JP3200750B2 - Method and apparatus for manufacturing pressure-resistant synthetic resin tube - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a synthetic resin pipe having excellent pressure resistance, which is mainly buried in the ground and used as water and sewage pipes, various drain pipes, culvert pipes, electric wire protection pipes, and the like. The present invention relates to a manufacturing apparatus.

[0002]

2. Description of the Related Art Conventionally, in order to improve the pressure resistance of a synthetic resin tube, a tube in which a metal strip is embedded in a tube wall of the synthetic resin tube has already been proposed. (For example, the actual opening 61-141
No. 889)

[0003] However, such a conventionally known synthetic resin pipe in which a metal strip is embedded in the pipe wall has a problem that the production of the pipe is complicated and there is room for improvement in production efficiency. There is room for enhancing the adhesiveness with the synthetic resin material that forms the wall, and the metal strip and the synthetic resin material may be separated by external pressure, and cracks occur in the synthetic resin wall in the separated portion. There was a problem that it was sometimes difficult to solve this problem.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of a synthetic resin pipe having a metal strip embedded in a pipe wall. An object of the present invention is to provide a method and an apparatus for manufacturing a synthetic resin tube which is easy to manufacture and can be efficiently manufactured when manufacturing a synthetic resin tube having no resin. Another object of the present invention is to provide a method for producing a synthetic resin tube having good adhesion between a metal strip and a synthetic resin material forming a tube wall, having both materials adhered firmly, and having high pressure resistance. And a manufacturing apparatus used for manufacturing such a synthetic resin tube.

[0005]

According to the present invention, a metal strip having a required width is used to enhance the pressure resistance of a synthetic resin pipe. Adhesion to a synthetic resin material that forms a tube wall by heating a metal-reinforced strip that has a thin-film-coated resin layer that has been previously thin-coated with a synthetic resin or resin paint on the peripheral surface or the front and back surfaces. The performance is enhanced, and the metal reinforcing strip is formed in a U-shaped cross section to improve the pressure resistance of the pipe.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; First
FIG. 1 is a plan view showing the overall arrangement of a device for manufacturing a synthetic resin tube according to the present invention, and FIG. 2 is a longitudinal sectional front view showing the structure of a tube forming portion for easy understanding. FIG. 3 is a cross-sectional view of the metal reinforcing strip, FIG. 4 is a cross-sectional view showing a process of forming the metal reinforcing strip into a U-shaped cross section over time, and FIG. FIG. 6 is a longitudinal sectional front view of a tube forming portion for explaining a method of manufacturing a tube, and FIG. 6 is a longitudinal sectional front view showing a structure of a tube wall portion of a tube formed by the method of the present invention.

As shown in FIG. 3, the metal strip used for the synthetic resin pipe of the present invention is formed on the entire front and back of the metal strip 1A having a required width of 0.15 to 2.0 mm, or over the entire circumference. A metal reinforcing strip having a thin-film-coated resin layer 1B, 1C formed by coating a thin film of a synthetic resin material or a resin coating material having good adhesiveness with a synthetic resin material forming a tube wall to a thickness of 0.1 to 1.0 mm. A plate 1 is formed. The metal reinforcing strip 1 thus formed is wound around a drum 11 as shown in FIG.

As shown in FIGS. 1 and 2, the apparatus for manufacturing a synthetic resin pipe according to the present invention mainly comprises
The metal reinforcing strip 1 is sequentially formed into a U-shaped cross section by a bending forming roll device 13 including a pair of bending forming rolls 13a, 13b, 13c, and 13d, and simultaneously formed into a spiral shape by self-winding. This bending forming roll device 13
The pipe forming device 21 is arranged beside the, and the bending forming roll device 1
A heating device 23 for heating the metal reinforcing strip 1 spirally wound by 3 is disposed so as to surround the transfer rod 23a in the tube forming device 21, and a hard synthetic resin strip A for forming the outer coating resin layer 2 of the tube. The first extruder 25 for extruding the resin is disposed beside the tube forming portion 24 of the tube forming device 21 and the hard synthetic resin strip A extruded from the nozzle portion 25a is formed on the metal reinforcing strip 1 on the forming rollers 24a, 24b. It is supplied above. Further, a second extruder 29 for extruding the synthetic resin strip B forming the internal resin layer 3 of the tube is arranged laterally outward of the rotary driving device 20, and a long tube 29b is connected to the extruding opening thereof. 29b is passed through the fixed pipe shaft 30 of the pipe forming apparatus 21 so that the nozzle 2
9a is arranged at the center of the tube forming portion 24 in the tube forming device 21, and the synthetic resin strip B is extruded from the nozzle portion 29a through the opening 30a of the fixed tube shaft 30 to the outer peripheral surface of the forming rollers 24a, 24b. There is a structure to supply.

The tube forming device 21 has a rotary drive device 20 on one end side, which is configured such that six or eight rotary shafts 20a, 20b... The rotation shaft 20 of the rotation drive device 20
a rod 22a provided with a guide roller (omitted in the drawing) at predetermined intervals in the axial direction, the end being connected to a universal joint 21a at one end by a universal joint 21a. The holding rod 22a that guides sequentially to the distal end side while temporarily holding the holding rod is arranged in an upwardly inclined shape.
A rod 23a provided with a guide roller (omitted in the drawing) at predetermined intervals in the axial direction, which is transferred from the holding rod 22a side, with one end connected to the universal joint 21b by a universal joint 21b so as to be driven to rotate. A transfer rod 2 that heats the spirally wound metal reinforcing strip 1 and guides it to the tube forming section 24 while sequentially moving the spirally wound metal reinforcing strip 1 in the heating device 23.
3a, a forming roller 24a connected to the transfer rod 23a by a universal joint 21c and rotationally driven, and one end connected to a rotating shaft 20b of the rotary driving device 20 by a universal joint 21d. A forming roller 24b connected to the other end of the rotation transmission shaft 23b via a universal joint 21e so as to be driven to rotate;
A plurality of forming rollers, each having five or seven rollers in the circumferential direction, are arranged in the same manner.

FIG. 1 shows a diagram in which seven rotation transmitting shafts 23b are arranged in the circumferential direction. These forming rollers 2
The spiral wound metal reinforcing strip 1 heated through the inside of the heating device 23 around 4a, 24b... Is inherited. As shown in FIG. 2, these forming rollers 2
4a, 24b... Are two support plates 31 fixed to the tube shaft 30.
Both ends are supported by a and 31b, and are arranged to be inclined and twisted in the same direction in the circumferential direction, and the twisting inclination automatically sends out the synthetic resin pipe P molded on the outer peripheral surface to the tip end side. I have to do it. First
In the figure, the part number 25b is a guide roller for the strip A, 26 is a press roller that presses against the valley of the strip A, and 27 is a supply of cooling air or cooling water for cooling the formed pipe P. The cooling device 28 is a support base on which a number of rollers 28a for supporting the formed pipe P are attached.

The invention of the method for manufacturing a synthetic resin tube according to the present invention is characterized in that the metal reinforcing strip 1 wound with the drum 11 is pulled out and the pair of bending forming rolls 13a, 13b, 13c in the bending forming roll device 13 is used. , 13d, are sequentially formed into a shape having a U-shaped cross section and the left and right side edges are extended in the horizontal direction as shown in FIGS. 4 (a) to (e) in FIG. A first step in which the metal reinforcing strip 1 thus formed is spirally wound and formed into a spiral shape, and the metal reinforcing strip 1 thus spirally wound in the tube forming apparatus 21 is raised. The second step of shifting around the tilt holding rod 22a and the rotation transmitting shaft 23b, and the metal reinforcing strip 1 inherited from the holding rod 22a is not guided by the transfer rod 23a in the pipe forming apparatus 21. A third step of shifting to the tube forming unit 24 while heating the metal reinforcing strip plate 1 wound in the spiral by successively migrating et heating device 23,
The heated spirally wound metal reinforcing strip 1 is connected to a pipe forming apparatus 2.
Plural forming rollers 24 in one tube forming section 24
a, 24b... and a hard synthetic resin extruded from the nozzle 25a of the first extruder 25 onto the spirally wound metal reinforcing strip 1 transferred onto the tube forming portion 24. A fifth step of spirally winding the band material A and bonding the band material to the band plate 1, and simultaneously forming side-by-side outer coating resin layers 2 by superimposing and connecting the side edges of the adjacent band materials A, A;
The synthetic resin strip B extruded from the nozzle part 29a of the second extruder 29 disposed inside the pipe forming part 24 is connected to the pipe shaft 3
Roller 24a, 24b through the opening 30a
And the spirally wound metal reinforcing strip 1 is guided and adhered to the inner surface of the strip 1, and at the same time, the side edges of the adjacent strips B, B are adhered to form a continuous internal resin layer 3. The pressure-resistant synthetic resin pipe P is manufactured by the sixth step of forming.

The synthetic resin pipe P thus manufactured
As shown in FIG. 6, the outer peripheral surface of the metal reinforcing strip 1 having a U-shaped cross section and the left and right side edges extending in the lateral direction was formed of a hard synthetic resin strip A. A spiral corrugated tube covered with an outer coating resin layer 2 and covered with a substantially straight inner resin layer 3 having an inner peripheral surface formed of a synthetic resin strip B;
The valley portion 4 located between the adjacent metal reinforcing strips 1 and 1 has a structure in which the inner and outer synthetic resin strips A and B are directly bonded.

A synthetic resin pipe P shown in FIG. 7 shows another embodiment of a pipe manufactured by the above-mentioned manufacturing method using the above-mentioned manufacturing apparatus of the present invention. An outer coating resin layer in which the left and right side edges are bent inward toward the center of the U shape and the outer peripheral surface of the metal reinforcing strip 1 is formed of a hard synthetic resin strip A. 2 to form an internal resin layer 3 between the metal reinforcing strips 1 and 1 adjacent to each other with the internal synthetic resin strip B and the inner peripheral surface of the bent portion of both strips 1 and 1. Has a spiral corrugated tube structure in which the internal resin layer 3 is not formed on the inner surface portion of the center portion of the metal resin strips 1, and the inner and outer synthetic resin strips A, B has a structure in which B is directly bonded.

As described above, the synthetic resin pipe manufactured by the manufacturing method of the present invention using the manufacturing apparatus of the present invention includes a pipe in which a straight tubular inner resin layer 3 is formed on the inner surface of the pipe and the inner resin layer 3.
Can be arbitrarily manufactured. Although not shown as an example, for example, in a pipe P having a structure shown in FIG. 6, the internal resin layer 3 is not formed into a straight pipe, Metal reinforcing strip 1 along the inner peripheral surface of metal reinforcing strip 1
It is also possible to form a tube in which both the inner and outer surfaces have a spiral wave shape with the structure adhered to the inner surface of the tube.

The pipe whose inner surface is a straight pipe as shown in FIG. 6 has a low flow resistance when passing water or other liquid or gas, and is suitable as a water and sewage pipe or a drain pipe. The pipe shown in FIG. 7 having an uneven inner surface has a low frictional resistance when a long linear member is drawn into the pipe, and thus is suitable as a cable protection pipe such as an electric wire or a telephone line. I have.

In the description of the above embodiment, whether the synthetic resin strip B forming the internal resin layer 3 is hard or soft is not particularly described, but the hardness may be arbitrarily selected depending on the pipe to be manufactured. Further, in order to use the pipe manufactured according to the present invention as a culvert pipe, a small hole for collecting water may be formed in the valley portion 4.

[0017]

As described above, the present invention uses a metal strip having a required width in order to enhance the pressure resistance of a synthetic resin pipe. Used as a metal reinforcing strip with a thin-film coating resin layer previously coated with a thin film of synthetic resin or resin paint, and then heating it to improve the adhesion performance with the inner and outer synthetic resin materials forming the tube wall As a result, the adhesion between the metal strip and the synthetic resin material forming the pipe wall is poor, as in a tube in which a metal strip is embedded in the pipe wall of a conventional synthetic resin pipe. Due to the pressure, the metal strip and the synthetic resin material are separated from each other, and the defect that the synthetic resin wall portion of the separated portion is easily cracked is reliably eliminated, and the metal strip and the synthetic resin material forming the tube wall are removed. Good adhesion, both materials are strong It has a significant effect that can be obtained are wearing tube.

Further, since the pressure-resistant performance of the pipe is enhanced by forming the metal reinforcing strip into a U-shaped cross section, there is an effect that a synthetic resin pipe having high pressure-resistant performance can be manufactured. In addition, since the inner and outer synthetic resin strips are bonded from the inner and outer surfaces to the heated metal reinforcing strip in the pipe forming section, a remarkable effect that the pipe can be manufactured easily and efficiently can be obtained. Have

[Brief description of the drawings]

FIG. 1 is a plan view showing the overall arrangement of a device according to the present invention.

FIG. 2 is a longitudinal sectional front view showing a structure of a tube forming portion.

FIG. 3 is a sectional view showing the structure of a metal reinforcing strip.

FIG. 4 is a sectional view showing a step of forming a metal reinforcing strip with time.

FIG. 5 is a longitudinal sectional front view of a main part showing a method for manufacturing a pipe.

FIG. 6 is a longitudinal sectional front view of a tube wall portion of a tube formed by the method of the present invention.

FIG. 7 is a longitudinal sectional front view of a tube wall portion of another embodiment of a tube formed by the method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal reinforcement strip 1A Metal strip 1B Thin coating resin layer of a metal strip 1C Thin coating resin layer of a metal strip 2 External coating resin layer 3 Internal resin layer 13a Bending roll 13b Bending roll 20 Rotary drive 21 Pipe Forming device 22 Base 22a Holding rod 23 Heating device 23a Transfer rod 24 Tube forming part 24a Forming roller 24b Forming roller 25 First extruder 25a Nozzle part 29 Second extruder 29a Nozzle part A Synthetic resin strip B Synthetic resin strip

Claims (2)

(57) [Claims] 1. A method of manufacturing a pressure-resistant synthetic resin pipe in which a metal strip is used for a part of a pipe wall, wherein the synthetic strip is formed on the entire peripheral surface of a metal strip (1A) having a required width or at least over the entire front and back surfaces. A metal reinforcing strip (1) having a thin film coating resin layer (1B), (1C) formed of resin or resin paint is formed by bending a plurality of rolls (13a),
(13b) a first step of forming a U-shaped cross section and spirally winding at the same time, and the spirally wound metal reinforcing strip;
(2) transferring the (1) onto the holding rod (22a) of the base (22) in the tube forming device (21); and heating the heating device (23) while guiding it by the transfer rod (23a) in the tube forming device (21). ) Is sequentially shifted to heat the spirally wound metal reinforcing strip (1), and the heated spirally wound metal reinforcing strip (1) is formed by a tube forming apparatus (21). A fourth step of moving over the plurality of forming rollers (24a), (24b)... In the section (24), and a spirally wound metal reinforcing strip (1) transferred onto the tube forming section (24)
A hard synthetic resin strip (A) extruded from the nozzle part (25a) of the first extruder (25) is spirally wound and bonded to the strip (1), and at the same time adjacent strips (A), A fifth step of forming an external coating resin layer (2) connected in series by polymerizing the side edges of (A), and a second extruder (29) disposed inside the tube forming section (24). The synthetic resin strip (B) extruded from the nozzle part (29a) is guided between the forming rollers (24a) and (24b) and the spirally wound metal reinforcing strip (1) to form the strip (1). A method for manufacturing a pressure-resistant synthetic resin pipe, wherein the pressure-resistant pipe (P) is manufactured by a sixth step of forming an internal resin layer (3) by bonding to the inner surface. 2. An apparatus for manufacturing a pressure-resistant synthetic resin pipe in which a metal strip is used as a part of a pipe wall, wherein the metal strip is formed on the entire peripheral surface of a metal strip having a required width or at least over the entire front and back surfaces. A metal reinforcing strip (1) having a thin film-coated resin layer (1B) and (1C) formed of resin or resin paint is formed on a plurality of bending rolls (13).
a), (13b)... a bend forming roll device (13) which is sequentially formed in a U-shaped cross section and spirally wound at the same time, and a tube forming device (21) arranged beside the bend forming roll device (13)
And a heating device (23) for heating the spirally wound metal reinforcing strip (1)
A first extruder (25) for extruding a hard synthetic resin strip (A) forming an outer coating resin layer (2) of a pipe; and an inner resin layer (3) of a pipe.
Extruder (29) for extruding a synthetic resin strip (B) that forms
The tube forming device (21) has a rotation driving device (20) on one end side, and is a rod that is rotationally driven by the rotation driving device (20), and the spiral wound metal reinforcing strip ( Holding rod (22) that guides the distal end side sequentially while temporarily holding 1)
a) and a spirally wound metal reinforcing strip (1) connected to the holding rod (22a) and driven to rotate and transferred from the holding rod (22a) in the heating device (23). The spiral wound metal reinforcing strip (1) is heated while sequentially transferring
A transfer rod (23a) guided to (24), a roller (24a) connected to this transfer rod (23a) and driven to rotate, and a roller driven to rotate by the rotation driving force of the rotation drive device (20).
(24b) and a plurality of forming rollers (24b) ... which inherit the heated spirally wound metal reinforcing strip (1), and the heating device (23) surrounds the transfer rod (23a). And the first extruder (25) is arranged on the side of the tube forming part (24),
The second extruder (29) is arranged laterally outward of the rotary driving device (20), and its nozzle portion (29a) is arranged at the center of the tube forming portion (24) via a tube (29b). Equipment for manufacturing pressure-resistant synthetic resin pipes.