摘要 |
<p>Evaluation of the durability or the coefficient of restitution of a golf club head 1 is performed by measuring a response signal of an impact surface 10 of a golf club head 1 when imparting a vibration to the impact surface 10 , finding a value of the peak frequency of the first resonance frequency or the like located within a predetermined frequency range of the measured response signal, and finding the ratio of this peak frequency value with respect to a reference value. Further, control of the quality of the restitution characteristics in a initial state, or quality of the golf club head that deteriorates over time, is conducted by utilizing the evaluation results. The golf club head 1 is provided with a label 12 for displaying the peak frequency measured immediately after manufacture as an initial value. Further, in manufacturing a golf club, the quality of the golf club head immediately after manufacture is controlled by the peak frequency.</p> |