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JP-2026075955-A - Laser welding machine and laser welding method

JP2026075955AJP 2026075955 AJP2026075955 AJP 2026075955AJP-2026075955-A

Abstract

[Problem] To provide a laser welding method that prevents the laser beam from entering the gap between a pair of flat wires and burning off the coating. [Solution] In the first step, the tip of the first flat wire 71L is melted by irradiating the center of the first tip surface of the first flat wire 71L with the first laser beam LB, thereby forming a first molten portion 72L on the first flat wire 71L. In the second step, the tip of the second flat wire 71R is melted by irradiating the center of the second tip surface of the second flat wire 71R with the second laser beam LB, thereby forming a second molten portion 72R on the second flat wire 71R. The irradiation start position of the third laser beam LB is set to a position on the surface of the second molten portion 72R that is shifted outward from the center of the second tip surface. In the third step, the third laser beam LB is moved from the irradiation start position toward the first molten portion 72L. [Selection Diagram] Figure 7

Inventors

  • 吉村 泰典
  • 福島 涼太

Assignees

  • 株式会社アマダ

Dates

Publication Date
20260511
Application Date
20241023

Claims (15)

  1. A laser oscillator that emits a laser beam, A transmission fiber for transmitting the laser beam emitted from the laser oscillator, A processing head having a collimating lens that converts a divergent laser beam emitted from the exit end of the transmission fiber into collimated light, a focusing lens that focuses the collimated laser beam and irradiates a pair of adjacent flat wires to be welded, and a displacement mechanism that displaces the laser beam irradiating the pair of flat wires, A control device that controls the emission of the laser beam by the laser oscillator and the displacement of the laser beam by the displacement mechanism, Equipped with, The control device is The laser oscillator and the displacement mechanism are controlled to melt the tip of the first rectangular wire, which is one of the pair of rectangular wires, by irradiating the center of the first tip surface of the first rectangular wire with a first laser beam, thereby forming a first molten portion on the first rectangular wire. The laser oscillator and the displacement mechanism are controlled to melt the tip of the second rectangular wire, which is the other of the pair of rectangular wires, by irradiating the center of the second tip surface of the second rectangular wire with a second laser beam, thereby forming a second molten portion on the second rectangular wire. A laser welding machine that controls the laser oscillator and the displacement mechanism to move the third laser beam from the irradiation start position toward the first molten portion, with the irradiation start position of the third laser beam being set as the irradiation start position of the third laser beam, which is a position on the surface of the second molten portion that is shifted outward from the center of the second tip surface opposite to the first tip surface.
  2. The displacement mechanism is a galvanoscanner that displaces the laser beam of collimating light emitted from the collimating lens and causes it to be incident on the focusing lens. The galvanometer scanner comprises first and second galvanometer mirrors and first and second galvanometer motors that drive the first and second galvanometer mirrors, respectively. The laser welding machine according to claim 1, wherein the control device controls the rotation of the first and second galvanometers by the first and second galvanometer motors.
  3. The laser welding machine according to claim 1 or 2, wherein the control device controls the laser oscillator so that metal vapor is generated from the second molten portion by irradiating the surface of the second molten portion with the third laser beam.
  4. The laser welding machine according to claim 1 or 2, wherein the control device controls the displacement mechanism so that a bridge connecting the first and second molten portions is formed by moving a portion of the molten metal of the second molten portion, which has been melted by irradiation with the third laser beam, to the first molten portion.
  5. The laser welding machine according to claim 4, wherein the control device irradiates the surface of the bridge with a fourth laser beam to control the laser oscillator and the displacement mechanism in order to increase the amount of molten metal as the bridge or to shape the bridge.
  6. The laser welding machine according to claim 1 or 2, wherein the control device controls the displacement mechanism to cause the first and second laser beams to wobble in a predetermined pattern.
  7. The laser welding machine according to claim 1 or 2, wherein the control device controls the displacement mechanism to cause the third laser beam to wobble in a predetermined pattern.
  8. The laser welding machine according to claim 5, wherein the control device controls the displacement mechanism to cause the fourth laser beam to wobble in a predetermined pattern.
  9. A first step is to irradiate the center of the first tip surface of a first flat wire, which is one of a pair of flat wires to be welded adjacent to each other, with a first laser beam to melt the tip of the first flat wire and form a first molten portion on the first flat wire, A second step is to irradiate the center of the second tip surface of the second rectangular wire, which is the other of the pair of rectangular wires, with a second laser beam to melt the tip of the second rectangular wire and form a second molten portion on the second rectangular wire. A third step involves setting a position on the surface of the second molten portion that corresponds to a position on the surface of the second tip surface that is shifted outward from the center of the second tip surface, opposite to the first tip surface, as the irradiation start position for the third laser beam, and moving the third laser beam from the irradiation start position toward the first molten portion. A laser welding method including [specific type of laser welding].
  10. The laser welding method according to claim 9, wherein, in the third step, metal vapor is generated by irradiating the surface of the second molten portion with the third laser beam.
  11. The laser welding method according to claim 10, wherein the third step is to move a portion of the molten metal of the second molten portion, which has been melted by irradiation with the third laser beam, to the first molten portion, thereby forming a bridge connecting the first molten portion and the second molten portion.
  12. The laser welding method according to claim 11, further comprising a fourth step of irradiating the surface of the bridge with a fourth laser beam to increase the amount of molten metal forming the bridge or to shape the bridge.
  13. The laser welding method according to any one of claims 9 to 12, wherein the first and second steps each include a step of wobbling the first and second laser beams in a predetermined pattern.
  14. The laser welding method according to any one of claims 9 to 12, wherein the third step includes a step of wobbling the third laser beam in a predetermined pattern.
  15. The laser welding method according to claim 12, wherein the fourth step includes a step of wobbling the fourth laser beam in a predetermined pattern.

Description

This invention relates to a laser welding machine and a laser welding method. In motors used in electric or hybrid vehicles, the ends of radially adjacent segment coils of multiple U-shaped segment coils mounted on a core are welded together by a laser welding machine (see Patent Document 1). The ends of radially adjacent segment coils are a pair of flat wires. Japanese Patent Publication No. 2020-142257 Figure 1 shows an example of the configuration of a laser processing machine according to one or more embodiments.Figure 2 is a perspective view showing a galvanoscanner that may be included in a laser processing machine according to one or more embodiments.Figure 3 is a side view showing the first step of a laser welding method according to one or more embodiments.Figure 4 is a plan view showing the first step of a laser welding method according to one or more embodiments.Figure 5 is a side view showing a second step of a laser welding method according to one or more embodiments.Figure 6 is a plan view showing a second step of a laser welding method according to one or more embodiments.Figure 7 is a side view showing a third step of a laser welding method according to one or more embodiments.Figure 8 is a plan view showing a third step of a laser welding method according to one or more embodiments.Figure 9 shows preferred irradiation start and end positions of the laser beam in the third step of a laser welding method according to one or more embodiments.Figure 10 shows the relationship between the irradiation start position of the laser beam and the direction in which metal vapor is ejected in the third step of a laser welding method according to one or more embodiments.Figure 11 is a side view showing a fourth step of a laser welding method according to one or more embodiments.Figure 12 is a plan view showing a fourth step of a laser welding method according to one or more embodiments.Figure 13 shows a fixed-point irradiation or wobbling of a laser beam that can be performed in the first or second step.Figure 14 shows the linear movement or wobbling movement of the laser beam that can be performed in the third step.Figure 15 shows the wobbling of the laser beam that can be performed in the fourth step.Figure 16 is a photograph used as a substitute for a drawing, showing a pair of flat wires before welding.Figure 17 is a photograph used as a substitute for a drawing, showing the state of a pair of rectangular wires in the first process.Figure 18 is a photograph used as a substitute for a drawing, showing the state of a pair of rectangular wires in the second process.Figure 19 is a photograph used as a substitute for a drawing, showing the state of a pair of rectangular wires in the third process.Figure 20 is a photograph used as a substitute for a drawing, showing the state of a pair of rectangular wires in the fourth step. The following describes laser welding machines and laser welding methods according to one or more embodiments, with reference to the attached drawings. First, using Figures 1 and 2, a laser welding machine 100 according to one or more embodiments for welding a pair of flat wires will be described. The laser welding machine 100 shown in Figure 1 performs a laser welding method according to one or more embodiments. As shown in Figure 1, the laser welding machine 100 comprises an NC device 10, a blue laser oscillator 20, a transmission fiber 30, a processing head 40, and a camera 50. The NC device 10 is an example of a control device that controls various parts of the laser welding machine 100. The blue laser oscillator 20 emits a blue laser beam with a wavelength of, for example, 400 nm to 460 nm. The transmission fiber 30 transmits the laser beam, indicated by the dashed line, emitted from the blue laser oscillator 20 to the processing head 40. The processing head 40 includes a collimating lens 41, a galvanoscanner 42, and a focusing lens 43. The collimating lens 41 converts the divergent laser beam emitted from the exit end of the transmission fiber 30 into collimated light. The collimated laser beam is incident on the focusing lens 43 via the galvanoscanner 42 (described later). The focusing lens 43 focuses the collimated laser beam, irradiating the pair of flat wires 71L and 71R to be welded. The laser beam emitted from the focusing lens 43 and irradiated onto the pair of flat wires 71L and 71R will be referred to as the laser beam LB. Below the processing head 40, multiple pairs of coated copper wires 61L and 61R are arranged. The ends of the coated copper wires 61L and 61R are flat rectangular wires 71L and 71R from which the coating has been removed. Typically, the coating is enamel coating. Gaps exist between the flat rectangular wires 71L and 71R due to the removal of the coating. As an example, multiple pairs of coated copper wires 61L and 61R (flat rectangular wires 71L and 71R) are arranged circumferentially and configured to rotate circumferentially. The processing head 40 c