JP2016178784A - Manufacturing device for magnet member, and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing device for a rotor for an inclusive magnet type motor capable of applying a higher orientation magnetic field to a slot of a rotor core during filling and molding with a bond magnet while using permanent magnets for an orientation magnetic field source.SOLUTION: The manufacturing device comprises: a cylindrical housing part (10) for housing a rotor core (R) including a plurality of slots (s1 or the like) equally disposed around a rotation center axis; an orientation yoke (M) for inducting the orientation magnetic field to be applied to the slots; and permanent magnets (m11-m62) for orientation that are orientation magnetic field excitation sources. The orientation yoke is formed from tabular orientation blades (11-16) that are disposed at an outer circumferential side of the housing part and radially extend in a radial direction from a plurality of positions that are equally arranged in a circumferential direction. An axial width of the orientation blades relating to the present invention is expanded radially outside of radially inner ends (11a-16a) that are located at a side of the housing part.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a manufacturing apparatus suitable for an internal magnet type motor rotor including an anisotropic bonded magnet and a manufacturing method thereof.

  There are various types of electric motors (simply called “motors” including generators). Recently, with the development of inverter control and the widespread use of rare earth magnets with high magnetic properties, attention has been focused on synchronous machines that can achieve power saving, high efficiency, high torque or high output.

  A synchronous machine is a motor in which a permanent magnet for a field is a rotor (rotor) and an armature winding (coil) is a stator (stator), and multi-phase alternating current (AC) is applied to the armature winding. It is a motor that is rotated by a rotating magnetic field that is supplied to the stator. The synchronous machine includes a surface magnet type motor (SPM) in which field permanent magnets are arranged on the surface of the rotor, and an encapsulated (embedded) magnet type in which the permanent magnets are arranged inside the rotor. There is a motor (IPM), but at present, a highly reliable IPM capable of preventing scattering of permanent magnets is becoming mainstream.

  In the conventional IPM, a rotor in which a rare earth sintered magnet cut or polished to a predetermined size is inserted into a slot in the rotor core is used. However, the sintered magnet has a small degree of freedom in shape, and is easily damaged when inserted into the slot. Accordingly, a rotor obtained by filling a slot with a bonded magnet made of anisotropic magnet powder and a binder resin in an orientation magnetic field has been adopted for IPM. A description related to such a rotor manufacturing apparatus (method) is, for example, in the following patent document.

JP 2003-47212 A JP-A-5-90053

  In Cited Document 1, a bonded magnet is filled and formed by applying an orientation magnetic field to a slot of a rotor core by a permanent magnet (orientation magnetic field source) and a pole piece (orientation yoke) arranged in a lower mold that accommodates the rotor core. By using a permanent magnet as the orientation magnetic field source, it is possible to reduce the size of the apparatus (mold), to obtain a large number of units, and to use a general-purpose molding machine.

  However, in the case of using a permanent magnet instead of an electromagnet as an orientation magnetic field source, the orientation magnetic field is not always sufficient. Therefore, in Cited Document 1, a pair of permanent magnets are arranged with opposite poles facing each other in the circumferential direction of each pole piece. In addition, the amount of magnetic flux supplied to the pole piece is ensured and the leakage magnetic flux that is not used for the orientation magnetic field is reduced.

  Further, although cited document 2 is not an IPM manufacturing apparatus, it proposes an alignment apparatus (mold) for manufacturing a multipolar anisotropic cylindrical magnet. In this orientation device, the circumferential width of the yoke sandwiched between permanent magnets (orientation magnetic field sources) arranged with the same poles facing each other is narrowed in the diameter increasing direction, and the same poles are also made to face both axial ends of the yoke. Another permanent magnet is arranged. Thus, in the cited document 2, the leakage magnetic flux is further reduced, and the orientation magnetic field applied to the cavity (slot) to be injection molded is increased.

  However, when a bonded magnet using rare earth anisotropic magnet particles exhibiting a very large coercive force is molded in a magnetic field, the orientation magnetic field is not always sufficient even with a conventional orientation device or the like. In particular, when a general-purpose injection molding machine or the like is used, it is not easy to increase the orientation magnetic field more than before because the size (physique) of the orientation permanent magnet and the orientation yoke is restricted within a predetermined range.

  The present invention has been made in view of such circumstances, and a rotor for an internal magnet type motor that can apply a higher orientation magnetic field to a slot of a rotor core when a bonded magnet is filled and molded while using a permanent magnet as an orientation magnetic field source. It is an object of the present invention to provide a manufacturing apparatus suitable for the above and a manufacturing method thereof.

  As a result of extensive research and trial and error, the present inventor has increased the axial width (height) of the orientation yoke on the outer side in the radial direction so that the magnetic flux supplied from the permanent magnet can be accommodated on the housing side. It was conceived that a large orientation magnetic field was efficiently applied from the orientation yoke to the slot of the rotor core by focusing (magnetizing) on the radially inner end of the rotor. By confirming that this idea is effective and developing this idea, the present invention described below has been completed.

<Embedded magnet type motor rotor manufacturing equipment>
(1) An apparatus for manufacturing a rotor for an internal magnet type motor according to the present invention includes a cylindrical accommodating portion that accommodates a rotor core having a plurality of slots evenly arranged around a rotation center axis, and an orientation applied to the slot. An orientation yoke for inducing a magnetic field and an orientation permanent magnet that is a magnetomotive source of the orientation magnetic field, and an anisotropic bonded magnet made of anisotropic magnet particles and a binder resin are placed in the slot of the rotor core in the orientation magnetic field. And the orientation yoke is disposed on the outer peripheral side of the housing portion and extends radially from a plurality of uniform circumferential positions in the radial direction. Each of the orientation blades has a pair of circumferential magnets facing the same magnetic poles on both sides of the circumferential side surface of the orientation blade. , In the radial direction on the housing side Characterized in that an enlarged axial width at the outer side in the radial direction than parts. In the present specification, as appropriate, the rotor for the internal magnet type motor is simply referred to as “IPM”, the rotor for the internal magnet type motor is simply referred to as the “rotor”, and the manufacturing apparatus for the internal magnet type motor rotor is simply referred to as the “rotor manufacturing apparatus”. That's it.

  In the rotor manufacturing apparatus of the present invention, each orientation blade constituting the orientation yoke is expanded (expanded) to the axial width on the outer side in the radial direction from the inner end portion in the radial direction on the housing portion side of the rotor core. In other words, the shape is narrowed from the radially outer side to the inner end. For this reason, the magnetic flux supplied from the circumferential magnet on both sides of the circumferential side surface of each orientation blade is focused (magnetized) on the inner end closest to the rotor core. Due to the magnetic collecting action by the inner end portion, it is possible to efficiently apply a stronger orientation magnetic field to the slot of the rotor core while using the permanent magnet as the orientation magnetic field source.

  By the way, the orientation blades are expanded in the axial width outside the radial inner end of the radial direction, so that the volume of the circumferential magnet facing each orientation blade is increased and the total magnetic flux is also increased. It is easy to plan and it is easy to apply a larger orientation magnetic field from each orientation blade to the slot of the rotor core. However, the circumferential magnets arranged on both sides of the circumferential side surface of the orientation wing are such that the total magnetic flux supplied is at least large enough to reach the saturation magnetization of the magnetic material at the inner end of the orientation wing. Preferably there is. Further, preferably, during the orientation molding of the rotor core, it is desirable that the material in the portion extending from the radial outer peripheral side of the slot of the rotor core facing the orientation blade to the outer periphery of the rotor core reaches saturation magnetization. It is desirable for many parts of the material to reach saturation magnetization.

  Thus, according to the rotor manufacturing apparatus of the present invention, the slot has the bonded magnet in which anisotropic magnet particles are sufficiently oriented regardless of whether a dedicated or general-purpose injection molding machine, transfer molding machine or compression molding machine is used. A rotor is obtained, and high performance of the IPM is achieved.

  In addition, the accommodating part which concerns on this invention should just form the cylindrical space which can accommodate a rotor core, and the exclusive member which comprises an accommodating part is not essential. For example, the accommodating part may be formed by the inner peripheral end surfaces of the respective orientation blades and the respective circumferential magnets. Of course, a thin cylindrical member (nonmagnetic ring) made of a nonmagnetic material or the like may be separately provided to form the accommodating portion, and each orientation blade and each circumferential magnet may be disposed on the outer peripheral side thereof.

  More specifically, each orientation blade may be integrated with a cylindrical portion constituting the housing portion. In this case, in order to prevent a magnetic short circuit (magnetic closed circuit) from occurring in the cylindrical portion, the portion where the inner end portion of the orientation wings is continuous has a low magnetic resistance (magnetic permeability portion), and the other portion (inside the circumferential magnet) What is necessary is just to let it be the state arrange | positioned alternately by the circumferential direction as a high magnetic resistance (shielding magnetic part) as the part where the peripheral side surface contact | connects. The magnetic resistance can be easily adjusted by adjusting the thickness or non-magnetic modification.

  Incidentally, the circumferential width of the inner end of the orientation blade is appropriately adjusted according to the slot width of the rotor. In order to effectively induce the orientation magnetic field into the slot, the circumferential width of the inner end portion is preferably equal to or smaller than the maximum inner width of the slot on the outermost circumferential side of the rotor. In this specification, the housing portion, the orientation yoke, and further the orientation permanent magnet are appropriately referred to as an “orientation die”.

<< Method for Manufacturing Rotor for Inner Magnet Type Motor >>
The present invention can be grasped not only as the above-described manufacturing apparatus, but also as a preferable manufacturing method of an internal magnet type motor rotor using the manufacturing apparatus. That is, the present invention includes an accommodating step of loosely inserting and accommodating the rotor core in the accommodating portion, and applying the orientation magnetic field into a slot of the rotor core accommodated in the accommodating portion, and the anisotropic magnet particles and the binder. It can also be grasped as a method of manufacturing a rotor for an encapsulated magnet type motor characterized by comprising a filling step of pressurizing and filling a resin mixture, and a step of taking out the rotor core after the filling step from the housing portion.

<< Magnetic member manufacturing apparatus and manufacturing method >>
The present invention is not limited to the orientation of the rotor for the internal magnet type motor (IPM) described above, the orientation of the rotor for the surface magnet type motor (SPM), the magnetization of the internal magnet or the surface magnet of the rotor, and the multipolar type. It can be extended to the orientation or magnetization of a cylindrical magnet.

  Therefore, the present invention includes a cylindrical housing portion that houses a cylindrical or columnar magnet member, a yoke that induces a magnetic field to be applied to the magnet member, and a permanent magnet that serves as a magnetomotive source of the magnetic field. An apparatus for manufacturing a magnet member, wherein the yoke is disposed on the outer peripheral side of the housing portion and includes a plate-shaped blade piece extending radially from a plurality of uniform positions in the circumferential direction, The permanent magnet includes a pair of circumferential magnets having the same magnetic pole facing both sides of the circumferential side surface of the blade piece for each blade piece, and the blade piece is a radially inner end portion on the housing portion side. It can also be grasped as an apparatus for manufacturing a magnet member, characterized in that the axial width is expanded outside in the radial direction.

  Moreover, this invention can be grasped | ascertained not only as said manufacturing apparatus but as a manufacturing method using it. That is, the present invention is a method of manufacturing a magnet member using the manufacturing apparatus described above, wherein the magnet member is loosely inserted and accommodated in the accommodating portion, and a magnetic field is applied to the magnet member accommodated in the accommodating portion. And a magnetic field applying step of applying orienting or magnetizing the magnetic member.

  Here, the magnet member is an IPM or SPM rotor or rotor core, a multipolar cylindrical magnet or a preform thereof, and the like, in addition to the case where it is made of a magnet material itself, a rotor core before the magnet is disposed, etc. Is also included. In short, what is necessary is just to be accompanied by an oriented or magnetized permanent magnet after the above-described magnet member housing step. Further, typical examples of the yoke, the blade piece, or the permanent magnet are the above-described orientation yoke, orientation blade, or orientation permanent magnet, respectively.

  For example, in the case of manufacturing a rotor for an SPM type motor, the above-described method for manufacturing a magnet member includes an accommodating step in which only a rotor core is loosely inserted and accommodated in an accommodating portion, and a gap (cavity between the accommodated rotor core and the accommodating portion). And a step of pressurizing and filling the mixture of the anisotropic magnet particles and the binder resin while applying an orientation magnetic field to the step), and a step of taking out the rotor core after the filling step from the accommodating portion. It can also be grasped as a manufacturing method of a rotor for an SPM type motor.

<Others>
(1) Each orientation blade according to the present invention is usually the same shape, and each circumferential magnet is also usually the same shape. Each of the axial end faces of the orientation wing and the circumferential magnet facing each other in the circumferential direction may be smoothly connected (for example, flush), or the axial width of the circumferential magnet is constant and the axial end face is It may be flat. The latter is preferable because it facilitates the production of a circumferential magnet (orienting permanent magnet). In particular, the axial width of the circumferential magnet is preferably equal to or greater than the axial width of the orientation blade. At this time, the leakage magnetic flux on the axial end side of the orientation blade is suppressed, and the orientation blade does not protrude in the axial direction on the outer diameter side, thereby improving the handleability of the rotor manufacturing apparatus. In addition, each outer peripheral side surface of the orientation wing and the circumferential magnet may be smoothly connected (for example, flush), or in a shape (for example, an uneven shape) that can reduce leakage magnetic flux or enhance the orientation magnetic field. It may be connected.

(2) The present invention is characterized by the shape of an orientation yoke (particularly an orientation wing) that can efficiently guide the magnetic flux of the orientation permanent magnet to a specific position. Therefore, as long as it has the characteristics, the present invention is not only used as an IPM rotor manufacturing apparatus (orientation apparatus), but also as a multipolar anisotropic cylindrical magnet manufacturing apparatus (orientation apparatus), or a magnetizing apparatus. It is possible to grasp.

(3) In this specification, cylindrical coordinates (r, θ, z) are used as appropriate in order to express the shape and the like of each member. More specifically, the cylindrical axis (rotation center axis) constituting the housing portion is referred to as the z axis, and the z direction is simply referred to as the axial direction. The r direction orthogonal to the z direction is simply referred to as the radial direction, and the θ direction around the z axis is simply referred to as the circumferential direction. The side with the smaller radius (r) (center side) is also simply referred to as “inside”, and the side with the larger radius (r) is also simply referred to as “outside”. In each member, the minimum radius portion is also referred to as an inner end portion, and the maximum radius portion is also referred to as an outer end portion.

(4) Unless otherwise specified, “x to y” in this specification includes a lower limit value x and an upper limit value y. Any numerical value included in various numerical values or numerical ranges described in the present specification can be newly established as a range such as “ab” as a new lower limit value or upper limit value.

It is a perspective view of the 4/6 cut model which shows the orientation metal mold | die which is one Example of this invention. It is a top view which shows typically the orientation magnetic field which acts on the orientation metal mold | die. It is sectional drawing which shows typically the orientation magnetic field which acts on the orientation metal mold | die. It is a perspective view of the 4/6 cut model which concerns on the Example used for the three-dimensional static magnetic field analysis. It is a perspective view of the 4/6 cut model concerning the comparative example used for the analysis.

  One or more components arbitrarily selected from the matters described in the present specification may be added to the configuration of the present invention described above. Which embodiment is the best depends on the target, required performance, and the like. A component related to a manufacturing method can be a component related to an object if understood as a product-by-process claim.

《Orientation yoke》
The orientation yoke is a member that efficiently induces an orientation magnetic field applied to the slot of the rotor, and is composed of a plurality of orientation blades extending in the diameter-expanding direction from a plurality of uniform positions on the outer peripheral side of the housing portion. These orientation blades are plate-shaped, and are easy to manufacture and face the circumferential magnet so that magnetic flux is easily supplied efficiently from the circumferential magnet. Furthermore, the orientation wing | blade which concerns on this invention has the axial direction width | variety expanded on the outer side of radial direction rather than the radial inner end part which exists in the accommodating part side. The total amount of magnetic flux increased by the magnetism collecting effect by the inner end portion can be efficiently supplied to the slot as a large orientation magnetic field.

  By the way, various modes in which the axial width of each orientation blade (appropriately, simply referred to as “height”) increases from the inner end portion toward the diameter increasing direction are conceivable. For example, it is preferable that the height monotonously increases (smoothly) from the inner end portion to a predetermined position in the radial direction (for example, the outer end portion). In this case, there may be a portion where the rate of change in height (f ′) is zero (a portion having a constant height) on the way from the inner end to the outer end of the orientation blade. When the height of the orientation blade monotonously increases in the radial direction (f ′ ≧ 0), the increase pattern may be linear (f ′ is constant) or curved upward (f ′ is monotonically decreasing) A downward convex curve (f ′ monotonically increasing) may be used.

  It is preferable that the orientation blades have a taper shape whose height increases from the inner end portion to the outer end portion in the radial direction or the vicinity thereof at a constant rate because the orientation blades and the circumferential magnet can be easily manufactured. In addition, although the taper inclination (change amount Δz in the axial direction / change amount Δr in the radial direction) can be adjusted as appropriate, it is preferably 0.1 to 1, and more preferably 0.3 to 0.8. If it is too small, the device (orientation mold) becomes large in the radial direction, and if it is too large, the device becomes large in the axial direction. In addition, if the height of the orientation blade is rapidly changed, the effect of collecting the magnetic force from the outer diameter side to the inner diameter side of the orientation blade is reduced, so that the effective orientation magnetic field cannot be improved. Therefore, it is preferable that the height of the orientation blade is smoothly changed from the inner end portion to the outer end portion.

  Thus, the upper and lower ends in the axial direction of the orientation wing change in the radial direction, but the orientation wing itself has a substantially trapezoidal (rz cross section) plate shape, and usually the minimum portion of its axial width is the inner end. Part. In the case where the orientation wing and the accommodating portion are integrated, the boundary portion where the circumferential cross section suddenly changes may be considered as the inner end portion of the orientation wing. The axial width (height) of the inner end is preferably at least the height of the rotor core. As a result, a strong magnetic field can be stably supplied to the vicinity of the upper and lower ends of the slot of the rotor core. The height of the inner end portion of the orientation blade is preferably 20% or more higher than the height of the rotor core. However, when the height of the inner end portion of the orientation blade exceeds 30% of the height of the rotor core, the above effect tends to be saturated.

  Contrary to the axial width, the circumferential width of the orientation blade is preferably a spire shape that decreases from the inner end to the outer side in the radial direction. As a result, the volume of the circumferential magnet that can be sandwiched between the orientation blades can be increased while avoiding an increase in the size of the apparatus (mold), and the orientation magnetic field applied to the slot can be strengthened.

<< Orientation magnetic field source >>
An exciting coil can be used for the orientation magnetic field source. However, by using a permanent magnet such as a rare earth sintered magnet, the rotor manufacturing apparatus can be made compact and energy-saving. When using a permanent magnet, in order to increase the orientation magnetic field, it is preferable to arrange the permanent magnet with the same pole facing the opposite side surface of the orientation blade. That is, the orientation permanent magnet is preferably provided with a pair of circumferential magnets having the same magnetic poles facing each other on both sides of the circumferential side surface of the orientation wing for each orientation wing.

  At this time, the circumferential magnet disposed between the adjacent orientation blades may be a single piece or a plurality of pieces (arrangement of divided permanent magnets). When the circumferential magnet is composed of a plurality of magnets, the magnetization direction (direction from the N pole to the S pole) of each divided permanent magnet is adjusted so that the orientation magnetic field induced to the orientation blade is maximized. Is preferred. For example, when two permanent magnets divided between adjacent orientation blades are arranged, the magnetization direction of each permanent magnet is preferably orthogonal to the circumferential side surface of the orientation blade.

  The permanent magnets for orientation are preferably opposed not only on both sides in the circumferential direction but also on both end surfaces in the axial direction (vertical direction). That is, it is preferable that the orientation permanent magnet includes a pair of axial magnets in which the same magnetic pole as the magnetic pole facing the circumferential side surface of the orientation blade is opposed to both sides of the axial side surface of the orientation blade for each orientation blade. By surrounding each side surface of the orientation blade with the same pole of the permanent magnet, the leakage magnetic field can be reduced and the orientation magnetic field induced to the rotor core can be strengthened. Furthermore, in order to prevent leakage of the alignment magnetic field, the outermost peripheral side of the alignment blade is preferably a non-magnetic member (including air).

<Rotor core>
The rotor core is made of a soft magnetic material, and is usually made of a laminated body of electromagnetic steel sheets with insulation coating on both surfaces, a dust core obtained by press-molding metal particles with insulation coating, or the like. The soft magnetic material may be any material, but is preferably an iron-based material such as pure iron, silicon steel, or alloy steel.

  As long as there are at least two slots arranged evenly around the rotation center of the rotor core, the shape and number thereof are not limited. For example, a radial slot extending linearly from the center in the radial direction may be used, or a convex slot having a convex shape on the inner peripheral side may be used. A convex slot having a smooth curved shape is preferable because a high orientation magnetic field can be uniformly applied to the entire slot. Specifically, a curved slot (including a U-shaped slot and a V-shaped slot) that is gently curved toward the inner peripheral side is preferable. From the same viewpoint, it is preferable that the slot has a uniform groove width. In other words, it is preferable that there is no sudden shape change or dimensional change in which the applied orientation magnetic field tends to concentrate locally. Further, the slot may be a multilayer slot having a plurality of slots in the radial direction. When a multilayer slot is used, the reluctance torque can be increased. The number of layers of the multilayer slot is not limited, but it is preferable that the number of layers is two or three because compatibility between the characteristics of the synchronous machine and productivity can be achieved.

《Anisotropic bonded magnet》
The anisotropic bonded magnet that is filled in the slot of the rotor core is made of anisotropic magnet particles and a binder resin. The type of anisotropic magnet particles is not limited, but at least a part of them is preferably high-performance rare earth anisotropic magnet particles. The rare earth anisotropic magnet particles are preferably Nd—Fe—B based magnet particles, Sm—Fe—N based magnet particles, Sm—Co based magnet particles, and the like. The anisotropic magnet particles may be composed of not only one type but also a plurality of types. The plural types of magnet particles are not limited to those having different component compositions, but may have different particle size distributions. For example, the anisotropic magnet particles according to the present invention may be composed of a mixed powder of coarse powder and fine powder of Nd-Fe-B magnet, or coarse powder of Nd-Fe-B magnet and Sm-Fe-. It may consist of a mixed powder of fine powder of N-based magnet. By using such a mixed powder, the filling rate of magnet particles in the bonded magnet can be improved, and it is possible to achieve both higher magnetic flux density of the bonded magnet and, consequently, higher performance and compactness of the rotor. Become. The bonded magnet according to the present invention may be a mixture of various isotropic magnet particles, ferrite magnet particles, and the like.

  As the binder resin, known materials including rubber can be used. For example, polyethylene, polypropylene, polystyrene, acrylonitrile / styrene resin, acrylonitrile / butadiene / styrene resin, methacrylic resin, vinyl chloride, polyamide, polyacetal, polyethylene terephthalate, ultrahigh molecular weight polyethylene, polybutylene terephthalate, methylpentene, polycarbonate, polyphenylene sulfide, It is preferable to use a thermoplastic resin such as polyetheretherketone, liquid crystal polymer, polytetrafluoroethylene, polyetherimide, polyarylate, polysulfone, polyethersulfone, and polyamideimide. Also, thermosetting resins such as epoxy resin, unsaturated polyester resin, amino resin, phenol resin, polyamide resin, polyimide resin, polyamideimide resin, urea resin, melamine resin, urea resin, direal phthalate resin, polyurethane, etc. should be used as appropriate. Can do.

  Filling molding of the anisotropic bonded magnet in the slot is performed by injection molding, transfer molding, or compression molding. The injection molding and transfer molding are performed, for example, by filling a molten mixture obtained by heating and melting raw material pellets made of anisotropic magnet particles and a binder resin into a slot to which an orientation magnetic field is applied, and then cooling and solidifying the mixture. The compression molding is performed, for example, by heating and melting a raw material preform made of anisotropic magnet particles and a binder resin in a slot and molding in a magnetic field, followed by cooling and solidification. The molding conditions are adjusted as appropriate. For example, in the case of performing injection molding, the molten mixture heated to about 280 to 310 ° C., which is less than the Curie point of the anisotropic magnet particles, is injected and filled into the slots, and then 140 to 160 An anisotropic bonded magnet is formed in the slot by solidifying by cooling to about ° C. In addition, when the above-mentioned thermosetting resin is used for binder resin, it is good to carry out heat solidification (curing process) after cooling solidification instead of cooling solidification.

<< Internal magnet type motor (IPM) >>
Unless otherwise specified, the motor in this specification includes a generator in addition to an electric motor. In this specification, the IPM includes a Hall element, a rotary encoder, as well as an original synchronous machine in which the number of revolutions changes in synchronization with the frequency of an alternating current supplied to a coil (armature winding) provided in a stator. Also included is a brushless direct current (DC) motor that generates a rotating magnetic field on the stator side based on the position of the rotor detected by a detecting means such as a resolver. Incidentally, since the brushless DC motor can change the rotation speed by changing the DC voltage supplied to the inverter, it is excellent in controllability like a normal DC motor.

  The use of the IPM according to the present invention is not limited, but it is suitable for, for example, a motor for driving a vehicle used for an electric vehicle, a hybrid vehicle, a railway vehicle, etc., a motor for home appliances used for an air conditioner, a refrigerator, a washing machine or the like .

  FIG. 1 shows a perspective view of a 4/6 cut model of an orientation mold M1, which is an embodiment of the rotor manufacturing apparatus of the present invention. The orientation mold M1 is used to manufacture a cylindrical six-pole rotor used for an internal magnet type motor (IPM). More specifically, the slots s1 to s6 (s5 and s6 and other parts corresponding to them) disposed at an equal pitch around the shaft hole h provided in the center of the rotor core R are appropriately omitted. ) Is used for injection molding a rare earth anisotropic bonded magnet in a magnetic field.

  Although not shown, the rotor manufacturing apparatus according to the present embodiment includes an injection apparatus that injects a molten mixture obtained by heating and melting pellets made of rare earth anisotropic magnet powder and a binder resin at a predetermined pressure, and an orientation mold M1. And an upper mold that guides the molten mixture to the slots s1 to s6, and a lower mold that is disposed on the lower side of the alignment mold M1 and supports the alignment mold M1 and closes the lower opening of each slot. A die and a driving device for restraining (clamping) or releasing each die are provided. In addition, the rotor core R after injection molding is cooled through each mold.

  The orientation mold M1 includes six plate-like orientation blades 11 to 16 (radially referred to as “orientation yoke Y” as appropriate) projecting radially in the outer diameter direction, and inner end wall surfaces (inside of the orientation blades 11 to 16). A thin cylindrical body 10 (accommodating portion) made of a nonmagnetic material (stainless steel or the like) with which the end portions 11a to 16a abut and a circumferential magnet serving as an orientation magnetic field source disposed adjacent to the orientation blades 11 to 16 m11 to m62 (appropriately collectively referred to as “orienting permanent magnet M”). The rotor core R is disposed in the cylindrical body 10.

  The circumferential magnets m11 to m62 are arranged with the same poles facing opposite circumferential sides of the orientation blades 11 to 16, respectively. For example, the S poles of the circumferential magnet m11 and the circumferential magnet m12 are in contact with both circumferential sides of the orientation blade 11, and the circumferential magnet m21 and the circumferential magnet are placed on both circumferential sides of the orientation blade 12. The N poles of m22 are in contact with each other (see FIG. 2). Moreover, the permanent magnets (for example, the circumferential magnet m12 and the circumferential magnet m21) between adjacent orientation blades are arranged in contact with different polarities (N pole and S pole). In this way, the circumferential magnets m11 to m62 are loaded between the orientation blades 11 to 16 with substantially no gap. Incidentally, all the permanent magnets M for orientation according to this embodiment are rare earth sintered magnets.

  By the way, as is clear from the cross-sectional view of FIG. 1, the orientation blades 11 to 16 have an axial width (height) that is primarily (linearly) increased from the inner end portions 11 a to 16 a along the diameter increasing direction. And a steeple shape with a reduced circumferential width. The axial end surfaces of the orientation blades 11 to 16 are flat surfaces (tapered surfaces) inclined from the outer peripheral side to the inner peripheral side. In addition, although the height (Yi) of the inner end parts 11a to 16a of the orientation blades 11 to 16 is the same height as the cylindrical body 10, it is 25% (100%) from the axial width (Ri) of the rotor core R. X (Yi-Ri) / Ri) It is large.

  Both end surfaces in the axial direction of the circumferential magnets m11 to m62 are also flat surfaces (tapered surfaces) inclined from the outer peripheral side to the inner peripheral side, and are smoothly connected to the both end surfaces in the axial direction of the orientation blades 11 to 16 without any step. ing. The axial end surfaces of the orientation blades 11 to 16 and the circumferential magnets m11 to m62 are flat surfaces for ease of manufacturing (processing), but conical curved surfaces inclined from the outer peripheral side to the inner peripheral side, etc. It may be. In any case, the magnetic flux supplied from the circumferential magnets m11 to m62 is collected through the orientation blades 11 to 16, collected by the inner end portions 11a to 16a, and supplied to the slots s1 to s6 of the rotor core R. Applied as an orientation magnetic field. This situation is shown in FIG.

  In addition, the outer diameter side tips of the alignment blades 11 to 16 protrude from the outer peripheral surface of the circumferential magnets m11 to m62 in order to ensure (positioning) the assembly of the alignment yoke Y. is there. Further, in the present embodiment, the case where the orientation permanent magnets (axial magnets) are not arranged on the axial end faces of the orientation blades 11 to 16 is shown, but the axial end faces of the orientation blades 11 to 16 are covered. If an axial magnet is arranged, the orientation magnetic field can be further strengthened by increasing the amount of supplied magnetic flux and reducing the leakage magnetic flux. At that time, in consideration of the magnetic poles of the circumferential magnets arranged on the circumferential side surfaces of the orientation blades 11 to 16, the same polarity of the orientation permanent magnets may be made to face each surface of the orientation blades 11 to 16. The same applies to the orientation mold M2 described later.

  Although the shape (size) which covers only the axial direction end surface of the orientation blades 11-16 may be sufficient as an axial magnet, it is good also as a shape which also covers the axial direction end surface of the circumferential direction magnets m11-m62. In the case of the latter, it is good to make it the direction which aims at increase of the magnetic flux supplied to each orientation blade | wing 11-16 and reduction of leakage magnetic flux similarly to the magnetic pole of the circumferential magnets m11-m62. The circumferential magnets m11 to m62 may extend in the axial direction and their axial end faces may exceed the axial end faces of the orientation blades 11 to 16. In any case, when the shapes of the permanent magnet for orientation M and the orientation yoke Y are selected so that the axial end face of the orientation die M1 is a continuous flat surface, the injection molding apparatus for the orientation die M1 is selected. This is preferable because of improved mounting properties. This also applies to the orientation mold M2 described later.

<Evaluation>
In addition to the orientation mold M1 (first embodiment) described above, an orientation mold M2 (second embodiment) and an orientation mold in which the shape of the orientation permanent magnet (circumferential magnet) or the orientation yoke (alignment blade) is changed. A type MC (comparative example) was prepared. A perspective view of the 4/6 cut model of the orientation mold M2 is shown in FIG. 4A, and a perspective view of the 4/6 cut model of the orientation mold MC is shown in FIG. 4B. The orientation mold M2 has an axial end face so that the axial width of the circumferential magnets m11 to m62 of the orientation mold M1 is extended radially inward and constant in the radial direction so that the outer end of the orientation blade does not protrude. It is a flat surface. The alignment mold MC further extends the axial width of the alignment blade radially inward to be constant in the radial direction (straight alignment blade), and the axial end surfaces of the alignment blade and the circumferential magnet are flush with each other. It is what I did.

A three-dimensional static magnetic field analysis (simulation) was performed on these orientation molds M1, M2, and MC, and the orientation magnetic field applied to each slot of the rotor core was evaluated. As an example, the specifications of each orientation mold were as follows. The rotor core had a height of 48 mm and an outer diameter of φ57.8 mm. The circumferential magnet had an outer diameter of φ160 mm. The inner end portion of the orientation blade was formed into a cylindrical side surface (curved surface having a circular arc cross section) with a central angle of 43 °. The cylindrical body had an inner diameter: φ58.0 mm and an outer diameter: φ59.0 mm. The height of the inner end portions of the alignment molds M1 and M2 (the height of the cylindrical body): 60 mm, and the height of the inner end portion of the alignment mold MC: 100 mm. In any case, the total magnet volume of the circumferential magnets was unified at 1319816 mm ³ . For this reason, the height of the outer end portion of the alignment mold M1 was 125 mm, and the height of the outer end portions of the alignment mold M2 and MC was 100 mm. Rare earth sintered magnets (NMX33UH: manufactured by Hitachi Metals) for permanent magnets for orientation, steel materials (SS440: JIS) for orientation yokes, non-oriented electrical steel sheets (35H440: JIS) for rotor cores, and magnetism for cylindrical bodies The material (SKD11) was used.

  When analyzed under such conditions, the average value of the orientation magnetic field applied to the slot is the orientation mold M1: 1.23T, the orientation mold M2: 1.24T, and the orientation mold MC: 1.20T. It was. Thus, the following can be understood from the comparison between the oriented mold M1 and the oriented mold MC. By making the orientation blades that make up the orientation yoke into a tapered shape, the orientation magnetic field (orientation per unit mold occupied volume) is achieved by an orientation device of the same size due to the magnetism collecting effect due to the yoke shape, despite the reduction in the amount of yoke used. (Magnetic field) could be raised.

  In addition, by making the orientation blades and circumferential magnets that make up the orientation yoke the same taper shape while keeping the magnet use volume constant, it is also possible to reduce the amount of yoke use by the magnetism collecting effect due to the yoke shape. The orientation magnetic field per unit mold occupied volume could be increased.

  Thus, from comparison between the alignment dies M1 and M2 and the alignment dies MC, it became clear that the alignment magnetic field that can be applied to the slots of the rotor core can be increased by tapering the alignment blades that constitute the alignment yoke. . From the comparison between the alignment mold M1 and the alignment mold M2, the alignment blade is tapered, and the circumferential magnet is formed into a columnar shape having a constant axial width (height), thereby making the alignment mold compact. It has also been clarified that the orientation magnetic field can be strengthened at the same time.

M1 orientation mold (IPM production equipment)
DESCRIPTION OF SYMBOLS 10 Cylindrical body 11-16 Orientation blade | wing 11a-16a Inner edge part R Rotor core s1-s6 Slot m11-m22 Permanent magnet (Permanent magnet for orientation)

Claims (12)

A cylindrical accommodating portion that accommodates a rotor core having a plurality of evenly arranged slots around the rotation center axis;
An alignment yoke for inducing an alignment magnetic field applied to the slot;
An orientation permanent magnet that is a magnetomotive source of the orientation magnetic field,
An apparatus for manufacturing a rotor for an encapsulated magnet type motor, in which an anisotropic bonded magnet made of anisotropic magnet particles and a binder resin is filled in an orientation magnetic field in a slot of the rotor core,
The orientation yoke comprises plate-like orientation blades that are disposed on the outer peripheral side of the housing portion and extend radially from a plurality of uniform circumferential positions in the radial direction,
The orientation permanent magnet includes a pair of circumferential magnets that face the same magnetic poles on both sides of the circumferential side surface of the orientation blade for each orientation blade.
An apparatus for manufacturing a rotor for an internal magnet type motor, wherein the orientation blade has an axial width that is larger outside in a radial direction than an inner end portion in a radial direction on the housing portion side.   2. The apparatus for manufacturing a rotor for an internal magnet type motor according to claim 1, wherein an axial width of the orientation blade monotonously increases from the inner end portion to a predetermined position in a radial direction.   The said orientation blade | wing is a manufacturing apparatus of the rotor for internal magnet type motors of Claim 2 with which the said axial width | variety is a taper shape which increases in a fixed ratio from the said inner end part to a radial direction outer end part.   The apparatus for manufacturing a rotor for an internal magnet motor according to any one of claims 1 to 3, wherein the orientation blade has a spire shape in which a circumferential width decreases from an inner end portion to a radially outer side.   The apparatus for manufacturing a rotor for an internal magnet type motor according to claim 1, wherein the circumferential magnet has a constant axial width.   The apparatus for manufacturing a rotor for an internal magnet type motor according to claim 1, wherein an axial width of the circumferential magnet is equal to or greater than an axial width of the orientation blade.   The inclusion according to any one of claims 1 to 6, wherein a total amount of magnetic flux supplied from a circumferential magnet disposed on both sides of a circumferential side surface of the orientation blade is equal to or less than a saturation magnetization at an inner end portion of the orientation blade. Magnet type motor rotor manufacturing equipment.   The permanent magnet for orientation further includes a pair of axial magnets each having the same magnetic pole as the magnetic pole facing the circumferential side surface of the orientation blade on both sides of the axial side surface of the orientation blade for each orientation blade. The manufacturing apparatus of the rotor for internal magnet type motors in any one of Claims 1-7 provided.   The said anisotropic magnet particle is a manufacturing apparatus of the rotor for internal magnet type motors in any one of Claims 1-8 containing rare earth anisotropic magnet particle. A method for manufacturing a rotor for an internal magnet type motor using the manufacturing apparatus according to claim 1,
A housing step of loosely inserting and housing the rotor core in the housing portion;
A filling step of pressurizing and filling the mixture of the anisotropic magnet particles and the binder resin while applying the orientation magnetic field into the slot of the rotor core housed in the housing portion;
Taking out the rotor core after the filling step from the accommodating portion;
A method for manufacturing a rotor for an internal magnet type motor, comprising: A cylindrical accommodating portion for accommodating a cylindrical or columnar magnet member;
A yoke for inducing a magnetic field applied to the magnet member;
A permanent magnet serving as a magnetomotive source of the magnetic field;
An apparatus for manufacturing a magnet member comprising:
The yoke is composed of a plate-shaped wing piece that is disposed on the outer peripheral side of the accommodating portion and extends radially from a plurality of uniform circumferential positions in a radial direction,
The permanent magnet is provided with a pair of circumferential magnets that face the same magnetic poles on both sides of the circumferential side surface of the blade piece for each blade piece,
The apparatus for manufacturing a magnet member, wherein the blade piece has an axial width that is larger on the outer side in the radial direction than the inner end portion in the radial direction on the housing portion side. A method for manufacturing a magnet member using the manufacturing apparatus according to claim 11,
A housing step of loosely inserting and housing the magnet member in the housing portion;
A magnetic field application step of applying a magnetic field to the magnet member accommodated in the accommodating portion to perform orientation or magnetization;
A method for manufacturing a magnet member, comprising: