JPS59101296A - Laser welding device - Google Patents

Abstract

PURPOSE:To perform stable laser welding over the entire length of a weld line in the stage of using laser light in welding objects to be welded by detecting the weld line forward in the advance direction of a laser torch and controlling the position of the laser torch according to the signal thereof. CONSTITUTION:Rails 7, 8 intersecting orthogonally with rails 2, 3 are provided on a table 4 moving in the X-axis direction shown in the figure on the rails 2, 3 on a bed 1. A table is fixed movably in the Y-axis direction on the rails 2, 3. A support base 14 for objects 12, 13 to be welded is placed on the table 9, by which the objects 12, 13 are made freely movable in both directions of X and Y- axes. The laser light from a laser light generator 26 is conducted to a laser torch 19, and the weld line 29 of the objects 12, 13 is welded by the movement of the tables 4, 9 in the X-, Y-axis directions. The light of a lamp 36 disposed in the lower part of the objects to be welded is detected with a photodetector type position detector 34 attached to the torch 19, by which the weld line 29 is detected and motors 5, 10 for moving the tables 4, 9 are driven according to the detected weld line. The weld line 29 is thus controlled always to the position right under the torch 19 and the stable welding is accomplished.

Description

[Detailed Description of the Invention] The present invention is characterized in that when a laser beam is irradiated onto a welding line of a workpiece,
This invention relates to a rede welding device that performs good welding.

Generally, a radar welding device that uses a laser beam focuses the laser beam using a convex lens to increase the energy density of the laser beam, and performs welding with a spot beam diameter of a small diameter (for example, φ = 1.0 M or less). There is. Further, the laser welding device requires a straight optical path to guide the laser beam generated from the radar light generating device to the laser torch provided at the tip. Therefore, the laser welding device is fixed and the object to be welded is moved, or vice versa, the object to be welded is fixed and the welding device is moved. Since it is easy to obtain a linear optical path due to the device structure, a relatively simple Rade welding device that mainly performs linear welding is generally used.

However, as mentioned above, because the spot beam diameter of the laser beam is small, even in simple and straight welding, the welding line of the workpiece becomes parallel to the axis of movement of the laser beam installed at the tip. It is necessary to set the axis with good accuracy. As a result, setting work requires a long time, and even if set accurately, the welding line of the workpiece is not always parallel to the axis of movement of the laser torch over the entire length, and the laser torch emits light during welding. The laser beam may come off the welding line of the workpiece, resulting in poor welding or deterioration of the quality of the welded part.Furthermore, the laser welding process may be interrupted and the process may have to be restarted, making it difficult to stabilize the welding process. There was a possibility that laser welding would not be possible.

The present invention has been made based on the above points, and its purpose is to detect the welding line of the object to be welded in front of the laser torch in the direction of movement, and to control the position of the laser torch based on the detection signal. In particular, it is an object of the present invention to provide a laser welding device capable of performing stable laser welding over the entire length of the weld line.

That is, the laser welding apparatus according to the present invention includes a workpiece support base that supports a workpiece, and a workpiece support base provided on the upper surface side of the weldwork workpiece support base, and two directions perpendicular to each other on a horizontal plane parallel to the workpiece support base. a laser torch movable relative to a workpiece support base; a laser beam generator that supplies laser light to the laser torch; a light-receiving position detector provided in front of the laser torch in a welding direction; The welding device has a configuration that includes a shape position detector and a light emitting device provided at opposing positions with the workpiece supporting base interposed therebetween.

A light-receiving position detector installed at the front of the laser torch in the welding direction detects light from a light emitting device installed at a position opposite to the workpiece support base through the gap between the weld lines of the workpiece. By doing this, the position of the weld line is detected. 1. Therefore, by making corrections based on this detection signal, the axis of the radial detorch can always be positioned on the actual welding line of the workpiece, and the radial light can be reliably irradiated and welded along the actual welding line. be able to. The time required for setting the workpiece to be welded can be shortened, and stable laser welding and high-quality welded workpieces can be provided.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 6. Reference numeral 1 in the figure indicates a ped. A pair of rails 2 and 3 are laid on the upper surface of this ped 1.

A traversing table 4 is provided along these rails 2 and 3 in a traversing position. That is, this traversing table 4 has an I'i4 configuration in which it traverses by a drive motor 5 provided on the ped 1 and one drive screw 6 connected to this one drive motor 5. A pair of rails 7 and 8 are laid on the upper surface of the transverse table 4 in a direction perpendicular to the rails 2 and 3. A traveling table 9 is provided on the rails 7 and 8 so as to be able to travel along the rails 7 and 8.

That is, this traveling table 9 is connected to the above-mentioned traveling table 4Vc.
The provided drive motor 1o and this drive motor 10 (
/C is configured to run along the connected driving screw IIK. A workpiece support base 14 for supporting workpieces 12 and 13 is provided on the traveling table 9.

The objects to be welded 12 and 13 set on the object support base 14 can be moved to arbitrary positions by the traversing of the traversing table 4 (in the X-axis direction in the figure) and the movement of the traveling table 9 (in the Y-axis direction in the figure). The configuration is set to . A main body ped 15 is installed at a position opposite to the drive motor 5 of the ped 1. A column 16 is erected on this main body ped 15, and a hollow laser torch holder 18 is attached to the column 16 via an arm 17 to hold the object to be welded.
It is located on the side. And this laser torch holder 1
A laser torch 19 is connected to the tip of 8. This laser torch 1g has a function of narrowing down the laser beam using a built-in convex lens. A beam pender 2Q is provided above the radar torch holder 18. This beam pender 20 is connected to a beam pender 22 provided on the column 16 via a Rade light passage duct 21, and this beam pender 22 is connected via a Rade light passage duct 23, a collimator 24, and a laser beam passage duct 25. It is connected to a laser beam generator 26. That is, the laser beam emitted from this laser beam generator 26 is supplied to the laser torch holder 18 via the Rade beam passage duct 25, the collimator 24, the laser beam passage duct 23, the beam pender 22, the Rade beam passage duct 21, and the beam pender 20. The configuration is such that the laser beam is supplied to the laser torch 19.

Next, the configuration near the radar torch 19 will be described with reference to FIGS. 3 and 4. That is, the laser torch 19
is attached to the laser torch holder 1 via the hollow adapter 27.
8 is connected. A nozzle 28 is connected below the laser torch 19, and the laser beam supplied to the laser torch 19 is configured to irradiate a welding line 29 of the objects 12 and 13 to be welded through the nozzle 28. . The laser torch 19 has a vertical position adjusted by a vertical fine adjustment dial 30, and the nozzle 28 has a vertical position adjusted by a vertical fine adjustment dial 31. It becomes. A cooling pipe 32 is connected to the laser torch 19, and the laser torch 19 is configured to be cooled by a cooling medium supplied through the cooling pipe 32. A gas supply pipe 33 is still connected to the nozzle 28, and an inert gas for welding, such as argon, is supplied via this gas supply pipe 33. A light-receiving position detector 34 is provided in front of the laser torch in the direction of welding progress, and is connected to the nozzle 28 via a support 35. A lamp 36 as a light emitting device is provided at a position opposite to the light-receiving position detector 34 with the workpiece support 14 in between, and is fixed on the main body ped 15 via a support support 37. There is.

A lamp hood 38 is provided around the outer periphery of the lamp '35. That is, the configuration is such that the light from the upper pipe 36 is received by the light-receiving position detector 34 via the welding line 29 of the objects 12 and 13 to be welded, and the welding line 29 is thereby detected. In the figure, numeral 39 indicates a shielding plate provided on the support base 35 of the light-receiving position detector 34.

Based on the above configuration, a description will be given of butt welding of steel plates as an example. First, the objects to be welded 12 and 1 are
3 is either temporarily welded or placed on a workpiece support 14 as shown in FIG. Then, the drive motor 5 is driven to cause the traverse table 4 to traverse via the drive screw 6. As a result, the traveling table 9 on the traveling table 4, the workpiece support stand 14, and the workpieces 12 and 13 are also
1tiiLMove in 1 direction. Then, when the welding line 29 reaches the axis 16 of the laser torch 19, the drive motor 5 is stopped. Next, the drive motor 1Of: is driven to cause the traveling table 9 to travel via the drive screw 11. As a result, the workpiece support 14 and workpieces 12 and 13 on the traveling table 9 also move in the Y-axis direction in the figure. Then, when the welding start position of the welding line 29 reaches the axial position of the laser torch 19, the drive motor IQ is stopped. This completes the positioning work of the objects to be welded 12, 13, the welding line 29, and the laser torch 19. And laser light generator 2
6 to generate a laser beam. The laser beam emitted by this laser beam generator 26 is transmitted to the laser torch holder 18 via the LED light passage duct 25, the collimator 24, the laser beam passage duct 23, the beam pender 22, the laser beam passage duct 2, and the beam pender 20. transmitted. The laser beam transmitted to the laser torch holder 18 is introduced into the laser torch 19, focused by a convex lens included in the laser torch 19 into a small diameter spot, and irradiated onto the welding line 29 from the tip of the nozzle 28 to perform welding. is started. At this time, argon gas is supplied into the nozzle 28 through the gas supply pipe 33 to shield the weld line 29 and its vicinity. From the above, the drive motor 10 is driven to move the traveling table 9 and progress the welding. However, the positioned welding line 29 is not always parallel to the rails 7 and 8 provided on the traversing table 4 over its entire length, and a misalignment may occur between the welding line 29 and the laser torch 19. be. If a deviation of more than the spot diameter of the laser beam occurs, the laser beam may be irradiated onto areas that should not be welded, thereby impairing the quality of the welded part.

Therefore, as shown in FIG. 4, light is emitted from the run f36, and the emitted light is received by the light-receiving position surface detector 34 through the gap between the welding lines 29.
Detect the position of 9.

Then, the position of the detected welding line 29 is detected by the light-receiving position detector 3.
The driving of the drive motor 5 is controlled so that the measurement range is located at the center of the preset measurement range. By kneading, the actual welding line 29 can be reliably irradiated with laser light to perform welding.

The above operation will be specifically explained with reference to FIGS. 5 and 6. As described above, in the light-receiving position, the detector 34 receives the light from run f3.6 only through the gap between the welding lines 29, and does not receive light from other sources. Therefore, only the portion of the light-receiving position detector 34 that receives light is sensitive, and a heavy detector output pressure is generated. For example, as shown in FIG. 5, the distance (
Assume that weld #29 is detected at a position X) away from the weld. At this time, the drive motor 5 is controlled to move the traversing table 4 by (child-x) so that the welding line 29 is at the center of the set measurement range (t) of the light-receiving position detector 34, in other words, the axis of the laser torch 19. Control so that it comes to the center position. Therefore, the position can be controlled to the axis of the laser torch 19 over the entire length of the welding line 29, and the laser beam can be reliably irradiated onto the actual welding line 29 for welding, thereby reducing the time required for positioning the objects 12 and 13 to be welded. It enables shortened and stable laser welding and provides high-quality welded parts. Note that in the above embodiment, the laser torch 19
Although this embodiment has been applied to the case where the side of the workpiece supporting base 14 is movable, it goes without saying that the same effect can be achieved even if the present invention is applied in the opposite case.

In other words, the welding apparatus according to the great invention includes a welding workpiece support base that supports the weld workpiece, and two welding workpiece support bases that are provided on the upper surface side of the weld workpiece support base and that are orthogonal to each other on a horizontal plane that is parallel to the weld workpiece support base. a laser torch movable relative to a welding object support base in a direction; a laser light generator that supplies laser light to the laser torch; a light-receiving position detector provided in front of the laser torch in a welding direction; This structure includes a light-receiving position detector and a light-emitting device provided at opposing positions with the workpiece supporting base interposed therebetween.

In other words, the light-receiving position detector installed in front of the laser torch in the welding direction detects the light from the light-emitting device installed at the opposite position across the workpiece support through the gap between the weld lines of the workpiece. This configuration detects the position of the weld line by doing this. Therefore, by making corrections based on this detection signal, the axis of the laser torch can always be positioned above the actual weld ta'1b of the workpiece, and the laser beam can be reliably irradiated along the actual welding line for welding. can do. The effects of this method are outstanding, such as being able to shorten the time required to set up the objects to be welded, providing stable laser welding, and providing high-quality welded objects.

[Brief explanation of drawings]

1 to 6 are diagrams showing an embodiment of the present invention, and FIG. 1 is a plan view and a diagram of a first chamber of the laser welding apparatus. 12.13... Workpiece to be welded, 14... Workpiece support stand, 19... Laser torch, 26... Laser light generator, 34... Light-receiving position detector, 36... Lamp (
light emitting device). Applicant Sub-Agent Patent Attorney Takehiko Suzue Figure 5 Figure 6

Claims (2)

[Claims] (1) A workpiece support stand that supports the workpiece, and a workpiece support stand that is provided on the upper surface side of the workpiece support stand and extends in two directions orthogonal to each other on a horizontal plane parallel to the workpiece support stand. a laser torch that is movable relative to the laser torch, a laser beam generator that supplies laser light to the laser torch, a light-receiving position detector provided in front of the laser beam in the direction of welding progress; What is claimed is: 1. A radar welding device comprising: a welding device; and a light emitting device provided at opposing positions across the workpiece support. (2) The radar welding apparatus according to claim 1, wherein the light emitting device is constituted by a lamp.