Motor core manufacturing method

Abstract

The manufacturing method of the motor core is to laminate a plurality of iron core pieces 11 and form a magnet housing portion MHb extending in the lamination direction. 10 a laminate manufacturing process for manufacturing the laminate 10 having the above-mentioned structure, and a process for inserting the permanent magnet 30 extending in the lamination direction of the core pieces 11 into the magnet receiving portion MHb 10 a magnet placement step of placing the permanent magnet 30 in the magnet housing portion MHb using a synthetic resin material Y that is softened at a first temperature T1 and hardens at a second temperature T2 higher than the first temperature T1; 10 The fixing step includes a step of fixing the synthetic resin material Y in the magnet receiving portion MHb by setting the temperature of the synthetic resin material Y to a first temperature T1 and using an injection device X having a container capable of holding the synthetic resin material Y in a softened state. 10 and a curing step of curing the synthetic resin material Y by increasing the temperature of the synthetic resin material Y injected into the laminate 10 to a second temperature T2 while the injection device X is retracted from the laminate 10.

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a motor core, and more particularly to a method for forming a laminate formed by stacking a plurality of thin plates (steel plates) and having a magnet housing portion extending in the stacking direction, inserting a permanent magnet into the magnet housing portion, and fixing (sealing) the permanent magnet in the laminate (inside the magnet housing portion). [Background technology]

[0002] For example, a method is known in which a permanent magnet inserted into a magnet housing portion of a laminate is fixed (sealed) to the laminate by using a thermoplastic resin material, as described in the following Patent Document 1. Also, methods are known in which a permanent magnet inserted into a magnet housing portion of a laminate is fixed (sealed) to the laminate by using a thermosetting resin material, as described in Patent Documents 2 and 3. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-245405 A [Patent Document 2] Patent No. 5357217 [Patent Document 3] Patent No. 4414417 Summary of the Invention

[0004] When the method of Patent Document 1 is used, the heated and softened thermoplastic resin material is cooled and begins to harden when it is injected from the injection device into the magnet accommodating portion and spreads in the magnet accommodating portion. Therefore, it is necessary to set the injection pressure of the thermoplastic resin material relatively high, fill the magnet accommodating portion hole with the thermoplastic resin material in as short a time as possible, and further, to prevent the thermoplastic resin material from flowing back, it is necessary to hold the pressure until the thermoplastic resin material hardens. Therefore, the injection device cannot be withdrawn from the laminate until the thermoplastic resin material hardens in the magnet accommodating portion. In other words, the injection device is occupied from the start of injection of the thermoplastic resin material until the hardening is completed. Therefore, the productivity of the motor core is low.

[0005] As described above, the injection pressure and the holding pressure of the thermoplastic resin material are relatively high, so if the thickness of the portion of the laminate that constitutes the peripheral portion of the magnet housing portion is relatively small, there is a risk that the peripheral portion will be deformed during the injection or hardening process of the thermoplastic resin material.

[0006] Furthermore, when the method of Patent Document 2 or Patent Document 3 is used, the thermosetting resin material that has been heated and softened is injected from an injection device into the magnet housing section. Generally, the thermosetting resin material is solid (tablet) before use, and once it is heated and softened, the hardening reaction starts immediately. Therefore, as in the case of using a thermoplastic resin material, it is necessary to keep the injection pressure and the holding pressure of the thermosetting resin material relatively high. Therefore, the same problems as in the case of using the method of Patent Document 1 arise.

[0007] In addition, due to the manufacturing accuracy (dimensional accuracy in the plate thickness direction, flatness, etc.) of each thin plate (steel plate), the height dimension (dimension in the stacking direction of the multiple thin plates) differs slightly for each laminate. That is, the volume of the magnet accommodating portion differs slightly for each laminate. Therefore, even if the volume of the magnet accommodating portion is relatively large, a slightly larger amount of thermosetting resin material (tablet) than the expected volume (maximum volume) of the magnet accommodating portion is used so that the thermosetting resin material can be filled inside the magnet accommodating portion. In other words, an amount of the thermosetting resin material that overflows from the magnet accommodating portion when softened is used. The thermosetting resin material overflowing from the magnet accommodating portion remains in the injection device. In other words, it hardens in the injection device. Therefore, after the permanent magnet is fixed to the laminate, it is necessary to remove the synthetic resin material that has hardened in the injection device.

[0008] The present invention has been made to address the above-mentioned problems, and an object of the present invention is to provide a motor core manufacturing method capable of improving the productivity of motor cores. In the description of each component of the present invention below, the reference numerals of corresponding parts in the embodiment are written in parentheses in order to facilitate understanding of the present invention, but each component of the present invention should not be interpreted as being limited to the configuration of the corresponding parts indicated by the reference numerals in the embodiment.

[0009] In order to achieve the above object, a manufacturing method of a motor core (1) according to the present invention includes a laminate manufacturing process of laminating a plurality of steel plates (11) to manufacture a laminate (10) having magnet accommodating portions (MHb10, MHc10, MHd10) extending in a lamination direction of the steel plates, and a magnet arrangement process of arranging a permanent magnet (30) extending in the lamination direction of the plurality of steel plates in the magnet accommodating portion, A synthetic resin material that is solid at room temperature, softens at a first temperature (T1) higher than room temperature, does not harden while maintained at the first temperature, and hardens at a second temperature (T2) higher than the first temperature. (Y) a fixing step of fixing the permanent magnet in the magnet accommodating portion, the fixing step being performed by setting a temperature of the synthetic resin material to the first temperature and maintaining the synthetic resin material in a softened state. A container having a heating device and a nozzle Using the injection device (X), A part of the softened synthetic resin material in the container is ejected from the nozzle. an injection step of injecting the magnet into the magnet housing; With the synthetic resin material remaining in the container and the nozzle in a softened state, the nozzle is withdrawn from the laminate,and a curing step of increasing the temperature of the synthetic resin material injected into the laminate to the second temperature to cure the synthetic resin material.

[0010] The curing process in one embodiment of the present invention includes a step of moving the injection device away from the stack, transporting the stack to a heating furnace or induction heating device located separate from the injection device, and raising the temperature of the synthetic resin material injected into the stack to the second temperature using the heating furnace or induction heating device to harden the synthetic resin material.

[0012] In one aspect of the present invention, the laminate has a plurality of the magnet housing portions, and the injection step includes injecting a part of the softened synthetic resin material in the container from a nozzle of the injection device into a first magnet housing portion of the plurality of magnet housing portions, 1 and then injecting the synthetic resin material remaining in the container and the nozzle from the nozzle of the injection device into a second magnet housing portion.

[0013] In another aspect of the present invention, the injection device includes a drive device that discharges the synthetic resin material from the container, and in the injection process, after the magnet accommodating section is filled with the softened synthetic resin material, the drive direction of the drive device of the injection device is reversed and then the injection device is retracted from the stack.

[0014] As described above, the synthetic resin material employed in the present invention does not harden when its temperature is held at the first temperature, but hardens when it reaches the second temperature, which is higher than the first temperature. Therefore, even if the synthetic resin material is injected into the magnet housing, the synthetic resin material does not harden in the magnet housing in this state. Therefore, unlike the case of using the motor core manufacturing methods of Patent Documents 1 to 3, the injection pressure of the synthetic resin material can be set relatively small. In addition, there is no need to maintain pressure to prevent the synthetic resin material from flowing back. Therefore, after filling all the magnet housings with the synthetic resin material, the injection device can be immediately released, the laminate can be moved to another location (downstream of the production line), and a hardening process can be performed at that location to heat and harden the synthetic resin material. That is, according to the present invention, once filling one laminate with the synthetic resin material is completed, the injection device can be immediately released without waiting for the synthetic resin material to harden, and the operation of filling the next laminate with the synthetic resin material can be started.

[0015] In one embodiment of the present invention, in the fixing process, prior to the injection process, the laminate is heated so that the temperature of the laminate is higher than the first temperature and lower than the second temperature, and in the injection process, a nozzle of the injection device is abutted against the open end of the magnet accommodating portion of the laminate, and the laminate is heated so that the temperature of the laminate into which the softened synthetic resin material is injected is higher than the first temperature and lower than the second temperature.

[0016] According to this, since the temperature of the laminate is higher than the melting temperature of the synthetic resin material in the injection process, the synthetic resin material can be maintained in a molten state. Also, since the temperature is lower than the hardening temperature of the synthetic resin material, hardening of the synthetic resin material can be suppressed. In other words, the synthetic resin material can be maintained in a good fluidity state in the injection process.

[0017] In the injection step according to one aspect of the present invention, when an injection pressure of the synthetic resin material exceeds a predetermined pressure, the injection of the synthetic resin material into the through-holes of the laminate is stopped.

[0018] According to this, the synthetic resin material can be injected from the injection device into each magnet housing section in an amount (an amount necessary and sufficient to fill the space) that is approximately equal to the volume of the space (gap) in each magnet housing section. After the synthetic resin material is filled into the magnet housing section, the laminate is heated to harden the synthetic resin material, but during the hardening process, the injection device is released (retracted) from the laminate. Therefore, the heat of the laminate heated in the hardening process is not transferred to the injection device. Therefore, unlike the cases where the manufacturing methods of Patent Documents 2 and 3 are used, the synthetic resin material does not harden inside the container and the injection device. Therefore, there is no need to remove the synthetic resin material from inside the injection device.

[0019] As described above, according to the present invention, the productivity of motor cores can be improved.

[0022] Here, the above-mentioned Patent Documents 2 and 3 disclose a method of fixing a permanent magnet in a magnet housing part using a thermosetting synthetic resin material. However, this thermosetting synthetic resin material is in a solid state (flake-like) before use, and once it is heated and softened, the hardening reaction begins immediately. Therefore, there is a risk that the thermosetting synthetic resin material hardens before the softened state is completely filled in the magnet housing part, and the fixing strength of the permanent magnet is not obtained sufficiently. In contrast, the thermosetting synthetic resin material used in the present invention softens when it is heated from room temperature (state before use) to reach a first temperature, but remains in a softened state until it reaches a second temperature higher than the first temperature. Therefore, the softened thermosetting synthetic resin material can be filled in the magnet housing part relatively easily, and sufficient fixing strength of the permanent magnet can be obtained. In addition, the thermosetting synthetic resin material can be held in a softened state in the injection device, and the surplus from the production of one motor core can be used for the production of the next motor core. [Brief description of the drawings]

[0023] [Figure 1] 1 is a perspective view of a rotor core manufactured using a manufacturing method according to an embodiment of the present invention. [Diagram 2]FIG. 2 is an exploded perspective view of the rotor core shown in FIG. [Diagram 3] FIG. [Figure 4A] FIG. [Figure 4B] FIG. 4 is an enlarged view of a portion of an outer peripheral edge portion of the core piece. [Diagram 5] 4 is a cross-sectional view perpendicular to the longitudinal direction (depth direction) of the magnet housing section. FIG. [Figure 6] FIG. 2 is a cross-sectional view perpendicular to the longitudinal direction of a permanent magnet. [Figure 7] 4 is an enlarged view of the outer circumferential edge portion of a cross section perpendicular to the central axis of the rotor core. FIG. [Figure 8] 1 is an enlarged view of an end face of the intermediate assembly in the direction in which the central axis extends, showing an enlarged view of the outer peripheral edge portion of the end face on one side of the opening of the magnet accommodating portion. [Figure 9] FIG. 2 is a perspective view showing an outline of an injection step and a curing step. [Figure 10] 1 is a cross-sectional view of the injection device and intermediate assembly taken along the central axis of the nozzle during the injection process. FIG. [Figure 11A] FIG. 11 is an enlarged plan view of the outer circumferential edge portion of the upper end plate during the injection process of the first modified example of the present invention. [Figure 11B] FIG. 11 is a cross-sectional view of the injection device and intermediate assembly taken along the central axis of the nozzle during the injection process of the first modified example. [Figure 12] FIG. 11 is an enlarged plan view of the outer circumferential edge portion of the upper end plate during an injection process according to a second modified example of the present invention. [Figure 13] FIG. 13 is an enlarged plan view of the outer circumferential edge portion of the upper end plate during an injection process according to a third modified example of the present invention. [Figure 14] FIG. 13 is an enlarged plan view of the outer circumferential edge portion of the upper end plate during the injection process of the fourth modified example of the present invention. [Figure 15] FIG. 13 is a plan view showing the positional relationship between the magnet housing portion and the nozzle in an injection step according to the fifth modified example of the present invention. [Figure 16] FIG. 13 is a plan view showing the positional relationship between the magnet housing portion and the nozzle in an injection step of the sixth modified example of the present invention. [Figure 17] FIG. 13 is a plan view showing the positional relationship between the magnet housing portion and the nozzle in an injection step of the seventh modified example of the present invention. [Figure 18] FIG. 13 is a plan view showing the positional relationship between the magnet housing portion and the nozzle in an injection step according to an eighth modified example of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] 1 and 2 using a manufacturing method for a motor core according to an embodiment of the present invention. The rotor core 1 is applied to a rotor of a well-known IPM motor. The rotor core 1 includes a laminate 10, an end plate 20, a plurality of permanent magnets 30, and an end plate 40.

[0025] (Laminate manufacturing process) The laminate 10 is formed by laminating core pieces 11 (see FIG. 3, 4A, and 4B) made of silicon steel plates. The core pieces 11 are formed by punching a base material. A circular through hole THa is formed in the center of the core piece 11. 11 In addition, the through holes THb are formed on the outer peripheral edge of each of eight regions A that are obtained by equally dividing the core piece 11 in the circumferential direction. 11 ,THc 11 ,THd 11 Through hole THb is provided. 11 ,THc 11 ,THd 11 are adjacent to each other in the circumferential direction of the core piece 11. 11 Through hole THc 11 and through hole THd 11 The through hole THb is located between the 11 The through hole THc has a substantially rectangular shape (isosceles trapezoid) extending in a direction perpendicular to the radial direction of the core piece 11 and in a direction perpendicular to the plate thickness direction. 11 ,THd 11 Each of the iron core pieces 11 has a generally pentagonal shape extending in a direction perpendicular to the radial direction of the iron core piece 11 and in a direction perpendicular to the plate thickness direction.

[0026] Through hole THb 11Among the sides, the side S on the outer periphery of the core section 11 THb The pair of protrusions P protruding toward the inner periphery THb ,P THb The protrusion P THb is the side S THb The through holes THc are formed at both ends in the extending direction of the 11 ,THd 11 Among the sides, the side S on the outer periphery of the core section 11 THc ,S THd The portion S1 on one end side in the extension direction of the THc ,S1 THd The through hole THb 11 The part located on the side of the through hole THb 11 The opposite site S2 THc ,S2 THd In other words, in a plan view of the core piece 11, the portion S1 THc and site S2 THc Boundary S12 THc , and site S1 THd and site S2 THd Boundary S12 THd A step is formed at each of the portions S1 and S2. THc ,S1 THd The inner circumferential protrusion P THc ,P THd The protrusions P THc ,P THd is the site S1 THc ,S1 THd The through hole THb is an end portion in the extension direction of the 11 are formed at the ends of the respective sides.

[0027] Through hole THa of each core piece 11 11 are arranged coaxially, and the through holes THb 11 ,THc 11 ,THd 11 The plurality of iron core pieces 11 are stacked so that the through holes THa of the respective iron core pieces 11 are coaxially arranged. The iron core pieces 11 are joined to each other by crimping. 11 and through hole THb 11,THc 11 ,THd 11 are connected to each other in a direction parallel to the extension direction of the central axis C of the laminate 10 (the lamination direction of the iron core pieces 11) (see FIG. 1). 10 (Through holes THa of each core piece 11 11 Furthermore, the laminate 10 has a plurality of magnet housing portions MHb extending parallel to the central axis C at its outer circumferential edge portion. 10 ,MHc 10 ,MHd 10 (Through holes THb of each core piece 11 11 ,THc 11 ,THd 11 The magnet housing part MHb 10 is the protrusion P THb ,P THb The convex portion P is formed by stacking MHb ,P MHb (See Figure 5.) Magnet housing part MHc 10 ,MHd 10 is the protrusion P THc ,P THd The convex portion P is formed by stacking the MHc ,P MHd Also, the magnet housing MHc 10 ,MHd 10 is the boundary S12 THc ,S12 THd Wall surface S12 formed by stacking MHc ,S12 MHd has.

[0028] Magnet housing MHb 10 ,MHc 10 ,MHd 10 A cross section CS perpendicular to the extension direction (lamination direction of the core pieces 11) b ,C.S. c ,C.S. d The widths Wb, Wc, and Wd of the cross section CS are substantially the same (see FIG. 5). c ,C.S. d The lengths Lc and Ld of the laminate 10 at the cross section CS b is greater than the length Lb.

[0029] (First end plate installation process) An end plate 20 (see FIG. 2) is attached to one end surface (lower surface) of the laminate 10 configured as described above in the extension direction of the central axis C. The end plate 20 is made of synthetic resin. The end plate 20 is a plate-like member having substantially the same shape as the core piece 11. The plate thickness of the end plate 20 is slightly greater than the plate thickness of the core piece 11. The end plate 20 is inserted through the through hole THa of the laminate 10. 10 A circular through hole THa of approximately the same diameter as 20 However, the magnet housing part MHb 10 ,MHc 10 ,MHd 10 There is no through hole corresponding to the

[0030] Through hole THa 20 and through hole THa 10 The end plate 20 is attached to one end surface (lower surface) of the laminate 10 so that the magnet housing portion MHb and the magnet housing portion MHb are coaxially arranged. 10 ,MHc 10 ,MHd 10 The magnet housing portion MHb is closed at one end (lower end) in the extending direction. 10 ,MHc 10 ,MHd 10 The other end side (upper side) in the extending direction is open.

[0031] (Magnet placement process) Next, the magnet housing MHb 10 ,MHc 10 ,MHd 10 From the other end (upper side) in the extension direction of the magnet housing portion MHb 10 ,MHc 10 ,MHd 10 The permanent magnets 30 are inserted into the magnet housing portions MHb and MHbc. The permanent magnets 30 are formed in a rectangular column shape. The length of the permanent magnets 30 is 10 ,MHc 10 ,MHd 10 As shown in FIG. 6, the depth of the magnet 30 is slightly smaller than the depth of the cross section CS 30 has a rectangular cross section CS 30Length L 30 But the cross section CS b The length Lb at the cross section CS (see Fig. 5) is smaller than the length Lb at the cross section CS 30 Width W 20 But the cross section CS b 5. The width Wb of the first embodiment is smaller than the width Wb of the second embodiment (see FIG. 5).

[0032] Magnet housing MHb 10 In the magnet housing portion MHb 10 (See FIG. 7). That is, each magnet housing MHb 10 The central axis of the permanent magnet 30 coincides with the central axis of the protrusion P. MHb ,P MHb The magnet housing MHb is located between the 10 In the cross section S of the permanent magnet 30 30 The permanent magnets 30 are arranged so that the extension direction of the short sides of the magnet housing portion MHb coincides with the radial direction of the laminate 10. 10 Since the outer dimensions of the permanent magnet 30 are smaller than the inner dimensions of the magnet housing portion MHb (see FIGS. 5 and 6), 10 A gap is formed between the inner circumferential surface of the

[0033] Magnet housing MHc 10 ,MHd 10 In the magnet housing MHc 10 ,MHd 10 Magnet housing part MHb 10 The magnet housing MHc is arranged toward the side (see FIG. 7). 10 In the permanent magnet 30, the protrusion P MHc and wall S12 MHc The magnet housing MHd is located between the magnet housing MHd and the magnet housing MHd. 10 In the permanent magnet 30, the protrusion P MHd and wall S12 MHd The magnet housing MHc is located between the magnet housing MHc and the magnet 10 ,MHd 10 In the figure, the cross section S of the permanent magnets 30, 30 30 ,S 30The permanent magnet 30 is arranged so that the extension direction of the short side of the magnet housing portion MHc coincides with the radial direction of the laminate 10. 10 ,MHd 10 A gap is formed between the inner circumferential surface of the

[0034] (Second end plate installation process) Next, an end plate 40 is attached to the other end surface of the laminate 10 in the extension direction of the central axis C (see FIG. 2). The end plate 40 is made of synthetic resin. The end plate 40 is a plate-like member having substantially the same shape as the core piece 11. The plate thickness of the end plate 40 is slightly greater than the plate thickness of the core piece 11. The end plate 40 is inserted through the through hole THa of the laminate 10. 10 A circular through hole THa of approximately the same diameter as 40 The end plate 40 has a magnet housing portion MHb 10 ,MHc 10 ,MHd 10 Multiple circular through holes THb 40 ,THc 40 ,THd 40 The through hole THb 40 ,THc 40 ,THd 40 That is, the through hole THb is tapered. 40 ,THc 40 ,THd 40 The inner diameters of the end plates 40 gradually decrease from one side to the other side of the end plate 40.

[0035] Through hole THa 40 and through hole THa 10 and are arranged coaxially, and the central axis of each permanent magnet 30 is connected to the plurality of through holes THb 40 ,THc 40 ,THd 40 The end plate 40 is disposed so that the central axes of the through holes THa and THaD are coaxially disposed (see FIG. 8). The other side surface of the end plate 40 abuts against the end surface of the laminate 10. In this manner, the intermediate assembly SA (see FIG. 9) is formed. In the intermediate assembly SA, the through holes THa 20, through hole THa 10 and through hole THa 40 are connected in the direction of extension of the central axis C. Furthermore, the magnet housing portion MHb 10 ,MHc 10 ,MHd 10 and through hole THb 40 ,THc 40 ,THd 40 are connected to each other in a direction parallel to the extension direction of the central axis C. 10 ,MHc 10 ,MHd 10 One end side (lower side) in the extension direction (depth direction) of each is closed, but the other end side (upper side) is open.

[0036] Next, the permanent magnets 30 are inserted into the magnet housings MHb 10 ,MHc 10 ,MHd 10 The process of fixing (sealing) the laminate 10 in the laminated body 10 will be described. First, the intermediate assembly SA is placed on a rotating table (not shown). The intermediate assembly SA and the rotating table are arranged coaxially. The end plate 40 is located on the upper side of the laminate 10, and the end plate 20 is located on the lower side of the laminate 10 (see the left diagram in FIG. 9). Next, the intermediate assembly SA (laminate 10) is heated using a heating device (not shown) so that the temperature of the laminate 10 becomes higher than a first temperature T1 (e.g., 80° C.) and lower than a second temperature T2 (e.g., 120° C.) described later.

[0037] The permanent magnets 30 are placed in the magnet housings MHb 10 ,MHc 10 ,MHd 10 In order to fix (seal) the resin within the resin, in this embodiment, a synthetic resin material Y as described in JP-A-2000-239642 is used. That is, the synthetic resin material Y is solid (flake-like) before use (at room temperature), and when heated from this state and its temperature reaches a first temperature T1, it softens. The synthetic resin material Y does not harden while held at the first temperature, but hardens when it reaches a second temperature T2 higher than the first temperature T1.

[0038] The synthetic resin material Y as described above is poured into each magnet housing portion MHb using an injection device X. 10 ,MHc 10 ,MHd 10 9 and 10, the injection device X includes a cylinder Xa, a heating device Xb, and a delivery device Xc. The cylinder Xa is formed in a cylindrical shape, and a nozzle Xa1 is provided at the tip of the cylinder Xa. The outer diameter of the tip of the nozzle Xa1 is 1 / 10 mm. 40 ,THc 40 ,THd 40 The cylinder Xa has a through hole TH on its side. Xa is provided, and the through hole TH Xa Unused (flake-like) synthetic resin material Y is fed into the cylinder Xa from the heater Xb. The heater Xb is attached to the side of the cylinder Xa and sets the temperature of the synthetic resin material Y in the cylinder Xa to a first temperature T1 to maintain the synthetic resin material Y in a softened state. The delivery device Xc includes a screw Xc1, a drive device Xc2, and the like. The screw Xc1 is housed in the cylinder Xa. The screw Xc1 and the cylinder Xa are arranged coaxially. One end of the screw Xc1 in the longitudinal direction (the end on the nozzle Xa1 side) is formed in a sharp shape. The other end of the screw Xc1 in the longitudinal direction is connected to the drive device Xc2. The drive device Xc2 includes an electric motor and a reduction gear. The drive device Xc2 rotates the screw Xc1 around its central axis.

[0039] (Injection process) First, above the intermediate assembly SA, the central axis of the nozzle Xa1 and the through hole THb 40 The injection device X is placed so that the central axis of the injection device 10 coincides with that of the injection device 10. The injection device X is supported by an actuator (robot arm) (not shown) and is moved up and down by this actuator.

[0040] Next, as shown in FIG. 10, the injection device X is lowered so that the tip of the nozzle Xa1 is aligned with the through-hole THb. 40The nozzle Xa1 is inserted into the cavity 10 so that the tip surface of the nozzle Xa1 comes into contact with the upper end surface of the laminate 10. Next, the control device of the injection device X drives the drive device Xc2 to rotate the screw Xc1 in the normal direction, and the softened synthetic resin material Y is fed out from the nozzle Xa1. As a result, the synthetic resin material Y is in contact with the outer peripheral surface of the permanent magnet 30 and the magnet receiving portion MHb. 10 In the above-mentioned synthetic resin material Y filling process, the control device of the filling device X monitors the injection pressure of the synthetic resin material Y. 10 When the space (gap) in the magnet housing MHb is filled with the synthetic resin material Y, the injection pressure rises suddenly. When the control device detects the sudden rise in the injection pressure, it stops the driving device Xc2. As a result, the magnet housing MHb 10 The amount of synthetic resin material Y injected into each magnet housing part MHb 10 The volume of the gap within the laminate 10 becomes approximately equal to the volume of the gap within the laminate 10. By heating the laminate 10 as described above, the temperature of the laminate 10 is higher than the melting temperature of the synthetic resin material Y in the injection process, so that the synthetic resin material Y can be maintained in a molten state. Furthermore, the temperature of the laminate 10 is lower than the hardening temperature of the synthetic resin material Y, so that the hardening of the synthetic resin material Y can be suppressed. In other words, the synthetic resin material can be maintained in a good fluidity state in the injection process.

[0041] Next, the control device drives the drive device Xc2 to slightly reverse the screw Xc1. Then, the injection device X is raised and separated from the intermediate assembly SA (see FIG. 11). By slightly reversing the screw Xc1 in this manner, it is possible to prevent the synthetic resin material Y from dripping from the nozzle Xa1 when the injection device X is raised.

[0042] Next, the magnet housing MHc 10 The rotating table is rotated by a predetermined angle so that the injection device X is disposed above the magnet housing portion MHb. 10 The magnet housing part MHc is filled with synthetic resin material Y in the same manner as in the filling procedure. 10 The synthetic resin material Y is filled in the magnet housing portion MHb. 10 , magnet housing MHc10 and magnet housing MHd 10 The synthetic resin material Y is filled in.

[0043] (hardening process) All magnet housings MHb 10 ,MHc 10 ,MHd 10 When the synthetic resin material Y is filled in the intermediate assembly SA, the injection device X is withdrawn (raised) from the intermediate assembly SA. Then, the intermediate assembly SA is transferred to the electromagnetic induction heater IH, and the outer peripheral surface of the intermediate assembly SA is heated by the electromagnetic induction heater IH (see the diagram on the right side of FIG. 9). As a result, all the magnet housing parts MHb 10 ,MHc 10 ,MHd 10 The temperature of the synthetic resin material Y in the magnet housing portion MHb reaches the second temperature T2 and hardens. 10 ,MHc 10 ,MHd 10 The sensor is fixed (sealed) in place.

[0044] As described above, the synthetic resin material Y does not harden when its temperature is maintained at the first temperature T1. 10 , M.H.c. 10 ,MHd 10 In the step of filling the synthetic resin material Y into the magnet housing portion MHb, the temperature of the laminate 10 is set to be equal to the first temperature T1. 10 , M.H.c. 10 ,MHd 10 Even if the magnet is injected into the magnet housing, in this state, 10 , M.H.c. 10 ,MHd 10 The synthetic resin material Y remains softened inside the magnet housing portion MHb. Therefore, unlike the motor core manufacturing methods of Patent Documents 1 to 3, the injection pressure of the synthetic resin material Y can be set to a relatively low value. Also, pressure holding to prevent the synthetic resin material Y from flowing back is not required. Therefore, all of the magnet housing portions MHb 10 , M.H.c. 10 ,MHd 10After filling one intermediate assembly SA with the synthetic resin material Y, the injection device X can be immediately released and the intermediate assembly SA can be transported to another location (downstream of the production line), where the synthetic resin material Y can be heated and hardened. That is, according to this embodiment, once filling one intermediate assembly SA with the synthetic resin material Y is completed, the injection device X can be immediately released without waiting for the synthetic resin material Y to be completely hardened, and the operation of filling the next intermediate assembly SA with the synthetic resin material Y can be started.

[0045] In addition, based on the change in the injection pressure of the synthetic resin material Y, each magnet housing portion MHb 10 , M.H.c. 10 ,MHd 10 Injection of the synthetic resin material Y into each magnet housing portion MHb is controlled. 10 , M.H.c. 10 ,MHd 10 The synthetic resin material Y is injected from the injection device X into each magnet receiving portion MHb in an amount substantially equal to the volume of the space (gap) therein (an amount necessary and sufficient to fill said space). 10 , M.H.c. 10 ,MHd 10 Then, all the magnet housings are filled with MHb 10 , M.H.c. 10 ,MHd 10 After the synthetic resin material Y is filled in the intermediate assembly SA, the intermediate assembly SA is heated by the electromagnetic induction heater IH to harden the synthetic resin material Y, but during the hardening process, the injection device X is released (retracted) from the intermediate assembly SA. Therefore, the heat of the intermediate assembly SA heated by the electromagnetic induction heater IH is not transferred to the injection device X. Therefore, unlike the cases where the manufacturing methods of Patent Documents 2 and 3 are used, the synthetic resin material Y does not harden in the injection device X. Therefore, the task of removing the synthetic resin material Y from inside the injection device X is not required.

[0046] As described above, according to this embodiment, the productivity of the rotor core 1 can be improved.

[0047] Furthermore, the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the object of the present invention.

[0048] For example, as shown in FIG. 11A, the through hole THb 40 ,THc 40 ,THd 40 The inner diameter of the through hole THb may be smaller than the outer diameter of the tip of the nozzle Xa1. In this case, as shown in FIG. 11B, the nozzle Xa1 is pressed against the end plate 40 so that the tip surface of the nozzle Xa1 is in close contact with the upper surface of the end plate 40. Also, as shown in FIG. 40 ,THc 40 ,THd 40 The central axis of the through hole THb may be shifted toward the outer periphery of the laminate 10 as viewed from the center of the permanent magnet 30. 40 ,THc 40 ,THd 40 The central axis of each magnet housing portion MHb may be shifted in the circumferential direction of the laminate 10 when viewed from the center of the permanent magnet 30. In other words, the discharge port of the nozzle Xa1 is not located above the permanent magnet 30, but is located at the circumferential direction of each magnet housing portion MHb 10 , M.H.c. 10 ,MHd 10 In the example shown in FIG. 12 and FIG. 13, the tip of the nozzle Xa1 is located above the through hole THb. 40 ,THc 40 ,THd 40 The through hole THb 40 ,THc 40 ,THd 40 The inner diameter of the nozzle Xa1 may be set to be slightly larger than the outer diameter of the tip of the nozzle Xa1.

[0049] As shown in FIG. 14, the end plate 40 is 10 and magnet housing MHc 10 Through hole THbc located at the boundary with 40 In this case, two magnet housing portions MHb 10 , M.H.c. 10 In the example shown in FIG. 14, the tip of the nozzle Xa1 is inserted into the through hole THbc. 40 Through hole THbc40 The inner diameter of the nozzle Xa1 may be set to be slightly larger than the outer diameter of the tip of the nozzle Xa1.

[0050] Also, for example, the end plates 20, 40 may be omitted (see Figs. 15 to 18). 10 , M.H.c. 10 ,MHd 10 In this case, the synthetic resin material Y may be injected into the magnet housing portion MHb 10 , M.H.c. 10 ,MHd 10 In this case, the opening end of the magnet housing portion MHb is preferably completely covered by the tip surface of the nozzle Xa1. 10 , M.H.c. 10 ,MHd 10 The opening on the opposite side to the surface against which the nozzle Xa1 is abutted is closed using a jig. As in the example shown in FIG. 11A and FIG. 11B, the central axis of the nozzle Xa1 may be located above the center of the permanent magnet 30 (see FIG. 15). In FIG. 15 to FIG. 18, the position of the nozzle Xa is illustrated by a double circle with a dotted line. The inner circle indicates the discharge hole Xa11 (hole for discharging the synthetic resin material Y) at the tip of the nozzle Xa1. The outer circle indicates the outer shape Xa12 of the tip surface of the nozzle Xa. As in the example shown in FIG. 12, the central axis of the nozzle Xa1 may be shifted toward the outer periphery of the laminate 10 when viewed from the center of the permanent magnet 30 (see FIG. 16). As in the example shown in FIG. 13, the central axis of the nozzle Xa1 may be shifted toward the circumferential direction of the laminate 10 when viewed from the center of the permanent magnet 30 (see FIG. 17). 14, the central axis of the nozzle Xa1 is aligned with the magnet housing portion MHb 10 and magnet housing MHc 10 It may be located above the boundary between the two (see FIG. 18).

[0051] In addition, a plurality of magnet housings MHb are arranged by using a plurality of injection devices X. 10 , M.H.c. 10 ,MHd 10The synthetic resin material Y may be filled into the intermediate assembly SA at the same time. In the curing step, the intermediate assembly SA may be placed in a heating furnace to heat and cure the synthetic resin material Y. core This is an example in which the manufacturing method is applied to the manufacture of rotor core 1, but the present invention may also be applied to the manufacture of stator cores.

[0052] Furthermore, in the above embodiment, the end plates 20, 40 are made of synthetic resin, but end plates made of metal (for example, stainless steel, aluminum alloy, etc.) may also be used.

[0053] In the above embodiment, the through hole THb of the end plate 40 40 ,THc 40 ,THd 40 That is, the through hole THb is tapered from one side surface of the end plate 40 to the other side surface. 40 ,THc 40 ,THd 40 Instead, the inner diameter of the through hole THb gradually decreases from one side surface of the end plate 40 to the other side surface. 40 ,THc 40 ,THd 40 The inner diameter of the through hole THb may be changed stepwise. 40 ,THc 40 ,THd 40 The inner diameter of the through hole THb may be constant in the thickness direction of the end plate 40. 40 ,THc 40 ,THd 40 The shape of the nozzle Xa1 is not limited to the above embodiment, and may be, for example, an ellipse, a polygon, or the like. 40 ,THc 40 ,THd 40 The thickness may be changed according to the shape of the

[0054] In the above embodiment, in the injection step, the tip surface of the nozzle Xa1 is in contact with the hole (through hole THb 40,THc 40 ,THd 40 , magnet housing MHb 10 ,MHc 10 ,MHd 10 ) are entirely closed, but may be configured to cover only part of the open end. In this case, the outer shape Xa12 of the nozzle tip surface may be changed according to the shape of the hole into which the synthetic resin material Y is to be injected. The shape and position of the discharge hole Xa11 on the nozzle tip surface may also be changed according to the shape of the hole into which the synthetic resin material Y is to be injected. Furthermore, the flow path for the synthetic resin material Y may be branched at the tip of the nozzle Xa to have multiple discharge holes Xa11. Furthermore, a nozzle Xa having multiple discharge holes Xa11 may be used to simultaneously discharge multiple holes (through holes THb 40 ,THc 40 ,THd 40 , magnet housing MHb 10 ,MHc 10 ,MHd 10 ) may be configured to inject synthetic resin material Y.

[0055] In addition, in the injection process (magnet housing portion MHb 10 ,MHc 10 ,MHd 10 In the process of filling the synthetic resin material Y into the mold (step of filling the mold with the synthetic resin material Y), the injection amount of the synthetic resin material Y is controlled based on a change in the injection pressure of the synthetic resin material Y. Alternatively, for example, the injection amount of the synthetic resin material Y may be controlled based on the rotation amount (number of rotations) of the screw Xc1. Also, a device that pressurizes and sends out the softened synthetic resin material Y may be used as the injection device X. In this case, it is preferable to control the injection amount of the synthetic resin material Y based on the pressure.

[0056] In the curing step of the above embodiment, the outer peripheral surface of the intermediate assembly SA is heated. Alternatively, or in addition, the inner peripheral surface, one end surface in the central axis direction, or the other end surface of the intermediate assembly SA may be heated. [Explanation of symbols]

[0057] MHb 10 ,MHc 10 ,MHd10 ...magnet housing section, T1...first temperature, T2...second temperature, X...injection device, Y...synthetic resin material, 1...rotor core, 10...laminated body, 11...iron core piece, 20, 40...end plate, 30...permanent magnet

Claims

1. a laminate manufacturing process for manufacturing a laminate having a magnet accommodating portion extending in a lamination direction of the steel plates by stacking a plurality of steel plates; a magnet arrangement step of arranging a permanent magnet extending in a lamination direction of the plurality of steel plates in the magnet accommodating portion; a fixing process for fixing the permanent magnet in the magnet housing portion using a synthetic resin material that is solid at room temperature, softens at a first temperature higher than room temperature, does not harden while being held at the first temperature, and hardens at a second temperature higher than the first temperature; A method for manufacturing a motor core comprising: The fixing step includes: an injection process in which a temperature of the synthetic resin material is set to the first temperature, and a nozzle is used to inject a part of the softened synthetic resin material in the container into the magnet accommodating portion through the nozzle by using an injection device having a container and a heater capable of maintaining the synthetic resin material in a softened state; a hardening step of hardening the synthetic resin material by raising the temperature of the synthetic resin material injected into the laminate to the second temperature after retracting the nozzle from the laminate while the synthetic resin material remaining in the container and the nozzle of the injection device is in a softened state; A method for manufacturing a motor core, comprising:

2. 2. The method for manufacturing a motor core according to claim 1, The laminate has a plurality of the magnet housing portions, A method for manufacturing a motor core, wherein the injection process includes a step of injecting a portion of the softened synthetic resin material in the container from a nozzle of the injection device into a first magnet accommodating portion among the plurality of magnet accommodating portions, and after retracting the nozzle from the first magnet accommodating portion, injecting the synthetic resin material remaining in the container and the nozzle from the nozzle of the injection device into a second magnet accommodating portion.

3. The method for manufacturing a motor core according to claim 1 or 2, heating the stack so that the temperature of the stack is higher than the first temperature and lower than the second temperature prior to the injection step; A method for manufacturing a motor core, wherein in the injection step, a nozzle of the injection device is abutted against the open end of the magnet accommodating portion of the laminate, and the softened synthetic resin material is injected.

4. The method for manufacturing a motor core according to any one of claims 1 to 3, A method for manufacturing a motor core, wherein, in the injection step, when an injection pressure of the synthetic resin material becomes greater than a predetermined pressure, injection of the synthetic resin material into the through hole of the laminate is stopped.

5. The method for manufacturing a motor core according to any one of claims 1 to 4, the injection device includes a drive device for discharging the synthetic resin material from the container; A method for manufacturing a motor core, in which, in the injection process, after the softened synthetic resin material is filled in the magnet accommodating section, the driving direction of the drive unit of the injection device is reversed and then the injection device is retracted from the laminate.

6. The method for manufacturing a motor core according to any one of claims 1 to 5, The hardening process includes a step of moving the injection device away from the laminate, transporting the laminate to a heating furnace or induction heating device located separate from the injection device, and raising the temperature of the synthetic resin material injected into the laminate to the second temperature using the heating furnace or induction heating device to harden the synthetic resin material.

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