Method and apparatus for determining weld quality in percussion welding
AssigneeGeneral Electric Company
InventorsStephen E. Grabkowski, Max W. Schulz, Jr., Robert D. Williamson
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Abstract
The quality of welds produced during a percussion welding process are determined in real time by sensing the vibrational impulse signals produced during the percussion welding process, filtering the impulse signal to select a frequency band containing frequency components associated with the vibrations imparted to the forge rod of the welding machine, measuring the mechanical damping characteristics of the selected spectral portion of the signal by determining the log-decrement of the envelope of the signal, and comparing the measured log-decrement value obtained with a preselected threshold value.
Claims20
A method of determining the quality of welds produced by a percussion welding process using a percussion welding machine including a movable forging member which comprises sensing a damped vibration impulse signal produced during the percussion welding;
- measuring a damping characteristic of the signal;
- comparing the measured damping characteristic with a predetermined damping characteristic;
- and determining the quality of the weld on the basis of said comparing.
Apparatus for determining the quality of welds produced by a percussion welding machine including a movable forge member comprising means for sensing a damped vibration impulse signal produced during percussion welding;
- means for measuring a damping characteristic of the signal;
- means for comparing the measured damping characteristic with a predetermined damping characteristic;
- and means responsive to the comparing means for determining the quality of the weld.
An apparatus for determining the quality of welds produced by a percussion welding machine including a movable forging member for forcing a first part into engagement with a second part in the presence of a welding arc to produce fusion of the first and second parts which comprises an accelerometer affixed to the forging member for measuring the vibration of the forging member during welding and for producing a corresponding impulse signal;
- means for measuring the damping characteristic of the weld process by measuring the time rate of change of an envelope of the impulse signal;
- means for comparing the measured damping characteristic with a preselected threshold value;
- and means for providing an output indication of a defective weld upon the measured damping characteristic being less than the threshold value.
Dependencies are inferred from the claim text.