JPH0136327B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for connecting a metal jacket of a cable.

Conventional cable sheathing (aluminum, lead sheathing, etc.) is welded or connected using lead work, which results in high temperatures at the connection point (for example, approximately 400°C when welding lead sheathing), which has the disadvantage of deteriorating the cable insulation directly below the welding point. It was hot. Particularly recently, low-loss materials such as plastic synthetic paper and plastic laminate paper have been used as insulators.
This effect is significant for OF cables.

As a countermeasure for this, in OF cables, a glass tape was interposed as a heat insulating sheet on the outside of the cable insulator directly under the metal sheath where the connection should be made, and the metal sheath was welded and connected using lead work.

However, since the above-mentioned glass tape used as a heat insulating sheet is not flexible, the bendability of the connection part of the metal jacket becomes uneven, resulting in a decrease in the bending properties of this part, and friction between the metal jacket and the metal jacket. Since the coefficient is large, this friction causes the glass tape to rub and the glass fibers to separate, resulting in drawbacks such as impurities being mixed into the oil in the case of OF cables, for example.

The present invention has been made in view of the above-mentioned drawbacks, and is characterized in that when connecting the metal jacket outside the cable insulator, a porous plastic sheet is used as the heat insulating sheet to connect the insulator at the connection point. After being interposed between the metal sheath and the metal sheath, the metal sheath is connected by welding and lead work.

An embodiment of the present invention will be explained with the help of figures. Figure 1 shows the case of a lead-sheathed cable. When two cables are connected, the conductor 1 is connected, the insulator 2 is connected, and then the metal sheath 3 of both cables is connected. A porous plastic sheet that is processed to contain many minute holes in the space between the insulator and the lead sheath that is created by expanding the lead sheath at the cable connection end to which a certain lead sheath is connected. 4 [For example, a porous sheet made of polytetrafluoroethylene resin (for example, WL Gore's product name Gore-Tex)] is interposed, and then the lead sheaths are welded or connected with lead metal fittings to completely connect the metal sheaths. achieved. In this case, if a material 5 having good thermal conductivity such as a copper tape is further interposed on the porous plastic sheet 4, heat will be uniformly dispersed in the porous plastic sheet 4.

Figure 2 shows the case of an aluminum corrugated sheath cable, in which a certain length of the aluminum corrugated sheath at the connecting end of two cables consisting of a conductor 11, an insulator 12, and an aluminum corrugated sheath 13 as a metal coating is cut off, and the conductor 11 and insulator 12 are
After that, the ends of the aluminum corrugate 13 as a metal coating are expanded and a porous material is added to the gap between the outside of the insulator 12 and the minimum inner diameter of the aluminum corrugate as a contact gap between the insulator 12 and the insulator 12. A metal pipe 15 (conductor 11 and insulator 12 slightly larger than the maximum outer diameter of the aluminum corrugate) is used as a metal coating to compensate for the cut length of the corrugated sheath by interposing a plastic sheet 14.
(previously fitted to the outside of one cable connection end before connection) is pulled back to cover the connection point of the cable, and the end of the metal pipe is overlapped with the end of the corrugated sheath as the metal sheath, and that part is welded. Or do lead work.

As described above, according to the present invention, a porous plastic sheet is interposed as a heat insulating material sheet between the insulator at the connection point and the metal sheath at the connection part of the metal jacket, and the connection is made by welding or lead work. The cable insulation does not deteriorate due to heat, and since it is a porous plastic sheet, an oil passage is secured, and because it is flexible, the bending characteristics of the connection point will not deteriorate, and the insulation sheet will not peel off, so it can be submerged in oil. It is possible to provide an excellent connection method that does not introduce impurities.

[Brief explanation of drawings]

Fig. 1 is a partial vertical sectional view showing a lead-sheathed cable connection part, Fig. 2 is a partial vertical sectional view of an aluminum corrugated sheath cable connection part, 1 and 11 in the figure are conductors, 2 and 12 are insulators, 3 is a metal coating, and 4 and 14 are porous plastic insulation sheets.

Claims (1)

[Claims] 1. When connecting the metal sheath outside the cable insulator, a porous plastic sheet is interposed between the insulator and the metal sheath at the connection point, and then the metal sheath is connected by welding and lead work. How to connect the metal jacket of a cable.