| 摘要 |
<p>PURPOSE:To shorten a stop distance by controlling a chopper according to plugging conductivity corresponding to a traveling speed, performing the chopper control until a plugging signal is ceased, and operating an electric brake while using an electromagnetic brake in combination. CONSTITUTION:When the unmanned carriage is stopped urgently, the electromagnetic brake 41 is put in operation and forward/backward traveling contactors 23-26 are so switched as to cause plugging operation. When the plugging operation occurs, the traveling speed of the unmanned carriage is detected by pulse encoders 36 and 39 and the chopper 21 is controlled according to the plugging conductivity corresponding to the detected traveling speed. This chopper control is performed until the plugging signal is ceased according to the detection outputs of pulse encoders 36 and 37 and the electric brake is put in operation in combination with the electromagnetic brake 41. Consequently, the stop distance is shortened in emergency and the wear of the brake shoe of the electromagnetic brake 41 can be reduced.</p> |
