Fuel tank valve device

Abstract

To provide a valve device for a fuel tank which can restrict fuel leakage to the outside of a fuel tank while rising a full load restriction position.SOLUTION: A valve device 10 for a fuel tank has: a housing 15 having a partition wall 30, an opening 33, and a fuel steam discharge port 55; and a float valve 70. In a draft chamber R, a cylindrical wall 60 communicating with the discharge port 55 is provided extending. A cutout part 61 is formed at a lower part of a tip as seen in an extending direction of the cylindrical wall 60. The partition wall 30 has a ceiling wall 31 formed with the opening 33, and a peripheral wall 35 extends downward from a peripheral edge of the ceiling wall 31. A part of the peripheral edge of the ceiling wall 31 and a part of the peripheral wall 35 enter the cylindrical wall 60 through the cutout part 61 when viewed in an axial direction of the cylindrical wall 60 and a valve axis direction.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a fuel tank valve device that is attached to a fuel tank of an automobile or the like, and prevents over-refueling into the fuel tank and prevents fuel from flowing out of the fuel tank.

Background Art

[0002] For example, a fuel tank of a vehicle such as an automobile is equipped with a valve device (full tank regulation valve) that prevents over-refueling into the fuel tank so that the liquid level in the fuel tank does not rise above a preset full tank liquid level, and a valve device (cut valve) that prevents the fuel in the fuel tank from leaking out of the fuel tank when the automobile tilts or rolls over.

[0003] Patent Document 1 listed below describes a fuel cutoff valve that includes a casing having a casing main body forming a valve chamber and a lid body welded to the upper part of the casing main body and provided with a tubular portion, and a float mechanism having a float housed in the valve chamber.

[0004] The casing further includes a valve storage case, and an inner lid that covers the upper part of the valve storage case and forms a connection passage. Further, the inner lid formed with the connection passage is disposed at a height reaching the tube passage of the tubular portion (see Fig. 1 of Patent Document 1).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of Invention

Problems to be Solved by the Invention

[0006] Incidentally, the amount of fuel supplied to the fuel tank is determined by the height of the opening formed in the partition wall of the housing, where the float valve moves in and out. In other words, if the opening formed in the partition wall is high, it is possible to increase the amount of fuel supplied to the fuel tank. The position or location that defines the full fuel level supplied to the fuel tank (the fuel height when the opening is closed by the float valve) is called the full tank limiting surface, lock point, SOH (Shut Off Height), etc.

[0007] In the case of the fuel shut-off valve of Patent Document 1, as described above, the connection passage formed in the inner lid is at a height that reaches the pipe passage in the pipe body, making it easy to set the SOH high. On the other hand, fuel that enters the space defined between the inner lid and the lid through the connection passage can easily flow into the pipe passage in the pipe body, potentially causing leakage outside the fuel tank.

[0008] Therefore, the object of the present invention is to provide a fuel tank valve device that can restrict fuel leakage outside the fuel tank while raising the full tank limit position. [Means for solving the problem]

[0009] To achieve the above objective, the valve device for a fuel tank according to the present invention comprises a housing having a valve chamber communicating with the inside of a fuel tank at the bottom and a ventilation chamber communicating with the outside of a fuel tank at the top, with an opening formed in the partition wall connecting the valve chamber and the ventilation chamber, and a fuel vapor outlet provided on the circumferential surface on the ventilation chamber side, and a float valve housed in the valve chamber so as to be able to move up and down and move toward and toward the opening, wherein the ventilation chamber is provided with a cylindrical wall communicating with the fuel vapor outlet and extending inward from the fuel vapor outlet, and a notch is formed at the lower part of the tip in the extending direction of the cylindrical wall, and the partition wall has a ceiling wall in which the opening is formed, with a circumferential wall extending downward from the periphery of the ceiling wall, and a part of the periphery of the ceiling wall and a part of the circumferential wall are configured to enter into the cylindrical wall through the notch when viewed from the axial direction and the valve axis direction of the cylindrical wall. [Effects of the Invention]

[0010] According to the present invention, a portion of the periphery of the ceiling wall and a portion of the peripheral wall are configured to enter the cylindrical wall through a notch when viewed from the axial direction of the cylindrical wall and the valve axis direction. This allows the opening of the partition wall to be positioned higher inside the housing, and the full tank limiting position can be raised.

[0011] On the other hand, fuel can easily flow into the fuel vapor outlet from the opening, but because a portion of the peripheral wall that makes up the partition wall extends into the cylindrical wall, the opening area of ​​the outlet can be narrowed, making it more difficult for fuel to flow into the fuel vapor piping through the outlet and less likely for it to leak out of the tank.

[0012] Therefore, the fuel tank valve device of the present invention can achieve both the conflicting effects of raising the full tank limit position and restricting fuel leakage outside the fuel tank. [Brief explanation of the drawing]

[0013] [Figure 1] This is an exploded perspective view showing one embodiment of a valve device for a fuel tank according to the present invention. [Figure 2] This is a perspective view of the valve device for the fuel tank. [Figure 3] This is a perspective view of the upper cover of the valve device for the fuel tank, taken from a different direction than in Figure 1. [Figure 4] This is a bottom view of the upper cover. [Figure 5] This is a cross-sectional view of the fuel tank valve device according to the present invention, showing the float valve in a lowered state with its opening open. [Figure 6] This is an enlarged cross-sectional view of section E in Figure 5. [Figure 7] This is a cross-sectional view taken along the line of sight of arrow AA in Figure 2. [Figure 8] Figure 2 is a cross-sectional view taken from the line of sight of arrow BB. [Figure 9] This is a cross-sectional view taken along the line of sight of the DD arrow in Figure 2. [Figure 10] In the valve device for a fuel tank according to the present invention, this is a cross-sectional view showing a state where a float valve has risen to close an opening. [Mode for Carrying Out the Invention]

[0014] (One Embodiment of Valve Device for Fuel Tank) Hereinafter, one embodiment of the valve device for a fuel tank according to the present invention will be described with reference to the drawings.

[0015] As shown in Figure 1 and Figure 5, a valve device 10 for a fuel tank (hereinafter also simply referred to as "valve device 10") in this embodiment is provided with a valve chamber V communicating with the inside of the fuel tank at the lower side and a vent chamber R communicating with the outside of the fuel tank at the upper side via a partition wall 30. The partition wall 30 is formed with an opening 33 that allows communication between the valve chamber V and the vent chamber R, and the peripheral surface on the vent chamber R side is provided with a fuel vapor discharge port 55 (hereinafter also simply referred to as "discharge port 55"). The valve device 10 includes a housing 15, a float valve 70 that is housed in the valve chamber V so as to be able to move up and down and closes the opening 33, and a biasing spring 17 that biases the float valve 70.

[0016] In addition, this valve device 10 has a fuel vapor pipe 57 (hereinafter also simply referred to as "pipe 57") connected to the discharge port 55 on the outer side of the housing 15.

[0017] Further, the housing 15 of this embodiment has a housing main body 20, a lower cap 40 mounted below the housing main body 20, and an upper cover 50 mounted above the housing main body 20.

[0018] In the following description, "fuel" means liquid fuel (including fuel droplets), and "fuel vapor" means vaporized fuel. In addition, the "valve axial direction" in the present invention means the axial direction of the float valve 70 (the direction along the axis C1 of the float valve 70) (the same applies to the following description).

[0019] First, the housing body 20 will be explained with reference to Figures 1, 5, and 6.

[0020] The housing body 20 has a roughly cylindrical body perimeter wall 21, with a partition wall 30 positioned above it. A roughly annular flange portion 23 protrudes from above the body perimeter wall 21. Multiple insertion holes 23a are formed in this flange portion 23.

[0021] Furthermore, multiple cap-side engaging protrusions 25 are provided on the outer circumference of the main body peripheral wall 21, near the axial lower end. In addition, multiple cover-side engaging protrusions 26 are provided on the outer circumference of the main body peripheral wall 21, near the flange portion 23, at a position aligned with the insertion hole 23a.

[0022] Furthermore, a flow hole 27 is formed in the main body peripheral wall 21 near the partition wall 30, which connects the inside of the fuel tank and the inside of the valve chamber V. This flow hole 27 is designed to remain free from liquid except when the vehicle is overturned or reversed, or when refueling the fuel tank, and it is a part that allows air from inside the fuel tank to flow into the valve chamber V.

[0023] As shown in Figures 1, 6, and 8, the partition wall 30 has a ceiling wall 31 that is roughly circular in shape, a peripheral wall 35 that is roughly cylindrical in shape and extends downward from the outer peripheral edge of the ceiling wall 31, and a protruding portion 37 that extends radially outward from the lower outer peripheral edge of the peripheral wall 35.

[0024] These ceiling walls 31, peripheral walls 35, and protruding sections 37 are components related to the notched section 61 of the cylindrical wall 60 shown in Figure 3, but this relationship will be described in the explanation of the upper cover 50.

[0025] An opening 33, shaped like a roughly circular hole, is formed in the radial center of the ceiling wall 31. A valve seat 33a, shaped like a roughly circular projection, is provided protruding from the rear (lower) periphery of the opening 33 (see Figure 6). The opening 33 is opened and closed by the movement of the float valve 70 toward and away from this valve seat 33a (see Figures 5 and 10). A roughly cross-shaped rib 34 is provided on the inner circumference of the opening 33. This rib 34 prevents the seal valve body 75 (see Figures 5, 6, and 10) from protruding from the front inner periphery of the opening 33.

[0026] Furthermore, as shown in Figure 6, a ring mounting portion 38 for attaching a seal ring 29 is provided on the outside of the protruding portion 37, and the partition wall 30 is connected to the upper part of the main body peripheral wall 21 via the ring mounting portion 38. In addition, an annular groove 39 is formed on the outer peripheral edge of the ring mounting portion 38.

[0027] Next, we will describe the lower cap 40 which is attached to the bottom of the housing body 20.

[0028] The lower cap 40 has a bottomed cap shape, comprising a roughly circular plate-shaped bottom wall 41 and a cap peripheral wall 43 erected from the outer edge of the bottom wall 41. Multiple passages 42 are formed in the bottom wall 41 to connect the inside of the fuel tank and the inside of the valve chamber V. Multiple engagement holes 43a are formed in the cap peripheral wall 43.

[0029] Furthermore, a spring support portion 45, which is roughly cross-shaped, is provided protruding from the radial center of the bottom wall 41, to support the lower end of the biasing spring 17.

[0030] Then, by engaging the corresponding cap-side engaging projections 25 of the housing body 20 with each engaging hole 43a of the lower cap 40, the lower cap 40 is mounted below the housing body 20. As a result, a valve chamber V communicating with a fuel tank (not shown) is formed below the housing via the partition wall 30 (see Figure 5).

[0031] Next, the upper cover 50, which is attached to the top of the housing body 20, will be described with reference to Figures 1, 3, 4, 6-9, etc.

[0032] The upper cover 50 has a roughly circular plate-shaped cover ceiling wall 51, a roughly cylindrical cover peripheral wall 52 extending downward from the outer peripheral edge of the cover ceiling wall 51, and a cover overhang 53 projecting radially outward from the lower outer peripheral edge of the cover peripheral wall 52, and has a roughly hat shape with an open bottom and a closed top.

[0033] Furthermore, the lower end portion 52a of the cover peripheral wall 52 is cylindrical in shape, with a larger diameter than the rest of the cover, via a stepped portion 52b (see Figure 3). In addition, the inner surface of the cover ceiling wall 51, that is, the surface of the cover ceiling wall 51 facing the partition wall 30, forms the ceiling surface 51a.

[0034] Furthermore, as shown in Figure 3, multiple engaging pieces 54 hang downward from the inner peripheral edge of the cover overhang 53 (the portion close to the outer circumference of the lower end 52a of the cover peripheral wall 52). Each engaging piece 54 has an engaging hole 54a formed in it.

[0035] Then, each engaging piece 54 of the upper cover 50 is inserted through the corresponding insertion hole 23a of the housing body 20, and the corresponding cover-side engaging projection 26 is engaged with the engaging hole 54a.

[0036] As a result, as shown in Figure 6, the lower end portion 52a of the cover peripheral wall 52 of the upper cover 50 is inserted into the annular groove 39 of the housing body 20, and the lower end portion 52a of the cover peripheral wall 52 abuts against the outer circumference of the seal ring 29 fitted to the ring mounting portion 38, so that the seal ring 29 is held in place, and the upper cover 50 is mounted above the housing body 20.

[0037] In this way, a ventilation chamber R is formed above the partition wall 30, which communicates with the outside of the fuel tank (see Figure 5).

[0038] Furthermore, a substantially circular outlet 55 is formed at a predetermined location in the circumferential direction of the cover wall 52, penetrating the cover wall 52. In addition, a pipe 57 extends for a predetermined length from the outer periphery of the outlet 55 on the cover wall 52. This pipe 57 is in communication with the outlet 55.

[0039] Furthermore, the ventilation chamber R is provided with a cylindrical wall 60 that communicates with the outlet 55 and extends inward from the outlet 55 into the ventilation chamber R, and a notch 61 is formed at the lower part of the tip of the cylindrical wall 60 in the extending direction.

[0040] In this embodiment, the notch 61 has a curved (arc-shaped) surface that curves along the circumferential direction at the bottom side of the cylindrical wall 60, and extends for a predetermined length in the extension direction of the cylindrical wall 60, and cuts out the bottom side of the tip in the extension direction of the cylindrical wall 60.

[0041] Specifically, the lower portion of the cylindrical wall 60 in the extending direction, that is, the portion on the circumferential bottom side of the cylindrical wall 60 (the portion located opposite to the ceiling surface 51a), is cut out by a transverse cross-section F1 (see Figure 3) that runs horizontally, and the portion of the cylindrical wall 60 in the lower portion of the extending direction, adjacent to the transverse cross-section F1, is cut out by a longitudinal cross-section F2 (see Figure 4) that is perpendicular to the transverse cross-section F1 and runs along the inner circumferential surface of the cover circumferential wall 52, which is arc-shaped.

[0042] In other words, the notch 61 of this embodiment has horizontal notches 61a, 61a cut out by the horizontal cross-section F1 and a vertical notch 61b cut out by the vertical cross-section F2.

[0043] Furthermore, the cylindrical wall 60 has a shape in which the lower part of the tip in the extending direction is open via a notch 61 consisting of a pair of horizontal notches 61a, 61a and a vertical notch 61b.

[0044] Furthermore, the portion of the cylindrical wall 60 that is on the ceiling surface 51a side of the portion cut out by the pair of horizontal notches 61a, 61a of the notch 61 forms an upward extension 63. Also, the portion of the cylindrical wall 60 that is on the base end side in the extension direction of the vertical notch 61b of the notch 61, and that is closer to the bottom of the cylindrical wall 60, forms a downward extension 64.

[0045] Furthermore, it can also be said that the cylindrical wall 60 is formed as follows.

[0046] Specifically, a pair of side walls 65 extend from the inner periphery of the exhaust port 55 on the ventilation chamber R side toward the inside of the ventilation chamber R, with their outer surfaces being parallel to each other. These pair of side walls 65, 65 are connected to each other by a connecting wall 66 that is connected to the ceiling surface 51a and has an arc-shaped inner circumference.

[0047] Then, the portion near the bottom of the leading edge of the pair of side walls 65, 65 in the extending direction is notched by the transverse cross-section F1, so that the transverse notches 61a, 61a of the notch 61 are located on the lower end surfaces of the leading edge of the pair of side walls 65, 65 in the extending direction, and the upward extension 63 is formed through the notch 61.

[0048] In other words, the upward extension 63 consists of the leading ends of the pair of side walls 65, 65 in the direction of extension and the portion of the connecting wall 66 that connects the leading ends of the pair of side walls 65, 65 in the direction of extension. Furthermore, the upward extension 63 has an open shape at its leading edge in the direction of extension and at the bottom of the partition wall 30 facing the ceiling wall 31.

[0049] Furthermore, the bottom of the base end of the cylindrical wall 60 in the extending direction, adjacent to the leading ends of the pair of side walls 65, 65 that constitute the upward extension portion 63, is notched by the vertical cross-section F2, thereby forming an arc-shaped downward extension portion 64 through the vertical notched portion 61b of the notched portion 61.

[0050] Furthermore, the downward extension portion 64 is positioned offset from the upward extension portion 63 in the axial direction of the cylindrical wall 60 (located on the base end side in the extension direction of the cylindrical wall 60) and is provided at a location facing the radial direction of the cylindrical wall 60.

[0051] Furthermore, in this valve device 10, a portion of the periphery of the ceiling wall 31 and a portion of the peripheral wall 35 are configured to enter the cylindrical wall 60 through the notch 61 when viewed from the axial direction of the cylindrical wall 60 and the valve axis direction.

[0052] In this embodiment, as shown in Figure 7, when viewed from the axial direction of the piping 57, a predetermined circumferential portion of the ceiling wall 31 including its peripheral edge, and a predetermined portion of the peripheral wall 35 in that portion (indicated by reference numeral M in Figure 1, the portion enclosed by the outer peripheral edge of the ceiling wall 31 and the arc along the circumferential direction of the peripheral wall 35 and the chord connecting its two ends; hereinafter also referred to as the "recessed portion M") are located within the notch 61, and as shown in Figure 8, when viewed from the valve axis direction, the recessed portions M of the ceiling wall 31 and the peripheral wall 35 are located within the notch 61.

[0053] As a result, the recessed portion M, which is part of the ceiling wall 31 and part of the peripheral wall 35, is positioned to extend into the cylindrical wall 60 via the notch 61 when viewed from the axial direction and the valve direction of the cylindrical wall 60 (see Figures 7 and 8).

[0054] Furthermore, as shown in Figure 8, the upward extension portion 63 that constitutes the cylindrical wall 60 is positioned so as to overlap (wrap around) the ceiling wall 31 that constitutes the partition wall 30 when the cylindrical wall 60 is viewed from the direction of the valve axis.

[0055] Furthermore, as shown in Figure 6, a gap S2 is formed in the valve axis direction between the protruding portion 37 and the downward extension portion 64 of the partition wall 30. Specifically, a gap S2 is formed between the upper surface of the protruding portion 37 and the lower surface of the bottom of the downward extension portion 64 (the gap S2 is formed at predetermined intervals in the valve axis direction).

[0056] As also shown in Figure 6, a gap S1 is formed in the valve axis direction between the ceiling wall 31 and the upward extension 63 of the partition wall 30. Specifically, a gap S1 is formed between the upper surface of the ceiling wall 31 and the lower end surfaces of the pair of side walls 65, 65 that constitute the upward extension 63 (the surfaces where the lateral notch portion 61a is located) (the gap S1 is formed at predetermined intervals in the valve axis direction).

[0057] Furthermore, the gap S1 between the ceiling wall 31 and the upward extension 63 is smaller than the gap S2 between the overhang 37 and the downward extension 64.

[0058] Furthermore, as shown in Figures 3, 5, and 6, an inflow restriction wall 68 extends from the ceiling surface 51a of the ventilation chamber R toward the ceiling wall 31, restricting the inflow of fuel into the discharge port 55.

[0059] In this embodiment, the inflow restricting wall 68 is roughly in the shape of a long plate, formed with an area that can generally cover the opening at the leading edge in the extension direction of the cylindrical wall 60, in this case the leading edge opening of the upward extension portion 63, and hangs down from the ceiling surface 51a of the cover ceiling wall 51 of the upper cover 50 toward the ceiling wall 31 of the partition wall 30.

[0060] Furthermore, as shown in Figure 8, the inflow restricting wall 68 is positioned between the tip of the upward extension 63 and the center C2 of the housing 15, which coincides with the axis C1 of the float valve 70 (which can also be called the radial center of the ceiling wall 31 of the partition wall 30), when viewed from the ceiling surface 51a side of the ventilation chamber R in the direction of the valve axis, and is spaced apart from the tip of the upward extension 63. Note that, as shown in Figure 8, when viewed from the ceiling surface 51a side of the ventilation chamber R in the direction of the valve axis, the inflow restricting wall 68 is positioned perpendicular to the extension direction of the upward extension 63.

[0061] Furthermore, as shown in Figure 9, when viewed from the axial direction of the cylindrical wall 60, the upper part of the cylindrical wall 60 is covered by the inflow restriction wall 68, and the lower part of the cylindrical wall 60 is covered by the peripheral wall 35 of the partition wall 30.

[0062] More specifically, as shown in Figure 9, when viewing the inside of the ventilation chamber R from the leading end of the pipe 57 in the extension direction, the upper half of the cylindrical wall 60 (the portion above the radial center of the cylindrical wall 60) and the area slightly below the radial center are covered by the inflow restricting wall 68, while a predetermined area of ​​the lower half of the cylindrical wall 60 (the portion below the radial center of the cylindrical wall 60 and below the lower end surface of the inflow restricting wall 68) is covered by the peripheral wall 35.

[0063] Next, the float valve 70, which is housed in the valve chamber V so as to be able to move up and down, will be described with reference to Figures 1, 5, and 6.

[0064] As shown in Figures 1 and 5, the float valve 70 of this embodiment includes a float body 71 that generates buoyancy when immersed in fuel, and a sealing member 73 that is mounted above the float body 71 and moves up and down relative to the float body 71, moving toward and away from the opening 33 of the partition wall 30.

[0065] Furthermore, a seal valve body 75 made of an elastic material such as rubber or elastic elastomer is mounted above the seal member 73. A vent hole 75a, which is open at the top and bottom, is formed through the center of the seal valve body 75. By moving the seal valve body 75 toward and away from the valve seat 33a of the opening 33, the opening 33 is opened and closed, causing the float valve 70 to function as a full tank regulating valve.

[0066] Furthermore, an intermediate valve body 77 is tiltably supported between the float body 71 and the sealing member 73. This intermediate valve body 77 normally abuts against the lower end of the sealing valve body 75, closing the vent hole 75a (see Figures 5 and 6), and opens the vent hole 75a when the float body 71 descends relative to the sealing member 73.

[0067] Furthermore, the float valve 70 is housed within the valve chamber V so as to be able to move up and down between itself and the lower cap 40 with a biasing spring 17 interposed between them. When the fuel is immersed, it rises due to its own buoyancy and the biasing force of the biasing spring 17, and when the fuel is not immersed, it descends due to its own weight.

[0068] (modified version) The shape, structure, layout, etc., of the housing, housing body, partition wall, lower cap, upper cover, cylindrical wall, float valve, etc., that constitute the present invention are not limited to the above-described embodiments.

[0069] Furthermore, although the housing 15 in the above embodiment is composed of a housing body 20, a lower cap 40, and an upper cover 50, the housing can be any structure that has at least a partition wall.

[0070] Furthermore, although the main body periphery wall 21 of the housing body 20, the periphery wall 35 of the partition wall 30, the cover periphery wall 52 of the upper cover 50, etc., are substantially cylindrical in this embodiment, they may also be elliptical or rectangular in shape, for example.

[0071] Furthermore, although the float valve 70 in this embodiment has a multi-component structure consisting of a float body 71, a sealing member 73, an intermediate valve body 77, etc., the float valve may also be, for example, a float valve with a sealing member made of an elastic material attached to the top, as long as it can open and close the opening 33.

[0072] Furthermore, in this embodiment, one float valve 70 is housed in one valve chamber V formed within the housing 15. However, for example, multiple float valves may be housed in one valve chamber (functioning as a fuel cut-off valve, pressure regulating valve, etc., in addition to a full tank regulation valve), or multiple valve chambers may be defined within the housing, with a float valve housed in each valve chamber.

[0073] Furthermore, the partition wall 30 in this embodiment has a ceiling wall 31, a peripheral wall 35, an overhanging portion 37, a ring mounting portion 38, etc., and its outer circumference has a stepped shape that widens in a stepped manner downward from the ceiling wall 31. However, the partition wall only needs to have at least a ceiling wall and a peripheral wall.

[0074] Furthermore, in this embodiment, the notch 61 of the cylindrical wall 60 has a curved shape that curves along the circumferential direction at the bottom of the cylindrical wall 60 and extends for a predetermined length in the extension direction of the cylindrical wall 60. However, the notch can be, for example, cut only with a horizontal cut surface at the bottom of the cylindrical wall, cut with an arc-shaped cut surface, or a combination of horizontal cut surfaces, arc-shaped cut surfaces, and cut surfaces oblique to the extension direction of the cylindrical wall to form a roughly trapezoidal, roughly U-shaped, roughly V-shaped, etc. shape, and the shape is not particularly limited as long as a part of the periphery of the ceiling wall and a part of the surrounding wall can fit into it.

[0075] Furthermore, although the inflow restricting wall 68 in this embodiment is roughly in the shape of a long plate, the inflow restricting wall may be, for example, semicircular, trapezoidal, rectangular, or roughly U-shaped or V-shaped when viewed from the direction of the valve axis, as long as it is a shape that can restrict the inflow of fuel into the discharge port.

[0076] (Effects and Benefits) Next, the effects and benefits of the valve device 10 having the above structure will be explained.

[0077] As shown in Figure 5, when the fuel tank is not sufficiently filled with fuel and the float valve 70 is not immersed in fuel, the float valve 70 descends under its own weight, opening 33, and thus the valve chamber V and the vent chamber R are in communication through the opening 33.

[0078] In this state, when fuel is supplied to the fuel tank, primarily air from inside the fuel tank flows into the valve chamber V through the vent 42 of the lower cap 40, passes through the gap between the float valve 70 and the cap periphery 43 of the lower cap 40 and the main body periphery 21 of the housing body 20, flows upward, flows into the ventilation chamber R through the opening 33, and is discharged to the canister outside the fuel tank. In this way, the air inside the fuel tank is discharged to the outside of the fuel tank, making it possible to supply fuel to the fuel tank.

[0079] As fuel is supplied to the fuel tank from the state shown in Figure 5 above, the fuel flows into the valve chamber V through the passage 42 of the lower cap 40, and the float body 71 of the float valve 70 becomes immersed in the fuel.

[0080] Then, when the fuel reaches a preset SOH (which can also be called a lock point or full tank limiting surface), that is, when the flow hole 27 provided in the housing body 20 is closed and the fuel is submerged, the biasing force of the biasing spring 17 and the buoyancy of the float body 71 of the float valve 70 cause the float valve 70 to rise rapidly, the seal valve body 75 to come into contact with the valve seat 33a, and the opening 33 is closed.

[0081] As a result, airflow between the valve chamber V and the ventilation chamber R through the opening 33 is blocked. This causes the fuel in the fuel tank to rise up the fuel supply pipe installed in the fuel tank, and when the fuel comes into contact with the full tank detection sensor on the fuel nozzle inserted into the fuel filler neck, the tank is detected as full, and the supply of fuel into the fuel tank is stopped, thereby preventing the tank from overfilling.

[0082] In this valve device 10, a portion of the periphery of the ceiling wall 31 and a portion of the peripheral wall 35 that constitute the partition wall 30 are configured to enter the cylindrical wall 60 through the notch 61 when viewed from the axial direction of the cylindrical wall 60 and the valve axis direction, as shown in Figures 7 and 8. Therefore, the opening 33 formed in the partition wall 30 can be positioned higher inside the housing 15, thereby raising the full tank restriction position.

[0083] On the other hand, fuel can easily flow from the opening 33 into the discharge port 55, but a portion of the peripheral wall 35 that makes up the partition wall 30 extends into the cylindrical wall 60, thereby narrowing the opening area of ​​the discharge port 55. As a result, fuel is less likely to flow into the piping 57 through the discharge port 55 and less likely to leak out of the tank.

[0084] As described above, this valve device 10 can achieve both the conflicting effects of raising the full-tank limit position and restricting fuel leakage outside the fuel tank.

[0085] In this embodiment, the cylindrical wall 60 has an upward extension 63 formed through a notch 61, and the upward extension 63 is positioned to overlap the ceiling wall 31 when viewed from the direction of the valve axis (see Figure 8). Furthermore, an inflow restricting wall 68 extends from the ceiling surface 51a of the ventilation chamber R toward the ceiling wall 31 to restrict the inflow of fuel into the discharge port 55, and the inflow restricting wall 68 is positioned between the tip of the upward extension 63 and the center C2 of the housing 15, which coincides with the axis C1 of the float valve 70, and is spaced apart from the tip of the upward extension 63 when viewed from the ceiling surface 51a side of the ventilation chamber R toward the direction of the valve axis (see Figure 8).

[0086] According to the above embodiment, before the float valve 70 rises and closes the opening 33, the fuel that has flowed into the ventilation chamber R collides with the inflow restricting wall 68 and diffuses, and then collides with the upward extension 63 and falls, making it difficult for fuel to flow from the discharge port 55 into the piping 57, and thus more effectively preventing fuel from leaking outside the fuel tank.

[0087] Furthermore, since the inflow restricting wall 68 and the tip of the upward extension 63 are spaced apart, ventilation can be maintained. As a result, there is no impediment to the performance of air discharge from inside the fuel tank when fuel is supplied into the fuel tank, and the ceiling wall 31 with the opening 33 can be positioned as high up inside the housing 15 as possible.

[0088] Therefore, the effects of raising the full-tank limit and restricting fuel leakage outside the tank can be further enhanced.

[0089] Furthermore, in this embodiment, when viewed from the axial direction of the cylindrical wall 60, the upper part of the cylindrical wall 60 is covered by the inflow restricting wall 68, and the lower part of the cylindrical wall 60 is covered by the peripheral wall 35 (see Figure 9).

[0090] According to the above embodiment, when viewed from the axial direction of the cylindrical wall 60, the upper part of the cylindrical wall 60 is covered by the inflow restricting wall 68 and the lower part of the cylindrical wall 60 is covered by the peripheral wall 35. Therefore, before the float valve 70 rises and closes the opening 33, it becomes more difficult for the fuel that has flowed into the ventilation chamber R to flow into the piping 57 from the outlet 55, thereby more effectively preventing fuel from leaking outside the fuel tank.

[0091] In this embodiment, an overhang 37 extends from the lower outer peripheral edge of the peripheral wall 35 of the partition wall 30, and the cylindrical wall 60 has an upward extension 63 and a downward extension 64 formed via a notch 61. Gaps S2 and S1 are formed in the valve axis direction between the overhang 37 and the downward extension 64, and between the ceiling wall 31 and the upward extension 63, respectively. The gap S1 between the ceiling wall 31 and the upward extension 63 is smaller than the gap S2 between the overhang 37 and the downward extension 64 (see Figure 6).

[0092] According to the above embodiment, the gap S2 formed between the overhanging portion 37 and the downward extension portion 64 can capture the fuel that has flowed into the ventilation chamber R. Furthermore, since the gap S1 between the ceiling wall 31 and the upward extension portion 63 is formed to be smaller than the gap S2 between the overhanging portion 37 and the downward extension portion 64, it is made less likely for the fuel captured in the gap S2 between the overhanging portion 37 and the downward extension portion 64 to escape, and it is made less likely for the fuel to flow into the piping 57 from the discharge port 55.

[0093] Furthermore, the present invention is not limited to the embodiments described above, and various modified embodiments are possible within the scope of the gist of the present invention, and such embodiments are also included in the scope of the present invention. [Explanation of Symbols]

[0094] 10. Valve device for fuel tank (valve device) 15 Housing 20 Housing body 30 Partition walls 31 Ceiling and Wall 33 Aperture 35 Peripheral wall 37. Protruding section 40 Lower cap 50 Top cover 51a Ceiling surface 55 Outlet 57 Fuel vapor piping (piping) 60 Cylindrical wall 61 Notch 63 Upper extension part 64 Downward extension part 68 Inflow restriction wall 70 Float valve R Ventilation Room V valve chamber

Claims

1. A housing is provided with a valve chamber below, which communicates with the inside of the fuel tank, and a ventilation chamber above, which communicates with the outside of the fuel tank, via a partition wall. An opening is formed in the partition wall that connects the valve chamber and the ventilation chamber, and a fuel vapor outlet is provided on the circumferential surface on the ventilation chamber side. It has a float valve housed within the valve chamber so as to be able to move up and down, and which moves toward and away from the opening, The ventilation chamber is provided with a cylindrical wall that communicates with the fuel vapor outlet and extends inward from the fuel vapor outlet into the ventilation chamber, and a notch is formed at the lower part of the leading end of the cylindrical wall in the extending direction. The partition wall has a ceiling wall in which the opening is formed, and a peripheral wall extends downward from the periphery of the ceiling wall. A valve device for a fuel tank, characterized in that a part of the periphery of the ceiling wall and a part of the periphery wall are configured to enter the cylindrical wall through the notch when viewed from the axial direction and the valve axis direction of the cylindrical wall.

2. The cylindrical wall has an upward extension formed through the notch, and the upward extension is positioned to overlap the ceiling wall when viewed from the direction of the valve axis. An inflow restricting wall extends from the ceiling surface of the ventilation chamber toward the ceiling wall, restricting the inflow of fuel into the fuel vapor outlet. The valve device for a fuel tank according to claim 1, wherein the inflow restricting wall is positioned between the tip of the upward extension and the center of the housing that coincides with the axis of the float valve, and is spaced apart from the tip of the upward extension, when viewed in the direction of the valve axis from the ceiling side of the ventilation chamber.

3. The valve device for a fuel tank according to claim 2, configured such that, when viewed from the axial direction of the cylindrical wall, the upper part of the cylindrical wall is covered by the inflow restricting wall and the lower part of the cylindrical wall is covered by the peripheral wall.

4. A protruding portion extends from the lower outer edge of the aforementioned peripheral wall. The cylindrical wall has an upward extension and a downward extension formed through the notch. A gap is formed between the protruding portion and the downward extension portion, and between the ceiling wall and the upward extension portion, in the direction of the valve axis. The valve device for a fuel tank according to claim 1 or 2, wherein the gap between the ceiling wall and the upward extension is formed to be smaller than the gap between the overhang and the downward extension.

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