JPS601513B2 - flexible composite pipe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flexible composite pipe, and more particularly to a flexible composite pipe with excellent flexibility and heat insulation properties, which is made by bonding a polyolefin resin corrugated pipe and two or more polybutene pipes together. It is something.

- Polybutene resin, which is a high polymer with an isotactic structure of n-butene-1, has excellent tear strength and creep resistance at high temperatures, as well as excellent chemical resistance and stress crack resistance. Possible applications include supply piping and heating and cooling piping.

However, polybutene pipes are relatively soft and are easily damaged during transportation and piping construction, and they also tend to buckle when curved in a strong manner. Furthermore, when polybutene pipes are used as hot water supply, cooling and heating pipes, it is necessary to insulate them to prevent heat loss due to heat radiation from the pipe surface. Therefore, a common method that can be considered is to cover the outer periphery of the polybutene pipe with a heat insulating protective material such as glass wool, asbestos, or foam material to improve the heat insulation and strengthen protection from the outside. However, with this method, the work of covering with a heat insulating material is complicated and costly. Furthermore, polybutene pipes have a large coefficient of linear expansion, so they expand and contract considerably due to changes in the temperature of the fluid, but with the above-mentioned insulation protection method, the polybutene pipe is fixed from the outer periphery by the insulation protection material, so it cannot expand or contract, and stress is placed on the polybutene pipe. durability will be impaired. The inventors of the present invention have focused on the above-mentioned circumstances and have conducted various studies in an attempt to develop a simple technique that would have excellent heat insulation and protection effects on polypropylene pipes and would allow them to expand and contract due to temperature changes.

As a result, it was found that the above objective could be easily achieved by creating a double structure in which a polyolefin resin corrugated pipe was arranged around the outer periphery of a polybutene pipe. However, depending on the application, it is often advantageous to insert two or more polybutene pipes into a corrugated pipe, and in such cases, the corrugated pipe itself deforms in a flat direction, deforming the polybutene pipe, and reducing the pressure loss inside the polybutene pipe. I learned that this can cause significant damage and other damage to durability. The present invention was made as a result of further studies to solve the above-mentioned difficulties, and its structure consists of inserting two or more polybutene pipes into a polyolefin resin corrugated pipe, and inserting two or more polybutene pipes into adjacent polybutene pipes. The gist lies in the fact that a spacer for reinforcement, positioning, and prevention of deformation is interposed between the corrugated pipes, thereby positioning and preventing deformation of the VORIBUTEN pipe within the corrugated pipe, and reinforcing the corrugated pipe itself.

That is, in the present invention, two or more polybutene pipes are protected by polyolefin resin corrugated pipes, buckling is prevented during curved piping, heat insulation is ensured by the wavy spaces on the outer surface of the group of polybutene pipes and the inner surface of the corrugated pipes, and furthermore, the corrugated pipes are By slidably inserting the polybutene pipe into the pipe, it is possible to expand and contract the polybutene pipe.In addition, by inserting a baser between adjacent polybutene pipes, the position of the polybutene pipe within the corrugated pipe is aimed at, and at the same time, the corrugated pipe is reinforced. This is what I did.

Moreover, the present invention has a structure in which a plurality of polybutene pipes are heat-insulated and protected by corrugated pipes, and can be obtained more easily and at a lower cost than heat-insulating protection using glass wool, asbestos, or the like. The configuration and effects of the present invention will be explained below based on the drawings which are examples. Of course, it is also possible to make appropriate changes and implementations in accordance with the later purpose. FIG. 1 is a partially cutaway side view of a main part illustrating a plurality of tubes according to the present invention, and FIG. 2 is a sectional view taken along the 0-RO line in FIG.
la and lb are polybutene pipes, 2 is a polyolefin resin corrugated pipe, and 3 is a baser. As is clear from the figure, the polybutene pipes la and lb are inserted into the corrugated pipe 2 via a baser 3.
Here, the waveform, wave pitch, wall thickness, etc. of the corrugated pipe 2 are not particularly limited and can be changed as appropriate depending on the pipe diameter and application, and the cross-sectional shape is also shown in Figs. 3, 4, and 6 in addition to Fig. 2. Thus, a cross-sectional shape that allows the polybutene pipes la and lb to be stably accommodated can be adopted. However, the material has moderate heat resistance,
In order to ensure weather resistance, durability, physical strength, flexibility, etc., polyolefin resins should be selected from polyethylene, polypropylene, polybutene, etc. Among them, the thermal properties (softening temperature, coefficient of thermal expansion, etc.) of polybutene pipes LA and LB should be selected. ), the most preferred is polypropylene corrugated pipe, which allows polybutene pipe la
, lb, the physical strength at high temperatures, which is insufficient, can be strengthened, and a composite pipe that can withstand high-pressure hot water as a whole can be obtained. In addition, a baser 3 is interposed between the polybutene pipes la and lb, so that each pipe la and lb
The corrugated pipe 2 itself is positioned to prevent it from being deformed in the bias direction. Therefore, when one of the pipes is deformed due to the difference in fluid pressure between the pipes la and lb, or when the pipe is curved or when the corrugated pipe 2 is subjected to an external force in the vertical direction, the corrugated pipe 2 itself is deformed in a flat direction, causing the pipe to become flat. la, lb
There is no fear of crushing it. Here, the shape of the spacer 3 may be any shape as long as it divides the inside of the corrugated pipe 2 almost equally according to the number of polybutene pipes to be inserted, and reinforces the corrugated pipe 2 while positioning each polybutene pipe. For example, a spacer 3 as shown in FIG. 3 may also be used. Further, the material of the baser 3 is not particularly limited and can be formed from various synthetic resin materials, but polyolefin resins, particularly polypropylene, are optimal in terms of flexibility, weather resistance, heat resistance, etc. As is clear from FIG. 1, a wavy space 4 is inevitably formed between the polybutene pipes la, lb and the spacer 3 and the corrugated pipe 2, and due to the heat insulation effect of this part, the polybutene pipes la, lb Since heat dissipation from hot water, etc. inside the tank is suppressed, heat loss is also suppressed as much as possible. Moreover, the corrugated pipe 2 originally has the advantage of being able to bend without buckling, but this advantage is further enhanced by the baser, and furthermore, the corrugated pipe 2 supports the polybutene pipes la and lb together with the baser 3,
It also has the effect of preventing buckling, so the construction of curved composite pipes can be carried out effortlessly and easily. Furthermore, corrugated pipe 2
Since the polybutene pipes la and lb can expand and contract in accordance with the polybutene pipes la and lb, there is little risk of internal stress occurring in the polybutene pipes la and lb, and their lifespan can be significantly extended. In addition, the polybutene pipes la and lb are simply inserted into the corrugated pipe 2 via the spacer 3, and even if, for example, this composite pipe is meandered and the corrugated pipe 2 is fixed on the floor or inside the wall, the polybutene Since the pipes la and lb can move freely in the space divided by the spacer 3 in the corrugated pipe 2, the expansion and contraction force of the pipes la and lb applied to the joint can be alleviated. 4 and 5 are cross-sectional views showing other examples of the flexible composite pipe according to the present invention, except that the shape of the corrugated pipe 2 has been slightly changed and the shape of the baser 3 has been changed accordingly. It is similar to

In addition, Figures 6 and 7 show three or four polybutene pipes la, lb, l placed in the corrugated pipe 2 via the baser 3.
This is a cross-sectional view illustrating a composite pipe inserted through c and ld.If the shapes of the corrugated pipe 2 and the spacer 3 are changed, three pipes can be formed.
4 or more polypropylene pipes into corrugated pipe 2
It is possible to obtain a composite tube inserted into the interior of the tube, and these also exhibit excellent effects similar to those shown in FIGS. 1 and 2. In the above-mentioned illustrated example, the explanation was mainly made of a case in which a spacer 3 formed separately from the corrugated pipe 2 is inserted, but the spacer 3 and the corrugated pipe 2 may be integrally formed as shown below. It is possible.

For example, FIG. 8 is a perspective explanatory view of the main part showing such an example, and FIG.
The figure is a cross-sectional view corresponding to the line K--K in FIG. 8, and is an example in which two corrugated pipes 2 are integrally joined via a spacer 3. 10 and 11 are views corresponding to FIG. 9 showing another example, which is the same as the example shown in FIGS. 8 and 9 except that the shape of the spacer 3 functioning as a connecting member has been changed. 12th,
FIG. 13 is a view corresponding to FIG. 9 showing still another example, and is an example in which the polybutene pipes la and lb can be easily inserted into the corrugated pipe 2 and the positioning can be made more accurate. That is, in the example shown in FIGS. 12 and 13, hooks 5c and 5b that engage with each other are provided on the baser 3 portion, and when inserting the polybutene pipes la and lb, the baser 3 portion is released and hooked as shown in FIG. 5a and 5b are engaged to keep the entire corrugated pipe 2 in an expanded state. After inserting the polybutene pipes 1 and 1b, as shown in FIG. 13, the baser 3 portion is tightened from the outer periphery using a suitable tightening tool such as a string to form the corrugated pipe 2 into a linear shape, and the polybutene pipes 1a and 1b are secured from the outer periphery. This is preferable because it facilitates the insertion of the polybutene pipes la and lb and further ensures their positioning. The present invention is roughly constructed as described above, and by combining a plurality of polybutene pipes with a substrate and a corrugated pipe made of polyolefin resin, the properties lacking in polybutene pipes are compensated for, and the insulation properties are suitable for hot water supply piping and cooling/heating piping. , a composite pipe with excellent piping workability, durability, etc. can be provided at a relatively low cost.

[Brief explanation of drawings]

FIG. 1 is a side view of a partially cut away main part illustrating a composite pipe according to the present invention, FIG. 2 is a view corresponding to the cross section taken on the zero line in FIG. 1, and FIG. 4 to 7 are cross-sectional views illustrating other composite pipes according to the present invention. Figures 8 to 13 illustrate still other composite pipes.
The figure is a perspective view of the main part, and FIGS. 9 to 13 are sectional views. la,
lb, lc, ld...Polyptene pipe, 2...Polyolefin resin corrugated tube, 3...Subacer, 4...
··gap. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13

Claims (1)

[Claims] 1. A flexible composite pipe comprising at least two polybutene pipes inserted into a corrugated pipe made of polyolefin resin, and a spacer for preventing deformation is interposed between adjacent polybutene pipes.