Method for Controlling and/or Regulating a Welding Apparatus, and Welding Apparatus

2:

• Method according to claim 1, wherein the welding current I is changed, particularly increased, during the electric-arc phase (36) and, thus, drop formation and/or melting-on of the end of the welding wire (13) occurs.

3:

• Method according to claim 1, wherein during the short-circuit phase (33), the welding current I is changed, wherein, during increasing the welding wire I, the filler material formed by the welding wire (13) is introduced into the melting bath of the work piece (16) and, during reducing the welding wire I, less filler material is introduced into the melting bath of the work piece (16).

4:

• Method according to claim 1, wherein after formation of a short circuit, the wire-conveying direction is reversed and the welding wire (13) is moved away from the work piece (16) until there is a freely selectable or predefined distance (34).

5:

• Method according to claim 1, wherein polarity of the welding current I and/or the welding voltage U is switched after each period (40, 41) formed by one short-circuit phase (33) and one electric-arc phase (36).

6:

• Method according to claim 1, wherein polarity of the welding current I and/or the welding voltage U is switched after several periods (40, 41) each formed by one short-circuit phase (33) and one electric-arc phase (36).

7:

• Method according to claim 6, wherein polarity of the welding current I and/or the welding voltage U is switched after a predefined or adjustable number of periods (40, 41).

8:

• Method according to claim 6, wherein polarity of the welding current I and/or the welding voltage U is switched aperiodically or irregularly after a changeable and/or variable number of periods (40, 41).

9:

• Method according to claim 8, wherein the point in time of switching polarity of the welding current I and/or the welding voltage U is automatically determined on the basis of at least one welding-process parameter which has been adjusted prior to the welding process or detected during the same, such as, e.g., the welding current I, a parameter for heat introduction, the material of the work piece (16), the material of the welding wire (13), the protective gas used and/or a welding gap in the work piece (16).

10:

• Method according to claim 1, wherein at least one welding parameter is manually selected and adjusted on the welding apparatus (1), and in that the point in time of switching polarity of the welding current I and/or the welding voltage U with respect to the short-circuit phase (33) is defined by the control device (4) on the basis of this at least one welding parameter.

11:

• Method according to claim 1, wherein switching polarity of the welding current I and/or the welding voltage U is triggered on the basis of a predefined period or by a trigger signal.

12:

• Method according to claim 1, wherein the feed rate V of the welding wire (13) is changed and determined on the basis of the polarity of the welding current I and/or the welding voltage U.

13:

• Method according to claim 1, wherein during a period (40;
• 41) formed by a short-circuit period (33) and an electric-arc phase (36), polarity of the welding current I and/or the welding voltage is at least twice controlledly switched, wherein, in particular, a polarity change occurs during the electric-arc phase (36) and during the short-circuit phase (33).

14:

• Method according to claim 13, wherein the timely controlled polarity switch of the welding wire I and/or the welding voltage U during a period (40;
• 41) is controlled on the basis of welding-process parameters, e.g. a parameter of heat introduction, the welding current I, the welding voltage U, a parameter of material introduction, etc.

15:

• Method according to claim 1, wherein the amplitude and/or polarity of the welding current I and/or the welding voltage U is regulated on the basis of the width and/or height of the gap detected between the work pieces (16) to be welded.

16:

• Method according to claim 1, wherein the amplitude and/or polarity of the welding current I and/or the welding voltage U is regulated on the basis of the depth of the weld penetration detected, in particular of the so-called welding root.

17:

• Welding apparatus (1) with a welding-current source (2), a control device (4) and a welding torch (20), further including an input and/or output device (22) and/or a remote control for adjusting the different welding parameters and for adjusting and selecting at least one parameter for heat balance or heat introduction into the work piece (16) to be processed, wherein a control means is associated to the input and/or output device (22) and/or the remote control, said means being designed for defining the points in time of a polarity change of the welding current I and/or the welding voltage U, on the basis of the at least one adjusted or selected parameter for heat balance or heat introduction.

18:

• Welding apparatus (1) according to claim 17, wherein at least one selecting or adjusting means is arranged for directly or indirectly adjusting the number or duration of the periods (40, 41) of the welding current I and/or the welding voltage U with positive or negative polarity, or the amplitude of the welding current I and/or the welding voltage U.

19:

• Welding apparatus (1) according to claim 17, wherein a memory is provided for depositing welding-parameter settings, particularly AC curve shapes, period durations or the like, for the welding current I and/or the welding voltage U.

20:

• Welding apparatus (1) according to claim 17, wherein the control means is formed by a software and program logic, respectively, deposited in the data memory of the control device (4), said data memory being connected with the input and/or output device (22) for changing or calling the data stored in said memory.