SU1382611A1 - Apparatus for arc welding - Google Patents

Description

(21) 4064686 / 25-27

(22) 05.05.86

(46) 03/23/88. Bksh. № 11

(71) Electric Welding Institute. E.O.Patona

(72) I.V. Pentegov, E.P. Stemkovsky, D.A. Sheykovsky, V.A. Legostaev

and A.A.Bolotaev

(53) 621.791.75 (088.8)

(56) USSR inventor's certificate 1147531, cl. In 23 K 9/00, 1982.

(54) DEVICE FOR ARC WELDING

(57) The invention relates to a power source for pulsed electric arc welding and can be used in various industries of the national economy. The purpose of the invention is to improve the mass and size parameters and the efficiency of the device. The device contains a power supply with a buffer capacitor at its output, an inductive energy storage device (INE) with tapping from the winding, a switch, a control unit, and two diodes. The INE winding part is common to charging and discharging currents. In the case of flow, for example, of a charging current across the entire winding, the discharge current, determined by the stored energy in the INE, flows through a diode in a part of the same winding. This allows the INE winding to be performed with a smaller number of turns, and therefore, to reduce the consumption of copper, which accordingly makes it possible to select the core for the INE with a smaller window size. The voltage level on the arc gap when the arc is broken can be set to any level (not exceeding the voltage allowed by safety), by selecting the number of turns of the recovery section of the INE winding, respectively. The recovery of energy into the buffer capacitor increases the efficiency of the device. 1 hp f-ly, 5 sp.

cl

This invention relates to arc welding power sources.

The purpose of the invention is to improve the overall dimensions and efficiency of the device.

Figure 1 shows a schematic diagram of an arc welding device for the case when a power source through a switch and a first diode is connected to the winding portion of an inductive energy storage device (INE), with a cathode diode connected to a tap from the middle winding portion in Figure 2 - graph of current change through the arc gap; Fig. 3 is a schematic diagram of an apparatus for arc welding for the case when the power source is connected via a switch to the outlet from the middle part of the winding, and the first diode to one end of the INE winding with its cathode; Fig. 4 is a graph showing the change in current through an arc gap in the device according to the scheme in Fig. 3; Fig. 5 is a schematic diagram of the device for arc welding for the case of IEE with the possibility of changing the number of turns between its outputs.

ycTpcJ cTBo for arc welding (Fig. 1) contains the power source 1, the buffer capacitor 2, INE 3, key 4, block 5 of the upper part, the first 6 and the second p.: -; 1 7 diodes, arc gap 8, with the first pole 9 A power supply source 1 is connected via a switch 4 to one of the leads of the INS 3. The cathode of the diode 6 is connected to the outlet 11 of the INE 3, and the outlet 12 through the diode 7 is connected to the pole 9 of the power supply. The second output 13 of the INE 3 winding is connected through an arc gap to the second pole of the power source, which is connected to; .1k and to the anode of diode 6.

On the graph (Fig. 2), section 14 is on interval C (t corresponds to current creeping through section 10-13 of INE 3 and the arc gap, and section 15 i: a interval through section 11-13 of INE 3 and the arc gap.

The device (FIG. 3) contains a power supply 1, a buffer capacitor 2, an INE 3, a switch 4, a control unit 5, a first 6 and a second 7 diodes, an arc gap 8, the first pole 9 of the power supply 1 1 being connected to the tap 4 11 from the part of the winding INE 3, the second pole of the power source 1 is connected to the output

0 5 0 5

0 Q

.

0

five

A d 10 winding through diode 6, an arc gap 8 is connected to another output 13 of an INE winding 3 and an anode of a diode 6, and a drain 12 through a diode 7 is connected to pole 9 of power supply 1.

Fig. 4 is a graph showing the change in current through an arc gap in the device according to the scheme of Fig. 3. Plot 16 of the graph is the current through sections 11-13 of the INE 3 winding, plot 17 of the graph is the current through sections 10-13 of the INE winding 3.

The device (Fig. 1) operates in the following manner.

In the steady state at time t, (Fig. 2), the arc is energized and the control unit turns on key 4 and closes diode 6. In this case, along the circuit, the first pole 9 of power supply 1 - key 4 - whole section 10-13 INE

3- arc gap 8 - the second pole of power supply 1 1 flows a current 1d, which ensures the burning of the pilot arc. When this happens, INE 3 is charged from a constant voltage source 1, the current 1d through the arc gap 8 increases (section 14

in figure 2). At time t, the key

4 is unlocked. Due to mutual induction (between sections 10-13 and 11-13), section 11-13 of the INE 3 induces a self-induction EMF applied through the arc gap 8 to the diode 6 in the forward direction.

Diode 6 is unlocked and current is transferred to section P-13. Since the inductance of section 11-13 is less than section 10-13, and the energy stored in the INE 3 magnetic field cannot change instantly, current I in section 11-13 increases (section 15 in figure 2) in proportion to the ratio of turns W, (sections 10-13) to turns W (sections 11-13) 1c, / Wj and flows through the circuit: pin 13 INE 3 - arc gap 8 - diode 6 - tap 11 INE 3. At the same time, the stored energy is dissipated in the arc interval 8, the current I- decreases (section 15 in Fig. 2). At time tj, key 4 is turned on again and diode 6 is locked, HHD 3 is charged again up to time t. Next, key 4 is turned off and the circuit operates similarly. By varying the instants of time t, t, and t, it is possible to control the frequency and duty cycle of current pulses through the arc.

When the arc is broken, the voltage at the output and, accordingly, in section 11-1 of the INE 3 winding increases by applying to diode 7 in the forward direction. The diode 7 is also unlocked and the current determined by the INE magnetic field remaining at that moment 3, closes along the circuit; tap 12, diode 7 — buffer capacitor 2 — diode 6 — tapping 11 of the INE winding 3. In this case, the stored energy is recovered into the buffer capacitor.The recovery voltage Up, determining the maximum possible voltage across the arc gap, does not exceed the values of Up Up.W, / Wp, where Ug - voltage the capacitor 2; W - the number of turns of the windings 11-13 Ine 3, Wp - the number of turns in the section 11-12.

The device (fig.Z) works as follows.

In the steady state at time t, (FIG. 4), the arc is energized and key D is turned on by control unit 5, while diode 6 is locked. A current 1c flows through circuit 9 - 4-11 - 13-8- (-) 1, the value of which is proportional. - on the ratio of the turns W of section 10-13 to the turns of W, section 11-13

„1d. ,

When this occurs, the INE 3 is charged from the power source 1. The current I (j through the arc gap increases (section 16 in Fig. A.). At time tj, switch 4 is turned off. Due to mutual induction between sections 10-13 and P- 13 in section 10-13 of the plant, 1, x / EMF of self-induction, applied HR

cutting the arc gap 8 to the diode 6 in the forward direction. Diode 6 is unlocked and the current is transferred to section 10-13. Since the inductance of section 10-13 is greater than section 11-13, and the energy stored in the INE 3 magnetic field cannot instantaneously change

flow I in section 10-13 decreases

BUT.,

proportional to the ratio of turns W,

(sections 11-13) to turns W (sections 10-13)

1 1a. W, / W2.

Leak on the circuit 13 - 8 - 6 - 10, this current ensures the burning of the pilot arc. Changing the time points C, and tj, you can adjust the frequency and duty cycle of current pulses through the arc. When voltage is applied across the arc gap, diode 7 and pro5 5 0 open

5 o

0

a recovery of accumulated energy to the capacitor 2 occurs.

In order to regulate the ratio between the amplitudes of the currents G1Ar and the discharge circuits IN 3, as well as to regulate the discharged power and recuperate the buffer capacitor, the device with HiiJ can be configured to change the number of turns between its windings (FIG. .five).

To increase the amplitude, for example, the charge current, the number of turns of section 10-13 is reduced. To do this, it is necessary to move pin 10 (using a sliding contact or switches) closer to pin 13. To increase the amplitude of the discharge current, the tap 11 should be moved closer to pin 13.

Using the switch, the number of turns of the WP of the recovery section 11-12 is changed, due to which the voltage level at the output of the device can be selected to a safe value in case of arc breaks.

Compared to an ichvest device in one section of the INE winding, the charging current passes through the prepa- rage device, which makes it possible to reduce the consumption of active materials for the production of the INE by approximately 20-ZOL.

Claims (2)

1. A device for arc welding, containing a power source with a buffer capacitor at the outlet, an inductive energy storage device (INE) with winding outlets, a key, a control box and a diode, which is In order to improve the overall dimensions and efficiency of the device, a second diode is inserted into it, and the output terminals are connected between the anode of the first diode and one of the INE windings, the power supply through the switch and the second diode are connected to the INE winding, and the anode of the first diode is connected to the negative terminal of the power source And one of the tap winding Ine through a second diode connected to the positive terminal of the power source, the other from taps Ine winding connected to the cathode of the first diode. 513826 2. The device according to claim 1, wherein the number of turns of the INE winding section connected between the cathode of the first diode and the anode of the second diode is selected from the ratio .. Wp W, -. where W is the number of turns of the winding section, Yu connected between the output winding terminal of the INE, connected to one of the output terminals, g is the cathode of the first diode; - voltage on buffer capacitor J - recovery voltage, which determines the maximum safety voltage at the output terminals. ag / L r.S gz 15 llfJL tjtz jt ts t FS12.2 f7 . " J. tt tz t t ts t, fa i4