JP2016107433A - Resin tank and production method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin tank capable of preventing peeling between an outer wall and an opening member, even when the outer wall is deformed, and a production method thereof.SOLUTION: A fuel tank 10 comprises: an outer wall 12 formed of a resin; and an opening member 20 comprising a cylindrical part 16 and a collar part 18 jointed to the cylindrical part 16. The fuel tank 10 comprises an opening part 14, formed by depositing a lower face 18d of the collar part 18 to an outer face 12o of the outer wall 12. In particular, a prepreg 70 is deposited over the outer face 12o of the outer wall 12 and an upper face 18u of the collar part 18.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a synthetic resin tank in which an outer wall is formed by blow molding and a method for manufacturing the same.

  Synthetic resin tanks manufactured by blow molding are used for vehicle fuel tanks and the like. The fuel tank includes several openings, for example, an opening for attaching a pump module that pumps up fuel stored in the fuel tank and sends it to the engine, an opening for attaching a pipe connected to a fuel filler port, and the like. A seal structure is employed at the opening of the fuel tank to prevent leakage of fuel (vapor) that volatilizes in the fuel tank.

  Patent Document 1 discloses a seal structure related to an opening for mounting a pump module. In the fuel tank shown in Patent Document 1, an outer wall and a cylindrical opening projecting from the outer wall are formed simultaneously with blow molding. The opening has a seal member disposed along the open end, and has an external thread portion on the outer peripheral surface. When the fastening member having the female threaded portion on the inner peripheral surface is fastened to the male threaded portion of the opening member in a state where the plate-shaped member is put on the end portion of the opening, the plate-shaped member is sealed by the fastening member by the fastening member. The opening is shielded and the seal is secured.

  By the way, it is desired to reduce the weight of the fuel tank, and it is preferable to reduce the thickness of the outer wall by thinning the synthetic resin of the outer wall. If the outer wall of the fuel tank shown in Patent Document 1 is reduced in weight, it is necessary to thin the synthetic resin during blow molding. When the outer wall synthetic resin is thinned, the synthetic resin in the opening formed together with the outer wall is also thinned. The opening portion needs to have rigidity to resist torsion acting when the fastening member is fastened. If the opening is thinned, the rigidity is impaired, so it is not desirable to make the opening thin.

  Patent Document 2 discloses a method of forming an opening as a fuel filler port in a fuel tank for a motorcycle. This discloses a method of manufacturing a fuel tank by forming an opening member separately from the outer wall and welding the opening member to the outer wall during blow molding of the outer wall. An opening member consists of a cylindrical part and a collar part connected to this cylindrical part, and an opening part is formed by welding the lower surface of a collar part to the outer surface of an outer wall. With this method, the outer wall can be thinned without thinning the opening, and the fuel tank can be reduced in weight.

JP 2002-362609 A (paragraph [0013], FIG. 1) JP 2003-236920 A (paragraph [0028], FIG. 2)

  The method disclosed in Patent Document 2 uses the blow molding pressure at the time of blow molding to weld the outer surface of the outer wall to the lower surface of the flange portion of the opening member. However, it is difficult to obtain a strong welding strength between the opening member and the outer wall only by the blow molding pressure. For this reason, there is a possibility that the opening member may be peeled off from the outer surface of the outer wall when the fuel tank is deformed, such as receiving external force at the time of a vehicle collision, or generating vapor in the fuel tank to become positive pressure.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a synthetic resin tank that can prevent the outer wall and the opening member from being peeled even if the outer wall is deformed, and a method for manufacturing the same. .

  The present invention includes an outer wall made of a synthetic resin and an opening member having a tubular portion and a flange portion connected to the tubular portion, and the opening portion is formed by welding the flange portion to the outer wall. A synthetic resin tank comprising a prepreg welded across at least a part of the outer wall and the flange, wherein at least a part of the flange is sandwiched between the outer wall and the prepreg. Features.

  According to the present invention, the prepreg is welded across the outer wall and the flange, and at least a part of the flange is sandwiched between the outer wall and the prepreg. Since the boundary portion between the outer wall and the collar portion is reinforced by the prepreg, the collar portion, that is, the opening member, is difficult to peel off from the outer wall. Further, the welding strength is further strengthened by welding the outer wall and the prepreg in a softened state. For this reason, an outer wall and a prepreg become difficult to peel. The hook part, that is, the opening member is also difficult to peel from the outer wall in that it is sandwiched between the outer wall and the prepreg which are difficult to peel.

  In the present invention, an inclined portion may be formed on the periphery of the flange portion so that the thickness of the flange portion decreases as the distance from the cylindrical portion increases. By forming the inclined portion on the periphery of the flange portion, it is possible to eliminate a step in the welding portion between the prepreg, the flange portion, and the outer wall, and the welding strength between the prepreg, the flange portion, and the outer wall becomes stronger.

  In this invention, the recessed part surrounding the said cylindrical part may be formed in the said cylindrical part side rather than the welding location with the said prepreg among the said collar parts. The lower end of the fastening member corresponding to the lid of the opening is received in the recess. In other words, the recess allows the fastening member to be easily fastened to the opening member while reducing the height of the opening member. When the height of the opening member with respect to the outer wall is high, the force acting on the collar portion becomes relatively large when a force is applied to the opening member. On the other hand, if the height of the opening member with respect to the outer wall is low, the force acting on the collar portion becomes relatively small when a force is applied to the opening member. As a result, the collar portion, that is, the opening member is hardly separated from the outer wall.

  The present invention includes an outer wall made of a synthetic resin and an opening member having a tubular portion and a flange portion connected to the tubular portion, and the opening portion is formed by welding the flange portion to the outer wall. A method for producing a synthetic resin tank, comprising: a first step of attaching a prepreg to a first mold; a second step of applying heat to the prepreg to soften; and the ridges of the prepreg and the opening member. A third step of welding at least a part of the part, a fourth step of supplying a parison made of synthetic resin between the first mold and the second mold, and the parison with the first mold A fifth step of sandwiching between the second mold, and blowing the gas into the parison so that the parison is brought into close contact with the first mold and the second mold to form the outer wall, and the outer wall and the prepreg And the flange of the opening member Characterized in that it comprises a sixth step of forming the opening by interposing at least a portion of the flange portion between the prepreg and the outer wall Te.

  In the present invention, the parison and the flange portion of the opening member are welded using blow molding pressure, and the parison and the prepreg are welded to manufacture a synthetic resin tank having an opening formed on the outer wall. According to the present invention, the prepreg is welded across the outer wall and the flange, and at least a part of the flange is sandwiched between the outer wall and the prepreg. Since the boundary portion between the outer wall and the collar portion is reinforced by the prepreg, the collar portion, that is, the opening member, is difficult to peel off from the outer wall. Further, the welding strength is further strengthened by welding the outer wall and the prepreg in a softened state. For this reason, an outer wall and a prepreg become difficult to peel. The hook part, that is, the opening member is also difficult to peel from the outer wall in that it is sandwiched between the outer wall and the prepreg which are difficult to peel.

  According to the present invention, the prepreg is welded across the outer wall and the heel portion, and at least a part of the heel portion is sandwiched between the outer wall and the prepreg, so that the heel portion, that is, the opening member is hardly peeled off from the outer wall.

FIG. 1 is an external view of a fuel tank and a pump module according to this embodiment. FIG. 2 is a sectional view of the outer wall. FIG. 3 is a sectional view of the opening. FIG. 4 is a process explanatory diagram for explaining a series of manufacturing steps of the fuel tank. FIG. 5 is a cross-sectional view of a flange according to another embodiment.

  Hereinafter, preferred embodiments of a synthetic resin tank and a method for producing the same according to the present invention will be described in detail with reference to the accompanying drawings. In the following description, an embodiment in which the synthetic resin tank according to the present invention is used as an automobile fuel tank will be described.

[Structure of fuel tank 10]
FIG. 1 is an external view of a fuel tank 10 and a pump module 22 according to this embodiment. As shown in FIG. 1, the fuel tank 10 according to this embodiment includes an outer wall 12 made of synthetic resin and an opening 14 formed in the outer wall 12. The opening 14 is formed by an opening member 20 that is separate from the outer wall 12. The opening member 20 includes a cylindrical portion 16 that opens and a flange portion 18 that projects outward from the cylindrical portion 16. A prepreg 70 is welded to the boundary portion between the flange 18 and the outer wall 12 (see FIG. 3). Inside the fuel tank 10, a pump body 22a of the pump module 22 is accommodated. The pump body 22 a is inserted into the fuel tank 10 through the opening 14. The top plate 22 b of the pump module 22 has a larger diameter than the pump main body 22 a and closes the opening 14 via the seal member 24. When the fastening member 26 is put on the top plate 22b of the pump module 22 and fastened to the tubular portion 16 of the opening member 20, the fuel tank 10 is sealed.

[Structure of outer wall 12]
The structure of the outer wall 12 will be described with reference to FIG. FIG. 2 is a cross-sectional view of the outer wall 12. The outer wall 12 is formed of a synthetic resin whose main material is high density polyethylene (hereinafter referred to as HDPE). The outer wall 12 is manufactured by blow molding. The blow molding will be described later. The outer wall 12 has a multilayer structure in which an innermost layer 32, an inner adhesive layer 34, a barrier layer 36, an outer adhesive layer 38, a recycled material layer 40, and an outermost layer 42 are laminated in this order from the inner surface 12i to the outer surface 12o. The The same structure as the structure of the outer wall 12 of this embodiment is disclosed by Unexamined-Japanese-Patent No. 2014-104920, for example.

  The innermost layer 32 forming the inner surface 12i of the outer wall 12 and the outermost layer 42 forming the outer surface 12o of the outer wall 12 mainly include new HDPE materials. The inner adhesive layer 34 and the outer adhesive layer 38 mainly contain modified polyethylene (hereinafter referred to as modified PE). The barrier layer 36 mainly includes an ethylene vinyl alcohol copolymer (hereinafter referred to as EVOH).

[Structure of opening 14]
The structure of the opening 14 will be described with reference to FIG. FIG. 3 is a cross-sectional view of the opening 14. As shown in FIG. 3, the opening 14 is formed by an opening member 20 including a cylindrical portion 16 and a flange portion 18. A prepreg 70 is welded to the periphery of the flange portion 18.

  The cylindrical portion 16 is made of nylon. A spiral male screw portion 50 is formed above the outer peripheral surface of the cylindrical portion 16, and the female screw portion formed on the inner peripheral surface of the fastening member 26 (see FIG. 1) with respect to the male screw portion 50. (Not shown) are screwed together. The inner peripheral surface 60 of the flange portion 18 is joined to the outer peripheral surface 52 located below the outer peripheral surface of the cylindrical portion 16.

  The collar portion 18 is made of polyethylene. An inclined portion 62 that is linearly inclined toward the outer circumferential direction is formed in a portion including the periphery of the lower surface 18d of the flange portion 18. Due to the inclined portion 62, the thickness of the flange portion 18 decreases as the distance from the tubular portion 16 increases. The starting point of the inclination of the inclined part 62 may be any position on the lower surface 18d. The outer surface 12 o of the outer wall 12 is welded to the lower surface 18 d of the flange portion 18.

  An annular recess 64 is formed on the upper surface 18 u of the flange 18. The recessed portion 64 is located on the tubular portion 16 side of the welded portion between the prepreg 70 and the flange portion 18 and is disposed so as to surround the tubular portion 16. When the fastening member 26 (see FIG. 1) is fastened to the tubular portion 16, the lower end portion of the fastening member 26 is accommodated in the recess 64.

  The prepreg 70 is a sheet member obtained by processing a synthetic resin reinforced with fibers such as carbon fibers and glass fibers into a ring shape. The prepreg 70 is welded across the periphery of the outer surface 12o of the outer wall 12 and the upper surface 18u of the flange portion 18. The prepreg 70 prevents the flange 18 from peeling from the outer wall 12 by covering the boundary between the flange 18 and the outer wall 12 and sandwiching the flange 18 together with the outer wall 12.

[Manufacturing Method of Fuel Tank 10]
A method for manufacturing the fuel tank 10 will be described with reference to FIG. FIG. 4 is a process explanatory diagram for explaining a series of manufacturing steps of the fuel tank 10. In this embodiment, the fuel tank 10 is manufactured by blow molding. In FIG. 4, a cross section of each component of the pair of molds (first mold 80 and second mold 82) and the fuel tank 10 used during blow molding is shown for each process.

  In the first step, the upper surface 70u of the annular prepreg 70 is attached to the mold surface (design surface) 80a of the first mold 80, and the prepreg 70 is temporarily placed at a predetermined position on the mold surface 80a of the first mold 80. Secure to.

  In the second step, a heated hot plate 84 is disposed in front of the lower surface 70d of the prepreg 70 fixed to the first mold 80, and the prepreg 70 is heated and softened. At this time, a contact type in which the hot plate 84 is brought into contact with the prepreg 70 or a non-contact type in which the hot plate 84 is not brought into contact with the prepreg 70 may be used.

  In the third step, the cylindrical portion 16 of the opening member 20 is inserted into the inner peripheral side of the softened annular prepreg 70. Then, the opening member 20 is pressed against the prepreg 70 by the pressing tool 86, and the inner peripheral surface of the lower surface 70 d of the prepreg 70 and the upper surface 18 u of the flange portion 18 of the opening member 20 are welded. Thus, the opening member 20 is temporarily fixed at a predetermined position on the mold surface 80a.

  A prepreg 72 for partially reinforcing the outer wall 12 (see FIG. 1) is attached at an arbitrary position on the mold surface 80a of the first mold 80 and / or the mold surface 82a of the second mold 82. It is also possible to keep it. The prepreg 72 partially reinforces the outer wall 12. Like the prepreg 70, it is desirable that the prepreg 72 is also softened by a hot plate 84 or the like.

  In the fourth step, the synthetic resin that has been heated and plasticized is extruded from the extruder 88 to the die 90, and the synthetic resin is formed into a cylindrical parison 12 ′ by the die 90. The parison 12 ′ extends downward by its own weight and is supplied between the first mold 80 and the second mold 82. The extruder 88 individually extrudes the material of each layer (the innermost layer 32, the inner adhesive layer 34, the barrier layer 36, the outer adhesive layer 38, the recycled material layer 40, and the outermost layer 42) shown in FIG. The die 90 forms a parison 12 ′ having a laminated structure equivalent to the laminated structure shown in FIG. Therefore, when the parison 12 ′ is supplied between the first mold 80 and the second mold 82, it already has a laminated structure of HDPE, modified PE and EVOH as shown in FIG.

  In the fifth step, the first mold 80 and the second mold 82 are closed, and the parison 12 ′ is sandwiched between the first mold 80 and the second mold 82. Unnecessary portions generated when the parison 12 'is sandwiched are reused as recycled materials later.

  In the sixth step, the nozzle 94 is inserted into the cavity 92 of the first mold 80 and the second mold 82 that are closed, and gas (air) is blown into the parison 12 ′ in the cavity 92 through the nozzle 94. Then, the parison 12 ′ expands and comes into close contact with the mold surface 80 a of the first mold 80 and the mold surface 82 a of the second mold 82. At this time, the parison 12 'and the outer peripheral surface of the lower surface 70d of the prepreg 70 are welded together by blow molding. Further, the parison 12 'and the lower surface 18d of the flange 18 are pressed against each other by blow molding pressure and welded. When the parison 12 'is cooled and solidified, the fuel tank 10 (see FIG. 1) having the opening 14 in the outer wall 12 is obtained.

  Through the above steps, the prepreg 70 is welded across the outer surface 12o of the outer wall 12 and the upper surface 18u of the flange portion 18. Unlike the flange portion 18, the prepreg 70 is welded in a softened state with respect to the parison 12 ′ to be the outer wall 12 later. At this time, since the parison 12 ′ is also softened, the welding between the parison 12 ′ and the prepreg 70 becomes strong. As a result, the welding strength between the outer wall 12 where the parison 12 ′ is cured and the prepreg 70 is high, and the prepreg 70 is difficult to peel from the outer wall 12.

[Summary of this embodiment]
A fuel tank (synthetic resin tank) 10 according to the present embodiment includes a synthetic resin outer wall 12 and an opening member 20 having a cylindrical portion 16 and a flange portion 18 joined to the cylindrical portion 16. The opening 14 is formed by welding the flange 18 to the outer wall 12. Further, the fuel tank 10 includes a prepreg 70 that is welded across the outer wall 12 and the flange 18, and at least a part of the flange 18 is sandwiched between the outer wall 12 and the prepreg 70.

  In addition, the manufacturing method of the fuel tank (synthetic resin tank) 10 according to the present embodiment includes a first step of attaching the prepreg 70 to the first mold 80, and a second step of applying heat to the prepreg 70 to soften it. The third step of welding the prepreg 70 and at least a part of the flange 18 of the opening member 20, and the first step of supplying the parison 12 ′ made of synthetic resin between the first mold 80 and the second mold 82. 4 steps, a fifth step of sandwiching the parison 12 ′ between the first mold 80 and the second mold 82, and blowing a gas into the parison 12 ′ to convert the parison 12 ′ into the first mold 80 and the second mold 82, the outer wall 12 is formed in close contact with the outer wall 12, the prepreg 70 and the flange portion 18 of the opening member 20 are welded, and at least a part of the flange portion 18 is sandwiched between the outer wall 12 and the prepreg 70, thereby opening the opening portion. 14 forms And a sixth step.

  According to the present embodiment, the prepreg 70 is welded across the outer wall 12 and the flange portion 18, and at least a part of the flange portion 18 is sandwiched between the outer wall 12 and the prepreg 70. Since the boundary portion between the outer wall 12 and the flange portion 18 is reinforced by the prepreg 70, the flange portion 18, that is, the opening member 20 is difficult to peel from the outer wall 12. Further, the welding strength is further strengthened by welding the outer wall 12 and the prepreg 70 in a softened state. For this reason, the outer wall 12 and the prepreg 70 become more difficult to peel. The flange 18, that is, the opening member 20 is also difficult to peel from the outer wall 12 in that it is sandwiched between the outer wall 12 and the prepreg 70 that are difficult to peel off.

  Further, in the present embodiment, an inclined portion 62 is formed on the peripheral edge (lower surface 18 d) of the flange portion 18 so that the thickness of the flange portion 18 decreases as the distance from the cylindrical portion 16 increases. By forming the inclined portion 62 in the flange portion 18, it is possible to eliminate a step in the welding position of the prepreg 70, the flange portion 18 and the outer wall 12, and the welding strength of the prepreg 70, the flange portion 18 and the outer wall 12 is further strengthened. Become.

  Moreover, in this embodiment, the recessed part 64 surrounding the cylindrical part 16 is formed in the cylindrical part 16 side rather than the welding location with the prepreg 70 among the collar parts 18. The lower end of the fastening member 26 corresponding to the lid of the opening 14 is received in the recess 64. That is, the recess 64 makes it possible to easily fasten the fastening member 26 to the opening member 20 while reducing the height of the opening member 20. When the height of the opening member 20 with respect to the outer wall 12 is high, when a force is applied to the opening member 20, the force acting on the flange 18 becomes relatively large. On the other hand, when the height of the opening member 20 with respect to the outer wall 12 is low, when a force is applied to the opening member 20, the force acting on the flange portion 18 becomes relatively small. As a result, the flange 18, that is, the opening member 20 is difficult to peel from the outer wall 12.

[Another embodiment]
It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention. For example, the inclined portion 62 formed on the lower surface 18d of the flange portion 18 may be inclined in a curved shape instead of linearly inclined toward the outer peripheral direction of the flange portion 18.

  In addition, the inclined portion 62 may not be formed on the lower surface 18d of the flange portion 18, but an inclined portion 98 may be formed on the upper surface 96u of the flange portion 96 as shown in FIG. FIG. 5 shows a cross section of the left half of the collar portion 96. Moreover, although not shown in figure, the inclination part may be formed in both surfaces of the collar part.

  In addition, unevenness may be formed on the entire or part of the lower surface 18 d of the flange 18. The surface area of the lower surface 18d is increased by the unevenness, and the welding area with the outer surface 12o of the outer wall 12 is increased, so that the welding strength between the two is increased. Similarly, irregularities may be formed on the periphery of the upper surface 18 u of the flange portion 18. The surface area of the periphery increases due to the unevenness, and the welding area with the prepreg 70 increases, so that the welding strength between them increases.

  Further, the prepreg 70 does not have to be annular as shown in FIG. In this case, if at least a part of the boundary portion between the outer wall 12 and the flange portion 18 is reinforced by the prepreg 70 straddling both, the effect of preventing the flange portion 18 from peeling off from the outer wall 12 can be expected to some extent. .

  In this embodiment, the structure of the outer wall 12 is a laminated structure as shown in FIG. 2, but another structure may be used. For example, instead of using HDPE recycled material for the recycled material layer 40, a new HDPE material may be used in the same manner as the innermost layer 32 and the outermost layer 42.

  The synthetic resin tank of the present invention can be widely used not only for automobile fuel tanks but also for tanks made of synthetic resin.

DESCRIPTION OF SYMBOLS 10 ... Fuel tank 12 ... Outer wall 12o ... Outer surface 14 ... Opening part 16 ... Cylindrical part 18, 96 ... Eaves part 18d ... Lower surface 18u, 22u ... Upper surface 20 ... Opening member 62, 98 ... Inclined part 64 ... Recessed part 70 ... Prepreg

Claims (4)

A synthetic resin comprising an outer wall made of synthetic resin, and an opening member having a tubular portion and a flange connected to the tubular portion, and the opening is formed by welding the flange to the outer wall A tank made of
Comprising a prepreg welded across at least a portion of the outer wall and the flange,
A synthetic resin tank, wherein at least a part of the flange is sandwiched between the outer wall and the prepreg. In the synthetic resin tank according to claim 1,
A synthetic resin tank, characterized in that an inclined portion is formed at a peripheral edge of the flange portion so that the thickness of the flange portion decreases as the distance from the cylindrical portion increases. In the synthetic resin tank according to claim 1 or 2,
A synthetic resin tank characterized in that a concave portion surrounding the cylindrical portion is formed on the cylindrical portion side of the flange portion relative to the welded portion with the prepreg. A synthetic resin comprising an outer wall made of synthetic resin, and an opening member having a tubular portion and a flange connected to the tubular portion, and the opening is formed by welding the flange to the outer wall A method for manufacturing a tank,
A first step of attaching a prepreg to the first mold;
A second step of softening the prepreg by applying heat;
A third step of welding the prepreg and at least a part of the flange of the opening member;
A fourth step of supplying a parison made of synthetic resin between the first mold and the second mold;
A fifth step of sandwiching the parison between the first mold and the second mold;
By blowing gas into the parison, the parison is brought into close contact with the first mold and the second mold to form the outer wall, and the outer wall, the prepreg, and the flange portion of the opening member are welded together. And a sixth step of forming the opening by sandwiching at least a part of the flange between the outer wall and the prepreg. A method of manufacturing a synthetic resin tank, comprising:

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