JP5872299B2 - Valve device for fuel tank - Google Patents

Description

  The technology of the present disclosure is a valve device attached to a fuel tank of a vehicle, and particularly relates to a valve device that switches between opening and closing depending on the position of a liquid level of fuel stored in the fuel tank.

  As described in Patent Documents 1 and 2, the function of detecting the position of the liquid level in the fuel tank valve device is borne by a float that is displaced by fluctuations in the position of the liquid level. FIG. 4 is a cross-sectional view showing the overall cross-sectional structure of such a fuel tank valve device. FIG. 5 is a cross-sectional view showing a detailed cross-sectional structure of the float constituting the fuel tank valve device. FIGS. 6 and 7 are operation diagrams for explaining the operation of the float when the positions of the fuel liquid levels are different from each other.

  As shown in FIG. 4, the lower valve body case 60 constituting the fuel tank valve device 50 has a double cylindrical shape. In the lower valve body case 60, a plurality of connecting plates extending radially from the outer peripheral surface of the inner cylindrical portion 62 in the gap between the outer cylindrical portion 61 that is the outer cylindrical portion and the inner cylindrical portion 62 that is the inner cylindrical portion. 63 connects the outer cylinder part 61 and the inner cylinder part 62. A coil spring 64 supported by a plurality of connecting plates 63 is wound around the inner cylinder part 62 in the gap between the outer cylinder part 61 and the inner cylinder part 62.

The upper valve body case 70 constituting the fuel tank valve device 50 has an L-shaped cylindrical shape formed by integrally molding two cylindrical portions orthogonal to each other. The accommodation cylinder part 71 which is one cylinder part in the upper valve body case 70 is a covered cylinder part fitted into the outer cylinder part 61 at the opening end thereof. In the upper valve body case 70, the other cylinder portion, which is the other cylinder portion 72, is integrally formed with a case lid portion 71t that is an upper portion of the accommodating cylinder portion 71, and passes through the inside of the fuel tank and the outside of the fuel tank. A ventilation path is constructed. A bent end portion 72 a, which is one end portion of both end portions of the through-cylinder portion 72, communicates with the inside of the accommodation cylinder portion 71 through a vent hole 71 h that penetrates the case lid portion 71 t of the accommodation cylinder portion 71. The connection end 72b, which is the other end of the both ends of the cylinder passing portion 72, communicates with, for example, a canister that suppresses transpiration of fuel. The inside of the fuel tank and the canister are connected to each other through the gap between the outer cylinder 61 and the inner cylinder 62, the cylinder of the inner cylinder 62, the cylinder of the through cylinder 72, and the vent hole 71h. Communicates. An annular case-side contact portion 73 projects around the opening of the vent hole 71h on the inner side surface of the case lid portion 71t.
Inside the housing cylinder 71, there are housed a float 80 that has a cylindrical shape with the same axis as the housing cylinder 71, and a disc-shaped valve body 90 that has the same outer diameter as the float 80. .

  As shown in FIG. 5, the float 80 has a covered cylindrical shape having an outer diameter smaller than the inner diameter of the housing cylinder portion 71. A circular hole-shaped spring accommodating hole 81 is formed in the lower part of the float, which is the end on the lower valve body case 60 side, in both axial end portions of the float 80. The inner cylinder part 62 and the coil spring 64 which were demonstrated are accommodated. The float 80 is biased by the coil spring 64 from the lower valve body case 60 toward the upper valve body case 70.

  A float-side contact portion 82 having a columnar shape extending toward the vent hole 71h protrudes at the center of the float upper portion, which is the end portion on the cylinder passing portion 72 side, in both axial end portions of the float 80. Further, around the float-side contact portion 82, an engaging portion 83 that protrudes from the upper portion of the float toward the case lid portion 71 t has a key-like tip portion that is bent outward in the radial direction of the float 80. .

  The valve body 90 has a disk shape having the same outer diameter as the float 80 and has a circular hole-shaped fixing hole 92 h that penetrates the central portion of the valve body 90. Further, around the fixed hole 92h, a plurality of engaged portions 91 having a key-like tip portion that is bent inward in the radial direction of the valve body 90 and extending toward the upper portion of the float protrude. In each of the plurality of engaged portions 91, the length of the float 80 in the axial direction is longer than that of the engaging portion 83, and the distal ends of the plurality of engaged portions 91 are engaged with the engaging portion 83. It is engaged with the tip of the. With this configuration, relative upward and downward displacement of the valve body 90 with respect to the float 80 is allowed, and the moving range of the valve body 90 is restricted by the length of the engaging portion 83.

  An umbrella-shaped seal member 93 is attached to the attachment surface 90t facing the inner surface of the case lid 71t among the side surfaces of the valve body 90. The case seal portion 93a constituting the seal member 93 has a disk shape that has an outer diameter larger than that of the case side contact portion 73 and extends along the attachment surface 90t. In addition, the float seal portion 93 b that constitutes the seal member 93 has a smaller outer diameter than the case side contact portion 73 and has a cylindrical shape that extends from the center of the case seal portion 93 a toward the float side contact portion 82. . The seal member 93 is fixed to the engaged portion 91 by fitting the float seal portion 93b into the fixing hole 92h. With this configuration, relative upward and downward displacement of the float seal portion 93 b with respect to the float side contact portion 82 is allowed, and the range of movement of the float seal portion 93 b is restricted by the length of the engaging portion 83.

  In the fuel tank valve device having the above-described configuration, for example, when a part of the float 80 is immersed in the fuel by tilting the fuel tank, the float 80 receives the urging force of the coil spring 64 and the buoyancy of the float 80. And the float 80 is arrange | positioned in the upper position which is the position nearest to the vent hole 71h.

  At this time, as shown in FIG. 6, the float-side contact portion 82 pushes the float seal portion 93b toward the vent hole 71h by the urging force of the coil spring 64 and the buoyancy of the float 80. Further, when the pressing force of the float side contact portion 82 acts on the entire seal member 93, the case seal portion 93 a presses the case side contact portion 73. As a result, the opening of the vent hole 71h and the opening of the float seal portion 93b are closed, and a passage connecting the inside of the accommodating cylinder portion 71 and the inside of the through cylinder portion 72 is formed by the float 80 and the valve body 90. Blocked. Thereby, it is possible to suppress the fuel in the fuel tank from flowing into the canister.

  From this state, when the liquid level in the fuel tank falls below the float 80, buoyancy does not act on the float 80, so that its own weight against the biasing force of the coil spring 64 acts on the float 80. Become.

  At this time, since the air pressure in the upper valve body case 70 is often higher than the air pressure in the through-cylinder portion 72, the case seal portion 93a having a seal area larger than the float seal portion 93b also has a pressing force due to such a pressure difference. growing. As a result, as shown in FIG. 7, in the state where the valve body 90 is disposed at the closed position where the case side contact portion 73 continues to push the case seal portion 93a, the float side contact portion 82 is first float-seal. It leaves | separates from the part 93b. Then, the float 80 is lowered to a lower position where the front end of the engaging portion 83 and the front end of the engaged portion 91 are engaged. As a result, a ventilation path that passes through the inside of the fuel tank and the outside of the fuel tank is constituted by the cylinder passing portion 72 and the float seal portion 93b. As a result, the air pressure in the upper valve body case 70 and the air pressure in the cylinder passing portion 72 are equal to each other.

  Next, when the pressure difference between the atmospheric pressure in the upper valve body case 70 and the atmospheric pressure in the cylinder passing portion 72 disappears, the case seal portion 93a is separated from the case side contact portion 73, and as shown in FIG. The float 80 is disposed at the lowest position, which is the position farthest from the center. As a result, even when the case seal portion 93a and the case side contact portion 73 are required to be enlarged, the force that is pushed by the pressure difference is released in advance by the float seal portion 93b, so the case seal portion 93a and the case side The contact with the contact portion 73 can be easily released.

Japanese Patent Application Laid-Open No. 2011-132917

Japanese Patent Laid-Open No. 02-112658

  By the way, in the fuel tank valve device described above, the fuel may scatter in the accommodating cylinder portion 71 in a state where the float 80 is disposed at the lower position or the lowermost position. In this case, fuel may adhere to the upper surface of the float-side contact portion 82 or the upper surface of the case seal portion 93a, and a part of the fuel that accumulates on the upper surface may reach the inside of the through-cylinder portion 72 or the canister. is there. Therefore, in the fuel tank valve device described above, it is desired to prevent fuel from accumulating in a sealed portion that is a portion that seals the fuel tank from the inside.

Note that the above-described demand for suppressing fuel from accumulating in the sealed portion is common to the fuel tank valve device in which the sealed portion is displaced by the liquid level. For example, a fuel tank valve device in which the through-cylinder portion is connected to a fuel supply path is also desired to suppress the accumulation of fuel in the sealed portion. Further, the fuel tank valve device in which the seal member is fixed to the float and the contact and separation of the seal member with respect to the case side contact portion 73 are switched by the displacement of the float can suppress the accumulation of fuel in the sealed portion. It is desired.
An object of the technology of the present disclosure is to provide a fuel tank valve device capable of suppressing fuel from being accumulated in a portion where the fuel tank is sealed from the inside thereof.

  Hereinafter, the fuel tank valve device according to the technology of the present disclosure for solving the above-described problems will be described together with the operation and effect thereof.

  One aspect of the fuel tank valve device according to the technology of the present disclosure is a fuel tank valve device attached to a fuel tank, the air passage communicating with the inside of the fuel tank and the outside of the fuel tank, and the opening of the air passage. A float that is displaced by fluctuations in the liquid level in the fuel tank at an upper position that is a position for closing the air passage and a lower position that is a position that opens the opening of the air passage, and the upper portion of the float An end surface that is a flat surface that closes the opening by contact with the surroundings; and a peripheral surface that extends downward from an outer edge of the end surface; and the peripheral surface is below the end surface and toward the outside of the end surface. It has an extending part.

  According to one aspect of the fuel tank valve device in the technology of the present disclosure, even if fuel is scattered on the end surface of the float in a state where the air passage is open, the fuel adhering to the vicinity of the outer edge on the end surface is It flows to the outside of the end face and downward. Therefore, it is possible to prevent fuel from accumulating on the end face of the float, which is a portion that seals the fuel tank from the inside.

  In another aspect of the fuel tank valve device according to the technology of the present disclosure, the end surface is a first flat surface, and the upper portion of the float is below the first flat surface and outward of the first flat surface. And a second flat surface parallel to the first flat surface, and the peripheral surface connects the first flat surface and the second flat surface.

  According to another aspect of the valve device for a fuel tank in the technology of the present disclosure, the second flat surface is formed in a portion below the first flat surface and outside the first flat surface. Scattering of the fuel itself from below with respect to the first flat surface is suppressed by the second flat surface. Therefore, it is possible to further suppress the fuel from accumulating on the first flat surface, which is a portion that seals the fuel tank from the inside.

  In another aspect of the fuel tank valve device according to the technique of the present disclosure, the opening is a first opening, and the air passage has a second opening larger than the first opening, An annular seal member having one opening, the seal member being connected to the float so as to be relatively displaceable upward and downward, and an open position for opening the second opening; Displacement to a closed position in which a part of the second opening is closed by passing the first opening through the first opening, and displaces to the closed position together with the displacement of the float to the upper position. Is displaced to the open position due to the displacement to the lower position.

  According to another aspect of the fuel tank valve device according to the technique of the present disclosure, when the float is displaced to the lower position and the first opening is opened, the seal member is displaced to the open position and the second opening is opened. Is released. With such a configuration, when the pressure inside the fuel tank is higher than the pressure outside the fuel tank, the first opening is opened before the second opening is opened, and the seal member is first pushed by the pressure difference. Power is released. Therefore, the responsiveness of the valve opening according to the position of the liquid level can be improved by suppressing the sealing member from being fixed in the closed position.

  At this time, since the first opening is smaller than the second opening, when the first opening is opened compared to the case where the second opening is opened under the same pressure difference, The flow velocity of gas increases around the opening of 1. That is, the flow velocity of the gas increases at the end face of the float that seals the first opening. Therefore, the effect of causing the fuel adhering to the vicinity of the outer edge of the end face to flow outward and downward from the end face becomes more effective.

  In another aspect of the fuel tank valve device according to the technology of the present disclosure, the peripheral surface is a cylindrical surface, and a portion of the peripheral surface that extends downward from the end surface and outward of the end surface is the peripheral surface. In a cross section including the central axis of the surface, it is in an arc shape projecting below the end surface and outward of the end surface.

According to another aspect of the fuel tank valve device according to the technology of the present disclosure, the fuel adhering to the vicinity of the peripheral edge of the end surface easily flows from the end surface and adheres to the peripheral surface as compared with the case where the peripheral surface is an inclined surface. It becomes difficult for the spent fuel to flow to the end face.
In another aspect of the fuel tank valve device according to the technology of the present disclosure, a portion of the peripheral surface that extends below the end surface and outward of the end surface is a slope.
According to another aspect of the fuel tank valve device in the technology of the present disclosure, it is possible to facilitate the formation of the peripheral surface as compared with the case where the peripheral surface is a complicated curved surface.
In another aspect of the fuel tank valve device according to the technology of the present disclosure, the peripheral surface has a groove extending below the end surface and outward of the end surface.

  According to another aspect of the fuel tank valve device according to the technology of the present disclosure, the fuel adhering to the vicinity of the outer edge of the end surface is guided by the groove below the end surface and toward the outside of the end surface. Therefore, the effect of suppressing fuel from accumulating on the end face of the float, which is the part that seals the fuel tank from the inside, becomes even more remarkable.

It is sectional drawing which shows the cross-sectional structure of the float in one Embodiment of the valve apparatus for fuel tanks in the technique of this indication, and the cross-sectional structure of a valve body. It is a partial side view which expands and shows a part of side structure of the float in one Embodiment. It is a fragmentary sectional view which expands and shows a part of sectional structure of the valve body in a modification. It is sectional drawing which shows the whole sectional structure of the valve apparatus for fuel tanks of a prior art example. It is sectional drawing which shows separately the cross-sectional structure of the float in the valve apparatus for fuel tanks of a prior art example, and the cross-sectional structure of a valve body. It is an operation | movement figure explaining the effect | action of a float in the valve apparatus for fuel tanks of a prior art example. It is an operation | movement figure explaining the effect | action of a float in the valve apparatus for fuel tanks of a prior art example.

  Hereinafter, an embodiment of a fuel tank valve device according to the technology of the present disclosure will be described with reference to FIGS. 1 and 2. The fuel tank valve device according to the present embodiment differs from the fuel tank valve device described with reference to FIGS. 4 to 7 in the structure of the float and the structure of the valve body. Therefore, in the following, the structure of the float and the structure of the valve body will be described in detail, and the same components as those of the fuel tank valve device described above will be denoted by the same reference numerals and redundant description thereof will be omitted.

  As shown in FIG. 1, a circular hole-shaped spring accommodating hole 11 is formed in a lower part 10b of a float 10 having a cylindrical shape with a lid, and the lower valve body described above is formed in the spring accommodating hole 11. The inner cylindrical portion 62 and the coil spring 64 of the case 60 are accommodated. Then, the float 10 is biased by the biasing force of the coil spring 64 from the lower portion 10 b of the float 10 toward the upper portion of the float 10. On the other hand, a float-side contact portion 12 having a multi-stage cylindrical shape extending in the axial direction of the float 10 protrudes from the upper portion of the float 10.

  The outer diameter of the valve body 20 that forms a disk shape and forms a ventilation path is larger than the largest outer diameter at the float-side contact portion 12 and is approximately half the outer diameter of the float 10. A circular hole-shaped fixing hole 22 h that penetrates the valve body 20 along the axial direction of the float 10 is formed at the center of the valve body 20. Further, a plurality of engaged portions 21 that protrude toward the upper portion of the float 10 having a key-like tip portion that is bent inward in the radial direction of the valve body 20 project around the fixed hole 22 h.

  An umbrella-shaped seal member 23 is attached to an attachment surface 20t which is a side surface opposite to the side surface facing the float 10 among the side surfaces of the valve body 20. The case seal portion 23a constituting the seal member 23 has a disk shape that spreads along the attachment surface 20t. The outer diameter of the case seal portion 23a is larger than the case-side contact portion 73 described above, and is substantially the same outer diameter as the mounting surface 20t. The float seal portion 23 b that constitutes the seal member 23 has a smaller outer diameter than the float-side contact portion 12 and has a cylindrical shape that extends from the center of the case seal portion 23 a toward the float-side contact portion 12. Then, the seal member 23 is fixed to the engaged portion 21 by fitting the float seal portion 23b into the fixing hole 22h.

  As shown in FIG. 2, the float-side contact portion 12 having a multi-stage cylindrical shape includes a base end cylindrical portion 13 that is four cylindrical portions having the same axis and different outer diameters, a first intermediate cylindrical portion 14, The second intermediate cylindrical portion 15 and the tip cylindrical portion 16 are configured.

  The proximal cylindrical portion 13 is a cylindrical portion that protrudes from the float upper surface 10t. The first intermediate cylindrical portion 14 is a cylindrical portion that extends from the distal end of the proximal cylindrical portion 13, has a larger outer diameter than the proximal cylindrical portion 13, and is thinner than the proximal cylindrical portion 13 in the axial direction. Have The second intermediate cylindrical portion 15 is a cylindrical portion extending from the distal end of the first intermediate cylindrical portion 14, has an outer diameter smaller than that of the proximal end cylindrical portion 13, and is larger than the first intermediate cylindrical portion 14 in the axial direction. It has a thin thickness. The distal end cylindrical portion 16 is a cylindrical portion extending from the distal end of the second intermediate cylindrical portion 15, and has a flat surface in contact with the float seal portion 23b as an end surface on the distal end side. Further, the distal end cylindrical portion 16 has an outer diameter smaller than that of the second intermediate cylindrical portion 15 and has a thickness thinner than that of the second intermediate cylindrical portion 15 in the axial direction.

That is, the outer diameter of the proximal cylindrical portion 13 is the proximal outer diameter, the outer diameter of the first intermediate cylindrical portion 14 is the first intermediate outer diameter, and the outer diameter of the second intermediate cylindrical portion 15 is the second intermediate outer diameter. If the outer diameter of the tip cylindrical portion 16 is the tip outer diameter, the float side contact portion 12 satisfies the condition expressed by the following formula 1.
Tip outer diameter <second intermediate outer diameter <proximal outer diameter <first intermediate outer diameter (Formula 1)

Further, the thickness of the base end cylindrical portion 13 is set as the base end thickness, the thickness of the first intermediate cylindrical portion 14 is set as the first intermediate thickness, and the thickness of the second intermediate cylindrical portion 15 is set as the second intermediate thickness. When the thickness of the portion 16 is the tip thickness, the float side contact portion 12 satisfies the condition expressed by the following formula 2.
Tip thickness <second intermediate thickness <first intermediate thickness <base end thickness (Formula 2)

  The base end thickness, which is the thickness of the base end cylindrical portion 13, is sufficiently smaller than the length of each of the plurality of engaged portions 21 in the axial direction, and the tip of each of the plurality of engaged portions 21. It is sufficiently larger than the thickness of the part. And when the front-end | tip of the to-be-engaged part 21 enters into the clearance gap between the float upper surface 10t and the 1st intermediate | middle cylindrical part 14, the relative displacement to the upper direction and the downward direction in the float side contact part 12 and the float seal | sticker part 23b is carried out. Allowed and the range of movement of the float seal portion 23 b is restricted by the gap between the float upper surface 10 t and the first intermediate cylindrical portion 14.

  The outer peripheral surface of the proximal cylindrical portion 13 is a concave curved surface that is recessed inward in the radial direction, and the first outer diameter of the proximal cylindrical portion 13 is the same as the end of the proximal cylindrical portion 13 on the float upper surface 10t side. It has a maximum value in the end cylindrical portion 13 and the end portion on the first intermediate cylindrical portion 14 side.

  The first intermediate outer peripheral surface 14s, which is the outer peripheral surface of the first intermediate cylindrical portion 14, has a convex curved surface in which the portion on the proximal cylindrical portion 13 side protrudes outward in the radial direction from the portion on the second intermediate cylindrical portion 15 side. Have around. The convex curved surface of the first intermediate outer peripheral surface 14s is formed at a portion of the first intermediate outer peripheral surface 14s on the second intermediate cylindrical portion 15 side, and is an end surface of the first intermediate cylindrical portion 14 on the second intermediate cylindrical portion 15 side. It is continuous on a flat surface. In other words, the first intermediate outer diameter of the first intermediate cylindrical portion 14 has a maximum value at the end portion on the proximal cylindrical portion 13 side, and has a minimum value at the end portion on the second intermediate cylindrical portion 15 side, Then, the rate of decrease in the first intermediate outer diameter is increased from the end on the proximal cylindrical portion 13 side toward the end on the second intermediate cylindrical portion 15 side. In the cross section of the first intermediate cylindrical portion 14 including the central axis of the first intermediate cylindrical portion 14, the curvature outer diameter of the convex curved surface that forms an arc shape on the first intermediate outer peripheral surface 14 s is that of the first intermediate cylindrical portion 14. It is smaller than the first intermediate outer diameter and smaller than the distal end outer diameter of the distal end cylindrical portion 16.

  A second intermediate outer peripheral surface 15 s that is an outer peripheral surface of the second intermediate cylindrical portion 15 constitutes a peripheral surface in the upper part of the float 10, which is also on the first intermediate cylindrical portion 14 side than the portion on the distal end cylindrical portion 16 side. Has a convex curved surface projecting outward in the radial direction. The convex curved surface of the second intermediate outer peripheral surface 15 s is formed in a portion of the second intermediate outer peripheral surface 15 s on the tip cylindrical portion 16 side and is continuous with the outer peripheral surface of the tip cylindrical portion 16. In other words, the second intermediate outer diameter of the second intermediate cylindrical portion 15 has a maximum value at the end portion on the first intermediate cylindrical portion 14 side, has a minimum value at the end portion on the distal end cylindrical portion 16 side, and The rate at which the second intermediate outer diameter decreases from the end portion on the first intermediate cylindrical portion 14 side toward the end portion on the distal end cylindrical portion 16 side is increased. In the cross section of the second intermediate cylindrical portion 15 including the central axis of the second intermediate cylindrical portion 15, the curvature outer diameter of the convex curved surface forming an arc shape on the second intermediate outer peripheral surface 15 s is the second intermediate cylindrical portion 15. It is smaller than the second intermediate outer diameter and smaller than the tip outer diameter of the tip cylindrical portion 16.

  The end surface on the distal end side in the distal end cylindrical portion 16 is an end surface in the upper part of the float 10 and is a flat surface that closes the opening by contact with the periphery of the opening in the float seal portion 23b. The outer peripheral surface of the distal end cylindrical portion 16 is a cylindrical surface having a constant outer diameter, and constitutes a peripheral surface in the upper part of the float 10.

  Next, the operation of the fuel tank valve device having the above-described configuration will be described. The fuel tank valve device described above mainly differs from the fuel tank valve device described with reference to FIGS. 4 to 7 in the structure of the float side contact portion 12. The actions involved will be described in detail.

  When the fuel tank is tilted and a part of the float 10 is immersed in the fuel, the vent hole 71h is generated by the urging force of the coil spring 64 and the buoyancy of the float 10 as in the fuel tank valve device described with reference to FIG. The float-side contact portion 12 pushes the float seal portion 23b. Further, the pressing force of the float side contact portion 12 acts on the entire seal member 23, whereby the case seal portion 23 a presses the case side contact portion 73. As a result, the float 10 is disposed at an upper position that is the position closest to the vent hole 71h, and the opening of the float seal portion 23b and the opening of the vent hole 71h are closed. The passage connecting the cylinder of the accommodating cylinder 71 and the cylinder of the through cylinder 72 is blocked by the float 10 and the valve body 20.

  From this state, when the liquid level in the fuel tank is lower than that of the float 10, buoyancy does not act on the float 10, and its own weight against the urging force of the coil spring 64 acts on the float 10. Become. At this time, like the fuel tank valve device described above, the float side contact portion 12 is first separated from the float seal portion 23b while the case seal portion 23a continues to push the case side contact portion 73, and the first The float 10 is lowered to a lower position where the intermediate cylindrical portion 14 and the tip of the engaged portion 21 are engaged. Then, the inside of the accommodation cylinder portion 71 and the inside of the cylinder portion 72 communicate with each other. As a result, the seal member 23 is displaced from a closed position where the case seal portion 23a and the case side contact portion 73 are in contact to an open position where the case seal portion 23a and the case side contact portion 73 are separated from each other.

  Here, when the fuel is scattered in the accommodating cylinder portion 71 in a state where the float 10 is disposed at the lower position, the first flat surface which is the end surface on the distal end side in the distal end cylindrical portion 16 and the first intermediate cylindrical portion 14. The fuel adheres to the second flat surface which is the end surface on the second intermediate cylindrical portion 15 side. At this time, the surface connecting the first flat surface and the second flat surface is the second intermediate outer peripheral surface 15s of the second intermediate cylindrical portion 15, and the tip cylindrical portion 16 side of the second intermediate outer peripheral surface 15s. This is a convex curved surface in which the part on the first intermediate cylindrical part 14 side projects outward in the radial direction from the part on the tip cylindrical part 16 side. Therefore, the fuel adhering to the outer edge of the first flat surface flows along the second intermediate outer peripheral surface 15s to the second flat surface as compared with the configuration in which the second intermediate outer peripheral surface 15s does not have the convex curved surface. It becomes easy. Moreover, it is maintained that the fuel adhering to the second flat surface is prevented from flowing to the first flat surface. Therefore, it is possible to prevent fuel from accumulating on the first flat surface, which is a portion that seals the fuel tank from the inside.

  Further, the curvature outer diameter of the convex curved surface at the second intermediate outer peripheral surface 15 s is smaller than the minimum outer diameter at the float side contact portion 12. Therefore, compared with the case where the curvature outer diameter of the convex curved surface in the second intermediate outer peripheral surface 15s is larger than the outer diameter of the tip and the case where the second intermediate outer peripheral surface 15s is a simple inclined surface, the fuel to the second flat surface Encouraging the flow, suppressing the flow of fuel from the second flat surface, and the like become more prominent.

  Further, the thickness of the tip cylindrical portion 16 having the first flat surface is the thinnest in each cylindrical portion constituting the float-side contact portion 12. Therefore, it becomes more remarkable that the fuel flow to the second flat surface is promoted as compared with the case where the thickness of the tip cylindrical portion 16 is larger than the thickness of the other cylindrical portions. In addition, since the second flat surface is formed below the first flat surface and outside the first flat surface, fuel scattering from the lower side of the first flat surface itself 2 is suppressed by the flat surface.

In the first intermediate outer peripheral surface 14 s of the first intermediate cylindrical portion 14, the portion on the second intermediate cylindrical portion 15 side is closer to the portion on the proximal cylindrical portion 13 side than the portion on the second intermediate cylindrical portion 15 side. Convex curved surface projecting outside. Therefore, the fuel adhering to the edge of the second flat surface flows toward the float upper surface 10t along the first intermediate outer peripheral surface 14s, and the tip of the engaged portion 21 slides on the first intermediate outer peripheral surface 14s. It becomes easy to move and enter the gap between the first intermediate cylindrical portion 14 and the float upper surface 10t.
As described above, according to the fuel tank valve device of the present embodiment, the effects listed below can be obtained.

  (1) Even if fuel is scattered on the end surface of the tip cylindrical portion 16 in a state where the air passage constituted by the cylinder passing portion 72 and the float seal portion 23b is opened, the fuel adhered to the vicinity of the outer edge on the end surface Flows along the outer peripheral surface of the second intermediate cylindrical portion 15 outward and downward of the end surface. Therefore, it is possible to prevent fuel from accumulating on the end surface of the distal end cylindrical portion 16 that is a portion that seals the fuel tank from the inside.

  (2) Since the second flat surface is formed below the first flat surface and outside the first flat surface, the fuel scattering itself from the lower side with respect to the first flat surface is the first. 2 is suppressed by the flat surface.

  (3) When the pressure inside the fuel tank is higher than the pressure outside the fuel tank, the float seal portion 23b is opened before the through-cylinder portion 72 is opened. Canceled. Therefore, it is possible to prevent the sealing member 23 from being fixed in the closed position, and to increase the responsiveness of the valve opening according to the position of the liquid level.

  (4) Further, since the opening of the float seal portion 23b is smaller than the opening of the cylinder passage portion 72, only the float seal portion 23b is compared with the case where the cylinder passage portion 72 is opened under the same pressure difference. In the case of opening, the gas flow rate increases around the float seal portion 23b. That is, the gas flow velocity is increased at the end surface of the tip cylindrical portion 16 that seals the float seal portion 23b. Therefore, the effect of causing the fuel adhering to the vicinity of the outer edge of the end surface of the tip cylindrical portion 16 to flow outward and downward from the end surface becomes more effective.

(5) The outer peripheral surface of the second intermediate cylindrical portion 15 has an arc shape projecting outward from the end surface of the tip cylindrical portion 16 in a cross section including the central axis of the outer peripheral surface. Therefore, as compared with the case where the outer peripheral surface of the second intermediate cylindrical portion 15 is an inclined surface, the fuel adhering to the vicinity of the peripheral edge at the end surface of the front end cylindrical portion 16 can easily flow from the end surface, and the second intermediate cylindrical portion 15 It becomes difficult for the fuel adhering to the outer peripheral surface to flow to the end surface.
In addition, the said embodiment can also be changed and implemented as follows.

  The outer peripheral surface of the second intermediate cylindrical portion 15 may be a slope extending below the end surface of the tip cylindrical portion 16 and outward of the end surface. According to this aspect, compared with the case where the outer peripheral surface of the second intermediate cylindrical portion 15 is a complicated curved surface, the outer peripheral surface can be easily formed.

The outer peripheral surface of the second intermediate cylindrical portion 15 may have a groove extending below the end surface of the tip cylindrical portion 16 and outward of the end surface. The outer peripheral surface of the second intermediate cylindrical portion 15 is a cylindrical surface extending downward from the outer edge of the end surface of the tip cylindrical portion 16, and is a groove extending below the end surface of the tip cylindrical portion 16 and outward of the end surface. You may have. According to this aspect, the fuel adhering to the vicinity of the outer edge of the end surface of the tip cylindrical portion 16 is guided by the groove toward the lower side of the end surface and outward of the end surface. Therefore, the effect of suppressing the accumulation of fuel on the end face of the float 10 which is a portion that seals the fuel tank from the inside becomes even more remarkable.
The outer peripheral surface of the tip cylindrical portion 16 may have a portion that extends below the end surface of the tip cylindrical portion 16 and outward of the end surface.

For example, as shown in FIG. 3, the engaged portion 21 of the valve body 20 includes a base valve body cylindrical portion 25 that is four cylindrical portions having the same axis and different outer diameters, and an intermediate valve body cylindrical portion. 26 and a tip valve body cylindrical portion 27. The proximal valve body cylinder portion 25 is a portion that has an end portion that enters a gap between the float upper surface 10 t and the second intermediate cylinder portion 15 and engages with the second intermediate cylinder portion 15. The distal valve body cylindrical portion 27 is a portion that protrudes from the intermediate valve body cylindrical portion 26 and to which the seal member 23 is attached. The outer diameter of the proximal valve body cylindrical portion 25 is the outer diameter of the proximal valve body, the outer diameter of the intermediate valve body cylindrical portion 26 is the outer diameter of the intermediate valve body, and the outer diameter of the distal valve body cylindrical portion 27 is the outer diameter of the distal valve body. Then, the valve body 20 satisfies the condition shown by the following formula 1.
Tip valve body outer diameter <base valve body outer diameter <intermediate valve body outer diameter (Formula 3)

  An intermediate valve body outer peripheral surface 26s, which is an outer peripheral surface of the intermediate valve body cylindrical portion 26, is a convex curved surface in which a portion on the proximal end valve body cylindrical portion 25 side projects outward in a radial direction from a portion on the distal end valve body cylindrical portion 27 side. Is on the entire circumference. The convex curved surface on the outer peripheral surface 26s of the intermediate valve body is formed at a portion on the distal valve body cylindrical portion 27 side on the outer peripheral surface 26s of the intermediate valve body, and is an end surface on the proximal valve body cylindrical portion 25 side in the intermediate valve body cylindrical portion 26. It is continuous on a flat surface. In other words, the outer diameter of the intermediate valve body cylindrical part 26 has a maximum value at the end on the proximal valve body cylindrical part 25 side, has a minimum value at the end on the distal valve body cylindrical part 27 side, and The rate at which the outer diameter decreases from the end on the proximal valve body cylinder 25 side toward the end on the distal valve body cylinder 27 side is increased. In addition, in the cross section of the intermediate valve body cylindrical portion 26 including the central axis of the intermediate valve body cylindrical portion 26, the curvature outer diameter of the convex curved surface that forms an arc shape on the outer peripheral surface 26s of the intermediate valve body 26 is that of the intermediate valve body cylindrical portion 26. It is smaller than the outer diameter and smaller than the outer diameter of the tip valve body cylindrical portion 27.

The distal valve body outer circumferential surface 27s, which is the outer circumferential surface of the distal valve body cylindrical portion 27, also has a convex curved surface in which a portion on the intermediate valve body cylindrical portion 26 side protrudes radially outward from a portion on the seal member 23 side. Has all around. The convex curved surface of the distal valve body outer peripheral surface 27 s is formed in a portion on the seal member 23 side of the distal valve body outer peripheral surface 27 s and is continuous with the outer peripheral surface of the seal member 23. In other words, the outer diameter of the tip valve body cylindrical portion 27 has a maximum value at the end on the intermediate valve body cylindrical portion 26 side, has a minimum value at the end on the seal member 23 side, and the intermediate valve body cylinder. The rate at which the outer diameter decreases from the end on the part 26 side toward the end on the seal member 23 side is increased. In the cross section of the tip valve body cylindrical portion 27 including the central axis of the tip valve body cylindrical portion 27, the curvature outer diameter of the convex curved surface forming an arc shape at the second intermediate outer peripheral surface 15s is Smaller than outer diameter.
According to this embodiment, in addition to the effects according to the above (1) to (5), the effects according to the above (1) to (3) and (5) can be obtained for the upper surface of the seal member 23. Is possible.

At this time, the outer peripheral surface of the second intermediate cylindrical portion 15 in the float side contact portion 12 may be a cylindrical surface extending downward from the end surface of the tip cylindrical portion 16. In this aspect, the valve body 20 constitutes a part of the float, the through-cylinder part 72 constitutes the air passage, and the upper surface of the case seal part 23a in the seal member 23 becomes the end face in the upper part of the float.
The cylinder passing portion 72 may be connected to a fuel supply path.

  -The float side contact part 12 may be the structure which has relationships other than following formula 1 regarding the outer diameter of each cylindrical part. For example, the tip outer diameter and the second intermediate outer diameter may be equal, or the tip outer diameter may be larger than the second intermediate outer diameter. In short, the upper part of the float has an end surface that is a flat surface that closes the opening by contact with the periphery of the opening of the air passage, and a peripheral surface that extends downward from the outer edge of the end surface, and the peripheral surface is What is necessary is just the structure which has the part extended toward the downward direction of an end surface, and the outward of an end surface. Even in this embodiment, it is possible to obtain the effects according to the above (1) and (3) to (5).

DESCRIPTION OF SYMBOLS 10,80 ... Float, 10b ... Lower part, 10t, 90t ... Mounting surface, 11, 81 ... Spring accommodation hole, 12, 82 ... Float side contact part, 13 ... Base end cylindrical part, 14 ... First intermediate cylindrical part, 14s 1st intermediate outer peripheral surface, 15 ... 2nd intermediate cylindrical portion, 15s ... 2nd intermediate outer peripheral surface, 16 ... tip cylindrical portion, 20, 90 ... valve body, 20t ... mounting surface, 21 ... engaged portion, 22h ... Fixed hole, 23 ... Seal member, 23a ... Case seal part, 23b ... Float seal part, 25 ... Base valve body cylindrical part, 26 ... Intermediate valve body cylinder part, 26s ... Intermediate valve body outer peripheral surface, 27 ... End valve body Cylindrical portion, 27 s ... outer peripheral surface of the tip valve body, 50 ... valve device for fuel tank, 60 ... lower valve body case, 61 ... outer cylinder portion, 62 ... inner cylinder portion, 63 ... coupling plate, 64 ... coil spring, 70 ... Upper valve body case, 71 ... Housing cylinder, 71h ... Vent, 71t Case lid portion, 72 ... vent tube portion, 72a ... bent end portion, 72b ... connection end portion, 73 ... case-side contact portion, 83 ... engaging portion.

Claims (4)

A fuel tank valve device attached to a fuel tank,
An air passage leading to the inside of the fuel tank and the outside of the fuel tank;
A float that is displaced by fluctuations in the liquid level in the fuel tank at an upper position that is a position for closing the opening of the air passage and a lower position that is a position for opening the opening of the air passage;
The top of the float is
An end surface that is a flat surface that closes the opening by contact with the periphery of the opening;
A peripheral surface extending downward from the outer edge of the end surface;
A tip cylindrical portion having an outer peripheral surface with a cylindrical surface having a constant outer diameter, the cylindrical portion having the end surface;
A circumference that is continuous with the outer peripheral surface and has an arc shape projecting below the end surface and outward of the end surface in a cross section including the central axis of the outer peripheral surface, and is thicker than the thickness of the tip cylindrical portion An intermediate cylindrical portion having a surface as an outer peripheral surface,
The upper peripheral surface of the float is
Have a portion extending outwardly of the lower and the end surface of said end face, and a fuel tank valve, characterized in that composed of the outer peripheral surface of the outer circumferential surface of the distal cylindrical portion intermediate cylindrical portion apparatus. The end surface is a first flat surface,
An upper portion of the float has a second flat surface parallel to the first flat surface at a position below the first flat surface and outside the first flat surface;
The valve device for a fuel tank according to claim 1, wherein a peripheral surface of an upper portion of the float connects the first flat surface and the second flat surface. The opening is a first opening,
The air passage is
A cylindrical portion having a second opening larger than the first opening;
An annular seal member having the first opening,
The sealing member is
It is connected to the float so as to be relatively displaceable upward and downward,
Displaced to an open position for opening the second opening and a closed position for closing the second opening by passing the first opening through the first opening;
Displacing to the closed position with displacement of the float to the upper position;
The fuel tank valve device according to claim 1, wherein the float is displaced to the open position by displacement of the float to the lower position. Peripheral surface of the upper portion of the float, the fuel tank valve device according to any one of claims 1 to 3 having a groove extending outward of the lower and the end face of the end face.

Images