Valve device

There is provided a valve device, including: a housing; a float valve; and a seal member. An opening portion includes a first region, and a second region. The seal member includes a first cover portion, and a second cover portion. The second cover portion includes a support portion, a wide portion, and a narrow portion. In a state where the seal member is retained and supported by the support portion with respect to the float valve, a width of the wide portion is set such that a tip end of the second region is covered, and that the second region of the opening portion is not exposed out of the seal member even in a state where the seal member is maximally displaced in a radial direction and; or a peripheral direction of the housing with respect to the opening portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on Japanese Patent Application No. 2021-207586 filed on Dec. 21, 2021, the contents of which are incorporated herein by way of reference.

TECHNICAL FIELD

The present invention relates to a valve device that is to be attached to a fuel tank of an automobile or the like and is used as a fuel outflow suppression valve, a filling-up restriction valve, or the like.

BACKGROUND

For example, a fuel tank of a vehicle such as an automobile is provided with a valve device for suppressing a fuel in the fuel tank from leaking out of the fuel tank when the vehicle is tilted or overturned. Such a valve device generally includes a housing provided with a ventilation chamber on an upper side and a valve chamber on a lower side via a partition wall having a ventilation hole, and a float valve disposed in the valve chamber so as to be raised and lowered. A seal member made of rubber or the like may be disposed on an upper side of the float valve for a purpose of improving a sealing property with respect to the ventilation hole.

For example, Patent Literature 1 listed below describes a valve device including a housing in which a valve chamber on a lower side and a ventilation chamber on an upper side are provided via a partition wall, and a ventilation hole for communicating is provided in the partition wall, and a float valve accommodated in the valve chamber so as to be raised and lowered. A valve seat is formed on a valve chamber side of the partition wall, and an opening portion is provided in an inner side of the valve seat. The opening portion includes a first opening, and a second opening extending in a slit shape from at least one position of the first opening, and a seal portion having elasticity for opening and closing the first opening and the second opening is disposed on an upper side of the float valve.Patent Literature 1: JP6898516B

When a vehicle is overturned, a float valve slides to close an opening portion in order to suppress a fuel from flowing into a ventilation chamber from the opening portion, but when the vehicle is overturned, a fuel tank and a valve device themselves are also overturned accordingly. Thus, the float valve is shifted to one side with respect to a valve chamber of a housing.

In a case of the valve device of Patent Literature 1, even if the float valve slides in a direction approaching the opening portion in the above state, a situation may occur in which the seal portion on the upper side of the float valve does not come into contact with the opening portion of the housing at a predetermined position, but rather comes into contact with the opening portion in a displaced manner, and the opening portion may not be reliably closed.

Therefore, an object of the present invention is to provide a valve device capable of reliably closing an opening portion even when a vehicle is overturned.

SUMMARY

There is provided a valve device, including: a housing in which a valve chamber configured to communicate with an inside of a fuel tank on a lower side and a ventilation chamber configured to communicate with an outside of the fuel tank on an upper side are provided via a partition wall, and an opening portion through which the valve chamber and the ventilation chamber are to communicate with each other is formed in the partition wall; a float valve slidably accommodated in the valve chamber; and a seal member disposed on an upper side of the float valve and configured to close the opening portion. The opening portion includes a first region, and a second region extending in a slit shape from the first region and forming an end portion of the opening portion. The seal member includes a first cover portion covering the first region, and a second cover portion extending from the first cover portion so as to cover the second region. The second cover portion includes a support portion disposed on a tip end side in an extending direction of the second cover portion and configured to retain and support the seal member with respect to the float valve, a wide portion disposed on a base end side in the extending direction with respect to the support portion, and a narrow portion provided on a base end side in the extending direction with respect to the wide portion and formed to be narrower than the wide portion. In a state where the seal member is retained and supported by the support portion with respect to the float valve, a width of the wide portion is set such that a tip end of the second region is covered, and that the second region of the opening portion is not exposed out of the seal member even in a state where the seal member is maximally displaced in a radial direction and/or a peripheral direction of the housing with respect to the opening portion.

DESCRIPTION OF EMBODIMENTS

Embodiment of Valve Device

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

As shown inFIGS.1and3, a valve device10in the embodiment includes a housing in which a valve chamber V communicating with an inside of a fuel tank on a lower side and a ventilation chamber R communicating with an outside of the fuel tank on an upper side are provided via a partition wall23, and an opening portion25through which the valve chamber V and the ventilation chamber R communicate with each other is formed in the partition wall23, a float valve40slidably accommodated in the valve chamber V, a seal member80disposed on an upper side of the float valve40and configured to close the opening portion25, and an urging spring S urging the float valve40.

The housing15in the embodiment has a substantially cylindrical shape, and includes a housing main body20provided with the partition INA23on an upper side, a lower cap30mounted on a lower side of the housing main body20, and an upper cover35mounted on an upper side of the housing main body20.

The housing main body20includes a peripheral wall21having a substantially cylindrical shape, and the partition wall23is disposed on an upper side of the peripheral wall21. A plurality of through holes21aand locking protrusions21bare formed on the upper side of the peripheral wall21, and locking holes21care formed on a lower side of the peripheral wall21. The opening portion25is formed in a central portion of the partition wall23. Further, a cylindrical wall27protrudes from an upper surface side of the partition wall23and an outside of the opening portion25. A plurality of ribs27aprotrude from an upper outer periphery of the cylindrical wall27. A flange portion28protrudes from an upper outer periphery of the peripheral wall21. Further, a ring mounting groove28ais formed between the flange portion28and the cylindrical wall27, and an annular seal ring29is mounted in the ring mounting groove28a(seeFIG.3).

As shown inFIG.7, the opening portion25has a first region25a, and second regions25beach extending in a slit shape from the first region25aand forming an end portion of the opening portion25. The opening portion25in the embodiment has the first region25ahaving a substantially circular hole shape, and a plurality of (here, four) second regions25bextending outward in a slit shape from an outer periphery of the first region25at equal intervals in a peripheral direction, and is a substantially cross-shaped opening having a diameter enlarged in a central portion. The second region25bcommunicates with the first region25a, and is narrower than a maximum inner dimension (here, an inner diameter) of the first region25a.

As shown inFIG.3, the opening portion25includes a valve seat26protruding downward from a peripheral edge of a rear side of the opening portion25(a valve chamber V side). The opening portion25is opened and closed when the seal member80is brought into contact with and separated from a lower end portion of the valve seat26.

On the other hand, the lower cap30includes a bottom wall31having a substantially circular plate shape, and a peripheral wall33erected from a peripheral edge of the bottom wall31. A spring support protrusion31athat supports a lower end portion of the urging spring S protrudes from a central portion in a radial direction of the bottom wall31. On the bottom wall31, a plurality of through holes31bare formed, and elastic pieces34for suppressing a hammering sound when the float valve40is lowered are formed to be deflectable and deformable. Further, a plurality of locking claws33aare formed on the peripheral wall33.

The lower cap30is mounted on the lower side of the housing main body20by locking the locking claws33aof the lower cap30to the locking holes21cof the housing main body20, respectively. As a result, the valve chamber V communicating with the inside of the fuel tank (not shown) is formed in a lower side of the housing via the partition wall23(seeFIG.3).

As shown inFIG.1, the upper cover35includes a peripheral wall36extending at a predetermined height, a ceiling wall37closing an upper portion of the peripheral wall36, and a flange portion36aannularly extending from the middle of an extending direction of the peripheral wall36. A ventilation hole (not shown) is formed at a predetermined position of the peripheral wall36, and a fuel vapor pipe38having a substantially cylindrical shape extends outward from an outer peripheral edge portion of the ventilation hole. A tube (not shown) communicating with a canister or the like disposed outside the fuel tank (not shown) is connected to the fuel vapor pipe38. As shown inFIG.3, frame-shaped locking pieces39which are locked to the respective locking protrusions21bof the housing main body20are vertically provided from a lower end surface of the peripheral wall36.

As shown inFIG.3, by locking the locking pieces39of the upper cover35to the corresponding locking protrusions21bof the housing main body20, the upper cover35is mounted on the upper side of the housing main body20in a state where the seal ring29mounted in the ring mounting groove28ais in contact with an inner periphery of the peripheral wall36of the upper cover35, As a result, the ventilation chamber R communicating with the outside of the fuel tank is formed on the upper side via the partition wall23(seeFIG.3).

Next, the float valve40will be described in detail.

The float valve40in the embodiment includes a float main body50, and a seal support member60that is disposed on an upper side of the float main body50, is retained and held swingably with respect to the float main body50, and retains and supports the seal member80so as to be movable by a predetermined distance.

The float main body50includes a peripheral wall51extending in an upper-lower direction with a predetermined length, and a ceiling wall53disposed on an upper side of the peripheral wall51, and has a substantially cylindrical shape opened downward and closed upward.

A pair of guide grooves51aand51aextending in an axial direction from the ceiling wall53toward a lower side of the peripheral wall are formed at two positions facing each other in a peripheral direction of the peripheral wall51. Guide ridges (not shown) provided on an inner periphery of the housing main body20are inserted into the guide grooves51aand51arespectively to guide a sliding operation of the float valve40. Further, a plurality of guide ribs51bradially provided on an outer periphery of the peripheral wall51extend along the axial direction. These guide ribs51bare disposed to face an inner periphery of the peripheral wall21of the housing main body20to guide the sliding operation of the float valve40.

A support protrusion53ahaving a curved outer surface protrudes from a center of a surface (also referred to as an “upper surface”. the same applies in the following description) of the ceiling wall53. A plate-shaped portion61of the seal support member60is placed on the support protrusion53a, and swingably supports the seal support member60. Further, a plurality of (here, four) protrusions55protrude from an outer peripheral edge portion of the ceiling wall53at equal intervals in the peripheral direction.

Retaining protrusions57and57for swingably retaining and holding the seal support member60with respect to the float main body50protrude from an outer peripheral surface of an upper end portion of the peripheral wall51near the ceiling wall53and at two locations facing each other in a radial direction. The retaining protrusion57is inserted into a retaining hole67a(to be described later) provided in the seal support member60so as to be slidable along an axial direction Z (seeFIG.4) of the float valve40and movable along a width direction Y (seeFIG.4) of the float valve40.

The float main body50is formed with a spring accommodating recess59opened downward (seeFIG.3), and the urging spring S is accommodated in the spring accommodating recess59. The float valve40is slidably accommodated in the valve chamber V in a state where the urging spring S is interposed between the float valve40and the lower cap30, slides upward by its own buoyancy and an urging force of the urging spring S when immersed by a fuel, and slides downward by its own weight when not immersed by the fuel. Further, the float valve40is slidable by the urging force of the urging spring S even when a vehicle such as an automobile is overturned by 90°, whereby the seal member80can be brought into contact with the valve seat26to close the opening portion25.

On the other hand, the seal support member60in the embodiment is disposed between the float main body50and the seal member80, and includes the plate-shaped portion61formed with a predetermined thickness. The seal member80is placed and supported on a placement surface61aof the plate-shaped portion61(seeFIG.3).

Referring also toFIGS.5A and5B, the plate-shaped portion61includes a central portion63and a plurality of extending portions65extending outward from the central portion63. The plate-shaped portion61in the embodiment has a shape adapted to the seal member so as to receive and support the seal member80having a substantially cross shape as a whole. That is, in the plate-shaped portion61, four extending portions65radially extend outward from the central portion63, and the extending portions65and65adjacent to each other in a peripheral direction are orthogonal to each other, so that the plate-shaped portion61has a substantially cross shape as a whole.

Retaining pieces67and67are vertically provided from a pair of extending portions65and65disposed to face each other with the central portion63interposed therebetween and rear sides of tip end portions of the extending portions65and65(a float main body50side), respectively. The retaining piece67is formed with the retaining hole67ahaving an elongated hole shape extending along the axial direction of the float valve40. The retaining hole67ahas a substantially rectangular shape that is longer than an axial length of the retaining protrusion57provided on the float main body50side and wider than a peripheral width of the retaining protrusion57.

As shown inFIG.4, by inserting the retaining protrusions57into the retaining holes67aof the retaining pieces67from an inside, respectively, the seal support member60is retained and held swingably with respect to the float main body50.

In a state where the retaining protrusion57is inserted into the retaining hole67a, a predetermined gap is formed between both sides in a width direction of the retaining hole67aand both sides in a width direction of the retaining protrusion57, and a predetermined gap is also formed between both ends in an axial direction of the retaining hole67aand both ends in an axial direction of the retaining protrusion57.

Therefore, as indicated by reference signs X, Y, and Z shown inFIG.4, with respect to the float main body50, the seal support member60can move a predetermined distance along the width direction Y orthogonal to a radial direction X of the float valve40, and can move a predetermined distance along the axial direction Z of the float valve40, and further, the seal support member60can swing with respect to the float main body50.

In addition, (1) when the seal support member60is moved to a maximum extent along the axial direction Z with respect to the float main body50, the retaining protrusion57is locked to inner surface of one of both ends in a longitudinal direction of the retaining hole67a, and (2) when the seal support member60is moved to a maximum extent along the width direction Y with respect to the float main body50, the retaining protrusion57is locked to inner surface of one of both sides in the width direction of the retaining hole67a, so that the seal support member60is retained and held with respect to the float main body50.

A retaining hook69, which is inserted into a support hole85a(seeFIGS.6A and6B) of the seal member80, protrudes from a front side of the tip end portion of each of the extending portions65(a seal member80side).

The retaining hook69has a substantially inverted L shape, and includes a shaft portion69aloosely fitted to the support hole85a, and a protruding portion69bprotruding from an upper end of the shaft portion69abeyond an inner peripheral edge of the support hole85a. The shaft portion69ais inserted into the support hole85aof the seal member80so as to be movable along the radial direction X of the float valve40and movable along the width direction Y of the float valve40.

A plurality of grooves71are formed in the placement surface61aof the seal support member60. In the embodiment, the plurality of (here, four) grooves71extending linearly from an outer peripheral edge portion between base end portions of the adjacent extending portions65and65toward a center of the central portion63are formed, and the grooves71communicate with each other via a circular recess71aprovided at the center of the central portion63.

Next, the seal member80will be described with reference toFIGS.1,4,6A and6B, and the like.

The seal member80is disposed on an upper side of the seal support member60, is retained and supported so as to be movable by a predetermined distance with respect to the seal support member60, and is brought into contact with and separated from the valve seat26provided on the opening portion25to open and close the opening portion25.

As shown inFIGS.6A and6B, the seal member80includes a first cover portion81covering the first region25aof the opening portion25, and second cover portions83extending from the first cover portion81so as to cover the second regions25bof the opening portion25. That is, the seal member80includes the first cover portion81, and a plurality of second cover portions83extending outward from an outer periphery of the first cover portion81. More specifically, in the seal member80in the embodiment, four second cover portions83radially extend outward (extend in four directions) from the outer periphery of the first cover portion81corresponding to the opening portion25forming the substantially cross-shaped opening, and the second cover portions83and83adjacent to each other in a peripheral direction are orthogonal to each other, so that the seal member80has a substantially cross shape as a whole.

The second cover portion83includes a support portion85that is disposed on a tip end side in an extending direction of the second cover portion83and retains and supports the seal member80with respect to the float valve40, a wide portion87that is disposed on a base end side in the extending direction of the second cover portion83with respect to the support portion85(it can be said that the wide portion87is disposed at a portion where a tip end of the second region25bof the opening portion25is located), and a narrow portion89that is disposed on a base end side in the extending direction of the second cover portion83with respect to the wide portion87(it can be said that the narrow portion89is disposed at a position near the first region25aof the opening portion25with respect to the wide portion87) and is formed to be narrower than the wide portion87, In the following description of each component of the second cover portion83, the terms “tip end” and “tip end portion” mean the tip end and the tip end portion in the extending direction of the second cover portion83, respectively, and the terms “base end” and “base end portion” mean the base end and the base end portion in the extending direction of the second cover portion83, respectively.

Hereinafter, each portion of the second cover portion83will be described in more detail.

As shown inFIG.6B, the tip end portion in the extending direction of the second cover portion83forms the support portion85. The support portion85extends with a constant width W1, and a tip corner portion in an extending direction thereof is formed in an R shape. The width W1 of the support portion85is smaller than a width W2 of the wide portion87and a width W3 of the narrow portion89. Further, the support hole85ahaving a substantially elongated hole shape and extending long along the extending direction of the second cover portion83is formed in the support portion85. The support hole85ahas a shape having rounded both ends in a longitudinal direction, and the shaft portion69aof the retaining hook69provided on the seal support member60is loosely inserted therein. A base end portion in an extending direction of the support hole85a(an end portion on a first cover portion81side) slightly overlaps with a region where the wide portion87is provided.

As shown inFIG.4, the shaft portion69aof the retaining hook69is inserted into the support hole85a, and the protruding portion69bis located on a peripheral edge of a front side of the support hole85a, so that the seal member80is retained and supported so as to be movable by a predetermined distance with respect to the seal support member60.

In a state where the shaft portion69ais inserted into the support hole85a, a predetermined gap is formed between both ends in an axial direction of the support hole85aand the shaft portion69a, and a predetermined gap is also formed between both sides in a width direction of the support hole85aand the shaft portion69a.

Therefore, as indicated by reference signs X, Y. and Z shown inFIG.4, with respect to the seal support member60, the seal member80can move a predetermined distance along the radial direction X of the float valve40, can move a predetermined distance along the width direction Y of the float valve40, and can further move a predetermined distance along the axial direction Z of the float valve40.

In addition, (1) when the seal member80is moved to a maximum extent along the radial direction X with respect to the seal support member60, the shaft portion69ais locked to inner surface of one of both ends in the radial direction of the support hole85a, (2) when the seal member80is moved to a maximum extent along the width direction Y with respect to the seal support member60, the shaft portion69ais locked to inner surface of one of both sides in the width direction of the support hole85a, and (3) when the seal member80is moved to a maximum extent along the axial direction Z with respect to the seal support member60, the protruding portion69bis locked to the peripheral edge of the front side of the support hole85a, so that the seal member80is retained and supported with respect to the seal support member60.

On the other hand, as shown inFIGS.6A and6B, the wide portion87is continuously provided at a position near the base end portion of the second cover portion83with respect to the support portion85. The wide portion87includes top portions87aand87ahaving a largest width in the second cover portion83, first tapered portions87band87bhaving a width gradually decreasing from the top portions87aand87atoward the tip end in the extending direction of the second cover portion83, and second tapered portions87cand87chaving a width gradually decreasing from the top portions87aand87atoward the base end in the extending direction of the second cover portion83, and has a shape protruding with a predetermined width from both sides in a width direction of the second cover portion83.

As shown inFIG.7, the wide portion87is located at the tip end of the second region25bof the opening portion25in a state where the vehicle is not overturned. In the embodiment, the wide portion87is provided such that the tip end of the second region25hof the opening portion25is located between the top portions87aand87aof the wide portion87. Further, the first tapered portion87bis longer than the second tapered portion87cin the extending direction of the second cover portion83.

When a width of the wide portion87, that is, a length between the top portions87aand87aof the wide portion87is defined as “W2”, the width W2 of the wide portion87is formed to be larger than the width W1 of the support portion85and the width W3 of the narrow portion89.

Further, in a state where the seal member80is retained and supported by the support portion85with respect to the float valve40, a width of the wide portion87is set such that the tip end in an extending direction of the second region25bof the opening portion25is covered, and the second region25bof the opening portion25is not exposed out of the seal member80even in a state where the seal member80is maximally displaced in a radial direction and/or a peripheral direction of the housing15with respect to the opening portion25.

FIG.10shows a state where the vehicle is overturned by 90°, a valve axial direction of the float valve40(a direction along an axial center of the float valve40) is lateral, and the25seal member80is maximally displaced in a radial direction and/or a peripheral direction of the housing main body20with respect to the opening portion25, and even in this state, the width W2 of the wide portion87is set such that the tip end of the second region25bof the opening portion25is covered, and the second region25bof the opening portion25is not exposed out of the seal member80. In this state, the tip ends of some of the second regions25b, among a plurality of second regions25bconstituting the opening portion25, are located in the wide portions87, respectively, and the tip ends of the other second regions25bare located in the narrow portions89instead of the wide portions87, respectively (seeFIG.10).

The narrow portion89is provided via cutouts91and91formed on both sides of the base end portion of the second cover portion83. More specifically, the cutout91is formed toward a center C of the first cover portion81, between the base end portions of the second cover portions83and83extending from the outer periphery of the first cover portion81and adjacent to each other in the peripheral direction, and the narrow portion89is provided via the cutout91.

In a case of the embodiment, the cutout91having a constant width and a rounded tip end is formed obliquely inward toward the center C of the first cover portion81, between the base end portions of the second cover portions83and83adjacent to each other in the peripheral direction (a boundary portion between portions where the base end portions of the adjacent second cover portions83and83are connected to each other) among the second cover portions83extending in four directions from the outer periphery of the first cover portion81. The narrow portion89having the width W3 smaller than the width W2 of the wide portion87and larger than the width W1 of the support portion85is formed at the base end portion in the extending direction of the second cover portion83via a pair of cutouts91and91formed adjacent to each other in the peripheral direction of the first cover portion81.

The narrow portion89is disposed on a base end portion side of the second cover portion83and at a boundary portion with the first cover portion81, and has a constricted shape. That is, the narrow portion89is disposed on the base end portion side in the extending direction of the second cover portion83with respect to the wide portion87and at the boundary portion with the first cover portion81, and the pair of cutouts91and91are each formed from the boundary portion of the portion where the base end portions of the adjacent second cover portions83and83are connected to each other, and as a result, the narrow portion89has the constricted shape in the width direction of the second cover portion83.

As shown inFIG.7, when the float valve40and the seal member80are viewed from the valve axial direction, the groove71of the seal support member60is visible from the cutout91of the seal member80.

In the seal member80described above, all components such as the first cover portion, the second cover portion, the support portion, the wide portion, and the narrow portion are integrally formed of, for example, an elastic material such as rubber or elastic elastomer.

Modifications

Shapes and structures of the housing, the housing main body, the lower cap, and the upper cover which constitute the housing, the seal member, the first and second regions of the opening portion, the first and second cover portions constituting the seal member, the support portion, the wide portion, and the narrow portion which constitute the second cover portion, and the like, which constitute the present invention, are not limited to the above embodiment.

The housing15in the above embodiment includes the housing main body20, the lower cap30, and the upper cover35, but a housing may have a structure including at least a partition wall and an opening portion.

Further, the opening portion25in the embodiment is the substantially cross-shaped opening having the diameter enlarged in the central portion, but an opening portion may have a first region, and a second region extending in a slit shape from the first region and forming an end portion of the opening portion.

For example, as shown inFIG.12A, the opening portion may be an opening portion having the first region25ahaving a substantially circular hole shape in a central portion, and a pair of second regions25band25bextending in a slit shape from two positions facing each other in a radial direction on an outer periphery of the first region25a(the second regions25bhaving the slit shape extend in two directions from the first region25a). The pair of second regions25band25bextend on the same straight line.

As shown inFIG.12B, the opening portion may be an opening portion25C having a slit shape extending linearly as a whole. In this case, a central portion in an extending direction of the opening portion25C is the first region25a, and both side portions in the extending direction extending from both sides of the first region25aare a pair of second regions25hand25b. The first region25aand the second region25bhave the same width.

Further, an opening portion may include a first region, and a second region extending in a slit shape from the first region in one direction, three directions, or five or more directions and having a width smaller than or equal to that of the first region.

The peripheral wall21of the housing main body20, the peripheral wall33of the lower cap30, and the peripheral wall36of the upper cover35in the embodiment each have a substantially cylindrical shape, but these peripheral walls may have, for example, an elliptic cylindrical shape, a square cylindrical shape, or the like.

Further, in the embodiment, one float valve40is accommodated in one valve chamber V formed in the housing15. Alternatively, for example, a plurality of float valves may be accommodated in one valve chamber (functioning as a fuel cut valve, a pressure adjusting valve, or the like in addition to a filling-up restriction valve), a plurality of valve chambers may be defined in the housing, and the float valves may be accommodated in the respective valve chambers.

The seal member80in the embodiment has a shape shown inFIGS.6A,6B and7, but may have, for example, shapes shown inFIGS.11,12A and12B.

Similar to the seal member80shown inFIGS.6A and6B, a seal member80A shown inFIG.11includes four second cover portions83and has a substantially cross shape as a whole, but the support portion85provided on a tip end portion side in the extending direction of the second cover portion83and the wide portion87provided near the base end portion with respect to the support portion85are formed with the same width. The wide portion87is provided such that a base end portion thereof is located at the tip end of the second region25bof the opening portion25.

A seal member SOB shown inFIG.12Aincludes a pair of second cover portions83and83extending on the same straight line from two positions facing each other in a radial direction on an outer periphery of the first cover portion81so as to correspond to the opening portion25B, and has a substantially long plate shape as a whole (the second cover portions83extend in two directions from the first cover portion81), In a case of the seal member80B, the wide portion87is provided such that the tip end of the second region25bof the opening portion25is located between the top portions87aand87aof the wide portion87. Two pairs of cutouts91and91forming the narrow portion89are formed at both sides in a width direction orthogonal to an extending direction of the seal member80B extending in the substantially long plate shape and at a predetermined interval in the extending direction of the seal member80B.

Further, a seal member80C shown inFIG.12Bhas a shape extending in a substantially long plate shape as a whole corresponding to the opening portion25C. A pair of cutouts91and91having a substantially triangular groove shape are formed on both sides in a width direction at a central portion in an extending direction of the seal member80C, one narrow portion89is provided at the center in the extending direction of the seal member80C via the cutouts91and9L and the narrow portion89also serves as the first cover portion81. Further, the top portions87aand87aof the wide portion87extend longer than those of the wide portions87of the seal member80shown inFIGS.6A,6B and7, the seal member80A shown inFIG.11, and the seal member80B shown inFIG.12A.

A seal member may include a first cover portion, and a second cover portion extending from the first cover portion in one direction, three directions, or five or more directions.

Further, the wide portion87in the embodiment includes the top portions87aand87a, the first tapered portions87band87b, and the second tapered portions87cand87cshorter than the first tapered portions87band87b, but for example, a wide portion may have a curved shape, an arc shape, a substantially triangular shape, or a substantially trapezoidal shape protruding from both sides in a width direction of a second cover portion. The wide portion may have a shape in Which a second tapered portion is longer than a first tapered portion, or a shape in which a first tapered portion and a second tapered portion extend by the same length.

The narrow portion89in the embodiment is provided via the cutouts91, but a narrow portion may be provided without using a cutout, and may be disposed near a first region with respect to a wide portion and narrower than the wide portion.

Operation and Effect

Next, operation and effect of the valve device10having the above configurations will be described.

As shown inFIG.3, in a state where a fuel liquid level in the fuel tank does not rise and the float valve40is not immersed in the fuel, the float valve40is lowered in the valve chamber V, the seal member80separates from the valve seat26, the opening portion25is opened, and the valve chamber V and the ventilation chamber R communicate with each other via the opening portion25. In this state, when the fuel vapor in the fuel tank increases and a tank internal pressure increases due to the traveling of the vehicle or the like, the fuel vapor flows into the valve chamber V from the through hole31bof the lower cap30and the through hole21aof the housing main body20, passes through the opening portion25, flows into the ventilation chamber R, and is sent to the canister (not shown) via the fuel vapor pipe38, thereby suppressing an increase in the pressure in the fuel tank.

When the vehicle turns in a curve, travels on a road, a slope, or the like having unevenness, or is overturned due to an accident, the fuel in the fuel tank oscillates vigorously, the fuel liquid level rises, and the float valve40is immersed in the fuel, the float valve40is raised due to buoyancy of the float valve40itself and the urging force of the urging spring S. As a result, as shown inFIG.8, the first cover portion81and the second cover portion83of the seal member80are brought into contact with the valve seat26to close the first region25aand the second region25bof the opening portion25, and thus it is possible to suppress the fuel from flowing into the ventilation chamber R through the opening portion25.

FIG.8shows a case where the float valve40is raised straight without being tilted with respect to an axial direction of the housing15, and the float valve40may be raised while being tilted with respect to the axial direction of the housing15. In this case, the seal support member60can swing with respect to the float main body50, and thus when the float valve40is raised in a tilted manner, and the seal member80is brought into contact with the valve seat26in a tilted state, the seal support member60swings as appropriate with respect to the float main body50, and the tilt of the seal member80is corrected. Therefore, the seal member80can be brought into contact with the valve seat26without a tilt, and the opening portion25can be firmly closed.

In the above state, when the oscillation or the like of the fuel is stopped, and there is no buoyancy from the fuel applied to the float valve40, or when the pressure in the fuel tank is lowered, the float valve40is lowered due to its own weight. Thus, as shown inFIG.9, the seal support member60is lowered by a predetermined distance with respect to the seal member80which is in contact with and attached to the valve seat26, and the retaining protrusion57of the float main body50is locked to an inner surface of a lower end of the retaining hole67aof the seal support member60.

As a result, a load of the float main body50is applied to the seal support member the shaft portion69aof the retaining hook69of the seal support member60is lowered in the support hole85aof the seal member80, and the protruding portion69hof the retaining hook69is locked to the peripheral edge of the front side of the support hole85a. Accordingly, loads of the float main body50and the seal support member60are applied to the second cover portion83of the seal member80via the seal support member60.

Thus, the second cover portion83of the seal member80is elastically deformed so as to be pulled obliquely downward, and the second cover portion83moves along the axial direction Z and the radial direction X of the float valve40. As a result, as shown inFIG.9, the second cover portion83is gradually separated from a base end portion of the wide portion87and a narrow portion89side with respect to the valve seat26to open the second region of the opening portion25, and then the first cover portion81is peeled off from the valve seat26, and thus the first region25aof the opening portion25can be opened to completely open the entire opening portion25. As a result, it is possible to increase a valve re-opening pressure of the float valve40. The expression “to increase a valve re-opening pressure” means a performance in which a float valve can be easily peeled off from a valve seat provided on an opening portion and the opening portion can be opened even in a state where a tank internal pressure is high. As the seal member80is peeled off from the valve seat26, the entire float valve40is lowered.

The vehicle such as the automobile may be overturned by 90° due to the accident or the like. In this case, as the vehicle is overturned, the fuel tank and the valve device are also overturned and are lateral (the valve axial direction of the float valve40is horizontal or nearly horizontal), and thus as shown inFIG.10, the seal member80is displaced in the peripheral direction and the radial direction of the housing15with respect to the opening portion25.

However, even in such a situation, the valve device10can reliably close the opening portion25.

That is, in the valve device10, in the state where the seal member80is retained and supported by the support portion85with respect to the float valve40, as shown inFIG.10, the width of the wide portion87is set such that the tip end in the extending direction of the second region25bof the opening portion25is covered, and the second region25bof the opening portion25is not exposed out of the seal member80even in the state where the seal member80is maximally displaced in the radial direction and/or the peripheral direction of the housing15with respect to the opening portion25.

Therefore, even when the vehicle is overturned and the seal member80is displaced in the radial direction and the peripheral direction of the housing15with respect to the opening portion25as described above, the first region25aand the second region25bof the opening portion25can be firmly covered by the seal member80, and thus the opening portion25can be reliably closed by the seal member80while improving a sealing property of the seal member80with respect to the valve seat26. As a result, it is possible to suppress the fuel from flowing into the ventilation chamber R when the vehicle is overturned.

The seal member80can be easily deflected and deformed by the narrow portion89provided on the second cover portion83, and thus the seal member80in contact with the valve seat26of the opening portion25can be easily peeled off from the opening portion25. That is, in a state shown inFIG.9, the second cover portion83is easily deflected and deformed when being pulled, and the base end portion of the wide portion87and the narrow portion89of the second cover portion83, and further the first cover portion81are easily peeled off from the valve seat26. As a result, it is possible to increase the valve re-opening pressure of the float valve40.

Further, in the embodiment, as shown inFIG.7, the first region25aof the opening portion25is formed to be larger than the second region25bof the opening portion25, and the narrow portion89of the second cover portion83of the seal member80is provided via the cutouts91and91formed on both sides of the base end portion of the second cover portion83.

According to the above aspect, the narrow portion89has the above shape, and thus it is possible to easily form the seal member80into a shape that is easily deflected and deformed while ensuring the sealing property of the seal member80with respect to the opening portion25.

In the embodiment, as shown inFIGS.6A,6B and7, the support portion85of the seal member80is formed to be narrower than the wide portion87.

According to this aspect, the support portion85of the seal member80can be easily deflected and deformed, and an area of the support portion85is reduced, so that gas such as air or fuel vapor is less likely to come into contact with the support portion85, and as a result, the seal member80and the float valve40as a whole can be made less likely to blow up. Further, in the embodiment, the second cover portions83of the seal member80extend from the outer periphery of the first cover portion81in at least three directions (here, four directions), and the cutouts91are formed toward the center C of the first cover portion81.

According to the above aspect, the second cover portions83extend from the outer periphery of the first cover portion81in at least three directions, and the cutouts91are formed toward the center C of the first cover portion81, and thus the second cover portions83can be easily deflected and deformed uniformly.

The present invention is not limited to the embodiment described above, and various modifications can be made without departing from the gist of the present invention, and such embodiments are also included in the scope of the present invention.