JP2024024955A - Manufacturing method of rotor for rotating electric machine - Google Patents

Abstract

An object of the present invention is to reduce the possibility of resin material leaking between steel plates of a laminated iron core when the resin material is injected or injected into a magnet hole of a laminated iron core. [Solution] A process of preparing a steel plate for a rotor core and having a magnet hole, a process of laminating a plurality of steel plates and pressing them in the axial direction to form an integrated laminated core, and an injection molding machine. and an injection process of injecting the resin material into the magnet hole of the laminated core through the injection process, and the injection pressure of the resin material in the injection process is set based on the value of a parameter related to the pressing force when forming the laminated core. A method of manufacturing a rotor for a rotating electric machine is disclosed. [Selection diagram] Figure 18

Description

The present disclosure relates to a method of manufacturing a rotor for a rotating electric machine.

BACKGROUND ART A technique is known in which a laminated rotor core in which a plurality of steel plates are laminated is pressed with upper and lower molds, and a magnet hole in the laminated core is filled with a resin material at a predetermined pressure (injection pressure).

Japanese Patent Application Publication No. 2002-34187

However, in the above-mentioned conventional technology, there is a risk that the resin material may leak from between the steel plates of the laminated core depending on how the injection pressure is set.

Accordingly, in one aspect, the present disclosure aims to reduce the possibility that resin material leaks between the steel plates of a laminated core when the resin material is injected or injected into the magnet hole of the laminated core.

In one aspect, a step of preparing a steel plate for a rotor core, the steel plate having a magnet hole;
forming an integrated laminated core by laminating a plurality of the steel plates and pressing them in the axial direction;
a resin placement step of injecting or injecting a resin material into the magnet hole of the laminated core through an injection molding machine or a resin injection machine,
A method for manufacturing a rotor for a rotating electrical machine is provided, wherein the injection pressure or injection pressure of the resin material in the resin placement step is set based on the value of a parameter related to the pressing force when forming the laminated core. .

In one aspect, according to the present disclosure, when the resin material is injected or injected into the magnet holes of the laminated core, it is possible to reduce the possibility that the resin material leaks between the steel plates of the laminated core.

1 is a cross-sectional view schematically showing a cross-sectional structure of a motor according to an embodiment. FIG. 3 is a cross-sectional view of the rotor. 3 is an enlarged view of a portion related to one magnetic pole shown in FIG. 2. FIG. 4 is a schematic cross-sectional view along line AA in FIG. 3; FIG. 5 is an enlarged view of part Q1 in FIG. 4. FIG. FIG. 3 is an explanatory diagram of a comparative example. FIG. 2 is an explanatory diagram of a structure (part 1) of a rotor core formed by rolling a plurality of laminated blocks. FIG. 2 is an explanatory diagram of a structure (part 2) of a rotor core formed by rolling a plurality of laminated blocks. 1 is a flowchart schematically showing the flow of a method for manufacturing the motor 1 according to the present embodiment. It is an explanatory view of a workpiece support process. It is an explanatory view of a magnet arrangement process. It is an explanatory view of a nozzle positioning process. It is an explanatory view of a resin placement process. FIG. 2 is an explanatory diagram of a resin placement device for realizing a resin placement process. FIG. 2 is an explanatory diagram of a resin placement device for realizing a resin placement process. It is an explanatory view of an example of a resin injection machine. It is an explanatory view of a resin curing process (axial force application process), and is a cross-sectional view schematically showing the state during the same process. It is a schematic flowchart concerning an example of the setting method of a resin injection machine. It is a schematic sectional view explaining a press machine. It is an explanatory view of the force required when peeling between steel plates. It is an explanatory view of injection pressure when resin material leaks from between steel plates.

Hereinafter, each embodiment will be described in detail with reference to the accompanying drawings. Note that the dimensional ratios in the drawings are merely examples, and are not limited thereto, and shapes, etc. in the drawings may be partially exaggerated for convenience of explanation.

FIG. 1 is a cross-sectional view schematically showing the cross-sectional structure of a motor 1 according to an embodiment. FIG. 2 is a cross-sectional view of the rotor 30 (a cross-sectional view taken along a plane perpendicular to the axial direction). Note that in FIG. 2 and the like, for ease of viewing, only some of the parts having the same attribute may be labeled with reference numerals.

FIG. 1 shows a rotating shaft 12 of the motor 1. As shown in FIG. In the following description, the axial direction refers to the direction in which the rotating shaft (rotation center) 12 of the motor 1 extends, the axially outer side refers to the side away from the axial center of the rotor core 32, and the axially inner side refers to the side away from the axial center of the rotor core 32. refers to the side toward the axial center of the rotor core 32. Further, the radial direction refers to the radial direction centered on the rotating shaft 12, the radially outer side refers to the side away from the rotating shaft 12, and the radially inner side refers to the side facing the rotating shaft 12. Further, the circumferential direction corresponds to the direction of rotation around the rotating shaft 12.

The motor 1 may be a vehicle drive motor used, for example, in a hybrid vehicle or an electric vehicle. However, the motor 1 may be used for any other purpose.

The motor 1 is of an inner rotor type, and the stator 21 is provided so as to surround the rotor 30 on the outside in the radial direction. The stator 21 is fixed to the motor housing 10 on the outside in the radial direction. The stator 21 includes a stator core 211 made of, for example, an annular magnetic laminated steel plate, and a plurality of slots (not shown) around which the coils 22 are wound are formed inside the stator core 211 in the radial direction.

The rotor 30 is arranged radially inside the stator 21.

The rotor 30 includes a rotor core 32, a rotor shaft 34, end plates 35A and 35B, and a permanent magnet 62.

The rotor core 32 is fixed to the radially outer surface of the rotor shaft 34 and rotates together with the rotor shaft 34. The rotor core 32 has a shaft hole 320 (see FIG. 2), into which the rotor shaft 34 is fitted. Rotor core 32 may be secured to rotor shaft 34 by a shrink fit, press fit, or the like. For example, the rotor core 32 may be coupled to the rotor shaft 34 by key coupling or spline coupling. The rotor shaft 34 is rotatably supported by the motor housing 10 via bearings 14a, 14b. Note that the rotor shaft 34 defines the rotation axis 12 of the motor 1.

The rotor core 32 is formed of, for example, an annular magnetic laminated steel plate. A permanent magnet 62 (see FIG. 2) is embedded inside the rotor core 32. That is, the rotor core 32 has a magnet hole 322 (see FIG. 2) that penetrates in the axial direction, and the permanent magnet 62 is inserted and fixed in the magnet hole 322. In addition, in a modified example, the rotor core 32 may be formed of a green compact obtained by compressing and solidifying magnetic powder.

As shown in FIG. 2, the rotor core 32 has a configuration that is rotationally symmetrical about the rotating shaft 12 when viewed in the axial direction. In the example shown in FIG. 2, the rotor core 32 is configured such that each set of permanent magnets 62 overlaps each time the rotor core 32 rotates 45 degrees about the rotating shaft 12.

The plurality of permanent magnets 62 may be made of neodymium or the like. In this embodiment, as an example, as shown in FIG. 2, the plurality of permanent magnets 62 are arranged in pairs when viewed in the axial direction. In this case, a common magnetic pole is formed between the pair of permanent magnets 62. Note that the plurality of permanent magnets 62 are arranged in such a manner that south poles and north poles alternate in the circumferential direction. In this example, the number of magnetic poles is eight, but the number of magnetic poles is arbitrary. Further, in this embodiment, the permanent magnets 62 have the same straight shape when viewed in the axial direction, but may have different shapes. Further, at least one of the permanent magnets 62 may have an arcuate shape when viewed in the axial direction. Further, another pair of permanent magnets may be arranged at a different radial position from the pair of permanent magnets 62. In this case, the fixing structure and the like related to the permanent magnet 62 described below can be similarly applied to other permanent magnets.

Although the motor 1 having a specific structure is shown in FIG. 1, the structure of the motor 1 is not limited to this specific structure. For example, in FIG. 1, rotor shaft 34 is hollow, but may be solid.

Next, the fixing structure of the permanent magnets 62 in the rotor core 32 will be described in detail with reference to FIG. 3 and subsequent figures. Although a configuration related to one magnetic pole will be described below, the same may be applied to configurations related to other magnetic poles.

FIG. 3 is a plan view schematically showing the fixing structure of the permanent magnet 62 in the rotor core 32 according to this embodiment, and is an enlarged view of a portion related to one magnetic pole shown in FIG. 2. The configuration related to one magnetic pole is basically symmetrical with respect to the d-axis (indicated in English as "d-axis" in FIG. 3). Note that the d-axis corresponds to the direction of the magnetic field generated by the permanent magnets 62 disposed on the rotor 30. FIG. 4 is a schematic cross-sectional view taken along line AA in FIG. FIG. 5 is an enlarged view of part Q1 in FIG. 4, and is a schematic explanatory diagram of the anchor effect.

In FIG. 4, the Z direction and the Z1 side and Z2 side, which are both sides thereof, are defined. The Z direction is a direction parallel to the axial direction of the motor 1. In the following description, the Z direction corresponds to the vertical direction for the sake of explanation, but it may be different from the vertical direction when the motor 1 is mounted in a vehicle. The Z1 side and the Z2 side represent a relative positional relationship, with the Z1 side corresponding to the upper side.

In this embodiment, as shown in FIGS. 3 and 4, the permanent magnet 62 is fixed within the magnet hole 322 of the rotor core 32 by a resin material layer 72.

The resin material layer 72 may be formed of, for example, a thermosetting resin or a thermoplastic resin. The method for forming the resin material layer 72 will be explained in detail later. As schematically shown in FIG. 5, the resin material layer 72 is bonded to both the permanent magnet 62 and the rotor core 32 with an anchor effect. In this case, the anchor effect on the permanent magnet 62 side may be realized by roughening the insulating layer 624 provided as a surface coating of the permanent magnet 62. The anchor effect on the rotor core 32 side may be realized by forming the rotor core 32 from laminated steel plates. Further, the anchoring effect on the rotor core 32 side is enhanced by the resin placement process "under no pressure", which will be described later.

As shown in FIG. 4, the resin material layer 72 is bonded to the permanent magnet 62 in such a manner that both axial end surfaces 621 and 622 of the permanent magnet 62 are exposed. That is, the resin material layer 72 is bonded only to the side surface of the permanent magnet 62 in the direction intersecting the axial direction.

In the example shown in FIG. 4, the resin material layer 72 is bonded to the outer bridge 42 (the outer bridge 42 on the outer circumferential surface 328 side of the rotor core 32) of both sides of the permanent magnet 62 in the circumferential direction. Alternatively or additionally, a resin material layer bonded to the central bridge 44 side may be provided. Also in this case, the resin material layer bonded to the central bridge 44 side of the permanent magnet 62 can be bonded to the peripheral wall surface of the magnet hole 322, thereby fixing the permanent magnet 62 to the rotor core 32.

Here, the effects of this example will be explained with reference to the comparative example shown in FIG.

In the comparative example shown in FIG. 6, the resin material layer 72' is provided so as to cover the Z1 side end surface 621 of both end surfaces 621 and 622 of the permanent magnet 62 in the axial direction. In this case, by increasing the bonding area between the resin material layer 72' and the permanent magnet 62, the bonding strength between the resin material layer 72' and the permanent magnet 62 can be increased. As mentioned above in the section ``Problems to be Solved'', the problem of thermal stress arises. That is, due to the difference in linear expansion coefficient between the permanent magnet 62 and the resin material layer 72', thermal stress caused by the difference in axial expansion and contraction that occurs between the two when the temperature changes becomes a problem. . In the comparative example, the resin material layer 72' exposes the end surface 622 on the Z2 side of both axial end surfaces 621 and 622 of the permanent magnet 62, so thermal stress caused by the difference in expansion and contraction is reduced. However, on the Z1 side, thermal stress caused by local differences in expansion and contraction still poses a problem.

In contrast, according to this embodiment, as described above, the resin material layer 72 is bonded to the permanent magnet 62 in a manner that exposes both end surfaces 621 and 622 of the permanent magnet 62 in the axial direction. On both sides of the magnet 62 in the axial direction, the permanent magnet 62 and the resin material layer 72 can be displaced with respect to each other without being substantially constrained in the axial direction. As a result, according to this embodiment, the inconvenience that occurs in the comparative example (the problem of thermal stress caused by the difference in expansion and contraction in the axial direction between the magnet 62 and the permanent magnet 62) can be reduced.

In this embodiment, the resin material layer 72 preferably has one end surface 7261 of the two axial end surfaces 7261 and 7262 with respect to the axial end surface 326 of the rotor core 32 more than the other end surface 7262. located on the inside in the axial direction. In the example shown in FIG. 4, the end surface 7261 on the Z1 side is located axially more inside than the end surface 7262 on the Z2 side with respect to the axial end surface 326 of the rotor core 32. In this embodiment, the end surface 7262 on the Z2 side is substantially flush with the axial end surface 326, whereas the end surface 7261 on the Z1 side is located significantly inside the axial end surface 326 in the axial direction. In this case, the space SP1 on the Z1 side with respect to the end surface 7262 easily faces the permanent magnet 62 in the radial direction. This improves workability when taking out the permanent magnet 62 during disassembly or the like. That is, it becomes easy to take out the permanent magnet 62 by inserting a tool or the like into the space SP1, and the space SP1 can be effectively used as a work area when taking out the permanent magnet 62. This will make it possible to contribute to achieving each of the Sustainable Development Goals (SDGs). Hereinafter, of both axial end surfaces 7261 and 7262 of the resin material layer 72, the end surface 7261 that is axially adjacent to the space SP1 is also referred to as the "space forming side end surface 7261."

Such an axially asymmetrical structure of the resin material layer 72 can also be effectively utilized when the rotor core 32 is formed by rolling a plurality of laminated blocks. 7 and 8 are explanatory diagrams of a configuration in which the rotor core 32 can be formed by rolling a plurality of laminated blocks.

For example, in the example shown in FIG. 7, the rotor core 32A is formed by four laminated blocks 325(1) to 325(4). Each of the laminated blocks 325(1) to 325(4) is provided with a permanent magnet 62 and a resin material layer 72 in a form separated from each other. In the example shown in FIG. ) and 325(3)). On the other hand, the two upper laminated blocks 325(1) and 325(2) and the two lower laminated blocks 325(3) and 325(4) are asymmetrical. For example, of the two upper laminated blocks 325(1) and 325(2), the upper laminated block 325(1) has the end surface 7261 on the space forming side facing the Z2 side, and the lower laminated block 325( In 2), the end surface 7261 on the space forming side faces the Z1 side.

In this case, the rotor core 32A, which is formed by rolling a plurality of laminated blocks 325(1) to 325(4), is constructed by combining the axially asymmetrical laminated blocks 325(1) to 325(4), and can have an axially symmetrical configuration. That is, the rotor core 32A is a plane passing through the axial center of the rotor core 32A, and can realize a symmetrical configuration with respect to a plane perpendicular to the axial direction.

Further, in the example shown in FIG. 8, the rotor core 32B is similarly formed by four laminated blocks 325(1) to 325(4), but the upper two laminated blocks 325(1) and 325(2) However, this is different from the rotor core 32A shown in FIG. In this case, of the two upper laminated blocks 325(1) and 325(2), the upper laminated block 325(1) has an end surface 7261 on the space forming side facing the Z1 side, and the lower laminated block 325(1) faces the Z1 side. In (2), the end surface 7261 on the space forming side faces the Z2 side. In this case, the rotor core 32B formed by rolling the plurality of laminated blocks 325(1) to 325(4) can have an asymmetrical configuration in the axial direction as a whole. Such asymmetry may be used to adjust the weight balance with other components.

Next, a method for manufacturing the motor 1 according to this embodiment will be described with reference to FIG. 9 and subsequent figures.

In the following description, as mentioned above, the axial direction refers to the direction in which the central axis I0 of the rotor core 32 (work W) corresponding to the rotating shaft 12 of the motor 1 extends, and the radial direction refers to the center of the rotor core 32. It refers to the radial direction centered on the axis I0. Therefore, the radially outer side refers to the side away from the central axis I0 of the rotor core 32, and the radially inner side I0 refers to the side facing the central axis I0 of the rotor core 32. Further, the circumferential direction corresponds to the rotation direction of the rotor core 32 around the central axis I0.

FIG. 9 is a flowchart schematically showing the flow of the method for manufacturing the motor 1 according to this embodiment. 10 to 17 are explanatory diagrams of specific steps in the manufacturing method shown in FIG. 9. Specifically, FIG. 10 is an explanatory diagram of the workpiece support process, FIG. 11 is an explanatory diagram of the magnet arrangement process, and FIG. 12 is an explanatory diagram of the nozzle positioning process, and each of them is an explanatory diagram of the workpiece support process, and FIG. 12 is an explanatory diagram of the nozzle positioning process. FIG. 3 is a cross-sectional view schematically showing the state. FIG. 13 is an explanatory diagram of the resin placement process, and is a cross-sectional view schematically showing each state ST61, ST62, ST63, and ST64 in the resin placement process with respect to one magnet hole 322. 14 and 15 are explanatory diagrams of the resin placement device 130 for realizing the resin placement process, and FIG. 14 schematically shows the state before the start of the resin placement process (the state after the nozzle positioning process is completed). FIG. 15 is a cross-sectional view schematically showing the state during the resin placement step. FIG. 16 is an explanatory diagram of an example of the resin injection machine 134. FIG. 17 is an explanatory view of the resin curing process (axial force applying process), and is a cross-sectional view schematically showing the state during the process.

This manufacturing method first includes a steel plate lamination process (step S1) in which a plurality of steel plates 3250 are laminated as a preparatory process for preparing the workpiece W of the rotor core 32. Note that, as described above with reference to FIGS. 7 and 8, the workpiece W of the rotor core 32 may be a unit of the laminated block 325.

Next, the present manufacturing method includes a workpiece supporting step (step S2) in which the workpiece W is placed on the support jig 120, as schematically shown in FIG. The support jig 120 is one element of the manufacturing apparatus 100, and may support the workpiece W while transporting the workpiece W between each process. In this case, the support jig 120 may itself be in the form of a movable conveyor or the like, or may be in the form of a transport tray that is placed on a conveyor or the like to be transported. Further, the support jig 120 may be configured to be gripped by a transport robot.

Next, the present manufacturing method includes a magnet placement step (step S3) of placing a permanent magnet 62 in the magnet hole 322 of the workpiece W on the support jig 120, as schematically shown in FIG. The permanent magnet 62 may be arranged in such a manner that the lower end surface 622 contacts the surface of the support jig 120 without a gap (that is, in surface contact).

Next, as schematically shown in FIG. 12, this manufacturing method includes a nozzle positioning step (step S5) of positioning the nozzle 131 of the resin placement device 130 within the magnet hole 322 of the work W on the support jig 120. including. The nozzle 131 of the resin placement device 130 is positioned so that it can be inserted into the remaining space in the magnet hole 322 into which the permanent magnet 62 is inserted. For example, in the example shown in FIG. 13, the nozzle 131 is positioned such that it can be inserted into the space related to the flux barrier on one circumferential side of the permanent magnet 62 (the outer bridge 42 side). Hereinafter, the remaining space in the magnet hole 322 into which the permanent magnet 62 is inserted will also be referred to as a "nozzle insertion space."

Next, the present manufacturing method includes a resin placement step (step S6) in which a resin material for forming the resin material layer 72 described above is placed in the magnet hole 322. In this case, the resin material does not need to fill the entire nozzle insertion space, and is arranged in such a manner that a part of the flux barrier remains as a space (a space where the resin material layer 72 does not exist), as shown in FIG. It's okay to be.

In this example, the resin material has a relatively high viscosity, but is placed in a pre-cured state (flowable state). Therefore, the resin material placed in the magnet hole 322 flows downward due to its own weight and reaches the surface of the support jig 120. However, if the resin material has a relatively high viscosity and is arranged in such a manner that the lower end surface 622 of the permanent magnet 62 is in contact with the surface of the support jig 120 without any gap, the resin material may be placed under the permanent magnet 62. There is no substantial penetration between the side end surface 622 and the surface of the support jig 120. Therefore, as described above, the resin material layer 72 can be formed in such a manner that the lower end surface 622 of the permanent magnet 62 is exposed.

In this manufacturing method, in the resin placement step (step S6), the nozzle 131, which is one element of the manufacturing apparatus 100, is connected so that its discharge port 1310 is connected to the axial end surface 326 of the rotor core 32 (the axial end surface 326 on the insertion side, the same applies hereinafter). (see state ST61 in FIG. 13), while discharging the resin material from the discharge port 1310. Further, in the resin placement step (step S6), the axial position of the discharge port 1310 of the nozzle 131 is determined within the range where the discharge port 1310 of the nozzle 131 is located axially inside (Z2 side) from the axial end surface 326 of the rotor core 32. This may include discharging the resin material from the discharge port 1310 while changing the amount. Thereby, the resin material layer 72 can be formed in such a manner that the upper end surface 621 is exposed as described above.

In the resin placement step (step S6) shown in FIG. 13, after the discharge port 1310 of the nozzle 131 is inserted to the vicinity of the lower part of the nozzle insertion space (see state ST61), discharge of the resin material 90 is started. In this case, the resin material 90 is discharged from the nozzle 131 while the nozzle 131 is gradually raised (see state ST62) within the range where the discharge port 1310 is located axially inside (Z2 side) from the axial end surface 326 of the rotor core 32. It is discharged. Then, when the discharge port 1310 of the nozzle 131 reaches the discharge stop position axially inner than the axial end surface 326 of the rotor core 32 (see state ST63), the discharge of the resin material 90 from the nozzle 131 is stopped, and the resin arrangement step (Step S6) is completed (see state ST64).

The resin placement device 130 that can be used in this manufacturing method is arbitrary as long as it has the above-mentioned nozzle 131, but it may have a configuration as shown in FIGS. 14 to 16, for example.

In the example shown in FIGS. 14 to 16, the resin placement device 130, which is one element of the manufacturing apparatus 100, includes a resin injection machine 134, a table section 135, and a mold section 136.

As shown in FIG. 16, the resin injection machine 134 includes a resin material input port 1340B for charging solid resin, and a plunger 1345 for injecting the molten resin material sent out via a screw 1346 from an injection port 1340A. Equipped with The table portion 135 may be fixed to the equipment. A mold section 136 is installed (supported) on the table section 135 . The mold section 136 includes paths for injection molding resin materials such as sprues, runners, and gates. The resin material path has a branch for communicating with each nozzle 131 provided corresponding to each magnet hole 322. The mold section 136 simultaneously places the resin material from the resin injection machine 134 into each magnet hole 322 through each nozzle 131 . Specifically, the mold section 136 is configured such that resin is injected from the injection port 1340A to the input port 1360A of the mold section 136, and furthermore, resin material is injected from each discharge port 1310 of the mold section 136. At the same time, a resin material is placed inside the magnet hole 322 of the magnet hole 322 . Note that in this embodiment, the resin injection machine 134 and the mold section 136 are separate bodies, but they may be integrated.

In this embodiment, the resin placement device 130 further includes a lifting mechanism 138 that lifts and lowers the support jig 120. The lifting mechanism 138 can change the vertical position of the workpiece W with respect to the mold part 136, as shown in FIGS. 14 and 15. Thereby, the position of the discharge port 1310 of the nozzle 131 relative to the workpiece W can be changed in the manner described above with reference to FIG. 13. In addition, in a modified example, the table portion 135 side may be movable up and down.

Although further details of the resin placement device 130 will not be explained here, the configurations of the resin injection machine 134, table section 135, and mold section (runner section) 136 are incorporated herein by reference. It may be substantially the same as the same element described in WO 2022/091389, the disclosure of which is incorporated. Furthermore, in the examples shown in FIGS. 14 to 16, the resin material is placed in the plurality of magnet holes 322 at the same time, but while the workpiece W is rotated, the resin material is placed in each of the plurality of magnet holes 322 one by one. may be done.

In this manufacturing method, the resin placement step (step S6) is performed without substantially pressing the rotor core 32 in the axial direction (that is, without applying any axial force to the rotor core 32). Therefore, a pressing mechanism that clamps and presses the workpiece W from above and below is substantially unnecessary, and the equipment can be simplified.

Note that in filling (injection molding) with a resin material using a general injection molding machine (the same applies to the resin injection machine 134), a pressure greater than at least atmospheric pressure is applied to the filled resin material from the viewpoint of preventing voids, etc. There is a tendency to maintain the injection pressure relatively high in order to keep the injection pressure constant. If the injection pressure is increased, the possibility that the resin material will leak out from between the steel plates 3250 forming the rotor core 32 increases. Note that such leakage of the resin material may cause deterioration in the characteristics of the rotor 30 into which the rotor core 32 is incorporated.

In this regard, in this embodiment, since the bonding force of the resin material layer 72 due to the above-mentioned anchor effect is high, even if voids or the like occur in the resin material layer 72, the necessary fixing strength can be easily ensured. Therefore, according to this embodiment, there is no need to apply a pressure higher than at least atmospheric pressure to the filled resin material, so it is possible to reduce the need for relatively high injection pressure. As a result, in the present manufacturing method, the possibility of the resin material leaking out from between the steel plates 3250 can be reduced without applying an axial force to the rotor core 32 in the resin arrangement step.

Particularly, in this embodiment, the resin material is placed in the magnet hole 322 in a pre-hardened state while the magnet hole 322 of the workpiece W is exposed to atmospheric pressure. As a result, the pressure of the resin material injected into the magnet holes 322 is immediately reduced, and the possibility that the resin material leaks from between the steel plates 3250 can be significantly reduced. Note that the state in which the inside of the magnet hole 322 of the workpiece W is released to atmospheric pressure is not simply a state in which it is communicated with the atmosphere through a vent hole, but a state in which, for example, the upper part of the magnet hole 322 is open to the atmosphere. Including etc.

Further, in this manufacturing method, the resin material is placed under no pressure without applying an axial force to the rotor core 32 (that is, in a state where the upper (Z1 side) axial end surface 326 of the rotor core 32 is released). As a result, the resin material can be joined to the rotor core 32 with a larger gap between the steel plates 3250 of the rotor core 32 than when the resin material is placed under pressure, and as a result, the above-mentioned anchor effect can be achieved. (i.e., the "pressure-free" resin placement process enhances the anchoring effect). Further, it is possible to omit or simplify the pressing mechanism that clamps and presses the workpiece W from above and below. That is, compared to the case where the resin material is placed under pressure, resources such as jigs and energy for pressurization can be reduced.

Next, the manufacturing method includes a resin curing step (step S7) of curing the resin material placed in the magnet holes 322 while applying an axial force to the rotor core 32. The resin curing process (step S7) may be performed after the workpiece W is taken out from the resin placement device 130. The resin curing step (step S7) includes thermosetting the resin material by heating the work W while applying an axial force to the rotor core 32 of the work W.

In the example shown in FIG. 17, the heating device 160, which is one element of the manufacturing apparatus 100, is disposed radially inside and radially outside the rotor core 32 of the workpiece W, and heats and hardens the resin material 90 via the rotor core 32. Can be done. The manufacturing apparatus 100 also includes a pressing jig 170 that applies axial force to the rotor core 32, as shown in FIG. By doing so (see pressing force F90), an axial force can be applied to the rotor core 32 (see axial force F92). In addition, in a modified example, pressing may be realized using a lower jig different from the support jig 120. For example, the resin curing process (step S7) may be realized using a mold jig that includes the heating device 160 and is capable of clamping the mold in the vertical direction. Moreover, the heating device may be realized by a heating furnace.

In this manufacturing method, the magnitude of the axial force F92 is preferably set based on the magnitude of the axial force that the rotor core 32 receives when the rotor 30 is assembled using the rotor core 32 in the subsequent step S8. The axial force that the rotor core 32 receives when assembling the rotor 30 may correspond to, for example, the axial force that is generated by being held between the end plates 35A (see force F10 in FIG. 1). In this case, the magnitude of the axial force F92 may correspond to a designed value or a measured value of the magnitude of the axial force F10. Note that the design value does not necessarily have to be a value described in a design drawing, but is a concept that includes a suitable value and a target value obtained in design through analysis or the like.

In this way, in this manufacturing method, the magnitude of the axial force F92 generated on the workpiece W is determined by the axial force F10 (hereinafter also simply referred to as "axial force F10 in the mounted state") that the rotor core 32 receives when assembling the rotor 30. It is set based on the size of

By the way, unlike the present manufacturing method, a configuration is also possible in which no axial force is applied to the rotor core 32 of the workpiece W (that is, the magnitude of the axial force F92 is set to 0) in the resin curing process. Alternatively, unlike the present manufacturing method, it is also possible to apply an axial force significantly larger than the axial force F10 in the mounted state in the resin curing process.

However, in these configurations, significant stress is generated in the resin material layer 72 due to a significant difference between the axial force applied to the rotor core 32 in the resin curing process and the axial force F10 in the mounted state. It becomes easier. Specifically, if there is a significant difference between the axial force applied to the rotor core 32 in the resin curing process and the axial force F10 in the mounted state, the axial length of the rotor core 32 changes before and after the mounting. Due to such a change in the axial length, significant stress is likely to occur in the resin material layer 72 bonded to the rotor core 32. Such a problem occurs in both a configuration in which no axial force is applied to the rotor core 32 of the workpiece W in the resin curing process, and a configuration in which an axial force significantly larger than the axial force F10 in the mounted state is applied in the resin curing process. also occurs.

On the other hand, according to the present embodiment, in consideration of the relationship between the axial force applied to the rotor core 32 in the resin curing process and the axial force F10 in the mounted state, the difference between them is reduced. A resin curing step is performed. Thereby, in the mounted state in which the rotor core 32 is incorporated into the motor 1, stress that may be generated in the resin material layer 72 due to the axial force F10 in the mounted state can be reduced or eliminated.

Furthermore, in the present manufacturing method, in the resin curing step, an axial force is applied to the rotor core 32 as described above, while in the resin arrangement step (step S6) described above, an axial force is applied to the rotor core 32 as described above. do not. Therefore, the resin curing process can be performed with the workpiece W taken out from the resin placement device 130 used in the resin placement process (step S6) described above. That is, the pressing jig 170 can be placed separately from the resin placement device 130. Thereby, the time during which the resin placement device 130 is restrained for one workpiece W can be shortened, and the resin placement process (step S6) can be efficiently executed for a plurality of workpieces W.

Next, the present manufacturing method includes a step of assembling the rotor 30 from the rotor core 32 after step S7 (step S8). For example, the rotor core 32 is fixed (for example, press-fitted) to the rotor shaft 34, and the end plates 35A and 35B are attached. As a result, an axial force F10 (see FIG. 1) in the mounted state is applied to the rotor core 32. Note that the rotor 30 assembled in this manner is assembled into a case (not shown) together with the stator 21 and the like, and the motor 1 is assembled.

Next, a preferred setting method for the injection pressure of the resin injection machine 134 in the resin placement step (step S6) described above will be described with reference to FIGS. 18 to 21. Note that in this embodiment, the resin injection machine 134 can also be used in a form that is not incorporated into the injection molding machine (resin placement device 130). That is, a resin injection machine having a plunger and a nozzle corresponding to the nozzle 131 in the discharge portion may be used instead of the resin placement device 130. In this case, in the following description and the above description, the term "injection" can be replaced with the term "injection". Therefore, the term "injection pressure" can be read as the term "injection pressure".

FIG. 18 is a schematic flowchart relating to an example of a method for setting the resin injection machine 134. FIG. 19 is a schematic cross-sectional view illustrating the press 142.

In step S61, the method for setting the resin injection machine 134 includes obtaining values of manufacturing parameters related to the steel plate lamination process (step S1) described above with reference to FIG.

In the example shown in FIGS. 18 and 19, the manufacturing parameters include a design value or a measured value of the pressing force by the press machine 142 when bonding the steel plates 3250 of the rotor core 32.

Here, an example of the press machine 142 that is a prerequisite will be described with reference to FIG. 19.

In the example shown in FIG. 19, the press machine 142 cooperates with the squeeze ring 144 and the support device 146 to realize pressing and lamination at the same time. Specifically, the press machine 142 may be a part of a progressive die, and may be a press machine that punches out the outer shape (outer contour) of the steel plate 3250. The press 142 includes, for example, a vertically movable punch 1421 and a die 1422. When the punch 1421 enters the die 1422, a material (for example, a rolled sheet that has undergone various pre-processing processes) is punched into a steel plate 3250. Note that the press machine 142 itself may be realized, for example, by a corresponding part of the press processing apparatus described in WO2019/066032, the disclosure of which is incorporated into the present specification by reference here.

The press machine 142 uses axial force (for example, force from a hydraulic cylinder) during press processing to apply pressure for joining (caulking joining) by dowels (not shown) formed on the steel plates 3250. It can be achieved. That is, the press machine 142 performs press processing (press forming) to punch out a new steel plate 3250, and at the same time presses the press-formed steel plate 3250 against the uppermost steel plate 3250 of the workpiece W below. They may be bonded by pressing.

Squeeze ring 144 has a cylindrical shape and is placed below die 1422. Squeeze ring 144 may be secured to die 1422 in such a manner that it is integral with die 1422.

The support device 146 is, for example, in the form of a back pressure pad, and cooperates with the punch 1421 to realize pressurization for bonding by dowels associated with the above-mentioned press processing. That is, as shown in FIG. 19, the punch 1421 generates a reaction force F2 to the force F1 that presses the workpiece W downward, thereby realizing the joining of the steel plates 3250 by the above-mentioned pressurization.

In the example shown in FIG. 19, the designed value or measured value of the pressing force by the press 142 may correspond to the designed value or measured value of the force F1. Alternatively, the designed or measured value of the pressing force by the press 142 may correspond to the designed or measured value of the reaction force F2 that is correlated to the force F1. Further, in the configuration in which each stacked block 325 is rolled as described above, the design value or measured value of the pressing force by the press 142 may include the same value when the stacked blocks 325 are combined.

Next, in step S62, the setting method of the resin injection machine 134 is such that the manufacturing parameters obtained in step S61 are set so that the resin material does not leak out between the steel plates 3250 during the resin placement process (step S6) described above. This includes adjusting the injection pressure of the resin injector 134 as appropriate based on the value. In this case, the injection pressure of the resin injection machine 134 may be adjusted to a target pressure corresponding to the value of the manufacturing parameter obtained in step S61. In this case, the target pressure may correspond to the pressure generated between the steel plates 3250 due to the pressing force by the press 142 (see force F1 in FIG. 19), as described above.

Note that the setting method of the resin injection machine 134 shown in FIG. 18 does not need to be executed for each workpiece W, and may be executed regularly or irregularly. Further, the setting method of the resin injection machine 134 may be adapted at the development and design stage, or may be executed only at the start of mass production. In this way, the injection pressure of the resin injection machine 134 can be adjusted at appropriate timing, and can also respond to changes over time, for example.

In this way, according to the example shown in FIGS. 18 and 19, the injection pressure of the resin injection machine 134 can be adjusted according to the pressing force of the press machine 142 when joining the steel plates 3250 of the rotor core 32, so that the steel plates It is possible to reduce the possibility that the resin material leaks from between the 3250 and 3250.

In the examples shown in FIGS. 18 and 19, the manufacturing parameters include the design value or measured value of the pressing force by the press machine 142 when joining the steel plates 3250 of the rotor core 32, but the manufacturing parameters are not limited to this. I can't. For example, the manufacturing parameters may include a calculated value or a measured value of the force required to separate the steel plates 3250, a calculated value or a measured value of the injection pressure when the resin material leaks from between the steel plates 3250, etc. . Even such manufacturing parameters can be used to adjust the injection pressure of the resin injection machine 134, similar to the pressing force of the press machine 142 described above, so that the possibility of resin material leaking from between the steel plates 3250 can be reduced.

FIG. 20 is an explanatory diagram of the force required to separate the steel plates 3250. FIG. 20 shows an outward force in the axial direction that acts on both end surfaces of the workpiece W as a force required to separate the steel plates 3250. For example, the measurement of the force F20 required to separate the steel plates 3250 may be performed periodically or irregularly on the workpiece W obtained in the steel plate lamination process (step S1). good. Alternatively, the force F20 may be derived or measured at the development and design stage, or may be measured only at the start of mass production. In this case, the injection pressure of the resin injection machine 134 can be adjusted with high precision based on the measurement results.

In this case, the injection pressure of the resin injection machine 134 may be adapted to be significantly smaller than the pressure related to the force F20 required to peel the steel plates 3250 (i.e., the pressure required to peel the steel plates 3250 apart). . Thereby, the possibility that the resin material leaks from between the steel plates 3250 during the resin placement process (step S6) can be reduced or eliminated.

FIG. 21 is an explanatory diagram of the injection pressure when the resin material 90 leaks from between the steel plates 3250. In FIG. 21, in an enlarged view of part Q2 in FIG. 20, a state in which the resin material 90 is leaking from between the steel plates 3250 is schematically shown together with the force (see force F21) that acts between the steel plates 3250 due to the resin material. It is shown.

As described above, if the injection pressure of the resin injection machine 134 in the resin placement step (step S6) is set to a relatively high value, there is a high possibility that the resin material will leak from between the steel plates 3250 forming the rotor core 32. Therefore, the injection pressure of the resin injector 134 may be adapted to be significantly lower than the injection pressure at which the resin material leaks from between the steel plates 3250. Thereby, the possibility that the resin material leaks from between the steel plates 3250 during the resin placement process (step S6) can be reduced or eliminated.

By the way, a preferable setting method for the injection pressure of the resin injection machine 134 described above with reference to FIGS. 18 to 21 is applicable not only to the resin placement step (step S6) described above, but also to It can also be applied to filling (injection) of other resin materials into. For example, in the embodiment described above, the permanent magnet 62 is a sintered magnet, but it can also be formed from a bonded magnet. In this case, the preferred setting method for the injection pressure of the resin injection machine 134 described above can also be applied to a configuration in which the magnet hole 322 is filled with a bonded magnet material (a material that is a mixture of magnet powder and a binding material). It is.

Although each embodiment has been described in detail above, it is not limited to a specific embodiment, and various modifications and changes can be made within the scope of the claims. It is also possible to combine all or a plurality of the components of the embodiments described above.

For example, in the embodiment described above, the upper surface of the support jig 120 (the surface that contacts the axial end surface 326 of the rotor core 32) is a flat plane, but the upper surface is not limited to this. The upper surface of the support jig 120 may be formed so that only the plane portion that abuts the end surface 622 of the permanent magnet 62 is convex above the other plane portions (toward the Z1 side). Note that in this case as well, the resin material layer 72 can be prevented from being formed on the end surface 622 of the permanent magnet 62 by bringing the upper surface of the support jig 120 into surface contact with the end surface 622 of the permanent magnet 62.

Furthermore, in the embodiments described above, the method of injection molding or resin injection is arbitrary, and may include, for example, transfer molding, resin injection by compression molding using a cylinder, and the like.

1... Motor (rotating electrical machine), 30... Rotor (rotor for rotating electrical machine), 32, 32A... Rotor core (laminated iron core), 322... Magnet hole, 3250... Steel plate, 62... - Permanent magnet, 72... Resin material layer, 130... Resin placement device (injection molding machine), 134... Resin injection machine, 142... Press machine, W... Work

Claims (5)

a step of preparing a steel plate for a rotor core and having a magnet hole;
forming an integrated laminated core by laminating a plurality of the steel plates and pressing them in the axial direction;
a resin placement step of injecting or injecting a resin material into the magnet hole of the laminated core through an injection molding machine or a resin injection machine,
The method for manufacturing a rotor for a rotating electrical machine, wherein the injection pressure or injection pressure of the resin material in the resin placement step is set based on the value of a parameter related to the pressing force when forming the laminated core. The resin placement step includes forming a resin material layer bonded to both the permanent magnet placed in the magnet hole and the laminated core, or injecting or injecting the resin material for a bonded magnet. A method for manufacturing a rotor for a rotating electric machine according to claim 1. The value of the parameter is a designed value or a measured value of the pressing force by a press when bonding the steel plates, a calculated value or a measured value of the force required to peel the steel plates in the laminated core, and The rotary electric machine according to claim 1, comprising at least one of a calculated value or a measured value of the injection pressure or the injection pressure when the resin material leaks from between the steel plates in the laminated core. Rotor manufacturing method. further comprising a measuring step of regularly or irregularly measuring the value of the parameter,
The method for manufacturing a rotor for a rotating electrical machine according to claim 1, wherein the resin placement step includes adjusting the injection pressure or injection pressure of the resin material based on the result of the measurement step. Any one of claims 1 to 4, wherein the resin arranging step is performed with one axial end face of the rotor core open and the inside of the magnet hole open to atmospheric pressure. A method for manufacturing a rotor for a rotating electrical machine according to item 1.