JPS61215883A - Corrugated double pipe made of synthetic resin - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a corrugated double pipe made of synthetic resin, which has improved crushing strength, reduced weight 1-1, and increased flexibility.
The purpose of this invention is to provide a tube that can be easily mass-produced at low cost even with a large diameter, and that is suitable for various uses.

This type of corrugated double pipe has an outer layer of corrugated pipe that strengthens crushing strength while increasing flexibility, and an inner layer of pipe that reduces flow resistance. By varying the thickness, it can be used in a wide range of applications, such as buried or non-buried drainage pipes, water supply pipes, and other applications such as road protection pipes, etc.

Conventional heavy corrugated pipes made of synthetic resin have a large internal flow resistance, and the improved corrugated outer layer pipes are made by extruding tubes or pipes in the axial direction of the pipe, making the inner and outer pipes straight. Since the corrugated outer layer tube is formed by extrusion molding and expanding the outer layer tube outward by a vacuum suction method or a continuous blow molding method from the inside of the tube, it has the following drawbacks.

+11 Since conventional corrugated outer layer pipes are extruded in the axial direction, the synthetic resin material is stretched in the axial direction of the tube when forming the inner and outer layer tubes, so the molecular arrangement direction is along the tube axis direction. Because of this structure, the strength of the finished pipe is relatively low in the circumferential direction compared to the strength in the axial direction.Especially for pipes that are subject to strong external pressure, such as those required for buried pipes, Strength in the circumferential direction became important, and it became necessary to make the tube wall thicker accordingly.

(2) In addition, in the conventional double pipe system, the wall thickness of the outer layer pipe is approximately uniform, so it is necessary to locally change the thickness of the pipe wall as appropriate. Because it is not possible to
The pipe wall structure has a lot of loss, making it difficult to reduce weight and cost, and it is suitable for a variety of applications. It was difficult to adapt the product.

(3) With conventional methods, for example, when manufacturing large-diameter pipes with a diameter of about -j 000 or more, the forming equipment becomes large and complicated, which not only results in high-cost products, but also However, it was technically extremely difficult.

In order to solve the above-mentioned drawbacks of the conventional pipe, the present invention forms a corrugated double pipe by spirally winding a corrugated band on the outer surface of an inner layer tube formed by spirally winding a flat band.

Embodiments of the present invention will be described below with reference to the drawings.

Synthetic resin corrugated double pipe P shown in Figures 1 and 2
For example, a corrugate made of the same or different type of polyolefin such as polyethylene or polypropylene or a synthetic resin such as hard PvC is attached to the outside of the thin inner layer tube 1 made of a polyolefin such as polyethylene or polypropylene, or a synthetic resin such as hard or soft PVC. The outer layer tube 2 is integrally formed.

That is, the inner layer tube 1 reduces the flow path resistance, and the corrugated outer layer tube 2 provides excellent flexibility while maintaining crush resistance.

This inner layer tube 1 is! As shown in Fig. 42, the inner layer pipe is made by spirally winding the synthetic resin flat strip 1a and joining the adjacent side edges 3 of the spirally wound flat strip 1m by fusion, adhesion, etc. Therefore, the molecular arrangement direction of the synthetic resin material is formed along the spiral winding direction.

By joining the adjacent side edges 4 of the two corrugated outer layer pipes and the synthetic resin corrugated body 2a formed into a corrugated cross-sectional shape by fusion, adhesion, etc., the molecular arrangement direction of the synthetic resin material is arranged in a spiral manner. The inner surface 6 of the valley portion 2A of the corrugated outer layer tube 2 is joined to the outer surface 5vC of the inner layer tube 1 by fusion or adhesion.

What is shown in FIGS. 3 and 6 is the same as that shown in FIG.

The inner layer tube and outer layer sonic band are made of the same material as shown in Figure 2, and the molecular arrangement is arranged along the spiral winding direction, and the adjacent side edges of each are joined. The one shown in Fig. 3 has a thicker wall thickness at the peak 2C and the valley 2A, and the one shown in Fig. 4 has a particularly thicker crest 2c. and the fifth
The figure shows the thickness of the mountain part made thicker locally.

These are examples of double-strapped corrugated pipes made to provide external wear-resistant corrugated pipes for applications where the pipes are subject to high external wear, and to maintain good flexibility while increasing crush strength. It is.

Moreover, what is shown in FIG. 6 is a double corrugated pipe in which the crushing strength without extreme bending characteristics is increased by increasing the thickness of the valley part.

The one in Fig. 7 is a corrugated double pipe in which inner, outer, flat or wave band bodies made of the same material as above and having the same molecular arrangement are spirally wound and the side edges of adjacent ones are joined. The structure of the vertical wall part 2B is made to be thinner in the b' part near the peak part and thicker in the U' part near the trough part to create an outer layer wave band body, which is more effective and economical and has high crushing strength. This shows a corrugated double pipe with a similar structure.

Furthermore, what is shown in Fig. 8 is an example of nine cases in which the wall thickness of the inner layer pipe is changed, and although the inner layer is a straight pipe, that is, the inner surface of the pipe is smooth, the part where the inner layer pipe and the outer layer pipe penetrate. (usually double corrugated throughout) to prevent the wall from becoming thicker? This shows a corrugated double pipe designed to improve the flexibility of the pipe.

Since the present invention constitutes a tube by winding the band on both the inner and outer layers as described above, it has the following effects.

(1) The inner layer pipe and the outer layer corrugated pipe each have a structure in which a synthetic resin flat band and a wavy band are extruded and stretched, and then spirally wound, so that the molecular arrangement direction of the synthetic resin material is Since the inner layer tube and the outer layer tube are along the spiral winding direction, the inner layer tube and the outer layer tube have excellent strength in the circumferential direction. Therefore, as a pipe requiring flat strength, the corrugated double pipe has excellent crush resistance and flexibility.

(2) When shaping the inner and outer layer pipes, by appropriately setting the cross-sectional shape of each flat band and wavy band, the thickness and shape of the pipe wall of the inner layer pipe and corrugated outer layer pipe can be freely set. Therefore, it is possible to form an ideal corrugated double pipe according to the use of the corrugated pipe. That is, it is possible to increase the crushing strength without impairing the flexibility, or to appropriately set the flexibility without changing the crushing strength.

In other words, this corrugated double pipe has a structural structure.

Furthermore, the corrugated double pipe of this configuration has a large diameter, for example, JO'WII or larger [J-diameter pipes are also manufactured by spirally winding a synthetic resin band, so there are no technical problems. It is possible to produce and provide products efficiently and inexpensively using simple equipment. Of course, the present invention can also be used. Furthermore, the joining point Wt of the inner and outer band bodies can be joined at any location as long as the gist of the present invention is not impaired, and the corrugated cross-sectional shape may be rectangular, trapezoidal, sinusoidal, etc. It is.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a vertical sectional side view of a main part, FIG. 2 is an enlarged view of the part ▪ in FIG. 1, and FIGS. 8 and 8 are equivalent to FIG. 2 of a modified example. It is a diagram. 1...Inner layer pipe 1a...Flat band body 2...Full gate outer layer pipe 2a...Wave band rest 2 people...2 trough 2B...Vertical wall part b'...2B The side closer to the peak b'... The side closer to the valley of 2B 2c... The peak 8 of the corrugated outer layer pipe 2... The side edge of 1a The side edge 5 of 2a...
External surface of 1 6... Inner surface of 2A P... Colgate double management agent Patent attorney Osamu Kitamura Figure 1

Claims (1)

[Claims] A synthetic resin pipe in which a corrugated outer pipe 2 is integrally fitted and joined to an inner pipe 1, characterized in that the inner pipe 1 and the corrugated outer pipe 2 are each made of a hard synthetic resin material. Made of corrugated double pipe.