JPH03221267A - Arc welding method by robot - Google Patents

Abstract

PURPOSE:To eliminate the need for teaching of an intermediate point and to simplify teaching operations by teaching the beginning point and end point of a weld line to a robot, tracing the weld line, measuring the distance between the beginning point and the end point and executing arc welding based on the beginning point, the end point and the distance. CONSTITUTION:The beginning point S and end point E of the weld line 8 of a work 7 are taught prior to welding. The weld line between this beginning point S and end point E is traced by the robot and the moving distance thereof is measured to measure the distance of the weld line 8 between the beginning point S and end the point E. The welding is executed until the measured distance is attained at the time of the welding so that the exact welding up to the end point E is executed. The need for teaching the intermediate point is, therefore, eliminated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a robot arc welding method for arc welding a IIIJ weld line using a robot, and in particular to a robot arc welding method that uses a robot to arc weld a IIIJ line welding line, and in particular, to a robot arc welding method that enables accurate arc welding to a predetermined end point. This article relates to an improved robot arc welding method.

[Conventional technology]

In arc welding using a robot, a method is used in which a laser sensor or the like is used to track a °C1 weld line and automatically perform welding along the weld line.

In such a welding method, arc welding can be performed using a laser sensor by teaching only the starting point and ending point of the welding line.

[Problem to be solved by the invention]

However, when the weld line is a curve, it is necessary to teach several points in addition to the start and end points of the weld line in order to approximate the weld line with a straight line. This is because the welding end point is defined by the straight distance from the start point. That is, if the end point is determined based on the straight-line distance between only the start point and the end point, the distance will be shorter than the actual distance, and welding will end before the actual end point.

In particular, when the radius of curvature of the weld line is small, unless the number of taught points is increased to some extent, the actual end point will be considerably closer to the taught end point.

The present invention has been made in view of these points, and it is an object of the present invention to provide an improved robot arc welding method that enables accurate arc welding to the taught end point.

[Means to solve the problem]

In order to solve the above problems, the present invention provides a robot arc welding method for arc welding a curved weld line using a robot, in which the start and end points of the weld line are taught and the weld line is traced. A robot arc welding method is provided, characterized in that a distance between the starting point and the ending point is measured, and arc welding is performed based on the starting point, the ending point, and the distance.

[Effect]

Prior to welding, teach the start and end points of the weld line. The robot tracks between the starting point and the ending point, measures the moving distance, and determines the starting point and ending point n.

Measure the distance of the weld line.

During actual processing, welding is performed until this measured distance is reached, and welding is performed accurately to the end point.

〔Example〕

Hereinafter, one embodiment of the Kinenori] will be described based on the drawings.

FIG. 2 is a schematic diagram of an arc welding robot system for implementing the present invention. A hand 2 of the robot 1 is provided with an arc welding torch 4 via a member 3. Further, the member 3 is provided with a laser +7' sensor 5, which outputs a laser beam 6 so that the torch 4 traces the welding line 8 of the workpiece 7.

This tracking operation is performed by driving a servo motor within the robot 1 by the robot control device 10.

FIG. 3 is a detailed view of a workpiece to be arc welded. The welding line 8 of the workpiece 7 is a curved line, and welding is performed from a welding start point S to an end point E.

In the conventional welding method, it was necessary to teach several points between the starting point S and the ending point E. In the present invention, only the starting point S and the ending point E need to be taught without such teaching.

FIG. 4 is a schematic block diagram of the robot control device.

The robot control device IO has a processor board 31, and the processor board 31 includes a processor 31a, RO
There are M3 l b and RAM31 c. processor 31
a controls the entire robot control device EIO according to a system program stored in the ROM3 lb. R.A.
M31c stores 6 pieces of data, as well as the operation program and arc welding conditions for the robot 1. RAM
A part of 31c is configured as non-volatile memory,
The operating program or welding conditions are stored in a manually operated memory section. Processor board 31 is coupled to bus 39.

The digital servo control 011 circuit 32 is coupled to a bus 39, and according to commands from the processor board 31, the servo motors 51, 52, 53 are connected via the servo amplifier 33.
．． 54, 55 and 56 are driven. These servo motors are built into the robot 1 and operate each phase of the robot 1.

The serial boat 34 is coupled to the bus 39 and connected to a teaching operation panel 57 with a display and other R3232tm devices 58. A teaching operation panel 57 with a display is used to input the starting point S, ending point E, etc. of the welding line. In addition, a CRT36a is connected to the serial port, and the CRT
Welding conditions and the like are displayed at 36a.

An operation panel 36b is connected to the digital l1035. Also, digital l1035 and analog l1
Welding conditions etc. to the welding machine are output via 037.

The analog l 1037 receives the signal from the laser sensor 5 and controls the torch 4 to track the weld line 8.

Further, the large-capacity memory 38 stores general teaching data, welding conditions used outside of Tanabe, and the like.

FIG. 1 is a flowchart of the robot arc welding method of the present invention. In the figure, the digits surrounding S indicate step numbers.

[S1] Teach the starting point S and ending point E of the welding line 8.

[S2] A flag is set to measure the moving distance of the weld line 8 during the tracking operation.

[S3] Weld line 8 is added using laser sensor 5.

(S4) Every time 1-1-chi 4 moves a certain distance, the amount of movement Δ
1 is added to update the transfer JIIJml.

[S5] Check whether the end point E has been reached, and if not, return to S3 and continue the tracking operation. If the end point has been reached, the process advances to S6.

[S6] Reset the distance measurement flag.

[S7] Every time a welding operation is performed and a certain distance Δl is welded, the welding distance 1a is updated in addition to the welding distance 1a.

[S8] Welding distance I! Check whether a becomes equal to the distance l between the starting point S and the ending point E, and if not, return to S7 and continue the welding operation.

In this way, welding can be performed accurately up to the end point E.

〔Effect of the invention〕

As explained above, in the present invention, the weld line is traced, the distance of the weld line is measured, and welding is performed based on this distance, so welding can be performed accurately to the end point.

Furthermore, there is no need to teach intermediate teaching points as in the prior art, which simplifies the teaching operation.

[Brief explanation of drawings]

Fig. 1 is a flowchart of the robot arc welding method of the present invention, Fig. 2 is a schematic diagram of an arc welding robot system for implementing the present invention, Fig. 3 is a detailed view of the workpiece to be arc welded, and Fig. 4 1 is a schematic block diagram of a robot control device. 1 ゛ Robot 2 - Hand 4 - Torch 5 - Laser sensor 6 Laser beam 7 Work 8 - Welding line 0 Robot control device Processor board patent author FANUC Corporation

Claims (2)

[Claims] (1) In a robot arc welding method for arc welding a curved weld line using a robot, the start point and end point of the weld line are taught, the weld line is traced, and the distance between the start point and the end point is taught. A robot arc welding method characterized in that arc welding is performed based on the starting point, the ending point, and the distance. (2) The robot arc welding method according to claim 1, wherein the tracking operation is performed by a laser sensor.