JP2015071983A - Fuel outflow prevention valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel outflow prevention valve which weakens a stream of a fuel flowing into a housing when swinging of the fuel and inhibits fuel leakage from a valve hole.SOLUTION: A fuel outflow prevention valve 10 includes: a housing 15 provided with a partition wall 23 having a valve hole 23a, a lower space R2, and an upper space R1; a float valve 40 which is disposed in the lower space R2 so as to move up and down; a spring 46 which biases the float valve 40 toward the valve hole 23a; and a cap 50 which is attached to an opening part of the lower space R2 of the housing 15. The cap 50 includes: a first wall part 60 which supports a bottom surface of the float valve 40 and one end part of the spring 46; and a second wall part 70 which is disposed below the first wall part 60 forming a predetermined space R3 therebetween. Communication holes 67, 77 which communicate with a fuel tank are respectively formed in the wall parts 60, 70.

Description

  The present invention relates to a fuel outflow prevention valve that is attached to a fuel tank of an automobile or the like and prevents outflow of fuel.

  The fuel tank of the automobile is provided with a fuel outflow prevention valve that prevents the fuel in the fuel tank from leaking out of the fuel tank when the automobile turns or tilts.

  Conventionally, as such a fuel outflow prevention valve, the following Patent Document 1 discloses a cylindrical valve chamber having an opening at the bottom and an exhaust hole at the top, and being accommodated in the cylindrical valve chamber so as to be movable up and down. A fuel outflow comprising: a float valve having a valve head; a filter attached to a lower opening of the cylindrical valve chamber; a filter having a plurality of small holes; and a spring for biasing the float valve toward the exhaust hole. A check valve is described.

  A fitting cylinder wall having an attachment hole is provided upright from the outer peripheral edge of the filter, and an outward claw is provided from the outer periphery of the lower end of the cylindrical valve chamber. And the fitting cylinder wall of a filter is arrange | positioned at the lower end outer periphery of the said cylindrical valve chamber, and the filter is mounted | worn with a cylindrical valve chamber because the said nail | claw engages with the said attachment hole. . In addition, the filter has a slightly raised shape at the center, a spring is supported at the center, and the float valve is disposed above the spring. Furthermore, the filter is provided with a small hole not only in the outer periphery of the central portion that supports the spring but also in the central portion.

  When the fuel swings and is immersed in the float valve, the float valve is lifted by the buoyancy and the biasing force of the spring, and the valve head closes the exhaust hole to prevent the fuel from flowing out of the fuel tank. When the pressure in the fuel tank rises with the float valve lowered and the exhaust hole opened, the fuel vapor passes through the small hole of the filter, the internal space of the cylindrical valve chamber, and the exhaust hole. It is designed to be discharged outside.

Japanese Utility Model Publication No. 5-30654

  In the fuel outflow prevention valve, the center of the filter is slightly raised, and a spring is supported at the center, so that a slight gap is provided between the bottom wall of the float valve and the outer periphery of the center of the filter. However, the gap is provided to engage the claw of the cylindrical valve chamber with the mounting hole, and is extremely short when viewed in the axial direction.

  As a result, when the fuel oscillates vigorously in the fuel tank or when a large amount of fuel splashes due to vibration during running, etc., before the float valve rises and closes the exhaust hole, There was a risk that fuel would flow into the cylindrical valve chamber through the hole and leak out of the fuel tank through the exhaust hole of the cylindrical valve chamber.

  Therefore, the object of the present invention is to effectively suppress the leakage of fuel from the valve hole to the outside of the fuel tank by weakening the momentum of the fuel flowing into the housing in the case where the fuel fluctuates. The object is to provide a fuel spill prevention valve.

  In order to achieve the above object, the fuel outflow prevention valve of the present invention is provided with a lower space communicating with the inside of the fuel tank below and an upper space communicating with the outside of the fuel tank via the partition wall in which the valve hole is formed. And a float valve disposed in the lower space of the housing so as to be movable up and down, a spring for urging the float valve toward the valve hole of the partition, and an opening in the lower space of the housing And a cap mounted on the bottom surface of the float valve and one end of the spring, and the cap is disposed below the first wall via a predetermined space. And a second wall portion, and each wall portion is formed with a communication hole communicating with the inside of the fuel tank.

  In the fuel outflow prevention valve of the present invention, it is preferable that the first wall portion and the second wall portion are connected and integrated through a connecting portion.

  In the fuel outflow prevention valve of the present invention, it is preferable that the first wall portion and the second wall portion are separated.

  In the fuel outflow prevention valve of the present invention, it is preferable that a distance between the first wall portion and the second wall portion is 5 to 20 mm.

  In addition, another fuel spill prevention valve according to the present invention is provided with a lower space communicating with the inside of the fuel tank through a partition wall in which a valve hole is formed, and an upper space communicating with the outside of the fuel tank above. A housing, a float valve disposed in the lower space of the housing so as to be movable up and down, a spring for urging the float valve toward the valve hole of the partition, and an opening in the lower space of the housing A cap to be mounted, and the cap includes an annular bottom wall, a raised bottom that is raised from the inner periphery of the bottom wall and formed at a position higher than the bottom wall, and an outer periphery of the raised bottom. And an annular space formed in an upper part of the annular bottom wall, one end of the spring is supported by the raised bottom, and a communication hole communicating with the inside of the fuel tank is formed in the bottom wall. A communication hole is formed in the raised bottom. And characterized by the absence.

  In the fuel outflow prevention valve of the above invention, the length of the annular space along the axial direction of the cap is preferably 5 to 20 mm.

  In the fuel outflow prevention valve of the above invention, a spring accommodating recess for accommodating the spring is formed in the center of the bottom surface of the float valve, on the outer peripheral side of the spring accommodating recess, and in the cap. It is preferable that a lightening recess is formed at a position corresponding to the annular space.

  In the fuel outflow prevention valve according to the invention, a plurality of support columns are provided on the annular bottom wall of the cap so as to abut against the bottom surface of the float recess of the float valve and support the bottom surface of the float valve. It is preferable to be provided.

  According to the fuel outflow prevention valve of the present invention, even if the fuel in the fuel tank swings and flows in vigorously from the communication hole of the cap, the force is reduced by the space provided in the cap, and the float Before the valve hole of the partition wall is closed by the valve, leakage into the upper space through the valve hole can be effectively suppressed.

It is a disassembled perspective view which shows one Embodiment of the fuel outflow prevention valve of this invention. It is an expansion perspective view of the cap which comprises the fuel outflow prevention valve. It is sectional drawing of the fuel outflow prevention valve. FIG. 3 is a cross-sectional view of the fuel outflow prevention valve with a float valve raised. It is a disassembled perspective view which shows other embodiment of the fuel outflow prevention valve of this invention. It is an expansion perspective view of the cap which comprises the fuel outflow prevention valve. It is sectional drawing of the fuel outflow prevention valve. It is a disassembled perspective view which shows other embodiment of the fuel outflow prevention valve of this invention. It is an expansion perspective view of the cap which comprises the fuel outflow prevention valve. It is sectional drawing of the fuel outflow prevention valve. 2A and 2B show an inclination repetition test, in which FIG. 1A is an explanatory diagram when the fuel tank is in a horizontal state, and FIG.

  Hereinafter, with reference to FIGS. 1-4, 1st Embodiment of the fuel outflow prevention valve of this invention is described.

  As shown in FIGS. 1 and 3, the fuel outflow prevention valve 10 includes a housing 15 including a main body 20 and a lid body 30 attached to the upper side of the main body 20. A cap 50 composed of a first wall portion 60 and a second wall portion 70 which are separated from each other is attached.

  The main body 20 includes a cylindrical peripheral wall 21 that is open at the bottom and a partition wall 23 that closes the top of the peripheral wall 21. The partition wall 23 has an umbrella shape with a diameter gradually reduced upward, and a valve hole 23a is formed at the center thereof. By mounting the lid 30 above the main body 20, an upper space R 1 communicating with the outside of the fuel tank 1 is defined above the partition wall 23 of the housing 15, and the cap is formed below the main body 20. By mounting 50, a lower space R2 communicating with the inside of the fuel tank 1 is defined below the partition wall 23 of the housing 15 (see FIG. 3). The valve hole 23a forms a portion that allows the upper space R1 and the lower space R2 to communicate with each other.

  In addition, an annular groove 29 into which the annular rib 35 of the lid 30 is fitted is formed on the outer periphery of the peripheral wall 21 of the main body 20, and a step-like seal member arrangement portion 25 is formed on the inner periphery of the annular groove 29. Is formed. And the sealing member 25a is arrange | positioned at the sealing member arrangement | positioning part 25, The annular rib 35 of the cover body 30 is inserted in the outer side, and the main body 20 and the cover body 30 are sealed airtightly (FIG. 3).

  As shown in FIG. 1, a flange portion 26 provided with a plurality of insertion holes 26 a extends from the outer periphery of the annular groove 29 above the peripheral wall 21. A locking projection 21a is formed on the outer periphery of the upper portion of the peripheral wall 21 at a position aligned with the insertion hole 26a. Further, a plurality of holes 21b communicating with the lower space R2 are formed at positions closer to the upper side of the peripheral wall 21. A plurality of engagement holes 28 and notches 28 a are formed on the lower outer periphery of the peripheral wall 21.

  On the other hand, the lid body 30 has a substantially hat shape with the upper part closed, a head part 31 that defines the upper space R1 together with the main body 20, and a flange part 32 that extends from the periphery of the head part 31. And have. A connecting pipe 33 that communicates with the upper space R1 extends from the side of the head 31, and a tube that communicates with a canister (not shown) disposed outside the fuel tank 1 is connected to the connecting pipe 33. It has come to be. A plurality of locking pieces 34 having a frame shape are provided from below the peripheral edge of the flange portion 32.

  Then, in a state where the seal member 25 a is arranged in the seal member arrangement portion 25 of the main body 20, the locking piece 34 of the lid body 30 is inserted into the insertion hole 26 a of the flange portion 26 of the main body 20, thereby By engaging with the portion 21a, the lid 30 is mounted on the upper side of the main body 20 in a state where the space between the main body 20 and the lid 30 is hermetically sealed with the seal member 25a ( (See FIG. 3).

  A float valve 40 is disposed in the lower space R2 of the housing 15 so as to be movable up and down. As shown in FIGS. 1 and 3, the float valve 40 of this embodiment has a stepped outer peripheral surface so that the diameter gradually decreases upward. At the center of the upper surface of the float valve 40, a valve head 41 that gradually decreases in diameter toward the upper side protrudes. The valve head 41 contacts and separates from the valve hole 23a of the housing 15 to open and close the valve hole 23a (see FIGS. 3 and 4). In addition, a plurality of guide ribs 43 extending along the axial direction are provided on the outer periphery of the lowermost portion of the float valve 40, which has the largest diameter, extending in the axial direction at equal intervals in the circumferential direction.

  Further, as shown in FIG. 3, a spring accommodating recess 45 for accommodating a spring 46 is formed in the center of the bottom surface of the float valve 40. A plurality of lightening recesses 47 are formed at a predetermined length along the axial direction of the float valve 40 on the bottom surface of the float valve 40 and on the outer peripheral side of the spring accommodating recess 45. In addition, the predetermined lightening recess 47 (here, a pair of ones arranged to face the circumferential direction of the float valve 40) penetrates the upper surface of the float valve 40 (FIGS. 1 and 3). reference).

  The spring 46 is housed in the spring housing recess 45 of the float valve 40, and its upper end is supported by the upper surface of the recess and its lower end is supported by the first wall 60 of the cap 50. Yes. When the fuel is not immersed, the float valve 40 compresses the spring 46 by its own weight, is placed on the cap 50, and is held in a state where the valve hole 23a is opened (see FIG. 3). . In this state, when the fuel level in the fuel tank 1 rises and the float valve 40 is immersed in the fuel by a predetermined height or more, the buoyancy of the float valve 40 itself is added to the urging force of the spring 46, and the float valve 40. And the valve head 41 closes the valve hole 23a (see FIG. 4).

  As shown in FIGS. 1 and 3, the cap 50 attached to the opening of the lower space R2 of the housing 15 has a first wall 60 and a predetermined space R3 (see FIG. 3) below the first wall 60. It has the 2nd wall part 70 arrange | positioned.

  Referring also to FIG. 2, the first wall portion 60 is provided with a substantially disc-shaped bottom wall 61 having an outer diameter adapted to the main body 20 of the housing 15, and standing from the periphery of the bottom wall 61. The outer peripheral wall 62 has a shallow cylindrical shape with an upper opening. On the outer periphery of the peripheral wall 62, a plurality of engaging protrusions 63 that engage with the engaging holes 28 of the main body 20 of the housing 15 are projected, and a plurality of engaging protrusions 63 that fit into the notches 28 a of the main body 20 are provided. A projecting portion 63a is projected.

  Further, a spring support protrusion 64 having a substantially cross shape protrudes from the center of the surface of the bottom wall 61 (the surface on the float valve 40 side). The spring 46 is stably supported by entering the inner periphery of the lower end. The spring support protrusion 64 may be hemispherical or trapezoidal, and is not particularly limited.

  Further, a plurality of float valve support protrusions 65 project from the surface of the bottom wall 61 so as to support the float valve 40 in a state of slightly floating from the surface of the first wall portion 60. (See FIG. 3). The float valve support protrusions 65 of this embodiment have a rectangular plate shape, and a plurality (four in this case) are provided at equal intervals in the circumferential direction at positions closer to the inner periphery of the peripheral wall 62. There are no particular limitations on the shape, number, arrangement position, and the like of the float valve support protrusion 65, and the float valve support protrusion 65 can be set as appropriate according to the shape, weight, etc.

  Engagement slits 66 and 66 are formed at positions facing the outer peripheral edge of the first wall portion 60.

  Further, a plurality of communication holes 67 that communicate with the inside of the fuel tank 1 are formed in the bottom wall 61 of the first wall portion 60, and the lower space R <b> 2 of the housing 15 and the space are formed via the communication holes 67. R3 communicates with each other. The inner diameter of the communication hole 67 is preferably 0.6 to 3 mm, and more preferably 1.2 to 1.8 mm.

  Note that the first wall portion 60 described above is not limited to the above shape, and may be, for example, a disk shape without the peripheral wall 62, and can be attached to the opening of the lower space R2 of the housing 15. That's fine.

  On the other hand, the second wall portion 70 has a substantially disc-shaped bottom wall 71 having an outer diameter adapted to the bottom wall 61 of the first wall portion 60, and a peripheral wall 72 erected from the periphery of the bottom wall 71. It has a bottomed cylindrical shape with an open top. The peripheral wall 72 is erected higher than the peripheral wall 62 of the first wall portion 60, and the second wall portion 70 has a bottomed cylindrical shape with a deeper bottom than the first wall portion 60. .

  Further, notches 73 and 73 are formed at positions facing the circumferential direction of the peripheral wall 72, and the first wall portion 60 is engaged at a position adjacent to the inside through the notches 73. Engaging pieces 74 and 74 that can be bent and inserted into the mating slits 66 and 66 are provided upright. Further, an engaging claw 74 a that engages with a front side peripheral edge of the engaging slit 66 of the first wall portion 60 protrudes from the outer end of each engaging piece 74.

  A plurality of communication holes 77 communicating with the inside of the fuel tank 1 are formed in the bottom wall 71 of the second wall part 70, and the communication holes 77 are formed in the first wall part 60 and the second wall part 70. It communicates with the space R3 between. The inner diameter of the communication hole 77 is preferably 0.6 to 3 mm, and more preferably 1.2 to 1.8 mm.

  In addition, the shape of the 2nd wall part 70 is not limited to the said aspect, What is necessary is just a shape which can form space R3 between the 1st wall parts 60. FIG.

  Then, the engagement pieces 74, 74 of the second wall portion 70 are inserted into the engagement slits 66, 66 of the first wall portion 60, and the engagement claws 74a are engaged with the front side peripheral edges of the engagement slit 66, respectively. Thus, the first wall portion 60 can be mounted with the first wall portion 60 being prevented from rotating with respect to the second wall portion 70. In this state, the plurality of convex portions 63a of the first wall portion 60 are fitted into the notches 28a of the main body 20 of the housing 15, and the plurality of engagement protrusions 63 of the first wall portion 60 are fitted to the notches 28a of the main body 20. Engage with the engagement hole 28. Accordingly, the first wall portion 60 is disposed so as to close the lower opening of the main body 20 of the housing 15, and the second wall portion 70 is disposed below the first wall portion 70 via the space R <b> 3. The cap 50 can be attached to the opening of R2 while being prevented from rotating (see FIG. 3).

  In this embodiment, the engaging claw 74a, the engaging hole 28, and the like are used as means for attaching the first wall portion 60 and the second wall portion 70 to the opening of the lower space R2 of the housing 15. It is not limited to this aspect, and can be set as appropriate according to the shape of the first wall portion 60 and the second wall portion 70.

  Further, when the cap 50 is attached to the opening of the lower space R2 of the housing 15, the bottom wall 61 of the first wall 60 and the bottom wall 71 of the second wall 70 are parallel to each other. The space R3 is defined between them.

  A distance D between the bottom wall 61 of the first wall portion 60 and the bottom wall 71 of the second wall portion 70 that defines the space R3 (that is, the length of the space R3 along the axial direction of the cap 50) is: As shown in FIG. 3, it is preferable that it is 5-20 mm, and it is more preferable that it is 10-15 mm. If the distance D is less than 5 mm, the momentum of the fuel flowing in from the communication hole 77 of the second wall portion 70 cannot be sufficiently reduced. If the distance D exceeds 20 mm, the axial length of the fuel outflow prevention valve 10 is reduced. As a result, the entire valve becomes larger and the fuel tank 1 may be hindered.

  Next, the function and effect of the fuel outflow prevention valve of the present invention will be described.

  The fuel outflow prevention valve 10 in this embodiment prevents the fuel in the fuel tank from leaking out of the fuel tank when the automobile turns or tilts, and assumes a so-called cut valve. However, it can also be applied to a so-called full tank control valve that stops fueling at the upper limit of the amount of oil supplied during refueling (the full tank control valve also has a float valve, and floats along with fuel refueling. The valve rises to close the opening and suppress fuel outflow).

  The fuel outflow prevention valve 10 is inserted into the opening 3 of the resin fuel tank 1 from the side of the main body 20 constituting the housing 15, and the flange portion of the lid 30 is formed on the front side periphery of the opening 3 of the fuel tank 1. By welding the lower peripheral edge portion 26a of 26, the fuel tank 1 can be attached as shown in FIG.

  Then, when the vehicle turns or greatly tilts and the fuel level in the fuel tank 1 rises, the fuel flows into the space R3 through the communication hole 77 of the second wall 70 and the first wall. It enters the lower space R2 through the communication hole 67 of the portion 60. As a result, when the fuel is immersed in the float valve 40 by a predetermined height or more, the float valve 40 is lifted by the buoyancy generated in the spring 46 and the float valve 40 itself, and the valve head 41 becomes the valve of the housing 15 as shown in FIG. Since the valve hole 23a is closed by coming into contact with the inner periphery of the hole 23a, the fuel is prevented from flowing into the upper space R1 through the valve hole 23a, and fuel leakage to the outside of the fuel tank 1 is prevented. Can be prevented.

  By the way, when the vehicle runs on a rough road and vibrates up and down, swings left and right, or turns sharply, liquid fuel, fuel splashes, etc. (hereinafter referred to as “fuel”) As indicated by the arrows in FIG. 3, the fluid may flow in vigorously from the communication hole 77 of the second wall portion 70 constituting the cap 50.

  However, in this fuel outflow prevention valve 10, since the space R <b> 3 is provided between the first wall portion 60 and the bottom wall 71 of the second wall portion 70, the momentum of the fuel flowing in from the communication hole 77 is increased. It can be weakened by the space R3. That is, the communication hole 77 of the second wall portion 70 has a small inner diameter and a small flow path area, so that the flow rate of fuel passing therethrough becomes faster. However, the space R3 has a larger diameter than the communication hole 77 and a flow path area. Therefore, the momentum of the fuel can be reduced by slowing the flow rate of the fuel. Furthermore, the fuel whose momentum has been weakened in the space R3 collides with the first wall portion 60 when passing through the communication hole 67 of the first wall portion 60, so that the momentum is further weakened. It is possible to effectively suppress the fuel from flowing into the upper space R1 through the valve hole 23a and leaking outside the fuel tank 1 before the valve hole 23a is closed.

  In the fuel spill prevention valve of Patent Document 1, the center of the filter below the float valve has a slightly raised shape, a spring is supported at the center, and the float valve is disposed at the upper end of the spring. A gap is formed below the float valve. Such a gap prevents the float valve from sticking to the upper surface of the filter, and a nail on the outer periphery of the lower end of the cylindrical valve chamber, and a mounting hole on the fitting cylindrical wall on the outer periphery of the filter. This is necessary for the fitting structure, and is not intended to weaken the momentum of the fuel flowing in from the small hole of the filter.

  As shown in FIG. 3, when the distance D between the bottom wall 61 of the first wall portion 60 constituting the cap 50 and the bottom wall 71 of the second wall portion 70 is 5 to 20 mm. The flow velocity of the fuel that has flowed into the space R3 from the communication hole 77 of the second wall portion 70 can be reduced more effectively.

  Furthermore, in this embodiment, since the first wall portion 60 and the second wall portion 70 constituting the cap 50 are separated, the first wall portion 60 and the second wall portion 70 with respect to the housing 15 are separated. By appropriately changing the mounting position, the distance D between the first wall portion 60 and the second wall portion 70 can be easily changed.

  5-7 show other embodiments of the fuel spill prevention valve of the present invention. Note that substantially the same parts as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The fuel outflow prevention valve 10a of this embodiment is different from the cap 50 of the above embodiment in the structure of the cap 50a.

  That is, as shown in FIGS. 5 and 6, the cap 50 a of this embodiment has a first wall portion 60 a having a thin disk shape and a disk shape thicker than the first wall portion 60. The formed second wall portion 70a is connected through a connecting portion 80 having a cross-shaped cross section, and has an integrated structure. In addition, the connection part 80 is good also as columnar shape, prismatic shape, etc., and is not specifically limited.

  The first wall 60a is formed with an outer diameter smaller than the inner diameter of the peripheral wall 21 of the main body 20 of the housing 15, and the first wall 60a is a lower space R2 of the main body 20 as shown in FIG. In the state of being disposed below, a gap C that communicates the lower space R2 and the space R3 is formed between the inner periphery of the peripheral wall 21 of the main body 20 and the outer periphery of the first wall portion 60a. ing. However, the gap C is not always necessary, and the inner periphery of the peripheral wall 21 of the main body 20 and the outer periphery of the first wall portion 60a may be substantially in contact with each other.

  Further, a plurality of engaging claws 74 a that are engaged with the engaging holes 28 of the main body 20 of the housing 15 protrude from the outer periphery of the second wall portion 70 a and are formed in the notches 28 a of the main body 20. A plurality of convex portions 74b to be fitted are projected.

  Then, the plurality of convex portions 74b of the second wall portion 70a are fitted into the notches 28a of the main body 20 of the housing 15, and the plurality of engaging claws 74a of the second wall portion 70a are engaged with the main body 20. By engaging with the hole 28, the cap 50a can be attached to the opening of the lower space R2 of the housing 15 with the cap 50a being prevented from rotating (see FIG. 7).

  According to this embodiment, since the first wall portion 60a and the second wall portion 70a constituting the cap 50a are integrated via the connecting portion 80, the first wall portion 60a and the second wall portion 70a. The cost can be reduced by reducing the number of parts while securing the space R3 between the two.

  8 to 10 show still another embodiment of the fuel outflow prevention valve of the present invention. Note that substantially the same parts as those of the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The fuel outflow prevention valve 10b of this embodiment is different from the caps 50 and 50a of the above embodiment in the structure of the cap 50b.

  That is, as shown in FIGS. 8 and 9, the cap 50 b of this embodiment has an annular bottom wall 51, and the communication hole 67 communicating with the inside of the fuel tank is formed on the bottom wall 51. Is formed. Further, the peripheral wall 52 is erected from the outer peripheral edge of the bottom wall 51 at a predetermined height. From the upper outer periphery, a plurality of engagement claws 74a and a plurality of engagement claws 74a and the second wall portion 70a of the cap 50a are provided. A plurality of convex portions 74b are provided so as to project.

  Furthermore, from the inner peripheral edge of the annular bottom wall 51, a raised bottom portion 53 that closes the upper end thereof is formed through a cylindrical wall 58 standing upward. The spring support protrusion 64 is provided on the raised bottom 53 to support the lower end of the spring 46 (see FIG. 10). Further, the raised bottom 53 is not formed with a communication hole 67 as provided in the bottom wall 51.

  An annular space R4 (hereinafter referred to as “annular space R4”) is formed on the outer periphery of the raised bottom portion 53 and the cylindrical wall 58 and in an upper portion of the annular bottom wall 51. The annular space R4 communicates with the communication hole 67 of the bottom wall 51.

  Further, as shown in FIG. 10, from the length of the annular space R4 along the axial direction of the cap 50b, that is, from the inner surface of the bottom wall 51 (the surface on the annular space R4 side), the surface (float) The distance D to the valve 40 side surface) is preferably 5 to 20 mm, and more preferably 10 to 15 mm. If the distance D is less than 5 mm, the momentum of the fuel flowing in from the communication hole 67 of the bottom wall 51 cannot be sufficiently reduced. If the distance D exceeds 20 mm, the fuel outflow prevention valve 10 becomes large, and the fuel tank 1 is moved to. There is a risk of hindering the installation. There is a possibility that the cap 50b is enlarged, and as a result, the entire fuel outflow prevention valve 10 is enlarged, thereby hindering attachment to the fuel tank 1.

  Further, as described in the above embodiment, the float valve 40 has a spring accommodating recess 45 formed in the center of the bottom surface and a plurality of lightening recesses 47 formed on the outer peripheral side thereof, as shown in FIG. The thinned recess 47 is formed to be at a position corresponding to the annular space R4 of the cap 50b. In the present invention, the formation position of the thinning recess is the “position corresponding to the annular space of the cap”, but the “corresponding position” referred to here is the thickness when viewed from the axial direction. It means that the formation position of the punched recess overlaps the annular space R4.

  Further, as shown in FIGS. 9 and 10, the annular bottom wall 51 constituting the cap 50 b comes into contact with the bottom surface on the outer peripheral side of the lightening recess 47 of the float valve 40, and the bottom surface of the float valve 40. The support | pillar 55 which supports is provided. In this embodiment, a plurality of (four in this case) support columns 55 are provided at equal intervals along the circumferential direction from a position near the peripheral wall 52 on the inner surface side of the bottom wall 51. Each column 55 has a rectangular section and a shaft portion 55a erected at a predetermined height, and projects from both side surfaces of the shaft portion 55a along the axial direction of the coaxial portion 55a, and is on the near side of the upper end of the shaft portion 55a. It consists of ribs 55b and 55b extending in a length up to. In addition, even if the support | pillar 55 is column shape, prismatic shape, the cross-shaped rib shape etc., for example, it does not specifically limit.

  In the fuel outflow prevention valve 10b, even if the fuel flows in vigorously from the communication hole 67 of the cap 50b due to the vibration or swing of the vehicle, the annular bottom wall 51 is located on the outer periphery of the raised bottom 53. Since the annular space R4 is formed in the upper portion of the, the momentum of the fuel flowing in from the communication hole 67 can be weakened in the annular space R4. At the same time, since the distance from the communication hole 67 to the valve hole 23a of the partition wall 23 of the housing 15 is increased, the fuel flows into the upper space R1 through the valve hole 23a before the valve hole 23a is closed by the float valve 40. Thus, leakage to the outside of the fuel tank 1 can be effectively suppressed.

  As shown in FIG. 10, when the length of the annular space R4 along the axial direction of the cap 50b, that is, the distance D is 5 to 20 mm, the bottom wall 51 of the cap 50b The flow rate of the fuel that has flowed into the space from the communication hole 67 can be reduced more effectively.

  Furthermore, in this embodiment, since the hollow portion 47 is formed in the bottom surface of the float valve 40 at a position corresponding to the annular bottom wall 51 of the cap 50b, the communication hole 67 of the bottom wall 51 of the cap 50b is formed. When the fuel flowing in from the fuel rises, at least part of the fuel enters the lightening recess 47, thereby weakening the momentum of the fuel and changing the flow direction so that the fuel flows into the upper space R1 through the valve hole 23a. Can be suppressed more effectively.

  Further, in this embodiment, the annular bottom wall 51 of the cap 50b is in contact with the bottom surface on the outer peripheral side of the thinning recess 47 of the float valve 40, and a plurality of columns 55 that support the bottom surface of the float valve 40. Therefore, when the float valve is lowered, the float valve 40 can be stably supported without tilting, and the fuel in the fuel tank 1 is oscillated, vibrated, or the like, so that the communication hole 57 of the bottom wall 51 is provided. When the fuel flows into the annular space R4 above the bottom wall vigorously, at least a part of the fuel does not prevent the fuel from entering the lightening recess 47 of the float valve 40, and the fuel is weakened so that the fuel flows into the upper space R1. Leakage can be suppressed.

  The fuel spill prevention valve was tested to see how much fuel leaked from the valve hole.

(Example)
A fuel spill prevention valve 10 according to the present invention shown in FIGS.

  The maximum inner diameter of the main body 20 of the housing 15 is 46 mm, and the height from the second wall portion 60 to the valve hole 23a is 41 mm.

  The inner diameter of the communication hole 67 of the first wall portion 60 of the cap 50 and the inner diameter of the communication hole 77 of the second wall portion 70 are both formed to be 1.8 mm. . The distance D between the bottom wall 61 of the first wall portion 60 and the bottom wall 71 of the second wall portion 70 is 17 mm, and the inner diameter of the valve hole 23a of the housing 15 is 2.5 mm.

(Comparative example)
As the cap for closing the lower space R2 of the housing, a cap having only the first wall portion 60 in the above embodiment was used. That is, this comparative example has a structure in which there is no member corresponding to the second wall portion in the embodiment and the space R3 is not provided.

(Inclined repeat test)
As shown in FIG. 11 (a), a fuel spill prevention valve is mounted in a fuel tank filled with fuel so that the distance L from the fuel level is 50 mm, and the fuel tank 1 is measured by an inclination test device (not shown). And rotated in the next cycle.

  That is, while blowing air from the air blowing pipe 5 into the fuel tank 1 at 5 L / min, the fuel tank 1 is first rotated counterclockwise so that the fuel tank 1 is inclined 45 ° with respect to the fuel liquid level FL. After that (see FIG. 11B), the operation of rotating the fuel tank 1 so that the fuel tank 1 is also inclined at 45 ° with respect to the fuel liquid level FL is then repeated clockwise. This one-cycle operation was performed in 5 seconds, and this was repeated for 5 minutes.

  The above operation was performed three times for each fuel outflow prevention valve, and the amount of fuel leakage from the valve hole 23a at that time was measured. As a result, it was confirmed that the fuel outflow prevention valve of the example had a smaller amount of fuel leakage from the valve hole than the fuel outflow prevention valve of the comparative example, and could effectively suppress the fuel leakage.

DESCRIPTION OF SYMBOLS 1 Fuel tank 10,10a, 10b Fuel outflow prevention valve 15 Housing 23 Partition 23a Valve hole 40 Float valve 45 Spring accommodation recessed part 46 Spring 47 Meat-removal recessed part 50, 50a, 50b Cap 51 Bottom wall 53 Raised bottom part 55 Column 57 Communication hole 60 , 60a First wall portion 67 Communication hole 70, 70a Second wall portion 77 Communication hole 80 Connection portion

Claims (8)

A housing provided with a lower space communicating with the inside of the fuel tank at a lower side and an upper space communicating with the outside of the fuel tank on the upper side through a partition wall formed with a valve hole;
A float valve disposed so as to be movable up and down in the lower space of the housing;
A spring for biasing the float valve toward the valve hole of the partition;
A cap attached to the opening in the lower space of the housing,
The cap includes a first wall portion that supports a bottom surface of the float valve and one end of the spring, and a second wall portion that is disposed below the first wall portion with a predetermined space interposed therebetween. And each wall is formed with a communication hole communicating with the inside of the fuel tank.   The fuel outflow prevention valve according to claim 1, wherein the first wall portion and the second wall portion are connected and integrated through a connecting portion.   The fuel outflow prevention valve according to claim 1, wherein the first wall portion and the second wall portion are separate bodies.   The fuel outflow prevention valve according to claim 1 or 2, wherein a distance between the first wall portion and the second wall portion is 5 to 20 mm. A housing provided with a lower space communicating with the inside of the fuel tank at a lower side and an upper space communicating with the outside of the fuel tank on the upper side through a partition wall formed with a valve hole;
A float valve disposed so as to be movable up and down in the lower space of the housing;
A spring for biasing the float valve toward the valve hole of the partition;
A cap attached to the opening in the lower space of the housing,
The cap includes an annular bottom wall, a raised bottom that is raised from the inner periphery of the bottom wall and formed at a position higher than the bottom wall, and an outer periphery of the raised bottom that is above the annular bottom wall. An annular space formed in the part,
One end of the spring is supported by the raised bottom, a communication hole communicating with the inside of the fuel tank is formed on the bottom wall, and a communication hole is not formed on the raised bottom. Outflow prevention valve.   The fuel outflow prevention valve according to claim 5, wherein a length of the annular space along the axial direction of the cap is 5 to 20 mm.   A spring accommodating recess for accommodating the spring is formed at the center of the bottom surface of the float valve, and is thinned at a position on the outer peripheral side of the spring accommodating recess and corresponding to the annular space of the cap. The fuel outflow prevention valve according to claim 5 or 6, wherein a recess is formed.   8. The fuel according to claim 7, wherein a plurality of support columns are provided on the annular bottom wall of the cap so as to be in contact with the bottom surface on the outer peripheral side of the hollow recess of the float valve and support the bottom surface of the float valve. Outflow prevention valve.