Squeezing detection control method for consumable electrode arc welding

Abstract

The invention provides a squeezing detection control method for consumable electrode arc welding along with short circuit which can increase squeezing detection precision. The method includes a step of detecting a droplet squeezing phenomenon by checking that a change in a voltage or resistance between the consumable electrode and base material reaches a squeezing detection reference value (Vtn), and a step of executing output control for rapidly decreasing a welding current (Iw) passing through a short-circuited load when the squeezing phenomenon is detected, so that arc re-striking occurs in a state of low current (Ia). The squeezing detection reference value (Vtn) is set to a first value (Vtn1) during the electrode positive polarity (EP), and set to a second value (Vtn2) during the electrode negative polarity (EN). The second value (Vtn2) is different from the absolute value of the first value.

Description

technical field [0001] The invention relates to a necking detection and control method for consumable electrode AC arc welding, which is used to detect the necking phenomenon of droplet during short circuit, so as to reduce the welding current sharply, thereby improving welding quality. Background technique [0002] Figure 5 It is a graph showing current, voltage waveform, and droplet transfer in consumable electrode arc welding in which short-circuit period Ts and arc period Ta are repeated. Figure 5 (A) shows the time change of the welding current Iw energized to the consumable electrode (hereinafter referred to as electrode 1), Figure 5 (B) shows the time change of the welding voltage Vw applied between the electrode 1 and the base metal 2, Figure 5 (C) to (E) show the state of transition of the droplet 1a. Refer below Figure 5 Be explained. [0003] During the short-circuit period Ts from time t1 to t3, the droplet 1a at the top of the electrode 1 is in a short-circ...

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Problems solved by technology

[0022] In order to solve the above-mentioned problems, Invention 1 is a constriction detection control method for consumable electrode AC arc welding, which alternately switches the output of the welding power supply to electrode positive polarity and electrode negative polarity, and the consumable electrode and the bus In the AC arc welding of the consumable electrode in which the arc generation state and the short circuit state are repeated between the materials, the polarity is detected based on the fact that the change in the voltage value or the resistance value between the consumable electrode and the base metal reaches the necking detection reference value. In the short-circuit state, the precursor phenomenon of regenerating the arc is the necking phenomenon of the droplet. If the necking phenomenon is detected, the output control is performed so that the welding current energized to the short-circuit load is reduced sharply, so that in the state of low current value The arc is regenerated, and the constriction detection and control method of consumable electrode AC arc welding is characterized in that,

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