JP2013240202A - Method of manufacturing laminated core - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a laminated core in which poor filling of resin is less likely to occur, even for a core body the volume of magnet insertion hole of which is large.SOLUTION: In the method of manufacturing a laminated core, permanent magnets 14 are inserted, respectively, into magnet insertion holes 12, 13 of a core body 15 having the plurality of magnet insertion holes 12, 13, and then the magnet insertion holes 12, 13 are filled with resin from a resin reservoir pot 30 while sandwiching the permanent magnets 14 by means of an upper die 17 and a lower die 18, thus securing the permanent magnets 14. The magnet insertion holes 12, 13 are filled with resin from the resin reservoir pot 30 via a common runner 31 and gate holes 33, 34, and a cull plate 16 is removed after the permanent magnets 14 is secured.

Description

The present invention relates to a method for manufacturing a laminated core (for example, a rotor laminated core), and more particularly, to a method for preventing unfilling of a resin into a magnet insertion hole.

Conventionally, in the manufacture of a rotor laminated core (also referred to as a rotor core) of a motor used in automobiles and home appliances, an unmagnetized permanent magnet is inserted into a plurality of magnet insertion holes formed corresponding to the number of magnetic poles of the core body. It has been practiced to put a magnet and put resin from the outside and fix it with resin sealing.
In resin sealing of this permanent magnet, for example, as shown in Patent Document 1, an iron core body in which a permanent magnet is inserted into a magnet insertion hole is sandwiched between an upper mold and a lower mold. It was performed by filling a molten thermosetting resin from a resin reservoir pot provided in the lower mold.

However, after resin sealing, after removing the resin-sealed laminated iron core from between the upper mold and the lower mold, it is necessary to remove the cured resin attached to the entrance portion of the magnet insertion hole and further clean the surface. Yes, workability was remarkably inferior. Therefore, as shown in Patent Document 2, a cull plate (also referred to as a dummy plate) is disposed between the core body into which the permanent magnet is inserted and the upper mold or the lower mold in which the resin reservoir pot is formed, and the resin sealing is performed. After finishing the stop, the resin soot is removed together with the calplate from the iron core body.

Japanese Patent No. 4865086 JP 2008-54376 A

However, when the calplate is removed from the laminated iron core together with the resin soot, there has been a problem that the surface of the resin that has been filled in the magnet insertion hole and hardened is peeled off to form a recess in that portion. Therefore, the applicant of the present application, in Japanese Patent Application No. 2010-272769 (hereinafter referred to as Document 3), as shown in FIGS. 8A and 8B, a part of the discharge region 91 of the resin reservoir pot 90 is A resin filling method is proposed in which the resin plate is provided so as to overlap the gate hole 93 of the cull plate 92 and the resin flows directly from the resin reservoir pot 90 into the gate hole 93. In the present invention, there is an advantage that the amount of resin used can be reduced because the remainder of the resin tub is small because the runner is not formed. In FIG. 8A, 94 indicates an iron core body, 95 indicates a magnet insertion hole, 96 indicates a permanent magnet, and 97 indicates a plunger.

However, in the method of pouring resin directly from the resin reservoir pot 90 into the gate hole 93 without a runner, the rate of occurrence of resin filling failure increases as the volume of the magnet insertion hole 95 of the iron core body 94 increases. The reason is that, for example, when the height of the iron core body 94 is increased, the volume of the magnet insertion hole 95 is inevitably increased. However, when the volume of the magnet insertion hole 95 is increased, the amount of resin needs to be increased accordingly. The size of the resin tablet (resin raw material) to be used is also increased. The filling time (the time from melting to curing) when melting and filling the magnet insertion hole 95 is determined by the conditions of the resin, and is not related to the volume of the magnet insertion hole 95. That is, the larger the volume of the magnet insertion hole 95, the more resin needs to be filled within a certain time.

In the case where the resin is poured directly from the resin reservoir pot 90 into the gate hole 93, the resin tablet size is increased, so that a resin having low fluidity that cannot be completely melted in time is generated. It was found that the resin filling was not in time for the predetermined resin filling time, and as a result, a defective filling into the magnet insertion hole 95 occurred.

Further, Document 3 discloses that a runner corresponding to each magnet insertion hole is formed in the cull plate, and a resin reservoir pot and a gate hole are communicated with each other through this runner. The gate is directly connected to the resin reservoir pot. Although the occurrence of poor filling is less than that in which resin is poured into the holes, it has been found that the proportion of defective resin filling increases as the volume of the magnet insertion hole increases.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a method for manufacturing a laminated core in which defective filling of a resin hardly occurs even for an iron core body having a large volume of a magnet insertion hole.

The method for manufacturing a laminated core according to the present invention is formed by laminating a plurality of core pieces, and after inserting a permanent magnet into each magnet insertion hole of an iron core body having a plurality of magnet insertion holes, In a state sandwiched between the upper mold and the lower mold, the permanent magnet is fixed by filling the magnet insertion hole with resin from a resin reservoir pot provided in one of the upper mold and the lower mold. In the method of manufacturing a laminated iron core,
A common runner that guides the resin from the resin reservoir pot to the at least two magnet insertion holes and a portion of the magnet insertion hole overlap between the mold in which the resin reservoir pot is formed and the core body. A cull plate having a gate hole is arranged, and after the resin is injected into the magnet insertion hole through the common runner and the gate hole and cured, the cull plate is removed from the core body.

In the method for manufacturing a laminated core according to the present invention, it is preferable that a part of the resin reservoir pot overlaps the gate hole, and a part of the resin is pushed directly into the gate hole from the resin reservoir pot.

In the method for manufacturing a laminated core according to the present invention, it is preferable that the resin discharged from the resin reservoir pot is pushed into the gate hole through the groove-shaped common runner formed in the cull plate.

In the method for manufacturing a laminated core according to the present invention, it is preferable that the laminated core is an inner rotor, and the gate hole overlaps the magnet insertion hole from the inside in the radial direction of the magnet insertion hole.

In the method for manufacturing a laminated core according to the present invention, the laminated core may be an outer rotor, and the gate hole may overlap the magnet insertion hole from the outside in the radial direction of the magnet insertion hole.

In the method for manufacturing a laminated core according to the present invention, by providing a common runner that guides resin to at least two magnet insertion holes at the same time in the calplate, a melt flow region in which the resin flows while melting the resin is secured. I was able to improve the sex. As a result, there is no resin with low fluidity as in the past, and this prevents the flow of resin into the gate hole from being hindered, so it is possible to increase the amount of resin to be filled within a predetermined time. .
Thereby, resin can be filled into the magnet insertion hole without causing unfilling of the resin even to the core body having a large volume of the magnet insertion hole.

(A) is explanatory drawing of the manufacturing method of the laminated core which concerns on the 1st Embodiment of this invention, (B) is the elements on larger scale of the calplate used for the manufacturing method. It is a top view of the cull plate used for the manufacturing method of the same laminated iron core. It is explanatory drawing of the apparatus for enforcing the manufacturing method of the laminated core. (A), (B) is explanatory drawing of the flow of the resin in the manufacturing method of the same laminated iron core, respectively. It is explanatory drawing which shows the flow of resin with which a magnet insertion hole is filled from the resin reservoir pot to which the manufacturing method of the laminated core which concerns on the 2nd Embodiment of this invention is applied. It is sectional drawing around the cull plate used for the manufacturing method of the laminated core which concerns on the 3rd Embodiment of this invention. (A) is sectional drawing of the resin sealing part which applied the manufacturing method of the laminated core which concerns on the 4th Embodiment of this invention, (B) is the partial top view. (A) is explanatory drawing of the manufacturing method of the prior art laminated iron core, (B) is a partially expanded view of the cull plate used for the method.

Next, embodiments of the present invention will be described with reference to the accompanying drawings.
As shown in FIGS. 1-3, the apparatus 10 which implements the manufacturing method of the laminated core which concerns on the 1st Embodiment of this invention is formed by laminating | stacking the several iron core piece 11, and becomes several pairs. An upper die 17 and a lower die 18, which are examples of molds, sandwiching an iron core body 15 in which unmagnetized permanent magnets 14 are inserted into the magnet insertion holes 12 and 13 via a cull plate (dummy plate) 16. And have.

In this embodiment, the iron core body 15 has a shaft hole 19 in the center and is mounted on a transport jig 22 having a rectangular transport plate 20 and a positioning shaft 21 provided at the center thereof. It is arranged between the upper mold 17 and the lower mold 18. A fixed upper frame 23 is provided on the upper mold 17, a lower mold 18 is mounted on a movable frame 24, and the movable frame 24 is moved up and down by a hydraulic cylinder 26 provided on the fixed lower frame 25, so that the upper core body 15 is sandwiched between the upper mold 17 and the lower mold 18. Reference numeral 28 denotes a post.

As shown by a broken line in FIG. 2, the iron core body 15 has magnet insertion holes 12 and 13 that form a pair, and the cull plate 16 formed of a metal plate is provided with each resin reservoir pot 30 formed in the upper mold 17. It has a common runner 31 that communicates with (indicated by a two-dot chain line in FIG. 2). The common runner 31 has gate holes 33 and 34 that communicate with the magnet insertion holes 12 and 13 located at the lower side on the outer side in the radial direction. The depth of the groove-like (ie bottomed) common runner 31 is 1/3 to 2/3 of the thickness of the cull plate 16.

In the center of the cull plate 16, a hole 35 through which the positioning shaft 21 passes is formed, and the diameter of the hole 35 is the same as that of the shaft hole 19 of the core body 15. In this embodiment, a projecting key that faces the shaft hole 19 of the core body 15 is provided, and the positioning shaft 21 is provided with a key groove that matches the projecting key. 35 is also provided with a projecting key that coincides with a key groove (not shown in FIG. 2) provided in the positioning shaft 21 to position the cull plate 16 and the core body 15. In addition, a protruding key may be provided on the positioning shaft, and a keyway that matches the protruding key may be provided in the core body and the cull plate. Further, the positioning of the cull plate 16 and the core body 15 may be other means, for example, a means for fitting the protruding piece of the cull plate 16 into a hole or notch provided in the core body 15. .

As shown in FIGS. 1A, 1B, 4A, and 4B, the gate holes 33 and 34 are radially inward of the magnet insertion holes 12 and 13, and are substantially the same as the magnet insertion holes 12 and 13, respectively. It is arranged at the center position. The gate holes 33 and 34 are rectangular in plan view, and the inner edges of the magnet insertion holes 12 and 13 pass through the center position in the width (short width) direction. In other words, the gate holes 33 and 34 partially overlap the magnet insertion holes 12 and 13 in plan view. The shaft center of the resin reservoir pot 30 having a circular cross section is provided on the curvature radius center position side of the fan-shaped common runner 31 in a plan view, and the radial outside 37 of the resin reservoir pot 30 (relative to the center of the core body 15). ) Is partially blocked by the upper surface of the culplate 16. As shown in FIG. 4A, the resin reservoir pot 30 may have a size that partially overlaps the gate holes 33 and 34, or as shown in FIG. May be of a size that does not overlap.

The paired magnet insertion holes 12 and 13 are formed symmetrically with respect to the radial line r of the iron core body 15 passing through the axis of the resin reservoir pot 30 in plan view.
With such a configuration, when the hydraulic cylinder 38 mounted on the fixed frame 23 is extended and the resin in the resin reservoir pot 30 is pushed out by the plunger 39, the resin in the radially outer portion 37 is removed from the calplate. It is blocked by the surface of 16 and flows inward in the radial direction and flows toward the common runner 31 side. At this time, the outer side of the common runner 31 enters the magnet insertion holes 12 and 13 toward the gate holes 33 and 34 along arcuate walls (curved walls) 41 and 42 that are symmetrical with respect to the radial line r.

As a result, a melt flow region in which the resin extruded by the plunger 39 flows while being melted is secured by the common runner 31, and the fluidity of the resin can be enhanced. As a result, there is no resin with low fluidity as in the past, and this prevents the flow of the resin into the gate hole from being obstructed. Therefore, the amount of resin to be filled can be increased within a predetermined time. It was.

Next, the details of the cull plate 43 used in the method for manufacturing a laminated core according to the second embodiment of the present invention will be described with reference to FIG.
In this embodiment, the resin reservoir pot 30, the common runner 44, the subsequent gate holes 45 and 46, and the magnet insertion holes 12 and 13 are represented by solid lines and represent a mutual relationship in plan view.

The paired magnet insertion holes 12 and 13 are formed symmetrically with respect to the center line m, and the gate holes 45 and 46 are also arranged in the center of the inner walls in the radial direction of the left and right magnet insertion holes 12 and 13 in the width direction center line. Is arranged to be located. The outer side of the resin reservoir pot 30 in the radial direction is closed by the surface of the cull plate 43, the arc wall 47 passes through the common runner 44 in the radial direction, and the straight walls 48 and 49 pass through both sides thereof, and further through the outer side. Guide walls 50 and 51 for guiding the resin to the gate holes 45 and 46 are provided. The depth of the common runner 44 is 1/3 to 2/3 of the thickness of the cull plate 43.

Therefore, the resin pushed out from the resin reservoir pot 30 is directed radially inward, and then divided into left and right and flows into the gate holes 45 and 46. In this case, since the volume of the common runner 44 is large, even if there is a partially unmelted resin in the resin reservoir pot 30, it melts while staying in the common runner 44, and the fluidity is improved and the magnet insertion hole 12, 13 is filled. In the resin reservoir pot 30, a part of the resin protruding region overlaps with the gate holes 45 and 46, and a part of the resin is pushed directly from the resin reservoir pot 30 into the gate holes 45 and 46.

Next, a method for manufacturing a laminated core according to the third embodiment of the present invention shown in FIG. 6 will be described. In this embodiment, the cull plate 53 will be described, but the side wall 55 of the common runner 54 is an inclined surface that opens upward. One side surface of the gate hole 56 is an inclined surface 56a that opens upward (that is, opens radially outward). The cull plate 53 can be easily removed from the core body 15 by slightly rotating the cull plate 53 with the inclined surface 56a. Further, when the resin is removed from the cull plate 53, it can be easily removed by the taper effect of the side wall 55 and the inclined surface 56a. This embodiment can be easily applied to the first and second embodiments and the fourth embodiment described below.

Then, the manufacturing method of the laminated core which concerns on the 4th Embodiment of this invention shown to FIG. 7 (A), (B) is demonstrated. In this embodiment, three magnet insertion holes 58 to 60 are provided in one magnetic pole of the iron core main body 57, and the permanent magnet 14 is inserted into each of them.
In this example, there is a cull plate 61a provided with a common runner 61 just below the resin reservoir pot 30, and the magnet insertion holes 58-60 are filled from the common runner 61 through the gate holes 62-64. . In this embodiment, since the volume of the common runner 61 is large, the resin pushed out from the resin reservoir pot 30 melts in the common runner 61 and smoothly flows into the magnet insertion holes 58-60.

In any of the embodiments described above, after the permanent magnet is sealed with the resin in the magnet insertion hole, the core body and the cull plate are taken out from the mold apparatus together with the conveying jig 22. Then, the calplate is removed and the adhered resin is cleaned and reused.

The present invention is not limited to the above-described embodiment, and the configuration thereof can be changed without changing the gist of the present invention. For example, the common runner may have another shape as long as the resin from the resin reservoir pot is smoothly flowed to the gate hole over a certain period of time.
Moreover, in the said embodiment, although the cull plate was arrange | positioned on an iron core main body, when providing a resin reservoir pot in a lower mold | type, a cull plate will be arrange | positioned under an iron core main body. In this case, the conveying jig can be used upside down.

The laminated iron core manufactured in the above embodiment is an inner rotor, and the gate hole overlaps with the magnet insertion hole from the inside in the radial direction of the magnet insertion hole, but when the laminated iron core is an outer rotor, the gate hole is It overlaps with the magnet insertion hole from the outside in the radial direction of the magnet insertion hole.

10: Device, 11: Iron core piece, 12, 13: Magnet insertion hole, 14: Permanent magnet, 15: Iron core body, 16: Cull plate, 17: Upper mold, 18: Lower mold, 19: Shaft hole, 20: Transport Plate: 21: Positioning shaft, 22: Transfer jig, 23: Fixed frame, 24: Movable frame, 25: Fixed lower frame, 26: Hydraulic cylinder, 28: Post, 30: Resin reservoir pot, 31: Common runner, 33 , 34: gate hole, 35: punching hole, 37: radially outer side, 38: hydraulic cylinder, 39: plunger, 41, 42: arc wall, 43: cul plate, 44: common runner, 45, 46: gate hole 47: Arc wall, 48, 49: Straight wall, 50, 51: Guide wall, 53: Cull plate, 54: Common runner, 55: Side wall, 56: Gate hole, 56a: Inclined surface, 57: Iron core body 58-60: magnet insertion holes, 61: common runner, 61a: Cal plates 62-64: gate hole

Claims (5)

In a state where a plurality of core pieces are stacked and a permanent magnet is inserted into each of the magnet insertion holes of the core body having a plurality of magnet insertion holes, the core body is sandwiched between an upper mold and a lower mold, In the manufacturing method of the laminated iron core in which the permanent magnet is fixed by filling the magnet insertion hole with a resin from a resin reservoir pot provided in one of the upper mold and the lower mold,
A common runner that guides the resin from the resin reservoir pot to the at least two magnet insertion holes and a portion of the magnet insertion hole overlap between the mold in which the resin reservoir pot is formed and the core body. A cull plate having a gate hole is arranged, the resin is injected into the magnet insertion hole through the common runner and the gate hole and cured, and then the cull plate is removed from the core body. Manufacturing method of laminated iron core. 2. The method of manufacturing a laminated core according to claim 1, wherein a part of the resin reservoir pot overlaps with the gate hole, and a part of the resin is pushed directly into the gate hole from the resin reservoir pot. Manufacturing method of laminated iron core. 2. The method of manufacturing a laminated core according to claim 1, wherein the resin discharged from the resin reservoir pot is pushed into the gate hole through the groove-shaped common runner formed in the cull plate. Manufacturing method of laminated iron core. The method for manufacturing a laminated core according to any one of claims 1 to 3, wherein the laminated core is an inner rotor, and the gate hole overlaps the magnet insertion hole from a radially inner side of the magnet insertion hole. A method for producing a laminated core as a feature. 4. The method of manufacturing a laminated core according to claim 1, wherein the laminated core is an outer rotor, and the gate hole overlaps the magnet insertion hole from a radially outer side of the magnet insertion hole. A method for producing a laminated core as a feature.

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