Magnetizing device

Abstract

To provide a magnetizing device capable of sufficiently magnetizing an entire magnet with respect to a rotor in which the magnet is arranged.SOLUTION: A magnetizing device magnetizes a magnet arranged on a rotor of a motor. The rotor has a configuration in which a plurality of magnets are arranged on the rotor and a hole passing through the rotor is provided except a section where the magnet is arranged. The magnetizing device includes: a first magnetized unit that has a yoke and a coil and magnetizes the magnet from outside of the rotor; a second magnetized unit that has a yoke and a coil, being inserted into the hole penetrating the rotor, and magnetizes the magnet from inside of the rotor; a first power source for passing a first current to a coil of the first magnetized unit; and a second power source for passing a second current to the coil of the second magnetized unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention magnetizes a magnet embedded in a rotor of a motor. Magnetizing device Regarding. [Background technology]

[0002] BACKGROUND ART In brushless motors in which a magnet is embedded inside the rotor of the motor, motors in which a magnet is disposed inside the rotor have been proposed (see, for example, Patent Documents 1 and 2).

[0003] Furthermore, when magnetizing the magnets of the rotor, a magnetizing yoke (outer periphery yoke) equipped with a coil is disposed on the outside of the rotor, and magnetization is performed by this magnetizing yoke (see, for example, Patent Document 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-107939 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-177721 [Patent Document 3] Japanese Patent Application Laid-Open No. 2010-104119 Summary of the Invention [Problem to be solved by the invention]

[0005] Even when magnetizing magnets in a rotor in which magnets are arranged at various positions, it is possible to arrange an outer peripheral yoke on the outside of the rotor and magnetize the magnets using the outer peripheral yoke.

[0006] However, depending on the position of the magnet, when magnetized by the outer yoke, the magnet may not be magnetized all the way to its inner end, resulting in insufficient magnetization.

[0007] In order to solve the above-mentioned problems, in the present invention, it is possible to sufficiently magnetize the entire magnets in a rotor in which magnetization may be insufficient. Magnetizing device It is what we provide. [Means for solving the problem]

[0008] The magnetizing device of the present invention is a magnetizing device that magnetizes a magnet placed on a rotor of a motor, the rotor having a plurality of magnets placed thereon and holes penetrating the rotor in areas other than the areas where the magnets are placed, and the magnetizing device is equipped with a first magnetizing section that has a yoke and a coil and magnetizes the magnet from the outside of the rotor, a second magnetizing section that has a yoke and a coil and is inserted into the holes penetrating the rotor and magnetizes the magnet from the inside of the rotor, a first power supply that passes a first current through the coil of the first magnetizing section, and a second power supply that passes a second current through the coil of the second magnetizing section, a delay circuit connected to either the first power supply or the second power supply; A magnet is disposed between the first magnetized portion and the second magnetized portion, The delay circuit The first current and the second current are caused to flow so that the time when the first current reaches its peak coincides with the time when the second current reaches its peak. [Effects of the Invention]

[0010] According to the magnetizing device and magnetizing method of the present invention described above, the magnet can be magnetized from the outside by the first magnetizing portion and the magnet can be magnetized from the inside of the rotor by the second magnetizing portion, making it possible to sufficiently magnetize the entire magnet.

[0011] Furthermore, the magnetizing device and magnetizing method of the present invention include a first power supply for passing a first current through the coil of the first magnetizing unit, and a second power supply for passing a second current through the coil of the second magnetizing unit. Therefore, by controlling the first current passed from the first power supply to the coil of the first magnetizing unit and the second current passed from the second power supply to the coil of the second magnetizing unit, it becomes possible to magnetize a magnet efficiently. [Brief explanation of the drawings]

[0012] [Figure 1]1 is a schematic configuration diagram (perspective view) of a magnetizing device according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a plan view of the magnetizing device of FIG. [Figure 3] FIG. 2 is a plan view of the rotor of FIG. 1. [Figure 4] 4 is a plan view of the magnetization device of FIG. 2 and the rotor of FIG. 3 assembled together. [Figure 5] FIG. 2 is a circuit block diagram including a power supply of the magnetizing device according to the first embodiment of the present invention. [Figure 6] FIG. 2 is a schematic configuration diagram (plan view of essential parts) of a rotor and a magnetization device of analysis example 1. [Figure 7] FIG. 10 is a diagram showing the relationship between the yoke current and the magnetic field generated at point A6 in analysis example 1. [Figure 8] FIG. 10 is a schematic configuration diagram (plan view of essential parts) of a rotor and a magnetization device of analysis example 2. [Figure 9] FIG. 10 is a diagram showing the relationship between the yoke current and the magnetic field generated at point B6 in analysis example 2. DETAILED DESCRIPTION OF THE INVENTION

[0013] First, before describing specific embodiments of the present invention, an outline of the present invention will be described.

[0014] The rotor of the motor has magnets embedded in holes provided in the rotor. In addition to the holes in which the magnets are embedded, the motor rotor may also be provided with holes or apertures (holes that penetrate the rotor) as needed. Specific examples include the air gap 37 and mass reduction holes 38 in Figure 2 of Patent Document 1, and the flux barrier 62 in Figure 5 of Patent Document 2. The purposes of providing holes or apertures in the rotor other than the part where the magnets are embedded include reducing the rotor weight, allowing the rotor to be air-cooled, making it easier to insert magnets, and acting as a flux barrier. Then, holes or apertures of appropriate size and shape are provided at appropriate positions depending on the purpose.

[0015] In the present invention, a second magnetizing section is configured by utilizing a hole (a hole that passes through the rotor) provided in the rotor other than the hole in which the above-mentioned magnet is embedded, and is inserted into this hole to magnetize the magnet from inside the rotor. Furthermore, in the present invention, magnetization is performed by passing currents from separate power sources through the coil of the first magnetizing unit, which magnetizes the magnet from the outside of the rotor, and the coil of the second magnetizing unit, which magnetizes the magnet from the inside of the rotor.

[0016] The magnetizing device of the present invention is a magnetizing device that magnetizes a magnet arranged in a rotor of a motor. In the magnetizing device of the present invention, the rotor has a plurality of magnets arranged thereon, and holes penetrating the rotor are provided in areas other than where the magnets are arranged. Furthermore, the magnetizing device of the present invention includes a first magnetizing unit having a yoke and a coil and magnetizing the magnet from the outside of the rotor, a second magnetizing unit having a yoke and a coil and inserted into a hole that passes through the rotor and magnetizes the magnet from the inside of the rotor, a first power supply for passing a first current through the coil of the first magnetizing unit, and a second power supply for passing a second current through the coil of the second magnetizing unit.

[0017] The magnetization method of the present invention is a method for magnetizing a magnet arranged in a rotor of a motor. In the magnetization method of the present invention, the rotor has a configuration in which a plurality of magnets are arranged on the rotor, and holes penetrating the rotor are provided in areas other than the areas where the magnets are arranged. Furthermore, the magnetization method of the present invention uses a first magnetizing unit having a yoke and a coil and arranged on the outside of the rotor, a second magnetizing unit having a yoke and a coil and inserted into a hole that penetrates the rotor, a first power supply for passing a first current through the coil of the first magnetizing unit, and a second power supply for passing a second current through the coil of the second magnetizing unit.The first current is passed from the first power supply to the coil of the first magnetizing unit to magnetize the magnet from the first magnetizing unit, and the second current is passed from the second power supply to the coil of the second magnetizing unit to magnetize the magnet from the second magnetizing unit.

[0018] In the present invention, the first magnetized portion is disposed on the outside of the rotor and magnetizes the magnet of the rotor from the outside. The first magnetized portion has a yoke and a coil. A first current is applied to the coil of the first magnetized portion from a first power supply, and the coil of the first magnetized portion is electrically connected to the first power supply.

[0019] In the present invention, the second magnetized portion is inserted into a hole provided in the rotor that passes through the rotor, and magnetizes the magnet of the rotor from inside the rotor. The second magnetized portion also has a yoke and a coil. A second current is applied to the coil of the second magnetized portion from a second power supply, and the coil of the second magnetized portion is electrically connected to the second power supply. The second power supply and the first power supply that supplies the first current to the coil of the first magnetizing unit are two separate power supplies. The magnetizing device is configured with the first power supply and the second power supply.

[0020] Since the first power supply and the second power supply are two separate power supplies, it is possible to make the first current passed through the coil of the first magnetized part and the second current passed through the coil of the second magnetized part different currents.

[0021] The hole provided in the rotor and penetrating the rotor, into which the second magnetized portion is inserted, may have the following configuration, for example. (1) Holes between adjacent magnets (for example, the mass reduction holes 38 in Figure 2 of Patent Document 1). (2) Holes located at the same radial position as the magnets but further inward than the magnets (for example, the gaps 37 in Figure 2 of Patent Document 1). (3) A hole that is located at a different radial position from the magnet and is provided inside the magnet (for example, the flux barrier 62 in FIG. 5 of Patent Document 2).

[0022] When magnetizing the rotor magnet, the second magnetizing portion is inserted into the hole provided in the rotor, and the rotor is assembled inside the first magnetizing portion. Then, the magnet of the rotor is magnetized from the first magnetized portion and the second magnetized portion, respectively. In particular, when the first magnetized portion and the second magnetized portion have coils, current is passed from each power source to the coil of the first magnetized portion and the coil of the second magnetized portion to generate a magnetic field in the coil, which allows the rotor magnet to be magnetized by the coil of the first magnetized portion and the coil of the second magnetized portion, respectively.

[0023] According to the magnetizing device and magnetizing method of the present invention, the magnet can be magnetized from the outside by the first magnetizing section, and the magnet can be magnetized from the inside of the rotor by the second magnetizing section, making it possible to sufficiently magnetize the entire magnet.

[0024] Furthermore, the magnetizing device and magnetizing method of the present invention include a first power supply for supplying a first current to the coil of the first magnetized portion, and a second power supply for supplying a second current to the coil of the second magnetized portion. This makes it possible to efficiently magnetize the magnet by controlling the first current flowing from the first power supply to the coil of the first magnetizing unit and the second current flowing from the second power supply to the coil of the second magnetizing unit.

[0025] In addition, in the magnetizing device of the present invention, the first current and the second current are preferably configured to flow so that the time when the first current reaches its peak and the time when the second current reaches its peak substantially coincide with each other. More preferably, a delay circuit is connected to either the first power supply or the second power supply, and the delay circuit causes the time when the first current reaches its peak to approximately coincide with the time when the second current reaches its peak. By adopting these configurations, the magnets can be magnetized more efficiently.

[0026] (First embodiment) Fig. 1 is a schematic configuration diagram (perspective view) of a magnetizing device according to a first embodiment of the present invention, showing a state in which a rotor 20 of a motor is assembled into the magnetizing device 1. The magnetizing device 1 of this embodiment is a device that magnetizes the magnet 21 embedded in the rotor 20. 2 shows a plan view of the magnetizing device 1 in FIG. 1, FIG. 3 shows a plan view of the rotor 20, and FIG. 4 shows a plan view of the magnetizing device 1 with the rotor 20 assembled therein.

[0027] The rotor 20, which is the target to be magnetized by the magnetizing device 1, is connected to a shaft (output shaft) . The magnets 21 are embedded in holes 22 provided radially along the radial direction of the rotor 20 .

[0028] Furthermore, a hole 23 penetrating the rotor 20 is provided between two adjacent magnets 21 of the rotor 20 . This hole 23 is located between two adjacent magnets 21 and is arranged so as to protrude inward (toward the shaft 24) beyond the inner ends of the magnets 21.

[0029] The magnetizing device 1 includes an outer yoke 2 and a coil 5 that magnetize the magnet 21 from the outside of the rotor 20 as a first magnetizing unit that magnetizes the magnet 21. The magnetizing device 1 also includes an inner yoke 6 and a coil 7 that magnetize the magnet 21 from inside the rotor 20 as a second magnetizing unit that magnetizes the magnet 21.

[0030] The outer yoke 2, which constitutes the first magnetized portion, is arranged to surround the outside of the rotor 20, and a coil 5 is inserted into a hole 3 provided near the inner periphery of the outer yoke 2 and is insulated and fixed by a coil support 4. The coil is configured to connect two coils 5 and extend above the coils 5 in a substantially U-shape, for example.

[0031] The coil support 4 can be made of, for example, glass epoxy (epoxy glass resin) or the like. Coil 5 of the first magnetized portion can be configured by using an electric wire made of a wire material with high conductivity such as a copper wire, and covering the periphery of the electric wire with an insulating covering material. A power supply for supplying a current to the coil 5 is connected to the coil 5 of the first magnetized portion.

[0032] The inner yoke 6 that constitutes the second magnetized portion is inserted into a hole 23 provided in the rotor 20 . Then, the coils 7 are provided on the inner circumferential yoke 6. The coils 7 are configured such that, for example, two coils 7 are connected together and extend upward in a substantially U-shape.

[0033] The inner yoke 6 can be made of, for example, glass epoxy (epoxy glass resin) or the like. The coil 7 of the second magnetizing portion, like the coil 5 provided on the outer yoke 2 of the first magnetizing portion, can be configured using an electric wire made of a wire material with high conductivity, such as copper wire, with the periphery of the electric wire covered with an insulating coating material. A power supply for supplying a current to the coil 7 is connected to the coil 7 of the second magnetized portion.

[0034] Furthermore, the magnetizing device 1 of this embodiment is configured with two separate power supplies: one for supplying current to the coil 5 of the first magnetizing part and the other for supplying current to the coil 7 of the second magnetizing part.

[0035] FIG. 5 shows a circuit block diagram including a power supply for the magnetizing device 1 of the present embodiment. As shown in FIG. 5, the magnetizing device 1 of the present embodiment includes a CPU (Central Processing Unit) 31, a delay circuit 32, a first gate circuit 33, and a second gate circuit .

[0036] The CPU 31 controls the delay circuit 32, the first gate circuit 33, and the second gate circuit 34 based on the magnetization command signal Sm. The first gate circuit 33 serves as a first power supply for supplying current to the coil 5 of the first magnetized portion, and generates a first gate signal S1 under the control of the CPU 31. Based on the pulse of this first gate signal S1, a pulsed current is supplied as a first current to the coil 5 of the first magnetized portion. The second gate circuit 34 serves as a second power supply for supplying a current to the coil 7 of the second magnetized portion, and generates a second gate signal S2 under the control of the CPU 31. Based on the pulse of this second gate signal S2, a pulsed current is supplied as a second current to the coil 7 of the second magnetized portion. The delay circuit 32 is connected to the second gate circuit 34 and delays the second gate signal S2 generated by the second gate circuit 34 relative to the first gate signal S1 generated by the first gate circuit 33.

[0037] Here, the reason why the delay circuit 32 delays the second gate signal S2 with respect to the first gate signal S1 in the magnetizing device 1 of the present embodiment will be described in detail below.

[0038] Since there are relatively no restrictions on the first magnetized portion (outer yoke 2, coil 5), a coil with a large winding diameter can be used for coil 5 of the first magnetized portion. In contrast, the second magnetized portion (inner yoke 6, coil 7) is inserted into a hole 23 that penetrates rotor 20, so it becomes necessary to use a coil with a small winding diameter for coil 7 of the second magnetized portion. Furthermore, the magnetizing device 1 is required to have durability so that it can magnetize a large number of rotors 20, and therefore, Joule loss (copper loss) occurring in the coil winding becomes a problem.

[0039] Coil 5 of the first magnetizing part has a large winding diameter, and therefore has high resistance and inductance. Furthermore, in order to generate a magnetic field for magnetization, coil 5 of the first magnetizing part needs to pass a current of several kA to several tens of kA, and the pulse width of the current also becomes large. The coil 7 of the second magnetized portion uses a coil with a small winding diameter, and therefore has small resistance and inductance. If one power supply were connected to both the coil 5 of the first magnetized part and the coil 7 of the second magnetized part, a current of several kA to several tens of kA would be supplied to the coil 7 of the second magnetized part, similar to that supplied to the coil 5 of the first magnetized part. In this case, the Joule loss in the coil 7 of the second magnetized part, which has low resistance and inductance, would be larger than necessary. This could result in a deterioration in the durability of the coil 7 of the second magnetized part.

[0040] Therefore, a first power supply for passing a current through coil 5 of the first magnetized part and a second power supply for passing a current through coil 7 of the second magnetized part are provided as separate power supplies. This makes it possible to set the current passed through coil 5 of the first magnetized part (first current) and the current passed through coil 7 of the second magnetized part (second current) to appropriate current amounts and pulse widths, respectively. In this case, since the resistance and inductance of coil 7 of the second magnetized portion are small, the second power supply supplies a current with a small current amount and a narrow pulse width to coil 7 of the second magnetized portion.

[0041] However, if the first current supplied from the first power supply to coil 5 of the first magnetizing unit and the second current supplied from the second power supply to coil 7 of the second magnetizing unit are supplied simultaneously, the pulse widths of the respective currents will be different, and the times at which the currents reach their peaks will not coincide, preventing efficient magnetization.

[0042] Therefore, in the magnetizing device 1 of the present embodiment, as shown in FIG. 5, a delay circuit 32 is connected to the second gate circuit 34 that constitutes the second power supply. This makes it possible to delay the supply of the second current, which has a narrow pulse width and is supplied from the second power supply (second gate circuit 34) to the coil 7 of the second magnetizing unit, relative to the first current, which has a wide pulse width and is supplied from the first power supply (first gate circuit 33) to the coil 5 of the first magnetizing unit, so that the times at which the currents reach their peaks are approximately the same.Also, by approximately matching the times at which the currents reach their peaks, efficient magnetization is possible.

[0043] In the magnetization device 1 of this embodiment, when magnetizing the magnets 21 of the rotor 20, as shown in Figures 1 and 4, the inner yoke 6 of the second magnetizing unit is inserted into the hole 23 provided in the rotor 20, and the rotor 20 is assembled inside the outer yoke 2 of the first magnetizing unit. Then, by passing current from the first power supply (first gate circuit 33) to the coil 5 of the first magnetized portion and from the second power supply (second gate circuit 34) to the coil 7 of the second magnetized portion, a magnetic field is generated in each of the coils 5 and 7, magnetizing the magnet 21 from the outside and the inside of the rotor 20, respectively. This makes it possible to sufficiently magnetize the entire magnet 21 that is arranged.

[0044] The magnetizing device 1 of the present embodiment described above includes a first magnetizing section formed by the outer circumferential yoke 2 and the coil 5, and a second magnetizing section formed by the inner circumferential yoke 6 and the coil 7. This allows the magnet 21 to be magnetized from the outside by the first magnetizing portion and from the inside of the rotor 20 by the second magnetizing portion, making it possible to sufficiently magnetize the entire magnet 21.

[0045] Furthermore, the magnetizing device 1 of this embodiment has a first power supply (first gate circuit 33) for passing a first current through the coil 5 of the first magnetizing portion, and a second power supply (second gate circuit 34) for passing a second current through the coil 7 of the second magnetizing portion. This makes it possible to efficiently magnetize magnet 21 by controlling the first current flowing from the first power supply to coil 5 of the first magnetizing unit and the second current flowing from the second power supply to coil 7 of the second magnetizing unit.

[0046] Furthermore, according to the magnetizing device 1 of the present embodiment, the delay circuit 32 is connected to the second power supply (second gate circuit 34), and the delay circuit 32 can delay the second current from the second power supply relative to the first current from the first power supply. This makes it possible to make the time when the first current reaches its peak almost coincide with the time when the second current reaches its peak, thereby enabling efficient magnetization.

[0047] (Variation) The position of the rotor hole for providing the inner circumferential yoke of the second magnetized portion is not limited to the position between two adjacent magnets as in the first embodiment described above, but may be in another position. For example, it is possible to use a hole that is located in the same radial position as the magnet but further inward than the magnet, such as the gap 37 in Figure 2 of Patent Document 1, or a hole that partially overlaps the magnet in radial position, such as the flux barrier 62 in Figure 5 of Patent Document 2. In either case, the inner circumferential yoke and coil of the second magnetized portion may be configured to match the position of the hole in the rotor.

[0048] Furthermore, in the first embodiment, the magnet 23 is disposed between the first magnetized portion and the second magnetized portion, but the positional relationship between the three components, i.e., the first magnetized portion, the second magnetized portion, and the magnet, is not particularly limited, and other positional relationships are also possible.

[0049] Furthermore, in the first embodiment, the magnet 21 is embedded in the hole 22 provided in the rotor 20, but other configurations in which the magnet is disposed on the rotor, such as a configuration in which the magnet is attached to the surface of the rotor, can also be adopted.

[0050] Furthermore, in the first embodiment, the magnets 21 in the rotor 20 are arranged radially, but the arrangement of the magnets in the rotor is not limited to a radial arrangement, and other arrangements can also be adopted. Even in other arrangements, the entire magnet can be sufficiently magnetized by the first magnetized portion and the second magnetized portion. Other examples of magnet arrangements include the arrangement in which magnets are arranged along the outer periphery of the rotor, such as the arrangement in FIG. 7 of Patent Document 2 and the arrangement in FIG. 1 of Patent Document 3.

[0051] In addition, in the first embodiment, the first current is a wide pulse and the second current is a narrow pulse, so the delay circuit 32 is connected to the second power supply (second gate circuit 34) that passes the second current. On the other hand, for example, when the first current is made to have a pulse width narrower than that of the second current, a delay circuit is connected to the first power supply that supplies the first current, so that the times at which the first current and the second current reach their peaks are approximately the same.

[0052] <Analysis example> Here, we actually analyzed by computer simulation the magnitude of the magnetic fields generated at several points on the magnet when magnetizing the magnet placed on the rotor for the configuration of the magnetizing device of the present invention having a first magnetizing portion and a second magnetizing portion, and for the configuration of the magnetizing device having only the first magnetizing portion. The configuration of the magnetizing device having only the first magnetizing portion was substituted by not passing a current through the coil of the second magnetizing portion in the configuration of the magnetizing device of the present invention.

[0053] (Analysis example 1) FIG. 6 shows a schematic configuration diagram (plan view of the main parts) of the rotor and magnetization device of analysis example 1. FIG. 6 shows a plan view of the rotor 20, which has a circular planar shape, and the main part (one repeating unit, the part bounded by the center lines of two radially arranged magnets 21) of the magnetization device. As shown in FIG. 6, the magnets 21 are arranged radially. The coil 5 in the outer yoke 2 has 6 × 2 = 12 windings, and the coil 7 in the inner yoke 6 has 2 windings. The inner yoke 6 is located between two adjacent magnets 21 and is positioned so as to include the same radial position as the inner ends of the magnets 21.

[0054] The generated magnetic field was analyzed at three locations (A1 to A3) near the side of magnet 21 and three locations (A4 to A6) near the center line of magnet 21. The current flowing through coil 5 in outer yoke 2 (hereinafter referred to as the "outer yoke current") was changed to 18kA, 19kA, 20kA, and 21kA, and the current flowing through coil 7 in inner yoke 6 (hereinafter referred to as the "inner yoke current") was changed to 0kA (no current), 15kA, 16kA, 17kA, 18kA, 19kA, and 20kA, and the magnitude of the magnetic field (T) generated for each current combination was analyzed.

[0055] Here, for point A6 (the innermost point on the center line of magnet 21) where the generated magnetic field is weakest among the six points A1 to A6, the relationship between the combination of the outer yoke current and the inner yoke current and the generated magnetic field is shown in Table 1 and Figure 7. In FIG. 7, the horizontal axis represents the inner yoke current, the vertical axis represents the generated magnetic field (T), and the same values ​​of the outer yoke current are connected by lines.

[0056] [Table 1]

[0057] As can be seen from Table 1 and Figure 7, a significant difference was observed in the magnetic field generated at point A6 when the inner yoke current was 15 to 20 kA and the second magnetized portion was also used, compared to when the inner yoke current was 0 kA and only the first magnetized portion was used. Also, as shown in FIG. 7, if a magnetic field of 1.5 T or more is required to be generated, the inner yoke current should be set to 17 kA or more while the outer yoke current is set to 20 kA.

[0058] Furthermore, among the six points A1 to A6, at the center and outer points A1, A2, A4, and A5, there was no clear difference in the magnitude of the generated magnetic field or the magnetic field lines depending on whether or not there was an inner yoke current. At these points, it is thought that the first magnetized portion had a large influence and was able to magnetize the magnet sufficiently. In contrast, at the inner points A3 and A6, differences occurred in the magnitude of the generated magnetic field and the magnetic lines of force depending on whether or not there was an inner yoke current. Therefore, by using the second magnetized portion, the inside of the magnet can also be sufficiently magnetized, and the range in which the desired magnetic field is generated can be expanded.

[0059] (Analysis example 2) FIG. 8 shows a schematic configuration diagram (plan view of the main parts) of the rotor and magnetization device of analysis example 2. FIG. 8 shows a plan view of a main portion (one repeating unit, a portion bounded by the center lines of two adjacent coil supports 4 in the outer yoke 2) of the rotor 20 and the magnetization device, which have a circular planar shape. As shown in Figure 8, a total of three magnets 21 are arranged in an approximately triangular shape, including two magnets 21 arranged diagonally relative to the radial direction of the rotor 20 and one magnet 21 arranged along the outer periphery of the rotor 20. The coil 5 in the outer yoke 2 has 12 × 2 = 24 windings, and the coil 7 in the inner yoke 6 has 4 windings. The inner yoke 6 is located between two magnets 21 arranged diagonally with respect to the radial direction of the rotor 20, and is located inside the same radial position as the inner end of the magnets 21. Analysis of the generated magnetic field was performed at six locations (B1 to B6) near the side of magnet 21 arranged diagonally relative to the radial direction of rotor 20, and at six locations (C1 to C6) near the side of magnet 21 arranged along the outer periphery of rotor 20. The outer yoke current was then changed to 15kA, 16kA, 17kA, 18kA, 19kA, and 20kA, and the inner yoke current was changed to 0kA (no current), 10kA, 11kA, 12kA, 13kA, 14kA, and 15kA, and the magnitude of the magnetic field (T) generated for each current combination was analyzed.

[0060] Here, of the 12 points B1 to B6 and C1 to C6, for point B6 (the innermost point of magnet 21) where the generated magnetic field is weakest, the relationship between the combination of the outer yoke current and the inner yoke current and the generated magnetic field is shown in Table 2 and Figure 9. In FIG. 9, the horizontal axis represents the inner yoke current, the vertical axis represents the generated magnetic field (T), and the same values ​​of the outer yoke current are connected by lines.

[0061] [Table 2]

[0062] As can be seen from Table 2 and Figure 9, a significant difference was observed in the magnetic field generated at point B6 when the inner yoke current was 10 to 15 kA and the second magnetized portion was also used, compared to when the inner yoke current was 0 kA and only the first magnetized portion was used. Also, as shown in Figure 9, if a magnetic field of 2.0 T or more is required, the inner yoke current should be 10 kA or more for an outer yoke current of 18 kA, and the inner yoke current should be 13 kA or more for an outer yoke current of 17 kA.

[0063] Furthermore, among the 12 points B1 to B6 and C1 to C6, at points B1, B2, B4, B5, and C1 to C6, there was no clear difference in the magnitude of the generated magnetic field or the magnetic field lines depending on whether or not there was an inner yoke current. At these points, it is thought that the first magnetized portion had a large influence and was sufficiently magnetizing the magnet. In contrast, at the inner points B3 and B6, differences occurred in the magnitude of the generated magnetic field and the magnetic lines of force depending on whether or not there was an inner yoke current. Therefore, in the configuration of Analysis Example 2, as in the configuration of Analysis Example 1, by using the second magnetized portion, the inside of the magnet can also be sufficiently magnetized, and the range in which the desired magnetic field is generated can be expanded.

[0064] The results of analysis examples 1 and 2 show that points other than the inner points A3, A6, B3, and B6 are almost fully magnetized by the first magnetized portion alone. Therefore, magnetization of the magnet, that is, formation of the north and south poles, is possible using only the first magnetized portion. Furthermore, the magnet can be magnetized by the first magnetized portion regardless of the magnet arrangement in the rotor.

[0065] Furthermore, when the first magnetized portion and the second magnetized portion are used, the inner points A3, A6, B3, and B6, which are difficult to sufficiently magnetize using only the first magnetized portion, can also be sufficiently magnetized, so that the entire magnet can be sufficiently magnetized.

[0066] The effect of sufficiently magnetizing the entire magnet by the second magnetizing portion is affected by the distance between the second magnetizing portion and the magnet, but the distance between the second magnetizing portion provided on the rotor and the magnet is not very large. Therefore, regardless of the arrangement of the magnet and second magnetizing portion on the rotor, the effect of sufficiently magnetizing the entire magnet by the second magnetizing portion can be obtained to a certain extent. [Explanation of symbols]

[0067] 1 magnetization device, 2 outer yoke, 3 hole, 4 coil support, 5 coil, 6 inner yoke, 7 coil, 20 rotor, 21 magnet, 22 hole, 23 hole, 24 shaft (output shaft), 31 CPU, 32 delay circuit, 33 first gate circuit, 34 second gate circuit

Claims

[Claim 1] A magnetizing device for magnetizing a magnet disposed in a rotor of a motor, the rotor is configured such that a plurality of the magnets are arranged on the rotor, and holes penetrating the rotor are provided in areas other than the areas where the magnets are arranged, a first magnetizing unit having a yoke and a coil, and magnetizing the magnet from the outside of the rotor; a second magnetizing unit having a yoke and a coil, inserted into a hole penetrating the rotor, and magnetizing the magnet from inside the rotor; a first power source for supplying a first current to a coil of the first magnetized portion; a second power source for supplying a second current to a coil of the second magnetized portion; Equipped with a delay circuit is connected to either the first power supply or the second power supply; the magnet is disposed between the first magnetized portion and the second magnetized portion, The delay circuit causes the first current and the second current to flow so that the time when the first current reaches a peak coincides with the time when the second current reaches a peak. Magnetizing device.

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