JPH07116844A - Controller for arc welding robot - Google Patents

Abstract

PURPOSE:To easily control an arc welding waveform in the real time even during arc welding. CONSTITUTION:A fine adjustment value (level variation) for every arc welding waveform control factor is expressed by the number of steps from a standard value and an adjustment value is inputted from a monitoring part 11 of a robot controller 10 which operates and controls arc welding, by which the arc welding waveform during arc welding can be controlled. Accordingly, the time required for forming arc welding conditions can drastically be shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a welding robot controller for performing arc welding.

[0002]

2. Description of the Related Art Conventionally, in arc welding, standard parameters for arc welding waveform control of an arc welding machine are set in a ROM for storing operating instructions of a CPU in a welding power source control device, which is easy. If you want to perform arc welding waveform control, create a new ROM in which the standard value stored in the ROM is changed, replace it with a new ROM, and perform trial welding to obtain a good result. The above operation was repeated until

[0003]

However, in the above-described method, every time the fine adjustment value for each factor of the arc welding waveform control is changed, the ROM in which the fine adjustment value is changed must be created and the trial welding must be performed. However, there is a problem that a huge amount of time is required for welding work.

The present invention solves the above problems and is intended to change the fine adjustment value of the arc welding waveform control factor between the robot controller that controls the operation of arc welding and the welding power source controller that performs arc welding. The object of the present invention is to provide an arc welding robot control device capable of performing arc welding waveform control even during arc welding each time.

[0005]

In order to achieve the above object, in the arc welding robot controller of the present invention, a fine adjustment value (level change amount) for each arc welding waveform control factor.
Is expressed as the number of steps from the standard value, and the fine adjustment value is input from the monitor section (teach pendant that can be operated at hand) of the robot control device that controls the operation of arc welding, and when the input is completed, or each teaching point of the robot By registering as a sequence command for each, the fine adjustment value (level change amount) for each arc welding waveform control factor is transmitted to the welding power source control device using communication means, and arc welding waveform control is performed even during arc welding. It is configured to be practicable.

[0006]

[Operation] First, arc welding is carried out at a desired welding current and voltage, but at the same time, by the above configuration, fine adjustment work of the arc welding waveform control factor can be performed easily during the arc welding. It is possible to obtain good welding work conditions, and it is possible to significantly reduce the time required to obtain arc welding work conditions.

Further, since the fine adjustment value from the standard value obtained above can be changed for each robot teaching point as a robot sequence command, optimum welding in the actual melting process can be achieved and welding time can be shortened.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In this embodiment, CO₂・ About MAG welding
It was carried out. FIG. 1 shows a welding robot according to an embodiment of the present invention.
Fig. 2 is a CO configuration diagram ₂・ MAG welding waveform
Contents of control factor and fine adjustment value per unit step (level
Change amount), FIG. 3 shows CO₂・ MAG welding waveform control
A diagram showing which part of the welding waveform the control factor corresponds to,
Figure 4 is CO₂・ Step for each MAG welding waveform control factor
FIG. 5 is a diagram showing a tendency with respect to changes, and FIG.₂・
Fine adjustment value for each MAG welding waveform control factor (number of steps)
FIG. 6 shows an example of a screen displaying a screen for setting
It is a principal part block diagram of an arc welding robot control device.

In the welding robot system of FIG. 1, 2
Is a robot control device that creates a program for performing arc welding based on the information input from the monitor unit 1, detects arc current, and continues welding, determines abnormality, etc.
Reference numeral 3 is a control device that controls welding and a welding power unit. In this embodiment, in order to make the communication path between the robot controller and the welding power source controller as short as possible, the welding power source (including the welding power source controller) 3 is sealed with a metal plate as shown in FIG. The control device 2 has a structure that is detachably mounted in the box. As the control factors of the CO ₂ MAG short-circuit arc welding performed this time, the slowdown shown in FIG. 2, the short-circuit initial time T _SO , the short-circuit current bending point I _SC , and the short-circuit current gradient 2I.
_SL2 , plunge prevention time T _SP , arc current refraction point I _ao
Was taken up.

The respective contents are that the slowdown changes the wire feeding speed immediately before the arc start, the initial short circuit time (T _SO ) is the time from the occurrence of the wire short circuit to the rise of the wire breaking current, and the short circuit current bending point. (I _SC ) is the point at which the gradient of the wire breaking short-circuit current is inflection, the short-circuit current gradient 2 (I _SL2 ) is the gradient of the short-circuit current before arc regeneration when the wire short-circuit time is a little long, and the trapping prevention time (T _SP )
Is the time until the wire rush current is output when the wire short circuit time is extremely long, such as when the welding voltage is low,
The arc current refraction point (I _ao ) is the point at which the arc current after the arc is regenerated changes.

In the present embodiment, the number of steps for each factor is ± 3 steps, and the fine adjustment value (level change amount) for a unit step is the value shown in FIG. Here, showed that each regulator of the current taken up with CO ₂ · MAG short arc welding corresponds to which part of the CO ₂ · MAG short arc welding waveform in FIG. Here, the wire slowdown, of course, is not directly related to the welding waveform, and thus is not represented in FIG. Further, when the level of each control factor of CO ₂ MAG short-circuit arc welding taken up this time is changed by the amount of change per unit step shown in FIG. 2, the tendency shown in FIG. 4 is seen. The influence of each control factor of CO ₂ / MAG short-circuit arc welding on the short-circuit arc welding, which was taken up this time, is the arc start property in the slowdown, the arc regularity in the initial short-circuit time (T _SO ), the short-circuit current refraction point (I _SC ). Is the amount of spatter,
The short-circuit current gradient 2 (I _SL2 ) and the plunge prevention time (T _SP ) plunge into the wire, and the arc current bending point (I _ao ) is the arc spread.

Next, during the welding operation, the operator observes the welding condition and the bead appearance, and the monitor section shown in FIG. 5 shows the number of steps for each control factor of the CO ₂ / MAG short-circuit arc welding taken up this time. It is changed and set through the liquid crystal display section of the monitor section shown in FIG. As the actual change operation, use the cursor movement keys to bring the blink (blinking) cursor to the step number of the desired CO ₂ · MAG short-circuit arc welding control factor, and press the “memory selection” key to select the number of steps (level change amount). ) Is changed and set. CO ₂
・ After changing and setting each control factor of MAG short-circuit arc welding, press the "End" key. At the time of pressing the key, the number of steps of each control factor of CO ₂ · MAG short-circuit arc welding (level change) Quantity) is communicated from the robot controller side shown in FIG. 6 to the welding power source controller side. Here, the number of steps of each control factor of CO ₂ MAG short-circuit arc welding changed and set from the monitor unit 11 of the arc welding robot controller 10 in FIG. 6 is determined by the CPU 12 on the robot controller side being connected to the bus 18. CPU 2 through the bus 25 through the communication interface 24
0 is read CO according to the number of steps (level change amount) of each welding waveform control factor of CO ₂ · MAG short circuit arc welding
₂ -MAG short-circuit arc welding Waveform control can be performed immediately even during welding.

Here, the communication protocol is: transmission speed: 9600 bps, transmission direction: full duplex, data length: 8 bits + even parity 1 bit, communication flow control: no X'ON, modem interface: RS422. .

ROM 13 and ROM 21 are CPU 12 and C
Each algorithm for operating the PU 20 is stored. In accordance with the program (robot operation procedure) taught in the RAM 14, the CPU 12 causes the motor control unit 15,
The welding torch fixed to the robot body 19 is moved via the servo driver unit 16. In addition, RAM22
Is the work area of the CPU 20 and the CPU 20 is the CPU 12
Various welding construction conditions etc. instructed by the communication are temporarily stored. According to the welding construction conditions and the like, a welding current is supplied to the welding wire through the welding control unit 23 to generate CO ₂
MAG short circuit arc welding is performed. In this way, C
O ₂ · MAG short circuit arc Welding waveform control The number of welding waveform control steps (level change amount) for each factor can be transmitted to the welding power source control device side even during welding by using the communication means.
The effort required for adjusting the O ₂ · MAG short-circuit arc welding waveform control can be far reduced as compared with the conventional method. Also, regardless of the CO ₂ / MAG short-circuit arc welding method, arc welding waveform control factors are extracted for other arc welding methods as well, and standard values for each welding waveform control factor and fine adjustment change amount per unit step are defined in advance. Obviously, it will be easy to develop if you do so.

[0016]

As described above, according to the present invention, CO ₂
A standard value for each welding waveform control factor of MAG short-circuit arc welding and a fine adjustment change amount per unit step are defined in advance, and the number of steps is transmitted to the welding power source control device by communication even during welding, and CO performed by easily and real-time using a teach pendant can be manipulated ₂ · MAG short number of steps each weld waveform regulator of arc welding (level variation) CO ₂ · MAG short arc welding waveform control according to the at hand . Therefore, as in the prior art CO ₂ · MAG short number of steps each weld waveform regulator of arc welding (level variation) is not necessary to perform the change created try welding the ROM each time set, CO ₂ · Since the MAG short-circuit arc welding process can be performed finely, desired welding process conditions can be obtained in a short time.

Further, since the fine adjustment value from the standard value obtained above can be changed for each robot teaching point as a robot sequence command, optimum welding in the actual melting step and shortening of welding time can be achieved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a welding robot system according to an embodiment of the present invention.

FIG. 2 is a diagram showing the level change amount per unit step defined as the extracted welding waveform control factor in the CO ₂ MAG short circuit arc welding method carried out in the present invention.

FIG. 3 is a diagram showing where in the welding waveform the extracted welding waveform control factor in the CO ₂ MAG short circuit arc welding method implemented in the present invention corresponds.

FIG. 4 is a diagram showing a tendency for a step (level) change for each extracted welding waveform control factor in the CO ₂ MAG short circuit arc welding method carried out in the present invention.

FIG. 5 is a diagram of a monitor unit for inputting the number of steps (level change degree) for each extracted welding waveform control factor in the CO ₂ / MAG short-circuit arc welding method implemented in the present invention.

FIG. 6 is a block diagram of a main part of a CO ₂ MAG short-circuit arc welding robot controller implemented in the present invention.

[Explanation of symbols]

 1 Teach Pendant (Monitor) 2 Robot Controller 3 Welding Power Supply 10 Arc Welding Robot Controller 11 Monitor 12 CPU 13 ROM 14 RAM 15 Motor Controller 16 Servo Driver 17 Communication Interface 18 Bus 19 Robot Main Body 20 CPU 21 ROM 22 RAM 23 Welding controller 24 Communication interface 25 Bus

Claims (2)

[Claims] 1. Fine adjustment from a standard value for each arc welding waveform control factor by means of communication from an industrial robot control device configured to control arc welding to a welding power supply control device section for performing the arc welding. A control device for an arc welding robot, which is capable of performing arc welding waveform control during welding operation by transmitting the amount. 2. The amount of fine adjustment from the standard value for each arc welding waveform control factor can be finely adjusted in real time from the teach pendant at hand while adjusting welding conditions, and in addition, during robot automatic operation. The arc welding robot controller is characterized in that the fine adjustment amount can be changed for each robot teaching point as a sequence command on the robot program.