JP2000312984A - Laser device - Google Patents

Abstract

(57) [Problem] To provide a laser device capable of reducing the size and weight of a head and controlling the amount of defocus. SOLUTION: The laser device includes a laser oscillator 10 that emits a laser beam for welding, and a head unit (a third mirror 4e) that irradiates a laser beam A1 for welding emitted from the laser oscillator 10 to a work 5. In addition, two positioning guide lasers 3a and 3b are provided in the laser oscillator 10, and two guide laser lights A2 and A3 emitted from the guide lasers 3a and 3b are used as welding laser lights A1. And the center point of a straight line connecting the center points of the cross sections of the two guide laser beams A2 and A3 coincides with the center point of the cross section of the welding laser beam. It is arranged to be.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser device used as a welding laser device and having a mirror transmission path for transmitting laser light and an optical fiber.

[0002]

2. Description of the Related Art According to a conventional welding apparatus using a laser beam, since a heat source can realize a minute spot diameter, a good bead can be obtained by low heat input and high speed welding.
However, on the other hand, it is necessary to position accurately with respect to the irradiation position (weld target position), and the allowable range of the deviation of the irradiation position of the laser beam from this irradiation position is usually 0.1 m.
m within 0.2 mm.

As an example of a welding apparatus using this laser beam, there is a laser apparatus having a mirror transmission path as shown in FIG.

[0004] This laser device comprises a laser oscillator 110 and a head unit, and transmits laser light from the laser oscillator 110 to the head unit via a mirror transmission path.

[0005] The laser oscillator 110 has a laser beam A for welding.
Two excitation lamps 101a and 101b and two excitation lamps 1 as welding lasers for emitting 101
Oscillator rod 102 sandwiched between the first mirror 104a, the first mirror 104a, the first half mirror 104b, and the second mirror 1 for transmitting the welding laser beam A101 to a predetermined position.
04c, a second half mirror 104d, and a guide laser 103 that emits a positioning guide laser beam A102 concentric with the welding laser beam A101. On the other hand, the head section includes a third mirror 104e as a laser beam focusing member.

In this laser device, the welding laser beam A101 emitted from the oscillation rod 102
After resonating between the first mirror 104a arranged near one end of the oscillation rod 102 and the first half mirror 104b arranged near the other end of the oscillation rod 102, the first half mirror 104b transmits through the first half mirror 104b, Due to the reflection by the second mirror 104c disposed in front of the first half mirror 104b,
The light is guided to one principal surface of the second half mirror 104 d, reflected, and extracted from the laser oscillator 110. The welding laser beam A101 extracted from the laser oscillator 110 is reflected and condensed by the concave surface of the third mirror 104e disposed on the head portion, and then is condensed.
5 is irradiated.

In this laser device, a small spot diameter is realized by the third mirror 104e disposed on the head. Therefore, when the height of the head portion is shifted and the focus of the laser beam is not appropriately focused (that is, when the focused height is shifted), a defect such as poor penetration at the welded portion of the work occurs. I was

Therefore, in a conventional welding laser device,
Within the oscillator, the laser beam for welding is irradiated with a coaxially concentric, narrow-diameter visible light laser, and the irradiation position is determined using this visible light laser emitted from the head along with the welding laser beam (Sumitomo Heavy Industries, Ltd.) (See “YAG Laser” catalog of Machine Industry Co., Ltd.)

Further, in a working robot or a servo table, a CCD (charge) is provided above the head of the laser device.
A coupled device) camera 106 is installed, and an image captured by the CCD camera 106 (FIG. 13)
(See FIG. 13 (a)) and the shift of the focal height on the work (see FIG. 13 (b)), and correct these shifts. The head height is automatically adjusted to adjust the focal height and irradiation position.

As a method of adjusting the deviation of the focal height, there is a method of using a jig, a scale, or the like. For example, in a work robot or a servo table, feedback control is performed using a height sensor to adjust the focal height. The deviation is adjusted (refer to the 21st Annual Meeting of the Robotics Society of Japan, "High-speed Follow-up Control of Robot Autofocus Mechanism").

Further, as another example of a conventional welding laser device, there is a laser device having an optical fiber for laser transmission as shown in FIGS. FIG.
5 is an explanatory diagram showing a part of a transmission path of a laser beam for welding in the laser device shown in FIG. 14, and FIG. 16 is an explanatory diagram showing a part of a transmission path of a guide laser beam in the laser device shown in FIG. It is.

This laser device has a laser oscillator 110 for emitting laser light, a head for irradiating the laser light extracted from the laser oscillator toward the work 105, and both ends connected to the laser oscillator 110 and the head. ,
And an optical fiber 112 for guiding the laser light extracted from the laser oscillator 110 to the head section.

The laser oscillator 110 has a laser beam A for welding.
Two excitation lamps 101a and 101b and two excitation lamps 1 as welding lasers for emitting 101
Oscillator rod 102 sandwiched between the first mirror 104a, the first mirror 104a, the first half mirror 104b, and the second mirror 1 for transmitting the welding laser beam A101 to a predetermined position.
04c and the second half mirror 104d, and the first lens 1 for condensing the transmitted laser light and guiding it to the optical fiber 112
11a and a guide laser 103 that emits a positioning guide laser beam A102 concentric with the welding laser beam A101.

On the other hand, the head section includes a second lens 111b and a third mirror 104f as a laser beam transmitting member for transmitting the welding laser beam A102 extracted from the laser oscillator 110 by the optical fiber 112, and the welding laser beam. A third lens 111c is provided as a laser beam focusing member for focusing A102.

In this laser device, the oscillation rod 10
The laser beam A101 for welding emitted from the second mirror 104 has a first mirror 104 disposed near one end of the oscillation rod 102.
a and a first rod disposed near the other end of the oscillation rod 102.
After resonating with the half mirror 104b, the first half mirror 104b transmits through the first half mirror 104b.
Due to the reflection at the second mirror 104c disposed in front of b, the light is guided to and reflected by one main surface of the second half mirror 104d, condensed by the first lens 111a and guided to the optical fiber 112 (welding at this time). Laser beam A101 D6-
A cross section taken along line D6 'is shown in FIG. The welding laser beam A101 extracted from the laser oscillator 110 by being guided to the optical fiber 112 passes through the second lens 111b provided on the head portion from one concave main surface to the other flat main surface, The light is reflected by the third mirror 104f and guided to the third lens 111c. The light passes through the third lens 111c from one flat main surface to the other main surface, which is a concave surface, and is irradiated to the work 105 arranged below the head portion. (Work 1
FIG. 15 (c) shows a cross section taken along line D7-D7 'of the welding laser beam A101 at a distance X from the top 05.

On the other hand, the guide laser beam A102 is
The light is radiated toward the half mirror 104d and passes through the second half mirror 104d from the other main surface to the one main surface. The laser beam A101 for welding is guided to one principal surface of the second half mirror 104d, and the laser beam A
102 is incident on the center point of the end face of the optical fiber 112 (D8-D8 'of the guide laser beam A102 at this time).
The cross section is shown in FIG. 16B), which is taken out of the laser oscillator 110 by the optical fiber 112. The guide laser beam A102 extracted together with the welding laser beam A101 by the optical fiber 112 is coaxial with the welding laser beam A101, and has a concentric ring-shaped cross-section laser beam (hereinafter also referred to as "ring beam"). In the same manner as the welding laser beam A101, the laser beam is radiated to the work 105 via the second lens 111b, the third mirror 104f, and the third lens 111c (the guide laser at a distance X from the work 105). D9 of light A102
A cross section taken along line -D9 'is shown in FIG.

In this laser device, a small spot diameter is realized by the third lens 111c arranged in the head portion. For this reason, the focal point P101 of the laser beam cannot be appropriately narrowed due to the deviation of the height of the head portion (see FIG.
(See (b)), a defect such as poor penetration occurred at the welded portion of the work.

For this reason, the head is moved up and down to adjust the focal point height in the same manner as in the case of the laser apparatus having the above-mentioned mirror transmission path, and the focal point P
(See FIG. 17A), and further, the head portion is moved in the left-right direction to adjust the irradiation position.

[0019]

However, when the irradiation position is determined using a visible light laser in the above-described apparatus for performing laser welding, the position other than near the focal point is proportional to the square of the focal length. Since the luminance is reduced, it is difficult to determine the laser irradiation diameter, and there has been a problem that the irradiation position cannot be accurately determined.

As described above, a visible light laser or a CCD
When adjusting the focal height and the deviation of the irradiation position using a camera, etc., a height sensor is added to the head part, which increases the weight and head size, and furthermore, the height sensor is located near the welded part. However, there is a problem that the durability of the sensor itself is concerned.

The present invention has been made in order to solve such a problem, and it is an object of the present invention to provide a laser device capable of reducing the size and weight of a head and controlling the amount of defocus. .

[0022]

According to a first aspect of the present invention, there is provided a laser device for emitting a laser beam for welding, and a head for irradiating the workpiece with the laser beam for welding emitted from the laser oscillator. A laser device comprising two lasers for positioning guides provided in a laser oscillator, and two guide laser beams emitted from the guide lasers are coaxial with the laser beam for welding. They are arranged so as to be eccentric, and are arranged such that the center point of a straight line connecting the respective center points of the cross sections of these two guide laser beams coincides with the center point of the cross section of the welding laser beam. Things.

According to a second aspect of the present invention, there is provided a laser device comprising: a laser oscillator for emitting a laser beam for welding; and a head unit for irradiating the workpiece with the laser beam for welding emitted from the laser oscillator. A laser device, wherein at least three positioning guide lasers are provided in a laser oscillator, and at least three guide laser lights emitted from the positioning guide lasers are coaxially eccentric with respect to the welding laser light. And the center of gravity or the center of the polygon obtained by connecting the center points of the cross sections of these three guide laser beams coincides with the center point of the cross section of the welding laser beam. It is arranged in.

A laser device according to a third aspect of the present invention includes a laser oscillator that emits a laser beam for welding, and a head unit that irradiates the laser beam for welding emitted from the laser oscillator toward a workpiece. A laser device, wherein a plurality of positioning guide lasers are provided in a laser oscillator, and guide laser light emitted from at least one of the plurality of positioning guide lasers is welded. The laser light for guiding is arranged coaxially eccentrically with respect to the laser light for guiding, and the laser light for guiding radiated from at least one further guiding laser of the plurality of positioning guide lasers with respect to the welding laser light. The center point of the cross section of the guide laser beam emitted from at least one other guide laser is arranged so as to be coaxial and concentric with the welding laser. In which are arranged to coincide with the center point of the cross section of the laser light.

According to a fourth aspect of the present invention, there is provided a laser device for emitting a laser beam for welding, a head unit for irradiating the laser beam for welding emitted from the laser oscillator to a work, A laser device comprising: an optical fiber for guiding a welding laser beam emitted from an oscillator to a head portion, wherein a positioning guide laser is provided in the laser oscillator, and the guiding laser beam emitted from the positioning guide laser is provided. Are arranged so as to be coaxial and eccentric with respect to the welding laser beam and to be incident on the outer peripheral portion of the optical fiber or in the vicinity thereof, so that the guide laser beam is output from the welding laser beam at the output side of the optical fiber. It is formed on coaxial and concentric ring light.

[0026]

Next, an embodiment of a laser device according to the present invention will be described. [First Embodiment] First, a laser device according to a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory view showing an embodiment of a laser device according to the present invention. FIG. 1 (a) is an explanatory diagram showing a configuration of the laser device, and FIG. It is explanatory drawing which shows the cross section of the laser beam for welding and the laser beam for guides in an apparatus.

In this laser device, a welding laser beam A radiated from an oscillation rod (welding laser) 2 sandwiched between two excitation lamps 1a and 1b is provided inside a laser oscillator 10.
1 and a small diameter visible light laser (for example, He-N
e laser light) and two guide lasers 3a and 3b for irradiating the laser light A2 and A3 for positioning guide.

The welding laser beam A1 emitted from the oscillation rod 2 is divided into a first mirror 4a arranged near one end of the oscillation rod 2 and a first mirror 4a arranged near the other end of the oscillation rod 2. After resonating with the half mirror 4b, the first
The first half mirror 4b is transmitted through the half mirror 4b.
Is reflected by the second mirror 4c disposed in front of the second half mirror 4d, guided and reflected by one main surface of the second half mirror 4d, and taken out of the laser oscillator 10. The welding laser beam A1 extracted from the laser oscillator 10 is reflected by the concave surface of the third mirror (laser light focusing member) 4e arranged on the head portion and is focused, and then is arranged below the head portion. Work 5
Is irradiated.

On the other hand, each of the guide laser beams A2 and A3 is
The light is radiated toward the second half mirror 4d and passes through the second half mirror 4d from the other main surface to the one main surface. This second
The laser beam A1 for welding is guided to one main surface of the half mirror 4d, and the laser beams A2 and A3 for guiding are
Each becomes coaxial and eccentric with respect to the welding laser beam A1,
That is, FIG. 1 shows a cross section taken along line D1-D1 ′ of the welding laser beam A1 and the guide laser beams A2 and A3, which overlaps with the welding laser beam A1 in the vicinity of the outer peripheral portion (preferably the outer peripheral portion).
(See (b)), and is extracted from the laser oscillator 10. Thereafter, the guide laser beams A2 and A3 extracted from the laser oscillator 10 are respectively reflected at the concave end portions of the third mirror 4e and guided to the focusing position of the welding laser beam A1. That is, the two guide lasers 3a and 3b that emit the two guide laser beams A2 and A3 respectively are:
Guide laser light A transmitted through second half mirror 4d
2 and A3 overlap the welding laser beam A1 in the vicinity of the outer peripheral portion (preferably the outer peripheral portion), and the distance between the optical axes of the two guide laser beams A2 and A3 is equal to the welding laser beam A1.
Are arranged to be approximately equal to the diameter of

When the focal height is appropriately adjusted as in the laser apparatus shown in FIG. 1, the optical axes of the guide laser beams A2 and A3 are adjusted as shown in FIG. Are guided to and intersect with the focusing position P of the welding laser beam A1. However, for example, when the focal height is too high, the optical axes of the guide laser beams A2 and A3 intersect above the workpiece 5, and FIG.
As shown in (b), two different positions P1 and P2 on the work 5 are irradiated with the guide laser beams A2 and A3.
That is, when two points of laser light are confirmed on the work 5, it can be recognized that the focal height is shifted.

Further, since the optical axis of the welding laser beam A1 is normally perpendicular to the laser irradiation surface of the work 5, if the focus height is shifted, the position where the guide laser beams A2 and A3 are irradiated ( Irradiation position) Center point P of a straight line connecting P1 and P2
0 corresponds to the focusing position P of the welding laser beam A1. Therefore, in this state, it is possible to adjust the arrangement of the laser device and move the focal position P of the welding laser beam A1 on the welding line B.

As one example of the specifications of the laser apparatus of the present embodiment, the output energy of 2 k
CO2 laser light of w is used, the laser diameter Lw when the laser light for welding oscillates is 10 mm, the laser diameter Lg when the laser light for guide oscillates is 0.2 mm, and the laser light for welding is focused. The spot diameter Sw at the time is 1 mm, and the converging angle θ of the welding laser light and the guide laser light is 30 degrees.

When the position of the laser device is manually adjusted, the guide laser light A on the work 5 is visually checked.
The irradiation positions of A2 and A3 and the number thereof are confirmed, and the position of the laser device may be adjusted so that there is one irradiation position on the welding line B.

On the other hand, when the position of the laser device is automatically adjusted, the CCD camera 6 is arranged above the head portion,
The work 5 is monitored by the D camera 6. The CCD camera 6 is connected to, for example, an automatic position correction system shown in FIG. In this system, first, the image data of the captured work 5 is image-processed by the image processing device 7 to extract data indicating the irradiation positions of the guide laser beams A2 and A3 and the number thereof. After that, the CPU (centra
1 processing unit) 8 to calculate the amount of movement of the laser device based on the extracted data, and the laser device position adjustment device 9 automatically adjusts the position of the laser device based on the amount of movement to adjust the focal height and laser irradiation. Adjust the position.

When the position of the laser device is automatically adjusted as described above, first, it is determined whether the irradiation position on the work 5 is one place or two places. If there is one, the laser device is moved in the left-right direction so that the irradiation position overlaps the welding line. On the other hand, when there are two irradiation positions on the workpiece 5, the laser device is moved in the left and right direction so that the center point of the two irradiation positions overlaps the welding line, and then the laser device is slightly moved up and down. Move in the direction
It is determined whether the focal height is too high or too low based on the change of the two irradiation positions, and the moving direction is determined. For example, if the distance between the two irradiation positions becomes shorter when moving upward, it can be determined that there is a focus below the work. Further, from the distance between the two irradiation positions and the converging angle of the third mirror, the magnitude of the shift of the focal height can be obtained. Then, the laser device is moved in the determined moving direction by an amount corresponding to the deviation of the focal height. Second Embodiment Next, a second embodiment of the laser device of the present invention will be described with reference to the drawings.

FIG. 4 is an explanatory view showing another embodiment of the laser device according to the present invention. FIG. 4 (a) is an explanatory diagram showing the configuration of the laser device, and FIG. It is explanatory drawing which shows the cross section of the laser beam for welding and the laser beam for guides in a laser apparatus.

This laser device is different from the above-mentioned laser device in the arrangement and number of guide lasers.
Except for the difference in the overlapping position of the guide laser beam on the welding laser beam, it is the same, so the details of the arrangement and the number of the guide lasers and the configuration other than the overlapping position of the guide laser beam are described in detail. Detailed description is omitted.

The laser device of this embodiment has three guide lasers 13a, 13b and 13c. Then, the guiding laser beams A12, A13, A14 emitted from the respective guiding lasers 13a, 13b, 13c overlap the welding laser beam A1 in the vicinity of the outer peripheral portion (preferably the outer peripheral portion), and the guiding laser beam A12 is emitted. , A13, A14
Pass through the vertex of the equilateral triangle drawn on the cross section of the welding laser beam A1, and the center of gravity of the equilateral triangle coincides with the optical axis of the welding laser beam A1 (the welding laser beam A1).
And D2 of the guide laser beams A12, A13, A14
(See FIG. 4 (b) showing a section cut along line -D2 '). Three guide lasers 13a, 13b and 13c are arranged. That is, the guide laser beams A12, A13, and A14 are coaxial and eccentric with respect to the welding laser beam A1. The number of guide laser beams is not limited to three, but may be four or more. In this case, so that the center of the polygon obtained by connecting the respective center points of the cross section of the guide laser light coincides with the center point of the cross section of the welding laser light,
A guide laser may be provided.

Therefore, if the focal height is accurately adjusted, the number of irradiation positions P confirmed on the work 5 is one as in the above-described embodiment (see FIG. 5A). ) On the other hand, if the focal height is not adjusted accurately, the work 5
The number of irradiation positions P11, P12, and P13 confirmed above becomes three (see FIG. 5B). Regarding the focal point, if the number of irradiation positions P confirmed on the work 5 is one,
If the number of the irradiation positions P11, P12, and P13 confirmed on the work 5 is three, the irradiation position P may be overlapped on the welding line 8 as in the above-described embodiment. Then, the center of gravity P0 of the equilateral triangle drawn by the three irradiation positions P11, P12, and P13 may be overlapped on the welding line 8.

The adjustment of the focal height and the irradiation position can be carried out by using the automatic position correction system shown in FIG.

As one example of the specifications of the laser apparatus of the present embodiment, the output energy of 2 k
CO2 laser light of w is used, the laser diameter Lw when the laser light for welding oscillates is 10 mm, the laser diameter Lg when the laser light for guide oscillates is 0.2 mm, and the laser light for welding is focused. The spot diameter Sw at the time is 1 mm, and the converging angle θ of the welding laser light and the guide laser light is 30 degrees. [Third Embodiment] Next, a third embodiment of the laser device of the present invention will be described with reference to the drawings.

FIG. 6 is an explanatory view showing still another embodiment of the laser device of the present invention. FIG. 6 (a) is an explanatory diagram showing the configuration of the laser device, and FIG. It is explanatory drawing which shows the cross section of the laser beam for welding and the laser beam for guides in this laser apparatus.

This laser device is different from the laser device of the second embodiment in that the arrangement of the guide laser is different and the overlapping position of the guide laser light on the welding laser light is different. Since the configuration is the same, detailed description of the configuration other than the arrangement of the guide laser and the overlapping position of the guide laser light is omitted.

The laser device of the present embodiment has two guide lasers 23a and 23b. Then, of the guide laser beams A22, A23 emitted from the guide lasers 23a, 23b, one of the guide laser beams A22 overlaps the welding laser beam A1 in the vicinity of the outer peripheral portion (preferably, the outer peripheral portion). . That is, the guide laser light A
Reference numeral 22 denotes coaxial eccentricity with respect to the welding laser beam A1. On the other hand, the other guide laser beam A23 is the welding laser beam A23.
1 (see FIG. 6 (b) showing a cross section taken along line D3-D3 'of the welding laser beam A1 and the guiding laser beams A22 and A23) so as to overlap the two laser beams 23 for guiding.
a and 23b are arranged. That is, the guide laser beam A23 is coaxial and concentric with the welding laser beam A1. Note that the number of guide laser beams coaxial and eccentric with the welding laser beam A1 and the number of guide laser beams coaxial with the welding laser beam A1 are not limited to one each, but are required. A plurality of them may be used depending on the situation.

Therefore, if the focal height is accurately adjusted, the number of irradiation positions P confirmed on the work 5 is one as in the above-described embodiment (see FIG. 7A). On the other hand, if the focal height has not been adjusted accurately, the irradiation position P confirmed on the work 5 as in the above-described embodiment.
The number of P21 and P22 is two (see FIG. 7B). Regarding the focal point, if the number of irradiation positions P confirmed on the work 5 is one, the irradiation position P may be superimposed on the welding line 8 as in the above-described embodiment. On the other hand, if the number of irradiation positions P21, P22 confirmed on the work 5 is two, the two irradiation positions P21, P22
Of these, the irradiation position P21 that does not move even if the laser device is slightly moved in the vertical direction may be overlapped on the welding line 8.

The adjustment of the focal height and the irradiation position can be performed by the same procedure as in the first embodiment, using the automatic position correction system shown in FIG.

As an example of the specifications of the laser device of the present embodiment, the output energy of 2 k
CO2 laser light of w is used, the laser diameter Lw when the laser light for welding oscillates is 10 mm, the laser diameter Lg when the laser light for guide oscillates is 0.2 mm, and the laser light for welding is focused. The spot diameter Sw at the time is 1 mm, and the converging angle θ of the welding laser light and the guide laser light is 30 degrees. Embodiment 4 Next, Embodiment 4 of the laser device of the present invention will be described with reference to the drawings.

FIG. 8 is an explanatory view showing still another embodiment of the laser device according to the present invention. FIG. 8 (a) is an explanatory diagram showing the configuration of the laser device, and FIG. It is explanatory drawing which shows the cross section of the laser beam for welding and the laser beam for a guide in the incident side end part of the optical fiber which comprises this laser apparatus, FIG.
It is explanatory drawing which shows the cross section of the laser beam for welding and the laser beam for guides in the place separated only.

In this laser device, a laser beam A1 radiated from an oscillation rod (for example, a YAG laser) 2 sandwiched between two excitation lamps 1a and 1b is coaxial and has a small diameter inside a laser oscillator 10. Visible light laser (eg, H
e-Ne laser beam) for positioning guide laser beam A32
And a guide laser 33a that emits light.

The welding laser beam A1 emitted from the oscillation rod 2 is divided into a first mirror 4a arranged near one end of the oscillation rod 2 and a first mirror 4a arranged near the other end of the oscillation rod 2. After resonating with the half mirror 4b, the first
The first half mirror 4b is transmitted through the half mirror 4b.
Is reflected by the second mirror 4c disposed in front of the first half mirror 4d and is reflected on one main surface of the second half mirror 4d, and transmits the first lens 11a from the flat main surface to the other main surface which is a concave surface. . The light is condensed by passing through the first lens 11 a, and one end is guided to the optical fiber 12 inserted and fixed to the laser oscillator 10 and extracted from the laser oscillator 10. Then, the welding laser light A1 extracted from the laser oscillator 10 passes through the second lens (laser light transmitting member) 11b provided in the head portion from one concave main surface to the other flat main main surface. The light is reflected by a third mirror (laser light transmitting member) 4f provided in the head portion and guided to a third lens (laser light condensing member) 11c, and the third lens 11c is concave from one flat main surface. The light is transmitted to the other main surface, and is irradiated on the work 5 arranged below the head portion.

On the other hand, the guide laser beam A32 is emitted toward the second half mirror 4d,
d is transmitted from the other main surface side to one main surface side. The laser beam A1 for welding is guided to one principal surface of the second half mirror 4d.
2 (refer to FIG. 8B showing a cross section taken along line D4-D4 ′ of the welding laser beam A1 and the guiding laser beam A32). It is taken out of the oscillator 10. The guide laser light A32 extracted together with the welding laser light A1 by the optical fiber 12 becomes a coaxial, concentric ring-shaped laser light (hereinafter, referred to as "ring light") with respect to the welding laser light A1. (FIG. 8 shows a cross section taken along line D5-D5 ′ at a distance X from the focal points of the welding laser beam A1 and the guiding laser beam A32.
(See (c)), similarly to the welding laser beam A1, the workpiece 5 is irradiated via the second lens 11b, the third mirror 4f, and the third lens 11c. That is, the guide laser beam 33 that emits the guide laser beam A32 is the guide laser beam A32 that has passed through the second half mirror 4d.
The optical fiber 12 is disposed so as to be incident near the outer peripheral portion (preferably, the outer peripheral portion).

In this laser device, the guide laser beam A32 having a small diameter is extracted from the optical fiber 12 as ring light and used. Here, with respect to the guide laser light A32, which has become the ring light, it is confirmed from the experimental results whether or not the ring light can be confirmed even when the focus height is shifted and the focus is not confirmed on the work.

FIG. 9 is a graph showing an illuminance reduction coefficient with respect to the deviation of the focal height of the guide light (the illuminance is lower as the value is closer to 0, making it difficult to confirm). In FIG. 9, the horizontal axis indicates the distance (mm) from the focal point, and the vertical axis indicates the illuminance reduction coefficient. Further, as in the laser apparatus of the present embodiment, the experimental results obtained by measuring the laser beam for guiding incident near the outer peripheral portion (preferably the outer peripheral portion) of the optical fiber 12 are shown by a solid line, An experimental result obtained by measuring the guide laser beam so as to overlap the welding laser beam on the center axis as in the case of the apparatus is indicated by a broken line.

In order to obtain the experimental results, a YAG laser beam having an output energy of 1 kW was used as the guide laser beam, and the laser diameter Lw during oscillation of the welding laser beam was used.
Is 10 mm, the laser diameter Lg at the time of oscillation of the guide laser light is 0.2 mm, the spot diameter Sw at the time of condensing the welding laser light is 1 mm, and the welding laser light and the guide laser light are A laser device having a converging angle θ of 30 degrees was used.

As is apparent from FIG. 9, when the guide laser light is incident near the outer peripheral portion (preferably the outer peripheral portion) of the optical fiber 12 as in the laser apparatus of the present invention, the distance from the focal point increases. However, it can be seen that the ring light can be clearly confirmed without the illuminance reduction coefficient converging to zero.

Therefore, in the conventional laser apparatus, it was difficult to confirm the guide laser light when the focal point height was shifted and the focal point was shifted from the work. However, according to the laser apparatus of this embodiment, Thus, even if the focal height is shifted, the irradiation position of the guide laser light can be easily confirmed on the work.

Next, a description will be given of the fact that the irradiation position of the ring light can be confirmed on the work because the brightness of the ring light does not decrease in the laser device of the present embodiment as compared with the conventional laser device.

In the equation, the laser diameter of the welding laser light at the time of oscillation is Lw, and the laser diameter of the guiding laser light is Lg.
The spot diameter of the laser beam for welding condensed by the third lens provided for condensing in the head portion is Sw, the spot diameter of the laser beam for guide is Sg, and the optical axis is from the outer peripheral end of the ring light. The first condensing angle which is an angle to C is θ, the second condensing angle which is an angle from the inner peripheral end of the ring light to the optical axis C is θ ′, and the distance from the focal point is X ( (See FIG. 10).

Irradiation area of welding laser beam Aw = (Sw /
2 + X × tan θ) ² × π, and in the conventional laser device, the area of the guide light is almost the same as the area of the welding laser light.

However, in the case of the ring light, the condensing angle tan θ 'on the inner circumference of the ring = (1−Lg / Lw)
× tan θ, and when | X | <(Sw / 2 / tan θ), the irradiation area Ag of the guide laser beam Ag = (Sw / 2 + X × t
an θ) ² × π | X | ≧ (Sw / 2 / tan θ), the irradiation area Ag of the guide laser light Ag = (Sw / 2 + X × t
anθ−X × tanθ ′) ² × π.

That is, the change in the illuminance of the laser light
The reciprocals of w and Ag can be expressed as coefficients, and the smaller the guide light is and the closer to the outer periphery of the welding laser light, the less the irradiation can be reduced.

In the laser device of the present embodiment, similarly to the laser device of the first embodiment, the focal height and the deviation of the irradiation position can be adjusted manually or automatically.

First, when the position of the laser device is manually adjusted, the guide laser beam A3 on the work 5 is visually observed.
Confirm the irradiation position and its shape of No. 2 and set the irradiation position to welding line B
The position of the laser device may be adjusted in the vertical and horizontal directions so as to be in a point-like shape on the upper side.

On the other hand, when the position of the laser device is automatically adjusted, the CCD camera 6 is arranged above the head portion,
The work 5 is monitored by the D camera 6. The CCD camera 6 is connected to, for example, an automatic position correction system shown in FIG. In this system, first, the image data of the captured work 5 is subjected to image processing by the image processing device 7 to extract data indicating the irradiation position of the guide laser beam A32 and its shape. Thereafter, the CPU 8 calculates the amount of movement of the laser device based on the extracted data, and the laser device position adjustment device 9 automatically adjusts the position of the laser device based on the amount of movement, and adjusts the focal height and the laser irradiation position. Make adjustments.

When the position of the laser device is automatically adjusted as described above, first, the guide laser light A32 on the work 5 is used.
Is determined to be a point shape or a ring shape. When the irradiation position P of the guide laser beam A32 is a point having a diameter equal to or smaller than a predetermined value (see FIG. 11A), the laser device is moved left and right so that the irradiation position P overlaps the welding line 8. Move in the direction. On the other hand, when the irradiation position P31 of the guide laser beam A32 on the workpiece 5 is a ring shape, that is, a ring beam (see FIG. 11B), the center point P0 of the ring beam is overlapped with the welding line 8. Then, the laser device is moved in the left-right direction, and then the laser device is slightly moved in the up-down direction to determine whether the focal height is too high or too low due to the change in the diameter of the ring light, and determine the moving direction. . For example, when the diameter of the ring light becomes smaller when moving upward, it can be determined that the focus is below the work. Further, from the diameter of the ring light and the converging angle of the third lens, the magnitude of the shift of the focal height can be obtained. Then, the laser device is moved in the determined moving direction by an amount corresponding to the deviation of the focal height.

In the first to fourth embodiments,
The guide laser is not limited to the He-Ne laser, but may be any laser having a visible light wavelength. Further, a half mirror or a switching method using a mirror may be used for the irradiation method of the guide laser light. As another irradiation method of the guide laser beam,
It may be supplied from a branch portion or the like provided in the middle of the optical fiber for sending the laser beam for welding to the head portion. In this case, the optical fiber for sending the laser beam for welding to the head portion may be supplied with respect to the laser beam for welding. It suffices if the guide laser beam can be projected coaxially and eccentrically at a position other than the center or near the outer periphery. However,
Preferably, the guide laser beam can be projected near the outer periphery of the welding laser beam.

[0068]

As described above, according to the present invention,
Since there is no need to provide a height sensor, a light projector, and the like in the head portion, the size and weight of the head can be reduced. Furthermore, by simply knowing the focusing angle of the third mirror in advance,
It is also possible to control the amount of defocus (that is, shift the focus to a desired position, such as placing the focus on or inside the work).

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing Embodiment 1 of a laser device according to the present invention.

FIG. 2 is an explanatory view showing an example of an irradiation position on a work of a guide laser beam emitted from a guide laser of the laser device shown in FIG. 1;

FIG. 3 is a block diagram showing an example of an automatic position correction system connected to the laser device of the present invention.

FIG. 4 is an explanatory view showing another embodiment of the laser device of the present invention.

5 is an explanatory diagram showing an example of an irradiation position on a work of a guide laser beam emitted from a guide laser of the laser device shown in FIG. 4;

FIG. 6 is an explanatory view showing still another embodiment of the laser device of the present invention.

FIG. 7 is an explanatory diagram showing an example of an irradiation position on a work of a guide laser beam emitted from a guide laser of the laser device shown in FIG. 6;

FIG. 8 is an explanatory view showing still another embodiment of the laser device of the present invention.

FIG. 9 is a graph showing an illuminance reduction coefficient with respect to a deviation of a focal height of guide light.

FIG. 10 is a laser beam for guiding a focal point and its peripheral portion in the laser device shown in FIG. 8;

FIG. 11 is an explanatory view showing an example of a guide laser beam emitted from the guide laser of the laser device shown in FIG. 8;

FIG. 12 is an explanatory view showing an example of a conventional laser device.

13 is an explanatory diagram illustrating an example of an irradiation position on a work of a guide laser beam emitted from the guide laser of the laser device illustrated in FIG. 12;

FIG. 14 is an explanatory view showing another example of a conventional laser device.

FIG. 15 is an explanatory view showing a part of a transmission path of a laser beam for welding in the laser device shown in FIG. 14;

16 is an explanatory diagram showing a part of a transmission path of a guide laser beam in the laser device shown in FIG. 14;

17 is an explanatory diagram illustrating an example of an irradiation position on a work of a guide laser beam emitted from the guide laser of the laser device illustrated in FIG. 14;

[Explanation of symbols]

 1a, 1b Excitation lamp 2 Oscillating rod 3a, 3b Guide laser 4a First mirror 4b First half mirror 4c Second mirror 4d Second half mirror 4e, 4f Third mirror 5 Work 6 CCD camera 7 Image processing device 8 CPU 9 Laser device position adjusting device 10 Laser oscillator 11a First lens 11b Second lens 11c Third lens 12 Optical fiber

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2F065 AA19 DD02 FF04 GG04 GG12 HH04 JJ03 JJ09 JJ26 LL02 LL19 QQ31 UU07 4E068 CA09 CA11 CC02 CD02 CD15 CE08

Claims (4)

[Claims] 1. A laser device comprising: a laser oscillator that emits a welding laser beam; and a head unit that irradiates a welding laser beam emitted from the laser oscillator toward a workpiece. Are provided, and two guide laser beams emitted from the guide laser are arranged so as to be coaxial and eccentric with respect to the welding laser beam. A laser device, wherein a center point of a straight line connecting respective center points of a cross section of a laser beam is arranged so as to coincide with a center point of a cross section of a laser beam for welding. 2. A laser device comprising: a laser oscillator that emits a welding laser beam; and a head unit that irradiates the welding laser beam emitted from the laser oscillator toward a workpiece. A positioning guide laser is provided, and at least three guide laser beams emitted from the positioning guide lasers are arranged so as to be coaxial and eccentric with respect to the welding laser beam. Wherein the center of gravity or the center of the polygon obtained by connecting the respective center points of the cross section of the guide laser beam is aligned with the center point of the cross section of the welding laser beam. . 3. A laser device comprising: a laser oscillator for emitting a welding laser beam; and a head unit for irradiating the welding laser beam emitted from the laser oscillator toward a work, wherein a plurality of laser units are provided in the laser oscillator. A positioning guide laser is provided, and a guide laser beam emitted from at least one of the plurality of positioning guide lasers is coaxially arranged with respect to the welding laser beam, Guide laser light emitted from at least one other guide laser of the plurality of positioning guide lasers is arranged so as to be coaxial and concentric with the welding laser light, and further another The center point of the cross section of the guide laser beam emitted from at least one guide laser is arranged to coincide with the center point of the cross section of the welding laser beam. The laser apparatus characterized by being. 4. A laser oscillator for emitting a laser beam for welding, a head unit for irradiating a laser beam for welding emitted from the laser oscillator toward a workpiece, and a head unit for emitting a laser beam for welding emitted from the laser oscillator. A laser device for positioning guide in a laser oscillator, comprising:
The guide laser light emitted from the positioning guide laser is arranged so as to be coaxial and eccentric with respect to the welding laser light and to be incident on the outer peripheral portion of the optical fiber or in the vicinity thereof. 3. The laser device according to claim 1, wherein the guide laser light is formed into a concentric ring light with respect to the welding laser light.