JPS6032286B2 - Manufacturing method of inorganic insulated wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for continuously manufacturing an inorganic insulated wire.

In the conventional manufacturing method of this type of insulated wire, the insulating layer is formed by filling a metal tube with inorganic powder or pellets,
A method of powder compaction has been used, but this method has the disadvantage that the workability of filling the insulator is poor and that only short products can be obtained.

If you try to increase the degree of surface reduction in order to obtain long products, the processability will be extremely poor because inorganic materials with no deformability are used, so you will have to repeat the intermediate sintering process many times. This inevitably led to an increase in product costs.

The present invention has been made in view of the above points, and an object of the present invention is to provide a continuous manufacturing method for an inorganic insulated wire that is easy to process and can simplify the process.

The method for manufacturing an inorganic insulated wire of the present invention involves supplying a balloon-shaped ceramic powder or metal oxide powder between a core conductor and a metal tape sent to surround the core conductor, while The method is characterized in that after forming the tape into a tubular shape and sealing the core wire conductor and insulating powder inside the tape, the thus obtained composite wire is subjected to an area reduction process at room temperature or warm temperature. .

In other words, in the present invention, a general refined powder of a metal oxide has a high hardness and cannot be subjected to surface reduction processing, but a balloon-shaped powder is crushed as the powder progresses, which promotes slipping. This is because it is easy to squeeze and mold.

In addition, in the present invention, the area-reducing process is performed at room temperature or in a warm environment, and in particular, in the case of a warm process, a metal pipe (or composite wire) that has been work-hardened by forming a metal tape or through an area-reducing process is performed at a warm temperature. By processing it while dulling it, it is possible to easily process the entire surface along with the balloon-shaped powder inside.

The warm temperature varies somewhat depending on the tape material, but in the case of copper tape, it is preferably a temperature with an upper limit of 40,000 ℃ to prevent seizure with processing tools.
Note that it is of course possible to perform the warm area reduction process by annealing the metal tube (or composite wire) separately, and it has been shown that this is a preferable method. Here, the balloon-shaped powder contains many small pores or voids (herein referred to as balloons) throughout its volume.

It refers to powder of something like so-called porous volcanic ash, and the one used in the present invention is, for example, Si02-based volcanic ash called Shirasu balloon, which is produced in large quantities in the Aso volcanic belt, as a natural product. Ru. In addition, as a method for industrially manufacturing balloon-shaped powder,
For example, there is a method of manufacturing by forcibly blowing gas into powder such as coal. The balloon-shaped powder may be used in combination with a non-balloon-shaped powder, that is, a solid powder, and this case is of course within the technical scope of the present invention. As the shirasu powder, Si02-based volcanic ash called shirasu balloon produced in the Aso volcanic zone of Kyushu was used.

However, if the proportion of non-balloon-shaped powder exceeds 90% of the total, it becomes extremely difficult to process the balloon-shaped powder, and good workability is lost, making it impossible to recognize the effects of the present invention. is limited to 1:9. Next, an embodiment of the method for manufacturing an inorganic insulated wire according to the present invention will be described with reference to the accompanying drawings. In FIG. A steel tape 2 with a thickness of 0.5 and a thickness of 22 is fed out from the side so as to surround the copper tape 1, and this copper tape 2 is also formed into a U-shaped cross section by a forming roll 3.

Steel tape 2 and conductor 1 located within its U-shaped cross section
A balloon-shaped shirasu powder 4 is supplied between the copper tape 2, which is then formed into a rod shape by forming the copper tape 2 into a tube shape, and the joint is welded 5 to the T to form a double coating. becomes a composite line 6. The cross section of the composite wire 6 has a structure in which a metal tube 7 is filled with a conductor 1 and a balloon-shaped shirasu powder 4, as shown in FIG.

Furthermore, this composite wire 6 passes through a dulling furnace 9 in which an inert gas 8 is circulated, is blown with cooling air 10 to be dulled, and is then heated in a heating atmosphere of 120 oo as shown in FIG. In the furnace 11, the wire is passed through a special drawing die 12 to reduce its area by 20%, resulting in a predetermined inorganic insulated wire 13 having a final outer diameter of 5.5 mm as shown in FIG. As can be seen by comparing this inorganic insulated wire 13 with the composite wire 6 in FIG. 3, the balloon-shaped powder is crushed by warm area reduction processing, and the insulating layer 14 becomes a fine powder-filled insulating layer. Become.

Figures 5, 6, 7 and 8 show other embodiments of the present invention, and Figures 5 and 6 show electric wires constructed by overlapping metal tapes. 7 and 8 show the structure of a multi-core electric wire using a plurality of core conductors.

According to the structure shown in FIGS. 5 and 6, welding can be omitted by tightening the metal tape.
The following table shows a comparison of workability between the method of the present invention and the conventional method.

Table ○: Processable, ×: Not processable, △): Processable if annealed Note: o Conventional method: Steel pipe is filled with KMg0 powder and processed to have a flat surface o Invention song 1): Balloon-shaped Enclose Sorazu powder and process the surface at room temperatureoo 〃 (
2) Enclose a balloon-shaped Solas powder and process the corrugated surface under warm conditions.

Note that the insulation resistance in the above table is a value measured at 120 qo x 20 qo with both ends sealed after heating, with insulation thickness of 1 rib and length of 50 arcs. As described above, according to the method for manufacturing an inorganic insulated wire of the present invention, processing is easy because balloon-shaped powder is used, and the number of steps is significantly simplified because the degree of surface reduction can be increased. In addition, since it is a continuous processing method using a metal tape, it is possible to easily manufacture the largest items in an extremely efficient manner, and it has the effect of being advantageous in terms of price. .

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of one embodiment of the method for manufacturing an inorganic insulated wire according to the present invention, FIG. 2 is an enlarged sectional view taken along line A-A in FIG. 4 are cross-sectional views of an inorganic insulated wire according to the method of the present invention, and FIGS. 5, 6, 7, and 8 are illustrations of other embodiments of the present invention. 1: Core wire conductor, 2: Steel tape, 3: Forming roll, 4: Balloon-shaped shirasu powder, 5: TIG welding, 6: Composite wire,
7: metal tube, 8: inert gas, 9: sintering furnace, 10: cooling air, 11: heating furnace, 12: drawing die, 13: inorganic insulated wire, 14: insulating layer. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8

Claims (1)

[Claims] 1. While supplying a balloon-shaped ceramic powder or metal oxide powder between the core conductor and the metal tape that is sent to surround the core, the metal tape is formed into a tube shape, and the inside of the metal tape is A method for manufacturing an inorganic insulated wire, comprising: sealing the core wire conductor and the insulating powder, and then subjecting the thus obtained composite wire to an area reduction process at room temperature or warm temperature.