To form a longitudinal hole of sufficient depth while making a device compact and lightweight on the whole regarding a hole excavating device for excavating the longitudinal hole, relatively large in hole diameter and depth, in the ground.
A hole excavating device is provided with a excavator 4 driving an excavating tool by a turning motor 15 to excavate a longitudinal hole in the ground, a hydraulic power unit 12 arranged on the ground to supply pressure oil to the turning motor 15. The excavator 4 is provided with a drain tank 21 for storing leakage oil generated from the turning motor 15, and an auxiliary hydraulic pump 22 for feeding the leakage oil to the hydraulic power unit 12. The hole excavating device is also provided with an auxiliary pipe line 43 for connecting the hydraulic power unit 12 on the ground to the auxiliary hydraulic pump 22 of the excavator 4, a switching valve 28 for holding the auxiliary pipe line 43 into either an opened state or a closed state, an oil quantity sensor 23 for outputting a detection signal when the oil quantity in the drain tank 21 reaches the specified quantity, and a control device 30 for outputting a driving signal for putting the switching valve in the opened state in response to the detection signal.
AIHARA YOSHIHIRO
SHIBA YOSHIMI
Next Patent: PRECEDENTLY RECEIVING CONSTRUCTION METHOD OF TUNNEL