| 摘要 |
PURPOSE:To construct a sand pile by effectively utulizing oil pressure by a method in which oil pressure is all concentrated on a vibrator during the penetrating operation, and the oil pressure is partly distributed to a sand forcibly pressing force and partly distributed to a drawing and vibrating force during the drawing operation. CONSTITUTION:The oil pressures of the first and second oil-pressure pumps are joined through a solenoid switch valves 7 and 8 and then supplied to oil- pressure motors 12 and 13 for vibrator. On the other hand, oil pressure in the third oil-pressure pump 3 is supplied through a solenoid switch valve 9 to a cylinder 14 for a sand forcibly discharging and pressing mechanism. Oil pressure of the oil-pressure pumps is divided by the pressure oil inlet side tube 6 of the solenoid switch valve 9 and led to the pressure oil inlet of the solenoid switch valve 8. All the pressure oil of these pumps can be supplied to the vibrator during the penetration period, and the oil pressure can be partly used in pressing sand and partly used in drawing force. The oil pressure source can thus be effectively utilized and the cost of the sand pile driver can be lowered. |
