JP5471753B2 - Fuel tank manufacturing method and fuel tank - Google Patents

Description

  The present invention relates to a fuel tank manufacturing method and a fuel tank.

  Some fuel tanks provided in vehicles such as automobiles are made of resin. For example, Patent Document 1 describes a method of manufacturing a fuel tank in which a fuel tank body is blow-molded and an opening is integrally formed. Patent Document 1 further describes that the portion that forms the opening is surrounded by an annular member, and the resin material is compressed on the stepped portion of the annular member to reliably prevent fuel from permeating. Has been.

  However, in the manufacturing method described in Patent Document 1, an annular member is required to compress the resin material, which increases the manufacturing process and causes an increase in manufacturing cost. Moreover, the number of parts increases also as a manufactured fuel tank.

JP 2003-220840 A

  In view of the above facts, the present invention takes into account the above facts, and a fuel tank manufacturing method capable of manufacturing a fuel tank that is made of a resin material and suppresses fuel permeation at low cost, and a component that can be made of resin material and can suppress fuel permeation The problem is to obtain a fuel tank that requires less.

  In the first aspect of the invention, the outer resin layer constituting the outside of the fuel tank, the inner resin layer constituting the inner side of the fuel tank, and the fuel permeability is lower than those of the outer resin layer and the inner resin layer. A fuel tank manufacturing method for manufacturing a fuel tank composed of a fuel tank structure including a barrier layer disposed between an outer resin layer and an inner resin layer depending on a material,

  By compressing the fuel tank constituting body with an outer mold and an inner mold, an annular recess in which the outer resin layer is partially thinned is formed outside the fuel tank.

  In the present invention, the fuel tank structure constituting the fuel tank includes an outer resin layer and an inner resin layer, and includes a barrier layer made of a material having lower fuel permeability than these resin layers. In the fuel tank, fuel permeation through the fuel tank structure is suppressed.

  Further, in this fuel tank manufacturing method, the annular recess can be formed with high accuracy by compressing the fuel tank structure with the outer mold and the inner mold. In the recess, the outer resin layer is partially thinned outside the fuel tank, so that fuel permeation is particularly suppressed. In addition, the recess (the portion where the outer resin layer is partially thinned) is formed by compressing the fuel tank structure with two molds (the outer mold and the inner mold). Since the conventional annular member is not necessary, steps such as molding and arrangement of the annular member are unnecessary, and the fuel tank can be manufactured at low cost.

  According to a second aspect of the present invention, in the first aspect of the present invention, when the fuel tank structural body is compressed by the outer mold and the inner mold, the fuel tank structural body protrudes in a cylindrical shape. And an extending portion extending radially inward of the neck portion from the protruding front end side of the neck portion, and the recessed portion is formed by compressing the extending portion with an outer mold and an inner mold.

  When the fuel tank structure is compressed by the outer mold and the inner mold, the neck and the extension are formed, and the extension is compressed by the outer mold and the inner mold to form a recess. That is, the fuel tank having the neck portion, the extending portion, and the concave portion can be formed in a single step of compressing the fuel tank structure with the outer mold and the inner mold.

  According to a third aspect of the present invention, in the second aspect of the present invention, after the recess is formed, the inner mold of the portion located radially inward of the neck and inside the fuel tank is retracted. Thus, a first cavity space is formed between the fuel tank structure and a resin material is supplied to the first cavity space to increase the thickness of the neck.

  Therefore, in this fuel tank manufacturing method, by supplying the resin material to the first cavity space, it is possible to easily increase the thickness of the neck portion and reinforce the extending portion. There is no need for a new member for reinforcing the extension.

  According to a fourth aspect of the present invention, in the second or third aspect of the present invention, the inner mold of a portion located radially inward of the neck inside the fuel tank with respect to the neck is moved backward to the fuel. A second cavity space is formed between the tank structure and a resin material is supplied to the second cavity space to increase the thickness of the base of the neck.

  Therefore, in this fuel tank manufacturing method, the thickness of the base of the neck can be easily increased by supplying the resin material to the second cavity space, and the base of the neck can be reinforced. There is no need for a new member for reinforcing the base of the neck.

  In the invention according to claim 5, the outer resin layer constituting the outside of the fuel tank, the inner resin layer constituting the inner side of the fuel tank, and the fuel permeability is higher than that of the outer resin layer and the inner resin layer. A fuel tank body comprising a fuel tank structure comprising a low material and a barrier layer disposed between the outer resin layer and the inner resin layer, and forming a shell shape of the fuel tank; and the fuel tank structure A neck portion protruding in a cylindrical shape from the fuel tank body, an extension portion extending radially inward of the neck portion from the protruding front end side of the neck portion, and the outer resin layer in the extension portion is the fuel tank. An annular recess that is partially thin on the outside, and is provided integrally with the fuel tank structure, radially inward of the neck and inside the fuel tank of the recess, and is continuous with the extension. To reinforce the extension It has a reinforcement unit.

  That is, in this fuel tank, the fuel tank structure includes an outer resin layer and an inner resin layer, and a barrier layer made of a material having lower fuel permeability than these resin layers. Fuel permeation through the body is suppressed.

  Moreover, since this fuel tank has a neck part and an extension part, it becomes possible to attach another member (attachment member) using these neck part and extension part. When the attachment member is attached in this way, it is possible to ensure high sealing performance between the fuel tank and the attachment member by disposing, for example, a gasket in the recess.

  The extending portion is reinforced by the reinforcing portion on the inner side in the radial direction than the neck portion and on the inner side of the fuel tank in the recessed portion. That is, the fuel tank in which the extending portion having the concave portion in which the outer resin layer is partially thinned is reinforced by the reinforcing portion. Since a member for reinforcing the extending portion is not necessary, the number of parts can be reduced.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the reinforcing portion extends from the inside of the fuel tank of the neck portion to the root portion of the neck portion.

  In other words, since the reinforcing portion extends from the inside of the fuel tank of the neck portion to the base portion of the neck portion, the neck portion and the base portion of the neck portion are reinforced. Since the neck and the member for reinforcing the base of the neck are not necessary, the number of parts can be reduced.

  Since the present invention has the above-described configuration, a fuel tank manufacturing method capable of manufacturing a fuel tank made of a resin material and suppressing fuel permeation at a low cost, and a number of parts that can be made of resin material and suppress fuel permeation. A fuel tank that requires less can be obtained.

It is a longitudinal section showing a fuel tank of one embodiment of the present invention. It is a longitudinal cross-sectional view which expands and shows the fuel tank of one Embodiment of this invention in a neck part and its vicinity. It is a longitudinal cross-sectional view which expands and shows the upper side fuel tank structure which comprises the fuel tank of one Embodiment of this invention in a neck part and its vicinity. It is sectional drawing which shows the process of manufacturing the fuel tank of one Embodiment of this invention. It is sectional drawing which shows the process of manufacturing the fuel tank of one Embodiment of this invention in the state advanced from FIG. It is sectional drawing which shows the process of manufacturing the fuel tank of one Embodiment of this invention in the state advanced from FIG. It is sectional drawing which shows the process of manufacturing the fuel tank of one Embodiment of this invention in the state advanced from FIG. It is sectional drawing which shows the process of manufacturing the fuel tank of one Embodiment of this invention in the state which advanced rather than FIG.

  FIG. 1 shows a fuel tank 12 according to a first embodiment of the present invention. As an example, the fuel tank 12 according to the present embodiment includes two fuel tank constituent bodies 16 (an upper fuel tank constituent body 16A and a lower fuel tank constituent body 16B) in which a substantially rectangular fuel tank main body 14 is divided into upper and lower parts. ). The upper fuel tank constituting body 16A is generally convex upward, and the lower fuel tank constituent body 16B is generally convex downward, and by joining these outer peripheral portions, a substantially rectangular parallelepiped fuel tank main body 14

  As shown in detail in FIG. 2, the fuel tank structure 16 includes a resin layer 22 (outer resin layer 22 </ b> A and inner resin layer 22 </ b> C) made of, for example, high-density polyethylene (HDPE), and a barrier between the resin layers 22. The layer 24 </ b> A is laminated and adhered by an adhesive layer (not shown). The barrier layer 24A is made of, for example, a material having a fuel permeability lower than that of the resin layer 22, such as EVOH (ethylene vinyl alcohol).

  The top plate 14T of the fuel tank main body 14 is formed with a neck portion 18 in which the upper fuel tank constituting body 16A protrudes upward in a substantially cylindrical shape. An annular extending portion 20 extending toward the radially inner side of the neck portion 18 is formed from the protruding tip portion of the neck portion 18. The upper surface of the neck portion 18 and the extension portion 20 is a circular support surface 20S, and an annular recess 26 that is locally recessed from above is formed in a radially intermediate portion of the support surface 20S. In this portion, the extending portion 20 is a thin layer portion 28 that is locally thin. As shown in FIG. 2, an annular gasket 32 is accommodated in the recess 26.

  An insertion hole 36 into which the pump module 30 (see FIG. 1) is inserted in the direction of arrow A is formed on the radially inner side of the extending portion 20. The pump module 30 is supported by the neck portion 18 by bringing the mounting flange 30F formed on the top of the pump module 30 into surface contact with the support surface 20S.

  In particular, as can be seen from FIG. 2, a retainer 34 is mounted from above the mounting flange 30F, and the retainer 34 presses the gasket 32 from above via the mounting flange 30F. The sealing performance between the mounting flange 30F and the fuel tank 12 (gasket 32) is enhanced.

  A male screw 38 is formed on the outer periphery of the neck 18. On the other hand, a female screw 40 is formed on the inner peripheral surface of the retainer 34, and the mounting flange 30F can be strongly pressed from the retainer 34 by screwing the female screw 40 into the male screw 38.

  Further, as described above, the portion where the concave portion 26 is formed is a thin layer portion 28 in which the plate thickness of the extension portion 20 is thinned. This thin layer portion 28 is shown in detail in FIG. In particular, the thickness of the outer resin layer 22A is particularly thin. For example, compared to the general portion 14G of the fuel tank main body 14 ((the portion where the extending portion 20 and the neck portion 18 are not formed, see FIG. 1), the inner resin layer 22C is also thinner in the thin layer portion 28. In this way, the outer resin layer 22A is thinner, so that the outer resin layer 22A is thinner, so that the permeation area when the fuel permeation path indicated by the arrow PP in FIG. The nature is also lowered.

  As can be seen from FIGS. 2 and 3, the concave portion 26 is located radially inward of the neck portion 18, but is formed below the concave portion 26 inward of the neck portion 18 and substantially in the radial direction. A thick neck portion 42 having a thick neck portion 18 is formed. In the present embodiment, the thick neck portion 42 is also formed in a substantially cylindrical shape on the inner peripheral side of the neck portion 18 and reinforces the neck portion 18 (male screw portion 38) over the entire circumference.

  Further, in such a structure in which the neck thick portion 42 is not formed, there is no member that supports the extended portion 20 (particularly, the thin layer portion 28) from below, but the neck thick portion 42 is not provided. Is positioned below the thin layer portion 28 to support the extending portion 20, and the extending portion 20 is also reinforced. That is, the neck thick part 42 is a “reinforcing part” in the present invention.

  Further, a base portion thick portion 46 is formed below the base portion 44 of the neck portion 18 so that the top plate 14T is substantially thick in the vicinity of the base portion 44. In the present embodiment, the base thick part 46 is formed in an annular shape that is continuous with the neck thick part 42, and reinforces the base part 44 of the neck 18. That is, in such a structure in which the base portion thick portion 46 is not formed, there is no member that supports the base portion 44 from the lower side, but the base portion thick portion 46 has the base portion 44 and its outer periphery. The side is supported from below. The base thick portion 46 is also a “reinforcing portion” in the present invention.

  Next, the fuel tank manufacturing method for manufacturing the fuel tank 12 of the present embodiment and the operation of the fuel tank 12 will be described.

  First, the upper fuel tank constituting body 16 </ b> A is formed in an upwardly convex shape as a whole using the outer mold 62 and the inner mold 52. As shown in FIG. 4, the inner mold 52 includes a plurality of inner mold components 52A, 52B, 52C, and 52D. The outer mold 62 is also composed of a plurality of outer mold components 62A, 62B, 62C.

  The upper portions of the inner mold components 52A and 52B constituting the inner mold 52 are located above the upper portions of the inner mold components 52C and 52D, and the neck portion 18 and the extension portion 20 of the fuel tank 12 are formed. As shown in FIGS. 6 and 7, the inner mold component 52B is slidable relatively downward with respect to the inner mold components 52A, 52C, and 52D. A material supply gate 58 for supplying resin to the first cavity space 54 is formed in the inner mold component 52A.

  On the other hand, the inner mold members 52C and 52D form a general part (the top plate 14T, etc.) of the fuel tank 12 with the outer mold member 62C. In particular, as shown in FIG. 7, the inner mold component 52C is integrated with the inner mold components 52A and 52D when the inner mold component 52B slides downward by a predetermined amount. It slides relatively downward. Thus, a second cavity space 56 that is surrounded by the top plate 14T and the inner mold components 52D and 52C and continues from the first cavity space 54 is formed.

  Further, the outer mold structure 62A forms the extending portion 20 between the inner mold structures 52A and 52B, and in particular, the upper fuel tank structure 16A is partially partially disposed between the outer mold structure 52A and the inner mold structure 52B. An annular convex portion 64 for forming the concave portion 26 by being sandwiched is formed.

  The outer mold component 62 </ b> B constitutes the neck portion 18, and a die portion 66 for forming a male screw 38 is provided on the outer periphery of the neck portion 18. That is, the outer mold component 62B is a structure that can form the male screw portion 38 between the outer mold component 62B and the inner mold component 52B by approaching the inner mold 52 while rotating.

  The outer structure 62C constitutes the general part 14G of the fuel tank 12 with the inner structures 52C and 52D.

  Using the inner mold 52 and the outer mold 62 having such a structure, first, as shown in FIG. 4, the upper fuel tank constituting body 16A is sandwiched vertically and molded while applying a predetermined heat. Thereby, the fuel tank structure 16A is formed into a convex shape as a whole, and the neck portion 18 and the extension portion 20 are formed.

  At this time, in the extended portion 20, when the outer mold 62 and the inner mold 52 are compressed, the convex portion 64 forms the concave portion 26 (thin layer portion 28). Then, the extension part 20 is supported by the inner structure 52B. Therefore, as compared with the configuration in which the lower side of the concave portion 26 is not supported as described above, the shape of the extending portion 20 can be stably maintained, and the thin shape of the thin layer portion 28 can be formed reliably.

  Thus, after the extension part 20 is formed, when only the inner mold component 52B is lowered (retracted), as shown in FIG. 6, the neck 18, the extension part 20, the inner mold component 52A, and A first cavity space 54 is formed between the inner mold members 52B. While supplying the resin material 60 from the material supply gate 58 to the first cavity space 54, as shown in FIG. 7, the inner mold component 52B is further located at the same position as the inner mold component 52C (the upper surface is flush with the upper surface). To the position). The resin material 60 may be the same material as the resin layer 22, but may be a different type of material as long as it can be melted with the resin layer 22. Thereby, since the supplied resin material 60 is melted by heat at the time of molding and integrated with the inner resin layer 22C in the neck portion 18, the neck portion 18 has a neck portion thickness that makes the neck portion 18 substantially thick. The meat part 42 is formed. The neck thick portion 42 is located below the thin layer portion 28 and supports the thin layer portion 28 from below.

  When the upper surface of the inner mold component 52B is lowered to the same position as the upper surface of the inner mold component 52C, the inner mold component 52B and the inner mold component 52C are then lowered integrally. Thus, a second cavity space 56 that is surrounded by the top plate 14T, the inner mold component 52D, and the inner mold component 52C and that continues from the first cavity space 54 is configured. The lowering amount L1 of the inner mold structure 52B and the inner mold structure 52C is, for example, approximately the same as the width W1 of the first cavity space 54 (see FIG. 7).

  Here, when the resin material is continuously supplied from the material supply gate 58, the resin material also flows into the second cavity space 56. As a result, a thick base portion 46 having a thick base portion 44 of the neck portion 18 is formed below the top portion 14T in the neck portion 18 and the vicinity thereof. The base thick portion 46 reinforces the top plate 14 </ b> T in the vicinity of the base portion 44.

  Then, with the neck thick portion 42 and the root thick portion 46 formed, the inner mold 52 and the outer mold 62 are removed, and the insertion hole 36 is formed in the center of the extended portion 20. Thereby, the upper fuel tank constituting body 16A molded into a desired shape is obtained.

  Also, the lower fuel tank constituting body 16B is formed into a desired shape (a convex shape downward) using an inner mold and an outer side (not shown). Then, the upper fuel tank constituting body 16A and the lower fuel tank constituting body 16B are joined together to obtain the substantially box-shaped fuel tank 12 as a whole.

  In the fuel tank 12 of the present embodiment manufactured as described above, the pump module 30 is inserted from the insertion hole 36, and the mounting flange 30F is brought into contact with and supported by the support surface 20S. When the retainer 34 is screwed into the neck portion 18, the gasket 32 is pushed downward by the mounting flange 30F, and the gap between the mounting flange 30F and the fuel tank 12 (gasket 32) is sealed with high sealing performance.

  The concave portion 26 (thin layer portion 28) is supported and reinforced by the neck thick portion 42, and the neck portion 18 is also reinforced by the neck thick portion 42. Therefore, even if the thin layer portion 28 receives a pressing force downward from the gasket 32, a reaction force against the pressing force can be secured, and the deformation of the thin layer portion 28 (and the extension portion 20) is suppressed, so that the recess 26 is formed. The extended portion 20 can be formed with high accuracy. Thereby, it becomes possible to ensure high sealing performance between the mounting flange 30F and the fuel tank 12 (gasket 32).

  In addition, in order to ensure such a high sealing performance, a separate member such as a conventional annular member is not required, so that the fuel tank 12 can have a small number of parts and can be configured at low cost.

  In particular, since the neck portion reinforcing portion 42 is formed on the radially inner side of the neck portion 18, the neck portion 18 is compared with a configuration in which the neck portion 18 is formed on the radially outer side of the neck portion 18 to reinforce the neck portion 18. Can be miniaturized.

  In addition, in the fuel tank 12 of this embodiment, the root portion 44 of the neck portion 18 is reinforced by the root portion thick portion 46. When an external force acts on the neck portion 18 from the outside, a moment may also act on the root portion 44, but the root portion 44 is reinforced by the thick portion 46 of the root portion, and the strength and rigidity are improved. By suppressing the deformation of the root portion 44, the reliability of the retainer 34 to the neck portion 18 and the attachment of the pump module 30 is improved. Since a member for reinforcing the base portion 44 is not required, the fuel tank 12 can be configured with a reduced number of parts and at a low cost.

  As described above, the fuel tank 12 of the present embodiment is configured so that the retainer 34 is screwed into the male threaded portion 38, thereby ensuring the reaction force of the gasket 32 and ensuring the strength and rigidity of the neck 18. The substantial plate thickness of the root portion 44 can be set by the neck thick portion 42 and the root thick portion 46. Since it is not necessary to increase the plate thickness of the fuel tank structure 16 in a portion (general portion 14G) other than the neck portion 18 and the base portion 44, the fuel tank 12 can be configured with a light weight and a low cost.

  In the above description, the fuel tank 12 in which both the neck thick part 42 and the base thick part 46 are formed is described. However, even if the fuel tank does not have the base thick part 46, the fuel tank 12 may be extended. It is possible to reinforce the protruding portion 20 and the neck portion 18 and to suppress the deformation of the thin layer portion 28 to ensure high sealing performance between the mounting flange 30F and the fuel tank 12 (gasket 32).

  In the case of manufacturing a fuel tank in which the base thick portion 46 is not formed, the inner structure 52B is lowered and its upper part is flush with the upper part of the inner structure 52C (FIG. 7). (See), the lowering of the inner structure 52B and the supply of the resin material from the material supply gate 58 may be stopped, and the inner mold 52 and the outer mold 62 may be removed.

  In the above manufacturing method, the base thick portion 46 is formed after the neck thick portion 42 is formed, but a manufacturing method in which these are formed at the same time may be used. For example, before supplying the resin material 60 from the material supply gate 58, the inner mold components 52 </ b> B and 52 </ b> C are first lowered to the position shown in FIG. 8 to form the first cavity space 54 and the second cavity space 56. If the resin material 60 is supplied from the material supply gate 58 in this state, the neck thick part 42 and the root thick part 46 can be formed substantially simultaneously.

  Further, the reinforcing portion of the present invention does not need to be continuously formed in the circumferential direction on the inner peripheral side of the neck portion 18 like the above-described thick neck portion 42. For example, the reinforcing portion has a predetermined interval in the circumferential direction. It may be formed intermittently.

DESCRIPTION OF SYMBOLS 12 Fuel tank 14 Fuel tank main body 16 Fuel tank structure 18 Neck part 20 Extension part 22A Outer resin layer 22C Inner resin layer 24A Barrier layer 26 Recess 28 Thin layer part 42 Neck part thick part (reinforcement part)
44 Root part 46 Root part thick part (reinforcement part)
52 Inner mold 54 First cavity space 56 Second cavity space 58 Material supply gate 60 Resin material 62 Outer mold

Claims (6)

An outer resin layer that forms the outside of the fuel tank, an inner resin layer that forms the inner side of the fuel tank, and the outer resin layer and the inner resin layer made of a material having lower fuel permeability than the outer resin layer and the inner resin layer. A fuel tank manufacturing method for manufacturing a fuel tank composed of a fuel tank structure including a barrier layer disposed between
A fuel tank manufacturing method in which an annular recess in which the outer resin layer is partially thinned is formed outside the fuel tank by compressing the fuel tank structure with an outer mold and an inner mold.   When the fuel tank structure is compressed by the outer mold and the inner mold, the fuel tank structure is protruded in a cylindrical shape, and extends radially inward of the neck from the protruding tip side of the neck. The fuel tank manufacturing method according to claim 1, wherein the extending portion is formed, and the extending portion is compressed by an outer mold and an inner mold to form the recess.   After forming the concave portion, the inner mold of the portion located radially inward of the neck portion and inside the fuel tank of the concave portion is retracted to form a first cavity space between the fuel tank constituting body and the first cavity space. The fuel tank manufacturing method according to claim 2, wherein the thickness of the neck portion is increased by supplying a resin material to the first cavity space.   A second cavity space is formed between the fuel tank constituent body by retreating the inner mold at a portion located radially inward of the neck portion inside the fuel tank from the neck portion, and the second cavity space. The fuel tank manufacturing method of Claim 2 or Claim 3 which increases the thickness of the base part of a neck part by supplying a resin material to. An outer resin layer and an inner resin are formed by an outer resin layer constituting the outside of the fuel tank, an inner resin layer constituting the inner side of the fuel tank, and the outer resin layer and a material having lower fuel permeability than the inner resin layer. A fuel tank body comprising a fuel tank structure having a barrier layer disposed between the fuel tank and the outer shell of the fuel tank;
A neck portion in which the fuel tank structure protrudes in a cylindrical shape from the fuel tank body;
An extending portion extending radially inward of the neck from the protruding tip side of the neck,
An annular recess in which the outer resin layer is partially thinned outside the fuel tank in the extension portion;
A reinforcing portion that is integrally provided with the fuel tank constituting body radially inward of the neck portion and inside the fuel tank of the recess, and that reinforces the extending portion continuously with the extending portion;
Having fuel tank.   6. The fuel tank according to claim 5, wherein the reinforcing portion extends from the inside of the fuel tank of the neck portion to a root portion of the neck portion.

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