JP7516654B2 - Coating removal method and coating removal device - Google Patents

Description

The present invention relates to a coating removal method and a coating removal device.

Conventionally, a coating removal method and a coating removal device are known that remove the coating of an electric wire by irradiating the wire with laser light to expose the conductor covered by the coating. (Patent Document 1)

JP 2017-220634 A

In this type of coating removal method, it would be beneficial to have a new and improved coating removal method that, for example, can remove the coating more reliably or more efficiently.

Therefore, one of the objectives of the present invention is, for example, to obtain an improved new coating removal method and coating removal apparatus.

The coating removal method of the present invention is, for example, a method for removing the insulating coating of an electric wire having a core wire and an insulating coating made of an organic polymer material by irradiating the wire with laser light, and the insulating coating is removed by irradiating the laser light while supplying oxygen.

In the coating removal method, the oxygen may be supplied from the side opposite the boundary between the remaining portion of the insulating coating and the removal area.

In the coating removal method, the oxygen may be supplied toward the boundary or toward the core wire of the removal area.

In the coating removal method, the removal area may expand in a first direction, and the oxygen may be supplied in a direction that includes a component of the first direction.

In the coating removal method, the laser light may be a continuous wave.

In the coating removal method, the beam of laser light may be scanned along the surface of the electric wire.

In the coating removal method, the oxygen may be supplied in a direction that includes a component in the scanning direction of the beam.

In the coating removal method, in a cross section intersecting the irradiation direction of the beam, the length of the irradiation area of the beam in a direction intersecting the scanning direction may be longer than the length of the irradiation area in the scanning direction.

In the coating removal method, when the beam is scanned over a predetermined area of the surface to remove the insulating coating, the irradiation area may extend to both ends of the predetermined area in a direction intersecting the scanning direction.

In the coating removal method, the beam may be shaped by a beam shaper.

In the coating removal method, the scanning direction of the beam may change over time.

In the coating removal method, the oxygen supply direction may be switched depending on changes in the scanning direction over time.

In the coating removal method, when the scanning direction changes over time, the oxygen may be supplied only when the beam is scanned in a particular direction.

In the coating removal method, the beam may move in a reversing or spiral manner on the surface so that the removal area of the insulating coating gradually expands during at least a portion of the beam scan.

In the coating removal method, the irradiation power of the laser light per unit area of the surface may be changed in the course of scanning the beam over a predetermined area of the surface to remove the insulating coating.

The coating removal method may include a step of lowering the irradiation power of the laser light per unit area of the surface while scanning the beam over a predetermined area of the surface to remove the insulating coating.

In the coating removal method, the irradiation power of the laser light per unit area of the surface may be changed by changing at least one of the scanning speed of the laser light and the output of the light source of the laser light.

In the coating removal method, the electric wire and the beam may move relative to each other in the axial direction of the electric wire during at least a portion of the scanning of the beam.

In the coating removal method, the electric wire and the beam may move relative to each other in a direction intersecting the axial direction of the electric wire during at least a portion of the scanning of the beam.

In the coating removal method, the electric wire and the beam may move relatively in a circumferential direction around the central axis of the electric wire during at least a portion of the scanning of the beam.

In the coating removal method, the concentration of oxygen supplied may be set lower the more flammable the material of the insulating coating is.

The coating removal method may include a first step of removing a first insulating coating by irradiating the laser light to a first insulating coating as the insulating coating while supplying the oxygen at a first concentration, and a second step of removing a second insulating coating by irradiating the laser light to a second insulating coating as the insulating coating having a lower flammability than the first insulating coating while supplying the oxygen at a second concentration higher than the first concentration.

In the coating removal method, the first insulating film is arranged to surround the second insulating film, and the coating removal method may include a first step of removing the first insulating film to expose the second insulating film by irradiating the first insulating film with the laser light while supplying the oxygen at the first concentration, and a second step of removing the second insulating film by irradiating the second insulating film with the laser light while supplying the oxygen at the second concentration.

In the coating removal method, in the second step, the second insulating coating may be removed at a position away from the first insulating coating.

In the coating removal method, the oxygen-containing gas may be supplied at a flow rate of 3.0 m/s or more and 35 m/s or less.

In addition, the coating removal device of the present invention includes, for example, a laser device that outputs laser light, an optical head that irradiates the laser light output from the laser device toward the surface of an electric wire having a core wire and an insulating coating made of an organic polymer material, and an oxygen supply mechanism that supplies oxygen toward the irradiation position of the laser light on the electric wire.

In the film removal device, the oxygen supply mechanism may have a plurality of nozzles that supply oxygen in different directions, and a switching mechanism that switches between starting and stopping the supply of oxygen by the plurality of nozzles.

According to the present invention, for example, a novel coating removal method and coating removal device can be obtained which are less inconvenient.

FIG. 1 is an exemplary schematic perspective view of a portion of an electric wire from which a coating is removed by a coating removal method according to a first embodiment. FIG. 2 is an exemplary schematic configuration diagram of the coating removal device according to the first embodiment. FIG. 3 is an exemplary block diagram of a coating removal device according to an embodiment. FIG. 4 is an exemplary schematic side view of a portion of an electric wire from which a coating is removed by the coating removal method of the first embodiment. FIG. 5 is a schematic diagram showing the direction of oxygen supplied by the film removal method of the first embodiment. FIG. 6 is an exemplary schematic side view of a portion of an electric wire from which a coating is removed by the coating removal method of the first embodiment, showing a case where the oxygen supply position is different from that in FIG. FIG. 7 is an exemplary schematic front view of a portion of the coating removal device of the second embodiment. FIG. 8 is an exemplary schematic rear view of a portion of an electric wire from which a coating is removed by the coating removal method of the second embodiment. FIG. 9 is a schematic diagram showing the direction of oxygen supplied by the film removal method of the second embodiment. FIG. 10 is an exemplary schematic front view of a portion of the coating removal device of the third embodiment. FIG. 11 is an exemplary schematic front view of a portion of the coating removal device of the fourth embodiment. FIG. 12 is an exemplary schematic front view of a portion of the coating removal device of the fifth embodiment. FIG. 13 is an exemplary schematic perspective view of an electric wire from which a coating is removed by the coating removal method of the sixth embodiment. FIG. 14 is an exemplary schematic side view of a portion of an electric wire from which a coating is removed by the coating removal method of the sixth embodiment. FIG. 15 is a diagram showing an example of an irradiation area of laser light in the coating removal method according to the sixth embodiment. FIG. 16 is a diagram showing a modification of the laser light irradiation region in the coating removal method of the sixth embodiment. FIG. 17 is a diagram showing a modification of the laser light irradiation region in the coating removal method of the sixth embodiment. FIG. 18 is a diagram showing a modification of the laser light irradiation region in the coating removal method of the sixth embodiment. FIG. 19 is a diagram showing a modification of the laser light irradiation region in the coating removal method of the sixth embodiment. FIG. 20 is a diagram showing a modification of the laser light irradiation region in the coating removal method of the sixth embodiment. FIG. 21 is a plan view showing an example of an image of an electric wire obtained by the film removal method of the sixth embodiment. FIG. 22 is a plan view showing an example of an image of an electric wire obtained by the coating removal method of the sixth embodiment. FIG. 23 is a plan view showing an example of an image of an electric wire obtained by the coating removal method of the sixth embodiment. FIG. 24 is a plan view showing an example of an image of an electric wire obtained by the coating removal method of the sixth embodiment. FIG. 25 is an exemplary schematic perspective view of a portion of an electric wire before the coating is removed by the coating removal method of the seventh embodiment. FIG. 26 is an exemplary schematic perspective view of a portion of an electric wire from which an outer coating has been removed by the coating removal method of the seventh embodiment. FIG. 27 is an exemplary schematic perspective view of a portion of an electric wire from which the outer and inner coatings have been removed by the coating removal method of the seventh embodiment.

Below, exemplary embodiments and variants of the present invention are disclosed. The configurations of the embodiments and variants shown below, and the actions and results (effects) brought about by said configurations, are merely examples. The present invention can also be realized by configurations other than those disclosed in the following embodiments and variants. Furthermore, according to the present invention, it is possible to obtain at least one of the various effects (including derivative effects) obtained by the configurations.

In this specification, ordinal numbers are used for convenience to distinguish between devices, parts, light, beams, etc., and do not indicate priority or order.

In each figure, the X direction is represented by an arrow X, the Y direction is represented by an arrow Y, and the Z direction is represented by an arrow Z. The X direction, Y direction, and Z direction intersect with each other and are perpendicular to each other. The X direction can also be called the longitudinal direction or extension direction, the Y direction can also be called the transverse direction or width direction, and the Z direction can also be called the thickness direction.

[First embodiment]
[Electrical wire]
Fig. 1 is a perspective view of an electric wire 10 from which an insulating coating 12 is removed by a coating removal method according to a first embodiment. As shown in Fig. 1, the electric wire 10 is, for example, a rectangular wire having a flattened rectangular cross section. The electric wire 10 has a conductor 11 having a belt-like and plate-like shape and an insulating coating 12 surrounding the conductor 11. The conductor 11 is an example of a core wire.

The conductor 11 is made of a copper-based material such as oxygen-free copper or a copper alloy. The insulating film 12 is made of an organic polymer material such as polyimide, polyether ether ketone, polyamide-imide, polyurethane, polyester, or polyester-imide.

1, in order to electrically connect the conductor 11 to another conductor, for example, the insulating coating 12 is removed in a predetermined range A from the end of the conductor 11. Note that the position where the insulating coating 12 is removed is not limited to the end of the electric wire 10, and may be, for example, a midway position in the longitudinal direction of the electric wire 10.

The insulating film 12 is removed by irradiating the surface 10a of the electric wire 10 set at a position where the laser light is irradiated with the laser light. When removing the insulating film 12, for example, as shown by the dashed arrow in FIG. 1, a point-like spot (beam) of laser light is scanned on the surface 10a, i.e., on the insulating film 12. At the position where the spot is irradiated, the insulating film 12 is burned and removed. The scanning direction of the spot may change over time. In this embodiment, the spot moves repeatedly while being folded back on the surface 10a. The spot and the electric wire 10 move relatively in a direction (width direction, short direction, Y direction, and the opposite direction Yo of the Y direction) intersecting the axial direction (longitudinal direction, X direction) of the electric wire 10. The scanning of the spot includes scanning in the scanning direction SD1 (Y direction) and scanning in the scanning direction SD2 (opposite direction Yo of the Y direction). In the example of FIG. 1, the spot is scanned from the surface 10a of the electric wire 10 to a position outside the surface 10a, and is folded back in the Y direction at the position outside the surface 10a. In this case, the output of the laser light may be reduced or stopped at the position outside the surface 10a. However, this is not limited to this, and the spot and the electric wire 10 may move in the axial direction of the electric wire 10 on the surface 10a between the scanning in the scanning direction SD1 and the scanning in the scanning direction SD2, so that the spot may be scanned in the axial direction on the surface 10a. As the spot moves while folding back, the removed area of the insulating coating 12 gradually expands. In this embodiment, the removed area expands macroscopically in the removal direction RD over time, and microscopically in the scanning direction SD1 and the scanning direction SD2 with the scanning of the spot (beam).

The scanning range, turning position, scanning direction, number of times, etc. are not limited to those shown in FIG. 1. For example, the scanning trajectory is not limited to a turning shape, but may be a spiral shape. In this case, too, the removal area of the insulating coating 12 will gradually expand as the spot moves in a spiral shape. Also, surfaces of the insulating coating 12 other than those shown in FIG. 1 can be removed in the same manner.

The electric wire 10 may be an electric wire other than a rectangular wire, such as a round wire having a conductor 11 with a circular cross section. In addition, the cross-sectional shape of the electric wire 10 is not limited to a rectangular shape or a circular shape.

[Laser processing equipment]
Fig. 2 is a schematic diagram of the laser processing apparatus 100A (100). As shown in Fig. 2, the laser processing apparatus 100A (100) includes a laser device 111, a laser device 112, an optical head 120, and an optical fiber 130.

Each of the laser devices 111 and 112 has a laser oscillator and is configured to output laser light with a power of several kW, for example. The laser devices 111 and 112 may also have multiple semiconductor laser elements therein and be configured to output multi-mode laser light with a power of several kW as the total output of the multiple semiconductor laser elements. The laser devices 111 and 112 may also have various laser light sources such as fiber lasers, YAG lasers, and disk lasers.

The laser device 111 outputs a first laser light having a wavelength of 800 nm or more and 1200 nm or less. The laser device 111 is also referred to as a first laser device. The laser oscillator of the laser device 111 is a light source and can also be referred to as a first laser oscillator.

On the other hand, the laser device 112 outputs a second laser light having a wavelength of 300 nm or more and 600 nm or less. The laser device 112 is also called a second laser device, and the laser oscillator of the laser device 112 is a light source and can also be called a second laser oscillator.

Laser devices 111 and 112 may each output a continuous wave of laser light or a pulse of laser light.

The optical fiber 130 guides the laser light output from the laser devices 111 and 112 to the optical head 120.

The optical head 120 is an optical device for irradiating the laser light input from the laser devices 111 and 112 toward the electric wire 10. The optical head 120 has a collimating lens 121, a condensing lens 122, a mirror 123, and a filter 124. The collimating lens 121, the condensing lens 122, the mirror 123, and the filter 124 may also be referred to as optical components.

The optical head 120 is configured to be able to change its position relative to the electric wire 10 in order to scan the laser light while irradiating the surface 10a of the electric wire 10 with the laser light. Note that scanning of the spot on the surface 10a may be achieved by at least one of the movement of the optical head 120, the movement of the electric wire 10, and a change in the emission direction of the laser light beam from the optical head 120.

In addition, the optical head 120 may be configured to be able to scan laser light on the surface 10a by having a galvanometer scanner (not shown) or the like.

The collimating lenses 121 (121-1, 121-2) each collimate the laser light input via the optical fiber 130. The collimated laser light becomes parallel light.

Mirror 123 reflects the first laser light that has been collimated by collimator lens 121-1. The first laser light reflected by mirror 123 travels in the opposite Z direction toward filter 124. Note that in a configuration in which the first laser light is input to optical head 120 so as to travel in the opposite Z direction, mirror 123 is not necessary.

Filter 124 is a high-pass filter that transmits the first laser light and reflects but does not transmit the second laser light. The first laser light passes through filter 124 and travels in the opposite Z direction toward the focusing lens 122. On the other hand, filter 124 reflects the second laser light that has been collimated by collimator lens 121-2. The second laser light reflected by filter 124 travels in the opposite Z direction toward the focusing lens 122.

The focusing lens 122 focuses the first laser light and the second laser light as parallel light, and irradiates the laser light (output light) to an irradiation point P on the surface 10a of the electric wire 10. The irradiation point P is an example of an irradiation position.

The optical head 120 has a DOE 125 (diffractive optical element) between the collimator lens 121-1 and the mirror 123. The DOE 125 can appropriately shape the beam of the first laser light. The DOE 125 is an example of a beam shaper.

The laser processing apparatus 100 also has a drive mechanism 150 and an oxygen supply mechanism 160.

The drive mechanism 150 changes the relative position of the optical head 120 with respect to the electric wire 10. The drive mechanism 150 has, for example, a rotation mechanism such as a motor, a reduction mechanism that reduces the rotation output of the rotation mechanism, and a motion conversion mechanism that converts the rotation reduced by the reduction mechanism into linear motion. The control device 140 can control the drive mechanism 150 so that the relative position of the optical head 120 with respect to the electric wire 10 in the X-direction, Y-direction, and Z-direction changes.

The oxygen supply mechanism 160 supplies oxygen gas Go (gas containing oxygen) toward the irradiation point P through the piping 161. The oxygen gas Go is discharged at a predetermined flow rate from the outlet 161a of a nozzle provided at the tip of the piping 161 and facing the irradiation point P. The laser processing device 100 removes the insulating film 12 from the electric wire 10 by irradiating the laser light while supplying the oxygen gas Go. The supply of the oxygen gas Go promotes the combustion of the insulating film 12, and the removal performance of the insulating film 12 can be improved compared to the case where the oxygen gas Go is not supplied.

Through intensive research by the inventors, it has been found that the distance L between the outlet 161a and the irradiation point P is preferably 10 mm or more and 25 mm or less, and more preferably 12 mm or more and 20 mm or less. It has also been found that the flow rate of the oxygen gas Go is preferably 3.0 m/s or more and 35 m/s or less at the outlet 161a. Furthermore, it is preferable that the inner diameter of the outlet 161a (nozzle) is equal to or more than the width of the electric wire 10 so that the amount of oxygen supplied is less likely to vary across the entire width of the electric wire 10. As an example, when the inner diameter is 8 mm, the flow rate of the oxygen gas Go required to obtain the above-mentioned flow rate of 3.0 m/s or more and 35 m/s or less is 10 L/min or more and 100 L/min or less. It was also found that in various cases, the flow rate of the oxygen gas Go is preferably 30 [L/min] or more, more preferably 50 [L/min] or more, and even more preferably 70 [L/min] or more. If the distance L is too short, the thermal effect on the nozzle increases, while if it is too long, it becomes difficult for the oxygen gas Go to be supplied to the irradiation point P. It was also found that within the range of the distance L, if the flow rate of the oxygen gas Go is less than 50 [L/min], the removal performance of the insulating coating 12 decreases.

The inventors have confirmed that by setting the distance L and the oxygen gas Go in this way, the laser processing device 100 can quickly remove the insulating coating 12 from the electric wire 10 having a thickness of 30 μm or more, 50 μm or more, or even 70 μm or more, and can obtain a high-quality surface of the conductor 11 with little residue, etc. The laser processing device 100 is an example of a coating removal device.

The laser processing apparatus 100 also has a control device 140 that controls the operation of the laser devices 111, 112, the drive mechanism 150, and the oxygen supply mechanism 160.

Figure 3 is a block diagram of the laser processing apparatus 100. The control device 140 is a computer and has a controller 141, a main memory unit 142, and an auxiliary memory unit 143. The controller 141 is a processor (circuit) such as a CPU (central processing unit). The main memory unit 142 is, for example, a RAM (random access memory) or a ROM (read only memory). The auxiliary memory unit 143 is, for example, a non-volatile memory device such as an SSD (solid state drive) or an HDD (hard disk drive).

The controller 141 operates as the output control unit 141a, the drive control unit 141b, and the oxygen supply control unit 141c by reading out the programs stored in the ROM of the main memory unit 142 or the auxiliary storage device 143 and executing each process. The programs can be provided in a computer-readable recording medium in an installable or executable format. The recording medium can also be called a program product. Information such as values, tables, and maps used in the arithmetic processing by the program and the processor may be stored in the ROM or the auxiliary storage device 143 in advance, or may be stored in a memory unit of a computer connected to a communication network and downloaded via the communication network to the auxiliary storage device 143. The auxiliary storage device 143 stores data written by the processor. The arithmetic processing by the controller 141 may also be performed at least in part by hardware. In this case, the controller 141 may include, for example, an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit). The controller 141 may include a control unit other than the output control unit 141a, the drive control unit 141b, and the oxygen supply control unit 141c.

The output control unit 141a can control the operation of the laser devices 111, 112, for example, to output laser light, stop outputting laser light, or change the output intensity of the laser light.

The drive control unit 141b can control the operation of the drive mechanism 150, for example, so that the irradiation point P of the laser light on the electric wire 10 moves and the irradiation point P is scanned, i.e., so that the relative position between the optical head 120 and the electric wire 10 changes.

In addition, the oxygen supply control unit 141c can control the operation of the oxygen supply mechanism 160, for example, to supply oxygen gas Go, stop the supply of oxygen gas Go, or change the supply flow rate of oxygen gas Go.

The oxygen concentration in the oxygen gas Go is set according to the combustibility of the material of the insulating film 12. Specifically, the higher the combustibility of the material of the insulating film 12, the lower the concentration of oxygen to be supplied is set, and the lower the combustibility of the material of the insulating film 12, the higher the concentration of oxygen to be supplied is set. The oxygen concentration is adjusted, for example, by a switching mechanism such as an electromagnetic valve that can change the discharge flow rate from the oxygen tank. The oxygen concentration is set to a fixed position, for example, the tip of the nozzle of the piping 161. With such a configuration and setting, for example, it is possible to suppress combustion of the insulating film 12 beyond the intended range, and to achieve more efficient and faster combustion. The oxygen concentration in the oxygen gas Go is appropriately set within a range equal to or higher than the oxygen concentration in air and equal to or lower than the oxygen concentration in pure oxygen.

[Oxygen supply]
Fig. 4 is a side view of a portion of the electric wire 10, showing the vicinity of a boundary Bo in the X direction between a removed region Ar and a remaining portion Pr of the insulating coating 12. In Fig. 4, an end face 12a of the insulating coating 12 appears at the boundary Bo by scanning a spot (beam) as illustrated in Fig. 1. The end face 12a is located at an end of the insulating coating 12 in the opposite direction to the X direction and faces the opposite direction to the removal direction RD. Note that, in Fig. 4, the end face 12a is depicted as extending generally along the Z direction in schematic form, but in reality, the end face 12a may extend at an angle to the Z direction or may have an uneven shape.

As shown in FIG. 4, oxygen gas Go is supplied from the side opposite the boundary Bo to the remaining portion Pr and is supplied toward the boundary Bo. If oxygen gas Go is supplied from the side opposite the boundary Bo to the removal area Ar, that is, if oxygen gas is supplied from the right side or upper right side of the boundary Bo in FIG. 4, the remaining portion Pr of the insulating coating 12 may become an obstacle to the oxygen gas, and the oxygen gas may not be sufficiently supplied to the surface 11a, particularly to the vicinity of the boundary Bo, for example, to the corner C between the surface 11a and the end face 12a of the remaining portion Pr. In this regard, in the present embodiment, oxygen gas Go is supplied from the side opposite the boundary Bo to the remaining portion Pr, and is supplied to the corner C without being hindered by the remaining portion Pr, which facilitates the combustion of the insulating coating 12 by irradiation with laser light, and the residue on the surface 11a can be reduced. Furthermore, even when the flow rate of the oxygen gas Go is increased and the residue is blown away by the oxygen gas Go, from the viewpoint of blowing the oxygen gas Go onto the surface 11a up to the corner C while avoiding interference with the remaining portion Pr, it is preferable that the oxygen gas Go be supplied from the opposite side of the boundary Bo to the remaining portion Pr and toward the boundary Bo.

Furthermore, experimental research by the inventors has revealed that the magnitude of the angle θ between the supply direction of the oxygen gas Go (the direction of the central axis of the outlet 161a) and the extension direction of the surface 11a (X direction, removal direction RD) is preferably 10° or more and 70° or less, and more preferably 20° or more and 50° or less, from the standpoint of avoiding interference between the piping 161 in the optical head 120 and the emission end of the laser light, and from the standpoint of supplying sufficient oxygen to the vicinity of the boundary Bo of the surface 11a.

Figure 5 is a schematic diagram showing the components of the vector of the supply direction of oxygen gas Go. The supply direction of oxygen gas Go (arrow Go in Figure 5) can be decomposed into a component Go_rd in the X direction (removal direction RD) and a component Go_z in the opposite direction to the Z direction. That is, oxygen gas Go is supplied in a direction that includes a component in the opposite direction to the Z direction, i.e., the direction opposite to the normal direction of surface 11a, and a component of the removal direction RD. The removal direction RD is an example of a first direction.

Figure 6 is a side view showing the same position as in Figure 4, and shows a case where the supply position of oxygen gas Go is different from that in Figure 4. In the example of Figure 6, oxygen gas Go is supplied toward a position away from the boundary Bo (corner C) in the opposite direction to the removal direction RD (rear of the removal direction RD). In this example, oxygen gas Go is also supplied from the opposite side of the boundary Bo to the remaining portion Pr, and the supply direction of oxygen gas Go is the same as in Figures 4 and 5. In such a case, oxygen gas Go is also supplied to the corner C without being hindered by the remaining portion Pr, so that the combustion of the insulating coating 12 by the irradiation of the laser light is easily promoted, and the residue on the surface 11a can be reduced. In addition, even when the flow rate of oxygen gas Go is increased and the residue is blown away by oxygen gas Go, the same effect as in Figure 4 can be obtained.

[Second embodiment]
FIG. 7 is a front view showing a part of the laser processing apparatus 100B (100) of the second embodiment. The laser processing apparatus 100B has the same configuration as the first embodiment, except for the part shown in FIG. 7. In this embodiment, the spot (beam) is scanned on the surface 10a in the same manner as the first embodiment. That is, in this embodiment, as shown in FIG. 1, the scanning of the spot includes scanning in the scanning direction SD1 (Y direction) and scanning in the scanning direction SD2 (opposite direction Yo of the Y direction). Therefore, in this embodiment, the removal area Ar expands macroscopically in the removal direction RD over time, and microscopically expands in the scanning directions SD1 and SD2 with the scanning of the spot.

The optical head 120 is provided with a pipe 161-1 (161) that supplies oxygen gas Go in a direction between the Y direction and the opposite direction of the Z direction.

In addition, in this embodiment, the control device 140 controls the oxygen supply mechanism 160 to supply oxygen gas Go only when scanning in the scanning direction SD1, and not to supply oxygen gas Go when scanning in the scanning direction SD2.

Figure 8 is a rear view (partial cross-sectional view) of a portion of the electric wire 10 as viewed in the X direction, showing the vicinity of the boundary Bo1 in the Y direction between the removed area Ar and the remaining portion Pr of the insulating coating 12 while the spot is being scanned in the scanning direction SD1. Note that in Figure 8, the end face 12a1 is depicted as extending generally along the Z direction, but in reality, the end face 12a1 may extend at an angle to the Z direction or may have an uneven shape.

As shown in FIG. 8, at the boundary Bo1, the end face 12a1 of the insulating coating 12 appears. The end face 12a1 is located at the end of the insulating coating 12 in the opposite direction to the scanning direction SD1, and faces the opposite direction to the scanning direction SD1. By scanning the spot in the scanning direction SD1, the end face 12a1 (boundary Bo1) moves in the scanning direction SD1, and the removal area Ar expands over time in the scanning direction SD1. In such a case, in this embodiment, as shown in FIG. 8, the oxygen gas Go is supplied from the opposite side of the boundary Bo1 to the remaining portion Pr and is supplied toward the boundary Bo1. In this case, as in the first embodiment, the oxygen gas Go is also supplied to the corner portion C1 between the surface 11a and the end face 12a1 without being obstructed by the remaining portion Pr, so that the burning of the insulating coating 12 by the irradiation of the laser light is easily promoted, and the residue on the surface 11a can be reduced. Furthermore, even when the flow rate of oxygen gas Go is increased and the residue is blown away by oxygen gas Go, from the viewpoint of blowing oxygen gas Go onto surface 11a up to corner C1 while avoiding interference with the remaining portion Pr, it is preferable that the oxygen gas Go is supplied from the opposite side of the boundary Bo1 to the remaining portion Pr, and is supplied toward the boundary Bo1 or toward a position away from the boundary Bo1 (corner C1) in the opposite direction to the scanning direction SD1 (rear of the scanning direction SD1).

Figure 9 is a schematic diagram showing the components of the vector of the supply direction of oxygen gas Go in the state of Figure 8. The supply direction of oxygen gas Go (arrow Go in Figure 9) can be decomposed into a component Go_sd in the Y direction (scanning direction SD) and a component Go_z in the opposite direction to the Z direction. That is, oxygen gas Go is supplied in a direction that includes a component in the opposite direction to the Z direction, i.e., the direction opposite to the normal direction of surface 11a, and a component in the scanning direction SD.

In the present embodiment, the same effect as in the first embodiment can be obtained. The supply direction of the oxygen gas Go may further include a component of the removal direction RD.

[Third embodiment]
FIG. 10 is a front view showing a part of the laser processing apparatus 100C (100) of the third embodiment. The laser processing apparatus 100C has the same configuration as the first embodiment, except for the part shown in FIG. 10. Also in this embodiment, the spot (beam) is scanned on the surface 10a in the same manner as the first embodiment. That is, also in this embodiment, as shown in FIG. 1, the scanning of the spot includes scanning in the scanning direction SD1 (Y direction) and scanning in the scanning direction SD2 (opposite direction Yo of the Y direction). Therefore, also in this embodiment, the removal area Ar expands macroscopically in the removal direction RD over time, and microscopically expands in the scanning directions SD1 and SD2 with the scanning of the spot.

However, in this embodiment, the optical head 120 includes a pipe 161-1 (161) that supplies oxygen gas Go in a direction between the Y direction and the opposite direction of the Z direction, and a pipe 161-2 (161) that supplies oxygen gas Go in a direction between the opposite direction Yo of the Y direction and the opposite direction of the Z direction. In other words, the optical head 120 has multiple pipes 161 (nozzles) that can supply oxygen gas Go in different directions.

Furthermore, in this embodiment, the control device 140 switches the supply direction of the oxygen gas Go in response to changes over time in the scanning direction of the spot. Specifically, the control device 140 controls the oxygen supply mechanism 160 to supply oxygen gas Go from pipe 161-1 when scanning in scanning direction SD1, and to supply oxygen gas Go from pipe 161-2 when scanning in scanning direction SD2. In this case, the oxygen supply mechanism 160 has a switching mechanism, such as an electromagnetic valve (not shown), that switches between supplying and stopping the oxygen gas Go through each pipe 161.

As in the second embodiment, the supply direction of oxygen gas Go from pipe 161-1 is a direction that includes a component in the opposite direction to the Z direction, i.e., the direction opposite to the normal direction of surface 11a, and a component in the scanning direction SD1. The supply direction of oxygen gas Go from pipe 161-2 is a direction that includes a component in the opposite direction to the Z direction and a component in the scanning direction SD2. In this case, the supply directions of oxygen gas Go from pipes 161-1 and 161-2 may each have a component in the removal direction RD.

In the present embodiment, the same effects as those of the first and second embodiments can be obtained. In addition, in the present embodiment, oxygen gas Go can be supplied in both the scanning directions SD1 and SD2, so that the residue can be removed more reliably.

[Fourth embodiment]
11 is a front view showing a part of a laser processing apparatus 100D (100) according to the fourth embodiment. In this embodiment, an optical head 120 has a similar configuration to that of the third embodiment.

However, in this embodiment, the spot (beam) is scanned on the surface 10a by rotating the electric wire 10 in the circumferential direction around the central axis Ax relative to the optical head 120. That is, in this embodiment, the electric wire 10 and the beam move relatively in the circumferential direction around the central axis Ax. When the electric wire 10 rotates in the counterclockwise rotation direction R1 in the state of FIG. 11, the spot moves relatively in the direction from the corner 10b1 of the electric wire 10 to the other corner 10b2 on the surface 10a facing the optical head 120. In this case, the control device 140 controls the oxygen supply mechanism 160 to supply oxygen gas Go from the pipe 161-1. On the other hand, when the electric wire 10 rotates in the clockwise rotation direction R2 in the state of FIG. 11, the spot moves relatively in the direction from the corner 10b2 of the electric wire 10 to the other corner 10b1 on the surface 10a facing the optical head 120. In this case, the control device 140 controls the oxygen supply mechanism 160 to supply oxygen gas Go from the pipe 161-2. By such control, the supply direction of the oxygen gas Go also has a component of the sweep direction of the spot on the surface 10a in this embodiment. Therefore, the same effect as in the third embodiment can be obtained in this embodiment.

[Fifth embodiment]
Fig. 12 is a front view showing a part of the laser processing apparatus 100E (100) of the fifth embodiment. The laser processing apparatus 100E has a configuration similar to that of the first embodiment, except for the part shown in Fig. 12. That is, in this embodiment, the optical head 120 has a galvano scanner 126 in front of the condenser lens 122.

The galvano scanner 126 has multiple mirrors 126a and 126b. The direction of emission of the laser light from the optical head 120 is switched by changing the angles of the multiple mirrors 126a and 126b. The angles of the mirrors 126a and 126b are changed by, for example, motors (both not shown) controlled by the control device 140. In this case, for example, the spot can be scanned in the scanning directions SD1 and SD2 on the surface 10a without moving the electric wire 10 and the optical head 120 relative to each other. The movement or scanning of the spot in the X direction may be realized by moving at least one of the electric wire 10 and the optical head 120.

Sixth Embodiment
FIG. 13 is a perspective view of the same electric wire 10 as in FIG. 1, and shows a different beam and scanning method from FIG. 1. As shown in FIG. 13, in this example, the irradiation area Ae of the laser beam has a long and thin linear shape and is scanned in the opposite direction to the X direction. In a cross section intersecting with the irradiation direction of the beam, i.e., the opposite direction to the Z direction, the length of the irradiation area Ae in the Y direction is longer than the length of the irradiation area Ae in the X direction. With this setting, the number of scans (number of turns) can be reduced compared to the case where a point-like spot (beam) of laser light is scanned. The X direction is an example of a scanning direction SD, and the Y direction is an example of a direction intersecting with the scanning direction SD.

The irradiation area Ae extends between the ends 10b on both sides of the surface 10a in the Y direction in the specified range A where the insulating coating 12 from the end of the conductor 11 is removed. In the example of FIG. 13, the ends Ae1 on both sides of the irradiation area Ae in the Y direction are located on the opposite side of the center of the specified range A in the Y direction with respect to the ends 10b of the specified range A, and the irradiation area Ae is arranged so as to straddle the surface 10a. With this setting, the linear irradiation area Ae of the laser light can remove the insulating coating 12 more quickly in the specified range A by a single scan along the X direction (sweeping direction SD). In this case, the X direction is also the removal direction RD.

Figure 14 is a side view of a portion of the electric wire 10, showing the vicinity of the boundary Bo in the X direction between the removal area Ar and the remaining portion Pr of the insulating coating 12. By irradiating the spot (beam) as illustrated in Figure 13, the end face 12a of the insulating coating 12 as shown in Figure 14 appears at the boundary Bo. The end face 12a is located at the end of the insulating coating 12 in the opposite direction to the scanning direction SD (removal direction RD) and faces the opposite direction to the scanning direction SD. By scanning the spot in the scanning direction SD, the end face 12a (boundary Bo) moves in the scanning direction SD, and the removal area Ar expands over time in the scanning direction SD (removal direction RD). In such a case, in this embodiment as well, as shown in Figure 14, oxygen gas Go is supplied from the opposite side of the boundary Bo to the remaining portion Pr and is supplied toward the boundary Bo. In this case, as in the first embodiment, the oxygen gas Go is supplied to the corner C between the surface 11a and the end face 12a without being hindered by the remaining portion Pr, so that the combustion of the insulating coating 12 by the irradiation of the laser light is easily promoted, and the residue on the surface 11a can be reduced. Even if the flow rate of the oxygen gas Go is increased and the residue is blown away by the oxygen gas Go, from the viewpoint of blowing the oxygen gas Go to the surface 11a up to the corner C while avoiding interference with the remaining portion Pr, it is preferable that the oxygen gas Go is supplied from the opposite side of the boundary Bo to the remaining portion Pr, and is supplied toward the boundary Bo or toward a position away from the boundary Bo (corner C) in the opposite direction to the scanning direction SD (rear of the scanning direction SD). In FIG. 14, the end face 12a is depicted as extending substantially along the Z direction, but in reality, the end face 12a may extend at an angle to the Z direction or may have an uneven shape. Although not shown, in this embodiment, the supply direction of the oxygen gas Go (arrow Go in FIG. 14) can also be decomposed into a component in the X direction (scanning direction SD) and a component in the opposite direction to the Z direction. That is, the oxygen gas Go is supplied in a direction including a component in the opposite direction to the Z direction, i.e., the direction opposite to the normal direction of the surface 11a, and a component in the scanning direction SD.

Figures 15 to 20 are diagrams showing various modified examples of the irradiation area Ae (beam B) of the laser light. All of these can be shaped by the DOE 125 (see Figure 1) as a beam shaper.

In the example of Figure 15, the irradiation area Ae has the shape of a single, elongated line extending in the Y direction.

In the example of Figure 16, the irradiation area Ae has the shape of two lines extending parallel to the Y direction and spaced apart in the X direction.

In the example of Fig. 17, the multiple spots are arranged in a zigzag pattern along the Y direction, so that the irradiation area Ae has a triangular wave shape extending in the Y direction. In this example, adjacent spots are in contact with each other.

In the example of Fig. 18, similar to Fig. 17, the multiple spots are arranged in a zigzag pattern along the Y direction, but in this example, adjacent spots are spaced apart from each other. That is, the irradiation area Ae has multiple point-like spots that are spaced apart from each other.

In the example of Figure 19, the irradiation area Ae has a sinusoidal shape extending in the Y direction.

In addition, when removing the coating, laser beams having different wavelengths may be irradiated. FIG. 20 shows a circular irradiation area Ae including a beam B1 of a first laser beam and a beam B2 of a second laser beam. In this case, the irradiation area Ae (beam B) includes a plurality of beams B1 and B2 of laser beams having different wavelengths. In the example of FIG. 20, the beam B2 of the second laser beam, which is a blue laser or a green laser, is arranged in the center, and the beam B1 of the first laser beam, which is an infrared laser, is arranged so as to surround it. In copper-based materials, blue lasers and green lasers have a higher absorption rate and a lower reflectance than infrared lasers. Therefore, by irradiating an infrared laser to an electric wire 10 having a conductor 11 made of a copper-based material, heat is directly applied to the coating in the irradiated area, and the laser light that reaches the copper-based material and is reflected can apply heat to the coating, so that heat is applied from the area where the insulating coating 12 and the copper-based material abut, and the coating can be efficiently removed. In this case, the first laser beam and the second laser beam may be irradiated to different regions. For example, by setting the irradiation region Ae as shown in FIG. 20, the insulating coating 12 can be efficiently removed by the first laser beam of moderate intensity in a wider range than that irradiated by the beam B1. In addition, the beam B2 is irradiated to the conductor 11 from which the insulating coating 12 has been removed, and the temperature of the insulating coating 12 that has not been removed is preliminarily increased, making it easier to burn more efficiently. In addition, the arrangement, size, area ratio, and other specifications of the multiple beams B1 and B2 are not limited to the example in Fig. 20, but from the above-mentioned viewpoint, when laser beams having different wavelengths are irradiated to different regions, the ratio of the area irradiated with only the first laser beam (area of B1-B2 in Fig. 20) to the area of the spot irradiated with only the second laser beam or with both the first laser beam and the second laser beam (area of B2 in Fig. 20), that is, (area of B1-B2)/(area of B2) is preferably 0.2 to 3.0, and more preferably 0.5 to 1.8. In this case, the area of B1-B2 is preferably 0.03 mm ² to 0.4 mm ² , and more preferably 0.05 mm ² to 0.2 mm ² .

表１において、◎は、絶縁皮膜１２や燃え残りのような残渣が殆ど無く良好な外観を呈し、かつ露出した導体１１の表面における抵抗値が十分に低い（例えば、２［Ω］未満）「優良」の状態を示し、○は、絶縁皮膜１２や残渣の残存状態が少なく、かつ抵抗値が低い（例えば、２［Ω］以上かつ２０［Ω］未満）「良」の状態を示し、また、×は、残渣が多く、かつ抵抗値も高い「不良」の状態を示す。 [Film removal conditions]
Table 1 shows the experimental results of removing the insulating coating 12 by scanning the linear irradiation area Ae shown in FIG. 15 with infrared laser light having a wavelength of 1070 [nm], and shows the experimental results of actual removal of the insulating coating 12 for several combinations of oxygen flow rate [L/min], spot scanning speed [mm/s], and laser light output [W].

In Table 1, ◎ indicates an "excellent" condition in which there is almost no residue such as insulating coating 12 or burnt remains, the appearance is good, and the resistance value on the surface of the exposed conductor 11 is sufficiently low (e.g., less than 2 Ω); ○ indicates a "good" condition in which there is little remaining insulating coating 12 or residue and the resistance value is low (e.g., 2 Ω or more and less than 20 Ω); and × indicates a "poor" condition in which there is a lot of residue and the resistance value is high.

As shown in Table 1, favorable results were obtained when the oxygen flow rate was 50 [L/min]. In addition, for the laser light output, "excellent" results were obtained for 500 [W] and 1000 [W], and the inventors' experiments showed that approximately 300 [W] or more was preferable. In addition, for the scanning speed, "excellent" results were obtained for 100 [mm/s], 200 [mm/s], and 250 [mm/s], and the inventors' experiments showed that approximately 50 [mm/s] or more was preferable. In addition, even when the laser light output was 500 [W], a "poor" result was obtained when the scanning speed was 250 [mm/s]. The faster the scanning speed, the lower the irradiation power per unit time. Therefore, when the scanning speed was 250 [mm/s], an "excellent" result was obtained by increasing the laser light output to 1000 [mm/s] to increase the irradiation power.

21 is an image I1 of an electric wire 10 from which the insulating coating 12 has been removed when the oxygen flow rate is 0 [L/min], the scanning speed is 100 [mm/s], and the laser light output is 200 [W]; FIG. 22 is an image I2 of an electric wire 10 from which the insulating coating 12 has been removed when the oxygen flow rate is 50 [L/min], the scanning speed is 100 [mm/s], and the laser light output is 500 [W]; FIG. 23 is an image I3 of an electric wire 10 from which the insulating coating 12 has been removed when the oxygen flow rate is 50 [L/min], the scanning speed is 250 [mm/s], and the laser light output is 500 [W]; and FIG. 24 is an image I4 of an electric wire 10 from which the insulating coating 12 has been removed when the oxygen flow rate is 50 [L/min], the scanning speed is 250 [mm/s], and the laser light output is 1000 [W]. In the predetermined area A (removal area), the surface 11a of the conductor 11 is exposed.

Figure 21 shows a "poor" state where the insulating coating 12 was not completely burned due to a lack of oxygen supply, leaving black unburned residues all over the specified range A. Figure 22 shows an "excellent" state where the insulating coating 12 was almost completely removed in the specified range A due to good combustion. Figure 23 shows a "poor" state where the insulating coating 12 was not completely burned due to insufficient irradiation power per unit time, leaving black unburned residues all over the specified range A. Figure 24 shows an "excellent" state where the insulating coating 12 was almost completely removed in the specified range A due to good combustion.

In addition, the inventors' experimental research has revealed that by changing the irradiation power of the laser light per unit area of the surface 10a during the process of removing the insulating film 12 by scanning the beam in a predetermined range A of the surface 10a, a "good" state is easily obtained and the film removal with good energy efficiency is easily performed. Specifically, as an example, in the latter stage of the process of removing the insulating film 12, it was preferable to lower the irradiation power of the laser light per unit area of the surface 10a than in the former stage. Furthermore, in that case, better results were obtained by lowering the irradiation power of the laser light per unit area of the surface 10a in a stepwise or gradual manner. This is thought to be because the conductor 11 is heated in the former stage of the process of removing the insulating film 12, so that in the latter stage, it is possible to remove the insulating film 12 with a lower irradiation power than in the former stage. The irradiation power of the laser light per unit area can be changed by changing at least one of the scanning speed of the laser light and the output of the light source of the laser light. The higher the scanning speed of the laser light or the lower the output of the light source of the laser light, the lower the irradiation power of the laser light per unit area. As an example, in the process of removing the insulating coating 12, the irradiation power of the laser light per unit area in the latter half of the irradiation time of the laser light irradiation is preferably 0.8 times or less, and more preferably 0.5 times or less, of the irradiation power of the laser light per unit area in the first half of the irradiation time of the laser light irradiation.

In addition, the irradiation power of the laser light may be lowered in the end region in the Y direction of the electric wire 10 compared to the central region in the Y direction. Since there are fewer places for heat to escape near the end of the Y direction of the electric wire 10 than in the central region in the Y direction, the insulating film 12 can be removed efficiently with a smaller power, and unnecessary oxidation of the electric wire 10 in the process of removing the insulating film 12 can be suppressed. More specifically, for example, in a region where the ratio of the distance from each Y direction end to the width of the electric wire 10 in the Y direction is 0.2 or less, more preferably 0.1 or less, the irradiation power of the laser light per unit area is preferably lower than the irradiation power of the laser light at the center of the Y direction of the electric wire 10, and more preferably 20% lower.

[Seventh embodiment]
Fig. 25 is a perspective view of an electric wire 10A (10) as a processing target of the coating removal method of the present embodiment. As shown in Fig. 25, the electric wire 10A has a conductor 11 and insulating coatings 12A, 12B (12) that surround the conductor 11 in multiple layers. The insulating coating 12B surrounds the conductor 11, and the insulating coating 12A surrounds the insulating coating 12B. The insulating coating 12A is an example of a first insulating coating, and the insulating coating 12B is an example of a second insulating coating.

In addition, in this embodiment, the insulating coatings 12A and 12B are made of different materials. As an example, the insulating coating 12B is made of polyurethane, and the insulating coating 12A is made of polyether ether ketone. In this way, when the electric wire 10A has multiple insulating coatings 12 made of different materials, attention should be paid to the flammability (ease of burning) of each insulating coating 12. If the flammability is different, for example, a highly flammable insulating coating 12 will not leave any residue, but a less flammable insulating coating 12 will be more likely to leave residue, or a highly flammable insulating coating 12 will burn beyond the desired range.

Therefore, in this embodiment, a process is set for removing each of the insulating coatings 12, and in each process, the oxygen concentration is set according to the combustibility of the material of the insulating coating 12. Specifically, the higher the combustibility of the material of the insulating coating 12, the lower the oxygen concentration in the supplied oxygen gas Go is set, and the lower the combustibility of the material of the insulating coating 12, the higher the oxygen concentration in the supplied oxygen gas Go is set.

Figure 25 is a perspective view of the electric wire 10 before the coating removal method of this embodiment is performed. Figure 26 is a perspective view showing the state after the outer insulating coating 12A has been removed, and Figure 27 is a perspective view showing the state after the inner insulating coating 12B has been removed.

In this embodiment, as in the sixth embodiment, a spot having an elongated irradiation area Ae (see Figures 13 and 14, etc.) whose length in the Y direction is longer than its length in the X direction is scanned in the scanning direction SD to remove the insulating coating 12. In this embodiment, the removal direction RD is also the scanning direction SD.

First, as shown in Figures 25 and 26, the spot is moved in the X direction from position x1 to a position beyond position xe, thereby removing the insulating coating 12A (first step).

26 and 27, the spot is moved in the X direction from position x2 to a position beyond position xe, thereby removing the insulating film 12B (second step). At this time, since the insulating film 12B is less combustible than the insulating film 12A, the oxygen concentration is made higher in the second step than in the first step. In other words, since the insulating film 12A is more combustible than the insulating film 12B, the oxygen concentration is made lower in the first step than in the second step. By setting the oxygen concentration in this way, the insulating films 12A and 12B can be removed more efficiently while reducing residue. The oxygen concentration in the first step is the first oxygen concentration, and the oxygen concentration in the second step is the second oxygen concentration.

26 and 27, in the second step, the position x2 where removal of the insulating coating 12B begins is separated in the X direction from the position x1 where removal of the insulating coating 12A begins. That is, in the second step, the insulating coating 12B is removed at a position separated from the insulating coating 12A. This makes it possible to more reliably prevent the more flammable insulating coating 12A from unintentionally burning in the second step in which the oxygen concentration is increased.

26 and 27, the electric wire 10A that has completed the second process has an exposed portion 11a1 that is a part of the surface 11a of the conductor 11, and an exposed portion 12b of the inner insulating coating 12B. The exposed portion 12b is adjacent to the exposed portion 11a1. The exposed portion 11a1 is an example of a first exposed portion, and the exposed portion 12b is an example of a second exposed portion.

In addition, setting the oxygen concentration according to the flammability of the material of the insulating coating 12, as in this embodiment, can also be applied to a configuration in which, for example, a more flammable insulating coating 12 is covered by a less insulating insulating coating 12, or a configuration in which multiple insulating coatings 12 of different materials are arranged in the longitudinal direction.

As described above, according to the laser processing device 100 (film removal device) and film removal method of this embodiment, the insulating film 12 of the electric wire 10 is removed by irradiating the laser light while supplying oxygen, and therefore the combustion of the insulating film 12 is promoted. This has the advantage that, for example, it is possible to obtain an electric wire 10 with a high-quality exposed surface 11a with less residue, and it is possible to perform film removal with higher energy efficiency. Furthermore, according to this embodiment, even if the insulating film 12 is relatively thick, the insulating film 12 can be removed more easily or more quickly with less residue.

Although the above describes embodiments and variations of the present invention, the above embodiments and variations are merely examples and are not intended to limit the scope of the invention. The above embodiments and variations can be implemented in various other forms, and various omissions, substitutions, combinations, and modifications can be made without departing from the spirit of the invention. Furthermore, the specifications of each configuration, shape, etc. (structure, type, direction, model, size, length, width, thickness, height, number, arrangement, position, material, etc.) can be modified as appropriate.

The present invention may also be embodied in the following forms.
(28)
In the coating removal method, the insulating coating may have a thickness of 50 μm or more.
(29)
In the coating removal method, the insulating coating may have a thickness of 70 μm or more.
(30)
In the coating removal method, a distance between the outlet of the oxygen nozzle facing the irradiation position of the laser light and the irradiation position of the laser light may be 10 mm or more and 25 mm or less, and a supply flow rate of the oxygen may be 30 L/min or more.
(31)
In the coating removal method, the core wire may be made of a copper-based material.
(32)
In the coating removal method, the electric wire may be a rectangular wire or a round wire.
(33)
In the coating removal method, the wavelength of the laser light may be equal to or greater than 300 nm and equal to or less than 1200 nm.
(34)
In the coating removal method, the laser light may include a beam having a wavelength of 300 nm or more and 600 nm or less.
(35)
In the coating removal method, the laser light may include a beam having a wavelength of 800 nm or more and 1200 nm or less.
(36)
In the coating removal method, the laser light may include a plurality of beams having different wavelengths.

The present invention can be used in a coating removal method and a coating removal device.

10, 10A... Electric wire 10a... Surface 10b... Ends 10b1, 10b2... Corners 11... Conductor (core wire)
11a...Surface 11a1...Exposed part (first exposed part)
12...insulating coating 12A...insulating coating (first insulating coating)
12B: Insulating film (second insulating film)
12a, 12a1... End surface 12b... Exposed part (second exposed part)
100, 100A to 100E...Laser processing device (film removal device)
111...Laser device (light source)
112...Laser device (light source)
120: Optical head 121, 121-1, 121-2: Collimator lens 122: Condenser lens 123: Mirror 124: Filter 125: DOE
126... Galvano scanner 126a, 126b... Mirror 130... Optical fiber 140... Control device 141... Controller 141a... Output control unit 141b... Drive control unit 141c... Oxygen supply control unit 142... Main memory unit 143... Auxiliary memory unit 150... Drive mechanism 160... Oxygen supply mechanism 161, 161-1, 161-2... Pipe 161a... Discharge port A... Predetermined range Ae... Irradiation area Ae1... End Ar... Removal area Ax... Central axis B, B1, B2... Beam Bo, Bo1... Boundary C, C1... Corner Go... Oxygen gas Go_rd... Component Go_sd... Component Go_z... Component I1 to I4... Image L... Distance P... Irradiation point Pr... Remaining part R1, R2... Rotation direction RD... Removal direction (first direction)
SD, SD1, SD2...scanning direction X...direction x1, x2, xe...position Y...direction Yo...opposite direction Z...direction θ...angle

Claims (26)

A method for removing an insulating coating of an electric wire having a core wire and an insulating coating made of an organic polymer material by irradiating the core wire with a laser beam, the method comprising the steps of:
removing the insulating film by irradiating the laser light while supplying oxygen;
scanning the beam of laser light along a surface of the wire;
The scanning direction of the beam changes over time,
The film removal method includes switching the oxygen supply direction in response to a change over time in the scanning direction . A method for removing an insulating coating of an electric wire having a core wire and an insulating coating made of an organic polymer material by irradiating the core wire with a laser beam, the method comprising the steps of:
removing the insulating film by irradiating the laser light while supplying oxygen;
scanning the beam of laser light along a surface of the wire;
The scanning direction of the beam changes over time,
A coating removal method, comprising: supplying the oxygen only when the beam is scanned in a specific direction when the scanning direction changes over time. A method for removing an insulating coating of an electric wire having a core wire and an insulating coating made of an organic polymer material by irradiating the core wire with a laser beam, the method comprising the steps of:
removing the insulating film by irradiating the laser light while supplying oxygen;
The coating removal method further comprises setting a lower concentration of the oxygen to be supplied as the combustibility of the material of the insulating coating increases. a first step of removing a first insulating film by irradiating a first insulating film as the insulating film with the laser light while supplying the oxygen at a first concentration;
a second step of removing a second insulating coating by irradiating a second insulating coating, which is an insulating coating having a lower flammability than the first insulating coating, with the laser light while supplying the oxygen at a second concentration higher than the first concentration;
The coating removal method according to claim 3 , comprising: The first insulating film is provided so as to surround the second insulating film,
a first step of irradiating the first insulating coating with the laser light while supplying the oxygen at the first concentration, thereby removing the first insulating coating and exposing the second insulating coating;
a second step of removing the second insulating coating by irradiating the second insulating coating with the laser light while supplying the oxygen at the second concentration;
The coating removal method according to claim 4 , comprising: The coating removal method according to claim 5 , wherein in the second step, the second insulating coating is removed at a position separated from the first insulating coating. The coating removal method according to claim 1 , wherein the oxygen is supplied from a side opposite to the remaining portion of the insulating coating with respect to a boundary between the remaining portion and the region to be removed. The coating removal method according to claim 7 , wherein the oxygen is supplied toward the boundary or toward the core wire of the removal region. The removed area expands in a first direction;
The coating removal method according to claim 7 or 8 , wherein the oxygen is supplied in a direction that includes a component in the first direction. The coating removal method according to any one of claims 1 to 9 , wherein the laser light is a continuous wave. scanning the beam of laser light along a surface of the wire;
The coating removal method according to any one of claims 1 to 10 , wherein the oxygen is supplied in a direction that includes a component in the scanning direction of the beam. scanning the beam of laser light along a surface of the wire;
A coating removal method according to any one of claims 1 to 11, wherein in a cross section intersecting the irradiation direction of the beam, a length of the irradiation area of the beam in a direction intersecting the scanning direction is longer than a length of the irradiation area in the scanning direction. 13. The coating removal method according to claim 12 , wherein when the insulating coating is removed by scanning the beam over a predetermined range of the surface, the irradiation area extends across both ends of the predetermined range in a direction intersecting the scanning direction. The coating removal method according to claim 12 or 13 , wherein the beam is shaped by a beam shaper. scanning the beam of laser light along a surface of the wire;
The coating removal method according to claim 1 , wherein the beam moves in a turning or spiral manner on the surface so that the removed area of the insulating coating gradually expands during at least a portion of the scanning of the beam. scanning the beam of laser light along a surface of the wire;
The coating removal method according to claim 1 , further comprising changing the irradiation power of the laser light per unit area of the surface during the process of removing the insulating coating by scanning the beam over a predetermined range of the surface. 17. The coating removal method according to claim 16 , further comprising a step of lowering the irradiation power of the laser light per unit area of the surface while the beam is scanned over a predetermined area of the surface to remove the insulating coating, compared to immediately before. 18. The coating removal method according to claim 16 , further comprising changing at least one of a scanning speed of the laser light and an output of a light source of the laser light to change the irradiation power of the laser light per unit area of the surface. scanning the beam of laser light along a surface of the wire;
The coating removal method according to claim 1 , wherein the electric wire and the beam move relatively in the axial direction of the electric wire during at least a portion of the scanning of the beam. scanning the beam of laser light along a surface of the wire;
The coating removal method according to claim 1 , wherein the electric wire and the beam move relatively in a direction intersecting an axial direction of the electric wire during at least a portion of the scanning of the beam. scanning the beam of laser light along a surface of the wire;
The coating removal method according to claim 1 , wherein the electric wire and the beam move relatively in a circumferential direction about a central axis of the electric wire during at least a portion of the scanning of the beam. The coating removal method according to any one of claims 1 to 21 , wherein the oxygen-containing gas is supplied at a flow rate of 3.0 m/s or more and 35 m/s or less. A laser device that outputs laser light;
an optical head that irradiates the laser light output from the laser device toward a surface of an electric wire having a core wire and an insulating coating made of an organic polymer material;
an oxygen supply mechanism for supplying oxygen toward the laser light irradiation position of the electric wire;
Equipped with
scanning the beam of laser light along a surface of the wire;
The scanning direction of the beam changes over time,
switching the supply direction of the oxygen in response to a change in the scanning direction over time;
A coating removal device that removes the insulating coating by irradiating the laser light while supplying oxygen . A laser device that outputs laser light;
an optical head that irradiates the laser light output from the laser device toward a surface of an electric wire having a core wire and an insulating coating made of an organic polymer material;
an oxygen supply mechanism for supplying oxygen toward the laser light irradiation position of the electric wire;
Equipped with
scanning the beam of laser light along a surface of the wire;
The scanning direction of the beam changes over time,
supplying the oxygen only when the beam is scanned in a specific direction when the scanning direction changes over time;
A coating removal device that removes the insulating coating by irradiating the laser light while supplying oxygen . A laser device that outputs laser light;
an optical head that irradiates the laser light output from the laser device toward a surface of an electric wire having a core wire and an insulating coating made of an organic polymer material;
an oxygen supply mechanism for supplying oxygen toward the laser light irradiation position of the electric wire;
Equipped with
The higher the combustibility of the material of the insulating coating, the lower the concentration of the oxygen to be supplied is set;
A coating removal device that removes the insulating coating by irradiating the laser light while supplying oxygen . The oxygen supply mechanism includes:
A plurality of nozzles supplying oxygen in different directions;
a switching mechanism for switching between supplying and stopping oxygen through the plurality of nozzles;
The coating removal device according to any one of claims 23 to 25 , comprising:

Images