WO2023157883A1

WO2023157883A1 - Laser welding device and method for correcting deviation of laser beam irradiation position

Info

Publication number: WO2023157883A1
Application number: PCT/JP2023/005266
Authority: WO
Inventors: 静波王; 俊輔川合; 憲三柴田; 敦樹山本
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2022-02-18
Filing date: 2023-02-15
Publication date: 2023-08-24
Also published as: JP7352787B1; JPWO2023157883A1

Abstract

A laser welding device (100) comprises a laser oscillator (10), a laser head (30), a controller (50), and a stage (70). The laser head (30) has a laser beam scanner (40) for scanning a laser beam (LB) two dimensionally, an optical sensor (38), and an optical system (39) for causing a reflected return beam from the laser beam (LB) to be incident on the optical sensor (38). When the periphery of a reflection spot (72b) provided on the stage (7) is irradiated while the laser beam scanner (40) scans the laser beam (LB) two dimensionally, the controller (50) corrects the deviation of the irradiation position of the laser beam (LB) on the basis of the center position of the reflection spot (72b) and a first peak position (O1) at which the output of the optical sensor (38) peaks.

Description

LASER WELDING APPARATUS AND METHOD FOR CORRECTING LASER LIGHT RADIATION POSITION DIFFERENCE

The present disclosure relates to a laser welding device and a method for correcting laser beam irradiation position deviation.

　Laser welding, in which workpieces are welded by irradiating a laser beam, can perform high-quality welding because the power density of the laser beam is high. For this reason, laser welding has been widely used in recent years.

Also, in laser welding, a scanning method is used to optically scan the irradiation position of the laser beam in order to weld the workpiece at high speed. In many cases, a galvanomirror is used to two-dimensionally scan a laser beam (see, for example, Patent Document 1).

However, in a laser welding device using a galvanomirror, part of the laser light is absorbed by the galvanomirror, so the temperature of the galvanomirror rises during laser welding. Due to this effect, the irradiation position of the laser light may deviate from the set position. In addition to this, when the temperature of the galvanometer mirror rises due to heat generation of the drive circuit that drives the galvanometer mirror, temperature rise in the internal atmosphere of the welding device during laser welding, etc., and the laser beam irradiation position shifts. There is As described above, the temperature of the galvanomirror rises due to various factors, and a displacement of the irradiation position of the laser beam, called temperature drift, occurs.

In order to reduce the displacement of the irradiation position of the laser beam due to temperature drift, for example, Patent Document 2 discloses a laser processing apparatus equipped with a CCD camera and a temperature sensor attached to a mount portion of a galvanomirror or the like. there is The CCD camera detects the actual position to be processed by the laser beam, and corrects the amount of deviation between the position to be processed and the set position using the temperature measured by the temperature sensor and a correction coefficient table obtained in advance.

JP 2005-95934 A JP-A-2005-40843

On the other hand, there are factors other than temperature drift that cause deviations in the irradiation position of the laser light. The main causes include insufficient adjustment, wear, and aged deterioration of the manipulator that holds and moves the laser head. If the adjustment of the moving mechanism of the manipulator is insufficient, or if it wears out or deteriorates over time, the laser beam irradiation position may deviate from the set position.

To solve this, regular inspection and maintenance of the manipulator is required. However, if the frequency of inspection is increased, there is a problem that the downtime of the equipment becomes longer and labor and maintenance costs increase.

The present disclosure has been made in view of the above points, and an object thereof is to provide a laser welding apparatus capable of correcting the deviation of the irradiation position of the laser beam with a simple configuration, and a method of correcting the deviation of the irradiation position of the laser beam. .

In order to achieve the above object, a laser welding apparatus according to the present disclosure controls a laser oscillator that generates a laser beam, a laser head that receives the laser beam and irradiates it toward a workpiece, and at least the operation of the laser head. a controller, and a stage on which the work is placed, wherein the laser head scans the laser light in a first direction and a second direction intersecting the first direction, respectively; a sensor, and an optical system for causing the reflected return light of the laser beam to enter the optical sensor, and the controller controls the laser beam to travel along a welding line while two-dimensionally scanning the laser beam. driving and controlling the laser beam scanner so as to scan, the stage having a correction section, the correction section having a reflector and a reflection spot provided on the surface of the reflector; The controller drives and controls the laser light scanner so as to irradiate the laser light around the reflection spot while two-dimensionally scanning the laser light, and the output of the optical sensor reaches a peak. A peak position is detected, and the controller is configured to correct irradiation position deviation of the laser beam based on the center position of the reflected spot and the first peak position.

A laser beam irradiation position deviation correction method according to the present disclosure is a laser beam irradiation position deviation correction method using the laser welding apparatus, the method comprising the step of moving the laser head to a center position of the reflection spot; a step of operating the laser light scanner to irradiate the periphery of the center position of the reflection spot while scanning the laser light two-dimensionally; determining whether or not the first peak position matches the center position of the reflected spot; and determining if the first peak position matches the center position of the reflected spot. , the step of completing the correction operation, and if the first peak position does not match the center position of the reflection spot, the step of obtaining the amount of deviation between the first peak position and the center position of the reflection spot; a step of correcting the displacement of the irradiation position of the laser light based on the coordinates of the center position of the reflected spot and the displacement amount.

According to the laser welding device of the present disclosure, it is possible to correct the irradiation position deviation of the laser light with a simple configuration. Further, according to the method for correcting the displacement of the irradiation position of the laser beam according to the present disclosure, the displacement of the irradiation position of the laser beam can be easily corrected.

1 is a schematic configuration diagram of a laser welding device according to Embodiment 1. FIG. 1 is a schematic configuration diagram of a laser beam scanner; FIG. 4 is a plan view of the stage; FIG. FIG. 4 is an enlarged plan view of a correction unit; FIG. 5 is a schematic cross-sectional view taken along line VV of FIG. 4; 1 is a schematic configuration diagram of a laser head; FIG. 4 is a flow chart showing a procedure for correcting a laser beam irradiation position deviation according to the first embodiment. FIG. 10 is a schematic diagram when the output of the optical sensor is plotted on the XY plane scanned by the laser light; FIG. 3 is a schematic diagram showing a mechanism of error generation in correction of irradiation angle deviation of laser light, and is a schematic diagram when laser light is perpendicularly incident on a reflected spot. FIG. 4 is a schematic diagram showing a mechanism of error generation in correction of irradiation angle deviation of laser light, and is a schematic diagram when laser light is obliquely incident on a reflected spot. It is a schematic diagram which shows the relationship between the incident angle deviation|shift amount from perpendicular|vertical incidence of a laser beam, and the positional deviation|shift amount in XY plane. 9 is a flow chart showing a procedure for correcting a laser beam irradiation position deviation according to the second embodiment.

Hereinafter, embodiments of the present disclosure will be described based on the drawings. It should be noted that the following description of preferred embodiments is merely illustrative in nature and is not intended to limit the present disclosure, its applications or uses.

(Embodiment 1)
[Configuration of laser welding device]
[Configuration of Laser Welding Device and Laser Light Scanner]
FIG. 1 shows a schematic diagram of the configuration of a laser welding apparatus according to this embodiment, and FIG. 2 shows a schematic configuration diagram of a laser beam scanner.

In the following description, the direction parallel to the traveling direction of the laser beam LB traveling from the mirror 33 to the optical sensor 38 may be called the X direction. A direction parallel to the optical axis of the laser beam LB emitted from the laser head 30 is sometimes called the Z direction. A direction orthogonal to the X direction and the Z direction is sometimes called the Y direction. If the surface of the workpiece 200 is flat, the XY plane including the X direction and the Y direction within the plane may be substantially parallel to the surface, or may form a certain angle with the surface.

As shown in FIG. 1, the laser welding device 100 includes a laser oscillator 10, an optical fiber 20, a laser head 30, a controller 50, a manipulator 60 and a stage 70.

The laser oscillator 10 is a laser light source that is supplied with power from a power source (not shown) and generates a laser beam LB. Note that the laser oscillator 10 may be composed of a single laser light source, or may be composed of a plurality of laser modules. In the latter case, laser beams respectively emitted from a plurality of laser modules are combined and emitted as laser beam LB. Also, the laser light source or laser module used in the laser oscillator 10 is appropriately selected according to the material of the workpiece 200, the shape of the welded portion, and the like.

The optical fiber 20 is optically coupled to the laser oscillator 10. A laser beam LB generated by the laser oscillator 10 enters the optical fiber 20 and is transmitted through the optical fiber 20 toward the laser head 30 .

The laser head 30 is attached to the end of the optical fiber 20 and irradiates the workpiece 200 with the laser light LB transmitted from the optical fiber 20 .

The laser head 30 also has a collimation lens 32, a mirror 33, a first condenser lens 34, and a laser beam scanner 40 as optical components. The laser head 30 also has a protective glass 35 , an aperture 36 , a second condenser lens 37 and an optical sensor 38 . These optical components are accommodated in the housing 31 while maintaining a predetermined arrangement relationship.

The collimation lens 32 receives the laser light LB emitted from the optical fiber 20 , converts it into parallel light, and makes it enter the mirror 33 . Also, the collimation lens 32 is connected to a drive section (not shown) and configured to be displaceable in the Z direction according to a control signal from the controller 50 . By displacing the collimation lens 32 in the Z direction, it is possible to change the focal position of the laser beam LB and appropriately irradiate the laser beam LB according to the shape of the workpiece 200 . In other words, the collimation lens 32 also functions as a focal position adjusting mechanism for the laser beam LB in combination with a drive section (not shown). FIG. 1 shows an example in which the collimation lens 32 is composed of one lens. The focal position can be adjusted by moving the collimation lens 32 in the Z direction, but the parallelism of the laser beam LB emitted from the collimation lens 32 is somewhat reduced. In order to prevent this, it is desirable to configure the collimation lens 32 by combining a plurality of lenses. It should be noted that the focus position of the laser beam LB may be changed by displacing the first condenser lens 34 by the drive section. The drive is, for example, an actuator or a motor.

The mirror 33 further transmits the laser light LB that has passed through the collimation lens 32 to enter the laser light scanner 40 . On the other hand, the mirror 33 reflects the reflected return light of the laser light LB that has passed through the laser light scanner 40 and is reflected by the reflection spot 72b (see FIGS. 3 to 5) of the stage 70 toward the aperture 36 (see FIG. 6). . The surface of the mirror 33 is provided so as to make an angle of about 45 degrees with the optical axis of the laser beam LB that has passed through the collimation lens 32 .

The first condenser lens 34 transmits the mirror 33 and converges the laser beam LB scanned by the laser beam scanner 40 onto the surface of the workpiece 200 .

The protective glass 35 is made of a material transparent to the laser beam LB. The protective glass 35 prevents spatters and fumes generated during laser welding from entering the housing 31 . The spatter is spattered molten material of the workpiece 200, and the fume is metal vapor generated by melting the workpiece 200. As shown in FIG.

The aperture 36 is arranged between the mirror 33 and the second condenser lens 37 along the X direction. A second condenser lens 37 is arranged between the aperture 36 and the optical sensor 38 along the X direction. The functions of the aperture 36, the second condenser lens 37, and the optical sensor 38 will be described later. As will be described later, the optical system 39 composed of the mirror 33, the aperture 36, and the second condenser lens 37 is configured to cause the reflected return light of the laser beam LB to enter the optical sensor 38. . In FIG. 1, the optical axis of the laser beam emitted from the end face of the optical fiber 20 and entering the laser beam scanner 40 and the optical axis of the laser beam LB emitted from the laser beam scanner 40 are depicted as being aligned. However, this is a schematic illustration, and the relationship between the first galvanometer mirror 41 and the second galvanometer mirror 42 (both of which are shown in FIG. 2) that constitute the laser beam scanner 40 does not actually match. . This will be described later in detail with reference to FIG.

As shown in FIG. 2, the laser light scanner 40 is a known galvanometer scanner having a first galvanometer mirror 41 and a second galvanometer mirror 42 . The first galvanomirror 41 has a first mirror 41a, a first rotating shaft 41b, and a first driving portion 41c, and the second galvanomirror 42 has a second mirror 42a, a second rotating shaft 42b, and a second driving portion. 42c. The laser beam LB that has passed through the first condenser lens 34 is reflected by the first mirror 41 a and further reflected by the second mirror 42 a to irradiate the surface of the workpiece 200 .

For example, the first driving section 41c and the second driving section 42c are galvanometer motors, and the first rotating shaft 41b and the second rotating shaft 42b are output shafts of the motors. Although not shown, the first drive unit 41c is rotationally driven by a driver that operates according to a control signal from the controller 50, so that the first mirror 41a attached to the first rotation shaft 41b is rotated by the first rotation shaft. It rotates around the axis of 41b. Similarly, the second driving section 42c is rotationally driven by a driver that operates in response to a control signal from the controller 50, so that the second mirror 42a attached to the second rotating shaft 42b moves along the axis of the second rotating shaft 42b. rotate around.

The laser beam LB is scanned in the X direction by rotating the first mirror 41a up to a predetermined angle around the axis of the first rotating shaft 41b. In addition, the laser beam LB is scanned in the Y direction by rotating the second mirror 42a up to a predetermined angle around the axis of the second rotating shaft 42b. That is, the laser light scanner 40 is configured to two-dimensionally scan the laser light LB within the XY plane and irradiate the workpiece 200 with the laser light LB.

The controller 50 controls laser oscillation of the laser oscillator 10 . Specifically, laser oscillation is controlled by supplying a control signal such as an output current having a predetermined relationship with the output of the laser beam LB and an on/off time to a power source (not shown) connected to the laser oscillator 10 . Also, the controller 50 controls the output of the laser beam LB.

Also, the controller 50 controls the operation of the laser head 30 according to the content of the selected laser welding program. Specifically, drive control of the laser beam scanner 40 provided in the laser head 30 and the drive unit (not shown) of the collimation lens 32 is performed. Further, controller 50 controls the operation of manipulator 60 .

The controller 50 has an integrated circuit such as an LSI or a microcomputer as an information processing unit 51. By executing a laser welding program, which is software, on this integrated circuit, the functions of the controller 50 described above are realized. be. In addition, the controller 50 has a memory device such as a RAM, a ROM, an SSD, etc. as a storage unit 52 . A laser welding program is stored in the storage unit 52 and called by the controller 50 according to a command from the controller 50 . Note that the storage unit 52 may be an SD card (registered trademark) detachable from the controller 50 . Also, the storage unit 52 may be provided at a location different from the controller 50 .

In addition, the storage unit 52 stores the correction result of the irradiation position of the laser beam LB, etc., which will be described later. For example, the amount of displacement of the irradiation position of the laser beam LB due to temperature drift and the correction result thereof are stored in the storage unit 52 . Specifically, the amount of displacement of the irradiation position of the laser beam LB caused by the absorption of the laser beam LB by the first galvano mirror 41 and the second galvano mirror 42 and the correction result thereof are stored in the storage unit 52 . Alternatively, the amount of deviation of the irradiation position of the laser beam LB due to the heat generation of the drive circuit that drives them and the correction result thereof are stored in the storage unit 52 .

The controller 50 for controlling the operation of the laser head 30 and the controller 50 for controlling the output of the laser beam LB may be provided separately.

The manipulator 60 is an articulated robot and is attached to the housing 31 of the laser head 30. Also, the manipulator 60 is connected to the controller 50 so that signals can be sent and received, and moves the laser head 30 so as to draw a predetermined locus according to the laser welding program described above. As a result, the surface of the workpiece 200 is irradiated with the laser beam LB along the welding line WL and while being two-dimensionally scanned around the welding line WL.

A separate controller (not shown) for controlling the operation of the manipulator 60 may be provided. However, even in that case, it is necessary to be able to communicate data with the controller 50 that controls the operation of the laser head 30 in order to configure the irradiation position of the laser beam LB.

The stage 70 has a body portion 71 and a correction portion 72 . The configuration of the stage 70 will be detailed later.

The laser welding device 100 shown in FIG. 1 can perform laser welding on workpieces 200 of various shapes.

[Configuration of stage and laser head]
3 is a plan view of the stage, FIG. 4 is an enlarged plan view of the corrector, and FIG. 5 is a schematic cross-sectional view taken along line VV of FIG.

As shown in FIG. 3, the stage 70 has a body portion 71 and a correction portion 72. A workpiece 200 is placed on the body portion 71, and the workpiece 200 is welded by irradiation with the laser beam LB. Therefore, although not shown, the body portion 71 includes a portion having a flat surface for supporting the workpiece 200 and a portion through which the laser beam LB passes.

On the other hand, the correction section 72 is arranged at one corner of the main body section 71 . As shown in FIGS. 4 and 5, the correction section 72 has a reflector 72a that reflects the laser beam LB and a reflection spot 72b provided on the surface of the reflector 72a. The diameter d of the reflected spot 72b is set to be about 1/10 to 1 times (1 times) the diameter of the laser beam LB. The shape of the reflection spot 72b shown in FIGS. 4 and 5 is circular when viewed from the Z direction and plate-like when viewed in cross section, but is not particularly limited to this. For example, the reflected spot 72b may be square when viewed from the Z direction. The reflection spot 72b may be provided such that the surface of the reflection spot 72b and the surface of the reflector 72a are flush with each other.

The reflectance of the laser beam LB at the reflection spot 72b is designed to be higher than the reflectance of the laser beam LB at the reflector 72a. Although the contents of the present disclosure are not limited, the correction unit 72 can be configured as follows as an example. For example, as the corrector 72, a printed circuit board having a copper foil of a predetermined shape on its surface can be used. In this case, the reflecting plate 72a may be a plate member made of epoxy resin from which the copper foil has been removed, and the reflection spot 72b may be a spot-shaped copper foil having a predetermined diameter. It is even better if the copper foil portion is plated with gold. With this configuration, the difference in reflectance with respect to the laser beam LB is sufficiently large between the copper foil portion and the epoxy resin, so that the role of the correcting portion 72 can be easily fulfilled. Further, the reflection spot 72b is not particularly limited to copper or gold, and any material having a reflectance of a predetermined value or higher with respect to the laser beam LB may be used. For example, it may be aluminum or silver. Further, the correcting portion 72 other than the reflected spot 72b may be made of a material having a lower reflectance than the reflected spot 72b with respect to the laser beam LB.

As will be described later, the correction unit 72 is used to determine whether or not the above-described temperature drift occurs in the laser beam scanner 40, and to measure the correction amount of the temperature drift if it occurs. be.

The position of the correction section 72 on the stage 70 is not particularly limited to that shown in FIG. However, when the work 200 is laser-welded, spatters and fumes may scatter in the vicinity of the weld line WL, and smut may adhere to the work 200 when the work 200 contains aluminum. In order to prevent these from adhering to the reflection spot 72b, the welding line WL of the workpiece 200 needs to be arranged at a position separated from the correcting portion 72 by a predetermined distance or more. Further, since the correction part 72 is not used in the welding process, a cover (not shown) may be attached to protect its surface.

The laser beam LB is irradiated onto the correction unit 72 along the dashed line shown in FIG. 4, in other words, while being sequentially scanned at predetermined intervals in each of the X direction and the Y direction. When the laser beam LB is incident on the reflection spot 72b, it is reflected along the original optical path without being scattered or the like. However, laser light other than the laser light incident perpendicularly to the reflected spot 72b does not return along the original optical path as it is and is slightly deviated from the original optical path. As will be described later, if this deviation is also corrected, it is possible to further improve the correction accuracy for the irradiation position deviation of the laser beam LB.

FIG. 6 shows a schematic configuration diagram of the laser head. For convenience of explanation, illustration of the housing 31 is omitted in FIG. Also, the laser light scanner 40 is illustrated in a simplified manner.

As shown in FIG. 6, the laser light LB guided from the optical fiber 20 into the housing 31 is collimated by the collimation lens 32 . The collimated laser beam LB is transmitted through the mirror 33 . The laser beam LB transmitted through the mirror 33 is incident on the laser beam scanner 40 . In this case, the incident position P1 of the laser beam LB in the laser beam scanner 40 is on the optical axis aa' of the laser beam LB guided from the optical fiber 20 into the housing 31. FIG.

The laser beam LB that has passed through the laser beam scanner 40 is emitted from the position P2 on the laser beam scanner 40 . When the laser beam scanner 40 is not operated and the first galvanometer mirror 41 and the second galvanometer mirror 42 are at their initial positions, the position P2 is on the optical axis c-c' in FIG. However, in the case of scanning with the laser beam LB, the position P2 is positioned at a different location along with the optical axis c-c' (not shown). Note that whether the laser beam scanner 40 scans the laser beam LB or not scans the laser beam LB, the actual laser beam LB is reflected by the first galvano mirror 41 and the second galvano mirror 42 inside the laser beam scanner 40 . receive. Therefore, the optical axis aa' of the incident beam does not coincide with the optical axis cc' of the outgoing beam. As a result, in FIG. 6, the laser beam LB emitted from the laser beam scanner 40 is depicted as being shifted in the X direction by a predetermined distance.

The laser beam LB is incident on the reflector 72a at the position P3 and is reflected toward the laser beam scanner 40, that is, in the direction opposite to the incident direction from the reflector 72a generally along the Z direction. The reflected return light of the laser beam LB enters the laser beam scanner 40 at the position P4, exits the laser beam scanner 40 from the position P5, and then enters the mirror 33. FIG. After entering the mirror 33 at the position P6, the laser beam LB is reflected in the X direction and enters the aperture . The light amount and diameter of the laser beam LB narrowed by the aperture 36 are adjusted. The optical axis of the laser beam LB from the position P6 to the center position P7 of the optical sensor 38 is indicated by bb' in FIG.

The second condenser lens 37 converges the laser beam LB that has passed through the aperture 36 onto the light receiving surface (not shown) of the optical sensor 38 . In other words, the optical system 39 described above causes the reflected return light of the laser light LB that has entered the housing 31 through the protective glass 35 to enter the optical sensor 38 .

The optical sensor 38 outputs an electrical signal corresponding to the amount of incident laser light LB. This output signal is input to the controller 50 and used to correct the irradiation position of the laser beam LB, which will be described later.

[Method for Correcting Laser Beam Irradiation Position Deviation]
FIG. 7 shows a flow chart of a procedure for correcting irradiation position deviation of the laser light, and FIG. 8 shows a schematic diagram when the output of the optical sensor is plotted on the XY plane scanned by the laser light. In FIG. 8, for the sake of explanation, it is assumed that the incident beam is always perpendicular to the reflected spot 72b on the XY plane.

　In the correction unit 72 shown in FIG. 3, the center position of the reflected spot 72b on the XY plane is made to coincide with the galvanometer origin of the laser light scanner 40, which is the origin O. Here, the galvanometer origin corresponds to the initial position of the laser beam LB on the XY plane of the laser head 30 when there is no temperature drift. In other words, the galvano origin corresponds to the initial position of the tip of the manipulator 60 on the XY plane. The origin O is stored in the storage unit 52 as coordinates on the XY plane.

When there is no temperature drift, the optical sensor 38 generates an output signal only when the laser beam LB is collated at the origin O and its vicinity. In this case, the term "nearby" refers to a distance of about 1/10 to 1/2 of the radius of the laser beam LB condensed from the origin O on the XY plane. Of course, this distance can also be shortened. In that case, the accuracy of correction, which will be described later, becomes higher.

On the other hand, if a temperature drift occurs, the origin during scanning may deviate from the origin O corresponding to the galvanometer origin due to the effect of the drift when the laser beam LB is scanned. That is, when the laser beam LB is irradiated at a position distant from the origin O by a predetermined distance or more, the optical sensor 38 may generate an output signal.

If such a thing occurs, it becomes impossible to irradiate the workpiece 200 with the laser beam LB along the desired irradiation trajectory, which may cause welding defects.

The "origin at the time of scanning" is the position command in the X-axis direction and the position in the Y-axis direction when the workpiece 200 or the surface of the stage 70 is irradiated with the laser light scanner 40 during actual welding or correction described later. (or a fixed value corresponding to the laser beam scanner 40. For the sake of explanation, hereinafter, this value is assumed to be zero.), the actual irradiation point of the laser beam LB on the XY plane. . The position command in the X-axis direction is a rotational position command (hereinafter referred to as a rotation command) for the first drive unit 41c, and the position command in the Y-axis direction is a rotation command for the second drive unit 42c. . In this case, since the position commands in the X-axis direction and the Y-axis direction are both zero, the origin during scanning coincides with the galvanometer origin if there is no temperature drift.

Therefore, by correcting the irradiation position of the laser beam LB, in this case, the deviation of the origin position during scanning, the workpiece 200 can be irradiated with the laser beam LB along a desired irradiation locus. It is possible to suppress the occurrence of welding defects. Further explanation is given below.

The manipulator 60 is moved to move the laser light scanner 40 of the laser head 30 to the center position of the reflection spot 72b of the corrector 72, that is, the origin O on the XY plane (step S1 in FIG. 7).

The laser light scanner 40 is operated to irradiate the laser light LB around the origin O while scanning along the dashed line shown in FIG. 4 (step S2 in FIG. 7). At step S2, the manipulator 60 is not moved. That is, the position of the laser head 30 itself is scanned along the broken line shown in FIG. 4 with the laser beam LB while maintaining the origin O. FIG. Also, the output of the laser beam LB in step S2 is significantly reduced from that during laser welding. This is to prevent the reflecting plate 72a and the optical sensor 38 from being damaged. For example, when the output of the laser beam LB during laser welding is several kW, the output of the laser beam LB in step S2 does not damage the reflecting plate 72a or the reflecting spot 72b and can be detected sufficiently by the optical sensor 38. A value of the order of magnitude (about several mW) may be used. Normally, in the laser oscillator 10, a guide laser (not shown) may be used for visually recognizing the irradiation position of the laser beam LB. may be scanned.

During or after execution of step S2, the output of the optical sensor 38 is checked, and the first peak position O1 where the output peaks is checked (step S3 in FIG. 7). The first peak position O1 is represented by coordinates on the XY plane. Also, the coordinates of the first peak position O1 and the output of the optical sensor 38 at the first peak position O1 are stored in the storage unit 52 .

Next, the information processing section 51 of the controller 50 determines whether or not the first peak position O1 matches the origin O (step S4 in FIG. 7). In the specification of the present application, “match” means not only match in a strict sense, but also the distance between the first peak position O1 and the origin O on the XY plane is the beam It also includes cases where it is about 1/10 to 1/2 or less of the radius. Of course, this distance can also be shortened, but then the accuracy of the correction will be higher.

Note that the position at which the surface of the stage 70 is irradiated with the laser beam LB reflected by the first galvanometer mirror 41 and the second galvanometer mirror 42 fixed at the preset initial position is the same as the above-described "during scanning." is the origin of For example, the laser head 30 is moved to the center position of the reflection spot 72b of the corrector 72 on the XY plane. It reflects the light LB. In this case, if there is no temperature drift, the origin during scanning of the laser beam LB coincides with the above-mentioned origin O, and the output from the optical sensor 38 peaks.

If the determination result in step S4 is affirmative, that is, if the first peak position O1 matches the origin O, it is determined that the origin during scanning of the laser beam LB matches the origin O. In other words, it can be determined that no temperature drift has occurred in the laser light scanner 40, and the series of operations is terminated.

On the other hand, if the determination result in step S4 is negative, that is, if the first peak position O1 does not match the origin O, as shown in FIG. It appears at a position away from the origin O. In the example shown in FIG. 7, the first peak position O1 is shifted to the negative side with respect to the origin O in both the X direction and the Y direction.

In this case, the controller 50 acquires the difference between the coordinates of the origin O and the coordinates of the first peak position O1, that is, the amount of deviation between the origin O and the first peak position O1, and stores the amount of deviation in the storage unit 52. (step S5 in FIG. 7).

The information processing unit 51 of the controller 50 corrects the deviation of the origin position during scanning using the equations (1) and (2) based on the coordinates of the origin O and the deviation amount obtained in step S5. 7 step S6).

In the example shown in FIG. 7, the origin position during scanning after correction satisfies the relationships shown in formulas (1) and (2).

Xc=X0-Xa (1)
Yc=Y0-Ya (2)
here,
X0: X coordinate of origin during scanning without temperature drift Y0: Y coordinate of origin during scanning with no temperature drift Xc: X coordinate of origin during scanning after correction Yc: Scanning after correction Y coordinate of the origin at time Xa: Amount of deviation in the X direction between the origin O and the first peak position O1 Ya: Amount of deviation in the Y direction between the origin O and the first peak position O1. As described above, since the galvano origin of the laser beam scanner 40 is the origin O, both the X coordinate X0 of the origin and the Y coordinate Y0 of the origin may be zero in Equations (1) and (2). In the example shown in FIG. 8, both the deviation amount Xa and the deviation amount Ya take negative values.

For actual correction, the rotation commands for the first drive unit 41c and the second drive unit 42c are corrected according to the results of equations (1) and (2). That is, the amount of rotation corresponding to the amount of deviation Xa, Ya is added or subtracted to or from the rotation command corresponding to the initially set origin (=(X0, Y0)) during scanning, so that the origin corresponding to scanning is obtained. Correct the rotation command.

The coordinates (Xc, Yc) of the origin at the time of scanning after correction and the deviation amounts Xa, Ya are stored in the storage unit 52 . The storage unit 52 also stores correction amounts of the rotation commands of the first driving unit 41c and the second driving unit 42c corresponding to the deviation amounts Xa and Ya, respectively. In the subsequent laser welding, when scanning with the laser beam LB, the coordinates of the origin during scanning are set to (Xc, Yc).

As shown in FIG. 6, the laser beam LB returns along its original optical path and is not reflected unless it is incident perpendicularly to the reflected spot 72b. That is, the position P2 at which the laser beam LB is emitted from the laser beam scanner 40 is the same as the position P4 at which the reflected beam is incident on the laser beam scanner 40, except when the laser beam LB is vertically incident on the reflected spot 72b. do not match exactly. Therefore, in practice, assuming that the beam is perpendicularly incident on the reflected spot 72b, the shift amounts Xa and Ya in the X direction or the Y direction between the origin O and the first peak position O1 shown in FIG. , and the error due to this incident angle is added. By performing correction including this error, it is possible to further improve the accuracy of correction. An outline of the error generation mechanism and correction method will be described below. In the example shown below, both positions P2 and P4 correspond to positions on the surface of the second mirror 42a.

9A and 9B are schematic diagrams showing the error generation mechanism in correcting the irradiation angle deviation of the laser light. FIG. 9A shows a schematic diagram when the laser beam LB is vertically incident on the reflection spot 72b, and FIG. 9B is a schematic diagram when the laser beam is obliquely incident on the reflection spot. Note that the angle α in FIG. 9B indicates the amount of deviation of the incident angle based on the case where the laser beam is incident vertically. In the example shown in FIG. 9B, 0°<α<90° In order for the reflected light from the spot 72b to enter the optical sensor 38 along the reflection route shown in FIG. 6, it is desirable that the angle is as close to 0° as possible.

FIG. 10 is a schematic diagram showing the relationship between the amount of incident angle deviation from vertical incidence of the laser light and the amount of positional deviation on the XY plane. As the incident angle shift amount α increases, the X-axis or Y-axis shift amounts Xa1 and Ya1 of the peak position increase. Although not shown, if the amount of deviation α of the incident angle is too large, the reflected light cannot enter the optical sensor 38, and sensing may not be possible. Therefore, as described above, it is better to set the deviation amount α of the incident angle to a value as close to 0 as possible.

In FIGS. 9A and 9B, incident light to the reflected spot 72b is indicated by a solid arrow, and reflected light is indicated by a dotted arrow. In FIG. 9A, since the incident light is perpendicular to the reflected spot 72b, the optical path of the reflected light is also perpendicular to the reflected spot 72b, and both are located at positions P2 and P4 on the surface of the second mirror 42a. matches.

On the other hand, in the example shown in FIG. 9B, since the incident angle of the incident light is α (0°<α<90°) with respect to the normal to the reflected spot 72b, the optical path of the reflected light is also the normal to the reflected spot 72b. forms an angle α with respect to Therefore, as shown in FIG. 9B, the position P2 where the incident light is incident on the surface of the second mirror 42a does not match the position P4 where the reflected light is incident. In a normal optical system, this angle α is very small.・It becomes α. Once the optical system is determined, this deviation amount ff·α can be measured in advance and stored in the controller 50 . Needless to say, when the deviation amount α of the incident angle becomes small, the deviation amount ff·α also becomes small. In the example shown in FIG. 10, the aforementioned shift amounts Xa1 and Ya1 monotonously increase with respect to the incident angle shift amount α.

Taking this into consideration, the X and Y coordinates of the origin at the time of scanning after correction are determined based on the following equations (3) and (4), respectively, instead of equations (1) and (2). be done.

Xc1=X0-Xa-Xa1 (3)
Yc1=Y0-Ya-Ya1 (4)
here,
Xc1: X coordinate of the origin during scanning after correction, taking into account the angle of incidence with respect to the reflected spot Yc1: Y coordinate of the origin during scanning after correction, with consideration given to the angle of incidence with respect to the reflected spot Xa1: Angle of incidence with respect to the reflected spot Amount of deviation in the X direction between the origin O and the first peak position O1 in consideration Ya1: A deviation in the Y direction between the origin O and the first peak position O1 in consideration of the incident angle with respect to the reflected spot.

Note that the deviation amounts Xa1 and Ya1 depend on the optical system of the laser beam scanner 40 and the installation position of the correction unit 72, and can be measured in advance under the condition of no temperature drift and stored in the controller 50. can.

[Effects, etc.]
As described above, the laser welding apparatus 100 according to the present embodiment includes the laser oscillator 10 that generates the laser beam LB, the laser head 30 that receives the laser beam LB and irradiates it toward the workpiece 200, and the laser head 30. It includes at least a controller 50 that controls the operation and the output P of the laser beam LB, and a stage 70 on which the workpiece 200 is placed.

The laser head 30 has a laser beam scanner 40 that scans the laser beam LB in both the X direction (first direction) and the Y direction (second direction) intersecting the X direction. The laser head 30 also has an optical sensor 38 . The laser head 30 further has an optical system 39 that causes the reflected return light of the laser beam LB to enter the optical sensor 38 . An optical system 39 is composed of a mirror 33 , an aperture 36 and a second condenser lens 37 .

The controller 50 drives and controls the laser beam scanner 40 so as to two-dimensionally scan the laser beam LB while advancing the laser beam LB along the welding line WL.

The stage 70 has a body portion 71 and a correction portion 72 . The corrector 72 has a reflector 72a and a reflection spot 72b provided on the surface of the reflector 72a.

While two-dimensionally scanning the laser beam LB, the controller 50 drives and controls the laser beam scanner 40 so as to irradiate the laser beam LB around the reflection spot 72b. 1 Peak position O1 is detected. The controller 50 is configured to correct the irradiation position deviation of the laser beam LB based on the origin O, which is the center position of the reflected spot 72b, and the first peak position O1. In this disclosure, "around reflected spot 72b" refers to the area including reflected spot 72b itself and the surroundings of reflected spot 72b.

According to this embodiment, the stage 70 is provided with the correction section 72 having the reflected spot 72b, and the laser head 30 is provided with the optical sensor 38 and the optical system 39 for causing the reflected return light of the laser beam LB to enter the optical sensor 38. With such an extremely simple configuration, it is possible to correct the displacement of the irradiation position of the laser beam LB. Further, by providing the optical system 39, especially the aperture 36, the amount of incident light to the optical sensor 38 can be controlled, and the saturation of the output signal of the optical sensor 38 can be suppressed. As a result, the first peak position O1 at which the output of the optical sensor 38 peaks can be detected with high accuracy.

Further, it is possible to accurately irradiate a desired position of the work 200 along the welding line WL while scanning the laser beam LB two-dimensionally. As a result, the occurrence of welding defects can be reduced, and the welding yield can be improved.

Further, the controller 50 is configured to correct the deviation of the origin position during scanning with the laser beam LB based on the deviation amount between the origin O, which is the central position of the reflected spot 72b, and the first peak position O1. .

By doing so, in particular, it is possible to easily correct the deviation of the irradiation position of the laser beam LB caused by the temperature drift.

The laser oscillator 10 and the laser head 30 are connected by an optical fiber 20 , and the laser light LB is transmitted from the laser oscillator 10 to the laser head 30 through the optical fiber 20 .

By providing the optical fiber 20 in this way, it is possible to perform laser welding on the workpiece 200 placed at a position away from the laser oscillator 10 . This increases the degree of freedom in arranging each part of the laser welding device 100 .

The laser beam scanner 40 is composed of a first galvanometer mirror 41 that scans the laser beam LB in the X direction and a second galvanometer mirror 42 that scans the laser beam LB in the Y direction.

By configuring the laser light scanner 40 in this way, it is possible to easily two-dimensionally scan the laser light LB. Further, since a known galvanometer scanner is used as the laser beam scanner 40, it is possible to suppress the increase in the cost of the laser welding device 100. FIG.

The laser head 30 further has a collimation lens 32, and the collimation lens 32 is configured to change the focal position of the laser beam LB along the Z direction that intersects with the X direction and the Y direction. In other words, the collimation lens 32 is configured to change the focal position of the laser beam LB along the Z direction that intersects the surface of the workpiece 200 . In other words, the collimation lens 32 also functions as a focal position adjusting mechanism for the laser beam LB in combination with a drive section (not shown). That is, the focal position can be changed according to an arbitrary irradiation position during welding, and the degree of freedom in setting welding conditions can be increased.

By doing so, the focal position of the laser beam LB can be easily changed, and the laser beam LB can be appropriately irradiated according to the shape of the workpiece 200 .

The laser welding device 100 further includes a manipulator 60 to which the laser head 30 is attached, and the controller 50 controls the operation of the manipulator 60. Manipulator 60 moves laser head 30 in a predetermined direction with respect to the surface of workpiece 200 .

By providing the manipulator 60 in this manner, the welding direction of the laser beam LB or the position of the welding point can be changed. In addition, laser welding can be easily performed on the work 200 having a complicated shape, for example, a three-dimensional shape.

The method of correcting the irradiation position deviation of the laser light according to the present embodiment comprises a first step (step S1 in FIG. 7) of moving the laser head 30 to the origin O, which is the center position of the reflected spot 72b provided on the stage 70; At least a second step (step S2 in FIG. 7) of operating the laser light scanner 40 to irradiate the surroundings of the origin O while scanning the laser light LB two-dimensionally is provided.

Further, the correction method of the present embodiment includes the third step (step S3 in FIG. 7) of confirming the first peak position O1 at which the output of the optical sensor 38 peaks, and and a fourth step (step S3 in FIG. 7) of determining whether or not they match.

The correction method of this embodiment includes a step of terminating the correction work if the determination result of the fourth step is affirmative, that is, if the first peak position O1 matches the origin O.

In the correction method of this embodiment, if the determination result of the fourth step is negative, that is, if the first peak position O1 does not match the origin O, the deviation between the first peak position O1 and the origin O is corrected. and a step of correcting the irradiation position deviation of the laser beam LB based on the coordinates of the origin O and the deviation amount.

By doing so, in particular, it is possible to easily correct the deviation of the irradiation position of the laser beam LB caused by the temperature drift. Further, it is possible to accurately irradiate a desired position of the workpiece 200 along the welding line WL while scanning the laser beam LB two-dimensionally. As a result, the occurrence of welding defects can be reduced, and the welding yield can be improved.

(Embodiment 2)
FIG. 11 shows a flowchart of a procedure for correcting deviation of irradiation position of laser light according to the present embodiment.

In the first embodiment, the device configuration and correction procedure for correcting the irradiation position deviation of the laser beam LB caused by temperature drift have been described.

On the other hand, as described above, the deviation of the irradiation position of the laser beam LB can also occur due to insufficient adjustment, wear, or deterioration over time of the manipulator 60 . If the manipulator 60 is insufficiently adjusted, worn or deteriorated over time, the tip position of the manipulator 60 itself may deviate from the position preset in the welding program or the like. In this case, since the position of the laser head 30 is also shifted, the workpiece 200 cannot be irradiated with the laser beam LB at a predetermined position.

Therefore, the adjustment state of the manipulator 60 is confirmed according to the procedure shown in FIG. 11, and the irradiation position deviation of the laser beam LB is corrected based on the result. Details are described below.

First, the manipulator 60 is moved from the initial position to move the laser light scanner 40 of the laser head 30 to the origin O (step S10). The laser light scanner 40 is operated to irradiate the laser light LB around the origin O while scanning along the dashed line shown in FIG. 4 (step S11). Further, the output of the optical sensor 38 is confirmed, and the first peak position O1 where the output peaks is confirmed (step S12). Subsequently, the deviation amount (first deviation amount) between the origin O and the first peak position O1 is obtained, and the first deviation amount is stored in the storage unit 52 (step S13). Note that steps S10 to S13 are the same processes as steps S1 to S3 and S5 in FIG.

Next, the manipulator 60 is moved to move the laser beam scanner 40 of the laser head 30 to a predetermined position P (hereinafter simply referred to as position P, see FIG. 4) near the origin O (step S14). The position P is a position stored in advance in the controller 50 during robot teaching. In the example shown in FIG. 4, the position P is deviated from the origin O by one segment in the X direction and the Y direction in the scanning locus of the laser beam LB indicated by the dashed line. However, the position P based on the origin O is not particularly limited to this, and may be set to another position. The distance between the position P and the origin O is also a value stored in the controller 50 in advance. It is desirable that both the position P and the origin O are not on the X-axis or the Y-axis of the XY plane described above. This is because there is a possibility that correction of irradiation position deviation of the laser beam LB that requires maintenance of the manipulator 60 exists in both the X-axis and the Y-axis. The specific contents of step S14 are the same as those of step S10, except that the destination of the laser beam scanner 40 is different.

Further, the laser light scanner 40 is operated to irradiate the surroundings of the position P while scanning the laser light LB along the dashed line shown in FIG. 4 (step S15). The output of the optical sensor 38 is confirmed, and the second peak position O2 at which the output peaks is confirmed (step S16). Subsequently, the deviation amount (second deviation amount) between the position P and the second peak position O2 is obtained, and the second deviation amount is stored in the storage unit 52 (step S17). Note that steps S15 to S17 are the same processes as steps S11 to S13.

Next, the information processing section 51 of the controller 50 determines the deviation amount between the first peak position O1 based on the origin O and the second peak position O2 based on the position P, in other words, the first deviation amount and the second peak position O2. Calculate the difference from the deviation amount. Further, it is determined whether or not the amount of deviation between the first peak position O1 based on the origin O and the second peak position O2 based on the position P is within an allowable range (step S18).

That is, in step S18, the X-direction deviation amount between the origin O and the second peak position O2 based on the position P is defined as Xb, and the Y-direction deviation amount between the origin O and the second peak position O2 based on the position P is defined as Xb. It is determined whether or not the relationship satisfying the equations (5) and (6) is satisfied, where Yb is the amount of deviation.

|Xa−Xb|≦εx (5)
|Ya−Yb|≦εy (6)
Here, εx is the allowable upper limit of the difference in the X direction, and εy is the upper limit of the allowable difference in the Y direction. εx and εy are appropriately set according to processing tolerances allowed during laser welding, assembly tolerances of the manipulator 60, and the like.

If the determination result in step S18 is affirmative, it can be determined that the position of the manipulator 60 has not deviated from the set position, or that the difference is within the allowable range. Therefore, the process proceeds to step S19.

Steps S19 to S21 are the same processes as steps S4 to S6 in FIG. 7, so a detailed description will be omitted. That is, if the determination result of step S19 is affirmative, the correction work is finished. If the determination result in step S19 is negative, the displacement of the origin position during scanning is corrected based on the coordinates of the origin O and the displacement amount obtained in step S13 (step S20).

On the other hand, if the determination result in step S18 is negative, it can be determined that the position of the manipulator 60 is out of the allowable range and not from the set position. Therefore, the laser welding device 100 is stopped, maintenance of the manipulator 60 is performed, and the position, posture, etc. are readjusted.

After that, return to step S10 and repeat the series of processes until the determination result of step S18 becomes affirmative. Further, step S19 and subsequent steps are executed to correct deviation of the origin position during scanning, and the correction work is finished.

As described above, in the laser welding device 100 according to this embodiment, the first process and the second process are respectively executed.

In the first process, the laser head 30 is moved to the central position of the reflection spot 72b, that is, the origin O, and while two-dimensionally scanning the laser beam LB, the laser is moved around the reflection spot 72b (around the origin O). Light LB is irradiated (steps S10 and S11 in FIG. 11).

In the second process, the laser head 30 is moved to a position P near the origin O, and the laser light LB is irradiated around the reflection spot 72b (around the position P) while scanning the laser light LB two-dimensionally. (Steps S14 and S15 in FIG. 11).

When the first process and the second process are executed, the controller 50 sets the origin O, which is the center position of the reflected spot 72b, and the first peak position O1, at which the output of the optical sensor 38 peaks in the first process. and a second peak position O2 at which the output of the optical sensor 38 peaks in the second process, the displacement of the irradiation position of the laser beam LB is corrected.

In other words, if the amount of deviation between the first peak position O1 and the second peak position O2 is within a predetermined allowable range, the controller 50 determines the laser beam based on the amount of deviation between the origin O and the first peak position O1. It is configured to correct deviation of the origin position during scanning of the light LB.

Further, the method of correcting the irradiation position deviation of the laser beam LB according to the present embodiment includes at least the first step (step S10 in FIG. 11) of moving the laser head 30 to the origin O.

Furthermore, the correction method of the present embodiment includes a second step (step S11 in FIG. 11) of operating the laser beam scanner 40 to irradiate around the origin O while scanning the laser beam LB two-dimensionally; A third step (step S12 in FIG. 11) of confirming the first peak position O1 at which the output of the optical sensor 38 reaches a peak, and a second step of obtaining a deviation amount (first deviation amount) between the first peak position O1 and the origin O. 4 steps (step S15 in FIG. 11).

Further, the correction method of the present embodiment comprises a fifth step (step S14 in FIG. 11) of moving the laser head 30 to the aforementioned position P after obtaining the first deviation amount, and operating the laser beam scanner 40. , and a sixth step (step S15 in FIG. 11) of irradiating the periphery of the position P while two-dimensionally scanning the laser beam LB.

In the correction method of the present embodiment, after the sixth step, the seventh step (step S16 in FIG. 11) of confirming the second peak position O2 at which the output of the optical sensor 38 peaks, and the second peak position O2 and the position and an eighth step (step S17 in FIG. 11) of obtaining a deviation amount (second deviation amount) from P.

Further, the correction method of this embodiment includes a ninth step (step S18 in FIG. 11) of determining whether or not the difference between the first deviation amount and the second deviation amount is within the allowable range. .

In the correction method of this embodiment, if the determination result in the ninth step is affirmative, that is, if the difference between the first deviation amount and the second deviation amount is within the above-described allowable range, the first peak position O1 is aligned with the origin O (step S19 in FIG. 11).

The correction method of this embodiment includes a step of terminating the correction work if the determination result of the tenth step is affirmative, that is, if the first peak position O1 matches the origin O.

In the correction method of the present embodiment, if the determination result in the tenth step is negative, that is, if the first peak position O1 does not match the origin O, the coordinates of the origin O and the first deviation amount Based on this, an eleventh step of correcting the irradiation position deviation of the laser beam LB is provided (step S20 in FIG. 11).

In the correction method of this embodiment, if the determination result in the ninth step is negative, that is, if the first peak position O1 does not match the origin O, the manipulator 60 is adjusted (step S21 in FIG. 11). After that, the process returns to the first step and repeats the series of processes until the determination result of the ninth step becomes affirmative.

According to this embodiment, the same effects as those of the configuration and method shown in Embodiment 1 can be achieved. That is, it is possible to accurately irradiate a desired position of the workpiece 200 along the welding line WL while scanning the laser beam LB two-dimensionally. As a result, the occurrence of welding defects can be reduced, and the welding yield can be improved.

Further, according to the present embodiment, it is possible to determine separately whether the displacement of the irradiation position of the laser beam LB, in this case, the displacement of the origin position during scanning, is due to insufficient adjustment of the manipulator 60 or due to temperature drift. Further, when irradiation position deviation occurs due to each factor, the irradiation position deviation can be eliminated by performing maintenance of the manipulator 60 or the correction procedure described in the first embodiment. As a result, the workpiece 200 can be irradiated with the laser beam LB along the predetermined welding line WL while being two-dimensionally scanned, and the occurrence of defective welding can be suppressed. In addition, it is not necessary to unnecessarily increase the frequency of periodic inspection and maintenance of the manipulator 60, and the downtime of the apparatus can be reduced. Therefore, an increase in the cost of the welding process can be suppressed.

In steps S19 to S21 shown in FIG. 11, it is determined whether or not the position P and the second peak position O2 match. may be used to correct deviation of the origin position during scanning.

That is, the laser welding apparatus 100 of the present embodiment determines the amount of the laser beam LB based on either the amount of deviation between the origin O and the first peak position O1 or the amount of deviation between the position P and the second peak position O2. It is configured to correct deviation of the origin position during scanning.

Further, in the method for correcting the irradiation position deviation of the laser beam LB according to the present embodiment, in the tenth step (step S19 in FIG. 11), it is determined whether or not the second peak position O2 matches the position P, If the determination result of the eleventh step is negative, that is, if the second peak position O2 does not match the position P, the irradiation of the laser beam LB is performed based on the coordinates of the position P and the second deviation amount. The positional deviation may be corrected (eleventh step; step S20 in FIG. 11).

The laser welding apparatus of the present disclosure is useful because it can correct the displacement of the irradiation position of the laser beam, particularly the displacement of the origin position during the scanning of the laser beam, with a simple configuration.

10 laser oscillator 20 optical fiber 30 laser head 31 housing 32 collimation lens 33 mirror 34 first condenser lens 35 protective glass 36 aperture 37 second condenser lens 38 optical sensor 39 optical system 40 laser light scanner 41 first galvanomirror 41a First mirror 41b First rotating shaft 41c First driving unit 42 Second galvanomirror 42a Second mirror 42b Second rotating shaft 42c Second driving unit 50 Controller 60 Manipulator 70 Stage 71 Body unit 72 Correction unit

72a Reflecting plate

72b Reflection spot 100 laser welding device 200 work

Claims

a laser oscillator that generates laser light;
a laser head that receives the laser beam and irradiates it toward a workpiece;
a controller that controls at least the operation of the laser head;
At least a stage on which the work is placed,
The laser head is
a laser beam scanner that scans the laser beam in a first direction and a second direction that intersects with the first direction;
an optical sensor;
an optical system for causing the reflected return light of the laser light to enter the optical sensor,
The controller drives and controls the laser beam scanner so as to two-dimensionally scan the laser beam while advancing the laser beam along the welding line,
The stage has a correction section,
The correction unit has a reflector and a reflection spot provided on the surface of the reflector,
The controller drives and controls the laser light scanner so as to irradiate the laser light around the reflection spot while two-dimensionally scanning the laser light, so that the output of the optical sensor reaches a peak. Detect one peak position,
The laser welding apparatus according to claim 1, wherein the controller is configured to correct the displacement of the irradiation position of the laser beam based on the center position of the reflected spot and the first peak position.
In the laser welding device according to claim 1,
The controller is configured to correct deviation of an origin position during scanning of the laser light based on a deviation amount between the center position of the reflected spot and the first peak position. Welding equipment.
In the laser welding device according to claim 1 or 2,
The laser oscillator and the laser head are connected by an optical fiber,
A laser welding apparatus, wherein the laser beam is transmitted from the laser oscillator to the laser head through the optical fiber.
The laser welding device according to any one of claims 1 to 3,
The laser beam scanner is composed of a first galvanometer mirror for scanning the laser beam in the first direction and a second galvanometer mirror for scanning the laser beam in a second direction intersecting the first direction. A laser welding device characterized by:
In the laser welding device according to any one of claims 1 to 4,
The laser head further has a focal position adjustment mechanism,
The laser welding apparatus, wherein the focal position adjusting mechanism is configured to change the focal position of the laser light along a direction intersecting the surface of the work.
In the laser welding device according to any one of claims 1 to 5,
further comprising a manipulator to which the laser head is attached;
the controller controls the operation of the manipulator;
A laser welding apparatus, wherein the manipulator moves the laser head in a predetermined direction with respect to the surface of the workpiece.
In the laser welding device according to claim 6,
a first process of moving the laser head to the center position of the reflection spot and irradiating the laser beam around the reflection spot while scanning the laser beam two-dimensionally;
a second process of moving the laser head to a predetermined position near the center position of the reflection spot and irradiating the laser beam around the reflection spot while two-dimensionally scanning the laser beam; is executed,
The controller controls the center position of the reflected spot, a first peak position at which the output of the optical sensor peaks in the first processing, and a second peak position at which the output of the optical sensor peaks in the second processing. A laser welding device characterized in that it is configured to correct the irradiation position deviation of the laser light based on.
In the laser welding device according to claim 7,
If the amount of deviation between the first peak position and the second peak position is within a predetermined allowable range,
The controller controls the amount of deviation between the center position of the reflected spot and the first peak position or the amount of deviation between the predetermined position and the second peak position during scanning of the laser beam. A laser welding device, characterized in that it is configured to correct deviation of an origin position.
A method for correcting a laser beam irradiation position deviation using the laser welding apparatus according to any one of claims 1 to 8,
moving the laser head to a center position of the reflected spot;
operating the laser light scanner to irradiate around the center position of the reflection spot while scanning the laser light two-dimensionally;
confirming a first peak position where the output of the optical sensor peaks;
determining whether the first peak position matches the center position of the reflected spot;
if the first peak position matches the center position of the reflected spot, terminating the correction operation;
if the first peak position does not match the center position of the reflected spot, determining the amount of deviation between the first peak position and the center position of the reflected spot;
and a step of correcting the displacement of the irradiation position of the laser beam based on the coordinates of the center position of the reflected spot and the amount of displacement.
A method for correcting a laser beam irradiation position deviation using the laser welding device according to any one of claims 6 to 8,
a first step of moving the laser head to a central position of the reflected spot;
a second step of operating the laser light scanner to irradiate around the center position of the reflection spot while scanning the laser light two-dimensionally;
a third step of confirming a first peak position where the output of the optical sensor peaks;
a fourth step of obtaining a deviation amount between the first peak position and the center position of the reflected spot;
a fifth step of moving the laser head to a predetermined position in the vicinity of the center position of the reflection spot after determining the amount of deviation between the first peak position and the center position of the reflection spot;
A sixth step of operating the laser light scanner to irradiate the surroundings of the predetermined position while two-dimensionally scanning the laser light;
After the sixth step, a seventh step of confirming a second peak position where the output of the optical sensor peaks;
an eighth step of determining the amount of deviation between the second peak position and the predetermined position;
A difference between a first shift amount, which is a shift amount between the first peak position and the center position of the reflected spot, and a second shift amount, which is a shift amount between the second peak position and the predetermined position, is within an allowable range. a ninth step of determining whether or not
a tenth step of judging whether the first peak position matches the center position of the reflected spot if the judgment result of the ninth step is affirmative;
if the determination result of the tenth step is affirmative, a step of terminating the correction work;
an eleventh step of correcting the displacement of the irradiation position of the laser beam based on the coordinates of the center position of the reflection spot and the first displacement amount if the determination result of the tenth step is negative;
If the judgment result of the ninth step is negative,
After adjusting the manipulator, returning to the first step and repeatedly executing a series of processes until the determination result of the ninth step becomes affirmative. .
In the method for correcting the irradiation position deviation of the laser beam according to claim 10,
In the tenth step, determining whether the second peak position matches the predetermined position;
In the eleventh step, the laser light irradiation position deviation correction method, wherein the laser light irradiation position deviation is corrected based on the coordinates of the predetermined position and the second deviation amount.