JP4305256B2 - 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 cutoff valve, patent document 1 etc. are known and it is a structure as shown in FIG. FIG. 11 is a cross-sectional view showing the fuel cutoff valve 100 mounted on the upper portion of the fuel tank. The fuel cutoff valve 100 includes a casing 110 having a valve chamber 110S that communicates the inside and outside of the fuel tank, 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, and an upper part of the float 120. A spring 122 placed, a first valve body 124 placed on the upper end of the spring 122, and a second valve body 126 placed in the upper center of the float 120 are provided.

  In the configuration of the fuel shut-off valve 100, when the fuel level in the fuel tank exceeds the first fuel level due to refueling, the float 120 rises and the first valve body 124 becomes the first connection passage. 112b is closed, and when the second fuel liquid level that is higher than the first fuel liquid level is exceeded, the second valve body 126 resists the urging force of the spring 122 and the second fuel liquid level. The connection passage 131a is closed. The passage area of the second connection passage 131a is narrower than that of the first connection passage 112b, that is, the passage area is narrowed in two steps according to the fuel level, so that the fuel tank is not abruptly sealed. Further, it is possible to prevent the fuel from blowing back at the fuel filler opening.

  However, since the fuel cutoff valve 100 determines the second fuel liquid level at which the second valve body 126 is closed by the load of the spring 122, a great amount of labor is required for setting the load of the spring 122 and the assembly process. It was.

  As another technique, a configuration is known in which supercharging is prevented by sequentially opening and closing two connection passages with two rubber valve bodies (Patent Document 2). However, in this configuration, since two rubber valve bodies are used, the configuration becomes complicated, and the restart valve characteristics are not good.

JP 2000-130271 A JP-A-7-280117

  An object of the present invention is to provide a fuel shut-off valve that can prevent fuel blow-back during refueling with a simple configuration in view of the above-described problems of the conventional technology.

The present invention made to solve the above problems
In the fuel shut-off valve that is attached to the top of the fuel tank and cuts off the communication between the inside and outside
A casing having a valve chamber communicating with the fuel tank;
A first connection passage that is provided in an upper portion of the casing and connects the valve chamber and the outside, and a second connection passage having a smaller opening area than the first connection 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 seat member that is mounted on the top of the float and is formed of a single flexible sheet and has a seat surface; A valve body mechanism having
With
In the seat member, when the fuel level rises to the first fuel level, the seat surface closes the first connection passage by the rise of the float, and the fuel level becomes the first fuel level. It is characterized in that the seat member is bent and the seat surface closes the second connecting passage when the fuel level rises to a second fuel level higher than the fluid level.

  When fuel is supplied to the fuel tank using the fuel shutoff valve according to the present invention, the fuel vapor accumulated in the upper part of the fuel tank as the fuel liquid level in the fuel tank rises is connected to the first and second connections. It escapes to the canister side through the passage. When the fuel level in the fuel tank reaches a predetermined first fuel level, the float rises due to buoyancy and closes the first connection passage on the seat surface of the seat member. Thereby, the tank internal pressure rises and the fuel level in the filler pipe rises.

  At this time, the sensor detects an increase in the tank internal pressure, or by detecting that the fuel in the filler pipe has reached the fuel supply gun, an automatic stop for stopping the fuel supply of the fuel gun can be activated. Even if the connection passage is closed, the second connection passage is secured, so that the tank internal pressure does not rise rapidly, and the accompanying fuel blowback can be prevented.

  When the fuel level reaches the second fuel level when the fuel is further supplied, the float is further raised, and the seat member is pressed by the second seal portion to bend and the seat surface becomes the second connection passage. Close. Thereby, the inside of the fuel tank is sealed with respect to the canister side to prevent the fuel from flowing out.

  In the fuel cutoff valve according to the present invention, one sheet member is seated on the first seal portion and the second seal portion at different fuel liquid levels, and the first connection passage and the second connection passage are sequentially provided. Since it is configured to be closed, there is no need to use a two-stage float or a spring as described in the prior art, the configuration is simple, and the assembly process is simplified. At the same time, it is not necessary to adjust the spring load.

  Further, since the opening area of the second connection passage is smaller than that of the first connection passage, the seat member is closed via the second connection passage when the fuel level in the fuel tank decreases. The pressure receiving area that receives the differential pressure in the valve direction is small. In addition, when the seat member is seated on the first and second seal portions, an elastic force is generated to lower the float by elastic deformation. Therefore, since the float descends quickly and the seat member opens the second connection passage, the fuel cutoff valve according to the present invention smoothly performs the valve opening operation of opening the first and second connection passages from the closed state. Excellent restart valve characteristics. In addition, a single sheet member may be used to improve the restart valve characteristics, and the two-stage structure of the float as described in the prior art is unnecessary, and the configuration can be simplified.

  As a preferred aspect of the fuel cutoff valve according to the present invention, a first seal portion and a second seal portion are formed on the valve chamber side of the first connection passage and the second connection passage, The seal portion is formed in a circular shape, and the second seal portion can be formed on a concentric circle of the first seal portion and with a larger diameter than the first seal portion.

  As another preferred aspect, the float includes a support portion that supports the sheet member at an upper portion of the float, and the support portion includes an outer peripheral support protrusion that supports the outer peripheral portion of the sheet member, and the outer periphery. The structure provided with the recess which accept | permits that the sheet | seat member supported by the support protrusion deform | transforms elastically can be taken.

  Furthermore, as a preferred embodiment, the sheet member is flexible and has a shape that can close the first and second connection passages in two stages. It can comprise from the hollow body to form.

  Moreover, as a suitable aspect of a 1st seal | sticker part and a 2nd seal | sticker part, what is necessary is just the shape and arrangement | positioning which can seat a sheet | seat member in two steps corresponding to the shape of a sheet | seat member. In addition to being arranged at different positions, at least one second connection passage can be formed, and the second connection passage can be formed to be seated on the seat member independently by the second seal 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 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 operates to automatically stop the fueling gun when the fuel in the fuel tank FT rises to the first fuel liquid level FL1 (full tank liquid level) during refueling, and the first fuel liquid level. The fuel is supplied beyond FL1 and is closed when the second fuel liquid level FL2 (supercharged liquid level) is exceeded, and the outflow of fuel to the outside is regulated.

 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 and operation 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. FIG. 3 is an enlarged view of the upper protrusion 32a as viewed from below. A first connection passage 32b and a second connection passage 32c pass through the upper protrusion 32a, and the valve chamber 30S side of the first and second connection passages 32b and 32c is the first seal portion 32d and This is the second seal portion 32e. The first seal portion 32d is formed in an annular shape. The second seal portion 32e is formed on a concentric circle of the first seal portion 32d and has a larger diameter than the first seal portion 32d, and is formed at a position above the first seal portion 32d. (Fig. 2).

  Returning to FIG. 2, the side wall 33 is attached to the lid 40 at a communication hole 33 a for communicating the valve chamber 30 </ b> S and the fuel tank FT, an engagement hole 33 b for attaching the bottom support plate 35 to the lower part thereof. And a flange portion 33c. 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 part 42 protruding 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 tube passage 42a is formed in the tube portion 42, and one end of the tube passage 42a is connected to the first and second connection passages 32b and 32c of the casing body 30, and the other end is connected. Connected to the canister. Further, 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. The welding surface 44 is formed so as to be welded to the flange portion 33c of the casing body 30, and for example, maleic acid-modified polyethylene 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 body 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 mounted on the top of the float 51. The float 51 is formed 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.

The float 51 includes a support portion 54 that supports the sheet member 55 on the top of the float 51. FIG. 4 is an enlarged sectional view showing the vicinity of the support portion 54 and the sheet member 55. The support portion 54 includes an annular outer periphery support protrusion 54a, the inside of which is a recess 54b, and the lower end of the outer periphery support protrusion 54a is a support lower end portion 54c having a reduced diameter.
The sheet member 55 is formed in a cup shape opened downward from a flexible material (rubber material, thermoplastic elastomer, etc.), that is, an upper surface portion 55a, a side wall portion 55b, and a reduced diameter attachment portion. 55c and is attached to the support portion 54 by inserting the support portion 54 into the inner space. The upper surface portion 55a includes a seat surface 55d that is attached to and detached from the first and second seal portions 32d and 32e. When the seat surface 55d is pushed by the first seal portion 32d, the seat member 55 is elastically deformed so as to be recessed in the recess 54b and is seated on the second seal portion 32e (see FIG. 6).

(3) Operation of the fuel cutoff valve 10 Next, the opening / closing operation of the fuel cutoff valve 10 will be described. In FIG. 1, when fuel is supplied to the fuel tank FT, the fuel vapor accumulated in the upper part of the fuel tank FT as the fuel liquid level in the fuel tank FT rises is connected to the communication hole 33 a of the casing body 30, the valve chamber. 30S, the first and second connection passages 32b and 32c, and the tube passage 42a are released to the canister side. When the fuel level in the fuel tank FT reaches the predetermined first fuel level FL1, the fuel flows into the valve chamber 30S through the communication hole 35b of the bottom support plate 35. Accordingly, due to the balance between 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, the float 51 rises when the former exceeds the latter, and FIG. As shown, the seat surface 55d of the seat member 55 is seated on the first seal portion 32d to close the first connection passage 32b. As described above, when fuel is supplied 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.

  At this time, since the second seal portion 32e is provided above the first seal portion 32d, the seat surface 55d of the sheet member 55 is not seated on the second seal portion 32e. Thus, the fuel tank FT communicates with the canister side through the second connection passage 32c. Since the passage area in this state is narrowed by the amount of the first connection passage 32b, the tank internal pressure increases. This increase in tank internal pressure is detected by the fuel gun, and an auto-stop that stops the fuel supply of the fuel gun is activated. Thus, even when the first connection passage 32b is closed when the fuel level in the fuel tank FT reaches the first fuel level FL1, the second connection passage 32c is secured. In addition, the tank internal pressure does not rise rapidly, and the fuel blow-back associated therewith does not occur.

  When the fuel level further reaches the second fuel level FL2 and the buoyancy of the float 51 increases, the seat member 55 is pushed by the first seal portion 32d as shown in FIG. It is elastically deformed so as to curve toward the point 54b. Then, the outer peripheral portion of the seat surface 55d of the seat member 55 is seated on the second seal portion 32e, and the seat surface 55d closes the second connection passage 32c. Thereby, since the inside of the fuel tank FT is sealed with respect to the canister side, the tank internal pressure further rises and the fuel supply by the fuel gun stops. Therefore, according to the fuel cutoff valve 10, the fuel tank FT is closed with respect to the canister side in two stages during refueling. Therefore, even if the fuel level reaches the first fuel level FL1, which is almost full. When the fuel level reaches the second fuel level FL2, which is the supercharged liquid level, fuel supply by the fuel gun is stopped. can do.

  On the other hand, when the fuel in the fuel tank FT is consumed and the fuel level is lowered, the float 51 reduces its buoyancy. In the state of FIG. 6, the pressure receiving area formed by the space formed between the first seal portion 32d and the second seal portion 32e is smaller than the pressure receiving area of the first connection passage 32b. The member 55 receives a small force in the valve closing direction received by the second connection passage 32c, and when the member 55 is seated on the first seal portion 32d and the second seal portion 32e, it lowers the float 51 by the elastic force. The power to make is generated. Therefore, the sheet member 55 quickly opens the second connection passage 32c. Due to the communication of the second connection passage 32c, the pressure below the seat member 55 becomes the same pressure as the vicinity of the first connection passage 32b through the second connection passage 32c. As the pressure difference becomes smaller in this manner, the force with which the sheet member 55 comes into close contact with the first seal portion 32d is weakened, so that the sheet member 55 is smoothly lowered. In this way, the seat member 55 functions to promote the improvement of the restart valve characteristic that allows the float 51 to be opened smoothly.

  The configuration of the fuel cutoff valve 10 of the above embodiment has the following effects.

(4) -1 In the fuel cutoff valve 10 according to the above embodiment, the first sheet member 55 is seated on the first seal portion 32d and the second seal portion 32e at different fuel liquid levels. Since it is configured to sequentially close the connection passage 32b and the second connection passage 32c, as described in the related art, there is no need to use a two-stage float or use a plurality of springs. The structure is simple, the assembly process is simplified, and adjustment of the spring load is not necessary.

(4) -2 When the fuel liquid level in the fuel tank FT is lowered, the seat member 55 applies an elastic force that lowers the float 51 by the curved elastic deformation, so that the float 51 is quickly lowered to the second position. Since the connection passage 32c is opened, it is possible to improve the restart valve characteristic for smoothly performing the valve opening operation for opening the first and second connection passages 32b and 32c from the closed state. In addition, in this embodiment, one sheet member 55 may be used to improve the restart valve characteristic, and the two-stage structure of the float as described in the prior art is not necessary, and the configuration can be simplified. it can.

  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. 7 and 8 are cross-sectional views showing the upper part of the fuel cutoff valve 10B according to the second embodiment. The second embodiment is characterized by a curved sheet member 55B. The sheet member 55B is a hollow body that has an elliptical curved surface facing upward and has a space inside, and is supported by the support portion 54B of the float 51B with an attachment portion 55Bc. On the other hand, a first seal portion 32Bd and a second seal portion 32Be are formed in the upper protruding portion 32Ba of the ceiling wall portion 32B. The first seal portion 32Bd is disposed above the second seal portion 32Be.

When the fuel level reaches the first fuel level FL1, the seat member 55B is seated on the first seal portion 32Bd to close the first connection passage 32Bb, and the fuel gun auto-stops. At this time, since the seat member 55B is not seated on the second seal portion 32Be and the inside of the fuel tank is connected to the outside through the second connection passage 32Bc, further supercharging can be performed. When the fuel level reaches the second fuel level FL2 due to supercharging, as shown in FIG. 8, the seat member 55B is pushed by the first seal portion 32Bd to expand in the horizontal direction, and the second seal Sit on the part 32Be. Thereby, 2nd connection channel | path 32Bc is closed and the oil supply by an oil supply gun can be stopped.
In addition, as a sheet | seat member, if it is the curved surface shape which closes two seal parts in steps, various shapes, such as a hemisphere, can be taken.

(5) -2 FIG. 9 is a cross-sectional view showing the main part of the fuel cutoff valve 10C according to the third embodiment. FIG. 10 is a view of the upper protrusion 32Ca as viewed from below. The third embodiment is characterized by the shape of the second seal portion 32Ce formed on the upper protruding portion 32Ca. That is, the first connecting passage 32Cb is arranged in a circular cross section in the upper projecting portion 32Ca of the ceiling wall portion 32C, and the first seal portion 32Cd is formed in an annular shape on the valve chamber 30S side of the first connecting passage 32Cb. Has been. In addition, four second connection passages 32Cc are arranged so as to surround the center of the first connection passage 32Cb. Each of the second connection passages 32Cc is a long hole in cross section, and a second seal portion 32Ce is formed in a tubular shape so as to protrude downward so as to surround the long hole. The seat member 55 closes the first connection passage 32Cb by sitting on the first seal portion 32Cd, and closes each second connection passage 32Cc by sitting on the four second seal portions 32Ce simultaneously. According to the third embodiment, since the seat member 55 is directly seated on the second seal portion 32Ce surrounding the second connection passage 32Cc, the seat member 55 has the pressure receiving area by the second connection passage 32Cc in the first implementation. Compared to the example, it can be made smaller, so that the restart valve characteristic can be further improved.

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 the figure which expanded the upper protrusion part provided in the casing main body seeing from the downward direction. It is sectional drawing which expands and shows the upper part of a float and the vicinity of 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 sectional drawing which shows the upper part of the fuel cutoff valve concerning a 2nd Example. It is explanatory drawing explaining operation | movement of the fuel cutoff valve concerning a 2nd Example. It is sectional drawing which shows the principal part of the fuel cutoff valve concerning a 3rd Example. It is the figure which looked at the upper protrusion provided in the casing body concerning the 3rd example from the lower part. It is sectional drawing which shows the upper part of the conventional fuel cutoff valve.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fuel cutoff valve 10B ... Fuel cutoff valve 10C ... Fuel cutoff valve 20 ... Casing 30 ... Casing main body 30S ... Valve chamber 30a ... Bottom opening 32 ... Ceiling wall Part 32B ... Ceiling wall part 32C ... Ceiling wall part 32a ... Upper protrusion part 32Ba ... Upper protrusion part 32Ca ... Upper protrusion part 32b ... First connection passage 32Bb ... No. 1 connection passage 32Cb ... 1st connection passage 32c ... 2nd connection passage 32Bc ... 2nd connection passage 32Cc ... 2nd connection passage 32d ... 1st seal part 32Bd ... first seal portion 32Cd ... first seal portion 32e ... second seal portion 32Be ... second seal portion 32Ce ... second seal portion 33 ... side wall 33a ... Communication hole 33b ... engagement hole 33c ... flange 35 ... bottom support plate 35a ... engagement claw 35b ... communication hole 40 ... lid body 41 ... lid body 42 ... Tube part 42a ... Tube body Path 43 ... Flange 43a ... Annular weld 44 ... Weld surface 50 ... Valve body mechanism 51 ... Float 51B ... Float 51S ... Buoyancy chamber 51a ... Guide protrusion 52 ... Upper wall part 53 ... Side wall part 54 ... Support part 54B ... Support part 54a ... Outer peripheral support projection 54b ... Recessed part 54c ... Support lower end part 55 ... Seat Member 55B ... Seat member 55a ... Upper surface part 55b ... Side wall part 55c ... Reduced diameter attachment part 55Bc ... Attachment part 55d ... Seat surface 60 ... Spring FT ... Fuel tank FTa ... Tank upper wall FTc ... Mounting hole

Claims (7)

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);
The first connection passage (32b) that is provided in the upper part of the casing (20) and connects the inside and outside of the valve chamber (30S) and the second connection having a smaller opening area than the first connection passage (32b). A passage (32c);
A float (51) that 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 flexible sheet that is attached to the top of the float (51). A valve member mechanism having a sheet member (55) formed of a sheet having a sheet surface (55d),
With
When the fuel liquid level rises to the first fuel liquid level (FL1), the seat member (55) moves the seat surface (55d) to the first connecting passage ( 32b) is closed, and when the fuel level rises to a second fuel level (FL2) higher than the first fuel level (FL1), the seat member (55) bends and the seat surface ( 55d) is formed so as to close the second connection passage (32c). The fuel cutoff valve according to claim 1,
A first seal portion (32d) and a second seal portion (32e) are formed on the valve chamber (30S) side of the first connection passage (32b) and the second connection passage (32c). ,
The first seal portion (32d) is formed in a circular shape, and the second seal portion (32e) is on the concentric circle of the first seal portion (32d) and more than the first seal portion (32d). A fuel shut-off valve with a large diameter. The fuel cutoff valve according to claim 1 or 2,
The second seal portion (32e) is a fuel cutoff valve formed above the first seal portion (32d). The fuel cutoff valve according to any one of claims 1 to 3,
The float (51) includes a support portion (54) for supporting the sheet member (55) on the top of the float (51).
In the support portion (54), the outer peripheral support protrusion (54a) that supports the outer peripheral portion of the sheet member (55) and the sheet member (55) supported by the outer peripheral support protrusion (54a) are elastically deformed. A fuel shut-off valve provided with a recess (54b) that permits this. The fuel cutoff valve according to claim 1 or 2,
The said seat member (55B) is a fuel cutoff valve formed from the hollow body which made the outer surface curved. The fuel cutoff valve according to claim 5,
The first seal portion (32Bd) is a fuel cutoff valve formed above the second seal portion (32Be). The fuel cutoff valve according to claim 1,
A first seal portion (32Cd) and a second seal portion (32Ce) are formed on the valve chamber (30S) side of the first connection passage (32Cb) and the second connection passage (32Cc). And
At least one second connection passage (32Cc) is formed, and each second connection passage (32Cc) is seated on the seat member (55) independently by the second seal portion (32Ce). The fuel shut-off valve is formed as follows.

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