connected to the valve chamber 30S is formed through the passage forming protrusion 31a. Yes. The valve chamber 30S side of the connection passage 31b is a seal portion 31c. In addition, a guide portion 31d is formed in a cylindrical shape on the lower surface of the ceiling wall portion 31 so as to surround the outer peripheral side of the passage forming protrusion 31a. The guide portion 31d guides the upper portion of the float mechanism 50 and also functions as a protective wall that blocks fuel from the valve chamber 30S toward the connection passage 31b.

  The side wall 32 is formed with a vent hole 32a for connecting the inside of the fuel tank FT (FIG. 3) and the valve chamber 30S, and an engaging hole 32b for attaching the bottom plate 35 is formed. The bottom plate 35 is a member that closes the opening 30 a of the casing body 30, and the engagement claw 35 a formed on the outer peripheral portion of the bottom plate 35 engages with the engagement hole 32 b of the casing body 30, thereby opening the opening 30 a of the casing body 30. It is mounted to close. The bottom plate 35 is formed with a spring support portion 35 c for supporting the communication hole 35 b and the lower end of the spring 70.

  The lid body 40 includes a lid body 41, a tube body portion 42 projecting laterally from the center of the lid body 41, a flange 43 formed on the outer periphery of the lid body 41, and a support portion 44, and these are integrated. Forming. The tube part 42 is formed with a lid side passage 42a. One end of the lid side passage 42a is connected to the valve chamber 30S of the casing body 30 through the connection passage 31b, and the other end is on the canister (not shown) side. Connected to. The support portion 44 is a cylindrical body that is formed at the lower portion of the lid main body 41 and that fits and supports the upper portion of the casing main body 30. An engagement hole 44 a is formed in the support portion 44. The engagement hole 44 a is engaged with an engagement claw 32 c formed in the side wall portion 32 of the casing body 30, so that the lid body 40 holds the casing body 30. Further, an outer welded portion 43a that is welded to the tank upper wall FTa (FIG. 3) of the fuel tank FT is formed at the lower end portion of the flange 43.

  The float mechanism 50 includes a float 52 and a seat member 57 constituting a valve portion. The float 52 includes a first float portion 53 and a second float portion 55, which are assembled together. 5 is a perspective view of the float mechanism 50, FIG. 6 is a cross-sectional view of the float mechanism 50, and FIG. 7 is a perspective view of the float mechanism 50 disassembled.

  The first float portion 53 includes an upper wall portion 53a, a cylindrical side wall 53b formed downward from the outer periphery of the upper wall portion 53a, and a columnar central portion 53c formed downward from the upper wall portion 53a. The inside space is a storage chamber 53S for storing the lower part of the second float portion 55. The upper wall portion 53a includes bridging portions 53d that are radially spanned from the upper outer peripheral portion of the central portion 53c to the side wall 53b at four locations, and between the bridging portions 53d are through holes 53e.

  The first float portion 53 includes a valve support portion 54 that supports the seat member 57 at the upper center thereof. The valve support portion 54 includes a columnar support base portion 54a protruding from the upper surface of the central portion 53c, a disc portion 54b formed on the upper portion of the support base portion 54a, and upward from the outer peripheral portion of the disc portion 54b. And a space surrounded by the support base portion 54a and the cylindrical portion 54c is a bending space 54S. Three liquid drain grooves 54d (FIG. 7) are formed in the disc part 54b of the valve support part 54. The liquid draining groove 54d discharges the fuel accumulated in the bending space 54S, and makes the sheet member 57 easy to be bent by venting air in the bending space 54S.

  A guide protrusion 53 f is formed on the outer peripheral portion of the side wall 53 b of the first float portion 53. The guide protrusions 53f are provided on the side wall 53b of the first float portion 53 so as to protrude in eight positions at equal intervals in the circumferential direction and in a rib shape in the vertical direction. Further, an engagement hole 53g for engaging with the second float portion 55 is formed through the lower portion of the side wall 53b.

  The second float portion 55 includes a columnar float main body 55a and an upwardly extending portion 55b composed of four fan-shaped blocks protruding from the upper portion of the float main body 55a. Fig. 6). Between each of the upper extending portions 55b, fitting grooves 55c are formed radially from the circular recess. The fitting groove 55c is formed so as to fit into the central portion 53c and the bridging portion 53d of the first float portion 53 and to project the upward extending portion 55b from the through hole 53e. In addition, an engaging claw 55 d for engaging with the engaging hole 53 g of the first float portion 53 is formed in the lower portion of the second float portion 55.

  In order to assemble the second float portion 55 to the first float portion 53, the second float portion 55 is inserted into the storage chamber 53S from the upper extension portion 55b of the second float portion 55, and the upper extension portion 55b is aligned with the through hole 53e. Further, the second float portion 55 is pushed into the first float portion 53, and the engagement claw 55d is engaged with the engagement hole 53g of the first float portion 53. As a result, the second float part 55 is integrated with the first float part 53. In this assembled state, the upper surface of the upper extending portion 55b of the second float portion 55 hits the ceiling wall portion 31 when the float mechanism 50 is in the raised position, as will be described later. It is a restricting part that restricts the upper limit position that moves up and down.

  Further, a spring chamber 52S opened downward is formed on the inner peripheral side of the storage chamber 53S shown in FIG. 6 and between the inner wall of the second float portion 55. As shown in FIG. 4, the spring 70 is housed in the spring chamber 52 </ b> S and supported between the spring support portion 53 h at the lower portion of the upper wall portion 53 a and the spring support portion 35 c of the bottom plate 35.

  In the fuel cutoff valve 10 of the present embodiment, the main components are made of resin such as polyethylene, POM, PPS (polyphenylene sulfide), PA (polyamide), and the like. Here, any of the above-described polyethylene, POM, PPS, PA, etc. is used for the resin material (hereinafter referred to as the first resin material) that forms the first float portion 53 of the float 52. On the other hand, as the resin material forming the second float portion 55 (hereinafter referred to as the second resin material), a foamed resin is used. Specifically, the foamed resin is obtained by injecting carbon dioxide or the like into any one of polyacetal, polyamide, polyethylene, and the like. As a result, the second float portion 55 has a specific gravity smaller than that of the first float portion 53.

  FIG. 8 is an explanatory diagram for explaining the main part of the fuel cutoff valve, and FIG. 9 is an explanatory diagram for explaining the operation following FIG. The sheet member 57 is formed in a cup shape that opens downward from a flexible material (rubber material, thermoplastic elastomer, etc.), that is, the sheet member 58 and the sheet member 58 from the outer periphery of the sheet member 58 downward. It is formed from a projecting supported portion 59, and the inside thereof is a mounting space 57S. The seat portion 58 includes a seat surface 58a that is attached to and detached from the seal portion 31c, and an elastic deformation portion 58b that is formed along the outer periphery of the seat surface 58a. When the seat surface 58a is pushed by the seal portion 31c, the elastic deformation portion 58b is elastically deformed so as to be recessed in the bending space 54S and is seated on the seal portion 31c (see FIG. 9). The supported portion 59 is formed by a cylindrical side wall portion 59a and a retaining portion 59b. The seat member 57 is attached to the valve support portion 54 by press-fitting the valve support portion 54 into the mounting space 57S.

(3) Operation of the fuel cutoff valve 10 Next, the operation of the fuel cutoff valve 10 will be described. In FIG. 3, the fuel vapor generated by the evaporation of fuel in the fuel tank FT enters the valve chamber 30S through the communication hole 35b and the vent hole 32a, and from the valve chamber 30S through the connection passage 31b and the lid side passage 42a, the canister Escape to the side. When the fuel level in the fuel tank FT rises due to vehicle inclination or the like, the fuel flows into the valve chamber 30S through the communication hole 35b. When the fuel level reaches a predetermined liquid level FL1, the former is balanced by the buoyancy of the float 52 and the upward force due to the load of the spring 70 and the downward force due to the weight of the float 52 and the seat member 57. Float rises when is above the latter. At this time, as shown in FIG. 9, the float mechanism 50 rises while being guided in the up-and-down direction by the guide portion 31d, and is curved toward the bending space 54S when the sheet member 57 is pushed by the seal portion 31c. The sheet surface 58a of the sheet member 57 closes the connection passage 31b. At this time, the upper surface of the upwardly extending portion 55b of the second float portion 55 hits the lower surface of the ceiling wall portion 31, whereby the amount of bending of the sheet member 57 is restricted. As described above, when the vehicle is tilted, the fuel vapor can escape from the fuel tank FT and the fuel can be prevented from flowing out of the fuel tank FT.
On the other hand, when the fuel level in the fuel tank FT is lowered and the fuel in the valve chamber 30S is discharged from the communication hole 35b or the like, the float 52 reduces its buoyancy and receives a downward force, so that the seat member 57 separates from the seal portion 31c and opens the connection passage 31b.

(4) Actions and effects of the embodiment The following actions and effects are exhibited by the configuration of the above embodiment.

(4) -1 The float 52 is composed of a plurality of members including the first float portion 53 and the second float portion 55, that is, the storage chamber 53 </ b> S of the cup-shaped first float portion 53 is formed in the second float portion 55. The thickness of the first float portion 53 can be reduced by adopting a configuration in which the float body 55a is filled. Thereby, when forming the 1st float part 53 by injection molding, sink marks, such as the valve support part 54 of the 1st float part 53 and the guide protrusion 53f, can be reduced, and a shaping | molding precision can be made high. In addition, since the first float portion 53 has a cup shape, the storage chamber 53S opened below the float 52 is filled with the second float portion 55 and the chamber sealed with fuel can be made small. Even if the fuel level is lower than the lower end, there is no fluctuation of the buoyancy of the float 52 due to the temperature change of the sealed gas, and the fluctuation of the valve closing liquid level can be reduced.

(4) -2 When the float 52 is formed by resin injection molding, the first float portion 53 can be provided with a cooling means in the mold for forming the storage chamber 53S by taking the storage chamber 53S large, Moreover, since the 2nd float part 55 should just be a small member which only fills the storage chamber 53S, both members do not require a long time for cooling. Therefore, the injection molding cycle can be shortened and the productivity is excellent.

(4) -3 The upward extending portion 55 b of the second float portion 55 increases the buoyancy of the float 52 as a whole. The increase in the buoyancy acts as a force for staying at the position where the connection passage 31b is closed against the downward force when the fuel tank vibrates in the submerged state. Therefore, even if the slight vibration caused by the vibration of the vehicle or the like reaches the fuel cutoff valve 10, the seat member 57 is hardly separated from the seal portion 31c, and the sealing performance is not deteriorated.

(4) -4 When the second float portion 55 is inserted into the storage chamber 53S of the first float portion 53 in order to assemble the second float portion 55 to the first float portion 53, the upward extending portion 55b becomes the through hole 53e. Since the engaging claw 55d engages with the engaging hole 53g, the assembling work is also easy.

(4) -5 As shown in FIG. 9, the guide portion 31d provided on the lower surface of the ceiling wall portion 31 is interposed between the valve support portion 54 and guides the float mechanism 50 in the up-and-down direction. The float mechanism 50 is prevented from tilting up and down, the seat member 57 is seated on the seal portion 31c with a high sealing performance, and there is a problem associated with a decrease in the sealing performance therebetween, that is, the fuel passes from the gap to the outside through the connection passage 31b. There will be no malfunctions that may occur.

(4) -6 Since the valve support portion 54 shown in FIG. 6 protrudes from the upper portion of the first float portion 53, the side thereof becomes a useless space. In order to make effective use of such a space, it is conceivable to integrally form a protruding portion on the outer peripheral side of the valve support portion 54 above the first float portion 53. However, since the disc support 54b is undercut, it is difficult for the valve support 54 to integrally form the protruding portion as described above with the first float 53 in the outer peripheral space of the valve support 54. . However, in this embodiment, a part of the second float portion 55 is formed as an upwardly extending portion 55b disposed on the upper portion of the first float portion 53, so that the side of the valve support portion 54 can be formed without undercutting. This space is used as a part that generates buoyancy.

(4) -7 As shown in FIG. 9, the upper surface of the upper extending portion 55 b of the second float portion 55 hits the lower surface of the ceiling wall portion 31, whereby the vertical distance between the float mechanism 50 and the ceiling wall portion 31. Is controlled within a predetermined range, and the amount of elastic deformation of the seat member 57 is suppressed when seated on the seal portion 31c of the seat member 57. Therefore, the seat member 57 can maintain high sealing performance for a long period of time.

(4) -8 The float mechanism 50 tries to descend when the fuel tank vibrates and receives a downward force in the submerged state, but the second float portion 55 has a specific gravity smaller than that of the fuel. Since the second float portion 55 can be lightened and the entire float 52 can be lightened, the second float portion 55 tries to stay at a position where the connection passage 31b is closed. Therefore, even if the slight vibration caused by the vibration of the vehicle or the like reaches the fuel cutoff valve 10, the seat member 57 is hardly separated from the seal portion 31c, and the sealing performance is not deteriorated.

(4) -9 The float 52 includes the first float portion 53 and the second float portion 55 as separate members, but the valve support portion 54 that supports the seat member 57 is the inner wall of the casing body 30. Therefore, the sheet member 57 has a small inclination and an excellent sealing property.

(5) Other Embodiments The present invention is not limited to the above-described embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

(5) -1 In the above embodiment, in order to make the second float part 55 have a specific gravity smaller than that of the first float part 53, the second float part 55 is made of foamed resin. It is good also as a structure which forms the 2nd float part 55 with the resin material with which the micro hollow spherical body was mixed. As the micro hollow sphere, for example, Scotchlite glass bubbles (manufactured by Sumitomo 3M, particle size range 15 to 135 μm, average particle size 30 to 70 μm) can be used. In addition, it is not necessary to restrict to Scotchlite glass bubbles, and it is good also as other glass micro hollow spheres, and it is good also as other micro hollow spheres, such as a ceramic sphere other than a glass sphere. Furthermore, it is not necessary to limit to a micro hollow spherical body, It is good also as a structure which mixes a hollow tubular body with resin and produces a resin material with small specific gravity.

(5) -2 In the above embodiment, the configuration in which the fuel shut-off valve is mounted on the upper surface of the upper wall of the tank has been described. An in-tank type may be used.

It is a side view which shows the fuel cutoff valve attached to the upper part of the fuel tank of the motor vehicle concerning one Example of this invention. It is a top view of a fuel cutoff valve. FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2. It is sectional drawing which decomposed | disassembled the fuel cutoff valve. It is a perspective view of a float mechanism. It is sectional drawing which decomposed | disassembled the float. It is the perspective view which decomposed | disassembled the float mechanism. It is explanatory drawing explaining the principal part of a fuel cutoff valve. It is explanatory drawing explaining the operation | movement following FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fuel cutoff valve 20 ... Casing 30 ... Casing main body 30S ... Valve chamber 30a ... Opening 31 ... Ceiling wall part 31a ... Passage formation protrusion 31b ... Connection passage 31c ... seal part 31d ... guide part 32 ... side wall part 32a ... vent hole 32b ... engagement hole 32c ... engagement claw 35 ... bottom plate 35a ... engagement claw 35b ... Communication hole 35c ... Spring support 40 ... Lid 41 ... Lid main body 42 ... Tube body 42a ... Lid side passage 43 ... Flange 43a ... Outer welding Part 44 ... Supporting part 44a ... Engagement hole 50 ... Float mechanism 52 ... Float 52S ... Spring chamber 53 ... First float part 53S ... Storage chamber 53a ... Top Wall part 53b ... Side wall 53c ... Center part 53d ... Bridge part 53e ... Through hole 53f ... Guide protrusion 53g ... Engagement hole 54 ... Valve support part 54S ... Space for bending 54a ... Support base 54b ... Disk part 54 ... Cylindrical part 54d ... Liquid draining groove 55 ... Second float part 55S ... Fitting insertion hole 55a ... Float body 55b ... Upper extension part 55c ... Fitting groove 55d. ..Engagement claw 57 ... sheet member 57S ... mounting space 58 ... sheet portion 58a ... sheet surface 58b ... elastic deformation portion 59 ... supported portion 59a ... side wall portion 59b ... Preventing part 70 ... Spring FT ... Fuel tank FL1 ... Liquid level FTa ... Tank upper wall FTb ... Mounting hole

Claims (7)

A fuel cutoff valve that is mounted on the upper part of the fuel tank (FT) and that opens and closes a connection passage (31b) that connects the inside of the fuel tank (FT) and the outside, thereby disconnecting the fuel tank (FT) from the outside. ,
A casing (20) forming a valve chamber (30S) communicating the fuel tank (FT) and the connection passage (31b);
A float (52) housed in the valve chamber (30S), which opens and closes the connection passage (31b) by raising and lowering the buoyancy according to the fuel level in the valve chamber (30S);
With
The float (52)
Surrounded by an upper wall portion (53a), a side wall (53b) extending in a cylindrical shape from the outer peripheral portion of the upper wall portion (53a), the upper wall portion (53a) and the side wall (53b) A first chamber having a storage chamber (53S) opened downward, a valve portion provided at an upper portion of the upper wall portion (53a), and a through hole (53e) formed through the upper wall portion (53a). A float section (53);
A float main body (55a) stored in the storage chamber (53S), and an upper portion formed integrally with the upper portion of the float main body (55a) and penetrating the through hole (53e) and arranged on the outer peripheral side of the valve portion A second float part (55) having an extending part (55b) and integrated with the first float part (53),
A fuel cutoff valve characterized by comprising: The fuel cutoff valve according to claim 1,
The said 2nd float part (55) is a fuel cutoff valve formed with specific gravity smaller than the said 1st float part (53). The fuel cutoff valve according to claim 1 or 2,
The casing (20), which is formed downward from an inner wall facing the valve chamber (30S), is interposed between the valve portion and the upper extension portion (55b) to raise and lower the float mechanism (50). A fuel cutoff valve having a guide portion (31d) for guiding in the direction. The fuel cutoff valve according to any one of claims 1 to 3,
The said 1st float part (53) and the said 2nd float part (55) are fuel cutoff valves integrated by the engaging means by an engaging claw and an engaging hole. The fuel cutoff valve according to any one of claims 1 to 4,
The said valve part is a fuel cutoff valve which is a sheet | seat member (57) formed from the flexible material. The fuel cutoff valve according to claim 5,
The first float part (53) includes a valve support part (54) protruding from an upper part of the first float part (53) and supporting the seat member (57),
The valve support portion (54) has a bending space (54S) having an inner diameter larger than the outer diameter of the seal portion (31c), and the bending space (54S) is formed by the seat member (57). A fuel cutoff valve configured to allow elastic deformation of the seat member (57) when seated on the seal portion (31c). The fuel cutoff valve according to claim 5 or claim 6,
The upper part of the upper extension part (55b) is configured to regulate the upper limit position of the float mechanism (50) by hitting the inner wall of the casing (20) when the float mechanism (50) is in the raised position. A fuel shut-off valve that is configured to.

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