SU536018A1 - Device for forming current during pulsed arc welding - Google Patents

Description

FIG. 1. Shows the basic diagram of the source iitani; in fig. 2 - curves of e. d. generator, voltage and that. arc.

The electrical circuit includes a base current source /, synchronous pulse generator 2, a welding arc 3, switching unit 4, winding 5 of the generator stator, excitation winding 6, damping winding 7 along the longitudinal axis of the rotor 7, damping winding 8 but the transverse axis of the rotor and switching apparatus 9.

The device works as follows.

In the initial state, the rotor of the synchronous generator rotates at a nominal speed, a direct current is supplied to its field winding 6, the switching devices / and 9 are open, the welding arc 3 is powered by a direct current from the base source. Amplitude uh. the distance from the stator induced in the winding 5 of the stator, however, rises to the magnitude of the arc burning voltage. At the time when e. d. the generator and the voltage drop across the arc act according to. and are equal in magnitude, i.e. when the voltage at the contacts of the switching device 4 passes through a zero value, it is closed. FIG. 2 this corresponds to the point in time / 1. On the stator winding 5 a current begins to flow, which creates a flow of the reaction box. The reaction current of the core is stationary in space and varies in accordance with the change in the current of the stator coil and pulse generator. Immediately at the moment of switching on the switching device 4, the axis of the damper winding 8 is located opposite to the axis of the stator winding 5, since e. d. The generator at this point in time is close to zero. Consequently, with further rotor turning, the axis of the demultiplier winding 8 will coincide with the axis of the stator winding 5 “an increase in part of the reaction flow of the core associated with the damper winding 5.

Amplifier winding 7 is used to reduce the super-intermediate inductive resistance of the generator along the longitudinal axis. To obtain a higher current ratio in the stator winding, the load resistance is chosen to be close to the value of the super-transient resistance of the generator. Thus, the generator operates in a mode close to a sudden short-circuit, which causes a large current ratio in the stator winding relative to the nominal one. Therefore, the flow of the reaction box in accordance with the characteristic of the magnetization of the generator can be 1.5–2 times higher than the nominal flow of idling.

At the moment of time corresponding to the maximum of the reaction flow of the core, which is connected with the damper winding 8, the closure of the switching apparatus 9 is closed. This time instant also corresponds to the equality Zero e. d. on the clips of the winding 8.

When the apparatus 9 is closed on the rotor, a system of contours is formed along the longitudinal and transverse axes, which create a net magnetic flux equal to the geometric sum of the currents created by the windings of the transverse and longitudinal axes. This flux exceeds the initial magnetic flux created by the excitation winding, e 1.5-2.5 times. With further rotor rotation, an additional increase in the current pulse occurs due to an increase in e. d. generator with considered forirBke flow. This causes a large power density of the generator in question.

compared with the known.

In the proposed device, due to the inclusion of a pulse generator on the load at sho / ment, its transition e. d. through zero, the current contains both the periodic and the maximum possible value of the aperiodic component, which causes its much greater impulse power, all other things being equal. The adjustment of the current pulse duration in the direction of decreasing is not limited, since switching on the load can be made at any phase angle e. d. These advantages of the proposed source and provide the best performance and adjustment characteristics in comparison with the known.

At the time of the change of time / 2, corresponding to the end of the current pulse, the commutation of the devices 4 vi 9 is opened. The subsequent pulse is generated depending on the desired frequency of their follow on any positive half-wave e. d. generator closure

apparatus 4. Further, the processes in the device are repeated.

The adjustment of the pulse duration is carried out by changing the frequency e. d. generator by changing the speed of rotation of the rotor. The amplitude of the current pulses superimposed on the direct current is controlled by changing the current of the excited generator. The pulse frequency is determined by the closure frequency of device 4, and its upper limit is determined by the frequency e. d. generator.

Claims (2)

Invention Formula A device for forming a current in pulsed arc welding, consisting of a source of base current and a source of current pulses connected in parallel to the welding arc, characterized in that, in order to increase the power of the pulses and improve the adjusting and operational characteristics, a single-phase synchronous is introduced into the device as a source of current pulses generator damper winding which the transverse axis of the rotor is equipped with a switching apparatus. Sources of information taken into account when executing: 1 USSR Author's Certificate No. 329972, M. Kl..V 23 K 9/16, 03.03.69. : 2. Australian Patent No. 416886, class 06.9 (prototype).