| 摘要 |
<P>PROBLEM TO BE SOLVED: To more properly control release of a brake when starting slewing of an upper structure. <P>SOLUTION: A slewing control device 30 for controlling slewing of an upper structure 3 by a hydraulic motor 40 for a slewing brake and an electric motor 21 for slewing holds the upper structure 3 in a stop state by interrupting oil passages 50a and 50b of the hydraulic motor 40 for the slewing brake, and releases the brake applied by the hydraulic motor 40 for the slewing brake when torque of slewing brought about by the electric motor 21 for slewing exceeds holding torque needed to hold the upper structure 3 in the stop state. <P>COPYRIGHT: (C)2013,JPO&INPIT |
