JP2006321468A - Fuel shut-off valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel shut-off valve 10, in which the alignment of the axis center of a casing 20, a float 52, and an upper valve element 60 can be accurately performed using a simple constitution, and the upper valve element 60 can be easily composed. <P>SOLUTION: The float 52 has a large diameter part 53, a valve support part 55 which is provided on the upper part of the large diameter part 53 and has smaller diameter than the outside diameter of the large diameter part 53, and a seal part 56a formed on the valve support part 55. The float 52 is constituted so as to be elevated by increasing and decreasing a buoyany with a fuel liquid level in a valve chest 30S. The valve support part 55 is equipped with a guide part 57 projected toward the upper part of the axial direction of the float 52. The guide part 57 has an inner guide surface 57d which encloses an outer peripheral part 61c of an upper part valve element 60 and elevates the upper part valve element 60 by guiding the outer peripheral part 61c, and an outer guide surface 57f which is guided by an inner wall surface of a casing body 30 to elevate the float 52. <P>COPYRIGHT: (C)2007,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 document 1 etc. are known as this kind of a 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. The float and the upper valve body mounted on the upper part of the float are provided. The float increases the buoyancy due to the rise in the fuel level in the fuel tank, and the upper valve body rises integrally with the float, thereby closing the connection passage and preventing the fuel from flowing out.
In such a fuel cutoff valve, when the connection passage has a large passage area, if the connection passage is directly opened and closed by a float, the float is adsorbed and the restart valve characteristic is not good, so the upper valve body having a passage with a small passage area A two-stage valve structure is provided. However, when the fuel shut-off valve having such a two-stage valve structure is miniaturized, the alignment of the axial center of the casing and the float and the alignment of the axial center of the float and the upper valve body can be realized easily and with high accuracy. There is a problem that it is difficult to form and small parts such as nails are difficult to mold.

Japanese Utility Model Publication No. 4-134733

  The present invention is based on solving the above-mentioned problems of the prior art, and in a two-stage valve structure having an upper valve body at the upper part of the float, the casing, the shaft of the float and the upper valve body for improving the sealing performance It is an object of the present invention to provide a fuel cutoff valve that can perform center alignment with high accuracy with a simple configuration and that can easily configure an upper valve body.

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 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;
The valve chamber is housed and has a large-diameter portion, a valve support portion provided at an upper portion of the large-diameter portion and having a smaller diameter than the outer diameter of the large-diameter portion, and a seal portion formed on the valve support portion. A float that increases and decreases buoyancy according to the fuel liquid level in the valve chamber;
A valve body having a flat plate portion supported by the valve support portion so as to be movable up and down and having a connection hole having a smaller passage area than the connection passage; and a first seat provided on an upper portion of the valve body and opening and closing the connection passage. And an upper valve body having a second seat part that opens and closes the connection hole by being attached to and detached from the seal part,
With
The valve support portion includes a guide portion projecting upward in the axial direction of the float, and the guide portion surrounds the outer periphery of the upper valve body and guides the outer periphery to guide the upper valve. It has an inner guide surface that raises and lowers the body, and an outer guide surface that is guided by the inner wall of the casing body and raises and lowers the float.

When fuel is supplied to a fuel tank using the fuel shut-off valve according to the present invention and reaches a predetermined liquid level in the fuel tank, the float rises by buoyancy due to the fuel flowing into the valve chamber, and the upper valve is integrated with the float. The body also rises. Then, by closing the connection passage by raising the upper valve body, the fuel tank is shut off from the outside, and the fuel is prevented from flowing out from the fuel tank.
Further, the valve support provided at the upper part of the float has a structure for performing both a guide for raising and lowering the upper valve body and a guide for raising and lowering the float in the casing body. In addition, the configuration of the alignment operation for the casing body can be simplified. In addition, since the valve support portion has a configuration in which the upper portion of the float adjacent to the first seal portion is made small in diameter, the clearance between them can be set small in terms of molding accuracy, and therefore the alignment between the float and the casing body can be adjusted. Accuracy can be increased and sealing performance can be increased.

  As a preferred aspect of the present invention, the upper valve body includes a valve main body formed of a resin material, and a sheet member formed of a rubber material and integrated with the valve main body by insert molding. A configuration in which the first sheet portion and the second sheet portion are provided on the upper and lower portions, respectively, can be employed. With this configuration, it is possible to easily form an upper valve body including two seat portions having excellent sealing properties.

  As another preferred aspect, the seal portion is a flat surface, and the second seat portion has a substantially conical shape penetrating the connection hole at the center so that the upper valve body can be tilted on the seal portion. A supported configuration can be taken. Even when the upper valve body is inclined on the seal portion of the float on the second seat portion, the second seat portion is bent, so that high sealing performance can be maintained. In this case, in order to prevent the angle of inclination of the upper valve body from becoming excessive and impairing the sealing performance, the valve support portion hits the lower part of the outer peripheral portion of the upper valve body, and the inclination of the upper valve body is set to a predetermined value. The structure provided with the step part controlled within an angle range can be taken.

Furthermore, as another preferable aspect, the guide portion includes a plurality of columnar guide bodies surrounding the upper valve body, and an engagement claw formed toward an axis of the float, and the engagement The nail | claw can take the structure currently formed so that the raising / lowering distance of the said upper valve body may be controlled. In this configuration, the guide body that supports the upper valve body so that the upper valve body can be moved up and down is formed with an engaging claw for retaining the upper valve body, so that the upper valve body without the claw can be easily molded by insert molding. Can be manufactured.
Further, in this configuration, between the adjacent guide bodies, the space from the side of the valve support portion is connected to the connection hole or the connection passage through the gap between the seal portion and the second seat portion. The structure which provides the ventilation path to take can be taken. According to this structure, even if it does not provide a rib between the inner wall of a casing and the upper part of a float, even if it is a small rib, the channel | path for escape of a vapor | steam can be ensured.

  Here, as a preferable aspect of the outer guide surface, the outer guide rib can be formed on the outer guide rib. Further, a guide rib that guides the outer guide surface may be formed on the inner wall of the casing, and the outer guide surface may be guided by the guide rib.

  Furthermore, as a preferable configuration of the upper valve body, the valve body may be configured to include a cylindrical side wall portion that extends downward from the outer peripheral portion of the flat plate portion and surrounds the outer peripheral portion of the valve support portion. it can. According to this configuration, the side wall portion of the valve body lowers the center of gravity of the upper valve body to reduce the inclination of the upper valve body, prevents horizontal displacement, and stabilizes the posture of the upper valve body. it can.

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 cutoff valve 10 regulates the flow of fuel in the fuel tank FT 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 first seal portion 31c. A communication hole 32a for connecting the inside of the fuel tank FT and the valve chamber 30S is formed in the side wall portion 32, and an engagement hole 32b for attaching the bottom plate 35 and allowing the fuel to flow into and out of the valve chamber 30S is formed. Has been. 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. A spring support portion 35 b for supporting the lower end of the spring 70 is formed on the upper surface of the bottom plate 35.

  The lid body 40 includes a lid body 41, a tube body portion 42 projecting laterally from the center of the lid body 41, and a flange 43 formed on the outer periphery of the lid body 41, and these are integrally formed. . The tube portion 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. An inner welding end 43a that welds the upper end of the casing body 30 is formed at the lower part of the lid body 41, and an outer welding portion 43b that is welded to the tank upper wall FTa of the fuel tank FT is formed at the lower end of the flange 43. Is formed.

  The float mechanism 50 includes a float 52 and an upper valve body 60 disposed on the top of the float 52. The float 52 has a buoyancy chamber 52 </ b> S for opening downward and inserting a spring 70. The float 52 has a large diameter portion 53, a reduced diameter portion 54 that is reduced in diameter from the upper portion of the large diameter portion 53, and a reduced diameter portion 54. And a valve support portion 55 formed on the upper portion thereof, which are integrally formed. The float 52 is supported by a spring 70 spanned between the spring support portion 35b of the bottom plate 35 and the upper surface of the buoyancy chamber 52S. A guide protrusion 53 a for guiding the float 52 in the vertical direction is provided on the outer peripheral portion of the large diameter portion 53. The guide ridges 53a are provided on the side wall of the large-diameter portion 53 in four circumferentially spaced positions and in a rib shape in the vertical direction.

FIG. 5 is an exploded perspective view showing the float 52 and the upper valve body 60, and FIG. 6 is a cross-sectional view of the vicinity of the float 52 and the upper valve body 60. The reduced diameter portion 54 formed on the upper portion of the large diameter portion 53 has a cylindrical shape, and a valve support portion 55 is formed on the upper portion. The valve support portion 55 is a portion that places and lifts the upper valve body 60 so as to be tiltable and guides the sliding of the float 52 in the axial direction. Four guide portions 57 are provided on the outer peripheral portion. The upper surface of the support portion 56 is a flat seal portion 56 a that is attached to and detached from the upper valve body 60, and the side surface thereof is an arc surface 56 b between the guide portions 57.
The guide portion 57 is provided with a columnar guide main body 57a disposed upward around the float 52, a stepped portion 57b that protrudes inside the guide main body 57a and restricts the inclination of the upper valve body 60, and protrudes at the upper end. An engaging claw 57c for retaining the upper valve body 60 is provided. Further, the arc surface on the inner side of the guide portion 57 is an inner guide surface 57d that guides the upper valve body 60, and an outer guide rib 57e is projected on the outer surface of the guide portion 57, and this outer guide The outer surface of the rib 57 e is an outer guide surface 57 f that is guided by the inner wall of the casing body 30. Further, in the space surrounded by the arc surface 56b of the support portion 56, the guide main body 57a, and the inner wall of the casing main body 30, airflow flows from the valve chamber 30S through the lower portion of the valve support portion 55 to the seal portion 56a and into the connection passage 31b. A ventilation path 58 for flowing is provided.

The upper valve body 60 is a valve for opening and closing the connection passage 31b and improving the restart valve characteristics, and is supported by the valve support portion 55 of the float 52 so as to be movable up and down and tiltable. The upper valve body 60 includes a valve main body 61 having a donut-shaped flat plate portion 61 a and a seat member 62 attached to the valve main body 61. A through hole 61 b (FIG. 6) is formed in the center of the valve body 61. The seat member 62 is formed of a rubber material that covers the wall surface of the through hole 61b and part of the upper surface and the lower surface of the valve body 61. A second sheet portion 62b protruding in a shape and a connection hole 62c formed by covering the through hole 61b are provided.
The seat member 62 is integrated with the valve body 61 by the following manufacturing process. That is, the valve body 61 is molded by injection molding using resin. Thereafter, an adhesive is applied to the part of the valve body 61 on which the seat member 62 is mounted, the valve body 61 is set as an insert member in a mold, and a rubber material is injected into the cavity. The rubber material is vulcanized at about 200 ° C., and the sheet member 62 is integrated with the valve body 61 by vulcanization adhesion. Here, as the resin material of the valve body 61, polyphenylene sulfide (PPS) having heat resistance at a vulcanization temperature of 200 ° C. can be used. As the rubber material, fluorine rubber, highly saturated nitrile rubber or the like can be used, and in particular, vinylidene fluoride / hexafluoropropylene copolymer (FKM) or hydrogenated butadiene acrylonitrile rubber (HNBR) is preferably used. .

  FIG. 7 is an explanatory view for explaining the operation of the upper valve body 60. Since the second seat portion 62b of the upper valve body 60 is formed in a substantially conical shape, the connection hole 62c is closed on the flat seal portion 56a. As shown in FIG. 7, even if the upper valve body 60 is inclined on the seal portion 56a, the inclination angle is regulated by the outer peripheral portion 61c of the valve main body 61 coming into contact with the stepped portion 57b. There is no. The upper valve body 60 is restricted from moving upward as the outer peripheral portion 61c engages with the engaging claw 57c, and receives downward force as the float 52 descends (see FIG. 10). .

(3) Operation of the fuel cutoff valve 10 Next, the operation of the fuel cutoff valve 10 will be described. In FIG. 8, when the fuel level in the fuel tank FT rises due to vehicle inclination or the like, the fuel vapor accumulated in the upper part of the fuel tank FT enters the valve chamber 30S through the communication hole 32a and the engagement hole 32b. Then, it escapes from the valve chamber 30S to the canister side through the connection passage 31b and the lid side passage 42a. Then, as the fuel level in the fuel tank FT rises, the fuel flows into the valve chamber 30S through the engagement hole 32b and the gap between the opening 30a and the bottom plate 35. When the fuel level reaches a predetermined fuel level FL1, the balance between 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 upper valve body 60 is obtained. When the former exceeds the latter, the float 52 and the upper valve body 60 rise together. That is, when the buoyancy of the float 52 increases, as shown in FIG. 9, the float 52 rises while the outer guide surface 57 f of the upper guide portion 57 of the float 52 is guided by the inner wall of the casing body 30. And the 1st sheet | seat part 62a of the upper valve body 60 seats on the 1st seal | sticker part 31c, and closes the connection channel | path 31b. As a result, when the vehicle is inclined, 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 decreases and the fuel in the valve chamber 30S is discharged from the engagement hole 32b or the like, the float 52 reduces its buoyancy and moves downward as shown in FIG. The seal portion 56a is separated from the second sheet portion 62b and the connection hole 62c is opened. Due to the communication of the connection hole 62c, the pressure below the upper valve body 60 becomes substantially the same pressure as that in the vicinity of the connection passage 31b, so that the opening force of the upper valve body 60 is reduced, and the engagement claw 57c is By engaging with the outer peripheral portion 61c of 60, the upper valve body 60 is pulled down, the first seat portion 62a is separated from the first seal portion 31c, and the connection passage 31b is opened.
Here, the reason why the restart valve characteristic can be improved in the fuel cutoff valve 10 will be described. In FIG. 10, the flow passage area of the connection hole 62c of the upper valve body 60 is S1, the tank side pressure is P1, the canister side pressure is P0, the spring load is K, and the total weight of the float 52 and the upper valve body 60 is W. Then, when the value satisfies the following expression (1), the first seat portion 62a of the upper valve body 60 is opened from the closed state.
(P1-P0) S1 ≦ W−K (1)
The right side of the formula (1) is a positive value due to the difference between the weight W and the spring load K, that is, a force applied to the upper valve body 60 in the valve opening direction. The left side is a force applied in the valve closing direction so that the second seat portion 62b of the upper valve body 60 is attracted to the seal portion 56a. Here, when the flow path area S1 is small, the valve opens even with a large differential pressure (P1-P0). That is, if the canister side pressure P0 is constant, the valve opens even at a large tank side pressure P1. Therefore, the upper valve body 60 is opened with a small force by setting the flow passage area S1 of the connection hole 62c to be smaller than the flow passage area of the connection passage 31b. Thus, the two-stage valve structure by the upper valve body 60 functions to promote the improvement of the restart valve characteristic.

(4) Actions and effects of the embodiment The following actions and effects are exhibited by the configuration of the above embodiment.
(4) -1 As shown in FIG. 5, the valve support 55 provided on the upper part of the float 52 is both a guide for raising and lowering the upper valve body 60 and a guide for raising and lowering the float 52 in the casing body 30. Therefore, the configuration of the upper valve body 60 can be simplified, and the alignment operation of the float 52 with respect to the casing body 30 can be simplified. Moreover, since the valve support portion 55 has a configuration in which the upper portion of the float 52 that is close to the first seal portion 31c has a small diameter, the setting of the clearance therebetween can be reduced in terms of molding accuracy, and thus the float The alignment accuracy between the casing 52 and the casing body 30 can be increased, and the sealing performance can be increased.

(4) -2 Since the engaging claw 57c for regulating the lifting distance of the upper valve body 60 shown in FIG. 5 is provided inwardly at the tip of the guide main body 57a, the claw is formed on the upper valve body 60. And a simple configuration. The upper valve body 60 having such a simple shape can be insert-molded with a simple mold structure, so that the assembling workability can be simplified and the sealing performance can be enhanced.

(4) -3 Since the air passage 58 is formed between the adjacent guide main bodies 57a, a connection hole is formed from the space on the side of the valve support portion 55 through the seal portion 56a and the second seat portion 62b. The passage connected to 62c and the passage connected to the connection passage 31b can be easily configured without complicating the shape of the upper valve body 60 and without providing a rib or the like on the inner wall of the casing body 30. it can.

(4) -4 Even if the float 52 is tilted due to the tilting of the vehicle or the like, as shown in FIG. 7, the upper valve body 60 is helped to tilt on the seal portion 56a by the rubber elasticity of the second seat portion 62b. Since it is in close contact with the seal portion 56a, high sealing performance can be obtained. In addition, even if the angle of inclination of the upper valve body 60 becomes excessive, the angle of inclination of the upper valve body 60 that contacts the upper portion of the stepped portion 57b is regulated within a predetermined angle range, so that the sealing performance is not impaired.

  FIG. 11 is a cross-sectional view showing the upper part of a fuel cutoff valve 10B according to another embodiment. The present embodiment is characterized by the shape of the casing 20B and the configuration of the valve support portion 55B and the upper valve body 60B. That is, a cylindrical valve support portion 55B projects from the upper portion of the float 52B. Further, on the upper surface of the float 52B on the outer peripheral side of the valve support portion 55B, guide portions 57B for preventing the upper valve body 60B from projecting upward at four locations. An engaging claw 57Bc is formed at the upper end of the guide portion 57B. The inner surface of the guide portion 57B is an inner guide surface 57Bd, and the outer surface is an outer guide surface 57Bf. The inner guide surface 57Bd guides the raising and lowering of the upper valve body 60B, and the outer guide surface 57Bf guides the raising and lowering of the float 52B by following the guide rib 33B protruding from the inner wall of the casing 20B. The upper valve body 60B is supported so as to be movable up and down and swingable with respect to the valve support portion 55B of the float 52B. The upper valve body 60B includes a valve body 61B having a bottomed cylindrical shape and a seat member 62B. The valve main body 61B includes a donut-shaped flat plate portion 61Ba and a cylindrical side wall portion 61Bd protruding from the outer peripheral portion of the flat plate portion 61Ba, and the inner space thereof serves as a support hole 61Be. An attachment portion 61Bf for attaching the sheet member 62B is formed at the central portion of the flat plate portion 61Ba. Further, four vent holes 61Bg for connecting the support hole 61Be to the outside are formed in the outer periphery of the upper portion of the valve body 61B. On the inner peripheral wall of the side wall portion 61Bd, rib-shaped guide portions 61Bh guided by the outer surface of the valve support portion 55B are projected in four vertical directions at equal intervals in the circumferential direction.

The sheet member 62B includes a first sheet portion 62Ba that is attached to and detached from the first seal portion 31Bc, a connection hole 62Bc that passes through the center of the first sheet portion 62Ba and is connected to the support hole 61Be, and a lower end of the connection hole 62Bc. The second sheet portion 62Bb formed in the portion and the mounting portion 62Bd formed in the outer peripheral portion of the connection hole 62Bc are integrally formed of a rubber material. The seat member 62B is mounted by being press-fitted into the mounting portion 61Bf of the valve main body 61B by the mounting portion 62Bd, and the first seat portion 62Ba has a gap with respect to the flat plate portion 61Ba of the valve main body 61B. When seated on the seal portion 31Bc, it is elastically deformed to enhance the sealing performance.
According to the present embodiment, the side wall 61Bd of the valve main body 61B lowers the center of gravity of the upper valve body 60B to reduce the inclination of the upper valve body 60B, prevents the horizontal displacement, and the attitude of the upper valve body 60B. Can be stabilized.
Further, when fuel enters the casing 20B, the pressure in the casing 20B temporarily increases, and when the fuel level rises to reach the valve body 61B, the space inside the cylindrical valve body 61B is reached. However, the vent hole 61Bg reduces the force that separates the second sheet portion 62Bb and the seal portion 56Ba in order to release the pressure in the inner space, thereby preventing the sealing performance from being lowered.

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.
The fuel cutoff valve of the above-described embodiment has been described with respect to the configuration for mounting so as to block the mounting hole formed in the upper wall of the tank. Also good.

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. It is sectional drawing which decomposed | disassembled the fuel cutoff valve. It is a perspective view which decomposes | disassembles and shows a float and an upper valve body. It is sectional drawing of the vicinity of a float and an upper valve body. It is explanatory drawing explaining an effect | action of an upper valve body. It is explanatory drawing explaining operation | movement of a fuel cutoff valve. It is explanatory drawing explaining the operation | movement following FIG. It is explanatory drawing explaining the operation | movement following FIG. It is sectional drawing which shows the upper part of the fuel cutoff valve which concerns on another Example.

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 ... first seal part 32 ... side wall part 32a ... communication hole 32b ... engagement hole 35 ... bottom plate 35a ... engagement claw 35b ... spring support part 40 ... Lid body 41 ... Lid body 42 ... Tube body part 42a ... Lid side passage 43 ... Flange 43a ... Internal weld end 43b ... Outer weld part 50 ... Float mechanism 52 .. Float 52S ... buoyancy chamber 53 ... large diameter part 53a ... guide protrusion 54 ... reduced diameter part 55 ... valve support part 56 ... support part 56a ... seal part 56b ..Arc surface 57 ... Guide part 57a ... Guide body 57b ... Step part 57c ... Engagement claw 57d ... Inner guide surface 57e ... Outer guide rib 57f ... Outer guide Surface 58 ... Ventilation path 60 ... Upper valve body 61 ... Valve body 61a. .. Flat plate part 61b ... Through hole 61c ... Outer peripheral part 62 ... Sheet member 62a ... First sheet part 62b ... Second sheet part 62c ... Connection hole 70 ... Spring 10B ... Fuel cutoff valve 20B ... Casing 31Bc ... First seal part 33B ... Guide rib 52B ... Float 55B ... Valve support part 56Ba ... Seal part 57B ... Guide part 57Bc. .. engaging claw 57Bd ... inner guide surface 57Bf ... outer guide surface 60B ... upper valve body 61B ... valve body 61Ba ... flat plate part 61Bd ... side wall part 61Be ... support hole 61Bf ... Mounting part 61Bg ... Vent hole 61Bh ... Guide part 62B ... Sheet member 62Ba ... First sheet part 62Bb ... Second sheet part 62Bc ... Connection hole 62Bd ... Mounting part FT ... Fuel tank FTa ... Tank upper wall FTb ... Mounting hole

Claims (9)

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 large-diameter portion (53) housed in the valve chamber (30S), and a valve support portion (55) provided at an upper portion of the large-diameter portion (53) and having a diameter smaller than the outer diameter of the large-diameter portion (53); A float (52) having a seal part (56a) formed in the valve support part (55) and moving up and down by increasing or decreasing buoyancy depending on the fuel liquid level in the valve chamber (30S);
A valve body (61) having a flat plate portion (61a) supported by the valve support portion (55) so as to be movable up and down and having a connection hole (62c) having a smaller passage area than the connection passage (31b); A first seat part (62a) provided at the upper part of the main body (61) for opening and closing the connection passage (31b) and a second sheet for opening and closing the connection hole (62c) by being attached to and detached from the seal part (56a). An upper valve body (60) having a seat portion (62b);
With
The valve support portion (55) includes a guide portion (57) projecting upward in the axial direction of the float (52), and the guide portion (57) is provided on the upper valve body (60). The float is guided by an inner guide surface (57d) that surrounds the outer peripheral portion (61c) and guides the outer peripheral portion (61c) to raise and lower the upper valve body (60), and an inner wall of the casing body (30). A fuel cutoff valve comprising an outer guide surface (57f) for raising and lowering (52). The fuel cutoff valve according to claim 1,
The upper valve body (60) includes a valve body (61) formed from a resin material, and a seat member (62) formed from a rubber material and integrated with the valve body (61) by insert molding, A fuel cutoff valve provided with the first seat portion (62a) and the second seat portion (62b) on the upper and lower portions of the seat member (62), respectively. The fuel cutoff valve according to claim 1 or 2,
The seal portion (56a) is a flat surface, and the second seat portion (62b) has a substantially conical shape penetrating the connection hole (62c) at the center, and an upper valve body (on the seal portion (56a)). 60) A fuel shut-off valve that supports the tiltable movement. The fuel cutoff valve according to any one of claims 1 to 3,
The valve support portion (55) includes a step portion (57b) that contacts the lower portion of the outer peripheral portion (61c) of the upper valve body (60) and regulates the inclination of the upper valve body (60) within a predetermined angle range. The fuel shut-off valve. The fuel cutoff valve according to any one of claims 1 to 4,
The guide portion (57) includes a plurality of columnar guide main bodies (57a) so as to surround the upper valve body (60) and an engaging claw (57c) formed toward the axial center of the float (52). ), And the engagement claw (57c) is a fuel cutoff valve that is formed so as to regulate the elevation distance of the upper valve body (60). The fuel cutoff valve according to claim 5,
Between the adjacent guide main bodies (57a), from the space on the side of the valve support portion (55), through the gap between the seal portion (56a) and the second seat portion (62b), the connection hole ( 62c) or a fuel shut-off valve provided with an air passage (58) connected to the connection passage (31b). The fuel cutoff valve according to claim 1,
The outer guide surface (57f) is a fuel cutoff valve formed on an outer guide rib (57e) protruding from the guide portion (57). The fuel cutoff valve according to claim 7,
A fuel cutoff valve in which a guide rib (33B) for guiding the outer guide surface (57Bf) is formed on the inner wall of the casing (20B). The fuel cutoff valve according to claim 1, claim 7 or claim 8,
The valve body (61B) extends downward from the outer peripheral portion of the flat plate portion (61Ba), and includes a cylindrical side wall portion (61Bd) surrounding the outer peripheral portion of the valve support portion (55B). valve.

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