Systems, methods, and apparatus to preheat welding wire

Patent metadata

Field	Value
Publication number	US-10675699-B2
Application number	US-201615343992-A
Country	US
Kind code	B2
Filing date	Nov 4, 2016
Priority date	Dec 10, 2015
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

A contact tip assembly with a preheating tip comprises a welding power source configured to provide welding current to a welding circuit, the welding circuit comprising a welding electrode and a first contact tip of a welding torch. The assembly also includes an electrode preheating circuit configured to provide preheating current through a portion of the welding electrode via a second contact tip of the welding torch, and a voltage sense circuit to monitor a voltage drop across the two contact tips, and the electrode preheating circuit adjusts at least one of the first current or the preheating current based on the voltage drop.

First claim

What is claimed is:

1. A consumable electrode-fed welding system, comprising:
a welding power source configured to provide welding current to a welding circuit, the welding circuit comprising a welding electrode and a first contact tip of a welding torch;
an electrode preheating circuit configured to provide preheating current through a first portion of the welding electrode via a second contact tip of the welding torch; and
an electrode preheat control circuit to monitor a voltage drop across a second portion of the welding electrode and to adjust at least one of the welding current or the preheating current based on the voltage drop, the second portion of the welding electrode comprising at least part of the first portion of the welding electrode and located prior to an arc end of the welding electrode.

2. The consumable electrode-fed welding system as defined in claim 1 , wherein the first contact tip is configured to conduct the preheating current, the first portion of the welding electrode being between the first and second contact tips of the welding torch.

3. The consumable electrode-fed welding system as defined in claim 1 , wherein the first contact tip is positioned closer to the arc end of the welding electrode than the second contact tip.

4. The consumable electrode-fed welding system as defined in claim 1 , wherein the second contact tip is positioned closer to the arc end of the welding electrode than the first contact tip.

5. The consumable electrode-fed welding system as defined in claim 1 , wherein the electrode preheating circuit is configured to conduct the preheating current via a third contact tip of the welding torch.

6. The consumable electrode-fed welding system as defined in claim 1 , wherein the electrode preheat control circuit is configured to control the electrode preheating circuit to increase the preheating current of the first portion of the welding electrode and control the welding power source to decrease the welding current based on the increase in the preheating current.

7. The consumable electrode-fed welding system as defined in claim 1 , further comprising a stickout sense circuit to determine an electrode stickout distance of the welding electrode, the electrode preheating circuit to control the preheating current through the first portion of the welding electrode based on the electrode stickout distance.

8. The consumable electrode-fed welding system as defined in claim 1 , further comprising an enthalpy measurement circuit to determine an enthalpy applied to an electrode based on at least one of a measured arc voltage, a measured welding current, or a measured preheating current, or the voltage drop across the second portion of the welding electrode, the electrode preheating circuit to control the preheating current based on the determined enthalpy and a target enthalpy to be applied to the electrode.

9. The consumable electrode-fed welding system as defined in claim 1 , wherein the welding current is controlled according to an advanced waveform.

10. The consumable electrode-fed welding system as defined in claim 1 , wherein the electrode preheating circuit is configured to heat the welding electrode wire and deposit heated filler material on a workpiece in one or more deposition passes without an electrical arc, the welding power source configured to perform one or more passes on the workpiece with the electrical arc.

11. The consumable electrode-fed welding system as defined in claim 1 , wherein the electrode preheating circuit comprises a second power source configured to provide the preheating current.

12. The consumable electrode-fed welding system as defined in claim 1 , further comprising: a preheat monitor to: monitor a preheating signal generated by a preheating power supply, wherein the preheating power supply outputs the preheating current: and based on the preheating signal, identify an anomaly in the preheating signal based on at least one of a threshold signal level, a time derivative of the preheating signal, an integral of the preheating signal, a statistical analysis of the preheating signal, or a stability over a time period of the preheating signal, the preheating signal comprising at least one of a preheat voltage, a preheat current, a preheat power, or a preheat circuit impedance, the statistical analysis comprising at least one of a mean of the preheating signal, a standard deviation of the preheating signal, or a root mean squared value of the preheating signal.

13. The consumable electrode-fed welding system as defined in claim 1 , wherein at least one of the first contact tip or the second contact tip are cooled via liquid cooling lines.

14. The consumable electrode-fed welding system as defined in claim 1 , where the welding system is configured to perform at least one of a gas metal arc welding process or a submerged arc welding process.

15. The consumable electrode-fed welding system as defined in claim 1 , further comprising a reciprocating wire feed controller.

16. The consumable electrode-fed welding system as defined in claim 1 , where wherein the electrode preheat control circuit is configured to control the preheating current based on the a target heat input to a workpiece.

17. The consumable electrode-fed welding system as defined in claim 1 , further comprising a control circuit configured to: detect that the voltage drop across the second portion of the welding electrode is outside of an expected range; and in response to the detecting, reduce or stop at least one of the preheating current or the welding current.

18. The consumable electrode-fed welding system as defined in claim 1 , further comprising a control circuit configured to: detect that a voltage between any two of the first contact tip, the second contact tip, and a workpiece is outside of an expected range; and in response to the detecting, control at least one of the welding power source or the electrode preheating circuit to control the voltage to within the expected range.

19. The consumable electrode-fed welding system as defined in claim 1 , further comprising a control circuit configured to control at least one of the welding e power source or the electrode preheating circuit to generate a first voltage between the first contact tip and the second contact tip, a second voltage between the first contact tip and a workpiece, and a third voltage between the second contact tip and the workplace to each be less than a threshold.

20. The consumable electrode-fed welding system as defined in claim 5 , wherein the third contact tip contacts the welding electrode such that the welding current and the preheating current are superimposed on the first portion of the welding electrode.

21. The consumable electrode-fed welding system as defined in claim 5 , wherein the third contact tip contacts the welding electrode such that the welding current does not flow through the first portion of the welding electrode that conducts the preheating current.

22. The consumable electrode-fed welding system as defined in claim 7 , wherein the stickout sense circuit comprises a welding current sensor to measure the welding current, the stickout sense circuit to determine the electrode stickout distance based on the measurement of the welding current.

23. The consumable electrode-fed welding system as defined in claim 7 , wherein the electrode preheating circuit is configured to control the preheating current through the first portion of the welding electrod

Assignees

• Illinois Tool Works

Inventors

• Hsu Christopher
• Sigl Dennis
• Zwayer Jake
• Uecker James Lee
• Patterson Jon Michael

Classifications

• B23K9/24

  Features related to electrodes · CPC title

• B23K9/1093 Primary

  Consumable electrode or filler wire preheat circuits · CPC title