| 摘要 |
PURPOSE:To raise the efficiency of pile driving operation by automatically switching the operations of pile driving by judging the starting time of the cutting operation of soil and sand and the starting time of redriving operation from the conditions of pile penetration. CONSTITUTION:In case where the penetration speed of a pile 25 is lowered to below the preset lowest penetration speed by the resistances of soil and sand adhered to the tip, etc., of the pile 25 during the driving operation of the pile 25, a driver 18 is operated to switch a winch 22 from winding-down state to winding-up state, and the edge between the tip end face of the pile 25 and soil and sand adhered to the tip end face of the pile 25 is cut. When the edge between the tip end face of the pile 25 and the adhered soil and sand is cut is detected from the variation in the pressure of a vibration chamber 7, the driver 18 is again operated to switch the winch 22 from winding-up state to winding- down state, and the pile 25 is again driven by a winch control circuit 44 provided in a winch controller 40. When the penetration speed of the pile 25 is lowered to less than a given speed, a control output is sent out from the circuit 44 to a winch control valve 19 to switch the winch 16 from winding-down state to winding-up state. |
