JPS58218708A - Nylon-coated anti-preventive cable - 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 termite-proof cables, particularly to nylon-coated termite-proof cables.

Conventional nylon coated termite-proof cables have a cable sheath or corrosion-resistant layer with a coating of 0.5 to 1. Although it is coated with nylon-11 and nylon-12 with a thickness of about 100%,
PVC, vinyl, and polyethylene used for cable sheaths and corrosion-resistant layers do not adhere to such nylon coatings, so for cables with an outer diameter of 10 mm or more, the generally accepted minimum bending diameter is When the cable is bent with a bending diameter that is 10 times the outer diameter of the cable, wrinkles occur in the nylon coating, which not only impairs the product value, but also tends to cause damage to the nylon coating during cable installation. there were.

For this reason, in the past, cables were transported wrapped around excessively large diameter drums so that the bending diameter was as large as possible, or routes were designed to have a large bending diameter to avoid wrinkles in the nylon sheathing during installation. Compared to general cables, cables have many restrictions in terms of handling and design, such as having to perform

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a nylon-coated termite-proof cable that eliminates the above-mentioned drawbacks of the prior art and substantially eliminates restrictions on handling and design.

The gist of the present invention is to make the thickness of the nylon coating layer of an anti-termite cable greater than the value calculated by a predetermined mathematical formula. The thickness of the nylon coating was officially calculated and selected to accommodate the most severe bending diameter.

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

Figure 1 shows an example of a nylon coated termite-proof cable, in which well-known coated insulating layers such as a cable insulator 2 and a cable north (or corrosion-resistant layer) 3 are laminated on the outer periphery of a cable conductor 1. The outer layer is provided with a nylon coating layer 4 made of termite-proofing material such as nylon-11 or nylon-12 and having a thickness selected as described below.

This anti-termite nylon coating layer 4 can theoretically be handled as a single plastic pipe since the nylon coating layer 4 has no adhesive relationship with the cable sheath 3 (or anti-corrosion layer, etc.) which is its inner layer. be able to.

On the other hand, for plastic pipes, regardless of the material of the pipe, there is a theoretical minimum bending diameter lA determined by the pipe's outer radius r and its wall thickness t, and if the pipe is bent below this bending diameter IA, the pipe will sit. I'm going to give in.

This theoretical minimum bending diameter lA is It is determined by

The outer radius r of the pipe, that is, the nylon coating layer, its wall thickness 1, and the minimum bending diameter IA calculated by this formula (1)
Figure 2 shows the correlation between

As is clear from FIG. 2, the conventional 0, 5 to 1.
It is clear that a nylon coating with a wall thickness of about 0 mm easily buckles and wrinkles due to slight bending. Here, the actual wall thickness of the nylon coating layer is an appropriate thickness of 1 or more, which is determined by the allowable bending diameter 1/' and the cable outer radius r, in order to prevent excessive bending during handling. It should be molded exactly.

As described above, according to the present invention, by selecting the thickness of the anti-termite nylon coating to be greater than the value calculated by the above formula (1), the cable can be wound on a drum with a smaller diameter. Because cables of the same length can be stored in a smaller volume, the cables can be handled more easily, and the number of cables per transport can be increased. It is possible to substantially eliminate the constraints in the installation work and actual installation work.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an example of a nylon-coated termite-proof cable. FIG. 2 is a diagram showing the correlation between the cable outer diameter, the allowable minimum bending diameter, and the wall thickness of the Nylon 61-/coating layer calculated according to the embodiment of the present invention. −[
Cable conductor, 2... Cable insulator, 3... Naojiru-kun 1 Figure 2 Mouth r-17 zu-F rear (2r)

Claims (1)

[Claims] In a termite-proof cable in which a nylon coating layer such as nylon-11 or nylon-12 is molded as the outermost layer, the thickness of the nylon coating layer [is defined by the radius r of the termite-proof cable and the permissible surface of the cable. A nylon-coated termite-proof cable, characterized in that the thickness is selected to be greater than the value calculated by putting the barb diameter 1 // in the formula: 3r4 2f+; K K3 - :=: Qt29r2.