JP2007137313A - Fuel leakage preventive valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel leakage preventive valve effectively suppressing fuel leakage before a float valve rises. <P>SOLUTION: The fuel leakage preventive valve has a connector including a connecting space therein for communicating with the outside and attached to an upper wall of a fuel tank, the housing 2 having a housing chamber defined therein and a valve seat disposed to an upper part thereof so as to communicate with the connecting space, and the float valve disposed in the housing chamber of the housing 2 so as to be capable of moving up and down in the housing chamber, and a plurality of air holes 12 formed in a side wall of the housing 2. By providing a wall 13 for covering, from the outside, a permeable opening of at least one air hole 12 out of the air holes 12 while ensuring its permeable opening area, since one of the air holes 12 is covered from the outside by the wall 13 while the permeable opening area of the permeable opening is secured, inflow of the fuel is effectively suppressed and an amount of leakage of the fuel from the valve seat is surely reduced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel leakage prevention valve that prevents fuel leakage from a fuel tank, for example, when a vehicle turns or falls.

  Although this type of conventional fuel leakage prevention valve is not specifically shown, it has a connection space that communicates with the outside and has a connector that is attached to the upper wall of the fuel tank, and a storage chamber that defines the interior. A housing having a valve seat communicating with the connection space at the upper part, a float valve disposed in the housing chamber of the housing so as to be movable up and down while receiving the biasing spring pressure of the spring, and a cap for closing the lower opening of the housing And a plurality of ventilation holes communicating with the inner and outer sides are formed on the side wall of the housing, and a plurality of ventilation holes communicating with the inner and outer sides are formed also on the lower wall of the cap (for example, patents) Reference 1).

In actual use, if the connector is thermally welded to the upper wall of the resin fuel tank through the flange portion while facing the housing in the mounting hole established in the upper wall of the fuel tank, Since the float valve is normally lowered in the housing chamber, the valve seat on the housing side is opened, and the fuel vapor in the fuel tank is allowed to flow between the housing and the cap. However, if the vehicle is turning, the fuel in the fuel tank is temporarily stored in the housing. When it reaches the room, the float valve automatically rises due to its buoyancy and the spring pressure of the spring, and the valve seat of the housing is closed by its own valve part. But to prevent the leaking to the outside following the canister and beyond.
JP 2003-175736 A

  Therefore, in the case of the conventional fuel leakage prevention valve, it is theoretically possible to prevent fuel leakage reliably by the action of the float valve. If the fuel in the tank undulates greatly, the fuel will flow into the housing, especially from the vent formed in the side wall of the housing, so that the valve seat opened before the float valve is raised There was a risk of fuel leaking out.

  The present invention was developed in order to effectively solve the problems of such a conventional fuel leakage prevention valve. The invention according to claim 1 has a connection space communicating with the outside inside, and a fuel tank. A connector attached to an upper wall of the housing, a housing having a valve seat that defines a storage chamber therein and communicates with the connection space at an upper portion thereof, and a float valve that is arranged to be movable up and down in the storage chamber of the housing A fuel leakage prevention valve having a plurality of vent holes communicating with the inner and outer sides of the side wall of the housing, the permeation opening area being ensured for at least one of the vent holes However, a wall that covers the transmission opening from the outside is provided.

  According to the second aspect of the present invention, on the premise of the first aspect, a plurality of vent holes are formed in the vertical direction of the side wall of the housing, a wall is provided in the uppermost vent hole, and the lowermost vent hole is provided. Is characterized in that no walls are provided.

  According to a third aspect of the present invention, on the premise of the first aspect, the wall that covers the transmission opening of the vent hole from the outside is offset in parallel from a center line that passes through the center of the housing and has a single diameter. It exists in the hole edge of the side away from a centerline, It is characterized by the above-mentioned.

  According to a fourth aspect of the present invention, on the premise of the first aspect, the housing is provided in the fuel tank so that the vent hole is parallel to the short direction of the fuel tank.

  Therefore, according to the first aspect of the present invention, the vent hole formed in the side wall of the housing before the vehicle turns sharply and the fuel in the fuel tank undulates and the float valve rises. Even when trying to flow into the housing from the outside, at least one of the vent holes is covered by the wall from the outside while ensuring the transmission opening area by the wall, thereby impairing the function of the vent hole. Therefore, the amount of fuel leakage from the valve seat can be reliably reduced by effectively suppressing the inflow of fuel.

  In the invention according to claim 2, since the uppermost vent hole close to the valve seat is covered with the wall, it is possible to suppress fuel leakage from the valve seat, but on the other hand, it is far from the valve seat. If a wall is provided in the lowermost vent hole, the fuel droplets generated there may invade from the upper vent hole and promote fuel leakage from the valve seat. It is preferable not to provide.

  In the invention of claim 3, the fuel that has swelled greatly flows into the vent hole in a large amount from the lateral direction of the housing and does not flow so much from the direction intersecting the lateral direction. Therefore, since the wall covering the vent hole is offset in parallel from the center line having one diameter passing through the center of the housing and is located at the hole edge on the side away from the center line in the offset direction, the housing is particularly It is possible to more effectively suppress the inflow of fuel from the lateral direction.

  In the invention according to claim 4, when the automobile turns sharply, generally, the fuel tends to undulate greatly from the longitudinal direction of the fuel tank. Since it is provided in a parallel state, the inflow of fuel from the vent hole of the housing is also suppressed from this point.

  The present invention includes a connector that has a connection space that communicates with the outside and is attached to the upper wall of the fuel tank, and a housing that defines a storage chamber inside and has a valve seat that communicates with the connection space at the top. And a float valve that is arranged to move up and down in the housing chamber of the housing, and on the premise of a fuel leakage prevention valve having a plurality of vent holes communicating with the inside and outside of the side wall of the housing, By providing a wall that covers the permeation opening from the outside while ensuring the permeation opening area for at least one vent hole, the inflow of fuel from the vent hole is effectively suppressed, and the float valve is raised. Before, it is intended to reduce the leakage of fuel from the valve seat.

  Hereinafter, the present invention will be described in detail with reference to a preferred embodiment shown in the drawings. The fuel leakage prevention valve according to the embodiment is basically configured as shown in FIG. A connector 1 that has a connection space 5 that communicates with the connector 1 and is attached to the upper wall of the fuel tank; a housing 2 that defines a storage chamber 6 therein and has a valve seat 7 that communicates with the connection space 5 at the top; The housing 2 of the housing 2 includes a float valve 3 that can be moved up and down while receiving the biasing spring pressure of the spring 8, and a cap 4 that closes the lower opening of the housing 2.

  And the connector 1 forms the annular flange part 9 which seals the attachment hole opened in the upper wall of the fuel tank in the outer periphery of the lower part, and the connection piping part 10 connected to the canister side is installed horizontally in the upper part It is the composition to do.

  Further, as shown in FIG. 2, the housing 2 connected to the connector 1 via an O-ring 11 is provided with fuel and fuel at four positions which are largely offset from the valve seat 7 on the cylindrical side wall. Ventilation holes 12 through which steam passes are formed in three upper and lower stages, and among these, at least one ventilation hole 12 formed at the uppermost position of each position is secured with its transmission opening area. A semicircular arc-shaped wall 13 that covers the transmission opening from the outside of the side wall is provided. Each wall 13 that covers the vent hole 12 from the outside passes through the valve seat 7 (center) of the housing 2 and is offset in parallel from a center line L (see FIG. 6) having a single diameter. It is assumed to be present at the hole edge on the side away from the center line L.

  Further, as shown in FIG. 3, the float valve 3 disposed in the housing chamber 6 of the housing 2 is integrally formed with a valve portion 14 for opening and closing the valve seat 7 of the housing 2 at the center of the upper surface thereof. At the same time, a plurality of guide rib portions 15 that abut on the inner surface defining the storage chamber 6 of the housing 2 are provided on the side surface at regular intervals.

  Finally, the cap 4 that closes the lower opening of the housing 2 has a connecting means with the housing 2 (not shown), and a plurality of ventilation holes communicating with the inside of the housing 2 are formed on the lower wall thereof. It is the structure to form.

  Therefore, even in the fuel leakage prevention valve having such a configuration, the connection state between the connector 1 and the housing 2 is obtained, and the float valve 3 and the spring 8 are housed in the housing chamber 6 of the housing 2 while the housing 1 If the lower opening of 2 is closed with the cap 4, the fuel leakage prevention valve can be easily assembled as shown in FIG. 4. In this state, the vent hole formed at the top of each position 12 are individually covered by the wall 13 from the outside of the side wall of the housing 2.

  Accordingly, as shown in FIG. 5, the connector 1 is thereafter inserted into the resin fuel tank T through the flange portion 9 while the housing 2 faces the mounting hole H formed in the upper wall Ta of the fuel tank T. If it is thermally welded to the upper wall Ta, it can be used. However, since the float valve 3 is always lowered in the housing chamber 6 of the housing 2 as shown in the drawing, the valve seat of the housing 2 is used. 7 is opened, and the fuel vapor in the fuel tank T is passed through the vent hole 12 on the housing 2 side and the vent hole on the cap 4 side from the connection pipe portion 10 provided in the connector 1 (not shown). As a result, the internal pressure of the fuel tank T can be effectively prevented from rising abnormally. When the fuel leakage prevention valve is attached, the vent holes 12 formed in the side wall of the housing 2 are provided in a state parallel to the short direction of the fuel tank T.

  In this state, if the fuel in the fuel tank T greatly undulates due to a sudden turn of the automobile or the like and attempts to flow into the housing 2 from the vent hole 12 formed in the side wall of the housing 2, at least the maximum The upper vent hole 12 is covered by the wall 13 from the outside while the permeation opening is secured while ensuring the permeation opening area, so that the inflow of fuel into the housing 2 can be effectively performed without impairing the function of the vent hole 12. Thus, it is possible to reliably reduce the amount of fuel leakage from the valve seat 7, that is, the leakage of fuel from the valve seat 7 into the connection space 5 of the connector 1.

  This will be described in detail. When a test was performed to compare the relationship between the permeation opening direction of the vent hole 12 formed in the housing 2 and the fuel inflow direction, the results shown in FIGS. 6 to 8 were obtained. That is, when the permeation opening direction of the vent hole 12 in FIG. 6 coincides with the fuel inflow direction, the leakage amount from the valve seat 7 is 1.1 cc when the wall 13 is not provided. Although it did not change to 1.1 cc, when the permeation opening direction of the vent hole 12 and the inflow direction of fuel in FIG. : When 1.3 cc is reduced to 1.0 cc, and the permeation opening direction of the vent hole 12 and the inflow direction of the fuel are shifted by 90 °, when the wall 13 is not provided: The result was reduced from 0.9 cc to 0.9 cc. In addition, the permeation | transmission opening area in FIG. 6 thru | or FIG. 8 means the area which the vent hole 12 is open seeing from the inflow direction (arrow direction in a figure) of a fuel.

  From this, a larger amount of leakage occurs as the offset amount ε of the vent hole 12 to the center line L of the housing 2 is smaller, and a larger amount of leakage occurs as the transmission aperture area is larger. Although it has been found that leakage occurs, in this embodiment, as described above, the vent hole 12 is formed with a large offset from the center line L passing through the valve seat 7 of the housing 2, and the valve seat 7 Since the wall 13 is provided in the uppermost vent hole 12 that is closest to the valve seat 7, the wall from the valve seat 7, regardless of the mounting direction, compared to the conventional one or the wall 13 not provided. It is possible to reduce the leakage amount on average.

In this embodiment, the wall 13 is provided only at the uppermost vent hole 12, but a similar wall 13 can be provided at the middle or lowermost vent hole 12. It is preferable not to provide the wall 13 for the lowest vent 12. This is because if there is an uneven shape on the outer periphery of the side wall of the housing 2, the wave of the fuel may break up and scatter, but if the wall 13 is provided in the lowermost vent hole 12, the generated splash This is because there is a possibility that the air enters from the upper vent hole 12 and leaks from the valve seat 7.

In addition, in the present embodiment, the fuel that has greatly swelled flows into the vent hole 12 in a large amount from the lateral direction of the housing 2 and does not flow so much from the direction intersecting the lateral direction. The wall 13 covering the wall 12 is offset in parallel from the center line L having one diameter passing through the center of the housing 2 and is present at the hole edge on the side away from the center line L in the offset direction. It is possible to more effectively suppress the inflow of fuel from the lateral direction.
For example, if the offset amount ε is 0, the fuel droplets or fuel mist flowing in from the vent hole 12 directly hit the valve seat 7 and the valve seat 7 is likely to leak. If the offset amount ε is large, It is difficult for the fuel to leak from the valve seat 7 without hitting the seat 7 directly.

Further, when the automobile turns sharply, generally, the fuel undulates from the longitudinal direction of the fuel tank T. In this embodiment, the vent hole 12 of the housing 2 is short of the fuel tank T. Since it is in a state parallel to the hand direction, the inflow of fuel from the vent hole 12 of the housing 2 can be suppressed also from this point.

When the fuel in the fuel tank T reaches the inside of the housing 2 through the vent hole 12 of the housing 2 and the vent hole of the cap 4, as shown in FIG. When the float valve 3 is automatically lifted by the spring pressure and the valve seat 7 of the housing 2 is closed by its own valve portion 14 and the automobile falls, this time, the weight of the float valve 3 itself and the spring 8 The float valve 3 acts in the same manner due to the biasing spring pressure, and the valve seat 7 of the housing 2 is closed by its own valve portion 14. In any case, fuel leakage at this point is prevented. Needless to say.

  The fuel leakage prevention valve according to the present invention effectively suppresses fuel leakage from the valve seat even if the fuel in the fuel tank attempts to flow into the housing through the vent hole before the float valve rises. Therefore, when applied to a fuel tank of an automobile, it is very convenient.

It is sectional drawing which decomposes | disassembles and shows the fuel leak prevention valve which concerns on the Example of this invention. (A) is a front view of a housing, (B) is a principal part perspective view which shows the relationship between a vent hole and a wall, (C) is a longitudinal cross-sectional view of FIG. 2B. It is a perspective view of a float valve. (A) is a front view which shows the assembly | attachment state of a fuel leak prevention valve, (B) is the same side view. It is sectional drawing which shows the state which open | released the valve seat of the housing. It is explanatory drawing which shows the test result in case the permeation | transmission opening direction of a ventilation hole and the inflow direction of a fuel correspond. It is explanatory drawing which shows the test result when the permeation | transmission opening direction of a vent hole and the inflow direction of fuel shift | deviate 45 degree | times. It is explanatory drawing which shows the test result when the permeation | transmission opening direction of a vent hole and the inflow direction of a fuel have shifted | deviated 90 degrees. It is sectional drawing which shows the state which obstruct | occluded the valve seat of the housing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Connector 2 Housing 3 Float valve 4 Cap 5 Connection space 6 Storage chamber 7 Valve seat 8 Spring 9 Flange part 10 Connection piping part 11 O-ring 12 Vent hole 13 Wall 14 Valve part 15 Guide rib part T Fuel tank Ta Fuel tank upper wall H Mounting hole L Center line ε Offset

Claims (4)

  A connector having a connection space communicating with the outside inside and attached to the upper wall of the fuel tank; a housing defining a storage chamber inside and having a valve seat communicating with the connection space at the top; A fuel leakage prevention valve comprising a float valve disposed in the storage chamber so as to be movable up and down, and having a plurality of vent holes communicating with the inside and outside of the side wall of the housing, wherein at least one of the vent holes A fuel leakage prevention valve, wherein a wall for covering the permeation opening from the outside is provided for each vent hole while ensuring the permeation opening area.   2. A plurality of vent holes are formed in the vertical direction of the side wall of the housing, a wall is provided in the uppermost vent hole, and no wall is provided in the lowermost vent hole. Fuel leak prevention valve.   The wall that covers the transmission opening of the vent hole from the outside is offset in parallel from the center line that has one diameter through the center of the housing, and exists on the edge of the hole that is away from the center line in the offset direction. The fuel leakage prevention valve according to claim 1.   2. The fuel leakage prevention valve according to claim 1, wherein the housing is provided in the fuel tank so that the vent hole is parallel to the short direction of the fuel tank.

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