JP2024030565A - Stator manufacturing method for rotating electric machines - Google Patents

Abstract

[Problem] To efficiently realize draining of liquid resin material when lifting a workpiece from a tank. [Solution] A preparation process for preparing a workpiece in which a plurality of coil pieces forming a stator coil are attached to a stator core, the tips of one coil piece and the other coil piece at one end in the axial direction. A preparation process of preparing a workpiece in which the two parts are joined together; After the preparation process, a dipping process of immersing the workpiece in a tank of liquid resin material so that the part to be impregnated including the joint between the tips is immersed; After the process, at the elevated position of the workpiece where the part to be impregnated is away from the tank, and in the first posture of the workpiece where the part to be impregnated faces the tank in the vertical direction, around the central axis of the workpiece corresponding to the central axis of the stator. Disclosed is a method for manufacturing a stator for a rotating electric machine, including a first rotation step of rotating a workpiece. [Selection diagram] Figure 1

Description

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

A workpiece for a rotating electrical machine in which a plurality of coil pieces forming a stator coil are attached to a stator core is prepared, and the tips of the plurality of coil pieces are joined to each other at one end in the axial direction of the workpiece, and the joined part (exposed conductor part) A method of manufacturing a stator for a rotating electric machine is known in which a region to be impregnated including a part of the rotor is impregnated with a liquid resin material, and then the liquid resin material is cured to cover the joint portion with an insulating coating of the resin material.

JP2021-136787A

By the way, in a manufacturing method for forming an insulating coating of this type of resin material, after a workpiece is immersed in a tank of liquid resin material, it is possible to efficiently prevent liquid draining (liquid draining related to liquid resin material) when the workpiece is pulled up. difficult to realize.

Therefore, in one aspect, an object of the present disclosure is to efficiently realize draining of liquid resin material when lifting a workpiece from a tank.

One aspect of the present invention is a preparation step for preparing a workpiece in which a plurality of coil pieces forming a stator coil are attached to a stator core, wherein one of the coil pieces and the other one of the coil pieces are arranged at one end in the axial direction. a preparation step of preparing the workpiece whose tips are joined to each other;
After the preparation step, a dipping step of immersing the workpiece in a tank of liquid resin material so that the region to be impregnated including the joint between the tips is immersed;
After the dipping step, the stator center is placed in a raised position of the workpiece where the region to be impregnated is away from the tank, and in a first posture of the workpiece in which the region to be impregnated faces the tank in the vertical direction. A method for manufacturing a stator for a rotating electric machine is provided, including a first rotation step of rotating the workpiece around a center axis of the workpiece corresponding to the shaft.

In one aspect, according to the present disclosure, it is possible to efficiently drain the liquid resin material when pulling up the work from the tank.

It is a schematic flowchart which shows an example of the stator manufacturing method for rotating electric machines. FIG. 2 is a diagram schematically showing the entire workpiece for forming a stator for a rotating electric machine. FIG. 2 is a cross-sectional view along the axial direction of a workpiece in a state where a coil piece is assembled to a stator core. It is a front view of one coil piece. FIG. 3 is a schematic cross-sectional view of a coil piece. FIG. 3 is an explanatory diagram of a joint portion, and corresponds to an enlarged view of section Q1 in FIG. 2. FIG. 3 is a diagram schematically showing a workpiece in a side view before being immersed in a tank of liquid resin material. FIG. 2 is a diagram schematically showing a workpiece immersed in a tank of liquid resin material in a side view. FIG. 3 is a diagram schematically showing the state of the workpiece in a rotation process in an immersed state in a side view. 10 is an enlarged view of section Q9 in FIG. 9. FIG. 9A is a cross-sectional view taken along line 9A-9A in FIG. 9A, schematically showing a state immediately after immersion (a state before starting a rotation process in an immersed state). FIG. 9A is a cross-sectional view taken along line 9A-9A in FIG. 9A, and is a diagram schematically showing a state after execution of a rotation step in an immersed state. FIG. FIG. 3 is a diagram schematically showing, in side view, the state of the work after the lifting process to near the liquid level has been completed. FIG. 3 is a diagram schematically showing a workpiece in a side view during a liquid draining rotation process. It is an explanatory view of the action of a liquid draining rotation process. It is an explanatory view of a preferable rotation direction of a liquid draining rotation process. FIG. 6 is a diagram schematically showing, in a side view, the state of the workpiece that has been pulled up further upward from the position during the liquid draining rotation process. FIG. 3 is a diagram schematically showing a state of a workpiece in a diagonally downward posture in a side view. FIG. 3 is a diagram schematically showing, in a side view, the state of a workpiece in an obliquely downward position undergoing a reattachment rotation process. FIG. 2 is an explanatory diagram (part 1) of the action of the reattachment rotation process. FIG. 3 is an explanatory diagram (part 2) of the action of the reattachment rotation process. FIG. 3 is an explanatory diagram (part 3) of the action of the reattachment rotation process. FIG. 2 is a side view schematically showing a state of a workpiece in an obliquely downward position with a relatively large inclination angle. FIG. 3 is a diagram schematically showing a state of a workpiece in a diagonally upward posture in a side view. FIG. 2 is a diagram schematically showing a side view of a workpiece in an upward posture. FIG. 3 is a diagram schematically showing a side view of a workpiece in a state where an upper surface resin curing process is being performed. FIG. 2 is a diagram schematically showing a workpiece in a side view while an inner diameter side resin curing process is being performed. FIG. 3 is a diagram schematically showing the state of the workpiece in a side view before the second insulation coating step. FIG. 2 is a diagram schematically showing the state of the workpiece in a side view in a heating process. FIG. 3 is a diagram schematically showing an example of a cooling structure. It is a schematic flowchart which shows another example of the stator manufacturing method for rotating electric machines. FIG. 3 is an explanatory diagram of deposits of liquid resin material on the stator core.

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.

The method for manufacturing a stator for a rotating electric machine described below can be applied to any stator for a rotating electric machine as long as the coil end portion has a joining portion of coil pieces. Below, as a preferred application example, a method for manufacturing a stator for a rotating electrical machine that can function as a power source that generates propulsive force for a vehicle will be described.

FIG. 1 is a schematic flowchart showing an example of a method for manufacturing a stator for a rotating electrical machine. Note that FIG. 1 is a flowchart showing a schematic flow, and further additional steps may be included at any stage. 2 to 6 are explanatory diagrams of the workpiece W. FIG. 2 is a diagram schematically showing the entire workpiece W including a stator core 112 and a stator coil 114 for forming the stator 10 for a rotating electric machine. FIG. 3 is a cross-sectional view along the axial direction of the workpiece W in which the coil piece 52 is assembled to the stator core 112. FIG. 4 is a front view of one of the plurality of coil pieces 52. FIG. 5 is a schematic cross-sectional view of the coil piece 52. FIG. 6 is an explanatory diagram of the joint portion 400, and corresponds to an enlarged view of portion Q1 in FIG. 7 to 18 are explanatory diagrams of this manufacturing method, and FIGS. 7 to 9, FIG. 10, FIG. 11, FIG. 13 to FIG. 15, and FIG. 17 to FIG. FIG. 2 is a diagram schematically showing a side view. 9A to 9C are explanatory diagrams of the action of the rotation process in the immersed state. FIG. 12 is an explanatory diagram illustrating the operation of the liquid draining rotation process at part Q11 in FIG. 11. FIG. 12A is an explanatory diagram of a preferred rotation direction of the liquid draining rotation process, and is a diagram schematically showing a part of the coil end portion 114A in a side view. 16A to 16C are explanatory diagrams of the effect of the rotation process.

The Z direction is shown in FIG. 2 and the like. The Z direction corresponds to the up-down direction, and the Z1 side and the Z2 side correspond to the upper side and the lower side, respectively. Moreover, the Y direction is shown in FIG. 3 and the like. The Y direction corresponds to the radial direction, with the Y1 side corresponding to the radially outer side and the Y2 side representing the radially inner side (the side closer to the central axis I of the stator core 112).

In the following description, unless otherwise specified, the axial direction refers to the direction in which the central axis I of the stator core 112 (=the central axis of the workpiece W) extends, and the radial direction refers to the diameter around the central axis I. Point in a direction. Therefore, the radially outer side refers to the side away from the central axis I, and the radially inner side refers to the side closer to the central axis I. Further, the axially outer side refers to the side away from the axial center of the stator core 112, and the axially inner side refers to the side closer to the axial center of the stator core 112. Further, the circumferential direction corresponds to the direction of rotation around the central axis I.

This manufacturing method first includes a preparation step (step S10) before the insulation coating step. In this embodiment, the preparation process (step S10) includes an assembly forming process (step S200) and a bonding process (step S202). However, in the modified example, a workpiece for which the assembly forming process (step S200) has already been performed may be used (prepared), or a workpiece for which the assembly forming process (step S200) and the joining process (step S202) have already been performed may be used. may be used (prepared).

The assembly forming step (step S200) includes attaching a plurality of coil pieces 52 forming the stator coil 114 to the stator core 112 to form an assembly (hereinafter also referred to as "work W").

Here, the stator coil 114 includes a U-phase coil, a V-phase coil, and a W-phase coil (hereinafter referred to as "phase coil" when U, V, and W are not distinguished). The base end of each phase coil is connected to an input terminal (not shown), and the end of each phase coil is connected to the end of another phase coil to form a neutral point. That is, stator coil 114 is star-connected. However, the connection mode of the stator coil 114 may be changed as appropriate depending on the required motor characteristics, etc. For example, the stator coil 114 may be delta connected instead of star connected.

Each phase coil of the stator coil 114 may be configured by combining a plurality of coil pieces 52. The coil piece 52 is in the form of a segment coil (segment conductor) obtained by dividing a phase coil into units that are easy to assemble (for example, units inserted into two slots 23). As shown in FIG. 5, the coil piece 52 is formed by covering a linear conductor (flat wire) 120 with a substantially rectangular cross section with an insulating film 130. Here, the linear conductor 120 is made of copper, for example. However, in variations, the linear conductor 120 may be formed of other conductive materials, such as iron. Furthermore, the cross-sectional shape of the linear conductor 120 may be other than rectangular.

In the example shown in FIG. 4, one coil piece 52 is formed into a substantially U-shape having a pair of linear slot accommodating parts 50 and a transition part 54 connecting the pair of slot accommodating parts 50. It's fine. The transition portion 54 on the other side in the axial direction (upper side in FIG. 4) may be formed by forming in the circumferential direction from the state shown in FIG. At the end of the transition portion 54 on the other side in the axial direction (upper side in FIG. 4), a coupling portion 40 that is coupled to a coupling portion 40 of the transition portion 54 of another coil piece 52 is set. Note that the coupling portion 40 is a portion where the insulating film 130 is removed (that is, a portion where the conductor portion of the linear conductor 120 is exposed).

When assembling the coil piece 52 to the stator core 112, the pair of slot accommodating portions 50 are each inserted into the slot 23 between the teeth 22 (see FIG. 3). In this case, the coil pieces 52 can be assembled, for example, in the axial direction.

A plurality of slot accommodating portions 50 of the coil pieces 52 shown in FIG. 4 are inserted into one slot 23 in a line in the radial direction. Therefore, at both ends of the stator core 112 in the axial direction, a plurality of transition portions 54 extending in the circumferential direction are arranged in the radial direction. Note that the transition portion 54 (and the coupling portion 40 that is a part thereof) forms a coil end portion 114A that is a portion that projects outward in the axial direction from the axial end surface 1120 of the stator core 112 (see FIG. 3). Note that the coil piece 52 may be wound around the stator core 112 in, for example, an overlapping form. In the example shown in FIG. 4, the lower transition portion 54 may have an offset portion 521B that is offset in the direction of being separated from each other by one layer in the radial direction. The upper transition portion 54 may also have a similar offset portion 521A (see FIG. 3).

Note that although the stator core 112 and the stator coil 114 have specific structures in FIGS. 2 to 5, the structures of the stator core 112 and the stator coil 114 are arbitrary as long as the stator coil 114 has the coupling portion 40. Further, the manner in which the stator coil 114 is wound is arbitrary, and may be wound in a manner other than the above-mentioned overlapped winding, such as wave winding.

The bonding step (step S202) includes bonding the coupling portions 40, which are the tips of one coil piece 52 and the other coil piece 52, to each other on one axial end side of the workpiece W. The coupling parts 40 may be overlapped and joined at opposing sides. The joining portions 40 may be joined together using any method, but welding may be used, for example. In this case, welding may be achieved by any method such as laser welding or TIG welding. FIG. 6 schematically shows a joint portion 400 including a welding portion 401 (joint portion) formed in two joint portions 40 stacked in the radial direction.

For example, when a plurality of coil pieces 52 are installed in each slot 23 of the stator core 112 in a manner in which four or more coil pieces overlap in the radial direction, the joining process is performed between two radially adjacent connecting parts 40 (tip parts). A plurality of sets may be joined in the radial direction, with each set being considered as one set.

Note that the bonding range of the bonding portions 40, the posture of the bonding portions 40 when bonding (the posture when overlapping), etc. are arbitrary. For example, in FIG. 6, the joint parts 40 are vertically upright and overlapped in the radial direction, but they may be overlapped in an X-shaped cross-shape when viewed in the radial direction, or they may be overlapped diagonally. Only the coupling portions 40 may be superimposed on each other in the radial direction in the orientation of the direction. Further, the coupling portions 40 may be stacked on each other in the axial direction in a posture extending in the radial direction.

In the bonding step, not only the coil pieces 52 may be bonded to each other, but also the coil pieces 52 may be bonded to a bus bar or a terminal block (an output bus bar for connection to an inverter (not shown)). FIG. 2 schematically shows a neutral line bus bar 59 as an example of such a bus bar. The neutral line bus bar 59 is a bus bar that forms the above-mentioned neutral point.

In this embodiment, as an example, the joint portion 400 is provided only on one side of the stator core 112 in the axial direction. Hereinafter, for distinction, the side having the joint portion 400 of both axial sides of the stator core 112 (or both axial sides of the workpiece W) will also be referred to as the lead side. In addition, in a modification, the joint portions 400 may be set on both sides of the stator core 112 in the axial direction.

After the preparation step (step S10), the present manufacturing method includes a step (step S204) of setting the workpiece W at a starting position (workpiece loading position) for the insulation coating step. At this time, the workpiece W may be set with the lead side facing upward (that is, the joint portion 400 facing upward). Hereinafter, this posture in which the lead side is on the upper side will also be referred to as the "upward posture of the workpiece W."

Next, the present manufacturing method includes, as the first step of the insulation coating step, an up-down reversal step (step S206) in which the posture of the workpiece W is reversed up and down. That is, the workpiece W is vertically inverted so that the lead side is on the lower side (that is, the joint part 400 is on the lower side). Hereinafter, such a posture with the lead side facing downward will also be referred to as a "downward posture of the workpiece W" (an example of a first posture). The vertical inversion of the posture of the workpiece W may be realized by a manufacturing device. Note that the manufacturing apparatus may be, for example, an articulated robot having a hand that grips the workpiece W, and a part of the workpiece gripping section 1000 of the manufacturing apparatus is shown in FIG. 7, etc., which will be described later.

Next, the present manufacturing method includes a dipping step (step S208) of dipping the workpiece W into the tank 600 of the liquid resin material M0. FIG. 7 is a side view schematically showing the work W before being immersed in the tank 600 of the liquid resin material M0, and FIG. 8 is a diagram schematically showing the work W immersed in the tank 600 of the liquid resin material M0. FIG. 2 is a diagram schematically showing a side view. In this manufacturing method, the liquid resin material M0 is preferably a resin material that has the property of being hardened by heating and the property of being hardened by a polymerization reaction when irradiated with ultraviolet rays. Further, the liquid resin material M0 has a relatively high viscosity, for example, a viscosity of more than 10 Pa·s, preferably 20 Pa·s or more. Note that the tank 600 may have an annular shape corresponding to the annular impregnation target region when viewed from above.

In the dipping step, the workpiece W maintains a downward attitude so that the part to be impregnated at the axial end (the lower end in the downward attitude) of the workpiece W is immersed in the liquid resin material M0 (i.e., the liquid resin material 601 below the liquid level 601 of M0). The parts of the workpiece W to be impregnated are set to the parts of the plurality of coil pieces 52 of the workpiece W. Specifically, the part of the workpiece W to be impregnated is the axial end (lead side end) of the plurality of coil pieces 52 and includes the joint part 400. More specifically, the part of the workpiece W to be impregnated is the part of each coil piece 52 of the workpiece W where the conductor (conductor part related to the linear conductor) is exposed (the part including the joint part 400). include. The region to be impregnated has an annular shape around the central axis I when viewed in the axial direction, and includes a portion of the coil end portion 114A (a portion on the axial end side).

Further, in this manufacturing method, the region to be impregnated is set to include the neutral wire bus bar 59. In this case, the electrical insulation of the neutral line bus bar 59 can be ensured by wrapping the neutral line bus bar 59 in the liquid resin material M0. That is, the neutral wire bus bar 59 does not need to be insulated in advance by insert molding or the like with an insulating material such as a resin material, and can be in the form of a sheet metal. Thereby, the electrical insulation of the neutral line bus bar 59 can be efficiently ensured.

In addition, in this manufacturing method, the dipping process is performed twice for one workpiece W, as described later. In this case, the parts of the workpiece W to be impregnated in each dipping step may be completely the same or may be partially different. However, in the modified example, the number of times the dipping step is performed on one workpiece W may be one time or three or more times.

In the dipping process, the workpiece W may be maintained in a downwardly immersed state for a certain period of time by the workpiece gripping section 1000 of the manufacturing apparatus.

In this manufacturing method, the immersion step includes a rotation step (see arrow R9 in FIG. 9) of rotating the workpiece W (downward posture) in the immersed state around the central axis I. Hereinafter, the rotation process performed during such an immersion process will also be referred to as a "rotation process in an immersion state" to distinguish it from other rotation processes described later.

9 to 9C are explanatory diagrams of a rotation process in an immersed state, FIG. 9 is a diagram schematically showing a side view of a work W during a rotation process in an immersed state, and FIG. 9 is an enlarged view of part Q9 of FIG. 9B and 9C are cross-sectional views taken along line 9A-9A in FIG. 9A, and FIG. 9B schematically shows the state immediately after immersion (the state before the rotation process starts in the immersion state), 9C schematically shows the state after execution of the rotation step in the immersed state. In FIGS. 9B and 9C, the L direction corresponds to the circumferential direction of the workpiece W, and L1 and L2 represent opposite sides (one side and the other side in the circumferential direction).

The rotation step in the immersed state is performed in order to efficiently wrap the neutral line bus bar 59 in the liquid resin material M0. In this embodiment, the neutral wire bus bar 59 is electrically insulated by being covered with the liquid resin material M0, as described above. Note that the neutral wire bus bar 59 may be arranged at any position with respect to the coil end portion 114A, and for example, the neutral wire bus bar 59 may be joined to the stator coil 114 in such a manner that it extends further axially outward than the coil end portion 114A. It's okay. However, in the present embodiment, as schematically shown in FIG. 9 etc., the neutral line bus bar 59 has an upper surface 591 (hereinafter also simply referred to as "upper surface 591") in a downward attitude that is connected to the stator coil 114 in the Z direction. It is joined to stator coil 114 in a relationship located between axial end surface 1140 and axial end surface 1120 of stator core 112 . In this case, it is possible to reduce the axial size of the stator 10 for a rotating electric machine. Note that the axial end surface 1140 of the stator coil 114 corresponds to the axial end surface of the coil end portion 114A.

By the way, when the neutral line bus bar 59 is wrapped in the liquid resin material M0 in this way, efficiently guiding the liquid resin material M0 onto the upper surface 591 of the neutral line bus bar 59 aims to reduce CT (Cycle Time). It becomes useful above.

Here, as in this embodiment, when the upper surface 591 of the neutral wire bus bar 59 is located on the Z1 side (upper side in the downward attitude) than the axial end surface 1140 of the stator coil 114, the Z1 side of the region to be impregnated is The boundary tends to be defined by the top surface 591 of the neutral busbar 59. For example, the Z1 side boundary of the region to be impregnated is set slightly closer to the Z1 side than the upper surface 591 of the neutral line bus bar 59. In such a manner of setting the region to be impregnated, the upper surface 591 of the neutral line bus bar 59 is located only slightly below the liquid level 601 of the liquid resin material M0 in the immersed state, and the liquid It tends to be difficult to spread the resin material M0 quickly.

However, in this manufacturing method, by performing the rotation process in an immersed state, it is possible to quickly spread the liquid resin material M0 over the upper surface 591 of the neutral line bus bar 59. It becomes possible.

Specifically, when the workpiece W is immersed in the immersion process so that the upper surface 591 is located slightly below the liquid level 601 of the liquid resin material M0, as shown schematically by arrows R91 and R92 in FIG. 9B. As shown, the liquid resin material M0 flows from the outer peripheral edge of the neutral line bus bar 59 to the upper surface 591 of the neutral line bus bar 59. However, if the workpiece W is simply held in a immersed state, the liquid resin material M0 has a relatively high viscosity as described above, so the flow rate is slow, and it is difficult to spread the liquid resin material M0 over the entire upper surface 591. It takes a relatively long time. Furthermore, it may be difficult for the liquid resin material M0 to flow toward the upper surface 591 due to surface tension, and in such a case, it takes a relatively long time to spread the liquid resin material M0 over the entire upper surface 591.

On the other hand, according to the present manufacturing method, the liquid resin material M0 flows from the outer periphery of the neutral line bus bar 59 to the upper surface 591 of the neutral line bus bar 59 by executing the rotation process in the immersed state. It becomes easier. For example, when the work W is rotated in the circumferential direction L1 side in FIG. 9B, the flow of the liquid resin material M0 in the direction of the arrow R91 (flow of the liquid resin material M0 on the upper surface 591 of the neutral line bus bar 59) is promoted. . Further, when the workpiece W is rotated in the circumferential direction L2 side in FIG. 9B, the flow of the liquid resin material M0 in the direction of the arrow R92 (the flow of the liquid resin material M0 on the upper surface 591 of the neutral line bus bar 59) is promoted. . As a result, compared to the case where the workpiece W is simply held in an immersed state, it becomes possible to efficiently guide the liquid resin material M0 onto the upper surface 591 of the neutral line bus bar 59, and it is possible to reduce CT. can.

In this manufacturing method, the rotation step in the immersed state may be realized by only rotating the workpiece W in one direction (either rotation in the circumferential direction L1 side or rotation in the circumferential direction L2 side), or This may be realized by rotating the workpiece W in two directions (both rotation toward the circumferential direction L1 side and rotation toward the circumferential direction L2 side). In the case where the work W is rotated in two directions, as described above with reference to FIG. 9B, the liquid resin material M0 is applied onto the upper surface 591 of the neutral line bus bar 59 from both sides in the circumferential direction of the neutral line bus bar 59. Since the liquid resin material M0 can be guided (see arrow R91 and arrow R92), it is possible to quickly spread the liquid resin material M0 over the entire upper surface 591 (see FIG. 9C).

Note that in this manufacturing method, the work W in the immersed state is rotated around the central axis I to efficiently guide the liquid resin material M0 onto the upper surface 591 of the neutral line bus bar 59. Alternatively or in addition, liquid may be deposited on the upper surface 591 of the neutral wire bus bar 59 by any movement such as rocking the immersed workpiece W, translating the workpiece W, or a combination thereof. It is also possible to efficiently guide the resin material M0. When translating the workpiece W, the translational movement may be achieved by maintaining the central axis I of the workpiece W parallel to the vertical direction, or by slightly tilting the central axis I of the workpiece W with respect to the vertical direction. It may also be realized by

Furthermore, in this manufacturing method, regarding the rotation step in the immersed state, the rotation of the workpiece W around the central axis I is achieved by maintaining the central axis I of the workpiece W parallel to the vertical direction; however, this is not limited to this. I can't do it. For example, the rotation of the workpiece W around the central axis I may be realized by slightly tilting the central axis I of the workpiece W with respect to the vertical direction. In this case, the inclination angle may be changed depending on the rotational position and/or rotational angle of the workpiece W.

In addition, in this manufacturing method, the rotation angle (rotation stroke) related to the rotation step in the immersed state is arbitrary, but is preferably 90 degrees or more, more preferably 180 degrees or more, for example, 360 degrees. There may be. For example, by setting the angle to 360 degrees or less, a rotation process in an immersed state can be realized even when using a robot with limited movable range.

In addition, in this manufacturing method, regarding the rotation process in the immersed state, the rotation of the workpiece W around the central axis I is performed in a state in which the upper surface 591 of the neutral line bus bar 59 is located below the liquid level 601 of the liquid resin material M0. is performed, but is not limited to this. For example, regarding the rotation process in the immersed state, the rotation of the workpiece W around the central axis I may be performed in a state where the upper surface 591 of the neutral wire bus bar 59 is aligned with the liquid level 601 of the liquid resin material M0. Further, the rotation of the workpiece W around the central axis I is performed while changing the height difference between the upper surface 591 of the neutral wire bus bar 59 and the liquid level 601 of the liquid resin material M0 (see dimension H1 in FIG. 9A). Good too. For example, in the process of immersing the workpiece W, the rotation of the workpiece W may be started from a state (for example, H1=0 or minus) before reaching the state in which the workpiece W is immersed the most.

Next, the present manufacturing method includes a lifting step (step S210) of slightly lifting the workpiece W from the tank 600. Hereinafter, the lifting process in step S210 will also be referred to as a "lifting process to near the liquid level" to distinguish it from further lifting described later. Note that lifting of the workpiece W may be realized by the workpiece gripping section 1000 of the manufacturing apparatus. FIG. 10 schematically shows the workpiece W in a downward posture after being pulled up slightly above the liquid level 601. After being pulled up, the workpiece W in the downward position has a liquid resin material M0 (schematically illustrated by the hatched area M1 in FIG. 10) in the impregnation target area at the axial end (lower end in the downward position). Impregnated.

Next, the present manufacturing method includes a rotation step (step S211) of rotating the workpiece W slightly lifted from the tank 600 and in a downward posture around the central axis I of the workpiece W. Hereinafter, the rotation process in step S211 (an example of the first rotation process) will also be referred to as a "liquid draining rotation process" to distinguish it from other rotation processes. In FIG. 11, rotation due to the draining rotation process is schematically shown by arrows R11A and R11B.

The liquid draining rotation step is executed in order to promptly return the liquid resin material M0 dripping from the region to be impregnated of the workpiece W in the downward position to the tank 600. Specifically, when the workpiece W is pulled up from the tank 600, the liquid resin material M0 drips from the part of the workpiece W to be impregnated due to its own weight, but since the liquid resin material M0 has a relatively high viscosity, it drips relatively slowly. drop down. In this case, if the workpiece W is held in a downward position and waits for the liquid resin material M0 to be dripped to finish dripping, CT tends to increase. Furthermore, when the workpiece W is held in a downward position for a relatively long time, an excessive amount of the liquid resin material M0 dripping into the tank 600 out of the liquid resin material M0 attached (impregnated) to the part of the workpiece W to be impregnated becomes excessive. becomes. In this case, in order to ensure the required thickness of the liquid resin material M0, an unnecessary increase in the number of dipping steps performed on one workpiece W (and an accompanying increase in CT) is caused.

On the other hand, in this manufacturing method, since the liquid draining and rotation step is executed, the liquid resin material M0 may drip from the impregnation target part of the workpiece W before it finishes dripping from the impregnation target part of the workpiece W due to its own weight. The liquid resin material M0 can be separated (divided) into a portion of the liquid resin material M0 that remains on the workpiece W and a portion of the liquid resin material M0 that returns to the tank 600.

Specifically, FIG. 12 shows a part corresponding to part Q11 in FIG. 11 (however, the illustration of the neutral line bus bar 59 is omitted), and the upper state ST2110 is the start of the liquid draining rotation process. The previous state is shown, and the lower state ST2111 shows the state during the liquid draining rotation process. When the workpiece W is rotated from state ST2110, as shown in state ST2111, there is a speed difference between the liquid resin material M0 attached to the part of the workpiece W to be impregnated and the liquid resin material M0 in the tank 600. (speed difference in the rotational direction) (arrow R2111 in FIG. 12) occurs. When such a speed difference (velocity gradient) in the shear direction occurs, the viscosity of the liquid resin material M0 decreases at the boundary of the speed difference, so that the part of the liquid resin material M0 adhering to the workpiece W and the tank A concave portion is formed in the radial direction between the portion of liquid resin material M0 within 600. When this concave portion is formed, free fall of the portion of the liquid resin material M0 below the concave portion is promoted. Therefore, when the workpiece W is further pulled up with the concave portion formed, the liquid resin material M0 attached to the part of the workpiece W to be impregnated with the concave portion as a boundary and the liquid resin material M0 in the tank 600 are removed. can be easily separated (separated).

In this way, according to the present manufacturing method, the liquid resin material M0 dripping from the target part of the workpiece W can be accelerated by utilizing the velocity difference (velocity gradient) in the shear direction in the liquid draining rotation step. It is possible to shorten the CT while minimizing the time. Furthermore, the number and frequency of occurrence of drooping portions M12 (liquid resin material M0 that drips down and forms an "icicle" shape), which will be described later, can be reduced, and the possibility of the liquid resin material M0 adhering to the stator core 112 can be reduced. As a result, CT can be shortened.

In this manufacturing method, the liquid draining rotation process may be realized by rotating the workpiece W in only one direction (either rotation toward the circumferential direction L1 side or rotation toward the circumferential direction L2 side), or the workpiece W It may be realized by rotation in two directions (both rotation toward the circumferential direction L1 side and rotation toward the circumferential direction L2 side).

In this regard, the inclination direction of the transition portion 54 of the coil piece 52 on the radially outer side or the radially inner side of the coil end portion 114A may be taken into consideration. For example, FIG. 12A schematically shows four transition portions 54 of the radially outer coil pieces 52, and the inclination direction thereof is such that the upper side is located closer to the L2 side than the lower side. In this case, when the workpiece W is rotated in the circumferential direction L2 side (see arrow R12B), the liquid resin material M0 impregnated between the transition parts 54 becomes easier to flow axially outward from the coil end part 114A (arrow (See R12A). In this case, there is a possibility that the liquid resin material M0 impregnated between the transition parts 54 may be insufficient. Therefore, in the case of such an inclined direction of the transition portion 54, in order to avoid such inconvenience, the rotation direction related to the liquid draining rotation step may be a direction in which the workpiece W is rotated in the circumferential direction L1 side.

In this embodiment, the vertical positional relationship between the workpiece W and the liquid level 601 when the liquid draining rotation step is executed is arbitrary. However, preferably, the rising position of the workpiece W in the lifting process to near the liquid level is such that the liquid resin material M0 adhering to the part of the workpiece W to be impregnated is connected (continuous) with the liquid resin material M0 in the tank 600. Within range. More specifically, the vertical positional relationship between the workpiece W and the liquid level 601 when the liquid draining rotation process is performed is preferably such that the lower end position of the workpiece W (lower coil The distance between the lowermost position of the end portion 114A) and the liquid level 601 is 10 mm or less, more preferably 5 mm or less, and most preferably about 1 mm to 3 mm. In addition, if it is larger than 10 mm, it is not preferable in that the liquid resin material M0 dripping from the coil end portion 114A is likely to scatter outside the tank 600 due to centrifugal force. On the other hand, if it is smaller than 1 mm, it is not preferable because the above-mentioned concave portion is difficult to form.

In addition, in this manufacturing method, the rotation angle (rotation stroke) related to the draining rotation step is arbitrary, but is preferably 90 degrees or more, more preferably 180 degrees or more, for example 360 degrees. Good too.

Next, the manufacturing method includes a step (step S212) of changing the diagonally downward attitude (an example of the second attitude) of the workpiece W further pulled up from the tank 600. FIG. 13 schematically shows the state of the workpiece W when the workpiece W is lifted further upward from the height of the workpiece W during the liquid draining rotation process (after the lifting process to near the liquid level). , FIG. 14 schematically shows the state of the workpiece W in an obliquely downward attitude.

In this manufacturing method, as described above, although the dripping of the liquid resin material M0 due to its own weight can be reduced by the liquid draining and rotation step, the liquid resin material M0 may drip due to its own weight. In FIGS. 13 and 14, the liquid resin material M0 that is dripping down due to its own weight is indicated by M12. Hereinafter, of the liquid resin material M0 impregnated into the part of the workpiece W to be impregnated, the liquid resin material M0 that is dripping down due to its own weight is also referred to as a drooping part M12, and the other part is also referred to as a normal part M13. The hanging portion M12 has a so-called “icicle” shape, and due to the relatively high viscosity of the liquid resin material M0, it tends not to fall down quickly (i.e., it remains in the “icicle” shape). , tends to grow downward). In addition, in FIG. 14 etc., the dashed-dotted line H represents a horizontal line.

Next, the present manufacturing method includes a rotation step of rotating the workpiece W around the central axis I of the workpiece W (step S213). Hereinafter, the rotation process in step S213 (an example of the second rotation process) will also be referred to as a "reattachment rotation process" to distinguish it from other rotation processes. In FIG. 15, rotation due to the reattachment rotation process is schematically indicated by an arrow R15.

The reattachment rotation step includes rotating the workpiece W so that the hanging portion M12 is absorbed into the normal portion M13 (integrated by adhering to the normal portion M13). That is, in the reattachment rotation process, the workpiece W is rotated so that the liquid resin material M0 (i.e., the hanging portion M12) dripping downward from one circumferential position in the impregnation target area adheres to another circumferential position in the impregnation target area. Including rotating.

Here, the principle of the reattachment rotation step will be explained with reference to FIGS. 16A to 16C. 16A to 16C are plan views schematically showing the workpiece W viewed along arrow V15 in FIG. 15.

In the example shown in FIGS. 16A to 16C, two hanging parts M12 are shown being absorbed into the normal part M13. Specifically, when the workpiece W rotates clockwise from the state shown in FIG. 16A, it becomes the state shown in FIG. 16B, and the right hanging portion M12 is at a position overlapping the normal portion M13 when viewed along arrow V15. . At this time as well, the workpiece W is in an obliquely downward position (see FIG. 15), but due to the relatively high viscosity of the liquid resin material M0, the rotation of the workpiece W causes the base side of the hanging portion M12 to move downward to the normal portion M13. In an absorbed manner, the entire hanging portion M12 is absorbed into the normal portion M13. Similarly, when the workpiece W further rotates clockwise from the state shown in FIG. 16B, it becomes the state shown in FIG. 16C, where the left hanging portion M12 is at a position overlapping the normal portion M13 when viewed along arrow V15. At this time as well, the workpiece W is in an obliquely downward position (see FIG. 15), but due to the relatively high viscosity of the liquid resin material M0, the rotation of the workpiece W causes the base side of the hanging portion M12 to move downward to the normal portion M13. In an absorbed manner, the entire hanging portion M12 is absorbed into the normal portion M13.

In this way, when each hanging portion M12 reaches a rotational position where it overlaps the normal portion M13 as seen from the arrow V15, the entire portion is absorbed into the normal portion M13. As a result, each hanging portion M12 is eliminated, and it is possible to prevent the inconvenience caused when the posture of the workpiece W is changed to an upward posture while the hanging portion M12 remains. Specifically, if the posture of the workpiece W is changed to an upward posture in the next step S214 while the drooping portion M12 remains, there is a possibility that the drooping portion M12 may adhere to the stator core 112. For example, it may adhere to the axial end face 1120 (upper end face) of the stator core 112. In this case, it is necessary to separately remove the liquid resin material M0 attached to the stator core 112 using a scraper or the like. On the other hand, according to the present manufacturing method, as described above, such inconveniences can be reduced and the CT can be shortened.

Further, according to the present manufacturing method, each hanging portion M12 is not removed from the workpiece W, but is returned to the part of the workpiece W to be impregnated in such a manner that it is integrated with the normal portion M13. Each hanging portion M12 can be eliminated without reducing the amount of liquid resin material M0 impregnated into the target area. Specifically, when each hanging portion M12 is removed from the workpiece W, the liquid resin material M0 attached to (impregnated with) the part of the workpiece W to be impregnated is reduced accordingly. In this case, in order to ensure the required thickness of the liquid resin material M0, an unnecessary increase in the number of dipping steps performed on one workpiece W (and an accompanying increase in CT) is caused. In contrast, according to the present manufacturing method, it is possible to shorten the CT while preventing such inconveniences.

In this manufacturing method, the reattachment rotation step may be realized by only rotating the workpiece W in one direction (for example, either clockwise rotation or counterclockwise rotation in the view of arrow V15), or This may be realized by rotating the workpiece W in both directions. Further, the rotation angle (rotation stroke) related to the reattachment rotation step is arbitrary, but is preferably 90 degrees or more, and more preferably 180 degrees or more.

Although the description has mainly been given here to the hanging portion M12 generated from the coil end portion 114A, the same effect can be obtained by the reattachment rotation process to the similar hanging portion M12 generated from the neutral line bus bar 59. be able to.

Further, in the present manufacturing method, in the reattachment rotation step, the workpiece W in the diagonally downward position may be located above the tank 600 in such a manner that it still faces the tank 600 in the vertical direction. That is, the workpiece W may be formed in a diagonally downward position such that the part of the workpiece W to be impregnated overlaps the tank 600 when viewed in the vertical direction. In this case, even if the hanging part M12 separates from the workpiece W and falls, it can return to the tank 600, and it is possible to prevent the yield of the liquid resin material M0 from decreasing due to the dropping of the hanging part M12.

Here, in this manufacturing method, the reattachment rotation process is performed on the workpiece W in the diagonally downward posture, but it is desirable that the angle α (see FIG. 15) of the diagonally downward posture is relatively small. For example, if the angle α exceeds 45 degrees, as schematically shown in FIG. ), the above-mentioned reattachment becomes difficult. Furthermore, when the process is performed on the workpiece W in an obliquely upward position, the hanging portion M12 tends to adhere to the stator core 112, as schematically shown in FIG. For example, the drooping portion M12 that hangs down from a circumferential position below the central axis I tends to adhere to the axial end surface 1120 of the stator core 112 on the radially outer side of the slot 23. Furthermore, the drooping portion M12 that hangs down from a circumferential position above the central axis I tends to adhere to the axial end surface 1120 or inner peripheral surface of the stator core 112 on the radially inner side of the slot 23. This tendency becomes noticeable when the angle α of the diagonally downward posture exceeds -20 degrees. Note that the angle α is positive in the direction in which the region to be impregnated is in a downward posture. Therefore, the angle α (see FIG. 15) of the diagonally downward posture is preferably smaller than 45 degrees and larger than −20 degrees.

Next, the present manufacturing method includes an inversion step (step S214) in which the posture of the workpiece W is turned upward. That is, the posture of the workpiece W is changed from a downward posture, through an obliquely downward posture, to an upward posture. FIG. 19 schematically shows a workpiece W in an upward posture.

By the way, when the posture of the workpiece W pulled up from the tank 600 is reversed vertically in the reversal step (step S214) without performing the above-described reattachment rotation step, the hanging portion M12 is aligned with the axial end surface 1120 of the stator core 112. (upper end face). In this case, it is necessary to separately remove the liquid resin material M0 attached to the stator core 112 using a scraper or the like. On the other hand, according to the present manufacturing method, as described above, the hanging part M12 is eliminated by the reattachment rotation process before being placed in the upward position (as it is absorbed into the normal part M13), thus reducing this inconvenience. can.

Next, the present manufacturing method includes an upper surface resin curing step (step S216) in which the upper surface of the part to be impregnated is subjected to resin curing treatment with the liquid resin material M0 for the workpiece W in the upward facing position. Hereinafter, the resin curing process related to the top resin curing step will also be referred to as "top resin curing process."

In this manufacturing method, the upper surface resin curing treatment includes irradiating the upper surface of the part of the workpiece W to be impregnated with ultraviolet rays. FIG. 20 schematically shows a state where the upper surface resin curing process is being performed. In the example shown in FIG. 20, the ultraviolet irradiation device 900 irradiates the upper surface of the part of the workpiece W to be impregnated with ultraviolet rays (see arrow R13). As a result, the upper part (mainly the upper surface part) of the liquid resin material M0 impregnated into the part of the workpiece W to be impregnated is cured.

The ultraviolet irradiation device 900 preferably irradiates the upper surface of the part of the workpiece W to be impregnated with ultraviolet rays over the entire circumference. Thereby, the liquid resin material M0 in the upper portion can be cured over the entire circumference of the region to be impregnated. In this case, the workpiece W may be rotated around the central axis I, or the ultraviolet irradiation device 900 may be rotated. Alternatively, a plurality of ultraviolet irradiation devices 900 may be disposed above the workpiece W in a circumferentially distributed manner.

The ultraviolet irradiation device 900 is preferably positioned with respect to the workpiece W so that the optical axis 901 is substantially perpendicular to the upper surface of the part of the workpiece W to be impregnated. That is, the ultraviolet irradiation device 900 is preferably positioned with respect to the workpiece W so that the optical axis 901 is located within a substantially vertical plane. Here, "approximately" is a concept that includes an error of 10% or less, for example. Further, the ultraviolet irradiation device 900 is preferably positioned with respect to the workpiece W such that the optical axis 901 passes through the part of the workpiece W to be impregnated, and more preferably, the optical axis 901 is located at the diameter of the part of the workpiece W to be impregnated. It is positioned relative to the workpiece W so as to pass near the center of the directional range (range from the innermost radial position to the outermost radial position). In this case, the liquid resin material M0 in the upper part of the part of the workpiece W to be impregnated can be efficiently hardened.

In this way, according to the present manufacturing method, the workpiece W is in an upward attitude, and the upper portion (axial end portion) of the liquid resin material M0 impregnated into the region to be impregnated is hardened. Therefore, it is possible to reduce inconveniences that may occur when the upper surface resin curing process is performed on the workpiece W pulled up from the tank 600 while the workpiece W is in a downward position. Specifically, when the resin curing process is performed on the lower surface of the part to be impregnated with the workpiece W pulled up from the tank 600 while it is in a downward position, the liquid resin material M0 impregnated into the part of the workpiece W to be impregnated is However, there is a risk that it will sag downward and harden due to its own weight. In this case, the liquid resin material M0 that is being cured returns to the tank 600, which may affect the fluidity of the liquid resin material M0 in the tank 600. On the other hand, according to the present manufacturing method, since the upper surface resin curing process is performed in the upward position as described above, such inconvenience can be reduced.

Further, according to the present manufacturing method, by hardening the upper part (axial end) of the liquid resin material M0 impregnated into the region to be impregnated, the corner of the rectangular cross section of the joint 40 (see FIG. 5, below) is cured. , referred to as "joint edge 122"), a thin film of liquid resin material M0 can be formed thereon. That is, even on the joint edge 122 where it is difficult to form the liquid resin material M0 due to the influence of wettability around the coil piece 52, a film of the liquid resin material M0 can be formed, although it is relatively thin. The joint edge 122 on which the film of the liquid resin material M0 is formed has high wettability due to the film. In this way, the wettability of the joint edge 122 (the wettability of the liquid resin material M0) can be increased. As a result, in the subsequent second dipping step (described later), the required thickness of the insulation coating (cured product of liquid resin material M0) on the joint edge 122 of the coil piece 52 can be easily ensured. That is, in the second dipping step, a relatively thick film can also be formed on the joint edge 122 using the film of the liquid resin material M0 formed in the first dipping step as a base.

Next, the present manufacturing method includes an inner diameter side resin curing step (step S218) in which a resin curing process of the liquid resin material M0 is performed on the radially inner side surface of the part to be impregnated with respect to the workpiece W that has been inverted to an upward position. including. Hereinafter, the resin curing process related to the inner diameter side resin curing process will also be referred to as "inner diameter side resin curing process" to distinguish it from the above-mentioned upper surface resin curing process.

In this manufacturing method, the inner diameter side resin curing treatment includes irradiating the radially inner side surface of the part of the workpiece W to be impregnated with ultraviolet rays. FIG. 21 schematically shows a state in which the inner diameter side resin curing process is being performed. In the example shown in FIG. 21, the ultraviolet irradiation device 900 irradiates the radially inner side surface of the part to be impregnated of the workpiece W with ultraviolet rays (see arrow R14). As a result, the radially inner portion (mainly the surface portion) of the liquid resin material M0 impregnated into the part of the workpiece W to be impregnated is hardened. Note that the ultraviolet irradiation device 900 may be the same as the ultraviolet irradiation device 900 used in the above-described upper resin curing process.

The ultraviolet irradiation device 900 preferably irradiates the radially inner side surface of the part of the workpiece W to be impregnated with ultraviolet rays over the entire circumference. Thereby, the liquid resin material M0 in the radially inner portion can be cured over the entire circumference of the region to be impregnated. In this case, the inner diameter side resin curing process may be performed sequentially in parallel with the top resin curing process. Specifically, the upper surface resin curing process and the inner diameter side resin curing process may be performed at once for each divided circumferential range of the entire circumference of the impregnation target region of the workpiece W. Alternatively, the inner diameter side resin curing process may be performed before the top resin curing process.

The ultraviolet irradiation device 900 is preferably positioned with respect to the workpiece W so that the optical axis 901 is substantially perpendicular to the radially inner side surface of the part of the workpiece W to be impregnated. That is, the ultraviolet irradiation device 900 is preferably positioned with respect to the workpiece W so that the optical axis 901 is located within a substantially vertical plane. Here, "approximately" is a concept that includes an error of 10% or less, for example. Further, the ultraviolet irradiation device 900 is preferably positioned with respect to the workpiece W such that the optical axis 901 passes through the region of the workpiece W to be impregnated, and more preferably, the optical axis 901 is the axis of the region of the workpiece W to be impregnated. It is positioned relative to the workpiece W so as to pass near the direction center. In this case, the liquid resin material M0 on the radially inner side surface portion of the part of the work W to be impregnated can be efficiently hardened.

However, depending on the size of the ultraviolet irradiation device 900 and the space inside the workpiece W in the radial direction, the ultraviolet irradiation device 900 may be attached to the radially inside side of the part of the workpiece W to be impregnated, as shown in FIG. , the optical axis 901 may be positioned relative to the work W in such a manner that the optical axis 901 intersects in an oblique direction. In this case, one of the inner diameter side resin curing treatment and the upper surface resin curing treatment may serve as the other.

When the inner diameter side resin curing process (step S218) by the inner diameter side resin curing process is completed, the insulation coating process for that time is completed.

Next, the present manufacturing method determines whether the number of times the insulation coating process has been performed on one workpiece W has reached a predetermined number of times (in this manufacturing method, as an example, two times) (step S220). Such a determination may be realized by a person or by image processing or the like. If the determination result is "YES", proceed to the next step; otherwise, the steps from step S206 to step S218 are similarly performed in order to perform the second insulation coating step. FIG. 22 schematically shows the workpiece W that has been turned upside down in step S206 to face downward in the second insulation coating step. After that, the workpiece W undergoes a second dipping process and the like.

The second insulation coating step may be exactly the same as the first insulation coating step. In this case, for example, control of the manufacturing equipment can be simplified.

However, the second insulation coating step is preferably different from the first insulation coating step in at least the dipping step. Specifically, in the dipping step in the second insulation coating step, the number of parts to be impregnated is reduced compared to the dipping step in the first insulation coating step. That is, the region to be impregnated in the second dipping step may be a part (part on the axial end side) of the region to be impregnated in the first dipping step. In this case, the region to be impregnated in the second dipping step may be the minimum region including the joint edge 122 of the coil piece 52. Thereby, an insulating coating (cured product of liquid resin material M0) having a necessary function can be efficiently formed using a relatively small amount (eg, minimum) of liquid resin material M0.

FIG. 22 schematically shows a range Q15 to which the impregnation target part in the second insulation coating process belongs, with respect to the range (hatched area M1) of the liquid resin material M0 impregnated into the workpiece W in the first insulation coating process. is shown.

In this way, in this manufacturing method, the insulation coating process is performed multiple times (in this manufacturing method, twice as an example). This makes it possible to ensure the necessary thickness of the insulation coating (cured product of liquid resin material M0) on the joint edge 122 of the coil piece 52.

When the second insulation coating step is completed, the present manufacturing method includes a heating step (step S222) of heating the workpiece W so that the liquid resin material M0 in the entire workpiece W is cured. This heating step has the function of completely hardening the portion of the liquid resin material M0 that has not been hardened in the various resin curing steps described above (for example, the portion inside the surface). The heating method in the heating step is arbitrary, and may be realized by placing the workpiece W in a furnace, for example. The liquid resin material M0 impregnated into the impregnated region of the workpiece W including the impregnated region is completely cured by being heated. As a result, an insulating coating of the liquid resin material M0 is formed on the stator coil 114.

The posture of the workpiece W in the heating process is arbitrary, but is preferably a downward posture as schematically shown in FIG. 23. Note that FIG. 23 schematically shows a plurality of workpieces W being subjected to a heating process while being arranged side by side in a downward posture. Note that although FIG. 23 schematically shows how a part of the workpiece gripping section 1000 of the manufacturing apparatus holds a plurality of workpieces W, the workpieces W are such that the end surface of the stator core 112 is on the top surface of the stand (not shown). It may be supported by a stand in such a manner that it abuts on the base. Further, in the figure, as an example, heat is radiated from the lower side of the workpiece W (see arrow R17), but the direction of heat radiation is arbitrary.

By the way, in the heating step, in the case of the upward orientation, the liquid resin material M0 that is in the middle of being cured before being completely cured may drip down to the stator core 112 due to its own weight. In this case, it is necessary to separately remove the liquid resin material M0 attached to the stator core 112 using a scraper or the like.

On the other hand, in the case of the downward attitude, even if the liquid resin material M0 that is in the middle of hardening before being completely hardened moves downward under its own weight, it will not reach the stator core 112. In addition, the part of the liquid resin material M0 that has been cured in the upper resin curing process and the inner diameter side resin curing process may function as a "lower lid", causing the dripping liquid resin material M0 to become icicle-shaped. can be reduced. That is, the downward movement of the liquid resin material M0 in the middle of curing is dammed by the portion of the liquid resin material M0 that has been cured in the upper surface resin curing process and the inner diameter side resin curing process. This can prevent inconveniences that may occur when the heating process is performed in a downward position.

In this way, according to the present manufacturing method, by performing the heating process in a downward position, the liquid resin material M0 is prevented from dripping onto the stator core 112, and is cured by the upper surface resin curing process and the inner diameter side resin curing process. The "lower lid" function of the portion of the liquid resin material M0 can reduce the icicle-like hardening of the liquid resin material M0 that drips downward. Note that a similar outer diameter side resin curing process may be performed instead of or in addition to the outer diameter side resin curing process.

Next, with reference to FIG. 24, a cooling structure suitable for the rotating electrical machine 1 incorporating the rotating electrical machine stator 10 manufactured by the present manufacturing method will be described.

FIG. 24 is a diagram schematically showing an example of a cooling structure, and is a diagram schematically showing a part of the cross-sectional structure of the rotating electric machine 1. As shown in FIG.

In the example shown in FIG. 24, oil is supplied to coil end portions 114A at both axial ends of the stator coil 114 from the radially outer side and the radially inner side. Specifically, the oil (see arrow R20A) supplied to the in-case oil passage 60 of the case 2 is supplied to the radially outer side surface of the coil end portion 114A via the oil hole 62 penetrating radially inward. (see arrow R20). Note that the oil hole 62 may be arranged on the upper side in the vertical direction so that dripping of oil by gravity is promoted. Further, the oil supplied to the axial oil passage 64 of the rotor shaft 112A (see arrow R21A) is supplied to the radially inner side surface of the coil end portion 114A through the oil hole 66 penetrating radially outward. (see arrow R21).

According to this manufacturing method, as described above, the coil end portion 114A of the stator coil 114 is provided with an insulating coating of the liquid resin material M0. The portions of the stator coil 114 that are coated with the insulating coating of the liquid resin material M0 have lower thermal conductivity than the portions that are not coated with the insulating coating (that is, the portions where the insulating film 130 is the surface). Therefore, if the exposed range of the radially outer side surface of the coil end portion 114A that is not covered by the insulating coating of the liquid resin material M0 becomes unnecessarily narrow, the cooling performance by the oil from the oil holes 62 described above will be unnecessarily reduced. There is a risk of Similarly, if the exposed range of the radially inner side surface of the coil end portion 114A that is not covered by the insulating coating of the liquid resin material M0 becomes unnecessarily narrow, the cooling performance of the oil from the oil holes 66 described above will deteriorate. There is a risk.

In this regard, according to the present manufacturing method, as described above, the drooping portion M12 of the liquid resin material M0 impregnated into the region to be impregnated in the reattachment rotation step is reduced, so that the workpiece W is then directed upward. Even in the posture, the liquid resin material M0 on the outside in the radial direction does not easily drip downward. This can reduce the possibility that the exposed range of the radially outer side surface of the coil end portion 114A that is not covered with the insulating coating of the liquid resin material M0 will become unnecessarily narrow. As a result, the cooling performance of the coil end portion 114A by the oil from the oil hole 62 described above can be effectively enhanced.

Next, a more preferable manufacturing method will be described with reference to FIGS. 25 and 26.

FIG. 25 is a schematic flowchart illustrating an example of another manufacturing method that may be performed instead of the manufacturing method described above with reference to FIG.

The manufacturing method shown in FIG. 25 differs from the manufacturing method described above with reference to FIG. 1 in that step S2210 and step S2211 are added between step S220 and step S222.

In this manufacturing method, after the insulation coating process is performed ("YES" in step S220), an inspection process (step S2210) is performed to determine whether or not the liquid resin material M0 is attached to the axial end surface 1120 of the stator core 112. including. The presence or absence of adhesion of the liquid resin material M0 may be determined based on the result of image processing on an image from a camera (not shown) that images the workpiece W. In this case, the determination may be performed visually, based on a predetermined algorithm, or using artificial intelligence (machine learning, etc.). Note that in the case of artificial intelligence, determination of a region of interest (ROI) in an image captured by a camera may also be realized based on artificial intelligence. In this case, only adhesion in a harmful manner (for example, adhesion over a range equal to or higher than a threshold value) may be detected.

In this inspection step, the presence or absence of adhesion of the liquid resin material M0 to portions other than the axial end surface 1120 of the stator core 112 (for example, the side surface of the stator core 112) may also be inspected. Note that the deposit M9 attached to the side surface 1122 of the stator core 112 is often also attached to the axial end surface 1120, and may be detected at the same time by inspecting the attachment to the axial end surface 1120.

In FIG. 26, the liquid resin material M0 deposited on the axial end surface 1120 of the stator core 112 is schematically shown as a deposit M9. Such deposits M9 may be generated by dripping from the coil end portion 114A or the neutral line bus bar 59, or by adhesion of the scattered liquid resin material M0.

By the way, in this manufacturing method, the possibility that the hanging portion M12 will adhere to the stator core 112 can be reduced by the liquid draining rotation process (step S211) and the reattachment rotation process (step S213) as described above. However, if the liquid resin material M0 adheres for some reason, it can be detected in the inspection process.

In this inspection process, when adhesion of liquid resin material M0 to stator core 112 (ie, adhesion M9) is detected, the present manufacturing method includes a step of removing adhesion M9 (step S2211). Although the method for removing the deposit M9 is arbitrary, for example, a scraper may be used. However, in this manufacturing method, since the step of removing the deposit M9 is performed before the heating step (step S222), the deposit M9 can be easily removed, and may also be removed by wiping with a waste cloth or the like. . Specifically, even if the deposit M9 is exposed to ultraviolet rays during the ultraviolet irradiation process, it is only cured to a certain extent and is still in a soft temporary hardened state, and it is difficult to remove compared to the completely hardened state caused by the heating process. is easy. For example, when wiping with a waste cloth or the like, unlike when using a scraper, there is no damage to the stator core 112, etc., and the workability is good.

In this manner, according to the present manufacturing method, the liquid resin material M0 attached to the stator core 112 can be easily removed by performing the above-described inspection step before the heating step. In particular, when the liquid resin material M0 contains an epoxy resin as a main component, it becomes difficult to remove even with a scraper after hardening by the heating process. Further, even if it can be removed with a scraper, the cured resin may scatter or crack, and the removed material (resin scum) may adhere to the workpiece W as a foreign material. Further, there is also a risk that the workpiece W (particularly the stator core 112) may be scratched (damaged) by the scraper. On the other hand, according to the present manufacturing method, as described above, by performing the inspection process before the heating process, these inconveniences can be effectively avoided.

In addition, in this manufacturing method, the inspection process (step S2210) and the process of removing the deposit M9 (step S2211) are performed after the ultraviolet irradiation process (step S216 and step S218) related to the second insulation coating process. However, it may be performed before the ultraviolet irradiation step (step S216 or step S218) related to the second insulation coating step and after step S214. In this case, the liquid resin material M0 may be cured (although only to a certain extent as described above) due to the ultraviolet irradiation in the ultraviolet irradiation step (step S216 or step S218) related to the second insulation coating step. It is possible to reduce the

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 this embodiment, since the liquid draining rotation process (step S211) and the reattachment rotation process (step S213) are included as described above, the workpiece W is changed from the downward position after the immersion process (step S208) to the upward position. The liquid resin material M0 that may drip onto the stator core 112 during inversion (see step S214) can be reduced or eliminated. Therefore, in this embodiment, it is possible to reduce or eliminate the need to irradiate the part to be impregnated with ultraviolet rays (for example, to the outer diameter side of the part to be impregnated) while the workpiece W pulled up from the tank 600 faces downward. . However, in a modified example, a step may be added after the liquid draining rotation step in step S211, in which the workpiece W is slightly raised while facing downward, and then the outer diameter side of the region to be impregnated is irradiated with ultraviolet rays. In this case, the subsequent steps S212 and S213 may be omitted.

Furthermore, in the above embodiment, as a preferable example, both the liquid draining rotation process (step S211) and the reattachment rotation process (step S213) are executed, but the reattachment rotation process (step S213) may be omitted. good.

DESCRIPTION OF SYMBOLS 1... Rotating electrical machine, 10... Stator for rotating electrical machine, 40... Coupling part (tip part), 114... Stator coil, 112... Stator core, W... Work, 52... Coil piece, 600...tank, M0...liquid resin material, I...center axis (stator center axis)

Claims (5)

A preparation step for preparing a workpiece in which a plurality of coil pieces forming a stator coil are attached to a stator core, the tip portions of one coil piece and the other coil piece being aligned at one end in the axial direction. a preparation step of preparing the workpieces to be joined;
After the preparation step, a dipping step of immersing the workpiece in a tank of liquid resin material so that the region to be impregnated including the joint between the tips is immersed;
After the dipping step, the stator center is placed in a raised position of the workpiece where the region to be impregnated is away from the tank, and in a first posture of the workpiece in which the region to be impregnated faces the tank in the vertical direction. A method for manufacturing a stator for a rotating electrical machine, comprising: a first rotation step of rotating the workpiece around a center axis of the workpiece corresponding to the shaft. The first rotation step includes rotating the workpiece at the elevated position where the liquid resin material adhering to the impregnation target site and the liquid resin material in the tank are connected. A method for manufacturing a stator for rotating electric machines. The rotation according to claim 2, wherein the first rotation step includes rotating the workpiece so that the liquid resin material adhering to the impregnating target region and the liquid resin material in the tank are separated. A method for manufacturing stators for electrical machinery. After the first rotation step, the posture of the workpiece is changed from the first posture to a second posture of the workpiece in which the region to be impregnated faces in a direction intersecting the vertical direction, and then the workpiece is rotated into the second posture. The method for manufacturing a stator for a rotating electric machine according to claim 1, further comprising a second rotation step of rotating the workpiece around the central axis. Liquid resin material has the property of being hardened by irradiation with ultraviolet rays.
5. The method for manufacturing a stator for a rotating electric machine according to claim 4, further comprising an irradiation step of irradiating the impregnation target region with ultraviolet rays after the second rotation step.