JPWO2016147985A1 - Manufacturing method of RTB-based sintered magnet, coating device and coating apparatus used in the method - Google Patents

Abstract

Step of applying paste containing powder particles of metal, alloy and / or compound (RH is Dy and / or Tb) of heavy rare earth element RH to the upper surface, lower surface and side surface of each R-T-B system sintered magnet And a step of heat-treating the RTB-based sintered magnet coated with the paste at a temperature lower than the sintering temperature. The step of applying the paste is a coating device including an internal space having an inlet opening and an outlet opening, and the R-T-B system sintered magnet is configured to sequentially pass through the internal space in the lateral direction. The step of sequentially supplying the R-T-B system sintered magnet to the coating device, and the R-T-B system sintering which is filling the internal space of the coating apparatus and moving in the internal space Contacting the paste with the upper surface, the lower surface and the side surface of the magnet.

Description

  The present disclosure relates to a technique for manufacturing an R-T-B based sintered magnet.

R-T-B system sintered magnets whose main phase is an R ₂ T ₁₄ B type compound (R is a rare earth element and T is a transition element that always contains Fe) are known as the most powerful magnets among permanent magnets. It is used for various motors such as a voice coil motor (VCM) of a hard disk drive, a motor for mounting on a hybrid vehicle, and home appliances.

The _RTB -based sintered magnet has an irreversible thermal demagnetization because its intrinsic coercive force H _cJ (hereinafter simply referred to as “H _cJ ”) decreases at a high temperature. In order to avoid irreversible thermal demagnetization, it is required to maintain high H _cJ even at high temperatures when used for motors and the like.

It is known that the RTB-based sintered magnet improves H _cJ when a part of R in the R ₂ T ₁₄ B-type compound is substituted with a heavy rare earth element RH (Dy, Tb). In order to obtain high H _cJ at a high temperature, it is effective to add a large amount of heavy rare earth element RH in the RTB-based sintered magnet. However, when the light rare earth element RL (Nd, Pr) is replaced as R by the heavy rare earth element RH in the RTB-based sintered magnet, H _cJ is improved, while the residual magnetic flux density B _r (hereinafter simply “ There is a problem that “B _r ”) is reduced. Further, since the heavy rare earth element RH is a rare resource, it is required to reduce the amount of use thereof.

In recent years, to improve the H _cJ of the R-T-B based sintered magnets have been studied with less heavy rare-earth element RH so as not to reduce the B _r. For example, as a method for effectively supplying and diffusing a heavy rare earth element RH to an RTB-based sintered magnet, Patent Documents 1 to 4 disclose RH oxides or RH fluorides and various metals M or M alloys. Is mixed with the R-T-B sintered magnet so that RH and M are efficiently absorbed by the R-T-B sintered magnet. A method for increasing H _cJ of a B-based sintered magnet is disclosed.

  Patent Document 1 discloses using a mixed powder of a powder containing M (where M is one or more selected from Al, Cu, and Zn) and an RH fluoride powder. Patent Document 2 discloses RTMAH that becomes a liquid phase at a heat treatment temperature (where M is one or more selected from Al, Cu, Zn, In, Si, P, etc., A is boron or carbon, H Is used, and it is disclosed that a mixed powder of the alloy powder and a powder such as RH fluoride may be used.

  In Patent Document 3 and Patent Document 4, RM alloy (where M is one or more selected from Al, Si, C, P, Ti, etc.) or M1M2 alloy (M1 and M2 are Al, Si, RH oxide is partially reduced by RM alloy or M1M2 alloy during heat treatment by using a mixed powder of RH oxide and one or more powders selected from C, P, Ti, etc. It is disclosed that a large amount of R can be introduced into the magnet.

JP 2007-287874 A JP 2007-287875 A JP 2012-248827 A JP 2012-248828 A

The methods described in Patent Documents 1 to 4 have the following problems with respect to the presence of mixed powder containing RH compound powder on the magnet surface. That is, in these methods, in the specific disclosure, the magnet is dipped in a slurry in which the mixed powder is dispersed in water or an organic solvent and pulled up (immersion pulling method). In that case, hot air drying or natural drying is performed on the magnet pulled up from the slurry. In addition, instead of immersing a magnet in such a slurry, spraying the slurry onto a magnet is disclosed (spray coating method). However, in the immersion pulling method, the slurry is inevitably biased to the lower part of the magnet due to gravity. Further, in the spray coating method, the coating thickness at the end of the magnet increases due to surface tension. In either method, it is difficult to make the RH compound uniformly exist on the magnet surface. As a result, there arises a problem that the H _cJ after the heat treatment varies greatly due to the nonuniform coating thickness.

In the present disclosure, a layer of powder particles containing heavy rare earth element RH is formed on the magnet surface in order to effectively supply and diffuse heavy rare earth element RH to an RTB-based sintered magnet to improve _HcJ. Sometimes, a paste containing these powder particles is uniformly applied to the surface of an R-T-B system sintered magnet, and a new device, apparatus, and method capable of uniformly presenting the heavy rare earth element RH on the surface of the magnet are provided. To do.

  An embodiment of a method for producing an RTB-based sintered magnet according to the present disclosure includes a step of preparing a plurality of RTB-based sintered magnets, and a step of preparing the plurality of RTB-based sintered magnets. Applying a paste containing powder particles of metal, alloy and / or compound (RH is Dy and / or Tb) of heavy rare earth element RH to each of the upper surface, the lower surface and the side surface; and R- Heat treating the TB-based sintered magnet at a temperature equal to or lower than a sintering temperature, and the step of applying the paste is an application device including an internal space having an inlet opening and an outlet opening. R-T-B based sintered magnets sequentially supply the plurality of R-T-B based sintered magnets to a coating device configured to pass through the internal space in the lateral direction. And in the internal space of the coating device Filled with paste, and a step of contacting the paste on the upper surface, a lower surface and side surfaces of the R-T-B based sintered magnet is moving the inner space.

  In one embodiment, when the RTB-based sintered magnet passes through the internal space of the coating device, the inlet opening slidably supports the RTB-based sintered magnet. And it has the shape and magnitude | size which control the motion of the said RTB type sintered magnet in the direction orthogonal to the said horizontal direction.

  In one embodiment, the outlet opening has a shape and a size that define a layer thickness of the paste applied to the RTB-based sintered magnet.

  In one embodiment, the step of sequentially supplying the plurality of RTB-based sintered magnets to the coating device includes the step of inserting each RTB-based sintered magnet into the inlet opening. The rear end surface of the RTB-based sintered magnet, which is partially inserted into the inlet opening, is pushed in the lateral direction by the front end surface of another RTB-based sintered magnet, and the other And inserting the R-T-B system sintered magnet into the inlet opening.

  In one embodiment, the RTB-based sintered magnet is conveyed while pressing gas against at least the lower surface of each RTB-based sintered magnet discharged from the outlet opening of the coating device. Process.

  In one embodiment, the step of separating a plurality of RTB-based sintered magnets discharged from the outlet opening and joined back and forth via the paste into individual RTB-based sintered magnets including.

  In one embodiment, the powder particles include particles of an RLM alloy (RL is Nd and / or Pr, M is one or more elements selected from Cu, Fe, Ga, Co, Ni, and Al), and RH compound. (RH is Dy and / or Tb, and the RH compound is at least one of RH fluoride, RH oxyfluoride, and RH oxide).

  In one embodiment, the RLM alloy includes 50 atomic% or more of RL, and the melting point of the RLM alloy is equal to or lower than the temperature of the heat treatment.

  In one embodiment, a mass ratio of the RLM alloy powder and the RH compound powder in the paste is RLM alloy: RH compound = 9.6: 0.4 to 5: 5.

  Embodiments of the coating device according to the present disclosure include a metal, an alloy and / or a compound (RH is Dy and / or RH) of a heavy rare earth element RH on each of an upper surface, a lower surface and a side surface of a plurality of RTB-based sintered magnets. An application device used in an apparatus for applying a paste containing powder particles of Tb), wherein an internal space filled with the paste and the plurality of RTB-based sintered magnets are sequentially formed in the internal space. An inlet opening and an outlet opening configured to pass laterally, the outlet opening defining a layer thickness of the paste applied to the RTB-based sintered magnet It has a shape and size.

  In one embodiment, the inlet opening slidably supports the RTB-based sintered magnet and the RTB-based sintered magnet in a direction orthogonal to the lateral direction. It has a shape and size that regulates movement.

  In one embodiment, a second internal space filled with a second paste of the same or different type from the paste type, and a plurality of RTB-based sintered magnets discharged from the outlet opening are provided. And a second outlet opening configured to sequentially pass through the second inner space in the lateral direction, and the second outlet opening is the RTB-based sintered magnet. And has a shape and size that define the total layer thickness of the paste applied to the substrate.

  In one embodiment, at least one restricting member that restricts a position of the RTB-based sintered magnet with respect to the outlet opening is provided.

  In one embodiment, an inclination for guiding the RTB-based sintered magnet to the inlet opening is provided around the inlet opening.

  In one embodiment, the outlet opening is tapered so that the paste filled in the internal space presses the RTB-based sintered magnet from the surroundings.

  In one embodiment, the apparatus further comprises a backflow prevention device that suppresses the paste from flowing out from a gap between the RTB-based sintered magnet being inserted into the inlet opening and the inlet opening. The backflow prevention device includes an airtight chamber that pressurizes the inlet opening with a gas supplied from the outside.

  In one embodiment, the internal space has a size of not less than half and not more than three-quarters of the length of each RTB-based sintered magnet in the direction in which the RTB-based sintered magnet passes. have.

  In one embodiment, a plurality of paste introduction holes communicating with the internal space are provided.

  In one embodiment, an inlet-side structure having the inlet opening, an outlet-side structure having the outlet opening and defining the internal space, the inlet-side structure, and the outlet-side structure And an intermediate plate having a magnet passage hole sequentially passing through the plurality of R-T-B sintered magnets, wherein the inlet-side structure has a first groove, A first paste flow path is defined by the groove and the intermediate plate, the outlet side structure has a second groove, and the second paste and the intermediate plate form the second paste. A flow path is defined, the intermediate plate has at least one paste passage hole communicating the first paste flow path and the second paste flow path, and the second paste flow path is A plurality of paste introduction holes communicating with the internal space are formed.

  An embodiment of a coating apparatus according to the present disclosure includes any one of the above coating devices, a paste supply apparatus that fills the internal space of the coating device with the paste, and the plurality of RTB-based sintered magnets. Sequentially, the R-T while pressing a gas against at least the lower surface of each R-T-B system sintered magnet discharged from the outlet opening of the coating device and a magnet supply device to be inserted into the inlet opening -The apparatus which conveys a B type sintered magnet.

  In one embodiment, the magnet supply device has a surface for sequentially sliding the plurality of RTB-based sintered magnets, and each RTB with respect to the inlet opening of the coating device. A positioning mechanism for adjusting the positioning of the sintered system magnet is further provided.

  An embodiment of an applicator device according to the present disclosure is an applicator device used in an apparatus for applying a paste containing powder particles of a metal, an alloy and / or a compound to each of an upper surface, a lower surface and a side surface of a plurality of magnets, An internal space filled with the paste, and an inlet opening and an outlet opening configured such that the plurality of RTB-based sintered magnets sequentially pass through the internal space in a lateral direction; And the outlet opening has a shape and a size that define a layer thickness of the paste applied to the magnet.

According to the embodiment of the present disclosure, in order to improve H _cJ of an R-T-B based sintered magnet, a paste including powder particles including a heavy rare earth element RH is used as a plurality of R-T-B based sintered magnets. It can apply | coat uniformly with respect to this surface simultaneously.

It is a perspective view showing an example of application device 100 used for an example of an application device by this indication, and RTB system sintered magnet 1 with which paste is applied by application device 100. 1 is a front view of a coating device 100 (a side on which a coated magnet is discharged). FIG. It is a rear view (apparatus figure by which the magnet before application | coating is inserted) of the coating device 100. FIG. It is the 2C-2C sectional view taken on the line of FIG. 2A and 2B. It is a front view of the coating device 100 in a state where an RTB-based sintered magnet is inserted (a view on the side where a coated magnet is discharged). It is a rear view (figure of the side by which the magnet before application | coating is inserted) of the application | coating device 100 in the state by which the RTB system sintered magnet was inserted. It is the 3C-3C sectional view taken on the line of FIG. 3A and 3B. The figure which shows a mode that the some R-T-B type sintered magnet 1 is sequentially inserted in the inlet opening part 12 of the coating device 100, passes through the internal space 10, and is discharged | emitted from the outlet opening part 14. FIG. It is. It is a figure which shows typically the RTB type | system | group sintered magnet 1 in the state by which the paste layer 2 was apply | coated. It is a figure which shows typically the example which apply | coats the paste layer 2 to the upper surface 1a and the lower surface 1b of the RTB type | system | group sintered magnet 1 using the conventional nozzle dispenser 24,84. It is a figure which shows typically the other example of a mode that the paste layer 2 is apply | coated to the upper surface 1a and the lower surface 1b of the RTB type sintered magnet 1 using the conventional nozzle dispenser 24,84. It is a figure which shows typically the other example of the RTB type | system | group sintered magnet 1 with which the paste layer 2 was apply | coated using the coating device of this indication. It is a figure which shows the principal part of the coating device by this indication. It is a figure which shows the coating device 100 provided with the additional structure 100c for forming the 2nd interior space 16. FIG. It is a figure which shows typically the example where the RTB system sintered magnet 1 is not fully positioned by the entrance-side structure 100b, and the attitude of the RTB system sintered magnet 1 is not stable. It is a figure which shows the structural example of the coating device 100 in which the some control member 104 is provided in the position of the exit opening part 14. As shown in FIG. FIG. 2 is a cross-sectional view schematically showing a stripe-shaped recess 22 formed in a part of a paste layer 2 covering an RTB-based sintered magnet 1. It is a figure which shows the structural example of the coating device 100 by which the taper 105 was provided in the exit opening part 14. FIG. It is a figure which shows the structure of the coating device 100 which added the backflow prevention apparatus 120 to the front | former part of the entrance side structure 100b. It is a figure which shows the structural example of the magnet supply part in embodiment of the coating device by this indication. It is a figure which shows the structural example of the conveyance part of the coated magnet in embodiment of the coating device by this indication. FIG. 3 is a cross-sectional view illustrating a configuration example of a coarse drying device 50. FIG. 19 is a perspective view of the coarse drying apparatus 50 schematically shown in FIG. 18. It is sectional drawing which shows the other structural example of the rough drying apparatus 50 typically. 6 is a cross-sectional view schematically showing still another configuration example of the coarse drying device 50. FIG. It is a figure which shows the structural example of the coating device 100 which introduce | transduces paste into the internal space 10 from several hole. FIG. 23 is an AA diagram of FIG. 22 in an example in which the number of holes for introducing the paste is two. FIG. 23 is a BB diagram of FIG. 22 in an example in which the number of holes for introducing paste is two. FIG. 23 is a CC diagram of FIG. 22 in an example in which the number of holes for introducing the paste is two. It is the AA diagram of FIG. 22 in the example where the number of the holes which introduce | transduce a paste is four. FIG. 23 is a BB diagram of FIG. 22 in an example in which the number of holes for introducing paste is four. FIG. 23 is a CC diagram of FIG. 22 in an example in which the number of holes for introducing the paste is four. In the coating device by this indication, it is a figure which shows the other example in which the R-T-B type | system | group sintered magnet 1 is not fully positioned. It is a figure which shows the further another structural example of the coating device by this indication. It is a figure which shows the further another structural example of the coating device 100 by this indication. 6 is a cross-sectional view schematically showing still another configuration example of the coarse drying device 50. FIG. It is a cross-sectional photograph of the RTB system sintered magnet which applied the paste in the Example. It is a schematic cross section which shows the area | region of sample AE in the RTB type | system | group sintered magnet of an Example.

<Coating device>
Before describing an embodiment of the present disclosure, a basic configuration example of a coating apparatus according to the present disclosure will be described. A coating apparatus according to a non-limiting example of the present disclosure includes a heavy rare earth element RH (RH is Dy and / or Tb) metal on each of an upper surface, a lower surface, and a side surface of a plurality of RTB-based sintered magnets, An apparatus for applying a paste containing powder particles of an alloy and / or a compound. The coating device described below is used for this apparatus.

  First, an example of a coating device will be described with reference to FIGS. 1, 2A, 2B, and 2C. FIG. 1 shows an example of a coating device 100 as an example and an RTB-based sintered magnet 1 to which a paste is applied by the coating device 100. The RTB-based sintered magnet 1 has an upper surface 1a, a lower surface 1b, a pair of side surfaces 1c, a front end surface 1d, and a rear end surface 1e. FIG. 2A is a front view of the application device 100 (a view on the side where the applied magnet is ejected), and FIG. 2B is a rear view of the application device 100 (a view on the side where the magnet before application is inserted). 2C is a cross-sectional view taken along line 2C-2C of FIGS. 2A and 2B. In FIG. 1, for reference, three arrows indicating orthogonal X-axis, Y-axis, and Z-axis are shown. In other drawings, two of the XYZ axes are shown for reference.

  The coating device 100 in this example includes a heavy rare earth element RH metal, an alloy, and / or an upper surface 1a, a lower surface 1b, and a pair of side surfaces 1c of an RTB-based sintered magnet 1 as shown in FIG. Alternatively, a paste containing powder particles of the compound (RH is Dy and / or Tb) is applied. A detailed description of the paste will be described later. The applied paste forms a layer such as a powder containing heavy rare earth element RH on the magnet surface after the drying step. From this powder layer, heavy rare earth elements RH diffuse into the RTB-based sintered magnet by subsequent heat treatment (diffusion treatment) to improve the magnet characteristics.

  The RTB-based sintered magnet 1 in FIG. 1 has a shape whose upper surface is convexly curved upward, but the RTB-based sintered magnet 1 to which the coating apparatus of the present disclosure can be applied. As long as it has a uniform cross-sectional shape along a specific direction, it can have any shape and size as a whole. In the example of FIG. 1, the RTB-based sintered magnet 1 extends in the Z-axis direction, and a cross section perpendicular to the Z axis (a cross section parallel to the XY plane) is uniform regardless of the position in the Z axis direction. Has shape and size. In this example, the upper surface 1a of the RTB-based sintered magnet 1 is a curved surface, but the upper surface 1a may be a flat surface. A groove or ridge extending in the Z-axis direction may be present on the upper surface 1a. In this example, the lower surface 1b and the side surface 1c of the RTB-based sintered magnet 1 are flat, but the lower surface 1b and / or the side surface 1c may be curved.

  As shown in FIG. 2C, the coating device 100 is configured so that the internal space 10 in which the paste can be filled and the plurality of R-T-B based sintered magnets 1 sequentially pass through the internal space 10 in the lateral direction. A configured inlet opening 12 and outlet opening 14 are provided. In the illustrated example, the coating device 100 has a configuration in which an outlet side structure 100a having an outlet opening 14 and an inlet side structure 100b having an inlet opening 12 are integrated. The configuration is not limited to such an example. A slope 18 may be provided around the inlet opening 12 on the inlet side of the applicator device 100, as shown in FIGS. 2B and 2C. Further, a hole 15 (paste introduction hole) for filling the internal space 10 with the paste communicates.

  Reference is now made to FIGS. 3A, 3B and 3C. 3C is a cross-sectional view taken along line 3C-3C in FIGS. 3A and 3B. These drawings correspond to FIGS. 2A, 2 </ b> B, and 2 </ b> C, and describe a state in which one RTB-based sintered magnet 1 is inserted from the inlet opening 12.

  As shown in FIGS. 3B and 3C, there is no large gap between the inlet opening 12 and the RTB-based sintered magnet 1, but as shown in FIG. 3A, the outlet opening 14 and A gap is provided between the RTB-based sintered magnet 1. A typical size t of this gap is shown in FIG. 3C. The gap size t is typically uniform along the periphery of the outlet opening 14, but the present disclosure is not limited to such examples. The size t of the gap may have a different value on each side of the upper surface 1a, the lower surface 1b, and the side surface 1c of the RTB-based sintered magnet 1.

  The inlet opening 12 of the coating device 100 in this example supports the RTB-based sintered magnet 1 so as to be slidable, and the RTB-based sintered magnet 1 is in the lateral direction (Z-axis direction). It is movable. The inlet opening 12 has a shape and a size that regulate the movement of the RTB-based sintered magnet 1 in a direction (XY in-plane direction) orthogonal to the lateral direction (Z-axis direction). Typically, the shape and size in a cross section perpendicular to the Z axis of the inlet opening 12 can be designed to be approximately equal to the shape and size in a cross section perpendicular to the Z axis of the RTB-based sintered magnet 1. Thus, the inlet opening 12 performs “positioning” of the inserted RTB-based sintered magnet 1 and prevents the paste filled in the internal space 10 from flowing out of the inlet opening 12. Can be designed to. As will be described later, the positioning of the RTB-based sintered magnet 1 with respect to the inlet opening 12 is not limited to this example, and may be performed using another device.

  The outlet opening 14 of the coating device 100 has a shape and a size that define the layer thickness of the paste applied to the RTB-based sintered magnet 1. Typically, the shape and size in the cross section perpendicular to the Z axis of the inlet opening 12 are more applied than the shape and size in the cross section perpendicular to the Z axis of the RTB-based sintered magnet 1. It has a shape and size expanded outward by the thickness of the layer. That is, the thickness of the paste layer is defined by the size t of the gap between the outlet opening 14 and the RTB-based sintered magnet 1. The paste layer contains a liquid component such as a solvent immediately after coating, but the liquid component is reduced by the drying process. For this reason, the thickness of the paste layer can change over time.

  The size of the internal space 10 can be determined to an appropriate value from various viewpoints. The size of the internal space 10 in the Z-axis direction is set to a value smaller than the size of the individual RTB-based sintered magnets 1 in the Z-axis direction. This is because when the tip of the RTB-based sintered magnet 1 protrudes outside from the outlet opening 14, at least a part of the RTB-based sintered magnet 1 is formed as shown in FIG. 3C. This is because it needs to be substantially held by the inlet opening 12. The size of the internal space 10 in the Z-axis direction can be typically set to a half or less of the size of the RTB-based sintered magnet 1 in the Z-axis direction, for example, 0.1 mm to 50 mm. Can be set to a value within the range of. If the size of the internal space 10 in the Z-axis direction is smaller than 0.1 mm, the fluidity of the paste in the internal space 10 is reduced due to the powder particles contained in the paste. Moreover, if this size exceeds 50 mm, the position of the tip of the RTB-based sintered magnet 1 tends to fluctuate. However, when the size of the RTB-based sintered magnet 1 in the Z-axis direction is large, and by additionally providing a configuration that regulates the tip position of the RTB-based sintered magnet 1, It is possible to enlarge the size of the space 10 in the Z-axis direction from 50 mm. The shape of the internal space 10 does not need to be a cube, and may be arbitrary in consideration of the fluidity of the paste 20. The internal space may be roughly disk-shaped or elliptical. The number of holes 15 (paste introduction holes) communicating with the internal space 10 and receiving the paste 20 is not limited to one and may be plural. For example, in FIG. 3C, the paste 20 is introduced into the internal space 10 from one of the holes 15 formed above the outlet-side structure 100a. The paste 20 may be introduced into the internal space 10 from 15. Further, as will be described in a modification of the coating device described later, a paste flow path communicating with the plurality of paste introduction holes is formed in the coating device 100, and the paste 20 is applied from the plurality of paste introduction holes in the coating device 100. You may make it introduce. In the present disclosure, a hole for introducing the paste 20 into the internal space 10 (the opening is referred to as a “paste introduction hole”).

  Reference is now made to FIGS. 4 (a), 4 (b) and 4 (c). 4A, 4 </ b> B, and 4 </ b> C, a plurality of RTB-based sintered magnets 1 are sequentially inserted into the inlet opening 12 of the coating device 100 and pass through the internal space 10. A mode that it discharges | emits from the exit opening part 14 is shown typically. Hereinafter, an example of the coating operation will be described with reference to these drawings.

  First, as shown in FIG. 4A, the RTB-based sintered magnet 1 is prepared and inserted into the inlet opening 12 of the coating device 100. For insertion, a magnet supply device (not shown) is used, and the RTB-based sintered magnet 1 is pushed leftward in the drawing along the arrow direction parallel to the Z axis. At this time, the slope 18 provided on the inlet side of the coating device 100 slides on the tip of the RTB-based sintered magnet 1 and guides it toward the center of the inlet opening 12. The RTB-based sintered magnet 1 passes through the internal space 10 and exits from the outlet opening 14. Even if the RTB-based sintered magnet 1 is inserted into the coating device 100 before the internal space 10 is filled with the paste after the start of the coating process, the coating of the paste is not executed. However, before filling the internal space 10 with the paste, it is preferable to insert at least one RTB-based sintered magnet 1 into the coating device 100 to reduce the opening area of the outlet opening 14.

  Next, the paste 20 is filled into the internal space 10 through a hole 15 of the coating device 100 from a paste supply device (not shown). Appropriate pressure is applied to the paste 20. FIG. 4B schematically shows a state in which the internal space 10 is filled with the paste 20. In the internal space 10, the paste 20 contacts the surface of the RTB-based sintered magnet 1 and covers the surface. By appropriately adjusting the gap size t, the paste pressure, and the moving speed of the RTB-based sintered magnet 1 described above, the amount of the paste 20 that goes out of the gap is controlled, and the appropriate thickness is achieved. An application layer (paste layer 2) of the paste 20 can be formed. The size t of the gap can be set in the range of 0.1 mm to 1 mm, for example. The paste layer 2 is preferably made thicker as the magnet size becomes larger. For example, a paste layer 2 having a thickness of about 200 to 500 μm can be formed on the RTB-based sintered magnet 1 having a thickness of about 6 mm.

  In the example shown in FIG. 4B, the first RTB-based sintered magnet 1 is moved along the arrow direction parallel to the Z-axis by the next RTB-based sintered magnet 1 in the drawing. Pushed to the left. As will be described later, a magnet supply device (not shown) is configured to sequentially supply a plurality of RTB-based sintered magnets 1 to the coating device 100.

  As shown in FIG. 4C, the paste layer 2 is formed on the surface of the RTB-based sintered magnet 1 being discharged from the outlet opening 14 of the coating device 100. The thickness of the paste layer 2 is defined by the size t of the gap from the end face of the outlet opening 14 to the surface of the RTB-based sintered magnet 1. In addition, in the first R-T-B system sintered magnet 1 inserted into the coating device 100 before the paste 20 is filled in the internal space 10, the formation of the paste layer 2 may not be sufficiently realized. In such a case, at least one RTB-based sintered magnet 1 immediately after the start of the coating process functions as a coating dummy.

  Since a plurality of R-T-B-based sintered magnets 1 are provided to the coating device 100 in succession, in a preferred embodiment, two R-T-B-based sintered magnets are moving adjacent to each other in the front-rear direction. No gap is formed between 1. When such a gap is formed, the paste 20 fills the gap, and as a result, the paste layer 2 may be formed on the front end face 1d and the rear end face 1e of the RTB-based sintered magnet 1 as well. There is sex. When a gap is formed between two RTB-based sintered magnets 1, it is difficult to appropriately adjust the size of the gap, so the front end of the RTB-based sintered magnet 1 Large variations are likely to occur in the thickness of the paste layer 2 covering the surface 1d and the rear end surface 1e. Therefore, the R-T-B system sintered magnet 1 is applied from the next to the next so as not to form a gap between the two R-T-B system sintered magnets 1 that are moving adjacently in the front-rear direction. It is preferably inserted into the device 100.

  The RTB-based sintered magnet 1 coming out from the outlet opening 14 of the coating device 100 is in a state in which the paste layer 2 is formed on its four surfaces (1a, 1b, 1c). -It is desirable to avoid supporting or holding the B-based sintered magnet 1 by hand or jig. In the embodiment to be described later, the R-T-B system sintered magnet 1 discharged from the outlet opening 14 of the coating device 100 is pressed against the gas from the lower surface side and floated by the air current while being left in the drawing. It is conveyed to. At the time of this conveyance, at least the surface of the paste layer 2 is dried. An apparatus for pressing a gas against the RTB-based sintered magnet 1 includes, for example, a table configured to eject air from many small holes. Since the RTB-based sintered magnet 1 is floating from the table, the surface of the paste layer 2 is dried in a substantially non-contact state with other objects. As a result, the powder layer included in the paste layer 2 can cover the surface (four surfaces) of the RTB-based sintered magnet 1 with a substantially uniform thickness.

  FIG. 5 schematically shows the RTB-based sintered magnet 1 in a state where the paste layer 2 is applied. FIGS. 5A, 5B, and 5C are respectively a top view, a front view, and 5C of FIG. 5A of the RTB-based sintered magnet 1 to which the paste layer 2 is applied. The -5C sectional view taken on the line is shown typically. As shown in FIG. 5, the upper surface 1 a, the lower surface 1 b, and the two side surfaces 1 c of the RTB-based sintered magnet 1 are covered with the paste layer 2. However, the front end face 1d and the rear end face 1e of the RTB-based sintered magnet 1 in this example are not covered with the paste layer 2.

  In the coating apparatus and the coating method of the present disclosure, the paste layer 2 is formed at once on the other surfaces except the front end surface 1d and the rear end surface 1e of the RTB-based sintered magnet 1, and after drying, a powder layer Can be covered uniformly, so that productivity is high and mass productivity is excellent.

  Next, for comparison, a method in which the R-T-B system sintered magnet 1 is sequentially applied to the front and back surfaces of the R-T-B system sintered magnet using a conventional nozzle dispenser. explain.

  FIG. 6 schematically shows an example in which the paste layer 2 is applied to the upper surface 1a and the lower surface 1b of the RTB-based sintered magnet 1 using conventional nozzle dispensers 24 and 84. In this example, first, with the RTB-based sintered magnet 1 placed on the table 80, the paste is applied to the upper surface 1 a of the RTB-based sintered magnet 1 by the nozzle dispenser 24. A paste layer 2c is formed. After the paste layer 2c is sufficiently dried and handling becomes possible, the RTB-based sintered magnet 1 is turned upside down. Next, the paste is applied to the lower surface 1b of the RTB-based sintered magnet 1 by the nozzle dispenser 84 to form the paste layer 2d. In the example of FIG. 6, the thickness of the paste layer 2c and the thickness of the paste layer 2d are substantially equal.

  FIG. 7 schematically shows another example of applying the paste layer 2 to the upper surface 1a and the lower surface 1b of the RTB-based sintered magnet 1 using conventional nozzle dispensers 24 and 84. . Also in this example, first, with the RTB-based sintered magnet 1 placed on the table 80, the paste is applied to the upper surface 1 a of the RTB-based sintered magnet 1 by the nozzle dispenser 24. A paste layer 2c is formed. However, at this time, it is assumed that the thickness of the paste layer 2c is larger than the design value by Dt. Thereafter, the RTB-based sintered magnet 1 is turned upside down. The level of the height from the table 80 of the lower surface 1b of the RTB-based sintered magnet 1 corresponds to the total value of the thickness of the paste layer 2c and the thickness of the RTB-based sintered magnet 1. Compared to the example of FIG. 6, since the thickness of the paste layer 2 c is larger by Dt, the distance between the lower surface 1 b of the RTB-based sintered magnet 1 and the lower end of the nozzle dispenser 84 is reduced. As a result, when the paste is applied to the lower surface 1b of the RTB-based sintered magnet 1 by the nozzle / dispenser 84 to form the paste layer 2d, the thickness of the paste layer 2d is smaller than the design value by Dt. . Thus, a difference twice as large as Dt occurs between the thickness of the paste layer 2c and the thickness of the paste layer 2d.

  As described above, the method using the conventional nozzle dispenser has a problem that it is difficult to control the thickness of the paste layer 2 formed on the upper surface 1a and the lower surface 1b of the RTB-based sintered magnet 1. is there. Further, when the paste is applied to the upper surface 1a and the lower surface 1b of the RTB-based sintered magnet 1 by the above-described conventional technique, the paste can protrude from the upper surface 1a and the lower surface 1b in the lateral direction (direction perpendicular to the side surface 1c). There is also sex. In such a case, if the paste is applied to both side surfaces 1c of the RTB-based sintered magnet 1, the paste layer tends to be thick in the vicinity of the side of the RTB-based sintered magnet 1. Moreover, when performing application | coating with respect to the side surface 1c of the R-T-B type | system | group sintered magnet 1, if a part of paste has already protruded to the side 1c side, the side surface 1c of the R-T-B type | system | group sintered magnet 1 will be shown. Therefore, it becomes difficult to uniformly form a paste layer having a desired thickness on the side surface 1c of the RTB-based sintered magnet 1.

  As described above, according to the coating device and the coating method of the present disclosure, it is possible to suppress the thickness variation of the paste layer that may occur in the conventional technique. Further, there is no need to invert the RTB-based sintered magnet 1 upside down and there is no need to dry the paste between the inversion steps, and the coating layer is simultaneously applied to the four surfaces of the RTB-based sintered magnet 1. Thus, productivity is improved.

  FIG. 8 schematically shows another example of the RTB-based sintered magnet 1 to which the paste layer 2 is applied using the application device of the present disclosure. The RTB-based sintered magnet 1 in this example has a rectangular parallelepiped shape having a rectangular cross section. FIGS. 8A, 8B, and 8C are a top view, a front view, and 8C of FIG. 8A, respectively, of the RTB-based sintered magnet 1 to which the paste layer 2 is applied. The -8C line sectional drawing is shown typically. The main difference between the RTB-based sintered magnet 1 in FIG. 8 and the RTB-based sintered magnet 1 in FIG. 5 is the cross-sectional shape orthogonal to the major axis direction. In the example of FIG. 5, this cross section is rectangular. As shown in FIG. 8, the upper surface 1 a, the lower surface 1 b, and the two side surfaces 1 c of the RTB-based sintered magnet 1 are covered with the paste layer 2. The shape and size of the inlet opening 12 and the outlet opening 14 of the application device 100 are designed so as to match the shape and size of such a cross section.

  Thus, according to the present disclosure, it is possible to apply a paste around the RTB-based sintered magnet 1 to form a paste layer whose thickness is uniformly adjusted.

<Coating device>
FIG. 9 shows a main part of a coating apparatus including the above-described coating device. The coating apparatus includes a pair of rollers 30a and 30b for sequentially inserting the RTB-based sintered magnet 1 into the coating device 100, and the RTB-based sintered magnet 1 into the rollers 30a and 30b. And a paste filling device 102 for supplying the paste 20 to the coating device 100. The pair of rollers 30a and 30b move the left and right directions in the drawing while pressing each of the plurality of RTB-based sintered magnets 1 from the upper and lower surfaces. The roller 30a, 30b may be configured to press each of the RTB-based sintered magnets 1 from the side. A plurality of RTB-based sintered magnets 1 can be supplied to the coating device 100 without gaps by the action of the rollers 30a and 30b.

  The coating apparatus further includes a coarse drying apparatus 50 that can perform a drying process while conveying the paste-coated RTB-based sintered magnet 1 that has come out of the coating device 100. The illustrated rough drying apparatus 50 presses air (gas) to at least the lower surface side of each R-T-B type sintered magnet 1 discharged from the coating device 100, thereby causing R-T-B type firing. The magnetized magnet 1 is slightly suspended from the coarse drying device 50 and conveyed. The RTB-based sintered magnet 1 is pushed by the subsequent RTB-based sintered magnet 1 and conveyed one after another. Furthermore, the upper surface of the coarse drying device 50 may be inclined. Depending on the magnet shape, the suspended RTB-based sintered magnet 1 can move in the downward direction of the inclined surface by its own weight.

  The coarse drying device 50 has an upper surface on which a large number of holes for blowing air are formed. The size of each hole can be, for example, a circle with a diameter of 2 mm. The air is typically dry air, but may be other types of gases such as nitrogen gas. A porous intermediate plate in which smaller holes are formed may be used. Moreover, what kind of shape may be sufficient as a hole, for example, may be slit shape like the below-mentioned structural example.

  Another configuration example of the coarse drying device 50 will be described later.

<Other configuration examples of coating device>
The coating device 100 in such a coating apparatus is not limited to what has the structure shown by FIG. 9, You may have another structure. For example, as shown in FIG. 10, an RTB-based sintered magnet 1 sequentially passes through a plurality of internal spaces each filled with a different type of paste, and the two paste layers are transferred to RT. A coating device 100 configured to be formed on the B-based sintered magnet 1 may be used.

  The coating device 100 of FIG. 10 includes an additional structure 100 c for forming the second internal space 16. The additional structure 100c covers a region including the outlet opening 14 in the outlet side structure 100a and defines the second internal space 16 together with the outlet side structure 100a. The outlet opening 17 of the additional structure 100c is larger than the outlet opening 14 in the outlet side structure 100a and is designed to define the total thickness of the two layers of paste formed by application.

  According to such a coating device, the first internal space 10 is filled with the first paste 20a, and the second internal space 16 is filled with the second paste 20b. When the RTB-based sintered magnet 1 passes through the first internal space 10, the paste 20a is applied to the surface of the RTB-based sintered magnet 1 to form the first paste layer 2a. The Thereafter, when the RTB-based sintered magnet 1 passes through the second internal space 16, the upper paste 20b of the first paste layer 2a is applied to form the second paste layer 2b.

  Furthermore, it is also possible to laminate three or more paste layers by arranging other additional structures.

  The 1st paste layer 2a and the 2nd paste layer 2b may be formed from the same material, and may be formed from a different material. In an embodiment to be described later, a paste containing powder particles formed from different materials is applied to the RTB-based sintered magnet 1. When the coating device 100 of FIG. 10 is used, the paste containing the RLM alloy powder is disposed at a position close to the surface of the R-T-B system sintered magnet 1, and from the surface of the R-T-B system sintered magnet 1. The paste containing the RH compound powder can be easily arranged at a distant position.

  FIG. 11 schematically shows an example in which the RTB-based sintered magnet 1 is not sufficiently positioned by the entrance-side structure 100b and the attitude of the RTB-based sintered magnet 1 is not stable. ing. In this example, the RTB-based sintered magnet 1 is inclined in the internal space 10. For this reason, the position of the RTB-based sintered magnet 1 with respect to the outlet opening 14 is shifted, and the thickness of the paste layer 2 deviates from the design value and becomes non-uniform.

  FIG. 12 is a diagram showing an improved example for preventing the above-described misalignment. In the coating device 100 of FIG. 12, a plurality of regulating members 104 are provided at the position of the outlet opening 14. Each of these restricting members 104 protrudes from the periphery of the outlet opening 14 toward the center, and the tip of the restricting member 104 restricts the position of the RTB-based sintered magnet 1. The regulating member 104 can partially slide on the surface of the RTB-based sintered magnet 1 and slide relative to the RTB-based sintered magnet 1. For this reason, the space | interval of the surface of the R-T-B type | system | group sintered magnet 1 and the periphery of the exit opening part 14 is maintained uniformly, and the thickness of the paste layer 2 does not remove | deviate greatly from a design value.

  FIG. 13 schematically shows a stripe-shaped recess 22 formed in a part of the paste layer 2 covering the RTB-based sintered magnet 1. The recess 22 of the paste layer 2 is a portion where the paste is not applied due to the presence of the regulating member 104. However, as shown in FIG. 13, after the RTB-based sintered magnet 1 is discharged from the coating device 100, the paste layer 2 before drying contains a liquid component and thus spreads quickly due to surface tension. . As a result, the recess 22 of the paste layer 2 disappears or is reduced to a negligible size. Since it is preferable to narrow the width of the recess 22, the width of each regulating member 104 can be set to a size of about 0.2 to 1 mm, for example.

  When the regulating member 104 slides on the surface of the RTB-based sintered magnet 1, there is a possibility that a small scratch or a shallow groove is formed on the surface of the RTB-based sintered magnet 1. However, since the surface of the RTB-based sintered magnet 1 is finally processed by polishing or the like, the formation of small scratches and shallow grooves does not adversely affect the final magnet characteristics.

  The regulating member 104 is not necessarily provided at the periphery of the outlet opening 14 and may be provided at another position on the outlet side structure 100a.

  FIG. 14 shows a configuration example in which the outlet opening 14 is provided with a taper 105. When such a taper 105 exists, a force is generated that presses the tip of the RTB-based sintered magnet 1 substantially uniformly from the periphery when the paste flows toward the outlet opening 17. Therefore, even if the RTB-based sintered magnet 1 is inclined in the internal space 10, the paste pushed by the taper corrects the position of the RTB-based sintered magnet 1 within an appropriate range. To do.

  FIG. 15 shows a configuration in which a backflow prevention device 120 is added to the front stage portion of the inlet side structure 100b. The backflow prevention device 120 has an airtight chamber 122 that applies the pressure of compressed air to the inlet opening 12 of the inlet-side structure 100b. Specifically, the backflow prevention device 120 caps the inlet opening 12 of the inlet side structure 100b, and externally enters a gap (airtight chamber) formed between the backflow prevention device 120 and the inlet side structure 100b. It is configured to accept air. The backflow prevention device 120 has an opening 19 through which the RTB-based sintered magnet 1 passes. If the pressure of the air is too high, air may enter the internal space 10 filled with the paste 20, but through an air gap that exists between the opening 19 and the RTB-based sintered magnet 1. Since air leaks to the outside, it is possible to prevent the air pressure from becoming too high.

<Configuration example of coating apparatus>
With reference to FIG. 16, the structural example of a coating device is demonstrated.

  The illustrated coating apparatus includes any of the above-described coating devices. This coating apparatus includes a pair of rollers 30a and 30b for sequentially inserting the RTB-based sintered magnet 1 into the coating device 100, and the RTB-based sintered magnet into the rollers 30a and 30b. 1 is provided. The conveyor device 64 includes rollers 64a and 64b and a conveyor belt 64c.

  Further, this coating apparatus includes a stocker 60 on which a large number of RTB-based sintered magnets 1 can be mounted. The RTB-based sintered magnet 1 mounted on the stocker 60 is pushed out onto the conveyor device 64 by the input cylinder 62. The stocker 60 and the input cylinder 62 constitute a loader. The RTB-based sintered magnet 1 placed on the conveyor belt 64c moves toward the coating device 100 together with the conveyor belt 64c rotated by the rotation of the rollers 64a and 64b. The RTB-based sintered magnet 1 sandwiched between the pair of rollers 30a and 30b is sequentially inserted into the coating device 100 and subjected to the coating process. The rollers 30 a and 30 b can sandwich the individual RTB-based sintered magnet 1 from above and below and can be reliably inserted into the inlet opening 12 of the coating device 100. The loader unit continues to supply the RTB-based sintered magnet 1 onto the conveyor device 64 so that the supply of the RTB-based sintered magnet 1 to the coating device 100 is not interrupted.

  Reference is now made to FIG. As shown in FIG. 17, the RTB-based sintered magnet 1 discharged from the coating device 100 moves while floating on the upper surface of the coarse drying device 50 by the jetted air. During the movement, rough drying is performed on the paste layer 2, and at least the surface of the paste layer 2 is dried. The temperature of the blown-out air can be typically room temperature, but the temperature of the blown-out air may be higher than the room temperature in order to promote rough drying. Thereafter, the RTB-based sintered magnet 1 moves to the main drying device 70, where it waits for a necessary time and advances the drying of the paste layer 2. The main drying device 70 includes rollers 70a and 70b, a conveyor belt 70c, and a pressing roller 70d. The coarse drying device 50 and / or the main drying device 70 may be disposed in a drying chamber (not shown).

  The R-T-B type sintered magnet 1 in which the paste layer 2 is sufficiently dried is paired with a plurality of R-T-B type sintered magnets 1 in a continuous state waiting on the drying apparatus 70. Are individually cut by the pinch rollers 72, and then discharged from the coating device by the discharge chute 74. The tangential speed of the pinch roller 72, that is, the rotational peripheral speed defines the moving speed of the R-T-B system sintered magnet 1 sandwiched between the pinch rollers 72. This moving speed is set higher than the moving speed of the conveyor belt 70c of the main drying apparatus 70. The RT roller sandwiched by the pinch rollers 72 from a plurality of RTB-based sintered magnets 1 in a continuous state waiting on the drying device 70 by the action of the pressing roller 70d of the drying device 70. The B-based sintered magnet 1 can be separated.

<Configuration example of coarse drying device>
First, referring to FIG. FIG. 18 schematically shows a cross section perpendicular to the Z-axis direction of the coarse drying apparatus.

  According to the embodiment of the present disclosure, the RTB-based sintered magnet 1 is discharged from the coating device 100 in a state where the periphery of the RTB-based sintered magnet 1 is covered with the paste layer 2. Since the paste layer 2 immediately after discharge is not dried, the thickness of the paste layer 2 is determined when the RTB-based sintered magnet 1 is placed on the conveyor belt as it is or is held by a human hand or a jig. May change locally or a part of the paste layer 2 may be peeled off. The rough drying apparatus 50 shown in FIG. 18 includes a plurality of holes (slit-like openings) 52a and 52b for blowing out air, an opening 54 for receiving supply of air, and a slit for letting excess air escape to the outside. Shaped opening 56.

  The hole 52a is configured to blow out air so as to lift the RTB-based sintered magnet 1 against gravity. The width of the hole 52a in this embodiment may be 1 mm, for example. The hole 52b is configured to blow out air for adjusting the position of the RTB-based sintered magnet 1 that is lifted by air and floats near the center from the side toward the center. The width of the hole 52b in the present embodiment may be a value within a range of 0.5 to 3 mm, for example. Since the position of the hole 52b in the width and height directions can form an airflow flowing on the upper surface or the lower surface of the RTB-based sintered magnet 1, the posture of the RTB-based sintered magnet 1 can be stabilized. It can be adjusted appropriately to keep. The width of the slit-shaped opening 56 for allowing air to escape to the outside can be set within a range of 1 mm to 10 mm, for example.

  FIG. 19 is a perspective view of the coarse drying apparatus 50 schematically shown in FIG. Since the air ejected from the slit-shaped holes 52 a and 52 b flows toward the slit-shaped opening 56, the RTB-based sintered magnet 1 that floats on the coarse drying device 50 has the side wall of the coarse drying device 50. Without being collided with, it is pushed by the subsequent RTB-based sintered magnet 1 and moves along the Z-axis direction. As described above, the upper surface of the coarse drying device 50 may be inclined with respect to the horizontal plane.

  The shape, size, and number of the holes 52a, 52b are not limited to the examples shown in FIGS. The holes 52a and 52b do not need to have a slit shape. The shape, size, and number of the openings 56 are not limited to the examples shown in FIGS.

  If the opening 56 is not provided, the air ejected from the holes 52a and 52b flows upward from one side surface of the R-T-B system sintered magnet 1, and the R-T-B system sintered magnet 1 is passed through. You may not be able to keep it level. For this reason, it is preferable to provide the opening part 56 which escapes the air which ejected from hole 52a, 52b out of an apparatus.

  Even if another configuration is adopted instead of providing such an opening portion 56, the posture of the RTB-based sintered magnet 1 can be stabilized.

  FIG. 20 is a cross-sectional view schematically showing another configuration example of the coarse drying device 50. The upper surface of the coarse drying device 50 in this example (the surface facing the RTB-based sintered magnet 1) is inclined by about 0.5 to 3 degrees with respect to the horizontal direction, for example. That is, the normal to the upper surface of the coarse drying device 50 is slightly rotated from the Y-axis direction toward the X-axis direction in the XY plane. Due to such an inclination, the floating RTB-based sintered magnet 1 receives a force in the X-axis direction in the figure. This force balances with the force of the air blown out from the hole 52b. Thus, the position of the floating RTB-based sintered magnet 1 in the X-axis direction is stabilized, and the RTB-based sintered magnet 1 The posture is also adjusted appropriately.

  FIG. 21 is a cross-sectional view schematically showing still another configuration example of the coarse drying apparatus 50. The upper surface of the coarse drying device 50 in this example (the surface facing the RTB-based sintered magnet 1) is curved so that the center is recessed. That is, due to such bending, the floating RTB-based sintered magnet 1 receives a force toward the vicinity of the center. In this way, the position of the floating RTB-based sintered magnet 1 in the X-axis direction is stabilized, and the attitude of the RTB-based sintered magnet 1 is also adjusted appropriately.

<Modification example of coating device>
FIG. 22 is a diagram illustrating a configuration example of the coating device 100 that introduces paste into the internal space 10 from a plurality of holes formed in the coating device 100. FIG. 23A is an AA diagram of FIG. 22 in an example in which the number of holes for introducing paste is two. Similarly, FIG. 23B and FIG. 23C are the BB diagram and CC diagram of FIG. 22 in the example in which the number of holes for introducing the paste is two, respectively.

  The coating device of FIG. 22 includes an inlet-side structure 100b having an inlet opening 12, an outlet-side structure 100a having an outlet opening 14 and defining an internal space 10, an inlet-side structure 100b, and an outlet-side structure. 100b, and an intermediate plate 130 having a magnet passage hole 134 through which a plurality of RTB-based sintered magnets pass sequentially. The intermediate plate 130 has paste passage holes 132a and 132b through which the paste passes.

  The entrance-side structure 100b shown in FIG. 23A has a first groove 140 formed from a recess opened on the side in contact with the intermediate plate 130. In the example of the figure, the first groove 140 extends along the plane parallel to the XY plane from the position of the hole 15 ′ for introducing the paste into the coating device 100 from the outside, and is branched into two in the middle. The branch portion of the first groove 140 extends on both sides of the inlet opening 12 in a direction parallel to the Y-axis direction. The depth of the first groove 140 (the depth of the recess) is smaller than the thickness of the entrance-side structure 100b. A space sandwiched between the first groove 140 and the intermediate plate 130 defines the first paste flow path 145.

The outlet-side structure 100a shown in FIG. 23C has a second groove 150 formed from a recess opened on the side in contact with the intermediate plate 130, and is a space sandwiched between the second groove 150 and the intermediate plate 130. Defines the second paste flow path 155. The channel cross sections of the first and second paste channels 145 and 155 are, for example, about 1 to 400 mm ² .

  The intermediate plate 130 shown in FIG. 23B has two paste passage holes 132a and 132b that allow the first paste flow path 145 and the second paste flow path 155 to communicate with each other. The number of paste passage holes provided in the intermediate plate 130 is not limited to two, and may be a single number, but is preferably a plurality.

  The second paste flow path 155 communicates with the internal space 10 through holes (paste introduction holes) 15a and 15b provided at a plurality of different positions.

  The paste introduced from the hole 15 ′ of the entrance-side structure 100 b shown in FIG. 23A flows through the first paste flow path 145 and fills the inside of the first paste flow path 145. The paste filling the inside of the first paste channel 145 passes through the paste passage holes 132a and 132b of the intermediate plate 130 shown in FIG. 23B, and the second paste channel of the outlet side structure 100a shown in FIG. 23C. Into 155. The paste that has flowed into the second paste flow path 155 is introduced into the internal space 10 through each of the plurality of paste introduction holes 15a and 15b. The paste introduction hole has a diameter of 1 to 20 mm, for example.

  FIG. 24A is an AA diagram of FIG. 22 in an example in which the number of holes for introducing paste is four. Similarly, FIG. 24B and FIG. 24C are the BB diagram and CC diagram of FIG. 22 in the example where the number of holes for introducing the paste is four, respectively.

  The entrance side structure 100b in FIG. 24A and the intermediate plate 130 in FIG. 24B have structures similar to the structures of the entrance side structure 100b in FIG. 23A and the intermediate plate 130 in FIG. 23B, respectively. The difference is in the structure of the outlet side structure 100a shown in FIG. 24C. The outlet side structure 100a of FIG. 24C also has the second groove 150, and the second paste flow path 155 is defined by the space between the intermediate plate 130 and the second groove 150. A characteristic point of this example is that the paste flowing into the second paste flow path 155 is introduced into the internal space 10 through each of the four paste introduction holes 15a, 15b, 15c, and 15d. In the point. If the number of holes 1 for introducing paste into the internal space 10 increases, the influence is dispersed even if the paste supply amount fluctuates. As a result, variation in the thickness of the paste layer formed by application can be reduced.

  22 to 24C, the paste 20 is introduced from the outside through one place of the hole 15 'formed above the entrance side structure 100a, but the same is applied to the lower side and the side surface of the entrance side structure 100a. A hole 15 ′ may be formed, and the paste 20 may be introduced into the coating device 100 from the plurality of holes 15 ′.

<Modification example of coating device>
As shown in FIG. 25, when the relative height of the conveyor device 64 with respect to the coating device 100 becomes higher or lower than the reference level, the RTB-based baking with respect to the inlet opening 12 of the coating device 100 is performed. It may happen that the position and the approach angle of the magnetized magnet 1 are shifted. When the RTB-based sintered magnet 1 is supplied from the inlet opening 12 into the coating device 100, the clearance between the RTB-based sintered magnet 1 and the inlet opening 12 is large. Deviations in position and entry angle tend to be large. When such a deviation occurs, the thickness of the applied best layer 2 becomes non-uniform as shown in FIG. The accuracy of the position of the inlet opening 12 and the accuracy of the approach angle affect the accuracy of the thickness of the paste layer 2 as it is, so high accuracy is required. The influence of the position of the inlet opening 12 and the deviation of the approach angle is significant when the RTB-based sintered magnet 1 has a shape extending long in the long axis direction.

  FIG. 26 is a diagram illustrating a configuration example of a coating apparatus including a reference block 35 that functions as a positioning mechanism in order to suppress such positional deviation. The positioning reference block 35 has an upper surface (sliding surface) for restricting the vertical movement (Y direction) of the RTB-based sintered magnet 1 sent from the conveyor device 64. The positioning reference block 35 has an accuracy of height and angle, for example, by machining, and enters the entrance opening 12 by pressing the RTB-based sintered magnet 1 on the positioning reference block 35 with a roller. The position and the approach angle of the R-T-B system sintered magnet 1 are regulated with high accuracy. Further, in addition to the positioning block 35, a further positioning block and a roller for restricting the movement in the left and right direction (X direction) with respect to the traveling direction of the RTB-based sintered magnet 1 may be provided. The positioning reference block for regulating the movement in the vertical direction (Y direction) and the positioning block for regulating the movement in the horizontal direction (X direction) may be integrated. That is, a positioning block for restricting movement in the XY directions and a roller corresponding to each direction may be provided.

  The RTB-based sintered magnet 1 moves horizontally with high accuracy and high entrance angle into the inlet opening 12 of the coating device 100 while being lightly pressed against the upper surface of the positioning reference block 35 by a roller. . The vertical position of the upper surface of the positioning reference block 35 can be adjusted according to the vertical position of the inlet opening 12 in the coating device 1. Further, the position in the left-right direction of the positioning block for restricting the movement in the left-right direction (X direction) (not shown) can be adjusted in accordance with the position in the left-right direction of the inlet opening 12 of the coating device 1. In the example of FIG. 26, the upper surface of the positioning reference block 35 is horizontal, but when the application device 100 itself is inclined for some purpose, the upper surface of the reference block 35 is inclined in accordance with the inclination of the application device 100. Thus, the approach angle can be adjusted to the inclination angle of the coating device 100.

  FIG. 27 is a diagram illustrating still another configuration example of the coating device 100 according to the present disclosure. In this coating device 100, the internal space 10 defined by the outlet side structure 100 a has each RTB-based sintering in the direction (Z-axis direction) through which the RTB-based sintered magnet 1 passes. The size of the magnet 1 is not less than half and not more than three quarters of the length. For example, the size of the internal space 10 in the Z-axis direction is set to 2 mm or more, and is typically in the range of 4 to 90 mm.

  In the example of FIG. 27, the tip of the RTB-based sintered magnet 1 is temporarily completely buried in the paste, and a state of floating in the paste is formed. Then, as the gap in the internal space becomes narrower, a larger dynamic pressure is applied, thereby realizing centering. The internal space 10 in FIG. 27 is dimensioned to realize temporary floating in the paste of each R-T-B type sintered magnet 1 in this way (more than half of the dimension of the R-T-B type sintered magnet 1). have. When the entire RTB-based sintered magnet 1 is completely floated in the paste, the centering effect due to the taper 105 is difficult to be exhibited. 3/4 or less of the dimension of the magnet 1 is preferable. That is, when the tip of the RTB-based sintered magnet 1 is in the internal space 10, the rear end of the RTB-based sintered magnet 1 is preferably outside the internal space 10. In addition, the R-T-B-based sintered magnet 1 is appropriately sized by the sufficiently long taper 105 so that the tip of the floating R-T-B-based sintered magnet 1 does not settle in the paste. It is preferable to form the following dynamic pressure. The size of the taper 105 in the Z-axis direction is set to one-twentieth or more of the size of the internal space 10 in the Z-axis direction, preferably one third or more of the size of the internal space 10 in the Z-axis direction, more than half. Further preferred. The internal space 10 may have the same size as that in the Z-axis direction, that is, the entire internal space 10 may be tapered.

  FIG. 28 is a cross-sectional view schematically showing still another configuration example of the coarse drying apparatus 50. The coarse drying device 50 in this example has a concave shape with a shorter curvature radius than the example of FIG. 21, and the curved surface of the bow-shaped RTB-based sintered magnet 1 faces downward. Rough drying in the state of facing. The radius of curvature of the curved surface of the RTB-based sintered magnet 1 and the radius of curvature of the concave portion of the coarse drying device 50 do not need to match. The important point is that the gap between the curved surface of the RTB-based sintered magnet 1 and the recess of the coarse drying device 50 is relatively shortened at the end 55a. By shortening such a gap, air is prevented from coming out from both sides of the R-T-B system sintered magnet, and appropriate conveyance is realized.

  Hereinafter, a preferred embodiment of the present disclosure will be described in detail.

[RTB-based sintered magnet base material]
First, in the present disclosure, an RTB-based sintered magnet base material is prepared as an object of diffusion of the heavy rare earth element RH. In the present specification, for the sake of easy understanding, an RTB-based sintered magnet that is a target of diffusion of the heavy rare earth element RH may be strictly referred to as an RTB-based sintered magnet base material. The term “R-T-B system sintered magnet” includes such “R-T-B system sintered magnet base material”. As this RTB-based sintered magnet base material, a known material can be used, for example, having the following composition.
Rare earth element R: 12-17 atom%
B (a part of B (boron) may be substituted with C (carbon)): 5 to 8 atomic%
Additive element M ′ (selected from the group consisting of Al, Ti, V, Cr, Mn, Ni, Cu, Zn, Ga, Zr, Nb, Mo, Ag, In, Sn, Hf, Ta, W, Pb, and Bi At least one): 0 to 2 atomic%
T (which is a transition metal element mainly containing Fe and may contain Co) and inevitable impurities: the balance Here, the rare earth element R is mainly a light rare earth element RL (Nd and / or Pr), It may contain rare earth elements. In addition, when a heavy rare earth element is contained, it is preferable to include at least one of heavy rare earth elements RH (Dy and / or Tb).

  The RTB-based sintered magnet base material having the above composition is manufactured by an arbitrary manufacturing method.

[paste]
The paste contains a diffusion agent or a mixture of a diffusion agent and a diffusion aid.

  The diffusing agent may typically be a powder of an RH compound (RH is Dy and / or Tb, RH compound is RH fluoride and / or RH oxyfluoride). In a preferred embodiment, the RH compound powder is equal to or less in mass ratio than the RLM alloy powder that functions as a diffusion aid described below. In order to uniformly apply the RH compound powder, the particle size of the RH compound powder is preferably small. According to the study by the present inventor, the particle size of the RH compound powder is preferably 20 μm or less, more preferably 10 μm or less, in the size of the aggregated secondary particles. Small particles are about several μm (1 μm or more) in primary particles.

The diffusion aid may typically be an RLM alloy powder. Here, a light rare earth element having a high effect of reducing the RH compound is suitable as RL, and RL is Nd and / or Pr. M is at least one selected from Cu, Fe, Ga, Co, Ni, and Al. When an Nd—Cu alloy or an Nd—Al alloy is used as the material for the diffusion aid, the ability to reduce the RH compound by Nd is effectively exhibited, and the effect of improving H _cJ is higher. In some embodiments, the RLM alloy contains 50 atomic% or more of RL, and its melting point is not higher than the heat treatment temperature. The particle size of the RLM alloy powder is preferably 150 μm or less, and more preferably 100 μm or less. If the particle size of the RLM alloy powder is too small, it is easy to oxidize. From the viewpoint of preventing oxidation, the lower limit of the particle size of the RLM alloy powder is about 5 μm. A typical example of the particle size of the RLM alloy powder is 20 to 100 μm.

An RLM alloy having an RL content of 50 atomic% or more has a high ability of RL to reduce the RH compound, and has a melting point equal to or lower than the heat treatment temperature. For this reason, it melts at the time of heat treatment and efficiently reduces the RH compound, and the RH reduced at a higher rate diffuses into the R-T-B system sintered magnet base material and efficiently even in a small amount. _HcJ of the system sintered magnet can be improved. In some embodiments, the RLM alloy contains 65 atomic percent or more of RL.

The paste can be prepared by mixing the above-described RH compound powder and RLM alloy powder with a binder, water, and / or a solvent. The solvent can be an organic solvent, for example. Since the coating amount of the RLM alloy powder is not directly _{related to} the degree of improvement in _HcJ, there is no problem even if it varies slightly due to gravity or surface tension. Note that the binder and the solvent can be removed from the surface of the R-T-B system sintered magnet by thermal decomposition or evaporation at a temperature lower than the melting point of the RLM alloy in the subsequent heating process. Well, the type is not particularly limited.

  According to the embodiment of the present disclosure, the paste applied to the surface of the RTB-based sintered magnet base material is uniformly shrunk from application to drying, and the uniformity of the shape of the application layer It is required to keep. When the weight ratio of the binder or the powder is increased, the viscosity of the paste increases, so that the ability to maintain the shape of the coating layer is improved. In addition, when a low boiling point solvent (ethanol or water) is included in the paste, the time required for drying is shortened, so that the shape of the coating layer is easily maintained.

[Paste application]
The above-mentioned paste is applied to the RTB-based sintered magnet base material using the above-described coating apparatus.

  By the coating process, the powder of the RH compound that is the diffusing agent is arranged on the magnet surface together with the RLM alloy powder that is the diffusion aid. At this time, a first paste layer containing RLM alloy powder particles is applied to the magnet surface to form a first paste layer, and then a second paste containing an RH compound is applied onto the first layer. A layer may be formed.

  Since the melting point of the RLM alloy contained in the paste is equal to or lower than the heat treatment temperature, the RH that is melted during the heat treatment and reduced with high efficiency is easily diffused into the RTB-based sintered magnet. become. Therefore, before the RLM alloy powder and the RH compound powder are present on the surface of the RTB-based sintered magnet, the surface of the RTB-based sintered magnet is specially cleaned such as pickling. There is no need to perform the conversion process. Of course, it does not exclude performing such a cleaning process.

  The abundance ratio (before heat treatment) of the RH compound contained in the paste layer on the surface of the RTB-based sintered magnet base material is RLM alloy: RH compound = 9.6: 0.4 to 5: 5 A more preferable abundance ratio is RLM alloy: RH compound = 9.5: 0.5 to 6: 4.

  In the present disclosure, a paste containing a powder (third powder) other than the powder of the RLM alloy and the RH compound is applied, and the third powder is applied to the surface of the RTB-based sintered magnet base material. Although not necessarily excluded, it should be noted that the third powder does not hinder the diffusion of RH in the RH compound into the RTB-based sintered magnet base material. The mass ratio of the “RLM alloy and RH compound” powder in the entire powder existing on the surface of the RTB-based sintered magnet base material is desirably 70% or more.

According to the present disclosure, it is possible to efficiently improve H _cJ of an _RTB -based sintered magnet with a small amount of RH. The amount of RH to be present on the surface of the RTB-based sintered magnet is preferably 0.03 to 0.35 mg, more preferably 0.05 to 0.25 mg, per 1 mm ² of the magnet surface. .

[Diffusion heat treatment]
In the present disclosure, heat treatment is performed in a state in which the powder of the RLM alloy and the powder of the RH compound contained in the paste are present on the surface of the RTB-based sintered magnet base material. Since the RLM alloy powder melts after the start of the heat treatment, it is not necessary for the RLM alloy to always maintain a “powder” state during the heat treatment. The atmosphere for the heat treatment is preferably a vacuum or an inert gas atmosphere. The heat treatment temperature is not higher than the sintering temperature of the RTB-based sintered magnet (specifically, for example, 1000 ° C. or lower) and higher than the melting point of the RLM alloy. The heat treatment time is, for example, 10 minutes to 72 hours. Moreover, you may perform the heat processing for 10 minutes-72 hours at 400-700 degreeC further as needed after the said heat processing.

  In addition, the coating device by embodiment of this indication is not necessarily limited to the example of the RTB system sintered magnet base material mentioned above. The coating device of the present disclosure can be used in a method of diffusing a desired element in a magnet base material by forming a powder paste layer on the surface of various magnet base materials.

  The paste was applied to the RTB-based sintered magnet base material by the apparatus and method having the application device shown in FIG.

The RTB-based sintered magnet base material used has a shape as shown in FIG. 1 and has a size of 28.4 mm in the X direction, 6.88 mm in the Y direction, 32.3 mm in the Z direction, R30.2 mm. The composition of the RTB-based sintered magnet base material is as follows: Nd = 13.4, B = 5.8, Al = 0.5, Cu = 0.1, Co = 1.1, balance = Fe (atom a%), was measured the magnetic properties by B-H tracer, H _cJ is 1035kA / m, B _r was 1.45 T.

The paste used was composed of a diffusing agent (commercially available TbF ₃ (at. Ratio) powder having a particle size of 10 μm or less) and a diffusion aid (spherical Nd ₇₀ Cu ₃₀ (at. Ratio) produced by the centrifugal atomization method and having a particle size of 100 μm or less. ) Powder) mixed at a mass ratio of 8: 2 was 80% by mass of mixed powder, 4% by mass of polyvinyl alcohol, and 16% by mass of water.

  In this way, four surfaces of the RTB-based sintered magnet base material were coated with the coating amounts shown in Table 1, and the drying process was performed. Samples 1 to 3 were produced. The time required for the coating process for one RTB-based sintered magnet base material was about 0.3 seconds.

  29A shows the sample No. after the drying step. 2 shows a cross section. As can be seen from FIG. 29A, paste layers having a substantially uniform thickness were formed on the four surfaces.

  Thereafter, heat treatment for diffusion was performed. Each surface of the obtained R-T-B system sintered magnet was removed by machining by 0.2 mm. A to E5 types of measurement samples were cut out as follows for each of 1 to 3. Sample A: 6.28 mm × 7.0 mm × 7.0 mm of the magnet center portion, Sample B: 1.0 mm × 1.0 mm × 1.0 mm of the surface portion of the magnet bottom center portion in the X-axis direction, Sample C: Magnet top surface 1.0 mm × 1.0 mm × 1.0 mm of the surface portion of the central portion in the X-axis direction (samples B and C are near the center in the Z-axis direction, near the portion where sample A was cut out), samples D and E: both sides of the magnet 1.0 mm × 1.0 mm × 1.0 mm of the surface portion of the center in the Y-axis direction and the Z-axis direction center of the surface Regions of samples A to E in the RTB-based sintered magnet are shown in the schematic cross-sectional view of FIG. 29B.

The magnetic characteristics of the sample A~E measured by B-H tracer, for Sample A the variation of H _cJ and B _r, the sample B~E was determined the amount of change in H _cJ. (The sample B~E not measure the B _r for the sample is so because the measurement accuracy is very low small.) The results are shown in Table 2 and Table 3. As can be seen from Table 2, no. All 1-3, without B _r little lowered, H _cJ was improved significantly. Further, as can be seen from Table 3, each sample B to E had almost the same improvement in H _cJ , and no large variation was observed due to the nonuniform coating thickness of the paste layer. Since samples B to E are measurement samples in the vicinity of the magnet surface, the concentration of diffused Tb is higher than that in the vicinity of the center of the magnet, so that H _cJ is higher than that in sample A. Also, the side samples D and E are close to the top and bottom surfaces and are also affected by diffusion from the top and bottom surfaces, so that the H _cJ is slightly higher than the top and bottom samples B and C.

  According to an embodiment of the present disclosure, a paste containing powder particles for modifying an RTB-based sintered magnet is simultaneously applied to a plurality of surfaces of the RTB-based sintered magnet. be able to. For this reason, for example, the mass productivity of the method of effectively supplying and diffusing the heavy rare earth element RH to the RTB-based sintered magnet is improved.

1 R-T-B system sintered magnet 1a Upper surface of R-T-B system sintered magnet 1b Lower surface of R-T-B system sintered magnet 1c Side surface of R-T-B system sintered magnet 1d R-T -Front end face of B-based sintered magnet 1e Rear end face of RTB-based sintered magnet 2 Paste layer 10 Internal space 12 Inlet opening 14 Outlet opening 15 Hole 16 Second inner space 18 Slope 19 Backflow prevention device 20 Paste 50 Coarse drying device 52a, 52b Multiple holes 54 Opening portion for receiving air supply 56 Opening portion 100 for releasing air to the outside Coating device 100a Outlet side structure 100b Inlet side structure 100c Additional structure 104 Regulation Member 105 Taper 120 Backflow prevention device 122 Airtight chamber

Claims (22)

Preparing a plurality of RTB-based sintered magnets;
A paste containing powder particles of a metal, alloy and / or compound (RH is Dy and / or Tb) of heavy rare earth element RH on each of the upper surface, the lower surface and the side surface of each of the plurality of R-T-B based sintered magnets. Applying step;
A step of heat-treating the RTB-based sintered magnet coated with the paste at a temperature below the sintering temperature;
Including
The step of applying the paste includes
A coating device having an internal space having an inlet opening and an outlet opening, wherein the plurality of R-T-B based sintered magnets are configured to sequentially pass through the internal space in the lateral direction. In contrast, a step of sequentially supplying the plurality of R-T-B sintered magnets;
Filling the paste in the internal space of the coating device, bringing the paste into contact with the upper surface, the lower surface and the side surface of the RTB-based sintered magnet that is moving in the internal space;
The manufacturing method of the RTB type | system | group sintered magnet containing this.   When the RTB-based sintered magnet passes through the internal space of the coating device, the inlet opening slidably supports the RTB-based sintered magnet, and the lateral opening The manufacturing method of the RTB system sintered magnet of Claim 1 which has the shape and magnitude | size which control the motion of the RTB system sintered magnet in the direction orthogonal to a direction.   3. The RT-T- according to claim 1, wherein the outlet opening has a shape and a size that define a layer thickness of the paste applied to the RTB-based sintered magnet. Manufacturing method of B system sintered magnet. The step of sequentially supplying the plurality of RTB-based sintered magnets to the coating device includes:
Inserting each RTB-based sintered magnet into the inlet opening;
The rear end surface of the RTB-based sintered magnet, which is partially inserted into the inlet opening, is pushed in the lateral direction by the front end surface of another RTB-based sintered magnet, and the other Inserting an RTB-based sintered magnet into the inlet opening;
The manufacturing method of the RTB type | system | group sintered magnet in any one of Claim 1 to 3 containing this.   A step of conveying the RTB-based sintered magnet while pressing gas against at least the lower surface of each RTB-based sintered magnet discharged from the outlet opening of the coating device. Item 5. A method for producing an RTB-based sintered magnet according to any one of Items 1 to 4.   The method includes a step of separating a plurality of RTB-based sintered magnets discharged from the outlet opening and joined back and forth through the paste into individual RTB-based sintered magnets. The manufacturing method of the RTB type | system | group sintered magnet in any one of 1-5.   The powder particles include particles of an RLM alloy (RL is Nd and / or Pr, M is one or more elements selected from Cu, Fe, Ga, Co, Ni, and Al) and powders of an RH compound (RH is Dy and 7. The RTB-based firing according to claim 1, wherein the Tb and / or RH compound includes powder particles of RH fluoride, RH oxyfluoride, and RH oxide). A manufacturing method of a magnet.   The method of manufacturing an R-T-B system sintered magnet according to claim 7, wherein the RLM alloy includes 50 atomic% or more of RL, and the melting point of the RLM alloy is equal to or lower than the temperature of the heat treatment.   The RTM according to claim 7 or 8, wherein the RLM alloy powder and the RH compound powder and mass ratio in the paste are RLM alloy: RH compound = 9.6: 0.4 to 5: 5. Manufacturing method of B system sintered magnet. A paste containing powder particles of metal, alloy and / or compound (RH is Dy and / or Tb) of heavy rare earth element RH is applied to the upper surface, lower surface and side surface of each of the plurality of R-T-B based sintered magnets. A coating device used in an apparatus for
An internal space filled with the paste;
The plurality of R-T-B based sintered magnets are sequentially configured to pass through the internal space in the lateral direction, and an inlet opening and an outlet opening,
With
The outlet device has a shape and size that define a layer thickness of the paste applied to the RTB-based sintered magnet.   The inlet opening is configured to slidably support the RTB-based sintered magnet and to regulate the movement of the RTB-based sintered magnet in a direction orthogonal to the lateral direction. The coating device according to claim 10, having a size and a size. A second internal space filled with a second paste of the same or different type from the paste type;
A plurality of RTB-based sintered magnets discharged from the outlet opening, the second outlet opening configured to sequentially pass through the second internal space in a lateral direction; ,
The said 2nd exit opening part has the shape and magnitude | size which prescribe | regulate the total layer thickness of the said paste apply | coated to the said RTB type sintered magnet, The size of Claim 10 or 11 Application device.   The coating device according to claim 10, further comprising at least one regulating member that regulates a position of the RTB-based sintered magnet with respect to the outlet opening.   The coating device according to claim 10, wherein an inclination for guiding the RTB-based sintered magnet to the inlet opening is provided around the inlet opening.   The application according to any one of claims 10 to 14, wherein the outlet opening is tapered so that the paste filled in the internal space presses the RTB-based sintered magnet from the surroundings. device. Further comprising a backflow prevention device that suppresses the paste from flowing out of the gap between the RTB-based sintered magnet being inserted into the inlet opening and the inlet opening;
The coating device according to any one of claims 10 to 15, wherein the backflow prevention device includes an airtight chamber that pressurizes the inlet opening with a gas supplied from outside.   The internal space has a size that is not less than half and not more than three-quarters of the length of each RTB-based sintered magnet in the direction in which the RTB-based sintered magnet passes. The coating device according to any one of claims 10 to 16.   The coating device according to claim 10, further comprising a plurality of paste introduction holes communicating with the internal space. An inlet-side structure having the inlet opening;
An outlet side structure having the outlet opening and defining the internal space;
An intermediate plate that is located between the inlet side structure and the outlet side structure and has a magnet passage hole through which the plurality of RTB-based sintered magnets pass sequentially,
With
The inlet side structure has a first groove, and a first paste flow path is defined by the first groove and the intermediate plate,
The outlet side structure has a second groove, and a second paste flow path is defined by the second groove and the intermediate plate,
The intermediate plate has at least one paste passage hole that communicates the first paste flow path and the second paste flow path,
The coating device according to any one of claims 10 to 17, wherein the second paste flow path forms a plurality of paste introduction holes communicating with the internal space. An application device according to any one of claims 10 to 19,
A paste supply device that fills the internal space of the coating device with the paste;
A magnet supply device for sequentially inserting the plurality of RTB-based sintered magnets into the inlet opening;
An apparatus for conveying the RTB-based sintered magnet while pressing gas against at least the lower surface of each RTB-based sintered magnet discharged from the outlet opening of the coating device;
An apparatus comprising:   The magnet supply device has a surface on which the plurality of RTB-based sintered magnets are sequentially slid, and each of the RTB-based sintered magnets with respect to the inlet opening of the coating device 21. The apparatus of claim 20, further comprising a positioning mechanism for adjusting the position. An application device used in an apparatus for applying a paste containing powder particles of a metal, an alloy and / or a compound to each of an upper surface, a lower surface and a side surface of a plurality of magnets,
An internal space filled with the paste;
The plurality of R-T-B based sintered magnets are sequentially configured to pass through the internal space in the lateral direction, and an inlet opening and an outlet opening,
With
The application device, wherein the outlet opening has a shape and a size that define a layer thickness of the paste applied to the magnet.

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