JP2005299399A - Fuel shut-off valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel shut-off valve 10 capable of surely preventing fluid from flowing out of a connection passage 32b even if fuel in a fuel tank FT rocks due to quick turn or vibration of a vehicle by a simple structure. <P>SOLUTION: The fuel shut-off valve 10 is provided with a casing 20, the connection passage 32b provided at an upper part of the casing 20, and a valve element mechanism 50. The valve element mechanism 50 includes a float 51, and a seat material 55 arranged on an upper part of the float 51. One end of the seat member 55 is supported by a valve support part 32d provided on an inner wall surface of the casing 20, and another end of the seat member 55 engages with an engagement part 52c at the upper part of the float 51 when the same drops from a condition that the float 51 closes the connection passage 32b and the seat member 55 opens the connection passage 32b. <P>COPYRIGHT: (C)2006,JPO&NCIPI

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, as this kind of fuel cutoff valve, patent document 1 etc. are known and it is a structure as shown in FIG. FIG. 10 is a cross-sectional view showing the upper part of the fuel cutoff valve 100. The fuel cutoff valve 100 includes a casing 110 having a valve chamber 110S communicating with a connection passage 112 connected to the outside, a float 120 that is housed in the valve chamber 110S and moves up and down according to the liquid level in the fuel tank FT, and the float 120. And a spring (not shown) for biasing the float 120 upward. The float 120 is lifted by receiving buoyancy from the fuel, and the valve seat 130 closes the connection passage 112 to prevent the fuel from flowing out to the outside (canister).

  Then, when the fuel level is lowered and the float 120 is lowered, the weight of the float 120 is utilized, and the valve seat 130 is peeled off by the claws 122 formed on the upper portion of the float 120 to stick the valve seat 130. Prevents and improves the restart valve characteristics.

  However, in the conventional fuel shut-off valve 100, the valve seat 130 cannot quickly close the connection passage 112 when the fuel fluctuates suddenly due to sudden turning or vibration of the vehicle. 112 may flow out.

U.S. Pat. No. 4,753,262

  The present invention is based on the above-mentioned problems of the prior art, and even if the fuel in the fuel tank is swung due to sudden turning or vibration of the vehicle, the fuel cutoff valve reliably prevents the fuel from flowing out from the connection passage. The purpose is to provide.

The present invention made to solve the above problems
In the fuel shut-off valve that is attached to the upper part of the fuel tank and cuts off the communication between the inside and outside of the fuel tank.
A casing having a valve chamber communicating with the fuel tank;
A connection passage provided at an upper portion of the casing and connecting the valve chamber and the outside;
A valve body mechanism that includes a float that is housed in the valve chamber and moves up and down according to a fuel level in the fuel tank; and a seat member that is disposed above the float;
With
The valve body mechanism is provided on the inner wall surface of the casing close to the connection passage, and has a valve support portion that supports one end of the seat member so that the seat member can open and close the connection passage. It is characterized by.

  In the fuel tank using the fuel cutoff valve according to the present invention, when the float rises with the fuel, the seat member arranged at the upper part of the float interlocks to close the connection passage and shuts off the inside of the fuel tank from the outside. To prevent the outflow.

  Also, since one end of the seat member is supported by the valve support portion of the casing provided at a position close to the connection passage, the fuel liquid level suddenly rises when the liquid level fluctuates when the vehicle turns, etc. Even if it is not possible to follow the rising speed of the fuel level, the seat member blocks the path from the valve chamber to the connection passage, so that the fuel can be prevented from flowing out.

  As a preferred aspect of the fuel cutoff valve according to the present invention, the valve body mechanism may be configured to open and close the connection passage when the seat member is pushed by the upper part of the float in conjunction with the vertical movement of the float. it can. Furthermore, as another preferred aspect, the valve body mechanism has an engagement portion formed at an upper portion of the float, and the engagement portion is configured so that the float is moved from a state where the seat member closes the connection passage. When lowered, the sheet member can be formed so as to engage with the other end of the sheet member to open the connection passage. With this configuration, when the float descends as the fuel level drops due to fuel consumption, the other end of the seat member is engaged with the engaging portion, and the connection passage is opened in the direction of opening one end of the seat member as a fulcrum. Since force is applied, the restart valve can be performed smoothly.

  As a preferred embodiment of the fuel cutoff valve according to the present invention, a configuration is provided in which a protective wall is provided at a portion on the opposite side of the valve support portion with the seat member as the center and blocking the path from the valve chamber toward the connection passage. Can take.

  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 cross-sectional view showing a fuel cutoff valve 10 attached to an upper portion of a fuel tank FT of an automobile according to a first embodiment of the present invention. The fuel shut-off valve 10 shuts off the passage to the external passage (canister) when the fuel in the fuel tank FT reaches a predetermined liquid level FL1, thereby restricting the outflow of fuel to the outside.

  The fuel tank FT includes a tank upper wall FTa whose surface is formed of a composite resin material containing polyethylene, and a mounting hole FTc is formed in the tank upper wall FTa. The fuel cutoff valve 10 is attached to the tank upper wall FTa in a state of entering the attachment hole FTc. The fuel cutoff valve 10 includes a casing 20, a valve body mechanism 50 having a float 51 and a seat member 55, and a spring 60, and a canister (illustrated) by raising and lowering the float 51 according to the fuel level in the fuel tank FT. Open and close the connection path to (omitted).

(2) Configuration of Each Part of Fuel Shutoff Valve 10 Hereinafter, the configuration of each part of the fuel cutoff valve 10 will be described.

(2) -1 Casing 20
The casing 20 includes a casing body 30, a bottom support plate 35, and a lid body 40. The casing body 30 and the bottom support plate 35 are made of a synthetic resin polyacetal or nylon having fuel oil resistance. The lid 40 is made of a composite material mainly composed of polyethylene.

  FIG. 2 is an exploded cross-sectional view of the fuel cutoff valve 10. The casing body 30 includes a ceiling wall portion 32 and a side wall 33 extending in a cylindrical shape downward from the ceiling wall portion 32, and a cup-shaped valve chamber 30 </ b> S surrounded by the ceiling wall portion 32 and the side wall 33. The lower part is made the lower opening 30a. An upper projecting portion 32 a is formed at the center of the ceiling wall portion 32 downward. A connection passage 32b passes through the upper protrusion 32a, and the valve chamber 30S side of the connection passage 32b serves as a seal portion 32c.

  Further, the side wall 33 includes a communication hole 33a that allows communication between the valve chamber 30S and the inside of the fuel tank FT (FIG. 1), an engagement hole 33b for attaching the bottom support plate 35 to the lower part thereof, and a lid 40 on the upper part thereof. And a flange portion 33c for attaching to the housing. The bottom support plate 35 is a member that closes a part of the lower opening 30a of the casing body 30, and an engagement claw 35a formed on the outer periphery of the bottom support plate 35 engages with the engagement hole 33b. Mounted at the bottom of the. A communication hole 35 b for communicating with the valve chamber 30 </ b> S is formed at the center of the bottom support plate 35.

  The lid body 40 is formed on the lid body 41, a tube body portion 42 projecting in an L shape from the center to the top of the lid body 41, a flange 43 formed on the outer periphery of the lid body 41, and a lower surface of the lid body 41. And a welding surface 44, which are integrally formed. Further, a tubular body passage 42a is formed in the tubular body portion 42. One end of the tubular body passage 42a is connected to the connection passage 32b of the casing body 30, and the other end is connected to the canister side. Furthermore, an annular 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. Further, the welding surface 44 is formed so as to be welded to the flange portion 33c of the casing body 30, and for example, a modified polyethylene modified with maleic acid is laminated by two-color molding or the like. The modified polyethylene has a heat-welding property to both polyacetal and polyethylene, and joins the lid 40 and the casing body 30.

(2) -2 Valve body mechanism 50
The valve body mechanism 50 includes a float 51 and a seat member 55 disposed above the float 51. The float 51 is configured in a container shape including an upper wall portion 52 and a cylindrical side wall portion 53 formed downward from the outer periphery of the upper wall portion 52, and the inner space generates buoyancy. Buoyancy chamber 51S. A plurality of guide protrusions 51 a are formed on the outer peripheral portion of the float 51 in the vertical direction. A spring 60 is disposed in the buoyancy chamber 51 </ b> S of the float 51. The spring 60 urges the float 51 upward by being interposed between one end of the float 51 and the upper surface of the bottom support plate 35.

  FIG. 3 is a perspective view showing the float 51 and the sheet member 55. A central protrusion 52 a is formed at the center of the upper wall 52 of the float 51. In addition, a protective wall 52b is provided on the outer peripheral portion of the upper portion of the float 51 so as to protrude approximately half a circumference. As shown in FIG. 1, the protective wall 52 b protrudes at a position that blocks a path from the casing body 30 toward the connection passage 32 b. Returning to FIG. 3, an engaging portion 52 c directed toward the center protrudes from one end portion of the inner periphery of the protective wall 52 b. The engaging portion 52 c is a claw that engages with one end of the outer peripheral portion of the sheet member 55.

The sheet member 55 includes a sheet main body 55a that is a disk-shaped plate, and a supported end 55b that protrudes from one end of the sheet main body 55a and has a claw 55b-1, and is integrally formed of resin. The upper surface of the sheet main body 55a is a sheet surface 55c. As shown in FIG. 1, the supported end 55 b is swingably supported by the upper inner wall of the casing body 30. That is, the valve support portion 32d protrudes from the inner wall of the ceiling wall portion 32 of the casing body 30 at a position close to the connection passage 32b. A support hole 32d-1 is formed in the valve support portion 32d. The support hole 32d-1 is formed at the same position in the horizontal direction as the communication hole 33a in order to facilitate the punching when a slide mold is used. When the supported end 55b is press-fitted into the support hole 32d-1 and is retained by the claw 55b-1, the seat member 55 is supported to be swingable with the supported end 55b and the valve support portion 32d as fulcrums. The connection passage 32b is opened and closed by the seat surface 55c.
Further, the other end of the sheet member 55 is formed to engage with the engaging portion 52 c of the float 51. That is, when the float 51 descends from the state where the connection passage 32b is closed, the sheet member 55 is engaged with the engaging portion 52c and opens the connection passage 32b with the supported end 55b as a fulcrum. It is formed (see FIG. 5).

(3) Operation of the fuel cutoff valve 10 and its operation and effect Next, the opening and closing operation of the fuel cutoff valve 10 will be described.
(3) -1 In FIG. 1, when fuel is supplied to the fuel tank FT by refueling, the fuel vapor accumulated in the upper part of the fuel tank FT as the fuel level in the fuel tank FT rises is the casing body 30. Through the communication hole 33a, the valve chamber 30S, the connection passage 32b, and the lid side passage 42a. As shown in FIG. 4, when the fuel level in the fuel tank FT reaches a predetermined liquid level FL1, the fuel flows into the valve chamber 30S through the communication path 35b of the bottom support plate 35. Thereby, when the former exceeds the latter by the balance of the upward force due to the buoyancy of the float 51 and the load of the spring 60 and the downward force due to the weight of the float 51 and the seat member 55, the float 51 and the seat member 55 and the seat surface 55c of the seat member 55 are seated on the seal portion 32c to close the connection passage 32b. Thereby, at the time of refueling to the fuel tank FT, it is possible to escape the fuel vapor from the fuel tank FT and to prevent the fuel from flowing out of the fuel tank FT.

(3) -2 When the fuel in the fuel tank FT is consumed and the fuel level decreases, the float 51 descends with its buoyancy reduced as shown in FIG. As the float 51 descends, the engaging portion 52c provided on the top of the float 51 engages with the end of the sheet member 55, and the sheet member 55 rotates with the supported end 55b as a fulcrum. Thereby, the sheet surface 55c of the sheet member 55 is separated from the seal portion 32c, and the connection passage 32b is opened. Since the seat member 55 receives a large opening force due to the weight of the float 51 against the force adsorbed to the seal portion 32c, the seat member 55 is excellent in the restart valve characteristic.

(3) -3 FIG. 6 is an explanatory diagram for explaining a state when the vehicle is rocking. When the vehicle swings violently and the fuel level reaches near the upper end of the fuel shut-off valve 10 and collides with the lower surface of the seat member 55, the seat member 55 rotates about the supported end 55b as a fulcrum to connect to the connection passage 32b. Close. At this time, since the seat member 55 is lighter than the float 51 even before the float 51 is completely lifted, it is possible to prevent the fuel from entering the connection passage 32b by being quickly closed by the rise of fuel. it can.

(3) -4 In FIG. 1, even when the seat member 55 does not immediately close the connection passage 32b due to the swing of the vehicle, a configuration is provided to prevent the fuel from entering the connection passage 32b. . That is, the protective wall 52b formed in the upper part of the float 51 blocks the fuel that has entered the valve chamber 30S due to the swinging of the vehicle on the upstream side of the connection passage 32b. Further, since the seat member 55 is supported at a position close to the connection passage 32b, fuel is blocked from entering the connection passage 32b even when the seat member 55 opens the connection passage 32b. FIG. 7 is an explanatory view for explaining a range for preventing the outflow of fuel to the connection passage 32b, as viewed from above with the connection passage 32b as a center. In the opening region of the connection passage 32b, the route to the connection passage 32b is blocked by the protective wall 52b in the region A-R, and the route to the connection passage 32b is blocked by the sheet member 55 in the region BR. In addition, since the member that blocks the inflow of fuel is disposed over almost the entire path from the valve chamber 30S toward the connection passage 32b, it is possible to reliably prevent the fuel from flowing out to the outside.

  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.

(1) FIG. 8 is a sectional view showing a fuel cutoff valve 10B according to the second embodiment. The second embodiment is characterized by the engaging means between the upper part of the float 51B constituting the valve body mechanism 50B and the seat member 55B. An engaging end 55Bb-2 projects from the outer periphery of the disc-shaped sheet member 55B on the opposite side of the supported end 55Bb. Further, an engagement hole 52Bd is formed in the protective wall 52Bb, and the engagement end 55Bb-2 protrudes into the engagement hole 52Bd. In this configuration, when the float 51B is in the raised position and the seat member 55B is closed, when the float 51B is lowered, the engagement end 55Bb-2 is engaged with the engagement hole 52Bd, and the supported end 55Bb is moved. By rotating around the fulcrum, the seat member 55B is easily separated from the seal portion 32c.

(2) FIG. 9 is a cross-sectional view showing a fuel cutoff valve 10C according to the third embodiment. The third embodiment is characterized by the configuration of the casing 20C. The casing 20C includes a casing body 30C, a ceiling wall 32C, and a lid body 40C. The casing body 30C and the ceiling wall 32C are formed of polyacetal, and the lid body 40C is formed of polyethylene. The casing body 30C has a side wall 33C and a bottom 35C integrally formed in a cup shape. The ceiling wall 32C is formed with an upper protrusion 32Ca having a connection passage 32Cb and a valve support 32Cd having a support hole 32Cd-1. An engaging protrusion 33Ce is formed on the side wall 33C. On the other hand, a support portion 45C protrudes from the lower portion of the lid 40C, and an engagement hole 45Ca that engages with the engagement protrusion 33Ce is formed in the support portion 45C.

  In order to assemble the fuel cutoff valve 10C, the spring 60 and the float 51 are housed in the casing body 30C. Thereafter, the upper end of the casing main body 30C is welded to the outer peripheral portion of the ceiling wall 32C to which the sheet member 55 is assembled. Furthermore, the support body 45C is fitted to the upper portion of the casing body 30C, and the engagement body 45C of the support section 45C is engaged with the engagement protrusion 33Ce, thereby assembling the lid body 40C to the casing 20C. Thus, by configuring the ceiling wall 32C separately from the casing body 30C, the support hole 32Cd-1 of the valve support portion 32Cd can be easily formed.

(3) In the above-described embodiment, the structure in which the seat member 55 is supported by being inserted into the support hole 32d-1 of the valve support portion 32d has been described. The structure which can be supported may be sufficient.

It is sectional drawing which shows the fuel cutoff valve attached to the upper part of the fuel tank of the motor vehicle concerning the 1st Example of this invention. It is sectional drawing which decomposed | disassembled the fuel cutoff valve. It is a perspective view which shows a float and a sheet | seat member. 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 state at the time of rocking | fluctuation of a vehicle. It is explanatory drawing explaining the effect | action of the fuel cutoff valve at the time of rocking | fluctuation of a vehicle. It is sectional drawing which shows the fuel cutoff valve concerning a 2nd Example. It is sectional drawing which shows the fuel cutoff valve concerning a 3rd Example. It is sectional drawing which shows the upper part of the fuel cutoff valve with which the upper part of the fuel tank concerning a prior art was mounted | worn.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fuel cutoff valve 10B ... Fuel cutoff valve 10C ... Fuel cutoff valve 20 ... Casing 20C ... Casing 30 ... Casing main body 30C ... Casing main body 30S ... Valve chamber 30a ... lower opening 32 ... ceiling wall 32C ... ceiling wall 32a ... upper protrusion 32Ca ... upper protrusion 32b ... connection passage 32Cb ... connection passage 32c ... seal part 32d ... Valve support part 32Cd ... Valve support part 32d-1 ... Support hole 32Cd-1 ... Support hole 33 ... Side wall 33C ... Side wall 33a ... Communication hole 33b ... Engagement hole 33c ... Flange part 33Ce ... Engagement projection 35 ... Bottom support plate 35C ... Bottom part 35a ... Engagement claw 35b ... Communication path 35b ... Communication hole .Cover body 40C ... Cover body 41 ... Cover body 42 ... Tube part 42a ... Tube passage 42a ... Cover side passage 43 ... Flange 43a ... Annular weld 44. ..Welding surface 45C ... Support part 45C ... engagement hole 50 ... valve mechanism 50B ... valve mechanism 51 ... float 51B ... float 51S ... buoyancy chamber 51a ... guide protrusion 52 ... upper wall 52a ... Center protrusion 52b ... Protective wall 52Bb ... Protective wall 52c ... Engagement part 52Bd ... Engagement hole 53 ... Side wall part 55 ... Sheet member 55B ... Sheet Member 55a ... Sheet body 55b-1 ... Nail 55Bb-2 ... engaging end 55b ... supported end 55Bb ... supported end 55c ... sheet surface 60 ... spring FT. .. Fuel tank FTa ... Tank upper wall FTc ... Mounting hole

Claims (4)

A fuel shut-off valve that is mounted on the upper part of the fuel tank (FT) and cuts off the communication between the inside and outside of the fuel tank (FT).
A casing (20) having a valve chamber (30S) communicating with the fuel tank (FT);
A connection passage (32b) provided in an upper portion of the casing (20) and connecting the inside of the valve chamber (30S) and the outside;
A float (51) that is housed in the valve chamber (30S) and moves up and down according to the fuel level in the fuel tank (FT), and a seat member (55) that is disposed on the top of the float (51). A valve body mechanism (50) having;
With
The valve body mechanism (50)
One end of the seat member (55) is provided near the connection passage (32b) and on the inner wall surface of the casing (20) so that the seat member (55) can open and close the connection passage (32b). Having a valve support (32d) to support,
A fuel shut-off valve characterized by The fuel cutoff valve according to claim 1,
The valve body mechanism (50) is a fuel cutoff valve configured such that the seat member (55) can open and close the connection passage (32b) in conjunction with the vertical movement of the float (51). The fuel cutoff valve according to claim 1 or 2,
The valve body mechanism (50)
There is an engaging part (52c) formed on the upper part of the float (51), and the engaging part (52c) is in a state where the seat member (55) closes the connection passage (32b). A fuel cutoff valve formed so that when the float (51) descends, the seat member (55) is engaged with the other end of the seat member (55) to open the connection passage (32b). The fuel cutoff valve according to any one of claims 1 to 3,
A path from the valve chamber (30S) to the connection passage (32b) is provided at the upper part of the float (51) and on the opposite side of the valve support (32d) with the seat member (55) as the center. A fuel cutoff valve provided with a protective wall (52b) for shielding.

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