JP2007285347A - Composite tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite tube having anisotropy in the circumferential direction and handled in the same manner as normal tubes. <P>SOLUTION: This composite tube is formed in a tubular shape by arcuate parts 2, 3 made of two or more types of thermoplastic resins A, B with different characteristics in the circumferential direction. Therefore, the composite tube has an anisotropy by the resins A, B with different characteristics in the circumferential direction. Since the composite tube is not visually different from the normal tubes, they can be handled in the same manner as the normal tubes. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a composite pipe used such as a drain pipe.

Conventionally, as a composite tube having anisotropy with different characteristics in the circumferential direction, for example, as shown in Patent Document 1, the inner layer made of a soft material having a substantially smooth inner circumferential surface and the outer circumferential surface of the inner layer are crossed. A surface S-shaped band-shaped body is composed of an outer layer made of a hard material that is spirally wound with its edges connected to each other. There has been proposed a flexible tube in which a bending restricting piece having a fitting portion that can be fitted is fitted.
Japanese Patent No. 3132800

  However, in the above-mentioned flexible tube, a special joint is necessary because the bending restriction piece is attached to increase the strength of the portion to which the bending restriction piece is attached and to have anisotropy in the circumferential direction of the pipe. In addition, when performing construction such as connection work, it is necessary to devise a device different from conventional pipe construction, which reduces workability and increases costs. Further, in order to give anisotropy, secondary processing is necessary, and there is a disadvantage that the molding cost increases.

  The present invention has been made in view of such problems, and provides a composite pipe that has anisotropy in the circumferential direction and can be handled in the same manner as a normal pipe.

  The present invention is characterized in that it is formed into a tubular shape by two or more types of thermoplastic resins having different characteristics in the circumferential direction.

  According to the present invention, an anisotropy can be imparted in the circumferential direction by forming an arc portion of a resin having different characteristics in the circumferential direction. Therefore, the type, grade, number, and ratio of the resin may be selected according to the purpose of use of the composite pipe.

  Here, examples of the anisotropy include elastic modulus, linear expansion coefficient, specific heat, and thermal conductivity.

  According to the present invention, although it has anisotropy in the circumferential direction, it can be handled in the same manner as a normal tube.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows an embodiment of the composite tube 1 of the present invention.

  This composite pipe 1 is formed between a circular arc part 2 made of a thermoplastic resin A formed at a position opposite to each other at an angle of approximately 180 degrees and a constant angle range, and a circular arc part 2 facing each other. It is formed in a tubular shape by an arc portion 3 made of a thermoplastic resin B different from A.

  According to such a composite pipe 1, anisotropy due to the difference in resin can be imparted in the circumferential direction while maintaining a uniform cross-sectional circular shape in appearance. In addition, during construction, joints used for conventional ordinary pipes can be used, and handling is the same as for ordinary pipes, so that no extra cost increases.

  Specifically, in the composite tube 1 shown in FIG. 1, the thermoplastic resin A is polyethylene having a tensile modulus of 800 MPa, the thermoplastic resin B is polyethylene having a tensile modulus of 300 MPa, and the thermoplastic resin A And the thermoplastic resin B are set to have a volume ratio of 2: 8, and are molded to have an outer diameter of 27 mm and a wall thickness of 2.4 mm.

  The composite pipe 1 configured as described above was subjected to structural analysis by giving a forced bending radius of 500 mm in the vertical direction and the direction perpendicular to the vertical direction. The force required for this bending radius was 133N in the vertical direction and 124N in the horizontal direction. As a result, the composite pipe 1 has a property that it is easy to bend in the horizontal direction and is less likely to bend in the vertical direction than in the horizontal direction.

  A forming apparatus 10 for forming such a composite pipe 1 is shown in FIG. The molding apparatus 10 includes an extruder 11 for resin A, an extruder 12 for resin B, a merge block 13 for resin A extruded from the extruder 11 and a resin B extruded from the extruder 12, and a merge block 13. Are formed of a mold 14 for extruding the resin merged as a parison, a cooling water tank 15 for cooling the parison extruded from the mold 14, and a take-up machine 16 for taking out the cooled composite pipe 1.

  Here, the extruders 11 and 12, the mold 14, the cooling water tank 15, and the take-up machine 16 are the same as those used for forming a normal pipe, and the description thereof is omitted, and only the merging block 13 is described. .

  4 and 5, the merging block 13 includes a merging block main body 131 to which the extruder 11 is connected, a connecting block 132 that connects the merging block main body 131 and the extruder 12, a merging block main body 131, and a gold block. The connection block 133 is connected to the mold 14. 6 and 7, the merging block main body 131 is formed by joining the left and right block main bodies 131A and 131B, and is formed symmetrically with respect to the vertical plane including the central axis that is the joint surface. Yes. Each block main body 131A, 131B is formed with a partition wall 1311 extending in the front-rear direction and positioned in the vicinity of the joint surface, and a longitudinal section on the outer surface side (surface on the side separated from the joint surface) of the partition wall 1311. A substantially semicircular resin flow path 131 x communicates with the flow path 132 a of the connection block 132. Furthermore, the inner surface of the partition wall 1311 (the surface closer to the joint surface) has a weir 131s, and the resin flow path 131y that gradually becomes wider as the distance from the center increases to the inner diameter of the resin flow path 131x. It is formed over a corresponding height. For this reason, when joining each block main body 131A, 131B and forming the confluence | merging block main body 131, the vertically long resin flow path which consists of the two resin flow paths 131y is formed in the inner side of the right-and-left partition 1311. These resin flow paths 131x and 131y communicate with the flow path 133a of the connection block 133.

  Therefore, if the extruders 11 and 12 are driven and the resin A is pushed out from the extruder 11, the resin A flows into the resin flow path 131y of the merge block main body 131, the flow rate is adjusted by the weir 131s, and the tip of the resin A The resin is pushed out from the opening into the resin flow path 133a of the connection block 133. On the other hand, the resin B extruded from the extruder 12 is diverted to the resin flow paths 131x and 131x of the merge block 131 through the resin flow path 132a of the connection block 132, and the resin flow path 133a of the connection block 133 from their tip openings. Extruded.

  As a result, the resin A and the resin B are joined in the resin flow path 133a of the connection block 133 as shown in FIG. At this time, since the resin flow path 131y is formed wider as the distance from the center increases, the amount of the resin A increases toward the inner peripheral surface of the resin flow path 133a of the connection block 133.

  By molding the composite pipe 1 with such a molding apparatus 10, the resin is fused at the junction block 13 at a high pressure before flowing into the mold 14, so that the resin can be fused well. Moreover, when changing the structure of the composite pipe 1, it can respond by changing the junction block 13. FIG.

  As described above, according to the present invention, a composite pipe having anisotropy in the circumferential direction and capable of being handled in the same manner as a normal pipe can be obtained. can do.

It is a perspective view which shows one Embodiment of the composite pipe | tube of this invention. It is a front view of the composite pipe | tube of FIG. It is the schematic of the shaping | molding apparatus which shape | molds the composite pipe | tube of FIG. It is a perspective view which shows the confluence | merging block which comprises a shaping | molding apparatus. It is a disassembled perspective view of the merge block of FIG. It is a perspective view which shows the confluence | merging block main body of the confluence | merging block of FIG. It is the cross-sectional view cut | disconnected by the horizontal surface containing the centerline of the confluence | merging block main body of FIG. It is explanatory drawing which shows the joining state of resin A and resin B in the joining block of a shaping | molding apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Composite pipe 2 Arc part by resin A 3 Arc part by resin B 13 Merge block 131 Merge block body

Claims (1)

  A composite pipe characterized by being formed into a tubular shape by two or more types of thermoplastic resins having different characteristics in the circumferential direction.

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