JP2007308039A - Welding structure for opening part of fuel tank, and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a welding structure for an opening part of a fuel tank, and a method for manufacturing a welded part of a fuel tank, in which a mounting member can be securely and strongly welded, and less fuel permeates from the opening part. <P>SOLUTION: In the welding structure for an opening part of a fuel tank, a fuel tank body 1 of thermoplastic synthetic resin comprising an outer layer 2, an inner layer 3, and an intermediate layer 4 is provided with the opening part 10, and the mounting member is welded with the opening part. At the periphery of the opening part, an insert member 20 comprising a circular metal member, and having an L-shaped cross section to compose a lower side part 21 and a vertical side part 22 is embedded. The opening part 10 is formed of a lower layer part 11, and a bent part 12. The bent part 12 is further bent in a hairpin bend at a root part of the lower side part 21 and the vertical side part 22 so as to form an upper and a lower layers overlapped with each other, forming an outer surface parallel to an opening surface. The bent part 12 is compressed to be thinner than twice of thickness of an outer wall of the fuel tank main body 1, and the mounting member 30 is welded with the bent part 12 to provide the welding structure for an opening part of a fuel tank, and a method for manufacturing the same. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a welded part structure of a fuel tank opening for welding a mounting member to an opening part of a fuel tank made of thermoplastic synthetic resin, and a method for manufacturing the same, and in particular, a synthetic resin member having a plurality of layers. The fuel tank main body is formed by blow molding, and an opening is formed on the upper surface of the fuel tank main body, and a mounting member for attaching a hose or the like is welded to the opening. The present invention relates to a welding structure and a manufacturing method thereof.

Conventionally, the structure of fuel tanks for automobiles and the like has been made of metal. However, in recent years, thermoplasticity has been achieved by reducing the weight of the vehicle, eliminating rust, and easily forming into a desired shape. Those made of synthetic resin have come to be used.
For the production of automobile fuel tanks made of synthetic resin, blow molding methods have been often used because of the ease of molding hollow bodies. In the blow molding method, a parison of a molten thermoplastic synthetic resin member is formed into a cylindrical shape and extruded from above, the parison is sandwiched between molds, and air is blown into the parison to manufacture an automobile fuel tank.

As shown in FIG. 5, an attachment member 130 for attaching a hose or the like for injecting fuel into the tank or taking out fuel or volatile gas from the inside of the tank is provided in the fuel tank. 110 (see, for example, Patent Document 1).
In this case, the fuel tank body 101 is formed of a thermoplastic synthetic resin having a multilayer structure. In this multi-layer structure, the inner layer 103 and the outer layer 102 are made of high-density polyethylene (HDPE) that retains the required strength as a fuel tank and is resistant to fuel, and an intermediate layer as a barrier layer that prevents fuel penetration between them. The layer 104 is formed of a thermoplastic synthetic resin member composed of three layers composed of ethylene vinyl alcohol copolymer (EVOH) having low fuel permeability.

The attachment member 130 is welded to the upper surface of the outer layer 102 in the vicinity of the opening 110. Since a barrier layer 139 for preventing the permeation of fuel is formed on the back surface of the mounting member 130, the fuel permeation from the mounting member 130 is small, but the fuel penetrates the outer layer 102 from the end face of the opening 110, In some cases, it was transmitted to the outside. When the thickness of the outer layer 102 is reduced, the strength of the outer wall of the tank of the opening 110 is reduced, and during welding, the force for pressing the attachment member 130 against the outer wall of the tank is weakened, making welding difficult.

For this reason, as shown in FIG. 6, the fuel tank main body 201 is divided into upper and lower parts, an attachment member 230 is placed in the opening 210, and the periphery of the opening 210 is pressed by the pressing tool 271 from the lower surface of the fuel tank main body 201. In addition to pressing, the attachment member 230 is held and welded by the holders 272 and 273 (see, for example, Patent Document 2).
In this way, the fuel tank body 201 and the attachment member 230 can be pressed and firmly welded.

Then, by pressing the portion of the fuel tank main body 201 with the pressing tool 271, the portion of the outer layer 202 of the outer wall of the fuel tank main body 201 can be compressed from the inside, and can be formed partially thin. It is possible to prevent the fuel from penetrating from the outer layer 202 on the end face.
In this case, in order to compress from the inside of the fuel tank body 201, the fuel tank body 201 needs to be divided and molded, which is difficult with blow molding, and requires injection molding or compression molding. This takes time and increases the cost. Further, the welding work requires the pressing tool 271 and the holding tools 272 and 273, which is troublesome.
JP 2002-160537 A JP 2004-52659 A

  Therefore, the present invention provides a welded portion structure of an opening portion of a fuel tank in which the welding of the mounting member can be reliably and firmly permeated from the opening portion and a manufacturing method of the welded portion of the fuel tank. Let it be an issue.

According to a first aspect of the present invention for solving the above problems, an opening is formed in a thermoplastic synthetic resin fuel tank body having at least an outer layer, an inner layer, and an intermediate layer therebetween, and a mounting member is welded to the opening. In the welding structure of the fuel tank opening,
Around the opening, an annular metal insert member having an L-shaped cross section consisting of a lower side parallel to the opening surface of the opening and a vertical side perpendicular to the opening surface of the opening is embedded,
The opening extends continuously from the fuel tank body and is in close contact with the lower surface of the lower side of the insert member, and is folded so as to wrap from the lower end of the lower part to the lower end of the lower part. It is formed from a bent part, and the bent part is further bent in the shape of a hairpin in the center direction of the opening at the base part of the lower side and the upright part, and the thermoplastic synthetic resin layer is overlapped on the upper and lower sides and is parallel to the opening surface of the opening A welded structure of an opening of a fuel tank that is configured to have an outer surface, the bent portion is compressed to be thinner than twice the thickness of the outer wall of the fuel tank body, and an attachment member is welded to the upper surface of the bent portion It is.

In the first aspect of the present invention, an annular metal section having an L-shaped cross section composed of a lower side parallel to the opening surface of the opening and a vertical side perpendicular to the opening surface of the opening is formed around the opening. An insert member is embedded. For this reason, the circumference | surroundings of an opening part can be reinforced with metal insert members. Further, the bent portion of the opening can be held at the lower side, and the bent portion can be easily compressed when the opening is formed. By holding the upright part, the insert member can be securely held when the attachment member is welded, the attachment member can be crimped to the opening, the welding strength can be improved, and the attachment The circumference | surroundings of a member can be enclosed and a welding part can be protected.

The opening extends continuously from the fuel tank body and is in close contact with the lower surface of the lower side of the insert member, and is folded so as to wrap from the lower end of the lower part to the lower end of the lower part. It is formed from a curved part. For this reason, the upper and lower surfaces of the lower side portion of the insert member are wrapped with the outer layer of the lower layer portion of the thermoplastic synthetic resin member and the outer layer of the bent portion, and the lower side portion is embedded therebetween to hold the insert member firmly. In addition, the strength of the opening can be improved.

The bent portion is further bent at the base portion of the lower side portion and the upright side portion in the form of a hairpin in the center direction of the opening portion, and is configured to have an outer surface parallel to the opening surface of the opening portion by overlapping the upper and lower layers of the thermoplastic synthetic resin. Is done. For this reason, the bent portion can have an intermediate layer with low fuel permeability inside, and fuel permeation from the opening can be reduced. In the bent portion, the thermoplastic synthetic resin member in the opening can be doubled, and the strength of the opening can be increased. By forming the outer surface of the bent portion parallel to the opening surface of the opening, the area for welding the attachment member can be increased, and the welding strength can be improved.

Since the bent portion is compressed to be thinner than twice the thickness of the outer wall of the fuel tank body, the thickness of the outer layer on the upper surface of the bent portion can be reduced, and the outer layer is maintained while maintaining the strength of the opening. Permeation of fuel penetrating the gas can be minimized.
Since the attachment member is welded to the upper surface of the bent portion, it is easy to attach a hose or the like to the attachment member.

The present invention of claim 2 is a welded portion structure of a fuel tank in which a lower side hole penetrating vertically is formed in the lower side portion of the insert member, and an outer layer thermoplastic synthetic resin is penetrated into the lower side hole.

In the present invention of claim 2, since the lower side hole penetrating vertically is formed in the lower side portion of the insert member, and the thermoplastic synthetic resin of the outer layer penetrates into the lower side hole, the insert member is fixed at the opening portion, and the insert member is opened. It can be firmly fixed to the part.

According to a third aspect of the present invention, there is provided a welded portion structure of a fuel tank in which the thickness of the outer layer of the uppermost layer of the bent portion welded to the mounting member is 0.5 mm or less.

In the present invention of claim 3, since the thickness of the outer layer of the uppermost layer of the bent portion welded to the mounting member is 0.5 mm or less, the permeation of fuel penetrating the outer layer of the uppermost layer of the bent portion is prevented. While being able to minimize, the synthetic resin layer of the outer layer part for welding an attachment member to an opening part can be ensured, and the intensity | strength of a welding part can be ensured.

According to a fourth aspect of the present invention, a barrier layer having a low fuel permeability is formed on the inner surface of the mounting member, and the distance from the barrier layer to the welding surface with the bent portion is 0.5 mm or less. It is a partial structure.

According to the fourth aspect of the present invention, a barrier layer having low fuel permeability is formed on the inner surface of the mounting member, and the distance from the barrier layer to the weld surface with the bent portion is 0.5 mm or less. Thus, it is possible to prevent the fuel from permeating from the mounting member and to prevent the fuel from permeating from the vicinity of the welded portion between the barrier layer of the mounting member and the lower bent portion.

According to the present invention of claim 5, a thermoplastic synthetic resin member having at least an outer layer, an inner layer, and an intermediate layer therebetween is blow-molded to form a fuel tank body, and an opening is formed in the fuel tank body. In the manufacturing method of the opening portion of the fuel tank for welding the mounting member,
At the time of blow molding of the fuel tank body, a part is extended outward from the fuel tank body to form an opening,
An annular metal insert member having an L-shaped cross section comprising a lower side parallel to the opening surface of the opening and a vertical side perpendicular to the opening surface of the opening around the periphery of the opening of the fuel tank body And wrap the tip of the lower side part with a thermoplastic synthetic resin member that forms an opening continuous with the lower layer part of the thermoplastic synthetic resin member with which the lower surface of the lower side part of the insert member abuts, and further, The thermoplastic synthetic resin member is further bent in the shape of a hairpin in the direction of the center of the opening at the base portion of the lower side and the upright side, and the layers of the thermoplastic synthetic resin member are overlapped vertically and parallel to the opening surface of the opening. A bent portion is formed so as to have an outer surface, and the bent portion is compressed to be thinner than twice the wall thickness of the outer wall of the fuel tank body, and the insert member is embedded in the opening portion, and the opening portion of the opening portion is formed. Sealing the thermoplastic synthetic resin member Dividing to form an opening,
It is a manufacturing method of the opening part of the fuel tank which welded the attachment member to the upper surface of the bending part.

According to the fifth aspect of the present invention, at the time of blow molding of the fuel tank main body, a part is extended outward from the fuel tank main body to form the opening, so the opening is formed simultaneously with the molding of the fuel tank main body. be able to.
An annular metal insert member having an L-shaped cross section consisting of a lower side parallel to the opening surface of the opening and a vertical side perpendicular to the opening surface of the opening is formed around the periphery of the opening of the fuel tank body. installed. For this reason, the insert member can be embedded in the opening simultaneously with the formation of the opening. Moreover, the circumference | surroundings of an opening part can be reinforced with metal insert members. Furthermore, when compressing a bending part, the bending part of an opening part can be hold | maintained at the lower side part of an insert member, and a bending part can be compressed easily. By the upright side portion, the periphery of the attachment member can be surrounded, and the welded portion can be protected.

The lower side portion is wrapped with the lower layer portion of the thermoplastic synthetic resin member with which the lower surface of the lower side portion of the insert member abuts and the thermoplastic synthetic resin member constituting the opening continuous from the tip of the lower layer portion. For this reason, when forming the opening, the lower side of the insert member is wrapped with the outer layer of the lower layer portion of the thermoplastic synthetic resin member and the outer layer of the bent portion, and the insert member is embedded between the lower layer and firmly fixed. be able to.

Furthermore, the thermoplastic synthetic resin member is further bent into a hairpin shape in the center direction of the opening at the base portion of the lower side and the upright side, and the layers of the thermoplastic synthetic resin member are overlapped vertically and parallel to the opening surface of the opening. The bent portion is formed so as to have an outer surface. For this reason, an intermediate layer having low fuel permeability can be formed inside the bent portion, and a layer for preventing fuel permeation from the opening can be provided. In the bent portion, the thermoplastic synthetic resin member in the opening can be doubled, and the strength of the opening can be increased. By forming the outer surface of the bent portion parallel to the opening surface of the opening, the area for welding the attachment member can be increased, and the welding strength can be increased.

Since the bent portion is compressed to be thinner than twice the wall thickness of the outer wall of the fuel tank body, the bent portion is set so as to minimize fuel permeation from the outer layer of the opening while maintaining the strength of the opening. Can be formed.
Since the insert member is embedded in the opening and the opening is formed by cutting away the thermoplastic synthetic resin member that closes the opening of the opening, the opening can be held by the insert member when the opening is cut off. Easy.
Since the attachment member is welded to the upper surface of the bent portion, it is easy to attach a hose or the like to the attachment member.

According to the present invention of claim 6, a thermoplastic synthetic resin member having at least an outer layer, an inner layer, and an intermediate layer therebetween is blow-molded to form a fuel tank body, and an opening is formed in the fuel tank body. In the manufacturing method of the opening portion of the fuel tank for welding the mounting member,
An annular metal insert member having a L-shaped cross section consisting of a lower side portion parallel to the opening surface of the opening portion and a vertical side portion perpendicular to the opening surface of the opening portion in a portion forming the opening portion of the blow molding die And a slide mold is provided outside the part that holds the insert member of the blow mold,
At the time of blow molding of the fuel tank body, the slide mold is moved backward, and a part of the thermoplastic synthetic resin member of the fuel tank body is extended outward to form an opening,
While inserting the thermoplastic synthetic resin member between the insert member and the slide mold and expanding the diameter, the thermoplastic synthetic resin member of the opening is brought into contact with the inner surface of the slide mold,
The thermoplastic synthetic resin member with which the lower surface of the insert member abuts is a lower layer portion of the opening, and the lower side portion is wrapped with a thermoplastic synthetic resin member that forms an opening continuous with the tip of the lower layer, and further, the thermoplastic synthetic resin member is At the base of the lower and vertical sides, it is further bent in the shape of a hairpin in the direction of the center of the opening, and the layers of thermoplastic synthetic resin members are stacked on top and bottom so that it has an outer surface parallel to the opening surface of the opening The bent portion is a thermoplastic synthetic resin member that is compressed to be thinner than twice the wall thickness of the outer wall of the fuel tank body, embeds the insert member in the opening, and closes the opening of the opening. Excise to form an opening,
It is a manufacturing method of the opening part of the fuel tank which welded the attachment member to the upper surface of the bending part.

In this invention of Claim 6, the cross section which consists of a lower side part parallel to the opening surface of an opening part in the part which forms the opening part of a blow molding metal mold | die, and an upright part perpendicular | vertical to the opening surface of an opening part is L-shaped. An annular metal insert member is held by a slide mold on the outside of the part holding the insert member of the blow mold, and the slide mold is moved backward when the fuel tank body is blow molded. Then, a part of the thermoplastic synthetic resin member of the fuel tank main body was extended outward to form an opening. For this reason, by moving the slide mold, it is possible to form the opening during blow molding and simultaneously embed the insert member in the opening.
The thermoplastic synthetic resin member is inserted between the insert member and the slide mold to expand the diameter, and the thermoplastic synthetic resin member in the opening is brought into contact with the inner surface of the slide mold. The bent portion of the opening can be formed by the peripheral portion of the thermoplastic synthetic resin member that is in contact with the peripheral portion of the inner surface of the slide mold.

The thermoplastic synthetic resin member with which the lower surface of the lower side of the insert member abuts is used as the lower layer of the opening, and the lower side is wrapped with a thermoplastic synthetic resin member that forms an opening continuous with the tip of the lower layer, and further thermoplastic synthesis The resin member is bent at the base of the lower side and the vertical side in the form of a hairpin in the direction of the center of the opening, and the layers of the thermoplastic synthetic resin member are overlapped on the top and bottom so as to have an outer surface parallel to the opening surface of the opening A bent part was formed. For this reason, an intermediate layer having low fuel permeability can be formed inside the bent portion, and a layer for preventing fuel permeation from the opening can be provided. In the bent portion, the thermoplastic synthetic resin member in the opening can be doubled, and the strength of the opening can be increased. By forming an outer surface parallel to the opening surface of the opening, the area for welding the mounting member can be increased to increase the welding strength.

Since the bent part is compressed to be thinner than twice the wall thickness of the outer wall of the fuel tank body, the bent part is formed so as to minimize the permeation of fuel from the outer layer of the opening while maintaining the strength of the opening. can do.
Since the insert member is embedded in the opening and the opening is formed by cutting away the thermoplastic synthetic resin member that closes the opening of the opening, the opening can be held by the insert member when the opening is cut off. Easy.
Since the attachment member is welded to the upper surface of the bent portion, it is easy to attach a hose or the like to the attachment member.

The present invention of claim 7 is a method for manufacturing an opening portion of a fuel tank in which an upright side hole is formed in an upright side portion of an insert member, the opening portion is held by the upright side hole, and a mounting member is welded.

In the present invention of claim 7, since the standing side hole is formed in the standing side part of the insert member, the opening part is held by the standing side hole, and the mounting member is welded, the opening part is formed when welding the mounting member. The attachment member can be crimped to the opening while being held at the lower side of the insert member.

In the present invention, the opening extends continuously from the fuel tank body and adheres to the lower surface of the lower side of the insert member, and the opening is bent so as to wrap around the lower side from the tip of the lower layer and adheres to the upper surface of the lower side Therefore, the lower side portion of the insert member can be wrapped with the outer layer of the lower layer portion of the thermoplastic synthetic resin member and the outer layer of the bent portion, and can be embedded firmly between them.
Further, the bent portion can have an intermediate layer with low fuel permeability inside, and fuel permeation from the opening can be prevented. Since the bent portion is compressed to be thinner than twice the thickness of the outer wall of the fuel tank body, the thickness of the outer layer on the upper surface of the bent portion can be reduced, and the outer layer is maintained while maintaining the strength of the opening. Permeation of fuel penetrating the gas can be minimized.

A fuel tank according to an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a cross-sectional view of a fuel tank according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of a portion where the attachment member 30 of FIG. 1 is welded.
3 and 4 are cross-sectional views of a mold part forming the opening 10 of the blow molding mold 60 showing the method for manufacturing the opening 10 of the fuel tank body 1 of the present invention.

In the first embodiment of the present invention, the fuel tank is attached with a hose 40 and a pipe for injecting fuel into the fuel tank and discharging fuel gas from the fuel tank as shown in FIG. The attachment member 30 is welded to the fuel tank body 1.
In addition, a pump mounting hole 50 is formed in the fuel tank main body 1 and a lid 51 is detachably formed in order to insert and remove the fuel pump 52 for sending fuel from the fuel tank to the fuel hose 53.

The fuel tank body 1 is formed into a hollow shape by blow molding, and its outer wall has three layers of an outer layer 2, an inner layer 3, an outer layer 2 and an intermediate layer 4 formed between the inner layer 3 as shown in FIG. It is composed of In blow molding, a parison composed of the above three layers is used.
The outer layer 2 and the inner layer 3 are made of a thermoplastic synthetic resin that has high strength and maintains strength against fuel oil, and the intermediate layer 4 is made of a thermoplastic synthetic resin that has very little permeation of fuel oil. .

The thermoplastic synthetic resin constituting the outer layer 2 and the inner layer 3 is, for example, high density polyethylene (HDPE), polyoxymethylene (POM), ethylene vinyl alcohol copolymer (EVOH), nylon, polybutylene terephthalate, polyethylene terephthalate, polyphenylene. At least one material of sulfide can be used.
Further, as the thermoplastic synthetic resin constituting the intermediate layer 4, for example, ethylene vinyl alcohol copolymer (EVOH), polybutylene terephthalate, polyethylene terephthalate, polyphenylene sulfide (PPS) can be used.
The intermediate layer 4 is a layer having good adhesion to high-density polyethylene (HDPE) or the like on both surfaces of the intermediate layer 4 film such as ethylene vinyl alcohol copolymer (EVOH), such as modified polyethylene (m-PE). The use of a multilayer parison with an adhesive layer interposed is preferred because the adhesion between the three layers is improved.

As shown in FIG. 2, an insert member 20 is embedded in the opening 10. The insert member 20 is formed of a metal and is formed in an annular shape so as to be embedded around the opening 10. The cross-sectional shape of the insert member 20 is formed in a substantially L shape, formed in parallel with the opening surface of the opening 10 and embedded in the opening 10, and bent at a right angle upward from the lower side 21. It is formed from the standing side part 22 to be formed.

The lower side portion 21 is formed with a lower side hole 23 penetrating up and down substantially in the vicinity of the center, and a thermoplastic synthetic resin member constituting the outer layer 2 of the bent portion 12 described later penetrates into the lower side hole 23 during blow molding. ing. For this reason, the insert member 20 can be firmly fixed to the opening 10 without shifting.
The upright side portion 22 is formed with an upright side hole 24 penetrating left and right substantially in the vicinity of the center. The upright side hole 24 is inserted into the insert member 20 by the upright side hole 24 when the attachment member 30 is welded to the opening 10. Lock and hold securely. For this reason, it can support by the lower side part 21 so that the opening part 10 may not deform | transform, and the attachment member 30 can be press-contacted to the opening part 10, and can be welded.

The opening 10 formed in the upper part of the fuel tank main body 1 is formed of a lower layer part 11 and a bent part 12 as shown in FIG.
The lower layer portion 11 has a thermoplastic synthetic resin wall consisting of three layers of an outer layer 2, an inner layer 3 and an intermediate layer 4 constituting the outer wall of the fuel tank body 1 slightly recessed in the inner direction of the fuel tank body 1. It is in close contact with the lower surface of the lower side portion 21 and extends substantially parallel to the outer wall. Since the lower layer portion 11 is recessed in the inner direction, the height of the attachment member 30 can be lowered, and the protrusion on the outside of the fuel tank body 1 can be lowered.
The base part of the upright side part 22 bent from the lower side part 21 and the lower side part 21 of the insert member 20 is embedded in the opening part 10.

The bent portion 12 is formed integrally and continuously from the tip of the lower layer portion 11 of the opening 10, bends upward from the tip of the lower layer portion 11 to cover the tip of the lower side portion 21, and on the upper surface of the lower side portion 21. They are in close contact with each other and extend to the root portion of the upright portion 22 in parallel with the opening surface of the opening. Further, the bent portion 12 is bent in the form of a hairpin in the center direction of the opening 10 so as to be folded from the root portion of the upright portion 22, and a thermoplastic synthetic resin layer is overlapped on the upper and lower sides, and is parallel to the opening surface of the opening 10. The outer surface is formed. In this way, the lower side portion 21 of the insert member 20 can be sandwiched and embedded between the upper surface of the lower layer portion 11 and the lower surface of the bent portion 12.

For this reason, the bent portion 12 includes two outer layers 2, an inner layer 3, and an intermediate layer 4 that constitute the wall of the fuel tank body 1. Therefore, the opening 10 is continuously formed integrally with the same material from the fuel tank main body 1 and has excellent sealing performance, and the strength of the opening 10 can be ensured. Further, the bent portion 12 can be present with the intermediate layer 4 bent therein, so that the penetration of fuel from the bent portion 12 can be reduced.

The bent portion 12 is formed by being compressed from a direction perpendicular to the surface of the opening 10 and is compressed so as to be thinner than when the outer wall of the fuel tank body 1 is folded into two layers. For this reason, the thickness of the outer layer 2 portion which is the uppermost layer of the bent portion 12 welded to the mounting member 30 can be reduced, and the fuel in the tank passes through the outer layer 2 from the end surface of the opening 10. Infiltration can be prevented.

When the thickness of the outer layer 2 which is the uppermost layer of the bent portion 12 is 0.5 mm or less, the permeation of fuel penetrating the outer layer 2 of the uppermost layer of the bent portion 12 can be minimized. When the attachment member 30 is welded to the opening 10, the thickness necessary for welding can be obtained, and the strength of the welded portion can be ensured.

As shown in FIG. 1, the attachment member 30 includes a hose attachment portion 31 for attaching the hose 40 and a flange portion 35 welded to the opening 10.
The hose attachment portion 31 extends vertically upward from the opening 10 and is further bent at a right angle in the lateral direction, and the inside is hollow. The fuel gas discharged from the opening 10 through this hollow portion can be passed and sent to the hose 40, and the fuel or the like can be injected into the tank from the outside.

As shown in FIG. 2, the flange portion 35 includes a disk-shaped flange upper wall portion 36, a flange side wall portion 37 formed by bending downward from the outer peripheral portion of the flange upper wall portion 36, The barrier layer 39 is made of a synthetic resin having low fuel permeability and is in close contact with the inner surface of the wall portion 36. The front end of the flange side wall portion 37 is welded to the upper surface of the bent portion 12 of the opening 10 to form a welding surface 38. The shorter the distance between the welded surface 38 and the barrier layer 39, the more preferable the fuel permeation can be prevented.

It is preferable that the mounting member 30 be made of the same material as the thermoplastic synthetic resin member that constitutes the outer layer 2 of the fuel tank body 1 because it is firmly welded.
If the distance from the barrier layer 39 to the welding surface 38 with the bent portion 12 is 0.5 mm or less, it is preferable because the permeation of fuel can be minimized between the barrier layer 39 and the welding surface 38.
In addition, around the welding part of the attachment member 30 and the opening part 10, the upright side part 22 of the insert member 20 surrounds the circumference | surroundings. For this reason, the welding part can be protected by the upright side part 22.

Next, the manufacturing method of the opening part 10 of a fuel tank is demonstrated based on FIG. 3 and FIG.
The fuel tank body 1 is molded by blow molding, and the opening 10 is also molded simultaneously with the blow molding.
First, the main body of the blow mold 60 used for blow molding is composed of an inner mold 62 and an outer mold 63. An opening is formed in a portion of the blow molding die 60 where the opening 10 is formed, and a slide die 61 is fitted into the opening so as to be slidable inward and outward.

As shown in FIG. 3, the insert member 20 is sandwiched between the inner mold 62 and the outer mold 63 of the opening of the blow molding die 60 to perform blow molding. In blow molding, air is blown into the inside of the parison of the thermoplastic synthetic resin member comprising the outer layer 2, the inner layer 3 and the intermediate layer 4 forming the fuel tank body 1, and the thermoplastic synthetic resin member swells outward and slides. It contacts the inner surface of the mold 61. After that, while maintaining the internal pressure of the parison, the slide mold 61 slides inward, downward in FIG. 3, and becomes as shown in FIG.

When the slide mold 61 slides, the fuel tank main body 1 and the opening 10 are formed while the parison of the thermoplastic synthetic resin member abuts on the inner surface of the blow mold 60. At this time, the insert member 20 is embedded in the parison of the thermoplastic synthetic resin member.
That is, the lower side portion 21 of the insert member 20 contacts the outer layer 2 of the lower layer portion 11 of the opening 10, and the lower surface of the bent portion 12 contacts the upper surface of the lower side portion 21 of the insert member 20. As the slide mold 61 is lowered, the bent portion 12 is compressed at the outer peripheral portion of the inner surface of the slide mold 61, and the bent portion 12 is crushed into a hairpin shape.
Thus, the formation of the opening 10 and the burying of the insert member 20 can be performed simultaneously with the molding of the fuel tank body 1.

When the slide mold 61 compresses the bent portion 12, the overall thickness of the bent portion 12 decreases. In particular, the thickness of the outer layer 2 on the uppermost surface of the bent portion 12 decreases more greatly, and the outer layer is reduced. The fuel can be prevented from permeating from 2.
Further, since compression is performed by the slide mold 61, the uppermost surface of the bent portion 12 is particularly smooth, and when the attachment member 30 is welded, the adhesion is good and the welding strength can be secured.
After forming the bent portion 12, the fuel tank main body 1 is taken out from the blow molding die 60, and the opening portion into which the lid portion 16 is fitted is cut out to form the opening portion 10.
Thereafter, the mounting member 30 is welded to the opening 10 while holding the vertical side portion 22 of the insert member 20.

It is sectional drawing of the fuel tank which is embodiment of this invention. It is a partial expanded sectional view which shows the structure of the part which welds the attachment member of the opening part of FIG. It is sectional drawing of the state which the slide metal mold | die slid upwards in the opening part part of the fuel tank main body of the blow molding metal mold | die used for implementation of this invention. It is sectional drawing of the state which the slide metal mold | die slid downward in the opening part part of the fuel tank main body of the blow molding metal mold | die used for implementation of this invention. It is sectional drawing of the opening part of the conventional fuel tank main body. It is sectional drawing of the opening part of the other conventional fuel tank main body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel tank main body 2 Outer layer 3 Inner layer 4 Middle layer 10 Opening part 11 Lower layer part 12 Bending part 20 Insert member 21 Lower side part 30 Mounting member 60 Blow molding die 61 Slide die

Claims (7)

In the weld structure of the fuel tank opening in which an opening is formed in the fuel tank body made of thermoplastic synthetic resin having at least an outer layer, an inner layer, and an intermediate layer therebetween, and a mounting member is welded to the opening.
An annular metal insert member having an L-shaped cross section consisting of a lower side parallel to the opening surface of the opening and a vertical side perpendicular to the opening surface of the opening is embedded around the opening. And
The opening portion extends continuously from the fuel tank main body and is in close contact with the lower surface of the lower side portion of the insert member, and is bent so as to wrap around the lower end portion from the lower end portion of the lower portion. The bent portion is formed at the base of the lower side and the vertical side and is further bent in the form of a hairpin in the center direction of the opening, and a thermoplastic synthetic resin layer is overlapped on the upper and lower sides. The bent portion is compressed to be thinner than twice the wall thickness of the outer wall of the fuel tank body,
A welding structure for an opening of a fuel tank, wherein the mounting member is welded to an upper surface of the bent portion. The welding structure of the opening part of the fuel tank of Claim 1 which formed the lower side hole penetrated up and down in the lower side part of the said insert member, and the thermoplastic synthetic resin of the said outer layer penetrated into this lower side hole. The welded structure of the opening portion of the fuel tank according to claim 1 or 2, wherein a thickness of an outer layer of the uppermost layer of the bent portion welded to the attachment member is 0.5 mm or less. The barrier layer with low fuel permeability is formed on the inner surface of the mounting member, and the distance from the barrier layer to the welding surface with the bent portion is 0.5 mm or less. A welded structure of an opening of a fuel tank according to claim 1. A fuel in which a thermoplastic synthetic resin member having at least an outer layer, an inner layer, and an intermediate layer therebetween is blow-molded to form a fuel tank body, an opening is formed in the fuel tank body, and an attachment member is welded to the opening In the manufacturing method of the opening of the tank,
At the time of blow molding of the fuel tank body, a part is extended outward from the fuel tank body to form the opening,
An annular metal having an L-shaped cross section including a lower side parallel to the opening surface of the opening and a vertical side perpendicular to the opening surface of the opening around the periphery of the fuel tank body forming the opening The lower side of the thermoplastic synthetic resin member constituting the lower part of the thermoplastic synthetic resin member with which the lower surface of the lower side of the insert member abuts and the opening continuous from the tip of the lower part is installed. The thermoplastic synthetic resin member is further wrapped in a hairpin shape in the direction of the center of the opening at the base portion of the lower side and the vertical side, and a layer of the thermoplastic synthetic resin member is vertically formed. A folded portion is formed so as to overlap and have an outer surface parallel to the opening surface of the opening, and the bent portion is compressed to be thinner than twice the wall thickness of the outer wall of the fuel tank body, and the insert member Embedded in the opening , And excised the thermoplastic synthetic resin member for closing a portion of the opening of the opening to form an opening,
A method for manufacturing an opening of a fuel tank, wherein the mounting member is welded to an upper surface of the bent portion. A fuel in which a thermoplastic synthetic resin member having at least an outer layer, an inner layer, and an intermediate layer therebetween is blow-molded to form a fuel tank body, an opening is formed in the fuel tank body, and an attachment member is welded to the opening In the manufacturing method of the opening of the tank,
An annular metal having an L-shaped cross section consisting of a lower side parallel to the opening surface of the opening and a vertical side perpendicular to the opening surface of the opening at the portion of the blow molding die forming the opening Hold the insert member made of
A slide mold is provided outside the portion of the blow molding mold that holds the insert member,
At the time of blow molding of the fuel tank body, the slide mold is moved backward, and a part of the thermoplastic synthetic resin member of the fuel tank body is extended outward to form the opening,
Between the insert member and the slide mold, the thermoplastic synthetic resin member enters and expands the diameter, and the thermoplastic synthetic resin member of the opening is brought into contact with the inner surface of the slide mold,
The thermoplastic synthetic resin member with which the lower surface of the insert member abuts is used as a lower layer portion of the opening, and the lower side is wrapped with a thermoplastic synthetic resin member that forms an opening continuous with the tip of the lower layer. The plastic synthetic resin member is further bent into a hairpin shape in the center direction of the opening at the base portion of the lower side and the upright side, and the layers of the thermoplastic synthetic resin member are overlapped vertically and parallel to the opening surface of the opening. A bent portion is formed to have an outer surface, the bent portion is compressed to be thinner than twice the wall thickness of the outer wall of the fuel tank body, the insert member is embedded in the opening, and the opening The thermoplastic synthetic resin member that closes the opening portion is cut out to form an opening portion,
A method for manufacturing an opening of a fuel tank, wherein the mounting member is welded to an upper surface of the bent portion. The fuel according to claim 5 or 6, wherein an upright hole is formed in an upright side portion of the insert member, the insert member is held by the upright side hole to support the opening, and the attachment member is welded. A method for manufacturing an opening of a tank.