JPS5854565B2 - How to connect metal tube coated cable - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for connecting a metal tube-covered cable in which an insulated conductor is covered with a metal corrugated tube made of aluminum or the like which has been treated with vinyl to prevent corrosion.

This type of cable is often used, for example, as an underground cable, but its length is limited due to manufacturing or transportation reasons, so multiple cables must be connected in order to be installed over long distances. I have to throw it.

However, in recent years, it has become difficult to secure the manholes necessary for connection work due to cost or land issues, so it has been desired to connect the above-mentioned cables to each other to make them longer before laying them.

However, the conventionally known cable connection method involves connecting the conductors, applying an insulating coating to the connection point, and then attaching a protective surface such as a steel pipe to the outer periphery. This section has a larger diameter than other sections, and is extremely rigid and has no flexibility. Therefore, when connecting the cable using the conventional method described above and then laying the cable, it is necessary to There were drawbacks such as excessive bending force being applied and electrical and mechanical properties being degraded.

This invention was made in view of the above circumstances, and it is possible to make the configuration and properties of the connection part almost the same as other parts,
Moreover, it is an object of the present invention to provide a method for connecting metal tube-covered cables that is easy to work with.

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

In the figure, 1a and 1b are connecting cables (corrugated tube covered cables that are butted against each other, and these are conductors 2a,
Aluminum corrugated pipes 4a, 4b are covered with an insulator (for example, insulating oil-impregnated paper) 3a, 3b, and the outer periphery is provided with a corrosion-resistant layer such as chloroprene.
The oil is coated with oil, and OF oils 5a and 5b are further sealed inside the oil.

When connecting these cables 1a and Ib, first, as shown in FIG.
, 4b along the axial direction from the end thereof to form a plurality of rectangular cut and raised pieces 6a, 6b, and each cut and raised piece 6a,
6b is folded back to expose the insulators 3a, 3b, and the ends of the insulators 3a, 3b are removed to expose the conductors 2a, 2b.

Thereafter, the conductors 2a and 2b are connected to each other by welding or through a sleeve (not shown), and insulating tape, insulating oil-impregnated paper, etc. are applied to the connection points of the insulator 3.
The reinforcing insulating layer 7 is formed by winding it until it has approximately the same diameter as a and 3b.

In this way, each of the conductors 2a, 2b and the insulator 3a
, 3b, each of the folded cut and raised pieces 6a
, 6b are returned to their original state, that is, aligned with the insulators 3a and 3b.

In this state, the cut and raised pieces 6a of one corrugated pipe 4a and the cut and raised pieces 6b of the other corrugated pipe 4b are in a state of abutting each other, and therefore the reinforcing insulating layer 7 is covered with these cut and raised pieces 6a and 6b. be done.

In order to integrate the corrugated pipes 4a and 4b and eliminate gaps, the ends of the cut and raised pieces 6a and 6b are cut together, and the cut and raised pieces 6a of one of the corrugated pipes 4a are and the cut and raised pieces 6b of the other corrugated pipe 4b are connected by welding.

Note that each cable 1a is processed using the method described above.

Of course, the connection formed by connecting 1b may be reinforced by providing a metal braid or, for example, a vinyl sheath (each not shown).

According to the above connection method, each corrugated pipe 4a
, 4b, so that the peaks and valleys, that is, the pitch, can be easily made into a continuous state by matching them, and the configuration and properties such as the outer diameter, rigidity, and flexibility of the connecting part are almost the same as other parts. The cables Ia and Ib can be connected to each other.

In addition, in the above embodiment, each folded cut and raised piece 5a,
When the parts 5b are returned to their original state, they are brought into contact with each other. However, this invention is not limited to the above embodiment, and if it is necessary to compensate for the decrease in mechanical strength due to welding, each When the cut and raised pieces 6a and 6b are returned to their original state, the ends of each may be slightly shaped.

In this case, it is preferable to overlap each other so that the respective peaks and valleys match each other.

In addition, when overlapping the ends of the cut and raised pieces 6a and 6b, the cuts made in one metal tube should be overlapped with the cut and raised pieces of the other metal tube, or the cuts made in one metal tube should be The cut and raised pieces of the other metal pipe may be inserted diagonally into the notches, and the cut and raised pieces may be overlapped one after another in a blind-like manner. As a result, the risk of oil leakage at the connections can be prevented.

As explained above, according to the connection method of the present invention, when connecting a metal pipe coated cable, a notch is made in the axial direction at the end of each metal corrugated pipe to form a cut and raised piece, and each cut and raised piece is Connect the conductor with the folded back, and apply insulation coating to the connection point, then return each cut and raised piece to its original state and cover the area with this insulation coating, and then each cut and raised piece Since the cables are connected by welding to each other and to the notched parts, the cables are connected so that the configuration and properties such as the outer diameter, rigidity, and flexibility of the connecting parts of the cables are almost the same as other parts. Therefore, even if the connection method of the present invention is applied to a cable before installation, the cable can be installed without any problem.

In addition, since the cut and raised pieces are strip-shaped along the axial direction, the pitch of the corrugate can be easily adjusted when returning to the dead state that was once folded back, and each cut and raised piece can be welded and connected to each other. Since the welding line is in a state along the axial direction of the cable, welding can be easily performed, and overall, according to the present invention, the connection work of the metal pipe coated cable can be easily performed, etc. can be obtained.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention; FIG. 1 is a front view showing a state in which each cut-and-raised piece is folded back, and FIG. 2 is a longitudinal sectional front view showing a state in which the connection of each cable is completed. 1a, 1b...Corrugated pipe covered cable, 2a. 2b...Conductor, 3a, 3b...Insulator, 4a
, 4b...corrugated pipe, 6a, 6b... cut and raised piece.

Claims (1)

[Claims] 1 Metal tube-sheathed cables made by sequentially covering a conductor with an insulator and a metal corrugated tube are arranged with their ends facing each other in order to connect them to each other, and the ends of the corrugated tubes of each of these cables are coated in the axial direction. A large number of cut and raised pieces are formed by making a number of cuts along the line, and the conductors are connected to each other while the cut and raised pieces are folded back, and an insulating coating is applied to the connection point. A metal characterized in that each cut and raised piece is returned to its original state to cover the part where the insulation coating is applied, and the cut and raised pieces of each of the corrugated pipes and the cut part are connected by welding. How to connect tube-sheathed cables.