JPS5950973A - Two electrode latent arc welding method - Google Patents

Abstract

PURPOSE:To prevent interference of an arc and turbulence of an arc between electrodes, and to raise a welding speed and a welding quality, by making a half-wave current being out of phase from a DC base current flow to each electrode of two electrode latent arc welding. CONSTITUTION:In case of welding, a half-wave current (a) flows through a diode 18, an electrode 11, a base metal 10 and a diode 17 from an electric power source transformer 14. Also, a half-wave current (b) flows through a diode 19, an electrode 12, the base metal 10 and a diode 16 from the electric power source transformer 14. In this case, a current being out of phase flows to each electrode 11, 12, therefore, arc interference between two electrodes can be reduced, and also a welding speed can be increased. Also, it is considered that an arc becomes unstable at the time of switching the phase, due to a fact that half-wave electrodes (a), (b) are used, but since a direct current is made to flow simultaneously, turbulence of the arc can be prevented, as well.

Description

[Detailed description of the invention] The present invention relates to a two-electrode young arc welding method.

In recent years, multi-electrode technology has been studied and put into practice in order to improve the efficiency of arc welding. However, in edge arc welding (submerged arc welding) where a large current is passed, due to the magnetism generated between each electrode according to the Biot-Zapard law, when the poles are the same, they attract each other, and when they are different poles, they repel. In addition, there was a problem in that a proper weld bead could not be formed in each case.

Therefore, at present, the C-AC method as shown in FIG. 1 is adopted for bath welding. That is, in FIG.
il is the parent phase, (2) is the DC electrode, and (3) is the AC' electrode. During welding, DC is passed from the Sanwa AC source to the warm electrode (2) via the transformer (4) and the rectifier circuit (6). There is a method 2 in which an alternating current is passed from a '+'-phase alternating current power source to an alternating current electrode (3) via a transformer (6).

For example, if this candlestick is made of spiral steel pipes, the distance t between two lamps is about 20 questions. However, conventionally,
Turtle, koshiki to prevent arc interference! If the interval between 2+ and +31 is widened, the arc on the AC electrode]3) side becomes unstable, and if the interval is narrowed, the arcs will interfere with each other, resulting in the generation of bubbles. Due to these reasons, conventional welding methods are unable to improve welding speed.

In view of these conventional problems, the present invention was provided for the purpose of reducing arc interference between two electrodes, which is a problem while increasing welding speed and quality of welded parts. Its characteristic lies in the fact that in the two-ton pole arc welding method using two Oka electrodes, a DC base current and a half-wave current out of phase are passed through each electrode.

The illustrated embodiment will be described below. In FIG. 2, (10) is the base material, and (11+12) is the pole 14. (1) is a DC source, and each material (II) (+2+) is for passing a DC base current of about 50A. (14) is connected to a commercial AC power supply (50V or 60H2). The (resource) transformer, θ6) is connected to each electrode (Ill
(12) is a half-wave rectifier circuit that allows the phase-shifted half-wave 'rlf to flow, and a diode (lllli +17)
It consists of (1→00).

Therefore, when welding, each electrode (o) (12) has a third
As shown in the figure, one DC base current is passed, and phase-shifted half-wave currents a and b are passed, and this causes the electrode (Ill (+
2) Generate an arc. That is, the half-wave current a flows from the power supply trough (+4) to the diode (1 barrel) and the electrode (11
), flows through the base material (+01, diode 07) as a pillar, and the half-wave current flows from the power transformer (14) to the diode (
19), electrode (12), base material 1101, diode 0f
It will flow through the il, each pole, pole (11) (12
), the arc interference between the 2' electrodes can be reduced and the welding speed can be increased. In this case, since half-wave current a-b is used, the arc may become unstable when switching the phase.
Since a DC current of about 50 A is flowing at the same time, arc disturbance can be prevented.

As described in detail in the embodiments above, according to the present invention, phase-shifted half-wave currents are passed through each electrode, so there is no arc contact between the electrodes, the bath contact speed is increased, and the welding area is Quality can also be improved. However, since a DC base current is passed through each electrode, it is possible to eliminate arc disturbances when switching between half-wave and torque currents.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a conventional example, FIG. 2 is a circuit diagram showing an example of the present invention, and FIG. 3 is a waveform diagram of the current. 110)...Mother 4o, (n) (12)...Electrode,
(1..DC power supply, θ(1)..power transformer,
(15)... Rectifier circuit.

Claims (1)

[Claims] 1. A two-electrode submerged arc welding method using two electrodes, characterized in that a half-wave current that is out of phase with the DC base current is passed through each electrode.