JP6586903B2 - Manufacturing method of resin fuel tank - Google Patents

Description

  The present invention relates to a method for manufacturing a resin fuel tank.

  2. Description of the Related Art Conventionally, when manufacturing a resin fuel tank for an automobile, built-in components are attached to a sheet body made of a molten resin shaped with respect to upper and lower cavities. In this case, a part of the sheet body (molten resin) is inserted into a hole formed in the mounting seat of the built-in component and pushed out. The built-in parts were attached to the seat body by sandwiching the attachment seat between the expanded portion located at the top of the seat and the seat body located at the bottom of the seat (hereinafter, this clamping portion is referred to as the “crimped portion”) Sometimes). In this case, a part of the sheet body (molten resin) is collected from the surroundings and inserted into the hole of the mounting seat to form the crimped portion, so that the thickness of the sheet body (fuel tank) changes locally. There was a risk.

  Therefore, by pre-blowing in the opposite direction before shaping the sheet body into the cavity, an extra length portion is secured in the sheet body, and after the sheet body securing the extra length portion is shaped into the cavity, The movable member protrudes, and a part (extra length portion) of the sheet body is inserted into the hole of the mounting seat of the built-in component, and then the movable member is retracted and inserted by pressing with the pressure member from the opposite side. It has been proposed to form a crimped portion by expanding the top of the sheet body (see, for example, Patent Document 1). In this way, if the extra length portion is formed in advance in the seat body, a local change in the thickness of the fuel tank can be suppressed even if a part of the seat body is inserted into the hole of the mounting seat. .

Japanese Patent Laying-Open No. 2015-85916

  However, when configured as described above, a drive mechanism and a heater for driving the movable member and the pressure member are required for the split mold and the core, respectively, which complicates the structure of the mold and reduces the cost. Has the disadvantage of becoming higher.

  The present invention has been made in consideration of the above facts, and an object of the present invention is to provide a method for manufacturing a resin fuel tank that does not require a complicated mechanism and suppresses a local change in the thickness of the fuel tank.

  The invention according to claim 1 is a method of manufacturing a resin fuel tank in which a built-in component is attached to the resin fuel tank, wherein a recessed portion is formed at a built-in component mounting position on the bottom surface of the cavity of the split mold, and the recessed portion is disposed in the recessed portion. A first step of shaping a sheet body made of a molten resin in the cavity in a state where a plurality of movable nests having different radial positions are respectively disposed below the bottom surface; and Later, a second step of placing the built-in component mounting portion with the undercut shape portion protruding from the bottom surface on the recess, and the diameter of the plurality of movable nests after the second step A third step of raising the first movable nest arranged on the outer side in the direction toward the mounting portion, and bringing the sheet body into close contact with the outer peripheral portion of the mounting portion; and after the third step, Of the movable inserts, the first movable insert A second step of moving the second movable nest arranged radially inward toward the mounting portion and forming a design surface on the bottom surface side of the mounting portion; and after the fourth step, the plurality of Among the movable nests, a fifth step of raising the innermost third movable nest toward the mounting portion and filling the undercut shape portion formed on the bottom surface with molten resin, Is provided.

  According to this structure, the recessed part is formed in the built-in component attachment position of the bottom face of the cavity, and a plurality of movable inserts having different radial positions are arranged in the recessed part. The sheet body is shaped in the cavity with the movable nest disposed below the bottom surface in the recess, so that the sheet body is arranged to hang down in the recess at the bottom surface of the cavity. The portion that hangs down in the recess of the sheet body is the extra length portion.

  The mounting part for the built-in component is arranged on the recessed portion of the sheet body shaped in this state. An undercut shape portion having an undercut shape is formed on the bottom surface side of the attachment portion.

  Here, first, among the plurality of movable nests, the first movable nest arranged on the outermost radial direction is raised to the mounting part side of the built-in component, and the sheet body hanging in the recess is the bottom surface of the mounting part It adheres to the outer periphery of Thereby, the outer peripheral part of the bottom face of the attachment part is sealed with the molten resin (sheet body).

  Next, the second movable nest disposed on the radially inner side of the first movable nest is raised to the mounting portion side, so that the sheet body moves from the radially outer side to the radially inner side of the bottom surface of the mounting portion. Are closely attached, and the design surface on the bottom surface side of the mounting portion is formed. At this time, since the sheet body is already in close contact with the outer peripheral portion of the attachment portion, the sheet body (molten resin) is prevented from flowing out to the general surface or the like.

  Finally, by raising the innermost third movable nest to the attachment portion side, the extra length portion of the sheet body (molten resin) wraps around to the back side of the undercut shape portion formed on the bottom surface of the attachment portion, Filled with molten resin. As a result, the molten resin (sheet body) is solidified, whereby both surfaces of the undercut shape portion are sandwiched between the resins, and the attachment portion (built-in component) is fixed to the resin fuel tank.

  Thus, in the mounting method for a built-in component according to the present invention, a portion including an undercut shape portion formed in the built-in component by providing a surplus length portion in the sheet body when the sheet body is shaped and raising the movable nest Since a built-in component is attached by filling molten resin into the plate, it is possible to suppress local changes in the thickness of the fuel tank.

  In addition, by raising the movable nest in order from the outside to the inside of the built-in part, the sheet body (molten resin) does not escape upward from the outer periphery of the mounting part, but the undercut shape part of the mounting part It can be reliably filled up to the back side.

  Since the manufacturing method of the resin fuel tank according to the first aspect of the present invention has the above-described configuration, a local change in the thickness of the fuel tank can be suppressed without requiring a complicated mechanism.

It is a longitudinal section showing a resin fuel tank concerning one embodiment of the present invention. It is a principal part perspective sectional view showing the caulking part of the resin fuel tank concerning one embodiment of the present invention. It is a principal part perspective sectional view showing the attachment mechanism concerning one embodiment of the present invention. It is a principal part longitudinal cross-sectional view of the attachment mechanism which concerns on one Embodiment of this invention, and is a figure which shows the state before a sheet | seat body shaping. It is a principal part longitudinal cross-sectional view of the attachment mechanism which concerns on one Embodiment of this invention, and is a figure which shows a sheet | seat body shaping state. It is a principal part longitudinal cross-sectional view of the attachment mechanism which concerns on one Embodiment of this invention, and is a figure which shows the state which closely_contact | adhered the sheet | seat body to the outer peripheral part of the attachment seat. It is a principal part longitudinal cross-sectional view of the attachment mechanism which concerns on one Embodiment of this invention, and is a figure which shows the state which contact | adhered the sheet | seat body to the outer side of the undercut shape part of an attachment seat. It is a principal part longitudinal cross-sectional view of the attachment mechanism which concerns on one Embodiment of this invention, and is a figure which shows the state which contact | adhered the sheet | seat body to the undercut shape part of the attachment seat. It is a longitudinal section showing a caulking part of a resin fuel tank concerning one embodiment of the present invention. It is a principal part perspective sectional view which shows the completion state of the crimping | crimped part by the attachment mechanism which concerns on one Embodiment of this invention.

  A method for manufacturing a resin fuel tank according to an embodiment of the present invention will be described with reference to FIGS. In addition, each figure is typical and the illustration with a low relevance to the present invention is omitted.

  First, the structure of the resin fuel tank 10 (hereinafter referred to as “fuel tank 10”) according to the present embodiment will be briefly described, and then the manufacturing apparatus 40 will be described.

  As shown in FIGS. 1 and 2, the fuel tank 10 includes a bottom surface 12, a side surface 14 extending upward from an end portion of the bottom surface 12, and an upper surface 16 extending in the width direction from the upper end of the side surface 14. ing. For example, a built-in component 18 is fixed to the bottom surface 12 inside the fuel tank 10. The built-in component 18 includes a built-in component main body 20, a mounting seat 22 fixed to the bottom surface 12, and a connecting member 24 that connects the mounting seat 22 and the built-in component main body 20. As shown in FIGS. 2 and 9, the mounting seat 22 includes a disk-shaped mounting seat main body 26 and an undercut-shaped portion 28 that protrudes downward from the center of the lower surface (bottom surface) of the mounting seat main body 26. ing. The undercut shape portion 28 includes a columnar neck portion 30 that protrudes downward from the center of the lower surface of the mounting seat body 26, and a disk having a smaller diameter than the mounting seat body 26 that protrudes radially from the lower end of the neck portion 30. And a brim-shaped brim portion 32. The mounting seat body 26 has a hole 34 that penetrates the upper surface and the lower surface at a position around the neck 30. Further, a flange portion 36 is formed on the outer peripheral portion of the mounting seat body 26. The flange portion 36 is thinner than the center side (in the radial direction).

  A portion where the undercut shape portion 28 is inserted (locked) inside the resin body constituting the bottom surface 12 is referred to as a caulking portion 38. The built-in component 18 is formed of a material having a melting point higher than that of the molten resin so as not to be fused to a sheet body 110 (molten resin) described later.

  Next, the manufacturing apparatus 40 will be described. As shown in FIG. 3, the manufacturing apparatus 40 includes a plurality of split molds 42 (only a part of one split mold is illustrated), and the split mold 42 is formed with a cavity (concave part) 44. The cavity insert 46 is attached to a split mold body 48. At the mounting position of the built-in component 18 (mounting seat 22) on the bottom surface 44A of the cavity 44, a cylindrical recess extending from the bottom surface 44A through the cavity insert 46 to the bottom surface 50 formed in the split mold body 48. 52 is formed. An attachment mechanism 53 that forms a crimped portion 38 by attaching a built-in component 18 (attachment seat 22) to a sheet body 110 (fuel tank 10) to be described later is formed in the recess 52.

  As shown in FIGS. 3 and 4, the bottom surface 50 of the recess 52 is formed in a ring-shaped first bottom surface 54 that is one step lower than the top surface 48 </ b> A of the divided mold main body 48, and on the radially inner side of the first bottom surface 54. And a ring-shaped second bottom surface 56 that is one step lower than the one bottom surface 54. In the center of the second bottom surface 56, a hole 58 through which a third movable insert 90 described later is inserted is formed.

  The side surface (outer peripheral surface) of the cylindrical recess 52 is formed at the center of the guide portion 60 in the vertical direction of the guide portion 60 that guides a first movable insert 66 described later in the vertical direction and has a larger diameter than the guide portion 60. It consists of an enlarged diameter part 62. A restricting member 64 that protrudes radially inward from the enlarged diameter portion 62 and regulates the downward movement amount of the first movable insert 66 is disposed at the lower end of the enlarged diameter portion 62.

  In the following description, the up-down direction is the axial direction of the recess 52, the upper direction is the cavity 44 side, and the lower direction is the bottom surface 50 side.

  A cylindrical first movable insert 66 is disposed on the outer peripheral surface side of the recess 52. The outer peripheral surface of the first movable insert 66 has a sliding portion 67 whose upper portion has an outer diameter corresponding to the inner diameter of the guide portion 60 of the concave portion 52, and the outer diameter of the first movable insert 66 protrudes radially outward below the sliding portion 67. A bulging portion 68 having an outer diameter corresponding to the inner diameter of the portion 62, and a reduced diameter portion 69 having a reduced diameter so as not to interfere with the regulating member 64 below the bulging portion 68. The vertical height of the bulging portion 68 is shorter than the vertical height of the enlarged diameter portion 62. Therefore, the amount of vertical movement of the first movable nest 66 is restricted by disposing the bulging portion 68 in the enlarged diameter portion 62.

  The inner peripheral surface of the first movable insert 66 includes an upper small-diameter portion 70 and a large-diameter portion 72 having a diameter larger than that of the small-diameter portion 70 below the small-diameter portion 70. At the lower end of the large diameter portion 72, a restricting member 74 for restricting the amount of downward movement of the second movable insert 76, which will be described later, is disposed so as to protrude radially inward from the large diameter portion 72. .

  A cylindrical second movable insert 76 is disposed inside the small diameter portion 70 and the large diameter portion 72 of the first movable insert 66. The outer peripheral surface of the second movable insert 76 has a sliding portion 78 whose upper side has an outer diameter corresponding to the inner diameter of the small diameter portion 70 of the first movable insert 66, and a sliding portion 78 below the sliding portion 78. In addition, a bulging portion 80 that protrudes outward in the radial direction and a reduced diameter portion 81 that is reduced in diameter so as not to interfere with the regulating member 74 below the bulging portion 80 are provided. The outer diameter of the bulging portion 80 corresponds to the inner diameter of the large diameter portion 72 of the first movable insert 66. The height in the vertical direction of the bulging portion 80 is shorter than the height in the vertical direction of the large diameter portion 72, and the lower end of the small diameter portion 70 (the upper end of the large diameter portion 72) and the upper end of the bulging portion 80. A coil spring 82 is disposed between the two.

  The inner peripheral surface of the second movable insert 76 includes an upper small diameter portion 84 through which a third movable insert 90 described later can be inserted, and a large diameter portion 86 having an inner diameter larger than the small diameter portion 84. A restricting member 88 for restricting the downward movement amount of the third movable insert 90 is provided at the lower end portion of the large diameter portion 86 so as to protrude radially inward from the large diameter portion 86.

  A cylindrical third movable insert 90 is inserted into the small diameter portion 84 and the large diameter portion 86 of the second movable insert 76. The third movable insert 90 includes a cylindrical column part 92 and a bulging part 94 that protrudes radially outward from the center of the column part 92 in the vertical direction. The bulging portion 94 has an outer diameter corresponding to the inner diameter of the large diameter portion 86 of the second movable nest 76, and the vertical height is shorter than that of the large diameter portion 86. A coil spring 96 is disposed between the lower end of the small diameter portion 84 (the upper end of the large diameter portion 86) and the upper end of the bulging portion 94 of the second movable insert 76. The shaft body 102 of the actuator 100 is fitted in the hole 98 at the lower end of the cylindrical portion 92. Therefore, the third movable insert 90 moves in the vertical direction together with the shaft body 102 by driving the actuator 100.

  Then, the manufacturing method of the resin fuel tank which attaches the built-in component 18 to the fuel tank 10 using the metal mold | die comprised in this way is demonstrated.

  First, the actuator 100 is driven to lower the shaft body 102 to the lower limit position, thereby lowering the third movable insert 90 to a position where the bulging portion 94 comes into contact with the regulating member 88. As a result, the second movable insert 76 supported by the third movable insert 90 via the coil spring 96 is also lowered to a position where the bulging portion 80 contacts the regulating member 74. Further, the first movable insert 66 supported by the second movable insert 76 via the coil spring 82 is also lowered to a position where the bulging portion 68 contacts the restriction member 64. As a result, as shown in FIGS. 3 and 4, the upper surface of the first movable insert 66 is located above the bottom surface 44 </ b> A of the cavity 44, the upper surface of the second movable insert 76 is located above the upper surface of the first movable insert 66, and the second It arrange | positions in a mortar shape so that the upper surface of the 3rd movable insert 90 may become a position lower than the upper surface of the movable insert 76. FIG.

  Next, the sheet body 110 made of the molten resin supplied to the split mold 42 is brought into close contact (vacuum shaping) with the bottom surface 44A of the cavity 44 by a negative pressure. At this time, as shown in FIG. 5, in the recess 52 formed in the bottom surface 44A of the cavity 44, the first movable insert 66 to the third movable insert 90 are retracted to a position lower than the bottom surface 44A. The shaped sheet body 110 hangs down into the recess 52, and an extra length portion 112 for forming the crimped portion 38 is formed.

  Subsequently, the built-in component 18 is installed at a predetermined position of the sheet body 110 formed on the bottom surface 44 </ b> A of the cavity 44. At this time, as shown in FIG. 6, the mounting seat 22 of the built-in component 18 is installed on the recess 52 (on the sheet body 110). In addition, since the flange part 36 whose plate | board thickness is thinner than the center side is formed in the outer peripheral part of the attachment seat main body 26, positioning of the attachment seat 22 becomes easy.

  After the installation of the built-in component 18 is thus completed, the actuator 100 is driven to raise the shaft body 102, whereby the third movable insert 90 is raised. As a result, the coil spring 96 disposed between the bulging portion 94 of the third movable insert 90 and the small diameter portion 84 of the second movable insert 76 is compressed. As a result, the second movable telescopic member 76 is biased upward and raised.

  As a result, the coil spring 82 disposed between the bulging portion 80 of the second movable insert 76 and the small diameter portion 70 of the first movable insert 66 is compressed. Thereby, the 1st movable insert 66 is urged | biased upwards, and is raised.

  Thus, by driving the actuator 100 to raise the shaft body 102, the first movable insert 66 to the third movable insert 90 move upward as shown in FIG. As a result, first, the uppermost first movable insert 66 presses the sheet body 110 against the outer peripheral portion of the lower surface of the mounting seat body 26.

  At this time, the outer diameter of the mounting seat body 26 is larger than the inner diameter of the recess 52. Further, the first movable insert 66 is restricted from moving upward by the upper end of the bulging portion 68 coming into contact with the lower end portion of the guide portion 60 (the upper end portion of the enlarged diameter portion 62). Therefore, when the first movable insert 66 moves upward, the molten resin flows out from the lower surface side of the mounting seat body 26 to the general surface, or the thickness of the fuel tank 10 becomes excessively thin locally. Can be prevented.

  Furthermore, by driving the actuator 100, the third movable insert 90 is raised together with the shaft body 102, as shown in FIG. Thereby, the upward biasing force by the coil spring 96 compressed by the rising of the third movable insert 90 is superior to the downward biasing force by the compressed coil spring 82, and the second movable insert 76 is moved upward. Move to.

  As a result, as shown in FIG. 7, the second movable nest 76 presses the sheet body 110 below the mounting seat body 26. That is, the sheet body 110 that has already been pressed against the outer peripheral portion of the lower surface of the mounting seat body 26 is pressed against the lower surface to the radially inner side (near the undercut shape portion 28). Since the sheet body 110 is continuously pressed against the lower surface of the mounting seat body 26 from the outer peripheral side in this way, the extra length portion 112 of the sheet body 110 is located above the third movable insert 90 (undercut shape portion 28). (Refer to FIG. 7).

  In this state, as shown in FIGS. 8 and 10, the actuator 100 is driven to move the shaft body 102 further upward, so that the third movable entry is performed against the downward biasing force of the coil spring 96. The child 90 moves upward. As a result, the extra length portion 112 of the sheet body 110 is pressed against the undercut shape portion 28 formed to protrude from the lower surface of the mounting seat body 26. At this time, since the sheet body 110 is already in close contact with a portion other than the undercut shape portion 28 on the lower surface of the mounting seat body 26, the molten resin constituting the extra length portion 112 of the sheet body 110 is below the flange portion 32. It wraps around the neck 30 from the side to the top.

  In addition, since the hole part 34 penetrated up and down is formed in the circumference | surroundings of the neck part 30 of the mounting seat main body 26, when molten resin has been filled, by discharging air from the hole part 34 to the upper surface side, The molten resin can be filled around the neck portion 30 without a gap.

  With the built-in component 18 attached to the sheet body 110 as described above, the split mold 42 is closed and the shaped sheet bodies are joined together to mold the resin fuel tank. Further, as shown in FIG. 9, the built-in component 18 is filled with molten resin on the upper side and the lower side of the undercut shape portion 28 (head portion 32) formed in the lower portion of the mounting seat body 26. Since the molten resin is solidified in the sandwiched state and the crimping portion 38 is formed, the built-in component 18 can be easily fixed to the fuel tank 10.

  In addition, the undercut shape portion is not formed by deforming the sheet body 110, but the undercut shape portion 28 is formed in the built-in component 18 (mounting seat 22), and the extra length of the sheet body 110 is formed in the undercut shape portion 28. Since the caulking portion 38 is formed by filling the molten resin in the portion 112, the thickness of the fuel tank 10 can be prevented or suppressed from greatly changing locally.

  In particular, when the sheet body 110 is shaped into the cavity 44, the first movable insert 66 to the third movable insert 90 are simply lowered into the recess 52 in the recess 52, and the extra length can be easily added to the sheet body 110. Portion 112 can be formed.

  The outer diameter of the mounting seat main body 26 is larger than the inner diameter (cross-sectional area) of the recess 52, and from the outer peripheral side of the mounting seat main body 26 in the order of the first movable insert 66 to the third movable insert 90. Since the sheet body 110 is pressed, the molten resin constituting the extra length portion 112 is prevented from flowing into the general surface from the outer peripheral portion of the mounting seat body 26 (around the upper side from the lower side of the mounting seat body 26). . In other words, the undercut shape portion 28 can be reliably filled with the molten resin by the extra length portion 112.

  Further, the attachment mechanism 53 for forming the crimping portion 38 has the first movable insert 66 to the third movable insert 90 driven by one actuator 100 in the recess 52 formed on the bottom surface 44 </ b> A of the cavity 44. Since only the configuration is provided, it is not necessary to provide an insert for forming the caulking portion 38 in the core between the divided molds, and the apparatus configuration is simplified.

  In the present embodiment, the mounting seat body 26 is formed in a circular shape, but the present invention is not limited to this. However, in terms of the extensibility of the sheet body 110 (molten resin), it is preferable that the mounting seat body 26 has a disk shape.

  Moreover, although the attachment mechanism 53 was formed from three movable inserts of the 1st movable insert 66 to the 3rd movable insert 90, it is not limited to this. However, it is preferable to form the sheet body 110 from the outer peripheral side of the mounting seat body 26 by forming it from at least three movable inserts.

  Furthermore, in this embodiment, although the hole 34 was provided in the attachment seat main body 26, it is not essential.

  In the present embodiment, the undercut shape portion 28 is provided on the mounting seat 22, but an undercut shape portion may be provided on the bottom surface of the built-in component main body 20.

DESCRIPTION OF SYMBOLS 10 Resin fuel tank 18 Built-in component 22 Mounting seat 28 Undercut shape part 42 Split mold 44 Cavity 44A Bottom face 52 Recess 66 First movable insert 76 Second movable insert 90 Third movable insert 110 Sheet body

Claims (1)

A method of manufacturing a resin fuel tank in which a built-in component is attached to the resin fuel tank,
In a state where a recessed portion is formed at a built-in component mounting position on the bottom surface of the cavity of the split mold, and a plurality of movable inserts having different radial positions disposed in the recessed portion are respectively disposed below the bottom surface, A first step of shaping a sheet of molten resin in the cavity;
After the first step, a second step of disposing the mounting part of the built-in component on which the undercut shape portion protrudes on the bottom surface on the concave portion;
After the second step, among the plurality of movable nests, the first movable nest arranged on the outermost radial direction is raised toward the mounting portion, and a sheet body is formed on the outer peripheral portion of the mounting portion. A third step of closely adhering
After the third step, of the plurality of movable nests, the second movable nest disposed radially inward of the first movable nest is raised toward the mounting portion, A fourth step of forming a design surface on the bottom side;
After the fourth step, among the plurality of movable nests, the innermost third movable nest is raised toward the mounting portion, and the undercut shape portion formed on the bottom surface is formed. A fifth step of filling the molten resin;
A method for manufacturing a resin fuel tank comprising:

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