Carbon dioxide gas shielded welding machine and method of arc ignition controlled by digital pulse

Abstract

The invention discloses a method of controlling the arc strike of a carbon dioxide gas shielded welding machine by adopting digital pulse. The method comprises the steps of feeding gas for a welding gun; feeding a welding wire in a slow wire feeding mode; when the output voltage is detected to be 0 volt, outputting a 250-500 ampere short-circuit current pulse signal to the welding wire for arc strike; when the output voltage is detected to be smaller than 8 volts, switching from the slow wire feeding mode of the welding wire into a quick wire feeding mode, outputting a 250-500 ampere short-circuit current pulse signal to the welding wire to build a molten pool, and controlling an arc to be subjected to transition from arc strike to a stable arc. According to the method, the transient impact stress which is borne by a hardware power device is reduced, and the service life is prolonged; the arc strike time is shortened, the arc strike process is stable, the reliability is strong, and the arc strike success rate is high; the molten pool is built in the arc strike process, and thus a basic is established for normal, stable and reliable welding in the future. The invention further discloses a carbon dioxide gas shielded welding machine.

Description

technical field [0001] The invention relates to the field of welding, in particular to a method and equipment for controlling the arc striking of a carbon dioxide gas shielded welding machine by using digital pulses. Background technique [0002] At present, the carbon dioxide gas shielded welding machine usually adopts the droplet transfer form of short-circuit transition, which is easy to realize all-position welding, and its arc ignition method adopts short-circuit arc ignition. Whether the arc ignition is successful or not and whether the arc can be started reliably at one time is directly related to whether the subsequent welding can be carried out normally, especially in the field of welding automation. However, if the arc is not properly controlled, a large section of welding wire will burst. On the one hand, this kind of bursting will directly affect the welding quality, cause weld defects, and affect the appearance; on the other hand, it may cause arc breaks. If th...

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Problems solved by technology

[0003] The common methods to improve the success rate of arc ignition are: start-up compensation for the characteristics of the welding power supply; increase the current rise rate; increase the short-circuit peak current; slow wire feeding arc ignition; parallel capacitor method; Point; in the semi-automatic carbon dioxide gas shielded welding machine, use scratch arc ignition method; connect capacitor in parallel between electrode and workpiece; and increase instantaneous arc ignition current, improve arc ignition performance, etc., so many methods are due to the consideration of circuit compatibility. Difficult to use with existing technology

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