JP7103963B2 - Rotor magnetizing method and rotor magnetizing device - Google Patents

Description

The present invention relates to a method for magnetizing a rotor and a magnetizing device for the rotor, which separately magnetize a group of magnets of the rotor.

A plurality of magnet groups embedded in a rotor used in an electric motor or a generator are magnetized by applying a magnetic field from the outside of the rotor using a magnetizing coil (magnetizing yoke). Normally, magnetism is performed on a plurality of magnet groups over the entire circumference of the rotor at once, but if magnetism is difficult due to magnets that are difficult to magnetize or the shape of the rotor, or if magnetism occurs. When it is desired to reduce the power supply capacity (total resistance of the magnetizing yoke), it is known to perform split magnetizing.

The split magnetizing is performed by magnetizing a partial magnet group out of all the magnet groups of the rotor, and repeating the partial magnetizing a plurality of times over the entire circumference of the rotor. However, when split magnetizing is performed, there is a problem that a reverse magnetic field opposite to the direction originally desired to be magnetized is applied to the magnet group to be non-magnetized other than the magnet group to be magnetized.

For this reason, conventionally, split magnetizing is performed using a magnetizing device in which subcoils having a winding direction opposite to that of the main coil and a smaller number of turns than the main coil are arranged on both outer sides of two or more main coils. As a result, a magnetizing method has been proposed in which a reverse magnetic field is prevented from being applied to a group of magnets to be non-magnetized (see, for example, Patent Document 1).

Japanese Patent No. 6062900

However, in the technique described in Patent Document 1, the number of magnetizing coils for one pole of the magnet group to be magnetized is at least two main coils 101 and 102 and the subcoils 201 on both outer sides thereof, as shown in FIG. Since at least four of 202 are required, there is a problem that the magnetizing yoke resistance is large and the capacity of the power supply cannot be reduced.

Further, the magnetizing portion of the rotor 300 by this magnetizing device is only the magnetic pole of the portion X in which the adjacent main coils 101 and 102 of the plurality of magnets 302 constituting the magnet group 301 of the rotor 300 overlap. Therefore, in order to apply a uniform magnetic field to the rotor 300, the magnetizing coils (main coil 101, 102, subcoils 201, 202) must be laid out, which causes restrictions on the placement of the magnetizing coils. In this case, in order to forcefully apply a magnetic field to a small-diameter rotor with a small coil arrangement space or a magnet that is difficult to magnetize, a high-capacity power supply is required because a magnetic field is generated by increasing the current. After all, it becomes difficult to reduce the capacity of the power supply. Moreover, there are problems that the durability of the magnetizing coil is deteriorated due to the load due to the high current, and the productivity is lowered due to the deterioration of the cycle time due to the increase in heat generation.

Further, in the technique described in Patent Document 1, there is a problem that the magnetic field is weakened because the magnetic field of the non-magnetized magnetic pole adjacent to the magnetized magnetic pole is strong (because the number of wires of the coil is large). That is, in the technique described in Patent Document 1, the number of turns of the main coils 101 and 102 is 15 turns, and the number of turns of the sub coils 201 and 202 is 3 turns, respectively. In this case, as shown in FIG. 8, when magnetism is performed by the two main coils 101 and 102 and the subcoils 201 and 202 on both sides thereof, the magnetic field mf1 for magnetism formed between the main coils 101 and 102 is formed. On the other hand, canceling magnetic fields mf2 and mf3 acting in the canceling direction are generated between the subcoils 201 and 202 and the main coils 101 and 102. Since the canceling magnetic fields mf2 and mf3 are magnetic fields based on the number of wires of the main coil 101 or 102 on one side + the number of wires of the subcoils 201 or 202 on one side, respectively, the canceling magnetic field component becomes large and the magnetic field mf1 for magnetizing is generated. It weakens. In order to secure the magnetic field mf1, it is necessary to increase the current, and in the end, as in the above case, a high current is applied and the power supply capacity becomes large.

Therefore, according to the present invention, the magnet group can be efficiently divided and magnetized with a small number of coils, the yoke resistance can be reduced, the power supply capacity can be reduced, and the influence of the canceling magnetic field on the magnet group to be magnetized can be affected. It is an object of the present invention to provide a method for magnetizing a rotor that can be suppressed and a magnetizing device for the rotor.

(1) The method for magnetizing a rotor according to the present invention is a magnetizing device (for example, magnetizing described later) having a coil group (for example, coil group 20 described later) composed of a plurality of coils that generate a magnetic field when energized. A rotor (for example, a rotor 1) is arranged in a magnetic device 2), and one of a plurality of magnet groups (for example, magnet groups 13, 13A to 13L described later) provided in the rotor by energizing the coil group. A step of partially magnetizing a magnet group by applying a magnetic field to the magnet group and a step of relatively moving the position of the magnetizing device and the rotor in the rotational direction are performed on the entire circumference of the rotor. This is a method of magnetizing a rotor that magnetizes all the magnet groups of the rotor by repeating the process a plurality of times, wherein the coil group is the magnet to be magnetized among the plurality of magnet groups. One main coil (for example, the main coil 21 described later) arranged to face the group and two subcoils (for example, two subcoils arranged adjacent to both sides of the main coil and having a smaller number of turns than the main coil). The sub-coils 22A and 22B) described later, and the magnetic field formed by the main coil and the magnetic field formed by the sub-coil (for example, the magnetic fields MF1 and MF2 described later) are used to magnetize the object. Magnetize the magnet group.

According to the invention described in (1) above, since magnetism is performed by the combined magnetic field of the main coil and the sub coil, the magnet group can be efficiently divided and magnetized with a small number of coils, and the yoke resistance is reduced. As a result, the power supply capacity can be reduced, and the influence of the reverse magnetic field on the magnet group to be magnetized can be suppressed.

(2) In the method for magnetizing the rotor according to (1), it is preferable that the main coil and the sub coil are wound in opposite directions.

According to the invention described in (2) above, when the magnetic field required for magnetizing the magnet group is formed, the directions of the currents flowing through the main coil and the sub coil can be the same, so that the configuration is simpler. Magnetization can be performed.

(3) In the method for magnetizing the rotor according to (1) or (2), when the magnet group to be magnetized is magnetized and then the adjacent magnet group is magnetized, the coil is used. It is preferable to switch the direction of the current energizing the group in the opposite direction.

According to the invention described in (3) above, by switching the direction of the electric current in the opposite direction, it is possible to apply a magnetic field in the opposite direction to the adjacent magnet groups in the same coil group.

(4) In the method for magnetizing the rotor according to any one of (1) to (3), both ends of the main coil (for example, both ends 21a and 21b described later) are attached to the magnet group to be magnetized. On the other hand, it may be configured to be arranged outside the rotor pole center line (for example, the rotor pole center line L2 described later) between the adjacent magnet groups.

According to the invention described in (4) above, it is possible to increase the magnetic field in the magnetization direction with respect to the magnet group to be magnetized, and it is possible to magnetize the magnet group to be magnetized more efficiently. ..

(5) The magnetizing device for the rotor according to the present invention has a coil group (for example, coil group 20 described later) composed of a plurality of coils that generate a magnetic field when energized, and energizes the coil group. Partial attachment by applying a magnetic field to a part of the magnet groups (for example, magnet groups 13, 13A to 13L described later) provided in the rotor (for example, rotor 1 described later). By repeating the step of performing magnetism and the step of relatively moving the positions of the magnetizing device and the rotor in the rotational direction a plurality of times over the entire circumference of the rotor, all the magnets of the rotor. A magnetizing device for a rotor that magnetizes a group, wherein the coil group is one main coil (for example, described later) arranged to face the magnet group to be magnetized among the plurality of magnet groups. 21) and two subcoils (for example, subcoils 22A and 22B described later) arranged adjacent to each other on both sides of the main coil and having a smaller number of turns than the main coil. The magnet group to be magnetized is magnetized by the combined magnetic field of the magnetic field formed by the magnet and the magnetic field formed by the subcoil.

According to the invention described in (5) above, it is possible to increase the magnetic field in the magnetization direction with respect to the magnet group to be magnetized, and it is possible to magnetize the magnet group to be magnetized more efficiently. It can be a magnetizing device.

(6) In the rotor magnetizing device according to (5), it is preferable that the main coil and the sub coil are wound in opposite directions.

According to the invention described in (6) above, when the magnetic field required for magnetizing the magnet group is formed, the directions of the currents flowing through the main coil and the sub coil can be the same, so that the configuration is simpler. can do.

(7) In the rotor magnetizing device according to (5) or (6), when the magnet group to be magnetized is magnetized and then the adjacent magnet group is magnetized, the coil is used. It is preferable that the direction of the current energizing the group can be switched in the opposite direction.

According to the invention described in (7) above, by switching the direction of the electric current in the opposite direction, it is possible to apply a magnetic field in the opposite direction to the adjacent magnet groups in the same coil group.

(8) In the rotor magnetizing device according to any one of (5) to (7), both ends of the main coil are located between the magnet groups adjacent to the magnet group to be magnetized. It is preferable that the rotor poles are arranged outside the center line.

According to the invention described in (8) above, it is possible to increase the magnetic field in the magnetization direction with respect to the magnet group to be magnetized, and it is possible to magnetize the magnet group to be magnetized more efficiently. ..

According to the present invention, the magnet group can be efficiently divided and magnetized with a small number of coils, the yoke resistance can be reduced, the power supply capacity can be reduced, and the influence of the reverse magnetic field on the magnet group to be magnetized can be affected. It is possible to provide a method for magnetizing a rotor that can be suppressed and a magnetizing device for the rotor.

It is a top view which shows an example of the rotor manufactured by the magnetizing method of the rotor which concerns on this invention. It is a top view which shows the state which arranged the rotor in the magnetizing apparatus used in the magnetizing method of the rotor which concerns on this invention. It is a top view which shows the main part of the magnetizing apparatus shown in FIG. 2 in an enlarged manner. It is explanatory drawing which enlarges and shows the main part about the partial magnetizing of a rotor by the magnetizing apparatus shown in FIG. It is explanatory drawing which enlarges and shows the main part about the canceling magnetic field by the magnetizing apparatus shown in FIG. It is explanatory drawing which enlarges and shows the main part about the partial magnetizing of a rotor by the magnetizing apparatus shown in FIG. It is explanatory drawing which enlarges and shows the main part about the magnetizing method of the conventional rotor. It is explanatory drawing which enlarges and shows the main part about the canceling magnetic field by a conventional magnetizing apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[Rotor]
First, the rotor manufactured by the magnetizing method of the rotor according to the present invention will be described with reference to FIG. FIG. 1 is a plan view showing an example of a rotor manufactured by the method for magnetizing a rotor according to the present invention. The rotor 1 has a rotor shaft 11 arranged at the center and a rotor core 12 arranged on the outer periphery of the rotor shaft 11.

The rotor core 12 is formed by laminating a plurality of electromagnetic steel sheets in the axial direction of the rotor shaft 11 (the direction perpendicular to the paper surface of FIG. 1). A plurality of magnet groups are embedded in the rotor core 12. The rotor 1 of the present embodiment is a 12-pole rotor in which 12 magnet groups 13A to 13L are embedded in a clockwise direction at equal intervals in the circumferential direction of the rotor core 12. In the following description, when the magnet groups 13A to 13L are pointed out without particular distinction, they are simply referred to as "magnet group 13".

The magnet group 13 is composed of three magnets M1, M2, and M3, respectively. The magnet M1 is arranged in the center of the magnet group 13, and the magnets M2 and M3 are arranged on both sides of the magnet M1 along the circumferential direction of the rotor core 12. The ends of the magnets M2 and M3 on the side farther from the magnet M1 are arranged closer to the outer side in the radial direction of the rotor core 12 than the ends on the side closer to the magnet M1. As a result, the magnets M2 and M3 are slightly inclined outward in the radial direction from the magnet M1 in the direction facing each other with the magnet M1 in between. In FIG. 1, only the magnets of the magnet group 13A are designated by the reference numerals M1 to M3, but the three magnets of the other magnet groups 13B to 13L also have the same arrangement configuration.

The magnetization directions of the magnet groups 13A to 13L are alternately reversed along the circumferential direction of the rotor core 12, as shown by the white arrows in FIG. That is, the magnetization directions of the magnet groups 13A, 13C, 13E, 13G, 13I, and 13K are directed outward in the radial direction of the rotor core 12, and the magnetization directions of the magnet groups 13B, 13D, 13F, 13H, 13J, and 13L are the rotor cores. It faces inward in the radial direction of 12. The magnetization directions of the three magnets M1 to M3 in the magnet group 13 are the same. As a result, the magnetization directions of the adjacent magnet groups 13 and 13 are opposite to each other, and the magnetic poles of the rotor 1 are configured to be alternately different in the circumferential direction.

In the rotor 1, magnet groups 13A to 13L composed of unmagnetized magnets M1 to M3 are arranged on the rotor core 12, and then the magnets M1 to M3 of the magnet groups 13A to 13L will be described below. It is manufactured by magnetizing in the magnetization direction shown in FIG. 1 by a magnetizing device.

[Magnetizer]
Next, a magnetizing device that separately magnetizes the magnet groups 13A to 13L of the rotor 1 will be described with reference to FIGS. 2 and 3. FIG. 2 is a plan view showing a state in which the rotor is arranged in the magnetizing device used in the method for magnetizing the rotor according to the present invention. FIG. 3 is an enlarged plan view showing a main part of the magnetizing device shown in FIG.

The magnetizing device 2 of the present embodiment has a coil group 20 that generates a magnetic field when energized. The coil group 20 is arranged concentrically with the rotor 1 along the outer circumference of the rotor 1. The rotor 1 and the coil group 20 of the magnetizing device 2 are relatively movable in the rotation direction about the axis of the rotor shaft 11 of the rotor 1. The coil group 20 of this embodiment is schematically shown. Further, the coil group 20 is arranged in, for example, an annular core of the magnetizing device 2, but the core of the magnetizing device 2 is not shown for simplification of description.

The coil group 20 of the present embodiment is composed of one main coil 21 and two subcoils 22A and 22B. The subcoils 22A and 22B are arranged adjacent to each other on both sides of the main coil 21 along the circumferential direction of the magnetizing device 2 so as to sandwich the main coil 21. The magnetizing device 2 applies a magnetic field from the outside of the rotor 1 to the magnet group 13 to be magnetized by energizing the main coil 21 and the subcoils 22A and 22B to magnetize the magnet group 13. .. In the present embodiment, the magnet group 13 to be magnetized is any one of the plurality of magnet groups 13A to 13L arranged in the rotor 1. The magnetizing device 2 can be arranged so that the main coil 21 of the coil group 20 faces the magnet group 13 to be magnetized by moving relative to the rotor 1 in the rotational direction. It is composed.

The main coil 21 and the subcoils 22A and 22B are wound so that the winding directions of the wires are opposite to each other. Further, the main coil 21 and the sub coils 22A and 22B each have a plurality of turns, but the number of turns of the sub coils 22A and 22B is smaller than the number of turns of the main coil 21. The number of turns of the two subcoils 22A and 22B is the same. The specific number of turns of each coil is not particularly limited, but in the present embodiment, the number of turns of the main coil 21 is 8 turns, and the number of turns of the sub coils 22A and 22B is 2 turns, respectively.

When the main coil 21 is viewed in a plan view as shown in FIG. 3, the three magnets M1 to M3 of the magnet group 13 (magnet group 13A in FIG. 3) to be magnetized are along the circumferential direction of the magnetizing device 2. It has a width that can cover the outside in the radial direction of the magnet. Specifically, the main coil 21 of the present embodiment is arranged so as to be substantially symmetrical with respect to the rotor pole center line L1 passing through the center of the magnet M1 of the magnet group 13A to be magnetized. However, the main coil 21 does not need to be arranged symmetrically between adjacent rotor magnetic poles as in the conventional case. Therefore, according to the magnetizing device 2, there are no restrictions on the coil arrangement as compared with the conventional case, and the coil structure can be simplified.

In this magnetizing device 2, it is not always necessary to strictly arrange the boundary portion between the main coil 21 and the sub coils 22A and 22B on the rotor pole interpole center lines L2 and L2. That is, the magnetizing device 2 can freely control the angle and distance of the magnetic flux with respect to the magnetizing direction of the magnet group 13 to be magnetized by arbitrarily setting the width of the main coil 21 along the circumferential direction of the magnetizing device 2. can do. In the present embodiment, both ends 21a and 21b of the main coil 21 along the circumferential direction of the magnetizing device 2 are rotors between the magnet group 13A to be magnetized and the magnet groups 13B and 13L adjacent thereto. It is arranged so as to slightly protrude to the outside (subcoils 22A, 22B side) in the circumferential direction from the interpole center lines L2 and L2. As a result, it is possible to increase the magnetic field in the magnetization direction with respect to the magnet group 13 to be magnetized, and it is possible to more efficiently magnetize the magnet group 13 to be magnetized.

When magnetizing the magnet group 13A, the subcoils 22A and 22B are arranged so as to face the magnet groups 13B and 13L adjacent to the magnet group 13A to be magnetized, and the positions of both ends of the subcoils 22A and 22B. There are no restrictions, and it is not necessary to set a precise position as long as a magnetic field can be appropriately applied to the magnet group 13 to be magnetized.

[Magnetization method]
Next, a specific method of applying a magnetic field to the magnet groups 13A to 13L of the rotor 1 to perform split magnetizing by using the magnetizing device 2 will be described with reference to FIGS. 4 to 6. FIG. 4 is an enlarged explanatory view showing a main part of magnetism of the rotor by the magnetizing device shown in FIG. FIG. 5 is an explanatory view showing an enlarged main part of the canceling magnetic field by the magnetizing device shown in FIG. FIG. 6 is an enlarged explanatory view showing a main part of magnetism of the rotor by the magnetizing device shown in FIG.

The split magnetizing of the rotor 1 using the magnetizing device 2 with respect to the magnet groups 13A to 13L is a magnetizing step in which a magnetic field is applied to the magnet group 13 to be magnetized by the energized coil group 20 to perform magnetization. And the moving step of relatively moving the rotor 1 and the magnetizing device 2 by a predetermined angle in the rotation direction are alternately repeated a plurality of times.

In the magnetizing step, as shown in FIG. 4, the main coil 21 of the magnetizing device 2 faces the magnet group 13 (magnet group 13A in FIG. 4) to be magnetized by any one of the magnet groups 13A to 13L. By energizing the coil group 20, a magnetic field is applied to the magnet group 13A to be magnetized to perform magnetization. In FIG. 4, the magnetized magnets M1 to M3 are shown by hatching.

In the magnetizing step, the main coil 21 and the subcoils 22A and 22B are energized in the same direction. As a result, the magnetic field MF1 interlinking the main coil 21 and the subcoils 22A and 22B, respectively, in the direction indicated by the arrow in FIG. 4 is generated. Since the main coil 21 and the subcoils 22A and 22B of the present embodiment are wound so that the winding directions are opposite to each other, the currents of the main coil 21 and the subcoils 22A and 22B are the same in the same direction. By flowing it, a magnetic field MF1 for magnetizing can be generated, and magnetizing can be performed with a simple configuration. When the winding directions of the main coil 21 and the sub coils 22A and 22B are the same, in order to generate the above magnetic field MF1, a current flows in the opposite directions to the main coil 21 and the sub coils 22A and 22B, respectively. This is because it is necessary and the circuit configuration becomes complicated.

The magnetic field MF1 generated by energizing the main coil 21 and the subcoils 22A and 22B is a combined magnetic field of the magnetic field formed by the main coil 21 and the magnetic fields formed by the subcoils 22A and 22B, respectively, from the magnetizing device 2. It extends to the area where the magnet group 13A to be magnetized of the rotor 1 inside the rotor 1 is arranged. Specifically, as shown by the white arrows in FIG. 4, the magnetic field MF1 composed of the synthetic magnetic field is from the inside in the radial direction of the rotor core 12 with respect to each of the magnets M1 to M3 of the magnet group 13A to be magnetized. It becomes a magnetic field applied toward the outside. As a result, the main coil 21 and the subcoils 22A and 22B are energized once to complete the magnetization of one magnet group 13A, and the magnets M1 to M3 of the magnet group 13A have S poles and diameters on the inside in the radial direction, respectively. It is magnetized so that the outside of the direction becomes the north pole.

When magnetizing the magnet group 13A, as shown in FIG. 5, in addition to the magnetic field MF1 which is a synthetic magnetic field applied to the magnet group 13A, a canceling magnetic field MFa which is opposite to the direction of the magnetic field MF1 is generated. Can be done. Although FIG. 5 shows only the canceling magnetic field MFa on the subcoil 22B side, it can also be generated on the subcoil 22A side as well. However, this canceling magnetic field MFa is a magnetic field generated only by the subcoils 22A and 22B, and is formed by a coil having a smaller number of turns than the canceling magnetic field formed by the main coil and the subcoil as in the conventional case shown in FIG. Since it is a magnetic field, the amount of canceling magnetic field is small. Therefore, the influence that the canceling magnetic field MFa weakens the magnetic field applied to the magnet group 13A to be magnetized is suppressed.

Next, when the magnetism of one magnet group 13A is completed, the energization of the coil group 20 is temporarily stopped, and a moving step of moving the rotor 1 and the magnetizing device 2 by a predetermined angle relative to the rotation direction is executed. To. By the moving step, the coil group 20 of the magnetizing device 2 is arranged so as to face the magnet group 13 to be magnetized next. In the present embodiment, the rotor 1 is rotated by 30 ° counterclockwise with respect to the magnetizing device 2, or the magnetizing device 2 is rotated by 30 ° clockwise with respect to the rotor 1. As a result, as shown in FIG. 5, the magnet group 13B adjacent to the magnet group 13A in the clockwise direction after magnetization is set as the next magnetizing target, and the main coil 21 is arranged so as to face the magnet group 13B. There is. Further, in this case, both the rotor 1 and the magnetizing device 2 may be rotationally moved by 15 ° in opposite directions.

After the main coil 21 is arranged so as to face the magnet group 13B to be magnetized, the main coil 21 and the subcoils 22A and 22B are energized again. At this time, the direction of the current with respect to the main coil 21 and the subcoils 22A and 22B is switched so as to be in the opposite direction to the case of magnetizing the magnet group 13A. As a result, the magnetic field MF2 interlinking the main coil 21 and the subcoils 22A and 22B, respectively, in the direction indicated by the arrow in FIG. 6 is generated.

Like the magnetic field MF1, this magnetic field MF2 is also a combined magnetic field of the magnetic field formed by the main coil 21 and the magnetic fields formed by the subcoils 22A and 22B, respectively, and is applied from the magnetizing device 2 to the rotor 1 inside the magnetic field MF2. Although it extends to the region where the magnet group 13B to be magnetized is arranged, the direction of the current is opposite, so that the magnetic field is opposite to that in the case of the magnetic field MF1. That is, as shown by the white arrows in FIG. 6, the magnetic field MF2 composed of the synthetic magnetic field is directed from the radial outer side to the inner side of the rotor core 12 with respect to each of the magnets M1 to M3 of the magnet group 13B to be magnetized. It becomes the magnetic field to be applied. As a result, the magnets M1 to M3 of the magnet group 13B are magnetized so that the inner side in the radial direction is the N pole and the outer side in the radial direction is the S pole, and the magnetic poles are inverted with respect to the magnet group 13A.

At this time, the subcoil 22B is arranged so as to face the magnet group 13A that has been magnetized first, but the direction of the magnetic field MF2 applied to the magnet group 13A at this time is the magnetism with respect to the magnet group 13A. Similar to the direction of the magnetic field MF1 applied at this time, the magnetic field is from the inside to the outside in the radial direction of the rotor core 12. Therefore, the influence on the magnet group 13A is hardly a problem.

The main coil 21 and the subcoils 22A and 22B of this embodiment are connected in series. Since these are wound so that the winding directions are opposite to each other, a magnetic field for magnetizing can be obtained simply by energizing in one direction in the order of the sub coil 22A, the main coil 21, and the sub coil 22B, or vice versa. MF1 or magnetic field MF2 can be generated. Since it is not necessary to set the direction of the current for each coil and energize them individually, the circuit configuration can be further simplified.

After that, the same magnetizing step and moving step as described above are alternately repeated a plurality of times. In the magnetizing step, by switching the direction of the current flowing through the coil group 20 between the adjacent magnet groups 13 and 13, the magnetization directions are alternately reversed with respect to the magnet groups 13C to 13L arranged in the rotor 1. Magnetize. Since the rotor 1 of the present embodiment has 12 poles, all the magnet groups 13A to 13L are shown in the figure by alternately executing 12 magnetizing steps and 11 moving steps between the magnetizing steps. It is magnetized so as to be in the magnetization direction shown by the white arrow in 1.

In this magnetizing device 2 and the magnetizing method, since the coil group 20 of the magnetizing device 2 is composed of only one main coil 21 and two subcoils 22A and 22B, the total magnetic field of the magnet groups 13A to 13L is , It tends to be lower as the number of coils is reduced, but in the part farthest from the coil group 20 and where the magnetic field is weak (for example, the magnet M1 in FIG. 1), all the magnet groups 13A to 13L of the rotor 1 are collectively combined. It can be about the same as when magnetizing. That is, according to the magnetizing device 2 and the magnetizing method, it is possible to efficiently perform split magnetizing with a smaller number of coils as compared with the conventional case.

Further, since the magnetic field generated by the subcoils 22A and 22B is used for magnetizing together with the main coil 21, not only for preventing the application of the reverse magnetic field as in the conventional case, it is necessary while suppressing the reverse magnetic field. A magnetic field can be secured. As a result, the number of coils for magnetizing can be reduced. For example, conventionally, an example of 15 turns of the main coil and 3 turns of the sub coil has been given, but in the case of the present embodiment, 18 turns of the main coil and 3 turns of the sub coil are sufficient to generate a magnetic field equivalent to that. .. Therefore, the yoke resistance can be reduced, and the power supply capacity can be reduced accordingly. As a result, the durability and life of the yoke can be improved, and the cycle time can be reduced.

In the magnetizing method described above, the magnet groups 13A to 12L arranged on the rotor 1 by the magnetizing device 2 are sequentially divided and magnetized along the circumferential direction. The magnetic method is not limited to such a method. For example, the magnetism may be divided and magnetized for each of the magnet groups 13 having the same magnetization direction arranged every other along the circumferential direction of the rotor core 12. That is, among the magnet groups 13A to 13L arranged in the rotor 1, the magnet groups 13A, 13C, 13E, 13G, 13I, and 13K having the same magnetization direction are first divided and magnetized, and then the opposite. The magnet groups 13B, 13D, 13F, 13H, 13J, and 13L, which are the magnetization directions of the magnets, may be separately magnetized. In this case, the step of switching the direction of the current flowing through the coil group 20 only needs to be performed once.

Further, the coil group 20 provided in the magnetizing device 2 is not limited to one set as long as the subcoils 22A and 22B are arranged so as not to be adjacent to each other. The magnetizing device 2 is provided with a plurality of coil groups 20 such as two sets of coil groups 20 arranged at an angle of 180 ° and three sets of coil groups 20 arranged at an angle of 120 °. You may do so. By providing the plurality of coil groups 20, all the magnet groups 13 of the rotor 1 can be magnetized in a shorter time.

1 Rotor 13, 13A to 13L Magnet group 2 Magnetizing device 20 Coil group 21 Main coil 21a, 21b (main coil) Both ends 22A, 22B Sub coil L2 Rotor pole center line MF1, MF2 Magnetic field (composite magnetic field)

Claims (8)

A rotor is arranged in a magnetizing device having a coil group composed of a plurality of coils that generate a magnetic field when energized, and a part of the plurality of magnet groups provided in the rotor by energizing the coil group. The step of partially magnetizing the magnet group by applying a magnetic field and the step of relatively moving the positions of the magnetizing device and the rotor in the rotational direction are carried out over the entire circumference of the rotor. This is a method of magnetizing a rotor that magnetizes all the magnet groups of the rotor by repeating the process a plurality of times.
The coil group includes one main coil which is arranged to face the magnet group to be magnetized among the plurality of magnet groups and is arranged adjacent to both sides of the main coil and is more than the main coil. It has two subcoils with a small number of turns,
Magnetization of a rotor that magnetizes the magnet group to be magnetized by a magnetic field interlinking with the main coil and one of the subcoils and a magnetic field interlinking with the main coil and the other subcoil . Method. The method for magnetizing a rotor according to claim 1, wherein the main coil and the sub coil are wound in opposite directions. The invention according to claim 1 or 2, wherein when the magnet group to be magnetized is magnetized and then the adjacent magnet group is magnetized, the direction of the current energizing the coil group is switched in the opposite direction. How to magnetize the rotor. One of claims 1 to 3, wherein both ends of the main coil are arranged outside the center line between the rotor poles between the adjacent magnet groups with respect to the magnet group to be magnetized. The method for magnetizing the rotor described in 1. It has a coil group composed of a plurality of coils that generate a magnetic field when energized, and energizes the coil group to apply a magnetic field to some of the magnet groups provided in the rotor. By repeating the step of partially magnetizing the magnetizing device and the step of relatively moving the positions of the magnetizing device and the rotor in the rotational direction a plurality of times over the entire circumference of the rotor. A rotor magnetizing device that magnetizes all the magnet groups of the rotor.
The coil group includes one main coil which is arranged to face the magnet group to be magnetized among the plurality of magnet groups and is arranged adjacent to both sides of the main coil and is more than the main coil. It has two subcoils with a small number of turns,
Magnetization of a rotor that magnetizes the magnet group to be magnetized by a magnetic field interlinking with the main coil and one of the subcoils and a magnetic field interlinking with the main coil and the other subcoil . Device. The rotor magnetizing device according to claim 5, wherein the main coil and the sub coil are wound in opposite directions. The claim is configured so that the direction of the current energizing the coil group can be switched in the opposite direction when magnetizing the adjacent magnet group after magnetizing the magnet group to be magnetized. The rotor magnetizing device according to 5 or 6. Claims 5 to 7 are configured such that both ends of the main coil are arranged outside the center line between the rotor poles between the adjacent magnet groups with respect to the magnet group to be magnetized. The rotor magnetizing device according to any one of the above items.

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