KR20090079160A - Valve device - Google Patents

Abstract

A valve device is provided to close a connecting hole according to a float valve when the surface of liquid fuel in a fuel tank raises and open a check value to discharge fuel vapor to outside when the pressure of the fuel tank increases. A valve device includes a float room(R1), a valve case, a float valve(50), a check valve(60), and a connecting hole(25). The float room is connected with a fuel tank through a barrier(23). The valve case includes a ventilation chamber connected with the outside of the tank. The float valve is arranged in the float room. The check valve is arranged in the ventilation chamber. The connecting hole is formed at the barrier to connect the float room with the ventilation chamber. A portion surrounding the bottom of the connecting hole forms a first valve seat(27) which comes into contact with and is separated from the float valve and a portion surrounding the top of the connecting hole forms a second valve seat(71) which comes into contact with and is separated from the check valve.

Description

VALVE DEVICE {VALVE DEVICE}

The present invention provides a float valve installed in a fuel tank of an automobile or the like, which prevents fuel swinging due to turning or tilting of the vehicle to leak out of the fuel tank, and a shank that sends fuel steam to the canister according to the pressure in the fuel tank. A valve device provided with a valve.

Fuel tanks, such as an automobile, are provided with a cut valve that prevents the fuel, which swings due to turning and tilting of the vehicle, from leaking to the outside of the tank. The communication port opened and closed by the cut valve communicates with the canister disposed outside the tank with the check valve interposed therebetween.

As a check valve, for example, Patent Document 1 below discloses a communication port communicating with a fuel tank interior, a cylindrical wall formed on an outer circumference of the communication port, and a spherical check valve disposed inside the cylindrical wall. A valve device provided is disclosed. In this valve device, the spherical shank valve always contacts the communication port communicating with the fuel tank to close the communication port. When the pressure in the fuel tank rises above a predetermined value, a spherical check valve rises from the communication port, and the fuel vapor generated in the fuel tank is sent to the canister through the communication port, so that the pressure in the fuel tank can be kept normal. Will be.

Moreover, the valve apparatus which has a cut valve and a check valve is also known. For example, in Patent Document 2, an opening is provided in a housing upper wall in which a float valve is housed, a mount having a nozzle communicating with the outside is provided so as to surround the opening, and a disc shaped check valve is provided on the inner circumference of the mount. The fuel vapor control valve which arrange | positions, the float valve folded around the lower surface of the said opening, and the said check valve was folded around the upper surface of the said opening is disclosed. In this valve device, when the liquid level rises, the opening is closed by a float valve to prevent the fuel from leaking to the outside of the tank.When the fuel vapor pressure in the tank rises, the check valve is opened so that the fuel vapor is sent through the nozzle to the canister. It is.

Patent Document 1: US Patent No. 5,253,668

Patent Document 2: US Patent No. 6,758,235

In the valve device, when a spherical valve such as that disclosed in Patent Document 1 is employed as the check valve, the thickness in the height direction increases, so that the size of the valve device is difficult. In addition, since the check valve has a spherical shape, there is a problem that the gap between the check valve outer periphery and the circumferential wall holding the check valve cannot be sufficiently secured and the fuel vapor cannot be discharged smoothly from the fuel tank.

In addition, the valve apparatus of the said patent document 2 has the advantage that the thickness of a height direction can be made thin by using a disc shaped shank valve, However, when the clearance gap of a check valve and the circumferential wall surrounding it is small, When the check valve was inclined due to turning or tilting, the check valve engaged with the circumferential wall, and there was a risk of not smoothly sliding up and down. In addition, when the clearance between the check valve and the circumferential wall is increased, it causes rattling and abnormal sound, and there is a problem in that the housing is easily worn or broken.

Accordingly, it is an object of the present invention to provide a valve device in which a float valve and a check valve are closed, the apparatus can be miniaturized, and the check valve can be operated reliably.

In order to achieve the above object, the first aspect of the present invention is a valve case provided with a float chamber communicating with the fuel tank inside downward through a partition wall, a ventilating chamber communicating with the outside of the tank, and the elevator chamber can be lifted up and down. The float valve, the check valve disposed in the ventilating chamber, and the partition wall so that the float chamber and the ventilating chamber communicate with each other, and the lower periphery forms a first valve seat in which the float valve is folded. And a communication port constituting a second valve seat in which the shank valve is folded, and a cylindrical wall surrounding the communication port is formed on an upper surface of the partition wall side of the partition wall, and the shank valve is a polygonal plate. And a valve device configured to be movable up and down inside the tubular wall and configured to always contact the second valve seat. To provide.

According to the above invention, when the fuel in the fuel tank fluctuates and the fuel liquid level rises, the float valve rises, contacts the first valve seat, closes the communication port, and prevents leakage of the fuel to the outside. In addition, when the pressure in the fuel tank is increased, the check valve is pushed up to the pressure at the bottom of the communication port to rise in the cylindrical wall, and the communication port is opened from the second valve seat to open the fuel vapor in the fuel tank. The pressure in the fuel tank is maintained at a predetermined value through the air chamber and discharged to an external flow path communicating with the canister. In addition, in this invention, since the check valve has a polygonal plate shape, the contact area with respect to the cylindrical wall inner periphery is small. For this reason, the slide resistance at the time of raising and lowering the shank valve in the cylindrical wall becomes small, and it is difficult for the shank valve to mesh with the inner circumference of the cylindrical wall. As a result, the check valve can be raised and lowered smoothly and reliably. In addition, when the shank valve moves up and down inside the cylindrical wall, wear of the inner wall of the cylindrical wall and the shank valve itself is reduced, and the shank valve rotates in the cylindrical wall due to the turning or tilting of the vehicle. Since there is little or no rattling, wear or damage of the cylindrical wall or the check valve itself can be suppressed. Since the check valve has a polygonal plate shape, a relatively large gap can be secured between the outer circumference of the check valve and the inner circumference of the cylindrical wall, so that the ventilation resistance of the fuel vapor can be made small and flow smoothly. have.

2nd of this invention WHEREIN: In the said 1st invention, the said shank valve provides the valve apparatus in which the polygonal plate shape is carried out, and the upper and lower edge parts of the outer periphery are chamfered in taper shape.

According to the above invention, since the upper and lower corner portions of the shank valve outer periphery are chamfered in a tapered shape, the contact area with respect to the cylindrical inner wall of the shank valve becomes smaller. As a result, the shank valve is less likely to engage with the cylindrical wall inner circumference, and the sliding resistance of the shank valve is smaller, which makes it possible to move up and down smoothly, thereby reducing the wear of the cylindrical wall inner circumference and the shank valve itself.

According to the valve device of the present invention, when the fuel liquid level in the fuel tank rises, the communication port is closed by the float valve, and when the pressure in the fuel tank is increased, the check valve can be opened to discharge the fuel vapor to the outside. Since the check valve has a polygonal plate shape, the contact area with the inner circumference of the cylindrical wall is reduced, thereby reducing sliding resistance and making it difficult to engage the inner circumference. Can be done. In addition, since the gap between the check valve and the cylindrical wall can be taken widely, the fuel vapor can be smoothly flowed. Furthermore, since the check valve has a plate shape, the valve device can be miniaturized.

EMBODIMENT OF THE INVENTION Hereinafter, 1st Embodiment of the valve apparatus of this invention is described with reference to FIGS.

As shown in FIG. 1 and FIG. 2, the valve device 10 includes a case body 20, a lower cap 30 attached to a lower opening of the case body 20, and a case body 20. The valve case 15 which consists of an upper cap 40 attached to the upper side is provided. The internal space formed by the case main body 20 and the lower cap 30 mounted below the float main body Rl is provided so that the float valve 50 which will be described later can be lifted, and the case main body ( 20) and the internal space formed by the upper cap 40 attached to the upper part is provided with the ventilation chamber R2 in which the shank valve 60 mentioned later is arrange | positioned so that elevation is possible. The float chamber Rl communicates with the inside of the fuel tank, and the ventilation chamber R2 communicates with an external flow path leading to a canister. Hereinafter, each component part is demonstrated.

The case main body 20 is provided with the cylindrical peripheral wall 21 and the partition 23 which closes the upper surface, The communication hole 25 penetrates and is formed in the center of the said partition 23. . From the periphery of the lower surface of the communication port 25, the cylindrical 1st valve seat 27 which the valve head 51 of the float valve 50 folds protrudes, and is provided from the upper surface periphery of the said communication port 25. The second valve seat 71 of the cylindrical shape in which the shank valve 60 is folded and a notch is formed in a part of the outer circumference is protruded. In other words, the upper and lower periphery of the communication port 25 forms a valve seat in which the check valve 60 and the float valve 50 are folded. Moreover, both the float chamber Rl and the ventilation chamber R2 communicate with this communication port 25. As shown in FIG. The circumferential wall 21 is provided with a plurality of through holes 21a serving as passages for fuel and fuel vapor. In addition, below the circumferential wall 21, a plurality of claw portions 21b to be coupled to the coupling holes 33a of the lower cap 30 to be described later are formed along the circumferential direction.

The lower cap 30, which is attached to the lower opening of the case body 20, has a circular shape in which a perforation hole 31a is formed to allow passage of fuel, like the circumferential wall 21 of the case body 20. The bottom plate 31 and the cover wall 33 which are installed from the periphery of the bottom plate 31 and are covered by the lower outer periphery of the circumferential wall 21 of the case body 20 are formed. In the center of the bottom plate 31, a support protrusion 34 for stably supporting one end of the float valve spring 55 is formed. In addition, the cover wall 33 is provided with a coupling hole 33a to which the toe portion 21b formed on the circumferential wall 21 of the case body 20 is engaged, thereby lowering the case body 20. The lower cap 30 can be mounted in the opening. In addition, a mouth wall 35 which is erected upward is formed at one outer circumference of the cover wall 33, and a stop wall 37 is formed outside the upper part of the mouth wall 35. When the lower cap 30 is attached to the case main body 20, this stop wall 37 is located below the valve body accommodating part 90 formed in the case main body 20, as shown in FIG. It serves to prevent foreign matters from entering into the opening 91 provided in the valve body accommodating part 90. In addition, the stop wall 37 is provided with a through hole 37a for allowing fuel to pass therethrough.

The float valve 50 is slidably accommodated in the case main body 20. The float valve 50 has a substantially cylindrical shape, the valve head 51 protrudes from the center of the upper surface thereof, and the valve head 51 is folded to the communication port 25 formed in the case main body 20. It is supposed to. Moreover, the outer periphery of the float valve 50 is provided with the some rib 53 extended up and down at equal intervals along the circumferential direction, and this rib 53 is the circumferential wall 21 of the case main body 20. As shown in FIG. It slides on the inner periphery and becomes the part which guides the up-and-down slide operation of the float valve 50. As shown in FIG.

The float valve 50 accommodates the float valve 50 in the case main body 20 in a state in which the float valve spring 55 is inserted into the recess 54 provided at a predetermined height from the bottom surface thereof. The lower cap 30 is lowered below the case body 20 by engaging the claw portion 21b formed on the lower outer circumference of the circumferential wall 21 with the engaging hole 33a of the lower cap 30. Is mounted. In this way, the float valve spring 55 which provides an upward elastic force to the float valve 50 is fitted between the float valve 50 and the bottom plate 31 of the lower cap 30. FIG. In the state where the float valve 50 is not immersed in fuel, the float valve 50 compresses the float valve spring 55 by its own weight and is placed on the bottom plate 31 of the lower cap 30. It is. When the fuel rises due to the inclination of the vehicle and the float valve 50 is immersed in the fuel, the float valve 50 floats due to the buoyancy force and the elastic force of the spring 55 for the float valve, and the valve head 51 ) Contacts the lower inner periphery of the communication port 25 of the case body 20 to close the communication port 25.

On the upper side of the partition wall 23 of the case body 20, the bracket 100 is fixed to the fixing bracket fixed to the fuel tank and the like to fix the valve device 10 in the fuel tank. have. This bracket 100 is provided with the frame-shaped outer wall part 101 standing up from the upper surface of the partition 23 of the case main body 20. As shown in FIG. As shown in FIG. 1, this outer wall part 101 is extended in the direction of the connection pipe 95 mentioned later, and is formed so as to surround the upper opening of the valve body accommodating part 90 mentioned later. Moreover, the opposite side of the connection pipe 95 of the outer wall part 101 protrudes toward the outer side of the case main body 20 in a thin plate form, and the engaging claw 105 is formed in the front-end | tip.

Referring to FIGS. 2 and 4 simultaneously, a cylindrical wall 70 is formed inside the outer wall portion 101 of the bracket 100 (it is formed in an annular shape in this embodiment). At least a part of the upper end 70a of the cylindrical wall 70 is lower than the upper end of the outer wall portion 101, and when the upper cap 40 described later is attached to the bracket 100, the cylindrical wall 70 is formed. The inner space and the outer space of 70 are in communication.

The communication port 25 formed in the partition 23 mentioned above is located inside the cylindrical wall 70, and the inside of the case main body 20 and the inside of the cylindrical wall 70 communicate with each other. It is. From the outer periphery of the communication port 25 of the partition 23, the above-mentioned substantially cylindrical 2nd valve seat 71 protrudes, and a part of the outer periphery of this 2nd valve seat 71 has an axial direction. A notch 73 is thus formed (see FIG. 4A). The notch portion 73 prevents the communication valve 25 from being completely closed in the state where the shank valve 60 is in contact with the upper end of the second valve seat 71. In addition, on the upper surface side of the partition 23, a plurality of uneven parts 72 provided at equal intervals in the circumferential direction protrude from the outer circumference of the second valve seat 71 and the inner circumference of the cylindrical wall 70. . In addition, the uneven portion 72 is formed at a height lower than that of the second valve seat 71. By providing the uneven portion 72, the inclination angle is limited by the uneven portion 72 even when the check valve 60 is inclined in the cylindrical wall 70 when the check valve 60 is slid. It is difficult for the check valve 60 to engage with the inner circumference of the cylindrical wall 70, and the slide can be reliably slid.

In addition, in the check valve 60, the flat surface 63 on one side of the check valve 60 is in contact with the second valve seat 71 at all times. When fuel vapor is generated in the fuel tank and the pressure in the fuel tank rises and exceeds the predetermined pressure, the check valve 60 is gradually pushed up by the pressure, and the second valve seat 71 and the check valve 60 are raised. A gap S is formed between the two ends, and finally it can be pushed up to the lower surface of the top plate 41 of the upper cap 40 (see FIGS. 6 and 7).

With reference to the cylindrical wall 70, the check valve 60 slidably disposed on the inner circumference thereof will be described. 3A is a front view of the shank valve 60, FIG. 3B is a plan view of the shank valve 60, FIG. 3C is a cross-sectional view taken along line BB of the shank valve 60, and FIG. 3D is a view of the shank valve 60. Perspective view.

As shown in FIG. 3, this check valve 60 is formed in the polygonal plate shape in which the some flat part 65 was formed along the circumferential direction. In the present invention, the shape of the shank valve 60 is not particularly limited as long as it is polygonal, but the contact area with the inner circumference of the cylindrical wall 70 can be reduced, and the cylindrical wall 70 is It is preferable that the gap between the inner circumference and the outer circumference of the shank valve 60 is made of a regular polygon of 8 to 32 angles. In other words, in the case where the shank valve 60 according to the present invention has a polygonal plate shape as shown in FIG. 4B, the cylindrical valve has a cylindrical shape as compared with the disk shaped shank valve indicated by the imaginary line Sl in FIG. 4B. The gap between the inner circumference of the wall 70 and the outer circumference of the shank valve 60 can be largely secured.

In this embodiment, the upper and lower corner portions 61 and 61 of the shank valve 60 are chamfered in a tapered shape as the diameter gradually decreases toward the upper and lower end faces. Accordingly, as shown in FIG. 3B, the outer circumference of the shank valve 60 in the middle in the thickness direction has a polygonal shape in which a plurality of planar portions 65 are formed along the circumferential direction, and the shank valve 60 is formed. The pattern line L has the circular shape in the upper and lower edges of the thickness direction of the cross section. By chamfering in this way, as shown in FIG. 3A, the several flat part 65 of the outer periphery of the shank valve 60 is a pair of side edges 65a and 65a extended along the thickness direction, and along the circumferential direction. It has a substantially ellipse shape, which is formed in a circular arc shape and extends around the edges 65b and 65b connected to both ends of the pair of side edges 65a and 65a.

As described above, by chamfering the upper and lower edges of the shank valve 60 in a tapered shape, it becomes difficult for the shank valve to engage in the cylindrical wall 70 and the sliding resistance of the shank valve 60 is increased. It can be made smaller so that the inside of the cylindrical wall 70 can be raised and lowered smoothly.

In addition, in this embodiment, the plurality of through-holes 62 (three in this embodiment) are provided with the taper 62a which becomes wider toward the upper and lower end surfaces. By providing the through hole 62, the fuel vapor can be discharged from the fuel tank not only from the gap between the inner circumference of the cylindrical wall 70 and the outer circumference of the shank valve 60 but also from the through hole 62. Therefore, the pressure in a fuel tank can be made into a predetermined value more quickly.

In addition, the check valve 60 is slidably accommodated inside the tubular wall 70, so that the check valve 60 must be smaller in diameter than the inner diameter of the tubular wall 70. It is preferable that the difference between the outer diameter of 60 and the inner diameter of the cylindrical wall 70 is 0.1 to 0.5 mm. When the value exceeds 0.5 mm, the shank valve 60 is easily rattled in the tubular wall 70 due to the turning or inclination of the vehicle, thereby increasing the occurrence of strange sounds or the shank valve 60 or the like. The cylindrical wall 70 breaks or wears easily. When the value is less than 0.1 mm, the sliding resistance at the time of sliding the check valve 60 becomes large, making it difficult to smoothly lift and lower the inside of the tubular wall 70, and the inner circumference of the tubular wall 70. Since the clearance between the outer periphery of the check valve 60 cannot be fully secured, it becomes difficult to discharge | evaporate fuel vapor from a fuel tank quickly.

Although the material of the check valve 60 is not specifically limited, It should just be a material hard to be deformed and corroded by fuel vapor, For example, metal materials, such as stainless steel, a ceramic material, etc. are mentioned. Moreover, as the shaping | molding method, the method of filling a predetermined | prescribed metal powder and a ceramic material into a predetermined mold, and sintering, cutting the thing formed in plate shape, etc. can be employ | adopted.

Again, the configuration of the valve device 10 will be described. In this embodiment, the portion on the connecting pipe 95 side of the outer wall portion 101 of the bracket 100 protrudes outward of the case body 20. The valve body accommodating part 90 which provided the frame shape below this protrusion part is provided, and the valve body 80 is accommodated up and down in that inside. An opening 91 is formed at the lower end of the valve body accommodating portion 90, and the valve body 80 is folded around the upper portion of the opening 91 so that the opening 91 is opened and closed. Moreover, in the valve body accommodating part 90, the spring 81 which elastically presses so that the opening part 91 may always be closed while pressing the valve body 80 toward the opening part 91 is accommodated, and the pressure in a fuel tank is predetermined | prescribed. When it is higher than the value, it constitutes a relief valve which serves to discharge the steam to the outside of the fuel tank.

Moreover, from the valve body accommodating part 90, the connecting pipe 95 for connecting the piping connected to the canister which is not shown in figure is provided in the state which integrally protruded. As shown in FIG. 2, the connecting pipe 95 communicates with the internal space of the valve body accommodating portion 90 and constitutes a part of a discharge passage of the fuel vapor which communicates with the inside and outside of the fuel tank.

The upper cap 40 is attached to the upper opening of the bracket 100. The upper cap 40 has a ceiling plate 41 having a shape suitable for the outer shape of the outer wall portion 101 of the bracket 100, and an inner circumference of the outer wall portion 101 from the periphery of the lower surface of the ceiling plate 41. It is comprised by the extended outer periphery rib 43, and is attached to the upper opening part of the bracket 100 by fixing means, such as ultrasonic welding and hot plate welding. In addition, although the bracket 100 is closed by this upper cap 40, as mentioned above, the inner space and outer space of the cylindrical wall 70 communicate with each other, and the valve body accommodating part provided in the front lower part ( The interior space of 90) is also in communication. For this reason, the fuel vapor which flowed in from the communication port 25 of the partition 23 is a valve body accommodating part (through the space enclosed by the partition 23, the cylindrical wall 70, and the upper cap 40). 90) Inflow to inside.

The uneven part 44 (refer FIG. 2) is formed in the place which is the lower surface of the top plate 41 of the upper cap 40, and is located above the check valve 60 when it is attached to the upper opening part of the bracket 100. On the outer circumference of the uneven portion 44, a recess 45 having a smaller diameter than the outer diameter of the shank valve 60 is formed. Then, when the check valve 60 is pushed up to the lower surface of the ceiling plate 41 by the fuel steam, the check valve 60 abuts against the uneven portion 44, so that the check valve 60 of the ceiling plate 41 It becomes difficult to paste on the bottom.

In addition, a cylindrical support protrusion 46 protrudes into the lower surface of the top plate 41 of the upper cap 40 to be forced into the valve body accommodating portion 90 when mounted on the bracket 100. Specifically, the support protrusion 46 is provided such that the center of the shaft thereof is located almost at the center of the opening portion 91 of the valve body accommodating portion 90, and has a shape in which the diameter gradually decreases downward and has a predetermined length. Extends. The support protrusion 46 is inserted into the inner circumference of the spring 81 that presses the valve body 80 so that one end of the spring 81 abuts against the ceiling plate 41 around the base thereof, whereby the spring 81 This is to be stably supported. In addition, when the valve body 80 slides upward by a predetermined distance against the spring force of the spring 81, the tip of the support protrusion 46 abuts on the upper portion thereof, and the valve body 80 slides further. It is also made into the part which stabilizes the slide operation | movement of the valve body 80 so that it may be restrict | limited so that it may not.

Next, the operation of the valve device 10 will be described with reference to FIGS. 5 to 7.

The valve device 10 is fixed to the fuel tank by engaging the engaging claw 105 with a not shown fixing bracket provided above in the fuel tank. When the vehicle is not shaken, the liquid level of the fuel in the fuel tank is not inclined, and the float valve 50 is not immersed in the fuel, the float valve spring 55 is compressed by the weight of the float valve 50. The valve head 51 of the float valve 50 is separated from the communication port 25. On the other hand, the flat surface 63 in one direction of the check valve 60 is in contact with the second valve seat 71, and the communication port 25 is closed except for the notch portion 73. This prevents fuel vapors from being released from the fuel tank indefinitely at all times. On the other hand, when the pressure in the fuel tank decreases due to a temperature drop or the like, air flows into the fuel tank from the notch portion 73 provided in the second valve seat 71, thereby preventing negative pressure in the fuel tank. Can be.

In the above state, if the liquid level of the fuel rises and the fuel is immersed in the float valve 50 for a predetermined height or more due to the vehicle turning or inclining greatly, buoyant force acts on the float valve 50 and the float valve spring 55 The float valve 50 floats due to the elastic force of), the valve head 51 abuts against the inner periphery of the communication port 25 below, and closes the communication port 25. As a result, the fuel passes through the communication port 25 and is prevented from flowing into the inner space of the cylindrical wall 70, and the fuel leakage to the outside of the fuel tank can be reliably prevented.

In the above state, when a large amount of fuel vapor is generated due to running of the vehicle or the like, and the pressure in the fuel tank is increased, the check valve 60 is gradually pushed up by the pressure, whereby the second valve seat 71 and the shank A gap S occurs between the valves 60 (see FIG. 6). In addition, when the pressure in the fuel tank becomes higher, the check valve 60 is pushed up to the lower surface of the top plate 41 of the upper cap 40 (see FIG. 7). The fuel vapor is formed into a cylindrical wall 70 through a gap between the outer circumference of the shank valve 60 and the inner circumference of the cylindrical wall 70, and a through hole 62 provided in the shank valve 60. It moves to the outer space of the tank, and is sent to the canister (not shown) through the inner space of the valve body accommodating part 90 and the connection pipe 95, and discharged to the outside of a fuel tank.

At this time, in the present invention, since the check valve 60 has a polygonal plate shape, the contact area with the inner circumference of the cylindrical wall 70 becomes small, and the check valve 60 opens the cylindrical wall 70. The sliding resistance at the time of sliding can be made small, the sliding of the check valve 60 can be softened, and the wear of the cylindrical wall 70 and the check valve 60 can be reduced.

In addition, even when the check valve 60 inclines with respect to the cylindrical wall 70 when the shank valve 60 slides the cylindrical wall 70, it may be tilted with respect to the cylindrical wall 70 by vibration, turning, inclination, etc. of an automobile. It becomes difficult to engage with the inner circumference of the wall 70, suppressing the lifting operation of the check valve 60 from being inhibited, and making it possible to raise and lower the check valve 60 reliably.

Moreover, since the check valve 60 has a polygonal plate shape, the clearance between the outer circumference of the check valve 60 and the inner circumference of the cylindrical wall 70 can be secured relatively large, so that the fuel vapor can be vented. The resistance can be made smaller and the fuel vapor can flow smoothly.

As described above, according to the present invention, a polygonal one is used as the check valve, and even if the pressure in the fuel tank rises, it can be quickly set to a predetermined value, and damage or deformation of the fuel tank can be prevented. In addition, since the communication port 25 is almost closed by the check valve 60, it is possible to prevent the fuel vapor from leaking at all times. Moreover, since the check valve has a plate shape, the valve device can be miniaturized.

In addition, there is a case where the pressure in the fuel tank is further increased while the liquid level of the fuel rises and the communication port 25 is closed by the float valve 50. In this case, the valve body 80, which is in contact with the periphery of the opening 91 of the valve body accommodating portion 90 and closes the opening 91, slides upward in response to the elastic force of the spring 81 to open the opening ( 91). Then, the fuel vapor introduced from the opening 91 is introduced into the valve body accommodating portion 90 through a gap between the outer circumference of the valve body 80 and the inner circumference of the valve body accommodating portion 90, and the valve body accommodating portion It is sent to the canister which is not shown in figure through the inside of the connection pipe 95 which communicates with the internal space of 90, and is discharged | emitted to the exterior of a fuel tank. As a result, it becomes possible to more reliably suppress that the pressure in a fuel tank becomes more than a predetermined value, and can prevent the rupture etc. by the internal pressure rise of a fuel tank.

1 is an exploded perspective view showing a valve device provided with a check valve of the present invention.

2 is a cross-sectional view taken along the line A-A of FIG.

Figure 3 shows the shank valve of the present invention, (a) is a front view, (b) is a plan view, (c) is a sectional view taken along the line B-B, (d) is a perspective view.

4 is an enlarged cross-sectional view of the main portion taken along the line A-A of FIG. 1, and (b) is a schematic explanatory diagram when (a) is viewed in a planar direction.

FIG. 5 is an explanatory view for explaining the action of the valve body constituting the shank valve of the present invention, showing a state in which the pressure in the fuel tank is less than a predetermined value.

FIG. 6 is an explanatory view for explaining the action of the valve body constituting the shank valve of the present invention, and showing a state when the pressure in the fuel tank rises. FIG.

FIG. 7 is an explanatory view for explaining the action of the valve body constituting the shank valve of the present invention, showing a state when the pressure in the fuel tank exceeds a predetermined value. FIG.

* Description of the symbols for the main parts of the drawings *

10 valve device 15 valve case

20: case body 25: communication port

27: first valve seat 30: lower cap

40: upper cap 46: support protrusion

50: float valve 51: valve head

60: check valve 70: cylindrical wall

71: second valve seat R1: float seal

R2: Ventilation Room

Claims (2)

A valve case provided with a float chamber communicating with the inside of the fuel tank downward through the partition wall, and a ventilation chamber communicating with the outside of the tank above; A float valve arranged to move up and down in the float seal; A check valve disposed in the ventilation chamber; It is formed in the partition wall so that the float chamber and the ventilation chamber communicate with each other, the lower surface periphery forms a first valve seat for folding the float valve, the upper surface periphery has a communication port forming a second valve seat for folding the shank valve , On the upper surface of the said ventilation chamber side of the said partition, the cylindrical wall surrounding the said communication port is formed, The check valve is formed in a polygonal plate shape and is arranged to be movable up and down inside the tubular wall, and is configured to always contact the second valve seat. The method of claim 1, The shank valve has a polygonal plate shape, and the upper and lower edge portions of the outer circumference are chamfered in a tapered shape.

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