JP2000263270A - Optical system for laser beam machining device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laser beam machining device which is small sized, inexpensive and capable of cutting to a shape suitable for welding and then welding. SOLUTION: An optical path switching optical system 12 is mounted to a YAG laser beam device 1, a laser beam is made incident on a focusing lens 13a or 13b. The laser beam made incident on the focusing lens 13a is guided to a machining head through a cone angle optical system 16 and an optical fiber 14a. The laser beam made incident on a focusing lens 13 is guided to the machining head through an optical fiber 14b. As the cone optical system is functioned, the cone angle of the laser beam emitted from the machining head 15a is made smaller than the laser beam emitted from the machining head 15b, the cutting face is turned to vertical.

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, and more particularly to a laser processing apparatus for continuously cutting and welding an object to be processed.

[0002]

2. Description of the Related Art A laser processing apparatus is an apparatus that cuts, drills, or welds a workpiece using laser light. Some types of laser processing equipment use a laser beam emitted from a laser oscillator to guide the laser light to the vicinity of the object using an optical fiber and irradiate the object through a processing head attached to the emission end of the optical fiber. There are things.

By the way, in the processing of a blank material or the like, an operation of cutting an object to be processed first and then welding the cut portion is performed. Such cutting and welding can all be performed using a laser processing apparatus.

[0004] Conventionally, when an object to be processed, such as blank material processing, is cut and then the cut portion is welded, both cutting and welding are performed using a single laser processing apparatus. Alternatively, cutting and welding are performed separately using a cutting device and a laser processing device for welding. As the cutting device, a fine blanking press device, a CO ₂ gas laser device, or the like is used.

[0005]

Conventionally, when both cutting and welding are performed using one laser processing apparatus, welding requires a larger power than cutting, so that it is necessary for welding. A laser processing device having a high power is used. However, in such a laser processing apparatus, the beam cone angle or the spot diameter is large, and the shape of the cut portion is tapered as shown in FIG.
Therefore, in this method, it is difficult to perform welding by abutting two cut portions, and there is a problem that desired quality cannot be obtained.

When a cutting device and a laser processing device for welding are used, devices suitable for cutting and welding can be used. Therefore, there are problems such as when cutting and welding are performed by one laser processing device. However, there is a problem that the apparatus is large and expensive as a whole. In particular, a fine blanking press device and a CO ₂ gas laser device are expensive, and thus are not suitable for cutting a small number of various types of processing objects.

An object of the present invention is to provide a small and inexpensive laser processing apparatus capable of cutting into a shape suitable for welding and thereafter performing welding.

[0008]

According to the present invention, in a laser processing apparatus optical system for irradiating a laser beam emitted from a laser oscillator onto a workpiece, the laser beam is applied to the workpiece. A plurality of processing heads, an optical path switching unit that switches an optical path so as to selectively supply a laser beam from the laser oscillator to any one of the plurality of processing heads, the optical path switching unit, and the plurality of processing heads. An optical system for a laser processing apparatus, comprising: a beam quality improving unit that is disposed on at least one of the optical paths connecting the respective processing heads and improves the quality of the laser light.

Specifically, the beam quality improving means includes:
It is a cone angle optical system. By using the cone angle optical system, the beam cone angle and / or the minimum spot diameter of the laser beam emitted from the processing head corresponding to the optical path equipped with the cone angle optical system are irradiated from the processing head corresponding to the other optical path. Laser light to be used.

In addition, an optical fiber is used as an optical path connecting the optical path switching means and each of the plurality of processing heads.

Here, the optical fiber in which the cone angle optical system is arranged may be made thinner than other optical fibers.

In the case where each of the processing heads has a collimating lens for collimating a laser beam emitted from an optical fiber and a processing lens for condensing the laser beam collimated by the collimating lens, The focal length of the collimating lens of the processing head connected to the optical fiber on which the cone angle optical system is arranged may be longer than the collimating lenses of the other processing heads.

Further, according to the present invention, as the optical path switching means, it is possible to use a mirror for reflecting the laser light and a mirror moving means for moving the mirror into and out of the optical path.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a laser processing apparatus according to an embodiment of the present invention. The laser processing apparatus includes a YAG laser 11 that generates a laser beam, and an optical path switching optical system 12 that switches an optical path of a laser beam emitted from the YAG laser 11.
Focusing lenses 13 a and 13 b provided corresponding to a plurality of (two in this case) optical paths selected by the optical path switching optical system 12;
Optical fibers 14a, 1 provided corresponding to the
4b, processing heads 15a and 15b fixed to the tips of the optical fibers 14a and 14b, and a beam cone angle optical system 16 for improving the beam quality of the laser light from the focusing lens 13a.

The optical path switching optical system 12 has three folding mirrors 121, 122 and 123 and is directly attached to the YAG laser 11. Folding mirror 12
The laser beams 1, 122, and 123 are arranged on a straight line, and the laser light reflected by the return mirror 121 travels toward the return mirrors 122 and 123. Note that the folding mirror 122 is provided so as to be able to enter / retreat on the optical path formed by the folding mirror 121. This can be realized by, for example, rotatably supporting one side of the folding mirror 122 about a side as a rotation axis, or providing moving means for performing parallel movement. When the folding mirror 122 enters the optical path, the laser beam from the folding mirror 121 is reflected by the folding mirror 1.
The light is reflected by 22 and enters the focusing lens 13b. When the return mirror 122 is retracted from the optical path, the laser beam from the return mirror 121 reaches the return mirror 123, is reflected there, and enters the focusing lens 13a.

The processing heads 15a and 15b are provided with the collimating lenses 151a and 151b and the processing lens 1 respectively.
52a and 152b, the optical fibers 14a and 14b
Are collimated and then condensed, and radiated toward the object to be processed. The processing head 15a is used for cutting, and the processing head 15a
b is used for welding.

The cone angle optical system 16 has an opening having a predetermined diameter, and allows only the laser light incident on the opening to pass therethrough, and reflects the other laser light to limit the beam diameter. And a collimating lens 1 for collimating the laser light passing through the aperture 161
62, and a focusing lens 163 that collects the collimated laser light and makes it incident on the optical fiber 14a.

Hereinafter, the operation of the laser processing apparatus will be described.

As shown in FIG. 2, this laser processing apparatus is used in a processing line for transporting an object to be processed from a cutting station to a welding station by a conveyor or the like. It can also be used when the cutting step and the welding step are performed on separate lines.

Returning to FIG. 1, the operation for cutting a workpiece will be described. In this case, the folding mirror 12
2 is assumed to be retracted from the optical path. The retracting of the folding mirror 122 from the optical path may be performed manually, or may be performed automatically by detecting that the processing target has been transported to the cutting station.

First, the YAG laser 11 emits a laser beam toward the return mirror 121. The folding mirror 121 reflects the laser light from the YAG laser 11 to change the traveling direction of the laser light, and
Incident on The return mirror 123 reflects the laser light from the return mirror 121 and makes the laser light incident on the focusing lens 13a. Focusing lens 13a
Collects the incident laser light and emits it toward the cone angle optical system 16.

The laser beam condensed by the focusing lens 13a once converges, and then enters the cone angle optical system 16 while diverging. The aperture 161 is
It reflects a part of the diverging laser light and limits the beam diameter. The laser beam whose beam diameter is limited enters the collimator lens 162. The collimating lens 162 collimates the incident laser light (converts it into parallel light) and makes the laser light incident on the focusing lens 163. The focusing lens 163 condenses the laser light from the collimator lens 162 and makes the laser light incident on the optical fiber 14a. The optical fiber 14a propagates the laser beam incident from the focusing lens 163 and makes the laser beam incident on the processing head 15a.

In the processing head 15a, the optical fiber 14a
The laser light emitted from the tip of the collimator lens 1
51a. The collimator lens 151a collimates the incident laser light and emits the collimated laser light to the processing lens 152a. The processing lens 152a is a collimating lens 15
The incident light from 1a is condensed and irradiated on the object to be processed.

Next, a case where a workpiece is welded will be described. In this case, it is assumed that the folding mirror 122 has entered the optical path. The folding mirror 12
The evacuation from the optical path 2 may be performed manually, or may be automatically performed by detecting that the workpiece is unloaded from the cutting station or that the workpiece is transported to the welding station. It may be.

As in the case of cutting, the YAG laser 11 emits a laser beam toward the turning mirror 121. The return mirror 121 reflects the laser light from the YAG laser 11 to change the traveling direction of the laser light and makes the laser light enter the return mirror 122. The return mirror 122 reflects the laser beam from the return mirror 121 and makes the laser light incident on the focusing lens 13b. The focusing lens 13b converges the incident laser light, and
4b. The optical fiber 14b propagates the laser beam incident from the focusing lens 13b,
The light is incident on the processing head 15b.

In the processing head 15b, the optical fiber 14b
The laser light emitted from the tip of the collimator lens 1
51b. The collimating lens 151b collimates the incident laser light and emits the collimated laser light to the processing lens 152b. The processing lens 152b is a collimating lens 15
The incident light from 1b is condensed and irradiated on the object to be processed.

As described above, the laser processing apparatus shown in FIG. 1 can cut and weld a workpiece using one laser oscillator.

The difference between the case of cutting and the case of welding in the laser processing apparatus of FIG. 1 lies in whether or not the laser beam passes through the cone angle optical system 16. The cone angle optical system 16 uses an aperture 161 to reduce the beam diameter of the laser light. As a result, when the processing head 15a and the processing head 15b have the same configuration, the beam cone angle α1 of the laser light emitted from the processing head 15a is changed to the beam cone angle of the laser light emitted from the processing head 15b. It can be smaller than α2. As a result, the cut surface of the object to be processed approaches vertical, and the subsequent welding process is facilitated.

Also, the provision of the cone angle optical system 16 reduces the beam diameter of the laser light, so that the focal length f _1R of the collimator lens 151a can be made larger than the focal length f _2R of the collimator lens 151b. ,
Even if the beam cone angles α1 and α2 are equal, the minimum spot diameter d ₁ of the laser beam by the processing head 15a is changed to the minimum spot diameter d ₂ of the laser beam by the processing head 15b.
Can be smaller than Also in this case, similarly to the case where the beam cone angle is reduced, the cut surface of the object to be processed can be made nearly vertical. That is, a cut shape as shown in FIG. 3 is obtained.

Further, the provision of the cone angle optical system 16 reduces the beam diameter of the laser light, so that light can be guided to the optical fiber 14a even if the focal length f _IN of the focusing lens 163 is reduced. Optical fiber 1
The core diameter of 4a can also be reduced. Again,
Even if the processing heads 15a and 15b have the same configuration, the spot d1 can be made smaller than d2, and the cut surface of the processing object can be made nearly vertical.

As described above, in the laser processing apparatus according to the present embodiment, the cone angle, the minimum spot diameter, or both can be reduced by using the cone angle optical system 16, so that one laser Cutting and welding can be performed using an oscillator. The optical path to the processing head 15a has a larger loss than the optical path to the processing head 15b because of the existence of the cone angle optical system 16. Therefore, the output of the processing head 15a is smaller than that of the processing head 15b.

In the above embodiment, a case has been described in which laser light from one laser oscillator or the like is selectively incident on two optical fibers. However, laser light is incident on three or more optical fibers. It is also possible to make it.

[0034]

According to the present invention, laser light from one laser oscillator is selectively supplied to one of a plurality of processing heads, and the laser light is supplied to at least one optical path. By providing the means for improving the beam quality, a small and inexpensive laser processing apparatus capable of cutting in a shape suitable for welding and thereafter performing welding can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention.

FIG. 2 is a view for explaining an example of use of the laser processing apparatus of FIG. 1;

FIG. 3 is a view showing a cutting shape using the laser processing apparatus of FIG. 1;

FIG. 4 is a diagram for explaining a problem of a conventional laser processing apparatus.

[Explanation of symbols]

 Reference Signs List 11 YAG laser 12 Optical path switching optical system 13a, 13b Focusing lens 14a, 14b Optical fiber 15a, 15b Processing head 16 Beam cone angle optical system 121, 122, 123 Folding mirror 151a, 151b Collimating lens 152a, 152b Processing lens 161 Aperture collimator Lens 163 Focusing lens

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4E068 CA07 CD03 CD05 CD08 CD16 CE08 5F072 AB01 JJ01 JJ08 KK30 MM08 MM09 RR01 YY06

Claims (8)

[Claims] 1. An optical system for a laser processing apparatus for irradiating a laser beam emitted from a laser oscillator onto a workpiece, a plurality of processing heads for irradiating the laser beam onto the workpiece, and the laser oscillator. Optical path switching means for switching an optical path so as to selectively supply laser light from the plurality of processing heads to the one of the plurality of processing heads; and an optical path connecting the optical path switching means and each of the plurality of processing heads. An optical system for a laser processing apparatus, comprising: a beam quality improving unit that is arranged in at least one of the laser light sources and improves the quality of the laser light. 2. The optical system according to claim 1, wherein said beam quality improving means is a cone angle optical system. 3. A beam cone angle of a laser beam emitted from a processing head corresponding to an optical path having the cone angle optical system is larger than a beam cone angle of a laser beam emitted from a processing head corresponding to another optical path. 3. An optical system for a laser processing apparatus according to claim 2, wherein said optical system is also small. 4. The minimum spot diameter of laser light emitted from a processing head corresponding to an optical path having the cone angle optical system is smaller than the minimum spot diameter of laser light emitted from a processing head corresponding to another optical path. 3. An optical system for a laser processing apparatus according to claim 2, wherein said optical system is also small. 5. An optical system for a laser processing apparatus according to claim 1, wherein an optical fiber is used as an optical path connecting said optical path switching means and each of said plurality of processing heads. . 6. The optical system for a laser processing apparatus according to claim 5, wherein the optical fiber on which the cone angle optical system is arranged is thinner than other optical fibers. 7. The cone angle optics, wherein each of the processing heads has a collimating lens for collimating a laser beam emitted from an optical fiber, and a processing lens for condensing the laser beam collimated by the collimating lens. 6. The optical system according to claim 5, wherein the collimating lens of the processing head connected to the optical fiber in which the system is disposed has a longer focal length than the collimating lenses of the other processing heads. system. 8. The apparatus according to claim 1, wherein said optical path switching means includes a mirror for reflecting said laser light, and a mirror moving means for moving said mirror into and out of the optical path.
2, 3, 4, 5, 6 or 7 optical systems for laser processing equipment.