JPS59193766A - Arc welding device - Google Patents

Abstract

PURPOSE:To abolish a control cable and to improve working efficiency by providing a mechanism for converting a welding output voltage regulating signal to a digital quantity, transmitting the same by a carrier, demodulating the carrier, converting the demodulated signal to an analog quantity, and drawing out the voltage regulating signal. CONSTITUTION:The signal of an analog quantity from a variable resistor 12 for regulating welding voltage is converted to a signal 34A of a digital quantity by an A-D converting circuit 34. On the other hand, the carrier 32A of a carrier generating circuit 32 is applied to a modulating circuit 31, where the signal is modulated by a modulating signal 34A to a signal 31A. The modulated signal is outputted from said circuit. The signal 31A is radiated by a diode 33 to a photodetector 29, from which the signal is applied to a demodulating circuit 28. Only the modulating signal 28A is drawn by the circuit 28 and is applied to a D-A converting circuit 30 which converts the signal to an analog quantity and applies the same to a firing phase control circuit 6 of a thyristor. The firing phase of the thyristor is controlled by the welding output voltage regulating signal converted to the analog quantity, by which the output voltage of a welding machine is regulated.

Description

[Detailed Description of the Invention] Field of Industrial Application In general, semi-automatic arc welding equipment has superior features such as faster welding speed than coated arc welding equipment and can be easily used even by amateurs. Its popularity is remarkable due to its ability to save labor.

However, semi-automatic arc welding equipment has a more complicated configuration than a covered arc welding machine, and is inferior to a covered arc welding machine in terms of maneuverability.

The present invention relates to an arc welding device, and is intended to reduce the weight of one device and improve the mobility of welding work to the same level as that of a covered arc welder.

Structure of conventional example and its problems FIG. 1 shows a schematic block diagram of a conventional arc welding device. 1 is a transformer, 2 is a voltage adjustment/rectification unit using Cyrisk, 3 is a smoothing unit, 4 is a control circuit for the consumable electrode feeding motor 50, 6 is an ignition phase control circuit for the Cyrisk, and 凯 is for feeding. roller, 8 is a consumable electrode wound in a coil, 9 is a current supply tip, 10 is the object to be welded, 11 is a variable resistor for adjusting the welding current, 12 is a variable resistor for adjusting the welding voltage, 13 is the start/stop of welding 14 is a welding DC power source; 15 is a wire feeding device connected to the welding DC power source 14 with large capacity welding current cables 16, 17 and control cables 18-27. To adjust the output of this arc welding device, the welding voltage setting signal VO, which is set by the welding voltage adjusting variable resistor 12 at the welding operator's hand, is controlled by the thyristor of the welding DC power source 14 using the control cable 23°24.26. This was done by transmitting the signal to the ignition phase control circuit 6.

When this arc welding machine is used in a large workshop, the welding DC power supply 14 and the welding voltage adjustment part of the wire feeder 15 must be extended several tens of meters using an extension cable, and this extension cable is used for welding work. This caused poor mobility and a significant drop in work efficiency. In addition, this extension cable was placed on the floor of a large workplace, causing frequent disconnection accidents.

OBJECTS OF THE INVENTION The present invention eliminates the above-mentioned drawbacks of the prior art, and aims to eliminate the control cable for transmitting the welding voltage setting signal that connects the welding DC power source and the variable resistor for adjusting the welding voltage. 0 Structure of the Invention As a further structure, the present invention provides a carrier wave generation circuit, a variable resistor for welding voltage adjustment, an A-D conversion circuit, and a modulation circuit in the wire feeding device or its vicinity. A circuit converts the analog variation of the variable resistor for welding voltage adjustment into a digital variation.

The configuration is such that the signal from the carrier wave generation circuit is modulated and transmitted to one welding DC power source, and the welding DC power source includes a demodulation circuit, D-
A human conversion circuit is provided to demodulate the modulated carrier wave signal and extract the welding voltage adjustment signal converted into a digital quantity -D-
The A conversion circuit converts the digitized signal into an analog welding voltage adjustment signal to control the welding voltage.

Description of examples FIG. 2 is a drawing showing one embodiment of the present invention.

01.2, 3, 4, 5°6.7 explained according to Figure 3
, 8, 9, 1Q, 11.12, 13.16-17, 18
-22 respectively have the same transformer as the conventional one, voltage adjustment/rectification section, smoothing section, control circuit, consumable electrode feeding motor 1 firing phase control circuit, feeding roller, consumable electrode 1 energizing chip,
Workpiece to be welded, variable resistor for adjusting welding current, variable resistor for adjusting welding voltage.

These are the hand switch, welding current cable, and control cable.

14' is a DC power supply for welding, 16' is a wire feeding device, 28 is a demodulation circuit, 29 is a light receiving element using a photo diode, 3o is a D-A conversion circuit, and 31 is a modulation circuit.
32 is a carrier wave generation circuit, 33 is a light emitting diode, and 34 is an A-D conversion circuit.

Next, the welding output voltage adjustment function of the arc welding apparatus of this embodiment will be explained.

The signal from the welding voltage adjusting variable resistor 12 in FIG. 2 is an analog quantity. This welding voltage adjustment signal becomes a modulation signal 34A which is converted into a digital quantity by the A-D conversion circuit 34 as shown in FIG.

On the other hand, a high frequency carrier wave 32 as shown in FIG. 3 is applied to the modulation circuit 31 from the carrier generation circuit 32. This high-frequency carrier wave 32A is modulated by a modulation signal 34A in a modulation circuit 31, and the O-modulated carrier wave signal outputted as a signal 31 as shown in FIG. 33 and reaches the light receiving element 29. The carrier wave signal received by the light receiving element 29 is applied to a demodulation circuit 28, and only a modulated signal 28A as shown in FIG. 3 is taken out by the demodulation circuit 28. Furthermore, this modulation signal 28A is transmitted to the D-A converter circuit 3 in FIG.
After being converted into an analog quantity, it is applied to the firing phase control circuit 6 of the thyristor. The output voltage of the welding machine is adjusted by controlling the firing phase of the thyristor using the welding output voltage adjustment signal converted into an analog value.

As described above, the welding output voltage adjustment signal is once converted into a digital quantity, transmitted between the wire feeder 15' and the welding DC power source 14' using a carrier wave, and modulated by the welding DC power source 14'. The output voltage of the welding machine can be adjusted externally from the welding DC power source 14' without using a control cable by demodulating the carrier wave, converting it into an analog value, and extracting a welding output voltage adjustment signal. There is.

Effects of the Invention As described above, the arc welding device of the present invention can perform welding at the welding operator's hand without using a control cable for transmitting the welding voltage setting signal, which was required between the welding DC power source and the welding operator. Since it is possible to adjust the output voltage of the machine, when welding in a large work area, it is easy to move, which not only improves work efficiency, but also eliminates the need for control cables to transmit welding voltage setting signals. This eliminates cable breakage accidents9, improving quality.In addition, if the distance between the welder and the welding DC power source is several tens of meters, there is no need for a control cable at all, which is advantageous in reducing costs. This has excellent effects.

[Brief explanation of the drawing]

FIG. 1 is a schematic block diagram of a conventional arc welding device, FIG. 2 is a schematic block diagram of an arc welding device according to an embodiment of the present invention, and FIG. 3 is a schematic block diagram of a welding output voltage adjustment signal of the arc welding device of the present invention. This is a transition diagram. 1...Transformer, 2...Voltage adjustment/rectification section, 3...Smoothing section, 4...Control circuit for consumable electrode feeding motor-5 ...Consumable electrode feeding motor, 6... Thyristor firing phase control circuit,
7...Feeding roller 5B...consumable electrode,
9... energizing tip -10... object to be welded,
11... Variable resistor for welding current adjustment, 12...
...Variable resistor for adjusting welding voltage, 13...Hand switch for starting and stopping welding, 14'...DC power supply for welding, 16'...Wire feeding device , 16.
17...Welding current cable, 18.19...
...Control cable for consumable electrode feeding motor, 20,2
1.22... Control cable for transmitting welding current adjustment signals -28... Demodulation circuit -29...
・・Photodetector-30・・・・・・D-person conversion circuit-31
... Modulation circuit, 32 ... Carrier wave generation circuit, 33 ... Light emitting diode, 34 ...
A-ri conversion circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 415. Figure 2

Claims (1)

[Claims] A wire feeding device that automatically feeds a consumable electrode to a welding part using an electric motor, and a welding DC power source whose output voltage can be controlled externally, are installed at or near the wire feeding device. , carrier wave generation circuit. A variable resistor for welding voltage adjustment, an A-D conversion circuit, and a modulation circuit are provided, and the analog change amount of the welding voltage adjustment variable resistor is converted into a digital change amount by the multi-conversion circuit, and the amount of change from the carrier wave generation circuit is The configuration is such that the signal is modulated and transmitted to the welding DC power source, and the welding DC power source is equipped with a demodulation circuit and a D-A.
A conversion circuit is provided. Demodulating the modulated carrier wave signal, extracting a welding voltage adjustment signal converted into a digital quantity, and converting the digitized signal into an analog welding voltage adjustment signal in the D-A conversion circuit, Arc welding equipment that controls welding voltage.