JP5622519B2 - Manufacturing method of rotor part - Google Patents

Description

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

  There is a risk that burrs may be formed in the rotor part employed in the motor during the manufacturing process. If burrs are formed in the rotor part, the burrs in the rotor part may come into contact with the stator, which may affect the rotation of the rotor part.

  Patent Documents 1 and 2 disclose techniques related to such a countermeasure against burrs. In the technique of Patent Document 1, after the core plate is laminated to form the rotor portion, the tooth tip is ground. In the technique of Patent Document 2, a synthetic resin is applied and cured so as to embed the teeth of the rotor core, and after curing, the teeth are cut or ground together with the resin composition. In addition, there are probably rotor parts that are almost free of burrs just by press punching the core plate, but no prior art documents related to this technology have been found.

Japanese Utility Model Publication No. 06-060260 Japanese Patent Publication No. 05-046185

  In the technique of Patent Document 1, since the rotor portion is ground, a grinding fluid is required, and a waste liquid treatment, a cleaning treatment of the rotor portion after grinding, and the like are necessary. In grinding processing, the grindstone must be cut into the rotor portion at a minute speed, and processing time is required. Therefore, the manufacturing cost also increases.

  In the technique of Patent Document 2, many man-hours are required to cure the synthetic resin, and time is also required. For this reason, there exists a possibility that manufacturing cost may increase.

  In a rotor part that has just been stamped, a step between the shearing surface and the fracture surface occurs in the teeth. As a result, the torque of the motor may be reduced.

  Then, an object of this invention is to provide the manufacturing method of the rotor part which suppresses the manufacturing cost and suppresses the fall of the performance of a motor.

  In the method for manufacturing a rotor portion having a plurality of teeth on the outer peripheral portion, the object is to form a core plate having a plurality of teeth by punching, and superimposing the plurality of core plates to form the rotor portion. It can be achieved by a method for manufacturing a rotor part comprising: a step of forming; and a step of rolling the rotor part using a roller die in which irregularities are not formed on the outer peripheral surface.

  By rolling, no cutting fluid is required and no application of synthetic resin is required. For this reason, it can process in a short time and manufacturing cost is suppressed. Further, by rolling the rotor portion using a roller die having a flat outer peripheral surface, the tooth tip surface of the teeth of the rotor portion can be flattened. Thereby, the fall of the performance of a motor can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the rotor part which suppresses manufacturing cost and also suppresses the fall of the performance of a motor can be provided.

FIG. 1 is a schematic diagram of a rotor employed in a motor. 2A and 2B are explanatory diagrams of teeth of the rotor core before and after rolling. 3A and 3B are explanatory views of teeth of the rotor core portion having a structure different from that of the present embodiment before and after rolling. FIG. 4 is an explanatory diagram of a rolling device employed in the method for manufacturing the rotor core of the present embodiment. FIG. 5 is an explanatory diagram of a rolling device employed in the method for manufacturing the rotor core of the present embodiment. 6A and 6B are photographs showing the periphery of the teeth of the rotor core after rolling.

  FIG. 1 is a schematic diagram of a rotor 1 employed in a hybrid stepping motor. The rotor 1 includes a rotor core portion 10 and a shaft 12 penetrating the rotor core portion 10. The rotor core portion 10 is formed by a plurality of core plates stacked in the direction of the shaft 12. Although a core board is a silicon steel plate etc., for example, it is not limited to this, What is necessary is just a raw material which lets magnetic flux pass. The core plate is formed by punching using a press die. A plurality of teeth 14 are formed on the outer periphery of the rotor core 10. Note that the rotor core 10 is divided into two in the direction of the shaft 12. While being divided, a ring-shaped permanent magnet (not shown) is arranged coaxially with the shaft 12.

  Here, the manufacturing method of the rotor 1 is demonstrated easily. First, a plurality of core plates are formed using a press die. The core plate has teeth formed on the outer periphery. A plurality of core plates are stacked and integrated so that the teeth of the core plates correspond. Thereby, the rotor core part 10 is formed. Next, the shaft 12 is press-fitted into the hole of the rotor core 10. Next, the rotor core part 10 is rolled. The rolling of the rotor core 10 will be described later in detail.

  2A and 2B are explanatory views of the teeth 14 of the rotor core 10 before and after rolling. As shown in FIG. 2A, one tooth 14 has a tooth tip surface 14t and a tooth side surface 14s. The tooth tip surface 14t is a surface facing the stator when the rotor core portion 10 is assembled to the motor. The tooth side surface 14s is continuous with the tooth tip surface 14t. The tooth tip surface 14 t and the two tooth side surfaces 14 s define one tooth 14. A predetermined radius is provided at the corner 14r between the tooth tip surface 14t and the tooth side surface 14s. Such a round is formed when the core plate constituting the rotor core portion 10 is formed. That is, a press die used for punching when forming the core plate is designed so that teeth having corners provided with such rounds are formed. Although details will be described later, burrs formed on the core plate can be removed by rolling the rotor core 10 formed by stacking such core plates. Further, by providing a predetermined radius on the core plate, it is possible to suppress the formation of protrusions on the tooth tip surface 14t, and to make the tooth tip surface 14t have a desired area.

  The tip surface 14t of the tooth 14 of the rotor core 10 is pressed by rolling. The roller die 55a is used when the rotor core portion 10 is rolled. The outer peripheral surface of the roller die 55a is not provided with irregularities or teeth. When the rotor core part 10 is rolled, the burr generated on the outer peripheral part of the rotor core part 10 is crushed and deformed so as not to contact the stator. Further, when the rotor core portion 10 is rolled, a force on the inner side in the radial direction of the rotor core portion 10 acts on the teeth 14, and the tooth tip surface 14t is pressed. As a result, as shown in FIG. 2B, the teeth 14 are plastically deformed so that the radius of curvature of the corners 14r becomes small. Thereby, generation | occurrence | production of a protrusion is suppressed, ensuring the required area of the tooth-tip surface 14t.

  Next, the rotor core portion 10 of the present embodiment will be described in comparison with the rotor core portion 10x having a structure different from that of the rotor core portion 10 of the present embodiment. 3A and 3B are explanatory views of the teeth 14x of the rotor core 10x having a different structure from that of the present embodiment before and after rolling. As shown in FIG. 3A, the radius of curvature at the corner 14rx is designed to be small in advance. That is, the press die used for the punching process when forming the core plate is designed such that teeth having corners with small radius are formed.

  When the tooth tip surface 14tx is rolled in this state, a force on the radially inner side of the rotor portion acts on the tooth tip surface 14tx, and the tooth tip surface 14tx is pressed. Thereby, as shown to FIG. 3B, a protrusion generate | occur | produces in the circumferential direction from the corner | angular part 14rx. When such a rotor part is employed in the motor, the width of the tooth tip surface 14tx is different from the designed width, which may affect the motor characteristics.

4 and 5 are explanatory views of the rolling device 50 employed in the method for manufacturing the rotor portion of the present embodiment.
The rolling device 50 includes power sources 51a and 51b, a rotation shaft 52a, a driven shaft 52b, an endless belt 53, bearings 54a and 54b, roller dies 55a and 55b, and support bases 56a and 56b. A rotating shaft 52a is connected to the power source 51a, and the rotating shaft 52a is rotated by the power of the power source 51a. The rotating shaft 52a and the driven shaft 52b are rotatably supported by bearings 54a and 54b, respectively. The rotating shaft 52 a and the driven shaft 52 b are rotated in the same direction in conjunction with the endless belt 53. Roller dies 55a and 55b are fixed to the respective distal ends of the rotating shaft 52a and the driven shaft 52b. As the power source 51a rotates, the rotating shaft 52a and the driven shaft 52b rotate in the same direction, and the roller dies 55a and 55b also rotate in the same direction. The bearing 54b is movable in the direction perpendicular to the axial direction of the driven shaft 52b. Specifically, the bearing 54b is slidably supported by a rail (not shown) extending in a direction perpendicular to the axial direction of the driven shaft 52b. The rail and bearing 54a are fixed to a table (not shown). The power source 51b moves the bearing 54b in a direction perpendicular to the axial direction of the driven shaft 52b, for example, in the direction of the rotating shaft 52a. The power source 51b is, for example, an air cylinder or a hydraulic cylinder.

  The power sources 51a and 51b are controlled by the controller 90. The controller 90 is a computer and includes a CPU, a ROM, a RAM, and the like. The ROM stores a program for controlling the power sources 51a and 51b.

  Between the roller dies 55a and 55b, support bases 56a and 56b for supporting the shaft 12 so as to be slidable and rotatable are provided. Thereby, the rotor 1 is rotatably supported by the support bases 56a and 56b. The support bases 56a and 56b are each substantially L-shaped. As shown in FIG. 5, the support base 56a has a support surface 56a1 extending in the vertical direction and a support surface 56a2 extending in the horizontal direction. The angle between the support surface 56a1 and the support surface 56a2 is approximately 90 degrees. The support base 56b has the same structure as the support base 56a. Thus, one end of the rotating shaft 12 is supported at two points, the support surface 56a1 and the support surface 56a2, and similarly, the other end of the rotating shaft 12 is supported at two points by the support base 56b. That is, since the shaft 12 is supported at four points, the position of the rotor core portion 10 can be stably supported.

  As shown in FIG. 5, the rotation center C1 of the roller die 55a, the rotation center C2 of the roller die 55b, and the rotation center of the shaft 12 are not on the same straight line. In other words, the horizontal line L1 passing through the rotation center C1 and the rotation center C2 does not coincide with the horizontal line L2 passing through the rotation center of the shaft 12. Although L1 is slightly higher and the distance between the horizontal lines L1 and L2 is 0 to 1 mm, for example, it is not limited to this.

  A method for rolling the rotor core 10 using the rolling device 50 will be described. The shaft 12 of the rotor core 10 is supported on the support bases 56a and 56b. Next, the power source 51a is driven. In this state, the roller die 55b is retracted from the rotor core portion 10. Next, the power source 51b is driven to move the bearing 54b so that the roller die 55b contacts the rotor core 10 with a predetermined pressure. Thereby, the rotor core part 10 is pinched | interposed into roller dice 55a and 55b, rotates following roller die 55a and 55b. As a result, a force acts on the rotor core 10 in the radially inner direction. In this way, the rotor core 10 is rolled. The magnitude of the pressure of the power source 51b is set to such an extent that the teeth 14 of the rotor core portion 10 are not crushed and the teeth 14t are crushed and no projections are formed on the corner portions 14r. The rolling time is about 4 to 7 seconds, although it depends on the size of the rotor core 10 and the rotational speed of the roller die 55a.

  FIG. 6A is a photograph showing the periphery of the teeth 14t of the rotor core 10 after rolling. In FIG. 6A, the horizontal direction is the direction in which the shaft 12 extends. It can be seen that the tooth tip surface 14t of the tooth 14 is formed flat.

  On the other hand, FIG. 6B is a photograph showing the periphery of the teeth of the rotor part that has just been stamped. It can be seen that breath marks are generated in the horizontal direction. On the other hand, when the rolling process is performed as in the present invention, there is a feature that a trace in the horizontal direction does not occur. In addition, when polishing to the fractured surface by polishing after press punching, polishing marks are generated in the vertical direction, and there is no possibility that no processing marks are generated as in the present invention.

  Thus, in the manufacturing method of the rotor core part 10 of a present Example, since the rotor core part 10 is formed using plastic deformation called rolling, cutting fluid is unnecessary and application of a synthetic resin is also unnecessary. is there. For this reason, it can process in a short time and manufacturing cost is suppressed. Further, by rolling the rotor core portion 10 using a roller die having no irregularities on the outer peripheral surface, the tip surface 14t of the tooth 14 of the rotor core portion 10 can be flattened. Thereby, the fall of the performance of a motor can be suppressed.

  Further, since the rotor core 10 rotates following the roller dies 55a and 55b, a mechanism for rotating only the rotor core 10 alone is unnecessary. Moreover, since the support bases 56a and 56b support the shaft 12 of the rotor core part 10 so that sliding rotation is possible, it is suppressed that the rotor core part 10 rotates eccentrically. Thereby, the dimensional accuracy of the tooth | gear 14 after rolling can be ensured.

  Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and modifications and changes can be made within the scope of the gist of the present invention described in the claims. Is possible.

  The rotor portion may have a structure different from that of the above embodiment, and may be a metal portion having teeth on the outer peripheral portion.

  When performing the rolling process, the rotor portion may not have a rotating shaft. For example, a fixed shaft may be provided in a case that houses the rotor, and the rotor portion may be rotatably supported by the fixed shaft. In this case, when rolling the rotor portion, the rotor portion is rolled after inserting a metal shaft into the hole of the rotor portion. After rolling, the shaft is pulled out from the rotor part.

  In addition, in the said Example, although substantially L-shaped support stand 56a, 56b was used, you may support the axis | shaft 12 of the rotor 1 using a substantially V-shaped support stand.

DESCRIPTION OF SYMBOLS 1 Rotor 10 Rotor core part 12 Axis 14 Tooth 14r Corner | angular part 14s Tooth side surface 14t Tooth tip surface 50 Rolling device 51a, 51b Power source 52a Rotating shaft 52b Driven shaft 53 Endless belt 54a, 54b Bearing 55a, 55b Roller die 56a, 56b Support stand

Claims (2)

In the manufacturing method of the rotor part having a plurality of teeth on the outer peripheral part,
Forming a core plate having a plurality of teeth by punching; and
Forming a plurality of the core plates to form the rotor portion;
Rolling the rotor part using a roller die having no irregularities on the outer peripheral surface, and
The said core board is a manufacturing method of the rotor part by which R is provided in the corner | angular part between a tooth tip surface and a tooth side surface . 2. The method of manufacturing a rotor part according to claim 1 , wherein the rotor part is rolled while being supported by a support base that supports a shaft provided in the rotor part so as to be slidably rotatable.

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