JP4371712B2 - Rehabilitation pipe manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a rehabilitated pipe, which is used for rehabilitating a line by lining an old line.
[0002]
[Prior art]
Conventionally, as one method for rehabilitating an old pipeline, it is known to line a rehabilitation pipe, that is, a synthetic resin liner, inside the old pipeline. As the rehabilitation pipe used for constructing this rehabilitation method, there is a rehabilitation pipe whose outer diameter is reduced by forming a circular cross section tube and then folding the cross section into a concave shape at a predetermined temperature. The construction method at the site of rehabilitating the old pipeline is to draw the rehabilitation pipe (liner material) with a reduced outer diameter of the concave cross section into the old pipeline while rewinding it from the drum, and after completion of the drawing, heat such as steam A method is used in which a medium is injected and heated, and the liner material is expanded and restored to the original circular shape in cross section, and is lined as a rehabilitation pipe on the inner surface of the old pipe.
[0003]
As an apparatus for manufacturing the rehabilitated pipe, for example, a hard plastic pipe for lining a pipe line is passed through a passage provided in the apparatus main body, and the deformed portion side of the half circumference of the hard plastic pipe is placed on another side. A molding device for deforming from a circular cross-sectional shape at the beginning of extrusion molding to a U-shaped cross-sectional shape with a reduced effective outer diameter by pressing toward the non-deformation processed portion side of the half circumference, Is installed in a plane that passes on the central axis of the passage, and presses the midpoint of the half-peripheral part of the hard plastic tube on the deformed part side toward the midpoint of the half-peripheral part on the non-deformed part side. At least one disk-shaped molding roll for recessing, at a position corresponding to the molding roll, the semi-circular portion on the non-deformation processed portion side of the hard plastic pipe is arranged at the midpoint of the half-circular portion and the convenience of both sides thereof. The holding part to be held at the place, and the above components And a presser roll that prevents the rigid plastic tube from being lifted from the holding portion of the deformed plastic at a position near the roll, and the molding roll and the presser roll are the same as the retreat position that goes out of the passage. Reciprocating between the advancing position entering the passage and being constrained at each position, the holding portion includes an intermediate roll that receives the midpoint of the non-deformed portion of the hard plastic tube, and both sides The pipe is characterized in that it is composed of two inclined rolls having an outward inclination for receiving the section, and the inclined roll is configured so that the opening degree can be adjusted and restrained at an arbitrary opening degree adjustment position. 2. Description of the Related Art A U-shaped device for a hard plastic pipe for road lining is known (for example, see Patent Document 1).
[0004]
In the manufacture of rehabilitated pipes, after a synthetic resin pipe is processed into a circular cross section by a conventionally used extrusion molding method, it is deformed into a concave cross section that can be inserted into the pipe line. It is necessary to deform the cross-section into a concave shape so that the cross-sectional shape can be expanded and restored to the original circular shape when heated after completion of drawing.
[0005]
However, since the liner material manufacturing apparatus described in Patent Document 1 uses a plurality of (many) forming rolls and sequentially forms a folded shape, whitening and cracking can be performed without applying excessive deformation at once in the circumferential direction. However, there is a tendency that a plurality of forming rolls exert a squeezing force and stretch the liner material in the axial direction. For this reason, when it is heated at the time of construction and the cross-sectional shape is restored, it contracts in the axial direction, and the end of the liner material enters the existing pipe, making it difficult to construct.
[Patent Document 1]
JP-A-8-118465 (pages 1 to 7)
[0007]
[Problems to be solved by the invention]
In view of the conventional problems, the present invention is a method for manufacturing a rehabilitated pipe that heats a synthetic resin pipe to a predetermined temperature and deforms it into a concave cross section that can be inserted into a pipe from a circular cross section. There is no stretching, no excessive deformation in the circumferential direction, no load on the circumferential direction, whitening and cracks that occur due to the load being applied, temperature management is easy, and diameter expansion and resilience during construction are easy. It aims at providing the manufacturing method of a good rehabilitation pipe | tube.
[0008]
[Means for Solving the Problems]
The present invention has been made to achieve the above object, and is a method for manufacturing a rehabilitated pipe having a concave cross section, which is used to rehabilitate a pipe line with a lining lining method, and has a circular cross section. The synthetic resin tube is heated to a predetermined temperature to form a concave cross section, and two sets of forming rolls are used in the deformation process, and the synthetic resin tube is flattened by the first set of rolls. Installed so as to flatten in the same direction as the flat direction of the roll of the assembly, the convex roll is installed so that the flat tube is sandwiched at right angles to the flat direction, and is composed of the concave roll and convex roll of the second set A method of manufacturing a rehabilitated pipe, comprising deforming a resin pipe into a concave cross section and winding up a synthetic resin pipe having a concave cross section.
[0009]
The synthetic resin tube used in the present invention is suitably made of a material that can have appropriate flexibility and elasticity at room temperature, such as vinyl chloride resin, chlorinated vinyl chloride resin, polyethylene, and polypropylene. .
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited only to the following embodiments.
[0011]
FIG. 1 is an explanatory view schematically showing an entire production line for a rehabilitation pipe according to the present invention.
The synthetic resin pipe having a circular cross section, which has passed through the mold b from the extrusion molding machine a, is cooled by the cooling device c and fed forward by the take-up device d. The synthetic resin tube 11 formed into a circular cross section is reheated to a predetermined temperature by the reheater chamber e and deformed into a concave cross section that can be inserted into the pipe from the circular cross section. The synthetic resin tube 11 having a circular cross section is processed by a conventionally used extrusion molding method.
[0012]
In the deformation process, in order to prevent the circularity of the liner material and the whitening of the liner material, the surface temperature when the liner material is folded is in the range from the glass transition temperature of the constituent resin of the liner material to the glass transition temperature + 40 ° C. It is adjusted so that it becomes.
In the case of a vinyl chloride resin, the temperature of the reheater chamber e is adjusted so that the surface temperature of the liner material is 80 to 120 ° C. If it is too low, excessive stress will be applied to the deformation process, and the surface will be whitened or cracked. If it is too high, the circular resilience deteriorates. The temperature of the reheater chamber e is set by supplying hot air, an infrared heater, or the like.
[0013]
The deformation process into a concave cross section includes the first set of forming rolls 2 in the step of flattening the cross section of the rehabilitated pipe, and the second set of forming rolls in the step of reducing the outer diameter of the rehabilitated pipe to a concave shape. Made by part 3. The forming roll used in this method is configured as follows.
[0014]
The first set forming roll section 2 includes a first set upper forming roll 21 and a first set lower forming roll 22. The reheated synthetic resin pipe 11 is flattened, and the flattened regenerated pipe 12 is formed. Is processed.
[0015]
The second set of forming rolls 3 is composed of a second set of concave forming rolls 31 and a second set of convex forming rolls 32, and is further heated and flattened rehabilitated pipe 12 further. The rehabilitation pipe 13 is processed into a concave shape whose outer diameter is reduced.
[0016]
The two forming rolls in the first set have respective rotation axes (not shown). Similarly, the second set of two forming rolls has respective rotation axes Z ₁ -Z ₁ and Z ₂ -Z ₂ . Preferably, a rotational drive is provided to feed the synthetic resin tube forward. Further, in order to control the temperature of the pipe reheated to a predetermined temperature, it is desirable to provide a function such as an internal heater and a circulation of heated oil.
[0017]
The rehabilitation pipe 13 whose outer diameter is reduced to a concave shape is wound on the winding device f. Moreover, in the said production line, the rehabilitation pipe | tube 13 which reduced the outer diameter to the concave shape with the 2nd group | molding roll between the winding apparatus f from the post process of the 2nd group | molding roll part 3 is carried out. You may install the apparatus (not shown) which takes up, hold | suppressing, in order to hold | maintain to a concave cross-sectional shape until it cools.
[0018]
FIG. 2 is a cross-sectional view of a main part when the step of reducing the outer diameter of the rehabilitation pipe in a concave shape in FIG. 1 is viewed from the side (cross-sectional view through the pipe axis XX).
FIG. 3 is a cross-sectional view of the main part of the first set of forming rolls in the step of reducing the outer diameter of the rehabilitation pipe to a concave shape in FIG. ).
FIG. 4 is a cross-sectional view of the main part when the second set of forming rolls in the step of reducing the outer diameter of the rehabilitation pipe to a concave shape in FIG. 2 is viewed from the front (Z ₁ -Z ₁ , Z ₂ is a cross-sectional view through Z ₂ ).
[0019]
When a vinyl chloride resin is used as a liner material (glass transition temperature = 60 ° C.), the circular cross section is reheated to reduce the folded cross section within the range of the glass transition temperature to the glass transition temperature + 40 ° C. The first set of forming rolls 2 has a round bar shape, and includes a first set of upper forming rolls 21 and a first set of lower forming rolls 22, and includes a synthetic resin tube 11 reheated to 60 to 100 ° C. Flatten below the height of the second roll. The flattening is performed without applying a stress in the tube axis direction with one set of rolls, and therefore, the axial extension is not substantially applied.
[0020]
The second set of forming rolls 3 is composed of a second set of concave forming rolls 31 and a second set of convex forming rolls 32, and is further heated and flattened rehabilitated pipe 12 further. The rehabilitation pipe 13 is processed into a concave shape whose outer diameter is reduced. Also in this case, since the processing into the concave shape is performed without any stress in the axial direction being exerted by one set of rolls, the stretching in the axial direction does not substantially occur.
[0021]
It is desirable that the first set of two forming rolls and the second set of two forming rolls are provided with rotational driving so that the synthetic resin pipes are fed forward around the respective rotation shafts. Further, in order to control the temperature of the pipe reheated to a predetermined temperature, it is desirable to provide a function such as an internal heater and a circulation of heated oil.
[0022]
As for the space | interval of the 1st set molding roll part 2 and the 2nd set forming roll part 3, 100-1000 mm is normally desired. The outer diameter of the first set of forming rolls 21 and 22 is usually 30 to 400 mm. If the thickness is less than 30 mm, the flattening resistance increases, which is not desirable. When it is larger than 1000 mm, the distance between the rolls is increased and the equipment is increased, which is not desirable because of cost increase.
[0023]
The distance between the first set forming roll part 2 and the second set forming roll part 3, that is, the distance between Y-Y and Z ₁ -Z ₁ , Z ₂ -Z ₂ is short. After flattening in the roll part 2, the liner material is folded with the second set roll before the shape returns to a circular shape, so the change in the surface temperature of the liner material is hardly observed since this time is short. Therefore, the folding process can be completed at a temperature suitable for circular restoration. In addition, an excessive stress does not act in the circumferential direction, there is no whitening or cracking, and because of processing by two sets of forming rolls, the circular cross section is molded into a concave cross section without substantial stretching.
[0024]
【The invention's effect】
The present invention is configured as described above, and heats a synthetic resin tube to a predetermined temperature and uses two sets of forming rolls in a deforming process for processing from a circular cross section to a concave cross section. Is a method of manufacturing a rehabilitated pipe characterized by sandwiching a flat tube perpendicularly to the flat direction with a second set of concave and convex rolls and deforming it into a concave cross section. Since the stress is not applied, there is virtually no stretching in the axial direction, no excessive deformation in the circumferential direction of the tube, and whitening or cracks that occur due to the load being applied in the circumferential direction. Therefore, since the deformation of the pipe by the forming roll is a short time, it is possible to provide a method of manufacturing a rehabilitated pipe that is easy to control the temperature and has good diameter expansion and restoration during construction.
[Brief description of the drawings]
FIG. 1 is an explanatory view schematically showing an entire production line for a rehabilitation pipe according to the present invention.
FIG. 2 is a cross-sectional view of the main part of the step of reducing the outer diameter of the rehabilitation pipe in a concave shape in FIG. 1 as viewed from the side (cross-sectional view taken through the pipe axis XX).
FIG. 3 is a cross-sectional view of the main part when the first set of forming rolls in the step of reducing the outer diameter of the rehabilitation pipe to a concave shape in FIG. 2 is viewed from the front (YY). Sectional view through
FIG. 4 is a cross-sectional view of the main part when a second set of forming rolls in the step of reducing the outer diameter of the rehabilitation pipe to a concave shape in FIG. 2 is viewed from the front (Z ₁ − Cross section through Z ₁ and Z ₂ −Z ₂ ).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rehabilitation pipe | tube 11 Cross-section circular rehabilitation pipe | tube 12 Rehabilitation pipe | tube 13 flattened by the 1st group forming roll 13 Rehabilitation pipe | tube reduced in outer diameter to the concave shape by the 2nd group forming roll The first set of forming rolls 21 in the process of reducing the outer diameter to the first set The first forming upper forming roll 22 The first set of lower forming roll 3 The second set of the process of reducing the outer diameter of the rehabilitated pipe into a concave shape Eye forming roll part 31 Second set of concave forming roll 32 Second set of convex forming roll

Claims (1)

A method of manufacturing a rehabilitation pipe having a concave cross section, which is used for rehabilitating a pipe line with a lining lining method, and heating a synthetic resin pipe having a circular cross section to a predetermined temperature to form a concave cross section. Two sets of forming rolls are used in the deformation process, the synthetic resin tube is flattened by the first set of rolls , and the second set of concave rolls is installed so as to be flattened in the same direction as the flattening direction of the first set of rolls. Te, convex rolls are installed write sandwiched flat direction perpendicular to the flat tubes useless, synthetic resin tube with concave roll and convex rolls of the second set is deformed in a concave sectional, sectional concave synthetic resin A method for producing a rehabilitated tube, comprising winding the tube .

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