JPH0613148B2 - Automatic welding machine controller - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a control device for applying a multi-layer buildup of an object to be welded in an automatic welding machine used for welding a piping system, for example.

[Technical background of the invention and its problems]

Generally, in an automatic welding machine that performs welding with a welding torch while traveling on the circumference of a pipe body of a piping system, it is desired to perform multi-layer welding of thick pipe bodies.

Conventionally, this kind of automatic welding machine reliably performs the entire circumference welding by overlapping the welding start point of the pipe body as the welded body and the welding end point after one round.

However, when the above-described automatic welding machine performs multi-layer welding on the pipe body, the overlapping positions due to the welding are always the same, so that in a thick pipe body having a large number of layers, the overlapping portion will rise. . For this reason, the state of the welded finish becomes a problem, and for example, polishing finish by a grinder is forced.

[Object of the Invention]

The present invention has been made in view of the above-mentioned circumstances, and even for objects to be welded such as thick-walled pipes that require multi-layer welding, a control device automatically performs welding to obtain a good finished state. The present invention provides a control device for an automatic welding machine, which is intended to be controlled in a mechanical manner.

[Outline of Invention]

The present invention provides a control device for an automatic welding machine that controls a drive mechanism, a welding power supply device, and a wire supply device by operating an operation panel, the control device being provided with a microprocessor having set values and a calculation program. First and second D / A converters having an input / output interface and a counter circuit are connected to the operation panel, the welding power supply device is connected to the first D / A converter, and the second D / A converter is connected. Is connected to the drive mechanism via a motor drive circuit, and the counter circuit is connected to the drive mechanism. After the welding start point and the end point of the object to be welded are overlapped, the overlap portion is the same. The welding start point is shifted by an amount to perform multi-layer welding.

Example of Invention

Hereinafter, the control device in the illustrated automatic welding machine in which the present invention is applied to a welded object having a thick-walled pipe will be described.

In FIG. 1 and FIG. 2, reference numeral 1 is a diagrammatical representation of a drive mechanism including respective operating axes of an electrode shaft 1a, a weaving shaft 1b and a traveling shaft 1c. The tip end is provided with the electrode shaft 1a and the weaving shaft 1b in this order, and the free end of the electrode shaft 1a is
A welding torch 2 is attached. Further, each wheel 3 is rotatably mounted on the traveling shaft 1c of the drive mechanism 1, and each wheel 3 has a ring shape attached to a tubular body 4 having a groove portion 4a. It can roll on the rail 4b.

On the other hand, a control device 5 having an operation panel 8 is connected to the drive mechanism 1, and a welding power supply device 6 is connected to the control device 5 so as to supply power to the welding torch 2. . A wire supply device 7 is attached to the control device 5 so as to supply a filler wire as a welding medium to the welding torch 2.

Therefore, the control device 5 sends control signals to the drive mechanism 1, the welding power supply device 6 and the wire supply device 7 based on the welding conditions set in advance or the welding conditions set on the operation panel 8. Is configured to.

On the other hand, in the above-described automatic welding machine, when the thick pipe body 4 is welded by the drive mechanism 1, multilayer welding is performed.
In this case, in order to securely weld the entire circumference of the pipe body 4,
It is necessary to overlap the welding start point and the end point (end point) of the pipe body 4 by a certain amount. However, when the groove portion 4a of the pipe body 4 is repeatedly welded or reciprocally welded for several layers, the welded overlapped portion of the pipe body 4 has about twice as many layers as other welded portions. When it is severe, it becomes a bump and rises, and it is forced to finish it with a grinder.

On the other hand, in FIG. 2, a control device 5 is provided on the operation panel 8.
A memory (memory device) 9 stores a program for automatic welding, set values such as the position of the electrode of the welding torch 2 and a weaving width, and a calculation program in the control device 5. The memory 9 is provided with the microprocessor 1 connected to the memory 9.
0 is provided so as to execute the above-mentioned arithmetic program, and a timer 11 for setting and starting time according to a command of the microprocessor 10 is connected.
Further, the operation panel 8 and the microprocessor 10 are
An input / output interface 12 having each port function is connected, and a first D / A converter 13, a second D / A converter 14, and a counter circuit 16 are provided on one side of the input / output interface 12, respectively. ing.

The first D / A converter 13 converts a current command value of a digital signal output from the microprocessor 10 to the welding power source device 6 via the input / output interface 12 into an analog signal. 2D
The / A converter 14 converts the current command value of the digital signal output from the microprocessor 10 to the motor drive circuit 15 connected to the drive mechanism 1 via the input / output interface 12 into an analog signal. . The motor drive circuit 15 is a control circuit for controlling the drive motors (not shown) for the respective operating shafts such as the electrode shaft 1a, the weaving shaft 1b and the traveling shaft 1c, which are built in the drive mechanism 1. .

The electrode shaft 1a is mounted on the welding torch 2 and is adapted to move in the radial direction of the pipe body 4 as the body to be welded.
Has the electrode shaft 1a attached to the tip thereof so as to move in the axial direction of the tubular body 4, the traveling shaft (not shown) is provided with the weaving shaft 1b, and the wheel 3 The rotation of the tube body 4 can be transmitted to the tube body 4 to move on the circumference thereof.

On the other hand, the counter circuit 16 is a circuit that counts pulse signals from a pulse generator (not shown) in the drive mechanism 1 and outputs the pulse signals to the input / output interface 12. The operation panel 8 is connected to directly operate via the input / output interface 12.

The operation of the present invention will be described below.

The time charts shown in FIGS. 3 (a) and 3 (b) are time charts showing the relationship between the carriage drive (by the drive mechanism) and the welding current, and FIGS. 4 and 5 (a),
(B), (c), (d) shows the flowchart of the control device of the automatic welding machine of the present invention.

On the other hand, the welding means for the thick-walled pipe body 4 includes the repeated welding after the entire circumference of the pipe body 4 is welded, the welding start point is returned to once again, and the welding is repeated again. There is reciprocating welding in which welding is performed while traveling in the reverse direction as a welding starting point for returning.

The time chart of FIG. 3 (a) shows the case of repetitive welding in which welding is repeated again, and the time chart of FIG. 3 (b) shows the case of reciprocal welding in which welding is performed while running in reverse. Is.

The welding sequence by these welding means will be described with reference to the flow charts of FIGS. 4 and 5 (a), (b), (c) and (d).

The operation panel 8 is composed of a keyboard, a digital switch, etc., and sets welding conditions and sequence time in advance, and is equipped with a welding start switch. Therefore,
When the activation switch of the operation panel 8 is turned on, the microprocessor 10 detects this via the input / output interface 12, and the welding power source device 6 receives the first D / A signal.
While outputting the command of the welding current via the converter 13,
Input / output interface 12 to the wire supply device 7
The start command is output via.

Next, the microprocessor 10 reads the trolley delay time T ₁ set by the digital switch of the operation panel 8 through the input / output interface 12 as in the trolley delay timer process of FIG. The timer 11 is set, the timer 11 is immediately activated, and the output signal of the timer 11 is waited for. In this way, when the trolley delay time T ₁ (see FIG. 3 (a)) set as the time until the welding start point is sufficiently melted has elapsed and the output signal from the timer 11 is output,
The microprocessor 10 sends a trolley travel command to the motor drive circuit 15 via the second D / A converter 14.
The driving mechanism 1 travels on the circumference of the pipe body 4 and is welded by the welding torch 2.

On the other hand, a pulse signal from a pulse generator (not shown) that outputs a pulse number proportional to the rotation speed of the drive motor in the drive mechanism 1 is counted by the counter circuit 16. The microprocessor 10 reads the count value of the counter circuit 16 via the input / output interface 12, determines whether or not the drive mechanism 1 has gone around the tube body 4, and when the drive mechanism 1 goes around once. Then, as in the overlap timer processing of FIG. 5B, the overlap time T ₂ set in the operation panel 8 is read through the input / output interface 12 and set in the timer 11. The timer 11 is immediately activated, and the truck drive command output is further output to the motor drive circuit 15 while waiting for the output signal of the timer 11.

In this way, when the overlap time T ₂ (see FIG. 2 (b)) has elapsed and the overlap welding is sufficiently performed, when the output signal is output from the timer 11, the microprocessor 10 As in the down slope processing of FIG. 5 (c), the down slope time (see FIG. 3) T ₃ and the crater current value I _C set on the operation panel 8 are input via the input / output interface 12. A downslope current value I _D that is read and decreases by a constant value every unit time Δt is obtained by the following formula, and is supplied to the welding power source device 6 via the first D / A converter 13 every unit time Δt. Output.

I _D = (1−Δt / T ₃ ) (I−I _C ), where I: welding current command value, and the microprocessor 10 has a down slope current value I _D and a crater current value for each unit time Δt. If the down slope current value I _D becomes equal to or less than the crater current value I _D by comparing with Ic, the crater current value I c is output instead of the down slope current value I _D , and the wire A stop command is output to the supply device 7, and the crater time T ₄ set on the operation panel 8 is read via the input / output interface 12 as in the crater stop timer process in FIG. The timer 11 is set, the timer 11 is activated, and the output signal of the timer 11 is waited for.

When an output signal is output from the timer 11 at the time when the crater time T ₄ has passed and the crater processing is sufficiently completed, the microprocessor 10 causes the welding means set in the operation panel 8 to operate the interface. In the case of the above reciprocation, zero is output as the welding current command value, and in the case of the above-mentioned reciprocation, the welding current command is output instead of the crater current value Ic, and input / output to / from the wire supply device 7 is performed. A start command is output via the interface 12, and further. As shown in FIG. 5 (a),
Carriage delay timer processing is performed.

Next, the microprocessor 10 outputs a trolley travel command to the motor drive circuit 15 via the second D / A converter 14 to cause the drive mechanism 1 to travel backward on the circumference of the pipe body 4. At this time, in the case of the above repetition, without welding,
Only in the case of the above-mentioned reciprocation, the entire circumference is welded. In the same manner as described above, the microprocessor 10 determines from the count value of the counter circuit 16 that the drive mechanism 1 has gone around the tubular body 4, and as shown in FIG. Execute the timer process twice.

As a result, from the welding start point of the first layer of the tubular body 4,
For the overlap time T _{2, the} trolley runs in reverse and stops, and this position becomes the welding start point of the second layer of repetitive welding or the welding start point of the third layer of reciprocal welding.

In the case of the reciprocating welding, the same as above
The down-slope process (Fig. 5 (c)) and the crater stop timer process (Fig. 5 (d)) are performed to complete the reverse traveling welding.

In this manner, the thick pipe body 4 is welded by repeating the multi-layer deposition by the required number of layers.

Therefore, in the case of performing the multi-layer deposition according to the present invention, in the case of the above-mentioned repeated welding, in the case of the above-mentioned second layer, in the case of the above-mentioned reciprocal welding, the welding starting point of the intention of the third layer (only odd layers) is the overlap portion. Since it is possible to sequentially shift each layer by the same amount, the swelling of the overlapping part that occurs when the welding start point is constant is averaged, and for example, good finishing can be achieved without the need for grinding finish by a grinder. Can be welded into condition.

Incidentally, although the present invention has been described with reference to the illustrated embodiment applied to the thick tube body 4, for example, in a multi-layer welding of all-round welding which requires overlap welding in a welded body with a flat or curved surface. Of course, it can also be implemented.

〔The invention's effect〕

As described above, according to the present invention, in the control device of the automatic welding machine that controls the drive mechanism 1, the welding power supply device 6, and the wire supply device 7 by the operation of the operation panel 8, the set value and the calculation are performed in this control device. Memory 9 that stores the program
And a first and second D / A converters 13 and 14 and a counter circuit 16 provided with a microprocessor 10 having a timer 11 connected to the microprocessor 10 and the operation panel 8 and an input / output interface 12.
, The welding power source device 6 is connected to the first D / A converter 13, and the drive mechanism 1 is connected to the second D / A converter 14 via a motor drive circuit.
Is connected to the counter circuit 16 to overlap the welding start point and the end point of the body 4 to be welded, and then the welding start point is shifted by the same amount as this overlap to form a multi-layer overlay. Therefore, the rise of overlap is averaged, and not only the grinding finish by the grinder can be omitted, but also the quality can be improved by welding.

[Brief description of drawings]

FIG. 1 is a diagram showing a control device of an automatic welding machine according to the present invention, FIG. 2 is a block diagram of the present invention, FIG. 3 (a),
(B) is a time chart showing the relationship between trolley drive and welding current, and FIGS. 4 and 5 (a), (b), (c),
(D) is each figure which shows the flowchart of the control apparatus of the automatic welding machine by this invention. 1 ... Drive mechanism, 2 ... Welding torch, 4 ... Welding object,
5 ... Control device, 6 ... Welding power supply device, 7 ... Wire supply device, 8 ... Operation panel, 9 ... Memory, 10 ... Microprocessor, 11 ... Timer, 12 ... Input / output interface, 13 ...... First D / A converter, 14 ……
Second D / A converter, 15 ... Motor drive circuit, 16 ...
Counter circuit.

Claims (1)

[Claims] 1. A controller of an automatic welding machine for controlling a drive mechanism, a welding power source device and a wire supply device by operating an operation panel, a memory storing set values and a calculation program in the controller, and a timer connected thereto. Is provided, and the microprocessor and the operation panel are connected to first and second D / A converters and counter circuits having input / output interfaces, and the welding power source device is connected to the first D / A converter. The driving mechanism is connected to the second D / A converter via a motor driving circuit, and the counter circuit is connected to the driving mechanism. The welding start point and the end point of the object to be welded are exceeded. After lapping, the welding start point is shifted by the same amount as the overlap so that the multi-layer deposition is performed, and the control device for the automatic welding machine is characterized.