JP2017051010A - Manufacturing method for rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for a rotor capable of maintaining a strength even in the case where junction is performed using friction stirring junction.SOLUTION: A manufacturing method for the rotor includes: a friction stirring junction step for performing friction stirring junction on a base material and a plurality of conductors by performing friction stirring on a region of the base material, the region including a core in a center axis direction of the rotor, in the state where ends of the plurality of conductors are housed in the base material; and a molding step for molding a first or second end ring by cutting the base material in such a manner that a surface of the base material after the friction stirring, the surface at an opposite side of the side where the conductors extend, becomes a surface that is formed by stirring of the friction stirring junction. In the friction stirring junction step, friction stirring is performed by revolving a stirring member around a center axis of the base material while rotating around its own center axis, and friction stirring is then performed by moving the stirring member to the side where the direction of rotation and the direction of revolution are the same direction, in a radial direction of the base material that passes the center axis of the stirring member.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for manufacturing a rotor.

  2. Description of the Related Art Conventionally, induction motors that include a stator that forms a rotating magnetic field and a rotor that is provided inside the stator and rotates by the formation of the rotating magnetic field are known. Induction motors are broadly classified into single-phase induction motors and three-phase induction motors depending on the type of AC power input. Of these, three-phase induction motors are widely used as general-purpose motors.

  The three-phase induction motor has a rotor in which thick conductors (bars) are arranged in a cage shape. The rotor includes an iron core, a plurality of conductors, and an end ring. The rotor is manufactured by inserting a plurality of conductors through an iron core formed by laminating a plurality of steel plates and fixing both ends of the conductors with end rings (see, for example, Patent Document 1).

  In Patent Document 1, a copper wire and an end ring are fixed by friction stir welding. By using the friction stir welding, it is possible to perform the bonding at a low cost as compared with a bonding method such as brazing.

Japanese Patent No. 3730531

  However, when the conductor and the end ring are joined by friction stir welding as in Patent Document 1, only heat due to friction is transmitted to the peripheral region of the friction stir region. For this reason, the mechanical strength of the peripheral region is lowered by the transmitted heat, which may cause damage to the rotor.

  This invention is made | formed in view of the above, Comprising: It aims at providing the manufacturing method of the rotor which can maintain intensity | strength even when it joins using friction stir welding.

  In order to solve the above-described problems and achieve the object, the rotor manufacturing method according to the present invention includes a plurality of rod-shaped conductors and a plurality of insertion holes through which the plurality of conductors can be inserted. A method of manufacturing a rotor including a cylindrical iron core and first and second end rings that are respectively joined to both ends of the plurality of conductors, wherein the plurality of the cores are formed on a hollow disk-shaped base material. The base material and the plurality of conductors are friction-stirred by friction-stirring the region of the base material and including the iron core in the direction of the central axis of the rotor in a state where the ends of the conductors are accommodated. Friction stir welding step to be joined, and the surface of the base material after the friction stir welding step, at least the surface opposite to the side from which the plurality of conductors extend is agitated by the friction stir welding The base material is cut so that Forming the second end-entanglement ring, and the friction stir welding step revolves around the central axis of the base material while rotating the stirring member around its central axis. After performing frictional stirring, in the radial direction of the base material passing through the central axis of the stirring member, the stirring member is moved to the side where the direction of rotation and the direction of revolution are the same direction. Friction stirring is performed in the region by performing friction stirring.

  In the rotor manufacturing method according to the present invention, in the above invention, the friction stir welding step moves the stirring member so as to include a part of the stirring regions adjacent in the radial direction to perform friction stirring. It is characterized by performing.

  According to the present invention, there is an effect that the strength can be maintained even when the friction stir welding is used.

FIG. 1 is a perspective view showing the configuration of the rotor according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view showing the configuration of the rotor according to the first embodiment of the present invention. FIG. 3 is a perspective view schematically illustrating the method for manufacturing the rotor according to the first embodiment of the present invention. FIG. 4 is a perspective view schematically illustrating the method for manufacturing the rotor according to the first embodiment of the present invention. FIG. 5 is a perspective view schematically illustrating the method for manufacturing the rotor according to the first embodiment of the present invention. FIG. 6 is a perspective view schematically illustrating the method for manufacturing the rotor according to the first embodiment of the present invention. FIG. 7 is a plan view schematically illustrating the method for manufacturing the rotor according to the first embodiment of the present invention. FIG. 8 is a schematic diagram illustrating the method for manufacturing the rotor according to the first embodiment of the present invention. FIG. 9 is a plan view illustrating the method for manufacturing the rotor according to the first embodiment of the present invention. FIG. 10 is a cross-sectional view illustrating a configuration of a main part of the rotor according to the first embodiment of the present invention. FIG. 11 is a cross-sectional view illustrating a configuration of a main part of the rotor according to the first embodiment of the present invention. FIG. 12 is a cross-sectional view illustrating a configuration of a main part of the rotor according to the first modification of the first embodiment of the present invention. FIG. 13 is a perspective view showing a configuration of the rotor according to the second modification of the first embodiment of the present invention. FIG. 14 is a perspective view illustrating a configuration of a main part of the rotor according to the third modification of the first embodiment of the present invention. FIG. 15 is a diagram illustrating a method for manufacturing the rotor according to the third modification of the first embodiment of the present invention. FIG. 16 is a perspective view schematically illustrating the method for manufacturing the rotor according to the second embodiment of the present invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by the following embodiment. The drawings referred to in the following description only schematically show the shape, size, and positional relationship so that the contents of the present invention can be understood. That is, the present invention is not limited only to the shape, size, and positional relationship illustrated in each drawing.

(Embodiment 1)
FIG. 1 is a perspective view showing the configuration of the rotor according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating the configuration of the rotor according to the first embodiment. A rotor 1 shown in FIGS. 1 and 2 is used in an induction motor, is provided inside a stator, and rotates according to a rotating magnetic field of the stator.

  The rotor 1 is a cage rotor in which thick conductors (bars) are arranged in a cage shape. The rotor 1 includes a plurality of bars (conductors) 10, end rings (end-entangled rings) 11 and 12, and an iron core 13.

  The bar 10 is formed using, for example, copper, aluminum, a copper alloy, or an aluminum alloy, and has a prismatic shape (bar shape). A plurality of bars 10 are provided according to the configuration of the rotor 1. In this specification, it is assumed that 16 bars 10 are used. However, the number is not limited to this number, and the number according to the design is provided. Further, in addition to a prismatic shape, any columnar shape such as a column shape can be applied.

  The end rings 11 and 12 are formed using copper, aluminum, a copper alloy, or an aluminum alloy, and have a hollow cylindrical shape. The end ring 11 (first end ring) is joined to one end of each of the plurality of bars 10 by friction stir welding (stirring region R in FIG. 2). The end rings 12 (second end entanglement rings) are respectively joined to the other ends of the plurality of bars 10 by friction stir welding.

  The iron core 13 is formed by laminating a plurality of electromagnetic steel plates 13a, for example. The electromagnetic steel sheet 13a is formed using steel (for example, iron added with silicon) having high conversion efficiency between electric energy and magnetic energy, and has a hollow disk shape. In addition, a plurality of through-holes penetrating in the plate thickness direction and capable of being inserted through the bars 10 are formed in the electromagnetic steel sheet 13 a according to the number of the bars 10. The iron core 13 is formed in a cylindrical shape by laminating a plurality of electromagnetic steel plates 13a with the end surfaces aligned, and has an insertion hole 131 through which the bar 10 is inserted by communicating a plurality of through holes. The iron core 13 is not limited to one in which the outer edge of the cross section orthogonal to the central axis forms a circle, but may be an ellipse or a polygon.

  The rotor 1 is manufactured by inserting a plurality of bars 10 into insertion holes 131 of an iron core 13 formed by laminating a plurality of electromagnetic steel plates 13a and fixing both ends of the bars 10 by end rings 11 and 12, respectively. The Further, the shaft of the induction motor is inserted into the hollow space of the rotor 1.

  Next, a method for manufacturing the rotor 1 will be described with reference to FIGS. 3 to 6 are perspective views schematically illustrating the method for manufacturing the rotor according to the first embodiment. FIG. 7 is a plan view schematically illustrating the method for manufacturing the rotor according to the first embodiment. FIG. 8 is a schematic diagram illustrating the method for manufacturing the rotor according to the first embodiment. FIG. 9 is a plan view schematically illustrating the method for manufacturing the rotor according to the first embodiment. 10 and 11 are cross-sectional views illustrating the configuration of the main part of the rotor according to the first embodiment. 10 and 11 are partial cross-sectional views in which a plane passing through the central axis N0 (longitudinal direction of the bar 10) of the rotor 1 and parallel to the central axis N0 is a cut surface.

  First, one end of the bar 10 is accommodated in the through hole 120a formed in the base material 120 (see FIG. 3). The base material 120 is for forming the end ring 12 and is formed using copper, aluminum, a copper alloy, or an aluminum alloy, and has a hollow cylindrical shape. The base material 120 has an outer diameter larger than the outer diameter of the end ring 12 and an inner diameter smaller than the inner diameter of the end ring 12. By the processing described above, the plurality of bars 10 are extended from the base material 120.

  Next, the plurality of electromagnetic steel plates 13a are sequentially inserted into the plurality of bars 10 extending from the base material 120 (see FIG. 4).

  Thereafter, the other end of the bar 10 extending from the iron core 13 (the electromagnetic steel plate 13a) is inserted into the through hole 110a formed in the base material 110 (see FIG. 5). The base material 110 is used to form the end ring 11, and is formed using copper, aluminum, a copper alloy, or an aluminum alloy, and has a hollow cylindrical shape. The base material 110 has an outer diameter larger than the outer diameter of the end ring 11 and an inner diameter smaller than the inner diameter of the end ring 11. When the base material 110 is inserted into the bar 10, the end surface of the bar 10 is on the same plane as the end surface of the base material 110, or is slightly inward from the opening end of the through hole 110 a.

  Subsequently, the base material 110 and the bar 10 are joined by friction stir welding (see FIG. 6: friction stir welding step). In the friction stir welding, a joining process is performed using the stirring member 200. The stirring member 200 includes a shoulder 202 having a probe 201 coaxially at the tip. The probe 201 and the shoulder 202 are cylindrical, and the outer diameter of the probe 201 is smaller than the outer diameter of the shoulder 202. Further, in the first embodiment, description will be made assuming that the outer diameter of the shoulder 202 is smaller than the difference between the outer diameter and the inner diameter of the base material 110. The shoulder 202 can rotate (rotate) around its own central axis N1 (arrow Y1). When the shoulder 202 rotates, the probe 201 attached to the shoulder 202 also rotates in conjunction with it.

  In friction stir welding, the base material 110 and the bar 10 are softened by frictional heat generated by pressing the shoulder 202 against the surface of the base material 110 (the surface opposite to the side where the bar 10 extends) while rotating the shoulder 202. Further, the periphery of the joint is plastically flowed and mixed by the rotational force of the shoulder 202, and then solidified, whereby a part of the base material 110 and the end of the bar 10 are integrated. By using friction stir welding, the metal structure after joining becomes finer, so that high joining strength can be obtained. In addition, the friction stir welding can join materials such as copper at a low temperature below the melting point, and the residual stress and deformation after bonding are smaller than the residual stress and deformation when melt-welded.

  In the friction stir welding, the shoulder 202 is rotated around the central axis N2 of the base material 110 (revolution: arrow Y2 in FIG. 6) while rotating around the central axis N1 (arrow Y1 in FIG. 6). Each bar 10 and the base material 110 are joined. Since the outer diameter of the shoulder 202 is smaller than the difference between the outer diameter and the inner diameter of the base material 110, the stirring member 200 is moved in the radial direction of the base material 110 as shown in FIG. . Trajectories L <b> 1 to L <b> 4 illustrated in FIG. 7 indicate trajectories drawn by the central axis of the probe 201 by the circumference of the shoulder 202.

  Here, when the rotation direction Y1 of the probe 201 and the revolution direction Y2 of the shoulder 202 are viewed in the radial direction of the base material 110, the rotation direction Y1 is separated from the revolution direction Y2 with a locus L passing through the center of the probe 201 as a boundary. The region is divided into a region having the same direction and a region in which the rotation direction Y1 is opposite to the revolution direction Y2. Hereinafter, a region where the rotation direction Y1 is the same direction as the revolution direction Y2 is referred to as a “forward region”, and a region where the rotation direction Y1 is opposite to the revolution direction Y2 is referred to as a “reverse region” (see FIG. 8). Note that the rotation direction and the revolution direction here are “the same direction” means that in the radial direction of the base material passing through the central axis N1 of the shoulder 202, the components in the tangential direction in the rotation direction are the same direction. Say.

  The forward region and the reverse region have different hardnesses after the friction stir welding, and the reverse region has a hardness greater than the forward region. For this reason, in this Embodiment 1, the stirring member 200 is moved to the advance area side, and stirring processing is performed. Specifically, in the base material 110, when the inner diameter side is the reverse region and the outer diameter side is the forward region, the stirring member 200 is moved to the outer diameter side to perform the stirring process. If it demonstrates in the locus | trajectory shown in FIG. 7, a stirring process will be performed in order of the locus | trajectory L1, the locus | trajectory L2, the locus | trajectory L3, and the locus | trajectory L4.

  The distance between the tracks (the movement distance in the radial direction of the shoulder 202) is not less than the diameter of the probe 201 and not more than the diameter of the shoulder 202. If the distance described above is satisfied, the region stirred by the probe 201 on the forward region side can be re-stirred by the probe 201 on the reverse region side. In this way, the advancing region side where the hardness is relatively reduced is re-stirred on the reverse region side of the probe 201, so that the region stirred on the forward region side is molded to the hardness when the reverse region side is stirred. can do. When the distance between the trajectories is the diameter of the shoulder 202, there is no overlapping region at the position of the shoulder 202 before and after the movement, but a part of the region agitated on the advance region side by the probe 201 on the reverse region side. It is possible to re-stir a part of the advance region.

  The stirring region R joined by friction stirring includes the iron core 13 when viewed in the direction of the central axis N0 of the rotor 1 (the central axis N2 of the base material 110). Further, in the stirring region R, the stirring region R1 joined by one frictional stirring, for example, the stirring region R1 when moving along the locus L4 has an annular shape on the surface of the base material 110 (see FIG. 9). ). Note that the length (width) of the stirring region R1 in the radial direction (the radial direction of the base material 110) is substantially equal to the outer diameter of the shoulder 202. By adjusting the outer diameter of the shoulder 202, the width of the stirring region R1 can be adjusted. In addition, as shown in the cross-sectional view of FIG. 10, the stirring region R1 has an arc shape at the boundary with the base material 110.

  Here, in friction stir welding, only the heat due to friction is transferred to the peripheral region of the friction stir region (stirring region R). For example, heat-affected regions H11 and H12 in which only frictional heat is transmitted without stirring are generated in the peripheral region of the stirring region R (see FIG. 10). The heat affected areas H11 and H12 are each formed in an annular shape along the moving direction of the shoulder 202. When the heat affected areas H11 and H12 are generated, the mechanical strength of these areas is lowered by heat, and there is a possibility that the rotor 1 is damaged. For this reason, in the first embodiment, a part of the base material 110 is cut to remove the heat-affected regions H11 and H12 from the base material 110.

In the radial direction of the base material 110, _{t 1} the distance between the cutting position C1, C2 for cutting the base material 110 at the outer peripheral side and inner peripheral side and the shortest distance between the heat affected zone H11, H12 and _{t 2,} t ₁ ≦ t ₂ holds. In the first embodiment, the diameter (width) between the outer peripheral side and the inner peripheral side of the iron core 13 is t ₃ , the diameter of the bar 10 is t ₄ , and the width of the stirring region R 1 on the surface of the base material 110 is set. Assuming t ₅ , the diameter t ₃ between the outer peripheral side and the inner peripheral side of the iron core 13 is not more than the distance t ₁ between the cutting positions (t ₃ ≦ t ₁ ), and the diameter t _{4 of the} bar 10 is the stirring region R 1. width _{t 5} smaller than that of _(t 4 _<t 5). Further, the stirring region R includes the iron core 13 in the direction of the central axis N2 (the central axis of the iron core 13).

  The end ring 11 shown in FIG. 11 can be formed by cutting the base material 110 at the cutting positions C1 and C2 that satisfy the above-described relationship (forming step). Since the end ring 11 does not have the heat affected areas H11 and H12, the mechanical strength as the end ring is prevented from being reduced by heat, and the strength as the end ring 11 is maintained.

  The end ring 12 can also be formed by cutting the base material 120 after the friction stir welding in the same manner as in the manufacturing process of the end ring 11 described above.

In the cutting process of the base material 110 (and the base material 120), for example, the distance t between the cutting positions C1 and C2 at which the base material 110 is cut on the outer peripheral side and the inner peripheral side with t ₁ ≦ 0.7t ₅ as a guide. ₁ may be set to determine the cutting position.

Further, in the cutting process of the base material 110 (and the base material 120), if the end ring 11 (end ring 12) that satisfies t ₁ ≦ t ₂ and does not have the heat affected regions H11 and H12 can be formed, FIG. It is not necessary to cut out symmetrically with respect to the central axis of the bar 10 in the cross section shown in FIG. If the base material 110 and the bar 10 are agitated and joined and the end ring 11 after cutting does not include the heat-affected regions H11 and H12, the base material 110 may be cut out at any location (the position of the cut surface). The position which cut | disconnects a part of side surface of the iron core 13 may be sufficient.

  According to the first embodiment described above, in the rotor 1, the region stirred by the probe 201 on the forward region side is re-stirred by the probe 201 on the reverse region side, and the base material 110 and the bar 10 are joined by friction stir welding. Since the end rings (end rings 11 and 12) are formed by removing the heat-affected regions (heat-affected regions H11 and H12) generated at the time of joining, the strength is increased even when joining is performed using friction stir welding. Can be maintained.

  In the first embodiment described above, the bar 10 and the end rings 11 and 12 may be formed using the same material, or may be formed using different materials. A combination of materials constituting the bar 10 and the end rings 11 and 12 can be arbitrarily designed.

  Moreover, in Embodiment 1 mentioned above, you may make it position the bar 10 with respect to a base material by providing the some recessed part which can fit the bar 10 in one surface of a base material. At this time, when the base material and the bar 10 are formed of different materials and the hardness of the base material is lower than the hardness of the bar 10, the base material is mixed by plastic flow by friction stirring, Both parts are joined by friction stirring only the part.

(Modification 1 of Embodiment 1)
In the first embodiment described above, it has been described that all the parts inserted into the through hole 110a are friction stir welded in the bar 10, but a part inserted into the through hole 110a is friction stir welded. It may be. FIG. 12 is a cross-sectional view illustrating a configuration of a main part of the rotor according to the first modification of the first embodiment, in which the central axis N0 (longitudinal direction of the bar 10) of the rotor 1 illustrated in FIG. It is sectional drawing which makes a cut surface the plane which passes and is parallel to this central axis N0. As shown in FIG. 12, a part of the bar 10 is included inside by performing friction stir welding using the stirring member 200 in which the protruding length of the probe 201 from the shoulder 202 is smaller than the thickness of the base material 110. The end ring 11a may be formed so that at least the surface opposite to the side on which the bar 10 extends is a surface that is frictionally stirred (stirring region R2 shown in FIG. 12).

  Thus, as long as at least the surface opposite to the side from which the bar 10 extends is a surface that is frictionally stirred, the end ring may partially include a region that is not frictionally stirred.

(Modification 2 of Embodiment 1)
FIG. 13 is a perspective view showing a configuration of the rotor according to the second modification of the first embodiment of the present invention. In the second modification, each end ring is formed by laminating two hollow disk-shaped members. The rotor 1a shown in FIG. 13 includes the above-described plurality of bars 10 (see FIG. 2 and the like), an iron core 13, and end rings (end-to-end rings) 21 and 22.

  The end ring 21 (first end ring) is formed using copper, aluminum, a copper alloy, or an aluminum alloy, and uses a first member 21a having a hollow cylindrical shape and copper, aluminum, a copper alloy, or an aluminum alloy. And a second member 21b having a hollow cylindrical shape having the same shape as the first member 21a. In the end ring 21, at least a member on the bar 10 side (second member 21 b in the second modification) is joined to one end of each of the plurality of bars 10 by friction stir welding.

  The end ring 22 (second end ring) is formed using copper, aluminum, a copper alloy, or an aluminum alloy, and uses a hollow cylindrical first member 22a and copper, aluminum, a copper alloy, or an aluminum alloy. And a second member 22b having a hollow cylindrical shape having the same shape as the first member 22a. In the end ring 22, at least a member on the bar 10 side (in the second modification example, the second member 22 b) is joined to one end of each of the plurality of bars 10 by friction stir welding.

  As in the second modification, the end ring may be formed by laminating a plurality of members. In addition, the plate | board thickness of a some member may be the same, and may differ. Further, the plurality of members may be formed using the same material, or may be formed using different materials.

(Modification 3 of Embodiment 1)
FIG. 14 is a perspective view illustrating a configuration of a main part of the rotor according to the third modification of the first embodiment. FIG. 15 is a diagram illustrating a method for manufacturing the rotor according to the third modification of the first embodiment. In the friction stir welding, a trace of the probe 201 may remain at the end point of the stirring process (stop position of the shoulder 202). If the trace of the probe 201 remains, there is a possibility that the uniformity of mixing due to plastic flow is lowered and the bonding strength is lowered.

  As shown in FIG. 14, the base material 130 according to the third modification example is provided in an annular part 131 having an annular shape and a part of a side surface of the annular part 131, and the diameter of the annular part 131 from the side surface. And an extending part 132 extending in the direction. A through hole 131 a for inserting the bar 10 is formed in the annular portion 131. The extending portion 132 protrudes so that the length in the radial direction and the width direction (direction orthogonal to the radial direction on the surface) is equal to or larger than the diameter of the shoulder 202.

  When the base material 130 and the bar 10 are joined, as shown in FIG. 202 is moved. Since the shoulder 202 moves so as to draw such a trajectory, the trace of the probe 201 at the end point of the stirring process (stop position of the shoulder 202) becomes a position away from the annular portion 131. The trace of the probe 201 does not remain on the surface. At this time, it is preferable that the extending portion 132 is provided on the side where the stirring member 200 is moved from the viewpoint of reducing the movement trace of the shoulder 202 even when the friction stirring process is performed a plurality of times. For example, when the friction stirring is performed in the order of the locus L1, the locus L2, the locus L3, and the locus L4, the extending portion 132 is provided on the locus L4 side (the outer peripheral side of the base material 130).

  In Modification 3, since the trace of the probe 201 is not left on the molded end ring, the remaining of the trace of the probe 201 reduces the uniformity of mixing due to plastic flow and causes a decrease in bonding strength. Therefore, even when the friction stir welding is used, the strength can be more reliably maintained.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. FIG. 16 is a perspective view for schematically explaining the method for manufacturing the rotor according to the second embodiment. In addition, the same code | symbol is attached | subjected to the same component as the component mentioned above in FIG. The rotor according to the second embodiment is the same as that of the first embodiment described above, and the manufacturing method is different.

  Specifically, as in Embodiment 1 described above, one end of the bar 10 is accommodated in the through-hole 120a formed in the base material 120 (see FIG. 3). Next, the plurality of electromagnetic steel plates 13a are sequentially inserted into the plurality of bars 10 extending from the base material 120 (see FIG. 4). Subsequently, the other end of the bar 10 extending from the iron core 13 (the electromagnetic steel plate 13a) is inserted into the through hole 110a formed in the base material 110 (see FIG. 5).

  Thereafter, the base material 110 and the bar 10 are joined by friction stir welding (see FIG. 16: friction stir welding step). In the friction stir welding, a stirring process is performed using the stirring member 200 described above, and cool air for cooling the stirred base material 110 is blown to the base material 110 through the pipe 203. Specifically, while rotating the shoulder 202 around the central axis N1 (arrow Y1 in FIG. 6), it follows the stirring member 200 that circulates around the central axis N2 of the base material 110 (arrow Y2 in FIG. 6). Then, the pipe 203 is rotated around the central axis N2.

  By rapidly cooling the base material after stirring with cold air while performing frictional stirring, the material refined by stirring can be cured. Thereby, compared with the case where it does not cool, it can be hardened as a finer crystal grain, and a part of base material 110 and the edge part of the bar | burr 10 can be integrated more firmly.

  Thereafter, in the same manner as in the first embodiment described above, the end ring 11 is formed by cutting a part of the base material 110 and removing the heat-affected region from the base material 110 (forming step). ). The end ring 12 can also be formed by cutting the base material 120 after the friction stir welding in the same manner as in the manufacturing process of the end ring 11 described above.

  According to the above-described second embodiment, when the base material 110, 120 and the bar 10 are joined by friction stirring in the rotor 1, the base material 110, 120 after stirring is cooled following the stirring. As a result, the bar 10 and the end rings 11 and 12 can be joined more firmly when joining is performed using friction stirring.

  In the first and second embodiments described above, it has been described that the upper surface of the end ring after molding and a part of the side surface include a frictionally stirred region (stirring region), but the base material and the bar are stirred. It is only necessary that the end ring after joining and cutting does not include the heat affected zone. For example, when the boundary of the agitation region has an average curvature radius smaller than the average curvature radius of the curve formed by the substantially semicircular boundary as shown in FIG. The upper surface (the surface on the side opposite to the side to be joined with the bar) may be formed by plastic working by friction stir welding.

  In the first and second embodiments described above, it has been described that the cutting position is determined symmetrically with respect to the center of the friction-stirred region (stirring region), but the base material and the bar are stir-joined and after cutting If the end ring does not include the heat-affected region, the center between the cutting positions may be shifted from the center of the stirring region.

  Moreover, in Embodiment 1, 2 mentioned above, the end rings 11 and 12 and the iron core 13 may be joined by friction stirring, and may be non-joined. In the case where the end rings 11 and 12 and the iron core 13 are joined by friction stirring, the electromagnetic steel sheet 13a that contacts the end ring by friction stirring includes that deformed by 1/3 or less of the plate thickness.

  Moreover, Embodiment 1 and 2 mentioned above are only the examples for implementing this invention, and this invention is not limited to these. Further, the present invention can form various inventions by appropriately combining a plurality of constituent elements disclosed in the respective embodiments and modifications. It is obvious from the above description that the present invention can be variously modified according to specifications and the like, and that various other embodiments are possible within the scope of the present invention.

  As described above, the method for manufacturing a rotor according to the present invention is useful for maintaining strength even when joining is performed using friction stir welding.

1, 1a Rotor 10 Bar 11, 11a, 12 End ring 13 Iron core 13a Electrical steel sheet 110, 120, 130 Base material

Claims (2)

A plurality of rod-shaped conductors, a cylindrical iron core formed with a plurality of insertion holes through which the plurality of conductors can be inserted, and first and second end junctions respectively joined to both ends of the plurality of conductors A method of manufacturing a rotor with a ring,
In a state in which the ends of the plurality of conductors are accommodated in a hollow disk-shaped base material, the region of the base material and the region including the iron core in the central axis direction of the rotor are frictionally stirred. A friction stir welding step for friction stir welding the base material and the plurality of conductors;
The surface of the base material after the friction stir welding step, wherein at least the surface opposite to the side where the plurality of conductors extend is a surface that is stirred by the friction stir welding. Forming step of cutting and forming the first or second end ring;
Including
The friction stir welding step performs friction stir by revolving around the central axis of the base material while rotating the stirrer around the central axis of the base material, and then passes through the central axis of the stirring member. In the radial direction of the base material, the friction stir of the region is performed by moving the stirring member to the side where the direction of rotation and the direction of revolution are the same direction. A method for manufacturing a rotor.   2. The method for manufacturing a rotor according to claim 1, wherein the friction stir welding step performs the friction stir by moving the stirring member so as to include a part of the stirring regions adjacent in the radial direction.

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