Device for manufacturing cladded tubes and method for manufacturing cladded tubes

Abstract

To achieve both shrinkage control of the foam sheet and proper joining of the side edges of the foam sheet to each other.SOLUTION: The manufacturing device 20 has a conveying section 22 that conveys the resin tube 12 and the foam sheet 14 in contact with each other, a heating section 24 that heats the side edges of the foam sheet 14, a forming section 26 that guides the foam sheet 14 to wrap around the outer circumference of the resin tube 12 during conveying by the conveying section 22 and also butt-joints the side edges of the foam sheets 14 heated in the heating section 24. The forming section 26 has a pressing portion 42 that presses a portion of the circumferential range of the foam sheets 14, including the side edges butted against each other, toward the resin tube 12.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This invention relates to an apparatus for manufacturing a coated pipe and a method for manufacturing a coated pipe.

Background Art

[0002] A coated pipe obtained by coating a resin pipe with a resin foam material is used as a pipe for water supply and hot water supply. The coated pipe is manufactured by continuously feeding a resin pipe and a foam sheet, passing them through a cylindrical former, winding the foam sheet around the resin pipe, joining both ends of the foam sheet by heat fusion, and continuously pulling the coated pipe with a take-up machine.

[0003] According to the above method, the foam material that has passed through the cylindrical former is stretched by the pulling force of the take-up machine. Then, after the stretched foam material passes through the take-up machine, it contracts in the longitudinal direction of the resin pipe. Therefore, a method has been proposed to suppress the shrinkage of the foam material by making the difference between the feeding speed of the coated pipe and the feeding speed of the resin pipe within 2% (see Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the method of Patent Document 1, when the difference between the feeding speed of the coated pipe and the feeding speed of the resin pipe is greater than 2%, the bonding strength of the heat fusion part at both ends of the foam sheet becomes weak.

[0006] In view of the above problems in the prior art, the present invention has been proposed to preferably solve these problems, and an object thereof is to provide a manufacturing apparatus for a coated tube capable of achieving both suppression of shrinkage of a foam sheet and appropriate joining of side edges of the foam sheet, and a manufacturing method for the coated tube.

Means for Solving the Problems

[0007] A first aspect of the manufacturing apparatus for a coated tube according to the present invention is a manufacturing apparatus for a coated tube including a non-foamed resin tube and a foam sheet covering the outer peripheral surface of the resin tube, a conveying unit that conveys the resin tube and the foam sheet in a state where they are in contact with each other, a heating unit that heats side edges of the foam sheet, a forming unit that guides the foam sheet to be wound around the outer peripheral surface during conveyance by the conveying unit, and abuts and joins the side edges of the foam sheet heated by the heating unit with each other, and the gist is that the forming unit has a pressing unit that presses a partial range in the circumferential direction including the side edges abutted with each other in the foam sheet toward the resin tube side.

[0008] A second aspect of the manufacturing apparatus for a coated tube according to the present invention is, in the first aspect, the forming unit may have a pressing adjustment unit that can adjust the pressing amount of the foam sheet by the pressing unit.

[0009] A third aspect of the manufacturing apparatus for a coated tube according to the present invention is, in the second aspect, the forming unit has a plurality of the pressing adjustment units arranged apart from each other in the conveying direction of the foam sheet, and each pressing adjustment unit may be capable of adjusting the pressing amount respectively.

[0010] A fourth aspect of the manufacturing apparatus for a coated tube according to the present invention is, in any one of the first aspect, the second aspect, and the third aspect, the conveying unit a feeding unit that feeds the resin tube toward the forming unit, a take-up part that takes out from the molding part a coated pipe in which the resin pipe is coated with the foam sheet; The take-up speed by the take-up part may be made faster than the feed speed by the feeding part.

[0011] A fifth aspect of the manufacturing apparatus of the coated pipe according to the present invention is, in the fourth aspect, The transport part may make the speed difference between the take-up speed and the feed speed larger than 2.1%.

[0012] One aspect of the manufacturing method of the coated pipe according to the present invention is While conveying a non-foamed resin pipe and a foam sheet in a state where they are in contact with each other, by winding the foam sheet whose side edges are heated around the resin pipe at a molding part and butting and joining the side edges of the foam sheet, it is a manufacturing method of a coated pipe that coats the outer peripheral surface of the resin pipe with the foam sheet, When passing through the molding part, the gist is to press a partial range in the circumferential direction including the side edges butted with each other in the foam sheet toward the resin pipe side by a pressing part provided in the molding part.

Effect of the Invention

[0013] According to the manufacturing apparatus of the coated pipe according to the present invention, it is possible to achieve both suppression of shrinkage of the foam sheet and appropriate joining of the side edges of the foam sheet. According to the manufacturing method of the coated pipe according to the present invention, it is possible to achieve both suppression of shrinkage of the foam sheet and appropriate joining of the side edges of the foam sheet.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0015] Next, a preferred embodiment of the coating tube manufacturing apparatus and the coating tube manufacturing method according to the present invention will be described below with reference to the accompanying drawings. It should be noted that the embodiments and drawings described below are examples of a part of the embodiments of the present invention, and are not used for the purpose of limiting to these configurations, and can be appropriately changed without departing from the gist of the present invention.

Example

[0016] As shown in Fig. 1, the manufacturing apparatus 20 according to the embodiment manufactures a coated pipe 10 including a resin pipe 12 and a foam sheet 14 covering the outer peripheral surface of the resin pipe 12. The coated pipe 10 is used, for example, for pipes for water supply and drainage, pipes for air conditioning, etc., and the foam sheet 14 disposed on the outer periphery improves the heat insulation and protects the resin pipe 12. The coated pipe 10 is not particularly limited, but is formed, for example, by winding a foam sheet 14 having a thickness of about 3 mm to 20 mm around a resin pipe 12 having a diameter of about 10 mm to 50 mm. The resin pipe 12 is formed of a non-foamed resin also called a solid. The resin pipe 12 is formed of, for example, a polyolefin resin such as polyethylene or a resin such as vinyl chloride. Further, the foam sheet 14 is formed of a foam such as polyurethane foam or polyolefin foam.

[0017] As shown in Fig. 1, the manufacturing apparatus 20 includes a conveying unit 22 that conveys the resin pipe 12 and the foam sheet 14 in a state of being in contact with each other, a heating unit 24 that heats the side edge of the foam sheet 14, and a molding unit 26 that guides the foam sheet 14 to be wound around the outer peripheral surface of the resin pipe 12. During the conveyance of the resin pipe 12 and the foam sheet 14 by the conveying unit 22, the manufacturing apparatus 20 heats the foam sheet 14 by the heating unit 24 and then joins the side edges of the foam sheet 14 by abutting them against each other under the guidance of the molding unit 26 to continuously form the coated pipe 10. The manufacturing apparatus 20 of the embodiment has a cooling unit 28 that supplies a cooling fluid such as water or air to the molding unit 26, and the foam sheet 14 with the side edges abutted and joined to each other can be cooled by the cooling fluid supplied from the cooling unit 28 during the passage through the molding unit 26.

[0018] The conveying unit 22 includes a feeding unit 30 that feeds out the resin tube 12 toward the molding unit 26, and a taking-up unit 32 that takes out the coated tube 10 with the foam sheet 14 coated on the resin tube 12 from the molding unit 26. The feeding unit 30 is arranged on the upstream side in the conveying direction from the molding unit 26, pulls out the resin tube 12 from the tube supply unit 34, and feeds it out toward the molding unit 26. The taking-up unit 32 is arranged on the downstream side in the conveying direction from the molding unit 26. By taking out the coated tube 10 from the molding unit 26, the foam sheet 14 is pulled out from the sheet supply unit 36 arranged on the upstream side in the conveying direction of the molding unit 26, and is conveyed in a state of being in contact with the resin tube 12 on the upstream side of the molding unit 26. Further, on the downstream side in the conveying direction of the taking-up unit 32, a product winding unit 38 for winding up the coated tube 10 is provided.

[0019] For the heating unit 24, known heating means such as a heater is used, for example. The heating unit 24 is arranged on the upstream side in the conveying direction from the molding unit 26. Here, it is preferable that the heating unit 24 is arranged close to the entrance of the molding unit 26 and heats the side edge of the foam sheet 14 immediately before it enters the molding unit 26.

[0020] As shown in FIGS. 2 and 3, the molding unit 26 includes a main body portion 40 having a through hole 40a through which the resin tube 12 and the foam sheet 14 pass, and a pressing portion 42 that presses a partial range in the circumferential direction including the side edges of the foam sheet 14 that are abutted against each other toward the resin tube 12 side. Further, the molding unit 26 includes a pressing adjustment portion 44 that can adjust the pressing amount of the foam sheet 14 by the pressing portion 42. The molding unit 26 of the embodiment guides both side edges of the foam sheet 14 arranged below the resin tube 12 to be lifted from the lower side to the upper side, and abuts the side edges of the foam sheet 14 against each other above the resin tube 12.

[0021] As shown in FIG. 2, the main body portion 40 is cylindrical and has a through hole 40a that penetrates in the conveying direction of the resin tube 12 and the foam sheet 14. An opening 46 connected to the through hole 40a is formed in the upper portion of the main body portion 40. The opening 46 is formed up to an intermediate position from the inlet to the outlet of the through hole 40a in the upper portion of the main body portion 40. Further, the main body portion 40 has a main body cooling port 48 connected to the through hole 40a on the downstream side in the conveying direction from the opening 46. The main body cooling port 48 is disposed on the outlet side of the through hole 40a in the main body portion 40 and is connected to the cooling portion 28. In the molding portion 26, the inside of the through hole 40a can be cooled by the cooling fluid supplied to the through hole 40a through the main body cooling port 48.

[0022] As shown in FIG. 3, the pressing portion 42 is fitted into the opening 46 of the main body portion 40, and a pressing surface 42a that abuts against the foam sheet 14 in the pressing portion 42 is disposed on the side of the through hole 40a. The pressing portion 42 is movably disposed on the side approaching the center of the through hole 40a (the lower side in the embodiment) or the side moving away from the center of the through hole 40a (the upper side in the embodiment), and the position of the pressing surface 42a in the through hole 40a can be adjusted in the radial inner and outer directions of the through hole 40a. Note that the pressing portion 42 in the embodiment is formed in a block shape that is long along the conveying direction.

[0023] The width of the pressing surface 42a is shorter than the circumference of the coating tube 10. The pressing surface 42a only needs to be able to press the side edges of the foam sheet 14 that are butted against each other and the periphery of the side edges. By doing so, it is possible to prevent the pressing portion 42 from applying excessive passing resistance to the foam sheet 14. Note that the pressing surface 42a may be a curved surface that conforms to the outer peripheral surface of the coating tube 10, but the pressing surface 42a in the embodiment is a flat surface.

[0024] As shown in FIG. 3, the pressing portion 42 has a pressing portion cooling port 50 that communicates with the through hole 40a. The pressing portion cooling port 50 is disposed at the central portion in the conveying direction in the pressing portion 42 and is connected to the cooling portion 28. In the forming portion 26, the through hole 40a can be cooled by the cooling fluid supplied to the through hole 40a through the pressing portion cooling port 50. Note that the cooling fluid supplied to the pressing portion cooling port 50 and the main body cooling port 48 may be the same or different. For example, by using water as the cooling fluid supplied from the pressing portion cooling port 50 and using air as the cooling fluid supplied from the main body cooling port 48, water can be removed by the air supplied from the downstream side in the conveying direction from the foam sheet 14 wetted with water on the upstream side in the conveying direction.

[0025] As shown in FIGS. 2 and 3, the forming portion 26 has two pressing adjustment portions 44 that are arranged apart from each other in the conveying direction of the foam sheet 14. Each pressing adjustment portion 44 can adjust the pressing amount of the foam sheet 14 by the pressing portion 42. The pressing adjustment portion 44 includes a gantry portion 52 that is provided above the pressing portion 42 and fixed to the main body portion 40, and an adjustment operation portion 54 that has a male screw 54a that meshes with a female screw 52a provided on the gantry portion 52. The lower end portion of the adjustment operation portion 54 is rotatably connected to the pressing portion 42. The pressing portion 42 of the embodiment is supported by two adjustment operation portions 54 that are arranged apart from each other in the conveying direction.

[0026] When the adjustment operation portion 54 is rotated, the adjustment operation portion 54 moves forward and backward in the vertical direction with respect to the gantry portion 52 due to the engagement between the female screw 52a and the male screw 54a. Along with this, the pressing portion 42 supported by the adjustment operation portion 54 moves forward and backward in the vertical direction (radially inward and outward directions of the through hole 40a). When the adjustment operation portion 54 on the upstream side in the conveying direction is rotated, the upstream side in the conveying direction of the pressing portion 42 moves in the vertical direction. When the adjustment operation portion 54 on the downstream side in the conveying direction is rotated, the downstream side in the conveying direction of the pressing portion 42 moves in the vertical direction. In this way, the pressing portion 42 can arrange the pressing surface 42a along the conveying direction (see FIG. 3(a)) or tilt the pressing surface 42a with respect to the conveying direction (see FIG. 3(b)) by the two pressing adjustment portions 44 that are arranged apart from each other in the conveying direction of the foam sheet 14.

[0027] As shown in FIG. 3, in the molding portion 26 of the embodiment, the diameter D2 of the through hole 40a is larger than the diameter D1 of the coating tube 10 (D2 > D1). Also, the vertical intervals D3 and D4 between the pressing surface 42a of the pressing portion 42 and the bottom of the through hole 40a are smaller than the diameter D1 of the coating tube 10 (D3 < D1, D4 < D1). In the embodiment, the diameter D2 of the virtual circle along the inner peripheral surface of the through hole 40a excluding the pressing portion 42 is set to be equal to or larger than the diameter D1 of the coating tube 10 to be manufactured. Therefore, when the foam sheet 14 passes through the through hole 40a, it is difficult for the foam sheet 14 to interfere with the main body portion 40 outside a partial range pressed by the pressing portion 42 in the foam sheet 14, and it is possible to prevent an excessive passing resistance from being applied to the foam sheet 14. Also, since there is a gap between the coating tube 10 on the outlet side of the through hole 40a in the main body portion 40, the cooling efficiency by the cooling fluid supplied from the main body cooling port 48 can be improved.

[0028] In the molding portion 26, by arranging the pressing surface 42a along the conveying direction, the pressing amount of the foam sheet 14 by the pressing portion 42 on the upstream side in the conveying direction becomes the same as the pressing amount of the foam sheet 14 by the pressing portion 42 on the downstream side in the conveying direction (see FIG. 3(a)). In the molding portion 26, by arranging the pressing surface 42a to be upwardly inclined from the upstream side to the downstream side in the conveying direction, the pressing amount of the foam sheet 14 by the pressing portion 42 on the upstream side in the conveying direction becomes larger than the pressing amount of the foam sheet 14 by the pressing portion 42 on the downstream side in the conveying direction (see FIG. 3(b)). In the molding portion 26, by arranging the pressing surface 42a to be downwardly inclined from the upstream side to the downstream side in the conveying direction, the pressing amount of the foam sheet 14 by the pressing portion 42 on the upstream side in the conveying direction becomes smaller than the pressing amount of the foam sheet 14 by the pressing portion 42 on the downstream side in the conveying direction. Here, according to the pressing portion 42 of the embodiment, since the pressing surface 42a is a flat surface, the pressing amount of the foam sheet 14 can be gradually changed from the upstream side to the downstream side in the conveying direction.

[0029] As described above, in the forming unit 26, the pressing amount of the foam sheet 14 by the pressing unit 42 can be adjusted. However, it is preferable that the pressing amount of the foam sheet 14 by the pressing unit 42 on the upstream side in the conveying direction is larger than the pressing amount of the foam sheet 14 by the pressing unit 42 on the downstream side in the conveying direction. In other words, it is preferable that the compression ratio ((D1 - D3) / D1) of the foam sheet 14 on the upstream side in the conveying direction is larger than the compression ratio ((D1 - D4) / D1) of the foam sheet 14 on the downstream side in the conveying direction. By increasing the pressing amount of the foam sheet 14 by the pressing unit 42 on the upstream side in the conveying direction, the side edges of the foam sheet 14 can be efficiently joined together. And by reducing the pressing amount of the foam sheet 14 by the pressing unit 42 on the downstream side in the conveying direction, it is possible to prevent excessive passing resistance from being applied to the foam sheet 14 by the pressing unit 42.

[0030] The manufacturing apparatus 20 can be driven and controlled independently of each other for the feeding unit 30 and the take-up unit 32, and the take-up speed of the coated tube 10 by the take-up unit 32 can be made different from or the same as the feeding speed of the resin tube 12 by the feeding unit 30. Further, the conveying unit 22 may set the speed difference between the take-up speed of the coated tube 10 and the feeding speed of the resin tube 12 to 2.0% or less, but the speed difference between the take-up speed of the coated tube 10 and the feeding speed of the resin tube 12 may also be made larger than 2.1%. Although not particularly limited, the take-up speed of the coated tube 10 and the feeding speed of the resin tube 12 may be 10 m / min or more.

[0031] When providing a speed difference between the take-up speed of the coating tube 10 by the take-up section 32 and the feeding speed of the resin tube 12 by the feeding section 30, it is preferable that the take-up speed of the coating tube 10 by the take-up section 32 is faster than the feeding speed of the resin tube 12 by the feeding section 30. Specifically, the set take-up speed V2 of the coating tube 10 set in the take-up section 32 may be made faster than the set feeding speed V1 of the resin tube 12 set in the feeding section 30 (V2 > V1). Also, it is preferable that the actually measured feeding speed V3 of the resin tube 12 measured by the first measuring section 56 (see FIG. 1) between the feeding section 30 and the molding section 26, the actually measured take-up speed V4 of the coating tube 10 measured by the second measuring section 58 (see FIG. 1) on the downstream side in the transport direction of the take-up section 32, and the set feeding speed V1 are the same (V1 = V3 = V4). In this case, the set take-up speed V2 becomes faster than the actually measured take-up speed V4 (V2 > V4).

[0032] Next, a method for manufacturing the coating tube 10 using the manufacturing apparatus 20 described above will be explained. As shown in FIG. 1, the resin tube 12 fed out from the tube supply section 34 is fed out by the feeding section 30 toward the molding section 26. By pulling the foam sheet 14 fed out from the sheet supply section 36 by the take-up section 32, the belt-like foam sheet 14 is conveyed toward the molding section 26 in a state of being in contact with the lower side of the resin tube 12 (see FIG. 4(a)). Both side edges of the foam sheet 14 are guided so as to be lifted from the lower side to the upper side by the molding section 26 as they approach the molding section 26, and the foam sheet 14 is gradually wound around the outer peripheral surface of the resin tube 12 (see FIG. 4(b)). Both side edges of the foam sheet 14 lifted to the upper side of the resin tube 12 come into contact with the heating section 24 before entering the molding section 26 (see FIG. 4(c)), and the side edges are melted by being heated by the heating section 24.

[0033] In the through-hole 40a of the forming part 26, the side edges of the foam sheet 14 surrounding the outer peripheral surface of the resin tube 12 are butted against each other, and in this state, the foam sheet 14 and the resin tube 12 pass through the through-hole 40a (see Fig. 5). When passing through the through-hole 40a of the forming part 26, a partial range in the circumferential direction including the side edges butted against each other in the foam sheet 14 is pressed against the resin tube 12 side (lower side) by a pressing part 42 provided at the upper part of the through-hole 40a in the forming part 26 (see Fig. 6). Then, the butted side edges of the foam sheet 14 are crimped in a state where they are in surface contact with each other, and in this state, the melted side edges are cured, so that the side edges of the foam sheet 14 are joined to form a tubular shape. Thereby, a coated tube 10 in which the outer peripheral surface of the resin tube 12 is covered with the foam sheet 14 is formed (see Fig. 7). Here, since the pressing part cooling port 50 is arranged at an intermediate position in the conveying direction in the pressing part 42, cooling by the cooling fluid from the pressing part cooling port 50 can be started at a relatively early stage after the butted side edges of the foam sheet 14 are crimped.

[0034] The coated tube 10 is pulled by the take-up part 32 and pulled out from the forming part 26. The coated tube 10 pulled out from the forming part 26 is continuously taken up by the take-up part 32 and wound around the product winding part 38. According to the manufacturing method, while conveying the resin tube 12 and the foam sheet 14 in a butted state, the foam sheet 14 with the side edges heated is wound around the resin tube 12 at the forming part 26, and the side edges of the foam sheet 14 are butted and joined, so that the coated tube 10 covering the outer peripheral surface of the resin tube 12 with the foam sheet 14 can be continuously manufactured.

[0035] The forming section 26 has a pressing portion 42 that presses a partial range in the circumferential direction including the side edges of the foam sheet 14 that are butted against each other toward the resin tube 12 side. Since the resin tube 12 is a non-foam material, the pressing portion 42 can appropriately press the foam sheet 14 that is a foam material. When passing through the forming section 26, the pressing portion 42 does not press the entire foam sheet 14 from the circumferential direction, but presses it within a range necessary for joining the side edges of the foam sheet 14. Thereby, the side edges of the foam sheet 14 can be appropriately joined by the pressing of the pressing portion 42. Further, since the pressing range of the foam sheet 14 by the pressing portion 42 is narrow, the passing resistance applied to the foam sheet 14 when passing through the through hole 40a can be reduced. Therefore, since the delay and stretching of the foam sheet 14 caused by passing through the through hole 40a can be suppressed, the shrinkage of the foam sheet 14 in the coated tube 10 drawn out from the forming section 26 can be suppressed. Therefore, according to the manufacturing apparatus 20 and the manufacturing method described above, it is possible to achieve both suppression of shrinkage of the foam sheet 14 and appropriate joining of the side edges of the foam sheet 14.

[0036] The forming section 26 has a pressing adjustment portion 44 that can adjust the pressing amount of the foam sheet 14 by the pressing portion 42. By adjusting the pressing amount of the foam sheet 14 by the pressing portion 42 by the pressing adjustment portion 44, it is possible to adjust the balance between appropriate joining of the side edges of the foam sheet 14 passing through the forming section 26 and reduction of the passing resistance of the foam sheet 14 passing through the forming section 26. The forming section 26 of the embodiment has a plurality of pressing adjustment portions 44 arranged apart from each other in the conveyance direction of the foam sheet 14, and each pressing adjustment portion 44 can adjust the pressing amount of the foam sheet 14 by the pressing portion 42. In this way, an appropriate pressing amount corresponding to the degree of joining of the side edges that progresses as the foam sheet 14 passes through the forming section 26 moves from the upstream side to the downstream side in the conveyance direction can be applied to the foam sheet 14 passing through the forming section 26 by the pressing portion 42.

[0037] By making the drawing speed of the coating tube 10 by the drawing section 32 faster than the feeding speed of the resin tube 12 by the feeding section 30, it is possible to return the foam sheet 14 that has been delayed due to the passing resistance in the through hole 40a in the molding section 26. And when the coating tube 10 exits from the drawing section 32, the speeds of the resin tube 12 and the foam sheet 14 can be approximately made to coincide. Specifically, by providing a speed difference between the feeding speed of the foam sheet 14 (= the drawing speed of the coating tube 10) and the feeding speed of the resin tube 12, even when the foam sheet 14 shrinks after the drawing of the coating tube 10 by the drawing section 32, the shrinkage can be offset by the above speed difference, and after the shrinkage of the foam sheet 14, the speeds of the resin tube 12 and the foam sheet 14 can be approximately made to coincide. As described above, in the molding section 26, while ensuring the joining strength between the side edges of the foam sheet 14, the passing resistance of the foam sheet 14 can be reduced, and it is also possible to make the shrinkage rate of the foam sheet 14 in the coating tube 10 3.0% or less. By achieving such a low shrinkage rate, the yield can be improved.

[0038] As described above, since it is possible to reduce the passing resistance of the foam sheet 14 while ensuring the joining strength between the side edges of the foam sheet 14 in the molding section 26, even if the conveying section 22 makes the speed difference between the drawing speed of the coating tube 10 and the feeding speed of the resin tube 12 larger than 2.1%, it is possible to reduce the adverse effect of the passing resistance of the foam sheet 14 while appropriately joining the side edges of the foam sheet 14 in the molding section 26. Thus, by increasing the speed difference between the drawing speed of the coating tube by the drawing section 32 and the feeding speed of the resin tube 12 by the feeding section 30, the shrinkage rate of the foam sheet 14 in the coating tube 10 can be made lower, and since the line speed can be improved, the manufacturing efficiency of the coating tube 10 can be improved.

[0039] (Modified example) Not limited to the above-described matters, for example, it may be as follows. Note that the present invention is not limited only to the specific descriptions of the embodiments and the following modified examples. (1) In the embodiment, one pressing part is arranged, but it is not limited thereto. For example, a plurality of pressing parts may be arranged side by side in the conveying direction. In this case, the pressing amount of the foam sheet may be adjustable for each of the plurality of pressing parts. (2) In the embodiment, one pressing part is configured such that the pressing amount can be adjusted by two pressing adjustment parts, but it is not limited thereto. The pressing amount of one pressing part may be adjusted by one pressing adjustment part, or the pressing amount of one pressing part may be adjusted by three or more pressing adjustment parts. (3) The pressing adjustment part of the embodiment is configured to change the pressing amount by moving the pressing part by a screw mechanism, but it is not limited thereto. Other mechanisms capable of adjusting the pressing amount of the pressing part may be used. (4) In the embodiment, while the resin tube is in contact with the upper side of the foam sheet and being conveyed, the side edge of the foam sheet is joined above the resin tube, but it is not limited thereto. While the resin tube is in contact with the lower side of the foam sheet and being conveyed, the side edge of the foam sheet may be joined below the resin tube, or while the resin tube is in contact with one lateral side of the foam sheet and being conveyed, the side edge of the foam sheet may be joined on the other lateral side of the resin tube. The arrangement of the resin tube and the foam sheet can be changed.

Explanation of Reference Numerals

[0040] 10 Coating tube, 12 Resin tube, 14 Foam sheet, 20 Manufacturing apparatus, 22 Conveying part, 24 Heating part, 26 Forming part, 30 Feeding part, 32 Taking-up part, 42 Pressing part, 44 Pressing adjustment part

Claims

1. A manufacturing apparatus for a coated tube including a non-foamed resin tube and a foamed sheet covering the outer peripheral surface of the resin tube, a conveying unit that conveys the resin tube and the foamed sheet in a contacting state, a heating unit that heats side edges of the foamed sheet, and a forming unit that guides the foamed sheet to be wound around the outer peripheral surface during conveyance by the conveying unit, and joins side edges of the foamed sheet heated by the heating unit by butting them against each other. The forming unit has a pressing unit that presses a partial range in the circumferential direction including the side edges butted against each other in the foamed sheet toward the resin tube side, in the manufacturing apparatus for a coated tube.

2. The manufacturing apparatus for a coated tube according to claim 1, wherein the forming unit has a pressing adjustment unit that can adjust a pressing amount of the foamed sheet by the pressing unit.

3. The forming unit has a plurality of the pressing adjustment units arranged apart from each other in the conveying direction of the foamed sheet, and each pressing adjustment unit can adjust the pressing amount respectively, in the manufacturing apparatus for a coated tube according to claim 2.

4. The conveying unit includes a feeding unit that feeds the resin tube toward the forming unit, and a taking-up unit that takes up a coated tube in which the foamed sheet is coated on the resin tube from the forming unit, and the manufacturing apparatus for a coated tube according to claim 1, wherein a taking-up speed by the taking-up unit is made faster than a feeding speed by the feeding unit.

5. The manufacturing apparatus for a coated tube according to claim 4, wherein a speed difference between the taking-up speed and the feeding speed is made larger than 2.1%.

6. A method for manufacturing a coated tube that coats an outer peripheral surface of a resin tube with a foam sheet, the method comprising: while conveying a non-foamed resin tube and a foam sheet in a state of being in contact with each other, heating side edges of the foam sheet and winding the foam sheet around the resin tube at a forming portion to butt and join the side edges of the foam sheet, A method for manufacturing a coated tube, wherein when passing through the forming portion, a pressing portion provided in the forming portion presses a partial range in the circumferential direction including side edges of the foam sheet that are butted against each other toward the resin tube side.

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