JPS5881586A - Laser working device - Google Patents

Abstract

PURPOSE:To apply sound welding despite the presance of minor gaps in the fayed surfaces of the work by oscillating a member provided over the optical path for laser light thereby moving the irradiating end of the laser light zigzag. CONSTITUTION:An electromagnet 18 is excited with an exciting coil 18a to generate magnetic lines phi of force indicated by broken lines between electrodes. When electric current I is conducted in an arrow direction to conductive springs 16a, 16b installed so as to cross the magnetic lines phi of force, the couple P acts upon the springs 16a, 16b respectively in the arrow direction. The couple is proportional to the current I and the angels phi of displacements of the springs 16a, 16b by the couple P are proportional to the couple P. Therefore the reflected light 2a of laser light 2 displaces accurately to the reflected light 2a shown by the broken lines in proportion to the current I. Thereupon, when the current I is changed periodically with an oscillator 20, the laser light 2 can be oscillated in follow up to said change.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a laser processing apparatus for welding a workpiece by condensing laser light and irradiating it onto a workpiece.

TECHNICAL BACKGROUND OF THE INVENTION As is well known, laser light has extremely good directionality and high energy density, so it is used as a heat source for processing such as laser gas cutting and welding. Laser light emitted from a laser oscillation device irradiates a workpiece using a reflecting mirror, a condensing lens, or the like. FIG. 1 shows such a laser processing device, in which a laser beam (2) emitted from a laser oscillation device w (1) is transmitted to a reflecting mirror (3), a vertically movable reflecting mirror (4), and this reflecting mirror ( Reflector (5) movable horizontally relative to 4)
The optical path is changed by , and the light is focused by a condenser lens (6) and irradiated onto the workpiece (7). At this time, the reflecting mirror (3
), (4), (5) and the condenser lens (6) are laser beams (2
), a protective case (8) with holes necessary for the passage of (
9), 00), and α1). Also, the laser optical path A-)B, C→D, E-+F.

In G-+H, the part that does not move in the axial direction is the metal pipe Q3, and the part that moves is the metal elastic cone or telescopic pipe side, α (A), (15+) to protect the worker and surrounding objects. .

Laser welding is a process in which metal is melted and welded using the high-density energy of laser light using such a laser processing device. Laser welding uses a laser beam with a diameter of 0.
．． Since the irradiation is focused in about 5 motions, the energy density is extremely high, the area of heat influence in the welding area is small, and there is almost no thermal deformation, making it possible to weld with high precision and an excellent appearance. Since the irradiation is concentrated, if there is a gap in the joint surface (7a) of the workpiece (7), a part of the laser beam will pass through the work surface, causing poor fusion and preventing normal joining. It may not be done. Therefore, while laser welding has the advantage of being able to obtain high-precision vertical joints, it also has the disadvantage of requiring a high-precision finish on the workpiece, and is technically and cost-effective. However, there were many drawbacks that often hindered its application.

Purpose of the Invention The present invention has been made in view of the above-mentioned drawbacks, and is a laser processing method that allows sound welding to be performed without causing defects such as poor fusion even if there are some gaps on the joint surfaces of workpieces. The purpose is to provide equipment.

SUMMARY OF THE INVENTION Namely, the present invention utilizes reflections in the middle of the laser optical path.
Or, by giving a slight vibration to the condensing lens and moving the irradiated end of the laser beam in a zigzag direction while swinging it in a direction perpendicular to the welding line, welding is performed while ignoring the gear lug that exists on the joint surface of the workpiece. It was made so that it could be done.

Embodiment of the Invention An embodiment of the present invention will be described below as shown in the drawings. Figures 2 and 3 show the reflector (5) in the optical path of the laser beam.
It is a reflective device that attaches to the Conductive springs (16a) and (16b) are respectively engaged with the upper and lower ends of the reflector (5), and both ends of the conductive springs (16a) and (16b) are connected to the fixed bases α on both sides.
An electromagnet Qal is fixed at η and has electrodes facing each other with conductive springs (16a) and (16b) sandwiched therebetween at right angles. Furthermore, one end of the conductive springs (16a) and (16b) is connected to the oscillator (2 (l) via a conductive wire (In), and the other end is connected to the oscillator (2 (l) via a conductive wire (19a). (18a) always generates lines of magnetic force φ shown by broken lines between the electrodes.

Next, the effect will be explained. Conductive springs (16a), (16b
) are installed to cross the lines of magnetic force φ, so when the current I flows in the direction of the arrow in the conductive springs (16a) and (16b), the conductive springs (16a) and (16b) flow in the direction of the arrow, respectively. Couple P acts. This couple P is the current I
The displacement angle θ due to the force couple P is proportional to the conductive spring (16a)
, (x6b) is proportional to the force couple P. The reflected light (2a) of this useless laser light (2) is accurately displaced to reflected light (2b) shown by a broken line in proportion to the electric current. Therefore, if the current (2) is periodically varied by the oscillator (2[), the laser light (2) can be made to follow it and vibrate. Note that since the laser beam itself is not affected by the magnetic field, the path of the laser beam will not become unstable.

The feeding speed of the laser beam in laser welding varies depending on the welding conditions, but for example, in the case of a steel plate about 3 mm thick, it is about 1
~3m/. In reality, the common welding method is to fix the ln position of the laser beam and move the workpiece, and the allowable gap between the joint surfaces of the workpiece is 0.
．． 3mm or less is required. If the reflection device of the present invention is used, the allowable gap can be further relaxed.

For example, if the allowable clearance is expanded to 0.5, the joint surface (7
Since it is sufficient to swing the laser beam (2) by the width of the gap existing in a), the amplitude is set to 0.5+u. On the other hand, although the feed speed needs to be delayed by the amount of vibration of the laser beam, the vibration frequency of the laser beam (2) may be increased accordingly.

For example, as shown in Figure 4, if the vibration frequency of the irradiation end of the laser beam (2) is F, the time it takes for the laser beam (2) to return to the same welding line again is 2Fsec, and during this time the laser beam The irradiation position (2a) in (2) is shifted by S.

If the diameter of the laser beam (2) is D, and the relative moving speed between the laser beam (2) and the workpiece is (■), then the amount of movement S is (2). For example, if the proper welding condition is to keep the movement amount S per period υ to less than 1 of the laser beam diameter, then the vibration frequency F can be determined as follows.

S≦0.1D 2F≦0. ID ■ F≧0.2− In other words, applying the precedent 16.7 F≧0.2 cold surface: 6.7 (Hz).

Generally, laser processing is sensitive to welding gaps, so it is necessary to maintain the welding gap within a certain amount for all welding lines, but the laser processing device of the present invention is insensitive to welding gaps, and the workpiece There is no problem even if the finishing accuracy of the object is made rough. Therefore, the finishing accuracy of the workpiece can be improved technically and economically. For example, in conventional laser welding, when a disc-shaped workpiece (7a) is placed in a circular hole of a workpiece (7b) and welded on the circumference as shown in Fig. 5, the gap G is uniform throughout the circumference. However, according to the present invention, it is possible to provide a margin for the gap G, which not only makes it possible to roughen the accuracy of the machined surface, but also facilitates the setup work during machining. The time can also be significantly reduced.

Furthermore, in laser welding, a welding rod is generally not used, and if the gap G at the joint is too large, a dent (7c) may occur as shown in FIG. 6, resulting in a defect. In such a case, as shown in FIG. 7, a welding rod (21) is placed horizontally on the welding line in advance, and the welding rod (21) is melted by the laser processing apparatus of the present invention to eliminate the dent (7c).

In the above embodiment, the reflecting mirror (5) was vibrated, but the same effect can be obtained by vibrating the condenser lens (6) in another embodiment. A conductive spring (16a) crosses the magnetic field through the condensing lens (6).
), (16b), and conductive springs (lf]a), (1
The direction of the optical axis of the condenser lens (6) may be controlled by controlling the current value passing through the condenser lens (6b). Further, if the reflecting mirror (5) or the condensing lens (6) is light, a permanent magnet may be used instead of the electromagnet.

Effects of the Invention As described above, according to the present invention, a member such as a reflecting mirror or a condensing lens in the optical path of the laser beam emitted from the laser oscillation device in a laser processing device is swung to zigzag the irradiation end of the laser beam. As a result, even if there is a slight gap on the joint surface of the workpiece, sound welding can be performed without causing poor fusion, etc., and the accuracy of the joint surface can be made coarser, making it easier to weld during machining. It has excellent effects such as making setup work easier and significantly reducing work time.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view showing a conventional laser processing device, Fig. 2 is a front view showing main parts of an embodiment of the laser processing device of the present invention, Fig. 3 is a right side view, and Fig. 4 is a laser processing device. FIG. 5 is a plan view showing the moving state of the light irradiation end; FIG. 5 is a plan view showing the welding gap; FIG. 6 is a longitudinal sectional view showing the welding state of the workpiece; FIG.
The figure is a vertical cross-sectional view of main parts showing another embodiment. (1)... Laser oscillation device (2)... Laser light (3
), (4), (5)...Reflector (6)...Condensing lens (force...Workpiece (16a), (1
6b)...Conductive spring (17)...Fixing base
(18... Electromagnet bite... Oscillator agent Patent attorney Inoue - Male Figure 1 Figure 2 Figure 3/d Figure 4 Figure 5

Claims (1)

[Scope of Claims] 1. In a laser processing device that processes a workpiece by irradiating it with a laser beam emitted from a laser oscillation device through an optical path, a member on the optical path is swung to direct the irradiation end of the laser beam. A laser processing device characterized by moving in a zigzag pattern. 2. A reflecting mirror on the optical path of the laser beam is supported by a conductive spring that crosses a magnetic field, and a current value passing through the conductive spring is controlled to give vibration or angle change to the reflecting mirror. A laser processing device according to scope 1. 3. A patent claim characterized in that a condensing lens on the optical path of the laser beam is supported by a conductive spring that crosses the magnetic field, and the direction of the optical axis of the condensing lens is controlled by controlling the current value passing through the conductive spring. The laser processing device according to the range 1 above. 4. The laser processing apparatus according to claim 1, wherein the welding rod is supplied onto the welding line of the workpiece to perform welding.