Laser removal method, method for manufacturing a rotating electrical machine, and laser removal apparatus

Abstract

A laser removal method according to an embodiment involves using a laser beam to irradiate a filmy body formed on a substrate to remove the filmy body. The laser removal method comprises the steps of: irradiating a filmy body with a first laser beam and moving the irradiation position of the first laser beam to form a linear recess in the filmy body; and using a second laser beam to irradiate the filmy body, which is in a region defined by the linear recess. The first laser beam has a wavelength at which absorptivity with regard to the filmy body is higher than absorptivity with regard to the substrate. The second laser beam has a wavelength at which absorptivity with regard to the substrate is higher than absorptivity with regard to the filmy body.

Description

Technical Field

[0001] Embodiments of the present invention relate to a laser removal method, a method for manufacturing a rotating electrical machine, and a laser removal device.

Background Art

[0002] An unnecessary film-like body may be formed on a base material. For example, when applying a material such as resin to the surface of a base material containing a metal such as iron, the material such as resin may adhere to an unintended area. For example, when an insulating material such as varnish, an adhesive, a paint, etc. are supplied to the base material, these may adhere to an unintended area of the base material. When a material such as resin adhering to an unintended area of the base material hardens, an unnecessary film-like body is formed on the base material. If an unnecessary film-like body is formed on the base material, it may be difficult to attach a member to the base material, or the commercial value may decrease.

[0003] Therefore, a technique has been proposed in which laser light having a wavelength that is more easily absorbed by the film-like body than by the base material is irradiated onto the film-like body to remove the film-like body. In this way, it is possible to remove the film-like body while suppressing damage to the base material. However, since the unnecessary film-like body does not have a controlled thickness, the thickness variation becomes large. When laser light is irradiated under predetermined conditions in the case of a large thickness variation, there may be a residue in the thick portion of the film-like body. In this case, if the thickness of the film-like body is measured and the irradiation conditions of the laser light are changed based on the measurement result, the removal time becomes long or the configuration of the laser removal device becomes complicated.

[0004] Also, a technique has been proposed in which laser light having a wavelength that is more easily absorbed by the base material than by the film-like body is irradiated onto the film-like body to remove the film-like body. In this case, the irradiated laser light passes through the film-like body and reaches the interface between the film-like body and the base material. Then, due to the impact, heat, etc. generated when the laser light is incident on the interface, the film-like body is peeled off from the base material. However, in the vicinity of the boundary between the area of the film-like body irradiated with the laser light and the surrounding area, there may be a residue of the film-like body. Therefore, the development of a technology capable of suppressing the remaining film-like body has been desired.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] The problem to be solved by the present invention is to provide a laser removal method, a method for manufacturing a rotating electrical machine, and a laser removal device capable of suppressing the remaining film-like body.

Means for Solving the Problems

[0007] The laser removal method according to the embodiment is a laser removal method for irradiating a film-like body formed on a base material with laser light to remove the film-like body. The laser removal method includes a step of irradiating the film-like body with first laser light and moving the irradiation position of the first laser light to form a linear recess in the film-like body, and a step of irradiating the film-like body in a region defined by the linear recess with second laser light. The first laser light has a wavelength at which the absorption rate with respect to the film-like body is higher than the absorption rate with respect to the base material. The second laser light has a wavelength at which the absorption rate with respect to the base material is higher than the absorption rate with respect to the film-like body.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

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Figure 5

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Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying out the Invention

[0009] In the laser removal method according to the present embodiment, laser light is irradiated onto a film-like body formed on a substrate to remove the film-like body. For example, the laser removal method according to the present embodiment can be used to remove an unnecessary film-like body formed on a substrate, or to cut out an arbitrary region of the film-like body into a predetermined shape and size. For example, the laser removal method according to the present embodiment can be used to remove an unnecessary resin film (for example, a film containing an adhesive, a paint, an insulating material, etc.) formed on a plate-like body or a block containing metal, or to cut out an arbitrary region of the resin film into a predetermined shape and size.

[0010] For example, in rotating electrical machines such as motors and generators, coils wound around a core are provided. In recent years, after inserting a plurality of segments into slots provided in the core, the ends of adjacent segments are laser welded to form a coil. Then, varnish is supplied to the gap between the slot and the coil, and the varnish is cured to fix the coil to the core.

[0011] Here, when the varnish is supplied, the varnish may adhere to the ends, outer portions, inner portions, etc. of the core. When the adhered varnish cures to form a film-like body, it may become difficult to attach a member such as a cover to the end of the core, or the commercial value may decrease.

[0012] Therefore, hereinafter, as an example, a laser removal method for removing an unnecessary varnish film formed on the end of the core, etc. in the manufacture of a stator will be described. Note that the laser removal method according to the present embodiment can also be used in the manufacture of a rotor. That is, the laser removal method according to the present embodiment can be used in the manufacture of rotating electrical machines.

[0013] Hereinafter, embodiments will be illustrated while referring to the drawings. In each drawing, the same reference numerals are given to the same components, and detailed descriptions are appropriately omitted. First, the stator 1 will be illustrated. FIG. 1 is a schematic perspective view for illustrating the stator 1. As shown in FIG. 1, the stator 1 is provided with a core 2 and a coil 3.

[0014] The core 2 can be formed by stacking a plurality of annular magnetic members in the axial direction (Z direction in FIG. 1) of the stator 1. The magnetic member can be formed of, for example, an electromagnetic steel sheet (silicon steel sheet). The core 2 has a yoke 21 and a plurality of teeth 22. The yoke 21 has a cylindrical shape and is located on the outer peripheral side of the core 2. The plurality of teeth 22 are provided at equal intervals on the inner peripheral surface of the yoke 21. Each of the plurality of teeth 22 protrudes from the inner peripheral surface of the yoke 21 toward the center of the core 2 and has a form extending in the axial direction of the stator 1. In addition, the groove provided between the teeth 22 becomes the slot 23. Note that the shape, number, and size of the teeth 22 are not limited to those exemplified, and can be appropriately changed according to the application, size, specifications, etc. of the rotating electrical machine in which the stator 1 is provided.

[0015] The coil 3 includes a plurality of segments 31. The segment 31 has a conductor portion 31a and an insulating film 31b (see, for example, FIG. 2). The conductor portion 31a has a substantially U shape and is formed of a material having a high conductivity. The conductor portion 31a is formed of, for example, so-called pure copper or a material mainly composed of copper. The conductor portion 31a is formed of, for example, a flat wire. The insulating film 31b covers the outer surface of the conductor portion 31a. However, the insulating film 31b is not provided in the vicinity of both ends of the conductor portion 31a, and the conductor portion 31a is exposed. The insulating film 31b contains, for example, enamel.

[0016] The ends of adjacent conductor portions 31a are laser welded. One coil 3 is formed by connecting the plurality of segments 31 via the welded portion 31c. In addition, an insulating portion 31d that covers the exposed portion of the conductor portion 31a and the welded portion 31c can be provided.

[0017] A plurality of coils 3 are provided. The plurality of coils 3 can be arranged in the radial direction of the core 2 (the direction perpendicular to the Z direction passing through the central axis of the core 2). For example, as illustrated in FIG. 1, three coils 3 of U-phase, V-phase, and W-phase can be provided. Note that the external shapes, numbers, sizes, etc. of the coil 3 and the segment 31 are not limited to those illustrated, and can be appropriately changed according to the application, size, specifications, etc. of the rotating electric machine in which the stator 1 is provided. For example, four coils 3 may be arranged side by side in the radial direction of the core 2.

[0018] Next, the laser removal method according to the present embodiment will be described together with the manufacturing method of the stator 1. First, the core 2 is formed. For example, a plurality of plate-shaped magnetic body members having yokes 21 and portions that become a plurality of teeth 22 are formed. For example, the magnetic body member is formed by punching an electromagnetic steel sheet having a thickness of about 0.05 mm to 1.0 mm. Then, the plurality of magnetic body members are laminated, and for example, the core 2 is formed by welding or caulking the plurality of magnetic body members. Note that the core 2 can also be formed by pressure-molding magnetic material powder and a resin binder.

[0019] Next, a plurality of segments 31 that are components of the coil 3 are formed. FIG. 2 is a schematic diagram for exemplifying the segment 31. First, a conductor portion 31a is formed by bending a flat wire having a predetermined length into a substantially U shape. Subsequently, a paint containing enamel or the like is applied to the outer surface of the conductor portion 31a to form an insulating film 31b. Note that a paint containing enamel or the like may be applied to the surface of the flat wire, and this may be cut to a predetermined length and bent into a substantially U shape. Alternatively, a flat wire coated with enamel or the like may be purchased, cut to a predetermined length, and bent into a substantially U shape.

[0020] Next, as shown in FIG. 2, the insulating film 31b in the vicinity of both ends of the conductor portion 31a is peeled off to expose the conductor portion 31a. The segments 31 are formed in the above manner.

[0021] Next, the ends of the plurality of segments 31 are welded together to form the coil 3. FIG. 3 is a schematic diagram for exemplifying the formation of the coil 3. First, as shown in FIG. 3, each of the plurality of segments 31 is mounted in a predetermined slot 23 of the core 2. For example, each of the plurality of segments 31 is inserted into the predetermined slot 23 from the axial direction (Z direction in FIG. 3) of the core 2. At this time, one segment 31 is inserted across a plurality of slots 23. The coil 3 can be a so-called distributed winding coil. Also, the coil 3 can be a so-called wave winding coil.

[0022] Subsequently, the portion of the segment 31 protruding from the core 2 is bent in a direction approaching the adjacent segment 31. Then, further, the vicinity of the portion of the conductor portion 31a exposed from the insulating film 31b is bent in the axial direction (Z direction in FIG. 3) of the core 2. In the circumferential direction of the core 2, the portion of the conductor portion 31a exposed from the insulating film 31b is made to overlap the portion of the adjacent conductor portion 31a exposed from the insulating film 31b. Then, by repeating the above procedure, a plurality of sets of the plurality of segments 31 arranged in the circumferential direction of the core 2 are provided in the radial direction of the core 2.

[0023] Note that, although the case where the bending process is performed after mounting the plurality of segments 31 in the slots 23 has been exemplified, it is not limited to this. For example, the plurality of segments 31 can be bent, and each of the plurality of bent segments 31 can be mounted in a predetermined slot 23. In this case, the bent segment 31 can be mounted from the inside to the outside of the core 2.

[0024] Subsequently, the ends of adjacent segments 31 (conductor portions 31a) are welded together to form the coil 3 mounted in the slot 23. When performing the welding, a jig for bringing the ends of adjacent conductor portions 31a closer to each other can be used. Note that the welding can also be performed without using a jig. However, if a jig is used, the quality of the welded portion 31c can be improved and the workability of the welding operation can be improved.

[0025] The welding of the ends of adjacent conductor portions 31a can be performed by irradiating the ends of the conductor portions 31a with laser light. That is, the ends of adjacent conductor portions 31a can be laser welded.

[0026] For laser welding, laser light having a wavelength in the infrared region can be used. If laser light having a wavelength in the infrared region is used, it becomes easy to irradiate laser light with a relatively high output. For example, the output of the laser light can be about 4 kW.

[0027] The laser welding apparatus used for welding the ends of the conductor portions 31a can be, for example, a fiber laser welding apparatus, a disk laser welding apparatus, or the like. The laser welding apparatus is preferably a CW laser (Continuous wave laser) welding apparatus capable of continuously emitting laser light. Further, the irradiation position of the laser light of the laser welding apparatus is movable. For example, the laser welding apparatus can be provided with a galvanometer mirror or the like.

[0028] By welding the ends of adjacent conductor portions 31a together, the welded portion 31c illustrated in FIGS. 1 and 3 is formed. Also, by connecting a plurality of segments 31 (conductor portions 31a) in series, one coil 3 is formed. Further, a plurality of coils 3 arranged in the radial direction of the core 2 are formed. For example, by shifting the slots 23 one by one, three coils 3 of U-phase, V-phase, and W-phase can be formed.

[0029] Next, a plurality of coils 3 are fixed to the core 2. For example, varnish is supplied to the gap between the slot 23 and the coil 3, and the varnish is cured to fix the coil 3 to the core 2.

[0030] Also, as shown in FIG. 3, an insulating material is applied to the exposed portion of the conductor part 31a of the coil 3 and the welding part 31c to form an insulating part 31d. The insulating material can be, for example, varnish. If the material used for fixing the coil 3 and forming the insulating part 31d is the same, the fixing of the coil 3 and the formation of the insulating part 31d can be performed in the same process. Note that the materials used for fixing the coil 3 and forming the insulating part 31d are not limited to varnish. For example, a material containing resin can be appropriately used.

[0031] Here, when varnish is supplied to the gap between the slot 23 and the coil 3, the varnish may adhere to the end portion, outer surface, inner surface, etc. of the core 2. Also, when, for example, varnish is applied to the exposed portion of the conductor part 31a and the welding part 31c, the varnish may adhere to the end portion, outer surface, inner surface, etc. of the core 2. When the adhered varnish cures, as shown in FIG. 1, an unnecessary film-like body 4 is formed on the end portion, outer surface, inner surface, etc. of the core 2.

[0032] When the film-like body 4 is formed, for example, it becomes difficult to attach a member such as a cover to the end portion or outer surface of the core 2, or it becomes difficult to attach a cylindrical insulating cover to the inner surface of the core 2.

[0033] Therefore, next, the film-like body 4 is removed. The removal of the film-like body 4 is performed by irradiating laser light toward the film-like body 4. FIG. 4 is a schematic cross-sectional view for exemplifying the removal of the film-like body 4 according to the comparative example. As shown in FIG. 4, the film-like body 4 can be removed by irradiating the film-like body 4 with the laser beam 201 to heat the film-like body 4. In this case, the absorption rate of the laser beam 201 with respect to the material is inherent to the material and depends on the wavelength of the laser beam 201. Therefore, the laser beam 201 preferably has a wavelength at which the absorption rate with respect to the film-like body 4 is higher than the absorption rate with respect to the core 2. In this way, heating of the film-like body 4, and thus removal of the film-like body 4, becomes easy.

[0034] As described above, the film-like body 4 contains varnish (resin), and the core 2 contains a magnetic material (metal). Therefore, the wavelength of the laser beam 201 can be, for example, about 9360 nm. If the laser beam 201 has such a wavelength, the film-like body 4 can be efficiently removed, and damage to the core 2 can be suppressed.

[0035] However, since the film-like body 4 is not intentionally formed by controlling the thickness or the like, as shown in FIG. 4, the thickness variation becomes large. When the laser beam 201 is irradiated under predetermined conditions in the case of a large thickness variation, there may be a residue in the thick portion of the film-like body 4. In this case, if the thickness of the film-like body 4 is measured and the irradiation conditions of the laser beam 201 are changed based on the measurement result, the removal time becomes long or the configuration of the laser removal device becomes complicated.

[0036] FIG. 5 is a schematic cross-sectional view for illustrating the removal of the film-like body 4 according to another comparative example. As shown in FIG. 5, the film-like body 4 can be peeled off from the core 2 by irradiating the interface between the film-like body 4 and the core 2 with the laser beam 202. In this case, the laser beam 202 preferably has a wavelength at which the absorption rate with respect to the core 2 is higher than the absorption rate with respect to the film-like body 4. The wavelength of the laser beam 202 can be, for example, about 1064 nm.

[0037] If the laser beam 202 has such a wavelength, the irradiated laser beam 202 passes through the film-like body 4 and reaches the interface between the film-like body 4 and the core 2. Then, due to the impact, heat, etc. generated when the laser beam 202 is incident on the interface, the film-like body 4 is peeled off from the core 2.

[0038] In this way, even if there is a variation in the thickness of the film-like body 4, the film-like body 4 can be removed without changing the irradiation conditions of the laser beam 202.

[0039] However, at the boundary between the region of the film-like body 4 irradiated with the laser beam 202 and the surrounding region, there may be a residue of the film-like body 4 on the surface of the core 2. FIGS. 6(a) to (c) are schematic process diagrams for exemplifying the residue of the film-like body 4. For example, when removing the film-like body 4 in the removal region S, as shown in FIG. 6(a), the laser beam 202 is irradiated toward the boundary of the removal region S. The laser beam 202 irradiated on the boundary of the removal region S passes through the film-like body 4 and reaches the interface between the film-like body 4 and the core 2. Then, the irradiation position of the laser beam 202 is moved over the entire removal region S.

[0040] As shown in FIG. 6(b), in the removal region S, due to the impact, heat, etc. generated when the laser beam 202 is incident on the interface between the film-like body 4 and the core 2, the film-like body 4 is peeled off from the core 2. However, the film-like body 4 in the removal region S is connected to the film-like body 4 around the removal region S. Also, since the laser beam 202 is not irradiated around the removal region S, the film-like body 4 around the removal region S remains joined to the core 2.

[0041] Therefore, as shown in FIG. 6(c), near the periphery of the removal region S, a part of the peeled film-like body 4 may be torn off and a part of the film-like body 4 may remain on the surface of the core 2. That is, there may be a residue of the film-like body 4 on the surface of the core 2.

[0042] In addition, the laser beam 202 is likely to be absorbed by the core 2. Therefore, if the output of the laser beam 202 is increased too much or the power density is increased too much, damage may occur on the surface of the core 2 as shown in FIG. 5. In this case, if the output of the laser beam 202 is decreased or the power density is decreased, it is possible to suppress the occurrence of damage on the surface of the core 2. However, if this is done, the removal time will become longer.

[0043] FIGS. 7(a) to 9(c) are schematic process diagrams for exemplifying the removal of the film-like body 4 using the laser removal method according to the present embodiment. Note that FIG. 7(b) is a schematic cross-sectional view in the direction of line A-A in FIG. 7(a). FIG. 8(b) is a schematic cross-sectional view in the direction of line B-B in FIG. 8(a). FIG. 9(b) is a schematic cross-sectional view in the direction of line C-C in FIG. 9(a). FIGS. 7(a) to 9(b) show the case of removing the film-like body 4b in the removal region S1.

[0044] First, as shown in FIGS. 7(a) and 7(b), the laser beam 203 (corresponding to an example of the first laser beam) is irradiated on the outer edge of the removal region S1. For example, the laser beam 203 is irradiated at the position of the contour of the removal region S1. The laser beam 203 has a wavelength with a higher absorption rate for the film-like body 4 than for the core 2, similar to the laser beam 201 described above. The wavelength of the laser beam 203 can be, for example, 6000 nm or more and 20000 nm or less. The average power of the laser beam 203 can be, for example, about 450 W. The repetition frequency of the laser beam 203 can be, for example, about 500 kHz. The pulse width of the laser beam 203 can be, for example, about 7200 ns.

[0045] Next, the irradiation position of the laser beam 203 is moved along the contour of the removal region S1. Although the case where the contour of the removal region S1 is a rectangle is exemplified, the shape (contour) and size of the removal region S1 can be appropriately changed.

[0046] Since the laser beam 203 has a wavelength with a high absorption rate for the film-like body 4, the portion of the film-like body 4 irradiated with the laser beam 203 is removed by being heated.

[0047] Therefore, as shown in FIGS. 8(a) and 8(b), a linear recess 4a (for example, a groove) is formed along the contour of the removal region S1. In this case, as shown in FIG. 8(b), the core 2 can be exposed at the bottom of the recess 4a.

[0048] Next, as shown in FIGS. 9(a) and 9(b), the film-like body 4b (the film-like body 4b in the region defined by the recess 4a) in the removal region S1 is irradiated with a laser beam 204 (corresponding to an example of a second laser beam). Similar to the laser beam 202 described above, the laser beam 204 has a wavelength with an absorption rate for the core 2 higher than the absorption rate for the film-like body 4b. The wavelength of the laser beam 204 can be, for example, 600 nm or more and 2000 nm or less. The average power of the laser beam 204 can be, for example, about 50 W. The repetition frequency of the laser beam 204 can be, for example, about 500 kHz. The pulse width of the laser beam 204 can be, for example, about 120 ns.

[0049] Next, the irradiation position of the laser beam 204 is moved over the entire removal region S1. In the removal region S1, the film-like body 4b is peeled off from the core 2 due to impacts, heat, etc. generated when the laser beam 204 is incident on the interface between the film-like body 4b and the core 2.

[0050] At this time, the film-like body 4b in the removal region S1 is separated from the film-like body 4 around the removal region S1 by the recess 4a. Therefore, as shown in FIG. 9(c), when the film-like body 4b in the removal region S1 is peeled off from the core 2, it is possible to suppress a part of the peeled film-like body 4b from being torn off. That is, it is possible to suppress the occurrence of remnants of the film-like body 4b on the surface of the core 2.

[0051] Although the case where the core 2 is exposed at the bottom of the concave portion 4a has been illustrated, even if a thin film-like body 4 remains at the bottom of the concave portion 4a, it is possible to suppress a part of the peeled-off film-like body 4b from being torn. However, if the core 2 is exposed at the bottom of the concave portion 4a, it is possible to more reliably suppress the remaining film-like body 4b on the surface of the core 2.

[0052] In addition, although the case where the frame-shaped concave portion 4a is provided in plan view has been illustrated, it is not necessarily limited to this. The planar shape of the concave portion 4a can be appropriately changed according to, for example, the planar shape of the film-like body 4, the position of the removal region S1 in the film-like body 4, and the planar shape and size of the removal region S1.

[0053] Figs. 10(a) to (d) are schematic diagrams for illustrating the planar shapes of the concave portions 4a1 to 4a4 according to other embodiments. When the planar shape of the film-like body 4 is strip-shaped, for example, as shown in Fig. 10(a), it can be a linear concave portion 4a1 extending between the end portions in the short-side direction of the film-like body 4. When the film-like body 4 is formed on the periphery of the base material 2a (for example, the core 2), for example, as shown in Figs. 10(b) and (c), it can be concave portions 4a2 and 4a3 opening to the periphery of the base material 2a.

[0054] In addition, although the concave portions 4a, 4a1 to 4a3 having a shape composed of straight lines have been illustrated, for example, as shown in Fig. 10(d), it can also be a concave portion 4a4 having a shape composed of curves. Note that it can also be a concave portion having a shape composed of straight lines and curves. That is, it is sufficient that a region defined by the linear concave portions 4a, 4a1 to 4a4 is formed.

[0055] In addition, in the above, as the laser removal method according to the present embodiment, the case of removing the unnecessary film-like body 4 formed on the base material 2a (for example, the core 2) has been described. However, the laser removal method according to the present embodiment can also be used, for example, when cutting out an arbitrary region of the film-like body 4 formed on the base material 2a into a predetermined shape and size.

[0056] As described above, the laser removal method according to this embodiment can include the following steps. A step of irradiating the film-like body 4 with the laser beam 203 and moving the irradiation position of the laser beam 203 to form a linear recess 4a in the film-like body 4. A step of irradiating the film-like body 4b in the region defined by the linear recess 4a with the laser beam 204. In this case, in the step of irradiating the laser beam 204, the film-like body 4b in the region defined by the linear recess 4a peels off from the base material 2a (for example, the core 2).

[0057] Also, as described above, the method for manufacturing a rotating electrical machine according to this embodiment can include the following steps. A step of providing the coil 3 in a plurality of slots 23 of the core 2. A step of supplying varnish between the plurality of slots 23 and the coil 3. A step of removing the unnecessary film-like body 4 formed by the curing of the varnish. Then, in the step of removing the unnecessary film-like body 4, the unnecessary film-like body 4 is irradiated with the laser beam 203, and the irradiation position of the laser beam 203 is moved to form a linear recess 4a in the unnecessary film-like body 4. The unnecessary film-like body 4b in the region defined by the linear recess 4a is irradiated with the laser beam 204. By irradiating the laser beam 204, the unnecessary film-like body 4b in the region defined by the linear recess 4a peels off.

[0058] Next, the laser removal device 100 will be exemplified. The laser removal device 100 irradiates a film-like body 4 formed on a base material 2a (for example, the core 2) with a laser beam to remove the film-like body 4. In the following, as an example, the laser removal device 100 for removing the film-like body 4 formed on the stator 1 will be described.

[0059] FIG. 11 is a schematic diagram for exemplifying the laser removal device 100. As shown in FIG. 11, the laser removal device 100 includes, for example, a laser irradiation unit 101 (corresponding to an example of a first laser irradiation unit), a laser irradiation unit 102 (corresponding to an example of a second laser irradiation unit), a detection unit 103, a placement unit 104, an illumination unit 105, and a controller 106.

[0060] The laser irradiation unit 101 irradiates the film-like body 4 with the laser beam 203 and moves the irradiation position of the laser beam 203 to form a linear recess 4a in the film-like body 4. The laser irradiation unit 101 has, for example, a laser oscillator 101a and a laser head 101b. The laser oscillator 101a oscillates the laser beam 203. The laser oscillator 101a can include a galvanometer mirror or the like. As described above, the laser beam 203 has a wavelength at which the absorption rate with respect to the film-like body 4 is higher than the absorption rate with respect to the core 2. The laser oscillator 101a can be, for example, a CO2 laser oscillator. When the laser oscillator 101a is a CO2 laser oscillator, the wavelength of the laser beam 203 is about 9360 nm. The laser head 101b irradiates the outer edge (the position of the contour of the removal region S1) of the removal region S1 of the film-like body 4 with the laser beam 203 transmitted from the laser oscillator 101a. The laser head 101b can include, for example, a reflecting mirror, a condenser lens, or the like.

[0061] The laser irradiation unit 102 irradiates the film-like body 4b in the region defined by the linear recess 4a with the laser beam 204. The laser irradiation unit 102 has, for example, a laser oscillator 102a and a laser head 102b. The laser oscillator 102a oscillates the laser beam 204. The laser oscillator 102a can be provided with a galvano mirror or the like. As described above, the laser beam 204 has a wavelength at which the absorption rate with respect to the core 2 is higher than the absorption rate with respect to the film-like body 4. The laser oscillator 102a can be, for example, an ytterbium nanosecond pulse laser oscillator. When the laser oscillator 102a is an ytterbium nanosecond pulse laser oscillator, the wavelength of the laser beam 204 is about 1064 nm. The laser head 102b irradiates the film-like body 4b in the removal region S1 with the laser beam 204 transmitted from the laser oscillator 102a. The laser head 102b can be provided with, for example, a reflecting mirror, a condenser lens, or the like.

[0062] The detection unit 103 detects the film-like body 4 formed on the stator 1. For example, the detection unit 103 can be provided for each part of the core 2. For example, a detection unit 103a that detects the film-like body 4 formed on the inner surface of the core 2 can be provided. For example, a detection unit 103b that detects the film-like body 4 formed at the end of the core 2 can be provided. For example, a detection unit 103a that detects the film-like body 4 formed on the outer surface of the core 2 can be provided. The detection units 103a to 103c can be, for example, a CCD image sensor or the like.

[0063] The mounting unit 104 holds the stator 1 and changes the position of the stator 1. For example, the mounting unit 104 rotates the stator 1 about the central axis of the core 2 as the rotation center. Also, the mounting unit 104 can arbitrarily set the rotation position of the stator 1. The mounting unit 104 can be provided with, for example, a control motor such as a servo motor.

[0064] The lighting unit 105 irradiates light toward the stator 1. For example, the lighting unit 105 irradiates light in the ultraviolet region toward the stator 1. When the light in the ultraviolet region is incident on the film-like body 4 containing the varnish, the film-like body 4 is excited and emits light. If the film-like body 4 emits light, it becomes easier to detect the film-like body 4 by the detection units 103a to 103c. The lighting unit 105 can be provided with, for example, a light-emitting diode that irradiates ultraviolet light having a peak wavelength of about 405 nm.

[0065] The controller 106 controls the operations of the respective elements provided in the laser removal device 100 to execute the above-described laser removal method. For example, the controller 106 includes an arithmetic unit such as a CPU (Central Processing Unit) and a storage unit such as a semiconductor memory. The controller 106 is, for example, a computer. The storage unit can store a control program for controlling the operations of the respective elements provided in the laser removal device 100. The arithmetic unit controls the operations of the respective elements provided in the laser removal device 100 using the control program stored in the storage unit and data input by the operator.

[0066] For example, the controller 106 controls the lighting unit 105 to irradiate light toward the stator 1. Further, the controller 106 controls the placement unit 104 to move the position of the stator 1. When the film-like body 4 is detected by the detection units 103a to 103c, the controller 106 calculates the position, planar shape, size, etc. of the removal region S1 based on the position information from the placement unit 104 and the information from the detection units 103a to 103c (for example, the shape and size of the film-like body 4). For example, the controller 106 can calculate the shape and size of the film-like body 4 by performing image processing.

[0067] Next, the controller 106 moves the film-like body 4 to be removed to the irradiation positions of the laser irradiation units 101 and 102. Next, the controller 106 controls the laser irradiation units 101 and 102 to execute the above-described laser removal method, thereby removing the film-like body 4. Since the procedure for removing the film-like body 4 is the same as the above-described laser removal method, detailed description thereof is omitted.

[0068] As described above, some embodiments of the present invention have been illustrated. However, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, changes, etc. can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof. Further, the above-described embodiments can be implemented in combination with each other.

Explanation of Reference Numerals

[0069] 1 Stator 2 Core 3 Coil 4 Film-like body 4a Concave portion 4a1 to 4a4 Concave portions 4b Film-like body 23 Slot 31 Segment 31a Conductor portion 31b Insulating film 31c Welding portion 31d Insulating portion 100 Laser removal device 101 Laser irradiation unit 102 Laser irradiation unit 103 Detection unit 203 Laser beam 204 Laser beam S1 Removal region

Claims

1. A laser ablation method for irradiating a film-like body formed on a substrate with laser light to remove the film-like body, comprising: a step of irradiating the film-like body with first laser light and moving the irradiation position of the first laser light to form linear recesses in the film-like body; a step of irradiating the film-like body in a region defined by the linear recesses with second laser light; The method is characterized by comprising: the first laser light having a wavelength at which the absorption rate with respect to the film-like body is higher than the absorption rate with respect to the substrate; the second laser light having a wavelength at which the absorption rate with respect to the substrate is higher than the absorption rate with respect to the film-like body.

2. The laser ablation method according to claim 1, wherein in the step of irradiating the second laser light, the film-like body in the region defined by the linear recesses is peeled off from the substrate.

3. The substrate contains metal; The film-like body contains resin. The laser ablation method according to claim 1 or 2.

4. a step of providing coils in a plurality of slots of a core; a step of supplying varnish between the plurality of slots and the coils; a step of removing an unnecessary film-like body formed by curing the varnish; The method is characterized by comprising: in the step of removing the unnecessary film-like body, irradiating the unnecessary film-like body with first laser light and moving the irradiation position of the first laser light to form linear recesses in the unnecessary film-like body; irradiating the unnecessary film-like body in a region defined by the linear recesses with second laser light; the first laser light having a wavelength at which the absorption rate with respect to the unnecessary film-like body is higher than the absorption rate with respect to the core; the second laser light having a wavelength at which the absorption rate with respect to the core is higher than the absorption rate with respect to the unnecessary film-like body. A method for manufacturing a rotating electrical machine.

5. The method for manufacturing a rotating electrical machine according to claim 4, wherein by irradiating the second laser light, the unnecessary film-like body in the region defined by the linear recesses is peeled off.

6. A laser ablation apparatus for irradiating a film-like body formed on a substrate with laser light to remove the film-like body, comprising: a first laser irradiation unit that irradiates the film-like body with first laser light and moves the irradiation position of the first laser light to form linear recesses in the film-like body; a second laser irradiation unit that irradiates the film-like body in a region defined by the linear recesses with second laser light; The apparatus is characterized by comprising: The first laser beam has a wavelength at which the absorption rate with respect to the film-like body is higher than the absorption rate with respect to the base material. A laser removal device in which the second laser beam has a wavelength at which the absorption rate with respect to the base material is higher than the absorption rate with respect to the film-like body. **Claim 7** The laser removal device according to claim 6, further comprising a detection unit that detects the film-like body.

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