Arc welding method, arc welding apparatus, and arc welding controller

Patent metadata

Field	Value
Publication number	US-9962786-B2
Application number	US-201614994778-A
Country	US
Kind code	B2
Filing date	Jan 13, 2016
Priority date	Feb 27, 2015
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

In an arc welding method of performing welding by employing CO 2 gas as shield gas, supplying a welding current to flow between a welding wire and a workpiece to be welded while feeding the welding wire toward the workpiece, and generating an arc with the welding current, the arc welding method includes a welding step of performing the welding of the workpiece while executing control to adjust the welding current, and a welding termination step of executing control to apply the welding current having a trapezoidal waveform when the welding of the workpiece is terminated.

First claim

What is claimed is:

1. An arc welding method, comprising:
employing a CO 2 gas as shield gas;
supplying a welding current to flow between a welding wire and a workpiece to be welded while feeding the welding wire toward the workpiece;
generating an arc with the welding current;
performing the welding of the workpiece while executing control to adjust the we current; and
wherein, when the welding of the workpiece is terminated, the executing control applies the welding current having a trapezoidal waveform, and
wherein, when the welding of the workpiece is terminated, the welding current having the trapezoidal waveform is additionally reapplied upon occurrence of a short circuit in the executing.

2. The arc welding method according to claim 1 , wherein, in the executing, the welding current having the trapezoidal waveform is applied in an arc period during which an arc is generated after a short circuit period during which a short circuit occurs.

3. The arc welding method according to claim 2 , wherein, in the executing, the welding current during the arc period is a constant current.

4. The arc welding method according to claim 1 , wherein the trapezoidal waveform includes a first period during which the welding current is linearly increased, a second period during which the welding current is a constant current, and a third period during which the welding current is linearly decreased,
the first period is selected from a range of not shorter than 0.5 ms and not longer than 2.0 ms,
the second period is selected from a range of not shorter than 1.0 ms and not longer than 5.0 ms, and
the third period is selected from a range of not shorter than 0.5 ms and not longer than 2.0 ms.

5. The are welding method according to claim 4 , wherein the welding current during the second period is selected from a range of not less than 250 A and not more than 300 A, and
the welding current before the first period and the welding current after the third period are each selected from a range of more than 0 A and not more than 50 A.

6. The arc welding method according to claim wherein, in the executing, the waveform of the welding current includes a rectangular waveform and the trapezoidal waveform.

7. The arc welding method according to claim 1 , wherein a droplet is formed at an end of the welding wire during the performing, and a slag formed at an end of the droplet is moved to a side portion of the droplet during the executing.

8. The arc welding method according to claim 7 , further comprising solidifying the slag at the side portion of the droplet.

9. The arc welding method according to claim 8 , further restarting arc welding, wherein the slag is not located between the welding wire and the workpiece.

10. The arc welding method according to claim 1 , further comprising stopping a feed of the welding wire before the executing.

Assignees

• Kobe Steel Ltd

Inventors

• Yashima Takashi

Classifications

• B23K9/0953

  using computing means · CPC title

• B23K9/09

  Arrangements or circuits for arc welding with pulsed current or voltage · CPC title

• B23K9/125

  Feeding of electrodes (for stabilising arc B23K9/073) · CPC title

• B23K9/1006

  Power supply · CPC title

• B23K9/32

  Accessories · CPC title