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US 2003/0165180 A1Published application
Monitoring of resistance welding
OwnerVijitha Maithri Weerasinghe, Sharif Abdul Hameedinventors
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OwnerVijitha Maithri Weerasinghe, Sharif Abdul Hameedinventors
Estimating the term…
A method of monitoring the nugget size of the welds produced by a spot welding machine, comprises optically imaging a region of a weld spot onto a transducer (21) after completion of the spot welding process. The transducer (21) produces an electrical signal having avalue dependent on the mean intensity and the wavelength distribution of the radiation emitted from the region of the weld spot (18) imaged on to the transducer (21). A computer (24) analyses the electrical signal produced by the transducer (21) to evaluate a weld nugget size indicator value and issue a warning through a visual display module (31) when welds of poor size are being, or about to be produced, so that corrective action can be taken by replacing or dressing the electrodes.
A method of monitoring the welds produced by a spot welding machine, which comprises optically imaging a region of a weld spot onto a transducer after completion of the spot welding process, producing by the transducer an electrical signal having a value dependent on the mean intensity and the wavelength distribution of the radiation emitted from the region of the weld spot imaged on to the transducer, and analysing the electrical signal produced by the transducer to evaluate a weld nugget size indicator value indicative of the condition of the welding electrode, characterised in that the analysing step comprises measuring the rate of change with time of the amplitude of the electrical signal as a result of the cooling of the weld spot.
Apparatus for monitoring the quality of the welds produced by a spot welding machine, comprising a radiation sensitive transducer, an optical imaging system for imaging a region of a weld spot onto the transducer after completion of the spot welding process, the transducer being operative to produce an electrical signal having a value proportional to the mean intensity of the radiation emitted from the region of the weld spot imaged on to the transducer, and means for analysing the electrical output signal of the transducer to evaluate a weld nugget size indicator value indicative of the condition of the welding electrode, characterised in that the transducer is sensitive to visible light emitted by the weld spot.
Dependencies are inferred from the claim text.