| 摘要 |
PROBLEM TO BE SOLVED: To provide a golf-ball flaw inspection device for accurately and securely detecting the flaw or the like in the golf ball by the impact sound thereof. SOLUTION: A golf ball 1 is dropped, and the vibration produced in a receiving table 2 is detected by an exciting-force sensor 11 for obtaining the ratio to an external force reference value by means of a ratio arithmetic unit 15. The sound produced in the golf ball 1 is detected by a microphone 3, and is separated into time-series signals of respective frequency zones by an analog BPF 5, and further is rectified for extracting the instantaneous maximum value in the respective frequency zones by means of a peak hold 7. The maximum value is normalized by the ratio calculated by the ratio arithmetic unit 15, and is compared with the vibration reference value predetermined in a comparator 9, and when it is deviated from a prescribed relationship, a comparison result signal is emitted, and when the number of the comparison result signal is, for instance, 3 or more, an alarm unit 18 gives a signal as abnormal. Since the comparison is made by extracting the maximum valve of the time-series signals for each of a plurality of frequency zones, the reliability of the inspection can be enhanced. |
