JP2018012119A - Welding equipment - Google Patents

Abstract

A welding apparatus capable of reducing the size and cost is provided.
A welding apparatus includes an irradiation unit, a moving unit, a light receiving unit, and a control unit. The control unit 50 includes an output control unit 51 that controls the output of the laser light and an irradiation direction control unit 52 that controls the irradiation direction of the laser light. Moreover, the control part 50 performs the welding process by irradiating the laser beam of 1st output, moving the irradiation part 10 along the welding object of a welding material, and prior to execution of a welding process. The welding target detection unit 55 that detects the welding target by scanning the workpiece with the laser beam from the irradiation unit 10 set to the second output, and the irradiation set to the third output after the execution of the welding process And a welding state detection unit 56 that detects a welding state by scanning the workpiece with a laser beam from the unit 10. The execution part 54 moves the irradiation part 10 along the welding object detected by the welding object detection part, and performs a welding process.
[Selection] Figure 2

Description

  The present invention relates to a welding apparatus for welding workpieces.

  Patent Document 1 discloses a welding apparatus that performs arc welding. This welding apparatus has a welding torch to which welding power is supplied from a power supply unit. When electric power is supplied to the welding torch, an arc is generated between the welding torch and the workpiece, and the workpiece is welded by the heat. In this welding apparatus, welding is performed by moving the welding torch along the object to be welded. In the welding apparatus described in Patent Document 1, a laser sensor that rotates around the welding torch about the welding torch is provided in order to accurately detect the welding target. A laser sensor detects a welding object by scanning a laser beam on a workpiece and detecting reflected light from the workpiece. In the welding apparatus described in Patent Literature 1, when welding is performed, a laser beam is rotated and scanned around the welding torch, and a welding target in the moving direction of the welding torch is detected. And welding is performed by moving the welding torch along the detected welding object. In this welding apparatus, the welding state of the material to be welded is also detected by the laser sensor behind the welding torch in the moving direction.

JP-A-8-150476

  The welding apparatus described in Patent Document 1 includes a laser sensor for detecting a welding target and a welding state, separately from a welding torch for performing welding. Therefore, the number of components of the welding apparatus increases, and it is difficult to reduce the size and cost of the welding apparatus.

  A welding apparatus for solving the above-described problems is directed to irradiating a workpiece with laser light and changing an irradiation direction of the laser light, a moving unit for moving the irradiation unit, and irradiation from the irradiation unit. A welding device including a light receiving unit that detects reflected light from the welded material of the laser beam, and a control unit that controls the irradiation unit and the moving unit, wherein the control unit includes: An output control unit for controlling the output of the irradiated laser light, an irradiation direction control unit for controlling the irradiation direction of the laser light irradiated from the irradiation unit, and the irradiation unit along the welding target of the welding material Prior to the execution of the welding process by the execution unit that executes a welding process for welding the material to be welded by irradiating the laser beam set to the first output from the irradiation unit while moving ,Previous The laser beam from the irradiation part set to the second output weaker than the first output is scanned in the first predetermined direction in the welded material, and the welded material of the welded material is based on the reflected light detected by the light receiving unit. After the execution of the welding process by the welding target detection unit for detecting the welding target and the execution unit, the laser beam from the irradiation unit set to the third output weaker than the first output is applied to the welding material. (2) a welding state detection unit that scans in a predetermined direction and detects a welding state of the welding material based on reflected light detected by the light receiving unit, and the execution unit is detected by the welding target detection unit. The irradiation process is performed by moving the irradiation unit along the welding target.

  In the said structure, the detection of the welding object of a welding material and the detection of the welding state after welding are performed using the irradiation part used for welding. Therefore, according to the said structure, it is not necessary to equip the welding apparatus with the apparatus for performing welding, and the apparatus for detecting the welding object and a welding state separately. Therefore, it is possible to contribute to simplification of the configuration of the welding apparatus, and it is possible to reduce the size and cost of the welding apparatus.

The schematic diagram which shows the structure of one Embodiment of a welding apparatus. The schematic diagram which shows the structure of the irradiation part and light-receiving part of a welding apparatus. The schematic diagram of the irradiation part which shows the change of the irradiation direction when rotating a 1st galvanometer mirror. The schematic diagram of the irradiation part which shows the change of the irradiation direction when rotating a 2nd galvanometer mirror. It is a schematic diagram which shows the scanning aspect of the laser beam controlled by the welding target detection part, Comprising: The figure in case the welding target of a to-be-welded material exists in an assumption position. (A) And (b) is a graph which shows the intensity | strength of the reflected light which a light-receiving part light-receives when a laser beam is scanned when the welding object of a to-be-welded material exists in an assumption position. It is a schematic diagram which shows the scanning aspect of the laser beam controlled by the welding target detection part, Comprising: The figure when the welding target of a to-be-welded material has shifted | deviated in parallel from the assumed position. (A) And (b) is a graph which shows the intensity | strength of the reflected light which a light-receiving part light-receives when scanning a laser beam, when the welding object of a to-be-welded material has shifted | deviated in parallel from the assumed position. It is a schematic diagram which shows the scanning aspect of the laser beam controlled by a welding target detection part, Comprising: The figure in case the welding target of a to-be-welded material has shifted | deviated and inclined with respect to the assumption position. (A) And (b) is a graph which shows the intensity | strength of the reflected light which a light-receiving part light-receives, when a laser beam is scanned, when the welding object of a to-be-welded material is inclined and shifted | deviated with respect to the assumed position. The schematic diagram which shows the other example of the scanning aspect of a laser beam. The schematic diagram which shows the other example of the scanning aspect of a laser beam.

An embodiment of a welding apparatus will be described with reference to FIGS.
As shown in FIG. 1, the welding apparatus includes an irradiation unit 10 that can irradiate laser light, and a moving unit 30 having one end connected to the irradiation unit 10. The irradiation unit 10 irradiates the workpiece 60 with laser light. The material to be welded 60 is a metal plate made of, for example, aluminum, and includes a first metal plate 61 and a second metal plate 62. The first metal plate 61 and the second metal plate 62 are partially in contact with each other, and the second metal plate 62 is located on the irradiation unit side (upper side in FIG. 1) than the first metal plate 61. . As shown in FIG. 1, in the welding apparatus, the workpiece 60 is welded by irradiating the irradiation unit 10 with laser light while moving the irradiation unit 10 by the moving unit 30. That is, the first metal plate 61 and the second metal plate 62 are welded. In addition, let the moving direction (left-right direction of FIG. 1) of the irradiation part 10 when performing welding in this way be a 1st direction.

  The moving unit 30 includes a first arm 31 having one end fixed to the fixed member 20. A support hole 31 </ b> A is formed at the other end of the first arm 31. The first rotation shaft 32 is rotatably supported in the support hole 31A. The first rotating shaft 32 is controlled to rotate by the first actuator 33. One end of a second arm 34 is connected to the first rotation shaft 32. The first rotating shaft 32 and the second arm 34 are fixed to each other. Therefore, when the first rotation shaft 32 is rotated by the first actuator 33, the second arm 34 swings the other end side about the first rotation shaft 32. As a result, the second arm 34 swings with respect to the first arm 31.

  An insertion hole 34 </ b> A is formed at the other end of the second arm 34. The second rotation shaft 35 is rotatably inserted into the insertion hole 34A. The second rotating shaft 35 is controlled to rotate by the second actuator 36. One end of a third arm 37 is connected to the second rotation shaft 35. The second rotation shaft 35 and the third arm 37 are fixed to each other. Therefore, when the second rotation shaft 35 is rotated by the second actuator 36, the third arm 37 swings the other end side about the second rotation shaft 35. As a result, the third arm 37 swings with respect to the second arm 34. The irradiation unit 10 is connected to the other end of the third arm 37. The moving unit 30 moves the irradiation unit 10 by rotating the first rotating shaft 32 and the second rotating shaft 35 and swinging the second arm 34 and the third arm 37. The first arm 31, the first rotation shaft 32, the first actuator 33, the second arm 34, the second rotation shaft 35, the second actuator 36, and the third arm 37 constitute a moving unit 30.

  As shown in FIG. 2, the irradiation unit 10 has a box-shaped housing 11. A light source 12 is accommodated in the housing 11. The light source 12 outputs a laser beam toward the lower side of FIG. 2 as indicated by a one-dot chain line arrow in FIG. A beam sampler 13 is also accommodated inside the housing 11. The beam sampler 13 is arranged in front of the output direction of the laser light when viewed from the light source 12. The beam sampler 13 is made of glass and has a plate shape. The beam sampler 13 is disposed at a predetermined angle with respect to the optical axis of the laser beam. An antireflection film is formed on the surface of the beam sampler 13 on the light source 12 side. Thereby, the beam sampler 13 transmits the laser light output from the light source 12, while reflecting the light incident from the opposite side of the light source 12.

  A first galvanometer mirror 14 and a second galvanometer mirror 15 are accommodated in the housing 11. The first galvanometer mirror 14 includes a first mirror 14A that reflects light, a first rotating shaft 14B fixed to the first mirror 14A, and a first motor 14C that rotates the first rotating shaft 14B. ing. The first galvanometer mirror 14 reflects the laser light transmitted through the beam sampler 13 toward the second galvanometer mirror 15. The second galvanometer mirror 15 includes a second mirror 15A that reflects light, a second rotating shaft 15B fixed to the second mirror 15A, and a second motor 15C that rotates the second rotating shaft 15B. Have. The second galvanometer mirror 15 reflects the laser beam reflected by the first galvanometer mirror 14 toward the workpiece 60 (downward in FIG. 2). An irradiation hole 11A is formed in the lower end surface of the housing 11, and the laser light reflected by the second galvanometer mirror 15 is irradiated to the outside of the housing 11 through the irradiation hole 11A. As described above, the laser light output from the light source 12 passes through the beam sampler 13 and enters the first galvanometer mirror 14 as shown by the one-dot chain line arrow in FIG. Then, the laser light reflected by the first galvanometer mirror 14 enters the second galvanometer mirror 15 and is irradiated from the second galvanometer mirror 15 to the outside of the housing 11, that is, the workpiece 60.

  In the first galvanometer mirror 14, the first mirror 14 </ b> A rotates about the first rotation shaft 14 </ b> B by controlling the driving of the first motor 14 </ b> C. As a result, the reflection angle of the laser light at the first galvanometer mirror 14 changes. In the first galvanometer mirror 14, the axis of the first rotation shaft 14B extends in a second direction (depth direction in FIG. 2) orthogonal to the first direction (left-right direction in FIG. 2).

  As shown in FIG. 3, when the first rotation shaft 14 </ b> B of the first galvanometer mirror 14 is rotated, the irradiation direction of the laser light from the irradiation unit 10 changes along the first direction with respect to the workpiece 60. .

  In the second galvanometer mirror 15, the second mirror 15A rotates about the second rotation shaft 15B by controlling the driving of the second motor 15C. The second galvanometer mirror 15 is arranged such that the axis of the second rotation shaft 15B extends in the first direction in plan view.

  As shown in FIG. 4, when the second rotation shaft 15 </ b> B of the second galvanometer mirror 15 is rotated, the irradiation direction of the laser light from the irradiation unit 10 changes along the second direction with respect to the workpiece 60. . In the irradiation unit 10, the irradiation direction of the laser light from the irradiation unit 10 can be changed by changing the reflection angle of the light in the first galvanometer mirror 14 and the second galvanometer mirror 15 in this way. The irradiation unit 10 includes a housing 11, a light source 12, a beam sampler 13, a first galvanometer mirror 14, and a second galvanometer mirror 15.

  As shown in FIG. 2, the welding apparatus also has a light receiving unit 40. The light receiving unit 40 has a case 41 fixed to the housing 11 of the irradiation unit 10. The inside of the case 41 and the inside of the housing 11 communicate with each other through a communication hole 42 extending through the case 41 and the housing 11. A spectroscopic lens 43 is arranged inside the case 41. The light reflected from the beam sampler 13 is incident on the spectroscopic lens 43. As indicated by a two-dot chain line arrow in FIG. 2, the laser light emitted from the irradiation unit 10 is reflected from the workpiece 60 and the reflected light enters the irradiation unit 10. The reflected light incident on the irradiation unit 10 enters the beam sampler 13 via the second galvanometer mirror 15 and the first galvanometer mirror 14. Since the beam sampler 13 reflects light incident from the side opposite to the light source 12 as described above, the reflected light from the workpiece 60 is reflected from the beam sampler 13 toward the spectroscopic lens 43. The spectroscopic lens 43 is disposed to be inclined with respect to the optical axis of the incident light. The spectroscopic lens 43 reflects only light in the same wavelength range as the laser light, and transmits light of other wavelengths. Therefore, light in the same wavelength range as the laser light among the light incident on the spectroscopic lens 43 from the beam sampler 13 is reflected by the spectroscopic lens 43 and enters the first detection unit 44. The case 41 also houses a reflection lens 45. Light that has passed through the spectroscopic lens 43 is incident on the reflection lens 45. The reflection lens 45 reflects incident light and makes it incident on the second detection unit 46. The first detector 44 and the second detector 46 detect the intensity of incident light. The light receiving unit 40 includes a case 41, a spectroscopic lens 43, a reflection lens 45, a first detection unit 44, and a second detection unit 46.

  The welding device is also provided with a control unit 50. Output signals from the first detection unit 44 and the second detection unit 46 are input to the control unit 50. The control unit 50 includes a movement control unit 51, an output control unit 52, an irradiation direction control unit 53, an execution unit 54, a welding target detection unit 55, and a welding state detection unit 56.

  The movement control unit 51 controls driving of the first actuator 33 and the second actuator 36 of the moving unit 30. The output control unit 52 controls the light source 12 of the irradiation unit 10 to control the output of the laser light emitted from the irradiation unit 10. The irradiation direction control unit 53 controls the driving of the first motor 14C of the first galvano mirror 14 and the second motor 15C of the second galvano mirror 15 in the irradiation unit 10 to control the laser light emitted from the irradiation unit 10. Control the direction of irradiation.

  The execution unit 54 executes a welding process for welding the welding target of the workpiece 60. In the welding process, the movement control unit 51 is controlled to move the irradiation unit 10 along the welding target of the material 60 to be welded, and the irradiation unit 10 is controlled to irradiate the welding target with laser light from the irradiation unit 10. . Moreover, the execution part 54 controls the output control part 52, and controls the output of the laser beam in a welding process so that it may become the 1st output which can weld the to-be-welded material 60. FIG.

  Prior to the execution of the welding process by the execution unit 54, the welding target detection unit 55 detects the welding target of the workpiece 60. The welding target detection unit 55 controls the output control unit 52 to set the output of the laser light emitted from the irradiation unit 10 to the second output. The second output is an output in which the workpiece 60 is not welded. Therefore, the second output is weaker than the first output set in the welding process. And the welding target detection part 55 scans the to-be-welded material 60 in the said 2nd direction with the laser beam of 2nd output. The second direction corresponds to the “first predetermined direction”. As shown in FIG. 1, the first metal plate 61 and the second metal plate 62 partially overlap each other, and the side surface of the second metal plate 62 stands upright with respect to the surface of the first metal plate 61. As a result, a step is formed. The side surface of the second metal plate 62 forming the step constitutes an edge portion 62A that is a welding target. When laser light is scanned from the irradiation unit 10, the light is reflected at the edge 62 </ b> A of the second metal plate 62, and the amount of reflected light incident on the irradiation unit 10 increases. Thereby, the intensity | strength of the light detected by the light-receiving part 40 becomes strong. As described above, the welding target detection unit 55 detects the welding target of the workpiece 60 based on the reflected light detected by the light receiving unit 40 when the laser beam is scanned.

  The welding state detection unit 56 shown in FIG. 2 detects the welding state of the workpiece 60 after the execution of the welding process by the execution unit 54. The welding state detection part 56 controls the output control part 52, and sets the output of the laser beam irradiated from the irradiation part 10 to a 3rd output. The third output is an output in which the workpiece 60 is not welded. Therefore, the third output is weaker than the first output set in the welding process. The third output may be the same output as the second output set by the welding target detection unit 55, or may be a different output. And the welding condition detection part 56 scans the to-be-welded material 60 in the said 2nd direction with the laser beam of 3rd output. The second direction corresponds to the “second predetermined direction”. When the welding process is performed, a weld bead is formed on the object to be welded. The quality of the bead shape can be determined based on the reflected light when the laser beam is irradiated to the weld bead. Therefore, the welding state detection unit 56 determines the quality of the bead shape based on the reflected light detected by the light receiving unit 40 when the laser beam is scanned, and detects the welding state of the material 60 to be welded.

Next, a series of flows when the workpiece 60 is welded by the welding apparatus will be described.
In the welding apparatus, when performing the welding process, the moving unit 30 is controlled to place the irradiation unit 10 at a preset initial position, and the irradiation direction control unit 53 is controlled to control the first galvanometer mirror 14 and the first one. The reflection angle of the 2 galvanometer mirror 15 is set to the initial angle. The initial position and the initial angle are such that the edge portion 62A of the second metal plate 62 is disposed when the first metal plate 61 and the second metal plate 62 are placed at predetermined positions and overlapped with each other. It is set according to the assumed position and stored in advance in the control device. In addition, the control device stores in advance an initial trajectory for moving the irradiation unit 10 during execution of the welding process. For this reason, if the position of the edge portion 62A is the same as the assumed position, the irradiation portion 10 is set to the initial position and irradiated with the laser beam while being moved in the initial trajectory, whereby the edge portion 62A to be welded. Can be welded.

  However, when the first metal plate 61 and the second metal plate 62 are arranged, the position of the edge portion 62A may deviate from the assumed position due to the dimensional tolerance of the second metal plate 62 or the like. Therefore, in the present embodiment, as shown in FIG. 5, the welding process is performed on the welding target of the material to be welded 60 divided into predetermined unit areas, and prior to the execution of the welding process in each unit area, The position of the welding object in the unit area is detected. And at the time of execution of welding processing, the above-mentioned initial starting is amended so that irradiation part 10 may be moved along the detected welding object.

A flow of a series of processes related to the welding process in each unit region will be described.
In the welding apparatus, first, before executing the welding process, the welding target detection unit 55 scans the workpiece 60 from the irradiation unit 10 with the second output along the second direction with the second output twice. .

  As shown in FIG. 5, the first laser beam scanning position indicated by the two-dot chain line arrow and the second laser beam scanning position indicated by the one-dot chain line are in the first direction (left-right direction in FIG. 5). It is separated. In other words, the scanning position of the first laser beam and the scanning position of the second laser beam are separated from each other in the moving direction of the irradiation unit 10 during the execution of the welding process. Further, as indicated by dots in FIG. 5, the scanning start point of the laser beam in each scanning is set in advance so as to be the same position in the second direction (vertical direction in FIG. 5). Then, the laser beam is scanned for a predetermined time at a predetermined speed from the scanning start point. This predetermined time is set with a margin so that the laser light passes through the edge portion 62A. When the laser light is applied to the edge portion 62A, the laser light is reflected at the edge portion 62A and detected by the light receiving unit 40 as compared with the case where the laser light is applied to a plane portion other than the edge portion 62A. The intensity of reflected light increases.

  As shown in FIGS. 6A and 6B, the light receiving unit 40 detects the intensity of the reflected light in two laser beam scans. The timing t0 at which the intensity of the reflected light becomes maximum corresponds to the timing at which the edge 62A is irradiated with the laser light. The welding object detection unit 55 calculates the distance from the scanning start point to the edge portion 62A based on the time from the start of the laser beam scanning to the timing t0 and the laser beam scanning speed. In the example shown in FIG. 6, the timing tk at which the intensity of the reflected light is maximum when the edge portion 62A is assumed to be at the assumed position is the same as the timing t0 described above. Therefore, it can be determined that the position of the edge portion 62A is not shifted from the assumed position described above. In this case, the irradiation unit 10 can be moved along the object to be welded by moving along the initial trajectory. The timing tk can be obtained in advance by experiments or simulations. When the welding target detection unit 55 detects the welding target in this unit region, the execution unit 54 moves the irradiation unit 10 from, for example, the left to the right in FIG. 5 along the welding target detected in the current unit region. The welding material 60 is welded by irradiating the irradiation unit 10 with the laser beam set to the first output.

  Moreover, as shown in FIG. 7, the welding target indicated by the solid line may be shifted in parallel from the assumed position indicated by the broken line. Even in this case, the welding object can be detected by scanning the laser beam twice as shown in FIG. The first scan is indicated by a two-dot chain arrow, and the second scan is indicated by a one-dot chain arrow.

  As shown in FIG. 8A, in this case, the timing t1 at which the intensity of the reflected light is maximum in the first scanning of the laser light is later than the timing tk described above. In addition, as shown in FIG. 8B, the timing t2 at which the intensity of the reflected light is maximized also in the second scanning of the laser light is later than the timing tk described above. Note that the timing t1 and the timing t2 are substantially the same timing. The difference Δta (= t1−tk) between the timing tk and the timing t1, that is, the difference Δtb (= t2−tk) between the timing tk and the timing t2, reflects the influence of the deviation of the edge portion 62A from the assumed position. Yes. Therefore, based on the difference Δta and difference Δtb and the scanning speed of the laser light, it is possible to detect how much the edge portion 62A is deviated from the assumed position. When the welding target detection unit 55 detects the welding target in this unit region in this way, the execution unit 54 corrects the initial trajectory according to the deviation from the assumed position. That is, as shown in FIG. 7, the initial trajectory is corrected to the side away from the scanning start point by a distance L1 corresponding to the difference Δta, Δtb. Thereafter, the execution unit 54 moves the irradiation unit 10 along the welding target by moving the irradiation unit 10 from the left to the right in FIG. 7 along the corrected initial trajectory, for example. And the to-be-welded material 60 is welded by irradiating the irradiation part 10 with the laser beam set to the 1st output from this irradiation part 10. FIG.

  Moreover, as shown in FIG. 9, the welding target indicated by the solid line may be inclined with respect to the assumed position indicated by the broken line. Even in this case, the welding object can be detected by scanning the laser beam twice as shown in FIG. The first scan is indicated by a two-dot chain arrow, and the second scan is indicated by a one-dot chain arrow.

  As shown in FIG. 10A, in the first laser beam scanning, the timing t3 at which the intensity of the reflected light is maximized is earlier than the timing tk described above. On the other hand, as shown in FIG. 10B, in the second scanning of the laser light, the timing t4 at which the intensity of the reflected light becomes maximum is later than the timing tk described above. The difference Δtc (= tk−t3) between the timing tk and the timing t3 and the difference Δtd (= t4−tk) between the timing tk and the timing t4 reflect the influence of the deviation of the edge portion 62A from the assumed position. . Therefore, based on the difference Δtc and the difference Δtd and the scanning speed of the laser light, it is possible to detect how the edge portion 62A is deviated from the assumed position. When the welding target detection unit 55 detects the welding target in this unit region in this way, the execution unit 54 corrects the initial trajectory according to the deviation from the assumed position. That is, as shown in FIG. 9, at the first scanning position of the laser beam, the initial activation is corrected so as to shift to the scanning start point side by a distance L2 corresponding to the difference Δtc, and the second scanning position of the laser beam Then, the initial activation is corrected so as to be shifted away from the scanning start point by a distance L3 corresponding to the difference Δtd. Thereby, the initial startup after correction is inclined with respect to the assumed position. And the irradiation part 10 is moved along a welding object by moving along the initial track | orbit after this correction | amendment. The execution unit 54 welds the workpiece 60 by irradiating the irradiation unit 10 with the laser beam set to the first output while moving the irradiation unit 10.

  When the welding apparatus finishes the welding process in the unit region, the welding state detection unit 56 next causes the welding target material 60 to scan the laser beam once with the third output along the second direction. And the welding state of the to-be-welded material 60 is detected based on the reflected light detected by the light-receiving part 40 at this time. When detecting the welding state, for example, the shape of the weld bead when the welding is successfully performed is obtained in advance by an experiment or the like, and an appropriate shape having a predetermined allowable width with respect to this shape is obtained in advance. Remember. And the quality of a bead shape is determined based on whether the shape of the weld bead detected based on reflected light is in the range of the said appropriate shape, and a welding state is detected.

  When the welding state is thus detected, the process proceeds to welding in the next unit region. Thereafter, the detection of the welding target, the execution of the welding process, and the detection of the welding state are repeated in the same manner for each unit region, and the entire welding target is welded.

Next, the effect of the welding apparatus according to the present embodiment will be described.
In this embodiment, the irradiation part 10 used for welding is utilized and the detection of the welding target of the to-be-welded material 60 and the detection of the welding state after welding are performed. Therefore, it is not necessary to separately provide an apparatus for performing welding and an apparatus for detecting a welding object and a welding state in the welding apparatus. Therefore, it is possible to contribute to simplification of the configuration of the welding apparatus, and it is possible to reduce the size and cost of the welding apparatus.

The above embodiment can be implemented with the following modifications.
-The structure of the irradiation part 10 is not restricted to the thing of the said embodiment. For example, in addition to or instead of the housing 11, the light source 12, the beam sampler 13, the first galvanometer mirror 14, and the second galvanometer mirror 15, other members may be provided. That is, the irradiation unit 10 may include an optical fiber that places the light source 12 outside the housing 11 and guides the laser light output from the light source 12 to the inside of the housing 11. Even with such a configuration, it is possible to configure the irradiation unit 10 that can irradiate the workpiece 60 with the laser beam and change the irradiation direction of the laser beam.

  -You may employ | adopt the structure provided with a condensing lens in the irradiation part 10. FIG. In this configuration, the focal point of the condensing lens is set according to the welding target of the material to be welded 60, thereby condensing the laser light output from the light source and performing welding. In this configuration, the output control unit 52 changes the position of the focal point by variably controlling the position of the condensing lens, etc., and changes the condensing diameter, thereby irradiating the material to be welded 60 from the irradiation unit 10. It is also possible to control the energy density of light.

  -The structure of the moving part 30 is not restricted to the thing of the said embodiment. For example, in addition to or instead of the first arm 31, the first rotation shaft 32, the first actuator 33, the second arm 34, the second rotation shaft 35, the second actuator 36, and the third arm 37, other A member may be provided. That is, the configuration is such that the irradiation unit 10 is not directly connected to the other end of the third arm 37 but the fourth arm is connected via the third rotation shaft, and the irradiation unit 10 is connected to the fourth arm. It may be adopted. Thus, the number of arms can be changed as appropriate. Further, the moving unit 30 may fix one end of the first arm 31 to the movable member instead of the fixed member 20. Even if it is such a structure, the function to move the irradiation part 10 can be ensured.

  -The structure of the light-receiving part 40 is not restricted to the thing of the said embodiment. For example, other members may be provided in addition to or instead of the case 41, the spectroscopic lens 43, the first detection unit 44, the reflection lens 45, and the second detection unit 46. That is, the spectroscopic lens 43 and the first detection unit 44 may be omitted, and all the light reflected by the beam sampler 13 may be incident on the second detection unit 46 via the reflection lens 45. Further, the spectroscopic lens 43 and the reflection lens 45 may be omitted, and instead of these, a prism that separates the incident light from the beam sampler 13 for each of a plurality of wavelengths may be disposed. In such a configuration, a detection unit corresponding to each of the dispersed light may be provided.

-In welding object detection part 55, the frequency | count of scanning a laser beam is not restricted to 2 times. For example, it may be three or more times. Further, the laser beam scanning is not limited to a straight line.
For example, as indicated by a two-dot chain line in FIG. 11, the laser beam may be rotationally scanned. In this configuration, the laser beam is scanned in a direction extending along the first direction from the scanning start point toward the scanning end point, as indicated by a dashed line arrow in FIG. The direction indicated by the arrow corresponds to the “first predetermined direction”. Even when the laser beam is rotated and scanned in this manner, the reflected light intensity detected by the light receiving unit 40 when the laser beam is irradiated onto the object to be welded is increased as in the above embodiment. Since the object to be welded is detected a plurality of times in a short time by performing rotational scanning, the reflected light detected by the light receiving unit 40 increases in noise, and the detection may not be stable. Therefore, the welding target detection unit 55 performs frequency analysis such as Fourier transform on the detection signal detected by the light receiving unit 40 to extract a frequency component. Thereby, the detection signal of the reflected light from which the influence of noise is removed can be calculated. In the welding target detection unit 55, a detection signal of reflected light when the laser beam is similarly rotated and scanned when the welding target is at the assumed position is obtained in advance through experiments or the like and stored as an assumed signal. Based on the deviation between the assumed signal and the calculated detection signal, the deviation from the assumed position of the welding target can be calculated. In addition, when performing the Fourier transform in this way, it is possible to determine the direction in which the welding target is deviated from the assumed position by paying attention to the imaginary component after the Fourier transform. Therefore, it is possible to detect the welding object by rotating and scanning the laser beam in this way.

  Further, as shown by a two-dot chain line in FIG. 12, the laser beam may be scanned in a polygonal line. In this configuration, the laser beam is scanned in a direction extending along the first direction from the scanning start point to the scanning end point, as indicated by a dashed line arrow in FIG. The direction indicated by the arrow corresponds to the “first predetermined direction”. In this configuration as well, the frequency analysis is performed on the detection signal detected by the light receiving unit 40, and the frequency component is extracted. Thereby, the detection signal of the reflected light from which the influence of noise is removed can be calculated. Similarly, when the welding target is at the assumed position, an assumed signal when the laser beam is scanned in a polygonal line is stored in advance, and based on the deviation between the assumed signal and the calculated detection signal, the assumed position of the welding target is stored. The deviation from is calculated.

  Even in these configurations, by correcting the initial trajectory based on the detected welding target, the execution unit 54 can execute the welding process by moving the irradiation unit in the first direction along the welding target. .

  -In the welding state detection part 56, the frequency | count of scanning a laser beam is not restricted to once. For example, it may be twice or more. In the welding state detection unit 56, for example, the laser beam may be scanned so as to intersect the welding target, or the laser beam may be scanned so as to trace the welding target along the welding target.

  The example in which the scanning direction of the laser beam controlled by the welding target detection unit 55 and the scanning direction of the laser beam controlled by the welding state detection unit 56 are each set as the second direction is illustrated. It may be other than two directions. Moreover, the scanning direction of the laser beam controlled by the welding target detection unit 55 and the scanning direction of the laser beam controlled by the welding state detection unit 56 may be different from each other. That is, the first predetermined direction and the second predetermined direction may be different directions.

  -The execution part 54 was made to move the irradiation part 10 along a welding target at the time of a welding process by correct | amending with respect to the preset initial track. However, the structure which moves the irradiation part 10 along a welding object is not restricted to this structure. For example, a moving trajectory is calculated for each unit area based on the distance from the scanning start point to the edge portion 62A, and the irradiation unit 10 is moved along the moving trajectory. Even with such a configuration, the irradiation unit 10 can be moved along the object to be welded.

  In the welding apparatus, plasma is generated by irradiating the workpiece 60 with laser light. In the above embodiment, it is also possible to detect the plasma as reflected light of the laser beam in the light receiving unit 40 and confirm the stability of welding during the execution of the welding process. Further, the welding target detection unit 55 may detect the welding target by detecting plasma in the light receiving unit 40. Further, the welding state detection unit 56 may detect the welding state by detecting plasma in the light receiving unit 40.

  A structure in which a lap joint in which the first metal plate 61 and the second metal plate 62 are overlapped is used as the material to be welded 60 of the welding apparatus, and fillet welding is performed with the edge portion 62A of the second metal plate 62 as a welding target. Although illustrated, the material to be welded can be appropriately changed. For example, the same configuration as that of the above embodiment can be applied to a welding apparatus that performs fillet welding of a T-shaped joint and butt welding of a T-shaped joint and a butt joint. In addition, the point where the intensity of the reflected light is maximum was detected as the welding object, but the point where the intensity of the reflected light is the minimum or a specific value as a threshold value can also be detected as the welding object. It is.

  DESCRIPTION OF SYMBOLS 10 ... Irradiation part, 11 ... Housing, 11A ... Irradiation hole, 12 ... Light source, 13 ... Beam sampler, 14 ... 1st galvanometer mirror, 14A ... 1st mirror, 14B ... 1st rotating shaft, 14C ... 1st motor, 15 ... 2nd galvanometer mirror, 15A ... 2nd mirror, 15B ... 2nd rotating shaft, 15C ... 2nd motor, 20 ... Fixed member, 30 ... Moving part, 31 ... 1st arm, 31A ... Support hole, 32 ... 1st Rotating shaft 33 ... first actuator 34 ... second arm 34A ... insertion hole 35 ... second rotating shaft 36 ... second actuator 37 ... third arm 40 ... light receiving portion 41 ... case 42 ... Communication hole, 43 ... Spectral lens, 44 ... First detection unit, 45 ... Reflection lens, 46 ... Second detection unit, 50 ... Control unit, 51 ... Movement control unit, 52 ... Output control unit, 53 ... Irradiation direction Control unit 54 ... execution unit 55 ... melt Target detection unit, 56 ... welding state detecting unit, 60 ... material to be welded, 61 ... first metal plate, 62 ... second metal plate, 62A ... edge section.

Claims (1)

An irradiation unit that irradiates a workpiece with laser light and can change the irradiation direction of the laser light;
A moving unit for moving the irradiation unit;
A light receiving unit for detecting reflected light from the material to be welded of the laser beam irradiated from the irradiation unit;
A welding device comprising a control unit for controlling the irradiation unit and the moving unit,
The controller is
An output control unit for controlling the output of laser light emitted from the irradiation unit;
An irradiation direction control unit for controlling the irradiation direction of the laser light emitted from the irradiation unit;
An execution unit that executes a welding process for welding the workpiece by irradiating the irradiation unit with the laser beam set to the first output while moving the irradiation unit along the welding target of the workpiece. When,
Prior to the execution of the welding process by the execution unit, a laser beam from the irradiation unit set to a second output weaker than the first output is scanned in the first predetermined direction in the material to be welded, and the light reception A welding target detection unit that detects a welding target of the welded material based on reflected light detected by the unit;
After the execution of the welding process by the execution unit, the laser beam from the irradiation unit set to a third output that is weaker than the first output is scanned in the second predetermined direction in the material to be welded, and the light receiving unit A welding state detection unit for detecting a welding state of the workpiece to be welded based on the detected reflected light,
The said execution part is a welding apparatus which moves the said irradiation part along the welding target detected by the said welding target detection part, and performs the said welding process.

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