JP4407534B2 - Fuel shut-off valve - Google Patents

Description

  The present invention relates to a fuel cutoff valve that is attached to an upper portion of a fuel tank and that cuts off communication between the inside and outside of the fuel tank in accordance with the fuel level in the fuel tank.

  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 blocking a small passage area like a rollover valve, it is difficult to sufficiently bend the outer peripheral portion of the rubber valve body, and high sealing performance cannot be obtained. In addition, since the rubber valve body is difficult to peel off from the connection passage in order to open and close the small connection passage, there is a problem that the restart valve characteristic is not good.

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 a high sealing performance even in a narrow connection passage and is excellent in a restart valve performance, in view of solving the problems of the conventional technology. To do.

The present invention made to solve the above problems
A fuel shut-off valve mounted on the top of the fuel tank and shutting off the communication between the inside and outside of the fuel tank;
A valve chamber communicating with the inside of the fuel tank, a connection passage connecting the valve chamber and the outside, and a seal portion projecting toward the valve chamber at an opening peripheral edge of the connection passage. A casing having,
A valve that is housed in the valve chamber and that moves up and down according to the fuel level in the fuel tank, and a seat member that is mounted on the top of the float and is formed of a flexible sheet and has a seat surface. Mechanism,
With
Between the upper surface of the float and the sheet member, a gap having an inner diameter larger than the outer diameter of the seal portion is provided,
The seat member is fixed to the upper portion of the float by a single valve mounting portion formed at the peripheral portion of the seat member , and hits the upper surface of the float at the peripheral portion of the seat member excluding the valve mounting portion. Supported and configured to be elastically deformed to the gap side by being pushed by the seal portion due to the rise of the float when the fuel liquid level exceeds a predetermined fuel liquid level, and to close the connection passage ,
The gap is formed so that the sheet member does not come into contact with the upper surface of the float in the gap when the sheet member is not pushed by the seal part and when the sheet member is pushed by the seal part. It is characterized by this.

  According to the fuel cutoff valve of the present invention, when the buoyancy of the float increases due to the increase of the fuel level in the fuel tank, the seat member sits on the seal portion and closes the connection passage. At this time, when the sheet member is pushed by the seal portion, the sheet member is elastically deformed into a gap provided between the upper surface of the float and the sheet member. Since the gap has an inner diameter larger than the outer diameter of the seal portion, the elastic deformation of the sheet member is not hindered. Therefore, even if the float is tilted and rises, the sheet member is elastically deformed along the seal portion. Therefore, when the diameter of the connection passage is small without generating a gap with the seal portion, for example, φ is 2 In the case of ˜3 mm, high sealing performance can be obtained.

  Further, when the fuel level in the fuel tank is lowered and the float is lowered, the seat member is separated from the seal portion, and the connection passage is opened. At the time of such a restart valve, the seat member is supported at one place away from the center of the float, and therefore, the seat member is partially and sequentially peeled off with a small force with respect to the seal portion, so that the restart valve characteristic is excellent.

  As a preferred embodiment of the present invention, the gap is a recess formed in the upper part of the float, a support protrusion protruding so as to support the peripheral edge of the sheet member from the upper part of the float, or the outer periphery of the sheet member. It can comprise from the support protrusion formed in the part.

  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 FIG. 1 is a sectional view showing a fuel cutoff valve 10 attached to a fuel tank FT according to one embodiment of the present invention. The fuel tank FT is formed by a two-part body made of a metal upper half and a lower half, and is configured by joining them together. The fuel shut-off valve 10 regulates the outflow of fuel when the fuel in the fuel tank FT rises to a predetermined liquid level when the vehicle is tilted or swings. The fuel cutoff valve 10 is attached to the tank upper wall FTa via a bracket FTb.

(2) Configuration of Each Part of Fuel Shutoff Valve 10 FIG. 2 is an exploded sectional view showing the fuel cutoff valve 10. The fuel cutoff valve 10 includes a casing 20, a valve mechanism 40 housed in the valve chamber 30 </ b> S of the casing 20, and a spring 60 that biases the valve mechanism 40 as main components.

  The casing 20 includes a casing main body 30, a tube part 35 attached to the upper portion of the casing main body 30, and a bottom lid 38 attached to the lower portion of the casing main body 30. Thus, the valve chamber 30S is formed. The casing body 30 has a cup shape including a ceiling wall 32 and a cylindrical side wall 33. A connecting passage 32a having a diameter of 2.0 mm passes through the central portion of the ceiling wall 32, and the valve chamber 30S side of the connecting passage 32a serves as a seal portion 32b. The diameter of the seal portion 32b is set to 2.5 mm. The side wall 33 is formed with a vent hole 33a that allows the fuel tank FT and the valve chamber 30S to communicate with each other. Further, a lid passage 35a is formed in the tubular body portion 35, and one end side of the lid passage 35a is connected to the fuel tank FT through the valve chamber 30S, and the other end side is connected through a tube (not shown). Connected to the canister.

  The bottom lid 38 is formed with a communication hole 38a that allows the valve chamber 30S to communicate with the inside of the fuel tank. Therefore, the inside of the fuel tank FT communicates with the valve chamber 30S through the vent hole 33a and the communication hole 38a of the side wall 33. An annular spring support portion 38 b is formed at the center upper portion of the bottom lid 38. The spring support portion 38 b supports the spring 60 between the inner lower surface of the float 50.

  The valve mechanism 40 is housed in the valve chamber 30 </ b> S, and includes a float 50 and a seat member 55 mounted on the top of the float 50. FIG. 3 is an exploded perspective view showing the valve mechanism 40. The float 50 includes a container-shaped float main body 51, and an inner space thereof is a buoyancy chamber 51a (FIG. 2) for generating buoyancy. In addition, a plurality of guide protrusions 51 b are provided on the outer peripheral portion of the float 50 so as to protrude in a plurality of locations in the vertical direction in order to improve the slidability with respect to the inner wall surface of the casing body 30. A mounting hole 52 for attaching the sheet member 55 is formed in the upper part of the float body 51, and a recess 53 for bending the sheet member 55 is formed. The recess 53 is formed with a diameter (diameter 6 mm) larger than the outer diameter (2.5 mm) of the seal portion 32b (see FIG. 2). In addition, on the upper surface of the float main body 51, three grooves 54 are formed so as to be connected to the recess 53 and radially. The grooves 54 discharge the fuel accumulated in the recesses 53 from the recesses 53 and allow the air in the recesses 53 covered with the sheet members 55 to escape so that the seat members 55 are easily bent.

  The seat member 55 is made of a flexible material (rubber material, thermoplastic elastomer, or the like), and includes a disc portion 56 and a valve mounting portion 57 projecting from the outer peripheral lower surface of the disc portion 56. I have. The upper surface of the disc portion 56 is a seat surface 56a that is attached to and detached from the seal portion 32b. Further, the valve mounting portion 57 protrudes in a rod shape from the lower surface of the disc portion 56, and a retaining portion 57a (FIG. 2) is formed on the outer peripheral portion thereof. The valve mounting portion 57 is fixed to the upper portion of the float body 51 by being press-fitted into the mounting hole 52. The seat member 55 is configured to be elastically deformed so as to be recessed toward the recess 53 and to be seated on the seal portion 32b when the seat surface 56a is pushed by the seal portion 32b. The shape of the recess 53 is formed so as not to interfere with the elastic deformation without contacting the upper surface of the recess 53 when the sheet member 55 is bent.

(3) Operation of the fuel cutoff valve Next, the operation of the first fuel cutoff valve will be described. In FIG. 1, 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 vent hole 33a and the communication hole 38a. The valve chamber 30S is released to the canister side through the connection passage 32a and the lid passage 35a. When the fuel level in the fuel tank FT reaches a predetermined fuel level, the fuel flows into the valve chamber 30S through the communication hole 38a of the bottom lid 38. Accordingly, when the former exceeds the latter by the balance between the buoyancy of the float 50 and the upward force due to the load of the spring 60 and the downward force due to the weight of the float 50 and the seat member 55, the float 50 and the seat member 55 and go up together. When the buoyancy of the float 50 increases, the seat surface 56a is seated on the seal portion 32b and the connection passage 32a is closed in a state where the sheet member 55 is pushed by the seal portion 32b as shown in FIG. Thus, when the sheet member 55 is pushed by the seal portion 32b, the sheet member 55 is elastically deformed toward the inside of the recess 53 having an outer diameter larger than the outer diameter of the seal portion 32b at the upper center portion of the float 50. At this time, since the recess 53 has an outer diameter larger than that of the seal portion 32b, the elastic deformation of the sheet member 55 is not hindered. Therefore, even if the float 50 is tilted and lifted as shown in FIG. 5, the sheet member 55 is elastically deformed along the seal portion 32b, so that a high sealing performance can be obtained without generating a gap with the seal portion 32b. Obtainable.

  On the other hand, when the fuel level in the fuel tank FT decreases, the fuel in the valve chamber 30S is discharged from the communication hole 38a, the float 50 descends, the seat member 55 is separated from the seal portion 32b, and the connection passage 32a is opened. The fuel tank FT communicates with the canister. At the time of the resumption valve, as shown in FIG. 6, the seat member 55 is supported by the valve mounting portion 57 at one place away from the center portion of the float 50. It is excellent in restart valve characteristics because it peels off gradually and sequentially.

  Next, the reason why the sheet member 55 according to the embodiment can be sufficiently bent and the degree of freedom in design can be increased will be described with reference to FIG. FIG. 7A shows the periphery of the sheet member 100, the float 102, the seal portion 104, and the connection passage 106 corresponding to the conventional technology. FIG. 7B shows the periphery of the sheet member 55 and the seal portion 32b according to the present embodiment. In the conventional technique of FIG. 7A, when the diameter of the tip portion where the sheet member 100 contacts the seal portion 104 is D1 (2.5 mm) and the inner diameter of the connection passage 32a is d1 (2 mm), the sheet member. The parameter indicating the ease of bending 100 is the distance L1 from the position of the sheet member 100 that contacts the seal portion 104 to the center of the sheet member 100. The sheet member 100 is bent toward the inside of the connection passage 106 by being pressed by the seal portion 104. In the prior art, when the diameter D1 of the seal portion 104 is small, the distance L1 cannot be increased. Therefore, in order to improve the sealing performance by sufficiently bending the sheet member 100 and closely contacting the seal portion 104 Further, a configuration such as reducing the thickness of the sheet member 100 or using a rubber material that can be easily deformed is required, and the degree of freedom in design is low. On the other hand, in the present embodiment of FIG. 7B, the parameter indicating the ease of bending of the sheet member 55 is that the end of the recess 53 (diameter D2 is 6 mm) and the sheet member 55 are in contact at the seal portion 32b. Represented by a distance L2. The distance L2 can be easily dealt with by increasing the outer diameter of the sheet member 55 or the recess 53 as a parameter independent of the diameter D1. Therefore, in this embodiment, even when the diameter D1 of the seal portion 104 is small, it can be easily handled by increasing the sheet member 55 and the like without considering other factors such as the elasticity of the rubber material. Can be designed with a high degree of design freedom.

  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.

FIG. 8 is an exploded perspective view showing a valve mechanism according to another embodiment, and FIG. 9 is a cross-sectional view illustrating a state when the valve mechanism according to another embodiment is closed. This embodiment is characterized by the structure of the upper part of the float for elastically deforming the sheet member. On the upper surface of the float 50B, there are formed substantially C-shaped support protrusions 54B which are divided into a plurality of slits 54Ba for removing liquid and air. An inner space of the support protrusion 54B is a gap 53B for bending the sheet member 55B. A mounting hole 52B for attaching the sheet member 55B is formed in the opening of the support protrusion 54B. According to this embodiment, as shown in FIG. 9, the sheet member 55B can close the connection passage 32Ba by elastically deforming toward the gap 53B formed by the support protrusion 54B.
FIG. 10 is a cross-sectional view showing a sheet member according to another embodiment. 8 and 9, the support protrusion is formed on the upper surface of the float. However, the present invention is not limited to this, and the support protrusion 55Ca is formed on the outer periphery of the sheet member 55C as shown in FIG. You may comprise so that a space | gap may be formed between upper surfaces.

The seat member in the above embodiment is attached by providing a mounting hole in the upper part of the float. However, the present invention is not limited to this, and a structure in which a support part protrudes from the upper part of the float and is attached thereto may be used. According to this configuration, it is easy to improve the sealing performance of the buoyancy chamber of the float.
Further, in FIG. 3 described in the above embodiment, a rough surface or slit is formed on the back surface of the sheet member 55 by embossing, or on the outer peripheral surface of the recess 53 which is the upper surface of the float 50 and the sheet member 55 contacts. You may form unevenness, such as a rough surface and a slit by embossing. Such unevenness can prevent the sheet member 55 from sticking to the upper surface of the float 50.
Furthermore, the fuel cutoff valve of the above embodiment has been described with respect to the in-tank type configuration installed in the fuel tank. However, the configuration is not limited to this, and the fuel cutoff valve is attached to the outer surface of the upper wall of the fuel tank by screwing or welding. The structure which rushes in a fuel tank may be sufficient.

It is sectional drawing which shows the fuel cutoff valve attached to the fuel tank concerning one Example of this invention. It is sectional drawing which decomposes | disassembles and shows a fuel cutoff valve. It is a perspective view which decomposes | disassembles and shows a valve mechanism. It is explanatory drawing explaining operation | movement of a fuel cutoff valve. It is explanatory drawing explaining the effect | action at the time of valve closing of a fuel cutoff valve. It is explanatory drawing explaining the effect | action at the time of the restart valve of a fuel cutoff valve. It is explanatory drawing explaining the effect | action of a fuel cutoff valve. It is a perspective view which decomposes | disassembles and shows the valve mechanism concerning another Example. It is sectional drawing explaining the state at the time of valve closing concerning another Example. It is sectional drawing which shows the sheet | seat member concerning another Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Fuel shutoff valve 20 ... Casing 30 ... Casing main body 30S ... Valve chamber 32 ... Ceiling wall 32a ... Connection passage 32b ... Seal part 33 ... Side wall 33a .. Ventilation hole 35 ... Tube part 35a ... Lid passage 38 ... Bottom lid 38a ... Communication hole 38b ... Spring support part 40 ... Valve mechanism 50 ... Float 51 ... Float body 51a ... Buoyancy chamber 51b ... Guide protrusion 52 ... Mounting hole 53 ... Recess 54 ... Groove 55 ... Sheet material 56 ... Disk part 56a ... Sheet Surface 57 ... Valve mounting part 57a ... Stopping part 60 ... Spring FT ... Fuel tank FTa ... Tank upper wall FTb ... Bracket 32Ba ... Connection passage 50B ... Float 52B. .. Mounting hole 53B ... Gap 54B ... Supporting protrusion 55B ... Sheet member 55C ... Sheet member 55Ca ... Supporting protrusion

Claims (4)

A fuel cutoff valve that is mounted on the upper part of the fuel tank (FT) and that cuts off communication between the inside and outside of the fuel tank (FT).
A valve chamber (30S) communicating with the inside of the fuel tank, a connection passage (32a) connecting the valve chamber (30S) and the outside, and an opening peripheral portion of the connection passage (32a), 30S) a casing (20) having a seal portion (32b) projecting toward the side,
A float (50) which is housed in the valve chamber (30S) and moves up and down in accordance with the fuel level in the fuel tank, and a sheet which is mounted on the top of the float (50) and has flexibility. A valve member (40) having a seat member (55) having a surface (56a);
With
Between the upper surface of the float (50) and the sheet member (55), a gap having an inner diameter larger than the outer diameter of the seal portion (32b) is provided.
The seat member (55) is fixed to the upper portion of the float (50) by a single valve attachment portion (57) formed at the peripheral edge of the seat member (55) , and the valve attachment portion (57). The sheet member (55) excluding the upper surface of the float (50) is supported by the peripheral edge of the seat member (55), and when the fuel liquid level exceeds a predetermined fuel liquid level, the float (50) rises to raise the seal part ( 32b) is configured to be elastically deformed to the gap side by being pushed and to close the connection passage (32a) ,
When the sheet member (55) is not pressed by the seal portion (32b) and when the sheet member (55) is pressed by the seal portion (32b), the gap is formed by the sheet member (55). Formed so as not to contact the upper surface of the float (50);
A fuel shut-off valve characterized by The fuel cutoff valve according to claim 1,
The said air gap is a fuel cutoff valve formed of the recess (53) formed in the upper part of the said float 50. As shown in FIG. The fuel cutoff valve according to claim 1,
The air gap is a fuel cutoff valve configured by a support protrusion (54B) that protrudes from the upper part of the float (50B) to support the peripheral edge of the seat member (55B). The fuel cutoff valve according to claim 3,
The said air gap is a fuel cutoff valve formed from the support protrusion (55Ca) formed in the outer peripheral part of the said sheet | seat member (55C).

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