JPH02142693A - Beam scanning device - Google Patents

Abstract

PURPOSE:To obtain the advantage of scanning at all times even if the direction of a processing line changes by providing a head part which oscillates a laser beam in the direction intersecting with the processing line and a rotational driving part which rotates the head part around the optical axis. CONSTITUTION:The eccentric motion of an eccentric shaft 6 is generated by driving of a motor 7, by which a cam shaft 5, a lens mount 4 and a condensing lens 2 are oscillated. The focal position of the incident laser beam 1 to the lens 2 oscillates with respect to a work 3. The head part 18 is rotated in order to correct the scanning direction always in a perpendicular direction according to a change in the processing line. A motor 17 is driven to rotate a revolving cylinder 13 and a support rest part 12 via a gear 16, a toothed belt 15 and a gear 14. A mount support 11 is rotated by this rotation by which the head 18 is rotated. The processing line 8 is detected by a sensor and the motor 17 is rotated at a prescribed angle by the signal thereof to rotate the head part. The advantage of the scanning of the laser beam is obtd. in this way.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a laser beam processing device that processes a workpiece by scanning it with a laser beam, and more particularly relates to a beam scanning device that swings a laser beam in a direction transverse to a processing line.

[Conventional technology]

2. Description of the Related Art Laser beam processing devices that process a workpiece by scanning it with a laser beam are used in various fields. Beam scanning devices are also used that do not simply scan a laser beam linearly, but oscillate the laser beam with respect to the processing line, so as to scan in a zigzag manner. FIG. 3 shows a conventional example of a lens scanning type beam scanning device in which the laser beam is caused to swing by reciprocating a lens for focusing the laser beam. A laser beam 1 is focused onto a workpiece 3 by a condenser lens 2 . The condensing lens 2 is fixed to a lens mount 4, which is connected to a camshaft 5, and the camshaft 5 is in contact with an eccentric shaft 6. The wound shaft 6 is configured to be rotated by a motor 7. Therefore, in order to swing the laser beam 1 (hereinafter referred to as scanning), the motor 7 is first driven to rotate the eccentric shaft 6, thereby swinging the camshaft 5 in the left-right direction in the drawing. As the camshaft 5 swings, the lens mount 4 and the condenser lens 2 also swing in the same direction. When the laser beam 1 is incident on the oscillating condenser lens 2, the laser beam 1 also oscillates in the same direction as the oscillation of the condenser lens 2. By swinging the laser beam 1 in this manner, the following technical advantages are produced. That is, in the case of a laser beam that is normally scanned in a straight line, the laser beam is focused on a minute spot, so for example, as shown in FIG. is very sensitive to errors in the gap G and weld line, and in order to perform sufficient welding even with gaps G and errors, the accuracy of the workpiece 3 and the jig that handles the workpiece 3 must be adjusted. It needs to be expensive. Therefore, by swinging the laser beam and scanning the laser beam in a so-called zigzag manner with respect to the processing line as described above, it is possible to widen the molten pool 10 in the welding 9 processing, for example, as shown in FIG. 4(b). Gap of butt G
Even if there is an error in the welding line or the welding line, sufficient welding 9 can be performed. For example, when the laser beam is oscillated with a width of 1.5 mm, ■ the thickness of the workpiece to be welded is 1 fi, and 0
Welding is possible even if there is a butt gap of 6+s+a. ■Fusion failure will not occur even if there is an error in the aim of the laser beam, that is, the focal point, being shifted by 0.75 m from the welding line.

[Problem to be solved by the invention]

However, in the conventional beam scanning apparatus as described above, the swinging direction of the laser beam, that is, the scanning direction is fixed in one direction, making it difficult to cope with changes in the direction of the processing line. For example, when the processing line 8 has a welding line as shown in FIG. 4(e), the direction of the processing line 8 is 90°.
If the gap changes, the advantages (1) and (2) of scanning are completely lost, and for example, when welding a workpiece with a large butt gap, there is a problem that welding becomes impossible. The present invention was made to solve the above-mentioned problems, and aims to provide a beam scanning device that does not always lose the advantage of scanning even if the direction of the processing line changes.

[Means to solve the problem]

A beam scanning device C according to the present invention includes a head portion having a mechanism for swinging (scanning) a laser beam irradiated onto a processing line of a workpiece in a direction transverse to the processing line, It is equipped with a rotation drive unit that rotates the beam along the optical axis.

[For production]

The head part, which has a mechanism for swinging the laser beam by the reciprocating movement of the lens or the oscillating movement of the pend mirror, is equipped with a rotary drive part that rotates the head part along the optical axis of the lens, making it possible to perform complex processing in which the direction of the processing line changes. Even for a workpiece that has a processing line, the swing motion of the laser beam irradiated from the head section can always be corrected so that it is perpendicular to the processing line, and the advantages of scanning can always be obtained. .

【Example】

An embodiment of the beam scanning device of the present invention is shown in FIG. A laser beam 1 is focused onto a workpiece 3 by a condenser lens 2 . The condensing lens 2 is fixed by a lens mount 4, and a camshaft 5 is connected to this lens mount 4. The other end of the camshaft 5 is in contact with an eccentric shaft 6, and the eccentric shaft 6 is rotated by a motor 7. The lens mount 4 is housed within a mount support 11 and is configured to swing in one direction with respect to the mount support 11. The mount support 11 is received by a support receiving part 12, and this support receiving part 12 is fixed to the lower end of a rotary cylinder 13 existing around the laser beam 1. A gear 14 is formed at the upper end of the rotating cylinder 13.
A toothed belt 15 is wound around the toothed belt 1.
5 is wound around another gear 16, which is directly connected to another motor 17. In addition, rotation @13
is supported by a fixed cylinder 19. The operation of this embodiment will be explained below. The drive of the motor 7 causes eccentric movement of the eccentric shaft 6, causing the camshaft 5, lens mount 4, and condensing lens 2 to swing. The focal position of the laser beam 1 incident on the moving condensing lens 2 swings relative to the workpiece 3. In order to correct this swinging direction, that is, the scanning direction so that it is always perpendicular to the machining line according to changes in the machining line of the workpiece 3, the motor 7, the eccentric shaft 6, the camshaft 5,
, a lens mount) 4, an optical lens 2, and a mount support 11. This rotation first drives the motor 17, the gear 16, the toothed bell I-15,
and rotation via the gear 14 [13 and the support holder are part 1
Rotate 2. This rotation causes the mount support 11 to
rotates, and thus the head portion 18 rotates. The head portion 18 is rotated by detecting the processing line 8 by a sensor (not shown) and rotating the motor 17 by a predetermined angle based on this detection signal. This sensor may be one that mechanically contacts and traces the processing line 8, or one that recognizes the image of the processing line 8 using an optical sensor and detects the processing line 8. According to the embodiment of the present invention as described above, the head swings and irradiates the laser beam in a direction perpendicular to the processing line of the workpiece by swinging and interlocking the condensing lens on which the laser beam is focused. Since the part is rotated around the optical axis by the rotary drive part, it is always perpendicular to the machining line 8 with a complicated shape, such as a machining line 8 with a shape where the machining direction changes by 90 degrees as shown in Fig. 2. It is possible to irradiate with a laser beam scanned in the direction. Therefore, when the direction of the processing line 8 in conventional welding work changes by 90 degrees, when the swinging direction of the laser beam is fixed in one direction, the processing line 8 in one direction as shown in FIG. 4(b)
However, for the processing line 8 in the same direction as the scanning direction of the laser beam, the same advantages as in the conventional case without scanning shown in FIG. 4(&) can be achieved. As a result, it is possible to completely eliminate the problem of not being able to widen the welded area and absorb errors in the butt of the workpiece or weld line, which is the original advantage of scanning. In the above embodiments, a lens scanning type beam scanning device in which the focusing lens 2 for focusing the laser beam 1 is oscillated in a direction perpendicular to the processing line 8 has been described as an example, but other embodiments may also be used. , a mirror scanning type beam scanning device (
This invention is still practicable even in this case. This second embodiment is shown in FIG. Note that the same parts as in FIG. 1 showing the first embodiment are given the same numbers and redundant explanation will be omitted. That is, in the rotary cylinder 13 there are bend mirrors 21, 22, 23, 2 that bend the optical axis of the laser beam 1 into a U-shape.
4 are provided. The last mirror 24 is the scanner 25
As a result, the laser beam 1 swings in a direction perpendicular to the processing line. The incident axis of the laser beam 1 coincides with the rotation axis of the rotating cylinder 13,
Further, in a neutral position where the last bend mirror 24 is not oscillated, the opposite axis of the laser beam 1 also coincides with the rotation axis of the rotary cylinder 13. As a result, the rotating cylinder 13
By rotating the entire unit, it is possible to correct the swinging direction of the bend mirror 24 so that it is always perpendicular to the processing line. In the above two embodiments, the rotational driving force of the motor 17 is transmitted by a belt drive system using a toothed belt 15, but in other embodiments, a gear drive system is used in which gears are used instead of the toothed belt. It is also possible to do this. [Effects of the Invention] As explained above, according to the beam scanning device of the present invention, by rotating the head section around the optical axis by the rotary drive section, it is possible to scan a workpiece having a processing line with a complicated shape. Also, the laser beam can always be oscillated (scanned) in a direction perpendicular to the processing line.
Even if there is a change in the direction of the processing line during processing, the advantage of laser beam scanning can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the overall outline of the laser beam scanning device of the present invention, FIG. 2 is a diagram showing the locus of the laser beam oscillated by the device in FIG. 1, and FIG. 3 is a conventional laser beam scanning device. Figure 4 (h) is a schematic explanatory diagram of workpieces welded together using a laser beam scanning device, and Figure 4 (b) is a welding process using a laser beam without using a laser beam scanning device. A schematic explanatory diagram of the case, Fig. 4 (C) is the third
FIG. 5 is a cross-sectional view showing the outline of the entire device showing a second embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Laser beam, 2... Condensing lens, 3... Workpiece, 4... Lens mount, 5... Camshaft, 6... Eccentric shaft, 7... Motor, 11 ...Mount support, 12...Support receiver is part, 13...Cylindrical shaft, 14...Gear, 15...Toothed belt, 16...
...Gear, 17...Motor, 21, 22, 23, 24
...Pendomiror 25...Scanner. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] A head section having a mechanism for swinging a laser beam irradiated onto a processing line of a workpiece in a direction crossing the processing line, and a rotation drive section for rotating the head section around an optical axis of the laser beam. Beam scanning device equipped with.