JP2011182488A - Motor core, and method of assembling the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor core that has a simple connection structure of a magnetic steel plate and is assembled easily, and to provide a method of assembling the motor core. <P>SOLUTION: A plurality of magnetic steel plates 22A to 22C are stacked, and a holding piece 23 engaged with edges of other magnetic steel plates 22A to 22C to hold the magnetic steel plates 22A to 22C in a stacked state is bent and formed at an edge of prescribed magnetic steel plates 22A, 22B. A spring force is imparted to the holding piece 23 in a direction where the holding piece 23 bends at an acute angle. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a motor core such as a stator core and a rotor core in a motor, and a method for assembling the motor core.

  As shown in FIG. 19, the rotor core 121 of the motor is configured by laminating a large number of magnetic steel plates 122. This magnetic steel plate 122 has insulating coatings on both the front and back surfaces. And in order to maintain the lamination | stacking state of the magnetic steel plate 122, conventionally, between magnetic steel plates is fixed with an adhesive agent, it fixes by welding, or as shown in FIG. A cutout was formed, and the protrusion 125 was fitted into the cutout hole 127 of the adjacent protrusion 125.

  Conventionally, for example, a configuration as disclosed in Patent Document 1 has been proposed as a stator core of a motor. In the configuration of Patent Document 1, as shown in FIG. 17, a plurality of holding pieces 43 are bent at right angles on the inner peripheral edge of one magnetic steel plate 42 of the magnetic steel plates 42 constituting the stator core 41. Thus, it is in contact with the inner periphery of the remaining magnetic steel sheet 42 adjacent thereto. Further, a bent portion 43 a is formed at the tip of each holding piece 43 toward the surface side of the magnetic steel plate 42 disposed at the other end in the stacking direction. And the magnetic steel plate 42 is hold | maintained in the lamination | stacking state by bending of this holding piece 43 and the bending part 43a.

JP 2001-119871 A

  In the configuration in which the magnetic steel plate is fixed with an adhesive, it is necessary to inject and apply the adhesive to the required position, which not only complicates the manufacturing process but also contributes to the rotation of the motor. No adhesive is needed.

  In the configuration in which the magnetic steel plate is fixed by welding, a welding operation is required, and thus the manufacturing process is complicated as in the case of the adhesive. In addition, there is a possibility that the insulation between the magnetic steel plates may be broken by the weld metal. In such a case, an electric circuit is formed between the magnetic steel plates, resulting in a large eddy current loss when the motor rotates. There was a risk that efficiency would decrease.

  Further, in the configuration in which the magnetic steel plates 122 are fixed by fitting the protrusions 125 and the cutout holes 127, there are cases where the arrangement positions of the protrusions 125 are restricted and an effective fixing position cannot be selected. That is, as apparent from FIG. 19, the rotor core 121 is provided with the through holes 123, and the permanent magnets 124 are accommodated in the respective through holes 123. Therefore, the protrusion 125 needs to be disposed avoiding the position of the through hole 123. For this reason, when the protrusion 125 cannot be disposed at an appropriate position, there is a possibility that a problem occurs in the fixing strength of the magnetic steel plate 122. Moreover, as shown in FIGS. 20 (a) and 20 (b), the side surface 126 of the cut-out projection 125 contacts the inner side surface of the cut-out hole 127, and an electric circuit is formed between the magnetic steel plates 122. Similarly, there has been a problem that the operating efficiency of the motor is reduced due to eddy current loss.

  Further, as in the configuration of Patent Document 1, in the configuration in which the holding piece 43 is bent at a right angle from the inner peripheral edge of one magnetic steel plate 42 and brought into contact with the inner circumference of the adjacent magnetic steel plate 42, the holding piece Due to the springback of 43, the contact force of the holding piece 43 with respect to the inner periphery of the adjacent magnetic steel plate 42 is reduced, and it is difficult to appropriately hold the magnetic steel plate 42 in the laminated state. For this reason, a bent portion 43a is formed at the tip of the holding piece 43 to resist the spring back of the holding piece 43, but even with this configuration, the spring back of the holding piece 43 is eliminated. Therefore, there is a possibility that a strong laminated state cannot be maintained.

  Further, when the motor core of Patent Document 1 is assembled, as shown in FIG. 18 (a), a plurality of magnetic steel plates 42 are punched and laminated, and then, as shown in FIG. The process of bending 43 at a right angle and the process of forming the bent portion 43a at the tip of the holding piece 43 as shown in FIG. For this reason, there has been a problem that the processing of the stator core takes time and causes an increase in cost.

  The present invention has been made paying attention to such problems existing in the prior art. An object of the present invention is to provide a motor core and a method of assembling the motor core that can be easily assembled while the coupling structure of magnetic steel plates is simple.

  In order to achieve the above object, in the invention relating to the motor core, several magnetic steel plates are laminated, and the magnetic steel plates are laminated on the edge of a predetermined magnetic steel plate by engaging with the edge of another magnetic steel plate. A motor core formed by bending a holding piece to be held in a state is characterized in that a resilient force is applied to the holding piece in a direction in which the holding piece forms an acute angle.

  Therefore, in the motor core according to the present invention, the holding piece is bent and formed at the edge of the magnetic steel plate, and the holding piece is pressed against the edge of the adjacent magnetic steel plate by its elastic force so that the magnetic The steel plate can be firmly bonded to the laminated state. Therefore, unlike the conventional configuration, it is not necessary to use an adhesive or welding, or it is not necessary to form a bent portion for preventing the spring back at the tip of the holding piece, and thus the magnetic steel plate coupling structure is simplified. Furthermore, insulation between magnetic steel sheets can be secured, and eddy current loss due to dielectric breakdown can be avoided.

The said structure WHEREIN: It is preferable to provide the said holding piece in the outer periphery part of a magnetic steel plate.
In the above configuration, the holding piece is preferably provided on the inner peripheral side of the magnetic steel plate.
The said structure WHEREIN: It is preferable to provide the said holding piece in the front-end | tip of the magnetic pole piece of the inner peripheral side in a magnetic steel plate.

  Further, in the invention relating to the method of assembling the motor core, a plurality of magnetic steel plates are laminated, and a holding piece formed on an edge portion of a predetermined magnetic steel plate is engaged with an edge portion of another magnetic steel plate. In the method of assembling the motor core so that the steel plates are held in a laminated state, the holding pieces are bent at an acute angle toward the other magnetic steel plates while the magnetic steel plates are laminated.

  Therefore, in the method of assembling the motor core of the present invention, it is not necessary to perform the bending process of the holding piece in a separate process separately from the punching and laminating process of the magnetic steel sheet, and these processes can be performed in the same process, The motor core can be easily assembled.

In the above method, it is preferable that the holding piece formed on the outer periphery of the magnetic steel plate is bent at an acute angle while punching out the magnetic steel plate.
Further, in the above method, the inner diameter hole of the motor core is formed in the punched portion of the magnetic steel plate of the workpiece, the holding piece formed on the inner periphery of the inner diameter hole is bent, and then the holding piece is removed while punching the magnetic steel plate. It is preferable to bend into an acute angle.

  As described above, according to the present invention, it is possible to easily combine the magnetic steel plates, to easily assemble them, and to suppress the eddy current loss.

The perspective view which shows the rotor core of 1st Embodiment. Sectional drawing of the rotor core of FIG. The top view which shows the 1st magnetic steel plate of the same rotor core. The top view which similarly shows the 2nd magnetic steel plate. The top view which similarly shows the 3rd magnetic steel plate. (A) is a figure which shows the preliminary | backup process at the time of stamping and forming the 1st-3rd magnetic steel plate, (b) is a figure which shows the stamping shaping | molding state of the 1st-3rd magnetic steel plate. The principal part sectional drawing which shows the punching lamination apparatus of the 1st-3rd magnetic steel plate. (A) and (b) are the figures which show the end surface shape of the punch and die | dye in the punching lamination apparatus of FIG. 7, respectively. The fragmentary perspective view which shows a part of die | dye in the punching lamination apparatus. The fragmentary perspective view which shows a part of squeeze ring in the punching lamination apparatus. (A) And (b) is sectional drawing which shows the lamination | stacking assembly method of the rotor core by the punching lamination apparatus in order. The principal part disassembled perspective view which shows the rotor core of 2nd Embodiment. The top view which shows the stator core of 3rd Embodiment. The perspective view which decomposes | disassembles and shows a part of stator core of FIG. (A) is a figure which shows the preliminary | backup process at the time of stamping and forming the magnetic steel plate of the same stator core, (b) is a figure which shows the bending process of the holding piece following the preliminary | backup process of (a). The principal part sectional drawing which shows the punching lamination apparatus of the magnetic steel plate of the same stator core. Sectional drawing which shows the conventional rotor core. (A)-(c) is a fragmentary sectional view which shows the assembly | attachment method of the rotor core of FIG. 17 in order. The disassembled perspective view which shows the conventional rotor core. (A) is a partial perspective view which shows the coupling | bonding structure of the magnetic steel plate in the conventional rotor core, (b) is sectional drawing similarly.

(First embodiment)
Hereinafter, a first embodiment in which the present invention is embodied in a rotor core of a motor will be described with reference to FIGS. FIG. 1 is a perspective view of a rotor core 21 of this embodiment, which includes through holes and permanent magnets as in the conventional rotor core 121 shown in FIG. 19, but is not shown. As shown in FIGS. 1 and 2, the rotor core 21 of this embodiment is formed by laminating a plurality of (usually several hundred) magnetic steel plates 22 stamped and formed with insulation coating on both front and back surfaces. It is constituted by. An inner diameter hole 25 is formed in the magnetic steel plate 22. Among the plurality of magnetic steel plates 22, a plurality of holding pieces 23 are bent and formed on the outer peripheral edge of the specific magnetic steel plate 22. The holding piece 23 is pressed against the outer peripheral edge of the other magnetic steel plate 22 to hold the other magnetic steel plate 22, whereby the magnetic steel plate 22 is held in a laminated state.

  In this embodiment, as shown in FIGS. 2 to 5, first to third magnetic steel plates 22 </ b> A, 22 </ b> B, and 22 </ b> C having different outer peripheral shapes are used as the magnetic steel plate 22. Then, one first magnetic steel plate 22A, two third magnetic steel plates 22C, one second magnetic steel plate 22B, and one third magnetic steel plate 22C are laminated in order from the bottom, The rotor core 21 is configured by repeating the lamination of the magnetic steel plates 22A to 22C a predetermined number of times.

  As shown in FIGS. 2 to 5, a pair of holding pieces 23 are formed at an interval of 180 degrees on the outer peripheral edge of the first magnetic steel plate 22 </ b> A, and a pair of recesses 24 are formed on the holding pieces. It is formed so as to be located at an interval of 90 degrees with respect to 23. A pair of holding pieces 23 are formed on the outer peripheral edge portion of the second magnetic steel plate 22B so as to be positioned corresponding to the concave portion 24 of the first magnetic steel plate 22A, and the pair of concave portions 24 are provided with the first magnetic steel plate 22B. It is formed so as to correspond to the holding piece 23 of the steel plate 22A. At the outer peripheral edge of the third magnetic steel plate 22C, four recesses 24 are formed at intervals of 90 degrees so as to be positioned corresponding to the holding pieces 23 of the first and second magnetic steel plates 22A and 22B. Yes.

  Then, as shown in FIG. 2, in a state where a plurality of magnetic steel plates 22 </ b> A to 22 </ b> C are stacked, each holding piece 23 is bent into the recess 24 of the adjacent magnetic steel plates 22 </ b> A to 22 </ b> C, Holds 22C. In this case, the length of each holding piece 23 is formed so that it can be brought into contact with the outer peripheral edge portions of the four adjacent magnetic steel plates 22A to 22C. Accordingly, each holding piece 23 holds four magnetic steel plates 22A to 22C adjacent to each other, and the holding pieces 23 of the magnetic steel plates 22A and 22B have four pieces at positions shifted in the stacking direction of the magnetic steel plates 22A to 22C. The magnetic steel plates 22A to 22C are held and thereby all the magnetic steel plates 22A to 22C are integrated as the rotor core 21. Thus, the number of the holding pieces 23 per magnetic steel plate and the length of the holding pieces 23 so that the magnetic steel plates 22A to 22C are integrated as the rotor core 21 by the holding pieces 23 formed on the predetermined magnetic steel plate. The magnetic steel plate having the circumferential position and the holding piece 23 is appropriately selected according to the size and required strength of the rotor core 21.

  As indicated by a chain line in FIG. 2, each holding piece 23 is given a resilience in a direction that is bent at an acute angle. By this elastic force, each holding piece 23 is pressed against the outer peripheral edge portion of the adjacent magnetic steel plates 22A to 22C, and each magnetic steel plate 22A to 22C is held and bonded in a laminated state.

Next, a method for assembling the rotor core 21 configured as described above will be described.
First, when punching out the first to third magnetic steel plates 22A to 22C, as schematically shown in FIG. 6 (a), as a preliminary process, on the work W having a strip shape in which both front and back surfaces are insulated. Each of the first to third magnetic steel plates 22A to 22C is punched at the inner diameter hole 25, and punched holes 26 are formed at different positions. This preliminary processing is performed in the order of the lamination of the first to third magnetic steel plates 22A to 22C described above. That is, in the punched portion of the first magnetic steel plate 22A, an inner diameter hole 25 is formed in the center portion, and a pair of upper and lower punched holes 26 in FIG. In the punched portion of the second magnetic steel plate 22B, an inner diameter hole 25 is formed in the central portion, and a pair of left and right punched holes 26 in FIG. At the forming portion of the third magnetic steel plate 22C, an inner diameter hole 25 is formed at the center portion, and four punching holes 26 are formed at the vertical and horizontal positions in FIG.

  After the preliminary processing, as shown in FIG. 7, the punching and laminating apparatus 30 punches the first to third magnetic steel plates 22 </ b> A to 22 </ b> C on the workpiece W. In this case, a punch 31 and a die 32 having an end face shape (blade edge shape) as shown in FIGS. 8A and 8B are used. As shown in FIGS. 7 to 9, four protrusions 31 a for forming the holding piece 23 are formed on the outer periphery of the punch 31. Four concave grooves 32 a corresponding to the protrusions 31 a of the punch 31 are formed on the inner periphery of the die 32. Then, by punching the workpiece W by the punch 31 and the die 32, as shown in FIG. 6B, the first to third magnetic steel plates having different positions and numbers of the holding pieces 23 and the recesses 24 are obtained. 22A to 22C are continuously punched in the above-described stacking order.

  Thereafter, the punched magnetic steel plates 22 </ b> A to 22 </ b> C are sequentially stacked by passing through a squeeze ring 33 disposed below the die 32. In this case, as the magnetic steel plates 22A to 22C are punched by the punch 31 and the die 32, the magnetic steel plates 22A to 22C are larger than the other portions with respect to the outer peripheral edge side corresponding to the cutting edge of the punch 31 and the die 32. A load is applied. For this reason, as shown in FIG. 7, the magnetic steel plates 22 </ b> A to 22 </ b> C are inclined in a conical shape so that the outer peripheral edge side is located below the inner peripheral edge side in the squeeze ring 33.

  As shown in FIGS. 7 and 9, four molding grooves 34 that are continuous with the concave groove 32 a of the die 32 are formed on the inner periphery of the squeeze ring 33. Formed on the bottom surface of each molding groove 34 is a molding surface 34 a that is inclined so as to gradually approach the axial center side of the squeeze ring 33 toward the lower end portion. As shown in FIG. 7, when the magnetic steel plates 22 </ b> A to 22 </ b> C are lowered while being stacked in the squeeze ring 33, the holding pieces 23 on the first and second magnetic steel plates 22 </ b> A and 22 </ b> B are formed into the forming grooves 34. By being in sliding contact with the surface 34a, the other magnetic steel plates 22A to 22C are bent upward into the recesses 24.

  In this case, as shown in FIGS. 7 and 11 (a), the magnetic steel plates 22A to 22C are laminated in a conical inclined state in the squeeze ring 33, so that the holding piece 23 is another magnetic steel plate 22A to 22C. When the holding piece 23 is bent to a position where it comes into contact with the inner surface of the recess 24, the bending angle of the holding piece 23 becomes an acute angle. Then, as shown by a chain line in FIG. 7, after a predetermined number of magnetic steel plates 22A to 22C are stacked, and discharged downward as the rotor core 21 from inside the squeeze ring 33, by releasing the stress on the magnetic steel plates 22A to 22C, The magnetic steel plates 22A to 22C are changed from the inclined state shown in FIG. 11 (a) to the horizontal state shown in FIG. 11 (b). At this time, as shown in FIG. 2, the holding piece 23 is expanded from an acute angle state to a right angle state. Therefore, as shown by a two-dot chain line in FIG. 2, the holding piece 23 tries to return to an acute angle, and therefore, a resilient force (spring back) in an acute angle direction is applied to the holding piece 23. As a result, the holding pieces 23 are pressed against the outer peripheral edge portions of the adjacent magnetic steel plates 22A to 22C, and the magnetic steel plates 22A to 22C are held by the holding pieces 23 and firmly bonded to the laminated state.

1 and 2, the rotor core 21 is drawn upside down from FIG.
Therefore, according to this embodiment, the following effects can be obtained.
(1) In the rotor core 21 of this embodiment, a resilient force in the bending direction is applied to the holding piece 23 so that the holding piece 23 is bent at an acute angle. For this reason, the magnetic steel plates 22A to 22C can be firmly bonded to the laminated state with a simple configuration in which the holding pieces 23 are bent and formed at the edges of the magnetic steel plates 22A and 22B. Therefore, unlike the conventional configuration, there is no need to form a bent portion for preventing springback at the tip of the holding piece, and the coupling and holding structure of the magnetic steel plates 22A to 22C can be simplified.

  (2) In the rotor core 21 of this embodiment, the holding piece 23 is provided on the outer peripheral edge of the magnetic steel plates 22A and 22B. For this reason, the magnetic steel plates 22A to 22C are held from the outer peripheral side, and the magnetic steel plates 22A to 22C can be firmly bonded to the laminated state as compared with the case where they are held from the inner peripheral side.

  (3) Since no adhesive or welding is used to bond the magnetic steel plates 22A to 22C, an extra member such as an adhesive that does not participate in the rotation function of the motor becomes unnecessary, and an adhesive is applied or welded. The manufacturing process can be simplified.

  (4) Since the magnetic steel plates 22A to 22C are held not by the end face of the holding piece 23 but by the surface on which the insulating coating is applied, the insulation between the magnetic steel plates 22A through 22C can be secured. Therefore, an electric circuit is not formed between the magnetic steel plates 22A to 22C, and eddy current loss due to the electric circuit can be avoided.

  (5) In the method of assembling the rotor core 21 of this embodiment, the holding pieces 23 are bent so as to form an acute angle toward the other magnetic steel plates 22A to 22C while the magnetic steel plates 22A to 22C are laminated. For this reason, after punching and laminating the magnetic steel plates 22A to 22C, it is not necessary to perform the bending process of the holding piece 23 in a separate process, and these processes can be performed in the same process, and the assembly of the rotor core 21 is facilitated. It can be carried out.

(Second Embodiment)
Next, a motor core according to a second embodiment of the motor core and its assembling method embodying the present invention will be described with a focus on differences from the first embodiment.

  In the second embodiment, as shown in FIG. 12, a first magnetic steel plate 22A having a pair of holding pieces 23 and a recess 24 on the outer peripheral edge portion, and an outer surface different from the first magnetic steel plate 22A. The rotor core 21 is configured by alternately laminating the pair of holding pieces 23 and the second magnetic steel plates 22B provided with the recesses 24 at the peripheral edge positions. In this embodiment, each holding piece 23 is formed so that the length of each holding piece 23 can hold the outer peripheral edge of one adjacent magnetic steel plate 22A, 22B. Accordingly, in the second embodiment, each of the magnetic steel plates 22A and 22B is coupled to the other adjacent magnetic steel plates 22A and 22B, and as a result, the entire rotor core 21 is integrated.

Therefore, also in the second embodiment, the same effects as those described in (1) to (5) in the first embodiment can be obtained.
(Third embodiment)
Next, a third embodiment of the motor core and its assembling method embodying the present invention will be described with a focus on the differences from the first embodiment. In the third embodiment, the present invention is embodied in the stator core 27.

  In the third embodiment, as shown in FIGS. 13 to 16, the first magnetic steel plates 22 </ b> A and the second magnetic steel plates 22 </ b> B having different formation positions of the holding pieces 23 and the recesses 24 are alternately laminated. Thus, the stator core 27 is configured. On the inner peripheral edge of each of the magnetic steel plates 22A and 22B, a plurality of narrow coil-shaped magnetic pole pieces 22a are formed so as to protrude in the radial direction at a predetermined angular interval. At the tip of each magnetic pole piece 22a of the first magnetic steel plate 22A, the holding pieces 23 and the recesses 24 are formed alternately. At the tip of each magnetic pole piece 22a of the second magnetic steel plate 22B, a holding piece 23 and a recess 24 are formed so as to correspond to the recess 24 and the holding piece 23 of the first magnetic steel plate 22A. In this embodiment, each holding piece 23 is formed such that the length of each holding piece 23 can hold the inner peripheral edge of one adjacent magnetic steel plate 22A, 22B.

Next, a method for assembling the rotor core 21 according to the third embodiment will be described.
First, when the first and second magnetic steel plates 22A and 22B are punched, as shown schematically in FIG. 15A, the punched portions of the first and second magnetic steel plates 22A and 22B on the workpiece W are punched out. On the other hand, preliminary processing of the inner diameter hole 25 including the plurality of magnetic pole pieces 22a is performed. In this case, at the punched portions of the magnetic steel plates 22A and 22B, the plate-like holding pieces 23 and the recesses 24 are alternately formed at different positions with respect to the other magnetic steel plates 22A and 22B adjacent to the tips of the magnetic pole pieces 22a. Is done. Subsequently, as shown in FIG. 15B, the holding pieces 23 at the punched portions of the first and second magnetic steel plates 22 </ b> A and 22 </ b> B on the workpiece W are flattened using the bending punch 37 and the die 38. It is bent from the shape to a substantially right angle downward.

  After that, as shown in FIG. 16, the punching and laminating apparatus 30 performs punching on the portions of the first and second magnetic steel plates 22 </ b> A and 22 </ b> B on the workpiece W. In this punching and laminating apparatus 30, a molding member 39 is disposed at the center of the die 32 and the squeeze ring 33, and a molding surface 39 a that is inclined so as to protrude toward the lower end is formed on the outer periphery of the molding member 39. . When the magnetic steel plates 22A and 22B are lowered in the squeeze ring 33 while being stacked in a conical inclined state with the outer peripheral edge side downward, each holding piece 23 slides on the forming surface 39a of the forming member 39. By contacting, it is further bent from a substantially right angle state to an acute angle state.

  As described above, when a predetermined number of the magnetic steel plates 22A and 22B are stacked and then discharged downward from the squeeze ring 33 as the stator core 27 as shown by a chain line in FIG. 16, the same as in the case of the first embodiment. Further, the magnetic steel plates 22A and 22B are changed from the inclined state to the horizontal state by releasing the stress. At this time, since the holding piece 23 is bent at an acute angle, a resilient force in the bending direction is applied to the holding piece 23. By applying this elastic force, the holding piece 23 is pressed against the tip surface of the magnetic pole piece 22a in the adjacent magnetic steel plates 22A and 22B, and the magnetic steel plates 22A and 22B are firmly bonded to the laminated state at the tip of each magnetic pole piece 22a. Is done.

Therefore, according to the third embodiment, in addition to the effects described in (1), (3), (4) and (5) in the first embodiment, the following effects can be obtained.
(6) In the stator core 27 of this embodiment, the holding piece 23 is provided at the tip of the magnetic pole piece 22a in the magnetic steel plates 22A and 22B. For this reason, since the front-end | tip of the magnetic pole piece 22a is couple | bonded in the lamination | stacking state by the holding piece 23, a possibility that magnetic steel plate 22A, 22B may isolate | separate can be prevented. Incidentally, when the magnetic steel plates 22A and 22B provided with the narrow magnetic pole piece 22a are laminated, the laminated state is easily separated at the tip of the magnetic pole piece 22a, but in this embodiment, such a risk can be avoided. .

(Example of change)
In addition, this embodiment can also be changed and embodied as follows.
In the first and second embodiments, the holding piece 23 and the concave portion 24 are formed on the inner peripheral edge of the magnetic steel plates 22A to 23C, and the plurality of magnetic steel plates 22A to 23C are coupled to each other in a laminated state by the inner peripheral edge. To be configured. In this case, the same process as in the third embodiment is employed.

  A combination of the configuration of the first embodiment and the configuration of the second embodiment.

  DESCRIPTION OF SYMBOLS 21 ... Motor core, 22, 22A-22C ... Magnetic steel plate, 22a ... Magnetic pole piece, 23 ... Holding piece, 24 ... Recessed part, 25 ... Inner diameter hole, 27 ... Stator core, 30 ... Punching laminating device, 31 ... Punch, 32 ... Die, 33 ... Squeeze ring, 34 ... Molding groove, 34a ... Molding surface, 39 ... Molding member, 39a ... Molding surface, W ... Workpiece.

Claims (7)

In a motor core in which a plurality of magnetic steel plates are laminated and a holding piece that holds the magnetic steel plates in a laminated state by being engaged with the edges of other magnetic steel plates at the edge of a predetermined magnetic steel plate,
A motor core, wherein a resilient force in a direction in which the holding piece forms an acute angle is applied to the holding piece. The motor core according to claim 1, wherein the holding piece is provided on an outer peripheral edge portion of the magnetic steel plate. The motor core according to claim 1, wherein the holding piece is provided on an inner peripheral side of the magnetic steel plate. The motor core according to claim 3, wherein the holding piece is provided at a tip of a magnetic pole piece on an inner peripheral side of the magnetic steel plate. A motor core that stacks a plurality of magnetic steel plates and engages holding pieces formed at the edges of a predetermined magnetic steel plate with the edges of other magnetic steel plates so that the magnetic steel plates are held in a laminated state. In the assembly method of
A method of assembling a motor core, wherein the holding piece is bent at an acute angle toward another magnetic steel plate while laminating the magnetic steel plates. 6. The motor core assembling method according to claim 5, wherein the holding piece formed on the outer periphery of the magnetic steel plate is bent at an acute angle while punching the magnetic steel plate. The inner diameter hole of the motor core is formed in the punched part of the magnetic steel plate of the workpiece, the holding piece formed on the inner periphery of the inner diameter hole is bent, and then the holding piece is bent at an acute angle while punching the magnetic steel plate. The motor core assembling method according to claim 5.

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