JP2988270B2 - Winding method of pipe composite power cable - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to a method for winding a pipe composite power cable, in which a plastic pipe is composited in a twisting groove in which strips are twisted, around a drum.

[0002]

2. Description of the Prior Art FIG. 1 is a cross-sectional view showing the structure of a pipe composite power cable.
Reference numeral 1 denotes a power cable core such as a cross-linked polyethylene insulated power cable (CV cable), and 2 denotes a composite cable which is previously combined with the above-mentioned power cable core so that a cable such as a future communication cable or an optical fiber cable is passed. A plastic pipe is provided in a twisting groove formed when the three lines of the power cable core 1 are twisted, and is compounded.

[0003] When such a composite power cable is wound on a drum, unless the twisting pitch of the power cable core and the body diameter of the drum to be wound are properly selected, the composite plastic pipe cannot be connected to the power cable. Cables such as communication cables, optical fiber cables, etc. cannot be passed through due to remarkable compression force when dropped into the gap of the twisting of the wire core,
Alternatively, a situation occurs in which the plastic pipe protrudes outward and separates, making it impossible to lay the plastic pipe.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems and prevents a composite plastic pipe from dropping into a twisting gap of a power cable core and dislodging, and is provided in a pipeline or in a cavity. The first feature of the present invention is to provide a method for winding a pipe composite power cable that can be smoothly introduced and laid on a shelf in a road. The purpose is to select the twisting pitch of the power cable core and the diameter of the winding drum so that the outer diameter dp of the plastic pipe is equal to or less than the outer diameter dp.

[0005]

(Equation 2)

A second feature of the present invention is that D 'given by the following equation approximates, with an elliptical spiral, the shape of the slackness of a composite plastic pipe caused when a power cable is bent by winding it on a drum. The purpose is to select the twisting pitch of the power cable and the diameter of the winding drum so as not to exceed the long diameter D at the time. D> D '= X + Dps + (dp / 2)

A third feature of the present invention resides in a method for winding a composite pipe power cable which satisfies the above two conditions simultaneously.

[0008]

When the above-described pipe composite power cable is wound around the drum, the length of the power cable right above the drum is excessive, and the power cable is actually twisted. It is alternately repeated that the length of the wire core is insufficient, and the length of the cable wire core is excessive inside. The difference between the inside and outside circumferences is absorbed by twisting and laughing. As a result of various investigations, it is considered that the striated body will drop when the gap G given by the following equation of the power cable core caused by this laugh reaches the outer diameter dp or near dp of the composite plastic pipe. Can be Therefore,
In order to prevent the composite plastic pipe from falling into the twisting gap of the twisted power cable core,
It is necessary to select the twisting pitch of the power cable core and the diameter of the winding drum so that the gap G is equal to or less than the outer diameter dp of the plastic pipe to be combined.

[0009]

(Equation 3)

In a composite cable as shown in FIG.
When the cable is straight, the composite pipe is considered to be a spiral wound around a cylinder with a diameter Dps (layer core diameter of the composite pipe),
In the bent state in which the cable is wound around the drum, it is considered that the cable is wound around an elliptic cylinder having a major axis D and a minor axis Dps approximated by an elliptical spiral. And in an actual cable, slack occurs inside the bend. This looseness is absorbed in the space between the layer diameter of the composite pipe and the tangent line of the power cable core.If the looseness exceeds this space, it hits the drum body surface and then forms a twisted groove. The striatum protrudes outside the bend along. In order to prevent such projection of the striatum, as a result of various studies, D ′ given by the following equation is larger than the major axis D when the shape of the compounded slack generated when the power cable is bent is approximated by an elliptical spiral. It has been found that it is necessary to select the twisting pitch of the power cable core and the diameter of the winding drum so as not to cause the problem.

[0011]

(Equation 4)

[0012]

EXAMPLE When the discrimination line obtained by the equation (1) was written in the actual measured value of the actual cable, it is as shown in FIG. 2, and it was confirmed that the equation (1) was valid. In addition, a plastic pipe is used as the composite pipe, and its outer diameter is constant at 11 mmφ.

When the discrimination line obtained by the equation (4) is written on the past production results, the result is as shown in FIG. 3, and the twisting pitch is in a range above (including on the line) each discrimination line. In this case, it indicates that the composite pipe protrudes outward. From this, it was confirmed that Equation 4 was valid. As described above, the smaller the outer diameter of the cable core, the smaller the twist pitch at which the pipe comes off, and the smaller the bending radius, the smaller the twist pitch at which the pipe comes off.

[0014]

As described above, according to the pipe composite power cable winding method of the present invention, by appropriately selecting the twisting pitch of the power cable core and the body diameter of the winding drum, the composite power cable can be formed. It is possible to prevent the power cable core of the pipe from dropping into the twisting gap or dispersal of the pipe, and to smoothly introduce and lay the pipe on a shelf in a pipeline or a sinus.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of a pipe composite power cable.

FIG. 2 is a relationship diagram of a gap between power cable cores of a pipe composite power cable and a trunk diameter / twisting pitch.

FIG. 3 is a line diagram for judging protrusion of a composite pipe of the composite pipe power cable.

[Explanation of symbols]

 1 Power cable core 2 Composite pipe

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) H01B 7/00 H02G 1/02 301 H01B 13/00

Claims (1)

(57) [Claims] 1. A power cable core which is generated when the power cable core is wound around a drum in winding a composite power cable having a plastic pipe provided in a twisting groove in which three power cable cores are twisted. The gap G given by the following equation is smaller than the outer diameter dp of the composite striatum,
A winding method for a pipe composite power cable, comprising selecting a twisting pitch of a power cable core and a body diameter of a winding drum. (Equation 1)