Apparatus and control system for laser welding
First Claim
1. A method of operating a head comprising:
- (a) automatically moving the head in a first direction while maintaining the workpiece in a stationary position in order to provide fine supplemental movement;
(b) automatically moving the head in a second direction transverse to the first direction while maintaining the workpiece in the stationary position in order to provide fine supplemental movement;
(c) automatically moving the head in a third direction toward a workpiece;
(d) tilting the head about a pivot point substantially coplanar with the workpiece; and
(e) transmitting a welding laser beam through a cable to the head, and transmitting the laser beam through the head free of mirrors.
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Abstract
In general, the present invention pertains to an apparatus and control system for working sheet material employs a tilting mechanism which automatically tilts a head about a theoretical point disposed upon the sheet material. In another aspect of the present invention, the head is defined as a laser head and the pivot point corresponds with the laser beam focal point. A further aspect of the present invention provides a seam tracking device and control system which automatically adjust a welding head height relative to the sheet material as a datum rather than relative to a gantry or other structure supporting the welding head. In yet another aspect of the present invention, an optical seam tracking device is employed to automatically tilt the welding head along differing rotational planes. In still another aspect of the present invention, various axial slides are employed in combination with a gantry. A further aspect of the present invention uses a seam tracking device and microprocessor to track a welding seam and move a welding head predetermined amounts due to sensed pre-weld gap widths. Another aspect of the present invention uses an automated tilting mechanism for creating a tailored blank butt weld between dissimilar materials. A method of operating the present invention is also provided.
67 Citations
49 Claims
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1. A method of operating a head comprising:
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(a) automatically moving the head in a first direction while maintaining the workpiece in a stationary position in order to provide fine supplemental movement;
(b) automatically moving the head in a second direction transverse to the first direction while maintaining the workpiece in the stationary position in order to provide fine supplemental movement;
(c) automatically moving the head in a third direction toward a workpiece;
(d) tilting the head about a pivot point substantially coplanar with the workpiece; and
(e) transmitting a welding laser beam through a cable to the head, and transmitting the laser beam through the head free of mirrors. - View Dependent Claims (2, 3, 4, 5, 6, 7)
(a) transmitting an optical beam upon a seam; and
(b) sensing the optical beam and determining a desired head movement path.
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4. The method of claim 2 further comprising:
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(a) sensing a gap width at a seam;
(b) comparing the sensed gap width to a predetermined value;
(c) automatically tilting a laser optic within the head; and
(d) emitting the laser beam at an angle in relation to a plane of the workpiece.
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5. The method of claim 1 further comprising butt welding together a pair of workpieces.
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6. The method of claim 1 further comprising locating dissimilar material sheets adjacent to each other for the butt welding.
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7. The method of claim 1 further comprising:
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(a) energizing a first electric motor;
(b) driving a first drive transmission;
(c) rotating a first bearing block in relation to a second bearing block along a first plane;
(d) energizing a second electric motor;
(e) driving a second drive transmission; and
(f) rotating the first and second bearing blocks along a second plane.
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8. A method of operating a laser welding head comprising:
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(a) emitting a welding laser beam from the head;
(b) transmitting an optical light upon a seam in front of the welding laser beam;
(c) sensing the optical light;
(d) determining a desired head movement path in response to step (c);
(e) automatically moving the head in a first substantially horizontal direction in response to step (d);
(f) automatically moving the head in a second direction substantially perpendicular to the first direction;
(g) automatically moving the head in a substantially vertical direction; and
(h) tailor blank welding workpieces together in response to step (a), the workpieces being of dissimilar material characteristics. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16)
(a) positioning a first of the focal points on one transverse side of the seam;
(b) positioning a second of the focal points on the opposite transverse side of the seam; and
(c) butt welding together the workpieces across the seam.
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11. The method of claim 8 further comprising:
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(a) sensing a gap width at the seam;
(b) comparing the sensed gap width to a predetermined value;
(c) tilting a laser optic within the head a predetermined amount in response to step (b); and
(d) emitting a laser beam at an angle in relation to a workpiece plane.
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12. The method of claim 8 further comprising butt welding together a pair of dissimilar thickness workpieces with a Yag laser beam.
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13. The method of claim 8 further comprising tilting the head by:
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(a) energizing a first electric motor;
(b) driving a first drive transmission;
(c) rotating a first bearing block in relation to a second bearing block along a first plane;
(d) energizing a second electric motor;
(e) driving a second drive transmission; and
(f) rotating the first and second bearing blocks along a second plane.
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14. The method of claim 8 further comprising automatically tilting the head about a pivot point substantially coplanar with a workpiece.
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15. The method of claim 8 further comprising manually tilting the head about a pivot point substantially equal to the focal point of the laser beam.
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16. The method of claim 8 further comprising moving a gantry to move the head.
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17. A method of operating a laser head to weld material sheets at a workpiece seam, the method comprising:
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(a) splitting a laser beam into multiple emitted beams within the head;
(b) emitting. the multiple laser beams from the head, the multiple laser beams having spaced apart focal points;
(c) automatically moving the head along the workpiece seam;
(d) automatically moving the head in a direction substantially perpendicular to the workpiece seam;
,(e) positioning a first of the focal points on one transverse side of the workpiece seam;
(f) positioning a second of the focal points on the opposite transverse side of the seam; and
(g) butt welding together the material sheets across the seam. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25)
(a) sensing a gap width at the workpiece seam;
(b) comparing the sensed gap width to a predetermined value;
(c) tilting a laser optic within the head a predetermined amount in response to step (b); and
(d) emitting the multiple laser beams at an angle in relation to a plane of the workpieces.
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19. The method of claim 17 further comprising butt welding together a pair of workpieces.
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20. The method of claim 17 further comprising tilting the head by:
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(a) energizing a first electric motor;
(b) driving a first drive transmission;
(c) rotating a first bearing block in relation to a second bearing block along a first plane;
(d) energizing a second electric motor;
(e) driving a second drive transmission; and
(f) rotating the first and second bearing blocks along a second plane.
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21. The method of claim 17 further comprising automatically tilting the head about a pivot point substantially coplanar with a workpiece.
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22. The method of claim 17 further comprising manually tilting the head about a pivot point substantially equal to the focal point of the laser beam.
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23. The method of claim 17 further comprising transmitting the laser beam through a cable to the head.
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24. The method of claim 23 further comprising tilting the head about a pivot point substantially coplanar with the workpieces, wherein the laser beam is a Yag laser beam and the workpieces are substantially flat.
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25. The method of claim 17 further comprising sensing the location of the workpiece seam with a camera prior to welding and moving the head in response to the sensed location in lateral, closeness and tilting directions relative to the seam.
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26. A method of operating a welding device relative to at least one workpiece, the welding device having a head, an optical sensor and a fiber optic cable, the method comprising:
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(a) transmitting a laser beam to the head through the fiber optic cable;
(b) projecting the laser beam in a direct path from the head to the workpiece;
(c) welding the workpiece with the laser beam;
(d) optically sensing the position of an elongated target feature of the workpiece to be welded;
(e) determining a desired orientation of the head relative to the target feature based at least in part on the sensed position of the target feature in a real-time, closed-loop feedback manner;
(f) adjusting a tilted orientation of the head along a radius about the target feature while welding, in response to the determination of step (e);
(g) adjusting two perpendicular lateral orientations of the head relative to the target feature, in response to the determination of step (e); and
(h) sensing and determining a gap to be welded and automatically adjusting a position of the head accordingly. - View Dependent Claims (27, 28, 29, 30, 31)
(a) moving the optical sensor along the seam;
(b) moving the head along the seam; and
(c) adjusting a third distance orientation of the head relative to the target feature. in response to the determination of a desired orientation of the head. the third orientation being substantially perpendicular to the lateral orientations.
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31. The method of claim 29 further comprising tailor blank welding the workpieces together with a Yag laser beam.
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32. A method of welding workpieces with a laser beam, head and robot, the method comprising:
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(a) positioning the head adjacent to the workpieces by a movable robot;
(b) welding the workpieces together at a mating seam by emitting the laser beam;
(c) optically sensing the location of the seam during welding and in advance of the welding laser beam;
(d) tilting the head relative to the workpieces, the head being tilted about the seam along a first plane substantially perpendicular to the faces of the workpieces, the head being tilted mechanically independent of the robot;
(e) automatically moving the head in at least two linear dimensions relative to the seam during welding and mechanically independent of the robot, with a gross movement mechanism, and (f) moving the head with a fine movement mechanism after the gross movement. - View Dependent Claims (33, 34, 35, 36, 37, 38, 39)
(a) moving the head along a first linear axis through actuation of a first linear slide; and
(b) moving the head along a second linear axis through actuation of a second linear slide.
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37. The method of claim 36 further comprising moving the head along a third linear axis through actuation of a third linear slide.
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38. The method of claim 32 further comprising:
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(a) continuously determining a seam gap dimension; and
(b) automatically tilting the head during welding, in response to step (a).
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39. The method of claim 32 wherein the robot includes a gantry, the method further comprising:
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(a) moving the head along an attached gantry bridge; and
(b) rotating, a carousel to rotate the head relative to the gantry bridge.
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40. A method of operating a laser welding head comprising:
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(a) optically tracking an elongated workpiece seam prior to welding;
(b) transmitting at least a pair of welding laser beams from the head;
(c) tilting the head along a plane substantially perpendicular to a workpiece and about a point adjacent the seam; and
(d) automatically moving the head along at least two linear axes which are substantially perpendicular to each other, during welding. - View Dependent Claims (41, 42, 43, 44)
(a) continuously determining a seam gap dimension; and
(b) tilting the head during welding, in response to step (a).
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44. The method of claim 40 further comprising transmitting at least one laser beam to the head through a fiber optic cable and automatically tilting the head during welding.
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45. A method of using a head to weld workpieces, the method comprising:
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(a) tracking an elongated workpiece feature by use of a camera;
(b) transmitting a welding Yag laser beam to the head through a cable to tailor blank weld the workpieces together;
(c) moving the head along an attached gantry bridge;
(d) moving the head along at least two linear axes which are substantially perpendicular to each other, during welding, even when the gantry bridge is stationary; and
(e) rotating a carousel attached to the gantry in order to rotate the head relative to the gantry bridge. - View Dependent Claims (46, 47, 48, 49)
(a) moving the head along a first linear axis through actuation of a first linear slide;
(b) moving the head along a second linear axis through actuation of a second linear slide; and
(c) moving the head along a third linear axis, all of the linear axes being substantially perpendicular to each other.
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47. The method of claim 45 further comprising simultaneously emitting at least two laser beams from the head to weld the workpieces.
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48. The method of claim 45 further comprising:
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(a) continuously determining a seam gap dimension; and
(b) automatically tilting the head during welding, in response to step (a).
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49. The method of claim 45 further comprising automatically tilting the head along a plane substantially perpendicular to the workpieces and along a radius about a laser beam focal point adjacent the workpiece feature, during welding.
Specification