JP2007092578A - Fuel cutoff valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cutoff valve 10 closable with high sealability even in a narrow connecting passage 31b. <P>SOLUTION: This fuel cutoff valve 10 has a valve support part 53 in an upper part of a float 51, and a seat member 55 is installed in this valve support part 53. The seat member 55 has an umbrella-shaped seat part 55a formed of a rubber material and a seat support part 55b. The valve support part 53 supports the seat support part 55b by being inserted into a fixing part 53b, and also supports the part on the reverse surface side of an outer peripheral part of the seat part 55a by a support step part 53e of the outer peripheral edge of a support base part 53a, and closes the connecting passage 31b by being seated on a seal part 31c by elastically arranging the seat part 55a toward a deflection space 53f on the outer peripheral side of the support step part 53e when pushing the seat part 55a by the seal part 31c. <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.

  At the upper part of the fuel tank, there is provided an evaporative fuel processing device provided with a full tank regulating valve connected to the canister and a fuel cutoff valve (rollover valve), and each valve opens and closes at a predetermined fuel level. As a result, the outside of the fuel tank is secured and the liquid fuel is prevented from flowing out. The rollover valve shuts off fuel to the outside at a fuel level higher than the full tank level in order to ensure ventilation when the vehicle is tilted or when the vehicle is running slalom.

By the way, in recent years, flattening of fuel tanks has been studied in order to cope with various and large living spaces of vehicles. In such flattened fuel tanks, in order to reduce the proportion of dead space above the fuel tanks. In addition, it is preferable to set the fuel level to be closed as high as possible. However, when the fuel level at the time of valve closing is set high, the rollover valve is liable to be submerged. Even in the case of such submergence, as shown in Patent Documents 1 and 2, in order to obtain a high sealing performance, a rubber valve body is attached to the center upper part of the float, and when the rubber valve body closes the connection passage, Means for elastically deforming the outer periphery is known.
However, when a connection passage having a small passage area such as a rollover valve is shut off, there is a problem that it is difficult to sufficiently bend the outer peripheral portion of the rubber valve body and high sealing performance cannot be obtained. .

JP 7-127540 A JP 11-190258 A

  An object of the present invention is to provide a fuel cutoff valve that can be closed with high sealing performance even in a narrow connection passage, in view of solving the above-described problems of the prior art.

The present invention made to solve the problems
In a fuel shut-off 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 having a valve chamber communicating with the inside of the fuel tank and the connecting passage, and a seal portion provided facing the connecting passage;
A float that is housed in the valve chamber and moves up and down according to the fuel level in the fuel tank, a valve support formed at the top of the float, and a valve support that is attached to and detached from the seal And a float mechanism having a seat member for opening and closing the connection passage,
With
The sheet member includes an umbrella-shaped sheet portion formed of a flexible material, and a sheet support portion protruding from the top of the sheet portion toward the float side,
The valve support portion includes a fixing portion that fixes the seat support portion and a support step portion that is supported on the back side of the outer peripheral portion of the seat portion.

  When fuel is supplied to a fuel tank using the fuel cutoff 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. When the float rises, the seat member closes the connection passage, thereby blocking the fuel tank from the outside and preventing the fuel from flowing out from the fuel tank.

  The seat member is formed of a flexible material, the seat support portion is supported by the support base portion of the valve support portion, the back side of the outer peripheral portion of the seat portion is supported by the support step portion, and the seat portion is the seal portion. The connection passage is sealed when seated on. The seat member is umbrella-shaped, and the back side of the outer peripheral part of the seat part is supported by the support step part and sits in a state of protruding outside the seal part, so it enters the connection passage in the seal part or connects You won't get stuck in the passage.

  As a preferred aspect of the present invention, a bending space that allows elastic deformation of the seat portion when the seat portion is pushed by the seal portion is formed between the support step portion and the seat portion. Can be configured. With this configuration, when the seat portion is seated on the seal portion, the seat portion is elastically deformed toward the bending space. That is, the bending space acts as a space for reliably elastically deforming the seat portion when pressed by the seal portion. Therefore, even if the seat portion is a small-diameter seal portion, the seat portion is elastically deformed so as to be in close contact with each other, so that high sealing performance can be obtained. Even when the float is inclined and seated on the seal portion, the seat portion is elastically deformed following the seal portion, so that high sealing performance can be obtained.

  Further, as another preferred aspect, when the seal portion is set smaller than the outer diameter of the support step portion in relation to the outer diameter of the portion in contact with the seat portion, the seal portion having a small passage area Can surely press the sheet portion and improve the sealing performance. In this case, the seal portion can push the seat portion with certainty by taking a configuration projecting toward the valve chamber.

  As another preferred embodiment, when the float is in the lowered position, the support step portion is separated from the back surface of the seat portion by a predetermined amount, and the seat portion is pushed by the seal portion. Furthermore, the structure formed so that it may contact | abut with the said support step part can be taken. Thus, the space for bending the seat portion can be provided in the peripheral portion of the valve support portion.

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 seal portion 31c. The side wall 32 is formed with a vent hole 32a for connecting the inside of the fuel tank FT and the valve chamber 30S, and an engagement 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. On the upper surface of the bottom plate 35, a spring support portion 35 c for supporting the communication hole 35 b and the lower end of the spring 70 is formed.

  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 43 a that is welded to the tank upper wall FTa of the fuel tank FT is formed at the lower end portion of the flange 43.

  The float mechanism 50 includes a float 51 and a sheet member 55 mounted on the top of the float 51. The float 51 is configured in a container shape having an upper wall portion 51a and a cylindrical side wall 51b formed downward from the outer periphery of the upper wall portion 51a. It is chamber 51S. A guide protrusion 51 c is formed on the outer periphery of the float 51. The guide protrusions 51c are provided on the side wall 51b of the float 51 so as to protrude in eight ribs at equal intervals in the circumferential direction. A spring 70 is disposed in the buoyancy chamber 51 </ b> S of the float 51. The spring 70 urges the float 51 upward by being interposed between one end of the float 51 and the upper surface of the bottom plate 35.

The float 51 includes a valve support portion 53 that supports the seat member 55 at the upper center thereof. FIG. 5 is an enlarged sectional view showing the vicinity of the upper part of the float 51 and the upper part of the casing body 30, and FIG. 6 is an exploded perspective view showing the float mechanism 50. The valve support portion 53 includes a columnar support base portion 53a, a fixing portion 53b formed from a hole penetrating the central portion of the support base portion 53a, and an insertion hole 53c having a diameter expanded from the fixing portion 53b. A stop step portion 53d is formed between 53b and the insertion hole 53c. The outer periphery of the support base 53a is a support step 53e for supporting the sheet member 55.
The sheet member 55 is formed into an umbrella shape (conical shape) from a flexible material (rubber material, thermoplastic elastomer, etc.), that is, a conical sheet portion 55a and a bar shape from the center lower portion of the sheet portion 55a. A protruding sheet support portion 55b and a retaining portion 55c formed in the middle of the sheet support portion 55b are provided. The sheet support portion 55b is press-fitted into the fixing portion 53b, and is engaged with the retaining step portion 53d by the retaining portion 55c. By doing so, it is attached to the valve support 53. The seat portion 55a includes a seat surface 55d that is attached to and detached from the seal portion 31c. In this state, the back surface side of the outer peripheral portion of the seat portion 55a is supported by the support step portion 53e, and a bending space 53f is formed between the support base portion 53a and the seat portion 55a. The bending space 53f acts as a space that allows elastic deformation of the seat portion 55a when the seat portion 55a is seated on the seal portion 31c.

(3) Operation of the fuel cutoff valve 10 Next, the operation of the fuel cutoff valve 10 will be described. In FIG. 3, 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 35b and the vent hole 32a. The valve chamber 30S is released to the canister side through the connection passage 31b and the lid side passage 42a. As the fuel level in the fuel tank FT rises, the fuel flows into the valve chamber 30S through the communication hole 35b. As shown in FIG. 7, when the fuel level reaches a predetermined level FL1, the buoyancy of the float 51 and the upward force due to the load of the spring 70 and the downward force due to the weight of the float 51 and the seat member 55 are shown. When the former exceeds the latter, the float 51 rises. At this time, as shown in FIG. 8, the seat portion 55a of the seat member 55 is elastically deformed to be warped by being pushed by the seal portion 31c while being supported by the support step portion 53e of the valve support portion 53. Thus, the seat surface 55d closes the connection passage 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 is lowered and the fuel in the valve chamber 30S is discharged from the communication hole 35b or the like, the float 51 receives the downward force by reducing its buoyancy, and the seat member 55 leaves the seal portion 31c and opens the connection passage 31b.

(4) Operation and effect of the embodiment The configuration of the fuel cutoff valve 10 of the above embodiment provides the following effects.
(4) -1 As shown in FIG. 8, the rubber sheet member 55 is elastically deformed toward a bending space 53 f formed between the rubber seat member 55 and the valve support portion 53 when seated on the seal portion 31 c. At this time, the bending space 53f acts as a space for reliably elastically deforming the seat portion 55a when pressed by the seal portion 31c. Therefore, since the seat portion 55a is elastically deformed so as to be in close contact with the small-diameter seal portion 31c, high sealing performance can be obtained.
(4) -2 The seat member 55 has an umbrella shape, and the outer peripheral portion thereof is supported by the support step portion 53e and is seated on the seal portion 31c in a state of protruding outside the seal portion 31c. There is no entry into the connection passage 31b in 31c and no entry into the connection passage 31b.
(4) -3 Since the sheet member 55 has an umbrella shape and is easily elastically deformed, the sheet member 55 can be reliably bent over a long period of time.
(4) -4 Even if the float 51 is inclined and seated on the seal portion 31c, the seat portion 55a is elastically deformed following the seal portion 31c, so that high sealing performance can be obtained.

(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 FIGS. 9 and 10 are explanatory views showing another embodiment. This embodiment is characterized by the state in which the seat member is supported by the valve support portion and the shape of the seal portion. That is, in FIG. 9, when the float 51B is in the lowered position, the seat member 55B is supported by the valve support portion 53B in a state where the seat portion 55Ba is separated from the support step portion 53Be by a predetermined distance L. Further, the seal portion 31Bc is formed in a conical shape that is recessed from the ceiling wall portion 31B, and is connected to the connection passage 31Bb. Here, when the diameter at which the seal portion 31Bc is sealed by the seat portion 55Ba is d and the outer diameter of the support step portion 53Be is D, d <D is set, that is, the seal diameter d of the seal portion 31Bc is set to the support step. It is smaller than the outer diameter D of the portion 53Be.
In the above configuration, as shown in FIG. 10, when the float 51B is raised and the seat portion 55Ba is seated on the seal portion 31Bc, the seat portion 55Ba is elastically deformed to reduce the angle of the seat portion 55Ba, and the back surface of the seat portion 55Ba. The side comes into contact with the support step 53Be. That is, when the seat portion 55Ba is pressed by the seal portion 31Bc while being supported by the support step portion 53Be, the seat portion 55Ba is elastically deformed toward the bending space 53Bf.

(5) -2 FIGS. 11 and 12 are explanatory views for explaining still another embodiment. The present embodiment is characterized by the shapes of the seal portion and the support step portion. That is, in FIG. 11, the position where the seal portion 31Cc presses the seat portion 55Ca is on the outer peripheral side from the support step portion 53Ce, and is provided outside the range of the bending space 53Cf. Further, d1 <D1 + 2t where d1 is the seal diameter at which the seal portion 31Cc is sealed by the seat portion 55Ca, D1 is the outer diameter of the support step portion 53Ce, and t is the wall thickness of the valve support portion 53C.
In this configuration, when the float 51C rises and the seat portion 55Ca is seated on the seal portion 31Cc and bends, it is elastically deformed to reduce the angle of the seat portion 55Ca. At this time, the sheet portion 55Ca is pushed and bent by the seal portion 31Cc on the outer peripheral side from the portion that is abutted and supported by the support step portion 53Ce. In this case, as described above, from the relationship of d1 <D1 + 2t, the seat portion 55Ca does not enter the connection passage 31Cb, and the seat portion 55Ca does not hinder the separation from the seal portion 31Cc.

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 sectional drawing which expands and shows the vicinity of the upper part of a float, and the upper part of a casing main body. It is a perspective view which decomposes | disassembles and shows a float mechanism. It is explanatory drawing explaining operation | movement of a fuel cutoff valve. It is explanatory drawing explaining operation | movement of a fuel cutoff valve. It is explanatory drawing which shows another Example. It is explanatory drawing which shows operation | movement of another Example. It is explanatory drawing which shows other Example. It is explanatory drawing which shows operation | movement of 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 ... seal 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 part 40 ... Cover body 41 ... Cover body 42 ... Tube part 42a ... Cover side passage 43 ... Flange 43a ... Outside weld part 44 ... Support 44a ... engagement hole 50 ... float mechanism 51 ... float 51S ... buoyancy chamber 51a ... upper wall 51b ... side wall 51c ... guide protrusion 53 ... valve support Part 53a ... support base part 53b ... fixing part 53c ... insertion hole 53d ... prevention step part 53e ... support step part 53f ... flexing space 55 ... sheet member 55a ... Sheet part 55b ... Sheet support part 55c ... Retaining part 55 ... seat surface 70 ... spring FT ... Fuel tank FTa ... tank upper wall FTb ... mounting hole

Claims (5)

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 to cut off the communication between the fuel tank (FT) and the outside. ,
A casing (20) having a valve chamber (30S) communicating the fuel tank (FT) and the connection passage (31b), and a seal portion (31c) provided facing the connection passage (31b). When,
A float (51) which is housed in the valve chamber (30S) and moves up and down in accordance with the fuel level in the fuel tank (FT); and a valve support (53) formed on the top of the float (51) A float mechanism (50) having a seat member (55) which is attached to the valve support part (53) and opens and closes the connection passage (31b) by being separated from the seal part (31c);
With
The sheet member (55) includes an umbrella-shaped sheet portion (55a) formed from a flexible material, and a sheet protruding from the top of the sheet portion (55a) toward the float (51) side. A support portion (55b),
The valve support part (53) has a fixing part (53b) for fixing the seat support part (55b) and a support step part (53e) supported on the back side of the outer peripheral part of the seat part (55a). A fuel cutoff valve characterized by the above. The fuel cutoff valve according to claim 1,
Between the support step part (53e) and the sheet part (55a), the sheet part (55a) is allowed to be elastically deformed when the sheet part (55a) is pushed by the seal part (31c). A fuel cutoff valve in which a bending space (53f) is formed. The fuel cutoff valve according to claim 1 or 2,
A fuel cutoff valve in which an outer diameter of a portion where the seal portion (31c) contacts the seat portion (55a) is set smaller than an outer diameter of the support step portion (53e). The fuel cutoff valve according to claim 3,
The seal part (31c) is a fuel shut-off valve projecting annularly toward the valve chamber (30S). The fuel cutoff valve according to claim 1,
When the float (51B, 51C) is in the lowered position, the support step (53Be, 53Ce) is separated from the back surface of the sheet portion (55Ba, 55Ca) by a predetermined amount, and the sheet portion (55Ba, 53Ce) 55Ca) is a fuel cutoff valve formed so as to come into contact with the support step portion (53Be, 53Ce) when pushed by the seal portion (31Bc, 31Cc).

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