JP4646143B2 - Fuel tank opening structure and manufacturing method thereof - Google Patents

Description

The present invention relates to an opening structure of a fuel tank made of a thermoplastic synthetic resin and a method for manufacturing the same, and in particular, a fuel tank body is formed by blow molding a synthetic resin member having a plurality of layers, and The present invention relates to an opening structure of a thermoplastic synthetic resin fuel tank in which an opening is integrally formed in a fuel tank body, and a method of manufacturing the same.

Conventionally, the structure of fuel tanks for automobiles and the like has been made of metal, but 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, and the parison is sandwiched between molds and air is blown into the parison to manufacture an automobile fuel tank.

The fuel tank has an opening for taking in and out components to be mounted inside the tank. The opening is formed by forming the fuel tank body by blow molding and simultaneously forming the opening.
For example, as shown in FIG. 8, an opening 110 and a lid 140 that closes the opening are attached (see, for example, Patent Document 1).

In the configuration of FIG. 8, a cam lock member 120 that locks the lid 140 around the opening 110 is embedded, the lid 140 is sandwiched between the ring-shaped fixing member 130 and the opening 110, and the fixing member 130 is sandwiched between the cam lock member 120. Is pressed to fix the lid 140. At this time, in order to seal between the lid 140 and the opening 110, a seal ring 150 is attached therebetween. In order to attach the seal ring 150, a groove 116 is formed on the surface of the opening 110 facing the lid 140.

The groove 116 is required to have a smooth surface in order to ensure sealing performance. However, when the groove 116 is formed by blow molding, it is sufficient to press the inner surface of the blow molding die with the internal pressure of the blow. A smooth surface could not be obtained. In addition, in order to prevent gasoline from penetrating from the end face of the opening 110, it is also necessary to reduce the thickness of the groove 116 of the opening 110. However, in order to form the groove 116 thinly, when the groove 116 is formed, if the slide mold is moved so as to form the groove 116 from the direction perpendicular to the opening 110 and compression is attempted, the cam lock member 120 is formed. Since it is only embedded in the opening 110 portion, there is nothing to hold the groove 116 portion, it cannot receive the pressure of the mold to be compressed, and it is difficult to compress.

Further, as shown in FIG. 9, there is a fuel tank body 201 formed of a thermoplastic synthetic resin having a multilayer structure (see, for example, Patent Document 2). In this case, the inner layer and outer layer are made of high-density polyethylene (HDPE) that maintains the required strength as fuel tanks and is also resistant to fuel, and consists of an intermediate layer as a barrier layer that prevents fuel penetration between them. It is made of a thermoplastic synthetic resin member.

In this case, in order to attach the lid 240 to the opening 210 in the opening 210, an annular member 220 having a screw formed on the outer periphery thereof is integrally fixed to the opening 210. A bent portion 212 of the opening 210 is integrally fixed to a surface of the annular member 220 facing the lid 240, and a compression portion 213 is formed in a part of the bent portion 212. A seal ring 250 is installed in the compression portion 213 to seal between the lid 240 and the opening 210. However, since this annular member 220 is formed of a synthetic resin, its strength is low, and it has been difficult to ensure sufficient synthesis against external force.

Further, in order to fix the lid 240 to the opening 210, the fixing member 230, which is annular and has a thread groove formed therein, is screwed into the annular member 220, so that it takes time to attach, and the screw portion has a predetermined length. Is required, the height of the opening 210 is increased, and a space is required. Further, if the screw is tightened too much, the annular member 220 and the fixing member 230 may be plastically deformed because they are made of synthetic resin.
JP 2002-187162 A JP 2003-220840 A

  Therefore, an object of the present invention is to provide a fuel tank opening structure and a method for manufacturing the fuel tank, in which the lid can be easily attached, the sealing property is excellent, and the fuel does not penetrate from the opening.

In order to solve the above-mentioned problems, the present invention of claim 1 is a fuel tank comprising a thermoplastic synthetic resin fuel tank body having at least an outer layer, an inner layer, and an intermediate layer therebetween, and an opening is integrally formed. In the opening structure,
The opening is bent in the direction of expanding the diameter of the tubular portion from the tip of the tubular portion extending outward from the fuel tank body, and is further bent in the form of a hairpin in the center direction of the opening and heated up and down. The outer layer, the inner layer and the intermediate layer of the plastic synthetic resin are each composed of two layers, and the bent portion has an outer surface parallel to the opening surface of the opening, and at least a part of the bent portion is formed on the opening surface. It has a compression part that is thinner than the other parts compressed from the vertical direction, and a metal annular lid locking member is embedded integrally in the outer layer below the overlapped part of the compression part ,
The lid locking member has a cylindrical lower vertical wall portion embedded in the cylindrical portion of the opening, and a surface parallel to the opening surface that is bent in the direction of increasing the diameter of the lower vertical wall portion from the tip of the lower vertical wall portion. A lower step portion to be formed, an upper step portion that bends in a stepwise manner from the tip of the lower step portion and further bends in a direction of expanding the diameter to form a plane parallel to the opening surface, and an upper vertical wall portion above the upper step portion at a plurality of locations. Is formed, and a locking claw portion bent in an L shape from the tip of the upper vertical wall portion toward the center of the opening is formed, and the lower step portion is embedded in the lower outer layer of the overlapped portion of the compression portion The lower part is a fuel tank opening structure that holds the bent part of the opening.

According to the first aspect of the present invention, the opening is bent in the direction of expanding the diameter of the cylindrical portion from the tip of the cylindrical portion, and further the center direction of the opening. The outer layer of the thermoplastic synthetic resin , the inner layer, and the intermediate layer between them are overlapped with each other in two layers, and the bent portion has an outer surface parallel to the opening surface of the opening portion. For this reason, the opening is integrally formed from the fuel tank main body and has excellent sealing performance, can secure the thickness of the bent portion, and can hold the seal member. Since the outer surface of the bent portion is formed by the outer layer of the fuel tank main body, the strength can be ensured, and since the intermediate portion is provided inside, the permeation of fuel can be prevented.

Since at least a part of the bent portion has a compression portion that is thinner than other portions compressed from the direction perpendicular to the opening surface, the thickness of the opening can be reduced by the compression portion, and the tip of the opening From the fuel penetration can be minimized. In addition, the seal member can be fitted into the thin portion, and the sealing performance can be ensured.
Since the metal annular lid locking member is integrally embedded in the lower outer layer of the overlapped portion of the compression portion, the bent portion is held from below by the lid locking member when the compression portion is formed. Therefore, it is easy to compress the bent portion, and the lid and the opening can be strongly adhered even when the lid is attached to the opening.

According to the first aspect of the present invention, since the lid locking member has the cylindrical lower vertical wall portion embedded in the cylindrical portion of the opening, the strength of the cylindrical portion of the opening is ensured and the lid is engaged with the opening. The stop member can be firmly fixed.
For holding the folded portion from the leading end of Shitatatekabe portion to have a lower portion which forms a plane parallel to the opening plane bent in a direction of diameter of the lower vertical wall portion, in the lower portion, the folding of the opening The bent portion can be held, and when the compression portion is formed, it is easy to compress the bent portion by holding the bent portion from below with the lid locking member, and the lid to the opening. Also when attaching, a lid and the bending part of an opening part can be stuck closely.

The upper step part is bent upward in a stepped manner from the tip of the lower step part and further bent in the direction of expanding the diameter to form a plane parallel to the opening surface, and the upper vertical wall part is extended from the upper step part above a plurality of locations, A locking claw portion that is bent in an L shape from the tip of the vertical wall portion toward the center of the opening is formed. For this reason, the upper vertical wall portion of the lid locking member and the claw portion for locking are formed in a bowl shape, the lid can be pressed via the fixing member, and the gap between the opening and the lid is strongly sealed be able to. Furthermore, since the lid locking member has a cam lock structure, the lid body can be locked only by slightly rotating the lid body and the fixing member at the time of locking. The height can be lowered.

According to the second aspect of the present invention, a notched portion or a fixing hole in which the thermoplastic synthetic resin in the cylindrical portion of the opening enters the lower vertical wall portion of the lid locking member to fix the lid locking member to the opening. It is the opening part structure of the fuel tank formed.

According to the second aspect of the present invention, a notched portion or a fixing hole in which the thermoplastic synthetic resin of the cylindrical portion of the opening enters the lower vertical wall portion of the lid locking member to fix the lid locking member to the opening. Therefore, the synthetic resin that has entered the notch or the fixing hole firmly fixes the opening and the lid locking member, and the lid locking member does not slip in the opening.

According to a third aspect of the present invention, the compression section is formed in a groove shape having a U-shaped cross section, and the groove bottom has a fuel tank opening structure in which a smooth surface is formed.

According to the third aspect of the present invention, since the compression portion is formed in a groove shape having a U-shaped cross section, and the groove-shaped bottom portion is formed with a smooth surface, the seal member can be securely held at a predetermined position and the seal member. Since it adheres to a smooth surface, the sealing property is good.

According to the fourth aspect of the present invention, the fixing member for holding the lid that closes the opening of the fuel tank is formed in a ring shape and a cross-sectional shape in a flat plate shape, and is engaged with a locking claw portion of the lid locking member. And a fuel tank opening structure in which convex portions are formed at portions corresponding to the locking claws.
According to the fourth aspect of the present invention, the fixing member for sandwiching the lid that closes the opening of the fuel tank is formed in a ring shape and a cross-sectional shape in a flat plate shape, and is engaged with the locking claw portion of the lid locking member. In addition, since the convex portion is formed at the portion corresponding to the locking claw portion, the convex portion can be elastically engaged with the locking claw portion of the lid locking member to lock the lid body. it can.

According to a fifth aspect of the present invention, there is provided a fuel tank manufacturing method 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, and an opening is integrally formed. In
By holding a metal ring-shaped lid locking member at the part forming the opening of the blow molding die,
The lid locking member has a cylindrical lower vertical wall portion embedded in the cylindrical portion of the opening, and a surface parallel to the opening surface that is bent in the direction of increasing the diameter of the lower vertical wall portion from the tip of the lower vertical wall portion. A lower step portion to be formed, an upper step portion that bends in a stepwise manner from the tip of the lower step portion and further bends in a direction of expanding the diameter to form a plane parallel to the opening surface, and an upper vertical wall portion above the upper step portion at a plurality of locations. Is formed, forming a claw portion for locking bent in an L shape from the tip of the upper vertical wall portion toward the center of the opening,
A slide mold is provided on the outer side of the portion that holds the lid locking member of the blow molding mold, and a ridge is formed on the peripheral edge of the inner surface of the slide mold,
At the time of blow molding of the fuel tank main body, the slide mold is retracted outwardly and extended outward from a part of the thermoplastic synthetic resin member of the fuel tank main body to form a cylindrical portion of the opening,
The thermoplastic synthetic resin member in the cylindrical portion is inserted between the lid locking member and the protruding strip portion of the slide mold to expand the diameter, and the thermoplastic synthetic resin member in the opening is placed on the inner surface of the slide mold. Bend in the direction that expands the diameter of the cylindrical part from the tip of the cylindrical part, and further bend in the shape of a hairpin in the center direction of the opening , and the outer layer, the inner layer and the intermediate layer of the thermoplastic synthetic resin member Each of the two layers is formed with a folded portion, the bent portion is held at the lower portion of the lid locking member, the slide mold is advanced in the direction of the lid locking member, and the slide mold and the lid locking member Compressing at least a part of the bent part from the direction perpendicular to the opening surface while sandwiching it with the lower step part to form a thinner compressed part than the other part, the lower part of the overlapped part of the compressed part The lid locking member is integrally embedded in the outer layer, and the opening of the opening is closed. Was excised thermoplastic synthetic resin member is a manufacturing method of a fuel tank to form an opening.

According to the fifth aspect of the present invention, a metal annular lid locking member is held at a portion where the opening of the blow molding die is formed, and outside the portion where the lid locking member of the blow molding die is held. A slide mold was provided, and a ridge was formed at the peripheral edge of the inner surface of the slide mold. Therefore, the bent portion can be formed by the lid locking member and the slide mold, and the lid locking member can be embedded in the opening during blow molding.
At the time of blow molding of the fuel tank main body, the slide mold is retracted outward, and a part of the thermoplastic synthetic resin member of the fuel tank main body is extended outward to form the cylindrical portion of the opening. The cylindrical portion can be formed by inflating the fuel tank main body in the portion where the slide mold is retracted.
Since the lid locking member has a cylindrical lower vertical wall portion embedded in the cylindrical portion of the opening, the strength of the cylindrical portion of the opening is secured and the lid locking member is firmly fixed to the opening. Can be done.
Since the lower vertical wall portion has a lower step portion that is bent in the direction of expanding the diameter of the lower vertical wall portion and forms a surface parallel to the opening surface, the lower step portion can hold the bent portion of the opening portion. When forming the compression part, it is easy to compress the bent part by holding the bent part from below with the lid locking member, and also when attaching the lid to the opening, the lid and the opening The bent part of the part can be closely attached.

The thermoplastic synthetic resin member in the cylindrical portion is inserted between the lid locking member and the protruding strip portion of the slide mold to increase the diameter, and the thermoplastic synthetic resin member in the opening is applied to the inner surface of the slide mold. The outer and inner layers of the thermoplastic synthetic resin member and the intermediate layer between them are bent by bending in the direction of expanding the diameter of the cylindrical portion from the tip of the cylindrical portion and further bending in the shape of a hairpin in the central direction of the opening. A folded portion was formed on two layers. For this reason, a bending part can be easily formed by making the synthetic resin member of a fuel tank main body penetrate | invade between the cover latching member and the protruding item | line part of a slide metal mold | die.
Bend from the tip of the cylindrical part in the direction to expand the diameter of the cylindrical part and further bend in the form of a hairpin in the center direction of the opening, and the outer layer, inner layer and intermediate layer of the thermoplastic synthetic resin member are each overlapped in two layers The bent portion is formed so as to have an outer surface parallel to the opening surface of the opening. For this reason, the opening including the bent portion can be integrally formed from the fuel tank body, and the opening has excellent sealing performance and ensures the thickness of the bent portion other than the compression portion. can do. Since the outer surface of the bent portion is formed by the outer layer of the fuel tank main body, the strength can be ensured, and since the intermediate portion is provided inside, the permeation of fuel can be prevented.

The bent portion is held at the lower step portion of the lid locking member, the slide mold is advanced in the direction of the lid locking member, and is sandwiched between the slide mold and the lower step portion of the lid locking member, and at least one of the bent portions. The portion is compressed from the direction perpendicular to the opening surface to form a thinner compressed portion than the other portions , and the lower wall portion of the lid locking member is integrated with the outer layer below the overlapped portion of the compressed portion. The opening was formed by excising the thermoplastic synthetic resin member that was buried and closed the opening of the opening. For this reason, a compression part can be formed in a bending part at the time of blow molding only by advancing a slide metal mold | die to a cover latching member direction. Further, when forming the compression portion, the bent portion can be held from below by the lower step portion of the lid locking member , it is easy to compress the bent portion, and also when the lid is attached to the opening The lid and the opening can be strongly adhered.
Since at least a part of the bent part is compressed from the direction perpendicular to the opening surface to form a thinner compressed part than the other part, only the bent part is compressed. It can be made thin, and the permeation of fuel passing through the outer layer from the tip of the opening can be minimized. The surface of the compression part can be formed smoothly and has good sealing properties.

The present invention of claim 6 is a method of manufacturing a fuel tank in which the compression portion is formed in a groove shape having a U-shaped cross section by the protruding strip portion of the slide mold, and the groove-shaped bottom portion is formed with a smooth surface. .

In the present invention of claim 6 , the compression portion is formed in a groove shape having a U-shaped cross section by the protruding strip portion of the slide mold, and the groove-shaped bottom portion is formed with a smooth surface. Since it can hold | maintain reliably and a sealing member closely_contact | adheres to a smooth surface, sealing performance is good.

In the present invention, the opening portion is bent in a direction in which the tubular portion expands from the tip of the tubular portion and extends outward from the fuel tank main body, and has an outer surface parallel to the opening surface of the opening portion. Therefore, the opening is formed integrally with the fuel tank body and has excellent sealing performance, and can hold the seal member. Since the bent portion has an intermediate layer inside, the penetration of fuel can be prevented.
Since at least a part of the bent portion has a thin compression portion, fuel permeation can be minimized. Since the metal annular lid locking member is integrally embedded in the lower outer layer of the overlapped portion of the compression portion, the bent portion is held from below by the lid locking member when the compression portion is formed. The lid and the opening can be strongly adhered even when the lid is attached to the opening.

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 an opening 10 of a fuel tank according to a first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of the portion of the lid 40 shown in FIG. FIG. 3 is a perspective view of a lid locking member (cam lock member) 20 embedded in the opening 10 according to the first embodiment of the present invention. FIG. 4 is a perspective view of another cam lock member 20 embedded in the opening 10 according to the first embodiment of the present invention.
FIG. 5 is an enlarged cross-sectional view of a portion of the fuel tank opening 10 where the lid body 40 is locked according to the second embodiment of the present invention.
6 and 7 are cross-sectional views of the 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, as shown in FIGS. 1 and 2, the fuel tank has an opening 10 for taking in and out a fuel tank main body 1 and a fuel pump (not shown) and the like. Is formed.
The fuel tank body 1 is formed by blow molding, and its outer wall is composed of three layers: an outer layer 2, an inner layer 3, and an intermediate layer 4 formed between the outer layer 2 and the inner layer 3. 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.
It should be noted that a layer having good adhesion to high-density polyethylene (HDPE) or the like, for example, an adhesive layer such as modified polyethylene (m-PE) is interposed on both surfaces of the intermediate layer 4 such as ethylene vinyl alcohol copolymer (EVOH). The use of a multilayer parison is preferred because the adhesion between the three layers is improved.

As shown in FIG. 1, the opening 10 is formed on the upper surface of the fuel tank body 1, and the opening 10 is locked with a lid 40 attached thereto.
As shown in FIG. 2, the locking structure of the lid 40 in the opening 10 is such that the lid 40 is sandwiched between a lid locking member (cam lock member) 20 embedded in the opening 10 and a fixing member 30.
The lid body 40 is formed in a substantially disk shape, and a flange portion 41 protruding along the inner periphery of the opening 10 is formed on the lower surface to prevent the lid body 40 from shifting.

The fixing member 30 that holds the lid 40 has a ring shape and a cross-sectional shape of a flat plate. On the upper surface of the fixing member 30, a convex portion 31 is formed at a portion corresponding to a locking claw portion (locking claw portion) 25 of the cam lock member 20 described later. The convex portion 31 can be formed by expanding a part of the fixing member 30 upward. The convex portion 31 can be elastically engaged with the locking claw portion 25 of the cam lock member 20 to lock the lid body 40.

The opening 10 of the fuel tank main body 1 is formed integrally and continuously from the fuel tank main body 1 with the same material, as will be described later in the manufacturing method. A cam lock member 20 is embedded in the opening 10.
The cam lock member 20 is formed of a metal plate as shown in FIGS. 2 and 3 and is formed in a bent substantially cylindrical shape.

As shown in FIG. 2, the lower cross-sectional shape of the cam lock member 20 forms a cylindrical shape and forms the lower vertical wall portion 21. A lower step portion 22 that is bent substantially at a right angle from the upper end of the lower vertical wall portion 21 and forms a surface parallel to the surface formed by the opening 10 is integrally formed. An upper step portion 23 is formed integrally with the lower step portion 22 so as to be bent in a step shape slightly upward from the tip of the lower step portion 22 and further bent in a direction of expanding the diameter to form a plane parallel to the opening 10. As shown in FIG. 3, an upper vertical wall portion 24 extends partially at the top of the upper step portion 23 at several locations. A lid locking member (locking claw portion) 25 bent in an L shape from the upper end of the upper vertical wall portion 24 toward the center of the opening 10 is formed. The locking claw portion 25 can be formed in a wave shape. Thereby, the convex part 31 and the locking claw part 25 described above can act as a spring to lock the lid 40.

As shown in FIG. 3, a corrugated notch 26 is formed at the lower end of the lower vertical wall portion 21. As will be described later, the thermoplastic synthetic resin member of the cylindrical portion 11 of the opening portion 10 can enter the notch portion 26 during blow molding, and the cam lock member 20 can be fixed to the opening portion 10.
Instead of the corrugated notch 26, a plurality of fixing holes 27 can be formed near the center of the lower vertical wall 21 as shown in FIG. In this case, similarly, the thermoplastic synthetic resin member of the cylindrical portion 11 can enter the fixing hole 27 at the time of blow molding, and the cam lock member 20 can be fixed to the opening portion 10.

As shown in FIG. 2, the opening 10 is formed of a cylindrical portion 11 and a bent portion 12.
The cylindrical portion 11 is formed by extending a thermoplastic synthetic resin wall composed 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 outwardly in a cylindrical shape. A lower vertical wall portion 21 of the cam lock member 20 is embedded in the outer layer 2 of the cylindrical portion 11. As described above, the material constituting the thermoplastic synthetic resin wall of the outer layer 2 enters the notch 26 or the fixing hole 27 of the cam lock member 20. For this reason, the cam lock member 20 can be firmly fixed to the opening 10.

The bent portion 12 is integrally and continuously formed from the tip of the cylindrical portion 11 of the opening 10, and expands in the diameter of the cylindrical portion 11, that is, outwards at right angles from the tip of the cylindrical portion 11. In addition to being bent, it is bent in the form of a hairpin in the center direction of the opening 10 so as to have an outer surface parallel to the opening surface of the opening 10 by overlapping layers of thermoplastic synthetic resin on the top and bottom.
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. Accordingly, the opening 10 is continuously formed integrally from the fuel tank body 1 with the same material, has excellent sealing properties, and the portions other than the compression portion 13 of the bent portion 12 ensure a thickness. And strength can be secured.

The bent portion 12 is formed by compressing in a substantially central portion from a direction perpendicular to the surface of the opening 10, and a compression portion 13 having a thinner thickness than other portions is formed. A concave groove is formed over the entire circumference of the opening 10. A rubber seal ring 50 is attached to the groove of the compression portion 13, and when the lid body 40 is attached to the opening portion 10, it comes into contact with the back surface of the lid body 40, and the lid body 40 and the opening portion 10. Can be sealed. Since the seal ring 50 is mounted in the groove, it can be securely held at a predetermined position.

As will be described later, since the surface of the groove is formed smoothly by the slide mold 61, the seal ring 50 is in close contact with each other, and the sealing performance is excellent.
The bottom portion of the groove of the compression portion 13 is formed into a thin wall shape by compressing the bent portion 12. The intermediate layer 4 is folded at the center, and the outer layer 2 is thinly formed above and below the intermediate layer 4.

Since the outer surface of the bent portion 12 is formed by the outer layer 2 of the fuel tank main body 1, the strength can be ensured, and since the intermediate layer 4 is provided inside, the fuel permeation can be prevented.
Furthermore, since the bending part 12 has the thin compression part 13, the thickness of the opening part 10 can be made thin by the compression part 13, and especially the thickness of the outer layer 2 can be made thin. It is possible to minimize the penetration of fuel from the end face of the opening 10 into the outer layer 2 of the compression portion 13.

Next, a reference example of the present invention will be described with reference to FIG.
The second embodiment is different from the first embodiment in the shape of the cam lock member 20, and the other parts are the same. Therefore, the different parts will be mainly described, and the description of the same parts will be omitted. .
The cam lock member 20 according to the second embodiment includes an embedded portion 28 embedded in the opening 10 and a locking portion 29 that presses and locks the lid body 40.

The embedded portion 28 is formed in a flat plate shape in a ring shape, and the inner side of the ring shape is embedded in the outer periphery of the opening 10. The buried portion 28 is buried between the lower surface of the compression portion 13 of the opening 10 and the fuel tank main body 1, holds the bent portion 12 when the compression portion 13 is formed, and a slide mold 61 described later is compressed. The part 13 can be formed.
The locking portion 29 is bent stepwise in cross section, and the lower lower flat surface portion 29b is in close contact with the embedded portion 28 and is formed in a hole formed in communication with the embedded portion 28 and the lower flat surface portion 29b. It is fixed by the inserted bolt 35.

The upper flat surface portion 29 c of the locking portion 29 abuts on the outer peripheral surface of the lid body 40 and can sandwich the lid body 40 together with the embedded portion 28 to seal the opening 10.
For this reason, when the opening 10 is formed by blow molding, only the embedded portion 28 needs to be held in the blow mold, and the molding is easy. Moreover, since the metal burying portion 28 and the locking portion 29 are formed separately, each structure is simplified, and the cam lock member 20 can be easily manufactured.

Next, the manufacturing method of the opening part 10 of a fuel tank is demonstrated based on FIG. 7 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 is composed of an inner mold 62 and an outer mold 63. An opening is formed in the portion of the blow molding die 60 where the opening 10 is to be formed, and the slide mold 61 is fitted into the opening so as to be slidable inward and outward. A ridge 64 is formed around the inner surface of the slide mold 61.

As shown in FIG. 6, the cam lock member 20 is sandwiched between the inner mold 62 and the outer mold 63 of the opening of the blow molding die 60, and blow molding is performed. 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 synthetic resin member swells outward, and the slide mold 61 Abut. Thereafter, while maintaining the internal pressure of the parison, the slide mold 61 slides inwardly in FIG. 6 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 synthetic resin member is in contact with the inner surface of the blow mold 60. At this time, the cam lock member 20 is embedded in the parison of the synthetic resin member.
That is, the lower vertical wall portion 21 of the cam lock member 20 is embedded in the outer layer 2 portion of the tubular portion 11 of the opening 10, and the lower surface of the bent portion 12 abuts on the upper surface of the lower step portion 22 of the cam lock member 20, The bent portion 12 is formed by compressing the bent portion 12 as the slide mold 61 descends and crushing the bent portion 12 into a hairpin shape.

Simultaneously with the compression of the bent part 12, a part of the bent part 12 is compressed into the convex strip part 64 to form the compressed part 13.
Since the compression part 13 is compressed by being sandwiched between the lower step part 22 and the ridge part 64 of the cam lock member 20, the compression part 13 is uniformly formed thin, and a concave groove is formed on the upper surface of the compression part 13. The rubber seal ring 50 is attached to the concave groove as described above. Since the bottom surface of the concave groove is formed by compression of the ridges 64 of the slide mold 61, it is formed smoothly and the seal ring 50 is in close contact with the smooth surface, so that the sealing performance is good.
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.

It is sectional drawing of the opening part of the fuel tank body which is the 1st Embodiment of this invention. It is a partial expanded sectional view which shows the structure of the part which latches the cover body of the opening part of FIG. It is a perspective view of a cam lock member used for a 1st embodiment of the present invention. It is a perspective view of the other cam lock member used for the 1st Embodiment of the present invention. It is a partial expanded sectional view which shows the structure of the part holding the cover body of the opening part of the fuel tank main body which is a reference example of this invention. It is sectional drawing of the state which the slide mold | type slid upwards in the opening part part of the fuel tank main body of the blow molding die used for implementation of this invention. It is sectional drawing of the state which the slide mold | type slid downward in the opening part part of the fuel tank main body of the blow molding 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 Intermediate layer 10 Opening part 11 Tubular part 12 Bending part 13 Compression part 20 Lid locking member (cam lock member)
30 Fixing member 40 Lid 60 Blow molding die 61 Slide mold

Claims (6)

In the fuel tank opening structure in which the opening is integrally formed in a fuel tank body made of a thermoplastic synthetic resin having at least an outer layer, an inner layer, and an intermediate layer therebetween,
The opening includes a tubular portion extending outward from the fuel tank main body, a bend in the direction of expanding the tubular portion from the tip of the tubular portion, and a hairpin shape in the center direction of the opening. The outer layer of the thermoplastic synthetic resin , the inner layer and the intermediate layer between them are overlapped in two layers, and each of the bent portions has an outer surface parallel to the opening surface of the opening. A part has a compression part that is thinner than the other part compressed from the direction perpendicular to the opening surface, and a metal ring-shaped lid lock is provided on the outer layer below the overlapped part of the compression part. Embed the members integrally ,
The lid locking member is bent in the direction of expanding the diameter of the lower vertical wall portion from the distal end of the cylindrical lower vertical wall portion embedded in the cylindrical portion of the opening portion, and the opening surface. A lower step portion that forms a plane parallel to the upper step portion, a top step portion that bends upward in a stepwise manner from the tip of the lower step portion, and further bends in a direction of expanding the diameter, and forms a plane parallel to the opening surface, and a plurality of steps from the upper step portion An upper vertical wall portion is extended above the portion, and a locking claw portion bent in an L-shape from the tip of the upper vertical wall portion toward the center of the opening is formed, and the lower step portion is formed of the compression portion. A fuel tank opening structure, wherein the fuel tank is embedded in the outer layer below the overlapped portion, and the lower step portion holds a bent portion of the opening. The lower vertical wall portion of the lid locking member is formed with a notch or a fixing hole in which the thermoplastic synthetic resin of the cylindrical portion of the opening enters and the lid locking member is fixed to the opening. The fuel tank opening structure according to claim 1 . 3. The fuel tank opening structure according to claim 1 , wherein the compression portion is formed in a groove shape having a U-shaped cross section, and the groove-shaped bottom portion is formed with a smooth surface. The fixing member that clamps the lid that closes the opening of the fuel tank has a ring shape and a cross-sectional shape that is formed into a flat plate shape, and is engaged with the locking claw portion of the lid locking member. The fuel tank opening structure according to any one of claims 1 to 3, wherein a convex portion is formed at a portion corresponding to the claw portion. In the method of manufacturing a fuel tank, the 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 integrally formed.
By holding a metal ring-shaped lid locking member at the portion forming the opening of the blow mold,
The lid locking member is bent in the direction of expanding the diameter of the lower vertical wall portion from the distal end of the cylindrical lower vertical wall portion embedded in the cylindrical portion of the opening portion, and the opening surface. A lower step portion that forms a plane parallel to the upper step portion, a top step portion that bends upward in a stepwise manner from the tip of the lower step portion, and further bends in a direction of expanding the diameter, and forms a plane parallel to the opening surface, and a plurality of steps from the upper step portion An upper vertical wall portion is extended above the portion, and a locking claw portion bent in an L shape from the tip of the upper vertical wall portion toward the center of the opening is formed.
A slide mold is provided on the outer side of the portion that holds the lid locking member of the blow molding mold, and a protruding strip is formed on the peripheral edge of the inner surface of the slide mold,
During blow molding of the fuel tank body, it is retracted the sliding die to the outside, a cylindrical portion of the opening is extended outward from a portion of the thermoplastic synthetic resin member of the fuel tank body Forming,
The thermoplastic synthetic resin member of the cylindrical portion is inserted between the lid locking member and the protruding strip portion of the slide mold to expand the diameter, and the thermoplastic synthetic resin member of the opening is The thermoplastic synthetic resin member is brought into contact with the inner surface of the slide mold, bent in the direction of expanding the cylindrical portion from the tip of the cylindrical portion, and further bent into a hair pin shape in the center direction of the opening. An outer layer, an inner layer, and an intermediate layer between the two layers are overlapped to form a bent portion, the bent portion is held at a lower step portion of the lid locking member, and the slide mold is attached to the lid locking member Forward, and at least a portion of the bent portion is compressed in a direction perpendicular to the opening surface while being sandwiched between the slide mold and the lower step portion of the lid locking member, and thinner than the other portions. Forming a compression part, and the compression part was overlapped The amount of the lower side of the outer layer integrally embedded Shitatatekabe portion of the lid locking member, to the formation of an opening by cutting the thermoplastic synthetic resin member for closing a portion of the opening of the opening A fuel tank manufacturing method characterized by the above. 6. The method of manufacturing a fuel tank according to claim 5 , wherein the compression portion is formed in a groove shape having a U-shaped cross section by the protruding strip portion of the slide mold, and a smooth surface is formed in the groove-shaped bottom portion.