JPH05220592A - Spinning beam scanner - Google Patents

Abstract

PURPOSE:To minutely swing the optical axis of a laser beam by attaching an oscillating plate rotatably around two axes orthogonally crossed and connecting a reflection mirror and providing a cooling chamber for the mirror successively to the oscillating plate. CONSTITUTION:The oscillating plate 7 is supported in a gimbal-like state around a Y axis by an elastic X spindle 9 and around X axis by an elastic Y spindle. A parabolic mirror 1 is fixed on the oscillating plate 7 via a joint shaft 5. The laser beam (a) is reflected by the parabolic mirror 1 and converged into a focus (b). While the displacement of the oscillating plate 7 is detected by displacement sensors X 15 and Y 16, the plate is oscillated by electro magnets Xa 12a, etc. By rotating the oscillating plate 7 around the spindles 9, 10 of the two axes orthogonally crossed, the optical axis of the laser beam (a) is minutely swung, and thereby the compact spinning beam scanner is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spinning beam scanner for a laser welding robot, for example.

[0002]

2. Description of the Related Art FIG. 3 is a perspective view showing a conventional laser welding robot, and FIG. 4 is a conventional spinning beam system using two sets of reflecting mirrors used in this laser welding robot.
It is a principle view of a scanner (“New Welding Report” No. 24)
7, 1991-9-2). In the figure, 1 is a parabolic mirror as a reflecting mirror, 2 is a main body, 24 is a robot main body, 25 is a first reflecting mirror arranged to face the parabolic mirror 1, and 26 is a first reflecting mirror. A second reflecting mirror arranged to face the mirror 25,
Reference numeral 27 is a first motor for rotationally driving the first reflecting mirror 25, 28 is a second motor for rotationally driving the second reflecting mirror 26, and 29 is a laser oscillator connected to the main body 2.

Next, the operation of this spinning beam scanner will be described. The laser beam emitted from the laser oscillator 29 enters the main body 2 from the left side of FIG. 4, is reflected by the second reflecting mirror 26, and is further reflected by the first reflecting mirror 2.
Reflected by 5, enters the robot body 24, and the parabolic mirror 1
It is reflected by and is squeezed to focus. The first reflecting mirror 25 is attached to the axis of the first motor 27 by Δθ _a , and the second reflecting mirror 26 is attached to the axis of the second motor 28 by Δθ _b. By rotating the reflecting mirror of the motor with a motor, the laser beam becomes 4Δθ _a ,
The direction can be changed by 4Δθ _b . Reflector 25,
The swing width and swing direction of the laser beam can be controlled by changing the rotation direction and phase of 26.

[0004]

Since the spinning beam scanner of the conventional laser welding robot using the reflecting mirrors 25 and 26 facing each other has the above-described structure, (1) it is incorporated in the wrist of the robot. It is too bulky to use. (2) Since the swing width of the laser beam increases toward the hand of the robot, it is necessary to narrow down the laser beam from the laser oscillator 29, and a diaphragm mechanism for that must be provided. (3) Since the reflecting mirrors 25 and 26 rotate, and it is difficult to attach a cooling mechanism for cooling the reflecting mirrors 25 and 26 and the parabolic mirror 1 due to space problems in the parabolic mirror 1. , (4) Since the spinning beam scanner is attached to the base side of the robot, it takes time to adjust the optical axis after the scanner. (5) Parabolic surface 1 and since the reflector 25 and 26 is required, the efficiency of the laser is absorbed partially laser had a problem, decreases respectively.

The present invention has been made to solve the above problems, and an object thereof is to obtain a spinning beam scanner having a compact structure and capable of easily cooling a reflecting mirror.

[0006]

According to a first aspect of the present invention, there is provided a spinning beam scanner, comprising: a swing plate which is attached to two orthogonal support shafts and is rotatable about each support shaft.
A reflecting mirror connected to the oscillating plate and a chamber for cooling the reflecting mirror formed inside the reflecting mirror are provided.

According to a second aspect of the present invention, a spinning beam scanner is provided with two oscillating shafts which are orthogonal to each other, and oscillating plates which are rotatable around the oscillating shafts. And a reflecting mirror housed in the holder with a spacer interposed therebetween, and a chamber for cooling the reflecting mirror formed inside the reflecting mirror.

[0008]

According to the first aspect of the present invention, the optical axis of the laser beam is slightly swung by swinging the swing plate, and the reflecting mirror is cooled by supplying cooling water to the chamber. ..

According to the second aspect of the present invention, the optical axis of the laser beam is slightly swung by swinging the swing plate, and the reflecting mirror is cooled by supplying cooling water to the chamber. .. Furthermore, the optical axis can be adjusted by adjusting the thickness of the spacer.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the present invention, the case where a parabolic mirror is used as a reflecting mirror will be described below with reference to the drawings. FIG. 1 is a side view showing an embodiment of the present invention, and FIG. 2 is a plan view of an essential part of FIG. In the figure, 1 is a parabolic mirror that is a reflecting mirror, 2 is a main body that houses the parabolic mirror 1, 3 is a holder that supports the parabolic mirror 1, and 4 is a parabolic mirror 1 and a holder 3. Spacers 5 interposed between them are joint shafts, 6 is packing interposed between the main body 2 and the joint shaft 5, 7 is a swing plate connected to the joint shafts 5, and 8 is a frame that covers the swing plates 7. Body, 9 is elastic X
The support shaft 10, 10 is an elastic Y support shaft, 11a is an iron piece Xa, and 11b is an iron piece Xb, 12a arranged to face the iron piece Xa 11a.
Is an electromagnet Xa, 12 disposed above the iron piece Xa11a.
b is an electromagnet Xb arranged above the iron piece Xb11b, 1
3a is an iron piece Ya, 13b is an electromagnet Yb arranged to face the iron piece Ya13a, 14a is an electromagnet Ya arranged above the iron piece Ya13a, 14b is an electromagnet Yb arranged above the iron piece Yb13b, and Displacement sensors X and 16 are displacement sensors Y, 17 is a water-cooling chamber formed in the parabolic mirror 1, 18 is a water-cooling nozzle whose tip is oriented in the water-cooling chamber 17, and 19 is a water-cooling hose connected to the water-cooling nozzle 18. , 20 is a main body lid for closing the main body 2, 21 is a robot wrist, 22 is a nozzle, and 23 is an attachment flange for attaching the spinning beam scanner to the robot wrist 21.

A laser beam (a in the figure) emitted from a laser oscillator (not shown) is guided to the robot wrist 21 through the inside of an arm (not shown) of the robot and reflected by the parabolic mirror 1. Then, it is focused and the focus (b in the figure) is set. Since this focal point is small, when two plates are butt-welded and there is a gap between the plates, the focal point does not extend between the two plates and effective butt welding cannot be performed. Therefore, it is necessary to shake the focal point so that the focal point extends over the two plates. Spinning beam scanners are used for this purpose.

Next, the operation of the embodiment implemented as described above will be described. The parabolic mirror 1 is fitted and fixed to the holder 3 with the spacer 4 interposed therebetween. Holder 3
Is fixed to the rocking plate 7 via the joint shaft 5. The inside of the main body 2 is filled with purge air, which is an inert gas, to prevent oxidation due to heat, and is ejected from the tip of the nozzle 22. Since the packing 6 is contained between the main body 2 and the joint shaft 5, the main body 2 is kept airtight. This packing 6
Since it is made of soft rubber or the like, it does not hinder the swing of the parabolic mirror 1 described later. In addition, since the swing angle of the parabolic mirror 1 is small, airtightness is maintained even when swinging.

At the center of the oscillating plate 7, an elastic X support shaft 9 rotates about the Y axis, and an elastic Y support shaft 10 rotates about the X axis.
It is supported in a gimbal shape and is swingably suspended on the frame body 8. The oscillating plate 7 has a square shape, and part 4
On the side, iron piece Xa11a, iron piece Xb11b and iron piece Ya1
3a and iron piece Yb13b are fixed so as to face each other in pairs. Inside the frame 8, a set of two electromagnets X
a12a, electromagnet Xb12b, and electromagnet Ya14
a, electromagnet Yb14b, two iron pieces Xa each
11a, the iron piece Xb11b, and the iron piece Ya13a and the iron piece Yb13b face each other with a gap. Electromagnet Xa1
By driving 2a, the iron piece Xa11a is sucked upwards,
The swing plate 7 rotates counterclockwise, and the parabolic mirror 1 tilts to the right in FIG. As a result, the focal point b of the laser beam moves to the right. Similarly, the focus b is driven to the left by driving the electromagnet Xb12b, the focus b is moved to the back of the paper by driving the electromagnet Ya14a, and the focus b is driven by driving the electromagnet Yb14b.
Moves to the front of the page. The displacement sensor X15 and the displacement sensor Y16 detect the inclination of the oscillating plate 7 due to the above operation, and the command current to each electromagnet is feedback-controlled from an external controller (not shown). This slightly rotates the focus of the laser beam.

A water-cooled chamber 17 formed in the parabolic mirror 1.
Two water-cooling hoses 19 are connected to and supplies and discharges cooling water. Thereby, the parabolic mirror 1 is cooled efficiently. The water cooling hose 19 connects between the parabolic mirror 1 and the main body 2, but since the water cooling hose 19 is flexible,
It does not hinder the swing of the parabolic mirror 1.

The adjusting ring 4 is used for adjusting the optical axis when the present spinning beam scanner is assembled. That is, the adjusting rings 4 having different thicknesses are prepared, and by exchanging the adjusting rings 4, the focus b of the laser beam is adjusted in the left-right direction (X-axis direction) in FIG.
By rotating about the axis of, the adjustment in the depth direction (Y-axis direction) of FIG. 1 is performed. These adjustments can be easily performed by removing the main body lid 20.

If welding spatter or the like adheres to the parabolic mirror 1, the reflectivity decreases, so the parabolic mirror 1 must be frequently replaced. At this time, after removing the main body lid 20, the parabolic mirror 1 may be removed from the holder 3 and removed, and a new parabolic mirror 1 may be inserted, so that the replacement work can be performed quickly. Since the main body 2 of the spinning beam scanner is fixed to the robot wrist 21 by the mounting flange 23, it can be easily attached and detached. Therefore, it can be easily replaced with a conventional parabolic mirror that does not have a spinning beam scanner. At this time, it is not necessary to adjust the optical axis on the robot side.

Although the above embodiment shows the case where the parabolic mirror 1 is used, a reflecting mirror may be used. In this case, a convex lens is inserted before or after the reflecting mirror to focus the laser beam. Further, in the above embodiment, the electromagnet is used as the driving means, but other means such as a piezoelectric element may be used. Further, although the above-mentioned embodiment shows the case where it is applied to the welding robot, it may be applied to the laser processing machine.

[0018]

As described above, according to the first aspect of the present invention, the optical axis of the laser beam is finely swung by rotating the oscillating plate around the two orthogonal axes. Since it is rotated, a compact spinning beam
There is an effect that a scanner can be obtained. Further, the chamber formed in the reflecting mirror efficiently cools the reflecting mirror, and there is no inconvenience that the focal length of the laser beam changes due to thermal distortion of the reflecting mirror.

According to claim 2 of the present invention, in addition to the effect of claim 1, there is also an effect that the optical axis can be easily adjusted by adjusting the thickness of the spacer.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a plan view of an essential part of FIG.

FIG. 3 is a perspective view of a conventional laser welding robot.

FIG. 4 is a principle diagram of a conventional spinning beam scanner.

[Explanation of symbols]

 1 Parabolic Mirror 3 Holder 4 Spacer 7 Swing Plate 9 Elastic X Spindle 10 Elastic Y Spindle 17 Water Cooling Chamber

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[Procedure amendment]

[Submission date] May 14, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

According to a second aspect of the present invention, a spinning beam scanner is provided with swing plates which are attached to two orthogonal support shafts and are rotatable around the respective support shafts, and which are connected to the swing plates. A holder, a reflecting mirror housed in the holder with a spacer interposed therebetween, and a chamber for cooling the reflecting mirror formed inside the reflecting mirror are provided.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of the present invention, the case where a parabolic mirror is used as a reflecting mirror will be described below with reference to the drawings. FIG. 1 is a side view showing an embodiment of the present invention, and FIG. 2 is a plan view of an essential part of FIG. In the figure, 1 is a parabolic mirror that is a reflecting mirror, 2 is a main body that houses the parabolic mirror 1, 3 is a holder that supports the parabolic mirror 1, and 4 is a parabolic mirror 1 and a holder 3. Spacers 5 interposed between them are joint shafts, 6 is packing interposed between the main body 2 and the joint shaft 5, 7 is a swing plate connected to the joint shafts 5, and 8 is a frame that covers the swing plates 7. Body, 9 is elastic X
The support shaft 10, 10 is an elastic Y support shaft, 11a is an iron piece Xa, and 11b is an iron piece Xb, 12a arranged to face the iron piece Xa 11a.
Is an electromagnet Xa, 12 disposed above the iron piece Xa11a.
b is an iron piece Xb, 13 arranged above the iron piece Xb11b.
a is an iron piece Ya, 13b is an electromagnet Yb arranged facing the iron piece Ya13a, 14a is an electromagnet Ya arranged above the iron piece Ya13a, 14b is an electromagnet Yb arranged above the iron piece Yb13b, Displacement sensors X and 16 are displacement sensors Y, 17 is a water-cooling chamber formed in the parabolic mirror 1, 18 is a water-cooling nozzle whose tip is oriented in the water-cooling chamber 17, and 19 is a water-cooling hose connected to the water-cooling nozzle 18. , 20 is a main body lid for closing the main body 2, 21 is a robot wrist, 22 is a nozzle, and 23 is an attachment flange for attaching the spinning beam scanner to the robot wrist 21.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0011

[Correction method] Change

[Correction content]

A laser beam (a in the figure) emitted from a laser oscillator (not shown) is guided to the robot wrist 21 through the inside of an arm (not shown) of the robot and reflected by the parabolic mirror 1. Then, it is focused and the focus (b in the figure) is set. Since this focal point is small, when two plates are butt-welded and there is a gap between the plates, the focal point does not extend between the two plates and effective butt welding cannot be performed. Therefore, it is necessary to shake the focal point so that the focal point extends over the two plates. Spinning beam scanners are used for this purpose.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

Next, the operation of the embodiment implemented as described above will be described. The parabolic mirror 1 is fitted and fixed to the holder 3 with the spacer 4 interposed therebetween. Holder 3
Is fixed to the rocking plate 7 via the joint shaft 5. Purge air, which is an inert gas, is injected into the main body 2 to prevent oxidation due to heat, and is ejected from the tip of the nozzle 22. Since the packing 6 is contained between the main body 2 and the joint shaft 5, the main body 2 is kept airtight. Since the packing 6 is made of soft rubber or the like, it does not hinder the swing of the parabolic mirror 1 described later. In addition, since the swing angle of the parabolic mirror 1 is small, airtightness is maintained even when swinging.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

At the center of the oscillating plate 7, an elastic X support shaft 9 rotates around the X axis, and an elastic Y support shaft 10 rotates around the Y axis.
It is supported in a gimbal shape and is swingably suspended on the frame body 8. The oscillating plate 7 has a square shape, and part 4
On the side, iron piece Xa11a, iron piece Xb11b and iron piece Ya1
3a and iron piece Yb13b are fixed so as to face each other in pairs. Inside the frame 8, a set of two electromagnets X
a12a, electromagnet Xb12b, and electromagnet Ya14
a, electromagnet Yb14b, two iron pieces Xa each
11a, the iron piece Xb11b, and the iron piece Ya13a and the iron piece Yb13b face each other with a gap. Electromagnet Xa1
By driving 2a, the iron piece Xa11a is sucked upwards,
The swing plate 7 rotates counterclockwise, and the parabolic mirror 1 tilts to the right in FIG. As a result, the focal point b of the laser beam moves to the right. Similarly, the focus b is driven to the left by driving the electromagnet Xb12b, the focus b is moved to the back of the paper by driving the electromagnet Ya14a, and the focus b is driven by driving the electromagnet Yb14b.
Moves to the front of the page. The displacement sensor X15 and the displacement sensor Y16 detect the inclination of the oscillating plate 7 due to the above operation, and the command current to each electromagnet from an external controller (not shown) is feedback-controlled. This slightly rotates the focus of the laser beam.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01S 3/04

Claims (2)

[Claims] 1. A swing plate mounted on two orthogonal support shafts and rotatable about each support shaft, a reflecting mirror connected to the swing plate, and a reflection formed inside the reflecting mirror. A spinning beam scanner that includes a chamber for cooling a mirror, and swings the swing plate to slightly swing the optical axis of the laser beam. 2. A swing plate that is attached to two orthogonal support shafts and is rotatable around each support shaft, a holder connected to the swing plate, and a spacer sandwiched in the holder. And a chamber for cooling the reflecting mirror formed inside the reflecting mirror, and a spinning beam scanner for slightly swinging the optical axis of the laser beam by swinging the swinging plate. ..