JPH0459073B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic processing method for a welding robot after a temporary stop occurs when a starting edge is detected.

Generally, when welding a welding line according to a program, a welding robot causes the welding torch to perform a search operation from a search start point, and automatically detects the starting end of the welding line based on the contact between the welding wire and the workpiece. It has a function. This is because the welding line and its teaching data do not necessarily match due to workpiece setting errors, tacking errors, workpiece variations, etc., so at least the starting end of the welding line is automatically detected before welding starts, and welding is started. This is to prevent you from getting the wrong position. Note that when automatic welding is started, a slight deviation between the welding line and the teaching data is automatically corrected by a welding line tracing function using an arc sensor.

Here, an example of a search when detecting the start end will be explained.

As shown in FIGS. 1 and 2, when detecting the starting end of the weld line 1 in a state where the workpiece 2 is set so that the weld line 1 is parallel to the X-axis direction, first As shown in FIG. 1, the end face 2a of the workpiece 2 is searched for. That is, the welding torch 3 is searched in the X-axis direction from the search start point P1, and when it is electrically detected that the welding wire 4 has contacted the workpiece 2, the welding torch 3 is stopped. Next, as shown in Figure 2, weld line 1
Perform a horizontal fillet search. That is, the welding torch 3 is searched in the Z-axis direction from the search start point P2, and when the welding wire 4 comes into contact with the workpiece 2, the welding torch 3 is stopped, the welding torch 3 is returned from that position by a certain amount, and then the welding is started. Torch 3 to Y
The welding torch 3 is searched in the axial direction, and when the welding wire 4 comes into contact with the workpiece 2, the welding torch 3 is stopped, and the welding torch 3 is moved by a certain amount in a predetermined direction from that position.

During such a search for starting edge detection, as shown in FIG. 3, even if the maximum search distance l (for example, 40 mm) is exceeded, the welding wire 4 and the workpiece 2 do not come into contact, which may cause a temporary stop. Furthermore, as shown in FIG. 4, the nozzle of the welding torch 3 may come into contact with the workpiece 2 during the search, which may cause a temporary stop.

In conventional welding robots, when a robot temporarily stops due to the above reasons, the operator must take appropriate actions and then operate a pause release button to restart the robot, which places a heavy burden on the operator and makes it difficult for robots to operate unattended. This was a hindrance to speedy driving.

The present invention has been made in view of the above circumstances, and when a welding robot temporarily stops during a search operation for starting edge detection, one of the causes of the pause is automatically resolved, significantly reducing the burden on the operator. An object of the present invention is to provide an automatic processing method after a temporary stop occurs when detecting a start end.

According to this invention, one of the main reasons why a welding robot pauses during a search operation for starting edge detection is that the protruding length of the welding wire is short, and when the welding robot pauses during a search operation for starting edge detection The welding wire is automatically moved from its stopping position to a predetermined position, and the protrusion length of the welding wire is adjusted there.
The above object is achieved by moving to the search starting point again and executing the search operation.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 5 is a flowchart showing an automatic processing method after a temporary stop occurs at the time of starting edge detection according to the present invention. In the figure, when starting edge detection is started from the search start point, starting edge detection is executed according to a starting edge detection program programmed in advance according to the joint shape of the workpiece. If the start end detection is temporarily stopped for various reasons (for example, when the welding wire does not contact the workpiece even after the maximum search distance is exceeded, or when the nozzle of the welding torch contacts the workpiece), the The prepared processing subroutine program is executed to adjust the protruding length of the welding wire to a predetermined length, and start detection of the starting end again. Then, the cause of the temporary stop is canceled by adjusting the wire protrusion length, and when the start end detection is completed, the next operation is started. Note that when the wire protrusion length is adjusted and then temporarily stopped again, it is necessary to maintain the temporarily stopped state without executing the processing subroutine program and wait for appropriate processing by the operator.

Next, the operation according to the above processing subroutine program is performed as shown in FIG.
A case will be described in which the welding torch 10 is caused to perform a search operation (operation) in the Z-axis direction, and the nozzle of the welding torch 10 comes into contact with the workpiece 11 during the search operation and is temporarily stopped.

In this case, the welding torch 10 is returned from the temporary stop position to the search start point P10 (operation), and then moved to the safe position C1 for adjusting the protrusion length of the welding wire 12 (operation). At this position C1, the protruding length of the welding wire 12 is adjusted, for example, by extending the welding wire 12 until it comes into contact with the reference surface 13. In addition,
At the position C1, the attitude of the welding torch 10 is controlled in the previous step so that the welding torch 10 assumes a predetermined attitude (facing downward).

When the adjustment of the wire protrusion length is completed, the welding torch 10 is moved again to the search start point P10 (operation), and the start end detection is started again here.

In this embodiment, the search starting point P10 is
However, the point is that the welding torch is moved from the temporary stop position to the safe position C1 to prevent interference between the welding torch and the workpiece.
1 or from the safe position C1 to the search start point.

As explained above, according to the present invention, when there is a temporary stop during the search operation for start end detection, the cause of the temporary stop due to a defective wire protrusion length can be automatically resolved, greatly reducing the burden on the operator. can be reduced. Furthermore, it is not necessary to adjust the wire protrusion length for all welding lines before starting detection, and the number of man-hours can be reduced.

[Brief explanation of drawings]

Figures 1 and 2 are diagrams each showing an example of the search operation when detecting the starting end of a weld line, and Figures 3 and 4 are diagrams showing temporary stop factors that occur during the search operation shown in Figures 1 and 2, respectively. FIG. 5 is a flowchart showing an automatic processing method after a temporary stop occurs when detecting a starting end according to the present invention, and FIG. 6 shows an example of the operation of a welding torch according to the method of the present invention. It is a schematic diagram. 10...Welding torch, 11...Workpiece, 12...
...Welding wire, 13... Reference plane, P10... Search start point, C1... Safety position.

Claims (1)

[Claims] 1. When welding a welding line according to a program,
The welding torch is searched from the search start point,
In a welding robot that has a function to automatically detect the starting end of the welding line based on the contact between the welding wire and the workpiece, the welding torch is moved from a temporary stop point to a predetermined position, and the protrusion length of the welding wire is adjusted there. Then, a subroutine is prepared to move the welding torch to the search start point again and start the search operation, and when the welding torch is temporarily stopped due to various factors during the search operation, the above subroutine is automatically executed.
An automatic processing method after a pause occurs when detecting a start end, characterized by executing the process twice. 2. The reason why the welding torch temporarily stops during the search operation is when the nozzle of the welding torch and the workpiece come into contact with each other, and when the welding wire does not come into contact with the workpiece even after the maximum search distance is exceeded. Automatic processing method after a temporary stop occurs when starting edge is detected as described in Section 2.