| 摘要 |
<P>PROBLEM TO BE SOLVED: To smoothly increase a braking torque in an electromagnetic brake. <P>SOLUTION: An electromagnetic brake device performs duty-ratio control of PMW energization to an exciting coil, by pressing an armature by biasing force of a braking spring to a rotor to hold the rotor between it and a fixed plate, thus braking during non-energization and by moving the armature in an opposite direction to the biasing force of the braking spring to release the braking of the rotor by energization to the exciting coil. In a shift process from a braking release state to a braking state, regarding a change range of a duty ratio at least in a braking initial period from just before contact of the armature with the rotor until a braking force is added to the rotor, a frequency is set so that the armature vibrates in response to a frequency of the duty ratio. As for frictional force related to the armature 5, vertical force in a direction vertical to strain sensors 73, 74 surfaces is detected by strain sensors 71, 72 to detect the braking torque. Feed-back control is performed so that the braking torque will follow temporally increasing a target torque. <P>COPYRIGHT: (C)2013,JPO&INPIT |
