JPH05114317A - Manufacture of superconducting moulded stranded wire with keystone angle - Google Patents

Abstract

PURPOSE:To eliminate the generation of a crossover or a stranded wire unevenness by compression molding a flat stranded wire immediately after stranding into a flat type molded stranded wire at first, and after that, compression molding into a molded stranded wire with a keystone angle. CONSTITUTION:After superconducting bare wires 11 are stranded into a flat form, they are compression molded by four-way rolling rolls 31a to 31d for flat type molding. Then, they are compression molded by four-way rolling rolls 33a to 33d for giving a keystone angle so as to manufacture a superconducting molded stranded wire with a keystone angle. By making the molded formation at the first rolling into a flat form without a keystone angle, the superconducting stranded wires 11 are contacted evenly with the rollers 31a to 31d when the flat stranded wires immediately after the stranding are compressedly molded, and an even compression molding can be carried out. Consequently, a superconducting molded stranded wire with keystone angle having no defects such as a crossover and a stranding unevenness, and having a high rigidity, can stably be manufactured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a superconducting molded stranded wire with a keystone angle.

[0002]

2. Description of the Related Art A superconducting molded twisted wire with a keystone angle generally has a sectional structure as shown in FIG. These molded stranded wires are obtained by flatly twisting a required number of superconducting wires 11 and then rolling and compression molding them. The molded stranded wire in FIG. 5 is obtained by twisting only the superconducting wires and compression molded, and the molded stranded wire in FIG. 6 is formed by twisting the superconducting wires 11 around the core material 13 as a reinforcing material or a stabilizing material and compression molding. It was done. Stainless steel as the core material 13,
Aluminum or copper is used. These superconducting molded stranded wires have different left and right thicknesses in cross section, and the upper and lower surfaces have an angle α, which is called a keystone angle.

A method for manufacturing the superconducting molded stranded wire of FIG. 5 is shown in FIGS. 7 and 8. The required number of superconducting wires 11 drawn from the supply bobbin 17 of the twisting machine 15 are arranged at a predetermined interval in the circumferential direction through the eye plate 19, and then twisted on the rectangular cored bar 21. Since the mandrel 21 is stationary, a plurality of superconducting wires 11 pass through it to form a flat twisted wire, and this twisted wire is drawn by the four-way rolling roll 23 immediately after the restraint is released at the tip of the mandrel 21. It is compression molded into a cross-sectional shape like 5.
It becomes superconducting molded twisted wire 25 with keystone angle. The finished formed stranded wire 25 is taken up by the take-up capstan 27 and taken up by the take-up bobbin 29.

Further, when manufacturing the superconducting molded stranded wire of FIG. 6, the core material is passed through the hollow shaft of the twisting machine without using the above-mentioned core bar, and the core material is run while the superconducting material is run thereon. The strands are twisted together and compression molded by a four-way rolling roll.

In either case, the compression molding by rolling is 1
There are cases where the final cross-sectional shape is obtained by rolling once, and cases where the final cross-sectional shape is obtained by rolling multiple times. Even when rolling is performed a plurality of times, conventionally, compression molding has been performed to give a keystone angle from the first rolling.

[0006]

In the conventional manufacturing method, since the superconducting element wires are flatly twisted, and immediately after compression molding for imparting a keystone angle, the superconducting element wires are not crossovered or twisted unevenly. Likely to happen. The reason will be described with reference to FIGS. 9 to 11.

When the superconducting wires 11 are twisted on a rectangular cored bar 21 and immediately after that, compression molding for imparting a keystone angle is carried out by four-way rolling rolls 23a to 23d, as shown in FIG. A void S may be formed on the thick side of the molded cross section of ~ 23d, and some of the strands 11 may escape toward the gap S as shown by a dotted line by pressing the adjacent strands 11 together.

Further, since the rolling surfaces of the upper and lower rolling rolls 23a, 23b are tapered surfaces, the rolling rolls 23a, 23b are
Fig. 10 shows the position of contact with the flat stranded wire immediately after it leaves the mandrel 21.
It becomes like the dotted line T. That is, the rolling rolls 23a, 23b
Immediately after leaving the cored bar 21, the time to restrain the stranded wire is delayed on the thick side rather than the thin side, which promotes the movement of the wire 11 in the void S direction.

As a result, the reduction force of the rolling roll is not evenly applied to each strand, and crossover and twist unevenness of the strands easily occur.

[0010]

SUMMARY OF THE INVENTION The present invention provides a method of manufacturing a superconducting molded twisted wire with a keystone angle, which solves the above-mentioned problems. The method comprises twisting superconducting wires flatly. After that, the stranded wire is compression-molded into a flat-shaped molded stranded wire having no keystone angle by the first rolling, and is compression-molded into a molded stranded wire with a keystone angle by the second and subsequent rollings.

[0011]

[Function] When the shape of the first rolling is made into a flat shape without a keystone angle, each superconducting element wire comes into uniform contact with the rolling roll during compression molding of a flat twisted wire after twisting. Since it is compression molded, crossover and twist unevenness do not occur. Since the position of each wire is stable in this first rolling, if compression molding is performed to give a keystone angle in the second and subsequent rolling, a healthy superconducting molded twisted wire with a keystone angle without crossover and twist unevenness can be obtained. can get.

[0012]

EXAMPLES Examples of the present invention will be described in detail below. The specifications of the keystone angled superconducting molded stranded wire to be manufactured are as follows. Molded strand size Width 15.000 mm Thickness Thick side 1.554 mm Thin side 1.100 mm Keystone angle 1.8 ° Superconducting wire outer diameter 0.800 mmφ Number of filaments 6340 Copper ratio 1.8 Number of twisted strands 37 Stranding pitch 110 mm Twisting direction Z Twist

In the embodiment of the present invention, a flat stranded wire immediately after being twisted is first compression-molded by square-shaped four-way rolling rolls 31a to 31d as shown in FIG. 1 and then as shown in FIG. Four-sided rolling rolls 33a to 33 for keystone angling
The molded stranded wire having the above specifications was manufactured by compression molding in d. Note that 11 is a superconducting wire.

For comparison, a molded stranded wire having the above specifications was also manufactured by a conventional manufacturing method. In the conventional method, a keystone angle of 1.0 ° was applied in the first rolling, and 1.8 in the second rolling.
It is a method of setting a keystone angle of °. Table 1 shows the evaluation results of the superconducting molded twisted wire with keystone angle manufactured by these methods.

[0015]

[Table 1]

The evaluation method of twist unevenness is as follows.
5mm from both edges of the molded stranded wire as shown in Fig. 3 and Fig. 4.
Areas A, B, C and D are determined, and the plane projected area (area of the shaded area in FIG. 4) of each strand is measured for one pitch (37 pieces) in each area, and the average value (Av) The standard deviation was obtained, and the standard deviation per pitch was evaluated. This means that the smaller the standard deviation is, the smaller the twist unevenness is (the degree of crushing of each wire due to rolling is uniform). According to these results, it can be seen that the twist unevenness is remarkably improved especially in the A part and the D part.

The twist breaking load is the load when the twist is broken by performing a tensile test on the formed stranded wire. When tension is applied to the molded stranded wire, twist breakage occurs from the crossover and uneven twist parts, so a large twist break load means a high-rigidity molded twisted wire with less crossover and uneven twist. You can say that.

[0018]

As described above, by adopting the manufacturing method of the present invention, it is possible to stably manufacture a superconducting molded twisted wire with high rigidity and without a defect such as crossover and twist unevenness. ..

[Brief description of drawings]

FIG. 1 is a front view showing a first rolling state in an embodiment of the present invention.

FIG. 2 is a front view showing a second rolled state in the same manner.

FIG. 3 is a cross-sectional view showing an evaluation portion of twist unevenness of a superconducting molded twisted wire with a keystone angle.

FIG. 4 is a plan view of the same.

FIG. 5 is a sectional view showing an example of a superconducting molded stranded wire with a keystone angle.

FIG. 6 is a sectional view showing another example of the same.

FIG. 7 is an explanatory view showing a conventional method for manufacturing a superconducting molded stranded wire with a keystone angle.

8 is an enlarged perspective view of a main part in the manufacturing method of FIG.

FIG. 9 is a front view for explaining problems in the conventional manufacturing method.

FIG. 10 is a plan view of the same.

FIG. 11 is a vertical sectional view of the same.

[Explanation of symbols]

11: Superconducting wire 31a to 31c: First-stage four-way rolling roll 33a to 33c: Second-stage four-way rolling roll

Claims (1)

[Claims] 1. A superconducting wire is flatly twisted, and then the stranded wire is compression-molded into a flat-formed stranded wire having no keystone angle in the first rolling, and a flat wire with a keystone angle is formed in the second and subsequent rollings. A method for manufacturing a superconducting molded twisted wire with a keystone angle, which comprises compression molding a molded twisted wire.