和弓のエネルギー伝達効率を用いた機械的性能の評価に関する力学的研究

抄録

Tacteristics of three kinds of Japanese bows using energy transfer efficiency. Energy transfer efficiency measured by shooting machine and subjects (two males, called subject A and subject B) in the experiment. The subject A was 43 years of age,178 centimeter in height,72 kilogram in weight, with 23 years of training experience and 5 dan degree. The subject was 21 years of age,167 centimeter in height,67 kilogram in weight, with 6 years of training experience and 3 dan degree. The relation between energy transfer efficiency and impulse of torque added to the grip of bow was also clarified.
The results were as follows:
1) Energy transfer efficiency saturation point were about 7kgF·m·ms (impulse of torque) in bamboobow,4 or 5kgF·m·ms (impulse of torque) in glassfiber-bow and carbonfiber-bow.
2) Energy transfer efficiency was constant a range of drawing from 0.8m to 0.9m in three bows. It is possible to compare energy transfer efficiency of Japanese bows in this drawing range.
3) Energy transfer efficiency of bamboo-bow was 53.7±0.8%, glassfiber-bow was 55.5±0.6%, carbonfiber-bow was 57.9±0.5%. Each value were significantly differece (p<0.01). It is possible to valuate mechanical characteristics of Japanese bows using energy transfer efficiency.
4) The traveling time of the torque added to the grip of fiber-bows to both sides was faster than bamboo-bow. As a result of this, energy transfer efficiency of fiber-bows was higher than bamboo-bow.
5) In the experiment by subject, energy transfer efficiency of bamboo-bow shooting by subject A was higher subject B (p< 0.01). The analyzation method with energy transfer efficiency is useful for the valuation of shooting technique.