JPH0626523Y2 - Oil-filled cable drum winding structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a drum winding structure for an oil-filled cable having a corrugated metal sheath.

(Prior Art) It is important from the viewpoint of quality control of cables to find oil leaks due to pinholes, foreign matters, hair cracks, etc. generated in the metal sheath of oil-filled cables during the manufacturing process.

Conventionally, when checking whether oil leakage occurs during the manufacturing process of an oil-filled cable having a metal sheath, the metal sheath of the cable is temporarily evacuated to perform a leak test,
After that, the cable is filled with insulating oil and a visual inspection is performed to see if there is any oil leakage.

(Problems to be solved by the invention) However, such a conventional oil leakage check method requires much labor and time, and is extremely difficult to find when the amount of oil leakage is very small.

Also, in the case of a cable to be corrugated on a metal sheath (for example, an aluminum sheath), lubricating oil is applied after the metal sheath is applied to the cable core, but this lubricating oil must be wiped off cleanly just before the oil leak check. However, this also has a drawback that it takes a lot of time and effort.

Therefore, the present invention has been made in order to solve such a conventional problem, and an object thereof is to provide an oil-filled cable drum winding structure capable of easily and accurately distinguishing a cable oil leak by a visual check. .

[Structure of the Invention] (Means for Solving the Problems) The oil-filled cable drum winding structure of the present invention has an oil-filled cable having a metal sheath vertically wound with a non-woven fabric and wound around a drum. It is characterized by the interposition of kraft paper.

(Example) Hereinafter, an oil-filled cable drum winding structure of the present invention will be described according to an example. FIG. 1 is a diagram showing a main part of an embodiment of the present invention. In the figure, the oil-filled cable 1 is subjected to a corrugation process in which an aluminum sheath is applied to the cable core and lubricating oil is applied onto the sheath before being wound around the drum 2.

The non-woven fabric 3 is vertically attached to the oil-filled cable 1 and wound around the drum 2 without removing the lubricating oil used in the corrugation process. Kraft paper 4 is interposed under each cable winding layer.

Although the non-woven fabric 3 and the kraft paper 4 are shown separately from the oil-filled cable 1 and the like in the drawing, they are actually in close contact with each other.

Then, the oil-filled cable wound around the drum is filled with insulating oil, and a hydraulic pressure resistance test is performed at a predetermined hydraulic pressure for an appropriate time. After that, in the next vinyl coating step, when the cable is delivered from the cable drum 2, the kraft paper 4 under the cable winding layer is pulled out and the surface of the kraft paper 4 is visually checked for oil leakage. At this time, if there is oil leakage, the oil flowing out from the cable sheath is first absorbed by the non-woven fabric 3 and further absorbed by the kraft paper 4. In addition, most of the lubricating oil during corrugation is absorbed by the nonwoven fabric.

Therefore, it is possible to accurately check whether or not there is oil leakage in the cable by appropriately selecting the oil pressure and time for the oil pressure resistance test and by observing the degree of oil adhesion on the surface of the kraft paper 4.

Actually, 6km / cm ² × 24 even with oil leakage of about 0.3cc / h
After the pressure test for about an hour, the kraft paper surface was visually checked to find that stains on the kraft paper with a diameter of about 200 mm caused spots due to oil leaks, and traces of the lubricating oil during corrugation processing (mostly absorbed by the nonwoven fabric). Some of them also appeared in kraft paper.)

[Effects of the Invention] As described above, according to the present invention, an oil-filled cable having a metal sheath is vertically wound around a drum, and a kraft paper is interposed under the cable winding layer. Even a slight oil leak during the cable manufacturing process can be easily and accurately detected by visual check.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing a main part of an embodiment of an oil-filled cable drum winding structure of the present invention. 1 ... Oil-filled cable 2 ... Drum 3 ... Nonwoven fabric 4 ... Kraft paper

Claims (1)

[Scope of utility model registration request] 1. An oil-filled cable drum winding structure in which an oil-filled cable having a metal sheath is longitudinally wound around a drum and wound around a drum, and kraft paper is interposed under the cable winding layer.