SAFETY DEVICE FOR REVOLVING-TYPE WORK MACHINE

Provided is a safety apparatus performing an accurate safety control regardless of the posture of an upper revolving body of a work machine. The safety apparatus includes: obstacle sensors (61 to 64) provided in the upper revolving body; a revolving angle detector (66); an upper-side coordinate position calculation section (71) that calculates an upper-side coordinate position of the obstacle in the upper-side coordinate system using the upper revolving body as a reference; a lower-side judgment area setting section (72) that sets a lower-side judgment area in the lower-side coordinate system using the lower traveling body as a reference; a coordinate transformation section (73) that transforms one of the upper-side coordinate position and the position of the lower-side judgment area into the other coordinate system to unify the coordinate system; a lower-side approach judgment section (74) that judges whether an obstacle exists within the lower-side judgment area in the unified coordinate system; and a safety operation command section (78) that outputs a safety operation command based on the judgment result.