| 摘要 |
PURPOSE:To eliminate the loss of energy in striking a ram by a method in which an oil-pressure cylinder is fitted into the hollow recession of the ram, a recessed face is formed on the lower end of the ram, a projected face is formed on the upper end of anvil, and a columnar cylinder is shortened. CONSTITUTION:Pressure oil in an oil tank 23 is charged into the inside port 11a of an oil-pressure cylinder 11, a piston 13 is raised, a ram 6 is pushed up above a columnar cylinder 1, the oil-pressure cylinder 11 is fitted into the hollow recession 15 of the hollow cylinder 6a of the ram 6, and the columnar cylinder 1 is allowed to be shortened. The pressure oil is released, the ram 6 is naturally dropped, an anvil 18 is struck, and the pile is driven into the ground through a cap. Since the recessed face 16a of the lower end of the ram 6 is contacted with the projected face 18a of the upper end of the anvil 18 in the driving operation, the whole weight of the ram 6 acts on the center line of the anvil 18, and the loss of energy in striking the ram 6 can be eliminated. |
