Welding of can bodies

Patent metadata

Field	Value
Publication number	US-11904414-B2
Application number	US-201917276528-A
Country	US
Kind code	B2
Filing date	Sep 16, 2019
Priority date	Sep 17, 2018
Publication date	Feb 20, 2024
Grant date	Feb 20, 2024

Abstract

Apparatus for controlling a welding station used for welding seams extending along cylindrical can bodies, the welding station comprising a pair of welding rolls and a calibration unit for causing a desired cylinder overlap during welding. The calibration unit is adjustable along at least three different adjustment axes. The apparatus comprises: a weld monitor configured to monitor welded seams and provide an electrical signal indicative of weld thickness at a series of predetermined points along the seam length; a controller configured to receive said signal and to generate one or more control signals; and adjustment mechanisms for coupling to the calibration unit, or forming part of the calibration unit. The adjustment mechanisms are configured to receive the signal(s) and to be responsive thereto to adjust the calibration unit relative to one or more of said three adjustment axes, to provide the desired cylinder overlap and/or a desired weld quality.

First claim

The invention claimed is:

1. Apparatus for controlling a welding station used for welding seams extending along cylindrical can bodies, the welding station comprising a pair of welding rolls and a calibration unit for causing a desired cylinder overlap during welding, said calibration unit being adjustable along at least three different adjustment axes, and the apparatus comprising:
a weld monitor configured to monitor welded seams and provide an electrical signal indicative of weld thickness at a series of predetermined points along the seam length;
a controller configured to receive said electrical signal and to be responsive to the signal to generate one or more control electrical signals;
a plurality of adjustment mechanisms for coupling to the calibration unit, or forming part of the calibration unit, said adjustment mechanisms configured to receive the one or more control electrical signals and to be responsive thereto to adjust the calibration unit relative to one or more of said three adjustment axes, to provide the desired cylinder overlap and/or a desired weld quality.

2. The apparatus according to claim 1 , wherein said signal indicative of weld thickness is derived from a signal indicative of displacement of an axis of rotation of one or both of the welding rolls.

3. The apparatus according to claim 2 , wherein said signal indicative of weld thickness includes a compensation for welding roll eccentricity and/or changes in the profile of a consumable wire located between the welding rolls and a cylinder to be welded.

4. The apparatus according to claim 1 , wherein said signal indicative of weld thickness is a signal indicative of an average or other statistically derived weld thickness at the series of predetermined points over a sequence of welded can bodies.

5. The apparatus according to claim 1 , wherein there are at least four predetermined points in the series, optionally comprising: a leading end of the cylinder; a middle of the seam length; a trailing end of the cylinder; a flip position.

6. The apparatus according to claim 5 , wherein the electrical signal is further indicative of a weld thickness averaged along the entire seam length.

7. The apparatus according to claim 1 , wherein the controller comprises a decision system configured to receive inputs comprising the electrical signal and a current position of one or more of the adjustment mechanisms, and to calculate as an output a required adjustment to one or more of the adjustment mechanisms.

8. The apparatus according to claim 7 , wherein the decision system is configured to compare the weld thickness at each one of the series of predetermined points with a target weld thickness for that point, and where one or more of the predetermined points deviates from the target weld thickness, to calculate an adjustment required to correct the deviation.

9. The apparatus according to claim 1 , wherein the adjustment mechanisms are responsive to the one or more control electrical signals in order to adjust: a radial position of a roller of the calibration unit relative to a direction of movement of cylinders through the weld station; a longitudinal position of the calibration unit along an adjustment axis perpendicular to a line passing through a centre of each welding roll; a combination thereof.

10. The apparatus according to claim 1 , wherein one of the adjustment mechanisms is responsive to the one or more control electrical signals in order to adjust a vertical position of the calibration unit along an adjustment axis parallel to a line passing through a centre of each welding roll.

11. The apparatus according to claim 9 , wherein one of the adjustment mechanisms is configured to adjust the radial position of a roller of the calibration unit using a co-operating dual-thread system operable using an encoded motor and gearbox.

12. The apparatus according to claim 1 , wherein said controller a proportional-integral-derivative controller.

13. A welding station comprising the apparatus of claim 1 such that the welding station incorporates a closed loop control system configured to maintain a desired weld quality.

14. A method of controlling a welding station used for welding seams extending along cylindrical can bodies, the welding station comprising a pair of welding rolls and a calibration unit for causing a desired cylinder overlap during welding, the calibration unit being adjustable along at least three different adjustments axes, the method comprising:
monitoring welded seams and providing an electrical signal indicative of the weld thickness at a series of predetermined points along a seam length;
generating one or more control electrical signals in response to said electrical signal indicative of the weld quality of welded seams; and
providing the one or more control electrical signals to one or more of a plurality of adjustment mechanisms configured to adjust the calibration unit relative to one or more of the three adjustment axes, to cause the desired cylinder overlap.

15. The method according to claim 14 , wherein said signal indicative of weld thickness is derived from a signal indicative of displacement of an axis of rotation of one or both of the welding rolls.

16. The method according to claim 15 , wherein said signal indicative of weld thickness includes a compensation for welding roll eccentricity and/or changes in the profile of a consumable wire located between the welding rolls and a cylinder to be welded.

17. The method according to claim 14 , wherein said signal indicative of weld thickness is a signal indicative of an average or other statistically derived weld thickness at the series of predetermined points over a sequence of welded can bodies.

18. A method of controlling a welding station used for welding seams extending along cylindrical can bodies, the welding station comprising a pair of welding rolls and a calibration unit for causing a desired cylinder overlap during welding, the method comprising:
monitoring welded seams and providing an electrical signal indicative of the weld thickness at a series of predetermined points along a seam length;
generating one or more control electrical signals in response to said electrical signal indicative of the weld quality of welded seams; and
providing the one or more control electrical signals to one or more of a plurality of adjustment mechanisms configured to adjust the calibration unit relative to one or more of the three adjustment axes, to cause the desired cylinder overlap,
wherein the adjustment mechanisms are responsive to the control signal(s) in order to adjust: a radial position of a roller of the calibration unit relative to a direction of movement of cylinders through the weld station; a longitudinal position of the calibration unit along an adjustment axis perpendicular to a line passing through a centre of each welding roll; a combination thereof,
wherein one of the adjustment mechanisms adjusts the radial position of a roller of the calibration unit using a co-operating dual-thread system operable using an encoded motor and gearbox.

19. The method according to claim 18 , wherein there are four predetermined points in the series, optionally comprising: a leading end of the cylinder; a middle of the seam; a trailing end of the cylinder; a flip position.

20. The method according to claim 19 , wherein the electrical signal is further indicative of a weld thickness averaged along the entire seam.

21. The method according to claim 18 , wherein the step of

Assignees

• Crown Packaging Technology Inc

Inventors

• Martins Joao Fernando Fanico
• Sollis Mark David
• Arnell Stephen Robert

Classifications

• B23K31/125 Primary

  Weld quality monitoring · CPC title

• B23K37/0443

  Jigs · CPC title

• B23K37/0535

  Longitudinal pipe seam alignment clamps · CPC title

• B23K11/066

  of tube sections · CPC title

• B23K2101/125

  Cans · CPC title