JPS6120835Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention particularly relates to the improvement of power transmission pipes (buried pipes) buried underground, in concrete, etc.

[Conventional technology]

Pipe made of synthetic resin such as vinyl chloride resin is a high-quality insulator, so it is widely used as a power transmission pipe by storing a high-voltage cable inside and hardening the pipe around it with concrete. However, since conventional power transmission pipes have smooth surfaces, they have the disadvantage that after the concrete hardens, gaps tend to form between the pipes and the concrete, making it easy for the pipes to shift.

In order to overcome these drawbacks, the inventor of the present invention conducted various studies on the shape of the pipe and found that it would be sufficient to attach a synthetic resin to the periphery of the pipe. That is, in FIG. 1, reference numeral 1 is a pipe to which a synthetic resin 2 is densely adhered while forming many irregularities on the outer surface.

[Problem that the invention attempts to solve]

However, in such a pipe, if a metal pipe is used as the pipe 1, it will not fit well with the synthetic resin 2 on the outside, creating a gap between the two, and since the pipe 1 has a circular cross section, the synthetic resin There was a drawback when 2 rotated. Also, if you solidify the surrounding area with concrete, when the concrete contracts when it hardens, a strong force will be applied to the pipe.
The drawback was that the pipes were prone to cracking.

The object of the present invention is to provide a pipe that eliminates these drawbacks.

[Means for solving problems]

In order to achieve this purpose, the present invention is constructed as follows. That is, the pipe is characterized in that a groove is provided on the outer periphery of the pipe, and a synthetic resin foam is densely adhered to the outer surface while forming a large number of irregularities.

The pipe may be made of synthetic resin such as polyvinyl chloride resin or polyethylene resin, or may be made of metal such as steel pipe, aluminum pipe, or copper pipe.

As the synthetic resin foam, polyurethane foam, polyvinyl chloride foam, polyethylene foam, etc. are used. The synthetic resin foam may be soft, semi-hard, or hard, depending on the purpose of the pipe. The diameter of the pipe may be large or small, and is appropriately selected depending on the application.

Although there are no particular limitations on the method of manufacturing the present invention, a preferred method is to spray a synthetic resin foaming stock solution onto a pipe and cause foaming on the surface of the pipe. With this method, the foam 2 can be formed without any particular process.
A large number of irregularities are appropriately formed on the surface.

[Effect]

The groove on the outer circumference of the pipe tightly fixes the pipe itself and the synthetic resin foam. Therefore, it is difficult to create a gap between the two. Furthermore, even if the concrete shrinks when it hardens, the synthetic resin foam absorbs the shrinkage force and does not apply excessive force to the pipe, making it difficult for the pipe to crack.

〔Example〕

As shown in Fig. 2, three grooves 3 are provided in the axial direction on the outer periphery of a pipe 1 made of polyvinyl chloride resin, and a polyvinyl chloride resin foam stock solution is sprayed onto the pipe 1 on the outside of the grooves. Foaming was performed to closely adhere the two layers of foam.

[Effect of idea]

By housing the high-voltage cable in the present invention and encasing the pipe around it with concrete, the pipe becomes less likely to shift and can be firmly fixed without cracking. Even metal pipes can be used satisfactorily as power transmission pipes because the surrounding two layers of synthetic resin electrically insulate the inside and outside of the pipe.

Furthermore, when the present invention is used in the following applications, it brings about the following effects.

(1) When used in water pipes, insulation properties are greatly improved,
The water in the pipes is less likely to freeze during the winter, making it less likely that pipes will burst. It also improves sound insulation, making it harder to hear the sound of water coming from the floors above or in neighboring rooms in reinforced concrete buildings.

(2) When used as heating or cooling piping, the piping is less susceptible to the effects of ambient temperature, increasing thermal efficiency.

(3) When used as a sewer pipe, it improves sound insulation and is particularly effective in reinforced concrete buildings, similar to (1).

(4) When a pipe is used as a clothesline, the unevenness of the surface makes it difficult for the items to be washed to be pushed in one direction by the wind.

(5) The foam lowers the specific gravity of the entire pipe, making it possible for the pipe to float on water. If it can float on water, construction efficiency will increase at waterside construction sites.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a conventional example, and FIG. 2 is a sectional view showing an embodiment of the present invention. 1...Pipe, 2...Synthetic resin foam, 3...
groove.

Claims (1)

[Scope of utility model registration request] A pipe characterized in that a groove is provided on the outer circumference of the pipe, and a synthetic resin foam is densely adhered to the outer surface while forming many irregularities.