JP2519435B2 - Magnetization method of electric motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a method of magnetizing a field in an electric motor having a permanent magnet as a field, which is used in industrial equipment, office equipment, home appliances and the like. Is.

<Prior Art> Generally, when manufacturing a magnetic field of an electric motor, a hard magnetic material to be a field is set in a magnetizing device equipped with a magnetizing coil, and the hard magnetic material is attached to the hard magnetic material by energizing the magnetizing coil. A magnet is applied to form a permanent magnet, and the permanent magnet is fixed to a yoke made of a magnetic material to form a field.
The field thus formed is arranged to face an armature having an armature coil, and one of the field and the armature is incorporated into an electric motor housing so as to be rotatable with respect to the other, thereby forming an electric motor. It was a thing.

<Problems to be Solved by the Invention> In the case of the electric motor manufactured by the above procedure, in the process of incorporating the field into the electric motor housing, the permanent magnet has an obstacle during rotation due to the attractive force of the permanent magnet. The work efficiency was extremely poor because iron powder or the like, which could become a permanent magnet, adheres, or the permanent magnet hits another magnetic substance and is damaged. When a hard magnetic material with a particularly small coercive force is used as the permanent magnet material, the magnetic circuit at the time of magnetization is opened when the magnetized permanent magnet is removed from the magnetizing device. There are drawbacks such that demagnetization occurs and the air gap magnetic flux density is reduced to deteriorate the characteristics of the electric motor, and if the characteristics before demagnetization are to be maintained, the size of the electric motor is increased.

In order to avoid the above drawbacks, after the completion of the assembly of the electric motor, the armature coil of this electric motor is diverted as a magnetizing coil to magnetize the field arranged opposite to the armature. The method is generally adopted. According to this method, for example, as disclosed in JP-A-60-121947, by energizing the armature coil wound around the salient pole of the armature, the number of energized armature coils, that is, the armature magnetic pole It is possible to magnetize the magnetic poles with the same number and the same opening angle as that of the salient poles of the armature.

However, in a commonly used brushless motor or the like, the armature has a salient pole structure, and the ratio of the number of armature coils to the number of field poles is 3: 2, and the armature coils are three-phase Y In many cases, they are connected and used. In such a case, the magnetic pole width required for the field cannot be obtained even if the built-in magnetization is performed by the above method, or the field poles are formed unevenly. Then, since the function as the electric motor is lost, the field magnet alone is usually magnetized using the above-mentioned magnetizing device.

<Means for Solving Problems> In the present invention, when n is a natural number, they are arranged at equal intervals.
3n Y-arm connection of 3n armature coils to form an armature,
A built-in magnetizing method capable of easily magnetizing a motor field in a motor configured by arranging a permanent magnet field of 2n poles facing the armature.

In the present invention, first, any two phases of the armature coil are extracted, one of them is connected to the positive electrode of the DC power supply, and the other is connected to the negative electrode, and the impulse current is applied to magnetize the field for the first time. The first step of applying, the second step of relocating the connection of the armature coil to the DC power source, and the relative rotation of the opposing position of the armature and the field by a predetermined angle, It comprises a third step of magnetizing the field for the second time by applying an impulse current to a predetermined two-phase armature coil connected to the DC power supply. As a result, equidistant magnetic poles having two-thirds the number of armature coils are formed in the field.

<Embodiment> FIGS. 1 to 3 are configuration diagrams of an electric motor for explaining a first embodiment of the present invention, which is a three-phase, four-pole inner rotor type brushless electric motor. The armature 1 has salient poles T1, T2, T3, T4, T5, T6 arranged at equal intervals and armature coils CU1,
It is configured by winding CV1, CW1, CU2, CV2, and CW2, respectively. The armature coils are 3-phase Y-connected, CU1 and CU2 are connected in series to form a U-phase coil, CV1 and CV2 are connected in series to form a V-phase coil, and CW1 and CW2 are connected in series to form a W-phase coil. Respectively, and three lead portions U, V, W are formed. The field 2 is composed of a cylindrical yoke 3 made of a magnetic material fitted to a shaft and a C-shaped or cylindrical hard magnetic material 4 fixed to the outer peripheral portion of the yoke 3. Finally, the magnets are uniformly distributed to the four poles to complete a permanent magnet. The armature 1 and the field 2 are arranged to face each other with an air gap in between, and the armature 1
On the other hand, the field 2 is incorporated in an electric motor housing (not shown) so as to be rotatable.

The magnetizing method of the present invention having the above structure will be described. First, any two phases are extracted from the three lead portions of the armature coil, and this is connected to the power supply terminal. Here, for the following description, as shown in FIG.
And 8, and the changeover switch mechanism 16 is turned on to the magnetizing DC power supply 5 side. When the open / close switch mechanism 9 that returns after energization is closed, an impulse current is applied from the magnetizing DC power supply unit 5 to the U phase and V phase of the armature coil, and as a result, the hard magnetic material 4 of the field magnet 2 1
As indicated by N and S in the figure, magnetic poles with an opening angle approximately equal to the opening angle of the armature salient pole, that is, a mechanical angle of about 60 °, are magnetized at the positions facing the armature salient poles T1, T2, T4, and T5, respectively. To be done. At this time, the hard magnetic material 4
In the portion facing the adjacent portion of the salient poles T1 and T2 or the adjacent portion of the salient poles T4 and T5, the interpole portion of the field magnetic pole is formed at the midpoint of the salient poles, while the salient pole T3 In the portion facing T6 and T6, a non-magnetized portion having a mechanical angle of about 60 ° is formed.

Next, the changeover switch mechanism 6 shown in FIG.
And V, the polarity of the connection power source is reversed and the field 2
Is rotated by an angle equal to the opening angle of the field magnetic pole to be finally produced in an arbitrary direction with respect to the armature 1 and held. FIG. 2 shows this state. After the first magnetization, the field 2
Is a 90 ° mechanical angle rotated in any direction. The rotation of the field from FIG. 1 to FIG. 2 can be performed by mechanically rotating the shaft of the electric motor from the outside, but it can also be achieved by utilizing electromagnetic action. is there. That is, the changeover switch mechanism 6 shown in FIG.
After performing the above-mentioned operation of reversing the polarity of the connected power source of the output portions U and V by the above, once the changeover switch mechanism 16 is turned on to the side of the low-voltage exciting DC power source 15 side, the V phase of the armature coil and the A small exciting current is applied to the U phase. As a result, the armature salient poles T1 and T4 are excited to the S pole and T2 and T5 are excited to the N pole, respectively, and the field is rotated by the attraction repulsion action with the magnetic pole formed in the field by the first magnetization. It is held at the position shown in FIG. At this time, the direction of rotation of the field is not uniform due to some imbalance in the air gap magnetic flux density or leakage magnetic flux, or due to the effect of external shock, etc. The magnetic relative positions of the fields are similar. After the rotation of the field is completed, the changeover switch mechanism 16 is turned on again to the magnetizing DC power supply unit 5 side.

After that, the open / close switch mechanism 9 is closed again, and an impulse current is applied to the V phase and U phase of the armature coil from the magnetizing DC power supply unit 5 to perform the second magnetization. As a result, the hard magnetic material 4 of the field magnet 2 is magnetized at the positions facing the armature salient poles T1, T2, T4, T5, respectively, in the same shape as that of the first magnetization but with the polarity reversed. . FIG. 3 shows this state, and the section indicated by reference numeral 10 in the hard magnetic material 4 is a portion newly magnetized by the second magnetization and is already formed by the first magnetization. Of the used magnetic pole, the section
The part of the open angle range of 30 ° which is close to 10 is overlapped and magnetized to have the same polarity when magnetized twice. As a result,
A quadrupole field is formed with a magnetic pole open angle of 90 ° mechanical angle.

Next, a second embodiment of the present invention will be described using the same electric motor as in the first embodiment with reference to FIGS. 1, 5 to 7. In the second embodiment, the steps of extracting any two phases out of the three lead portions of the armature coil, connecting the two phases to the power supply terminal, and performing the first magnetization are the first. Although it is similar to the embodiment, the magnetizing circuit as shown in FIG. 7 is used here because the post-process is different. Now, connect the output terminals U, V, and W to the power supply terminal 11,
It is assumed that the power source terminal 13 is connected to the DC power source unit by the changeover switch mechanism 14 first, and the changeover switch mechanism 16 is turned on to the magnetizing DC power source unit 5 side. When the open / close switch mechanism 9 that returns after energization is closed, an impulse current is energized from the magnetizing DC power supply unit 5 to the U phase and V phase of the armature coil, and as a result, the hard magnetic material 4 of the field.
Is magnetized as shown by N and S in FIG. Since FIG. 1 has the same form as that of the first embodiment, detailed description thereof will be omitted.

Next, by the changeover switch mechanism 14 shown in FIG.
12 is connected to the DC power supply, and the field 2 is connected to the armature 1.
In the clockwise direction, the field magnetic pole is rotated by 30 ° at a mechanical angle, that is, one-third of the opening angle of the magnetic field pole to be finally held. FIG. 5 shows this state. The rotation of the field from FIG. 1 to FIG. 5 can be achieved by utilizing the electromagnetic action as in the first embodiment. That is, the changeover switch mechanism 14 shown in FIG.
After performing the above-mentioned operation of connecting 12 to the DC power supply unit, once the changeover switch mechanism 16 is turned on to the side of the DC power supply unit 15 for low-voltage excitation, and a small excitation current is applied to the U and W phases of the armature coil. To energize. As a result, the armature salient poles T1 and T4 are excited to the N pole, and T3 and T6 are excited to the S pole, respectively, and the field is rotated by the attraction repulsion action with the magnetic pole formed in the field by the first magnetization. It is held in the position shown in FIG. After the rotation of the field is completed, the changeover switch mechanism 16 is turned on again to the magnetizing DC power supply unit 5 side.

After that, the opening / closing switch mechanism 9 is closed again, and an impulse current is supplied from the magnetizing DC power supply unit 5 to the U phase and the W phase of the armature coil. As a result, as shown in FIG. 6, the hard magnetic material 4 of the field magnet 2 is magnetized for the second time at the positions facing the armature salient poles T1, T3, T4, T6, and is shown by reference numeral 10. A magnetic pole is newly formed in the section to be formed, and among the magnetic poles already formed by the first magnetization, the portion of the opening angle range of 30 ° close to the section 10 is overlapped by the two-time magnetization. Will be magnetized to the same polarity. As a result, a quadrupole field having a magnetic pole opening angle of 90 ° and a mechanical angle of 90 ° is formed.

In the second embodiment, when the field is rotated by 30 ° in the counterclockwise direction with respect to the armature at the mechanical angle after the first magnetization, the U phase and the W phase are retained. It is connected to the DC power supply part by exchanging them, and in this case, in the second magnetization, the W phase and the V phase of the armature coil are energized with an impulse current, and the equally distributed quadrupole field as described above is applied. Can be formed.

Although the magnetizing method in the three-phase, four-pole inner rotor type motor has been described above, the present invention is not limited to the number of armature coils and the number of field poles regardless of the magnetic path form of the motor and the specifications of the number of poles. It can be easily analogized that it is applicable to all electric motors having a ratio of 3: 2.

<Effect of the Invention> According to the present invention, it is not necessary to change the internal wiring of the armature even when the opening angle of the armature coil or the armature salient pole is narrower than the opening angle of the field magnetic pole. By the built-in magnetization of the motor as it is completed, it is possible to magnetize the field with a ratio of the number of armature coils to the number of field poles of 3: 2, and the procedure is very easy. Is. Therefore, as compared with the conventional magnetization using a field alone, iron powder or the like adheres to the field in the process of incorporating the field into the motor housing, or the field hits another magnetic substance and is lost. In addition, the work efficiency of assembling the electric motor is significantly improved, because it is not necessary to take it in and out of the magnetizing device. Even when a hard magnetic material having a small coercive force is used as the permanent magnet material, the magnetic circuit does not open after magnetization, so the air gap magnetic flux density does not decrease, and the characteristics of the motor are improved or It also contributes to miniaturization.

[Brief description of drawings]

The drawings show an embodiment of the present invention, FIGS. 1 to 3 are block diagrams of an electric motor for explaining the procedure of the present invention, and FIGS. 5 and 6 show an electric motor for explaining another procedure. The configuration diagrams, FIGS. 4 and 7 are magnetizing circuit diagrams showing different embodiments. 1 ... Armature, 2 ... Field, 3 ... Yoke, 4 ... Hard magnetic material, 5 ... Magnetizing DC power supply section, 6, 14, 16 ... Changeover switch mechanism, 9 ... Open / close switch Mechanism, 15 ... DC power supply for excitation, T1, T2, T3, T4, T5, T6 ... Armature salient pole, CU1, CV
1, CW1, CU2, CV2, CW2 …… Armature coil, U, V, W …… Lead.

Claims (4)

(57) [Claims] 1. An armature is constructed by connecting 3n (n is a natural number) armature coils at equal intervals in a three-phase Y connection, and a permanent magnet field of 2n poles is arranged facing the armature. In the method of magnetizing a motor configured as described above, among the armature coils having the first phase, the second phase, and the third phase, the first phase output portion and the second phase A first step of magnetizing the field for the first time by connecting the output portion to a DC power source and applying an impulse current, and rearranging the connection of the armature coil to the DC power source, A second step of relatively rotating the facing position of the armature and the field relative to each other by a predetermined angle; and applying an impulse current to a predetermined two-phase armature coil connected to the DC power supply by the rearrangement. An electric motor comprising a third step of magnetizing the field for a second time. Magnetization method. 2. In the second step, the polarities of the first phase and the second phase are reversed and connected to a DC power source, and the opposing positions of the armature and the field are machined. 18 at the corner
The method of magnetizing an electric motor according to claim 1, wherein the method is a relative rotation of 0 ° / n. 3. In the second step, the third phase is replaced with a predetermined one of the first phase and the second phase to connect to a DC power source, and the armature and the The method of magnetizing an electric motor according to claim 1, wherein the opposed positions of the field are relatively rotated at a mechanical angle of 60 ° / n. 4. In the second step, after exchanging the connection of the armature coil to the DC power source, a small amount of excitation is applied to the predetermined two-phase armature coil connected to the DC power source by the rearrangement. The electric motor according to any one of claims 1 to 3, wherein the facing position of the armature and the field is relatively rotated by a predetermined angle by passing an electric current. Porcelain method.