JP2013109948A - Joining structure and joining method for rectangular wires - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a joining structure and a joining method for rectangular wires, which are capable of reducing a peeling area of an insulating film required for joining rectangular wires together and are capable of reducing an insulation treatment area after joining.SOLUTION: In a joining structure of an assembly (10) in which ends of rectangular wires (11, 12) coated with insulating films (11b, 12b) and having rectangular cross sections are welded together, the rectangular wires (11, 12) are heated and welded by irradiating end faces of the rectangular wires (11, 12) with laser light (L) in spots from above in a state where film-peeled surfaces (11c, 12c) obtained by peeling the insulating films from only one face of the ends are butted against each other so as to face each other.

Description

  The present invention relates to a bonding structure in which square wires are bonded to each other, and a bonding method that realizes the structure. More specifically, the present invention relates to a joining structure of square lines in which end portions are joined by welding after peeling off an insulating coating, and a joining method for realizing the structure.

  2. Description of the Related Art Conventionally, in rotating electrical machines such as an AC generator, a coil to be attached to a stator is configured with a coil wire (square wire) having a rectangular cross section in order to improve the space factor. This type of coil is formed by inserting a rectangular wire formed into a predetermined shape into a slot of a stator core and joining ends of the respective rectangular wires protruding from the slot.

Specifically, for example, the square line is formed in a U-shape having two straight portions, and the two straight portions are separated from each other by different slots of the stator core, for example, approximately the magnetic pole pitch of the stator. After passing through the slot, the end side protruding from the slot is tilted (or tilted in advance) in the circumferential direction of the stator core, and the respective square line end portions are sequentially joined to form a continuous coil. And the joining of the square wires is performed by arc welding with the entire surface of the insulating coating at the end portions of the square wires peeled off (see Patent Document 1).
In general, the insulating film is peeled off on the four sides (four-sided peeling) at the end of the square line or on eight sides (8-sided peeling) including the corners.

JP 2008-154433 A

However, in the joining technique described above, in order to join the ends of the square wires, it is necessary to peel off the insulating film at the ends of the square wires and to insulate a large area of the joint and the peeled portion after joining. there were. Here, if the four-sided peeling is performed as the peeling of the insulating film, it is advantageous in terms of efficiency and cost, but the conductor volume decreases in the square line after peeling, so the resistance between the lines increases at the joint. Resulting in. On the other hand, when eight-sided peeling is performed as the insulating coating peeling, the conductor volume is hardly reduced in the square line after peeling, but it is disadvantageous in terms of efficiency and cost. In addition, the insulating film is peeled over the entire end portion of the square line regardless of whether the four-side peeling or the eight-side peeling is performed, so that the insulation treatment area after the bonding is large, and the insulation treatment takes time and cost.
Thus, in the conventional joining technique, the peeling area of the insulating coating is large, and the insulation treatment area after joining is also large. Therefore, it is disadvantageous in terms of efficiency and cost.

  Accordingly, the present invention has been made to solve the above-described problems, and it is possible to reduce the peeled area of the insulating film necessary for joining the square wires and to reduce the insulation treatment area after joining. An object of the present invention is to provide a bonding structure and a bonding method for rectangular wires.

One embodiment of the present invention made to solve the above problem is that, in a joint structure in which end portions of rectangular wires having a rectangular cross section provided with an insulating coating are welded to each other, the insulating coating is peeled only on one surface of the end portion. In the state where the square lines are abutted so that the respective coating peeling surfaces face each other, the corner lines are welded by spot heat input from above to each square line. Features.
The one surface from which the insulating coating is peeled off at the end portion of the square line is one surface of the four surfaces other than the end surface of the end portion.

  In this joining structure, since the coating peeling surface from which the insulating coating has been peeled is bonded to only one surface of the end portion of the square wire, the peeling area of the insulating coating necessary for joining the square wires can be reduced. . In addition, since the square wires are spot-heated from above to the end surfaces of the square wires where the conductor portions are exposed, the square wires are welded to each other, so that the insulation coating is damaged by the heat during welding. Can be prevented. For these reasons, the insulation treatment after joining is performed on the joining side surface and end face (when high insulation performance is required, for example, when the joined rectangular wires are adjacent), or only on the joining side surface (when insulation performance is not required). Therefore, it is possible to reduce the insulation processing area. As described above, according to this joining structure, joining between the square wires can be realized efficiently and at low cost.

  In the above-described joining structure of square wires, it is desirable that the square wire is a flat wire, and the long side of the flat wire is a joint surface.

  By being joined in this way, it is possible to obtain a welded structure that ensures a sufficient joining strength and melting cross-sectional area.

  In the above-described square wire bonding structure, it is desirable that the heat input to each square wire is performed by a laser or an electron beam.

  Thus, by joining the square lines by laser welding or electron beam welding, the above welded structure can be obtained easily and quickly.

  In this case, it is desirable that the laser or the electron beam is irradiated at equal intervals along the boundary line of each square line.

  Thus, by irradiating the laser or the electron beam at equal intervals along the boundary line of each square line, a welded structure in which the square lines are reliably and satisfactorily joined can be obtained. Here, increasing the laser or electron beam irradiation interval (decreasing the number of welding points) decreases the welding strength, and decreasing the laser or electron beam irradiation interval (increasing the number of welding points) increases the welding strength. For this reason, by adjusting the laser or electron beam irradiation interval, it is possible to obtain a welded structure that ensures the required bonding strength.

  Further, another aspect of the present invention made to solve the above-described problems is that, in the joining method of welding the end portions of rectangular wires having a rectangular cross section with an insulating coating applied, only one surface of each end portion of each square wire is welded. The insulation coating is peeled off, the respective square lines are brought into contact with and brought into contact with each other so that the respective peeling faces of the coatings face each other, and the square lines are welded to each other by spot heat input from above to the respective square lines. It is characterized by that.

In this bonding method, first, only one surface of the insulating coating at the end of each square line is peeled off. Here, the one surface from which the insulating coating is peeled off at the end of the square line is one of the four surfaces other than the end surface of the end. Since the end surface is a cut surface, the conductor portion is exposed.
Next, the respective square lines are brought into contact with each other so that the respective film peeling surfaces face each other. And it heat-spots to each square line from the upper part to the end surface of those square lines, and square lines are welded. Thus, the square lines are joined at the ends. Note that the spot-like heat input may be performed near the junction boundary.

  Thus, according to this joining method, in order to join (weld) the square wires, it is only necessary to peel off one surface of the insulation coating at the end of each square wire, so that the insulation coating necessary for joining the square wires. The peeling area can be reduced. And, since the square wires are welded to each corner line from the top by spot heat on the end face of the square line, it is possible to prevent damage to the insulation coating due to heat at the time of welding, and the peeling area of the insulation coating is small Therefore, if the insulation treatment after joining is performed on the joining side surface and the end face (when high insulation performance is required, for example, when the joined square lines are adjacent), or only on the joining side surface (when insulation performance is not required). good. Therefore, the insulation processing area can be reduced. Therefore, the joining of the square wires can be performed efficiently and at a low cost.

  Further, in the above-described method for joining rectangular wires, it is desirable that each of the square wires is a flat wire and the long side of the flat wire is brought into contact with and welded.

  By joining in this way, it is possible to ensure a greater joining strength and melting cross-sectional area than in the case where welding is performed by bringing the short side of the flat wire into contact.

  In the above-described method for joining rectangular wires, it is desirable to heat and heat each square wire with a laser or an electron beam for welding.

  Thus, it can join simply and rapidly by joining square lines by laser welding or electron beam welding.

  In this case, the laser or electron beam may be irradiated at equal intervals along the boundary line of each square line.

  In this way, by irradiating a laser or an electron beam at equal intervals along the boundary line between the square lines, the square lines can be reliably and satisfactorily joined. Here, increasing the laser or electron beam irradiation interval (decreasing the number of welding points) decreases the welding strength, and decreasing the laser or electron beam irradiation interval (increasing the number of welding points) increases the welding strength. For this reason, the required bonding strength can be ensured by adjusting the laser or electron beam irradiation interval.

  According to the joining structure and joining method of the square wire according to the present invention, as described above, the insulation coating area after joining is reduced while reducing the peeling area of the insulating film necessary for joining the square wires while ensuring the joining quality. Can be reduced.

It is a side view which shows typically the conjugate | zygote which has the joining structure of the flat wire which concerns on this Embodiment. It is a top view which shows typically the conjugate | zygote which has the joining structure of the flat wire which concerns on this Embodiment. It is a perspective view which shows the flat wire which peeled only one surface of the insulating film. It is a figure which shows the state faced in order to join a flat wire. It is a figure which shows typically the state which is performing laser welding. It is a figure which shows the irradiation point of a laser typically. It is a figure which shows typically the mode of the laser irradiation in the AA cross section of FIG. It is a figure which shows typically a mode that laser irradiation is performed from the diagonal direction. It is a figure which shows the modification of a conjugate | zygote.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying a bonding structure and bonding method for rectangular wires according to the present invention will be described below in detail with reference to the drawings. Here, in order to join two flat wires, the case where the end part is laser-welded is illustrated.

  First, a rectangular wire joining structure according to the present embodiment will be briefly described with reference to FIGS. 1 and 2. FIG. 1 is a side view schematically showing a joined body having a flat wire joining structure according to the present embodiment. FIG. 2 is a top view schematically showing a joined body having a flat wire joining structure according to the present embodiment.

  As shown in FIG. 1, the joined body 10 is obtained by joining the ends of two rectangular wires 11 and 12 at a joint 15 by welding. And the flat wire 11 and 12 is joined in the state which faced and faced | matched the insulating-coating peeling surfaces 11c and 12c which peeled the insulating coating only on one surface at the edge part. As shown in FIG. 2, the flat wires 11 and 12 are electric wires having a rectangular cross-sectional shape, and conductor portions 11a and 12a made of copper, and an insulating film coated around the conductor portions 11a and 12a. (Enamel) 11b, 12b. In addition, the end surfaces of the flat wires 11 and 12 are cut surfaces, and the conductor portions 11a and 12a are exposed.

  In the joined body 10, the insulating film peeling surfaces 11 c and 12 c of the rectangular wires 11 and 12 are faced and faced to face each other in a spot manner from above the end face where the conductor portions 11 a and 12 a are exposed. Heat is applied and welded, and the ends of the rectangular wires 11 and 12 are fused and joined at the joint 15.

  Therefore, in the joined body 10 having such a joined structure, the peeled areas of the insulating coatings 11b and 12b necessary for joining can be reduced. Moreover, damage to the insulating coatings 11b and 12b due to heat during welding can be prevented. From these things, the insulation process area after joining can be made small compared with the conventional joining structure. Specifically, when high insulation performance is required, for example, when joined square wires are adjacent to each other, insulation treatment may be performed on the joining side surface and end surface, and when insulation performance is not required. It suffices to perform only on the joining side surface. Therefore, according to the joined structure of the joined body 10, the joining of the rectangular wires can be realized efficiently and at low cost.

  Further, in the joined body 10, as shown in FIG. 2, the long sides of the flat wires 11 and 12 are joined surfaces (insulating coating peeling surfaces 11c and 12c). For this reason, compared with the case where the short sides of the rectangular wires 11 and 12 are brought into contact with each other and welded, it is possible to secure a larger bonding strength and a molten cross-sectional area. Therefore, according to the joined body 10, it is possible to ensure a sufficient joint strength and melt cross-sectional area.

  Next, a bonding method for realizing the above-described bonding structure will be described with reference to FIGS. FIG. 3 is a perspective view showing a rectangular wire from which only one surface of the insulating coating is peeled off. FIG. 4 is a view showing a state in which the flat wires are joined together for joining. FIG. 5 is a diagram schematically showing a state in which laser welding is performed. FIG. 6 is a diagram schematically showing laser irradiation points. FIG. 7 is a diagram schematically showing a state of laser irradiation in the AA cross section of FIG. FIG. 8 is a diagram schematically showing how laser irradiation is performed from an oblique direction.

  In the present embodiment, the above-described joint structure is realized by laser welding. That is, since the heat input necessary for welding is performed by laser spot-like irradiation, the rectangular wires 11 and 12 can be joined easily and quickly.

  First, as shown in FIG. 3, the insulating coatings 11 b and 12 b on one surface to be joined are peeled off at the ends of the flat wires 11 and 12. Note that the insulating film may be peeled by a known method. In the present embodiment, the insulating coatings 11b and 12b are peeled off on one side of the long side of each of the rectangular wires 11 and 12. By this peeling of the insulating coating, insulating coating peeling surfaces 11c and 12c are formed on the long sides of the end portions of the rectangular wires 11 and 12, respectively. As a result, the conductor portions 11a and 12a are partially exposed at the ends of the rectangular wires 11 and 12, respectively. In this way, since it is only necessary to peel off the insulating film necessary for joining on each of the rectangular wires 11 and 12, the insulating film peeling treatment, which is a pretreatment for welding, is performed in a short time and at low cost. be able to.

  Then, as shown in FIGS. 3 and 4, the insulating coating peeling surface 11 c of the flat wire 11 and the insulating coating peeling surface 12 c of the flat wire 12 are opposed to face each other. Then, the rectangular wires 11 and 12 are held in contact with each other by the pair of holding jigs 20 so that the end surfaces of the rectangular wires 11 and 12 have the same height.

After that, as shown in FIG. 5, a plurality of spots of laser L are irradiated from above the end faces of the flat wires 11 and 12 that are abutted, and the flat wires 11 and 12 are joined by laser welding. At this time, since the end surfaces of the flat wires 11 and 12 are cut surfaces, the conductor portions 11a and 12a are exposed, and it is not necessary to peel off the insulating coating for bonding. In this embodiment, a YAG laser is used as a laser used for laser welding. However, the type of laser to be used is not particularly limited. In addition to the YAG laser, for example, a fiber laser, a CO ₂ laser, and the like. A semiconductor laser or the like can be used.

  Further, the spot-like irradiation of the laser L may be performed by relatively moving the rectangular wires 11 and 12 and the laser light source. For example, the flat wires 11 and 12 can be fixed and the laser light source can be moved, or the laser light source can be fixed and the flat wires 11 and 12 can be moved.

  Here, in laser welding, as shown in FIG. 6, the irradiation points 16 of the laser L are set on the boundary line 14 of the rectangular wires 11 and 12 at equal intervals, and the laser L is irradiated to these irradiation points 16. Then, heat is input (heated) to the rectangular wires 11 and 12 in a spot manner. Thereby, since the vicinity of the boundary line of the flat wires 11 and 12 can be reliably melted and integrated, the flat wires 11 and 12 can be bonded reliably and satisfactorily.

  In addition, what is necessary is just to set the irradiation point 16 according to the joining strength requested | required in the range of 3-10 places. In the present embodiment, there are eight irradiation points (welding points). At this time, as shown in FIG. 7, the laser L irradiates each irradiation point 16 perpendicularly to the end faces of the flat wires 11 and 12. The laser L may be irradiated obliquely as shown in FIG.

  Then, by the heating by the irradiation of the laser L, the conductor portions 11a and 12a are melted and integrated in the vicinity of the boundary line 14 of the flat wires 11 and 12, and the joint portion 15 is formed. Thereafter, in the joint portion 15, the melted portions of the conductor portions 11 a and 12 a are solidified and metal-bonded, and the flat wires 11 and 12 are joined. Thus, the joined body 10 shown in FIGS. 1 and 2 is obtained.

  In the above-described embodiment, the case where the joining of the square wires is performed by laser welding has been described. However, electron beam welding (EBW) can be used instead of laser welding. Even in the case of joining by electron beam welding, the effects described above can be obtained by joining in the same manner as the laser welding described above.

  Here, when the bonding strength at the bonding portion 15 was examined for the plurality of bonded bodies 10 obtained by the bonding method described above (number of samples N = 5), the average bonding strength was 605N. The output of the YAG laser used for laser welding is 8 kW. Further, when electron beam welding (beam current of 25 mA) was performed, the same result as that obtained by laser welding was obtained. In contrast, in the conventional TIG welding (welding current 150A, welding time 0.2 seconds), the average joint strength (number of samples N = 5) was 413N. It was confirmed that strength could be obtained.

  Note that the bonding strength changes by adjusting the number of welding points and the laser output (or beam output). That is, increasing or increasing the number of welding points or laser output (or beam output) increases the welding strength, and decreasing or decreasing the number of welding points or laser output (or beam output) decreases the welding strength. Therefore, the required joining strength can be ensured by adjusting the number of welding points and the laser output (or beam output) according to the required welding strength.

  On the other hand, the melt cross-sectional area at the joint 15 is smaller than that of the conventional TIG welding, but it is greater than the required value and the line resistance does not increase. Moreover, there was no damage of the insulating film by laser welding.

  As described above in detail, according to the joined body 10 according to the present embodiment, the insulating coating peeling surfaces 11c and 12c from which the insulating coating is peeled off at only one surface at the end portions of the flat wires 11 and 12 are abutted and joined. Therefore, the peeled area of the insulating film necessary for bonding can be reduced. Further, the end faces of the flat wires 11 and 12 from which the conductor portions 11a and 12a are exposed are heated by being irradiated with the laser beam L spotwise from above to the respective end faces, and the flat wires 11 and 12 are welded. Therefore, damage to the insulating coatings 11b and 12b due to heat during welding can be prevented. For these reasons, it is possible to reduce the insulation processing area for performing the insulation treatment after bonding. Therefore, joining of the rectangular wires 11 and 12 can be realized efficiently and at low cost.

  It should be noted that the above-described embodiment is merely an example and does not limit the present invention in any way, and various improvements and modifications can be made without departing from the scope of the invention. For example, in the above-described embodiment, the case where the present invention is applied when joining two flat wires is illustrated, but as shown in FIG. 9, three flat wires 11, 12, and 13 are joined. The present invention can also be applied to the case (joined structure of the joined body 10a). Of course, the present invention can also be applied when four or more rectangular wires are joined.

  Moreover, in above-mentioned embodiment, although it joined on the long side of each rectangular wire, it can also join on the short side. However, in this case, the bonding strength and the weld cross-sectional area are smaller than those in the above embodiment.

DESCRIPTION OF SYMBOLS 10 Junction body 11 Flat wire 11a Conductor part 11b Insulating film 11c Insulating film peeling surface 12 Flat wire 12a Conductor part 12b Insulating film 12c Insulating film peeling surface 14 Boundary line 15 Joint part 16 Irradiation point L Laser

Claims (8)

In the joint structure in which the ends of the rectangular wires with a rectangular cross section provided with the insulating coating are welded,
The square lines from which the insulating coating has been peeled off on only one end face are spot-heated from above to the respective square lines in a state where the coating peeling faces face each other. Square wire joining structure characterized in that the square wires are welded together. In the joining structure of the square wire according to claim 1,
The square wire is a flat wire, and the long side of the flat wire is a joint surface. In the junction structure of the square wire according to claim 1 or claim 2,
A joining structure of square wires, wherein heat input to each square wire is performed by a laser or an electron beam. In the junction structure of the square wire according to claim 3,
A junction structure of square lines, wherein a laser or an electron beam is irradiated at equal intervals along a boundary line of each square line. In the joining method of welding the end portions of the rectangular wire having a rectangular cross section to which the insulating coating is applied,
The insulating coating is peeled off only on one surface of each corner wire, and each corner wire is abutted and brought into contact with each other so that each coating peeling surface faces, and spotted from above to each corner wire. A method of joining square wires, wherein the square wires are welded by heat input. In the joining method of the square wire of Claim 5,
Each said square wire is a flat wire, and the long side of the flat wire is brought into contact with each other and welded. In the method of joining square wires according to claim 5 or claim 6,
A method of joining square wires, wherein welding is performed by applying heat to each square wire with a laser or an electron beam. In the joining method of the square wire of Claim 7,
A method of joining square lines, characterized by irradiating a laser or an electron beam at equal intervals along a boundary line of each square line.

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