JP4678774B2 - Multipolar ring permanent magnet magnetizer - Google Patents

Description

  The present invention relates to an apparatus for magnetizing a permanent magnet. More specifically, the present invention lowers the temperature of an object to be magnetized from a temperature above its Curie point to a temperature below its Curie point while applying a magnetizing magnetic field. The present invention relates to a magnetizing device used in a permanent magnet magnetizing method. Although this technique is not particularly limited, it is effective for, for example, multipolar magnetization of a ring-shaped permanent magnet used for a rotor of a very small diameter stepping motor.

  In order to multi-polarize a ring-shaped permanent magnet rotor incorporated in a radial gap type permanent magnet stepping motor or the like, a coil energization type magnetizing apparatus is generally used. This type of magnetizing device is provided with a magnetized object accommodation hole into which a ring-shaped permanent magnet, which is a magnetized object, can be inserted / extracted in a magnetic yoke, for example, and an inner wall surface of the magnetized object accommodation hole In this structure, a plurality of grooves extending in the axial direction are formed, and insulation-coated conductors are embedded in the grooves, and adjacent insulation-coated conductors are continuously folded to form a coil. The magnetized object is inserted into the magnetized object receiving hole, and the electric charge stored in the capacitor is instantaneously released, so that a pulse current is passed through the coil and magnetized by the magnetic field generated thereby.

  As is well known, in response to the recent remarkable downsizing of electronic devices, stepping motors and the like used therefor have also been downsized and reduced in diameter. When a ring-shaped permanent magnet used as a rotor is magnetized in multiple poles, a large pulsed current is passed using the coil energization type magnetizing device as described above. Since the pitch (distance between magnetized magnetic poles) is narrowed, the diameter of a conducting wire is reduced, and the current value that can be passed through the conducting wire is limited. Therefore, there has been a problem that sufficient magnetization characteristics cannot be obtained.

  As one method that can solve such a problem, a plurality of inverted magnetic poles are formed in the central portion by arranging a plurality of permanent magnets radially, and four or more poles are provided by arranging an adherend in the central portion. Has been proposed (see Patent Document 1). Certainly, by using such a permanent magnet type magnetizing apparatus, the insufficient magnetization which becomes a problem when the magnetic pole pitch of the object to be magnetized is reduced can be improved to some extent.

  However, there is a great demand for downsizing (smaller diameter) and higher performance of recent stepping motors. For example, in an autofocus mechanism of a portable video device, a stepping motor magnetized with a narrow pitch multipolar magnet capable of controlling a lens actuator with high accuracy in order to obtain a high-definition image is an important electronic component. Here, as a ring-shaped permanent magnet constituting the rotor, for example, there is a demand for a magnetization characteristic of a saturation magnetization level for a narrow pitch structure having a diameter of 3 mm or less and a number of magnetic poles of 10 or more. For such a magnetized structure, in the conventional magnetizing method as described above, there is a problem that magnetization is insufficient even if the permanent magnet method is used, and the variation of the surface magnetic flux density peak value is large.

  As a technique for improving the lack of magnetization, a method of magnetizing an object to be magnetized using a decrease in saturation magnetization magnetic field in a high-temperature atmosphere or liquid has been proposed (see Patent Document 2). For example, in a Pr—Fe—B magnet, which is a kind of rare earth permanent magnet, the magnetization magnetic field at 100 ° C. has a lower value than the magnetization magnetic field at 25 ° C., and thus magnetization is performed in this temperature region. Thus, it is disclosed that it is possible to perform saturation magnetization in a stable low magnetic field.

However, when actually magnetizing, in the ring-shaped permanent magnet with a narrow magnetization pitch such as the above-mentioned minimum diameter and multipole, the average value of all the poles of the surface magnetic flux density peak value is somewhat magnetized. However, the variation in the surface magnetic flux density peak value is still large, and high quality magnetization is extremely difficult.
JP 2001-268860 A JP-A-6-140248

  The problem to be solved by the present invention is that even with a ring-shaped permanent magnet with a narrow magnetization pitch, such as extremely small diameters and multiple poles, there is no shortage of magnetization, the magnetization quality can be improved, and strong magnetization at low cost. It is to provide a device that can perform work efficiently and quickly. Another problem to be solved by the present invention is to provide a small magnetizing apparatus capable of sufficiently magnetizing an object to be magnetized. Still another problem to be solved by the present invention is to provide a magnetizing apparatus that can easily control the magnetizing characteristics of the object to be magnetized.

  As a technique that does not cause insufficient magnetization and can improve the magnetization quality, the present inventors have first made a permanent magnet, which is an object to be magnetized, from a temperature above its Curie point to a temperature below its Curie point. A permanent magnet magnetization method was proposed in which the magnetizing magnetic field was continuously applied to the object to be magnetized while the temperature was lowered (Japanese Patent Application No. 2005-343193). According to this method, it is possible to obtain a ring-shaped permanent magnet having high magnetization characteristics (magnetic force characteristics) and good magnetization quality even with a very small diameter / multipole magnetization structure.

The present invention is an apparatus effective for implementing such a magnetization method. That is, according to the present invention, the heating part and the magnetized part are arranged in the axial direction as separate structures, and the holding member for the ring-shaped magnetized object can be moved relative to the heating part and the magnetized part. the heating unit is set to a temperature above the Curie point of the magnetization object, magnetized has become a temperature lower than the Curie point of the object to be magnetized was above the Curie point of the deposited磁物 by the heating unit wherein heated to a temperature cooled deposited磁物is to a temperature below the Curie point of the deposition磁物 been moved to the magnetized portion, while the multi-continues to be magnetizing field is applied in the magnetized portion a magnetizer for multipolar ring-shaped permanent magnet, characterized in that it has to be very magnetized. Specifically, a heating part in which the inner surface of the heating space for accommodating the magnetized object becomes a heating surface and a magnetized part in which the inner surface of the magnetizing space for accommodating the magnetized object becomes a magnetized surface are combined, It is assumed that a rod-like holding member for holding a magnetized material is installed so as to pass through the heating part and the magnetized part so as to be relatively movable in the axial direction. In the present invention, the heating part and the magnetized part may be fixed, and the holding member for the magnetized object may be moved relative to them, or conversely, the holding member for the magnetized object may be fixed and heated against it. It is configured so as to move the parts and magnetized not good. Magnetized from an inner surface of the adherend磁物, or to sometimes performed from the outer surface, there is also a case where the inner and outer surfaces.

  The heating part and the magnetized part are supported, for example, so that the mutual positional relationship does not change. It is preferable to interpose a heat insulating member between the heating part and the magnetized part. Moreover, it is preferable to attach to the magnetized portion a temperature adjusting device that can be set to a temperature not lower than the room temperature and lower than the Curie point of the object to be magnetized.

  The magnetized portion may be a coil energization system that applies a magnetic field generated by energizing the coil, but in particular when a very small permanent magnet is magnetized in multiple poles, a permanent magnet that applies a magnetic field by the permanent magnet is used. A magnet system is preferred. In the case of such a magnetized portion, a plurality of magnetizing permanent magnets having a Curie point higher than that of the object to be magnetized are arranged. It is preferable that the temperature adjusting device sets the temperature at which the permanent magnet for magnetization does not cause permanent demagnetization as an upper limit. As a permanent magnet for magnetization, for example, an SdCo-based sintered magnet having a high Curie point, an Nd-based sintered magnet having a relatively low Curie point, etc. can be used depending on the magnetization conditions. For example, in the case where the magnetized object is a ring magnet, the magnetized portion is provided with a magnetized object accommodation hole into which a magnetized object that becomes a magnetized space can be inserted / extracted in the center of the non-magnetic block, A plurality of grooves extending radially outward from the inner surface of the magnetized object accommodation hole are provided at equal angles, and a permanent magnet for magnetizing is embedded in each groove.

  The present invention may be a saddle arrangement type in which magnetized portions and heating portions are arranged vertically and the axis direction is vertical, or the heating portions and magnetized portions are arranged side by side, and the axis direction is horizontal. It may be a horizontal arrangement form.

  The magnetizing apparatus of the present invention has a structure in which the heating unit and the magnetizing unit are separated from each other, and the holding member of the magnetized object is relatively movable with respect to them. A series of operations makes it easy to quickly apply a magnetizing magnetic field while heating an object to a temperature above the Curie point and then lowering the temperature to a temperature below the Curie point. This can improve the workability of magnetization. As a result, even in a ring-shaped permanent magnet with a narrow magnetization pitch, such as a very small diameter and multiple poles, insufficient magnetization does not occur, the magnetization quality can be improved, and powerful magnetization can be efficiently performed at low cost.

  In particular, if a permanent magnet system using a permanent magnet with a high Curie point is used as the magnetized portion, it is easy to cope with the narrowing of the magnetization pitch. It is effective for the magnetization of the device, and it is possible to simplify the device and extend its life, and there is an advantage that the operation cost can be reduced due to the necessity of energization.

  If a temperature adjusting device that can set the magnetized part at a temperature above room temperature and below the Curie point of the object to be magnetized is attached, the object to be magnetized can be taken out at a temperature higher than room temperature, and the thermal demagnetization action Thus, desired characteristics can be obtained, and the temperature can be controlled by the holding time of the magnetized object in the magnetized portion.

  The magnetized portion has a structure in which a plurality of magnetizing permanent magnets having a Curie point higher than that of the object to be magnetized are arranged, and the upper limit is a temperature at which the magnetizing permanent magnet does not cause permanent demagnetization. When a temperature control device is provided, magnetization can be performed at a temperature at which permanent demagnetization (irreversible demagnetization) does not occur. Therefore, sufficient magnetization can be performed even using a permanent magnet such as an Nd-based sintered magnet.

  In particular, in the case of the saddle arrangement type and the magnetized part is in the upper position and the heated part is in the lower position, a heat insulating member is interposed between the magnetized part and the heated part, so that the heat of the heated part is natural. It is possible to prevent the magnetized portion from reaching due to convection.

  FIG. 1 is an explanatory view showing an embodiment of a magnetizing apparatus according to the present invention. This magnetizing apparatus includes a heating unit 10 having a cylindrical structure and an inner wall surface (an outer peripheral surface of a cylindrical heating space) serving as a heating surface, and an inner wall surface (an outer peripheral surface of a cylindrical magnetizing space). ) Includes a magnetized portion 12 serving as a magnetized surface, which are separate and are disposed in the axial direction (in the direction along the axis). This example is a saddle arrangement format in which the heating unit 10 is positioned below and the magnetized unit 12 is positioned vertically so that the axis direction is vertical. The heating unit 10 and the magnetized unit 12 are supported so that their positional relationship does not change, are provided at a predetermined interval, and a heat insulating member 14 is interposed therebetween. A cooling unit 16 is provided outside the magnetized unit 12. On the other hand, a rod-shaped holding member 22 that holds the magnetic object (permanent magnet) 20 is installed so as to be movable in the axial direction through the heating unit 10 and the magnetized unit 12. Here, the heating unit 10 and the magnetized unit 12 are fixed, and the magnetized object 20 is moved by the holding member 22 being driven in the vertical direction by the vertical drive mechanism 24. This is because the holding member is generally lighter and can be easily moved quickly. Of course, the holding member may be fixed, and the heating unit and the magnetizing unit may be moved by a driving mechanism. The temperature of the heating unit 10 and the operation of the vertical drive mechanism 24 (position of the magnetized object, stop time, etc.) are controlled by the control unit 26.

  An example of the internal structure of the magnetized portion is shown in FIG. This example is a permanent magnet system in which a magnetic field generated by a permanent magnet is applied to an object to be magnetized as a magnetizing magnetic field. FIG. 2 shows a horizontal cross section at the position xx in FIG. The object to be magnetized 20 is a ring-shaped permanent magnet, and is an example of magnetizing it. The magnetized portion 12 is provided with a circular magnetized object accommodation hole 32 into which a magnetized object 20 can be inserted and extracted at the center of a nonmagnetic block (for example, a stainless steel block) 30 and the magnetized part. Ten grooves 34 having a rectangular cross section extending radially from the inner wall surface of the object accommodation hole 32 are provided at equal angles, and each groove 34 has a quadrangular rod-shaped permanent magnet 36 having a Curie point higher than that of the magnetized object. It is the structure which buried each. Therefore, the inner wall surface of the magnetized portion 12 becomes a magnetized surface.

  Here, the heating unit 10 includes a heating unit main body 40 on the outer peripheral side and a heat transfer unit 42 located on the inner peripheral side thereof. For example, the heating unit 10 has a sheath heater (resistance heater) oriented in a number of axial directions. Are arranged in a circumferential shape. The heat generated in the heating unit main body 40 is transmitted to the inside by the heat transfer unit 42 made of brass having good thermal conductivity. Therefore, the inner wall surface of the heat transfer section 42 becomes a heating surface. The heating unit 10 has the capability of heating the magnetic object positioned in the magnetic object receiving hole 44 to a temperature above its Curie point and maintaining it at a predetermined constant temperature.

  The rod-shaped holding member 22 that holds the ring-shaped magnetic object 20 is a combination of a lower support 46 and an upper presser 48 and has a structure that holds the magnetic object 20 from above and below. Of course, the holding can be performed only by the support. The heating unit 10 also heats the surrounding air, and the heated air rises and tries to heat the magnetized unit 12. The heat insulating member 14 prevents the magnetized portion 12 positioned above the heating unit 10 from being heated by natural convection or the like. It may be a shape (thickness). The cooling unit 16 serves to cool the magnetized unit 12 and maintain the temperature of the magnetized unit 12 substantially constant. By controlling the heating unit 10 at a constant temperature, the magnetized unit 10 is kept substantially constant by natural cooling of the cooling unit 16. Of course, the cooling unit 16 may also perform temperature control.

  In the present invention, the Curie point of the magnetizing permanent magnet is set so that the magnetizing permanent magnet 36 can generate a magnetic field that can magnetize the magnetized object 20 at a high temperature. Set higher than the Curie point. In order to minimize the magnetic field required for magnetization of the magnetized object, the heating temperature is set higher than the Curie point of the permanent magnet that is the magnetized object, and the magnetizing permanent magnet is Usually, the heating temperature is set lower than the Curie point of the permanent magnet for magnetization in order to leave a magnetic field that can be magnetized on the object to be magnetized and to have a magnetizing ability.

  Taking the case where the object to be magnetized 20 is an NdFeB isotropic magnet (Curie point: about 350 to 390 ° C. depending on the material) as an example, the permanent magnet 36 for magnetization is an SmCo sintered magnet (Curie point: about 850). ° C) is preferred. The heating unit 10 needs to be capable of being heated to a Curie point Tc or higher of the adherend (it is desirable that it can be heated to about Tc + 30 ° C. or higher according to experimental results).

  FIG. 3 is an explanatory view showing the operation of this magnetizing apparatus. A indicates a heating process, and B indicates a magnetization process. As shown in A, the object to be magnetized 20 is placed in the heating unit 10 and heated to the Curie point or more of the object to be magnetized. For example, when the adherend is an NdFeB isotropic magnet (Curie point: about 350 ° C.), the adherend 20 is heated to about 380 ° C. by the heating unit 10. Next, the holding member 22 is quickly driven, and the object to be magnetized 20 is inserted into the magnetized portion 12 as shown in B, and a predetermined magnetizing magnetic field is applied by the magnetizing permanent magnet 36. Then, the object to be magnetized 20 is cooled to a temperature lower than the Curie point while being installed in the magnetized portion 12 (according to the experimental results, it is preferable to cool to Tc−50 ° C. or lower). As a result, the maximum magnetization can be applied to the object to be magnetized, and the object to be magnetized is magnetized. Therefore, when the object is cooled to a temperature below the Curie point of the object to be magnetized, sufficient Magnetic force is generated. Thereafter, the object to be magnetized 20 is taken out from the magnetized portion 12. Although depending on the size of the object to be magnetized 20, when the heat capacity is small with a very small diameter, magnetization can be performed in a cycle of about several seconds.

  Through the series of operations described above, a magnetic pole corresponding to the magnetized magnetic pole appears on the outer peripheral surface of the ring-shaped permanent magnet, which is an object to be magnetized, and a permanent magnet that is sufficiently magnetized at room temperature can be obtained. FIG. 4 shows the situation of multipolar magnetization applied to the ring-shaped permanent magnet that is the product 50.

  FIG. 5 is a longitudinal sectional view showing another embodiment of the magnetizing apparatus according to the present invention. The magnetizing device shown in FIG. 5A also includes a heating unit 10 having a cylindrical structure and an inner wall surface serving as a heating surface, and a magnetizing unit 12 having a cylindrical structure and an inner wall surface serving as a magnetization surface. Is a separate body and is disposed in the axial direction. In this example, the heating unit 10 and the magnetized unit 12 are arranged side by side, and the direction of the axis is horizontal. The heating unit 10 and the magnetized unit 12 are supported so that their positional relationship does not change. A cooling unit 16 is provided on the outer peripheral side of the magnetized unit 12. On the other hand, a rod-shaped holding member 22 that holds the magnetized object 20 is installed so as to be movable in the axial direction through the heating unit 10 and the magnetized unit 12. In this configuration, since the magnetized part 12 and the heating part 10 are arranged side by side, the magnetized part is not heated by natural convection or the like. Therefore, it is not always necessary to interpose a heat insulating member between the magnetized part 12 and the heating part 10. The object to be magnetized 20 heated by the heating unit 10 moves in the horizontal left-hand direction and is magnetized by the magnetizing unit 12. In addition, illustration of the horizontal drive mechanism and control unit of the object to be magnetized is omitted.

  The magnetizing apparatus shown in FIG. 5B also includes a heating unit 10 having a cylindrical structure and an inner wall surface as a heating surface, and a magnetizing unit 12 having a cylindrical structure and an inner wall surface as a magnetization surface. Are separate and arranged in the axial direction. This example is a saddle arrangement type in which the magnetized portion 12 is positioned below and the heating portion 10 is positioned vertically so that the axis direction is vertical. The heating unit 10 and the magnetized unit 12 are supported so that their positional relationship does not change. A cooling unit 16 is provided on the outer peripheral side of the magnetized unit 12. On the other hand, a rod-like holding member 22 that holds the magnetized object 20 is installed so as to be movable in the axial direction through the heating part and the magnetized part. In this configuration, since the magnetized part is located below the heating part, the magnetized part is not heated by natural convection or the like. Therefore, also in this configuration, it is not always necessary to interpose a heat insulating member, and the magnetized part and the heating part can be arranged close to each other, so that the apparatus can be downsized. The object to be magnetized 20 heated by the heating unit 10 descends and is magnetized by the magnetizing unit 12.

  When the magnetized object is ultra-small, the heat capacity is small, and therefore cooling may proceed excessively when moving from the heating part to the magnetized part. In such a case, it is effective to provide a heat insulating material so as to surround the holding member for the object to be magnetized between the heating unit and the magnetizing unit. The heat insulating member in FIG. 1 also functions as a heat insulating material at that time.

  In addition to resistance heating as shown in the embodiments, any means such as high-frequency heating, laser heating, high-temperature gas flow heating, or high-temperature liquid heating may be used for heating. The cooling may be natural cooling or forced cooling such as water cooling or air cooling. If work in an inert atmosphere is required, an inert gas flow can also be performed. Further, the magnetizing method and the specific structure in the magnetized portion may be appropriately changed according to the diameter and material of the permanent magnet that is the magnetized object, the number of magnetized poles, and the like.

  FIG. 6 is a longitudinal sectional view showing still another embodiment of the magnetizing apparatus according to the present invention. Since the basic configuration is the same as that of the apparatus shown in FIG. 1, the corresponding members are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, a temperature adjusting device 60 is attached outside the magnetized portion main body. The magnetized portion temperature by the temperature adjusting device 60 is controlled by the control unit 26 together with the temperature of the heating unit 10 and the operation of the vertical drive mechanism 24 (position of the magnetized object, stop time, etc.).

  A ring-shaped Nd-based bonded magnet having an outer diameter of 1.6 mm, an inner diameter of 0.6 mm, and a length of 3.8 mm was used as an object to be magnetized, and 10-pole magnetization was performed on the object using the apparatus of the present invention shown in FIG. . At that time, an Nd-based sintered magnet (Curie temperature: 320 ° C.) was used as the field magnet. In order to cause permanent demagnetization (irreversible demagnetization) at 120 ° C., the temperature was set at 100 ° C. as the upper limit by the temperature adjusting device 60 and magnetized. The heating temperature was set to 380 ° C., and the magnetized material was moved to the magnetized portion whose temperature was controlled immediately after heating, and magnetized. FIG. 7 shows the result of evaluating the magnetization characteristics. Since the magnetized portion has a large heat capacity with respect to the object to be magnetized, the temperature of the permanent magnet for magnetization greatly increases even if the object to be magnetized heated to 380 ° C. is inserted into the magnetizing space. There is no.

As can be seen from FIG. 7, Bo (ave) of 100 mT or more sufficient as the magnetizing characteristic was obtained and the Bo variation was suppressed even though the 0.5 mm pitch and the dimension in which the magnetizing characteristic was difficult to obtain. . Note that Bo is the surface magnetic flux density (open), and Bo (ave) is the average value of all the Bo peak values. Bo variation is
Bo variation = {Bo (max) −Bo (min)} / Bo (ave)
It is a value defined in. However,
Bo (max): Maximum value of Bo peak value in all poles Bo (min): Minimum value of Bo peak value in all poles.

  Therefore, a large Bo (ave) indicates that the magnetization characteristic (magnetic force characteristic) is high, and a small Bo variation indicates that high quality magnetization is performed. From the result of FIG. 7, it can be seen that the effect of magnetization by the device of the present invention is effective.

  Next, a ring-shaped Nd-based bond magnet (Curie point: 350 ° C.) having an outer diameter of 2.9 mm, an inner diameter of 1.0 mm, and a length of 3.0 mm was used as the adherend, and the book shown in FIG. Ten-pole magnetization was performed by the inventive apparatus. At that time, an Sm—Co sintered magnet was used as the field magnet. The heating temperature is set to 400 ° C. and the magnetized part temperature is set to 80 ° C. After the heating, the magnetized object is immediately moved to the magnetized part and magnetized, and after being held in the magnetized part for a predetermined time, It was taken out from the magnetic part.

  FIG. 8 shows the magnetization characteristics corresponding to the holding time in the magnetized portion. From FIG. 8, it can be seen that since the heating exceeding the Curie point Tc of the object to be magnetized is performed, the Bo variation is suppressed and the magnetization characteristics can be finely adjusted. In FIG. 8, the range surrounded by the dotted line indicates that the magnetization characteristic can be controlled. In the case of this example, it was possible to appropriately adjust Bo within a range from the Bo peak value to a value reduced by about 8% by changing the holding time of the magnetized object in the magnetized portion.

  Furthermore, the use of a temperature control device attached to the magnetized portion can solve the problem of thermal demagnetization of a permanent magnet incorporated in a driving device such as a motor. In conventional magnetization at room temperature, when the motor temperature rises, demagnetization is caused by heat and the characteristics change. Therefore, thermal demagnetization is performed in advance so that the characteristics do not change. However, in any case, demagnetization causes a reduction in torque. In the apparatus of the present invention, the temperature adjusting device in the magnetized portion is used to lower the temperature of the magnetized object from the temperature above its Curie point to the motor guaranteed temperature below the Curie point. Meanwhile, the magnetic field for magnetization is continuously applied to the object to be magnetized, but the magnetic field is removed at a temperature equal to or higher than the motor guarantee temperature. For example, when the guaranteed motor temperature is 120 ° C., the temperature is lowered while applying a magnetizing magnetic field to about 140 ° C., and the magnetizing magnetic field is removed to cool to room temperature. By such a magnetizing method, even if the motor temperature rises within the range of the guaranteed motor temperature, thermal demagnetization does not occur and high torque can be obtained.

Explanatory drawing which shows one Example of the magnetizing apparatus which concerns on this invention. The horizontal sectional view which shows an example of the internal structure of a magnetization part. Operation | movement explanatory drawing of this magnetization apparatus. Explanatory drawing which shows the multipolar magnetization state to a ring-shaped permanent magnet. The longitudinal cross-sectional view which shows the other Example of the magnetizing apparatus which concerns on this invention. The longitudinal cross-sectional view which shows further another Example of the magnetizing apparatus which concerns on this invention. The graph which shows the relationship between a magnetization part temperature, Bo (ave), and Bo dispersion | variation. The graph which shows the relationship between magnetized part holding time, Bo (ave), and Bo dispersion | variation.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Heating part 12 Magnetization part 14 Heat insulation member 16 Cooling part 20 Magnetized object 22 Holding member

Claims (9)

The heating part and the magnetized part are disposed in the axial direction as separate structures, and the holding member for the ring-shaped magnetized object is movable relative to the heating part and the magnetized part. is set to a temperature above the Curie point of the magnetization object, magnetized has become a temperature lower than the Curie point of the object to be magnetized was heated to a temperature above the Curie point of the deposited磁物 by the heating unit said deposition磁物is transferred to the magnetizing portion is cooled to a temperature below the Curie point of the deposition磁物, during which magnetizing field by the magnetized portions is multi-pole magnetized continuously applied the A magnetizing device for a multipolar ring-shaped permanent magnet, characterized in that it is configured as described above. The heating part in which the inner surface of the heating space that houses the magnetized material becomes the heating surface and the magnetized part in which the inner surface of the magnetizing space that houses the magnetized material becomes the magnetized surface are combined to hold the magnetized material 2. A multipolar ring-shaped permanent magnet magnetizing apparatus according to claim 1, wherein a rod-shaped holding member is installed so as to pass through the heating section and the magnetizing section and be relatively movable in the axial direction. 3. The multipolar ring-shaped permanent magnet according to claim 1, wherein the heating unit and the magnetized unit are supported so that the mutual positional relationship does not change, and a heat insulating member is interposed therebetween. Magnetic device. The multipolar ring-shaped permanent magnet according to any one of claims 1 to 3, wherein the magnetized portion is provided with a temperature adjusting device capable of setting a temperature above room temperature and below the Curie point of the object to be magnetized. Magnetizing device. The magnetized portion has a structure in which a plurality of magnetizing permanent magnets having a Curie point higher than that of an object to be magnetized are arranged, and the temperature control device does not cause permanent demagnetization of the magnetizing permanent magnet. The multipolar ring-shaped permanent magnet magnetizing apparatus according to claim 4, wherein the temperature is set to an upper limit. The magnetized portion has a structure in which a sintered Nd base magnets are arranged, the temperature regulating device is set to the upper limit temperature of the sintered Nd base magnet magnetizing does not produce a permanent demagnetization The multipolar ring-shaped permanent magnet magnetizing device according to claim 4. The magnetized portion is provided with a magnetized object receiving hole through which a magnetized object that becomes a magnetized space can be inserted / extracted at the center of the nonmagnetic block, and outward from the inner surface of the magnetized object receiving hole. The multipolar ring-shaped permanent magnet magnetizing device according to any one of claims 1 to 6, wherein a plurality of radially extending grooves are provided at equal angles, and a magnetizing permanent magnet is embedded in each groove. . The magnetized portion and the heating portion is arranged vertically, magnetizing apparatus of the multipolar ring-shaped permanent magnet according to any one of claims 1 to 6 axis is vertical arrangement format is vertical. The magnetizing device for a multipolar ring-shaped permanent magnet according to any one of claims 1 to 6, wherein the heating unit and the magnetized unit are arranged side by side and the direction of the axis is horizontal.

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