SLEWING TYPE CONSTRUCTION MACHINE

摘要

The present invention provides a slewing construction machine having an upper slewing body and a slewing speed sensor for detecting the slewing speed. The present invention can accurately control the slewing construction machine regardless of the output error of the slewing speed sensor. The construction machine comprises: the upper slewing body; a slewing motor (8); a hydraulic pump (7); a control valve (10); a slewing operation device (11); a slewing brake (12); the slewing speed sensor (27); a slewing operation detector (26) for outputting a slewing operation signal by detecting an operation that the slewing operation device receives; and a controller (17). The controller (17) memorizes the slewing speed detected by the slewing speed sensor (27) during slewing at set time intervals, and operates the slewing brake (12) based on the neutrality returning operation of the slewing operation device (11) to reset the memorized value of the slewing speed of the time as 0.