SU108347A1 - The method of operation of the welding generator with split poles - Google Patents

Description

The invention relates to methods of operating welding generators with split poles. Generators of this type have “falling external characteristics, like all single-station welding generators. When welding in a protective gas environment, for example in a carbon dioxide environment, to increase the arc stability when working on automatic welding machines with an independent electrode feed rate, it is required that the generator has gently dipping or even temperate external characteristics. At the same time, the current of a short volcano should be limited.

To obtain such characteristics, a generator with split poles, equipped with an unregulated excitation winding of main points, as well as adjustable and unregulated excitation windings of the transverse poles and having three contact brushes on the core, provides for switching the excitation windings

in the following way. In order to obtain gestures or footprints in the working part of the external characteristics, the excitation windings are disconnected from the third brush and connected to an independent DC source with adjustable voltage, and the measles are rotated in the opposite direction compared to the normal mode of operation. To increase the generator idling, the adjustable winding of the zero points is connected to the auxiliary winding and to the main negative brushes of the generator through a valve. To further increase the voltage of the generator, an extraneous voltage source can be included in the circuit of this winding. To limit the short-circuit current in parallel to the valve, a nonlinear resistance of Tina selenium plugs or counter-ed sources is connected.

The change in the angle of inclination of the external characteristics is made by changing the angle of the shear of the brushes.

FIG. 1 shows a conventional generator switching circuit; in fig. 2-user mode, providing a hard and polonadal P1, not in the working part of the characteristics; in fig. 3 and 4 are diagrams with a high no-load voltage and with a cut-off current for welding.

The armature / generator has two main P1, ets 2 and auxiliary brush 3. The main poles have an excitation winding 4, the transverse poles are an unregulated winding 5 and an adjustable winding 6. The DC source consists of an autotransformer 7 and a selenium rectifier 8.

The operation of the generator is as follows.

When connecting the excitation windings to an independent source of direct current and changing the direction of rotation - the core changes the direction of the reaction of the core; while the unsaturated transverse poles are magnetized, and the saturated main poles are demagnetized. External characteristics of the generator at low currents are increasing in nature, and with increasing load they become rigid or gently dipping.

To increase the no-load voltage (Fig. 3), the adjustable winding 6 of the transverse poles is connected through the valve 9 to the brushes 2 to 3, the voltage on which decreases due to the demagnetizing effect of the core reaction, and then for some values of the welding current this voltage changes your sign. In this case, the generator voltage increases due to the biasing effect of the winding 6 at idle and at low loads, and drops sharply at high loads. When the sign of the voltage on the brushes 2 v 3 changes, the valve 9 turns off the winding 6. The performance characteristics are hard or gently dipping.

To increase the voltage of the generator to idle

a chain of winding 6 may be included additional emf. In order to limit the short-circuit current, nonlinear resistance in the form of selenium shields 10, 1k can be used, as shown in FIG. 4. Here, at high currents, winding 6 is turned on again and begins to act oppositely to winding 4, reducing the voltage on brushes 2 and 5. External characteristics of the generator of etans are steeply dipping in the region of large currents.

The described method of operation of welding generators makes it possible to obtain optimal external characteristics that ensure the stable operation of the welding installation, depending on the welding conditions.

Subject invention

Claims (5)

1. A method of operating a welding generator with split poles, equipped with an unregulated excitation winding of the main poles, as well as adjustable and unregulated excitation windings of the transverse poles and having three-contact brushes on the core, characterized in that, in order to convert the generator to an operating mode with gently dipping in the working part of the external characteristic, the excitation windings are disconnected from the third brush and connected to an independent DC source with adjustable voltage, and the measles rotated in the opposite direction to its rotation in self-excitation mode and steeply dipping external characteristic. 2. A variation of the method according to claim I, characterized in that, in order to increase the idle voltage, the adjustable winding of the transverse poles is connected to the auxiliary and to the main negative brushes of the generator through a valve. 3. The method according to claim 2, characterized in that, for a greater increase in the no-load voltage, the controlled winding of the transverse poles in the circuit includes a source of emf. 4. A method according to claim 2, characterized in that, in order to limit the short-circuit current, a nonlinear resistance such as selenium shields or counter-current sources is connected in parallel to the valve. 5. In the method according to paragraphs. 1-4, changing the slope of the external characteristics by changing the shear angle of the brushes. 4ALLffl