JP2000104867A - Synthetic resin waveform tube and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a manufacturing means for a synthetic resin tube body by a continuous blow type molding method and a synthetic resin waveform tube provided with a discriminating line on a surface of a tube wall manufactured by using this means. SOLUTION: On a surface of a recessed and projecting waveform tube wall 1, a discriminating line L formed by yarn filament bodies 2a, 2b of colors different from a color of the tube wall 1 is formed along a tube shaft direction. Recessed and projecting waveforms matched with a large diameter part 11 and a small diameter part 12 of the tube wall 1 continuously supply yarn filament bodies 2a, 2b of colors different from the color of tube between a mold block 32 and a tube extrusion die 4 on an entrance side 31 of a caterpillar metallic mold 3 in a blow type synthetic resin tube molding machine formed on an inside surface and form the discriminating line L formed by the supplied yarn filament bodies along the tube shaft direction on the surface of the tube wall 1 at the same time as blow molding of a synthetic resin waveform tube P.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin pipe in which a pipe wall is formed in a corrugated shape, for example, a cable protection pipe such as an electric wire, a telephone line, an optical cable, etc. which is buried in the ground, and a drainage pipe. The present invention relates to a synthetic resin corrugated pipe such as a pipe, a culvert pipe, etc., which has an identification line formed along the pipe axis direction and a method of manufacturing the same.

[0002]

2. Description of the Related Art Heretofore, there has been known a tube of this type, which is a synthetic resin corrugated tube having a tube wall having an irregular corrugated shape and provided with an identification line formed along the tube axis direction. This identification line makes it easy to identify the type of cable to be inserted into the pipe, or the type of cable already inserted, the type of piping system, the pipe factory, the manufacturing line, etc.
In order to improve the appearance of the product, as shown in FIG. 10, a part of the tube wall 1 is integrally formed along the tube axis direction with a resin material having a color different from the color of the main tube wall. Thus, the identification line Lc was formed.

[0003] On the other hand, conventionally, as one of means for producing a synthetic resin corrugated tube, an annular large diameter portion 1 using a caterpillar mold has been used.
1 and a tube wall 1 in which annular small-diameter portions 12 are alternately arranged
Continuous blow molding means for producing a corrugated tube having the following are generally known and used. The tube body Pc provided with the identification line Lc was manufactured by the continuous blow molding means.

[0004]

The conventional synthetic resin corrugated pipe Pc provided with the identification line is, as described above, and as shown in FIG. 10, the part of the identification line Lc itself is a tube wall 1. , And has a structure in which a wall from the inner surface to the outer surface of the tube wall 1 is formed. The method of producing the pipe body Pc by blow molding means is roughly divided into two means, one of which is a means using a multicolor simultaneous extruder having two or three or more hoppers, The other is a means for simultaneously using one or more resin extruders for identification lines separately from the main extruder.

[0005] However, in any of these means, the production equipment is inevitably more expensive than in the case of producing a monochromatic tube having no identification line, and a complicated, large or large space is required. The task of necessity cannot be dispelled, and it takes a lot of time and effort to change or increase or decrease the color. The production must be interrupted, and there is a problem to be solved in that these factors can hardly be changed or increased or decreased during the production.

SUMMARY OF THE INVENTION An object of the present invention is to fundamentally solve the problem of the conventional means for manufacturing a resin corrugated tube having an identification line, and to provide a multi-unit having a hopper for forming an identification line. There is no need to separately use a color extruder or a resin extruder for forming the identification line, and as a resin extruder, it is sufficient to use only a generally used single-color tube extruder. An arbitrary number of identification lines having an arbitrary color and an arbitrary width can be formed at a desired circumferential position on the tube wall on the surface of the tube wall simultaneously with the manufacture of the body, and the manufacture of the tube body Even in the middle, the production of the tube is interrupted due to changes in the color of the identification line, changes in the width of the identification line, increase or decrease in the number of identification lines, and changes in the circumferential relative positions of multiple identification lines. Without making any changes Means for producing a synthetic resin tube by a continuous blow molding method, and a tube produced by using such means, wherein the entire circumference of the tube wall is formed of a single seamless resin tube However, an object of the present invention is to provide a synthetic resin corrugated tube having an identification line on the surface of the tube wall.

[0007]

Means for Solving the Problems The structure of the synthetic resin corrugated tube according to the present invention which has been adopted to achieve the above object is that the tube wall 1 is a synthetic resin tube having an irregular corrugated shape, On the surface, a discrimination line L formed of a thread material 2 of the same or similar kind of resin material as the tube wall and having a color different from the color of the tube wall is formed over the entire length along the tube axis direction. It is configured.

The method of manufacturing such a synthetic resin corrugated tube comprises a large-diameter portion 11 and a small-diameter portion 12 of the tube wall 1.
In the blow-type synthetic resin pipe molding machine, an irregular waveform corresponding to the above is provided between the mold block 32 and the tube extrusion die 4 at the entrance side 31 of the caterpillar mold 3 in the blow-type synthetic resin tube molding machine. Alternatively, a thread-like body 2 of a similar kind of resin material having a color different from the color of the tube is continuously supplied, and at the same time as the blow molding of the synthetic resin corrugated tube P, the surface of the tube wall 1 is arranged along the tube axis direction. The identification line L formed by the supply thread 2 is formed.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In carrying out the method for manufacturing a synthetic resin corrugated tube according to the present invention having such a configuration,
The material of the supply filament 2 is not particularly limited, and is a flat yarn formed of the same type of synthetic resin material or the same type of synthetic resin material as the synthetic resin corrugated tube,
Since a monofilament or a plurality of monofilament twisted yarns is selectively used, it is preferable in that it has excellent fusion or adhesion to the tube forming tube. Further, these filaments 2 to be supplied can be preliminarily heated before being supplied into the caterpillar mold 3, so that flexibility and extensibility can be enhanced. This is preferable in that it is possible to make the fusion bonding or adhesion more excellent, and it is easy to make the finished state of the boundary portion between the surface of the tube wall and the identification line easy to feel uncomfortable.

More specifically, the material of the filament 2 is
For example, when the material of the tube wall material of the synthetic resin corrugated tube, that is, the material of the tube wall forming tube is polyethylene resin, it is preferable to use a polyethylene resin or a polyolefin resin material such as ethylene vinyl acetate resin. It is desirable from the viewpoint of affinity with. In addition, by selecting an unstretched thread-like material or a thread-like material such as a flat yarn with a small amount of stretching, and using a thread-like material 2 which is easily stretched in the mold 3, expansion of the extruded tube to the inner surface of the mold can be achieved. It is preferable that the material be easily extended with the change. Also,
In order to promote that the filament 2 is extruded and change with the expansion of the tube to the inner surface of the mold, it is necessary to allow the filament 2 to be fed more actively than the extrusion speed of the tube. Good.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 3 schematically show a main part of the manufacturing apparatus, in which a side shape vertically cut along a main axis, a vertical cross section viewed from an input side, and a vertical cross section viewed from an output side are shown. Show. FIG. 4 is a perspective view of a synthetic resin corrugated tube manufactured by the manufacturing apparatus, and FIG. 5 is a reference diagram illustrating a use state of the synthetic resin corrugated tube of FIG.

First, a first method for manufacturing a resin corrugated tube using the manufacturing apparatus shown in FIGS. 1 to 3 will be described.
An embodiment will be described. The continuous blow molding machine 3 for manufacturing the resin corrugated tube and the extrusion die 4 for the resin tube t shown in these figures are of the same type as a device generally used conventionally as a device for manufacturing a resin corrugated tube. In this apparatus, a plurality of half-shaped mold blocks 32 are connected endlessly to form a caterpillar structure, and are arranged to face each other with an extrusion die 4 for a tube t interposed therebetween. The resin tube t moves at a constant speed in a direction away from the die 4, and the resin tube t in a molten state is continuously extruded from the tube extrusion port 41 of the die 4 with this movement, and at the same time, is coaxial with the tube extrusion port 41. High-pressure air w is ejected from the blow nozzles 42 which are arranged in a suitable manner, and presses the molten resin tube t against the inner surface mold of the mold block 32 to deform it into a corrugated shape.

On the other hand, the two bobbins 5a and 5b around which the thread 2 forming the identification line L is wound are connected to a continuous blow molding machine 3.
Is disposed near the entrance side 31 of the winding thread 2a,
2b is supplied from the entrance side 31 between the mold block 32 and the resin tube extrusion die 4. Radiation heaters 6a, 6 are provided between the bobbins 5a, 5b and the supply point.
b is arranged so that the filaments 2a, 2b unwound from the bobbins 5a, 5b are heated before being supplied into the mold.

The filament 2 supplied between the mold block 32 and the resin tube extrusion die 4 in this manner.
(2a, 2b) indicates that when the resin tube t extruded from the nozzle 41 of the die 4 is spread by the blow w and pressed against the inner mold of the mold block 32,
It is sandwiched between the resin tube t and the mold block 32 and pressed against the inner surface of the mold block 32, and the surface of the uncured high-heat synthetic resin corrugated tube itself is also melted by the heat of the synthetic resin corrugated tube to generate heat. The identification line L that is fused and integrated with the surface of the tubular body can be formed. The appearance shape of the identification line is determined by setting various factors such as the number, the color, the width, the position on the wall surface of the tube, the material, and the like of the color lines including white which constitute the identification line.

By this means, the effective inner diameter of the tube (the inner surface diameter of the small diameter portion) = 50 mm, and the maximum outer diameter (the outer diameter of the large diameter portion)
= 66mm, pitch interval = 15mm, weight = 0.40k
The g / m black PE corrugated tube P shown in FIG. 4 was manufactured. At this time, the material of the filament 2 was 5 mm in width,
Red / orange / blue / yellow flat yarns made of PE having different thicknesses every 0.1 mm from 0.1 to 0.5 mm in thickness were used. From the experimental results, it was confirmed that a flat yarn having a thickness of 0.1 to 0.2 mm formed a line having a sufficient distinctiveness in any color.

The synthetic resin corrugated pipe P thus obtained as shown in FIG. 4 has an annular large diameter portion 1 as shown in FIG.
1 is a corrugated tube having a tube wall 1 in which a small-diameter portion 12 and an annular small-diameter portion 12 are alternately formed in the tube axis direction, and the entire circumference of the tube itself is a seamless continuous cylinder, The tube has identification lines L formed on two opposing surfaces along the length direction. This synthetic resin corrugated pipe P is naturally used alone, but as shown in FIG. 5, a plurality of pipes are arranged in parallel and used as one block.

FIGS. 6 and 7 show a manufacturing method of the second embodiment. In this embodiment, a resin tube extrusion die 4 is provided in addition to the slightly wider threadlike bodies 2a and 2b shown in the first embodiment.
In the left and right direction, two narrow filaments 2c,
Four bobbins 5c to 5f wound around 2d, 2e and 2f are arranged, and a total of six filaments 2a to 2f are arranged on the surface of the tubular body.

The synthetic resin corrugated pipe P manufactured according to the manufacturing method of the second embodiment is as shown in FIG.
The pipe P shown in FIG. 8 is also a corrugated pipe in which the pipe wall 1 includes an annular large-diameter portion 11 and an annular small-diameter portion 12, similarly to the pipe P in the first embodiment. The slightly wider identification lines La and La similar to those in the first embodiment are formed at two opposing locations on the surface of the device 1 and are opposed to each other in the left-right direction.
This is a tube having a structure in which identification lines Lb, Lb each formed of two parallel color lines are formed at two places.

The synthetic resin corrugated tube shown in FIG. 9 uses a mold block having a different inner mold shape from the mold blocks 32 shown in the first and second devices.
As in the case of the second embodiment, six bobbins and 6
A tubular body manufactured using the thread-like body of the present invention, wherein the tubular body P has a structure in which a large-diameter portion 11 having a square cross section and a small-diameter portion 12 having a circular cross section are sequentially arranged in the tube axis direction. Corresponding to the supply positions of the six filaments, the identification lines La, La slightly wider in the vertical direction on the surface of the tube wall 1.
Is a tube having a structure in which identification lines Lb, Lb each formed of two narrow parallel color lines in the left-right direction are formed.

Although the embodiments which are considered to be representative of the present invention have been described above, the present invention is not necessarily limited to only the structures of these embodiments. The arrangement position, the material, and the like are not limited to those of the above-described structure of the embodiment, but can be appropriately selected and set. The present invention can be implemented by appropriately modifying it within the range of achieving the object and having the following effects.

[0021]

As has been apparent from the above description, the present invention is directed to an ordinary process for continuously blow-molding a synthetic resin corrugated tube in an entrance of a caterpillar mold for continuous blow-molding of a filamentous body. From the side, it is continuously supplied between the mold block and the resin tube extrusion die, and at the same time as the blow molding of the synthetic resin corrugated tube, the filament is fused to the surface of the synthetic resin corrugated tube in the process of molding, and the surface of the tube wall Since the identification line is formed along the pipe axis direction, the supply means of the thread-like body is made using a continuous blow molding machine for forming a single color tube which does not have the identification line forming device. By simply adding, the desired number of identification lines having an arbitrary color and an arbitrary width can be formed at an arbitrary position in the circumferential direction of the tube, and the production can be performed even during the production of the tube. While continuing without interruption, Another line changing in different colors and different number, remarkable effect of the formation position of the line can be or modify obtained.

Further, in the tube provided with the identification line formed by such means, the identification line is fused to the tube wall on the surface of the tube wall and is present in an inseparable and integral state. Since it is easy to clearly see the external appearance, and since the tube wall itself is formed of a substantially continuous tube, the tube is a durable tube having no local fragile portions. It also has the effect.

[Brief description of the drawings]

FIG. 1 is a central longitudinal side view schematically showing a main part of a manufacturing apparatus according to a first embodiment.

FIG. 2 is a vertical sectional front view of a main part on the input side of the apparatus.

FIG. 3 is a longitudinal rear view of a main part on the output side of the apparatus.

FIG. 4 is a perspective view showing a synthetic resin corrugated tube of the first embodiment.

FIG. 5 is a perspective view showing an example of a use state of the tubular body of FIG. 4;

FIG. 6 is a sectional view of a portion corresponding to FIG. 1 showing a main part of the manufacturing apparatus of the second embodiment.

FIG. 7 is a front view of a portion corresponding to FIG. 2 of the device.

FIG. 8 is a perspective view showing a synthetic resin corrugated tube of a second embodiment.

FIG. 9 is a perspective view showing a synthetic resin corrugated tube of a third embodiment.

FIG. 10 is a perspective view of a synthetic resin corrugated tube provided with an identification line obtained by a conventional manufacturing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pipe wall of synthetic resin corrugated pipe 2 Thread 3 Caterpillar mold 31 Entrance side of caterpillar mold 32 Mold block of caterpillar mold 4 Tube extrusion die 5 Bobbin P Synthetic resin corrugated pipe L Identification line

Claims (5)

[Claims] 1. A synthetic resin pipe in which a tube wall (1) is formed in a corrugated shape, the surface of the tube wall (1) being made of a resin material of the same type or a similar type as the tube wall. A synthetic resin corrugated tube in which an identification line (L) formed by a thread body (2) having a color different from the above color is formed over the entire length along the tube axis direction. 2. The synthetic resin corrugated tube according to claim 1, wherein the filament (2) is a flat yarn. 3. At the entrance side (31) of the caterpillar mold (3) in the blow-type synthetic resin tube molding machine, between the mold block (32) and the tube extrusion die (4), the same type or the same as the tube. Continuously supply a thread (2) of the same type of resin material and a color different from the color of the tube, and blow molding of the synthetic resin corrugated tube (P) and simultaneously with the tube axis (1) on the surface of the tube wall (1). A method for producing a synthetic resin corrugated tube in which the identification line (L) formed by the supply filament (2) is formed along the line. 4. The method for producing a synthetic resin corrugated tube according to claim 3, wherein the supplied filament (2) is a flat yarn. 5. The method for producing a synthetic resin corrugated tube according to claim 3, wherein the supply is performed after the filament (2) is preheated.