| 摘要 |
PURPOSE:To require no filling of a water-tight compound in twisted conductors by adopting conductors free from breaks due to stress-corrosion interaction. CONSTITUTION:A strand 12 is produced by covering a core 14 made of high tensile copper alloy with annealed copper 16. For a high tensile copper alloy working as a strand 14 it is desirable to use a high tensile copper alloy having high electric conductivity, and for annealed copper used as the covering layer 16, electrolytic copper used as common strand conductors is applied. In addition, because a copper covering 16 is formed of annealed copper, around the strand 12, any internal strain that has developed during cable production does not remain in the covering layer 16 (i.e., the surface layer of the strand 12) that is thus free from any factor leading to stress. Accordingly, even if the surface of the strand 12 undergoes oxidation to form an oxide film, under corrosive atmosphere no break takes place on this oxide film so that corrosion does not invade into the interior of the strand 12 that is kept free from breaks due to stress-corrosion interaction. With this procedure it is possible to obtain a cable for which filling with a water-tight compound is not required. |
