Multi-mode structural weld monitor on a time base
AssigneeMartin Marietta Corporation
InventorsRussell Alexander Chihoski, John Charles De Fellippie
Life of this patent
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Abstract
To provide a plurality of different weld quality indicators in resistance, projection and forge welding, the varying separation of two electrodes during a plurality of different time brackets defined within a weld cycle is measured. At least one interval timer is used to define such time brackets. These weld quality indicators include the surface resistance of the workpieces, the melting rate, the maximum expansion, the expansion rate, the weld size, the forge force, the set-down rate, etc.
Claims10
A method of measuring a plurality of characteristics of a weld during a welding process in which a workpiece is clamped between two welder electrodes, one of which is movable to permit a change in electrode separation due to a dimensional change of the weld in the workpiece during a weld cycle, said method comprising:
- selecting a plurality of predetermined time brackets within an individual weld cycle such that each bracket corresponds to one of the characteristics;
- and
- measuring the change in electrode separation during each of said time brackets, whereby each measurement represents an indication of a weld characteristic for its corresponding time bracket.
In a weld monitor system for tracking the separation between a pair of welder electrodes, at least one of which is movable, wherein a workpiece is positioned between the electrodes, and wherein the expansion, melting, contraction and solidification of the weld in the workpiece during a weld cycle causes variation in electrode separation, the improvement comprising:
- means for producing a continuous output potential proportional to electrode separation occurring during a plurality of predetermined time brackets within the weld cycle;
- means for defining a first time bracket of a predetermined duration within the weld cycle;
- means responsive to said output potential for producing a first signal proportional to the change in electrode separation during said first time bracket;
- means for defining a later, second time bracket of a predetermined duration within the weld cycle;
- and
- means responsive to said output potential for producing a second signal proportional to the change in electrode separation during said second time bracket.
Dependencies are inferred from the claim text.