ARC WELDING METHOD AND ARC WELDING APPARATUS

• US 20120111842A1
• Filed: 07/16/2010
• Published: 05/10/2012
• Est. Priority Date: 07/29/2009
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Fujiwara, Junji, Mukai, Yasushi, Kawamoto, Atsuhiro, Kowa, Masaru
• Granted Patent: US 8,993,925 B2
• Time in Patent Office: Days
• US Class Current: 219/130.33
• CPC Class Codes: B23K 9/09 Arrangements or circuits for arc welding with pulsed current or voltage
• CPC Class Codes: B23K 9/125 Feeding of electrodes for stabilising arc B23K9/073

Abstract

An arc welding method relates to consumable electrode arc welding in which a welding wire feeding rate suitable for a welding current is determined as an average feeding rate, and the short circuit state and the arc generation state are alternately generated by changing the wire feeding periodically and repeatedly between the forward feeding and the reverse feeding. The method offers arc welding with the average feeding rate according to a welding current, a predetermined frequency, and a predetermined velocity amplitude. In the method, at least any one of the frequency and the velocity amplitude is set to a value suitable for the welding current.

Claims

1. An arc welding method using a consumable electrode, in which method a welding wire feeding rate suitable for a welding current is determined as an average feeding rate and a short circuit state and an arc generation state are repeated periodically by changing wire feeding of a welding wire between forward feeding and reverse feeding with a predetermined frequency and a predetermined velocity amplitude,

the method comprising:

determining at least one of the frequency and the velocity amplitude is set to a value suitable for the welding current.

2. The arc welding method of claim 1, wherein at least one of an upper limit and a lower limit is set in at least one of the frequency and the velocity amplitude determined to be suitable for the welding current.

3. The arc welding method of claim 1, wherein the wire feeding of the welding wire is carried out by changing the welding wire feeding rate so as to have a sinusoidal waveform.

4. The arc welding method of claim 1, wherein the wire feeding of the welding wire is carried out by changing the welding wire feeding rate so as to have a trapezoidal waveform.

5. The arc welding method of claim 4, wherein welding operation is timed to at least any one of a peak time, a rising time, and a falling time determined to be suitable for the wire feeding rate.

6. The arc welding method of claim 5, wherein at least one of an upper limit and a lower limit is set in at least any one of the peak time, the rising time, and the falling time determined to be suitable for the wire feeding rate.

9. The arc welding method of claim 2, wherein the wire feeding of the welding wire is carried out by changing the welding wire feeding rate so as to have a sinusoidal waveform.

10. The arc welding method of claim 2, wherein the wire feeding of the welding sire is carried out by changing the welding wire feeding rate so as to have a trapezoidal waveform.

7. An arc welding apparatus that carries out arc welding where an arc generation state and a short circuit state are repeated alternately between a welding wire as a consumable electrode and an object to be welded, the apparatus comprising:

a welding current setting section for determining a welding current;

an average feeding rate setting section for determining an average feeding rate of a welding wire feeding rate for wire feeding control in which a feeding direction of a welding wire is changed periodically and repeatedly between forward feeding and reverse feeding according to the welding current;

a frequency setting section for determining a frequency for the wire feeding control in which the feeding direction of the welding wire is changed periodically and repeatedly between the forward feeding and the reverse feeding according to the welding current;

a velocity amplitude setting section for determining a velocity amplitude for the wire feeding control in which the feeding direction of the welding wire is changed periodically and repeatedly between the forward feeding and the reverse feeding according to the welding current;

a switching element for controlling welding output;

a welding voltage detecting section for detecting welding voltage;

a state detecting section for detecting whether the arc welding is in the short circuit state or in the arc generation state according to a result detected by the welding voltage detecting section;

a short circuit control section for controlling a short circuit current during a short circuit period that maintains the short circuit state in response to a short circuit signal fed from the state detecting section; and

an arc control section for controlling an arc voltage during an arc period that maintains the arc generation state in response to an arc generation signal fed from the state detecting section,

wherein, welding operation is carried out by feeding the welding wire with the frequency and the velocity amplitude determined to be suitable for the welding current.

8. The arc welding apparatus of claim 7, wherein the average feeding rate setting section determines a frequency for the feeding control in which the feeding of the welding wire is changed periodically and repeatedly between the forward feeding and the reverse feeding so as to have a trapezoidal waveform, and the velocity amplitude setting section determines a velocity amplitude for the feeding control in which the feeding of the welding wire is changed periodically and repeatedly between the forward feeding and the reverse feeding so as to have a trapezoidal waveform,

the apparatus further comprising:

a peak time setting section for determining a peak time of the trapezoidal waveform according to the welding current;

a rising time setting section for determining a rising time of the trapezoidal waveform according to the welding current; and

a falling time setting section for determining a falling time of the trapezoidal waveform according to the welding current,

wherein, welding operation is carried out in a manner that the feeding of the welding wire is timed to at least any one of the peak time, the rising time, and the falling time according to the welding current.