JP2019149901A - Coil end bonding method and coil end structure - Google Patents

Abstract

To reduce failures in soldering such as insufficient wetting of a solder material and occurrence of voids in solder-bonding of a coil end to a clip.SOLUTION: A coil end bonding method includes: a strand arraying step of arraying ends of a plurality of coil strands 11 each containing a hollow coil strand 11a and horizontally extending, in a horizontal direction and a vertical direction within a metal clip 12; a solder member arrangement step of arranging a solid solder member 13 extending in the horizontal direction on at least upper end of the end of the plurality of coil strands 11 within the clip 12; a plate member arrangement step of arranging a plate member 15 made of a material having a melting point higher than that of the solder member 13 and horizontally extending; and a soldering step of heating and melting the solder member 13, making the solder member 13 flow down using the plate member 15 as a guide, and soldering the coil strands 11 to each other, and the coil strand 11 and the clip 12.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a coil end joining method and a coil end structure using brazing.

  As a structure of a stator coil of a rotating electrical machine such as a large generator, a structure is known in which ends of the strands of the stator coil are bundled in a lattice shape and brazed to a clip (water supply / drainage box). In this case, a part of the strands of the stator coil has a hollow structure, and cooling is performed by flowing water into the hollow portion of the strands of the stator coil through the water supply / drainage box.

JP 2009-254027 A Japanese Patent No. 3424450

  When brazing and joining the coil ends of the above structure to the clip, brazing defects such as insufficient wetting of the brazing material between the coil strands or between the coil strand and the clip, insufficient wetting length, void generation, etc. May occur, and there is a problem that the reliability of the brazed joint due to the brazing failure cannot be sufficiently obtained.

  An embodiment of the present invention is to solve such a problem, and in brazing and joining a coil end portion to a clip, a brazing material between coil wires or between a coil wire and a clip. The purpose is to prevent the occurrence of brazing defects such as insufficient wetting, insufficient wetting length and voids.

  In order to solve the above-described problem, a coil end joining method according to an embodiment includes at least one hollow coil strand and the ends of a plurality of coil strands extending in parallel to each other in a metal clip. And arranging at least one solid brazing member extending in the horizontal direction at least at the upper ends of the ends of the plurality of coil strands in the clip. After the member disposing step, the plate member disposing step of disposing a horizontally extending plate member made of a material having a higher melting point than the brazing member, the wire arranging step, the brazing member disposing step, and the plate member disposing step, The brazing member is heated and melted, and the brazing member is caused to flow down using the plate member as a guide, so that the coil strands and the coil strands and the clip And having a brazing step of brazing the flop, the.

  In addition, the coil end structure according to the embodiment includes a plurality of coil strands including at least one hollow coil strand, extending parallel to each other in the horizontal direction, and having end portions arranged in the horizontal direction and the vertical direction. A metal clip in which ends of the plurality of coil strands are fixed and communicated with a hollow portion of the hollow coil strand; ends of the plurality of coil strands; and ends of the plurality of coil strands A brazing member that brazes the portion and the clip, and a plate member that is made of a material having a higher melting point than the brazing member and extends horizontally in the clip and guides the brazing material during the brazing joining. It is characterized by having.

It is a figure which shows the condition immediately before the brazing step in the stator coil end joining method according to the first embodiment of the present invention, and is a cross-sectional view taken along the line II in FIG. It is an arrow longitudinal cross-sectional view which follows the II-II line of FIG. It is a flowchart which shows the procedure of the stator coil end part joining method which concerns on the 1st Embodiment of this invention. It is a flowchart which shows the procedure of the stator coil edge part joining method which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the brazing member and board member coupling | bond body in the stator coil edge part joining method which concerns on the 2nd Embodiment of this invention. It is a cross-sectional view which shows the condition just before the brazing step in the stator coil end joining method according to the third embodiment of the present invention. It is a cross-sectional view showing the situation immediately before the brazing step in the stator coil end joining method according to the fourth embodiment of the present invention. It is sectional drawing of the plate member used with the stator coil edge part joining method which concerns on the 5th Embodiment of this invention. It is typical sectional drawing of the plate member used with the stator coil edge part joining method concerning the 6th Embodiment of this invention, and the brazing member which opposes it.

  Hereinafter, an embodiment of a stator coil end joint method according to the present invention will be described with reference to the drawings. Here, the same or similar parts are denoted by common reference numerals, and redundant description is omitted.

[First Embodiment]
FIG. 1 is a cross-sectional view showing a state immediately before a brazing step in the stator coil end joining method according to the first embodiment of the present invention. 2 is a longitudinal sectional view taken along the line II-II in FIG. FIG. 3 is a flowchart showing the procedure of the stator coil end joining method according to the first embodiment.

  The object of the joining method of this embodiment is, for example, an end portion of a stator coil of a rotating electrical machine such as a large generator.

  The coil wires 11 of the plurality of stator coils are arranged and bundled in a lattice shape, and are brazed and joined to the inside of the clip (water supply / drain box) 12 by a brazing member 13 (13a, 13b, 13c, 13d). 12 is sealed. The coil wires 11 of the plurality of stator coils include a hollow coil wire 11a and a solid coil wire 11b. In the example shown in FIG. 1 and FIG. 2, two hollow coil wires 11 a and two solid coil wires 11 b, a total of four coil wires 11, are arranged in parallel and horizontally, A coil element wire is formed, and the same four coil element wires 11 are arranged horizontally and parallel to each other to form a lower coil element wire. The clip 12 and the coil wire 11 are made of a material having high electrical conductivity such as copper.

  The brazing members 13 immediately before brazing are spread in the horizontal direction and cover the entire upper and lower sides of the upper coil element wire 11, respectively, and the upper and lower parts of the lower coil element wire 11. It consists of brazing members 13c and 13d covering the entire side. Here, the brazing member 13 is made of a brazing material having a melting point lower than that of copper, and may be solder.

  The clip 12 accommodates the end of the coil wire 11 and is connected to the cooling pipe 14. A coolant such as water is supplied into the clip 12 through the cooling pipe 14 so that the inside of the hollow coil wire 11a can be circulated, whereby the coil wire 11 can be cooled. As the coolant, hydrogen gas can be used in addition to water.

  A conductor (not shown) is electrically connected to the clip 12, and the conductor and the coil wire 11 are electrically connected via the clip 12.

  The procedure of the stator coil end joining method according to the first embodiment will be described with reference to FIG.

  First, the end portions of the coil wires 11 are arranged in a grid pattern in the clip 12 as described above (element arrangement step S10). Next, solid brazing members 13a and 13b are arranged in the clip 12 so as to sandwich the upper row of coil wires 11 vertically. In the clip 12, the solid brazing members 13c and 13d are arranged so as to sandwich the lower row of coil wires 11 vertically (waxing member arranging step S20).

  Next, between the two brazing members 13b and 13c arranged so as to overlap vertically between the row of the upper coil strands 11 and the row of the lower coil strands 11, these two brazing members A horizontally extending plate member 15 is inserted so as to partition between 13b and 13c (plate member arrangement step S30). The plate member 15 is made of a material having a melting point higher than that of the brazing member 13, and is made of, for example, copper.

  Next, the brazing member 13 and its periphery are heated by induction heating or the like to melt the brazing member 13 and braze (brazing step S40). At this time, the molten brazing member 13 is dropped due to gravity, and due to the penetration force due to surface tension, the gap between the coil strands 11, the gap between the coil strand 11 and the clip 12, and the coil strand 11 and the plate A gap between the member 15 and the like is filled. Thereby, while the coil strand 11 and the clip 12 are joined electrically and mechanically, the leakage of the coolant at the joined portion can be prevented.

  Due to the presence of the plate member 15, the molten brazing members 13 a and 13 b around the row of the upper coil wires 11 fall to the periphery of the row of the lower coil wires 11 below the plate member 15. Since it is suppressed, the distribution of the brazing member 13 in the vertical direction is made uniform. Further, since the brazing member 13 tends to spread along the upper and lower surfaces of the plate member 15, the upper and lower brazing members 13 of the plate member 15 are likely to spread horizontally, thereby making the horizontal distribution of the brazing member 13 uniform. Is done. This improves the brazing quality.

  As described above, according to this embodiment, when the coil end is brazed to the clip 12, the brazing material is wetted between the coil wires 11 or between the coil wire 11 and the clip 12. Brazing defects such as shortage, insufficient wet length, and void generation are less likely to occur.

  In the above description, the wire arrangement step S10, the brazing member arrangement step S20, and the plate member arrangement step S30 are performed in this order, but it is not always necessary to perform them in that order. For example, the coil wire 11, the brazing member 13, and the plate member 15 may be stacked in order from the bottom.

  In the example shown in FIGS. 1 and 2, the coil strands 11 are arranged in two upper and lower stages, but may be arranged in three or more stages. Moreover, in the example shown in FIG. 1 and FIG. 2, the upper and lower two-stage coil strands 11 include four hollow coil strands 11a and two solid coil strands 11b, respectively, for a total of four coil strands. 11, the configuration of the coil wire 11 in each stage is arbitrary.

[Second Embodiment]
FIG. 4 is a flowchart showing the procedure of the stator coil end joining method according to the second embodiment of the present invention. FIG. 5 is a cross-sectional view showing the brazing member / plate member combination in the stator coil end joining method according to the second embodiment.

  The second embodiment is a modification of the first embodiment, and the configuration shown in FIGS. 1 and 2 is the same in the second embodiment.

  In the second embodiment, the wire arranging step S10 and the brazing member arranging step S20 are performed as in the first embodiment. However, in the brazing member arranging step S20 in this embodiment, only the brazing member 13a above the upper coil wire 11 and the brazing member 13d below the lower coil wire 11 among the brazing members 13 are placed in the clip 12. Deploy. Of the brazing member 13, the two brazing members 13b and 13c sandwiching the plate member 15 are arranged in the clip 12 in a coupling member arranging step S32 described later.

  In the second embodiment, before placing the plate member 15 in the clip 12, the brazing member 13 b is coupled to the upper surface of the plate member 15 outside the clip 12, and the brazing member 13 c is coupled to the lower surface of the plate member 15. By combining, a brazing member / plate member combination 40 shown in FIG. 5 is generated (coupling step S31). This coupling step S31 is performed, for example, as rolling coupling. Then, after the coupling step S31, a coupling member arrangement step S32 for arranging the brazing member / plate member combination 40 in the clip 12 is performed.

  After the strand arrangement step S10, the brazing member placement step S20, and the coupling member placement step S32, a brazing step S40 similar to that of the first embodiment is performed.

  According to the second embodiment, the step of arranging the plate member 15 in the clip 12 is performed as the coupling member arrangement step S32 of arranging the brazing member / plate member combination 40 in the clip 12, so that, for example, a plate Even when the member 15 is thin and difficult to handle by itself, the brazing member / plate member assembly 40 can be easily disposed in the clip 12.

  In the above description, the wire arranging step S10, the brazing member arranging step S20, and the connecting member arranging step S32 are performed in this order, but it is not always necessary to perform them in that order. For example, the coil wire 11, the brazing member 13, and the coupling member arranging step S32 may be stacked in order from the bottom.

[Third Embodiment]
FIG. 6 is a cross-sectional view showing a state immediately before the brazing step in the stator coil end joining method according to the third embodiment of the present invention. This third embodiment is a modification of the first embodiment.

  In the third embodiment, in the plate member arranging step S30, as in the first embodiment, the upper coil element 11 and the lower coil element 11 are vertically overlapped with each other. A horizontally extending plate member 15 is inserted between the two brazed members 13b and 13c so as to partition the two brazed members 13b and 13c. Further, plate members 15 a and 15 b similar to the plate member 15 are respectively connected to the upper portion of the brazing member 13 a above the row of upper coil strands 11 and the lower brazing member 13 d of the lower row of coil strands 11. Below, it arrange | positions so that it may spread in the clip 12 horizontally.

  Other configurations and procedures (see FIG. 3) are the same as those in the first embodiment.

  In the third embodiment, the same effect as that of the first embodiment is obtained, and in the brazing step S40, the molten brazing member 13 is easily spread horizontally along the plate members 15a and 15b. As a result, the distribution of the molten brazing member 13 in the vicinity of the plate members 15a and 15b becomes uniform. This further improves the quality of brazing.

[Fourth Embodiment]
FIG. 7 is a cross-sectional view showing a state immediately before the brazing step in the stator coil end joining method according to the fourth embodiment of the present invention.

  The fourth embodiment is a modification of the third embodiment. In the illustrated example, the coil strands 11 are composed of four hollow coil strands 11a in total, arranged in two rows in the horizontal direction and two rows in the vertical direction. On the upper hollow coil element wire 11a, a plate member 15a extending horizontally throughout the clip 12 via a brazing member 13a is disposed. Further, a plate member 15b extending horizontally throughout the clip 12 is disposed under the lower hollow coil element wire 11a via a brazing member 13d. Between the upper hollow coil wire 11a and the lower hollow coil wire 11a, the brazing members 13b and 13c (FIG. 1) are not arranged, and the plate member 15 (FIG. 1) is also not arranged.

  A wire member 20 extending horizontally in parallel to the hollow coil element 11a is disposed at a central position sandwiched between the four hollow coil elements 11a. The wire member 20 is made of a material having a melting point higher than that of the brazing member 13 like the plate members 15a and 15b, and is made of, for example, copper.

  The procedure of the stator coil end joining method according to the fourth embodiment is the same as that of the first and second embodiments (FIG. 3). However, in the third embodiment, the plate member arrangement step S30 (FIG. 3) includes not only the step of arranging the plate members 15a and 15b but also the step of arranging the line member 20.

  Other configurations and procedures (see FIG. 3) are the same as those in the first and second embodiments.

  In the fourth embodiment, since there is no plate member 15 (see FIGS. 1, 2 and 6) for vertically dividing the row of the upper hollow coil strands 11a and the row of the lower hollow coil strands 11a, brazing is performed. The flow from the upper stage to the lower stage of the brazing member 13 in step S40 cannot be completely prevented. However, in the brazing step S40, the presence of the wire member 20 reduces the gap between the hollow coil wires 11a, and the molten brazing member 13 tends to flow along the wire member 20. The molten brazing member 13 tends to flow into the gap between the strands 11a. This reduces the possibility that the brazing member 13 will not be sufficiently melted in the brazing step S40.

  In the example shown in FIG. 7, the case where all the coil wires 11 are hollow coil wires 11a is shown. However, in addition to the hollow coil wires 11a, solid coil wires 11b (FIGS. 1 and 6). Reference) may be included. In general, a gap at a position where the coil strands 11 are diagonally opposed to each other can be made relatively large. Therefore, it is preferable to arrange the wire member 20 in such a relatively large gap.

[Fifth Embodiment]
FIG. 8 is a cross-sectional view of a plate member used in the stator coil end joining method according to the fifth embodiment of the present invention.

  In the first to fourth embodiments, the plate members 15, 15 a, and 15 b are made of a material having a melting point higher than that of the brazing member 13, and are made of, for example, copper. The fifth embodiment is a modification of any of the first to fourth embodiments, and the plate members 15, 15 a and 15 b are made of a ceramic plate-like core member 25 and a plate-like core member 25. And a metal coating 26 covering the. The melting points of the plate core member 25 and the coating 26 are higher than the melting point of the brazing member 13. The coating 26 is, for example, metal plating or metal plating applied to the surface of the plate-like core member 25.

  According to this embodiment, ceramics with higher heat resistance can be used as compared with the case where the entire plate members 15, 15a, 15b are made of a metal material, and low-cost and highly durable stator coil end joining is realized. it can.

  Similarly, the wire member 20 in the fourth embodiment may be configured to include a ceramic wire core member and a metal coating covering the wire core member (not shown). ).

[Sixth Embodiment]
FIG. 9 is a schematic cross-sectional view of a plate member used in the stator coil end joining method according to the sixth embodiment of the present invention and a brazing member facing the plate member. This embodiment is a modification of any of the first or third to fifth embodiments, and a plurality of grooves 30 are formed on the surfaces of the plate members 15, 15 a, 15 b at positions facing the brazing member 13. ing.

  Other configurations and procedures are the same as those of the first or third to fifth embodiments.

  In the sixth embodiment, in the brazing step, the molten brazing member 13 spreads along the surfaces of the plate members 15, 15 a and 15 b and penetrates into the groove 30 and spreads. Thereby, there is an effect that the brazing member 13 spreads uniformly in the clip 12.

  In the above description, the plurality of grooves 30 are formed on the surfaces of the plate members 15, 15 a, 15 b, but instead of forming the grooves 30, a plurality of protrusions are formed on the surface, or irregularities are formed on the surface. Thus, the same effect can be obtained.

[Other Embodiments]
The features of the plurality of embodiments described above can be combined as appropriate.

  In the coupling step S31 of the second embodiment, the brazing member 13b is coupled to the upper surface of the plate member 15, and the brazing member 13c is coupled to the lower surface of the plate member 15, thereby generating the brazing member / plate member combination 40. . As another example of such a coupling step, the plate member 15a and the brazing member 13a of the third or fourth embodiment can be coupled to generate a brazing member / plate member combination (not shown). . Similarly, the plate member 15b and the brazing member 13d of the third or fourth embodiment may be coupled to generate a brazing member / plate member combination (not shown).

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These embodiments can be implemented in various other forms, and various omissions, replacements, changes, and combinations can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 11 ... Coil strand, 11a ... Hollow coil strand, 11b ... Solid coil strand, 12 ... Clip (water supply / drain box), 13, 13a, 13b, 13c, 13d ... Brazing member, 14 ... Cooling piping, 15, 15a , 15b ... plate member, 20 ... wire member, 25 ... plate core member, 26 ... coating, 30 ... groove, 40 ... brazing member / plate member combination

Claims (9)

A strand arrangement step for arranging the ends of a plurality of coil strands including at least one hollow coil strand and extending parallel to each other in a horizontal direction in a horizontal direction and a vertical direction in a metal clip;
A brazing member disposing step of disposing at least one solid brazing member extending in a horizontal direction on at least upper ends of end portions of the plurality of coil wires in the clip;
A plate member arranging step of arranging a plate member made of a material having a higher melting point than the brazing member and extending horizontally;
After the strand arranging step, the brazing member arranging step, and the plate member arranging step, the brazing member is heated and melted, and the brazing member is caused to flow down using the plate member as a guide, and the coil strands and the A brazing step of brazing the coil wire and the clip;
A coil end joining method characterized by comprising: The brazing member disposing step includes a step of disposing a solid brazing member extending in a horizontal direction at least at an upper end and an inside of the ends of the plurality of coil strands in the clip,
The plate member arranging step includes a step of arranging a plate member extending horizontally so as to partition the plurality of coil wires in the vertical direction between the upper end and the brazing member arranged inside.
The coil end joining method according to claim 1, wherein: The plate member arranging step includes a step of arranging the plate member along an upper surface of the brazing member arranged at an upper end of an end portion of the plurality of coil strands;
The coil end joining method according to claim 1 or 2, characterized by the above-mentioned. Before the brazing member arranging step and the plate member arranging step, a coupling step of coupling at least a part of the brazing member and the plate member outside the clip to generate a brazing member / plate member combination is further provided. Have
Performing at least a part of the brazing member arranging step and the plate member arranging step simultaneously;
The coil end joining method according to any one of claims 1 to 3, wherein: The joining step includes rolling and joining at least a part of the brazing member and the plate member;
The coil end bonding method according to claim 4, wherein: Unevenness is formed on the surface of the plate member at a position where the plate member faces the brazing member,
The coil end joining method according to any one of claims 1 to 3, wherein: The plate member includes a plate-shaped core member made of ceramic and a coating that covers a surface of the plate-shaped core member made of a metal having a melting point higher than that of the brazing member.
The coil end joining method according to any one of claims 1 to 6, wherein: Before the brazing step, in the clip, the plurality of coil strands are made of a material having a melting point higher than that of the brazing member, and extend in parallel to the coil strands at a position between the plurality of coil strands diagonally facing each other. Arranging a linear member, arranging a linear member,
The coil end joining method according to any one of claims 1 to 7, further comprising: A plurality of coil strands including at least one hollow coil strand, extending in parallel with each other in the horizontal direction, and having ends thereof arranged in the horizontal direction and the vertical direction;
A metal clip in which ends of the plurality of coil strands are fixed and communicated with the hollow portion of the hollow coil strand;
Brazing members for brazing and joining the ends of the plurality of coil strands and the ends of the plurality of coil strands to the clip;
A plate member made of a material having a higher melting point than the brazing member, extending horizontally in the clip, and guiding the brazing material during the brazing joining;
A coil end structure characterized by comprising:

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