Take, for example, the power supply of the arc, which includes a welding transformer T1 (publications on this, see No. 8’92 and 1 in’96), t diode bridge VD1—VD4 and the choke L1 and thyristor voltage regulator (see no. 1’2000). The voltage across the primary winding T1, and thus the arc, is set by resistor R5. The latter forms together with C1 and C2 of the phase-shifting chain, which receives signals of the thyristor control VS1 and VS2.
The feature used here is the schematics such that each of the thyristors operable only if a corresponding half cycle of the mains voltage of the anode. And open these managed semiconductor devices on time adjustable electric parameters of the phase-shifting chains.
The welding transformer T1 is no different from their counterparts. In fact, it is familiar to all network Converter 220 volt AC voltage in low, 56-V, performed on the stator of the burnt motor. The cross section of toroidal magnetic core formed after removal of the jumper slots the workpiece is in the original 40 cm2.
As practice shows, the primary winding of the welding transformer for ESPA should contain 220 turns of copper wire with a diameter of 1.9 mm, better in the glass cloth insulation and the secondary Well enough to have, respectively, 56 turns of stranded cable or bus-section (copper!) 60 mm2.
Schematic diagram of semi-automatic welding in carbon dioxide environment and design features of his self-made power units:
a — choke; — welding transformer — rectifier;
1 — magnetic circuit; 2 — the PCB (transformer — insulating tape); 3 — wire or bus; 4 — diode BJ1200 (2); 5 — diode B200 (2); 6 — section of a dual radiator (2); 7 — stud with nuts and washers (4 set).
The mechanism of the automated supply welded wire (engine with gear from the wiper motor car GAZ-69 is not shown):
1 — angle base (STZ, listst); 2,10 — master and slave rollers wire feed (steel 35, after fabrication — tempering); 3 — sleeve-bearing with lock nut; 4 — output shaft gear-drive (from the wiper of the GAZ-69, modified); 5 — bracket under the guide wire (2); 6 — guide sleeve with lock nuts (2 sets.); 7 — wire; 8 — axis holder (M5 bolt); 9 — clamping strip of the driven roller; 11 — pressure spring; 12 — bracket presser spring with two screws MOH (2 sets.); 13 — yoke of the driven roller; 14 — axis of the slave roller (M5 bolt); 15 — puck (2 PCs); 16 — remote sleeve
Welding torch (textolite case and place soldering a power cable not shown):
1 — guide; 2 — channel for the welding wire (cable sheath drive cable, L1200); 3 — the channel-bottom of burner (copper); 4 — pipe-injector (copper); 5 — rubber hose-dioxide; 6 — connections to the relay coil (flexible mounting wire mgshv-2,5); 7 — button KM 1-1; 8 — U-shaped bracket; 9 — the screw is MZ; 10 — brass nut MZ; 11 — asbestos washer-cap; 12 — bushing-nozzle; 13 — tube (brass tube 30×2, L60); 14 — copper tip
The diodes of the rectifier bridge is designed for direct current of at least 100 A. In order to better cool the each of them is provided with a radiator, the heat transfer area of which is 200 cm2.
Very nice, like the bridge, consisting of two powerful bipolar fupp valves B200 and ВЛ200, the design of which (“anode” or, conversely, the “cathode” heat transfer and, respectively, green or maroon case) makes it easy to combine them into a compact rectifier unit with “positive” and “negative” halves of the bridge. Homogeneous groups are held together by pins M8, and between dissimilar rubber strip is installed with two symmetric sections of radiators. Extensive material of such a technical solution has been published in the journal “modelist-Konstruktor” No. 5, 1997.
Inductor L1 is used for reliable ignition of the arc. Magnetic wire in this case is the core of the power transformer TV 3rd generation (“Temp-738”) or similar cross-section of 15-20 cm2
Basic silovik disassembled, removed from it all the windings. Between the halves of the billet the core is placed on the plate of textolite with a thickness of 2 mm Obtained with a gap of MAG-metoprolol wrapped with two layers of surgical tape, over which is placed a coil consisting of 30 turns of insulated copper conductors or wire harness cross section of 20 mm2.
The power supply of the motor M1 of the infeed mechanism and pneumatic-malapena K2 is a scheme of the parametric stabilizer. The transformer T2 reduces the voltage to 15 V, which after rectification by a diode bridge VD5—VD8 is smoothed by a capacitor NW and served on VT2 that serves as a regulating element. With the help of resistor R7 sets the output voltage, and hence the rotational speed of the motor M1.
When you press the button SB2 relay K1. This, in turn, closes the supply circuit of the motor and the valve, and the diode VD13 protects the contacts K1.1 from abharana.
As K1 is used relay for the high beam. The pneumatic valve K2 from the system idle econimizer of the car VAZ-2107. The role of T2 is acceptable any, including homemade, step-down transformer with a voltage in the secondary winding 15— 20 V and a current of 10 A. the Capacitors and resistors are the most common, indicated in the diagram of the values. The exception can only R6, whose resistance is Ohm’s law, where the voltage U = Ucj — 18 (B), and the current is I = 0,01 (A).
The welding torch serves as the “electrode” wire, arc voltage and carbon dioxide to weld. Channel for the welding wire from the shell of 1.2-mm cable driven speedometer. In one end is soldered into the copper tube-on-Pralaya with external M4 thread on the end, and the other is soldered into the channel of the burner.
Button SB2 is mounted on U-shaped bracket which is soldered the copper to the channel of the burner. Using copper solder is connected (or bound) not shown power cable 20 mm2 cross-section extending from the inductor L1. And is soldered into the copper tube while wearing her hose carbon dioxide.
Textolite has a demountable torch body, not shown in the figure design. All hoses and cables are collected into bundles and fastened in place by four or five lighter bands.
For the feeder used engine with gear from the wiper motor GAZ-69. The output shaft of the gearbox shortened to 25 mm and the end is threaded M5 Lev., needed to zamostyany leading roller when the supply of wire. The driven roller is free to rotate on the axis 5 mm diameter, passing through the strap and firmly tighten the nut a frame, formed with the clip and strap.
From the front both rollers on a width of 5 mm cut teeth, which mesh with each other during operation of the mechanism. Number and the module of the teeth can be any (in this case, z = 15; m = 2 mm). And the rear of the both is performed knurling width 10 mm for better engagement of the welding wire. Of course, these videos after they were made must be quenched
The frame of the driven roller with one end fixed on the axis passing through the bracket and the bushing, and tighten the nut. The thickness of the sleeve is selected with the adjustment mechanism so that both rollers have the same teeth. At the other end of the frame stretches the spring by means of which welding wire is clamped between the rollers, the height of the brackets under the rails of the welding wire is selected so that it cuts through the middle of the knurled surface of the rollers.
Feeder, pneumatic valve, switch SB1, resistors R5 and R7 fixed on the textolite plate of thickness 6 mm, which is the top of the box which houses the electronic part of the ESPA. On the side walls and the bottom of the box are drilled ventilation holes. The coil of welding wire is fixed by a clamp on the capstan of the player.
The capstan is placed at a distance of 200 mm from the feeder so that when half the rest of the wire when it was on the same axis with the guide.
Before work is necessary to bring the guide as close as possible to the rollers and tighten the nuts. Then skip the welding wire through the guide, the mechanism of the burner tip. Tip it is necessary to screw in the channel of the burner and put on the protective cover which needs to preload screw. Connecting the hose from the carbon dioxide cylinder from the gearbox to the valve, you must install the gearing a gas pressure of about 1.5 ATM. After power on it remains only to adjust the resistor R7, the wire feed speed (and with the help of R5 — required voltage) and start welding.
ESPA can work with wire diameter 0.8—1.2 mm, you only need to change the hole diameter of the tip and adjust the arc voltage. Welding is best done “angle back” (referring to the angle between the seam and the burner), this gives a stable arc and high quality weld.
However, please note and features. When welding nahles-precise compounds, the burner should preferably be sent at an angle of 55— 60° to the plane of the sheets and welding of t-joints with a vertical wall at an angle of 45-50° to the bottom wall. The wire extension (distance from the plane of the weld tip) when welding is to be set in the range 5-15 mm for wire diameter 0,5—0,8 mm and 8-18 mm, when the wire is thicker.
The reduction of emission pollution threatens rapid burner spatter and complexity of monitoring the welding process, however, in this operation mode is better excited by the arc and increases its stability.
Working with the ESPA is required in a suit welder with protective gloves, a face mask with a filter corresponding to the welding current. Moreover, if SW is 15-30 And should use a filter so, C4 is advisable to apply 30 to 60 A. At higher welding current can be recommended C5 and swarupananda filters (C6 or C7), given that the maximum value SW ESPA from about 120 A. we Must also remember the strict observance of the rules of electrical and fire safety.
M. Costin, G. P e n s a
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