RU1836199C - Welding rectifier - Google Patents

Description

there is an operating mode switch 11, the input of which is connected to the output of the thyristor rectifier 8, one of the outputs is connected to one of the inputs of the current relay 12, and the other output is connected to the electronic switch 1. The output of the current relay 12 is also connected to the electronic switch 1, and one from the inputs with the current sensor 10. The mode reference node 13 is connected to one of the inputs of the adder 3. The auxiliary three-phase transformer 14 is connected by secondary windings to the phase distributor 6 and the secondary windings of the three-phase transformer 15 are connected to the thyristor rectifier Ithel 8. The primary windings of transformers 14 and 1S5 are connected to a three-phase AC network.

The welding rectifier operates as follows.

The signal from the output of the current sensor 10. Arrives at the electronic switch 1 and the current relay 12, and the signal from the output of the thyristor rectifier 8 is fed to the electronic switch 1 and the mode switch 11. Electronic switch 1, depending on the position of the mode switch 11 and the output signal with current relay 12, it switches either to the output of current sensor 10 or to the output of thyristor rectifier 8. Next, the signal is fed to the input of amplitude-phase corrector 2, while the welding rectifier is covered by current or voltage feedback leniyu. The amplitude-phase corrector 2 corrects the phases of the feedback signal, while ensuring the stability of the welding rectifier. From the output of the amplitude-phase corrector 2, the signal is fed to the input of the adder 3, where it is summed with the signal coming from the mode reference node 13. From the output of the adder 3, the total feedback signal and the mode reference node 13 is fed to the integrator 4, which has a high constant voltage transmission coefficient provides highly stable static characteristics of welding rectifiers. From the output of the integrator 4, the signal is fed to the input of the relay element 5, which in the case of a deviation of the feedback signal from the value of the signal from the output of the mode node 13 generates a pulse to the input of the phase distributor 6. The phase distributor 6 distributes the pulse to the inputs of the six the terminal amplifier 7, depending on the phase of the voltage supplied by the transformer 14. The terminal amplifier 7 amplifies the signal to the level required

to turn on thyristor rectifier 8. The signal from thyristor rectifier 8 is fed to inductor 9, which filters the welding current from the mains frequency. Next, the signal is fed to a current sensor 10, from which information about the magnitude of the flowing current is removed, then to the welding electrode.

The welding rectifier can be

made, for example, as shown in figure 2.

The electronic switch 1 is made on transistor switches 16, 17, resistances 18-24, a capacitor 25 and a diode 26.

5 The amplitude-phase corrector 2 is made on an operational amplifier 27, capacitors 28, 31 and resistances 29, 30, 32, an adder 3 and an integrator 4 are implemented on an operational amplifier 35, a capacitor

0 33 and diode 34. The relay element 5 is made on the resistance 36 and the operational amplifier 37. The mode reference node 13 is implemented at the resistances 38, 39. The phase distributor 6 is implemented on the logical

5 elements, terminal amplifier 7 - on transistors, thyristor rectifier 8 - on thyristors. As a current sensor 10 used a shunt. The operation mode switch is made on a tinker switch, and the current relay 12 is on an operational amplifier.

K 553 UD 2 microcircuits were used as operational amplifiers, and K 511 LA microcircuits were used as logic elements

5 1 and K 511 LI 1. KT 315 B transistors were used as transistor keys in the electronic switch, and KT 816 B as transistors in the terminal amplifier. Used thyristors

0 thyristors T161-160-9-1, as a throttle and transformers used a choke and three-phase transformers used in. straightener mitu VDU-506UZ (prototype).

5 Ultrasonic testing of welds made using a welded rectifier showed that the content of microdefects in them is much lower than when welding with a known

0 with a welding straightener (prototype), i.e. the welding quality is significantly improved. Improving the quality of the weld reduces scrap and improves productivity by reducing time

5 to fix the marriage.

SUMMARY OF THE INVENTION A welding rectifier comprising an adder with a mode set node connected to the first of its inputs, interconnected with a pa6oiw mode switch and a current relay, and a circuit of a phase distributor b connected in series with one another by a three-phase auxiliary input connected to the first of its inputs a transformer, an amplifier, a thyristor rectifier with a three-phase transformer connected to its power input, a throttle and a current sensor, and the thyristor rectifier output is also connected to a switch-mode work, and the output of the current sensor is connected to a current relay, and this is so that, in order to improve the quality of welding by increasing the static and dynamic

characteristics of the welding rectifier, an electronic switch is inserted into it, the inputs of which are connected to the outputs of the current sensor, thyristor rectifier, current relay and mode switch, the amplitude-phase corrector is connected in series with the electronic switch, the output of which is connected to the second input of the adder, an integrator and a relay element interconnected in series and included in the circuit between the output of the adder and the second input of the phase distributor.

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.Fig. 2