JPS61154784A - Laser welding device - Google Patents

Abstract

PURPOSE:To automate the positioning of laser light by marking preliminarily a welding position, providing a reflected light detector for laser light for guiding and controlling a moving mechanism in accordance with the result of the detection thereof. CONSTITUTION:The weld point 27 of a part A to be welded is preliminarily marked with materials having different reflectivities of light. A laser welding device is provided with a laser light oscillator 12 and a laser oscillator 14 for guiding. A receiver 16 for detecting the reflected laser light is disposed to the oscillator 14. The reflected laser light is received by a light receiver 16 through a lens 21 and a mirror 18 and the power density of the reflected light is detected when the laser light for guiding is irradiated to the material to be welded. The welding position is set in the position where the powder density of the reflected light of the receiver 6 is largest by adjusting finely driving parts. The positioning is automated by the above-mentioned method.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a laser welding device. In particular, the present invention relates to a laser welding apparatus that can automatically align a laser beam to a welding position of a workpiece.

The development of optical communication technology is not only due to improvements in the quality of optical fibers, but also to a large extent due to improvements in the accuracy of various optical components. In such an optical component, it is necessary to precisely align the optical axis between the incident light side and the output light side.

Optical components usually consist of multiple optical elements, so
After position adjustment is performed to align the optical axes of the plurality of optical elements, they are fixed with adhesive. However, fixing with adhesive has low reliability against aging and heat. For this reason, instead of fixing with adhesives, a technology has been developed in which each part is fixed to metal by laser welding.

[Conventional technology]

Laser welding equipment that performs laser welding consists of a YAG laser oscillator or Cot laser oscillator that outputs the laser beam actually used for laser welding, and a device that adjusts the welding position of the workpiece to the optimal position (focus of the laser beam). It is equipped with a He-Ne laser oscillator that outputs a guiding laser beam. Before laser welding, the laser beam is guided by a guiding laser beam (the position of the optical system and the workpiece installation table is adjusted). After the adjustment of the optical system and workpiece installation table is completed, the welding laser beam is (YAG laser or C02 laser) and spot weld the welding position.

[Problems to be Solved by the Invention] In reality, the above-mentioned position adjustment is performed manually and visually.

However, the beam spot diameter of laser light is 0.3~
It is as small as 0.8 Nφ, and it is difficult to accurately adjust the position by visual inspection. Further, even if the welding position is adjusted, the welding position may shift due to variations in the dimensions of the welded object.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to enable laser welding with optical ellipse by automatically adjusting the positions of an optical system and a workpiece installation table.

[Means for solving problems]

The above-mentioned problem is solved by the workpiece installation table, the welding laser beam generator, the guide laser beam generator, and the output optical system that guides the welding laser beam and the guide laser beam to the welding position. After adjusting the welding position to the optimum position with respect to the guide laser beam, a laser welding device that performs welding by irradiating the welding laser beam onto the welding position is placed in a position where the welding position is in the vicinity of the surrounding light. a moving mechanism for moving the workpiece installation table, a moving mechanism for moving the output optical system, and a moving mechanism for moving the welding object installation table, and a moving mechanism for moving the welding object installation table; A photodetector that outputs a power density, and a control means that controls the moving mechanism to irradiate the guide laser beam at the welding position at an optimal position based on the detection result of the photodetector. This is solved by

[Effect]

With the above configuration, the power density of the guiding laser beam becomes maximum or minimum when it is irradiated to the welding position of the workpiece, so by sequentially comparing the power densities and controlling the moving mechanism, the optical It is possible to align the system and the workpiece installation table.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings. The first is a perspective view showing an embodiment of the laser welding apparatus of the present invention, and FIG. 2 (al is a front view of the optical system alignment mechanism, and FIG. 2(b) is a main perspective view.

The rotary drive section 1 rotates the support section 1' of the optical system 2, 3.2', 3' in the 0 direction.

Further, the rotary drive section 1 is driven by a rail 5 and a linear drive section 4. That is, the support portion 1' is driven in the X direction in the figure. Further, the optical system 2.3 is driven in four directions in the figure by the rotation drive unit 6, and similarly, the optical systems 2' and 3' are driven by the rotation drive unit 6.
6 in the direction 4' in the figure.

Further, on the welding object installation table 7, an object to be welded, such as an optical component, is installed. This workpiece fixing part 7 is Z
Directional movement mechanism 8. Movement mechanism in the y direction9. It includes a moving mechanism 10 in the X direction and a rotating mechanism 11 in the 0' direction.

Figure 3 (al is a detailed diagram of optical system 2.3,
', 3' also have the same configuration. In addition, the third figure (bl is a main perspective view of the workpiece A shown in FIG. 3 (al).

As mentioned above, the laser welding device includes a welding laser beam oscillator 12 (for example, a YAG laser) and a guide laser oscillator 1.
3 (for example, a He-Ne laser), and the laser light outputted from these is guided to an optical fiber 15 by an optical coupler 14.

The welding laser beam or guide laser beam emitted from the optical fiber 15 is made into parallel light by the lens 19, totally reflected by the quick lock mirror 18, and guided to the lens 21.

The lens 21 collects the collimated laser light and irradiates it onto the object A to be welded. The workpiece A to be welded is, for example, shown in FIG.
As shown in bl, the optical component 24 is fixedly installed vertically on the substrate via a round bar 25.26.
is maintained. Then, by irradiating the round bar 26.25 with a laser beam, the optical component 24 is attached to the support member 22.
Fix the metal to 23. FIG. 3(b) is a diagram of the workpiece A seen from the direction of the arrow. The shaded part is the support member 22
．． This is a perspective view of No. 23. As shown in Fig. 3, for example, four welding points 27 are provided for the round bar 25 and 26. Each of these welding points 27 is marked. A material with higher reflectance than other parts is used for this marking.

Next, a method of controlling the welding point 27 to the optimum position using the guiding laser beam oscillator 13 will be explained.

As described above, the guide laser beam is guided by the optical system, focused by the lens 21, and irradiated onto the workpiece A.

This laser light is reflected, and the reflected laser light passes through the lens 21 again, passes through the quick clock mirror 18, and is focused by the lens 17. The focused reflected laser light is
The reflected light passes through the pinhole 20 and is received by the optical receiver 16, and the power density of the reflected light is detected.

FIG. 4 is a block diagram of a processing section of reflected light power density information detected by the optical receiver 16. The reflected light power density information is converted into a digital signal by the A/D converter 28, and is input to the MPU 31 via the selector 30. MPU3
1 reads the previously input reflected light power density information from the memory 32 and compares it with the currently input reflected light power density information. Based on the comparison result, the MPU 31 sends out the rotary drive section 1 and the linear drive section 4 of the optical system 2.3.

At the same time, a moving mechanism 8 for the workpiece installation table 7 is provided.

Control information is sent to each control unit 8', 11', 9'10' of 9, 10, and 11. The MPU 31 obtains this control information as follows. Since the position to be welded (welding point) 27 is marked with a higher reflectance than the surrounding area, when this part is irradiated with the guide laser beam, the reflected light power density becomes maximum.

First, the MPU 31 stores the reflected light power density in the memory 32 as well as the rotation drive unit 1 and linear drive unit 4 of the optical system 2.3.
The position information of the one-rotation drive unit 6 and the position information of each moving mechanism 8, 9, 10, and 11 of the workpiece installation table are stored. Then, the control units 4', 1', 6',
66'. 8', 11', 9'.

10' is sequentially moved by small distances, the reflected light power density is compared, and the position is set at the position where the reflected light power density is maximum. Note that the optical system 2.3 and the optical systems 2' and 3' have different moving ranges so that laser welding can be performed over the entire range of the workpiece, and this information is stored in the memory 32. 9MPU3 1 selector 3 based on this information
Switch 0.

The alignment control between the optical systems 2 and 3 and the optical systems 2' and 3' is switched. After the alignment is completed, the laser beam is switched to a welding laser beam and laser welding is performed.

In the above explanation, we have described the case where a material with a higher reflectance than the surrounding area is applied to mark the welding position.
Conversely, alignment can be performed in a similar manner even with materials of low reflectance.

In addition, the beam spot diameter of the laser beam is approximately 0.3 to 0.8
Since the crane is as small as φ, it is necessary to mark it accordingly.

〔Effect of the invention〕

As described above in detail, according to the present invention, by marking the welding position of the workpiece with a different reflectance from the surrounding area, the optical system is It is also possible to automatically align the position of the workpiece installation table, thereby improving the fixing accuracy of optical components.

[Brief explanation of drawings]

Figure 1 is a perspective view of the laser welding equipment. Fig. 2 is a detailed view of the optical system moving mechanism, and Fig. 3 is a detailed view of the optical system. FIG. 4 is a block diagram of the control system. In the figure, 2.3 and 2'3' are optical systems, 16 is an optical receiver,
20 is a pinhole, 12 is a welding laser oscillator, 13 is a guide laser oscillator, and 27 is a marked welding point. ,, -7;-x. Agent: Patent Attorney, Calculator: Hiroshibe. '“-1!, 2nd 1st partner

Claims (1)

[Claims] A welding object installation table, a welding laser beam generator, a guide laser beam generator, and an output optical system that guides the welding laser beam and the guide laser beam to a welding position, the guide laser A laser welding device that performs welding by irradiating the welding laser beam to the welding position after adjusting the welding position to an optimal position with respect to light, the welding position being surrounded by a A moving mechanism for moving the workpiece installation table, a movement mechanism for moving the output optical system, and a power density of the reflected light of the guide laser beam irradiated on the workpiece are provided with different marks. a photodetector to detect;
A laser welding apparatus comprising: control means for controlling the moving mechanism to irradiate the guide laser beam to the welding position at an optimal position based on the detection result of the photodetector.