JP3514129B2 - Laser processing equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser processing apparatus for performing welding, joining, drilling, cutting, removing, modifying, etc. by using the energy of a plurality of laser beams.

[0002]

2. Description of the Related Art As a conventional laser processing technique, one using a single laser beam is widely used. Moreover, a laser processing technique using a plurality of laser beams is disclosed in
It is disclosed in Japanese Patent Publication No. 300087.

[0003]

However, in the former laser processing technique, the faster the moving speed of the laser beam, the more unstable the keyhole becomes. As a result, since the keyhole depth becomes shallower, the reflected light also increases. That is, when the moving speed of the laser beam is high, there is a problem that the melting depth becomes shallow.

In the latter laser processing technique, as shown in FIG. 9, the focal points 90f and 92f of the laser beams 90 and 92 having mutually different optical axes are focused and irradiated on one point 96 of the workpiece 94. Therefore, when the position of the workpiece 94 changes in the optical axis direction of the laser beams 90 and 92, the laser beams 90 and 92 do not gather at one point on the workpiece 94, which causes a problem that sufficient processing cannot be performed. It was Further, when the laser beams 90 and 92 are moved on the workpiece 94, there is a problem that the melting depth differs depending on the moving direction. It is considered that this is because the positional relationship between the laser beams 90 and 92 is directional.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a laser processing apparatus that achieves any of the following items. ． Even if the moving speed of the laser beam is high, a sufficient melting depth can be obtained. ． Even if the position of the work piece varies in the optical axis direction of the laser beam, the plurality of laser beams are not separated. ． The melting depth does not change depending on the moving direction of the laser beam.

[0006]

According to a first aspect of the present invention, there is provided a laser processing apparatus in which a plurality of laser resonators for generating a laser beam and optical axes of the plurality of laser resonators are aligned with each other. Beam mixing means for mixing by mixing, and at least one of the plurality of laser resonators
Provided between the laser resonator and the beam mixing means.
And the remaining laser beam generated from the laser cavity
The at least one laser resonance with respect to the focal position of
The relative focus position of the laser beam generated from the
A first focal position changing means that is movable in the present position, a beam irradiating means that irradiates the workpiece with the laser beam mixed by the beam mixing means, and a beam mixing means that mixes by the beam mixing means.
Position of the focused laser beam and the workpiece
A gap sensor for detecting this, and the beam mixing means
Provided between said beam irradiation means, the gap Se
Beam mixing based on displacement data from the sensor
Freely move the focus position of laser beam mixed by means
And a second focus position changing means that enables the second focus position .

The plurality of laser beams are applied to the work piece with their optical axes aligned. Therefore, no matter how the position of the workpiece changes, the plurality of laser beams are not separated. Further, since the positional relationship between the plurality of laser beams is not directional on the workpiece, the melting depth does not change depending on the moving direction.

[0008] The laser processing apparatus according to claim 2, wherein the laser
The multiple laser cavities that generate the beam and the
Light for multiple laser beams emitted from a laser
Beam mixing means for mixing by aligning the axes and this beam
Provided between the mixing means and the plurality of laser resonators,
The focus positions of the laser beams can be freely moved.
A plurality of movable focus position changing means and the beam mixing means.
Irradiate the workpiece with the laser beam mixed by the coupling means
Beam irradiating means.

According to a third aspect of the present invention, there is provided a laser processing apparatus according to the third aspect.
In the laser processing apparatus according to 1 or 2, the plurality of laser
The laser beam consists of the first and second laser beams,
The beam mixing means is irradiated with the first laser beam.
And the second laser beam is irradiated.
And a second irradiation surface that is
The second laser beam reflected by the first irradiation surface
Dichroic mirror that transmits light on the second irradiation surface
And a dustproof housing that houses this dichroic mirror,
The first laser beam slightly passing through the first irradiation surface.
With a photodetector for detecting
It The first laser beam passes through the dichroic mirror
See through. So I passed through the dichroic mirror
Providing a photodetector to detect the first laser beam
More, the deterioration and damage of the dichroic mirror are detected.
That is, the first laser beam detected by the photodetector
If it is abnormal, the dichroic mirror may be deteriorated or damaged.
It can be judged that it is closed.

A laser processing apparatus according to a fourth aspect is the following.
1. The laser processing apparatus according to 1, 2, or 3 , wherein the plurality of
Laser beam has short wavelength and long wavelength
A laser beam consisting of a laser beam with a short wavelength
Of the focal point of the
-Deeper than the focus position of the laser beam with respect to the workpiece
To do. Since a plurality of focal points are formed on the optical axis, a deeper melting depth can be obtained.

[0011]

1 is a block diagram showing a first embodiment of a laser processing apparatus according to the present invention. Hereinafter, description will be given with reference to this drawing.

The laser processing apparatus 10 according to the present embodiment includes laser resonators 12A and 12 that generate laser beams A and B, respectively.
B, a beam mixing means 14 for mixing the laser beams A, B generated from the laser resonators 12A, 12B by matching the optical axes Aa, Ba, and the laser beams A, B mixed by the beam mixing means 14. Beam irradiation means 16 for irradiating the workpiece 94 with the laser beam A and the focal points Af of the laser beams A and B.
Focus position changing means 1 capable of freely moving Bf
8 and 20 are provided.

The laser resonator 12A is a carbon dioxide gas laser (wavelength 10.6 [μm]), and the laser resonator 12B is YAG.
It is a laser (wavelength 1.06 [μm]). Laser resonator 12
Mirrors 22 with a return light reflection film are provided on A and 12B, respectively.
A and 22B are provided. The mirrors 22A, 22B with the return light reflection film protect the laser resonators 12A, 12B by preventing the return light of the laser beams A, B from entering the laser resonators 12A, 12. A reflecting mirror 24 is provided between the mirror 22A having a return light reflecting film and the beam mixing means 14.

The beam mixing means 14 transmits a laser beam A and reflects the laser beam B, and a dichroic mirror 141 and a dichroic mirror 141.
And a dust-proof housing 142 for housing. Laser beam A
Is transmitted through the dichroic mirror 141 at an incident angle of 45 °, and the laser beam B is transmitted through the dichroic mirror 141 by 45 °.
By reflecting at an incident angle of °, each optical axis A
a and Ba match.

The beam irradiation means 16 comprises a concave mirror 161 and can be moved to a desired processing position by a moving mechanism (not shown).

The focus position changing means 18 is a deformable mirror 18.
1, the focus position changing means 20 is a deformable mirror 20.
It consists of 1,202. Deformable mirrors 181, 201, 2
02 includes a piezoelectric actuator (not shown) that deforms according to a current value, and a metal reflective film (not shown) that continuously deforms from a concave surface to a convex surface by a force generated by the piezoelectric actuator, The signal changes the curvature of the mirror surface. Deformable mirror 18
By controlling the concavities and convexities of 1, ..., the spot diameter, focus position, depth of focus, etc. at the condensing point of the laser beams A, B can be arbitrarily set without moving the optical components in the optical path length direction. . Such a deformable mirror is a German DI
It is sold as "Adaptive Optics" by EHL.

The focal position changing means 20 is provided between the mirror 22B with the return light reflection film and the beam mixing means 14. The laser beam B that has passed through the mirror 22B with the return light reflection film is reflected by the deformable mirror 201, then by the deformable mirror 202, and then proceeds to the beam mixing means 14. The focal position changing means 20 causes
The focus position of the laser beam B can be arbitrarily set with respect to the focus position of.

The focus position changing means 18 is provided between the beam mixing means 14 and the beam irradiation means 16. By the focus position changing means 18 and 20, the laser beam A,
It is possible to make the light collection states of B coincide or different. Further, a gap sensor (not shown) that detects the positional deviation between the focal points Af and Bf and the workpiece 94, and a controller (not shown) that controls the irregularities of the deformable mirror 181 based on the positional deviation data from the gap sensor. ), The positions of the focal points Af and Bf with respect to the workpiece 94 can be corrected.

Since the laser processing apparatus 10 has the focus position changing means 20 including the two deformable mirrors 201 and 202, when the divergence angle of the laser beam B is significantly larger than that of the laser beam A, and when the laser beams A and B are used. Is suitable for a total output of 5 [kW] or less.

FIG. 2 shows a welding state of the workpiece 94 by the laser processing apparatus 10. FIG. 2 [1] is a plan view and FIG.
[2] is a vertical sectional view taken along line II-II in FIG. 2 [1].
The operation of the laser processing apparatus 10 will be described below with reference to FIGS. 1 and 2.

The laser beams A and B travel on the workpiece 94 in the direction of arrow 26. A keyhole 941 is formed in a portion irradiated with the laser beams A and B, and a welding bead 9 is formed in a portion already irradiated with the laser beams A and B.
42 is formed.

The laser beams A and B are applied to the workpiece 94 while the optical axes Aa and Ba are aligned. Therefore, even if the position of the workpiece 94 changes, the laser beams A and B are not separated. Further, since the positional relationship between the laser beams A and B on the workpiece 94 has no directivity, the melting depth does not change depending on the moving direction. Further, since the positions of the focal points Af and Bf of the laser beams A and B are different, the two focal points Af and Bf are arranged on one optical axis Aa and Ba.
Is formed, a deeper melting depth is obtained. Therefore, a good welding state is maintained even during high-speed welding.
The positions of the focal points Af and Bf are not limited to the shallow focal point Af and the deep focal point Bf as shown in the figure, and the focal point Af may be deep and the focal point Bf may be shallow, as shown in FIG. Good.

FIG. 3 is a block diagram showing a second embodiment of the laser processing apparatus according to the present invention. Hereinafter, description will be given with reference to this drawing. However, the same parts as those in FIG.

The laser processing apparatus 30 of the present embodiment includes laser resonators 12A and 12 for generating laser beams A and B, respectively.
B, a beam mixing means 14 for mixing the laser beams A, B generated from the laser resonators 12A, 12B by matching the optical axes Aa, Ba, and the laser beams A, B mixed by the beam mixing means 14. Beam irradiation means 16 for irradiating the workpiece 94 with the laser beam A and the focal points Af of the laser beams A and B.
Focus position changing means 2 capable of freely moving Bf
0 and 32 are provided.

The focus position changing means 32 is a deformable mirror 3.
21 and is provided between the return light reflection film-attached mirror 22A and the beam mixing means 14. The laser beam A that has passed through the mirror 22A with the return light reflection film is reflected by the deformable mirror 321 and then advances to the beam mixing means 14.
With the deformable mirror 321, the focal point A of the laser beam A is
The position of f can be set arbitrarily. Also, the beam mixing means 1
A reflecting mirror 34 is provided between the beam irradiation unit 4 and the beam irradiation unit 16.

Since the laser processing apparatus 30 has the focus position changing means 20 consisting of the two deformable mirrors 201 and 202, when the divergence angle of the laser beam B is significantly larger than that of the laser beam A and when the laser beams A and B are used. Is suitable for a total output of 5 [kW] or more.

FIG. 4 is a block diagram showing a third embodiment of the laser processing apparatus according to the present invention. Hereinafter, description will be given with reference to this drawing. However, the same parts as those in FIG. 1 and FIG.

The laser processing apparatus 40 of this embodiment includes laser resonators 12A and 12 for generating laser beams A and B, respectively.
B, a beam mixing means 14 for mixing the laser beams A, B generated from the laser resonators 12A, 12B by matching the optical axes Aa, Ba, and the laser beams A, B mixed by the beam mixing means 14. Beam irradiation means 16 for irradiating the workpiece 94 with the laser beam A and the focal points Af of the laser beams A and B.
Focus position changing means 3 capable of freely moving Bf
2 and 42 are provided.

The focal position changing means 42 is the deformable mirror 4
21 and is provided together with the reflecting mirror 44 between the mirror 22B with the return light reflection film and the beam mixing means 14. The laser beam B that has passed through the mirror 22B with the returning light reflection film is reflected by the reflecting mirror 44, and then is deformed.
It reflects at 21, and then proceeds to the beam mixing means 14. The position of the focal point Bf of the laser beam B can be arbitrarily set by the deformable mirror 421.

The laser processing apparatus 40 includes a deformable mirror 32.
Focus position changing means 32 and deformable mirror 42
Since the focal position changing means 42 consisting of 1 is provided, it is suitable when the divergence angle of the laser beams A and B is relatively small and when the total output of the laser beams A and B is 5 [kW] or more.

FIG. 5 is a block diagram showing a fourth embodiment of the laser processing apparatus according to the present invention. Hereinafter, description will be given with reference to this drawing. However, the same parts as those in FIG. 1 and FIG.

The laser processing apparatus 50 of the present embodiment has laser resonators 12A and 12A for generating laser beams A and B, respectively.
B, a beam mixing means 14 for mixing the laser beams A, B generated from the laser resonators 12A, 12B by matching the optical axes Aa, Ba, and the laser beams A, B mixed by the beam mixing means 14. Beam irradiation means 16 for irradiating the workpiece 94 with the laser beam A and the focal points Af of the laser beams A and B.
Focus position changing means 1 capable of freely moving Bf
8 and 42.

The laser processing apparatus 50 comprises a deformable mirror 18
Focus position changing means 18 and deformable mirror 321
Focal position changing means 32 and deformable mirror 421
Since the focal position changing means 42 is composed of, it is suitable when the divergence angle of the laser beams A and B is relatively small and when the total output of the laser beams A and B is 5 [kW] or less.

FIG. 6 is a block diagram showing a fifth embodiment of the laser processing apparatus according to the present invention. Hereinafter, description will be given with reference to this drawing. However, the same parts as those in FIG. 1 and FIG.

The laser processing apparatus 60 of the present embodiment includes laser resonators 12A and 12 for generating laser beams A and B, respectively.
B, a beam mixing means 14 for mixing the laser beams A, B generated from the laser resonators 12A, 12B by matching the optical axes Aa, Ba, and the laser beams A, B mixed by the beam mixing means 14. Beam irradiation means 16 for irradiating the workpiece 94 with the laser beam A and the focal points Af of the laser beams A and B.
Focus position changing means 2 capable of freely moving Bf
0 and 62.

The focal position changing means 62 is a deformable mirror 6
21, 622, and a mirror 22A with a return light reflection film
And the beam mixing means 14. The laser beam A transmitted through the mirror 22A with the return light reflection film is
After being reflected by the deformable mirror 621, the deformable mirror 622
And then proceeds to the beam mixing means 14. The deformable mirrors 621 and 622 allow the focal point A of the laser beam A to be changed.
The position of f can be set arbitrarily.

The laser processing apparatus 50 includes a deformable mirror 20.
Since the focus position changing means 20 composed of 1,202 and the focus position changing means 62 composed of the deformable mirrors 621 and 622 are provided, when the divergence angles of the laser beams A and B are both relatively large, and the laser beams A and B Total output of 5
It is suitable for the case of [kW] or more.

FIG. 7 is a partial block diagram showing a sixth embodiment of the laser processing apparatus according to the present invention. Hereinafter, description will be given with reference to this drawing. However, the same parts as those in FIG.

The laser processing apparatus of this embodiment is characterized by the beam mixing means 74. The beam mixing unit 74 detects the dichroic mirror 141 that transmits the laser beam A and reflects the laser beam B, the dust-proof housing 142 that houses the dichroic mirror 141, and the laser beam B that slightly transmits the dichroic mirror 141. And a photodetector 741.

The irradiation surface S1 of the laser beam B of the dichroic mirror 141 is provided with a coating that transmits the laser beam A (carbon dioxide gas laser) and reflects the laser beam B (YAG laser). The irradiation surface S2 of the dichroic mirror 141 irradiated with the laser beam A is provided with a coating that allows the laser beam A to pass therethrough. However, since there is no coating that totally reflects the YAG laser by 100%, the laser beam B slightly passes through the dichroic mirror 141. Therefore,
In the beam mixing means 74, the dichroic mirror 141
By providing the photodetector 741 that detects the laser beam B that has passed through, the deterioration or damage of the dichroic mirror 141 is detected. That is, if the laser beam B detected by the photodetector 741 is abnormal, it can be determined that the dichroic mirror 141 is deteriorated or damaged.

FIG. 8 is a schematic view showing the focal position of the laser beam in the laser processing apparatus according to the present invention.
[1] is the first example, FIG. 8 [2] is the second example, FIG. 8 [3] is the third example, and FIG. 8 [4] is the fourth example. Hereinafter, description will be given with reference to this drawing. However, the same parts as those in FIG.

The focal points Af and Bf of the laser beams A and B are
Other than the one shown in FIG. 2, the following positional relationship can be taken.
In the first example of FIG. 8 [1], both the focal points Af and Bf are on the processed surface 940. The second example in FIG. 8 [2] is the focus A.
Both f and Bf are outside the processed surface 940. Figure 8
In the third example of [3], one focus Af is on the processed surface 940 and the other focus Bf is on the processed surface 940. In the fourth example of FIG. 8 [4], one focus Af is the processed surface 940.
It is on the top and the other focus Bf is in the surface 940 to be processed.

In the example of FIG. 2, both the focal points Af and Bf are within the surface 940 to be processed. Although not shown, the focal points Af and Bf
One is inside the work surface 940 and the other is the work surface 940
It may be outside. In the drawing, the focus Af,
The position of Bf may be reversed.

Needless to say, the present invention is not limited to the above embodiment. For example, the laser beam is not limited to the carbon dioxide laser and the YAG laser, and the number may be three or more. The focal position changing means can also be configured by a lens or the like.

[0045]

According to the laser processing apparatus according to claim 1 to 4, wherein, according to the present invention, by providing a beam mixing means such as mixing to match the optical axis for a plurality of laser beams, light of a plurality of laser beams It is possible to irradiate the work piece with the axes aligned. Therefore, it is possible to prevent the plurality of laser beams from being split due to the change in the position of the workpiece. Further, since the laser beams have no directional relationship with each other, it is possible to prevent the melting depth from changing depending on the moving direction.

In addition to this, by providing the focal position changing means capable of moving the focal position of the laser beam freely, a desired melting depth can be obtained.

According to the laser processing apparatus of the third aspect,
Slightly a dichroic mirror as a beam mixing means
Equipped with a photodetector to detect the laser beam passing through
Thus, deterioration and damage of the dichroic mirror can be detected.

According to the laser processing apparatus of the fourth aspect,
By making the focal positions of the plurality of laser beams different from each other by the focal position changing means, a deeper melting depth can be obtained. Therefore, it is possible to prevent the melting depth from becoming shallow due to the high speed movement of the laser beam.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a laser processing apparatus according to the present invention.

2 shows a welding state of a workpiece by the laser processing apparatus of FIG. 1, FIG. 2 [1] is a plan view, and FIG. 2 [2] is FIG.
FIG. 2 is a vertical sectional view taken along line II-II in [1].

FIG. 3 is a configuration diagram showing a second embodiment of a laser processing apparatus according to the present invention.

FIG. 4 is a configuration diagram showing a third embodiment of a laser processing apparatus according to the present invention.

FIG. 5 is a configuration diagram showing a fourth embodiment of a laser processing apparatus according to the present invention.

FIG. 6 is a configuration diagram showing a fifth embodiment of a laser processing apparatus according to the present invention.

FIG. 7 is a partial configuration diagram showing a sixth embodiment of the laser processing apparatus according to the present invention.

FIG. 8 is a schematic view showing a focus position of a laser beam in a laser processing apparatus according to the present invention, FIG. 8 [1] being a first example, FIG. 8 [2] being a second example, and FIG. 8 [3] being Third example, FIG.
[4] is the fourth example.

FIG. 9 is an explanatory diagram showing a problem of a conventional laser processing apparatus.

[Explanation of symbols] 10, 30, 40, 50, 60 Laser processing equipment 12A, 12B laser resonator 14,70 Beam mixing means 16 beam irradiation means 18, 20, 32, 42, 62 Focus position changing means 94 Workpiece A, B laser beam Aa, Ba Optical axis of laser beam Af, Bf Laser beam focus

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B23K 26/00-26/42

Claims (4)

(57) [Claims] 1. A plurality of lasers for generating a laser beam
A resonator, Multiple laser beams generated from these laser cavities
A beam mixing means for matching and mixing the optical axes with respect toThe laser of at least one of the plurality of laser resonators
Provided between the resonator and the beam mixing means, the rest
Of the laser beam generated from the laser cavity of
From the at least one laser resonator for
Freely move the relative focus position of the generated laser beam
First focus position changing means that enables, Processing the laser beam mixed by this beam mixing means
Beam irradiation means for irradiating an object,Focal position of the laser beam mixed by the beam mixing means
Gap sensor for detecting the positional deviation between the workpiece and the workpiece.
And Provided between the beam mixing means and the beam irradiation means
Based on the positional deviation data from the gap sensor.
Of the laser beam mixed by the beam mixing means.
A second focus position variable hand that can freely move the focus position
Dan, Laser processing equipment equipped with. 2.Multiple lasers that generate a laser beam
A resonator, Multiple laser beams generated from these laser cavities
A beam mixing means for matching and mixing the optical axes with respect to Between the beam mixing means and the plurality of laser resonators
Are provided, and the focus positions of the plurality of laser beams are respectively set.
A plurality of focal position changing means that can be freely moved, Processing the laser beam mixed by the beam mixing means
Beam irradiation means for irradiating an object, Laser processing equipment equipped with. 3.The plurality of laser beams are first and second
Consists of a laser beam of The beam mixing means is A first irradiation surface irradiated with the first laser beam,
A second irradiation surface on which the second laser beam is irradiated,
And has the first laser beam reflected by the first irradiation surface.
The second laser beam on the second irradiation surface.
A dichroic mirror to transmit, A dustproof housing that houses this dichroic mirror, The first laser beam slightly passing through the first irradiation surface.
With a photodetector for detecting the dome, The laser processing apparatus according to claim 1. 4.The plurality of laser beams are lasers with short wavelengths.
Laser beam and a laser beam with a long wavelength, The focus of the short wavelength laser beam on the workpiece
The point position is the work piece of the laser beam having the long wavelength.
Deeper than the focus position for The laser processing apparatus according to claim 1, 2 or 3.