JP2004343929A - Rotor manufacture method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a rotor, each pole piece of which is not connected and which can prevent magnetic flux leakage. <P>SOLUTION: This rotor manufacturing method consists of a first process of manufacturing a rotor core 14 by stacking core plates 12 that have a plurality of pole pieces 18 protruding from the inside circumference side of an annular outer frame plate 16, and that are connected by a push-back system with each of pole pieces 18 connected to the outer frame plate 16; a second process of encasing with a molding resin the portion other than the outer frame plate 16 after inserting magnets 20 between the pole pieces 18 in the rotor core 14 so manufactured and storing it in a mold with a shaft 22; and a third process of removing the outer frame plate 16 that is not covered by the molding resin from the rotor core 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a rotor in a motor.
[0002]
[Prior art]
BACKGROUND ART Conventionally, as a method for manufacturing a stator (stator) or a rotor (rotor), a core is manufactured by punching and laminating core plates obtained by punching steel plates (Patent Document 1).
[0003]
A conventional method of manufacturing the rotor of the present applicant will be described with reference to FIGS.
[0004]
As shown in FIG. 5, the core plate 100 of the rotor 112 has a plurality of substantially triangular pole pieces 104 protruding radially from the outer peripheral portion of the ring-shaped inner frame plate 102.
[0005]
The core plate 100 made of the steel sheet is punched and laminated to manufacture the rotor core 106.
[0006]
The magnet 108 is inserted between the pole pieces 104 of the manufactured rotor core 106, and the rotor core 106, the magnet 108, and the shaft 110 are integrally molded with the mold resin 111 in a state where the shaft 110 is arranged at the center of the rotor core 106. Thus, the rotor 112 is manufactured. In FIG. 6, portions covered with the mold resin 111 are hatched.
[0007]
Such a rotor 112 is used, for example, for a motor used in a direct drive washing machine using a brushless motor, and can use a low-cost ferrite magnet as the magnet 108 to increase the number of poles, so that a high torque can be obtained. Thus, both the magnet torque by the magnet 108 and the reluctance torque by the pole piece 104 can be obtained.
[0008]
[Patent Document 1]
JP-A-2002-247788
[0009]
[Problems to be solved by the invention]
However, since the structure of the conventional rotor 112 is complicated, the inner peripheral side of the rotor core 106 needs to be integrally formed with the inner frame plate 102. There is a problem that torque and motor efficiency are reduced.
[0010]
In view of the above problems, the present invention provides a method for manufacturing a rotor in which each pole piece is not connected and magnetic flux leakage can be prevented.
[0011]
[Means for Solving the Problems]
The invention according to claim 1 is a method of manufacturing a rotor in a motor in which a magnet is inserted between a plurality of pole pieces radially arranged around a shaft, wherein the plurality of poles are arranged from an inner peripheral side of a ring-shaped outer frame plate. A first step of manufacturing a rotor core in which pieces are protruded, and a connection core plate in which the outer frame plate and each of the pole pieces are connected by a pushback method, and between each pole piece in the manufactured rotor core. The rotor cores other than the outer frame plate, the plurality of magnets, and the shaft are integrally molded with a mold resin. A second step of removing the outer frame plate not covered with the mold resin from the rotor core. Is a manufacturing method of a rotor characterized by Rukoto.
[0012]
The invention according to claim 2, wherein in the first step, the connecting core plate has a straight shape in which the outer frame plate is divided for each of the pole pieces, and the divided outer frame plates are connected via a connecting portion. A plurality of the connection core plates, wherein a plurality of the connection core plates are stacked and then bent at the connection portion, thereby forming the stacked connection core plates in a ring shape to manufacture a rotor core. The method for manufacturing a rotor according to claim 1, wherein
[0013]
The invention according to claim 3 is characterized in that, in the first step, a divided core plate composed of divided pole pieces that are not connected by the outer frame plate is placed between the connected core plates or the stacked connected core plates. The method according to claim 1, wherein the rotor is laminated.
[0014]
[Operation]
According to the method of manufacturing the rotor having the above configuration, the pole pieces are connected by the outer frame plate until the rotor core, the plurality of magnets, and the shaft are integrally molded with the mold resin, so that the production is easy. .
[0015]
Further, since the outer frame plate is removed from the rotor core after being integrally molded with the mold resin, each pole piece becomes independent, and no magnetic flux leakage occurs.
[0016]
Furthermore, since the outer frame plate is connected to each pole piece by a pushback method, it can be easily excluded.
[0017]
According to the rotor manufacturing method of the second aspect, since the connecting core plate is formed of a straight connecting core plate, when the connecting core plate is punched from a steel plate, it is possible to perform the punching with minimum waste of material.
[0018]
According to the method of manufacturing a rotor of claim 3, since the divided core plates are connected between the connected core plates or next to the stacked connected core plates, the number of outer frame plates is reduced, and the number of outer frame plates is reduced. Exclusion can be made easier.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
(1st Embodiment)
Hereinafter, a rotor 10 in a motor according to a first embodiment of the present invention will be described with reference to FIGS.
[0020]
The motor of the present embodiment is a brushless motor for direct drive used in a washing machine or the like, and is, for example, a rotor 10 used in a brushless synchronous motor, a brushless DC motor, a brushless servomotor, or the like.
[0021]
(1) Method of Manufacturing Rotor 10 A method of manufacturing the rotor 10 will be sequentially described with reference to FIGS.
[0022]
(1-1) First Step In the first step, the rotor core 14 is manufactured by punching and laminating the core plates 12.
[0023]
As shown in FIG. 1, the core plate 12 has twenty pole pieces 18 radially protruding from the inner peripheral side of the ring-shaped outer frame plate 16 toward the center at equal intervals. The pole piece 18 has a substantially triangular shape, and its tip is formed in a T-shape.
[0024]
The core plate 12 having the ring-shaped outer frame 16 having the pole piece 18 is punched from a steel plate. In this punching, the connecting portion between the pole piece 18 and the outer frame plate 16 is connected by a pushback method. ing. The push-back method refers to a processing method in which when a steel plate is punched, the punched material is pushed back to the original state, and is a JIS term defined in JIS number C5603.
[0025]
The rotor core 14 is manufactured by laminating a plurality of core plates 12 punched out as described above by punching and caulking.
[0026]
(1-2) Second Step The rotor core 14 manufactured in the first step is housed inside a mold for performing molding, and a rod-shaped magnet 20 made of a ferrite magnet is provided in a space between the pole pieces 18. To store. In addition, a shaft 22 serving as a rotation axis of the rotor 10 is arranged at the center of the rotor core 14.
[0027]
Then, the rotor core 14, the plurality of magnets 20, and the shaft 22 are integrally molded with the mold resin 11. In this case, only the outer frame body 16 located on the outer peripheral portion of the rotor core 14 is molded so that only the outer frame plate 16 is exposed from the integrally molded product so as not to be covered with the mold resin.
[0028]
(1-3) Third Step After integrally molding with the mold resin 11 as described above, the molded product is taken out of the mold, and the outer frame plate 16 exposed on the outer peripheral portion of the rotor core 14 is removed by pressing or the like. By excluding, the rotor 10 is completed.
[0029]
When the outer frame plate 16 is removed by a press or the like, the pole piece 18 and the outer frame plate 16 are connected by a push-back method, so that the removal can be easily performed.
[0030]
In FIGS. 2 and 3, portions covered with the mold resin 11 are hatched.
[0031]
(2) Effect of Rotor 10 According to the above manufacturing method, the plurality of pole pieces 18 are integrally connected by the outer frame plate 16 before the rotor core 14, the magnet 20, and the shaft 22 are molded. The workability is good and the assemblability is good.
[0032]
Further, since the outer frame plate 16 is excluded from the rotor 10, each pole piece 18 is independent, there is no leakage of magnetic flux, and the torque and the efficiency of the motor are improved.
[0033]
(Second embodiment)
The core plate 12 according to the second embodiment will be described with reference to FIGS.
[0034]
The core plate 12 of the second embodiment is formed from a straight core plate 12, as shown in FIG.
[0035]
That is, the outer frame plate 16 is integrally connected to the outer peripheral side of the pole piece 18 by the pushback method, but is connected to the outer frame plate 16 connected to the adjacent pole piece 18 via the connecting portion 24. Are linked. The connecting portion 24 has a structure in which adjacent outer frame plates 16 are separated from each other by a V-shaped groove, and only outer ends thereof are connected.
[0036]
The straight core plate 12 is punched from a steel plate, and the punched straight cores 12 are laminated by caulking or the like. Thereafter, the laminated straight core 12 is bent at the connecting portion 24 and bent into a ring-shaped rotor core 14 as shown in FIG.
[0037]
Steps after the rotor core 14 manufactured as described above are the same as those in the first embodiment.
[0038]
With the straight core plate 12 as described above, a steel plate can be used more efficiently than punching the ring-shaped core plate 12.
[0039]
(Modification 1)
In the above embodiment, the outer frame plate 16 and the pole piece 18 are made of a steel plate having the same thickness. Alternatively, if the strength is sufficient, the thickness of the outer frame plate 16 that is excluded may be changed to the pole piece 18. May be thinner than the thickness of.
[0040]
(Modification 2)
In the above embodiment, when the rotor core 14 is manufactured, the core plates 12 are stacked and configured. However, between the core plates 12, the divided cores including the independent pole pieces 18 that are not connected by the outer frame plate 16. The rotor core 14 may be manufactured by laminating plates.
[0041]
In this case, since the number of the outer frame plates 16 is reduced, the operation of removing the outer frame plates 16 can be performed more easily.
[0042]
In addition to the structure in which the split core plates are sandwiched between the core plates 12, a structure in which the split core plates are stacked on the stacked core plates 12 may be used.
[0043]
(Application example)
In the above embodiment, a motor used for direct drive for a washing machine has been described. However, the present invention is not limited to this, and its application range can be widened as a method for manufacturing a rotor in a multi-pole configuration such as a direct drive motor.
[0044]
【The invention's effect】
As described above, according to the rotor manufacturing method of the present invention, it is possible to manufacture a rotor having good assemblability, low magnetic flux leakage and high torque efficiency.
[Brief description of the drawings]
FIG. 1 is a plan view of a core plate in a first step in a first embodiment.
FIG. 2 is a plan view of a rotor core in a second step.
FIG. 3 is a plan view of the rotor in a third step.
FIG. 4 is a plan view of a straight core plate according to a second embodiment.
FIG. 5 is a plan view of a conventional rotor core.
FIG. 6 is a plan view of a conventional molded rotor.
[Explanation of symbols]
Reference Signs List 10 rotor 11 mold resin 12 connecting core plate 14 rotor core 16 outer frame plate 18 pole piece 20 magnet 22 shaft 24 connecting portion

Claims (3)

In a method of manufacturing a rotor in a motor in which a magnet is inserted between a plurality of pole pieces radially arranged around a shaft,
A first method for manufacturing a rotor core in which a plurality of pole pieces protrude from the inner peripheral side of a ring-shaped outer frame plate, and a connected core plate in which the outer frame plate and each of the pole pieces are connected by a pushback method is laminated. Process and
A magnet is inserted between each pole piece in the manufactured rotor core, and is housed in a mold with the shaft arranged at the center of the rotor core. A second step of integrally molding the magnet and the shaft with a mold resin;
A third step of excluding the outer core plate not covered by the mold resin from the rotor core;
A method for manufacturing a rotor, comprising: In the first step,
The connection core plate is a straight connection core plate in which the outer frame plate is divided for each of the pole pieces, and the divided outer frame plates are connected via a connection portion.
2. The rotor core according to claim 1, wherein after stacking a plurality of the connection core plates, the connection portion is bent at the connection portion to form the stacked connection core plates in a ring shape to manufacture a rotor core. 3. Production method. In the first step,
The split core plate composed of split pole pieces that are not connected by the outer frame plate is stacked between the connection core plates or next to the stacked connection core plates. Manufacturing method of the rotor.

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