| 摘要 |
PURPOSE:To ensure simple and accurate discrimination/detection of the unevenness of the outer skin thickness of a golf ball in a nondestructive way, by holding a golf ball of double-layer structure between a sound wave transmitter and a receiver having a range of specific frequency and according to the size of the signal emerging on the cathode-ray tube of an oscilloscope. CONSTITUTION:A golf ball is held between a sound wave transmitter and a receiver having a range of frequencies 4.9kHz-7.0kHz, and the unevenness of the outer skin thickness of the ball is discriminated by the size of the signal that emerges on the cathode-ray tube of an oscilloscope. For instance, a disk-type piezoelectric ceramics 10 is stuck onto a metallic vibrating plate 11 to obtain an oscillator 12. A golf ball 4 is held between such oscillator 12 and an accelerometer 13, and the oscillator 12 is vibrated with a frequency of 5.15kHz. The output is obtained from the vlaue of voltage on the cathode-ray tube of an oscilloscope to discriminate the unevenness of the outer skin thickness of the ball. |
