Manufacturing method of pallet member and motor

Abstract

A pallet member and a motor manufacturing method that can contribute to improving productivity in the motor core manufacturing process are provided. A pallet member that can be used in a core heating process, comprising: a plate portion having a first surface on which the core is placed; and a first protrusion that protrudes from a second surface of the plate portion opposite the first surface and suppresses heat conduction from the pallet member to a support surface that supports the pallet member when the core placed on the plate portion is heated.

Description

[Technical Field]

[0001] The present disclosure relates to a method of manufacturing a pallet member and a motor. [Background technology]

[0002] A rotating electric machine is provided with a motor core (e.g., including a rotor core (rotor iron core) and a stator core (stator iron core). Hereinafter, the rotor core and stator core will be collectively referred to simply as the core). The core has a plurality of slots arranged in a circular ring shape at predetermined intervals, each of which has a permanent magnet attached to it. A known method for attaching the permanent magnet to the core is to insert the permanent magnet into the slot, then fill the surrounding area with resin and allow it to harden (see, for example, Japanese Patent No. 5939295 or Japanese Patent No. 7099936).

[0003] In the rotor manufacturing process, a pallet member is used on which the core is placed. Patent Document 1 below discloses a gate plate 2 that also serves as a pallet on which a laminated iron core 3 is placed. The lower surface of the gate plate 2 has an apparatus positioning portion 25, which is configured to be connectable to a predetermined position on the upper surface of a mold body portion 110 of a resin feed mold 11.

[0004] Furthermore, Japanese Patent No. 7099936 discloses a conveying plate 153 that is a metal plate-like body and is configured so that the stack 11 can be placed thereon. Summary of the Invention [Problem to be solved by the invention]

[0005] In the motor core manufacturing process, the core may be preheated in a heating device before the resin filling portion of the core is filled with resin. During this preheating process, heat is conducted from the plate on which the core is placed, which requires a long time to heat the core, resulting in a decrease in productivity in the motor core manufacturing process. Therefore, there is room for improvement in improving productivity in the motor core manufacturing process.

[0006] In view of the above-mentioned problems, the present disclosure aims to provide a pallet member and a motor manufacturing method that can contribute to improving productivity in the motor core manufacturing process. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, a first aspect of the technology disclosed herein is a pallet member that can be used in a core heating process, comprising a plate portion having a first surface on which the core is placed, and a first protrusion that protrudes from a second surface of the plate portion opposite the first surface and suppresses heat conduction from the pallet member to a support surface that supports the pallet member when the core placed on the plate portion is heated.

[0008] A second aspect of the technique of the present disclosure is the pallet member according to the first aspect, in which the plate portion has a first through hole formed in a position facing the resin-filled portion of the core.

[0009] A third aspect of the technology disclosed herein is a pallet member according to the second aspect, in which the pallet member can also be used in a filling process for filling resin into the resin filling section, and resin is filled into the resin filling section through the first through hole.

[0010] A fourth aspect of the technology of the present disclosure is a pallet member according to the first aspect, in which the pallet member can also be used in a filling process for filling resin into a resin filling section, and the first protrusion can be inserted into a positioning hole provided in a mold for filling the resin.

[0011] A fifth aspect of the technology of the present disclosure is a pallet member according to the first aspect, wherein the plate portion has a second protruding portion protruding from the first surface, and the second protruding portion is inserted into a hole formed in the core.

[0012] A sixth aspect according to the technique of the present disclosure is the pallet member according to the fifth aspect, in which a plurality of second protruding portions are provided along the circumferential direction of the core.

[0013] A seventh aspect of the technique of the present disclosure is the pallet member according to the first aspect, wherein the first protrusion includes a plurality of pin-shaped members provided along the outer edge of the plate portion.

[0014] An eighth aspect of the technique of the present disclosure is the pallet member according to the first aspect, wherein the first protrusion includes a columnar member provided in the center of the plate portion.

[0015] A ninth aspect according to the technique of the present disclosure is the pallet member according to the first aspect, wherein the plate portion has a second through hole formed in a position corresponding to the central through hole of the core.

[0016] A tenth aspect of the technology of the present disclosure is a pallet member according to the ninth aspect, which is provided with a third protrusion that is arranged along the periphery of the second through hole and protrudes from the first surface.

[0017] An eleventh aspect of the technology of the present disclosure is a pallet member according to the first aspect, in which the pallet member can also be used in a conveying process, and the first protrusion portion is capable of forming a gap between the plate portion and the conveying surface.

[0018] A twelfth aspect of the technology of the present disclosure is a method for manufacturing a motor core using a pallet member having a plate portion having a first surface on which a core is placed, and a first protrusion protruding from a second surface of the plate portion opposite the first surface and suppressing heat conduction from the pallet member to a support surface that supports the pallet member when the core placed on the plate portion is heated, the method including placing the core on the pallet member and heating the core while it is placed on the pallet member.

[0019] A thirteenth aspect of the technology of the present disclosure is a pallet member used in a core preheating process and a filling process in which resin is filled into the resin filling section of each of a plurality of cores while the cores are lined up along the axial direction, the pallet member comprising a plate portion having a first surface on which a first core of the plurality of cores is placed, and a first protruding portion protruding from a second surface of the plate portion opposite the first surface.

[0020] A fourteenth aspect of the technology of the present disclosure is a pallet member according to the thirteenth aspect, in which when a second core is arranged in a row below a first core in a plurality of cores, the first protrusion is insertable into a hole formed in the second core.

[0021] A fifteenth aspect of the technology of the present disclosure is a pallet member according to the thirteenth aspect, in which the plate portion has a second protruding portion protruding from the first surface, and the second protruding portion is inserted into a hole formed in the first core.

[0022] A sixteenth aspect of the technology of the present disclosure is a pallet member according to the fourteenth and fifteenth aspects, in which when the hole formed in the second core is the second hole and the hole formed in the first core is the first hole, the first hole in the first core corresponds to the second hole in the second core.

[0023] A seventeenth aspect of the technique of the present disclosure is the pallet member according to the fifteenth aspect, wherein the second protruding portion is provided on the opposite side of the plate portion from the first protruding portion.

[0024] An eighteenth aspect of the technique of the present disclosure is a pallet member according to the thirteenth aspect, in which a first through hole is formed in the plate portion at a position facing the resin filling portion of the first core.

[0025] A nineteenth aspect of the technique of the present disclosure is the pallet member according to the eighteenth aspect, in which resin is filled into the resin filling portion through the first through hole.

[0026] A twentieth aspect of the technique of the present disclosure is a pallet member according to the thirteenth aspect, in which the plate portion is provided with a second through hole at a position corresponding to the central through hole of the first core.

[0027] A 21st aspect of the technology of the present disclosure is a pallet member according to the 13th aspect, in which, when the first core placed on the pallet member is the lowest core among multiple cores, the first protrusion is insertable into a positioning hole provided in a mold into which resin is filled.

[0028] A 22nd aspect of the technology of the present disclosure is a method for manufacturing a motor core using a pallet member having a plate portion having a first surface on which a first core of a plurality of cores is placed, and a first protruding portion protruding from a second surface of the plate portion opposite the first surface, the method including preheating the core placed on the pallet member, and filling resin into the resin filling portion of each of the plurality of cores while arranging the plurality of cores along the axial direction via the pallet member. [Effects of the Invention]

[0029] According to the present disclosure, a pallet member and a motor manufacturing method are provided that can contribute to improving productivity in the motor core manufacturing process. [Brief explanation of the drawings]

[0030] [Figure 1] 1 is a schematic explanatory diagram illustrating an outline of a series of steps for manufacturing a rotor core according to an embodiment. [Figure 2] FIG. 2 is a perspective view showing a schematic configuration of a rotor core and a pallet member according to the embodiment. [Figure 3] FIG. 4 is a schematic explanatory diagram showing an example of preheating of a rotor core according to an embodiment. [Figure 4] 3A and 3B are schematic explanatory views showing an example of molding of a rotor core according to an embodiment. [Figure 5] 4 is a flowchart illustrating an example of a rotor core manufacturing process according to an embodiment. [Figure 6] FIG. 4 is a schematic explanatory diagram showing an example of preheating of a rotor core according to an embodiment. [Figure 7] FIG. 4 is a schematic explanatory diagram showing an example of preheating of a rotor core according to an embodiment. [Figure 8] FIG. 4 is a schematic explanatory diagram showing an example of preheating of a rotor core according to an embodiment. [Figure 9] FIG. 4 is a schematic explanatory diagram showing an example of preheating of a rotor core according to an embodiment. [Figure 10] FIG. 4 is a schematic explanatory diagram showing an example of preheating of a rotor core according to an embodiment. [Figure 11] 3A and 3B are schematic explanatory views showing an example of molding of a rotor core according to an embodiment. [Figure 12] 3A and 3B are schematic explanatory views showing an example of molding of a rotor core according to an embodiment. [Figure 13] 3A and 3B are schematic explanatory views showing an example of molding of a rotor core according to an embodiment. [Figure 14] 3A and 3B are schematic explanatory views showing an example of molding of a rotor core according to an embodiment. [Figure 15] 3A and 3B are schematic explanatory views showing an example of molding of a rotor core according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0031] Hereinafter, each embodiment for carrying out the present disclosure will be described with reference to the drawings. Note that the scope necessary for the explanation to achieve the object of the present disclosure will be schematically shown below, and the scope necessary for explaining the relevant parts of the present disclosure will be mainly explained, and the parts for which explanation is omitted will be referred to as publicly known technologies. Furthermore, identical or corresponding components in the drawings will be given the same or similar reference numerals, and redundant explanations will be omitted. Furthermore, when a single drawing includes multiple identical or corresponding components, only some of them may be given reference numerals to make the drawing easier to understand.

[0032] <<First Embodiment>> <Outline of rotor manufacturing process> First, an outline of the flow of a rotor manufacturing process according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic explanatory diagram showing an outline of the flow of a rotor manufacturing process according to this embodiment.

[0033] As shown in FIG. 1, in the rotor manufacturing process, the rotor core 2 is transported while placed on a pallet member 10 and subjected to various treatments and machining. As will be described in detail later, the pallet member 10 is a platform-shaped member on which the rotor core 2 can be placed. The pallet member 10 has a plate portion 12 on which the rotor core 2 is placed and a first protruding portion 14 that protrudes from the lower surface 12B (see FIG. 2) of the plate portion 12. The pallet member 10 may also be formed by stacking multiple platform-shaped members. The rotor core 2 is an example of a "core" according to the technology of the present disclosure. The pallet member 10 is an example of a "pallet member" according to the technology of the present disclosure.

[0034] For example, the rotor core 2 is placed on a pallet member 10 and then transported together with the pallet member 10 by the conveyor C. In other words, the pallet member 10 can also be used in the transport process of the rotor core 2. In this case, a gap is formed between the plate portion 12 and the transport surface C1 (here, the upper surface of the transport belt of the conveyor C) by the first protrusion 14 provided on the pallet member 10. In other words, the lower surface of the plate portion 12 is prevented from coming into contact with the transport surface C1 of the conveyor C. The transport surface C1 is an example of a "transport surface" according to the technology of the present disclosure.

[0035] Furthermore, the rotor core 2 is placed on the pallet member 10 and housed inside the heating furnace 20. The rotor core 2 is then preheated inside the heating furnace 20. In this case, the first protruding portion 14 forms a gap between the plate portion 12 and the bottom of the heating furnace 20. In other words, the lower surface of the plate portion 12 is prevented from coming into contact with the bottom of the furnace.

[0036] After preheating, the rotor core 2 is placed on a pallet member 10 and held in a molding device 30. Specifically, an upper die 31 abuts against the upper surface of the rotor core 2 placed on the pallet member 10, and a lower die 32 abuts against the lower surface of the pallet member 10. In this case, the pallet member 10 is positioned relative to the lower die 32 by the first protrusions 14. Then, the rotor core 2 held in the molding device 30 is molded by filling the magnet insertion holes 4 (see FIG. 2) with resin.

[0037] In this embodiment, a rotor core 2 is used as an example of a motor core, but the present disclosure is not limited to this. Specifically, the pallet member 10 described in this embodiment can also be used to resin-mold the coil-wound portion of a stator core (stator iron core) serving as a motor core, or to fix the laminated core together by filling resin into through-holes provided in the axial direction of an uncrimped laminated core. In this specification, the term "motor" also includes a semi-finished product in which some parts are attached to a motor core (rotor core or stator core).

[0038] <Configuration of rotor core and pallet components> Next, a schematic configuration of the rotor core 2 and the pallet member 10 according to this embodiment will be described with reference to Fig. 2. Fig. 2 is a perspective view showing the schematic configuration of the rotor core 2 and the pallet member 10 according to this embodiment.

[0039] As shown in FIG. 2 , the rotor core 2 is formed by laminating multiple thin electromagnetic steel sheets. The rotor core 2 has a cylindrical shape, and a through-hole 5 is provided in the center of the rotor core 2 (i.e., a region including the central axis of the cylindrical shape). When the rotor core 2 is assembled into a motor, a shaft constituting a rotating shaft is inserted into the through-hole 5. The rotor core 2 also has multiple (four in FIG. 2 ) magnet insertion holes 4 arranged in the circumferential direction, extending along the axial direction of the rotor core 2, surrounding the through-hole 5. The magnet insertion holes 4 can be configured in a shape that allows insertion of permanent magnets 3, such as a rectangular parallelepiped or arc-shaped through-hole that penetrates the rotor core 2 in the thickness direction, but the specific shape is not particularly limited. Similarly, the number of magnet insertion holes 4 can be arbitrarily changed and can be more than the four shown in FIG. 2 , for example, approximately 10 to 40. The magnet insertion holes 4 are an example of a "resin-filled portion" according to the technology disclosed herein. The through-hole 5 is an example of a "central through-hole" according to the technology disclosed herein.

[0040] The permanent magnets 3 are inserted into and fixed in the magnet insertion holes 4 of the rotor core 2. The permanent magnets 3 may be formed, for example, as rectangular parallelepiped or arc-shaped blocks slightly smaller than the magnet insertion holes 4. The permanent magnets 3 may be magnetized or not when inserted into the magnet insertion holes 4. Furthermore, the permanent magnets 3 may be divided in the stacking direction or in a direction perpendicular to the stacking direction. When the permanent magnets 3 are inserted into the magnet insertion holes 4, at least partial gaps are formed between the outer circumferential surface of the permanent magnets 3 and the inner circumferential surface of the magnet insertion holes 4. The gaps formed in the magnet insertion holes 4 function as spaces into which resin is filled. These spaces communicate with the first through holes 16 provided in the plate portion 12 of the pallet member 10.

[0041] In this embodiment, the magnet insertion holes 4 of the rotor core 2 are exemplified as being rectangular parallelepiped-shaped holes that are open in the vertical direction and have substantially no gaps in the front-rear or left-right directions. Therefore, the upper and lower dies 31 and 32 have substantially flat contact surfaces, but the shapes of the contact surfaces of the upper and lower dies 31 and 32 can be changed as appropriate to match the shape of the rotor core 2 to be held. For example, when the molding apparatus 30 according to this embodiment is used for resin molding an inner rotor type stator core, it is preferable to use the upper and lower dies 31 and 32 that include protrusions that are inserted into spaces formed in the center of the stator core.

[0042] In the example shown in FIG. 2, the pallet member 10 has a disk-shaped plate portion 12. The rotor core 2 is placed on an upper surface 12A of the plate portion 12. The rotor core 2 is placed on the plate portion 12 with the central axis of the disk-shaped plate portion 12 and the central axis of the rotor core 2 approximately aligned. The plate portion 12 also has a shape that allows the rotor core 2 to be placed thereon (for example, an outer diameter larger than the outer diameter of the rotor core 2, and a plate thickness that can exert sufficient rigidity to support the rotor core 2). The plate portion 12 is an example of a "plate portion" according to the technology of the present disclosure, and the upper surface 12A is an example of a "first surface" according to the technology of the present disclosure.

[0043] The pallet member 10 also has a first protrusion 14 that protrudes from the surface (here, the lower surface 12B) opposite to the surface on which the rotor core 2 is placed (here, the upper surface 12A, hereinafter also simply referred to as the "placement surface"). The first protrusion 14 is, for example, a cylindrical pin-shaped member whose base end is attached to the plate portion 12. The diameter of the tip of the pin-shaped member 14A becomes smaller as it approaches the tip. The lower surface 12B is an example of a "second surface" according to the technology of the present disclosure.

[0044] Furthermore, a plurality of pin-shaped members 14A are provided along the outer edge of the plate portion 12. Here, the pin-shaped members 14A are provided on the outer peripheral side of the plate portion 12. Specifically, the pin-shaped members 14A are provided on the plate portion 12 on the outer peripheral side of the first through holes 16. The first protrusion 14 is an example of a "first protrusion" according to the technology of the present disclosure, and the pin-shaped members 14A are an example of a "pin-shaped member" according to the technology of the present disclosure.

[0045] Here, an example of a cylindrical pin-shaped member 14A is shown, but this is merely one example. For example, the pin-shaped member 14A may be a polygonal pillar (e.g., a rectangular pillar). Also, the tip of the pin-shaped member 14A may be cone-shaped instead of hemispherical. The pin-shaped member 14A may be molded integrally with the plate portion 12, or may be provided as a separate part.

[0046] The number and arrangement of the first protrusions 14 are not particularly limited as long as they can support the weight of the rotor core 2 and stabilize the posture of the pallet member 10. For example, four first protrusions 14 may be arranged at equal intervals along the outer periphery of the plate portion 12.

[0047] The plate portion 12 is formed with first through holes 16 that penetrate in the plate thickness direction. The first through holes 16 are formed at positions facing the magnet insertion holes 4 of the rotor core 2. That is, as described above, the first through holes 16 communicate with the magnet insertion holes 4. The number and arrangement of the first through holes 16 are determined according to the number and arrangement of the magnet insertion holes 4 in the rotor core 2. The first through holes 16 are an example of a "first through hole" according to the technology of the present disclosure.

[0048] The pallet member 10 also has a second protruding portion 18 that protrudes from the surface (here, the upper surface 12A) on which the rotor core 2 is placed. The second protruding portion 18 is insertable into a hole 6 formed in the rotor core 2. By inserting the second protruding portion 18 into the hole 6, the rotor core 2 is positioned relative to the pallet member 10. Furthermore, by engaging the second protruding portion 18 with the hole 6, the rotor core 2 is prevented from falling off the placement surface of the pallet member 10.

[0049] In the example shown in Fig. 2, four second protrusions 18 are arranged along the circumferential direction of the rotor core 2. The number and arrangement of the second protrusions 18 are determined according to the number and arrangement of the holes 6. Furthermore, the protrusion length of the second protrusions 18 (i.e., the height from the mounting surface to the tip) is set appropriately according to the positioning accuracy, etc. The second protrusions 18 are an example of a "second protrusion" according to the technology of the present disclosure.

[0050] The holes 6 formed in the rotor core 2 are, for example, through holes provided in the rotor core 2 to reduce the weight. Furthermore, the holes 6 may be, for example, through holes that serve as flow paths for cooling the motor core when the rotor core 2 is used as part of a motor core. Furthermore, the holes 6 may be dedicated holes for inserting the second protrusions 18. In this case, the holes 6 do not have to be through holes. The holes 6 are an example of "holes formed in a core" according to the technology of the present disclosure.

[0051] 2 shows an example of second protrusion 18 that is a cylindrical pin-shaped member, but this is merely one example. For example, second protrusion 18 may be a polygonal prism (e.g., a rectangular prism), or a hemispherical or conical protrusion. Furthermore, second protrusion 18 may be molded integrally with plate portion 12, or may be provided as a separate component.

[0052] Next, with reference to FIG. 3, the preheating of the rotor core 2 according to this embodiment will be described. FIG. 3 is a schematic explanatory diagram showing an example of the preheating of the rotor core 2 according to this embodiment. As shown in FIG. 3, the rotor core 2 is placed on a pallet member 10 and housed inside a heating furnace 20. In other words, the pallet member 10 is usable in the heating process of the rotor core 2 (here, the preheating process before the molding process). The heating furnace 20 is heating equipment capable of preheating the rotor core 2 before molding. In the example shown in FIG. 3, the heating furnace 20 is a hot air circulating furnace. Specifically, an atmosphere heated by a heat source (not shown) is introduced into the furnace, and the atmosphere inside the furnace is circulated by a fan 24 provided on the furnace ceiling 22. The preheating temperature of the rotor core 2 can be, for example, about 100 to 200°C.

[0053] The pallet member 10 on which the rotor core 2 is placed is installed in the furnace via the first protrusions 14. In the example shown in FIG. 3, the first protrusions 14 of the pallet member 10 abut against the furnace bottom 26. In other words, during the preheating process of the rotor core 2, the pallet member 10 is supported by the furnace bottom 26. As a result, a gap t is formed between the furnace bottom 26 and the plate portion 12 according to the height of the first protrusions 14. In other words, the pallet member 10 is installed in the furnace without the lower surface 12B of the plate portion 12 coming into contact with the furnace bottom 26. This suppresses heat conduction from the plate portion 12 to the furnace wall (here, the furnace bottom 26). In this configuration, the furnace bottom 26 is an example of a "support surface" according to the technology of the present disclosure.

[0054] For example, consider a case where the lower surface 12B of the plate portion 12 is in direct contact with the hearth 26. In this case, heat conduction occurs via the contact interface between the lower surface 12B of the plate portion 12 and the hearth 26, and heat moves from the plate portion 12 to the hearth 26. This may make it difficult for the plate portion 12 and the rotor core 2 placed on the plate portion 12 to increase in temperature. In this configuration, the first protruding portion 14 forms a gap t between the plate portion 12 and the hearth 26, thereby suppressing heat conduction due to contact between the lower surface 12B of the plate portion 12 and the hearth 26.

[0055] Here, an example has been described in which the pallet member 10 in the heating furnace 20 is supported by the furnace bottom 26, but this is merely one example. The pallet member 10 may also be supported by a support shelf provided in the heating furnace 20. Also, here, an example has been described in which one rotor core 2 is heated in the heating furnace 20, but this is merely one example. For example, multiple rotor cores 2 may be heated simultaneously in a heating furnace 20 that is partitioned into multiple furnace chambers.

[0056] The protruding height of the pin-shaped members 14A may be any height that allows for the formation of a gap t that does not impede the flow of the heating atmosphere inside the heating furnace 20. The protruding height of the pin-shaped members 14A is, for example, about 1 mm, and may be at least 0.25 mm or more.

[0057] Furthermore, a flow of the heating atmosphere may occur within the furnace. For example, if the heating furnace 20 is a hot air circulation furnace, the fan 24 generates a flow of the heating atmosphere within the furnace. Even in furnaces that use a heating method other than a hot air circulation furnace, a flow of the heating atmosphere occurs due to convection caused by differences in local temperature within the furnace. This flow of the heating atmosphere passes through the magnet insertion holes 4 and the first through holes 16 of the rotor core 2. The flow of the heating atmosphere then passes through the gap t between the plate portion 12 and the furnace bottom 26. In this way, the flow of the heating atmosphere is less likely to be obstructed around the rotor core 2 and the pallet member 10.

[0058] Next, the manner in which the rotor core 2 according to this embodiment is molded will be described with reference to Fig. 4. Fig. 4 is a schematic explanatory diagram showing an example of the manner in which the rotor core 2 according to this embodiment is molded.

[0059] As shown in FIG. 4 , the rotor core 2 is placed on a pallet member 10 and held by a molding device 30. In other words, the pallet member 10 can also be used in a filling step in which resin is filled into the magnet insertion holes 4. The molding device 30 includes an upper mold 31, a lower mold 32, and supports 33. The upper mold 31 abuts against an upper portion of the rotor core 2, specifically its upper surface, to support it. The lower mold 32 abuts against a lower portion of the rotor core 2, specifically its lower surface, to support it. The supports 33 are columnar members erected between the upper mold 31 and the lower mold 32. The supports 33 may be able to raise and lower the upper mold 31 in the vertical direction using an actuator (not shown). The raising and lowering operation of the upper mold 31 is mainly performed when the rotor core 2 is held in the molding device 30 or when the rotor core 2 is removed and carried out from the molding device 30.

[0060] As described above, the upper mold 31 may be movable in the vertical direction. When the rotor core 2 is placed on the lower mold 32 via the pallet member 10, the upper mold 31 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 mold 31 and the lower mold 32. The shapes, materials, etc. of the surfaces of the upper mold 31 and the lower mold 32 that come into contact with the rotor core 2 can be adjusted so that the filled resin does not leak out of the rotor core 2 when the resin is filled into the magnet insertion holes 4. Specifically, the contact surfaces can be adjusted so that they are sealed when the rotor core 2 is sandwiched between the upper mold 31 and the lower mold 32.

[0061] In this embodiment, as described above, a structure is adopted in which the upper mold 31 is directly moved up and down, but other structures can be adopted as long as they are structures that allow the relative vertical positions of the upper mold 31 and the lower mold 32 to be changed. Specifically, for example, instead of moving the upper mold 31 up and down, a structure may be adopted in which the lower mold 32 is moved up and down, or both the upper mold 31 and the lower mold 32 are moved up and down.

[0062] A resin filling passage 35 is formed between the lower mold 32 and the plate portion 12 to supply softened resin R to the multiple magnet insertion holes 4 of the rotor core 2. That is, the pallet member 10 also functions as a gate member when filling the magnet insertion holes 4 with resin. The path structure of the resin filling passage 35 is appropriately set according to the number and shape of the magnet insertion holes 4 of the rotor core 2, the shape of the pots, etc. In addition, a positioning hole 32A is formed in the outer periphery of the lower mold 32 along the thickness direction. The positioning hole 32A is provided at a position corresponding to the first protrusion 14 of the pallet member 10. When the pallet member 10 is placed on the lower mold 32, the first protrusion 14 is inserted into the positioning hole 32A. This positions the pallet member 10 relative to the lower mold 32. The positioning hole 32A is an example of a "positioning hole" according to the technology disclosed herein.

[0063] The lower mold 32 is provided with pin-shaped members 32B. The pin-shaped members 32B are capable of ascending and descending relative to the lower mold 32. When ascending, the pin-shaped members 32B come into contact with the lower surface of the plate portion 12. The plate portion 12 and the rotor core 2 are then pushed up by the pin-shaped members 32B, thereby removing them from the lower mold 32. A spacer member 32C is disposed between the plate portion 12 and the lower mold 32. The spacer member 32C is a plate-shaped member capable of forming a gap between the plate portion 12 and the lower mold 32. The shape and arrangement of the spacer member 32C are not particularly limited. For example, the spacer member 32C may be an annular member disposed outside the first protruding portion 14, or may be an annular member extending in the circumferential direction of the plate portion 12. Instead of the spacer member 32C, a portion protruding from the lower mold 32 may form a gap between the plate portion 12 and the lower mold 32.

[0064] Since the rotor core 2, in which the magnet insertion holes 4 are filled with resin, can often be changed to a different shape, it is advisable to prepare a plurality of lower dies 32 having resin filling passages 35 with different structures in advance and use them by appropriately changing them according to the rotor core 2 held by the upper die 31 and the lower die 32. The lower die 32 may further include a lifter that can raise and lower the lower die 32 in order to put tablets into the pot, clean the resin filling passages 35, etc.

[0065] The molding device 30 further includes a plunger 34. The plunger 34 is heated by a heater (not shown) to press the softened resin R. In the example shown in FIG. 4, the cylindrical plunger 34, located in the center of the lower mold 32, presses the resin R toward the center of the plate portion 12. This causes the softened resin R to flow, pass through the resin filling passage 35, and then fill the magnet insertion holes 4 of the rotor core 2 through the first through holes 16. The resin R mainly contains a thermosetting resin material. Specifically, the resin R may be a resin mainly containing a thermosetting resin material such as an epoxy resin, a phenolic 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 resin R.

[0066] <Motor manufacturing method> Next, a method for manufacturing a motor according to this embodiment will be described with reference to Fig. 5. Fig. 5 is a flowchart showing an example of a rotor core manufacturing process according to this embodiment.

[0067] In the manufacturing method of the rotor core according to this embodiment, first, as shown in Fig. 5, the rotor core 2 is placed on the pallet member 10 (step S01). Specifically, the rotor core 2 is placed on the upper surface of the plate portion 12 of the pallet member 10. In this case, the second protrusion portion 18 of the plate portion 12 is inserted into the hole 6 formed in the rotor core 2, thereby positioning the rotor core 2 with respect to the pallet member 10.

[0068] Next, permanent magnets 3 and a rotor core 2 to which the permanent magnets 3 are to be attached are prepared, and the permanent magnets 3 are inserted into the magnet insertion holes 4 of the rotor core 2 (step S02). Then, the rotor core 2 is transported to a preheating step using a pallet member 10 (step S03). The rotor core 2 transported to the preheating step is preheated (step S04). The rotor core 2 is preheated using a heating furnace 20 shown in FIG. 3. That is, the rotor core 2 placed on the pallet member 10 is heated in the heating furnace 20. Furthermore, separately from preheating the rotor core 2, the upper mold 31 and the lower mold 32 may be preheated using a mold heater (not shown).

[0069] After preheating, the rotor core 2 is transported to the molding process while being placed on the pallet member 10. The rotor core 2 is then placed on the lower mold 32 via the pallet member 10, and then the upper mold 31 is moved downward to hold the rotor core 2 within the upper mold 31 and lower mold 32 (i.e., the metal mold) (step S05). At this time, the upper mold 31 is adjusted to press the upper surface of the rotor core 2 with a predetermined pressure, thereby allowing the upper mold 31 and the upper surface of the rotor core 2, and the lower mold 32 and the lower surface of the pallet member 10, to be tightly attached to each other.

[0070] Once the tablet is placed in the lower mold 32, a heater (not shown) is operated to soften the resin R (step S06). Specifically, the viscosity of the resin forming the tablet (resin solidified into a predetermined shape) is reduced by heating it in the pot inside the molding device 30, resulting in softened resin (hereinafter referred to as "softened resin") R. It is preferable that the heater used for this heating be controlled so as not to cause local temperature differences in the tablet. By this heating, the tablet melts, its viscosity is reduced, and it changes into softened resin R with high fluidity.

[0071] Once the tablet has turned into softened resin R, the softened resin R is then filled into the magnet insertion holes 4 via the plunger 34, as shown in Fig. 4 (step S07). Specifically, the plunger 34 is moved upward to press the resin R, and the softened resin R is injected into the resin filling path 35. The softened resin R that has flowed through the resin filling path 35 is then filled into the magnet insertion holes 4 of the rotor core 2. Note that, in order to smoothly fill the magnet insertion holes 4 with the softened resin R in step S07, air holes (not shown) for venting air from inside the magnet insertion holes 4 may be provided in appropriate positions on the upper mold 31, for example.

[0072] Once the filling of the softened resin R into the magnet insertion holes 4 is completed, a mold heater (not shown) is operated to harden the softened resin R in the magnet insertion holes 4 (step S08). When hardening the softened resin R, for example, it is advisable to heat it at 100 to 180°C for several minutes. As the softened resin R hardens through heating, the permanent magnets 3 are fixed in the magnet insertion holes 4 of the rotor core 2 by the resin mold. The heating time in step S08 can be adjusted as appropriate depending on the specific composition of the resin used in the tablet.

[0073] When the series of resin molding processes described above is complete, the upper mold 31 is raised, and the resin-molded rotor core 2 is removed from the apparatus using a transport means (not shown), such as a robot arm (step S09). The removed rotor core 2 can be transferred to another apparatus, for example, for the attachment of a shaft. Then, when removal of the rotor core 2 is complete, the molding apparatus 30 is cleaned (step S10). Cleaning the molding apparatus 30 includes removing the resin that has hardened within the resin filling passage 35. In addition, cleaning the surfaces of the upper mold 31 and lower mold 32 and the inside of the pot, etc., using a cleaning member such as a brush, may also be included.

[0074] As described above, the pallet member 10 according to the first embodiment is provided with a plate portion 12 and a first protrusion 14. The rotor core 2 is placed on the upper surface 12A of the plate portion 12. The first protrusion 14 protrudes from the lower surface 12B of the plate portion 12. When the rotor core 2 placed on the plate portion 12 is heated, the first protrusion 14 suppresses heat conduction from the pallet member 10 to the furnace bottom 26 of the heating furnace 20. Specifically, the first protrusion 14 forms a gap t between the plate portion 12 and the furnace bottom 26, suppressing heat conduction from the pallet member 10. This facilitates uniform heating of the rotor core 2, thereby shortening the heating time for the rotor core 2. This contributes to improving productivity in the rotor manufacturing process.

[0075] Furthermore, in the pallet member 10 according to the first embodiment, the plate portion 12 is provided with a first through hole 16 at a position facing the magnet insertion hole 4 of the rotor core 2. The presence of the first through hole 16 prevents the flow of the heated atmosphere inside the magnet insertion hole 4 from being impeded, making it easier to make the heated atmosphere uniform. As a result, it becomes easier to make the heated state of the portion of the rotor core 2 around the magnet insertion hole 4 uniform, which contributes to improving the productivity of the rotor manufacturing process.

[0076] Furthermore, for example, when filling resin into magnet insertion hole 4 after the preheating step, if the area around magnet insertion hole 4 is not heated sufficiently, the resin will cool and its fluidity will decrease. As a result, the degree of filling of resin into magnet insertion hole 4 may be insufficient. In this configuration, first through hole 16 does not impede the flow of the heated atmosphere, and the area around magnet insertion hole 4 is heated sufficiently, making it easier to fill resin after preheating.

[0077] Furthermore, the pallet member 10 according to the first embodiment can also be used in a molding process, which is a process of filling the magnet insertion holes 4 of the rotor core 2 with resin R, and the resin R is filled into the magnet insertion holes 4 via the first through holes 16 provided in the pallet member 10. Because the first through holes 16 are also used for filling the resin R, the configuration of the pallet member 10 is simplified compared to when a separate through hole for filling resin is provided in the pallet member 10.

[0078] Furthermore, the pallet member 10 according to this first embodiment can also be used in a molding process, and the first protrusions 14 provided on the pallet member 10 can be inserted into positioning holes 32A of a lower mold 32 that is filled with resin R. Because the first protrusions 14 are used for positioning, the configuration of the pallet member 10 is simplified compared to when a separate positioning protrusion is provided on the pallet member 10.

[0079] Furthermore, in the pallet member 10 according to the first embodiment, the plate portion 12 is provided with a second protruding portion 18 that protrudes from the upper surface 12A. The second protruding portion 18 is inserted into a hole 6 formed in the rotor core 2. The rotor core 2 is positioned relative to the plate portion 12 by the second protruding portion 18.

[0080] Furthermore, in the pallet member 10 according to the first embodiment, a plurality of second protrusions 18 are provided along the circumferential direction of the rotor core 2. The second protrusions 18 formed along the circumferential direction are inserted into the holes 6, so that the rotor core 2 is positioned with greater precision relative to the plate portion 12. Furthermore, compared to when a cylindrical protrusion is provided in the center of the plate portion 12 and inserted into the through hole 5 of the rotor core 2 for positioning, the flow of the heating atmosphere within the through hole 5 is less likely to be obstructed, making it easier to heat the area around the through hole 5 of the rotor core 2.

[0081] Furthermore, in the pallet member 10 according to this first embodiment, the first protrusions 14 are pin-shaped members 14A provided in multiple locations along the outer edge of the plate portion 12. Because the first protrusions 14 are pin-shaped members 14A, the contact areas of the first protrusions 14 are reduced compared to when they are block-shaped protrusions, suppressing heat conduction. Furthermore, the posture of the pallet member 10 is stable because it is supported by multiple pin-shaped members 14A provided along the periphery.

[0082] Furthermore, the pallet member 10 according to the first embodiment can also be used in the conveying process of the rotor core 2, and the first protrusions 14 are capable of forming a gap between the plate portions 12 and the conveying surface C1. Because a gap is formed between the first protrusions 14 and the conveying surface C1, the adhesion of contaminants (for example, dust) to the lower surfaces 12B of the plate portions 12 of the pallet member 10 and the occurrence of scratches are suppressed.

[0083] For example, if the pallet member 10 is also used in the resin filling process, the pallet member 10 may form part of the resin filling path 35. In this case, if contaminants are attached to the pallet member 10, the contaminants may be mixed into the resin R, or the contaminants may create a gap between the pallet member 10 and the mold, which may result in leakage of the resin R. Furthermore, if the pallet member 10 is scratched, the pressing force acting on the resin R will be concentrated at the scratched area, increasing the likelihood of leakage of the resin R. In this configuration, the first protrusion 14 prevents contact with the conveying surface C1, thereby preventing the occurrence of problems in filling the resin R as described above.

[0084] (First Modification) In the first embodiment described above, an example was given in which the first protrusion 14 is a pin-shaped member 14A, but the technology of the present disclosure is not limited to this. In this first modified example, a step 14B is provided as the first protrusion 14. As shown in FIG. 6, the step 14B is provided along the periphery of the plate portion 12 of the pallet member 10. The step 14B is a step that partially protrudes from the lower surface 12B (see FIG. 3) of the plate portion 12. The height of the step 14B may be any height that is sufficient to form a gap t that does not obstruct the flow of the heating atmosphere in the heating furnace 20. The step 14B may be formed continuously along the circumferential direction of the plate portion 12, or may be formed partially along the circumferential direction of the plate portion 12.

[0085] In this first modified example, the step portion 14B forms a gap t between the plate portion 12 and the furnace bottom 26, suppressing heat conduction from the pallet member 10. This facilitates uniform heating of the rotor core 2, thereby shortening the heating time of the rotor core 2. As a result, this can contribute to improving productivity in the rotor manufacturing process.

[0086] (Second Modification) In the first embodiment described above, an example was described in which the first protrusion 14 is a pin-shaped member 14A. However, the technology of the present disclosure is not limited to this. In the second modified example, a columnar member 19 is provided as the first protrusion 14. As shown in FIG. 7 , a columnar member 19 is provided in the center of the plate portion 12. The columnar member 19 is provided at a position corresponding to the through hole 5 of the rotor core 2. The columnar member 19 is, for example, a cylindrical member, but may also be a polygonal columnar member. The lower end of the columnar member 19 protrudes from the plate portion 12 of the pallet member 10. The protruding length of the lower end of the columnar member 19 may be any length that is sufficient to form a gap t that does not obstruct the flow of the heating atmosphere in the heating furnace 20. The upper end of the columnar member 19 is inserted into the through hole 5 of the rotor core 2. This positions the rotor core 2 relative to the pallet member 10. In this case, the pallet member 10 does not need to be provided with the second protrusion 18. The columnar member 19 is an example of the "columnar member" according to the technology of the present disclosure.

[0087] In the second modified example, the columnar members 19 form a gap t between the plate portion 12 and the furnace bottom 26, suppressing heat conduction from the pallet member 10. This facilitates uniform heating of the rotor core 2, thereby shortening the heating time of the rotor core 2. As a result, this can contribute to improving productivity in the rotor manufacturing process.

[0088] Furthermore, in this second modified example, since the columnar members 19 are provided in the central portion, the flow of the heating atmosphere toward the outer periphery of the pallet member 10 is not obstructed, and heating is therefore more efficient. Furthermore, since the central portion of the pallet member 10 is supported, the posture of the pallet member 10 is stable.

[0089] (Third Modification) In the first embodiment, the plate portion 12 of the pallet member 10 is circular, but the technology of the present disclosure is not limited to this. In the third modified example, a second through hole 13 is provided in the center of the plate portion 12.

[0090] As shown in Fig. 8, a second through hole 13 is formed in the center of the plate portion 12. In the plate portion 12, the second through hole 13 is formed at a position corresponding to the through hole 5 of the rotor core 2. The diameter of the second through hole 13 is set appropriately based on the area of ​​the mounting surface required for the plate portion 12, the strength of the plate portion 12, and the like. The second through hole 13 is an example of a "second through hole" according to the technology of the present disclosure.

[0091] As described above, a flow of the heating atmosphere may occur inside the furnace. This flow of the heating atmosphere passes through the through holes 5 and the second through holes 13 of the rotor core 2. The flow of the heating atmosphere then passes through the gap t between the plate portion 12 and the furnace bottom 26. In this way, the flow of the heating atmosphere is less likely to be obstructed around the rotor core 2 and the pallet member 10.

[0092] In this third modified example, a second through hole 13 is provided in the plate portion 12 of the pallet member 10. The second through hole 13 is less likely to obstruct the flow of the heating atmosphere in the space at the center of the rotor core 2, and therefore the flow of the heating atmosphere inside the through hole 5 is not obstructed, making it easier to make the heating atmosphere uniform. As a result, the heating state of the portion of the rotor core 2 around the through hole 5 can be made uniform. This makes it easier to do this, which contributes to improving the productivity of the rotor manufacturing process.

[0093] (Fourth Modification) In the first embodiment, an example in which the second protrusion 18 is provided on the pallet member 10 has been described, but the technology of the present disclosure is not limited to this. In the fourth modified example, the pallet member 10 has a third protrusion 13A provided along the periphery of the second through hole 13.

[0094] As shown in FIG. 9 , in the pallet member 10, a third protrusion 13A is formed on the plate portion 12. The third protrusion 13A is provided along the periphery of the second through hole 13 and is a portion that protrudes toward the upper surface 12A (see FIG. 2 ) of the plate portion 12. The third protrusion 13A is inserted into the through hole 5 of the rotor core 2. The protrusion height and radial thickness of the third protrusion 13A are set appropriately. Note that, although an example is shown here in which the third protrusion 13A is formed around the entire circumference of the second through hole 13, this is merely an example, and the third protrusion 13A may be formed partially around the entire circumference of the second through hole 13. In other words, the third protrusion 13A may have a shape of multiple arcs when the plate portion 12 is viewed from above. The third protrusion 13A is an example of a “third protrusion” according to the technology of the present disclosure.

[0095] In this case, the second protrusion 18 may not be provided on the pallet member 10, and phase alignment of the rotor core 2 (i.e., circumferential alignment of the rotor core 2) may be achieved by engagement of a key (not shown) provided on the rotor core 2 with a cutout portion (not shown) provided on the pallet member 10.

[0096] In the fourth modified example, the pallet member 10 has a third protrusion 13A formed on the periphery of the second through hole 13. The third protrusion 13A is inserted into the through hole 5 of the rotor core 2. This positions the rotor core 2 with respect to the pallet member 10.

[0097] <<Second embodiment>> In the first embodiment described above, an example was given in which one rotor core 2 is filled with resin R in the molding process, but the technology of the present disclosure is not limited to this. In the second embodiment, a plurality of rotor cores 2 are filled with resin R in the molding process. Note that in this embodiment, description of content common to the configuration described in the first embodiment may be omitted.

[0098] FIG. 10 is a schematic explanatory diagram showing an example of how the rotor core 2 according to this embodiment is preheated. FIG. 11 is a schematic explanatory diagram showing an example of how the rotor core 2 according to this embodiment is molded. As shown in FIG. 10 , the rotor core 2 is placed on a pallet member 10A and placed in a heating furnace 20. The pallet member 10A has a first protrusion 14. In the example shown in FIG. 10 , the first protrusion 14 is a pin-shaped member 14A. The first protrusion 14 is provided on the opposite side of the plate portion 12 from the second protrusion 18. In other words, the first protrusion 14 is provided on the lower surface 12B (see FIG. 3 ) of the plate portion 12 at a position corresponding to the second protrusion 18. The second protrusion 18 is provided on the plate portion 12 on the inner peripheral side of the first through hole 16. Therefore, the first protrusion 14 is also provided on the plate portion 12 on the inner peripheral side of the first through hole 16.

[0099] Furthermore, in the pallet member 10A, a second through hole 13 is provided in the center of the plate portion 12. The flow of the heating atmosphere passes through the through hole 5 of the rotor core 2 and the second through hole 13. The flow of the heating atmosphere also passes through the magnet insertion holes 4 and the first through hole 16 of the rotor core 2. The flow of the heating atmosphere then passes through the gap t between the plate portion 12 and the furnace bottom 26.

[0100] As shown in FIG. 11 , the rotor core 2 is placed on a pallet member 10A and held by a molding device 30. A plurality of rotor cores 2 are arranged in the molding device 30. The plurality of rotor cores 2 are arranged side by side along the axial direction of the rotor core 2 (i.e., the central axial direction of the cylindrical rotor core 2). That is, the plurality of rotor cores 2 are arranged in multiple stages. The plurality of rotor cores 2 are each separately preheated in a heating furnace 20. For example, a plurality of heating furnaces 20 may be prepared, and each of the plurality of rotor cores 2 may be preheated in each of the plurality of heating furnaces 20.

[0101] 11, of the three rotor cores 2, the upper and middle two rotor cores 2 are placed on pallet members 10A and arranged in the molding device 30. Furthermore, the bottom rotor core 2 is placed on a pallet member 10 and arranged in the molding device 30.

[0102] When multiple rotor cores 2 are arranged side by side in the axial direction, the first protrusion 14 of the pallet member 10A on which the rotor core 2 in the upper tier is placed is inserted into the hole 6 of the rotor core 2 in the tier immediately below. In the example shown in FIG. 11 , the first protrusion 14 of the pallet member 10A on which the rotor core 2 in the upper tier is placed is inserted into the hole 6 of the rotor core 2 in the middle tier. Furthermore, the first protrusion 14 of the pallet member 10A on which the rotor core 2 in the middle tier is placed is inserted into the hole 6 of the rotor core 2 in the lower tier. The rotor core 2 in the upper tier is an example of a "first core" according to the technology of the present disclosure, and the rotor core 2 in the middle tier is an example of a "second core" according to the technology of the present disclosure.

[0103] When the first protrusion 14 is inserted into the hole 6 of the middle-stage rotor core 2, the first protrusion 14 engages with the hole 6, and the pallet member 10A on which the upper-stage rotor core 2 is placed and the middle-stage rotor core 2 are positioned. The pallet member 10A on which the middle-stage rotor core 2 is placed and the lower-stage rotor core 2 are similarly positioned. In other words, each of the multiple rotor cores 2 lined up along the axial direction is positioned relative to each other. Here, the protruding height of the first protrusion 14 only needs to be equal to or greater than the thickness of the laminated electromagnetic steel plates that make up the lower-stage rotor core 2. This allows the first protrusion 14 to engage with the rotor core 2.

[0104] Furthermore, when multiple rotor cores 2 are arranged side by side in the axial direction, the magnet insertion holes 4 of each of the multiple rotor cores 2 are in communication with each other via the first through holes 16 of the pallet member 10A. In other words, the first through holes 16 of the pallet member 10A on which the rotor core 2 of the upper tier is placed are located at positions corresponding to the magnet insertion holes 4 of the rotor core 2 of the tier immediately below. In the example shown in FIG. 11 , the magnet insertion holes 4 of the rotor cores 2 of the upper tier, middle tier, and lower tier are in communication with each other via the first through holes 16 of the pallet member 10A.

[0105] In the molding device 30, the plunger 34 presses the resin R that has been softened by heating. This causes the softened resin R to flow and fill the magnet insertion holes 4 of the rotor cores 2 via the resin filling passages 35. The flowing resin R first enters the magnet insertion holes 4 of the rotor cores 2 in the lower tier, then enters the magnet insertion holes 4 of the rotor cores 2 in the middle tier, and finally enters the magnet insertion holes 4 of the rotor cores 2 in the upper tier. In this manner, the resin R is filled into each of the magnet insertion holes 4 of the multiple rotor cores 2.

[0106] Next, a method for manufacturing a motor according to this embodiment will be described with reference to Fig. 12. Fig. 12 is a flowchart showing an example of a rotor core manufacturing process according to this embodiment. Steps S11 to S14 and steps S18 to S20 are similar to steps S01 to S04 and steps S08 to S10 in the rotor core manufacturing process according to the first embodiment, and therefore description thereof will be omitted.

[0107] The preheated rotor core 2 is placed on a pallet member 10A and transported to a molding process. In the molding device 30, multiple rotor cores 2 are arranged side by side in the axial direction. The rotor core 2 is then placed on the lower mold 32 via the pallet member 10, and the upper mold 31 is then moved downward to hold the rotor core 2 within the upper mold 31 and lower mold 32 (i.e., the mold) (step S15). At this time, the upper mold 31 is adjusted to press the top surface of the uppermost rotor core 2 with a predetermined pressure, thereby allowing the upper mold 31 and the top surface of the uppermost rotor core 2, and the lower mold 32 and the pallet member 10, to be tightly attached to each other 12A.

[0108] Once the tablet is placed in the lower mold 32, a heater (not shown) is operated to soften the resin R (step S16). Once the tablet has turned into softened resin R, the softened resin R is then filled into the magnet insertion holes 4 via the plunger 34, as shown in FIG. 11 (step S17). Specifically, the plunger 34 is moved upward to press the resin R, and the softened resin R is injected into the resin filling passage 35. The softened resin R that has flowed through the resin filling passage 35 is then filled into each of the magnet insertion holes 4 of the multiple rotor cores 2 that are lined up along the axial direction.

[0109] As described above, the pallet member 10A according to the second embodiment is used in the preheating process of the rotor core 2 and the process of filling the magnet insertion holes 4 with resin while arranging multiple rotor cores 2 in the axial direction. In the preheating process, the first protrusions 14 form a gap t between the plate portion 12 and the furnace bottom 26, suppressing heat conduction from the pallet member 10A. This makes it easier to uniformly heat the rotor cores 2, thereby shortening the heating time for the rotor cores 2. As a result, this can contribute to improving productivity in the rotor manufacturing process.

[0110] Furthermore, in the molding process, multiple rotor cores 2 can be filled with resin R at once using one molding device 30, which contributes to improved productivity. For example, productivity in the rotor manufacturing process is improved compared to when multiple rotor cores 2 are filled with resin R using separate molding devices 30.

[0111] Furthermore, in the pallet member 10A according to the second embodiment, when the rotor core 2 is placed on a lower level of the pallet member 10A on which the rotor core 2 is placed, the first protrusion 14 can be inserted into the hole 6 formed in the rotor core 2 on the lower level. As a result, the first protrusion 14 is inserted into the hole 6 of the rotor core 2 on the lower level, which stabilizes the state in which the multiple rotor cores 2 are lined up along the axial direction and achieves space saving in the axial direction.

[0112] Furthermore, in the pallet member 10A according to the second embodiment, the plate portion 12 has a second protruding portion 18, and the second protruding portion 18 is inserted into a hole 6 formed in the rotor core 2 placed on the pallet member 10A. As a result, the rotor core 2 is positioned relative to the plate portion 12 by the second protruding portion 18.

[0113] Furthermore, in the second embodiment, the first protruding portion 14 of the pallet member 10A on which the upper rotor core 2 is placed is inserted into the hole 6 formed in the middle rotor core 2. Furthermore, the second protruding portion 18 of the pallet member 10A on which the middle rotor core 2 is placed is inserted into the hole 6 formed in the middle rotor core 2. This allows the middle rotor core 2 to share the same hole 6 for inserting the first protruding portion 14 and the second protruding portion 18, thereby simplifying the structure of the rotor core 2 compared to when the rotor core 2 is provided with separate holes for inserting the first protruding portion 14 and the second protruding portion 18. Furthermore, because the hole 6 is shared, the positioned rotor core 2 is less likely to be misaligned in the radial direction.

[0114] In the pallet member 10A according to the second embodiment, the second protrusion 18 is a plate portion The second protruding portion 18 is provided at a position opposite the first protruding portion 14 across the plate portion 12. As a result, the rotor core 2 is positioned with respect to the plate portion 12 by the second protruding portion 18. Furthermore, because the second protruding portion 18 is located on the opposite side of the first protruding portion 14, even when the rotor cores 2 are arranged in multiple stages, the upper and lower rotor cores 2 are positioned relative to each other and are unlikely to be arranged with radial misalignment.

[0115] Furthermore, in the pallet member 10A according to the second embodiment, the plate portion 12 is provided with a first through hole 16 at a position facing the magnet insertion hole 4 of the rotor core 2. The presence of the first through hole 16 prevents the flow of the heated atmosphere inside the magnet insertion hole 4 from being obstructed, making it easier to make the heated atmosphere uniform. As a result, it becomes easier to make the heated state of the portion of the rotor core 2 around the magnet insertion hole 4 uniform, which contributes to improving the productivity of the rotor manufacturing process.

[0116] Furthermore, for example, when filling resin into magnet insertion hole 4 after the preheating step, if the area around magnet insertion hole 4 is not heated sufficiently, the resin will cool and its fluidity will decrease. As a result, the degree of filling of resin into magnet insertion hole 4 may be insufficient. In this configuration, first through hole 16 does not impede the flow of the heated atmosphere, and the area around magnet insertion hole 4 is heated sufficiently, making it easier to fill resin after preheating.

[0117] Furthermore, for example, in a molding process, when multiple rotor cores 2 are arranged in multiple stages, the magnet insertion holes 4 of each of the multiple rotor cores 2 are communicated with each other via the first through holes 16. This makes it easier to fill the magnet insertion holes 4 with the resin R.

[0118] Furthermore, the pallet member 10A according to the second embodiment can also be used in a molding process, which is a process of filling the magnet insertion holes 4 of the rotor core 2 with resin R, and the resin R is filled into the magnet insertion holes 4 via first through holes 16 provided in the pallet member 10A. Because the first through holes 16 are also used to fill the resin R, the configuration of the pallet member 10A is simplified compared to when a separate through hole for filling resin is provided in the pallet member 10A.

[0119] Furthermore, in the pallet member 10A according to the second embodiment, second through holes 13 are provided in the plate portion 12. The second through holes 13 are less likely to impede the flow of the heating atmosphere in the space at the center of the rotor core 2, and therefore the flow of the heating atmosphere inside the through holes 5 is not impeded, making it easier to make the heating atmosphere uniform. As a result, it becomes easier to make the heating state of the portion of the rotor core 2 around the through holes 5 uniform, which can contribute to improving the productivity of the rotor manufacturing process.

[0120] Furthermore, the pallet member 10 according to this second embodiment can also be used in a molding process, and the first protrusions 14 provided on the pallet member 10 can be inserted into positioning holes 32A of a lower mold 32 that is filled with resin R. Because the first protrusions 14 are used for positioning, the configuration of the pallet member 10 is simplified compared to when a separate positioning protrusion is provided on the pallet member 10.

[0121] In the second embodiment, an example in which three rotor cores 2 are arranged along the axial direction has been described, but the technology of the present disclosure is not limited to this. For example, two rotor cores 2 may be arranged along the axial direction, or four or more rotor cores 2 may be arranged along the axial direction.

[0122] Furthermore, in the second embodiment, the third protruding portion 13A shown in the fourth modified example may of course be applied to the pallet member 10A.

[0123] (Fifth Modification) In the second embodiment described above, an example was given in which the lowest rotor core 2 is placed on a pallet member 10A during the molding process, but the technology of the present disclosure is not limited to this. In the present fourth modified example, the lowest rotor core 2 is placed on a pallet member 10A in the same manner as the other rotor cores 2.

[0124] As shown in Fig. 13, the rotor core 2 is placed on a pallet member 10A and held by an upper mold 31 and a lower mold 32 of a molding device 30. A plurality of rotor cores 2 are arranged in the axial direction in the molding device 30. In the example shown in Fig. 13, three rotor cores 2 are arranged in the molding device 30, each placed on a pallet member 10A.

[0125] In the molding device 30, the multi-plunger 36 presses the resin R softened by heating. The multi-plunger 36 is configured to include a plurality of plungers 36A. The plurality of plungers 36A are arranged along the circumferential direction of the lower mold 32 at positions facing the first through holes 16 of the pallet member 10A. Each of the plurality of plungers 36A presses the resin R toward the first through holes 16. This causes the softened resin R to flow and fill the magnet insertion holes 4 of the rotor core 2 through the first through holes 16. In this manner, the resin R is filled into each of the magnet insertion holes 4 of the plurality of rotor cores 2.

[0126] Although the embodiment in which the resin is filled by the multi-plunger 36 has been described above, this is merely one example. For example, the resin R may be pressed toward the first through-hole 16 by an annular plunger that presses an annular resin tablet. In this fifth modified example, the same effects as those of the second embodiment described above can be obtained.

[0127] (Sixth Modification) In the second embodiment described above, an example was given in which the pallet member 10A on which the lowest rotor core 2 is placed forms part of the resin filling path 35 during the molding process, but the technology of the present disclosure is not limited to this. In the present fifth modified example, the lowest rotor core 2 is placed on the molding device 30 without the pallet member 10A.

[0128] As shown in FIG. 14, the rotor core 2 is held by an upper mold 31 and a lower mold 32 of a molding apparatus 30. A plurality of rotor cores 2 are arranged in the molding apparatus 30, lined up along the axial direction. In the example shown in FIG. 14, of the three rotor cores 2, the upper and middle two rotor cores 2 are arranged in the molding apparatus 30, each placed on a pallet member 10A. Furthermore, the rotor core 2 in the bottom tier is arranged in the molding apparatus 30 without the pallet member 10A in between.

[0129] The rotor core 2 at the bottom tier is placed on the pallet member 10 or pallet member 10A during the transport process and / or preheating process. Then, it is removed from the pallet member 10 or 10A before being placed in the molding device 30, and then placed in the molding device 30. Then, the other rotor cores 2 are placed on the rotor core 2 at the bottom tier while still placed on the pallet member 10A. Note that the process of placing the other rotor cores 2 on the rotor core 2 at the bottom tier may be performed outside the molding device 30.

[0130] The lowest rotor core 2 is placed on the upper surface of a gate member 38. A resin filling passage 35 is formed inside the gate member 38. The plunger 34 presses the resin R softened by heating toward the gate member 38. This causes the softened resin R to flow and be filled into the magnet insertion holes 4 of the rotor core 2 via the resin filling passage 35. In this sixth modified example, the same effects as those of the second embodiment described above can be obtained.

[0131] <<Third Embodiment>> In the second embodiment, the rotor cores 2 are arranged in multiple stages in the molding process, but the technology of the present disclosure is not limited to this. In the third embodiment, the rotor cores 2 are also arranged in multiple stages in the preheating process.

[0132] FIG. 15 is a schematic explanatory diagram showing an example of how the rotor core 2 according to this embodiment is preheated. As shown in FIG. 15, a pallet member 10A on which the rotor core 2 is placed is placed inside a heating furnace 20. A plurality of rotor cores 2 are arranged inside the heating furnace 20. The plurality of rotor cores 2 are arranged side by side along the axial direction of the rotor core 2. The plurality of rotor cores 2 are preheated by the heating furnace 20.

[0133] 15, three rotor cores 2 are placed on pallet members 10A and arranged in a heating furnace 20. When multiple rotor cores 2 are arranged lined up along the axial direction, the first protrusions 14 of the pallet member 10A on which the rotor cores 2 in the upper row are placed are inserted into the holes 6 of the rotor cores 2 in the row below.

[0134] Furthermore, when multiple rotor cores 2 are arranged side by side in the axial direction, the magnet insertion holes 4 of each of the multiple rotor cores 2 are in communication with each other via the first through hole 16 of the pallet member 10A. Furthermore, a second through hole 13 is provided in the center of the plate portion 12. When multiple rotor cores 2 are arranged side by side in the axial direction, the spaces in the center portions of each of the multiple rotor cores 2 (i.e., the spaces inside the through holes 5) are in communication with each other via the second through hole 13.

[0135] As described above, a flow of the heating atmosphere may occur within the furnace. This flow of the heating atmosphere passes through the through holes 5 and the second through holes 13 of the rotor core 2. That is, the flow of the heating atmosphere passes through the space formed by the central portions of the rotor cores 2 arranged along the axial direction. The flow of the heating atmosphere also passes through the magnet insertion holes 4 and the first through holes 16 of the rotor core 2. That is, the flow of the heating atmosphere passes through the space formed by the magnet insertion holes 4 of the rotor cores 2 arranged along the axial direction. The flow of the heating atmosphere then passes through the gap t between the plate portion 12 and the furnace bottom 26. In this way, the flow of the heating atmosphere is less likely to be obstructed around the rotor core 2 and the pallet member 10A.

[0136] After the preheating step, a molding step is performed. The molding step may be performed on a single rotor core 2 after separating the plurality of rotor cores 2 as in the first embodiment, or may be performed on a single rotor core 2 after arranging the plurality of rotor cores 2 in the axial direction as in the second embodiment.

[0137] In addition, in the preheating process, an example in which three rotor cores 2 are arranged in the axial direction has been described, but the technology of the present disclosure is not limited to this. For example, two rotor cores 2 may be arranged in the axial direction, or four or more rotor cores 2 may be arranged in the axial direction. The same applies to the molding process.

[0138] As described above, the pallet member 10A according to the third embodiment is used in the preheating process of the rotor cores 2 with multiple rotor cores 2 lined up in the axial direction. During the preheating process, the first protrusions 14 form a gap t between the plate portion 12 and the furnace bottom 26, suppressing heat conduction from the pallet member 10. This makes it easier to uniformly heat the rotor cores 2, thereby shortening the heating time for the rotor cores 2. As a result, this can contribute to improving productivity in the rotor manufacturing process.

[0139] Furthermore, in the preheating process, multiple rotor cores 2 can be preheated at once using one heating furnace 20, which contributes to improving productivity. For example, productivity in the rotor manufacturing process is improved compared to when multiple rotor cores 2 are preheated using separate heating furnaces 20.

[0140] Furthermore, when preheating the rotor cores 2 while the rotor cores 2 are lined up in the axial direction, a space is formed in which the magnet insertion holes 4 of the rotor cores 2 are connected via the first through holes 16 of the pallet member 10A. The space connected via the first through holes 16 does not impede the flow of the heating atmosphere inside the magnet insertion holes 4, making it easier to make the heating atmosphere uniform. As a result, it becomes easier to make the heating state of the portions of the rotor core 2 around the magnet insertion holes 4 uniform, which contributes to improving productivity in the rotor manufacturing process.

[0141] Furthermore, when preheating the rotor cores 2 while the rotor cores 2 are lined up in the axial direction, a space is formed in which the through holes 5 of the rotor cores 2 are connected via the second through holes 13 of the pallet member 10A. The space connected via the second through holes 13 does not impede the flow of the heating atmosphere inside the through holes 5, making it easier to make the heating atmosphere uniform. As a result, it becomes easier to make the heating state of the portions of the rotor core 2 around the magnet insertion holes 4 uniform, which contributes to improving productivity in the rotor manufacturing process.

[0142] (Other variations) In the above-described embodiments, the heating furnace 20 is a hot air circulating furnace, but the technology of the present disclosure is not limited to this. For example, the heating furnace 20 may be a heating method using a lamp heater, a high-frequency heater, a block heater, and / or an infrared heater.

[0143] In addition, in each of the above embodiments, the heating furnace 20 has been described as a batch-type furnace, but the technology of the present disclosure is not limited to this. For example, the heating furnace 20 may be a continuous heating furnace.

[0144] In addition, in each of the above embodiments, an example in which the resin R is filled from the side of the lower die 32 in the molding apparatus 30 has been described, but the technology of the present disclosure is not limited to this. For example, the resin R may be filled from the side of the upper die 31, or the resin R may be filled from both the upper die 31 and the lower die 32.

[0145] In addition, in each of the above embodiments, the plate portion 12 has a disk shape when viewed from above, but the technology of the present disclosure is not limited to this. The plate portion 12 may have a polygonal shape (for example, a rectangular shape).

[0146] In addition, in each of the above embodiments, the pallet member 10 is used in a preheating step before the molding step, but the technology of the present disclosure is not limited to this. The pallet member 10 may be used in a heating step (e.g., a heat treatment step) other than preheating the rotor core 2.

[0147] The above-described description and illustrations are a detailed explanation of the parts related to the technology of the present disclosure and are merely an example of the technology of the present disclosure. For example, the above description of the configuration, functions, actions, and effects is an explanation of an example of the configuration, functions, actions, and effects of the parts related to the technology of the present disclosure. Therefore, it goes without saying that unnecessary parts may be deleted, new elements may be added, or replacements may be made to the above-described description and illustrations within the scope of the gist of the technology of the present disclosure. Furthermore, to avoid confusion and facilitate understanding of the parts related to the technology of the present disclosure, the above-described description and illustrations omit explanations of common technical knowledge that do not require particular explanation to enable the implementation of the technology of the present disclosure.

[0148] In this specification, "A and / or B" is synonymous with "at least one of A and B." In other words, "A and / or B" means that it may be only A, only B, or a combination of A and B. Furthermore, in this specification, the same concept as "A and / or B" is also applied when three or more things are expressed connected by "and / or."

[0149] All publications, patent applications, and technical standards mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, or technical standard was specifically and individually indicated to be incorporated by reference.

[0150] The following additional notes are further disclosed regarding the above embodiment. <Appendix 1> A pallet member that can be used in a core heating process, a plate portion having a first surface on which the core is placed; a first protrusion that protrudes from a second surface of the plate portion opposite to the first surface and that suppresses heat conduction from the pallet member to a support surface that supports the pallet member when the core placed on the plate portion is heated. Pallet material. <Appendix 2> The plate portion has a first through hole formed at a position facing the resin-filled portion of the core. 10. A pallet member as described in Appendix 1. <Appendix 3> The pallet member can also be used in a filling step of filling the resin filling section with resin, The resin is filled into the resin filling portion through the first through hole. 1. A pallet member as described in Appendix 2. <Appendix 4> The pallet member can also be used in a filling step of filling a resin into a resin filling section, The first protrusion can be inserted into a positioning hole provided in a mold into which the resin is filled. A pallet member according to any one of Supplementary Notes 1 to 3. <Appendix 5> the plate portion has a second protruding portion protruding from the first surface, The second protrusion is inserted into a hole formed in the core. A pallet member according to any one of Supplementary Notes 1 to 4. <Appendix 6> The second protrusion is provided in plurality along the circumferential direction of the core. 6. A pallet member as described in Appendix 5. <Appendix 7> The first protrusion includes a plurality of pin-shaped members provided along the outer edge of the plate portion. A pallet member according to any one of Supplementary Notes 1 to 6. <Appendix 8> The first protrusion includes a columnar member provided at the center of the plate portion. A pallet member according to any one of Supplementary Notes 1 to 7. <Appendix 9> The plate portion has a second through hole formed at a position corresponding to the central through hole of the core. A pallet member according to any one of Supplementary Notes 1 to 8. <Appendix 10> a third protruding portion provided along a periphery of the second through hole and protruding from the first surface is formed; 10. A pallet member as described in Appendix 9. <Appendix 11> The pallet member can also be used in a conveying process, The first protrusion is capable of forming a gap between the plate portion and the conveying surface. A pallet member according to any one of Supplementary Notes 1 to 10. <Appendix 12> A method for manufacturing a motor core using a pallet member comprising: a plate portion having a first surface on which a core is placed; and a first protrusion protruding from a second surface of the plate portion opposite the first surface, the first protrusion suppressing heat conduction from the pallet member to a support surface that supports the pallet member when the core placed on the plate portion is heated, placing the core on the pallet member; and heating the core while it is resting on the pallet member; Motor manufacturing method. <Appendix 13> A pallet member used in a core preheating step and a filling step of filling resin into the resin filling portions of each of the plurality of cores with resin while the plurality of cores are arranged in an axial direction, a plate portion having a first surface on which a first core of the plurality of cores is placed; a first protruding portion protruding from a second surface of the plate portion opposite to the first surface; Pallet material. <Appendix 14> When a second core is arranged in a row below the first core among the plurality of cores, the first protrusion is insertable into a hole formed in the second core. 14. A pallet member as described in Appendix 13. <Appendix 15> the plate portion has a second protruding portion protruding from the first surface, The second protrusion is inserted into a hole formed in the first core. 14. A pallet member as described in Appendix 13. <Appendix 16> When the hole formed in the second core is referred to as a second hole and the hole formed in the first core is referred to as a first hole, the first hole of the first core corresponds to the second hole of the second core. 16. A pallet member as described in attachments 14 and 15. <Appendix 17> The second protruding portion is provided at a position opposite to the first protruding portion across the plate portion. 16. A pallet member as described in Appendix 15. <Appendix 18> The plate portion has a first through hole formed at a position facing the resin-filled portion of the first core. 18. A pallet member according to any one of claims 13 to 17. <Appendix 19> The resin is filled into the resin filling portion through the first through hole. 19. A pallet member as described in Appendix 18. <Appendix 20> The plate portion is provided with a second through hole at a position corresponding to the central through hole of the first core. 20. A pallet member according to any one of Supplementary Notes 13 to 19. <Appendix 21> When the first core placed on the pallet member is the lowest core among the plurality of cores, the first protrusion is insertable into a positioning hole provided in a mold into which the resin is filled. A pallet member according to any one of Supplementary Note 13, Supplementary Note 15, and Supplementary Note 17 to Supplementary Note 20. <Appendix 22> A method for manufacturing a motor core using a pallet member including: a plate portion having a first surface on which a first core of a plurality of cores is placed; and a first protruding portion protruding from a second surface of the plate portion opposite to the first surface, preheating the core while it is resting on the pallet member; and and filling the resin filling portions of the cores with resin while arranging the cores in the axial direction via the pallet member. Motor manufacturing method.

[0151] The disclosure of Japanese Patent Application No. 2024-054450, filed on March 28, 2024, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually indicated to be incorporated by reference.

Claims

1. A pallet member used in a core preheating step and a filling step of filling resin into the resin filling portions of each of the cores with resin while arranging the cores along the axial direction, a plate portion having a first surface on which a first core of the plurality of cores is placed; a first protruding portion protruding from a second surface of the plate portion opposite to the first surface, When a second core is arranged in a row below the first core among the plurality of cores, the first protrusion is insertable into a hole formed in the second core. Pallet material.

2. the plate portion has a second protruding portion protruding from the first surface, The second protrusion is insertable into a hole formed in the first core. The pallet member of claim 1 .

3. When the hole formed in the second core is referred to as a second hole and the hole formed in the first core is referred to as a first hole, the first hole of the first core corresponds to the second hole of the second core. A pallet member according to claim 2.

4. The second protruding portion is provided on the opposite side of the plate portion from the first protruding portion. A pallet member according to claim 2.

5. The plate portion has a first through hole formed at a position facing the resin-filled portion of the first core. The pallet member of claim 1 .

6. The resin is filled into the resin filling portion through the first through hole. A pallet member according to claim 5.

7. The plate portion is provided with a second through hole at a position corresponding to the central through hole of the first core. The pallet member of claim 1 .

8. When the first core placed on the pallet member is the lowest core among the plurality of cores, the first protrusion is insertable into a positioning hole provided in a mold for filling the resin. The pallet member of claim 1 .

9. A method for manufacturing a motor core using a pallet member, the pallet member comprising: a plate portion having a first surface on which a first core of a plurality of cores is placed; and a first protruding portion protruding from a second surface of the plate portion opposite to the first surface, wherein when a second core of the plurality of cores is placed in a row below the first core, the first protruding portion is insertable into a hole formed in the second core, Preheating the core while it is placed on the pallet member; and and filling a resin into a resin filling portion of each of the plurality of cores with resin while arranging the plurality of cores in the axial direction via the pallet member. Motor manufacturing method.

Images