JPH0782937B2 - Superconducting coil manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a method of manufacturing a superconducting coil used in a superconducting turbine generator, a superconducting nuclear magnetic resonance image diagnostic apparatus, a superconducting magnetic propulsion ship, and the like.

(Prior Art) A passage of a coil refrigerant of a conventional superconducting device is provided between a coil (2) and a support frame (3) each of which is formed by winding a superconducting wire (1) multiple times as shown in FIG. The spacer (5) is inserted through the insulator (4), the coil is fixed by using the wedge (6), etc., and the void (7) which becomes the refrigerant passage (shown by an arrow in the figure) is formed. It was However, this method has a drawback that the quench current cannot be increased because the superconducting wire can move.

Therefore, the low-temperature melting material, such as wood metal, is filled in advance in the void (7) that serves as a passage for the refrigerant, the resin is impregnated in the gap between the superconducting wires, and the resin is cured, and then the low-temperature melting material is heated and removed. A method to do so is considered (Japanese Patent Publication Sho 60-560)
59 publication). However, this method has a drawback that the work is complicated and it is difficult to completely remove the low temperature melting material.

[Problems to be solved by the invention]

The present invention has a problem that it is desired to firmly fix the wires between the wires and the superconducting wires and to secure the passage of the refrigerant without going through the complicated process of the resin impregnation method as described above.

An object of the present invention is to provide a method for manufacturing a superconducting coil in which the quenching current can be increased by firmly fixing the wires and the superconducting wires to each other and ensuring the passage of the refrigerant.

(Means for Solving the Problems) In order to achieve the above object, the present invention applies a superconducting filament as a core to the surface of an insulating film of a wire with an adhesive or a self-bonding agent to form a semi-cured state. Manufacture of a superconducting coil characterized in that the strands of the superconducting wire are blown with a prepreg tape, bundled into a coil, wound into a coil, and then heated while being pressurized to bond the strands to each other and to each other. Provide a way.

(Operation) Here, if the adhesive or the self-fusing agent is sticky during the winding work, dust may adhere or it may be difficult to work.
Must be non-greasy. Therefore, it is preferable that the adhesive or the self-bonding agent is in the B stage (semi-cured state).

Further, the pressurization / heating is performed in order to bond or fuse the strands and the superconducting wires in a state where there is no room for movement of the strands and the superconducting wires.

In the superconducting coil manufactured by such a method, the wires and the superconducting wires are firmly bonded to each other with an adhesive or a self-bonding agent, so that the wires and the superconducting wires bundled with the wires cannot move when electricity is applied, Also, since the adhesive or self-fusing agent has a small film thickness, it does not flow out due to pressurization and heating to block the passage of the refrigerant, and minute voids generated between the wires and the superconducting wires also serve as the passage of the refrigerant. Since it can be used, it is sufficiently cooled and a high quench current can be obtained.

〔Example〕

A method of manufacturing a field coil of a superconducting turbine generator, which is an embodiment of the present invention, will be described below with reference to FIGS. 1 to 5.

First, as shown in Fig. 1, a large number of ultra-fine CuNi matrix-NbTi superconducting filaments (8) were placed in the central part, and stabilized copper (10) separated by CuNi (9) was placed on the outside of the 0.5 mmφ. Get the wire (11) of. 5 to 10μ for this strand
An m-thick formal film is formed as the wire insulation (12), and an epoxy-based bond film with a thickness of 10 to 15 μm is semi-cured as the self-fusing agent film (13) on the wire insulation. Is formed in. Seven strands of this wire are bundled and twisted at intervals of 10 mm to form a primary stranded wire (14), and the primary stranded wire (1
13) are combined into two rows, and the flat twist compression molded superconducting wire (1) is obtained by transposing and compressing as shown in FIG. Next, as shown in FIG. 3, an insulating tape (15) made of an epoxy prepreg Kevlar roving sheet (other prepreg sheets may be used) is blown around the flat twist compression molded superconducting wire. The voids (7) formed in the blown and wound portion later form a passage for the refrigerant.

The superconducting wire thus obtained is assembled as a field coil of a superconducting turbine generator as follows. That is, as shown in the sectional view of the slot portion in FIG. 4, a lower cripage block (16) for ground insulation and a side spacer (17) on the pole side are installed in the slot (18). Next, the superconducting wire (1) for the coil (2) on the pole center side is wound in the slot from the lower stage toward the upper stage.

Next, an intermediate spacer (19) that serves as interlayer insulation is placed in the slot. Next, the superconducting wire (1) is wound as a field coil in a row on the side opposite to the central pole from the lower step toward the upper step.

Next, the side spacer (17) on the opposite side and the temporary upper cripage block (20) are installed in the slot. Place the pressure hose (21) on this temporary upper clip page block,
A temporary wedge (22) is inserted into the slot wedge groove (23) from above and fixed. After the pressure-resistant hose is filled with the pressurized medium (24) consisting of gas or liquid of 50 kg / cm ² G, the coil (2) is pressed and the supporting frame is heat-treated in the oven for a predetermined time and then molded. , Return to room temperature. In this state, the temporary wedge (22), the pressure-resistant hose (21) and the temporary upper clip page block (20) are removed, and the regular upper clip page block (25) and regular wedge are removed as shown in FIG. Insert (6). At that time, a corrugated epoxy glass laminated plate as a ripple spring (26) was placed between the upper clip page block (25) and the wedge (6), and the wedge (6) was inserted while pressing this.

Here, heating and cooling while pressing the field coil through the pressure hose melts the bond film on the surface of the wire,
The wires are fused together so that they can no longer move, and the insulating tape made of epoxy prepreg Kevlar roving sheet is heat-cured while the superconducting wires are pressed against each other, resulting in centrifugal force on the entire field coil. This is because it is not possible to move due to electromagnetic force or to easily quench.
Also, the reason why the ripple spring is inserted under the wedge is to exert the effect of holding the coil even if the coil becomes loose over time, and by using the corrugated plate at the same time,
This is for ensuring the passage of the refrigerant. The reason why the insulating sheet made of the epoxy prepreg Kevlar roving sheet was skipped and wound was to allow liquid helium as a refrigerant to flow into the space (7) between the insulating sheets.

The epoxy resin in the self-fusing agent film (13) composed of a bond film and the insulating tape (15) has a considerably high viscosity, and by heating, the lower cripage block (16), the side spacers (17), the intermediate spacers ( 19), the gap (7) through which the refrigerant can pass is secured between the strands without flowing into the cooling duct (27) formed in the upper cripage block (25), the wedge (6) and the like.

As described above, according to this method, a superconducting coil can be obtained relatively easily. In addition, according to this method, the field wires having high rigidity can be obtained by firmly fixing the wires or the superconducting wires to each other, and the refrigerant can pass between the wires (11) and between the superconducting wires (1). Since the gap is secured and the cooling performance is good, the quench current can be made high.

In this embodiment, an example in which a bond coating is used as the self-fusing agent coating has been described, but a thermosetting B-stage epoxy prepreg adhesive layer may be used instead of the bond coating. In this case, the adhesive layer is hardened after being bonded by heating and becomes insoluble and infusible.

In addition, although the slot portion is described in this embodiment, the slot is formed by FRP (fiber reinforced plastics) such as a glass epoxy laminated plate or non-magnetic steel outside the slot, and the field coil is formed in accordance with this embodiment. Should be manufactured.

Although the method of manufacturing the field coil of the superconducting turbine generator has been specifically described in the present embodiment, the present invention is also applied to the superconducting coil for other devices such as the superconducting nuclear magnetic resonance image diagnostic apparatus and the superconducting magnetic propulsion ship. it can.

〔The invention's effect〕

In the present invention, since the superconducting wire and the element wire are heated in a pressed state, the superconducting wire and the element wire are firmly bonded to each other through an adhesive or a self-bonding agent. The superconducting wires and the wires do not move due to centrifugal force or electromagnetic vibration. Therefore, quenching can be strongly prevented. Also,
Since the adhesive or the self-bonding agent does not flow into the cooling duct, and a space through which the refrigerant can flow is secured between the superconducting wires and between the strands, the cooling performance is good. Therefore, the superconducting coil according to the present invention can have a high quench current.

Moreover, the present invention is an extremely simple method for manufacturing a superconducting coil, which does not require the complicated process of the conventional impregnation method.

[Brief description of drawings]

FIG. 1 is a schematic view showing a superconducting coil used in an embodiment of the present invention in an enlarged order of a primary twisted wire and an element wire.
-A cross-sectional view taken along the line A, Fig. 2 is an elevational view of an essential part in the step of transposing the superconducting wire of Fig. 1, and Fig. 3 is a state in which a prepreg insulating tape is wound around the superconducting wire of Fig. 2. FIG. 4 is a sectional view of the slot portion in the molding process, FIG. 5 is a sectional view of the completed superconducting coil slot portion, and FIG. 6 is a fragmentary perspective view of the conventional example. 1 ... Superconducting wire, 2 ... Coil 3 ... Support frame, 4 ... Insulator 5 ... Spacer, 6 ... Wedge 7 ... Void, 8 ... Superconducting filament 9 ... CuNi, 10 ... Stabilized copper 11 ... Element wire, 12 ... Element wire Insulation 13… Self-bonding agent film, 14… Primary stranded wire 15… Prepreg insulation tape, 16… Lower cripage block 17… Side spacer, 18… Slot 19… Intermediate spacer 20… Temporary upper cripage block 21… Pressure hose , 22 ... Provisional wedge 23 ... Wedge groove, 24 ... Pressurized medium 25 ... Regular upper cripage block 26 ... Ripple spring 27 ... Cooling duct

Claims (1)

[Claims] 1. A plurality of strands of a superconducting wire which are semi-cured by applying an adhesive or a self-bonding agent to the surface of an insulating film of a strand having a superconducting filament as a core, and wrapping them with a prepreg tape. A method for manufacturing a superconducting coil, which comprises bundling and winding into a coil shape, and then heating the wire while applying pressure to bond the wires to each other and the coils to each other.