| 摘要 |
A working machine provided with an automatic hammering function which can be operated easily and which does not cause hammer breakage due to blank firing. Operating oil supplied to a hydraulic breaker (14) at the tip of a working device is controlled by first and second spools (33, 34). A single rod type boom cylinder (12bm) is operated in the retracting direction by an operation lever (24), and the hydraulic breaker (14) is pressed against an object to be crushed. The pressure (Ph) on the head side of the boom cylinder (12bm) and the pressure (Pr) on the rod side of the boom cylinder (12bm) are detected by pressure detectors (44, 45). One of switches (25, 26, 27) selects between a state in which automatic hammering is prohibited and a state in which the automatic hammering is permitted. A controller (51) performs opening control of the first and second spools (33, 34) of the hydraulic breaker (14) only when, in the state in which automatic hammering is permitted, the pressure (Ph) on the head side of the boom cylinder (12bm) and the pressure (Pr) on the rod side of the boom cylinder (12bm) which are detected by the pressure detectors (44, 45) are in a predetermined pressing pressure condition. |
