| 摘要 |
PROBLEM TO BE SOLVED: To achieve accurate control by reliably setting a slewing speed at zero without reference to an actual value of sensor output at the stop of slewing.SOLUTION: An super structure is driven for slewing by a revolving motor 8. While a remote control valve 11 serving as slewing operation means is operated for slewing, a slewing speed detected by a revolving speed sensor 27 is stored at a set time interval in a controller 17. A slewing brake 12 is operated after a lapse of set time from neutral return of the remote control valve 11, and a storage value of the slewing speed at a point of time of output of this brake operation command is recognized as zero and set. |
