JPS60187475A - Welding robot - Google Patents

Abstract

PURPOSE:To provide a titled robot which performs satisfactory multi-layer welding in conformity with the direction of works in teaching playback welding of automatic multi-layer welding by calculating the direction of a torch and weld line direction by two-point teaching and recognizing the direction of the works from the result of the calculation and the conversion of the torch angle. CONSTITUTION:A weld line vector 13 is determined by a welding start point 11 and end point 12. A torch vector 14 perpendicular to a weld line 13 and a vector 15 perpendicular thereto are determined and a torch angle 16 is calculated. The vectors 14, 15 and the vector 13 are converted to axes and the vectors 17, 18 in the plane direction of works 2 is calculated. These vectors are converted and stored by the functional equation of a robot control device to the X-Y-Z vectors of the robot. If the welding torch is subjected to teaching of multi-layer welding along the weld line 13, the exact automatic multi-layer teaching playback robot welding is executed irrespectively of the attitude direction of the works.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to the improvement of welding robots, and more specifically, calculates the orientation of a workpiece and the workpiece coordinate system from given teaching data, and calculates the calculated workpiece coordinates. This invention relates to a welding robot that can perform multilayer welding depending on the system.

[Prior art]

Conventionally, this type of robot and workpiece were arranged as shown in Figure 1. In Fig. 1, (1) is the arc welding robot body with multilayer welding function, (2) is the workpiece to be welded, (
3) is a welding torch, (4) to (9) are welding robots (1
) is a multilayer weld that is built up by a weld build-up. As shown in FIG. 1, the welding robot (1) and the workpiece (2) are both installed on a horizontal plane. Further, α1 is a control device that includes an arithmetic processing unit, memory, etc., and controls the welding robot main body (1).

Next, the operation will be explained. The welding robot (1) is taught the welding line in advance, and when it starts automatic welding, it first positions the welding torch (3) at the position of the weld overlay (4) and welds the weld overlay (4) of the first layer. Do 4). Weld overlay (4)
Once completed, the welding robot (1) will move the welding torch (3)
Move to the weld overlay (5) position, and perform the first pass of the second layer (
Perform welding in step 5). At this time, the amount of movement from (4) to (5) is stored in the control panel aQ. The same operation is repeated up to weld overlay (9) to complete all welding.

By the way, as shown in Fig. 2, the conventional welding robot described above operates in the same way as shown in Figs. 1 (4), (5), etc. even when the workpiece (2) is placed not on a horizontal surface but at an angle.・Since the welding torch (3) is moved to the (9) position, the result will be welding as shown in (4a) to (9a) in Fig. 2. Either the welding torch (3) is moved to the workpiece (2) ) may also be expected to interfere.

Conventional arc welding robots have the above-mentioned characteristics, and therefore have the disadvantage that the orientation of the workpiece must be limited when performing multilayer welding.

[Summary of the invention]

This invention was made in order to eliminate the drawbacks of the conventional ones as described above.The invention calculates the orientation of the workpiece, that is, the workpiece coordinate system, from the teaching data given to the arithmetic processing unit, and The purpose is to provide a welding robot that can perform multilayer welding according to the coordinate system.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

In Figure 3, (2) is a workpiece, (3) a brush, as in Figure 1, a welding torch attached to the tip of the robot arm;
0]) is the point at which welding starts, that is, teaching point 1, (2) is the welding completion point, that is, teaching point 2, α is the welding line vector calculated from the teaching point data, and 04 is the welding line vector (towards ) The similarly calculated torch vector (g) is a vector orthogonal to the welding line vector 0→torch vector 04. Further, OQ is the welding torch angle.

The robot body (1) and the control device 00 are the same as the conventional robot.

Note that the control device (10 is not shown).

Next, the operation will be explained. When the tip of the welding torch (3) is positioned at point α and this position is taught to the robot, the arithmetic processing unit in the control device calculates the torch vector α.
→ Calculate. Next, when point (6) is taught, weld line vector (6) is calculated, and vector (11) is calculated by the vector cross product of vector < 11 and vector α◆.The actual workpiece coordinate system is (90° - torch angle α→) The rotated vector αη becomes 0→, so the vector α→, (
Calculate the vector αη% 0→ by the coordinate transformation formula when rotating the vector α→axis rotation υ,
Define moan as the y-axis and 0→ as the y-axis to form the work coordinate system.

Next, define the robot coordinate system that the robot has (X, Y
. (χBHVB+ 夛8)
The relationship between the robot coordinates (Xs, Ys, Zs) is shown in the table below.

Here, x, y, , z are teaching points 1αη
The robot coordinates x-, y-, ze are obtained at the welding starting point, that is, the aiming position of the torch (3) at the teaching point 1α■.

Part of the data on the amount of torch movement between each layer and each pass of the multi-layer welded part of the workpiece (2) is stored in the control device α1 in the workpiece coordinate system, and this data is converted into the above coordinate transformation formula. By converting to the robot coordinate system, the direction and amount of movement of the robot can be determined according to the orientation of the workpiece (2). Therefore, multi-layer welding by the robot is possible for workpieces in all directions. Note that the above vector calculations, coordinate transformation calculations, etc. are performed by the arithmetic processing unit in the control device C1O according to a pre-stored program. .

Further, although the above embodiments have been described with respect to fillet welding, the same effect can be obtained when welding L-shaped, V-shaped, J-shaped, and U-shaped grooves.

Figure 4 shows an example of a V-groove, where (2a) is a workpiece, (
3) is a welding torch, and the robot is not shown.

〔Effect of the invention〕

As described above, according to the present invention, the workpiece coordinates are recognized depending on the direction of the welding torch and the direction of the welding line.
Multi-layer welding with uniform quality is possible even if the workpiece is placed at an angle. Furthermore, it is completely disrespectful to modify the hardware, and functions can be added very easily. Another great advantage is that the teaching method can be the same as the conventional method.

[Brief explanation of the drawing]

Figure 1 is a front view showing the arrangement of a conventional welding robot and a workpiece, Figure 2 is a side view showing the welding state when the workpiece is tilted in the conventional welding robot shown in Figure 1, and Figure 6 is a side view of the conventional welding robot shown in Figure 1. FIG. 4 is a perspective view showing one embodiment of the invention. FIG. 4 is a perspective view showing another embodiment of the invention. In the figure, (1) is the robot body, (2), (2a [workpiece], (3) is the welding torch, (4) to (9), (4a) to (
9a) is the welding overlay, (11 is the robot control device, α■ is the teaching point 1, (c) is the teaching point 2, (2) is the welding line vector (y axis), α→ is the torch vector, (2) are orthogonal vectors, αQ is the torch angle, CLη is the y-axis, and α barrel is the y-axis. In addition, the same symbols in the figures represent the same or equivalent parts.
Patent Attorney Sanro Kimura

Claims (1)

[Claims] In a teaching playback type welding robot that automatically performs multi-layer welding, the direction of the welding torch attached to the tip of the robot and the direction of the welding line are calculated based on the teaching data of two points, and this calculation result and the direction of the welding line are This welding robot is characterized by being able to recognize the orientation of a workpiece based on its corners and perform multi-layer welding according to the orientation of the workpiece.