Method for manufacturing rotor

Abstract

To provide a method for manufacturing a rotor that can simplify a manufacturing process of a rotor.SOLUTION: A method for manufacturing a rotor includes a thickness management step, a mounting step, a mold clamping step, and a filling step. In the thickness management step, the thickness TR of a rotor core is managed so that the thickness TR of the rotor core falls within a predetermined range set for every kind of the rotor core. In the mold clamping step, an upper mold is lowered to a mold clamping position stored in a storage unit of a controller, to perform mold clamping. In the mold clamping step, in performing mold clamping of a rotor core for the first time which is of a kind different from that of a rotor core subjected to mold clamping immediately before, the controller detects whether the rotor core has been subjected to mold clamping. Further, the controller stores, in the storage unit, the position of the upper mold in the vertical direction when detecting that the rotor core has been subjected to mold clamping, as a mold clamping position, and stops raising and lowering of the upper mold.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a rotor.

Background Art

[0002] Patent Document 1 describes a resin filling device for a magnet-embedded core. The core is formed by laminating a plurality of core pieces, and has a magnet insertion hole that extends along the lamination direction of the core pieces and into which a magnet is inserted. The resin filling device described in Patent Document 1 includes a lower mold on which the core is placed and configured to be movable up and down, and an upper mold configured to perform mold clamping by pressing the upper surface of the core as the lower mold rises. With the core clamped by the lower mold and the upper mold, resin is filled into the magnet insertion hole through a passage in the lower mold, thereby fixing the magnet to the core.

[0003] In addition, in a conventional resin filling device, there is one that controls the driving of a movable mold as follows. That is, the resin filling device detects the mold clamping position of the movable mold in the vertical direction by a detection unit of a control device, and stores the mold clamping position detected by the detection unit in a storage unit of the control device. Then, mold clamping is performed by raising or lowering the movable mold until the movable mold reaches the mold clamping position.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, in the manufacturing process of the rotor using such a resin filling device, the variety of the core to be manufactured may be switched to a core having a different thickness from the core that was clamped immediately before. At this time, it is necessary to detect and store the clamping position of the movable mold corresponding to the core after the variety switch. At this time, generally, the detection and storage of the clamping position are performed using a master workpiece that simulates the core after the variety switch. However, in this case, there is a problem that the manufacturing process of the rotor becomes complicated by the amount of clamping performed using the master workpiece. In addition, there is a problem that it is necessary to prepare a master workpiece formed with high dimensional accuracy for each variety of the core.

Means for Solving the Problems

[0006] A method for manufacturing a rotor for solving the above problems is applied to a rotor including a rotor core formed by laminating a plurality of core pieces and having an insertion hole extending along the lamination direction of the core pieces, a magnet inserted into the insertion hole, and a resin filled into the insertion hole to fix the magnet. In a state where the rotor core is clamped by a fixed mold and a movable mold configured to be movable up and down of a resin filling device, the rotor is manufactured by filling the resin into the insertion hole. The method includes a thickness management step of managing the thickness of the rotor core so that the thickness of the rotor core falls within a predetermined range set for each variety of the rotor core, a placing step of placing the rotor core with the magnet inserted into the insertion hole on the fixed mold or the movable mold after the thickness management step, a clamping step of performing clamping by moving the movable mold up and down until it reaches the clamping position stored in the storage unit of the control device, and a filling step of filling the resin into the insertion hole. In the clamping step, when clamping the rotor core of a variety different from the rotor core that was clamped immediately before for the first time, it is detected whether it is in the clamped state, and when it is detected that it is in the clamped state, the position of the movable mold in the vertical direction at that time is stored in the storage unit as the clamping position and the up and down movement of the movable mold is stopped.

[0007] According to the same method, when first clamping a rotor core of a different variety from the rotor core clamped immediately before, it is detected whether the clamping has been performed. Then, when it is detected that the state is a clamped state, the position of the movable die in the vertical direction at that time is stored in the storage unit as the clamping position, and the lifting of the movable die is stopped through the control device. Here, in the thickness management process, which is the process before the clamping process, the thickness of the rotor core is managed so as to be within a predetermined range set for each variety of the rotor core. Therefore, by detecting the clamped state and storing the clamping position using the rotor core formed with high dimensional accuracy required for the product, the clamping position can be accurately changed without using a master workpiece. As a result, when clamping the second and subsequent rotor cores after the variety change, clamping can be performed by a simple control method of raising and lowering the movable die until it reaches the clamping position stored in the storage unit through the control device. Therefore, the manufacturing process of the rotor can be simplified.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0009] Hereinafter, with reference to FIGS. 1 to 6, an embodiment of a method for manufacturing a rotor will be described. <Rotor 10> First, referring to FIGS. 1 and 2, the rotor 10 constituting the magnet-embedded type motor will be described.

[0010] The rotor 10 includes a rotor core 11 having a plurality of insertion holes 13, magnets 14 inserted into the insertion holes 13, and a thermoplastic resin 15 filled in the insertion holes 13 and fixing the magnets 14 to the rotor core 11.

[0011] The rotor core 11 has a substantially cylindrical shape with a central hole 12. The rotor core 11 is formed of a laminate in which a plurality of core pieces 20 made of electromagnetic steel sheets are laminated. Hereinafter, the lamination direction of the rotor core 11 will be simply referred to as the lamination direction, the radial direction of the rotor core 11 will be simply referred to as the radial direction, and the circumferential direction of the rotor core 11 will be simply referred to as the circumferential direction for explanation.

[0012] The plurality of insertion holes 13 are provided at intervals in the circumferential direction. In the present embodiment, the cross-sectional shape of the insertion hole 13 is schematically substantially rectangular. The central hole 12 and each insertion hole 13 penetrate the rotor core 11 along the lamination direction.

[0013] As shown in FIG. 1, on the inner peripheral surface of the central hole 12, a pair of key portions 12a facing each other in the radial direction project. <Core piece 20> As shown in FIGS. 1 and 2, the plurality of core pieces 20 include a plurality of first core pieces 21 laminated continuously and one second core piece 25 laminated on one side (the lower side in FIGS. 1 and 2) of the plurality of first core pieces 21.

[0014] As shown in FIG. 2, the first core piece 21 has dowels 22 that bulge toward the second core piece 25 side in the lamination direction. A plurality of dowels 22 are provided at intervals in the circumferential direction (see FIG. 1). The adjacent first core pieces 21 in the lamination direction are joined by caulking the dowels 22 together.

[0015] The second core piece 25 has through holes 26 into which the dowels 22 of the first core piece 21 adjacent to the second core piece 25 are inserted. A plurality of the through holes 26 are provided at intervals in the circumferential direction and are respectively provided at positions overlapping the dowels 22 in the stacking direction.

[0016] <Resin filling device 30> Next, the resin filling device 30 will be described. As shown in FIG. 3, the resin filling device 30 includes a lower mold 31, a transfer plate 32, a first plate 36, an upper mold 41, a second plate 42, and a control device 50.

[0017] (Lower mold 31 and upper mold 41) As shown in FIG. 3, the lower mold 31 is a fixed mold. The upper mold 41 is a movable mold and is configured to be movable up and down above the lower mold 31. The upper mold 41 is provided with a sprue passage 41a connected to a nozzle (both not shown) of an injection molding machine.

[0018] A motor 60 is connected to the upper mold 41. The upper mold 41 moves up and down by the driving force of the motor 60. (Transfer plate 32) As shown in FIG. 3, the transfer plate 32 transports the rotor core 11 and is disposed on the upper surface of the lower mold 31.

[0019] The transfer plate 32 has a plate body 33 in a substantially square plate shape and a post portion 34 in a substantially cylindrical shape. The post portion 34 projects upward from the central portion of the plate body 33. The post portion 34 is inserted into the center hole 12 of the rotor core 11. A pair of key groove portions (not shown) are provided on the outer peripheral surface of the post portion 34 along the axial direction of the post portion 34. By inserting each key portion 12a of the rotor core 11 into the pair of key groove portions, positioning of the rotor core 11 in the circumferential direction with respect to the plate body 33 is achieved.

[0020] A plurality of engaging pins 35 projecting upward are provided at the upper end of the post portion 34. (First Plate 36) As shown in FIG. 3, the first plate 36 is disposed on the upper surface of the plate body 33.

[0021] The first plate 36 is provided with a through hole 36a through which the post portion 34 is inserted. On the inner peripheral surface of the through hole 36a, a pair of regulating protrusions (not shown) are provided which are inserted into the pair of key groove portions of the post portion 34 to position the first plate 36 with respect to the plate body 33.

[0022] By bringing the lower surface of the rotor core 11 into contact with the upper surface of the first plate 36, the lower openings 13a of the plurality of insertion holes 13 are blocked. (Second Plate 42) As shown in FIG. 3, the second plate 42 is brought into contact with the upper surface of the rotor core 11 to block the upper openings 13b in the plurality of insertion holes 13.

[0023] The second plate 42 has a passage 43 for supplying the resin 15 to the upper openings 13b. The passage 43 includes a plurality of branch passages 44 connected to the sprue passage 41a and extending radially outward, and a plurality of gate passages 45 extending from the radially outer ends of the branch passages 44 along the vertical direction toward the lower surface of the second plate 42. The plurality of gate passages 45 are provided corresponding to the plurality of insertion holes 13 respectively.

[0024] On the lower surface of the second plate 42, a plurality of engaging holes 46 for engaging the engaging pins 35 are provided. The plurality of engaging holes 46 are provided at positions corresponding to the plurality of engaging pins 35 respectively.

[0025] (Control Device 50) The control device 50 controls the driving of the motor 60 and is electrically connected to the motor 60.

[0026] The control device 50 is electrically connected to a current sensor 52 that detects the value IM of the current flowing through the motor 60 and a rotation angle sensor 53 that detects the rotation angle θ of the output shaft of the motor 60. The control device 50 includes a storage unit 51 that stores the mold clamping position of the upper mold 41.

[0027] Based on the mold clamping position and the rotation angle θ of the output shaft of the motor 60, the control device 50 grasps the position of the upper mold 41 in the vertical direction with the mold clamping position as the origin, and controls the drive of the motor 60 to change the position of the upper mold 41 in the vertical direction.

[0028] The control device 50 performs mold clamping by lowering the upper mold 41 until it reaches the mold clamping position stored in the storage unit 51. When the control device 50 first performs mold clamping on a rotor core 11 of a variety different from the rotor core 11 that was previously mold clamped, it detects whether or not it is in a mold clamped state. Then, when the control device 50 detects that it is in a mold clamped state, it stores the position of the upper mold 41 in the vertical direction at that time as the mold clamping position in the storage unit 51, and controls the drive of the motor 60 to stop the descent of the upper mold 41.

[0029] In the present embodiment, the control device 50 detects whether or not the rotor core 11 is mold clamped by the upper mold 41 and the lower mold 31 based on the current value IM detected by the current sensor 52.

[0030] <Manufacturing method of the rotor 10> As shown in FIGS. 2 to 5, the manufacturing method of the rotor 10 includes a thickness management step, a placement step, a mold clamping step, and a filling step.

[0031] (Thickness management step) As shown in FIG. 2, in the thickness management process, a predetermined load is applied to the rotor core 11 in the stacking direction by a caulking device (not shown). As a result, the dowels 22 of the first core pieces 21 are caulked together, and the dowels 22 of the first core pieces 21 and the through holes 26 of the second core pieces 25 are caulked, and the thickness TR of the rotor core 11 in the stacking direction is managed. At this time, the thickness TR of the rotor core 11 is managed so as to be within a predetermined range set for each type of the rotor core 11. In the thickness management process, for the rotor core 11 whose thickness TR is outside the predetermined range set for each type of the rotor core 11, it is determined as a defective product and excluded from the production line.

[0032] (Placement process) As shown in FIG. 3, in the placement process, the rotor core 11 after the thickness management process is placed on the upper surface of the transfer plate 32. Subsequently, the magnet 14 is inserted into the insertion hole 13. Subsequently, the second plate 42 is placed on the upper surface of the rotor core 11. Then, the rotor core 11 on which the second plate 42 is placed is placed on the lower mold 31 together with the transfer plate 32.

[0033] (Molding process) As shown in FIG. 4, in the molding process, the upper mold 41 is lowered by the control device 50 until it reaches the molding position stored in the storage unit 51, thereby performing molding.

[0034] (Filling process) As shown in FIG. 5, in the filling process, the molten resin 15 is supplied from the sprue passage 41a of the upper mold 41 to each branch passage 44, so that the resin 15 is filled into each insertion hole 13 through each gate passage 45.

[0035] Thereafter, the resin 15 is cooled, whereby the magnet 14 is fixed to the rotor core 11. <Processing procedure of the molding process> Next, with reference to the flowchart of FIG. 6, the control processing procedure of the control device 50 in the molding process will be described.

[0036] This series of processes is executed by the control device 50 every time the rotor core 11 is placed on the lower die 31 in the placing process. First, it is determined whether the variety of the rotor core 11 has been switched (step S1). That is, based on the signal input to the control device 50, it is determined whether the rotor core 11 placed on the lower die 31 is a rotor core 11 of a different variety from the rotor core 11 that was clamped immediately before.

[0037] If it is determined that the variety of the rotor core 11 has been switched (step S1: "YES"), then next, the motor 60 is driven to lower the upper die 41 (step S2). Next, it is determined whether the current value IM of the motor 60 is equal to or greater than the threshold value Ith (step S3).

[0038] Here, if it is not determined that the current value IM is equal to or greater than the threshold value Ith (step S3: "NO"), the processes of step S2 and step S3 are repeatedly executed until the current value IM becomes equal to or greater than the threshold value Ith.

[0039] If it is determined that the current value IM is equal to or greater than the threshold value Ith (step S3: "YES"), the position of the upper die 41 at that time is stored as the clamping position, and the driving of the motor 60 is stopped to stop the lowering of the upper die 41 (step S4).

[0040] Then, the control device 50 ends this series of processes. On the other hand, if it is not determined that the variety of the rotor core 11 has been switched (step S1: "NO"), then next, the motor 60 is driven to lower the upper die 41 (step S5). Next, it is determined whether the position of the upper die 41 is the clamping position (step S6).

[0041] Here, if it is not determined that the position of the upper die 41 is the clamping position (step S6: "NO"), the processes of step S5 and step S6 are repeatedly executed until the position of the upper die 41 becomes the clamping position.

[0042] When it is determined that the position of the upper mold 41 is the mold clamping position (step S6: "YES"), the driving of the motor 60 is stopped to stop the lowering of the upper mold 41 (step 7). Then, the control device 50 ends this series of processes.

[0043] <Operation of this Embodiment> As shown in FIG. 6, when starting to clamp the rotor core 11 of a variety different from the rotor core 11 clamped immediately before, it is detected whether the rotor core 11 has been clamped. Then, the position of the upper mold 41 in the vertical direction when it is detected that the mold is in the clamped state is stored in the storage unit 51 as the mold clamping position, and the lowering of the upper mold 41 is stopped through the control device 50. Here, in the thickness management process, which is a pre-process of the mold clamping process, the thickness TR of the rotor core 11 is managed so as to be within a predetermined range set for each variety of the rotor core 11. For this reason, by detecting the clamped state and storing the clamping position using the rotor core 11 formed with high dimensional accuracy required for the product, the clamping position can be accurately changed without using a master workpiece. As a result, when clamping the rotor core 11 for the second and subsequent times after the variety change, the clamping can be performed by a simple control method of lowering the upper mold 41 through the control device 50 until it reaches the clamping position stored in the storage unit 51.

[0044] <Effects of this Embodiment> (1) In the mold clamping process, when the control device 50 starts to clamp the rotor core 11 of a variety different from the rotor core 11 clamped immediately before for the first time, it detects whether the rotor core 11 is in the clamped state. Further, the control device 50 stores the position of the upper mold 41 in the vertical direction when it is detected that the mold is in the clamped state in the storage unit 51 as the mold clamping position and stops the lowering of the upper mold 41.

[0045] According to such a method, since the above operation is achieved, the manufacturing process of the rotor 10 can be simplified. (2) When the current value IM flowing through the motor 60 that drives the upper mold 41 becomes equal to or greater than the threshold value Ith, the control device 50 detects that the rotor core 11 is in the clamped state.

[0046] According to such a method, it is possible to detect by the control device 50 that the rotor core 11 is in the clamped state using the conventional configuration. Therefore, a configuration for detecting that the rotor core 11 is in the clamped state can be easily realized.

[0047] <Modification Example> This embodiment can be implemented with the following modifications. This embodiment and the following modification examples can be implemented in combination with each other within a technically consistent range.

[0048] · In the above embodiment, it is detected whether or not it is in the clamped state by comparing the current value IM flowing through the motor 60 that drives the upper mold 41 with the threshold value Ith, but it is not limited to this. For example, the rotor core 11 and the upper mold 41 may be photographed by a camera, and the photographed image may be processed to detect whether or not it is in the clamped state.

[0049] · In this embodiment, the resin filling device 30 that fills the insertion hole 13 with the thermoplastic resin 15 is used, but a resin filling device that fills the insertion hole 13 with a thermosetting resin may also be used. · In this embodiment, the upper mold 41 is a movable mold and the lower mold 31 is a fixed mold, but the upper mold 41 may be a fixed mold and the lower mold 31 may be a movable mold.

Description of Reference Numerals

[0050] 10… Rotor 11… Rotor Core 12… Central Hole 12a… Key Portion 13… Insertion Hole 13a… Lower Opening 13b… Upper Opening 14… Magnet 15… Resin 20…Iron core piece 21…First iron core piece 22…Lug 25…Second iron core piece 26…Through hole 30…Resin filling device 31…Lower mold (fixed mold) 32…Transfer plate 33…Plate body 34…Post portion 35…Engagement pin 36…First plate 36a…Through hole 41…Upper mold (movable mold) 41a…Sprue passage 42…Second plate 43…Passage 44…Branch passage 45…Gate passage 46…Engagement hole 50…Control device 51…Memory unit 52…Current sensor 53…Rotation angle sensor 60…Motor

Claims

1. A method for manufacturing a rotor, which is applied to a rotor comprising a rotor core formed by laminating a plurality of iron core pieces and having insertion holes extending along the lamination direction of the iron core pieces, magnets inserted into the insertion holes, and a resin filled in the insertion holes to fix the magnets. In this method, with the rotor core clamped by a fixed mold and a movable mold that can be moved up and down of a resin filling device, the resin is filled into the insertion holes to manufacture the rotor, and the method includes: a thickness management step of managing the thickness of the rotor core so that the thickness of the rotor core falls within a predetermined range set for each type of the rotor core; a placement step of placing the rotor core with the magnets inserted into the insertion holes on the fixed mold or the movable mold after the thickness management step; a clamping step of performing clamping by moving the movable mold up and down until it reaches a clamping position stored in a storage unit of a control device; a filling step of filling the resin into the insertion holes, In the clamping step, when clamping a rotor core of a type different from the rotor core clamped immediately before for the first time, it is detected whether it is in a clamped state, and when it is detected that it is in a clamped state, the position of the movable mold in the vertical direction at that time is stored in the storage unit as the clamping position and the lifting and lowering of the movable mold is stopped; A method for manufacturing a rotor.

2. In the clamping step, when clamping a rotor core of a type different from the rotor core clamped immediately before, when the current value flowing through a motor that drives the movable mold becomes equal to or greater than a threshold value, it is detected that it is in a clamped state. The method for manufacturing a rotor according to Claim 1.

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