JP5040619B2 - Member mounting structure to fuel tank - Google Patents

Description

  The present invention relates to a member mounting structure to a fuel tank.

  Some fuel tanks provided in vehicles such as automobiles are made of resin. For example, in Patent Document 1, an intermediate layer formed of a barrier material is provided between an inner layer and an outer layer of a resin member, and a sealing member accommodated in an annular groove around the opening of the resin member is in contact with the lid The structure in which the fixing member is mounted is described.

However, in the structure described in Patent Document 1, there is a risk that the fuel leaks through the gap between the lid and the opening, and it is desired to further suppress the permeation of the fuel.
JP 2003-220840 A

  In view of the above facts, an object of the present invention is to obtain a member mounting structure for a fuel tank capable of suppressing fuel permeation from between the opening of the fuel tank main body and the mounting member attached to the opening.

In the first aspect of the present invention, a fuel tank body comprising a resin tank and a fuel tank structure comprising a resin layer and a barrier layer laminated with the resin layer by a material having lower fuel permeability than the resin layer. And an opening that is opened in the fuel tank structure and an end of the barrier layer is exposed at the opening edge, an insertion portion that is inserted into the opening, and a state in which the insertion portion is inserted into the opening. A flange portion opposed to the fuel tank structure at the periphery of the opening, and formed by a mounting member attached to the fuel tank body, and a material having lower fuel permeability than the resin layer, and the opening edge a gasket for sealing said barrier layer exposed from parts in contact with both of the flange portion, is provided in the gasket, said fuel tank structure at the opening edge portion of the fuel tank body of the insertion portion A clamping portion for clamping the ingress direction, and having a.

In this invention, the fuel tank structure which comprises a fuel tank main body is provided with the barrier layer, and the edge part of this barrier layer is exposed to the opening edge part of the opening part of a fuel tank main body. And when the insertion part of an attachment member is inserted in an opening part, a gasket contacts both the barrier layer exposed from the opening edge part, and the flange part of an attachment member, and seals between these. Since the gasket is also made of a material having low fuel permeability, fuel permeation from between the opening and the mounting member can be suppressed. In addition, since the gasket is provided with a clamping portion that clamps the fuel tank structure in the insertion direction of the insertion portion at the opening edge of the fuel tank body, the gasket can be positioned with respect to the fuel tank body, and the gasket can be removed. Misalignment can be prevented.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, the sizes of the gasket and the insertion portion are set so that a gap is formed between the gasket and the insertion portion. And

  Therefore, when the gasket swells, the increased volume of the swelled enters the gap between the gasket and the insertion part (so-called “escape”), so excessive stress is applied to the gasket between the opening and the insertion part. Does not act, and the desired sealing performance can be maintained.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the gasket is formed with a bent portion that contacts the flange portion by bending deformation.

  The contact property with respect to the flange portion is enhanced by bending and deforming the bending portion. For this reason, the sealing performance with respect to the flange part of a gasket becomes higher.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the gasket is coated on a portion located inside the fuel tank body to suppress fuel permeation. And a permeation suppression layer.

  The permeation suppression layer can further suppress the permeation of fuel.

  Since the present invention is configured as described above, it is possible to suppress fuel permeation from between the opening of the fuel tank body and the mounting member attached to the opening.

  FIG. 1 shows a fuel tank 12 to which a member mounting structure (hereinafter simply referred to as “member mounting structure”) 18 according to the first embodiment of the present invention is applied. As an example, the fuel tank 12 according to the present embodiment includes a fuel tank main body 14 having a substantially rectangular parallelepiped shape and a fuel tank structure 16.

  The fuel tank structure 16 is configured by, for example, two resin layers 22A and 22C made of high-density polyethylene (HDPE) and a barrier layer 24A between these resin layers 22A and 22C being laminated and adhered by an adhesive layer (not shown). Has been. The barrier layer 24A is made of, for example, EVOH (ethylene vinyl alcohol) or the like, which has a lower fuel permeability than the resin layers 22A and 22C (it is difficult for fuel to permeate).

  As shown in detail in FIG. 2, an insertion hole 36 into which the fuel tank component 30 is inserted is formed in the top surface 14 </ b> T of the fuel tank main body 14, and the fuel tank structure is formed around the insertion hole 36. A mounting portion 20 to which the body 16 is joined is configured. By joining the fuel tank component 30 to the attachment portion 20, the member attachment structure 18 of the present embodiment is obtained. The insertion hole 36 is an opening according to the present invention.

  Around the insertion hole 36, the fuel tank structure 16 is once bent upward and further bent in a direction away from the fuel tank component 30, and a locally constricted neck 38 is formed. In addition, at the upper part of the neck portion 38, the fuel tank component 16 extending in a direction away from the fuel tank component 30 is folded inward so as to approach the fuel tank component 30, and the annular portion 40. Is formed. As a result of folding the fuel tank structure 16 in this way, the folded portion 26 is also formed in the barrier layer 24 </ b> A, and the barrier layer 24 </ b> A is doubled radially inward from the folded portion 26. Further, the barrier layer 24A is exposed from the inner edge of the annular portion 40, and the barrier layer exposed portion 28 is configured. In the annular portion 40, the fuel tank constituting body 16 is compressed in the thickness direction, and the thickness of the resin layers 22A and 22C is locally reduced.

  On the other hand, the fuel tank component 30 includes a cylindrical portion 32 that is inserted into the insertion hole 36, and a flange portion 34 that extends radially outward from the upper end of the cylindrical portion 32. In a state where the fuel tank component 30 is attached to the fuel tank main body 14, the flange portion 34 faces the upper surface 40 T of the annular portion 40, that is, the fuel tank component 16 at the periphery of the insertion hole 36.

  The inside of the cylindrical portion 32 of the fuel tank component 30 is, for example, a pipe for moving fuel or gas between the inside and outside of the fuel tank body 14, a valve that opens and closes under predetermined conditions in the fuel tank body 14, etc. Used for mounting. Further, at least the flange portion 34 is made of a material having low fuel permeability compared to the material of the fuel tank structural body 16 (such as HDPE described above), such as PON, PA, or the like. The cylindrical portion 32 may be integrally formed with the same material as the flange portion 34, or may be formed integrally with the flange portion 34 after being formed with a different material.

  An annular receiving groove 42 surrounding the insertion hole 36 is formed on the upper surface 40T of the annular portion 40, and an annular seal ring 44 is also accommodated therein. The seal ring 44 is made of a material having low fuel permeability compared to the material of the fuel tank structure 16 (such as HDPE described above), for example, fluorine rubber (FKM rubber). The thickness (height) of the seal ring 44 is set so as to protrude slightly upward from the housing groove 42. When the fuel tank component 30 is attached to the fuel tank main body 14, the seal ring 44 is flanged. It adheres to the part 34. That is, the space between the annular portion 40 and the flange portion 34 is sealed so that the seal ring 44 surrounds the cylindrical portion 32.

  An annular thin portion 46 in which the resin layers 22A and 22C constituting the annular portion 40 are locally thin is formed at the inner edge portion of the annular portion 40. The thin-walled portion 46 is attached with a gasket 48 formed in an annular shape with a material having low fuel permeability compared to the material of the fuel tank structural body 16 (such as HDPE described above), for example, fluoro rubber (FKM rubber). ing.

  As shown in detail in FIG. 3, the gasket 48 has a substantially “U” -shaped sandwiching portion 48 </ b> N open radially outward in a cross-sectional view, and extends radially inward and upward from the sandwiching portion 48 </ b> N. Lip portion 48L. As can be seen from FIG. 2, the sandwiching portion 48N sandwiches the thin portion 46 from above and below, so that the gasket 48 is positioned and attached to the annular portion 40, and the gasket 48 from the fuel tank body 14 (attachment portion 20) is attached. Dropping is prevented. Even when the fuel tank component 30 is removed, inadvertent misalignment of the gasket 48 is prevented. In this state, the sandwiching portion 48N is in contact with the barrier layer exposed portion 28 on the entire circumference.

  On the other hand, the lip portion 48 </ b> L is positioned above the upper surface of the annular portion 40 when the gasket 48 is attached. Therefore, when the fuel tank component 30 is attached to the fuel tank main body 14, the lip portion 48L is pushed by the flange portion 34 over the entire circumference, and comes into close contact while being bent and deformed. That is, the gap between the barrier layer 24A and the flange portion 34 is sealed so that the lip portion 48L surrounds the cylindrical portion 32. In particular, in the present embodiment, the lip portion 48L is formed so as to gradually become thinner toward the tip, facilitating bending deformation at the tip portion.

  The inner diameter of the sandwiching portion 48N of the gasket 48 is set larger than the outer shape of the cylindrical portion 32 of the fuel tank component 30, and a predetermined gap 50 is formed between the sandwiching portion 48N and the cylindrical portion 32. When such a gap 50 is not configured, the cylindrical portion 32 comes into contact with the gasket 48 when the cylindrical portion 32 is inserted, but if the variation in dimensions between the insertion hole 36 and the cylindrical portion 32 is large, this The contact pressure also increases, and a large frictional force (insertion resistance) acts on the insertion of the cylindrical portion 32. The reaction force may reduce the adhesion between the flange portion 34 and the seal ring 44 or the lip portion 48L. On the other hand, in the present embodiment, since the gap 50 is configured, the cylindrical portion 32 is not in contact with the gasket 48 at the time of insertion, and no insertion reaction force is generated. For this reason, it becomes easy to ensure the sealing performance with respect to the flange part 34, the seal ring 44, and the lip part 48L. Further, when the fuel tank component 30 is removed from the fuel tank main body 14 (extracted from the cylindrical portion 32), no frictional force acts between the cylindrical portion 32 and the gasket 48, and no resistance to removal acts.

  As shown in FIG. 3, a permeation suppression coating layer 52 is provided on a portion of the gasket 48 facing the inside of the fuel tank body 14. The permeation suppression coating layer 52 is made of a material having lower fuel permeability than the material (FKM or the like) constituting the gasket 48. Such a material is determined in consideration of components contained in the fuel. For example, when the fuel is a mixed fuel of gasoline and alcohol, a fluororesin (ETFE, PTFE, PPS) or the like may be mentioned. it can.

  A cylindrical male retainer 54 is attached to the outer periphery of the neck portion 38 of the fuel tank main body 14, and a male screw 54 </ b> S is formed on the outer periphery of the male retainer 54. On the other hand, from the outer peripheral side of the male retainer 54, a female retainer 56 having a cylindrical shape and a female screw 56S formed on the inner periphery is screwed. A pressing flange piece 58 is formed radially inward from the rear end (upper end) of the female retainer 56 in the screwing direction. When the female retainer 56 is screwed into the male retainer 54 and moves in the direction of arrow S, the pressing flange piece 58 presses the flange portion 34 of the fuel tank component 30, and the fuel tank component 30 is prevented from coming off. It is attached to the fuel tank body 14. At this time, the flange portion 34 comes into close contact with the seal ring 44 and the lip portion 48L of the gasket 48.

  In the member mounting structure 18 of the present embodiment configured as described above, the seal ring 44 is in close contact with the flange portion 34 of the fuel tank component 30 in a state where the fuel tank component 30 is mounted on the fuel tank body 14. ing. For this reason, the space between the annular portion 40 and the flange portion 34 of the fuel tank body 14 is sealed. In other words, from between the insertion hole 36 (opening portion) of the fuel tank body 14 and the fuel tank component 30. Permeation of the fuel is suppressed.

  Further, considering the fuel permeation path from the inside of the fuel tank main body 14 to the outside with the fuel tank component 30 attached, as can be seen from FIG. This is suppressed because the fuel tank structure has the barrier layer 24A. Similarly, since the gasket 48 and the flange portion 34 of the fuel tank component 30 are also made of a material having low fuel permeability, fuel permeation is suppressed. Further, since the gasket 48 is in contact with the barrier layer exposed portion 28 on the entire circumference at the boundary portion between the fuel tank constituting body 16 and the gasket 48, fuel permeation from the boundary portion is also suppressed. Further, since the lip portion 48L is in close contact with the flange portion 34 at the entire boundary portion between the gasket 48 and the flange portion 34, fuel permeation from the boundary portion is also suppressed.

  In particular, since the lip portion 48L is in close contact with the flange portion 34 of the fuel tank component 30 in a deformed state, followability and contact with the flange portion 34 are improved, and high sealing performance is obtained. Further, after the flange portion 34 of the fuel tank component 30 comes into contact with the lip portion 48L, the lip portion 48L is bent and deformed, thereby reducing the insertion reaction force. For this reason, the adhesiveness of the seal ring 44 and the flange part 34 can be ensured high, and the sealing performance by the seal ring 44 can be maintained.

  As described above, in this embodiment, the barrier layer 24A, the gasket 48, and the flange portion 34, which are made of a material having low fuel permeability, are directly connected to each other, and the material having the barrier property against the fuel permeability is integrated. Is done. For this reason, it becomes difficult to evaporate the fuel in the fuel tank main body 14 to the outside, and the emission can be reduced.

  In particular, since the gasket 48 is provided with the permeation suppression coating layer 52, it is more difficult for the fuel to permeate compared to a configuration without such a permeation suppression coating layer 52. For example, when the permeation suppression coating layer 52 is configured using a fluororesin (ETFE, PTFE, PPS) or the like as in the present embodiment, the fuel permeation resistance can be enhanced with respect to both gasoline and alcohol. it can.

  Note that some materials that can be used as the permeation suppression coating layer 52 have a higher hardness than the material constituting the gasket 48. However, since the lip portion 48L is exposed at the portion that is in close contact with and sealed with the flange portion 34, it is more flexible than the transmission suppressing coating layer 52. Therefore, the fuel permeation resistance can be improved by the permeation suppression coating layer 52 while ensuring the sealing performance of the gasket 48 (lip portion 48L) with respect to the flange portion 34.

  As described above, in the present embodiment, the permeation of the fuel to the gasket 48 is suppressed, but it is assumed that the fuel slightly adheres and swells over time. Since the gasket 48 is deformed so as to increase in diameter due to swelling, the contact property with the exposed portion 28 of the barrier layer is improved. Further, since the gasket 48 is deformed so as to have a larger cross-sectional area due to swelling, the clamping force of the clamping part 48N with respect to the thin part 46 also becomes strong. As described above, the gasket 48 is further swelled to further improve the sealing performance with respect to the fuel tank body 14 and improve the fuel permeation resistance.

  In the present embodiment, a predetermined gap 50 is formed between the sandwiching portion 48N of the gasket 48 and the cylindrical portion 32 of the fuel tank component 30. In other words, as described above, since the sealing performance is secured by the lip portion 48L of the gasket 48 and the flange portion 34 of the fuel tank component 30, the gasket 48 is brought into close contact with the cylindrical portion 32, Since there is no need to ensure sealing performance, the gap 50 can be formed.

  When the gasket 48 swells and the volume increases, the gap 50 acts as a so-called “escape” for the volume increase. For this reason, excessive stress does not act between the gasket 48 and the fuel tank main body 14 and between the gasket 48 and the fuel tank component 30, and the gasket 48 can maintain a desired sealing property.

  FIG. 4 shows a member mounting structure 72 according to the second embodiment of the present invention. In the second embodiment, the same components and members as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the second embodiment, the fuel tank body 14 is not formed with the neck portion 38 or the annular portion 40 of the first embodiment, and the insertion hole 36 is directly formed in the top surface 14T. Further, a welding retainer 74 is used instead of the male retainer 54 and the female retainer 56 of the first embodiment. The welding retainer 74 has a pressing flange piece 58 similar to the female retainer 56, but an annular welding piece 76 is formed from the outer periphery of the pressing flange piece 58 toward the top surface 14 </ b> T of the fuel tank body 14. The seal portion 78 is configured by extending and welding the tip (lower end) of the welding piece 76 to the top surface 14T. Since the seal portion 78 has an action in place of the seal between the seal ring 44 and the flange portion 34 in the first embodiment, the seal ring 44 is not provided in the second embodiment.

  Also in the second embodiment having such a configuration, the barrier layer 24A, the gasket 48, and the flange portion made of a material having low fuel permeability in a state where the fuel tank component 30 is attached to the fuel tank main body 14. 34 is directly connected, and the material having a barrier property against the permeation of fuel is integrated. For this reason, it becomes difficult to evaporate the fuel in the fuel tank main body 14 to the outside, and the emission can be reduced.

It is sectional drawing which shows the fuel tank to which the member attachment structure to the fuel tank of 1st embodiment of this invention was applied. It is sectional drawing which expands and shows the member attachment structure to the fuel tank of 1st embodiment of this invention in the vicinity of the attaching part. It is sectional drawing which shows the gasket which comprises the member attachment structure to the fuel tank of 1st embodiment of this invention. It is sectional drawing which expands and shows the member attachment structure to the fuel tank of 2nd embodiment of this invention in the vicinity of the attaching part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 Fuel tank 14 Fuel tank main body 16 Fuel tank structure 18 Member attachment structure 20 Attachment part 22A, 22C Resin layer 24A Barrier layer 28 Barrier layer exposure part 30 Fuel tank component (attachment member)
32 Cylindrical part (insertion part)
34 Flange part 36 Insertion hole (opening)
44 Seal ring 46 Thin part 48 Gasket 48L Lip part (flexible part)
48N Nipping part 50 Gap 52 Permeation suppressing coating layer 54 Male retainer 56 Female retainer 58 Press flange piece 72 Member mounting structure 74 Weld retainer 76 Weld piece 78 Seal part

Claims (4)

A fuel tank body comprising a resin tank and a fuel tank assembly comprising a resin layer and a barrier layer laminated with a resin layer having a lower fuel permeability than the resin layer;
An opening that is opened in the fuel tank structure, and an end of the barrier layer is exposed at an opening edge;
An insertion portion that is inserted into the opening, and a flange that faces the fuel tank structure on the periphery of the opening in a state in which the insertion portion is inserted into the opening, and is attached to the fuel tank body A mounting member;
A gasket that is made of a material having lower fuel permeability than the resin layer, and that contacts and seals both the barrier layer exposed from the opening edge and the flange;
A sandwiching portion provided in the gasket and sandwiching the fuel tank structure in the insertion direction of the insertion portion at the opening edge of the fuel tank body;
A member mounting structure to a fuel tank, characterized by comprising:   2. The member mounting structure for a fuel tank according to claim 1, wherein sizes of the gasket and the insertion portion are set such that a gap is formed between the gasket and the insertion portion.   The member mounting structure for a fuel tank according to claim 1 or 2, wherein the gasket is formed with a bent portion that comes into contact with the flange portion by bending deformation.   The fuel according to any one of claims 1 to 3, further comprising a permeation suppression layer that is coated on a portion of the gasket that is positioned inside the fuel tank body and prevents permeation of fuel. Member mounting structure to the tank.

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