JP2011172441A - Motor core and assembling method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor core that secures the insulation between a steel plate and a permanent magnet to reduce an eddy current loss, and to provide an assembling method of the motor core. <P>SOLUTION: A plurality of core plates 22A to 22C having an insulation film on both sides are laminated, and the permanent magnet 24 is stored in the through-hole 23 formed in each of the core plates 22A to 22C. A fixing piece 25, which is compressed with the permanent magnet 24 on the face of the insulation film to fix the permanent magnet 24, is provided to the inner side edge of the through-hole 23 in at least one core plate 22A. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a motor core such as a rotor core and a stator core in a motor, and particularly a motor core in which a steel plate made of a plurality of magnetic bodies is laminated and a permanent magnet is accommodated in a through hole formed in the steel plate, and The present invention relates to a method for assembling the motor core.

  Conventionally, as this type of motor core, for example, in a rotor core, a permanent magnet is accommodated in a through hole of a steel plate, and a resin is filled in a gap between the inner edge of the through hole and the permanent magnet to fix the permanent magnet. The configuration is known.

  Moreover, as a fixed configuration of the permanent magnet element in this type of rotor core, a configuration as disclosed in Patent Document 1, for example, has been proposed. In this conventional configuration, as shown in FIGS. 11 and 12, two through holes 42, 43 are formed in the steel plate 41, and a protruding portion 44 is formed at the inner edge of one through hole 42, while the other A recess 45 is formed in the inner peripheral edge of the through hole 43. And between the steel plates 41 adjacent to each other in the stacking direction, the plurality of steel plates 41 are rotated by 180 degrees with respect to other adjacent steel plates 41 so that the protrusions 44 and the recesses 45 correspond to each other. Are stacked.

  And in the lamination state of this steel plate 41, the permanent magnet 46 is press-fitted in the through holes 42 and 43. For this reason, the protruding portion 44 engages with the outer surface of the permanent magnet 46 and is bent toward the concave portion 45 side of the through hole 43 in the adjacent steel plate 41. For this reason, the tip edge of the protruding portion 44 in the bent state is permanent. The magnet 46 is in pressure contact. Further, the permanent magnet 46 is pressed against the inner edges of the through holes 42 and 43 on the opposite side of the protrusion 44 and the recess 45. As described above, the permanent magnet 46 is fixedly held in the through holes 42 and 43.

JP-A-5-146103

However, the conventional configuration has the following problems.
(1) In a conventional configuration in which a permanent magnet is fixed by filling a resin, it is necessary to fill the resin using a molding device and to perform a deburring operation after filling the resin. For this reason, there has been a problem that the assembly work of the permanent magnet becomes complicated and the cost is increased.

  (2) In the conventional configuration described in Patent Document 1, the tip edge of the projecting portion 44 is pressed against the permanent magnet 46, and the permanent magnet 46 is pressed against the inner edges of the through holes 42, 43, so A magnet 46 is held in the through holes 42 and 43. By the way, this kind of rotor core steel plate 41 is formed by cutting out with a punch press a material having an insulating film on both front and back surfaces. Therefore, the surface on which the insulating film is not provided is exposed on the outer peripheral end surface including the inner edges of the through holes 42 and 43 and the tip of the protruding portion 44. For this reason, when the permanent magnet 46 comes into contact with the inner edges of the through holes 42 and 43 and the tip end surface of the protruding portion 44, electrical insulation between the permanent magnet 46 and the steel plate 41 cannot be ensured. In such a state, an electric circuit passing through the entire permanent magnet 46 and the rotor core is formed, and a large eddy current loss occurs, which causes a problem that the operation efficiency of the motor is remarkably reduced.

  The present invention has been made paying attention to such problems existing in the prior art. A main object of the present invention is to provide a motor core capable of ensuring insulation between a steel plate and a permanent magnet and reducing eddy current loss.

  In order to achieve the above object, in the invention relating to the motor core, the steel plates made of a plurality of magnetic bodies having insulating films provided on both the front and back surfaces are laminated, and permanent magnets are placed in the through holes formed in the steel plates. The accommodated motor core is characterized in that a fixing piece for fixing the permanent magnet is provided on the inner edge of the through hole in at least one steel plate by being pressed against the permanent magnet on the surface of the insulating film. .

  Therefore, in the motor core of the present invention, the permanent magnet can be fixedly held in the through hole by pressing the fixing piece against the permanent magnet in a state where the permanent magnet is accommodated in the through hole of the steel plate. In this case, since the fixed piece is in contact with the permanent magnet on the surface of the insulation coating, and the portion without the insulating film on the steel plate is not in contact with the permanent magnet, it is possible to ensure insulation between the steel plate and the permanent magnet. it can. Therefore, eddy current loss can be reduced.

The said structure WHEREIN: It is good to provide the said fixing piece in the inner edge of the through-hole of the steel plate arrange | positioned every predetermined number.
In the above configuration, the fixed pieces are provided at a plurality of locations on the inner edge of the through hole, and the permanent magnet is held at a position separated from the inner edge of the through hole of each steel plate in a state where the fixed piece is pressed against the permanent magnet. It is preferable to do so.

  In the above configuration, among the fixed pieces at a plurality of locations in the through-hole, the pressure contact force of the fixed piece arranged on the side that receives the movement force in the centrifugal direction of the permanent magnet accompanying the rotation of the motor is used as another fixed piece. It is preferable to be larger than the pressure contact force.

  In the invention relating to the motor core assembling method, in the assembling method for assembling the motor core configured as described above, the permanent magnet is pushed into the through hole so that the fixed piece is curved and deformed. It is said.

  Therefore, in the method for assembling the motor core according to the present invention, the permanent magnet is not required to be troublesome in that the permanent magnet is inserted into the through hole of the steel plate and then the resin is filled in the gap between the permanent magnet and the through hole. Can be easily assembled in the through hole of the steel plate, and can be fixedly held in a stable state.

  As described above, according to the present invention, the insulation between the steel plate and the permanent magnet can be secured, the eddy current loss during the rotation of the motor can be reduced, and the operation efficiency of the motor is improved. Demonstrate the effect that you can.

1 is an exploded perspective view showing a first embodiment in which the present invention is embodied in a rotor core of a motor. The fragmentary sectional view which expands and shows the accommodating part of the permanent magnet in the rotor core of FIG. The fragmentary sectional view which shows the assembly method of the permanent magnet with respect to the through-hole of the rotor core of FIG. The principal part front view which shows the 1st steel plate in the rotor core of FIG. The principal part front view which shows the 2nd steel plate in the same rotor core. The principal part front view which shows the 3rd steel plate in the same rotor core. The top view which shows the punching process of the same rotor core. (A) is a figure which shows the preliminary process at the time of forming the through-hole part of a 1st-3rd steel plate, (b) is a figure which shows the end surface shape of the punch and die used for forming a through-hole part, (c) ) Is a view showing a through-hole portion of the formed first to third steel plates. (A) And (b) is a figure which shows the method of bending the fixing piece in the through-hole of a 1st steel plate, (c) is a figure which shows the processing state of the through-hole of a 2nd and 3rd steel plate. The principal part front view which shows the 1st steel plate in the rotor core of 2nd Embodiment. Sectional drawing which shows the principal part which shows the conventional rotor core. FIG. 12 is a partially enlarged cross-sectional view taken along line 12-12 in FIG.

(First embodiment)
A first embodiment in which the present invention is embodied in a rotor core of a motor will be described below with reference to FIGS.

  As shown in FIG. 1, the rotor core 21 is configured by laminating a core plate 22 made of electromagnetic steel plates as a plurality of punched and formed magnetic bodies. Insulating films (not shown) are provided on both front and back surfaces of each core plate 22. Each core plate 22 has a plurality of through holes 23 formed in a specific arrangement pattern. A field permanent magnet 24 is housed and fixed in each through hole 23. A central hole 27 is formed in the axial portion of each core plate 22.

  Next, a configuration for fixing the permanent magnet 24 to the through hole 23 of the core plate 22 will be described. As shown in FIGS. 2 and 3, in this embodiment, first to third core plates 22 </ b> A, 22 </ b> B, and 22 </ b> C having different shapes of the through holes 23 are used. Then, one first core plate 22A, three second core plates 22B, and three third core plates 22C are sequentially laminated, and the lamination pattern of the core plates 22A to 22C is repeated. Thus, the rotor core 21 is configured.

  As shown in FIG. 4, fixing pieces 25 having a substantially L-shaped cross section are formed at a plurality of locations on the inner peripheral edge of the through hole 23 in the first core plate 22A. As shown in FIG. 5, a plurality of recesses 26 corresponding to the inner peripheral edge of the through hole 23 in the second core plate 22 </ b> B at the same position as each fixing piece 25 in the through hole 23 in the first core plate 22 </ b> A. Is formed. As shown in FIG. 6, the fixed piece 25 and the recessed part 26 are not formed in the inner periphery of the through-hole 23 of the 3rd core board 22C. Then, as shown in FIG. 2, when the permanent magnets 24 are pushed into the through holes 23 in the stacked state of the core plates 22 </ b> A to 22 </ b> C, the fixed pieces 25 having a substantially L-shaped cross section are formed by the permanent magnets 24. The second core plate 22B is curved and deformed in the recess 26 of the through hole 23, and is pressed against the permanent magnet 24 on the surface of the insulating film. As a result, insulation between each of the core plates 22 </ b> A to 22 </ b> C and the permanent magnet 24 is ensured, and the permanent magnet 24 is fixedly held in the through hole 23.

  Moreover, the outward moving force of the permanent magnet 24 acts by the centrifugal force accompanying the rotation of the motor. In this case, of the plurality of fixed pieces 25, the pressure contact force of the fixed piece 25 arranged on the side receiving the outward moving force of the permanent magnet 24 is the pressure contact force of the fixed piece 25 arranged on the opposite side. It is comprised so that it may become larger. That is, as shown in FIG. 4, in each through-hole 23, the number of fixing pieces 25 arranged on the outer peripheral side of the first core plate 22A is fixed to the center side of the first core plate 22A. It is configured to be larger than the number of pieces 25.

  Next, a method for assembling the motor core configured as described above will be described. FIGS. 8A and 8B show the process of forming the through holes 23 of the first to third core plates 22A to 22C. In the same drawing, the first to third core plates 22A to 22C are shown. Although only one of each through hole 23 is shown, in practice, all the through holes 23 are formed simultaneously as shown in FIG.

  When forming the through holes 23 of the first to third core plates 22A to 22C, first, as shown in FIG. 7, the center hole 27 is punched into the work W by a punch and a die (not shown). Next, as schematically shown in FIG. 8A, the second and third core plates 22 </ b> B are formed at the positions where the through holes 23 are formed in the molding portions of the first to third core plates 22 </ b> A to 22 </ b> C on the workpiece W. , 22C different preliminary processing is performed. In other words, the forming position of the first core plate 22A is not processed for the position where the through hole 23 is formed. A plurality of holes 31 are formed in the forming portion of the second core plate 22 </ b> B so as to straddle the inner edge positions of the through holes 23 in the portions where the respective recesses 26 are formed in the through holes 23. In the molding portion of the third core plate 22C, a plurality of holes 32 facing the inner edge position of the through hole 23 are formed at positions corresponding to the fixing pieces 25 in the through hole 23.

  Next, when forming the through holes 23 of the first to third core plates 22A to 22C, a punch 33 and a die 34 having an end face shape (blade edge shape) as shown in FIG. 8B are used. By forming the through holes 23 in the molding portions of the core plates 22A to 22C by the punch 33 and the die 34, the through holes 23 having different structures are formed as shown in FIG. That is, in the molding part of the first core plate 22 </ b> A, a plurality of fixing pieces 25 are formed on the inner edge of the through hole 23 so as to protrude in a flat plate shape. A plurality of recesses 26 are formed on the inner edge of the through hole 23 at the molding site of the second core plate 22B. Only the through hole 23 is formed at the molding portion of the third core plate 22C.

  Subsequently, as shown in FIG. 7, the core plates 22 </ b> A to 22 </ b> C are punched and formed from the workpiece W by a punch and a die having an end face shape (blade shape) of the outer diameters of the core plates 22 </ b> A to 22 </ b> C. The core plates 22A to 22C are stacked. The rotor core 21 is configured by this lamination. In the punching process, as shown in FIGS. 9A to 9C, the punch 35 includes die portions 35a and 36a for bending the fixing piece 25 into a substantially L-shaped cross section. And a die 36 is used. That is, at the time of punching the first core plate 22A, as shown in FIGS. 9A and 9B, the plate-shaped fixing piece 25 in the through hole 23 is formed by the punch 35 and the die portions 35a and 36a of the die 36. Is bent and formed in a substantially L-shaped cross section. On the other hand, when the second and third core plates 22B and 22C are punched, as shown in FIG. 9C, the fixing piece 25 does not protrude into the through hole 23. The mold parts 35a and 36a perform the blanking operation.

  And after the rotor core 21 is comprised as mentioned above, as shown in FIG.1 and FIG.3, the permanent magnet 24 is inserted and assembled | attached to each through-hole 23 of the rotor core 21. As shown in FIG. In this case, when the permanent magnets 24 are pushed into the through holes 23, the fixing pieces 25 having a substantially L-shaped cross section in the through holes 23 of the first core plates 22 </ b> A arranged at intervals of a plurality of the permanent magnets 24. Is bent and deformed in the recess 26 of the through hole 23 of the second core plate 22B adjacently disposed. Accordingly, the fixed piece 25 in the curved state is pressed against the permanent magnet 24 on the surface of the insulating film by the spring back, and is separated from the inner edge of the through hole 23, and the core plates 22 </ b> A to 22 </ b> C and the permanent magnet 24 are separated from each other. The permanent magnet 24 is fixedly held in the through hole 23 in a state where insulation between the two is ensured.

Therefore, according to this embodiment, the following effects can be obtained.
(1) In the rotor core 21, when the permanent magnet 24 is accommodated in the through holes 23 of the core plates 22 </ b> A to 22 </ b> C, the fixed piece 25 on the inner edge of the through hole 23 is pressed against the permanent magnet 24. A permanent magnet 24 is held in the through hole 23. In this case, the fixed piece 25 is in contact with the permanent magnet 24 on the surface of the insulation coating, and the portion without the insulating film on the core plates 22A to 22C is not in contact with the permanent magnet 24. Insulation with the magnet 24 can be ensured. Therefore, unlike the conventional configuration, eddy current loss during rotation of the motor can be reduced, and the operating efficiency of the motor can be improved.

  (2) In the rotor core 21, a plurality of the fixed pieces 25 are provided on the inner edge of the through-hole 23, and the permanent magnet 24 is in contact with the permanent magnets 24 in a state where the fixed piece 25 is pressed against the permanent magnets 24. It is held at a position spaced from the inner edge of the through hole 23. For this reason, in the through-hole 23 of each core board 22A-22C, it can prevent that the inner edge of the part in which the fixing piece 25 is not provided contact | abuts to the permanent magnet 24. FIG. Therefore, the insulation between the core plates 22A to 22C and the permanent magnet 24 can be enhanced, and the eddy current loss during the rotation of the motor can be further reduced.

  (3) In this rotor core 21, since the fixed pieces 25 resist the centrifugal force acting on the permanent magnets 24, the number of the fixed pieces 25 on the side receiving the outward moving force of the permanent magnets 24 is the center. More than the number of the fixing pieces 25 on the side is provided. Therefore, even if the rotor core 21 is rotated at a high speed, the fixed state of the permanent magnet 24 can be maintained.

  (4) In the rotor core 21, the permanent magnet 24 is held by the spring back of the deformed fixed piece 25 by inserting the permanent magnet 24 into the through hole 23. Therefore, the permanent magnet 24 can be fixed regardless of the thickness difference of the permanent magnet 24, and the variation in the dimensions of the permanent magnet 24 can be allowed.

  (5) In this method of assembling the rotor core 21, the permanent magnet 24 is pushed into the through hole 23 and assembled so that the fixed piece 25 is curved and deformed. For this reason, unlike the conventional assembly method, after inserting the permanent magnet into the through hole of the steel plate, the complicated work of filling the gap between the permanent magnet and the through hole with resin is not required, and the permanent magnet 24 Can be easily assembled into the through holes 23 of the core plates 22A to 22C.

(Second Embodiment)
Next, a second embodiment embodying the present invention will be described with a focus on differences from the first embodiment.

  In the second embodiment, as shown in FIG. 10, in the through-hole 23, the permanent magnet 24 is disposed on the side receiving the outward force by centrifugal force, that is, on the outer peripheral side of the first core plate 22A. The width L1 of the fixed piece 25 is configured to be larger than the width L2 of the fixed piece 25 disposed on the central axis side. Therefore, the wide fixing piece 25 exerts a larger pressure contact force against the permanent magnet 24 than the narrow fixing piece 25.

Therefore, also in the second embodiment, substantially the same effects as the effects described in (1) to (5) in the first embodiment can be obtained.
(Example of change)
In addition, this embodiment can also be changed and embodied as follows.

  In the first and second embodiments, the third core plate 22C in which the fixing piece 25 and the recess 26 are not provided in the through hole 23 is omitted, and the first core plate in which the fixing piece 25 is provided in the through hole 23. The rotor core 21 is constituted by 22A and the second core plate 22B in which the recess 26 is provided in the through hole 23.

  In the first embodiment, the number of the fixing pieces 25 in the through holes 23 of the first core plate 22A and the recesses 26 in the through holes 23 of the second core plate 22B are set to the required pressure contact with the permanent magnet 24. Change it to gain power. For example, the number of the fixed pieces 25 and the recesses 26 on the side where the permanent magnet 24 receives the outward force is set to 3 or more.

  For example, the fixing piece 25 on the side where the permanent magnet 24 receives the outward force is omitted, and instead, the burring is performed on the inner surface of the through hole 23 except for the portion of the fixing piece 25 arranged on the axis side of the rotor core 21. Processing is performed, and the insulating coating portion of the inner edge of the through hole 23 curved by the burring process is pressed against the permanent magnet 24. Even if comprised in this way, the permanent magnet 24 will not contact the end surface in which the insulation coating of the through-hole 23 does not exist, and the insulation between the permanent magnet 24 and the core plates 22A-22C can be ensured.

-Change the number of core plates 22A to 22C as appropriate.
-The invention is embodied in a stator core of a motor.

  DESCRIPTION OF SYMBOLS 21 ... Rotor core, 22, 22A-22C ... Steel plate, 23 ... Through-hole, 24 ... Permanent magnet, 25 ... Fixed piece, 26 ... Recessed part

Claims (5)

While laminating a steel plate made of a plurality of magnetic bodies provided with an insulating film on both the front and back surfaces, and in a motor core containing a permanent magnet in a through-hole formed in the steel plate,
A motor core characterized in that a fixing piece for fixing a permanent magnet is provided on an inner edge of the through hole in at least one steel plate and pressed against the permanent magnet on the surface of the insulating film. 2. The motor core according to claim 1, wherein the fixing pieces are provided on an inner edge of a through hole of a steel plate arranged at predetermined intervals. The fixing pieces are provided at a plurality of locations on the inner edge of the through hole, and the permanent magnet is held at a position spaced from the inner edge of the through hole of each steel plate in a state where the fixing piece is pressed against the permanent magnet. The motor core according to claim 2. Among the plurality of fixed pieces in the through hole, the pressure contact force of the fixed piece arranged on the side receiving the moving force in the centrifugal direction of the permanent magnet accompanying the rotation of the motor is greater than the pressure contact force of the other fixed pieces. The motor core according to claim 3, wherein the motor core is made large. The assembly method for assembling the motor core according to any one of claims 1 to 4, wherein the permanent magnet is pushed into the through hole so that the fixed piece is curved and deformed. Assembling method of motor core.

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