Tip-base metal distance control method for arc welding system, and arc welding system

Patent metadata

Field	Value
Publication number	US-9623507-B2
Application number	US-98407711-A
Country	US
Kind code	B2
Filing date	Jan 4, 2011
Priority date	Feb 18, 2010
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

A tip-base metal distance control method is provided. In this method, actual welding currents are measured under a predetermined actual welding condition, and an average actual welding current under the actual welding condition is then calculated. From a reference-current storage table, an average welding current under a welding condition that corresponds to the actual welding condition is extracted, and the extracted current value is set as a reference current. The calculated average actual welding current is then compared with the reference current to obtain a comparison result. The position of a welding torch in an upward or a downward direction is then corrected based on the comparison result.

First claim

What is claimed is:

1. A tip-base metal distance control method for an arc welding system, the method comprising:
(i) measuring actual welding current values under a predetermined actual welding condition, and calculating an average actual welding current value under the actual welding condition to obtain a calculated average actual welding current value;
(ii) extracting, from a reference-current storage table, a stored average welding current value under a stored welding condition corresponding to the actual welding condition to obtain an extracted average welding current value, and setting the extracted average welding current value as a reference current value;
(iii) comparing the calculated average actual welding current value with the reference current value to obtain a comparison result; and
(iv) correcting a position of a welding torch in arc welding in an upward or a downward direction based on the comparison result so as to maintain a fixed distance between a tip at an end of the welding torch and a base metal.

2. The method according to claim 1 , wherein in (ii), in the absence of the stored welding condition corresponding to the actual welding condition,
a weld condition corresponding to the actual welding condition is calculated by interpolation based on stored welding conditions in the reference-current storage table, and
the reference current value is set as a welding current value calculated by interpolation based on stored average welding current values.

3. The method according to claim 1 , further comprising, prior to (i):
(v) measuring welding current values under a predetermined test welding condition and calculating an average welding current value under the test welding condition; and
(vi) storing the average welding current value under the test welding condition and the corresponding test welding condition in a table so as to generate the reference-current storage table.

4. The method according to claim 3 , wherein the arc welding is performed by bead welding for a flat plate or fillet welding in (v).

5. The method according to claim 3 , wherein, when a test welding in (v) and an actual welding in (i) are performed by different methods, the reference current value in (ii) is corrected by using a parameter obtained beforehand.

6. The method according to claim 3 , wherein, in (v), when welding current values are measured under a plurality of changing test welding conditions a range of variations in the welding current values in calculating average welding current values is determined to exceed a predetermined threshold value, the average welding current values under the changing test welding conditions are regarded as errors.

7. The method according to claim 3 , wherein
the actual welding current values in (i) are measured when a predetermined time elapses from start or change of the actual welding condition, and
the welding current values in (v) are measured when the predetermined time elapses from start or change of the test welding condition.

8. A single arc welding system, comprising:
a welding torch that supplies a wire to a base metal; and
an arc copying unit that controls a copying operation of the welding torch,
wherein
the single arc welding system corrects a position of the welding torch based on a reference-current storage table that stores predetermined welding conditions and corresponding average welding current values under the predetermined welding conditions, and
the arc copying unit
calculates an average actual welding current value under an actual welding condition,
extracts, from the reference-current storage table, an extracted average welding current value corresponding to the actual welding condition and sets the extracted average welding current value as a reference current value,
compares the average welding current value with the reference current value to obtain a comparison result, and
corrects the position of the welding torch in an upward or a downward direction based on the comparison result so as to maintain a fixed distance between a tip at an end of the welding torch and the base metal.

9. A tandem arc welding system, comprising:
a welding torch that supplies two wires comprising a preceding wire and a following wire to a base metal; and
an arc copying unit that controls a copying operation of the welding torch,
wherein
the tandem arc welding system corrects a position of the welding torch based on a reference-current storage table for each of the two wires in which predetermined welding conditions and corresponding average welding current values under the predetermined welding conditions are stored, and
the arc copying unit
calculates an average welding current value of the preceding wire under an actual welding condition,
extracts, from the reference-current storage table for the preceding wire, an extracted average welding current value corresponding to the welding condition and sets the extracted average welding current value as a reference current value,
compares the average welding current value under the welding condition with the reference current value to obtain a comparison result, and
corrects the position of the welding torch in an upward or a downward direction based on the comparing result so as to maintain a fixed distance between a tip at an end of the welding torch and the base metal.

Assignees

• Shigeyoshi Masayuki
• Kobe Steel Ltd

Inventors

• Shigeyoshi Masayuki

Classifications

• B23K9/1278

  Using mechanical means · CPC title

• B23K9/0956 Primary

  using sensing means, e.g. optical · CPC title

• B23K9/1735

  making use of several electrodes · CPC title

• B23K9/126 Primary

  Controlling the spatial relationship between the work and the gas torch (between wire tip and piece B23K9/073) · CPC title

• B23K9/173

  and of a consumable electrode · CPC title