Drawn arc welding

Patent metadata

Field	Value
Publication number	US-9463522-B2
Application number	US-201213440198-A
Country	US
Kind code	B2
Filing date	Apr 5, 2012
Priority date	Apr 5, 2012
Publication date	Oct 11, 2016
Grant date	Oct 11, 2016

Abstract

A drawn arc welding assembly and method for simultaneously welding a stud to a first workpiece and a second workpiece that are affixed together and have an electrically insulating joining layer between the workpieces. A pair of leads attach to the first workpiece and the second workpiece, with electrically opposite diodes connected between the leads and a power supply. The power supply also provides power to a stud. During welding, two arcs are simultaneously maintained between the stud and first workpiece and between the stud and second workpiece. The power supply may be chopped AC from a dual inverter power supply.

First claim

What is claimed is:

1. A method of drawn arc welding a stud simultaneously to a first workpiece and a second workpiece, with the first workpiece affixed to the second workpiece and with an electrically insulating joining layer between the first and second workpieces, the method comprising the steps of:
(a) boring a cavity through the first workpiece, the joining layer and only a portion of the second workpiece;
(b) connecting a first electrode from a first output of a power supply to the stud;
(c) connecting a first lead to the first workpiece, the first lead electrically connected via a first diode, having a first electrical orientation, to a second output of the power supply;
(d) connecting a second lead to the second workpiece, the second lead electrically connected via a second diode, having a second electrical orientation opposite to the first electrical orientation, to the second output of the power supply;
(e) pressing the stud into the cavity into contact with the first workpiece and the second workpiece;
(f) activating the power supply to apply a pilot arc;
(g) moving the stud away from the first and second workpieces to simultaneously form a first arc between the stud and the first workpiece and a second arc between the stud and the second workpiece;
(h) increasing the power output from the power supply so as to cause the surfaces of the first and second workpieces in the cavity to partially melt; and
(i) pressing the stud into the partially melted surfaces to thereby simultaneously weld the stud to the first workpiece and the second workpiece.

2. The method of claim 1 wherein step (f) is further defined by the activating a chopped AC current from the power supply.

3. The method of claim 1 wherein step (b) is further defined by the stud being supported and moved by a stud gun and the power from the power supply transferring through the stud gun to the stud.

4. The method of claim 3 wherein step (e) is further defined by the stud gun moving the stud into the cavity.

5. The method of claim 1 wherein step (c) is further defined by the joining layer being a layer of adhesive securing the first workpiece to the second workpiece and the boring of the cavity bores through the adhesive layer.

6. The method of claim 1 including providing a resistor extending between the first lead and the second lead.

Assignees

• Gugel Mark D
• Gm Global Tech Operations Llc

Inventors

• Gugel Mark D

Classifications

• B23K9/202 Primary

  by means of portable equipment, e.g. stud-welding gun · CPC title

• Y10T29/49968

  Metal fusion joining · CPC title

• B23K2201/185

  Operations & Transport · mapped topic

• B23K9/205

  Means for determining, controlling or regulating the arc interval · CPC title

• B23K2203/18

  Operations & Transport · mapped topic