JP2018182118A - Magnetizing device and magnetizing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetizing device which improves a magnetization ratio and enhances efficiency of magnetization operation when magnetizing a plurality of unmagnetized magnet pieces arranged at equal intervals.SOLUTION: The magnetizing device includes a pair of left and right magnetized coils 5a, 5b for magnetizing a plurality of unmagnetized magnet pieces 3 arranged at equal intervals. When denoting a width of each of the magnetized coils 5a, 5b along an arrangement direction of the magnet pieces 3 as β, denoting an arrangement pitch of the magnet pieces 3 as θ1, and denoting a width of the magnet piece difference 3 in the arrangement direction as θ2, a setting is so made to satisfy a relationship of θ1<β<θ1+(θ1-θ2)/2. Magnetization is performed so that mutually adjacent magnet pieces 3 have mutually different polarities.SELECTED DRAWING: Figure 3

Description

  According to the present invention, there is provided a magnetizing apparatus for magnetizing a plurality of unmagnetized magnet pieces arranged along the core of the rotor of the rotating electrical machine or the core of the stator of the rotor or the base of the stator of the linear motor. It relates to the magnetization method.

  In the prior art, as a magnetizing device for magnetizing a plurality of unmagnetized magnet pieces disposed in or on a rotor core, a magnet of a magnetizing yoke in which a magnetizing coil is wound around an iron core The width along the arrangement direction of the pieces is set smaller than the width in the arrangement direction of each magnet piece, and a plurality of the magnetizing yokes are arranged at positions separated by a predetermined number of magnet pieces, respectively. There has been proposed a magnetizing apparatus in which the magnet pieces adjacent to each other are magnetized so that the polarities thereof are different from each other (for example, see Patent Document 1 below).

  In this prior art magnetizing apparatus, the influence of the reverse magnetic field on the magnet pieces adjacent to each other can be suppressed, and the rotor of a different rotating electrical machine or the stator of a linear motor such as the outer diameter, the shape of the magnet pieces and the number of poles can be reduced. The magnet pieces can be magnetized.

JP, 2014-72223, A

  However, in the prior art described in Patent Document 1, since the width along the arrangement direction of the magnet pieces of the magnetizing yoke is smaller than the width in the arrangement direction of each magnet piece, the individual magnet pieces are magnetized Also in this case, it is necessary to change the position of the magnetizing yoke with respect to a single magnet piece and carry out the magnetizing operation a plurality of times, and it takes time and effort to magnetize each magnet piece.

  In the prior art magnetizing apparatus of the prior art, when it is attempted to magnetize each magnet piece in a single magnetizing operation, the magnetic field at the end of the magnet piece is weak and not sufficiently magnetized. The magnetization rate decreases. Furthermore, when the magnetization is performed so that the polarities of the adjacent magnet pieces are different from each other, if the position of the magnetization yoke is changed a plurality of times and the magnetization is performed, the leakage magnetic flux from the magnetization yoke causes the magnetic flux to leak. There is a possibility that a magnetic field opposite to the magnetization direction is applied, resulting in a decrease in the magnetization of the magnet pieces.

  The present invention has been made to solve the above problems, and in the case of magnetizing a plurality of unmagnetized magnet pieces arrayed at equal intervals, the magnetization rate is improved and the magnetizing operation is efficiently performed. An object of the present invention is to provide a magnetizing device and a magnetizing method that can be performed.

The magnetizing apparatus according to the present invention magnetizes the plurality of unmagnetized magnet pieces arranged at equal intervals so that the polarities of the adjacent magnet pieces are different from each other, A pair of left and right magnetizing coils for magnetizing is provided, the width of the magnetizing coils along the arrangement direction of the magnet pieces is β, the arrangement pitch of the magnet pieces is θ1, and the width of the magnet pieces in the arrangement direction Where θ 2
θ1 <β <θ1 + (θ1−θ2) / 2
It is characterized in that it is set to satisfy the following relationship.

  A magnetizing method according to the present invention uses the magnetizing device described above, and a pair of magnetizing coils are to be magnetized next from the position of the magnetized magnet piece in the arrangement direction of the magnet pieces. The moving step of moving to position with respect to two adjacent magnet pieces, and the magnetizing coil which magnetizes the two poles simultaneously so that the polarities of the two magnet pieces are different from each other by energizing the magnetizing coil after the moving step And a step of

  According to the magnetizing apparatus and the magnetizing method of the present invention, the magnetic fields generated at the left and right ends of the individual magnet pieces can be strengthened, and the magnetizing rates of the individual magnet pieces can be improved. Since the magnet pieces can be magnetized by one magnetizing operation so that the polarities of the magnet pieces are different from each other, the efficiency of the magnetizing operation can be enhanced.

It is a top view showing roughly the rotor of the rotation electrical machinery provided with the magnet piece magnetized using the magnetizing device of this invention. It is a top view in the case of magnetizing a magnet piece of a rotor using a magnetizing device by Embodiment 1 of this invention. It is the top view to which the part which magnetizes a magnet piece in FIG. 2 was expanded. FIG. 3 is a plan view when the magnetizing yoke of the magnetizing device according to Embodiment 1 is rotated from the magnetizing position shown in FIG. 2 to the position of another magnet piece to be magnetized; It is the top view to which the part which magnetizes the magnet piece of a rotor using the magnetization apparatus by Embodiment 2 of this invention was expanded.

Embodiment 1
FIG. 1 is a plan view schematically showing a rotor of a rotating electrical machine provided with magnet pieces magnetized by using the magnetizing apparatus of the present invention.

  The rotor 1 of the rotating electrical machine shown in FIG. 1 is a rotor of a rotating electrical machine used for a direct drive motor, and as a method of using a general rotating electrical machine, a rotational output is reduced using a reduction gear such as a gear. On the other hand, the direct drive motor does not use a reduction gear, but operates by connecting a load directly.

  When used in combination with a reduction gear, backlash or loss of power of the reduction gear or loss of power occurs, but since the direct drive motor does not have a reduction gear, there is no such problem, and rotation of the machine tool or transfer robot It is widely used for shafts and the like.

  On the other hand, there is a problem that the diameter of the rotor 1 tends to be large in order to obtain a large torque. In the rotor 1 of the direct drive motor, as shown in FIG. 1, a surface magnet type in which a plurality of magnet pieces 3 consisting of permanent magnets are arranged at equal intervals along the circumferential direction on the outer peripheral side of the rotor core 2 A rotor 1 is used. A segment magnet is used as the magnet piece 3 of the surface magnet type rotor 1 in order to minimize the amount of magnet.

  When manufacturing the rotor 1, in order to arrange the plurality of magnet pieces 3 at equal intervals along the circumferential direction of the outer periphery of the rotor core 2, convex portions extending in the axial direction of the rotor core 2 are used. A plurality of magnet pieces 3 are provided evenly at the base of the protrusion, and the thin end of the magnet piece 3 is brought into contact with the outer periphery of the protrusion and fixed by a method such as adhesion.

  In this case, if the arrangement interval of the magnet pieces 3 along the circumferential direction of the rotor core 2 is uneven, the cogging torque increases, the torque ripple during rotation increases, and noise or vibration occurs, etc. Positioning is done so as to be an interval. In addition, when the distance between the magnet pieces 3 adjacent to each other is wide, the cogging torque is increased and the torque ripple is increased. In order to suppress such problems, the distance between the magnet pieces 3 is set to be relatively short.

  The material of each magnet piece 3 for constituting a permanent magnet varies depending on the magnitude of the magnetic force, but for example, a rare earth sintered magnet such as neodymium, a ferrite sintered magnet, a rare earth material or a ferrite material and a resin are mixed Bond magnets and the like. As the configuration of the bond magnet, the magnet powder is uniformly mixed with the resin material so that the magnetic resistance per unit length becomes constant, so that the magnet piece 3 is directed radially outward from the radially outer side. The magnetic resistance is formed to be constant. Further, the shape of the magnet piece 3 is a semicylindrical type in which the outer peripheral surface is an arc and the inner peripheral surface is a straight line, and the shape of the surface of the rotor core 2 on which the magnet piece 3 is disposed It corresponds to the shape of the inner peripheral surface side of 3.

  FIG. 2 is a plan view in the case of magnetizing a magnet piece of a rotor using a magnetizing apparatus according to a first embodiment of the present invention, and FIG. 3 is an enlarged plan view of a portion for magnetizing a magnet piece in FIG. is there.

  In order to obtain magnetism, the magnet piece 3 is magnetized using a magnetizing device 4 for generating a magnetic field. The magnetizing device 4 includes a magnetizing yoke 7 that simultaneously magnetizes two magnet pieces 3 adjacent to each other along the circumferential direction of the rotor core 2 at two poles.

  The magnetizing yoke 7 has a pair of magnetizing coils 5 a and 5 b along the circumferential direction of the rotor core 2. The magnetizing coils 5a and 5b are connected to a magnetizing power supply (not shown), and when a large pulse current is applied instantaneously from the magnetizing power supply, the magnetic field generated by the magnetizing coils 5a and 5b is a magnet. By penetrating the inside of the piece 3, the magnet piece 3 is magnetized.

  In order to magnetize a large number of magnet pieces 3 included in a large diameter multipolar rotor 1 like a direct drive motor in one magnetizing operation, the size of the magnetizing apparatus 4 is increased and the number of poles is different. It is difficult to sufficiently cope with the case where the number of magnet pieces 3 is different.

  Therefore, in the magnetizing apparatus according to the first embodiment, as will be described in detail later, two magnet pieces 3 adjacent to each other along the circumferential direction of the rotor core 2 are simultaneously changed by two poles so as to have different polarities. The magnetizing yoke 7 is configured to magnetize, and this makes it possible to magnetize the plurality of magnet pieces 3 provided in the rotor 1 and to suppress an increase in size and cost of the device.

  Next, the specific configuration of the magnetizing device 4 and the method of magnetizing the magnet piece 3 will be described in more detail with reference to FIGS. 3 and 4.

  In the magnetizing yoke 7 included in the magnetizing device 4, the magnetizing coils 5a and 5b are wound around the iron core (not shown) by a predetermined number of turns, and the pair of magnetizing coils 5a and 5b adjacent to each other The direction of winding is reversed. That is, if one magnetizing coil 5a is wound clockwise, the magnetizing coil 5b next to it is wound counterclockwise.

Moreover, assuming that the width along the arrangement direction of the magnet pieces 3 of the magnetizing coils 5a and 5b is β, the arrangement pitch of the magnet pieces 3 is θ1, and the width of the magnet pieces 3 in the arrangement direction is θ2.
θ1 <β <θ1 + (θ1−θ2) / 2 (1)
It is set to satisfy the relationship. Here, β, θ1 and θ2 are shown as angle units.

  With the magnet piece 3 and the magnetizing coils 5a and 5b arranged in such a positional relationship, when a pulse current is applied, the pair of magnetizing coils 5a and 5b is centered on FIG. Magnetic flux lines P as indicated by broken lines and magnetic flux lines Qa and Qb indicated by broken lines at the left and right positions of the magnetic flux lines P respectively occur in the directions of arrows.

  Here, if reference numerals 3a and 3b are added to distinguish two adjacent magnet pieces 3 to be magnetized in FIG. 3, the magnetic flux line P mainly includes two magnet pieces 3a to be magnetized and The magnetic flux lines Qa and Qb pass through the inside of the magnet piece 3b, and the magnetic flux lines Qa and Qb respectively pass through the outer end portions of the magnet pieces 3a and 3b. Therefore, these two adjacent magnet pieces 3a and 3b have opposite polarities to each other. It is simultaneously magnetized to become

  In this case, focusing on the magnetic flux lines inside the magnet pieces 3 (3a or 3b) to be magnetized, the width β along the arrangement direction of the magnet pieces 3 of the magnetizing coils 5a and 5b is the magnet pieces When the pitch is the same as or smaller than the arrangement pitch θ1 of 3 (in the case of β ≦ θ1), the magnetic field generated at the end of each of the magnet pieces 3 becomes weak, and the magnetization rate decreases.

  Further, a value (= θ1 +) obtained by adding the width β of each magnetizing coil 5a, 5b to the arrangement pitch θ1 of the magnet pieces 3 and the separation distance (θ1−θ2) / 2 along the arrangement direction of the magnet pieces 3 adjacent to each other. If it is larger than (θ1−θ2) / 2), the magnetizing coils 5a and 5b of the magnetizing yoke 7 are then moved along the circumferential direction onto the two unmagnetized magnet pieces 3 for coloring. At the time of magnetizing, a reverse magnetic field opposite to the original magnetization direction is applied to both ends of each magnet piece 3, so the magnetic field generated at the end of the magnet piece 3 is similarly weakened and the magnetic susceptibility decreases. I will.

  Therefore, as shown in the first embodiment, the lower limit and the upper limit of the width β of the magnetizing coils 5a and 5b along the arrangement direction of the magnet pieces 3 are defined as shown in the above equation (1). By doing this, it is possible to improve the magnetization efficiency to the left and right ends of each magnet piece 3 and to improve the magnetization rate.

  FIG. 4 is a plan view when the magnetizing yoke of the magnetizing device is rotated from the magnetizing position shown in FIG. 2 to the position of another magnet piece to be magnetized. Although the case where the magnetizing yoke 7 is rotated is shown here, the position of the magnetizing yoke 7 may be fixed to rotate the rotor 1 side.

  The magnetizing yoke 7 is rotated to the position of the two unmagnetized magnet pieces 3 of the rotor 1, and the adjacent two magnet pieces 3 are magnetized so that the polarities thereof are different from each other. The magnetization method in this case is as shown in FIG. Then, this magnetizing operation is performed on all the magnet pieces 3 disposed on the entire circumference of the rotor 1.

  As described above, by performing the magnetizing operation on all the magnet pieces 3 arranged at equal intervals all around the rotor core 2, the magnetization efficiency to both end portions of each magnet piece 3 is improved, and the magnet It is possible to improve the magnetization of the piece 3. If the magnetization ratio in the magnet piece 3 is low, demagnetization is likely to occur, which causes a decrease in the efficiency of the rotating electrical machine, and an increase in torque ripple causes a problem such as generation of noise during rotation. If the rotor 1 magnetized by the magnetizing device 1 is used, demagnetization is difficult and torque ripple can be suppressed, so that the rotation characteristics of the rotor 1 can be improved.

  In the prior art magnetizing apparatus, since the circumferential width of the magnet head is smaller than the circumferential width of the magnet pieces, multiple magnetizing operations are required to completely magnetize the individual magnet pieces. When the rotor 1 of a rotating electrical machine such as a direct drive motor has a large diameter and the number of magnet pieces 3 is large, it takes much time to magnetize the entire magnet piece 3 I will. On the other hand, two magnet pieces 3 adjacent to each other can be simultaneously magnetized so that their polarities differ from each other by one magnetization operation using the magnetizing device 4 having the configuration of the first embodiment. Therefore, it is possible to significantly shorten the magnetization time as compared with the prior art.

Second Embodiment
FIG. 5 is an enlarged plan view of a portion of a rotor for magnetizing a magnet piece using a magnetizing device according to a second embodiment of the present invention.

  The magnetizing device 4 in the second embodiment is the left and right along the arrangement direction of the magnet pieces 3 with respect to the pair of magnetizing coils 5a and 5b having the configuration shown in the first embodiment (FIGS. 1 to 3). Auxiliary coils 6a and 6b each having a number of turns smaller than the number of turns of each of the magnetizing coils 5a and 5b are wound around the outer position.

  Similar to the configuration of the first embodiment, adjacent magnetizing coils 5a and 5b are formed such that the winding directions are opposite to each other between the poles. Further, the respective auxiliary coils 6a and 6b are also wound so that the direction of winding is opposite to that of the adjacent magnetizing coils 5a and 5b.

Moreover, when the width of the auxiliary coil 6 in this case along the arrangement direction of the magnet pieces 3 is α,
α <θ 1 (2)
It is set to satisfy the relationship.

  In order to magnetize the magnet piece 3 of the rotor 1, a pulse current of a large current is applied to the magnetizing coils 5a, 5b and the auxiliary coils 6a, 6b. By the application of this pulse current, as shown by the broken line in FIG. 5, magnetic flux lines P are generated in the direction of the arrow in the magnetizing coil 5a and the magnetizing coil 5b adjacent thereto, and one magnetizing coil 5a and A magnetic flux line Qa is generated in the direction of the arrow in the auxiliary coil 6a adjacent to this, and a magnetic flux line Qb is generated in the direction of the arrow in the other magnetized coil 5b and the auxiliary coil 6b adjacent thereto.

  Here, in order to distinguish the individual magnet pieces 3, assuming that the reference numerals 3c, 3a, 3b, 3d are given from the left side of FIG. 5 to the four magnet pieces adjacent to each other in FIG. Mainly passes through the magnet pieces 3a and 3b to be magnetized, and the magnet pieces 3a and 3b are magnetized. The magnetic flux lines Qa and Qb pass through one end in the unmagnetized magnet pieces 3c and 3d located on the left and right of the adjacent magnet pieces 3a and 3b which are mainly to be magnetized, and further to be magnetized The ends of the pieces 3a, 3b also pass.

  In the rotor 1 using a plurality of magnet pieces 3 with a large diameter, such as a direct drive motor, the distance between the magnet pieces 3 is set to be narrow in order to reduce the cogging torque. If the distance between the magnet pieces 3a and 3b and the unmagnetized magnet pieces 3c and 3d located next to the magnet pieces 3a and 3b to be magnetized is close, the leakage flux of the magnetizing coils 5a and 5b causes the effects of In the unmagnetized magnet pieces 3c and 3d, the possibility that a reverse magnetic field opposite to the original magnetization direction is applied is increased, resulting in a decrease in the magnetization rate.

  On the other hand, as in the configuration of the second embodiment, auxiliary coils 6a and 6b are arranged at the left and right positions adjacent to a pair of magnetized coils 5a and 5b, respectively, and the arrangement direction of magnet pieces 3 of auxiliary coil 6 By setting the width α along the direction smaller than the arrangement pitch θ1 of the magnet pieces 3 (α <θ1), the influence of the leakage flux of the magnetizing coils 5a and 5b is cancelled, and the magnetic flux lines Qa and Qb shown in FIG. It is possible to suppress the generation of a reverse magnetic field in the magnet pieces 3c and 3d adjacent to the magnet pieces 3a and 3b to be magnetized.

  The width α along the arrangement direction of the magnet pieces 3 of each of the auxiliary coils 6a and 6b needs to satisfy the above equation (2), but depending on the shape and spacing of the magnet pieces 3, the influence of the reverse magnetic field It is preferable to set the width α so as to reduce the

  Other configurations and effects are the same as in the case of the first embodiment, and thus detailed description will be omitted here.

Other Embodiments
The present invention is not limited to only the configurations of the first and second embodiments described above, and a part of the configuration of each of the first and second embodiments is modified without departing from the scope of the present invention. Alternatively, the configuration can be omitted, and the configurations of the first and second embodiments can be combined as appropriate.

  That is, in the above-described first and second embodiments, although the rotor 1 of the direct drive motor has been described as an example, the present invention is not limited to this, and the large diameter rotor 1 having a plurality of magnet pieces 3 or fixing The present invention may be applied to children.

  Moreover, although the rotor 1 shown to said Embodiment 1, 2 uses 30 magnet pieces 3, it is applicable also with another number. Further, the present invention is not limited to the surface magnet type rotor 1 and may be an embedded magnet type rotor 1 or a stator in which the magnet pieces 3 are embedded in an iron core.

  Further, the shape of the magnet piece 3 is a tile type whose outer and inner circumferences are both arcs, a semicylindrical type whose outer peripheral surface is an arc and whose inner peripheral surfaces are straight, and a flat type whose both outer and inner circumferences are straight. For example, any shape may be used.

  By using the rotor or stator having such a configuration, it is possible to magnetize while suppressing the occurrence of a reverse magnetic field inside all the magnet pieces disposed all around, so that high efficiency and low noise can be achieved. Can provide a rotating electric machine. Furthermore, since it is possible to magnetize the magnet pieces of a plurality of types of rotors or stators with one magnetizing device, investment can be reduced, and a low cost rotating electric machine can be provided.

  Furthermore, in the above description, the case of magnetizing the magnet pieces provided on the rotor or the stator has been described, but the present invention is not limited thereto, and a plurality of linear motors arranged along the base of the linear motor stator The present invention is also applicable to the case of magnetizing an unmagnetized magnet piece. In this case, a unit of length is employed instead of an angle unit as β, θ 1, θ 2 and α shown in the above equations (1) and (2).

DESCRIPTION OF SYMBOLS 1 rotor, 2 rotor core, 3, 3a, 3b, 3c, 3d magnet piece, 4 magnetization apparatus, 5a, 5b magnetization coil, 6a, 6b auxiliary coil, 7 magnetization yoke,
Array pitch of θ1 magnet segments, width of θ2 magnet segments in the array direction,
β Width along the arrangement direction of the magnet pieces of each magnetizing coil,
α Width along the arrangement direction of the magnet pieces of the auxiliary coil.

Claims (4)

A magnetizing apparatus which magnetizes the plurality of unmagnetized magnet pieces arranged at equal intervals so that the polarities of the adjacent magnet pieces are different from each other,
The left and right magnetizing coils for magnetizing the magnet pieces are provided, the width along the arrangement direction of the magnet pieces of each magnetizing coil is β, the arrangement pitch of the magnet pieces is θ1, and the magnet pieces are When the width in the array direction is θ2,
θ1 <β <θ1 + (θ1−θ2) / 2
A magnetizing device characterized in that it is set to satisfy the following relationship. An auxiliary coil having a number of turns smaller than the number of turns of the magnetizing coil is wound around the pair of magnetizing coils at the left and right outer positions along the arrangement direction of the magnet pieces. The magnetizing device according to claim 1. When the width of each of the auxiliary coils along the arrangement direction of the magnet pieces is α,
α <θ1
The magnetizing device according to claim 2, wherein the magnetizing device is set to satisfy the following relationship: The magnetizing device according to any one of claims 1 to 3, wherein a pair of the magnetizing coils are magnetized in the direction of arrangement of the magnet pieces from the position of the magnet piece which has been magnetized. The moving step of moving so as to be positioned with respect to two adjacent magnet pieces to be targeted, and after the moving step, the magnetizing coil is energized and two poles are simultaneously attached so that the polarities of the two magnet pieces are different from each other. And a magnetizing step of magnetizing.

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