JPH08267601A - Synthetic resin-made corrugated pipe having plain end part and production thereof - Google Patents

Abstract

PURPOSE: To obtain a synthetic resin-made corrugated pipe with a plain end part having superior cut-off properties and a good connecting workability. CONSTITUTION: A synthetic resin-made corrugated pipe is so structured as to have a plain inner peripheral surface 1 and a recessed and projected corrugation on an outer peripheral surface, on which recessed parts 2 and projected parts 3 having hollow parts 4 are alternately formed. On either or both of end parts of the pipe, a flat same-outer diameter periphery 6 having a thickness at least higher than the projected part 2 and a length at least one pitch, pref. two or more pitches, of the recessed and projected corrugation from the end and a plain end face 7 orthogonally connected to the same-outer diameter periphery 6 are formed out of a thermosetting resin 5 composed of a reactive curable filler.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin corrugated tube having a smooth tube end and a method for producing the same.

[0002]

2. Description of the Related Art A corrugated pipe made of synthetic resin has a corrugated shape by providing a thin convex structure on the outer periphery of the pipe having a smooth inner surface. Since this structure is lightweight, has excellent strength, and is easy to handle, this synthetic resin corrugated pipe is used in the field of drainage pipes where conventional fume pipes, polyvinyl chloride single layer pipes, iron pipes, etc. are used. It is being used heavily. In connection with this type of corrugated pipe, a rubber-like sheet or the like is wound around the connecting portion, and a semicircular metal plate is wound thereon to be connected with a bolt.

[0003] Among corrugated pipes of this type, however, a pipe having a spiral outer periphery (spiral pipe) is particularly connected to have a concave groove portion parallel to the convex mountain portion of the pipe and a convex mountain portion having a hollow structure. Due to the formation of water, the water blocking property at the connecting portion was not sufficient. As a method of improving such waterproofness,
For example, a method in which a block-shaped foam or the like is wound around the groove of the abutted pipes and a plastic sheet is wound around the outer periphery of the abutted pipes, a mortar containing a cement resin called a mouth in the groove of the abutted pipes and the gap between the pipe and the joint Or a method of injecting a filling agent such as a foaming agent, or with a joint in which the sealing band is wrapped around the pipe end groove at two locations and fitted into the joint, and the space with the sealing band is filled with foamed resin. There has been proposed a method in which a large block-shaped water blocking material is press-fitted into a pipe from a groove portion of the pipe, and then a pipe end covered with an elastic seal ring is press-fitted into a joint.

However, although the water-stopping property of this type of pipe by the conventional connecting method is improved, it is not always sufficient, and particularly the water-stopping property of the spiral pipe and the workability of the connection still have room for improvement. It was

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems relating to the connection of the corrugated pipe, to provide a corrugated pipe made of synthetic resin which is excellent in water-stopping property and easy in connection workability, and a manufacturing method thereof. .

[0006]

As a result of earnest research to achieve the above object, the present inventor has found that a thermosetting resin composed of a reaction-curable filler that rapidly undergoes an exothermic reaction and cures, The present invention has been completed by finding that a corrugated pipe having excellent water-stopping property and easy pipe connection workability can be obtained by smoothing the outer peripheral surface of the subsequent pipe end.

That is, according to the present invention, the pipe end of the corrugated pipe made of a synthetic resin having an uneven corrugated structure in which the inner peripheral surface is smooth and the convex portion of the outer peripheral surface has a hollow structure is at least higher than the inner peripheral surface by the convex portion. The present invention relates to a corrugated pipe made of synthetic resin having a smooth pipe end and a smooth outer periphery having a corrugated shape at least one pitch length from the pipe end to the pipe longitudinal direction.

In addition, a pipe end of a corrugated pipe made of a synthetic resin having a corrugated corrugated pipe whose inner peripheral surface is smooth and whose convex portion on the outer peripheral surface has a hollow structure is arranged at least from the inner peripheral diameter of the corrugated pipe to the outer periphery of the convex portion. The corrugate is inserted into the annular groove of a mold having a flat annular groove having a width corresponding to the height up to the diameter and a length of at least one pitch of the corrugated shape as a depth, and the pipe axis is vertical. A synthetic method with a smooth pipe end characterized by injecting and filling a reaction curable filler into the voids between the pipe and the outer peripheral surface and bottom of the mold, and after the reaction curable filler has undergone reaction curing The present invention relates to a method for manufacturing a resin corrugated pipe.

Next, a corrugated pipe made of synthetic resin (hereinafter also referred to as a corrugated pipe or simply a pipe) of the present invention having a smooth pipe end.
Further, the manufacturing method thereof will be described in detail with reference to the drawings. (1) Synthetic resin for corrugated pipe Various kinds of thermoplastic resins can be used as the synthetic resin for corrugated pipe in the present invention. Among them, polyolefin resins such as polyethylene and polypropylene have chemical properties, moldability, It is preferable in terms of mechanical properties and economical efficiency. Among the polyolefin resins, high-density polyethylene is particularly preferable in terms of moldability and rigidity. (2) Structure of Corrugated Pipe As shown in FIGS. 1 and 2, the structure of the corrugated pipe according to the present invention is such that the inner peripheral surface 1 is smooth and the outer peripheral surface has a concave portion 2 and a convex portion 3 having a hollow portion 4. And a thermosetting resin 5 composed of a reaction-curable filler at one or both ends of the tube, and at least the height of the convex portion 2, preferably the convex shape. The same outer circumference diameter 6 having a thickness of a height slightly covering the portion 2 and one pitch, preferably a length of two pitches or more, from the pipe end to the uneven outer circumference 6 and the same outer circumference diameter 6 connected to the same outer circumference diameter 6 (Vertical in FIGS. 3 and 4) is made of synthetic resin having a smooth tube end surface 7.
It should be noted that FIG. 1A shows a concave portion 2 and a convex portion 3 on the outer peripheral surface of the pipe.
2 is a spiral tube that forms a spiral corrugated waveform connected to each other, while B in FIG. 2 is a ring-shaped tube that forms an independent annular corrugated waveform in which the concave portions 2 and the convex portions 3 are not continuous.

Further, FIGS. 3 and 4 are cross-sectional views of the essential part showing an embodiment of the pipe end. FIG. 3A shows a partial cross section of the end of the spiral pipe, in which the thermosetting resin composed of the reaction-curable filler is loaded in the concave and convex spaces with the same outer diameter of two pitch lengths of the corrugated corrugation. A tube end face 7 which is covered and filled together with the charged loading member 8 and which is vertically connected to the coating layer 6 having the same outer diameter is formed. 4B shows a partial cross section of the end of the ring-shaped tube, and the tube end 7 that is vertically continuous with the coating layer 6 having the same outer diameter is the spiral tube B.
However, since the convex portion of the tube has a ring shape which is not continuous, the loading member 8 does not need to be loaded in the convex portion and is loaded only in the concave portion. (3) Thermosetting Resin The thermosetting resin of the present invention is a liquid or solid of a relatively low molecular weight substance before curing, and exhibits fluidity at room temperature or by heating. It is polymerized from a reactive curable filler that causes a chemical reaction (curing reaction) by the action of heat.

Examples of such a reaction-curable filler include a main component of dicyclopentadiene (hereinafter also referred to as DCPD) and a catalyst, an acrylic ester or a methacrylic ester and a carboxyl group, a methylol group, an amide group, A copolymer of acrylic monomers having a functional group such as a glycidyl group and a crosslinking agent reactive with these functional groups, or 1,2-polybutadiene is added with a peroxide catalyst to obtain a terminal dimer. The thing which bridge | crosslinks a heavy bond and hardens etc. are mentioned. Of these, the cross-linking type composed of the main component of DCPD and the catalyst is preferable.
As the filler, a two-pack type which is usually composed of liquid A and liquid B containing DCPD is used. For example, this liquid A contains a DCPD monomer liquid and a cocatalyst, while liquid B contains a DCPD monomer liquid and a main catalyst. When using the two liquids, they are mixed and injected at an appropriate ratio, for example, 1: 1. The two liquids thus mixed have a fluidity close to that of water, and rapidly react with heat to cure to form a thermosetting resin in the filled portion. Since this reaction generates heat at 50 ° C. or higher, in a polyethylene tube having a relatively low melting point, the thermosetting resin composed of this reaction-curable filler is bonded to polyethylene by instantaneous melting only on the surface. Is done. Therefore, the reaction-curable filler made of this DCPD is preferable for polyolefin-based resins, particularly polyethylene pipes.

A loading member may be used in addition to the thermosetting resin in the present invention. As the loading member, various materials are used, but a polyolefin material, particularly a polyethylene material is preferable in view of compatibility with the thermosetting resin composed of the reaction-curable filler. Although the shape thereof is not particularly limited, as shown in FIGS. 3 and 4, a flexible round bar-shaped member that is easy to insert is preferably used as a loading member for the convex portion 3 of the tube. Besides, corners, trapezoids, etc. may be used. In addition to the flexible round, square, trapezoidal rod-shaped body, a foam packing made of polyethylene foam, an O-ring, or the like is used as a member for loading the concave portion 2. By using such a loading member, it is possible to reduce the space of the concavo-convex portion of the tube and reduce the amount of the reaction-curable filler used, which is economical and the reaction curing of the reaction-curable filler. The time can be shortened. (4) Mold The mold in the present invention is made of metal, and examples thereof include iron, aluminum and alloys. In addition, an annular groove having a gap into which the pipe end of the corrugated pipe can be inserted and the reaction curable filler can be injected and filled is provided on the mold.
The inside of the mold may be a donut type in which the inner side of the inner peripheral diameter 19 is annular as shown in FIG. 6 or a solid type, but the donut type is preferable in terms of weight reduction. Furthermore, in order to facilitate the insertion of the pipe end into the annular groove of the mold 13,
It is preferable that the inner peripheral diameter 11 of the groove of the mold 13 is smaller than the inner peripheral diameter 1 of the tube and the taper 14 is provided at the corner between the bottom portion 9 and the inner peripheral diameter 11. (5) Method for Manufacturing Synthetic Resin Corrugated Pipe with Smooth Pipe Ends In the method for manufacturing a synthetic resin corrugated pipe with smooth pipe ends according to the present invention, the spiral pipe A or ring-shaped pipe B shown in FIG.
As shown in the cross-section of the main part, at least the outer peripheral diameter of the convex portion 2 of the pipe, preferably slightly larger than the outer peripheral diameter, the corrugated shape of the pipe is at least one pitch length, preferably two pitches or more. A horizontal end of the bottom 9 that can accommodate the flatness, and a horizontal inner mold 11 having the same inner circumference 11 and having a circular groove, the pipe end is perpendicular to the pipe axis as shown in FIG. Insert in the direction. By inserting this tube axis in the vertical direction, the reaction curable filler can be uniformly filled without flowing out, and a smooth outer peripheral diameter parallel to the tube and a smooth tube end surface orthogonal to this can be obtained. Is necessary in order to obtain. In addition, in the manufacturing method using the ring-shaped tube, since there is no spiral concave portion on the outer circumference of the tube, in order to inject and flow down the reaction-curable filler, be sure to insert it between the outer diameter of the groove of the tube and the die. A gap is needed. That is, the groove width of the mold must be slightly larger than the height from the inner diameter of the corrugated tube to at least the outer diameter of the convex portion.

Next, the above-mentioned reaction-curable filler is injected into the gaps 12a, 12b, 12c between the tube A or B and the mold 13 to fill the mold 13 up to almost the outer diameter 10 thereof. The reaction curable filler is usually injected from a nozzle by a pump while mixing a two-component type. If it overflows, it is received in the receiving groove 15. The injected reaction curable filler has a fluidity close to that of water,
In each of the above-mentioned gaps and spiral pipes, the concave portion 2 and the convex portion 3 at the end of the pipe flow in from the front portion (not shown) of the concave portion 2 and react with heat to cure to form a thermosetting resin. Due to this exothermic reaction, a part of the tube is joined by melting.

After the reaction-curable filler has reacted and cured,
Remove the tube A or B from the mold. As shown in FIGS. 3 and 4, the pipe ends of the pipes A and B form a smooth outer peripheral diameter 6 and a flat pipe end face 7 having a flat thickness to be connected thereto by a thermosetting resin and have a convex shape. The space 4 of the part 3 or the gap with the loading member as shown in FIG. 3 is filled. Such a corrugated tube manufacturing method is performed on one or both of the tube ends.

The corrugated pipe obtained by the above method is smooth by coating and filling the same outer diameter of the pipe end face and the pipe end portion with the thermosetting resin composed of the reaction curable filler. Next, an embodiment of the corrugated pipe connection obtained by the above method will be described.

As shown in FIG. 7, the smooth pipe end surfaces 7 of the corrugated pipes A1 and A2 obtained by the above-mentioned method are butted against each other, and a joint is placed on the smooth outer peripheral diameter 6 of both pipes,
For example, a rubber-like sheet 16 is wound, a synthetic resin joint 17 is wound thereon, and the outer bands 18a, 18b, 18c for tightening are further tightened and fixed thereon.
Or, by covering the smooth outer diameter 6 of the abutted pipes with an annular heat-shrinkable joint made of synthetic resin, for example, a heat-shrinkable tube made of polyethylene, and heat-shrinking the joints so that the joints closely adhere to the pipes. You can also connect.

[0017]

In the synthetic resin corrugated pipe of the present invention, the pipe end face and at least one pitch in the pipe longitudinal direction from the pipe end are smooth, and in particular, the same outer peripheral diameter of the pipe end face and the pipe end is smooth with the thermosetting resin. Since the opening of the convex portion of the pipe is also closed, the abutting of the pipe end faces in the connection can be brought into close contact with each other, and the joint from the outer periphery can be easily fixed in close contact. In addition, the manufacturing method is also easy because the tube end is inserted into a mold with a simple structure, and the reaction curable filler injected into the gap between the mold and the tube end is cured and resinified in a short time. Can be manufactured.

[0018]

Example A flexible round bar-shaped loading member 8a, 8b made of high-density polyethylene is cut into two convex and concave pitches and inserted into the opening of the convex end of the spiral corrugated pipe 1A made of high-density polyethylene. did. Next, the tube end was inserted into an aluminum alloy mold having an inner diameter slightly smaller than the inner diameter of the tube, a taper 14 at the inner diameter bottom, and an annular groove larger than the same outer diameter of the tube as shown in FIG. . As shown in FIG. 5, with the tube axis vertical to the horizontally placed mold, the distance between the pipe and the outer diameter of the mold groove was 5 mm, and the height of the two-pitch corrugation of the pipe was higher than the bottom of the mold groove. The void was filled with dicyclopentadiene, a two-part AB exothermic reaction-curable filler (DCPD) containing a catalyst and an additive while being pumped while being mixed.
The injected DCPD was exothermicly reacted and cured in a few minutes at room temperature to form a thermosetting resin. The corrugated tube in which the thermosetting resin was formed at the tube end could be easily taken out from the mold.

Next, as shown in FIG. 7, the smooth corrugated pipes A1 and A2 of the obtained smoothed corrugated pipes are butted against each other as shown in FIG. , A rubber sheet 16 is wound, a synthetic resin joint 17 is wound thereon, and an outer band 18a is further wound thereon.
18b and 18c were tightened and connected.

The pipe end of the obtained connected corrugated pipe was closed (stopped) with a rubber ball, and water was filled into the pipe to make it full of water, but no leakage was observed.

[0021]

As described above, according to the present invention, the same outer peripheral diameter of the pipe end face and the pipe end portion of the corrugated pipe is smooth, and the pipe end faces are closely contacted at the time of pipe connection, and the joint is closely adhered to the connection portion. Excellent water resistance and easy connection workability. Further, the corrugated pipe having a smooth pipe end portion of the present invention uses a mold having a relatively simple structure and only injects the reaction-curable filler into the gap between the inserted pipe and the mold, and the short time is required. Since the thermosetting resin can be formed on the substrate, the operation is simple in the manufacturing method.

[Brief description of drawings]

FIG. 1 is a partially cutaway side view of a spiral corrugated pipe showing an embodiment of the present invention.

FIG. 2 is a partially cutaway side view of a ring-shaped corrugated pipe showing an embodiment of the present invention.

FIG. 3 is a cross-sectional view of main parts in FIG.

FIG. 4 is a cross-sectional view of main parts in FIG.

FIG. 5 is a front view showing a forming means of a spiral corrugated tube showing an embodiment of the present invention.

6 is a cross-sectional view of the main parts in FIG.

FIG. 7 is a front view showing a connecting means of a spiral corrugated pipe showing an embodiment of the present invention.

[Explanation of symbols]

 A spiral corrugated pipe B ring corrugated pipe 1 inner peripheral surface 2 concave portion 3 convex portion 4 convex portion space 5 thermosetting resin 6 same outer diameter of thermosetting resin 7 pipe end surface 8a, 8b loading member 9 gold Mold bottom 10 Mold groove outer circumference 11 Mold groove inner circumference 12a, 12b, 12c Mold-tube gap 13 Mold 14 Mold bottom angle taper 15 Receiving groove 16 Rubber sheet 17 Joint 18a, 18b, 18c Exterior band 19 Mold inner circumference

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location B29K 101: 10 B29L 23:18

Claims (3)

[Claims] 1. A corrugated pipe made of a synthetic resin having a corrugated corrugated shape having a smooth inner peripheral surface and a convex portion on the outer peripheral surface having a hollow structure has a thickness of at least the height of the convex portion from the inner peripheral surface. A corrugated pipe made of synthetic resin having a smooth pipe end, wherein the corrugated pipe has a smooth outer peripheral surface having at least one pitch length of a corrugated shape in the pipe longitudinal direction from the pipe end. 2. A corrugated pipe made of a synthetic resin, wherein at least one pitch of the corrugated shape of the pipe end portion is formed by filling the space of the concave portion and / or the convex portion with a thermosetting resin. The corrugated pipe made of a synthetic resin having a smooth pipe end according to claim 1. 3. A pipe end of a corrugated pipe made of a synthetic resin having a corrugated corrugated pipe having a smooth inner peripheral surface and a convex portion on the outer peripheral surface having a hollow structure, at least the outer periphery of the convex portion from the inner peripheral diameter of the corrugated pipe. The corrugate is inserted into the annular groove of a mold having a flat annular groove having a width corresponding to the height up to the diameter and a length of at least one pitch of the corrugated shape as a depth, and the pipe axis is vertical. A synthetic method with a smooth pipe end characterized by injecting and filling a reaction curable filler into the voids between the pipe and the outer peripheral surface and bottom of the mold, and after the reaction curable filler has undergone reaction curing Method for manufacturing resin corrugated pipe.