Motor core manufacturing apparatus and method for manufacturing motor core

Abstract

A motor core manufacturing device according to the present disclosure includes: a die including a first die and a second die that can hold a motor core including a plurality of resin filling portions that are annularly disposed at prescribed intervals; an annular chamber that is in communication with a resin filling passage which is formed in the first die and an end portion of which can be in communication with each of the plurality of resin filling portions and can accommodate an annular resin material having a prescribed thickness in the interior thereof; an annular plunger that can move within the annular chamber; and one to a plurality of projecting portions that project from the inner surface except the portion in communication with the resin filling passage within the annular chamber toward the inner side of the annular chamber.

Description

[Technical field]

[0001] The present disclosure relates to a motor core manufacturing apparatus and a motor core manufacturing method. [Background technology]

[0002] Some rotating electric machines have permanent magnets attached to a motor core, for example, a rotor core, which has a number of slots arranged in a circular shape at predetermined intervals. A known method for attaching permanent magnets to a motor core is to insert the permanent magnets into the slots, fill the surrounding area with resin, and then harden the resin.

[0003] Patent No. 6410776 (see Figures 4 to 6 in particular) describes a method in which resin is filled into the magnet insertion holes of a rotor core to fix the magnets in place by pouring a resin tablet into the center of a gate mold. Summary of the Invention [Problem to be solved by the invention]

[0004] In the case of the device described in Patent No. 6410776, the part of the gate where the resin tablet is poured (generally called the "pot" or "chamber") is formed in the center of the gate mold, while the magnet insertion hole is disposed on the outer periphery of the rotor core, the distance between the pot and the magnet insertion hole is great, and the overall length of the gate (also called the resin filling path) is long. If the resin filling path becomes longer like this, the amount of resin that hardens outside the resin filling part (generally called "cull") increases, and the amount of resin required to fill the magnet insertion hole tends to increase.

[0005] The present disclosure provides a motor core manufacturing apparatus and a motor core manufacturing method that reduce the amount of resin used. [Means for solving the problem]

[0006] A motor core manufacturing apparatus according to a first aspect of the present disclosure includes a mold capable of holding a motor core including a plurality of resin filling sections arranged in a ring at a predetermined interval, and including a first mold located at one axial end side of the motor core and a second mold located at the other axial end side of the motor core, an annular chamber formed in the first mold and communicating with a resin filling passage whose end is capable of communicating with each of the plurality of resin filling sections, and capable of containing annular resin material having a predetermined thickness therein, an annular plunger capable of moving within the annular chamber, and one or more protrusions protruding toward the inside of the annular chamber from an inner surface of the annular chamber excluding a portion that communicates with the resin filling passage.

[0007] In the motor core manufacturing apparatus as described above, by forming a convex portion in the chamber, the amount of resin that hardens in the chamber can be reduced, and the amount of resin used can be suppressed.

[0008] A motor core manufacturing apparatus according to a second aspect of the present disclosure is a motor core manufacturing apparatus according to the first aspect of the present disclosure, wherein the annular chamber is formed at a position that overlaps with the resin filling portion of the motor core held in the mold in a planar view, and the resin filling path is composed of a plurality of passages extending in a vertical direction from the upper or lower surface of the annular chamber toward the resin filling portion.

[0009] In the motor core manufacturing apparatus as described above, the resin filling path can be made short, so that the amount of resin that hardens outside the resin filling portion can be reduced.

[0010] A motor core manufacturing apparatus according to a third aspect of the present disclosure is a motor core manufacturing apparatus according to the first or second aspect of the present disclosure, wherein the convex portion includes a first convex portion formed on the surface of the first mold facing the plunger at a position excluding the area communicating with the resin filling path, and extending in a direction intersecting the surface of the first mold facing the plunger.

[0011] In the motor core manufacturing apparatus as described above, the first convex portion can reduce the amount of resin that hardens in the chamber.

[0012] A motor core manufacturing apparatus according to a fourth aspect of the present disclosure is a motor core manufacturing apparatus according to the third aspect of the present disclosure, wherein a side wall of the resin filling passage includes a tapered surface inclined by a first angle with respect to the extension direction of the resin filling passage so that the diameter decreases from one opening communicating with the annular chamber to the other opening communicating with the multiple resin filling sections, and a side wall of the first convex portion includes a tapered surface inclined by a second angle smaller than the first angle with respect to the extension direction of the resin filling passage so that the area of ​​the first convex portion decreases toward its tip.

[0013] In the motor core manufacturing apparatus as described above, the core can be easily released from the mold.

[0014] A motor core manufacturing apparatus according to a fifth aspect of the present disclosure is a motor core manufacturing apparatus according to the third or fourth aspect of the present disclosure, wherein the convex portion further includes a second convex portion formed in a portion of the surface of the annular plunger facing the first die excluding the area facing the first convex portion, and extending in a direction intersecting the surface of the annular plunger facing the first die.

[0015] In the motor core manufacturing apparatus as described above, the first convex portion and the second convex portion can further reduce the amount of resin that hardens in the chamber.

[0016] A motor core manufacturing apparatus according to a sixth aspect of the present disclosure is a motor core manufacturing apparatus according to the fifth aspect of the present disclosure, wherein a side wall of the resin filling passage includes a tapered surface inclined by a first angle with respect to the extension direction of the resin filling passage so that the diameter decreases from one opening communicating with the annular chamber to the other opening communicating with the multiple resin filling sections, a side wall of the first convex portion includes a tapered surface inclined by a second angle smaller than the first angle with respect to the extension direction of the resin filling passage so that the area of ​​the first convex portion decreases toward its tip, and a side wall of the second convex portion includes a tapered surface inclined by a third angle smaller than the second angle with respect to the extension direction of the resin filling passage so that the area of ​​the second convex portion decreases toward its tip.

[0017] In the motor core manufacturing apparatus as described above, the cull can be separated from the die simply by moving the die, and the cull can then be smoothly released from the plunger.

[0018] A motor core manufacturing apparatus according to a seventh aspect of the present disclosure is a motor core manufacturing apparatus according to the first or second aspect of the present disclosure, wherein the convex portion includes a third convex portion formed on the surface of the annular plunger facing the first mold at a position excluding the area facing the resin filling passage, and extending in a direction intersecting the surface of the annular plunger facing the first mold.

[0019] In the motor core manufacturing apparatus as described above, the amount of resin that hardens in the chamber can be further reduced by the third convex portion.

[0020] A motor core manufacturing apparatus according to an eighth aspect of the present disclosure is a motor core manufacturing apparatus according to the seventh aspect of the present disclosure, wherein a side wall of the resin filling passage includes a tapered surface inclined by a first angle with respect to the extension direction of the resin filling passage so that the diameter decreases from one opening communicating with the annular chamber to the other opening communicating with the multiple resin filling sections, and a side wall of the third convex portion includes a tapered surface inclined by a fourth angle smaller than the first angle with respect to the extension direction of the resin filling passage so that the area of ​​the third convex portion decreases toward its tip.

[0021] In the motor core manufacturing apparatus as described above, the plunger can be easily released from the mold when the cull is released from the mold.

[0022] A manufacturing method for a motor core according to a ninth aspect of the present disclosure includes the steps of: pouring an annular resin material having a predetermined thickness into an annular chamber, wherein the inner surface of the annular chamber, excluding a portion communicating with a resin filling path in the annular chamber, has one or more convex portions formed so as to protrude toward the inside of the annular chamber; holding a motor core including a plurality of resin filling portions arranged in a ring shape at predetermined intervals in a mold in which the resin filling path communicating with the annular chamber is formed, so that ends of the resin filling path communicate with the plurality of resin filling portions; heating and softening the annular resin material in the annular chamber; operating an annular plunger in a direction approaching the mold to fill the plurality of resin filling portions with softened resin made of the annular resin material softened in the annular chamber; and hardening the softened resin filled in the plurality of resin filling portions.

[0023] In the manufacturing method of the motor core as described above, by forming a convex portion inside the chamber, the amount of resin that hardens outside the resin filling portion can be reduced, and the amount of resin used can be saved. Effect of the Invention

[0024] According to the motor core manufacturing apparatus and motor core manufacturing method disclosed herein, it is possible to reduce the amount of resin used. [Brief description of the drawings]

[0025] [Figure 1] 1 is a schematic explanatory diagram showing an example of a motor core manufacturing apparatus according to a first embodiment of the present disclosure. [Figure 2A] 2 is a schematic perspective view showing an example of a rotor core used in the motor core manufacturing apparatus shown in FIG. 1. [Figure 2B] 2 is a schematic perspective view showing an example of an annular resin material used in the motor core manufacturing apparatus shown in FIG. 1. [Figure 3A] FIG. 2 is a perspective view showing an example of a lower mold shown in FIG. [Figure 3B] FIG. 3B is a cross-sectional view taken along line AA in FIG. 3A. [Figure 4] 4 is a flowchart showing an example of a method for manufacturing a motor core according to the first embodiment of the present disclosure. [Diagram 5] 2 is an explanatory diagram showing an example of an operating state of the motor core manufacturing apparatus shown in FIG. 1. [Figure 6] 2 is an explanatory diagram showing an example of an operating state of the motor core manufacturing apparatus shown in FIG. 1. [Figure 7] 2 is an explanatory diagram showing an example of an operating state of the motor core manufacturing apparatus shown in FIG. 1. [Figure 8] 2 is an explanatory diagram showing an example of an operating state of the motor core manufacturing apparatus shown in FIG. 1. [Figure 9A] FIG. 7 is an enlarged cross-sectional view taken along line BB in FIG. 6. [Figure 9B] 8 is an enlarged cross-sectional view taken along line CC in FIG. 7. [Figure 10] This is an oblique view showing an example of the cull shown in Figure 8. [Figure 11] FIG. 13 is an enlarged view showing a first modified example of a protrusion. [Figure 12] FIG. 13 is an enlarged view showing a second modified example of a protrusion. [Figure 13]FIG. 13 is an enlarged view showing a third modified example of a protrusion. [Figure 14] FIG. 13 is an enlarged view showing a fourth modified example of a protrusion. [Figure 15] FIG. 11 is a schematic explanatory diagram showing an example of a motor core manufacturing apparatus according to a second embodiment of the present disclosure. [Figure 16A] 1. FIG. 4 is a perspective view showing a modified example of a lower die of the motor core manufacturing apparatus shown in FIG. [Figure 16B] 1. FIG. 4 is a bottom view showing a modified example of a lower die of the motor core manufacturing apparatus shown in FIG. [Figure 17] FIG. 11 is a schematic explanatory diagram showing an example of a motor core manufacturing apparatus according to a third embodiment of the present disclosure. [Figure 18] FIG. 18 is a perspective view showing an example of the lower mold shown in FIG. [Figure 19] 18 is a perspective view showing a modified example of a lower die of the motor core manufacturing apparatus shown in FIG. 17. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] This application is based on Patent Application No. 2023-048548 filed in Japan on March 24, 2023, the contents of which form part of the content of this application. In addition, the present disclosure will be more fully understood from the following detailed description. Further scope of application of the present application will become apparent from the following detailed description. However, the detailed description and specific examples are preferred embodiments of the present disclosure and are described for the purpose of explanation only. From this detailed description, various changes and modifications within the spirit and scope of the present disclosure will be apparent to those skilled in the art. Applicants have no intention of dedicating any of the described embodiments to the public, and all disclosed modifications and alternatives, which may not literally fall within the scope of the claims, are intended to be part of the invention under the doctrine of equivalents. Like reference numbers and designations in the various drawings indicate like elements.

[0027] Hereinafter, each embodiment for carrying out the present disclosure will be described with reference to the drawings. In addition, the scope necessary for the description to achieve the object of the present disclosure will be shown in a schematic manner below, and the scope necessary for the description of the relevant part of the present disclosure will be mainly described, and the parts for which description is omitted will be described according to the publicly known technology. In addition, the same or similar reference numerals are given to the same or corresponding members in the drawings, and duplicate descriptions are omitted. Furthermore, when a single drawing contains a plurality of the same or corresponding members, in order to make the drawing easier to see, only some of them may be given reference numerals.

[0028] <First embodiment> An example of a motor core manufacturing apparatus and a motor core manufacturing method according to the present disclosure will be described below as a first embodiment. In the motor core manufacturing apparatus according to the present embodiment, an inner rotor type rotor core is used as the motor core. The motor core manufacturing apparatus is an apparatus used for fixing permanent magnets to slots formed in the rotor core. Here, the motor core in the present disclosure includes not only a laminated body formed by laminating electromagnetic steel sheets, but also a semi-finished product (of a motor) in which some parts are attached to the laminated body. The motor core manufacturing apparatus according to the present embodiment may be used to fix magnets to a motor core having an open slot in which a part of the slot is open to the outside, instead of a completely closed slot as in the embodiment shown below. Alternatively, the motor core manufacturing apparatus according to the present embodiment may be used to resin-mold a portion of a stator core around which a coil is wound, or to fill a through hole or the like provided in the axial direction of a laminated core without crimping with resin to fix the laminated core together.

[0029] (Motor core manufacturing equipment) Fig. 1 is a schematic explanatory diagram showing an example of a motor core manufacturing apparatus according to a first embodiment of the present disclosure. As shown in Fig. 1, the motor core manufacturing apparatus 1 according to this embodiment is an apparatus capable of fixing the permanent magnets 3 by injecting and hardening resin into slots 4 into which the permanent magnets 3 of an inner rotor type rotor core 2 are inserted. In the following description, to facilitate understanding, the X direction shown in Fig. 1 may be described as the left-right direction, the Y direction as the front-rear direction, and the Z direction as the height direction (or up-down direction).

[0030] 2A and 2B are schematic perspective views showing an example of a rotor core and an annular resin material used in the motor core manufacturing apparatus shown in FIG. 1. As shown in FIG. 2A, the rotor core 2 can be made of a substantially cylindrical magnetic body formed by laminating a plurality of thin electromagnetic steel sheets having a thickness of about 0.10 to 10.00 mm, more preferably about 0.20 to 0.65 mm. The axial center portion of the rotor core 2 may be provided with a through hole 5 into which a shaft constituting a rotating shaft is inserted when assembled into a motor. In addition, the rotor core 2 may be provided with a plurality of (16 in FIG. 2A) slots 4 arranged in an annular shape extending along the axial direction of the rotor core 2 so as to surround the through hole 5. The slots 4 are an example of a resin-filled portion, and can be configured as a shape into which a permanent magnet 3 (see FIG. 1) can be inserted, for example, a rectangular parallelepiped or arc-shaped through hole penetrating the rotor core 2 in the thickness direction, but the specific shape is not particularly limited. Similarly, the number and arrangement of the slots 4 can be arbitrarily changed.

[0031] The permanent magnets 3 are inserted and fixed into the slots 4 of the rotor core 2. The permanent magnets 3 can be formed, for example, of a rectangular parallelepiped or arc-shaped block body slightly smaller than the slots 4. The permanent magnets 3 may or may not be magnetized when inserted into the slots 4. Furthermore, the permanent magnets 3 may or may not be divided in the lamination direction or in a direction perpendicular to the lamination direction. When the permanent magnets 3 are inserted into the slots 4, at least a partial gap is formed between the outer peripheral surface of the permanent magnets 3 and the inner peripheral surface of the slots 4. The gap formed in the slots 4 can function as a filling space 6 into which resin is filled.

[0032] The annular resin material P used in the motor core manufacturing apparatus 1 according to this embodiment can be mainly made of a thermosetting resin material. More specifically, the annular resin material P can be made of a material mainly containing a thermosetting resin material such as an epoxy resin, a phenol resin, an unsaturated polyester resin, or a cyanate resin. In addition to the thermosetting resin material, a curing agent, a filler, etc. may be added to the annular resin material P.

[0033] 2B, the annular resin material P can be formed of a resin molded body molded into an annular, preferably circular, shape having a predetermined thickness. In other words, the annular resin material P according to this embodiment can be said to be a resin molded body molded into a doughnut shape having a through hole H in the center. The detailed dimensions of this annular resin material P may be adjusted according to the shapes of the chamber 30 and the resin filling path 25, which will be described later, and the capacity of the filling space 6.

[0034] 1, the motor core manufacturing apparatus 1 according to this embodiment includes at least a mold 20 capable of holding a rotor core 2, an annular chamber 30 capable of accommodating an annular resin material P, and an annular plunger 35 capable of moving within the chamber 30. Furthermore, each of the above-mentioned components can be accommodated within the manufacturing apparatus main body 10 or attached to the manufacturing apparatus main body 10 in an appropriate position.

[0035] The manufacturing apparatus main body 10 may include a base 11, a plurality of (for example, four) support columns 12 erected on the surface of the base 11, and a top plate 13 supported at the tip portions of the support columns 12. An upper die 21, which is an example of a second die of a die 20 described below, may be fixed to the lower surface of the top plate 13, and may be capable of being raised and lowered in the vertical direction together with the support columns 12 and this upper die 21 by using an actuator (not shown). The raising and lowering operation of the top plate 13 may be performed mainly when the rotor core 2 is held in the die 20, or when the rotor core 2 is removed from the die 20 and carried out.

[0036] The die 20 is a member for holding the rotor core 2. Specifically, the die 20 may include a lower die 22 as an example of a first die located at one end, for example, the lower end side, of the rotor core 2 in the axial direction, and an upper die 21 as an example of a second die located at the other end, for example, the upper end side, of the rotor core 2 in the axial direction.

[0037] Upper die 21 may be configured as a plate-like member having a predetermined thickness, with its upper surface attached to top plate 13 and its lower surface capable of coming into contact with the upper surface of rotor core 2 .

[0038] FIG. 3 shows an example of the lower die shown in FIG. 1, where FIG. 3A is a perspective view and FIG. 3B is a cross-sectional view cut along line AA in FIG. 3A. As shown in FIG. 3A, the lower die 22 may be made of a plate-like member having a predetermined thickness, and at least a part of its lower surface 22L side may function as a part of an annular chamber 30 described later, and its upper surface 22U side may be capable of abutting against the lower surface of the rotor core 2. A columnar protrusion 23 that defines the inner wall surface of the chamber 30 described later may be provided in the center of the lower surface 22L side of the lower die 22. In addition, the lower die 22 may further include a lifter 24 that can raise and lower the lower die 22 in order to introduce an annular resin material P into the chamber 30 or clean the resin filling path 25, etc., as shown in FIG. 1.

[0039] Furthermore, a plurality of resin filling paths 25 for connecting between the chamber 30 and a plurality of filling spaces 6 of the rotor core 2 placed on the upper surface 22U of the lower mold 22 may be arranged in the region near the protruding portion 23 on the lower surface 22L of the lower mold 22. As shown in Fig. 3B, the resin filling paths 25 can be composed of a plurality of passages having one end opening to the upper surface 22U of the lower mold 22 and the other end opening to the lower surface 22L, more specifically, to the bottom surface of an annular resin inflow groove 26 formed outside the side surface of the protruding portion 23 of the lower surface 22L.

[0040] The resin inflow groove 26 can function as the upper surface of the chamber 30 described later. The resin inflow groove 26 that can function as the upper surface of the chamber 30 is preferably formed at a position that overlaps with the slot portion 4 of the rotor core 2 held in the mold 20 in a plan view. In this case, the resin filling path 25 can communicate the upper surface of the chamber 30 and the slot portion 4 over a short distance, and the amount of resin that hardens in the resin filling path 25 and the chamber 30, i.e., the amount of cull P3 (see FIG. 10), can be reduced compared to the conventional case. Note that the resin inflow groove 26 is formed with a first protrusion 61 as an example of a protrusion 60 described later, and the configuration of the first protrusion 61 will be described later.

[0041] Resin filling path 25, which is made up of a plurality of passages, extends vertically from resin inflow groove 26, which constitutes part of the upper surface of chamber 30, toward filling space 6 in slot portion 4. In addition, side wall 27 of resin filling path 25 may be a tapered surface that is inclined so that the diameter becomes smaller toward the top.

[0042] Furthermore, the upper die 21 may be movable in the vertical direction together with the top plate 13, as described above. When the rotor core 2 is placed on the lower die 22, the upper die 21 descends and presses the upper surface of the rotor core 2 with a predetermined pressing force, thereby holding the rotor core 2 sandwiched between the upper die 21 and the lower die 22. The shapes, materials, and the like of the surfaces of the upper die 21 and the lower die 22 that come into contact with the rotor core 2 may be adjusted so that the filled resin does not leak out of the rotor core 2 when the filling space 6 is filled with resin. Specifically, the contact surfaces may be adjusted so that they are substantially sealed when the rotor core 2 is sandwiched between the upper die 21 and the lower die 22.

[0043] In the present embodiment, as described above, a structure is adopted in which the upper die 21 moves up and down together with the top plate 13, but other structures can be adopted as long as they enable the relative change of the vertical positions of the upper die 21 and the lower die 22. Specifically, for example, instead of moving the upper die 21 up and down, a structure may be adopted in which the lower die 22 moves up and down, or both the upper die 21 and the lower die 22 move up and down.

[0044] In this embodiment, the slots 4 of the rotor core 2 are exemplified as rectangular parallelepipeds that are open in the up-down direction and have substantially no gaps in the front-rear and left-right directions. In this regard, the upper and lower dies 21 and 22 have substantially flat contact surfaces, but the shapes of the contact surfaces of the upper and lower dies 21 and 22 with the rotor core 2 can be appropriately changed to match the shape of the rotor core 2 to be held. For example, when the motor core manufacturing apparatus 1 according to this embodiment is used for resin molding of an inner rotor type stator core, it is preferable to use the upper and lower dies 21 and 22 that include protrusions to be inserted into a space formed in the center of the stator core.

[0045] The chamber 30 forms an annular space into which the annular resin material P to be filled in the filling space 6 can be poured. In other words, the chamber 30 is composed of a cylindrical space extending in the vertical direction, which is formed inside the annular support base 31 provided on the base 11. The chamber 30 communicates with a resin filling passage 25 formed in the lower mold 22. Note that, although the shape of the chamber 30 in this embodiment is exemplified as a space formed in an annular shape in a plan view, it can be appropriately changed according to the shape of the annular resin material P to be poured, etc.

[0046] The chamber 30 according to this embodiment may be a space defined by the support base 31, the lower mold 22, and the annular plunger 35. More specifically, the chamber 30 may be defined by the outer circumferential surface thereof by the support base 31, the inner circumferential surface thereof by the protruding portion 23 of the lower mold 22, the bottom surface thereof by the pressing surface 37 of the annular plunger 35, and the upper surface thereof by the resin inflow groove 26 formed in the lower surface 22L of the lower mold 22.

[0047] In addition, one or more convex portions 60 protruding toward the inside of the chamber 30 are formed on any of the inner surfaces of the chamber 30 except for the portion communicating with the resin filling path 25. The convex portion 60 may be such that a predetermined gap is formed between the tip of the convex portion 60 and the surface of the chamber 30 facing the surface on which the convex portion 60 is formed, regardless of the position of the annular plunger 35. In this embodiment, the convex portion 60 is exemplified by a first convex portion 61 formed on the bottom surface of the resin inflow groove 26 of the lower mold 22, which constitutes the surface facing the annular plunger 35.

[0048] 3, the first protrusion 61 may be formed on the lower surface 22L of the lower mold 22, at a position on the bottom surface of the resin inflow groove 26 that functions as a surface defining a part of the chamber 33, excluding the region that communicates with the resin filling path 25. The first protrusion 61 may extend in a direction that intersects with the lower surface 22L of the lower mold 22, for example, downward, and the height of the first protrusion 61 may be adjusted so that its tip is positioned substantially on the same plane as the lower surface 22L.

[0049] The annular plunger 35 may be a member for conveying the resin in the chamber 30, which is an annular space, toward the resin filling path 25. Therefore, the annular plunger 35 may have at least a portion that enters the chamber 30, including the pressing surface 37 located at the upper part, in an annular shape. The pressing surface 37 may be disposed so as to seal the chamber 30. As a result, the pressing surface 37 also functions as the lower surface of the chamber 30. In addition, a lifting arm 36 connected to an actuator (not shown) may be attached to the surface of the annular plunger 35 opposite to the pressing surface 37. The operation of the actuator is transmitted to the annular plunger 35 via the lifting arm 36, so that the pressing surface 37 moves up and down within the chamber 30. If a seal member (preferably a metal seal) is provided on the inner and outer periphery of the tip of the annular plunger 35, the configuration can be further improved in terms of preventing resin leakage.

[0050] Here, it should be noted that even when the pressing surface 37 of the annular plunger 35 is moved to the upper limit position UP (see FIG. 9B, etc.) as the position closest to the mold 20 within the movable area set for the annular plunger 35, the pressing surface 37 and the tip of the first convex portion 61 do not come into contact with each other, and a gap is secured between them. This is to prevent the annular plunger 35 from coming into contact with the first convex portion 61 when the annular plunger 35 is moved to the upper limit position UP, causing the resin injected into the filling space 6 to not receive an upward pressure (also called a holding pressure). Note that, in this embodiment, the case where the annular plunger 35 is moved to the upper limit position UP to complete the filling of the resin into the slot portion 4 as the resin filling portion is illustrated as an example, but the timing of completion of the filling of the resin may be determined based on the pressure generated in the annular plunger 35. In this case, the height position of the pressing surface 37 of the annular plunger 35 when the filling of the resin into the slot portion 4 is completed may change.

[0051] Incidentally, in order to apply a pressure to the resin, it is necessary to secure a gap of about 3 to 5 mm between the annular plunger 35 and the upper surface of the chamber 30. In this embodiment, a structure is adopted in which a plurality of first convex parts 61 are arranged at a predetermined interval on the bottom surface of the annular resin inflow groove 26. Therefore, if the above-mentioned gap of about 3 to 5 mm is secured in an area where the first convex parts 61 are not formed, for example, an area where the resin filling path 25 is formed, the necessary pressure can be secured. Therefore, the gap G1 (see FIG. 9) between the pressing surface 37 at the upper limit position UP and the tip of the first convex part 61 can be made sufficiently smaller (for example, the gap G1 can be made half or less of the gap G2) than the gap G2 (see FIG. 9) between the pressing surface 37 at the upper limit position UP and the bottom surface of the resin inflow groove 26. As a result, the amount of resin cured in the resin inflow groove 26 can be reduced compared to the case where the first convex parts 61 are not provided. In this embodiment, as described above, the gap for applying a pressure to the resin is set to 3 to 5 mm, but the gap is not limited to this value. The value of the gap varies depending on the shape of the core and magnet, the type of resin to be filled, etc., so it is advisable to select an appropriate optimal distance.

[0052] The rotor core 2, in which the resin is filled into the slots 4, can often be changed to a different shape. For this reason, a plurality of lower dies 22 having resin filling paths 25 and resin inflow grooves 26 of different sizes or shapes can be prepared in advance, and can be appropriately replaced according to the rotor core 2 held in the die 20.

[0053] Furthermore, in addition to the above-mentioned configuration, the motor core manufacturing apparatus 1 according to this embodiment can further include a heater 40 capable of heating the resin in the chamber 30 and the mold 20. This heater 40 can be configured with a well-known heater such as an infrared heater or a sheath heater, and may be provided at an appropriate location in the manufacturing apparatus main body 10. The heater 40 according to this embodiment can include at least a mold heater 41 as a first heater disposed in the mold 20, and a chamber outer periphery heater 42 as a second heater disposed around the outside of the annular chamber 30.

[0054] The mold heater 41 is preferably disposed in at least one of the upper mold 21 and the lower mold 22. The chamber outer periphery heater 42 is preferably disposed on the outer wall surface of the annular chamber 30, for example, in the support base 31, so as to surround the periphery of the chamber 30.

[0055] After the annular resin material P is introduced into the chamber 30, the chamber peripheral heater 42 is operated to heat the annular resin material P in the chamber 30. Here, since the annular resin material P has a through hole H formed therein, the entire resin material is disposed at a relatively short distance from the chamber peripheral heater 42. This makes it possible to reduce partial temperature differences that may occur due to differences in distance from a heat source (e.g., the chamber peripheral heater 42) when the annular resin material P is heated and softened in the chamber 30.

[0056] In addition to the above-mentioned mold heater 41 and chamber outer periphery heater 42, the heater 40 may also include a chamber inner periphery heater 43 as a third heater arranged around the inside of the annular chamber 30. The chamber inner periphery heater 43 according to this embodiment is exemplified as being arranged in the protruding portion 23 of the lower mold 22. The chamber inner periphery heater 43 arranged in the protruding portion 23 may be arranged in the center portion of the annular chamber 30 along the inner wall surface of the chamber 30. By providing this chamber inner periphery heater 43, it is possible to assist in heating the inner portion of the annular resin material P located relatively far from the chamber outer periphery heater 42. Therefore, it is possible to more reliably perform uniform heating of the resin material. The heater 40 according to this embodiment is not limited to the above-mentioned various heaters. For example, it is also possible to provide a separate heater at a position adjacent to the pressing surface 37 of the annular plunger 35.

[0057] The motor core manufacturing apparatus 1 according to the present embodiment may further include a control device 50 for controlling each of the above-mentioned components. The control device 50 may be a device that is electrically connected to each of the above-mentioned components and controls their operation to realize any manufacturing process. The control device 50 may be communicatively connected to each of the components via wired or wireless communication, for example, as shown by the dotted line in FIG. 1. The control device 50 may be realized using a programmable logic controller (PLC) or a well-known computer. The control device 50 may be configured from only one of the above-mentioned computers or a combination of multiple computers.

[0058] This control device 50 can realize the manufacturing method of a motor core according to this embodiment, which will be described later, by operating each of the above-mentioned components. In this regard, the manufacturing method of a motor core according to this embodiment can be provided in the form of a program such as software including instructions for causing a computer constituting the control device 50 to execute predetermined operations, in the form of a non-transitory computer-readable recording medium on which this program is stored, or in the form of an application program provided via a network or the like. The manufacturing method of a motor core according to this embodiment will be described in detail later.

[0059] In the motor core manufacturing apparatus 1 having the above-mentioned configuration, it is particularly important that the multiple filling spaces 6 of the rotor core 2 to be filled with resin are arranged in a ring shape, and that the chambers 30 and the resin material to be poured into the chambers 30 are both ring-shaped. When the arrangement of the filling spaces 6 and the shapes of the chambers 30 and the resin are roughly the same in this way, the length of the resin filling path 25 connecting the chambers 30 and the filling spaces 6 can be made shorter than, for example, a conventional apparatus in which the pot is located in the center of the mold. Therefore, according to the motor core manufacturing apparatus 1 of this embodiment, the time required for the resin to pass through the resin filling path 25 can be shortened compared to the conventional one, and the unintended progress of the curing reaction of the resin in the resin filling path 25 can be suppressed.

[0060] In relation to the above, the outer diameter and inner diameter of the chamber 30 may be set in consideration of the arrangement of the filling space 6. Preferably, the chamber 30 is formed at a position overlapping with the slot portion 4 of the rotor core 2 held in the mold 20 in a plan view, whereby the resin filling path 25 can be shortened and the amount of resin that hardens outside the slot portion 4 can be suppressed.

[0061] Next, a method for manufacturing a motor core according to the present embodiment will be described. In the following description of the method for manufacturing a motor core, the case where rotor core 2 is manufactured using motor core manufacturing apparatus 1 described above will be described as an example, but the method can also be realized using an apparatus other than motor core manufacturing apparatus 1. At least a part of the effects described in the following method for manufacturing a motor core also serve as an explanation of the effects achieved by motor core manufacturing apparatus 1 described above.

[0062] (Manufacturing method of motor core) FIG. 4 is a flow chart showing an example of a manufacturing process carried out by the motor core manufacturing apparatus shown in FIG. 1. Also, FIGS. 5 to 8 are operation explanatory diagrams showing an example of an operating state of the motor core manufacturing apparatus shown in FIG. 1. Furthermore, FIG. 9A is an enlarged view of part B in FIG. 6, and FIG. 9B is an enlarged view of part C in FIG. 7. Below, the manufacturing method of the motor core according to this embodiment will be described mainly with reference to FIGS. 4 to 9. Note that in FIGS. 5 to 8, in order to make the drawings easier to see, some of the members less relevant to the series of operations and their reference numerals are omitted or simplified.

[0063] The manufacturing method of the motor core according to the present embodiment includes at least a step of pouring an annular resin material having a predetermined thickness into an annular chamber, in which one or more convex parts formed to protrude toward the inside of the annular chamber are formed on the inner surface of the annular chamber except for the part communicating with the resin filling passage in the annular chamber (corresponding to step S01 described later), a step of holding a motor core including a plurality of resin filling parts arranged in an annular shape at a predetermined interval in a mold in which a resin filling passage communicating with the annular chamber is formed, so that the end of the resin filling passage communicates with the plurality of resin filling parts (corresponding to step S04 described later), a step of heating and softening the annular resin material in the annular chamber (corresponding to step S05 described later), a step of moving an annular plunger in a direction approaching the mold to fill the plurality of resin filling parts with a softened resin made of the annular resin material softened in the annular chamber (corresponding to step S06 described later), and a step of hardening the softened resin filled in the plurality of resin filling parts (corresponding to step S07 described later). The method will be described in detail below with reference to the drawings.

[0064] In the manufacturing method of the motor core according to this embodiment, as shown in Fig. 4, first, lifter 24 is operated to raise lower die 22, and annular resin material P is poured into chamber 30 exposed thereby (step S01). As shown in Fig. 5, the annular resin material P poured into chamber 30 is placed on pressing surface 37 of annular plunger 35 which functions as the lower surface of chamber 30. The size (particularly its thickness) of the annular resin material P poured into chamber 30 may be adjusted taking into consideration the sizes of filling space 6 and resin filling path 25 of rotor core 2 which will be held later.

[0065] It is preferable to preheat the chamber 30 before introducing the annular resin material P into the chamber 30. The preheating of the chamber 30 can be achieved, for example, by operating at least one of the chamber outer peripheral heater 42 and the chamber inner peripheral heater 43.

[0066] In addition, before or after the annular resin material P is poured into the chamber 30, or in parallel with the pouring of the annular resin material P, the permanent magnets 3 and the rotor core 2 to which the permanent magnets 3 are attached are prepared, and the permanent magnets 3 are inserted into the slots 4 of the rotor core 2 (step S02). Then, the mold 20 and the rotor core 2 are preheated (step S03). The mold 20 can be preheated, for example, by using a mold heater 41. The rotor core 2 may be preheated separately from the mold 20 by using a known heating means (not shown), but if the mold heater 41 is operated while the mold 20 is placed on the lower mold 22, the mold 20 and the rotor core 2 can be preheated simultaneously, and the series of processes can be simplified. When the mold 20 and the rotor core 2 are preheated simultaneously, it is advisable to carry out step S04 described later before step S03. The preheat temperature of the mold 20 and the rotor core 2 can be, for example, about 100 to 180°C. Moreover, the preheating can be performed on only either the die 20 or the rotor core 2.

[0067] Furthermore, the order of steps S02 and S03 can be changed. In that case, the permanent magnets 3 (which may or may not be preheated separately) are inserted into the slots 4 of the rotor core 2 after the rotor core 2 and the mold 20 are preheated.

[0068] When the preheating of the mold 20 and the rotor core 2 is completed, as shown in Fig. 6, the lifter 24 is operated to lower the lower mold 22, the rotor core 2 is placed on the lower mold 22, and then the upper mold 21 is moved downward to hold the rotor core 2 in the mold 20 (step S04). At this time, the upper mold 21 is adjusted to press the upper surface of the rotor core 2 with a predetermined pressure, thereby making it possible to closely contact the upper mold 21 with the upper surface of the rotor core 2, and the lower mold 22 with the lower surface of the rotor core 2. Note that in this step S04, it is preferable that the rotor core 2 placed on the lower mold 22 is positioned so that the filling spaces 6 of the multiple slot portions 4 are connected to the resin filling paths 25 opening on the upper surface 22U of the lower mold 22.

[0069] In the motor core manufacturing apparatus 1 in the state shown in Fig. 6, the upper surface of the chamber 30, which is sealed by lowering the lower die 22, is defined by the resin inflow groove 26. In the state shown in Fig. 6, the inside of the resin inflow groove 26 is a space with no resin present therein, as shown in Fig. 9A.

[0070] At an appropriate timing after step S01 described above, the annular resin material P is heated by operating the chamber outer heater 42 and the chamber inner heater 43 (step S05). The heating in the chamber 30 is intended to reduce the viscosity of the annular resin material P and turn it into a softened resin (hereinafter referred to as "softened resin") P1. The chamber outer heater 42 and the chamber inner heater 43 used for this heating are preferably controlled so that no partial temperature difference occurs in the annular resin material P. By this heating, the annular resin material P melts and its viscosity decreases, and it can be changed into a softened resin P1 with high fluidity.

[0071] 7, the annular plunger 35 is raised in the direction of arrow A1 to push up the softened resin P1, thereby filling the filling space 6 in each slot 4 with the softened resin P1 (step S06). The softened resin P1 pushed up by the pressing surface 37 of the annular plunger 35 flows into the resin inflow groove 26 that defines the upper surface of the chamber 30, and then passes through the resin filling path 25 and flows into each filling space 6. In order to smoothly fill the filling space 6 with the softened resin P1 in step S06, for example, an air hole (not shown) for venting air from within the filling space 6 may be provided in an appropriate position of the upper mold 21.

[0072] When the pressing surface 37 of the annular plunger 35, which has pushed up the softened resin P1 in step S06, reaches the upper limit position UP set slightly below the height position of the tip of the first convex portion 61, its ascent is stopped while maintaining a predetermined pressure. The gap G1 between the pressing surface 37 that has reached the upper limit position UP and the tip of the first convex portion 61 is sufficiently smaller than the gap G2 between the pressing surface 37 and the bottom surface of the resin inflow groove 26, as shown in FIG. 9B. This suppresses the amount of cull P3 described later. On the other hand, since the gap G2 between the pressing surface 37 and the bottom surface of the resin inflow groove 26 is relatively large (for example, 3 to 5 mm), sufficient pressure is maintained on the resin when the softened resin P1 is hardened in step S07 described later.

[0073] When the filling of the filling space 6 with the softened resin P1 is completed, the mold heater 41 is operated to heat the softened resin P1 in the filling space 6 at a temperature higher than that in step S05, thereby hardening the softened resin P1 (step S07). When hardening the softened resin P1, it is preferable to heat the softened resin P1 by the mold heater 41 for about several minutes within a temperature range in which the viscosity of the softened resin P1 increases significantly. The softened resin P1 is transformed into a hardened resin P2 by the heating, and the permanent magnets 3 are fixed in the slots 4 of the rotor core 2 by the resin mold. The heating time in step S07 can be adjusted as appropriate according to the type of resin used in the annular resin material P.

[0074] In step S07, as described above, heating is performed with the pressing surface 37 moved to the upper limit position UP. Therefore, the hardening reaction of the softened resin P1 in the filling space 6 and the resin filling path 25 progresses with a holding pressure acting in the upward direction. This makes it possible to eliminate uneven filling of the softened resin P1 and to suppress a decrease in the filling density of the softened resin P1 in the filling space 6.

[0075] When the series of resin molding processes described above is completed, the upper mold 21 is raised, and the resin-molded rotor core 2 is carried out of the apparatus using a conveying means (not shown) such as a robot arm (step S08). The carried-out rotor core 2 can be transferred to another apparatus, for example, for the attachment of a shaft. Then, when carrying out of this rotor core 2 is completed, cleaning of the manufacturing apparatus 1 is performed (step S09). Cleaning of the manufacturing apparatus 1 includes removing the resin that has hardened outside the slot portion 4, i.e., the cull P3, by operating the lifter 24, as shown in FIG. 7. In addition, it may include cleaning the surface of the mold 20 and the inside of the chamber 30, etc., using a cleaning member such as a brush.

[0076] Fig. 10 is a perspective view showing an example of the cull shown in Fig. 8. As shown in Fig. 10, the cull P3 generated as a result of the series of steps described above has a thinner wall at the portion X where the first protrusion 61 was formed than at the portion where the first protrusion 61 is not formed. Therefore, the amount of cull P3 can be reduced compared to when resin molding is performed using a lower mold where the first protrusion 61 is not formed.

[0077] As described above, according to the motor core manufacturing apparatus 1 and motor core manufacturing method of the present embodiment, the first protrusion 61 is formed on the upper surface of the chamber 30, thereby making it possible to reduce the amount of resin that hardens outside the slot portion 4 during resin filling. Therefore, the permanent magnet 3 can be fixed in the slot portion 4 with a small amount of resin.

[0078] Furthermore, according to the motor core manufacturing apparatus 1 and motor core manufacturing method of this embodiment, since the chamber 30 and the annular resin material P charged into the chamber 30 are both annular, temperature differences are unlikely to occur when the resin is heated in the chamber 30, and it is possible to heat it uniformly. Furthermore, since the shape of the chamber 30 matches the arrangement of the filling space 6, it is possible to shorten the length of the resin filling path 25 connecting them, which prevents the resin curing reaction from unintentionally progressing in the resin filling path 25 and ensures stable filling of the resin into the slot portion.

[0079] In the above-described embodiment, the resin filling path 25 is provided in the lower mold 22, and the softened resin P1 is filled into the filling space 6 from below, but the filling direction is not limited to this. For example, a resin filling path, a resin inflow groove, a first convex portion, etc. may be provided in the upper mold 21 instead of the lower mold 22, and the softened resin may be filled from above, or a resin filling path, a resin inflow groove, a first convex portion, etc. may be provided in both the lower mold 22 and the upper mold 21, and the resin may be filled from both below and above.

[0080] (Modification) In the above-described embodiment, as an example of the protrusion 60, a first protrusion 61 is used, the wall of which extends substantially perpendicularly from the bottom surface of the resin inflow groove 26 as the surface facing the annular plunger 30. However, the shape and arrangement of the protrusion 60 are not limited to those described above. Therefore, several modified examples of the protrusion 60 are described below. In the modified examples shown below, only the protrusion 60 will be described, and the same components as those in the motor core manufacturing device 1 will be given the same reference numerals and their description will be omitted. Also, FIGS. 11 to 14 described below are all enlarged cross-sectional views corresponding to FIG. 9B in a state in which the pressing surface 37 of the annular plunger 35 is in the upper limit position UP. In addition, the resin and the rotor core are not shown in FIGS. 11 to 14.

[0081] 11 is an enlarged view showing a first modified example of the protrusion. As shown in FIG. 11, the protrusion 60 according to the first modified example may further include, in addition to the above-mentioned first protrusion 61, a second protrusion 62 formed on a part of the surface of the annular plunger 35 facing the lower die 22, i.e., a position of the pressing surface 37 excluding the region facing the first protrusion 61. The second protrusion 62 may extend in a direction intersecting the pressing surface 37 of the annular plunger 35, for example, in an upward direction. More specifically, the second protrusion 62 shown in this modified example is exemplified as a plurality of second protrusions 62 erected at a position facing the resin filling path 25 of the pressing surface 37.

[0082] The second protrusion 62 is disposed only at a part of the position excluding the region facing the first protrusion 61. In other words, it is preferable that at least a part of the circumferential direction of the chamber 30 is an area where neither the first protrusion 61 nor the second protrusion 62 is formed. In the example shown in FIG. 11, the second protrusion 62 is disposed at a position facing the resin filling path 25, and its circumferential length is adjusted so that both circumferential side surfaces are disposed at a predetermined distance from the side surfaces of the adjacent first protrusion 61. In this way, by securing an area where neither the first protrusion 61 nor the second protrusion 62 is formed in at least a part of the circumferential direction of the chamber 30, a relatively large gap G2 can be secured when the pressing surface 37 of the annular plunger 35 is pushed up to the upper limit position UP.

[0083] The gap G3 between the tip of the second protrusion 62 and the bottom surface of the resin inflow groove 26 can be made smaller than the gap G2 between the pressing surface 37 at the upper limit position UP and the bottom surface of the resin inflow groove 26, similar to the gap G1 described above. Therefore, the amount of cull that hardens outside the slot portion 4 can be further reduced compared to the case where the third protrusion 63 is not provided in the chamber 30. In addition, by ensuring the above-mentioned three gaps G1 to G3, a holding pressure can be applied to the softened resin P1.

[0084] 12 is an enlarged view showing a second modified example of the protrusion. As shown in FIG. 12, the third protrusion 63 as the protrusion 60 according to the second modified example may be formed on the surface of the annular plunger 35 facing the lower die 22, i.e., on the pressing surface 37, except for the area facing the resin filling path 25. The third protrusion 63 may extend in a direction intersecting the pressing surface 37 of the annular plunger 35, for example, in the upward direction. The third protrusion 63 shown in this modified example is exemplified as a plurality of protrusions provided at intervals along the circumferential direction of the annular pressing surface 37.

[0085] The height of the third convex portion 63 may be adjusted so that a predetermined gap G4 is formed between the tip of the third convex portion 63 and the bottom surface of the resin inflow groove 26 when the pressing surface 37 is in the upper limit position UP. This gap G4 can be made smaller than the gap G2 between the pressing surface 37 in the upper limit position UP and the bottom surface of the resin inflow groove 26, similar to the above-mentioned gaps G1 and G3. Therefore, the amount of resin cured in the resin inflow groove 26 can be reduced compared to the case where the third convex portion 63 is not provided in the chamber 30.

[0086] Fig. 13 is an enlarged view showing a third modified example of the protrusion. As shown in Fig. 13, the fourth protrusion 64 as the protrusion 60 according to the third modified example is similar to the first protrusion 61 in that it is formed on the bottom surface of the resin inflow groove 26. On the other hand, the fourth protrusion 64 is different from the first protrusion 61 in that both side walls 64A located in the circumferential direction are formed as tapered surfaces that are inclined so that the area of ​​the fourth protrusion 64, more specifically, the circumferential length of the fourth protrusion 64 becomes smaller toward the tip of the fourth protrusion 64.

[0087] Here, the inclination angle (corresponding to the second angle) θ2 of the side wall 64A of the fourth protrusion 64 with respect to the extension direction of the resin filling path 25 is preferably set smaller than the inclination angle (corresponding to the first angle) θ1 of the side wall 27 of the resin filling path 25 with respect to the extension direction of the resin filling path 25. In this way, by making the inclination angle θ2 smaller than the inclination angle θ1, the part of the cull P3 that has hardened within the resin filling path 25 is more easily released from the mold than the part that has hardened within the resin inflow groove 26. This makes it possible to prevent a part of the cull P3 from remaining in the resin filling path 25 when the cull P3 is released from the lower mold 22.

[0088] 14 is an enlarged view showing a fourth modified example of the protrusion. The protrusion 60 according to this modified example may further include a fifth protrusion 65 formed in a part of the pressing surface 37 of the annular plunger 35 except for the region facing the first protrusion 61, in addition to the fourth protrusion 64 described above. The fifth protrusion 65 is disposed in the same manner as the second protrusion 62 described above. On the other hand, the fifth protrusion 65 is different from the second protrusion 62 in that both side walls 65A located in the circumferential direction are formed as tapered surfaces that are inclined so that the area of ​​the fifth protrusion 65, more specifically, the circumferential length of the fifth protrusion 65 becomes smaller toward the tip of the fifth protrusion 65.

[0089] The inclination angle θ3 (corresponding to the third angle) of the side wall 65A of the fifth protrusion 65 with respect to the extension direction of the resin filling passage 25 is preferably set to be smaller than the above-mentioned inclination angle θ2. In this way, by making the inclination angle θ3 smaller than the above-mentioned inclination angles θ1 and θ2, the cull P3 can be more easily released from the lower die 22 than from the pressing surface 37 of the annular plunger 35. Therefore, when the lower die 22 is moved upward, the cull P3 is not lifted up together with the lower die 22, making the cleaning operation easier.

[0090] Although detailed description is omitted, the sidewall of the third protrusion 63 as the protrusion 60 of the second modified example described above may be a tapered surface inclined at a predetermined angle (for example, inclination angle θ2) similar to the sidewalls 64A, 65A of the fourth and fifth protrusions 64, 65 described above. In this case, it will be clear to those skilled in the art that by making the inclination angle of the sidewall of the third protrusion 63 with respect to the extension direction of the resin filling path 25 smaller than the inclination angle θ1 described above, the same effect as that described in the fourth modified example can be obtained.

[0091] <Second embodiment> In the motor core manufacturing apparatus 1 according to the first embodiment described above, the chamber 30 is formed at a position overlapping the slot portion 4 of the rotor core 2 held in the mold 20 in a plan view in consideration of the length of the resin filling path 25, but the present disclosure is not limited thereto. Therefore, below, as an example of a motor core manufacturing apparatus 1A according to a second embodiment of the present disclosure, an apparatus capable of resin molding a rotor core 2A having a larger outer diameter than the rotor core 2 described above is described. Note that the motor core manufacturing apparatus 1A according to this embodiment can adopt a configuration similar to that of the motor core manufacturing apparatus 1 according to the first embodiment, except for the rotor core 2A and the mold 20A that holds this rotor core 2A. Therefore, below, a description will be given of the motor core manufacturing apparatus 1B according to this embodiment, focusing on the configuration different from the motor core manufacturing apparatus 1 described above, and the same components as those of the motor core manufacturing apparatus 1 will be given the same reference numerals and their description will be omitted.

[0092] Fig. 15 is a schematic explanatory diagram showing an example of a motor core manufacturing apparatus according to a second embodiment of the present disclosure. As shown in Fig. 15, the motor core manufacturing apparatus 1A according to this embodiment is capable of resin molding a rotor core 2A whose outer diameter is larger than that of the rotor core 2 described above and whose slots 4A are located on the outer periphery side relative to the slots 4. Therefore, the mold 20A of the motor core manufacturing apparatus 1 according to this embodiment has an outer diameter larger than that of the mold 20 described above.

[0093] The mold 20A includes an upper mold 21A that contacts the upper surface of the rotor core 2A, and a lower mold 22A that is located on the lower surface of the rotor core 2A. A resin inflow groove 26A that functions as the upper surface of the chamber 30 is provided on a lower surface 22AL of the lower mold 22A. Furthermore, the lower mold 22A is provided with a resin filling path 25A that communicates the resin inflow groove 26A with a filling space 6A in a slot portion 4A of the rotor core 2A placed on an upper surface 22AU of the lower mold 22. As shown in FIG. 13, the resin filling path 25A is formed as a passage having a substantially L-shaped cross section, part of which extends in the radial direction.

[0094] In the motor core manufacturing apparatus 1A according to the present embodiment, one or more convex portions 60 can be formed on a part of the inner surface of the chamber 30. Specifically, a sixth convex portion 66 can be formed so as to extend downward on the bottom surface of the resin inflow groove 26A constituting the surface facing the annular plunger 35. In the portion where the resin filling path 25A is formed, the sixth convex portion 66 is preferably provided only on the inner portion of the resin inflow groove 26A as shown in FIG. 15 so that the resin filling path 25A is not blocked by the sixth convex portion 66. By providing the sixth convex portion 66, the motor core manufacturing apparatus 1A according to the present embodiment can also reduce the amount of resin that hardens outside the slot portion 4A when filling the slot portion 4A with resin, compared to the case where the convex portion 60 is not provided. Therefore, the permanent magnet 3 can be fixed in the slot portion 4A with a small amount of resin.

[0095] In the motor core manufacturing apparatus 1A according to the present embodiment, the chamber 30 and the annular resin material P introduced into the chamber 30 are both annular, so that the temperature difference is less likely to occur during heating of the resin in the chamber 30 compared to the conventional case where a tablet-shaped resin is used, and the resin can be heated uniformly. Although the radial dimensions are different, the outer shape of the chamber 30 matches the arrangement of the filling space 6A, so that the length of the resin filling path 25A connecting the two can be made shorter than in the conventional case. Therefore, when the softened resin P1 is sent to the filling space 6A, the resin hardening reaction is prevented from unintentionally proceeding in the resin filling path 25A, and the resin can be stably filled into the slot portion 4A.

[0096] In the above-described embodiments, the protrusion 60 is formed to protrude from the bottom surface or the pressing surface of the resin inflow groove 26, 26A, but the present disclosure is not limited to this. Specifically, the protrusion 60 may be formed on the side surface of the chamber.

[0097] Fig. 16 is a diagram showing a modified lower die of the motor core manufacturing apparatus shown in Fig. 1, Fig. 16A being a perspective view and Fig. 16B being a bottom view. As shown in Fig. 16, the outer shape of lower die 22B according to the modified example is generally the same as that of lower die 22 of the first embodiment. That is, lower die 22B is made of a plate-like member having a predetermined thickness, and a columnar protrusion 23 that defines a part of the inner surface of chamber 30 is provided in the center of lower surface 22BL thereof, and resin inflow groove 26B may be formed around this protrusion 23 to which resin filling path 25 that is connected to upper surface 22BU of lower die 22B communicates.

[0098] Resin inflow groove 26B of lower mold 22B also serves as part of the upper portion of chamber 30. Seventh protrusions 67A, 67B may be formed on the outer peripheral wall surface and inner peripheral wall surface extending in the vertical direction of resin inflow groove 26B, respectively, except for the region where resin filling path 25 is formed, as shown in Fig. 16. The outer peripheral wall surface and inner peripheral wall surface of resin inflow groove 26B define part of the inner surface of chamber 30.

[0099] The seventh protrusion 67A formed on the outer peripheral wall surface of the resin inflow groove 26B may be formed so as to extend from the outer peripheral wall surface toward the inner peripheral wall surface of the resin inflow groove 26B. Also, the seventh protrusion 67B formed on the inner peripheral wall surface of the resin inflow groove 26B may be formed so as to extend from the inner peripheral wall surface toward the outer peripheral wall surface of the resin inflow groove 26B. Also, the seventh protrusions 67A and 67B may have their upper wall surfaces connected to the bottom surface of the resin inflow groove 26B, and their lower wall surfaces adjusted to a position where a predetermined gap is formed when the pressing surface 37 of the plunger 35 is located at the upper limit position UP. Note that, even in the case of this embodiment, as in the embodiment shown in FIG. 11, a protrusion formed on a part of the surface of the annular plunger 35 facing the lower die 22B, i.e., the pressing surface 37, excluding the region facing the protrusions 67A and 67B may be further included.

[0100] By providing the seventh protrusions 67A and 67B, it is expected that the same effects as those described in the above-mentioned embodiments can be achieved. That is, the amount of resin that hardens outside the slot portion 4 during resin filling can be reduced. Therefore, the permanent magnet 3 can be fixed in the slot portion 4 with a small amount of resin.

[0101] <Third embodiment> In the motor core manufacturing apparatuses 1 and 1A according to the first and second embodiments described above, the lower die 22 is provided with the protrusion 23, but the present disclosure is not limited thereto. Therefore, below, a motor core manufacturing apparatus 1C according to a third embodiment of the present disclosure is illustrated as including a lower die 22C that does not have the protrusion 23 described above. The motor core manufacturing apparatus 1C according to this embodiment can adopt the same configuration as the motor core manufacturing apparatus 1 according to the first embodiment, except for the configuration of the die 20C and the configuration related to the block body 70 described later. Therefore, below, the motor core manufacturing apparatus 1C according to this embodiment will be described mainly with respect to the configuration different from the motor core manufacturing apparatus 1 described above, and the same components as those of the motor core manufacturing apparatus 1 will be denoted by the same reference numerals and their description will be omitted.

[0102] 17 is a schematic explanatory diagram showing an example of a motor core manufacturing apparatus according to the third embodiment of the present disclosure. A mold 20C included in the motor core manufacturing apparatus 1C according to this embodiment includes a lower mold 22C as an example of a first mold located on the lower end side in the axial direction of the rotor core 2, and an upper mold 21C as an example of a second mold located on the upper end side in the axial direction of the rotor core 2. Of these, the upper mold 21C may be similar to the upper mold 21 of the motor core manufacturing apparatus 1 according to the first embodiment.

[0103] Fig. 18 is a perspective view showing an example of the lower mold shown in Fig. 17. As shown in Figs. 17 and 18, lower mold 22C differs from lower mold 22 described above in that lower surface 22L thereof is substantially flat except for the portion where resin filling path 25 is formed. With this configuration, lower mold 22D defines the upper surface of chamber 30 but does not define the inner peripheral surface of chamber 30.

[0104] As described above, lower die 22C of the present embodiment does not include protrusion 23 included in lower die 22 of the first embodiment. In relation to this, in motor core manufacturing apparatus 1C of the present embodiment, block body 70 that defines the inner circumferential surface of chamber 30 is disposed in the central portion of substantially annular support stand 31 that constitutes chamber 30.

[0105] The block body 70 may be, for example, a substantially cylindrical block body, and the diameter thereof may be adjusted to be slightly smaller than the inner diameter of the annular plunger 35. The block body 70 may be installed at an arbitrary height position by a plurality of support rods 71 ​​having a predetermined length and having their base ends installed on the base 11. A chamber inner circumferential heater 43A constituting a part of the heater 40 may be disposed inside the block body 70.

[0106] According to the motor core manufacturing apparatus 1C of the present embodiment having the above-mentioned configuration, the same effects as those described in the first and second embodiments can be obtained. In addition, according to the motor core manufacturing apparatus 1C of the present embodiment, by providing the block body 70, for example, when feeding the annular resin material P into the chamber 30, the annular resin material P can be fed into a space defined by the inner peripheral surface as well as the outer peripheral surface of the chamber 30, improving the workability. In addition, since the block body 70 is fixed to the base 11 and does not move, wiring work to the chamber inner peripheral heater 43A arranged in the block body 70 is easy. Furthermore, since the block body 70 is fixed to the base 11, the clearance between the block body 70 and the side surface of the annular plunger 35 can be narrowed. This makes it possible to prevent the softened resin P1 from leaking out from the gap between the block body 70 and the annular plunger 35.

[0107] The process of manufacturing a motor core using the motor core manufacturing apparatus 1C according to this embodiment may be similar to the process of the motor core manufacturing method according to the first embodiment. Therefore, detailed description thereof will be omitted here.

[0108] Fig. 19 is a perspective view showing a modified example of the lower die of the motor core manufacturing apparatus shown in Fig. 17. In the above-mentioned third embodiment, too, convex portion 60 can be formed on the side surface of the chamber, similarly to the example shown in Fig. 16. Specifically, lower die 22D according to this modified example may be made of a plate-like member having a predetermined thickness, as shown in Fig. 19, and may be formed with resin inflow groove 26B communicating with resin filling path 25 that connects from lower surface 22BL to upper surface 22BU.

[0109] 19, seventh protrusions 67A, 67B may be formed on the outer peripheral wall surface and inner peripheral wall surface extending in the vertical direction of resin inflow groove 26B, which also serves as a part of the upper portion of chamber 30, except for the region where resin filling path 25 is formed. By providing these seventh protrusions 67A, 67B, it is expected that the same effects as those described in each of the above-mentioned embodiments can be obtained. That is, the amount of resin that hardens outside slot portion 4 during resin filling can be reduced.

[0110] The present disclosure is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present disclosure. All of these modifications are included in the technical concept of the present disclosure. In the present disclosure, each component may be present in one or more of the above-described embodiments, provided that no contradiction occurs.

[0111] All references cited in this specification, including publications, patent applications, and patents, are herein incorporated by reference to the same extent as if each reference was individually and specifically indicated to be incorporated by reference and the contents of each reference were fully set forth herein.

[0112] The use of nouns and similar referents in connection with the description of this disclosure (particularly in connection with the claims below) shall be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms "comprises," "has," "includes," and "comprises" shall be construed as open-ended terms (i.e., meaning "including but not limited to"), unless otherwise indicated. The recitation of numerical ranges herein is intended merely to serve as a shorthand method for individually referring to each value falling within the range, unless otherwise indicated herein, and each value is incorporated into the specification as if it were individually recited herein. All methods described herein may be performed in any suitable order, unless otherwise indicated herein or clearly contradicted by context. Any examples or exemplary phrases used herein (e.g., "such as") are intended merely to better illustrate the disclosure and do not pose limitations on the scope of the disclosure, unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the disclosure.

[0113] Preferred embodiments of the disclosure are described herein, including the best mode known to the inventors for carrying out the disclosure. Variations of these preferred embodiments will become apparent to those skilled in the art upon reading the above description. The inventors expect that skilled artisans will apply such variations as appropriate, and intend to practice the disclosure otherwise than as specifically described herein. Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, the disclosure encompasses any combination of the above-described elements in all variations thereof unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

1. a mold capable of holding a motor core including a plurality of resin-filled portions arranged in an annular shape at predetermined intervals, the mold including a first mold located at one end of the motor core in an axial direction, and a second mold located at the other end of the motor core in an axial direction; an annular chamber formed in the first mold, the annular chamber being connected to a resin filling passage having an end that can be connected to each of the plurality of resin filling portions, and capable of accommodating an annular resin material having a predetermined thickness therein; an annular plunger movable within the annular chamber; and one or more protrusions protruding from an inner surface of the annular chamber excluding a portion communicating with the resin filling path toward the inside of the annular chamber. Motor core manufacturing equipment.

2. The annular chamber is formed at a position overlapping with the resin filling portion of the motor core held in the mold in a plan view, and the resin filling path is composed of a plurality of passages extending in a vertical direction from an upper surface or a lower surface of the annular chamber toward the resin filling portion.

2. An apparatus for manufacturing a motor core according to claim 1.

3. The convex portion includes a first convex portion formed at a position excluding a region communicating with the resin filling path on a surface of the first mold facing the annular plunger, the first convex portion extending in a direction intersecting the surface of the first mold facing the annular plunger, 3. The motor core manufacturing apparatus according to claim 1 or 2.

4. a side wall of the resin filling path has a tapered surface inclined at a first angle with respect to the extending direction of the resin filling path so that a diameter of the side wall decreases from one opening communicating with the annular chamber toward the other opening communicating with the plurality of resin filling sections, and a side wall of the first convex portion has a tapered surface inclined at a second angle smaller than the first angle with respect to the extending direction of the resin filling path so that an area of ​​the first convex portion decreases toward a tip of the side wall. The motor core manufacturing apparatus according to claim 3 .

5. The convex portion further includes a second convex portion formed in a part of a position of the surface of the annular plunger facing the first die excluding a region facing the first convex portion, the second convex portion extending in a direction intersecting the surface of the annular plunger facing the first die. The motor core manufacturing apparatus according to claim 3 .

6. a side wall of the resin filling path has a tapered surface inclined by a first angle with respect to the extension direction of the resin filling path so that a diameter of the side wall decreases from one opening communicating with the annular chamber toward the other opening communicating with the plurality of resin filling sections; a side wall of the first convex portion has a tapered surface inclined by a second angle smaller than the first angle with respect to the extension direction of the resin filling path so that an area of ​​the first convex portion decreases toward its tip; and a side wall of the second convex portion has a tapered surface inclined by a third angle smaller than the second angle with respect to the extension direction of the resin filling path so that an area of ​​the second convex portion decreases toward its tip.

6. An apparatus for manufacturing a motor core according to claim 5.

7. The protrusion includes a third protrusion formed on a surface of the annular plunger facing the first mold at a position other than a region facing the resin filling path, the third protrusion extending in a direction intersecting the surface of the annular plunger facing the first mold.

3. The motor core manufacturing apparatus according to claim 1 or 2.

8. a side wall of the resin filling path has a tapered surface inclined at a first angle with respect to the extending direction of the resin filling path so that a diameter of the side wall decreases from one opening communicating with the annular chamber toward the other opening communicating with the plurality of resin filling sections, and a side wall of the third convex portion has a tapered surface inclined at a fourth angle smaller than the first angle with respect to the extending direction of the resin filling path so that an area of ​​the third convex portion decreases toward a tip of the third convex portion.

8. An apparatus for manufacturing a motor core according to claim 7.

9. A process of pouring an annular resin material having a predetermined thickness into an annular chamber, wherein one or more convex portions are formed on an inner surface of the annular chamber except for a portion communicating with a resin filling path in the annular chamber so as to protrude toward an inside of the annular chamber; a step of holding a motor core including a plurality of resin filling portions arranged in a ring shape at predetermined intervals in a mold in which the resin filling passage communicating with the ring-shaped chamber is formed, such that ends of the resin filling passage communicate with the plurality of resin filling portions; heating and softening the annular resin material within the annular chamber; a step of moving an annular plunger in a direction approaching the die to fill the plurality of resin filling portions with softened resin made of the annular resin material softened in the annular chamber; and hardening the softened resin filled in the plurality of resin filled portions. A manufacturing method for a motor core.

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