抄録
In this study we aim to realize an actuator that is comparable with a natural muscle from a viewpoint of flexibility, the output force and the responses. In the 1st report we constructed the Shape Memory Alloy (SMA) actuator protected by “a rolled film tube” with the high heat resistance and the high flexibility, and it is named “the unit cell”. In this report we constructed an actuator named “a motor unit” with the larger output force by bunching up 7 unit cells, and the characteristics of the motor unit are investigated by the experiments in which the motor unit is driven in Pulse Frequency Modulation (PFM). The result of the experiments shows that the static characteristics of the output force and the displacement to the input pulse frequency in the motor unit near proportion relations in comparison with the unit cell still more and the output force increases almost 7 times as large as the unit cell. It is found out that the time constant of the motor unit becomes larger compared to that of the unit cell, and the power conversion efficiency falls when pulse width is extended to improve the time constant.
