JPH0699277A - Twin welding method for fillet joint by robot - Google Patents

Abstract

PURPOSE:To obtain the satisfactory welding quality by carrying out specified starting end boxing welding operation when torches are stopped and arcs are generated after the lapse of specified time. CONSTITUTION:A lower plate 1 and a vertical plate 2 are twin-welded by using robots 16 simultaneously with forming of fillet weld beads 3. In welding a joint starting end, since operations of two robots 16 are synchronized, a torch switch to a welding power source is turned on. Afterward, the welding torches 18 are stopped at the position by the specified time more than the time required for generating the arcs in normal welding. After the lapse of specified time, generation of the arcs is confirmed and when the arcs are generated, specified starting end boxing welding operation is carried out. Consequently, bead uneveness and the occurrence of defect can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a pair of fillet welded joints for shipbuilding or bridge panels, and two multi-joint arc welding robots and a common external synchronous control shaft to simultaneously weld both sides under the same welding conditions. The present invention relates to a robot twin welding method for fillet joints.

[0002]

2. Description of the Related Art For example, when welding a pair of fillet welded joints for shipbuilding or a bridge panel under the same welding conditions (this is called twin welding), for example, a 6-axis articulated arc welding robot. Each of the articulated arc welding robots has an independent external control axis that moves on each fillet welded joint, and is not completely synchronized with each fillet welded joint. In addition, the method of individually welding each was adopted.

However, since such a method does not have a common external control axis, two sets of external control axes are required, resulting in a high manufacturing cost and a narrow space and operating range of the apparatus. there were.

Therefore, it has been considered that two 6-axis articulated arc welding robots have a common external control axis. However, for example, if the number of common external control axes is 3 and the welding robot is 6 axes each, the total of these is 1
A robot controller for synchronously controlling 5 axes is required, and a robot controller for synchronously controlling 15 axes must be newly designed, resulting in high cost. For this reason, two general-purpose robot controllers are prepared, a 9-axis robot controller that also controls a common external control axis is used for one multi-joint arc welding robot, and the other multi-joint arc welding robot is used. Is 6
A 6-axis robot controller uses a 9-axis robot controller, and the 9-axis robot controller receives position information for the 3-axis external control axes, so that the two robot controllers can synchronously control two articulated arc welding robots. Then, a method of performing arc welding on a pair of fillet welded joints is currently adopted.

[0005]

SUMMARY OF THE INVENTION In the conventional control method,
After the torch switch is turned on, the welding robot waits at that position until it detects the occurrence of an arc.However, the time from turning on the torch switch to the occurrence of an arc is When two welding robots share an external control axis due to variations in the protruding length, wire feed speed, and wire surface condition, perfect synchronization cannot be achieved, and the torch rod is discontinuous. Therefore, there is a problem that unevenness of beads and generation of defects are unavoidable. Further, there is a problem in that even when the welding is finished, the welding is uneven at the end portion due to the deviation of the start of the arc generation.

The present invention has been made to solve the above problems, and when twin welding is performed on a pair of fillet welded joints, the occurrence of arc at the start of welding is eliminated, and a pair of fillet welded joints is eliminated. It is an object of the present invention to provide a twin welding method by a robot for fillet joints, which enables turning welding and does not cause uneven welding at the end of welding.

[0007]

A twin welding method by a robot for fillet joints according to the present invention is a method in which two articulated arc welding robots are attached to a common external control shaft which is movable in the welding line direction, and a joint start end is provided. At the start of welding, a predetermined joint start welding operation is started after a lapse of a certain time after turning on a torch switch for turning on / off the welding power source of each articulated arc welding robot.

[0008]

According to the present invention, at the start of welding a pair of fillet welded joints, a predetermined joint start end welding is performed after a certain time has elapsed after turning on the torch switch for turning on / off the welding power source of each articulated arc welding robot. Since the operation is started, when each articulated arc welding robot at the start of welding for a pair of fillet welded joints starts moving, the arc is generated because a certain time has passed since the torch switch was turned on. Both occur, and no welding deviation occurs at the welding start portion of the pair of fillet welded joints. Further, even when the welding is completed, the unevenness of the welding does not occur at the end portion.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a sectional view showing a state in which the method of the present invention is being carried out, FIG. 2 is a perspective view showing a state in which the method of the present invention is being carried out, and FIG. FIG. 4 is an explanatory view of a state in which the welding torch is shifted in twin welding.

In the drawings, 1 is a lower plate, 2 is a standing plate standing on the lower plate 1, and 3 is a pair of fillet weld joints formed by the lower plate 1 and the standing plate 2. It is a welding bead. 1
0 is a gate type control shaft support frame which is laid over the lower plate 1,
Reference numeral 11 is a guide rail provided on the upper surface of the horizontal frame of the control shaft support frame 10, and 12 is a three-axis external control shaft that moves on the horizontal frame of the control shaft support frame 10 guided by the guide rails 11 in the longitudinal direction thereof. Is. The external control shaft 12 has an X-axis 13 that moves in the length direction (X-axis direction) of the control-shaft support frame 10, a Y-axis 14 that moves in a direction orthogonal to the X-axis 13 (Y-axis direction), and a Y-axis. It is provided at both ends of 14 and is composed of a pair of Z-axes 15 that move vertically (Z-axis direction). Reference numeral 16 is a 6-axis articulated arc welding robot attached to each of the pair of Y axes 15 of the external control shaft 12, and 17 is an articulated arc welding robot 1.
6 is an arm tip, 18 is a welding torch attached to the arm 17, and 20 is a welding wire. Further, the groove contour control of the welding torch 18 by the arc sensor or the like can be performed by the articulated shaft of the robot.

Next, the method of the present invention will be described. First, a case where welding is started from the ends of a pair of fillet welded joints will be described with reference to FIGS. 3 and 4. First, the external control shaft 12 and the multi-joint shaft of each welding robot 16 cause the tip of the welding wire 20 of each welding torch 18 to rotate at a predetermined starting end and the starting point of the welding operation (positions A and A'in FIG. 3).
Set each to come to. Next, welding torch 1
After turning on the torch switch (not shown) to the welding power source (not shown) of No. 8, the welding torch 1 is operated for a predetermined time longer than the time required for arc generation in normal welding.
8 is stopped at that position, and after a lapse of a predetermined time, the occurrence of an arc is detected. If the arc is generated, a predetermined starting end is turned around to perform a welding operation, and the final point of the operation (C in FIG. 3). , C'position)
Move the welding torch to. Therefore, even if there is a deviation in the arc generation timing of the two sets of welding torches 18 (the time from the turning on of the torch switch to the detection of the arc generation), the welding at the start end can be synchronized. . Further, the external control shaft 12 is stopped during the welding operation around the start end (from the A, A'position to the C, C'position). After the lapse of the predetermined time, when it is confirmed that the arc is generated, if the arc is not generated, it is determined that the arc start is defective, and the welding is stopped.

By the above control method, the two welding wires 2
When 0 reaches the C and C'positions shown in FIG. 3 at the same time, each articulated arc welding robot 16 stops the welding torch 18 in the welding direction, and this time, the X axis 13 of the external control shaft 12 is moved along the welding line direction. To perform twin welding on both sides of the pair of fillet welded joints 3. When the welding progresses by such twin welding and each welding torch 18 or the welding wire 20 reaches near the end of the standing plate 2, the external control shaft 12 is moved a predetermined distance before the end of the standing plate 2, for example, 50 mm before the end. Stop and start welding operation at the end of the joint. In the end-turn welding operation, the end-turn welding is independently performed by each axis operation of each articulated arc welding robot 16 with the external control shaft 12 stopped.

Next, in twin welding, when two welding torches are shifted in the welding advancing direction (shown in FIG. 4).
This will be described with reference to FIGS. 5 and 6. FIG. 5 shows the operation of the welding torch L (preceding) and T (trailing) around the starting ends in this case. In this case, the timing of turning on the torch switch of welding torch L and the timing of turning on the torch switch of welding torch T are the end points CL of each starting end turning operation.
A time difference is provided so that the welding torches L and T reach the position and the CT position at the same time. In each starting end turning operation, the starting point of the operation is the same as the operation in FIG. 3, that is, AL in FIG.
At the AT position, after turning on the torch switch to the welding power source, the welding torch is stopped at that position for a predetermined time, and after the predetermined time has elapsed, the occurrence of arc is confirmed,
If a crack has occurred, the welding operation is performed around the predetermined start end.
In addition, the welding operation around each start end stops the external control axis,
Performed by the multi-joint shaft of each welding robot. Welding torch L,
When T reaches the end point CL position and CT position of the turning motion at the same time, the arms of each welding robot do not move in the welding advancing direction, but the twin robots move in the welding direction by the common external control axis while the twin robot moves. Weld.

Next, FIG. 6 shows the operation of the end turning welding of the welding torches L and T. By the control described above, each welding
The ends L and T are turned at the same time to reach the starting points DL and DT of the welding operation. At this point, the common external control axis is stopped, and the welding operation around the end is independently performed by the arm of each robot. In addition, when the start end and the end turn welding are not performed, the welding residuals can be aligned by performing the operations shown in FIGS. 7 and 8. Further, in FIG. 3, FIG. 5, FIG. 6, FIG. 7, and FIG. 8, only a few points are shown for the position of the welding torch for simplification, but in actual welding, the welding condition is gradually changed to the main welding condition. Since the fine control such as shifting is performed, the number of operating points of the start end and end turning welding may increase.

In the above-mentioned embodiment, since the external control shaft 12 is one in common, the manufacturing cost of the welding device composed of the two articulated arc welding robots 16 and 16 is low. . Further, in the above-described embodiment, the pair of fillet welded joints 3 formed by the lower plate 1 and the standing plate 2 is used, but it goes without saying that the present invention is also applicable to twin welding of lap joints and joints having a groove. Absent.

[0016]

As described above, according to the present invention, in twin welding of fillet welded joints, the welding torch is turned on for a predetermined time after the torch switch to the welding power source is turned on at the start of welding of the joint start end. Stop at the position, check the arc generation after a lapse of a predetermined time, and if an arc is generated, perform a welding operation by turning a predetermined start end to turn on the torch switch until the arc is generated. By synchronizing the welding operation of two arc welding robots mounted on a common external control axis by absorbing the variation of
This has an effect that good welding quality can be obtained without causing unevenness of beads or generation of defects due to a discontinuous torch carrying rod.

[Brief description of drawings]

FIG. 1 is a sectional view showing a state in which a method of the present invention is being carried out.

FIG. 2 is a perspective view showing a state in which the method of the present invention is being carried out.

FIG. 3 is an explanatory view showing a welding operation around the starting end.

FIG. 4 is an explanatory view of a state in which a welding torch is shifted in twin welding.

FIG. 5 is an explanatory view showing a starting end turning welding operation when the welding torch is shifted.

FIG. 6 is an explanatory view showing the end-turn welding operation when the welding torch is shifted.

FIG. 7 is an explanatory diagram showing a welding operation in which the start end is not rotated when the welding torch is shifted.

FIG. 8 is an explanatory view showing a welding operation without turning the terminal when the welding torch is shifted.

[Explanation of symbols]

 3 fillet welding bead 12 external control axis 16 articulated arc welding robot 18 welding torch 20 welding wire

Claims (1)

[Claims] 1. Two articulated arc welding robots are attached to a common external control axis that is movable in the welding line direction, and two robots simultaneously weld both sides of a pair of fillet weld joints under the same welding conditions. In the case of the joint start end region, that is, the welding is started, the start end turning welding is performed, and the region gradually shifts to the main welding condition, and the joint end portion region, that is, the main welding condition gradually shifts to the end turning welding condition. In the region where the welding is stopped and the welding is stopped, the common external control axis is stopped, and the start and end turning welding is performed by the operation of each robot independently, and the movement of the joint intermediate region, that is, the joint start end is performed. In the region from the completion to the operation of the joint end part, the arms of each welding robot do not move in the welding advancing direction, but while moving the robot in the welding direction by the common external control axis, one fillet In the twin welding method by the robot for fillet joints that welds both sides of the joint at the same time, when welding the joint start point, after turning on the torch switch to the welding power source in order to synchronize the operation of the two robots, In welding, the welding torch is stopped at that position for a predetermined time that is longer than the time required for the arc to occur, and after the predetermined time has elapsed, the arc is confirmed and the arc is generated. If so, a twin welding method by a robot for fillet joints is characterized in that a predetermined starting end welding operation is performed.