JP2017034763A - Manufacturing device for magnet-inclusion type rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing device for a magnet-inclusion type rotor capable of obtaining a high-precision rotor in which slots are filled with anisotropic bond magnets at a high orientation degree.SOLUTION: A manufacturing device for a magnet-inclusion type rotor is configured to obtain the magnet-inclusion type rotor comprising magnetic poles consisting of anisotropic bond magnets in which a plurality of slots (12) disposed around an axis of a rotor core (1) are filled with a floating mixture that is a mixture of a binder resin and anisotropic magnet particles, and the floating mixture is solidified. The manufacturing device comprises a flow passage metal mold (73) including: a sprue (731) that is a flow passage for guiding the floating mixture injected from an injection nozzle from an upstream side to a downstream side in an axial direction; and a runner (732) consisting of a plurality of flow passages branched from the downstream side of the sprue in a lateral direction for guiding the floating mixture to the slots. The flow passage metal mold is capable of directly filling openings of the slots with the floating mixture from an opening or an open groove at a downstream side of the runner.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an apparatus for manufacturing an internal magnet type rotor using an anisotropic bonded magnet as a magnetic pole.

  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 motor is a motor having a permanent magnet in a rotor (rotor) and an armature winding (coil) in a stator (stator), and supplying alternating current (AC) to the armature winding. This is an AC motor that drives the rotor by generating a rotating magnetic field in the stator. In the synchronous machine, a surface magnet type motor (also referred to as “SPM motor”) in which a permanent magnet is disposed on the surface of the rotor, and the permanent magnet is disposed in the rotor. There is a built-in (implanted) magnet type motor (Interior Permanent Magnet Synchronous Motor / also simply referred to as “IPM motor” or “motor”). At present, not only high torque and power saving, but also IPM motors that can improve reliability by preventing scattering of permanent magnets are becoming mainstream.

  In conventional IPM motors, an internal magnet type rotor in which magnetic poles are formed by inserting rare earth sintered magnets cut or polished to a predetermined size into slots of the rotor core has been used. However, when optimizing an IPM motor, the shape of the permanent magnet contained in the rotor is substantially arc-shaped or substantially elliptical, the inner side surface and the outer side surface have different radii, the magnet thickness Often changes in the circumferential direction. Therefore, as a permanent magnet constituting the magnetic pole of the encapsulated magnet type rotor (appropriately referred to as “IPM rotor” or simply “rotor”), the shape can be freely replaced with a sintered magnet having a small degree of freedom in shape and easily causing defects. Rare earth anisotropic bonded magnets (which are also simply referred to as “bonded magnets”), which have a high degree of productivity and excellent productivity, have come to be used. Such a bonded magnet is formed by injecting a fluid mixture of rare earth anisotropic magnet particles (powder) and a binder resin into a slot in an orientation magnetic field. There is a description related to this in Patent Document 1 below.

JP 2003-47212 A

  In Patent Document 1, a rotor core is accommodated on the inner peripheral side of an orientation device (lower mold) in which permanent magnets and pole pieces are arranged on the outer peripheral side, and resin magnets (bond magnets) are filled into slots of the rotor core. Manufactures IPM rotors. At this time, the flow path from the outlet of the nozzle of the injection molding machine (simply referred to as “injection nozzle”) to the slot of the rotor core is formed by an intermediate mold and an upper mold stacked on the lower mold. Specifically, the upper mold is formed with an inlet (primary sprue) connected to the outlet of the injection nozzle, and the intermediate mold is connected to the downstream side of the upper mold inlet in the lateral direction (shaft). A runner extending in the direction perpendicular to the direction), a secondary sprue with a reduced diameter extending further in the orthogonal direction (axial direction) from the downstream side of the runner, and a gate (pin gate) formed at the tip thereof. Yes.

  As described above, in Patent Document 1, the resin magnet in a heated and melted state is inserted into the slot of the rotor core through the primary sprue, the runner, the secondary sprue, and the gate, as in the case of injection molding of a general resin product. Is filled.

  However, according to the research of the present inventor, when a bonded magnet (resin magnet) is injection molded in a slot of a rotor, at least the following points are greatly different from the case of injection molding of a general resin product. Became clear. First, unlike a cavity formed by a robust mold, a slot of a rotor is formed by laminating electromagnetic steel plates punched into a desired shape, and often has a thin and low rigidity portion on the outer peripheral side. For this reason, if the injection pressure (speed) is easily increased in order to prevent poor filling or improve the filling efficiency, distortion (deterioration of roundness, cylindricity, etc.) occurs around the slot (especially on the outer periphery). ) May occur. Such a rotor causes a decrease in the performance of the IPM motor and causes vibration and noise.

  Next, in the case of simple injection molding of a resin product, the viscosity of the resin during filling does not become a significant problem unless appearance defects such as short shots and sink marks occur. However, when injection molding a bonded magnet, anisotropic magnet particles (also simply referred to as “magnet particles”) mixed in the molten resin are within a short period of time from filling the slot to solidifying. It is necessary to change the orientation (orientation) along the orientation magnetic field applied to the slot. At this time, if the fluid mixture (especially molten resin) has an excessively high viscosity, the orientation variation of the magnet particles becomes insufficient, and the orientation degree of the bonded magnet filled in the slot is lowered, and consequently the performance of the rotor or motor is lowered. Can be invited.

  Furthermore, since a strong magnetic force acts on the magnet particles filled in the slot, the viscosity of the whole fluid mixture (apparent viscosity) in the slot tends to be higher than the viscosity of the binder resin itself. For this reason, when the bonded magnet is injection molded in the slot of the rotor core, the flow resistance from the outlet of the injection nozzle to the deepest part of the slot through the slot inlet becomes larger than in the case of injection molding of a resin product. Fillability and fluidity are likely to be lowered, and the fluidity in the flow path is also likely to be lowered. Such a decrease in filling property and fluidity can cause not only a decrease in productivity of the rotor but also a destabilization of quality.

  The present invention has been made in view of such circumstances, and can reduce the degree of orientation of the bond magnet filled in the slot and suppress deformation of the rotor, and efficiently produce an encapsulated magnet type rotor with stable quality. It is an object of the present invention to provide a manufacturing apparatus capable of performing the above.

  As a result of extensive research and trial and error, the present inventors have come up with the idea that a fluid mixture, which is a mixture of a binder resin and anisotropic magnet particles, is directly filled into the slot from the runner. It was. By realizing and developing this idea, the present invention described below has been completed.

<Embedded magnet type rotor manufacturing equipment>
(1) An encapsulated magnet type rotor manufacturing apparatus (simply referred to as “manufacturing apparatus”) of the present invention is heated to a slot that is disposed around the axis of the rotor core and that is open at least on one end side to flow. An encapsulated magnet used for obtaining an encapsulated magnet type rotor having magnetic poles made of an anisotropic bonded magnet that is filled with a fluid mixture, which is a mixture of the binder resin and anisotropic magnet particles, and solidified the fluid mixture A manufacturing apparatus of a mold rotor, wherein a sprue that is a flow path for guiding the fluid mixture injected from an injection nozzle from the upstream side to the downstream side along the axial direction is branched laterally from the downstream side of the sprue. And a runner comprising a plurality of flow paths for guiding the fluid mixture to each of the slots, and the fluid mixing from the opening or open groove on the downstream side of the runner to the slot opening. Characterized in that it comprises a flow path mold can be filled directly.

(2) According to the production apparatus of the present invention, a fluid mixture (also simply referred to as “mixture”) composed of a binder resin (also simply referred to as “resin”) and anisotropic magnet particles (also simply referred to as “magnet particles”). .) Is filled directly into the slot of the rotor core via the sprue and runner. For this reason, the injected mixture can pass through a thicker and shorter passage than before, and can be filled in the slot. In other words, the mixture is filled in the slot without passing through a gate (such as a pin gate) that narrows the flow path of the runner. For this reason, the flow resistance which a mixture receives in the flow path from the exit of an injection nozzle to the entrance of a slot is small. As a result, even if the injection pressure (injection speed) is not increased too much, the mixture is sufficiently filled in the slot, and a rotor with less deformation and distortion can be obtained.

  In addition, such a mixture that moves through a thick and short flow path has a small amount of heat removed from the flow path mold, and a temperature drop during the movement of the flow path is small. For this reason, the mixture is filled into the slots while maintaining a relatively low viscosity state. As a result, the flow resistance is reduced and the increase in the injection pressure is suppressed, and the posture variation of the magnet particles in the slot is facilitated, so that a rotor having a bond magnet with a high degree of orientation can be obtained.

<Others>
(1) Unless otherwise specified, the motor referred to in this specification includes a generator in addition to an electric motor and can be called a rotating machine. In addition, in the internal magnet type motor referred to in this specification, in addition to the original synchronous machine in which the rotation speed changes in synchronization with the frequency of the alternating current supplied to the coil (armature winding) provided in the stator, 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 Hall element, a rotary encoder, or a resolver is also included. 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.

(2) The rotor referred to in this specification may be an inner rotor or an outer rotor. In the case of the outer rotor, the form of the rotor core when the bonded magnet is injection-molded may be a form that can be easily attached to the manufacturing apparatus, and may be different from the final form of the outer rotor when assembled to the motor. Good.

  The form and number of the slots are selected according to the specifications of the rotor and the motor, and it is preferable that the plurality of slots be evenly arranged around the axis of the rotor core during injection molding. “Equally arranged” means that the pitch of slots arranged in the circumferential direction is equal.

(3) In this specification, the side closer to the rotation center of the rotor is referred to as “inner circumference side”, and the side far from the rotation center is referred to as “outer circumference side”. The “axial direction” is a direction along the central axis of the rotor core or the rotation axis when the injection molding is performed. Usually, this axial direction is the moving direction of the mold (movable side) constituting the manufacturing apparatus of the present invention, and the extending direction of the sprue connected to the injection nozzle. Similarly, “around the axis” is the circumferential direction around the central axis of the rotor core or its rotation axis when injection molding is performed. The “lateral direction” is a direction orthogonal to the axial direction unless otherwise specified, and is usually a direction along the dividing surface of the mold. Unless otherwise specified, the injection molding referred to in this specification includes transfer molding.

(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 sectional drawing which shows the state which opened the shaping die. It is sectional drawing which shows the state which closed the mold (mold clamping). It is a perspective view which shows a rotor core and the solidified material which arises in the flow path which reaches the slot.

  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 as a product-by-process claim in a certain case.

<Flow path mold>
The flow path mold according to the present invention constitutes a flow path of the mixture from the outlet of the injection nozzle to the inlet of the slot. This flow path includes a sprue extending from the upstream side to the downstream side along the axial direction, and a runner branching laterally from the downstream side of the sprue and extending to at least the inlet (opening) of the slot. The cross-sectional shape of each flow path is not limited, but if the shape is circular or arcuate (fan-shaped), the ratio (S / V) of the surface area (S) to the volume (V) of the flow path can be reduced, and the flow is performed. The amount of heat removed from the mixture and thus the temperature drop can be suppressed.

  If the runner is formed by bringing one end surface (for example, the lower end surface) of the flow channel mold into contact with the opening side end surface (for example, the upper end surface) of the rotor core, the cross-sectional shape of the flow path of the runner is shown in FIG. A shape as shown is preferable. Specifically, the upper cross-section of the runner channel is semicircular or arcuate (fan-shaped), which is an ideal part of the circular shape, but the lower cross-section connected to the upper cross-section is A shape or a trapezoid is preferable. In this case, the runner formed on one end surface of the flow path mold has an open groove shape. During injection molding, a part of the groove is connected to and communicates with the opening of the slot, and the mixture is filled into the slot.

  The flow path mold may be composed of one piece (sheet), or may be composed of two or more pieces. The flow path mold according to the present invention does not require a secondary sprue or gate, and it is sufficient to have a sprue and a runner.

  When the one end surface of the flow path mold contacts the opening side end surface of the rotor core, it is preferable that the whole or at least the vicinity of the contact surface is made of a nonmagnetic material. Thereby, the leakage to the flow-path die side of the orientation magnetic field applied to a rotor core can be suppressed. In addition, the nonmagnetic material referred to in this specification means a material having a lower magnetic permeability or saturation magnetization than a ferromagnetic material constituting the rotor core or the yoke. Examples of such a nonmagnetic material include austenitic stainless steel.

  The flow path mold may be a type that does not heat the flow path (sprue or runner) (so-called cold runner) or a type that heats the flow path (so-called hot runner). However, in the case of the present invention, since the flow path can be shortened and the cross-sectional area thereof can be easily expanded, the viscosity or high fluidity of the mixture can be ensured without heating the flow path. For this reason, even the cold runner type, which can simplify the structure of the flow path mold and the manufacturing equipment, can reduce the injection pressure and hence the filling pressure in the slot, and can stably suppress the distortion of the rotor and increase the orientation of the bond magnet. Can be planned. Of course, by further heating the flow path, further reduction in viscosity and high fluidity of the mixture may be stably ensured.

<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 insulation-coated metal particles (soft magnetic particles), 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 around the shaft hole provided in the center of the rotor core, the shape and the number thereof do not matter. Since the slot according to the present invention is filled with the bond magnet, the degree of freedom of the shape is high. For example, even in the radial type extending linearly from the center to the radial direction, the convex type having a convex shape on the inner peripheral side However, it may be a multilayer type having a plurality in the radial direction.

《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 powder to be used is not limited. For example, high-performance rare earth anisotropic magnet powder such as Nd-Fe-B magnet powder, Sm-Fe-N magnet powder, Sm-Co magnet powder, etc. Is preferred. The anisotropic magnet powder is not limited to a single powder, and may be a mixed powder obtained by mixing a plurality of types of powders. The mixed powder is not limited to those having different component compositions, and may have different particle size distributions. For example, a combination of coarse powder and fine powder of Nd-Fe-B magnet powder or a combination of coarse powder of Nd-Fe-B magnet powder and fine powder of Sm-Fe-N magnet powder may be used. By using such an anisotropic magnet powder, it is possible to increase the density of the magnet particles and thus improve the performance of the rotor and motor. The anisotropic bonded magnet according to the present invention may be a mixture of isotropic magnet particles, ferrite magnet particles, and the like as long as anisotropic magnet particles are present.

  As the binder resin, known materials including rubber can be used. Considering the fluidity and filling properties of the mixture, the binder resin is preferably a thermoplastic resin in the case of injection molding. Examples of the thermoplastic resin include polyethylene, polypropylene, polystyrene, acrylonitrile / styrene resin, acrylonitrile / butadiene / styrene resin, methacrylic resin, vinyl chloride, polyamide (PA), polyacetal, polyethylene terephthalate, ultrahigh molecular weight polyethylene, polybutylene terephthalate. Methylpentene, polycarbonate, polyphenylene sulfide (PPS), polyetheretherketone, liquid crystal polymer, polytetrafluoroethylene, polyetherimide, polyarylate, polysulfone, polyethersulfone, polyamideimide and the like.

  The fluid mixture according to the present invention is prepared by, for example, heating raw material pellets made of magnet particles and resin introduced from a hopper with a heater provided in an injection cylinder or the like. The heating temperature at this time is usually adjusted within a temperature range equal to or higher than the melting point of the resin. If the flow path mold according to the present invention is used, the binder resin is not limited to a resin having a low melting point or crystallization temperature (for example, PA), but also to a resin having a high melting point or crystallization temperature (for example, PPS). A highly accurate (low distortion) rotor having a bond magnet with a high degree of orientation can be obtained. A resin having a high melting point is suitable as a binder resin because it has excellent heat resistance and durability. As these resins, for example, a resin having a melting point of 280 ° C. or higher, further 300 ° C. or higher can be used as the binder resin. Note that the crystallization temperature is lower than the melting point, but can be changed depending on the cooling rate or the like. Therefore, the melting point is used here as one index for classifying the resin. However, the binder resin according to the present invention may be crystalline or amorphous regardless of its crystallinity.

  When the anisotropic bonded magnet is formed by transfer molding, a thermosetting resin may be used as the binder resin. As the thermosetting resin, for example, epoxy resin, unsaturated polyester resin, amino resin, phenol resin, polyamide resin, polyimide resin, polyamideimide resin, urea resin, melamine resin, urea resin, diallyl phthalate resin, polyurethane, etc. are used. Can do.

《Use of internal magnet type motor》
The motor provided with the rotor according to the present invention may be used for any purpose. For example, a motor for driving a vehicle used in an electric vehicle, a hybrid vehicle, a railway vehicle, etc., an electric appliance used in an air conditioner, a refrigerator, a washing machine, or the like. Suitable for motors and the like.

  The present invention will be described more specifically with reference to examples. In this embodiment, an inner rotor manufacturing apparatus used for an IPM motor will be described. Note that the vertical direction described below is the vertical direction in the figure unless otherwise specified, regardless of the actual arrangement, movable direction, and the like.

《Inner rotor》
As shown in FIG. 2, the rotor core 1 serving as the skeleton of the inner rotor is formed by laminating silicon steel plates punched into a desired shape. More specifically, the rotor core 1 has a substantially cylindrical shape, a shaft hole (not shown) provided in the center, and six substantially U-shaped through-holes arranged evenly around the central axis. Slots 121 to 126 (collectively referred to as “slot 12”). Each silicon steel plate from which the shaft hole and the slot 12 are punched is fixed by rivets or caulking.

  A rare earth anisotropic bonded magnet (simply referred to as “bonded magnet”) is injection-molded in each slot 12 of the rotor core 1 in an orientation magnetic field, whereby an inner rotor is obtained. FIG. 2 also shows the solidified product 2 of the fluid mixture formed in the flow path from the injection nozzle to the inlet (opening) of each slot 12 during the injection molding.

  The solidified product 2 reflects a flow path when the fluid mixture is filled in each slot 12, and includes a single short and thick sprue portion 21 extending in the axial direction, and each slot from the sprue portion 21. 12 runner portions 221 to 226 extending in the lateral direction toward the center of the 12 openings (collectively referred to as “runner portions 22”). More specifically, the sprue portion 21 has a conical shape whose diameter increases from the upstream side toward the downstream side. The runner portion 22 has a semi-cylindrical shape that is smoothly connected from the downstream side of the sprue portion 21, and the plane side thereof is in contact with one end surface (the upper end surface in FIG. 2) of the rotor core 1. The runner portion 22 straddles the opening portion in the vicinity of the center (innermost peripheral side) of each slot 12.

<Molding mold>
(1) Outline FIG. 1A and FIG. 1B (hereinafter referred to as “FIG. 1”) show a molding die D used when injection molding a rare earth anisotropic bonded magnet into the slot 12 of the rotor core 1. . FIG. 1A shows a state in which the mold is opened, and FIG. 1B shows a state in which the mold is closed.

  The molding die D is used by being set in a general-purpose vertical or horizontal injection molding machine. Such an injection molding machine usually measures a raw material supplied from a hopper and a hopper for feeding pellets produced by kneading a binder resin and rare earth anisotropic magnet powder (particles), which are raw materials for a bond magnet. Screw to transport, Cylinder to store screw, Heater to heat and melt raw material in cylinder, Injection nozzle attached to tip of cylinder and connected to injection port of molding die D, Applying back pressure to screw and moving forward And an actuator that ejects the melted raw material (fluid mixture) from the injection nozzle. Further, a mold clamping mechanism (hydraulic actuator or the like) for opening and closing the molding die D, a protruding mechanism for taking out the inner rotor after injection molding, and the like are also provided. In addition, although the manufacturing apparatus of this invention may be grasped | ascertained as the injection molding machine which set the molding die, it can also grasp | ascertain as a molding die single-piece | unit. Below, the molding die D important for this invention is explained in full detail.

(2) Molding Mold The molding mold D is a so-called two-plate mold as shown in FIG. 1, but specifically, a three-layer structure of a base mold 5, an orientation mold 6 and an injection mold 7. Consists of.

  The base mold 5 is housed in an attachment portion 51 attached to the movable side of the injection molding machine, a protrusion distance securing portion 52 disposed on the attachment portion 51, and a center of the protrusion distance securing portion 52 so as to be able to advance and retreat. And a protruding portion 53. One side (upper side in FIG. 1) of the protrusion 53 is formed in a cylindrical shape having substantially the same outer diameter as that of the rotor core 1, and is fitted into the shaft hole of the rotor core 1 at the tip (upper end side in FIG. 1). A shaft portion 531 is formed to protrude. Therefore, the tip end side of the protrusion 53 has a stepped shape that can hold the rotor core 1. Further, the protruding portion 53 is supported by the protruding distance securing portion 52, and its protruding amount is regulated.

  When the shaft hole of the rotor core 1 is fitted into the shaft portion 531, the other end surface (lower end surface) of the rotor core 1 comes into contact with the stepped surface on the distal end side of the protruding portion 53. In this way, the rotor core 1 is held with high accuracy on the tip side of the protrusion 53. The protruding portion 53 is made of austenitic stainless steel (nonmagnetic material). Further, the forward and backward driving of the protrusion 53 is performed by a protrusion mechanism (actuator or the like) of an injection molding machine (not shown).

  The orientation mold 6 includes a base portion 61, a frame portion 62 that is coaxially installed in the center of the base portion 61 in the axial direction, and is accommodated in the frame portion 62 so as to abut against each end surface of the frame portion 62. The shielding plates 63 and 64, the shielding ring 65 inscribed in the frame 62 and sandwiched between the shielding plates 63 and 64, and the annular orientation magnetic field body 66 accommodated by the shielding plates 63 and 64 and the shielding ring 65. Is provided. The shielding plates 63 and 64 and the shielding ring 65 are made of austenitic stainless steel (nonmagnetic material).

The orientation magnetic field body 66 has six orientation yokes (not shown) projecting radially and outwardly on the outer peripheral side corresponding to the slots 12 of the rotor core 1 and bridges the orientation yokes in a circular arc shape, and smoothly continues in the center. 12 permanent magnets (not shown) that serve as orientation magnetic field sources arranged with the same poles facing the opposite side surfaces in the circumferential direction of the orientation yokes. ).
An electromagnet can be used as the orientation magnetic field source. However, by using a permanent magnet made of a rare earth sintered magnet or the like, the orientation magnetic field 66 and, consequently, the molding die D can be reduced in size and simplified. Thereby, the injection molding of the bond magnet becomes possible by combining the molding die D according to the present embodiment with various general-purpose injection molding machines.

  The injection mold 7 includes an annular base part 71, an attachment part 72 attached to the fixed side of the injection molding machine, a flow path part 73 (flow path mold) fitted into the base part 71, an injection nozzle, A locating ring 74 for centering the mold and a nozzle touch part 7311 for contacting the injection nozzle and suppressing leakage of the fluid mixture are provided.

  The flow path portion 73 has a substantially T-shaped annular shape, and has a sprue portion 731 and a runner portion 732 respectively corresponding to the sprue portion 21 and the runner portion 22 described above. The opening on the upstream end side of the sprue portion 731 contacts the outlet of the injection nozzle. The runner portion 732 is an open groove having a substantially semicircular cross section extending in six lateral directions that are evenly arranged from the downstream end side of the sprue portion 731.

  When the mold is closed and injection molding is performed as shown in FIG. 1B, the upper end surface and the lower end surface of the rotor core 1 are sandwiched between the lower end surface of the flow path portion 73 and the upper end surface (stepped surface) of the protruding portion 53, respectively. It is in the state. When the lower end surface of the runner portion 732 and the upper end surface of the rotor core 1 are pressed against each other, a closed flow path having a substantially semicircular cross section is formed, but the open groove of the runner portion 732 and the opening of the slot 12 overlap. Only the area to be connected is in the communication state. As can be seen from FIG. 1B, the shaft portion 531 of the protruding portion 53 slightly protrudes at the lower end side center of the runner portion 732 when the mold is closed. It may be considered that the tip portion of the shaft portion 531 also constitutes a part of the flow path according to the present embodiment. In addition, the flow path part 73 is also made of austenitic stainless steel (nonmagnetic material), like the protruding part 53.

  A combination of the molding die D according to the present embodiment and a general-purpose injection molding machine, after performing injection molding in a state where the mold is closed as shown in FIG. 1B, the mold is opened as shown in FIG. 1A, When the protrusion 53 is advanced, an inner rotor of the IPM rotor in which the bond magnet is filled in the slot 12 is obtained. The solidified product 2 generated in the flow path portion 73 is recovered and reused after being subjected to a pulverization process or the like.

DESCRIPTION OF SYMBOLS 1 Rotor core 12 Slot 5 Base mold 6 Orientation mold 7 Injection mold 73 Flow path part (flow path mold)

Claims (2)

A fluid mixture, which is a mixture of a binder resin and anisotropic magnet particles that are heated and in a fluid state, is filled into a slot that is disposed around the axis of the rotor core and that is open at least on one end side. An apparatus for producing an encapsulated magnet type rotor for use in obtaining an encapsulated magnet type rotor having magnetic poles made of an anisotropic bonded magnet obtained by solidifying a mixture,
A sprue that is a flow path for guiding the fluid mixture injected from the injection nozzle from the upstream side to the downstream side along the axial direction and the fluid mixture is branched from the downstream side of the sprue in the lateral direction to each of the slots. And a runner comprising a plurality of flow paths for guiding the flow mixture, and comprising a flow path mold capable of directly filling the fluid mixture into an opening of the slot from an opening or an open groove on the downstream side of the runner. An apparatus for producing an internal magnet type rotor.   The internal magnet rotor manufacturing apparatus according to claim 1, wherein the flow path mold is made of a nonmagnetic material.

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