JP4953069B2 - Superconducting cable terminal structure - Google Patents

Description

  The present invention relates to a terminal structure of a superconducting cable in which a superconducting conductor layer is formed by spirally winding a plurality of superconducting wires around a former. In particular, the present invention relates to a terminal structure of a superconducting cable capable of confirming the soundness of each superconducting wire forming a superconducting conductor layer.

  Conventionally, in a superconducting cable using a superconducting conductor (superconducting wire) made of Bi-based high-temperature superconducting tape wire, the cable core includes a former, a superconducting conductor layer, an electrical insulating layer, a shield layer, and a protective layer in order from the center. .

  The superconducting conductor layer is formed, for example, by winding a tape-shaped superconducting wire in which a high-temperature superconducting filament such as a bismuth-based superconductor is covered with a silver sheath in a spiral shape so as to form a multilayer.

  The superconducting conductor layer has a multilayer structure so that the twisting pitch of the superconducting wire and the winding direction are different, and between each wire layer and between the innermost layer and the former of the wire layers, an interlayer insulating layer Is formed.

  This interlayer insulating layer is formed by winding kraft paper around the outer periphery of the former and the outer periphery of each wire layer of the superconducting conductor layer. With this interlayer insulating layer, each wire layer of the superconducting conductor layer can be configured to be electrically independent for each layer. In this way, the current flowing through each wire layer is equalized by changing the twist pitch and the winding direction in each wire layer.

  The electrical insulating layer is formed by winding semi-synthetic insulating paper. The shield layer is formed by spirally winding a superconducting wire on the electrical insulating layer in the same manner as the superconducting conductor layer. And a cable core is accommodated in the inside of the double SUS pipe | tube for vacuum insulation.

  In order to connect such a superconducting cable to a normal conductor, usually the cable core is stripped from the outside, the superconductor layer is exposed for a predetermined length from the end, and all the superconducting wires are collectively connected to the normal conductor. Connected to the connection.

  However, when the superconducting conductor layer is composed of multiple layers, there is a high possibility that a drift phenomenon occurs in which the current value flowing through each wire layer is not uniform due to the difference in impedance between the layers. In that case, since the amount of AC loss generated in the conductor varies depending on the current distribution, it is necessary to grasp the characteristics such as the energization current distribution for each wire layer.

  Further, when a drift phenomenon occurs in which current flows first from the wire layer outside the conductor, there is a possibility that the AC loss becomes larger than when current flows uniformly in each wire layer. If insulation between the wire layers is not sufficiently ensured, current transfer occurs due to contact conductance between the wire layers, leading to an increase in loss.

  Therefore, the terminal structure of the superconducting cable disclosed in Patent Document 1 is a terminal structure capable of measuring the energization current value of each wire layer in the cable core in which the superconducting conductor layer is composed of a plurality of wire layers. .

  As shown in FIG. 7, the terminal structure of the superconducting cable disclosed in Patent Document 1 is as follows. First, each wire layer A1, A2, A3, A4 of the superconducting conductor layer A, and each of these wire layers A1, A2, A3, All of the interlayer insulating layers B1, B2, B3 formed between A4 are stripped and exposed to the outside. Each wire layer A1, A2, A3, A4 is individually joined by a plurality of terminal members C1, C2, C3, C4 made of a normal conducting member. Each terminal member C1, C2, C3, C4 is electrically insulated from each other.

  The terminal members C1, C2, C3, and C4 that are joined to the wire layers A1, A2, A3, and A4 include a pipe portion that surrounds the wire layers A1, A2, A3, and A4, and a protruding portion that protrudes from the outer peripheral surface of the pipe portion. And have. The pipe portions of the terminal members C1, C2, C3, and C4 have different inner diameters and outer diameters in accordance with the outer diameters of the corresponding wire layers A1, A2, A3, and A4.

  Then, the pipe portions of the terminal members C1, C2, C3, C4 are inserted into the wire layers A1, A2, A3, A4 of the superconducting conductor layer A from the end of the cable core in descending order of the inner diameter. And each terminal member C1, C2, C3, C4 is arranged on a predetermined corresponding wire layer A1, A2, A3, A4, and each wire member layer A1, A2, A3, A4 and each terminal member C1, C2, Solder C3 and C4. Thereafter, by connecting the protrusions of the terminal members C1, C2, C3, and C4 to the normal conducting conductor, the energization current value for each wire layer can be measured.

Japanese Patent Laid-Open No. 10-126917

  In the terminal structure of the superconducting cable disclosed in Patent Document 1, the energization current value can be measured for each wire layer A1, A2, A3, A4. However, each wire layer A1, A2, A3, A4 is composed of a plurality of superconducting wires wrapped around, so that each of these superconducting wires is pulled out from the terminal individually, and the current value of the superconducting wire It is impossible to measure the influence of the magnetic field and to check the soundness.

  As described above, according to the present invention, when each superconducting wire of a superconducting cable is pulled out from the terminal individually, the workability is good and the influence of the energizing current value and the magnetic field is reliably measured for each superconducting wire. An object of the present invention is to provide a terminal structure of a superconducting cable that can be confirmed and sound.

  In the terminal structure of the superconducting cable according to the present invention, the superconducting conductor layer is unwrapped of the superconducting wire over a predetermined length at the end in the axial direction, and the former on the former side of the portion where the winding of the superconducting wire is unwound. An insulating portion for expanding the wire interval having an inclined surface extending toward the end surface in the axial direction is provided, and each superconducting wire is placed along the inclined surface of the insulating portion for expanding the wire interval, and the interval between the end portions in the axial direction of these superconducting wires. It is characterized by expanding.

  After unwinding and spreading the superconducting wire at the axial end of the superconducting conductor layer, the superconducting wire is spread along the inclined surface of the insulating portion for expanding the gap between the wires so that the superconducting wire can be easily The wire can be kept in an expanded state.

  The insulating portion for expanding the wire interval can be formed by winding reinforcing insulating paper around the outer periphery of the former. Examples of the reinforcing insulating paper include kraft paper.

  When the insulating portion for expanding the wire interval is formed of reinforcing insulating paper, the reinforcing insulating paper is preferably formed by winding the outer periphery of the former in a tapered shape so that the inclined surface is formed. Since one sheet of the reinforcing insulating paper is thin, it is easy to form the inclined surface with respect to the central axis of the former so as to have a desired angle. As a result, the interval between the superconducting wires can be set to a desired size by setting the angle of the inclined surface to an arbitrary angle.

  In addition, the thickness of the sheet of reinforced insulation paper is thin, and the inclination angle of the superconducting wire can be made gentle, so the burden on the superconducting wire is reduced, and the insulation part for expanding the wire interval is reinforced with insulation paper as follows. Can be formed. That is, a reinforcing insulating paper is wound and wound until a predetermined taper shape is formed to form an insulating portion for expanding the lower layer side wire interval on the lower layer side, and the superconducting wires are alternately placed on the lower layer on the adjacent superconducting wires. Along the insulation for expanding the distance between the side wires. Thereafter, an insulating portion for expanding the upper-layer-side wire interval is formed by further wrapping the reinforcing insulating paper so as to cover the superconducting wire along the insulating portion for expanding the lower-layer-side wire interval. Keep the remaining superconducting wire along the part.

  In this way, by arranging the superconducting wires alternately on the back surface side and the front surface side of the insulating layer for expanding the upper-layer-side wire spacing, adjacent superconducting wires can be reliably isolated with the reinforcing insulating paper.

  Furthermore, when connecting the superconducting wire to the normal conducting conductor, in order to ensure the current capacity in the normal conducting conductor, the width of the connecting end of the normal conducting conductor compared to the width of the connecting end of the superconducting wire is: Inevitably grows.

  Therefore, when winding the reinforcing insulating paper around the former, the inclination angle of the taper portion can be freely set, so that the plurality of superconducting wires wound around the cable core have a sufficiently wide interval between adjacent wires. Can take. As a result, a sufficient space for connecting the superconducting wire to the normal conducting conductor can be secured, and the connection work for connecting the superconducting wire and the normal conducting conductor can be easily performed.

  Further, the insulating portion for expanding the wire interval can be formed not by using reinforcing insulating paper but by a cylindrical body configured by combining half-cracked members formed of an insulating resin material. When forming into a cylindrical body, it is preferable to provide the taper part which becomes an inclined surface in the outer peripheral surface of a cylindrical body.

  The insulating resin material is preferably formed of a material that can be used in a cryogenic region, and examples thereof include fiber reinforced plastic (FRP).

  When the insulating portion for expanding the wire interval is formed of resin, it is preferable to form a half-cracked member of the cylindrical body by injection molding. In this way, by forming the insulating portion for expanding the wire interval by resin molding, the insulating portion for increasing the interval of the wire can be easily manufactured and can be easily attached to the former.

  Moreover, it is preferable that the terminal structure of the superconducting cable of the present invention has a configuration in which each superconducting wire is individually connected to a plurality of normal conducting braided wires. In this case, a normal conducting braided wire mounting member formed of an insulating material and formed in a cylindrical shape having a plurality of axially extending grooves on the outer peripheral surface is disposed on the outer periphery of the insulating portion for expanding the wire interval, It is preferable to place one normal conducting braided wire in each groove. The normal conductive braided wire mounting member is preferably formed of a synthetic resin such as FRP.

  A plurality of normal conductive braided wires are arranged one by one along each groove of the normal conductive braided wire mounting member, and this normal conductive braided wire mounting member is placed on the outer periphery of the insulating portion for expanding the wire interval. By arranging, the normal conducting braided wire can be easily connected to the superconducting wire without being displaced, and the connection work efficiency can be improved.

  Furthermore, it is preferable that each groove of the normal conductive braided wire mounting member has a guide portion that is notched in the same direction as the winding direction of the superconducting wire at the connection side end with the superconducting wire.

  Thus, even if the normal conducting braided wire is disposed along the groove in the axial direction, the superconducting wire rod is connected to the superconducting wire of the normal conducting braided wire along the guide portion formed in each groove. Can be directed in the winding direction. As a result, the normal conducting braided wire is not damaged at the end of the groove, and the superconducting wire is not bent forcibly in the direction of the former axis. I can do it. As a result, it becomes easier to connect the normal conducting braided wire to the superconducting wire.

  Further, the normal conductive braided wire mounting member is composed of a plurality of cylindrical bodies that are coaxially stacked, and a plurality of the grooves in which the normal conductive braided wires are disposed are formed on the outer peripheral surface of each cylindrical body. The cylindrical body disposed at least on the outermost side preferably has a normal conductive braided wire extraction hole formed at a position corresponding to each groove of the cylindrical body disposed on the inner side. And it is preferable to form each cylindrical body of the normal conductive braided wire mounting member by combining half-cracked members formed of an insulating resin material.

  Since the normal conducting braided wire is wider than the superconducting wire, in order to connect adjacent superconducting wires to the normal conducting braided wire one after another, these normal conducting braided wires are also installed in the circumferential direction to greatly expand the superconducting wire. It will be necessary. However, by forming the normal conductive braided wire mounting member with a plurality of cylindrical bodies, even if the width of the normal conductive braided wire is relatively large, the normal conductive braided wires are overlapped in the radial direction by the respective cylindrical bodies. Can be arranged. As a result, the adjacent superconducting wires can be connected to the normal conducting braided wires arranged above and below, so that the interval between the superconducting wires does not become too large, and the normal conducting braided wire mounting member is in the radial direction. The contact of the normal conductive braided wire can be prevented without becoming too large.

  Moreover, since the normal conductive braided wire extraction hole is formed at least on the outermost tubular body, for example, even when the outermost tubular body covers the tubular body immediately below the outermost tubular body. The normal conductive braided wire arranged in the cylindrical body directly below is pulled out from the extraction hole, so that the normal conductive braided wire arranged on the inner side can be made as soon as possible with the refrigerant outside the normal conductive braided wire mounting member. Can be cooled.

  Further, the normal conductive braided wire mounting member is preferably fixed to the former via a fixing mechanism that prevents the former from moving in the axial direction.

  The member for attaching a normal conductive braided wire can be restrained in the axial direction, for example, by being mechanically fixed via a pull-out bar compression-connected to the former of the cable core and a fixing mechanism.

  To prevent the normal conductive braided wire mounting member from moving in the axial direction, for example, when the normal conductive braided wire mounting member is formed of a plurality of cylindrical bodies, first, the innermost cylindrical body is formed. It fixes to the said drawer | drawing-out stick | rod via fixing members, such as a screw. Then, a protrusion is formed on the outer peripheral surface in the axial direction of the cylindrical body excluding the outermost cylindrical body, and the inner periphery of the cylindrical body excluding the innermost cylindrical body is fitted to each of the protrusions. By forming recesses on the surface and fitting these protrusions and recesses, movement of each cylindrical body in the axial direction can be prevented.

  Specifically, when the normal conductive braided wire mounting member is constituted by four cylindrical bodies, the innermost first cylindrical body is fixed to the drawer rod with screws or the like. And the protrusion formed in the outer peripheral surface of this 1st cylindrical body is fitted to the recessed part formed in the internal peripheral surface of the 2nd cylindrical body outside it. Next, the protrusion formed on the outer peripheral surface of the second cylindrical body is fitted into a recess formed on the inner peripheral surface of the third cylindrical body arranged outside the second cylindrical body. Then, the protrusion formed on the outer peripheral surface of the third cylindrical body is fitted into the concave portion formed on the inner peripheral surface of the fourth cylindrical body arranged on the outermost side outside the third cylindrical body. .

  By fitting the protrusions and the recesses in this way, each cylindrical body is prevented from moving in the axial direction, and the first cylindrical body is fixed to the drawer rod. The whole can be prevented from moving in the axial direction. In addition, when assembling each cylindrical body, it is preferable to make it a half crack shape.

  Thus, by preventing the normal conducting braided wire mounting member from moving in the axial direction, the normal conducting braided wire can be prevented from moving not only in the circumferential direction but also in the axial direction. The breakage of the connecting portion between the wire and the superconducting wire can be prevented.

  In the axial end of the superconducting conductor layer, the present invention unwinds a plurality of superconducting wires over a predetermined length, and insulates the gap between the wires on the former side of the unwound portion of the superconducting wires. A portion is provided so that each superconducting wire is along the inclined surface of the insulating portion for expanding the wire interval. As a result, the superconducting wire at the axial end of the superconducting conductor layer can be reliably maintained in a state where the interval between adjacent superconducting wires is widened to a desired size. It is possible to reliably measure the current value and the influence of the magnetic field, and also to confirm the soundness.

  Embodiments of the terminal structure of the superconducting cable of the present invention will be described below. In the present embodiment, a connection structure between a superconducting wire and a normal conducting braided wire in a cable core of a superconducting cable in which a single-core cable core is housed in a heat insulating tube will be described.

  As shown in FIG. 1, the cable core 1 of the superconducting cable of the present invention includes a former 11, a superconducting conductor layer 12, an electric insulating layer 13, a shield layer 14, and a protective layer (not shown) in order from the center. Yes.

  The former 11 is formed of a hollow pipe made of a metal such as copper, aluminum, a copper alloy, and an aluminum alloy. However, the former may be formed by twisting a plurality of metal wires. In the case where the former is formed of a strand, an insulation coating is applied to the outer surface of the strand.

  The superconducting conductor layer 12 is formed by spirally winding a tape-like superconducting wire 10 on the former 11 so as to have a multilayer structure. The superconducting wire 10 is formed by embedding a large number of Bi2223 series superconducting filaments in a silver matrix.

  A cushion layer 15 made of insulating paper is formed between the former 11 and the superconducting conductor layer 12.

  The superconducting conductor layer 12 is divided into a lower first layer 12A and an upper second layer 12B via an interlayer insulating layer (not shown) formed of insulating paper. The winding direction of the superconducting wire of the first layer 12A is opposite to the winding direction of the superconducting wire of the second layer 12B.

  The electrical insulating layer 13 is formed by winding semi-synthetic paper obtained by bonding insulating paper and a polypropylene film around the superconducting conductor layer 12.

  The shield layer 14 is formed by winding a superconducting wire 10 similar to that used for the superconducting conductor layer 12 around the electric insulating layer 13.

  Although not shown, the cable core 1 is housed in a heat insulating tube including an inner tube and an outer tube. In the heat insulating tube, a vacuum heat insulating layer is formed between the inner and outer tubes. The inner tube and the outer tube are both composed of corrugated tubes, and a so-called super insulation (trade name) in which a plastic mesh and a metal foil are laminated is disposed in the vacuum heat insulating layer.

  Next, the configuration of the terminal structure of the superconducting cable for connecting the superconducting cable to the normal conducting conductor will be described with reference to FIG.

  The terminal structure of the superconducting cable of the present embodiment is configured such that each superconducting wire of the superconducting conductor layer 12 of the cable core 1 is connected to the normal conducting braided wire 2 that is a normal conducting conductor.

  At the end of the cable core 1, a shield layer 14, an electrical insulating layer 13, a first layer 12A of the superconducting conductor layer 12, and a second layer 12B of the superconducting conductor layer 12 are stepped off.

  In the present embodiment, the winding of the superconducting wire at the ends of the shield layer 14 and the superconducting conductor layer 12 is loosely unwound so that a spiral state remains, and the former end in the former axial direction of the former in the axial end of the former 11 An insulating portion 3 for expanding the wire interval having an inclined surface that extends toward the surface, and a normal conductive braided wire mounting member 5 in which a plurality of normal conductive braided wires 2 can be arranged separately are provided.

  The insulating portion 3 for expanding the wire interval is composed of four first insulating portions 31, a second insulating portion 32, a third insulating portion 33, and a fourth insulating portion 34, which are formed by being laminated in the radial direction. ing.

  The first insulating portion 31, the second insulating portion 32, the third insulating portion 33, and the fourth insulating portion 34 are connected to the end portion of the superconducting wire 10 and the normal conducting braided wire connected to the superconducting wire 10. 2 is disposed, and a tapered portion (inclined surface) whose diameter is increased toward the axial end portion of the former 11 is formed. The first insulating part 31, the second insulating part 32, the third insulating part 33, and the fourth insulating part 34 are all formed by winding semi-synthetic insulating paper in which a plastic film and kraft paper are laminated.

  The first insulating portion 31 includes a first inclined surface 31a on which an end of the superconducting wire 10 forming the first layer 12A of the superconducting conductor layer 12 is disposed, and a first cylindrical portion continuous with the first inclined surface 31a. 31b. The first insulating portion 31 is formed on the cushion layer 15 so that the first inclined surface 31a is located on the axially central side of the former 11. The superconducting wires 10 arranged on the first inclined surface 31a are arranged every other superconducting wire 10 so that half of the number of the first layers 12A is arranged.

  The second insulating portion 32 is formed so as to cover the first inclined surface 31a of the first insulating portion 31 and the superconducting wire 10 and the normal conductive braided wire 2 disposed on the first inclined surface 31a. It has a surface 32a. The second insulating portion 32 is formed only by a tapered portion that becomes the second inclined surface 32a. On the second inclined surface 32a, the remaining half of the superconducting wire 10 forming the first layer 12A of the superconducting conductor layer 12 is disposed.

  The third insulating portion 33 covers the interlayer insulating layer formed on the first layer 12A and covers both the superconducting wire 10 and the normal conductive braided wire 2 disposed on the second inclined surface 32a of the second insulating portion 32. Is formed. The third insulating portion 33 includes a third inclined surface 33a formed on the axially central side of the former 11, a second cylindrical portion 33b continuous with the large diameter portion of the third inclined surface 33a, and the second cylindrical shape. A third cylindrical portion 33c having an outer diameter larger than that of the portion 33b and continuing to the second cylindrical portion 33b via a tapered portion is provided. On the third inclined surface 33a, every other superconducting wire 10 is disposed so that half of the superconducting wire 10 forming the second layer 12B of the superconducting conductor layer 12 is disposed.

  The fourth insulating portion 34 is formed so as to cover the third inclined surface 33a of the third insulating portion 33 together with the superconducting wire 10 and the normal conductive braided wire 2 disposed on the third inclined surface 33a. The fourth insulating portion 34 has a fourth inclined surface 34a, and the remaining half of the superconducting wire 10 forming the second layer 12B of the superconducting conductor layer 12 is disposed on the fourth inclined surface 34a.

  In this embodiment, the insulating portion 3 for expanding the wire interval is formed of reinforced insulating paper, but may be formed of an insulating resin material by injection molding or the like. In this case, it is preferable to form in the cylindrical shape comprised combining a half crack member. When the insulating portion 3 for expanding the wire interval is formed by injection molding, a tapered portion that becomes an inclined surface is formed on the outer peripheral surface of the cylindrical body. As described above, when the insulating portion 3 for expanding the wire interval is formed by injection molding, it is not necessary to perform a complicated operation of winding the insulating paper, and it can be assembled to the former 11 with a simple operation.

  The normal conductive braided wire mounting member 5 has a plurality of grooves extending in the axial direction on the outer peripheral surface, and has a structure in which four cylindrical bodies formed of an insulating resin material are laminated. The normal conductive braided wire mounting member 5 is configured by laminating a first cylindrical body 6, a second cylindrical body 7, a third cylindrical body 8, and a fourth cylindrical body 9 from the radially inner side. .

  The grooves formed in the first cylindrical body 6, the second cylindrical body 7, the third cylindrical body 8, and the fourth cylindrical body 9 are formed so that the width of the opening is narrower than the width of the bottom surface. One normal conducting braided wire 2 is fitted in each groove so that the normal conducting braided wire 2 does not fall off. The normal conducting braided wire 2 arranged in the first tubular body 6 is connected to the superconducting wire 10 arranged on the first inclined surface 31a of the first insulating portion 31. The normal conducting braided wire 2 arranged in the second cylindrical body 7 is connected to the superconducting wire 10 arranged on the second inclined surface 32a of the second insulating portion 32. The normal conducting braided wire 2 disposed in the third cylindrical body 8 is connected to the superconducting wire 10 disposed on the third inclined surface 33a of the third insulating portion 33. The normal conducting braided wire 2 disposed in the fourth tubular body 9 is connected to the superconducting wire 10 disposed on the fourth inclined surface 34a of the fourth insulating portion 34. The first cylindrical body 6, the second cylindrical body 7, the third cylindrical body 8, and the fourth cylindrical body 9 are all different in axial length and shape.

  Hereinafter, each cylindrical body will be described in detail. As shown in FIG. 1, the first tubular body 6 is arranged so as to cover the outer periphery of the first cylindrical portion 31 b of the first insulating portion 31 with half the axial length, and the remaining half axial direction The end is screwed to a cylindrical conductor lead bar 41. The conductor lead bar 41 is fixed to the fixing member 42, and one end side is compression-connected to the end portion of the former 11.

  Further, as shown in FIGS. 2 and 3, the first tubular body 6 is formed in a half-cracked tubular shape, and the inner diameter is the same in the axial direction and the outer diameter is different in the axial direction. The first cylindrical body 6 has a large diameter portion 61 disposed above the first cylindrical portion 31b of the first insulating portion 31, and a small diameter portion 62 subsequent thereto. Furthermore, the outer peripheral surface of the opening end portion of the large diameter portion 61 is formed in a tapered shape. On the outer peripheral surface of the large-diameter portion 61, a plurality of first grooves 63 in which the normal conducting braided wire 2 is arranged extending in the axial direction are formed at equal intervals in the circumferential direction. The first groove 63 is formed so that the bottom surface of the first groove 63 and the outer peripheral surface of the small diameter portion 62 are flush with each other.

  Further, a guide portion 64 cut out in the same direction as the winding direction of the superconducting wire 10 forming the first layer 12A of the superconducting conductor layer 12 is formed at the taper side end of each first groove 63. A plurality of first protrusions 65 are formed at equal intervals in the circumferential direction at the end of the large diameter portion 61 opposite to the taper forming position.

  Near the opening of the small diameter portion 62, four screw insertion holes 66 are formed. The screw insertion hole 66 is opposed to a screw fixing member 41a provided on the outer periphery of the conductor lead bar 41. The first tubular body 6 is disposed on the first insulating portion 31 so that the large diameter portion 61 is located on the center side in the former axial direction.

  Next, as shown in FIGS. 1 and 2, the second cylindrical body 7 is disposed above the large-diameter portion 61 in the first cylindrical body 6, and the axial length excluding the taper of the large-diameter portion 61. It is formed to be slightly shorter.

  As shown in FIGS. 2 and 4, the second cylindrical body 7 is also formed in a half cracked cylindrical shape. The second cylindrical body 7 has the same inner diameter in the axial direction, but a first annular groove 71 is formed near the opening at one end in the axial direction. In the first annular groove 71, a first protrusion 65 formed on the first cylindrical body 6 is fitted.

  On the outer peripheral surface of the second cylindrical body 7, a plurality of second grooves 72 in which the normal conducting braided wire 2 is arranged extending in the axial direction are formed at equal intervals in the circumferential direction. Further, the other axial end portion of the outer peripheral surface is formed in a tapered shape. A plurality of second protrusions 73 are formed at equal intervals in the circumferential direction at positions corresponding to the first annular groove 71 on the outer peripheral surface of the second cylindrical body 7. The second cylindrical body 7 is disposed on the first cylindrical body 6 so that the taper side is located on the axially central side of the former.

  Next, as shown in FIGS. 2 and 5, the third tubular body 8 includes a first tubular portion 81, a second tubular portion 83 having a diameter larger than the first tubular portion 81, It has a tapered tubular portion 82 that is continuous with the one tubular portion 81 and the second tubular portion 83. The third cylindrical body 8 has a length that covers the second cylindrical portion 33 b and the third cylindrical portion 33 c of the third insulating portion 33 and the second cylindrical body 7. The first cylindrical portion 81 is along the outer shape of the second cylindrical portion 33b of the third insulating portion 33, and the second cylindrical portion 83 is along the outer shape of the third cylindrical portion 33c and the second cylindrical body 7. It has become.

  The third cylindrical body 8 is formed in a half-cracked cylindrical shape, and the first cylindrical portion 81 is formed not only with an outer diameter but also with an inner diameter smaller than that of the second cylindrical portion 83.

  The outer peripheral surface of the opening end portion of the first cylindrical portion 81 is formed in a tapered shape. On the outer peripheral surface of the first tubular portion 81, a plurality of third grooves 81a in which the normal conducting braided wire 2 is disposed extending in the axial direction are formed at equal intervals in the circumferential direction.

  Further, a guide portion 81b cut out in the same direction as the winding direction of the superconducting wire 10 forming the second layer 12B of the superconducting conductor layer 12 is formed at the tapered end of each third groove 81a.

  On the outer peripheral surface of the second cylindrical portion 83, a plurality of normal conductive braided wire drawing grooves 83a in which the normal conductive braided wire 2 extends in the axial direction are formed at equal intervals in the circumferential direction. Has been. The normal conducting braided wire lead-out groove 83a has a length equal to or less than half of the axial length of the second cylindrical portion 83, and the normal conducting braid is disposed at the axial central portion of the second cylindrical portion 83. An annular recess 83b having a bottom surface having the same height as the bottom surface of the line drawing groove 83a is formed. In this annular recess 83b, the normal conducting braided wire 2 is drawn outward in the radial direction.

  Further, a flange-like annular projection 83c is formed near the opening on the outer peripheral surface of the second cylindrical portion 83, and is located at a position corresponding to the annular projection 83c on the inner peripheral surface of the second cylindrical portion 83. The second annular groove 83d is formed. A second protrusion 73 formed on the second cylindrical body 7 is fitted into the second annular groove 83d.

  The tapered cylindrical portion 82 has a minimum outer diameter that becomes a small-diameter side end portion equal to the outer diameter of the bottom surface position of the third groove 81a formed in the first cylindrical portion 81, and the large-diameter side end portion. The maximum outer diameter is the same as the outer diameter of the bottom surface position of the normal conducting braided wire drawing groove 83a formed in the second cylindrical portion 83. Further, the inner surface of the tapered cylindrical portion 82 is also tapered.

  Next, as shown in FIGS. 2 and 6, the fourth cylindrical body 9 includes a first cylindrical portion 91, a second cylindrical portion 93 having a diameter larger than that of the first cylindrical portion 91, It has a tapered tubular portion 92 that is continuous with the one tubular portion 91 and the second tubular portion 93. The fourth cylindrical body 9 has a length that covers almost the entire third cylindrical body 8. The first cylindrical portion 91 is fitted to the first cylindrical portion 81 of the third cylindrical body 8, and the second cylindrical portion 93 is fitted to the second cylindrical portion 83 of the third cylindrical body 8. It has become.

  The fourth cylindrical body 9 is also formed in a half-cracked cylindrical shape, and the first cylindrical portion 91, the tapered cylindrical portion 92, and the second cylindrical portion 93 have not only an outer diameter but also a large inner diameter. It is also different.

  The outer peripheral surface of the opening end portion of the first cylindrical portion 91 is formed in a tapered shape. On the outer peripheral surface of the first cylindrical portion 91, a plurality of fourth grooves 91a in which the normal conducting braided wire 2 is disposed extending in the axial direction are formed at equal intervals in the circumferential direction.

  On the outer peripheral surface of the second cylindrical portion 93, a plurality of normal conductive braided wire drawing grooves 93a in which the normal conductive braided wire 2 extends in the axial direction are formed at equal intervals in the circumferential direction. Has been. The normal conducting braided wire lead-out groove 93a has a length that is about 1/4 of the axial length of the second cylindrical portion 93. On the part side, an annular recess 93b having a bottom surface having the same height as the bottom surface of the normal conducting braided wire drawing groove 93a is formed. In the annular recess 93b, the normal conductive braided wire 2 is drawn outward in the radial direction.

  Further, a plurality of normal conducting braided wire extraction holes 93c are formed at positions facing the respective annular recesses 83b formed in the third cylindrical body 8 at the central portion in the axial direction of the second cylindrical portion 93. The normal conductive braided wire 2 arranged in the third cylindrical body 8 is drawn out from these normal conductive braided wire extraction holes 93c.

  Further, a third annular groove 93d is formed near the opening on the inner peripheral surface of the second tubular portion 93 at a position facing the annular protrusion 83c formed on the third tubular body 8. An annular protrusion 83c formed on the third cylindrical body 8 is fitted into the third annular groove 93d.

  Next, a procedure for configuring a terminal structure in which the superconducting wire 10 in the superconducting conductor layer 12 of the superconducting cable is connected to the normal conducting braided wire 2 will be described.

  After the cable core 1 is exposed for a certain length from the end of the heat insulating tube, the shield layer 14, the electrical insulating layer 13, and the superconducting conductor layer 12 are stepped off at the end of the cable core 1 as follows.

  First, before stripping, the end of the former 11 exposed in advance at the end of the cable core 1 is compression-connected to a cylindrical conductor lead bar 41 as shown in FIG.

  In a state where the cable core 1 is fixed to the fixing member 42 via the conductor lead bar 41, a protective layer (not shown) is removed from the end portion of the cable core 1 by a predetermined length, and the shield layer 14 is exposed.

  Then, the end of the shield layer 14 is unwound and spread to expose the electrical insulating layer 13. Further, the electrical insulating layer 13 is removed by a predetermined length. Next, the winding of the superconducting wire 10 of the second layer 12B outside the superconducting conductor layer 12 is unrolled and spread so that the spiral state is gently left close to the electrical insulating layer 13. After that, remove about half of the exposed axial length of the interlayer insulating layer, and unwind the superconducting wire 10 on the inner first layer 12A so that the spiral state remains gently near the interlayer insulating layer. spread.

  Next, reinforcing insulating paper is wound around the exposed cushion layer 15 to form the first insulating portion 31. The first insulating portion 31 is continuous with the first inclined surface 31a having a diameter expanded from the base of the superconducting wire 10 of the first layer 12A, which has been unwound, toward the end surface of the former 11, and the first inclined surface 31a. The first cylindrical portion 31b is formed.

  Then, the first cylindrical body 6 in a half-cracked state of the normal conductive braided wire mounting member 5 is inserted into the first groove 63 with the normal conductive braided wire 2 fitted in each first groove 63. It arrange | positions around the columnar part 31b. Then, a screw is inserted from the screw insertion hole 66, and the first tubular body 6 is fixed to a screw fixing member 41a provided on the conductor lead bar 41. Each normal conducting braided wire 2 is arranged in the first groove 63 in a state where a predetermined length is drawn from both axial ends of the first groove 63.

  Of the superconducting wires 10 that form the unwound first layer 12A, every other superconducting wire 10 runs along the first inclined surface 31a while maintaining the spiral state in the same direction as the winding direction. One superconducting wire 10 along one inclined surface 31a is connected to the normal conducting braided wire 2 arranged in the first cylindrical body 6 one by one.

  Next, the second tubular body 7 in a half-cracked state of the normal conductive braided wire mounting member 5 is inserted into the second groove 72 and the normal conductive braided wire 2 is fitted into each second groove 72. It arrange | positions around the diameter part 61. FIG. Each normal conducting braided wire 2 is arranged in the second groove 72 in a state where a predetermined length is drawn from both axial ends of the second groove 72. Further, the first annular groove 71 formed in the second cylindrical body 7 is fitted to the first protrusion 65 formed in the large-diameter portion 61 of the first cylindrical body 6 so that the second cylindrical body 7 is pivoted. Do not move in the direction.

  And, to cover the superconducting wire 10 and the normal conducting braided wire 2 disposed on the first inclined surface 31a of the first insulating portion 31, the cushion layer 15, the first inclined surface 31a of the first insulating portion 31, and A reinforcing insulating paper is wound around the taper formed in the opening of the second cylindrical body 7 to form the second insulating portion 32. The second insulating portion 32 is tapered so that it is formed only by the second inclined surface 32a.

  The other half of the superconducting wire 10 forming the unwound first layer 12A is placed along the second inclined surface 32a of the second insulating portion 32 so as to form a gentle spiral, and these superconducting wires 10 Are connected to the normal conductive braided wire 2 arranged on the second cylindrical body 7 one by one on the second inclined surface 32a.

  Then, the superconducting wire 10 and the normal conducting braided wire 2 disposed on the second inclined surface 32a of the second insulating portion 32 are reinforced around the interlayer insulating layer of the superconducting conductor layer 12 and the second insulating portion 32. A third insulating portion 33 is formed by winding the insulating paper. The third insulating portion 33 is formed to have a third inclined surface 33a, a second cylindrical portion 33b, a tapered portion, and a third cylindrical portion 33c.

  Next, a state where the normal conductive braided wire 2 is fitted into each third groove 81a and the normal conductive braided wire drawing groove 83a of the third cylindrical body 8 in a half-broken state of the normal conductive braided wire mounting member 5 Thus, the third insulating portion 33 and the second cylindrical body 7 are arranged around the third insulating portion 33 so as to cover from the second cylindrical portion 33b to the third cylindrical portion 33c. Each normal conducting braided wire 2 has a predetermined length drawn from one axial end of the third groove 81a and a predetermined length drawn from the other axial end of the normal conducting braided wire drawing groove 83a In each groove. Furthermore, the second protrusion 73 formed on the second cylindrical body 7 is fitted with the second annular groove 83d formed on the third cylindrical body 8, so that the third cylindrical body 8 does not move in the axial direction. To.

  Of the superconducting wires 10 forming the second layer 12B that has been unwound, every other superconducting wire 10 holds a spiral state in the same direction as the winding direction on the third inclined surface 33a of the third insulating portion 33. The superconducting wire 10 along the third inclined surface 33a is connected to the normal conductive braided wire 2 arranged in the third cylindrical body 8 one by one.

  Next, a state in which the normal conductive braided wire 2 is fitted into each fourth groove 91a and the normal conductive braided wire lead-out groove 93a of the fourth tubular body 9 in a half cracked state of the normal conductive braided wire mounting member 5 Thus, the third cylindrical body 8 is arranged around the third cylindrical body 8 so as to cover almost the whole. Each normal conducting braided wire 2 has a predetermined length drawn from one axial end of the fourth groove 91a and a predetermined length drawn from the other axial end of the normal conducting braided wire drawing groove 93a In each groove.

  At this time, the end of the normal conducting braided wire 2 arranged in the third tubular body 8 is drawn out from the normal conducting braided wire extraction hole 93c formed in the fourth tubular body 9. Then, the third annular groove 93d formed in the fourth cylindrical body 9 is fitted to the annular protrusion 83c formed in the third cylindrical body 8, so that the fourth cylindrical body 9 does not move in the axial direction. To do.

  A taper formed in the opening of the third insulating portion 33 and the fourth tubular body 9 so as to cover the superconducting wire 10 and the normal conducting braided wire 2 disposed on the third inclined surface 33a of the third insulating portion 33. A fourth insulating portion 34 is formed by winding reinforcing insulating paper around the periphery. The fourth insulating portion 34 is tapered so as to be formed only by the fourth inclined surface 34a.

  Next, the other half of the superconducting wire 10 forming the unwound second layer 12B is placed along the fourth inclined surface 34a of the fourth insulating portion 34 so as to form a gentle spiral, and this fourth The superconducting wires 10 along the inclined surface 34a are connected to the normal conducting braided wire 2 arranged in the fourth tubular body 9 one by one.

  Finally, the end of the electrical insulating layer 13, the superconducting wire 10 and the normal conducting braided wire 2 on the fourth inclined surface 34a of the fourth insulating portion 34, and the first cylindrical portion 91 of the fourth cylindrical body 9 and The electric insulation reinforcing part 16 is formed so as to cover the tapered cylindrical part 92. The electric insulation reinforcing portion 16 is also formed by winding a reinforcing insulating paper.

  Thus, in this embodiment, after unwinding and spreading the superconducting wire at the axial end portion of the superconducting conductor layer 12, the spread superconducting wire is spread on each inclined surface of the insulating portion 3 for expanding the wire interval. By keeping along, the superconducting wire can be easily maintained in a state where it is spread at a desired interval.

  In addition, in each of the first layer 12A and the second layer 12B of the superconducting conductor layer 12, every other superconducting wire is disposed between the insulating portions, so that the adjacent superconducting wires can be reliably secured with reinforced insulating paper. Can be isolated.

  Further, one normal conducting braided wire is fitted into each groove of the normal conducting braided wire attaching member 5 and the normal conducting braided wire attaching member 5 is connected to the insulating portion for expanding the wire interval. Since it is arranged on the outer periphery of 3, the normal conducting braided wire can be easily connected to the superconducting wire without the positional deviation of the normal conducting braided wire.

  In addition, since the normal conductive braided wire mounting member 5 is formed of a plurality of cylindrical bodies, even if the width of the normal conductive braided wire is relatively large, the normal conductive braided wires can be displaced by each cylindrical body. And can be arranged in the radial direction. As a result, the normal conductive braided wire attaching member 5 can be prevented from becoming too large in the radial direction, and contact of the normal conductive braided wire can be prevented.

  In addition, since the guide portions 64 and 81b are formed in the grooves of the first cylindrical body 6 and the third cylindrical body 8 of the normal conductive braided wire mounting member 5, the normal conductive braided wire extends along the grooves. Even if it is arranged in the axial direction, the connection-side end of the normal conducting braided wire with the superconducting wire can be directed in the winding direction of the superconducting wire along the guide portions formed in each groove. As a result, the normal conducting braided wire is not damaged at the end of the groove, and the superconducting wire does not need to be forcibly bent in the former axial direction, thereby facilitating connection work.

  By constructing the terminal structure of the superconducting cable as described above, each of the superconducting wires 10 of the superconducting conductor layer 12 can be connected to the normal conducting braided wire 2 surely and easily. It is possible to reliably measure the current value of each wire and the influence of the magnetic field, and also check the soundness.

  Note that the terminal structure of the superconducting cable of the present invention may be adopted in any of the superconducting cables for DC power transmission and AC power transmission. Moreover, the terminal structure of the superconducting cable of the present invention is not limited to the above embodiment, and the scope of the present invention is not limited to the above embodiment.

  The terminal structure of the superconducting cable of the present invention can be suitably used when measuring the current value of each superconducting wire.

The fragmentary sectional view of the terminal structure of the superconducting cable of the present invention is shown. It is sectional drawing in the assembly | attachment state of the member for normal conducting braided wire attachment used for the terminal structure of this invention superconducting cable. It is an explanatory view of a first cylindrical body of a member for mounting a normal conductive braided wire used in the terminal structure of the superconducting cable of the present invention, (a) is a side view of the first cylindrical body, (b) is a first cylinder It is the front view seen from the large diameter part side opening part of a cylindrical body. It is explanatory drawing of the 2nd cylindrical body of the member for normal conducting braided wire attachment used for the terminal structure of this invention superconducting cable, (a) is a side view of the 2nd cylindrical body, (b) is the 2nd cylinder. It is the front view seen from the taper side opening part of a cylindrical body. It is explanatory drawing of the 3rd cylindrical body of the member for normal conducting braided wire attachment used for the terminal structure of this invention superconducting cable, (a) is a side view of the 3rd cylindrical body, (b) is the 3rd cylinder. It is the front view seen from the taper side opening part of a cylindrical body, (c) is XX sectional drawing in (a). It is explanatory drawing of the 4th cylindrical body of the member for normal conducting braided wire attachment used for the terminal structure of the superconducting cable of the present invention, (a) is a side view of the 4th cylindrical body, (b) is the 4th cylinder It is the front view seen from the taper side opening part of a shape body, (c) is the YY sectional view taken on the line in (a), (d) is the ZZ sectional view taken on the line in (a). It is explanatory drawing of the terminal structure of the conventional superconducting cable.

Explanation of symbols

1 Cable core
11 Former
12 Superconducting conductor layer 10 Superconducting wire
12A 1st layer 12B 2nd layer
13 Electrical insulation layer
14 Shield layer 15 Cushion layer 16 Electrical insulation reinforcement
2 Normal conductive braided wire
3 Insulation part for expanding wire spacing
31 First insulation
31a First inclined surface 31b First cylindrical part
32 Second insulation
32a Second inclined surface
33 Third insulation
33a Third inclined surface 33b Second cylindrical part 33c Third cylindrical part
34 Fourth insulation
34a Fourth inclined surface
41 Conductor extraction rod 41a Screw fixing member 42 Fixing member
5 Normal conductive braided wire mounting member
6 First cylinder
61 Large diameter part 62 Small diameter part 63 First groove 64 Guide part
65 First protrusion 66 Screw insertion hole
7 Second cylindrical body
71 First annular groove 72 Second groove 73 Second protrusion
8 Third cylinder
81 First cylindrical part 81a Third groove 81b Guide part
82 Tapered tube
83 Second cylindrical part
83a Groove for normal conducting braided wire drawing 83b Ring recess
83c annular projection 83d second annular groove
9 Fourth cylinder
91 1st cylindrical part 91a 4th groove
92 Tapered tube
93 Second cylindrical part
93a Groove for normal conducting braided wire drawing 93b Annular recess
93c Normal conductive braided wire entry hole 93d Third annular groove

Claims (7)

A superconducting cable terminal structure in which a superconducting conductor layer is formed by spirally winding a plurality of superconducting wires around a former,
In the superconducting conductor layer, the winding of the superconducting wire is unwound over a predetermined length at the end in the axial direction. Insulating part for expanding the wire interval, having the superconducting wire along the inclined surface of the insulating part for expanding the wire interval, widening the interval between the axial ends of these superconducting wires ,
While connecting each superconducting wire individually to multiple normal conducting braided wires,
A normal conductive braided wire mounting member formed of an insulating material and formed in a cylindrical shape having a plurality of grooves extending in the axial direction on the outer peripheral surface is disposed on the outer periphery of the insulating portion for expanding the wire interval, A terminal structure of a superconducting cable, in which normal conducting braided wires are arranged one by one .   The superconducting cable terminal structure according to claim 1, wherein the insulating portion for expanding the wire interval is formed by winding reinforcing insulating paper around the outer periphery of the former.   The insulating portion for expanding the wire interval is composed of a cylindrical body configured by combining half-cracked members formed of an insulating resin material, and has a tapered portion that becomes an inclined surface on the outer peripheral surface of the cylindrical body. The terminal structure of the superconducting cable according to claim 1, wherein Each groove | channel of the member for normal conducting braided wire attachment has the guide part notched in the same direction as the winding direction of a superconducting wire at the connection side edge part with a superconducting wire . The terminal structure of the superconducting cable according to any one of the above. The normal conductive braided wire mounting member is composed of a plurality of cylindrical bodies that are coaxially stacked, and a plurality of the grooves in which the normal conductive braided wires are disposed are formed on the outer peripheral surface of each cylindrical body, and at least The cylindrical body arranged on the outermost side has a normal conductive braided wire extraction hole formed at a predetermined position corresponding to each groove of the cylindrical body arranged on the inner side of the cylindrical body. The terminal structure of the superconducting cable according to any one of 1 to 4 .   The normal conducting braided wire mounting member is composed of a plurality of cylindrical bodies that are coaxially stacked, and each cylindrical body is formed by combining half-cracked members,
  Among the cylindrical bodies, a protrusion is provided on the outer peripheral surface in the axial direction of the cylindrical body excluding the outermost cylindrical body, and is fitted to the protrusion on the inner peripheral surface of the cylindrical body excluding the innermost cylindrical body. Provide a recess at the mating position,
  The movement of each cylindrical body in the axial direction is prevented by fitting the protrusion of the inner cylindrical body and the concave portion of the outer cylindrical body. The terminal structure of the superconducting cable according to any one of 5. Normal conductive braided wire mounting member, a superconducting cable according to any one of claims 1 to 6, characterized in that it is fixed to the former via a locking mechanism for preventing axial movement of the former Terminal structure.

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