METHOD OF CONTROLLING ULTRASONIC WELDING PROCESS Russian patent published in 1994 - IPC

FIELD: ultrasonic welding. SUBSTANCE: method comprises steps of introducing to a control system (before welding process) a reference signal and a reference time period; energizing an ultrasonic transducer at idle period, forming two feed back signals OC1 and OC2, dividing one signal by another and memorizing the received ratio signal CO; driving the ultrasonic transducer at welding, forming two signals OC1 and OC2, dividing them one by another and analyzing the signal CO, had been received, for presence of an extremum over the reference time period from the beginning of the welding process; after detection of the extremum or after the reference time period had been lapsed without detection of the extremum, forming a difference signal PC by subtraction from the ratio signal CO, written at the idle period, the ratio signal CO, written at welding process, integrating the signal PC, had been received, and comparing the result with the reference signal; interrupting the welding process at time moment, when both these signals are the same. EFFECT: enhanced reliability of welding process control. 1 cl, 2 dwg