SYSTEMS AND METHODS FOR AUTOMATED ROOT PASS WELDING

• US 20170157693A1
• Filed: 12/07/2015
• Published: 06/08/2017
• Est. Priority Date: 12/07/2015
• Status: Active Grant

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Albrecht, Bruce Patrick, Barhorst, Steven Edward
• Granted Patent: US 10,610,946 B2
• Time in Patent Office: Days
• CPC Class Codes: B23K 2101/06 Tubes
• CPC Class Codes: B23K 9/0052 Welding of pipe panels
• CPC Class Codes: B23K 9/0282 for welding tube sections
• CPC Class Codes: B23K 9/09 Arrangements or circuits for arc welding with pulsed current or voltage
• CPC Class Codes: B23K 9/0956 using sensing means, e.g. optical
• CPC Class Codes: Y10S 901/42 Welding

Abstract

An automated welding system includes a welding robot and control circuitry. The welding bug robot includes a welding torch. The welding bug robot is configured to move on a track disposed around a circumference of a first pipe and perform a root pass welding operation at a joint between the first pipe and a second pipe. The control circuitry is configured to control movement of the welding bug robot around the circumference of the first pipe, apply a high energy welding phase via the welding torch to establish a first root condition, and apply a low energy welding phase via the welding torch to establish a second root condition.

Claims

19. A system comprising:

a welding torch configured to perform a root pass welding operation at a joint between a first pipe and a second pipe;

a welding robot configured to move at least one of the welding torch and the first pipe relative to one another;

a sensor configured to detect one or more parameters indicative of first and second root conditions, and to output a root condition signal; and

control circuitry configured to;

receive the root condition signal from the sensor;

control movement of the welding robot and the first pipe relative to one another based at least in part on the received root condition signal;

control a rate at which a wire feeder supplies welding wire to the welding robot based at least in part on the received root condition signal;

control an amount of welding power a power supply supplies to the welding robot based at least in part on the received root condition signal;

apply a high energy welding phase of the welding power until the root condition signal indicates establishment of the first root condition; and

apply a low energy welding phase of the welding power until the root condition signal indicates establishment of the second root condition.

1. An automated root pass welding system comprising:

a welding torch configured to perform a root pass welding operation at a joint between a first workpiece and a second workpiece;

a welding robot configured to move at least one of the welding torch and the first workpiece relative to one another; and

control circuitry configured to;

control movement of the welding robot and the first workpiece relative to one another;

apply a high energy welding phase via the welding torch to establish a first root condition; and

apply a low energy welding phase via the welding torch to establish a second root condition.

2. The automated root pass welding system of claim 1, comprising a sensor configured to sense one or more parameters indicative of the first and second root conditions, wherein the sensor outputs a root condition signal to the control circuitry.

3. The automated root pass welding system of claim 2, wherein the sensor is an infrared camera.

4. The automated root pass welding system of claim 2, wherein the sensor is an optical sensor.

5. The automated root pass welding system of claim 2, wherein the sensor is configured to sense a parameter indicative of a keyhole size, a parameter indicative of welding wire pushing through the joint, or both.

6. The automated root pass welding system of claim 2, wherein the sensor is a voltage sensor or a current sensor.

7. The automated root pass welding system of claim 2, wherein the sensor is a power sensor.

8. The automated root pass welding system of claim 2, wherein the sensor is an audio sensor.

9. The automated root pass welding system of claim 2, wherein the sensor is a wire position sensor.

10. The automated root pass welding system of claim 2, wherein the control circuitry is configured to determine establishment of the first and second root conditions based at least in part upon the root condition signal received from the sensor.

11. The automated root pass welding system of claim 1, wherein the first root condition is creation of a keyhole between the first and second workpieces.

12. The automated root pass welding system of claim 1, wherein the second root condition is that the joint is filled with deposited weld material.

13. The automated root pass welding system of claim 1, wherein the high energy welding phase includes providing a current greater than 150 amps to the welding torch.

14. The automated root pass welding system of claim 13, wherein the high energy welding phase includes providing welding wire at a first wire feed speed.

15. The automated root pass welding system of claim 14, wherein the low energy welding phase includes providing a current less than 250 amps to the welding torch.

16. The automated root pass welding system of claim 15, wherein the low energy welding phase includes providing welding wire at a second wire feed speed, wherein the second wire feed speed is lower than the first wire feed speed.

17. The automated root pass welding system of claim 1, wherein the welding robot is configured to move the welding torch in a direction substantially perpendicular to a direction of movement of the welding robot.

18. The automated root pass welding system of claim 1, wherein the welding robot comprising a motion control assembly comprising a motor and a cam, wherein the motion control assembly is configured to move a welding wire in a desired pattern with respect to a central axis of the welding torch.

20. The system of claim 19, wherein the first root condition is creation of a keyhole between the first and second pipes.

21. The system of claim 19, wherein the high energy welding phase includes the welding power having a current greater than 150 amps.

22. The system of claim 19, wherein the low energy welding phase includes the welding power having a current less than 250 amps.

23. The system of claim 19, wherein the sensor is an infrared camera.

24. The system of claim 19, wherein the sensor is an optical sensor.

25. The system of claim 19, wherein the system is configured to perform a current, a voltage, or a power calculation based at least in part on the received root condition signal.

25-1. The system of claim 19, wherein the system is configured to output a control signal based on signals received from a plurality of sensors.

26. A welding method comprising:

applying a high energy welding phase of welding power, using a welding torch attached to a welding robot, to a joint formed between first and second sections of pipe until a first root condition is established;

applying a low energy welding phase of the welding power to the joint until a second root condition is established; and

moving the welding robot and the first section of pipe relative to one another.

27. The welding method of claim 26, comprising:

receiving, from a sensor disposed radially inside the first or second sections of pipe, a root condition signal;

switching from the high energy welding phase of the welding power to the low energy welding phase of the welding power when the root condition signal indicates establishment of the first root condition; and

switching from the low energy welding phase of the welding power to the high energy welding phase of the welding power when the root condition signal indicates establishment of the second root condition.

28. The welding method of claim 27, wherein the sensor is an infrared camera.

29. The welding method of claim 27, wherein the sensor is an optical sensor.

30. The welding method of claim 27, wherein the sensor is a voltage sensor, current sensor, or power sensor.

31. The welding method of claim 26, wherein the first root condition is creation of a keyhole between the first and second sections of pipe.

32. The welding method of claim 26, wherein the low energy welding phase of the welding power includes a current less than 250 amps, and the high energy welding phase of the welding power includes a current greater than 150 amps.

33. The welding method of claim 26, comprising applying variable polarity to the joint.

34. The welding method of claim 26, wherein the low energy welding phase is applied as needed to create penetration with controlled burn through.