Method and apparatus for automatic multi-run welding
AssigneeESAB Aktiebolag
InventorsBengt Ekelof, Peder Hansson
Life of this patent
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Abstract
This invention relates to a method and apparatus for automatic multi-run welding of a joint such as a square butt joint, a V-type joint, or a U-type joint, etc. This invention incorporates a sensor which moves along the joint and which scans a number of points along portions of the joint. The points scanned are used to calculate the cross-sectional area of the portions of the joint and the cross-sectional areas are then used to determine welding parameters, such as weld speed and weld rod feed, for the welding which is to be done in each of the joint portions. Thus, the joint is filled with weld material uniformly along its length despite deviations which may be inherent in the edges of the materials which are being welded.
Claims20
A method for automatic multi-run welding of a joint formed between at least two adjacent pieces to be welded by a weld head to form a weld, said welding comprising feeding a solid welding material into the weld at a speed of feed while moving at least one of the weld head and the two adjacent pieces relative to the other of the weld head and the two adjacent pieces at a relative speed of movement, each of the at least two adjacent pieces comprising a joint surface, each joint surface being disposed for being welded to at least one adjacent joint surface, said method comprising the steps of:
- scanning at least a cross-section of at least a portion of the joint with scanning means;
- depositing at least a first bead of solid welding material along said at least a portion of the joint;
- directly measuring by said scanning a plurality of actual points on the joint surfaces of said at least a portion of the joint;
- generating data corresponding to coordinates of said plurality of actual points;
- calculating with said data to obtain values to determine at least a cross-sectional area of said at least a portion of the joint;
- calculating a cross-sectional area of the at least a first bead of solid welding material deposited along said at least a portion of the joint;
- calculating a residual area for said at least a portion of the joint, said residual area being the different between said calculated cross-sectional area of said at least a portion of the joint and said calculated cross-sectional area of the at least a first bead of solid welding material deposited along said at least a portion of the joint;
- depositing at least a second bead of solid welding material along said at least a portion of the joint;
- calculating at least one of:
- said speed of feed of the solid welding material being fed into the weld for said at least a portion of the joint as a function of said residual area of said at least a portion of the joint;
- and
- said relative speed of movement between the weld head and the two adjacent pieces for said at least a portion of the joint as a function of said residual area of said at least a portion of the joint;
- for said depositing of the at least a second bead of solid welding material along said at least a portion of the joint.
Apparatus for automatic multi-run welding of a joint formed between at least two adjacent pieces to be welded by a weld head to form a weld, each of the at least two adjacent pieces comprising a joint surface, each joint surface being disposed for being welded to at least one adjacent joint surface, said apparatus comprising:
- a welding housing;
- a weld head disposed on the welding housing, the weld head comprising means for receiving a solid welding medium and means for feeding the solid welding medium to the weld;
- a welding power supply for providing current for the weld head;
- means for providing relative movement between the weld head and the at least two adjacent pieces;
- sensor means for scanning at least a portion of the joint, said sensor means being for directly measuring a plurality of actual points on at least one joint surface to generate data corresponding to coordinates of said points;
- processing means for receiving said data corresponding to coordinates of said points, for calculating a cross-sectional area of the joint from said data corresponding to coordinates of said points, for calculating a cross-sectional area of a deposited bead of welding material, for calculating a residual area for the joint, said residual area being the difference between said calculated cross-sectional area of the joint and said calculated cross-sectional area of the deposited bead of welding material, for calculating at least one of:
- a speed of feed of the solid welding medium into the weld, and
- a relative speed of movement between the weld head and the at least two adjacent pieces,
- and for producing signals for control of the welding;
- and
- control means for receiving said signals for control of the welding, and for controlling at least one of:
- said means for controlling the means for feeding the weld rod to control the amount of solid welding material being fed into the weld as a function of the residual cross-sectional area, and
- said means for controlling the means for providing relative movement between the weld head and the at least two pieces to control the amount of solid welding material being deposited along the joint as a function of the residual cross-sectional area.
Dependencies are inferred from the claim text.