JPH0688150B2 - Beam welding equipment - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a beam welding apparatus for butt welding an object to be welded with a beam such as a laser beam.

(Prior Art) Recently, a welding method using a high-density concentrated heat source such as a laser beam has been attracting attention. In this laser welding, since the laser is a high-density concentrated heat source, high-speed welding is possible and Arm welding that has been done so far because it has little heat effect on the material,
It is superior to seam welding or TIG welding. Further, since the laser beam is light, there is an advantage that accurate welding can be performed even in a narrow place by using an optical system.

One example of beam welding using the laser is butt welding of thin mild steel plates, and laser welding is particularly effective for welding members such as thin mild steel plates that are easily deformed by heat.

By the way, in the laser welding as described above, since the beam is focused on the welding portion by the lens or the like to form the beam spot, strict positioning of the welding portion is required. Also,
Welding is easy if the abutting parts are in close contact, but in reality, the abutting surfaces of the materials to be abutted are not polished, so the abutting accuracy is also variable, so there will be gaps in the abutting parts. . And if the width of this gap exceeds a certain allowable value, the laser beam will pass through the gap,
Welding becomes impossible.

Therefore, with respect to the point that the welding portion is strictly positioned, for example, as described in JP-A-59-144590, the welding portion is advanced while advancing the beam spot along the welding line using an image sensor. It is considered that the problem can be solved by correcting the target position of the welding, and the problem that there is a gap at the butt portion is considered to be solved by feeding the filler wire to the welded portion and filling the gap. . However, the above solution is feasible only when the abutting welds are perfectly parallel, and in practice the width of the abutment gap varies momentarily along the weld line and this gap Since the width of the wire also changes due to a slight heat effect, the amount of the wire fed to the weld portion becomes excessive and deficient, making it difficult to perform good welding. Further, when the image sensor is used, the detector is expensive.

Further, for example, as disclosed in JP-A-54-4257, based on the detection of reflected light from the surface of the workpiece,
Detecting the position of the gap in the butted part of the work piece, a beam welding device is also proposed that controls the relative position of the work piece mounting table to the beam source, but when using reflected light, Depending on the surface condition of the object to be welded, since the reflected light is weak, there is a drawback that the detection of the gap position becomes inaccurate.

(Object of the Invention) The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a relative position of an object to be welded with respect to a beam source corresponding to a change in a position and a width of a gap of a butt portion. Another object of the present invention is to provide a beam welding apparatus capable of controlling the relative moving speed and controlling the wire feeding speed in accordance with the change in the width of the gap of the butting portion.

(Structure of the Invention) Therefore, the beam welding apparatus according to the present invention includes a detecting means for detecting a change in the position and width of the gap of the butting portion by light passing through the gap, and a welding wire at the position where the beam spot of the butting portion is formed. And the wire feeding means for feeding, and the relative position and the relative movement speed of the mounting table of the workpiece to the beam source based on the output signal from the detecting means, and to change the width of the gap of the abutting portion. According to another aspect of the present invention, there is provided control means for controlling the wire feeding means so that the welding wire is fed at different feeding speeds.

(Advantageous Effects of the Invention) According to the present invention, since the detection means capable of detecting the position and width of the gap of the abutting portion is provided, the position to be joined regardless of the joining shape of the two members to be joined. It is possible to accurately move the beam spot and to perform good welding. Since the wire supply amount can be adjusted according to the change in the width of the gap at the abutting portion, excellent welding can be performed regardless of the width of the gap.

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

FIG. 1 is a system diagram showing a schematic configuration when the present invention is applied to a laser welding apparatus. In the laser welding apparatus, the first member 1 and the second member 2 which are members to be welded are joined together at their joints. A mounting table 3 placed in this state, a laser oscillator 4,
A mirror 8 and a lens 9 for forming a beam spot 7 by focusing laser light 5 emitted from the laser oscillator 4 on the abutting portion 6 of the first member 1 and the second member 2.
A laser control device 10, motors 11 and 12 for moving the mounting table 3 in the X and Y directions, and these motors 1
And a driving device 13 for driving the first and the second devices 12. Further, a wire feeder 15 for feeding the welding wire 14 to the position where the beam spot 7 of the butt portion 6 is formed, and a wire feeding control for controlling the wire feeding speed of the wire feeder 15. And a device 16.

Further, on the mounting table 3, a light source 17 and an adapter 18 for introducing light emitted from the light source 17 into the gap between the abutting portions 6 of the first member 1 and the second member 2 are provided. Above 6 is provided an optical sensor 20 for receiving the light that passes through the gap of the abutting portion 6 and is emitted upward. The optical sensor 20 is provided in front of the portion where the beam spot 7 is formed, and the optical information received by the optical sensor 20 is converted into an electric signal by the reader 21,
It is given to the controller 23 via the A / D converter 22. Controller 2
3 determines the laser irradiation conditions, the position coordinates of the mounting table 3 and the feeding speed of the welding wire 14 based on the information sent from the optical sensor 20, and the laser control device 10 and the motor drive device 13
And wire feed control device 16 respectively. Incidentally, 24 is a power source of the light source 17.

Next, FIG. 2 is a perspective view showing a processing head 25 having a laser oscillator 4 and forming a beam spot 7 on the abutting portion 6 and an optical sensor 20 arranged in front of the processing head 25.
The welding wire 14 is fed from the wire feeder 15. As is apparent from FIG. 3, the optical sensor 20 for detecting the position and width of the gap of the abutting portion 6 has a large number of optical fiber bundles 26 formed by bundling a large number of optical fibers. The end faces are arranged in a matrix to form a flat light receiving surface. Then, the position occupied by each optical fiber bundle 26 on the light receiving surface is coordinated, and an address name is given corresponding to each coordinate, whereby a large number of optical fiber bundles 26 can be identified by the address name. For example, when the optical sensor 20 is arranged in the gap 27 of the abutting portion 6 with the relative positional relationship shown in FIG. 4, the amount of light received by each optical fiber bundle 26 is shown in the state shown in FIG. Therefore, the reader 21 reads the signal propagating through the optical fiber and determines the amount of light received by each optical fiber bundle 26 as follows.

A-4 Very strong B-4 Very strong B-5 Very weak C-4 Strong C-5 Weak D-4 Very strong D-5 Very weak The above judgment result is digitized by the A / D converter 22 and the controller 23 Is calculated. By this arithmetic processing,
The position, shape, and width of the gap 27 of the abutting portion 6 can be easily detected, and the controller 23 determines the laser irradiation conditions, the position coordinates of the mounting table 3, and the feeding speed of the welding wire 14 based on this detection. Laser control device 10 and motor drive device
13 controls the wire feed control device 16 so as to increase the feed speed of the welding wire 14 when the width of the gap 27 is wide and to decrease the feed speed of the welding wire 14 when the width of the gap 27 is narrow. Have control.

Next, FIG. 6 shows a flowchart of a part of the processing executed by the controller 23. First, the data from the reader 21 is read in step S1, and the arithmetic processing is performed in step S2. Next, it is determined whether or not the data processing is completed in step S3, and if this determination result is “YES”, the process proceeds to step S4 to file the data, and the laser control device 10 is controlled based on this data. In step S5, the motor drive device 13 is controlled to move the mounting table 3 so as to come to the center of the butt, that is, the center of the optical sensor at the center of the gap 27. The result is determined in step S6, and the center of the optical sensor 20 is a gap.
If it is determined to be at the center of 27, that is, at the butt center,
In step S7, it is determined whether or not it is a butt end face, and if the result of this determination is "YES", the control ends.

The description of the flow of the process executed when the controller 23 controls the wire feeding control device 16 is omitted.

As is clear from the above description, in the present embodiment, since a large number of optical fiber bundles 26 are used as the optical sensor 20, the position, shape and width of the gap 27 of the abutting portion 6 can be easily and at low cost. There is an advantage that can be detected. Moreover, since the width of the gap is detected and the feed rate of the welding wire 14 is changed according to the size of the width to control the amount of buildup of the welding, high quality welding can be performed.

[Brief description of drawings]

FIG. 1 is a system diagram showing a schematic configuration when the present invention is applied to a laser welding apparatus, FIG. 2 is a perspective view showing a processing head and an optical sensor, and FIG. 3 shows a light receiving surface of the optical sensor. FIG. 4 is a plan view, FIG. 4 is an explanatory view showing a relative position between the optical sensor and a gap between the abutting portions, FIG. 5 is an explanatory view showing a light receiving state of the optical sensor, and FIG. 6 is a flowchart. 3 ... Mounting table, 4 ... Laser oscillator 5 ... Laser light, 6 ... Butt portion 7 ... Beam spot, 10 ... Laser control device 11, 12 ... Motor, 13 ... Motor drive device 14 ... Welding wire, 15 ... Wire feeder 16 ... Wire feeding controller 17 ... Light source, 20 ... Optical sensor 21 ... Reader, 23 ... Controller 25 ... Processing head, 26 ... Optical fiber bundle 27 ... Gap

Claims (1)

[Claims] 1. A beam welding device for butt-welding an object to be welded by forming a beam spot by a beam emitted from a beam source at the butt part of the object to be welded, wherein the position and width of the gap of the butt portion are Based on an output signal from the detecting means for detecting the change by the light transmitted through the gap, a wire feeding means for feeding the welding wire to the position where the beam spot of the butting portion is formed, and an output signal from the detecting means. While controlling the relative position and relative movement speed of the mounting table of the object to be welded with respect to the beam source, the welding wire is fed at different feeding speeds depending on the change in the width of the gap of the butting portion. A beam welding apparatus, comprising: a control unit that controls the wire feeding unit.