Apparatus and method for welding with AC waveform

Patent metadata

Field	Value
Publication number	US-10744584-B2
Application number	US-201715418647-A
Country	US
Kind code	B2
Filing date	Jan 27, 2017
Priority date	Jan 27, 2017
Publication date	Aug 18, 2020
Grant date	Aug 18, 2020

Abstract

A welder power supply and welding method are provided which utilizes a short arc welding method in which the waveforms have a positive polarity portion and negative portion to optimize heat input and provide heat and current control.

First claim

What is claimed is:

1. A welding system, comprising:
a welding power converter configured to receive an input power and output a welding waveform to a welding electrode for a welding operation on a workpiece;
a short circuit detection circuit which detects a short circuit event between said welding electrode and said workpiece and detects a short clearing event between said welding electrode and said workpiece; and
a controller operatively connected to the short circuit detection circuit, wherein the controller includes a timer, where said timer begins counting at the detection of said short clearing event for a predetermined duration, wherein the controller is further operatively connected to the welding power converter to control the welding waveform,
wherein said welding waveform comprises:
a short circuit clearing portion which is initiated by the controller after the detection of said short circuit event;
an arc generation portion which is initiated by the controller after the detection of said short clearing event, wherein the arc generation portion includes a peak current level and a background current level that is lower than the peak current level, and wherein said predetermined duration ends while the arc generation portion is at the background current level, and
a short promotion portion which promotes contact between said welding electrode and said workpiece, where said short promotion portion is initiated by the controller upon said timer counting to the predetermined duration, and said short promotion portion has a lower current level than the background current level and the lower current level is maintained until another short circuit event is detected.

2. The welding system of claim 1 , wherein said current level of said short promotion portion is in a range of 0 to 50 amps, and wherein said arc generation portion includes a tailout portion from the peak current level to the background current level.

3. The welding system of claim 2 , wherein said current level of said short promotion portion is maintained for a duration in a range of 0.2 to 8 ms.

4. The welding system of claim 1 , wherein said peak current level of said arc generation portion is higher than a peak current level of said short circuit clearing portion.

5. The welding system of claim 1 , wherein said predetermined duration is determined by the controller according to at least one of a wire feed speed and a diameter of said welding electrode.

6. The welding system of claim 1 , wherein said predetermined duration is in a range of 8 to 30 ms.

7. The welding system of claim 1 , wherein said predetermined duration is in a range of 12 to 20 ms.

8. The welding system of claim 1 , wherein said welding electrode is advanced towards said workpiece by a wire feeder during said short promotion portion and is retracted from said workpiece during said short circuit clearing portion.

9. The welding system of claim 8 , wherein a transition from said advancement to said retraction occurs during said short circuit event.

10. The welding system of claim 9 , wherein a second transition from said retraction to said advancement occurs during said arc generation portion of said welding waveform.

11. The welding system of claim 1 , further comprising a wire feeder configured to advance the welding electrode towards the workpiece, wherein a wire feed speed of the welding electrode is in a range of 200 to 400 inches per minute.

Assignees

• Lincoln Global Inc
• Lincoln Global Inc

Inventors

• Peters Steven R

Classifications

• B23K9/092 Primary

  characterised by the shape of the pulses produced · CPC title

• B23K9/173

  and of a consumable electrode · CPC title

• B23K9/1043

  characterised by the electric circuit (B23K9/1012 takes precedence) · CPC title

• B23K9/0734 Primary

  Stabilising of the arc power · CPC title

• B23K9/10 Primary

  Other electric circuits therefor; Protective circuits; Remote controls · CPC title