METHOD OF MACHINE ARC WELDING IN ACTIVE GASES AND DEVICE TO THIS END Russian patent published in 2009 - IPC B23K9/95 

FIELD: welding jobs.

SUBSTANCE: invention covers the method and device of machine arc welding in active gases that features intermittent alternation of the stages and arc discharge and short-circuiting, and can be used for producing seams in whatever spatial positions, for example, in welding the pipelines joints. At the stage of arc discharge bath damping is provided for by stabilising the voltage in two automatic control cycles. The first of them stabilises the voltage of arc proper, while the second stabilises the medium welding voltage. At the short-circuit stage bath damping is provided for by reducing electro dynamic effects onto the bath via reduction in sizes of transferred drops, which is reached thanks to bringing the frequency of pulsed effects into agreement with the natural frequency of drop formation by generating the current fall that initiates the transfer process, and the subsequent short-circuit current peak that allows the drop to detach from the electrode. The device primary power circuit outputs and high-voltage backfeed circuits are integrated and connected, via the current pickup, to external terminals. The current pickup output is connected to the microprocessor controller first measuring input. The voltage pickup output is connected to the microprocessor controller first measuring output. The first control output of microprocessor controller is connected to the controlled input of thyristor rectifier unit. The second control output of microprocessor controller is connected to the control input of the fist magnetic starter. The output of the operating conditions control unit is connected to the data input of microprocessor controller. The device low-voltage backfeed circuit is made up of the following components connected in series, i.e. transformer third output, second magnetic starter, second diode rectifier and controlled throttle. The output of low-voltage backfeed circuit is connected to the current pickup input. The fourth control input of microprocessor controller is connected to the controlled input of the second magnetic starter. The third control output of microprocessor controller is connected with the controlled input of controlled throttle. The output of the external feedback communication voltage pickup is connected to the third measuring input.

EFFECT: control of fused metal bath to produce high-quality welded seam.

6 cl, 6 dwg