JP4518022B2 - Fuel shut-off valve - Google Patents

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 shut-off valve, a buoyancy is increased or decreased by a fuel level in a casing provided on the upper part of a fuel tank and connected to the outside (canister) and a valve passage of the casing. What is provided with the float which raises / lowers and the upper valve body mounted in the upper part of the float is known. 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 shut-off valve, when the connecting passage has a large passage area, if the connecting passage is directly opened and closed by a float, the float is adsorbed and the restart valve characteristic is not good. With the two-stage valve structure provided with, the restart valve characteristic of quickly opening the valve is improved.

  In such fuel shut-off valves, flattening of the fuel tank is being studied in order to cope with various and large living spaces of the vehicle. In such a flattened fuel tank, when the seal portion is submerged when the vehicle is tilted, However, high sealing performance is required. As a technique corresponding to this problem, as shown in Patent Documents 1 and 2, a rubber seat member is provided on the upper valve body, the first seat portion on the upper portion of the seat member is used as a seal portion of the connection passage, and the lower portion thereof. There is known a configuration in which the connection passage and the connection hole are opened and closed by opening and closing the second sheet portion with a seal portion at the top of the float.

  However, when the rubber sheet member is subjected to repeated large elastic deformations, it is easy to cause aging. In particular, the second sheet part smaller than the first sheet part directly hits the seal part on the upper part of the heavy float. There is a problem that it is easily subjected to elastic deformation and has a large secular change.

JP 2000-130271 A JP 2002-235623 A

  In view of solving the above-described problems of the conventional technology, the present invention has a durability of a flexible seat member attached to an upper valve body in a two-stage valve structure having an upper valve body on an upper part of a float. An object of the present invention is to provide a fuel shut-off valve with an improved fuel efficiency.

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 having a valve chamber communicating the fuel tank and the connection passage, and a first seal portion facing the connection passage;
A float that is housed in the valve chamber and moves up and down with increasing or decreasing buoyancy depending on the fuel level in the valve chamber;
An upper valve body mounted on the upper part of the float and opening and closing the connection passage by raising and lowering the float;
With
On the upper surface of the float, a cylindrical protrusion having an outer diameter smaller than the outer diameter of the float, and a support protrusion having a second seal portion on the upper part thereof,
The upper valve body has an upper surface portion and a circular side wall projecting from the outer peripheral portion of the upper surface portion. The upper valve body surrounds the support protrusion with the upper surface portion and the side wall, and is above and below the support protrusion. A valve body formed to be movable up and down in a direction, and a rubber seat member attached to the upper surface part ,
The seat member is opened and closed by the connection hole having a smaller passage area than the connection passage, a first seat portion that opens and closes the connection passage and has an opening above the connection hole, and the second seal portion. A second sheet portion having an opening at the bottom of
The support protrusion includes a valve-side guide portion that protrudes in the vertical direction in the form of a rib on the outer periphery of the support protrusion and slides on the side wall of the valve body to guide the upper valve body in the vertical direction. Provided with a restricting portion at the upper part of the valve side guide portion, and the restricting portion hits the upper surface portion when the second seat portion is seated on the second seal portion, whereby the second seat portion is The vertical distance between the upper valve body and the float is regulated so as to be regulated by the amount of elastic deformation within a predetermined range .

  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, as the upper valve body rises, the first seat portion of 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. Further, the upper valve body has a connection hole having a smaller passage area than the connection passage, and this connection hole is opened when the second seal portion is separated from the second seat portion before the connection passage is opened. The force in the valve closing direction applied to the first seat portion is reduced, and the connection passage is quickly opened, so that excellent restart valve characteristics can be obtained.

  Further, at least one of the upper valve body and the float is provided with a restricting portion. The restricting portion restricts the vertical distance between the upper valve body and the float within a predetermined range, so that the second seat portion is elastically deformed when the second seat portion is seated on the second seal portion. The amount is regulated within a predetermined range. Thus, since the second sheet portion does not repeatedly undergo large elastic deformation, it is possible to maintain high sealing performance over a long period of time.

  Further, as a preferred aspect of the present invention, a configuration is provided in which a valve-side guide portion that guides the inner peripheral portion of the valve main body in the vertical direction is provided on the upper portion of the float, and the restriction portion is provided on the upper portion of the valve-side guide portion. Can be taken. With this configuration, the valve-side guide portion can be raised and lowered while suppressing rattling of the upper valve body. Further, since the restricting portion is provided at the upper portion of the valve side guide portion, the configuration can be simplified.

  Further, as a preferred aspect of the present invention, a case-side guide portion that guides the outer peripheral portion of the upper valve body is provided on the inner wall of the casing, and the case-side guide portion and the valve-side guide portion are provided on the upper valve body. The structure provided so that an upper valve body may be guided over the full length of the raising / lowering range can be taken. According to this configuration, the upper valve body is guided by the case-side guide portion and the valve-side guide portion over the entire length of the float raising / lowering range, so that a stable raising / lowering operation can be performed.

  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 an embodiment of the present invention. 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 outflow to the canister when the fuel in the fuel tank rises to a predetermined liquid level FL1 during refueling.

(2) Configuration of Each Part of Fuel Shutoff Valve 10 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 member 37, and a lid body 40. A space surrounded by the casing main body 30 and the bottom member 37 is a valve chamber 30S. A spring 70 is provided in the valve chamber 30S. The float mechanism 50 supported by the housing is housed.

  FIG. 2 is an exploded cross-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 projection 31a is formed in the center of the ceiling wall 31 so as to project downward. A connection passage 31b is formed through the passage forming projection 31a. The valve chamber 30S side of the connection passage 31b is a first seal portion 31c. The side wall portion 32 is formed with a first communication hole 32a that connects the inside of the fuel tank FT and the valve chamber 30S. Further, on the inner wall of the side wall portion 32, case side guide portions 34 for guiding the float mechanism 50 are provided in four circumferential rib shapes. The case side guide portion 34 includes a lower guide rib 34a formed at the lower portion of the casing body 30, and an upper guide rib 34b formed on the axial center side from the lower guide rib 34a.

  The bottom member 37 is a member for closing a part of the opening 30a of the casing body 30 and introducing fuel vapor and liquid fuel into the valve chamber. The bottom member 37 integrally forms a bottom plate 38 and a cylindrical portion 39, and is welded to the lower end of the casing body 30 at the outer peripheral portion of the bottom plate 38. The bottom plate 38 has flow holes 38 a and 38 b and a spring support portion 38 c for supporting the lower end of the spring 70. The cylindrical portion 39 includes an introduction passage 39a, and guides fuel vapor and liquid fuel from the introduction opening 39b into the valve chamber 30S through the flow hole 38a.

  The lid body 40 includes a lid main body 41, a tube body portion 42 projecting laterally from the center of the lid main body 41, and a flange 43 formed on the outer periphery of the lid main body 41, and these are integrally formed. . 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 a canister (not shown). Connected to. An inner welding end 43a for welding the upper end of the casing body 30 is formed at the lower portion of the lid body 41, and an outer welding portion 43b to be welded to the tank upper wall FTa of the fuel tank FT is formed at the lower end portion of the flange 43. Is formed.

  The float mechanism 50 has a two-stage valve structure with improved restart valve characteristics, and includes a float 52 and an upper valve body 60 disposed on the float 52. The float 52 includes a first float portion 53 and a second float portion 54, which are assembled together. The first float unit 53 includes a first float body 53a. The second float portion 54 has a cylindrical shape and includes a second float body 54b having a storage hole 54a. The first float portion 53 is integrated with the first float portion 53 by being inserted into the storage hole 54a. A step portion on the outer peripheral portion of the first float main body 53 a serves as a spring support portion 53 b and supports the upper end of the spring 70. The spring 70 is disposed between a spring housing gap 52a (FIG. 1), which is a space between the first float portion 53 and the second float portion 54, and between the spring support portion 38c of the bottom member 37. I am passing.

  3 is an exploded perspective view showing the float 52 and the upper valve body 60, and FIG. 4 is a cross-sectional view showing the vicinity of the upper valve body 60. A valve support 55 projects from the upper part of the first float body 53a. The valve support portion 55 is a portion that supports the upper valve body 60 and includes a support protrusion 56 that is a cylindrical protrusion. The upper surface of the support protrusion 56 is a second seal portion 56a that is a flat surface. Further, on the outer peripheral portion of the valve support portion 55, valve-side guide portions 57 for guiding the upper valve body 60 in the up-and-down direction are formed in four ribs at equal intervals in the circumferential direction. The upper part of the valve side guide part 57 is a restricting part 57a extending beyond the upper surface of the second seal part 56a. Further, on the upper surface of the first float portion 53 on the outer peripheral side of the valve support portion 55, there are two engaging claws 58 for retaining the upper valve body 60 (one is shown in FIG. 3). Is formed.

In FIG. 4, the upper valve body 60 is a valve for opening and closing the connection passage 31 b and improving the restart valve characteristics, and is supported so as to be movable up and down with respect to the valve support portion 55 of the float 52. The upper valve body 60 includes a valve main body 62 having a bottomed cylindrical shape and a seat member 64.
The valve main body 62 includes a disk-shaped upper surface portion 62a and a cylindrical side wall 62b protruding from the outer peripheral portion of the upper surface portion 62a, and an inner space thereof serves as a support hole 62c. An attachment portion 62d for attaching the sheet member 64 is formed at the center of the upper surface portion 62a. In addition, four vent holes 62e for connecting the support holes 62c to the outside are formed in the outer periphery of the upper portion of the valve body 62. Two engaging claws 62f that engage with the engaging claws 58 of the float 52 are formed on the inner peripheral wall of the side wall 62b.
The side wall 62b of the valve main body 62 is guided by the upper guide rib 34b on the inner wall of the casing main body 30 at the outer peripheral portion thereof, and the upper and lower range of the upper valve body 60 by the valve side guide portion 57 of the valve support portion 55 at the inner peripheral portion. It is provided so that it may be guided over the full length.

  FIG. 5 is an enlarged half-sectional view of the vicinity of the sheet member 64. The sheet member 64 includes a first sheet portion 64a that is attached to and detached from the first seal portion 31c, a connection hole 64b that passes through the central portion of the first sheet portion 64a and is connected to the support hole 62c, and a lower end of the connection hole 64b. The second sheet portion 64c formed in the portion and the attached portion 64d formed in the outer peripheral portion of the connection hole 64b are integrally formed of a rubber material. The seat member 64 has a gap with respect to the upper surface portion 62a of the valve main body 62 so that the first seat portion 64a is elastically deformed when seated on the first seal portion 31c to enhance the sealing performance.

The seat member 64 is mounted in a state in which the seat member 64 is press-fitted and fitted into the mounting portion 62d of the valve main body 62 at the mounted portion 64d. That is, the attachment portion 62d includes an attachment hole 62g that penetrates the upper surface portion 62a. On the other hand, the attached portion 64d includes an extended portion 64e that extends in the radial direction, and the upper portion 62a is sandwiched between the extended portion 64e and the lower portion of the first sheet portion 64a by being press-fitted into the attachment hole 62g. is doing. Thereby, the seat member 64 is attached to the valve body 62 in a state of being prevented from being removed. At this time, not only the tightening allowance for the mounted portion 64d to be compressed by the mounting portion 62d is set, but a gap Gp is secured between the mounting portion 62d and the mounted portion 64d, Thereby, the elastic deformation of the attached portion 64d is allowed. Therefore, the first sheet portion 64a and the second sheet portion 64c are not elastically deformed in a state where the sheet member 64 is attached to the attachment portion 62d.
Further, the second seat portion 64c hits the lower surface of the upper surface portion 62a of the upper valve body 60 against the regulating portion 57a extending on the upper side of the valve side guide portion 57, so that the elastic deformation amount is within a predetermined range. Is provided.

(3) Operation of the fuel cutoff valve Next, the operation of the fuel cutoff valve 10 will be described. As shown in FIG. 1, when fuel is supplied into the fuel tank FT by refueling, the fuel vapor that has accumulated in the upper part of the fuel tank FT as the fuel liquid level in the fuel tank FT rises is stored in the cylindrical portion 39. From the introduction opening 39b through the introduction passage 39a, it flows into the valve chamber 30S through the flow holes 38a, 38b. Further, the fuel vapor is released from the valve chamber 30S to the canister side through the connection passage 31b and the lid side passage 42a. When the fuel liquid level in the fuel tank FT reaches the predetermined liquid level FL1, the fuel closes the introduction opening 39b, thereby increasing the tank internal pressure in the fuel tank FT. In this state, the differential pressure between the tank internal pressure and the pressure in the valve chamber 30S increases, and the liquid fuel flows into the valve chamber 30S through the introduction passage 39a and the flow holes 38a and 38b, and the fuel liquid level passes through the valve chamber 30S. To rise. As shown in FIG. 6, when the fuel level in the valve chamber 30S reaches the height h0, the upward force due to the buoyancy of the float 52 and the load of the spring 70 and the downward force due to the weight of the float mechanism 50 are reduced. Due to the balance, the former exceeds the latter and the float mechanism 50 is integrally raised, and the seat member 64 of the upper valve body 60 is seated on the first seal portion 31c to close the connection passage 31b. At this time, when fuel accumulates in the inlet pipe and the fuel touches the fuel gun, the auto-stop is activated. 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.

  On the other hand, when the fuel in the fuel tank FT is consumed and the fuel liquid level is lowered, the float 52 is lowered with its buoyancy lowered as shown in FIG. 7, and the second seal portion 56a is moved to the second seat portion. The connection hole 64b is opened away from 64c. Due to the communication of the connection hole 64b, the pressure below the upper valve body 60 becomes the same pressure as the vicinity of the connection passage 31b. Since the engaging claw 58 is engaged with the engaging claw 62f, the upper valve body 60 is pulled down. Then, when the upper valve body 60 is lowered, the seat member 64 is separated from the first seal portion 31c, and the connection passage 31b is opened. At this time, since the connection hole 64b whose passage area is reduced by the separation of the second seat part 64c from the second seal part 56a communicates first, the pressure at the lower part of the upper valve body 60 is reduced, and the upper valve body 60 However, the force in the valve closing direction that closes the connection passage 31b is reduced, so that the restart valve characteristic is excellent.

(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 FIGS. 4 and 5, the restricting portion 57 a provided on the upper portion of the float 52 restricts the vertical distance between the upper valve body 60 and the float 52 so as not to be shorter than the distance ST <b> 0. Thus, since the amount of elastic deformation of the second seat portion 64c is suppressed when the second seat portion 64c is seated on the second seal portion 56a, the second seat portion 64c maintains a high sealing performance over a long period of time. Can do.

(4) -2 The upper valve body 60 is guided by the upper guide rib 34b of the case side guide part 34 on the inner wall of the casing 20 and the valve side guide part 57 on the upper side of the float 52, so that the upper valve body 60 is stable. Ascending and descending operations can be performed.

(4) -3 As shown in FIG. 4, the seat member 64 is attached to the valve body 62 via the attached portion 64d and the attaching portion 62d, but between the attaching portion 62d and the attached portion 64d. Since there is a gap Gp that allows elastic deformation, the elastic deformation of the mounted portion 64d does not reach the first sheet portion 64a and the second sheet portion 64c. Therefore, since the 1st sheet | seat part 64a and the 2nd sheet | seat part 64c cannot be attached in the distorted state, it can exhibit high sealing performance.

(4) -4 The extended portion 64e of the attached portion 64d prevents the seat member 64 from coming off from the valve body 62. Therefore, even if a large fastening margin is not set for the attaching portion 62d and the attached portion 64d, the seat The member 64 does not fall off from the valve body 62.

The present invention is not limited to the above embodiment, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.
Although the restriction part of the above embodiment has been described with respect to the structure formed on the upper part of the float, the present invention is not limited to this, and may be a structure provided on the valve body. Any configuration may be used as long as it is regulated.
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 sectional drawing 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 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 which shows the vicinity of an upper valve body. It is the half sectional view which expanded the neighborhood of a sheet member. It is explanatory drawing explaining operation | movement 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 ... 1st seal part 32 ... Side wall part 32a ... 1st communicating hole 34 ... Case side guide part 34a ... Lower guide rib 34b ... Upper guide rib 37 ... Bottom member 38a, 38b ... circulation hole 38 ... bottom plate 38c ... spring support part 39 ... cylindrical part 39a ... introduction passage 39b ... introduction opening 40 ... lid body 41 ... lid body 42. ..Tube part 42a ... Ladder side passage 43 ... Flange 43a ... Inner welding end 43b ... Outer welding part 50 ... Float mechanism 52 ... Float 52a ... Spring storage gap 53 ... First float part 53a ... First float body 53b ... Spring support part 54 ... Second float part 54a ... Storage hole 54b ... Second float body 55 ... Valve Supporting part 56 ... Supporting projection part 56a ... Second seal part 57 ... Valve side guide part 57a ... Regulating part 58 ... engaging claw 60 ... Upper valve body 62 ... Valve Main body 62a ... Upper surface part 62b ... Side wall 62c ... Support hole 62d ... Mounting part 62e ... Vent hole 62f ... Engaging claw 62g ... Mounting hole 64 ... Sheet member 64a ... first seat 64b ... connection hole 64c ... second seat 64d ... attached part 64e ... expansion part 70 ... spring FT ... fuel tank FTa ... tank Upper wall FTb ... Mounting hole

Claims (2)

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) having a valve chamber (30S) communicating the fuel tank (FT) and the connection passage (31b), and a first seal portion (31c) facing the connection passage (31b);
A float (52) which is housed in the valve chamber (30S) and moves up and down with increasing or decreasing buoyancy depending on the fuel level in the valve chamber (30S);
An upper valve body (60) placed on top of the float (52) and opening and closing the connection passage (31b) by raising and lowering the float (52);
With
Provided on the upper surface of the float (52) is a cylindrical protrusion having an outer diameter smaller than the outer diameter of the float (52), and a support protrusion (56) having a second seal portion (56a) on the upper portion thereof.
The upper valve body (60) includes an upper surface portion (62a) and a circular side wall (62b) protruding from the outer peripheral portion of the upper surface portion (62a). 62b) a valve body (62) which surrounds the support protrusion (56) and is vertically movable with respect to the support protrusion (56), and a rubber attached to the upper surface part (62a). A sheet member (64) made of,
The seat member (64) has a connection hole (64b) having a passage area smaller than that of the connection passage (31b), a first opening and closing the connection passage (31b), and an opening above the connection hole (64b). A sheet part (64a), and a second sheet part (64c) opened and closed by the second seal part (56a) and having an opening below the connection hole (64b),
The support protrusion (56) is provided on the outer periphery of the support protrusion (56) so as to protrude in the vertical direction in a rib shape and slides on the side wall (62b) of the valve body (62). A valve-side guide portion (57) for guiding the body (60) in the vertical direction; a restricting portion (57a) is provided at an upper portion of the valve-side guide portion (57); and the restricting portion (57a) When the seat portion (64c) is seated on the second seal portion (56a), the second seat portion (64c) is regulated to an elastic deformation amount within a predetermined range by hitting the upper surface portion (62a). So as to regulate the vertical distance between the upper valve body (60) and the float (52),
A fuel shut-off valve characterized by The fuel cutoff valve according to claim 1 ,
A case-side guide part (34) for guiding the outer peripheral part of the upper valve body (60) on the inner wall of the casing (20);
The said case side guide part (34) and the said valve side guide part (57) are fuel cutoff valves provided so that an upper valve body (60) may be guided over the full length of the raising / lowering range of the said upper valve body.

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