JP6646423B2 - Valve device for fuel tank - Google Patents

Description

  The present invention relates to a valve device for a fuel tank which is mounted on a fuel tank of an automobile or the like and is used as a fuel outflow prevention valve, a full tank control valve, or the like.

  For example, in a fuel tank of a car, when the car turns or tilts, the fuel in the fuel tank is prevented from leaking out of the fuel tank by a fuel outflow prevention valve, and the liquid level in the fuel tank is In order to prevent the fuel tank from rising above a preset full tank level, a full tank regulating valve for preventing supercharging into the fuel tank is mounted.

  As this kind of conventional one, Patent Literature 1 listed below includes a cylindrical case having a storage chamber, and a float valve housed in the storage chamber and having a valve body at an upper portion. Has a structure in which the movement of the valve body in the direction along the center axis of movement of the float body is allowed, and when the float body descends, the seated valve body is separated from the seat body. A valve device for a fuel tank is described.

  The float body has a substantially cylindrical main body, and a head protruding from an upper end of the main body. The head includes a shaft protruding from an upper end of the main body, It consists of a circumferential collar connected to the tip. The main body has a gap for inserting a spring therein, and a through hole formed on the ceiling surface thereof, which communicates with the gap and allows fuel, steam, and the like in the tank to flow out. On the other hand, the valve body has a disk shape and has a plurality of legs protruding downward from the periphery thereof, and a hooking claw protrudes from the inside of the distal end of the predetermined leg. Then, the plurality of legs of the valve body are arranged on the outer periphery of the orbiting flange of the head of the float body, and the hooks on the inner side of the legs are hooked on the back side of the orbiting flange, thereby forming the float body. The valve body is assembled such that the valve body is allowed to move up and down.

Japanese Patent No. 4990020

  In the case of the above-mentioned device, since the orbiting collar portion on which the engaging claw of the valve element is engaged is formed on the upper part of the float element, the height of the float element and the valve element in the axial direction is increased, and the valve apparatus is increased in size. Cheap. In addition, since the through hole is formed in the ceiling surface of the float body, when the fuel vibrates violently in the fuel tank, the fuel flows out from the through hole so as to blow up, and the fuel flows through the valve seat. There is a risk of leaking out of the tank.

  Therefore, an object of the present invention is to provide a valve device for a fuel tank that can reduce the size of the valve device and suppress fuel leakage to the outside of the fuel tank.

  In order to achieve the above object, a valve device for a fuel tank of the present invention is provided with a valve chamber below and a ventilation chamber above, via a partition wall, and connects the valve chamber and the ventilation chamber to the partition wall. An opening is formed, a housing having a valve seat provided on a peripheral edge of the opening, a float body arranged to be movable up and down in a valve chamber of the housing, and a valve body attached to the float body, the float comprising: The body has a peripheral wall and a ceiling wall disposed above the peripheral wall, a cavity is formed therein, and a through-hole communicating with the cavity is formed in the ceiling wall, and the valve is provided with the valve. A support portion for tiltably supporting the body is provided; the valve body is a seal portion that opens and closes the opening by coming into contact with and separating from the valve seat; and an engagement leg portion that engages the seal portion with the float body. And the engaging leg portion is inserted into a through hole of the ceiling wall. While urchin extends, characterized in that it is configured to engage the back side of the through hole.

  In the fuel tank valve device according to the present invention, it is preferable that an engagement claw projecting toward an outer diameter side of the peripheral wall is provided on a side surface of the engagement leg.

  In the valve device for a fuel tank according to the present invention, the peripheral wall of the float body has an outer peripheral wall and an inner peripheral wall concentrically arranged inside the outer peripheral wall, and on the back side of the ceiling wall, A plurality of ribs connecting the outer peripheral wall and the inner peripheral wall are formed, and an air chamber is formed between the outer peripheral wall, the inner peripheral wall, and the adjacent ribs inside the cavity. And when the float body is viewed from the axial direction, the air chamber is arranged at a position that does not overlap with the through hole in the circumferential direction, and the inner peripheral wall is provided with respect to the through hole. It is preferable that a slit is provided at a position overlapping in the circumferential direction to allow a space formed outside the inner peripheral wall and a space formed inside the inner peripheral wall to communicate with each other.

  In the valve device for a fuel tank according to the present invention, the peripheral wall of the float body has an outer peripheral wall and an inner peripheral wall concentrically arranged inside the outer peripheral wall, and on the back side of the ceiling wall, A plurality of ribs connecting the outer peripheral wall and the inner peripheral wall are formed, and an air chamber is formed between the outer peripheral wall, the inner peripheral wall, and the adjacent ribs inside the cavity. And when the float body is viewed from the axial direction, the air chamber is arranged at a position that does not overlap with the through hole in the circumferential direction, and the plurality of ribs are on the side opposite to the ceiling wall. It is preferable that the end is formed closer to the ceiling wall than the lower end of the peripheral wall, and the end forms a spring contact portion for biasing the float body.

  According to the present invention, the engaging leg portion of the valve body is inserted into the through hole in the ceiling wall of the float body and engages with the back side thereof, so that the valve body engages with the float body. With the inserted engaging leg, it is possible to make it difficult for fuel to flow out of the through hole and to make it difficult for the fuel to leak out of the fuel tank, and that the engaging leg extends through the ceiling wall of the float body. The height direction of the float body and the valve body can be made small, and the whole apparatus can be made compact.

It is an exploded perspective view showing one embodiment of the valve device for fuel tanks of the present invention. It is sectional drawing of the valve apparatus. It is a perspective view of the float body which comprises the same valve apparatus. It is sectional drawing of the same float body. It is a bottom view of the float body. It is a sectional perspective view of the float body. 3A and 3B show a valve element constituting the valve device, wherein FIG. 3A is a perspective view thereof, and FIG. 3B is a perspective view when viewed from a different direction from FIG. . It is sectional drawing in the state which the float body rose in the valve apparatus. FIG. 3 is a cross-sectional view of the valve device in a state where a valve body is tilted.

  Hereinafter, an embodiment of a fuel tank valve device of the present invention will be described with reference to FIGS. In the following description, “fuel” refers to liquid fuel (including fuel droplets), and “fuel vapor” refers to evaporated fuel.

  As shown in FIGS. 1 and 2, the fuel tank valve device 10 (hereinafter, referred to as a “valve device 10”) includes a substantially cylindrical housing body 20 having a partition wall 22 provided thereon, and a housing body 20. The housing 15 includes an upper cap 30 disposed above the housing 20 and a lower cap 40 mounted below the housing body 20.

  As shown in FIG. 2, by mounting the lower cap 40 below the housing body 20, a valve chamber V communicating with a fuel tank (not shown) is defined below the partition wall 22 through the partition wall 22. By disposing the upper cap 30 above the main body 20, a ventilation chamber R communicating with the outside of the fuel tank is defined above the partition wall 22 via the partition wall 22.

  Further, the valve device 10 includes a float body 50 that is arranged to be able to move up and down in the valve chamber V of the housing 15, and a valve body 70 that is attached to the float body 50.

  The housing body 20 has a substantially cylindrical shape with an opening at the bottom, and has a peripheral wall 21 in which a through hole 21a is formed. A seal ring 28 is mounted on the upper outer periphery of the peripheral wall 21 to enhance the sealing performance with the cover member 45 shown in FIG.

  A circular opening 23 is formed at the center of the partition wall 22 formed above the housing body 20, and a valve seat 24 is protrudingly provided at a peripheral edge on the back side (see FIG. 2). .

  Further, as shown in FIG. 2, a communication port 25 communicating with the valve chamber V and the ventilation chamber R is formed on the outer periphery of the opening 23 of the partition wall 22. From the upper surface of the partition wall 22, a valve accommodating wall 26 having a shape in which two cylindrical walls having different outer diameters are continuously provided is provided so as to surround the opening 23 and the communication port 25. ing. An upper cap 30 provided with a through-hole 30a is attached to an upper opening of the valve housing wall 26.

  A check valve 35 having a negative pressure valve 35a is accommodated in the ventilation chamber R and above the opening 23. The check valve 35 is normally urged downward by a spring 35b, contacts the upper peripheral portion of the opening 23, and closes the opening 23. When the pressure in the fuel tank rises, the check valve 35 rises against the urging force of the spring 35b, opens the opening 23, and discharges the fuel vapor out of the fuel tank. When the pressure drops, the negative pressure valve 35a opens to allow external air to flow into the fuel tank.

  Further, a relief valve 37 is accommodated in the ventilation chamber R and above the communication port 25. The relief valve 37 normally closes the upper opening of the communication port 25 via the spring 37a, and further in a state where the valve body 70 contacts the valve seat 24 and closes the opening 23 (the state of FIG. 8). When the pressure in the fuel tank increases, the fuel tank is pushed up against the urging force of the spring 37a, opens the communication port 25, and releases the fuel vapor out of the fuel tank. The relief valve 37 and the check valve 35 need not be provided.

  In addition, a cover member 45 having a fuel vapor pipe 46 (hereinafter, referred to as “pipe 46”) as shown in FIG. 2 is mounted above the housing body 20. The pipe 46 communicates with the ventilation chamber R via a fuel vapor discharge port (not shown), and a tube (not shown) that communicates with a canister disposed outside the fuel tank is connected to the outer periphery of the pipe 46.

  The lower cap 40 mounted below the housing main body 20 has a through hole 40a formed at the bottom thereof so as to communicate with the valve chamber V (see FIGS. 1 and 2). A spring 69 for urging the float body 50 is mounted on the lower cap 40, and the float body 50 is mounted on the lower cap 40 via the spring 69.

  Next, the float body 50 will be described with reference to FIGS.

  The float body 50 has a peripheral wall 51 and a ceiling wall 52 disposed above the peripheral wall 51, has a substantially cylindrical shape that is open at the bottom and closed at the top, and has a hollow portion K (FIG. 4). Reference) is formed.

  The ceiling wall 52 has a substantially disk shape, and a support portion 53 having a rounded mountain-shaped projection at the tip protrudes from the center of the upper surface. The support portion 53 is a portion that supports a receiving portion 73 (see FIGS. 2 and 7B) in a mortar shape described later of the valve body 70, and supports the valve body 70 in a tiltable manner. . Note that the support portion only needs to be able to tiltably support the valve body with respect to the float body. For example, the support body may have a hemispherically projecting shape, or a protrusion may be provided on the valve body side to receive the protrusion on the float body side. A concave support portion may be provided, and there is no particular limitation.

  Further, a pair of rectangular through holes 54 communicating with the hollow portion K are formed at positions on the ceiling wall 52 which are circumferentially opposed to each other on the outer periphery of the support portion 53. As shown in FIG. 5, the pair of through-holes 54, 54 are formed in a space K <b> 1 formed outside the inner peripheral wall 59 and a space formed inside the inner peripheral wall 59 in the cavity K. K2 is communicated with each other. In addition, the through-hole may be a round hole, an elliptical hole, or the like, and the shape is not limited, and the number is not particularly limited. Further, a plurality of arc-shaped walls 55 are erected at predetermined intervals on the outer peripheral edge of the ceiling wall 52.

  Further, the peripheral wall 51 in this embodiment has a substantially cylindrical shape, and an upper end thereof is concentric with the outer peripheral wall 57 inside the outer peripheral wall 57 connected to the peripheral edge of the ceiling wall 52. And an upper end thereof connected to the back side of the ceiling wall 52, a substantially cylindrical inner peripheral wall 59, and inside the inner peripheral wall 59, with respect to the outer peripheral wall 57 and the inner peripheral wall 59. And a cylindrical wall 61 having a substantially cylindrical shape, the upper end of which is connected to the central portion on the back side of the ceiling wall 52, and has a multi-cylindrical shape (here, a triple cylindrical shape). Has made. Note that the peripheral wall 51 may be a single wall portion, may have a double cylindrical shape of the outer peripheral wall and the inner peripheral wall, or may have a shape of three or more multiple cylinders, and may have a hollow portion in relation to the ceiling wall. The shape and structure are not particularly limited as long as they can be formed.

  Further, as shown in FIGS. 3 and 5, the inner surface side of the inner peripheral wall 59 and the outer surface side of the cylindrical wall 61 arranged inside the inner peripheral wall 59 are arranged at equal intervals in the circumferential direction. (Here, four). The upper end of the connection wall 63 is connected to the back side of the ceiling wall 52.

  As shown in FIG. 4, the connection wall 63, the inner peripheral wall 59, and the cylindrical wall 61 are formed with lengths whose lower ends are aligned. On the other hand, from the lower end of the outer peripheral wall 57, a thin rib-like projection 57 a is projected from the lower end of the outer peripheral wall 57 at equal intervals (see FIG. 4), and extends longer than the inner peripheral wall 59 and the like. (See FIG. 4). The protrusion 57a is a part that reduces the contact area with the bottom surface of the lower cap 40 to prevent the float body 50 from sticking.

  An annular space K1 is formed outside the inner peripheral wall 59, and a plurality of arc-shaped spaces K2 defined by the connecting wall 63 are formed inside the inner peripheral wall 59. . A first air chamber K3 for storing air to increase buoyancy is formed inside the cylindrical wall 61, and the upper end side of the first air chamber K3 is above the ceiling wall 52. And extends to the inside of the support portion 53 (see FIG. 4).

  Further, a plurality of guide ribs 57b extending in the axial direction are formed on the outer periphery of the outer peripheral wall 57 at equal intervals in the circumferential direction, and these guide ribs 57b are arranged near the inner surface of the peripheral wall 21 of the housing body 20. It is arranged and serves as a guide when the float body 50 moves up and down.

  A rib 65 connecting the upper end of the outer peripheral wall 57 and the upper end of the inner peripheral wall 59 has a predetermined interval on the back side of the ceiling wall 52 so as to be radial with respect to the axis of the float body 50. A plurality of protrusions are provided apart (see FIGS. 5 and 6). The plurality of ribs 65 are formed to be shorter than the lower end of any of the outer peripheral wall 57, the inner peripheral wall 59, and the cylindrical wall 61 constituting the peripheral wall 51 (see FIG. 4). An end of the rib 65 opposite to the ceiling wall 52 forms a contact portion of a spring 69 for biasing the float body 50 (see FIG. 2).

  Further, a plurality of slits 67 extending in the axial direction from the lower end to the upper end of the inner peripheral wall 59 are formed in the inner peripheral wall 59 at equal intervals in the circumferential direction. Here, four slits 67 are formed radially with respect to the axis of the float body 50 (see FIG. 5). Through these slits 67, a space K1 outside the inner peripheral wall 59 and a space K2 inside the inner peripheral wall 59 communicate with each other. The slit may have a shape extending from the lower end of the inner peripheral wall 59 to a predetermined position in the axial direction, and the number thereof is not particularly limited.

  In addition, the inside of the cavity K defined by the peripheral wall 51 and the ceiling wall 52, and between the outer peripheral wall 57, the inner peripheral wall 59, and the ribs 65, 65 adjacent to each other in the circumferential direction, air is stored. Two air chambers K4 are formed (see FIGS. 5 and 6). The second air chamber K4 forms the “air chamber” in the present invention. In this embodiment, as shown in FIG. 5, the ribs 65 are located at positions matching the plurality of connecting wall portions 63, and are not adjacent to the slit 67, and are located at positions adjacent to each other in the circumferential direction. A plurality of (here, four) second air chambers K4 are formed (if the slits 67 are provided, the air chambers cannot accumulate air).

  Further, as shown in FIG. 5, when the float body 50 is viewed from the axial direction, the second air chamber K4 is disposed at a position that does not overlap the pair of through holes 54 in the circumferential direction. At the same time, of the plurality of slits 67 formed in the inner peripheral wall 59, a position where a predetermined pair of slits 67, 67 which are arranged to face in the circumferential direction overlap with the pair of through holes 54, 54 in the circumferential direction. Are located in

  Next, the valve body 70 mounted on the float body 50 will be described with reference to FIG.

  The valve body 70 of this embodiment has a seal portion 71 that opens and closes the opening 23 by coming into contact with and separating from the valve seat 24, and a pair of engaging legs 74 and 75 that engage the seal portion 71 with the float body 50. are doing.

  As shown in FIG. 7A, the seal portion 71 in this embodiment has a substantially disc-like shape formed so as to cover a pair of through holes 54 formed in the ceiling wall 52 of the float body 50. A receiving portion 73 having a mortar-shaped inner surface is provided at the center of the back surface of the seal portion 71 (see FIG. 7B). The receiving portion 73 is placed on the rounded tip portion of the support portion 53 so that the valve body 70 is rotatably supported with respect to the float body 50.

  In addition, an elastic seal member made of rubber or an elastic resin material may be arranged on the upper surface side of the seal portion 71, and the "seal portion" in the present invention means including such an elastic seal member. .

  In addition, a pair of engaging legs 74 and 75 having different lengths extend from opposing portions on the back surface side of the seal portion 71. As shown in FIG. 2, the engagement leg 74 extends longer than the engagement leg 75. Further, each of the engaging leg portions 74 and 75 extends from the back surface side of the seal portion 71 and is provided with a flexible extending portion 77 inserted into the through hole 54 of the ceiling wall 52, and a distal end side of the extending portion 77. And engagement claws 78 protruding from the outer surface of the through hole 54 toward the outer diameter side of the through hole 54. Each of the engaging claws 78 can be engaged with a peripheral portion 54a on the outer diameter side on the back side of the through hole 54 in a state of being disposed on the back side of the through hole 54 (see FIG. 2). Further, on the outer surface side of the engagement claw 78, a tapered surface 78a whose projection height gradually decreases toward the tip of the engagement leg portion is formed, so that it is easy to insert into the through hole 54 and to easily project from the back side. ing.

  Then, as shown in FIG. 2, by inserting the pair of engaging legs 74, 75 of the valve body 70 from the front side of the through holes 54, 54 of the ceiling wall 52, the extending portions 77 of the engaging legs 74, 75 are inserted. , 77 are inserted through the through holes 54, 54, and engaging claws 78, 78 are arranged on the back side peripheral edges of the through holes 54, 54 so as to be engageable. 70 is fitted and stopped.

  In this embodiment, as described above, the sealing portion 71 of the valve body 70 is tiltably supported by the support portion 53 of the float body 50 via the receiving portion 73. Although the engaging claws 74, 75 do not engage with the back sides of the through holes 54, 54 (see FIG. 2), the float body 50 descends after the seal portion 71 contacts the valve seat 24. Accordingly, when the valve body 70 is tilted (see FIG. 9), the valve body 70 is engaged with the back side of the through hole 54. That is, in the present invention, the engagement leg engages with the back side of the through hole in a normal state (a state in which the float body is not immersed in the fuel) even if the engagement leg does not engage with the back side of the through hole. This includes the case where it can be engaged with the back side of the through hole when the valve body is tilted.

  In this embodiment, the housing 15, the float body 50, and the valve body 70 are formed of a synthetic resin such as polyacetal (POM) or polyamide (PA). If dipped or immersed, it may have the property of swelling with fuel. At this time, the through hole 54 formed in the ceiling wall 52 of the float body 50 swells so as to increase its inner diameter (see the imaginary line in FIG. 2). On the other hand, as shown by an arrow A1 in FIG. 2, the engagement legs 74 and 75 of the valve body 70 swell outward so as to spread in a C shape. At this time, since the engaging leg portions 74 and 75 are formed as thin leg portions, the swelling amount of the engaging leg portions 74 and 75 to the outside is larger than the swelling amount of the inner diameter of the through hole 54. More.

  The float body 50 to which the above-described valve body 70 is mounted is placed on the lower cap 40 with the spring 69 compressed. When the fuel level rises and is immersed in the fuel F by a predetermined height or more, the buoyancy of the float body 50 itself is added to the urging force of the spring 69, and the float body 50 rises and the valve body 70 The seal portion 71 comes into contact with the valve seat 24 of the partition wall 22 to close the opening 23 (see FIG. 8). Thereafter, when the fuel level is lowered and buoyancy does not act on the float body 50, the float body 50 is lowered by its own weight, and the short engaging leg of the valve body 70 is provided behind the through hole 54 of the float body 50. Since the engagement claws 78 of 75 are engaged and the short engagement leg 74 is pulled downward (see the arrow A3 in FIG. 9), the valve body 70 tilts via the support portion 53, and On the other hand, the seal portion 71 is inclined so that a gap is formed between the valve seat 24 and the seal portion 71 (see FIG. 9).

  In addition, the valve device 10 in this embodiment closes the opening 23 by abutting on the valve seat 24 when the float body 50 abnormally rises in liquid level in the fuel tank due to fuel swing or the like. When the liquid level in the fuel tank reaches the set full liquid level, the float body 50 rises and comes into contact with the valve seat 24. It may be used as a so-called full tank regulating valve that closes the opening 23 to prevent further supercharging, and is not particularly limited.

  Next, the operation and effect of the valve device 10 of the present invention having the above configuration will be described.

  First, a method of attaching the valve body 70 to the float body 50 will be described. That is, as shown in FIG. 1, the pair of engaging legs 74, 75 of the valve body 70 are aligned with the pair of through holes 54, 54 of the float body 50, and from the surface side of the ceiling wall 52 of the float body 50. Then, the valve body 70 is pushed in. Then, the engaging claw 78 is pressed on the inner periphery of the through hole 54 via the tapered surface 78a, and the pair of engaging legs 74 and 75 bend inward. When the outermost portion of the through hole 54 comes out of the rear side of the through hole 54, the pair of engaging legs 74, 75 elastically return, and the engaging claws 78, 78 move to the outer diameter of the rear side of the through holes 54, 54. The support portion 53 of the float body 50 is in contact with the receiving portion 73 of the valve body 70 so as to be tiltable. Thus, the valve body 70 can be attached to the float body 50 so that the valve body 70 can be prevented from falling off and can be tilted via the support portion 53.

  As shown in FIG. 2, when the fuel level in the fuel tank does not rise and the float body 50 is not immersed in the fuel, the opening 23 formed in the partition wall 22 is opened and the partition wall 22 is opened. Is closed by a relief valve 37.

  In the above state, when the vehicle turns or leans greatly and the fuel level in the fuel tank rises, the fuel passes through the through hole 40a of the lower cap 40 and the through hole 21a of the housing body 20, and the valve chamber V When the fuel flows into the float body 50 and the fuel is immersed in the float body 50 at a predetermined height or more, the float body 50 is lifted by the buoyancy of the spring 69 and the float body 50 itself, and as shown in FIG. Since the opening 23 is closed by contacting the valve seat 24, fuel is prevented from flowing into the ventilation chamber R through the opening 23, and fuel leakage to the outside of the fuel tank can be prevented.

  When this valve device 10 is used as a full tank regulating valve, a pair of through-holes 54, 54 are formed in the ceiling wall 52 of the float body 50. The floating point of the float body 50 can be delayed by flowing out from the through hole 54, and the position of a so-called lock point (a position that defines the full fuel amount) can be set high.

  By the way, the float body 50 in the valve device 10 has a cavity K inside the cavity body K (here, the space K1 outside the inner peripheral wall 59 and the inside of the inner peripheral wall 59). A through hole 54 communicating with the space K2) is formed. Therefore, when the vehicle travels on a rough road and vibrates up and down, swings left and right, or turns sharply, fuel passes through the space K1 or the space K2 of the float body 50 and passes through the through hole 54. It may spill as if spouting.

  Even in such a case, in the valve device 10, as described above, the pair of engagement legs 74, 75 of the valve body 70 are connected to the pair of through holes 54, 54 of the ceiling wall 52 of the float body 50. The valve body 70 is mounted on the float body 50 by being engaged with the peripheral edges 54a, 54a on the rear side thereof, and the engagement legs 74, 75 inserted through the through holes 54, 54. It is possible to make it difficult for fuel to flow out of the through holes 54, 54. As a result, it is possible to suppress the fuel from leaking out of the fuel tank through the opening 23 of the partition wall 22, the ventilation chamber R, and the pipe 46. it can. In addition, since the engaging leg portions 74 and 75 extend through the ceiling wall 52 of the float body 50 (see FIG. 2), the height direction of the float body 50 and the valve body 70 is reduced. Thus, the overall size of the valve device 10 can be reduced.

  Further, since the seal portion 71 of the valve body 70 is disposed above the ceiling wall 52 of the float body 50 so as to cover the pair of through holes 54, the fuel flowing out of the through hole 54 is It is possible to block the housing body 20 from going to the opening 23 side, so that fuel leakage to the outside of the fuel tank can be suppressed.

  Further, in this embodiment, since the engaging claws 78 project from the side surfaces of the engaging legs 74 and 75 toward the outer diameter side of the through hole 54, the fuel adheres to or immerses in the valve body 70. When the valve body 70 swells and the pair of engaging legs 74 and 75 expands to the outer diameter side of the pair of through holes 54 and 54 as shown by the arrow A1 in FIG. The margin of engagement of the engaging claw 78 with the outer peripheral side portion 54a on the back side is increased, so that the strength of engagement between the float body 50 and the valve body 70 is increased, and the valve body 70 is separated from the float body 50. It can be hard to come off.

  In this embodiment, as shown in FIGS. 5 and 6, the outer peripheral wall 57, the inner peripheral wall 59, and the space between the adjacent ribs 65, 65 inside the hollow portion K of the float body 50. In addition, since the second air chamber K4 is formed, it is possible to increase a portion where air is accumulated in the hollow portion K, increase the buoyancy of the float body 50, and improve the responsiveness of the float body 50. it can.

  Further, as shown in FIG. 5, a space K1 outside the inner peripheral wall 59 and a space K2 inside the inner peripheral wall 59 are provided on the inner peripheral wall 59 of the float body 50 at positions overlapping the through hole 54 in the circumferential direction. Since the slits 67 that communicate with each other are formed, the fuel that flows into the valve chamber V, flows through the space K2 inside the inner peripheral wall 59, and flows out from the through hole 54 is formed by the slits 67. By diffusing into the space K1 outside the peripheral wall 59 (see the arrow A2 in FIG. 6), it is possible to suppress the concentration of the fuel from flowing through the through-hole 54 and to make it more difficult for the fuel to flow out from the through-hole 54. it can.

  In this embodiment, as shown in FIG. 6, the plurality of ribs 65 forming the second air chamber K4 between the outer peripheral wall 57 and the inner peripheral wall 59 inside the hollow portion K of the float body 50 include: The lower end of the peripheral wall 51 (the outer peripheral wall 57, the inner peripheral wall 59, and the cylindrical wall 61) of the float body 50 is formed to be shorter than the lower end, and the opposite end is provided by a spring 69 for urging the float body 50. Since the contact portion is formed, the air chamber can be formed in the hollow portion K while forming the contact portion of the spring 69, so that the valve device 10 can be made more compact.

  By the way, the float body 50 rises due to the rise of the fuel level, and the sealing portion 71 of the valve body 70 contacts the valve seat 24 to close the opening 23, and then the fuel level falls and the buoyancy of the float body 50 is increased. When the state of the float body 50 does not work, the float body 50 usually descends by its own weight. However, the seal portion 71 of the valve body 70 may be stuck to the valve seat 24, and the float body 50 may be difficult to descend (referred to as a stick phenomenon or the like).

  In the valve device 10 according to this embodiment, when the float 50 does not act on the float body 50 in a state where the seal portion 71 of the valve body 70 is in contact with the valve seat 24 and the float body 50 tries to descend by its own weight, the float body The engaging claw 78 of the short engaging leg 75 of the valve body 70 is engaged with the back side of the through hole 54 of the valve body 50, and the short engaging leg 74 is pulled downward (see the arrow A3 in FIG. 9). Thereby, as shown in FIG. 9, the valve body 70 tilts via the support portion 53, the seal portion 71 tilts with respect to the valve seat 24, and a gap is formed between the valve seat 24 and the seal portion 71. As a result, the seal portion 71 can be peeled off from the valve seat 24, and the float body 50 can be lowered smoothly.

  Note that the present invention is not limited to the above-described embodiments, and various modified embodiments are possible within the scope of the present invention, and such embodiments are also included in the scope of the present invention. .

10 Valve device for fuel tank (valve device)
15 Housing 21 Peripheral wall 22 Partition wall 23 Opening 24 Valve seat 50 Float body 51 Peripheral wall 52 Ceiling wall 53 Supporting part 54 Through hole 55 Outer peripheral wall 59 Inner peripheral wall 65 Rib 67 Slit 69 Spring 70 Valve body 71 Seal part 74, 75 Engagement leg 77 Extension part 78 Engagement claw K Hollow part K4 Second air chamber (air chamber)
R Vent room V Valve room

Claims (4)

A housing provided with a valve chamber below and a ventilation chamber above the partition wall, an opening communicating the valve chamber and the ventilation chamber formed in the partition wall, and a valve seat provided on a peripheral edge of the opening; ,
A float body arranged to be able to move up and down in a valve chamber of the housing;
And a valve body attached to the float body,
The float body has a peripheral wall and a ceiling wall disposed above the peripheral wall, and a cavity is formed therein,
In the ceiling wall, a through-hole communicating with the hollow portion is formed, and a support portion that tiltably supports the valve body is provided,
The valve body has a seal portion that opens and closes the opening by coming into contact with and separating from the valve seat, and an engagement leg portion that engages the seal portion with the float body.
The engaging leg extends so as to be inserted into the through hole of the ceiling wall, and is configured to engage with the back side of the through hole.
The peripheral wall of the float body has an outer peripheral wall and an inner peripheral wall arranged concentrically inside the outer peripheral wall,
The inner peripheral wall is provided with a slit that allows a space formed outside the inner peripheral wall and a space formed inside the inner peripheral wall to communicate with each other,
The valve device for a fuel tank, wherein the through hole is disposed so as to overlap in a circumferential direction and a radial direction with respect to the slit when the float body is viewed from an axial direction.   2. The valve device for a fuel tank according to claim 1, wherein an engagement claw that protrudes toward an outer diameter side of the peripheral wall is provided on a side surface of the engagement leg. 3. On the back side of the ceiling wall, a plurality of ribs are formed to connect the outer peripheral wall and the inner peripheral wall,
Inside the hollow portion, the outer peripheral wall, the inner peripheral wall, and an air chamber is formed between the adjacent ribs,
3. The valve device for a fuel tank according to claim 1, wherein the air chamber is disposed at a position that does not overlap with the through hole in a circumferential direction when the float body is viewed from an axial direction. 4. The peripheral wall of the float body includes an outer peripheral wall, and an inner peripheral wall concentrically arranged inside the outer peripheral wall, and a plurality of connecting parts that connect the outer peripheral wall and the inner peripheral wall to the back side of the ceiling wall. Ribs are formed,
Inside the hollow portion, the outer peripheral wall, the inner peripheral wall, and an air chamber is formed between the adjacent ribs,
When the float body is viewed from the axial direction, the air chamber is arranged at a position that does not overlap with the through hole in the circumferential direction, and ends of the plurality of ribs opposite to the ceiling wall. The portion is formed so as to be located closer to the ceiling wall than a lower end portion of the peripheral wall, and the end portion forms a contact portion of a spring for biasing the float body. Fuel tank valve device.