| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the durability of an electromagnetic coil without necessitating conducting a large amount of current by realizing a predetermined driving force transmission condition by a mechanical means independently from an electromagnetic means and holding or reducing an amount of electric power supplied to the electromagnetic means as it is or reducing it. SOLUTION: When pressing force applied from an electromagnetic pilot clutch mechanism 10d through a first cam mechanism 10e is small, a second cam mechanism 10f is in a non-operation condition. Pressing force generated in the first cam mechanism 10e increases, friction engaging force of a mechanical main clutch mechanism 10c increases, and transmission torque increases gradually due to an increase of friction engaging force of the pilot clutch mechanism 10d. When friction engaging force of the pilot clutch mechanism 10d reaches a predetermined value, the second cam mechanism 10f is operated to press a retainer 13 to a main clutch mechanism 10c side so that they are friction-engaged further firmly and are connected. Consequently, it is unnecessary to conduct a large amount of current to an electromagnetic coil 14d and improve the durability influenced by the generation of heat.</p> |
