DIE CLAMPING DEVICE IN HYDRAULIC TYPE MOLDING MACHINE

摘要

PURPOSE:To provide a titled device which varies the advanced speed of the main ram of a hydraulic molding machine to various stages such as high middle low, etc. by fitting the bottomed cylindrical 2nd booster ram onto the 1st booster incorporated in the die clamping cylinder of the main ram and changing and controlling the oil pressures on the inside and outside thereof. CONSTITUTION:The pressure oil filled in a high-speed operating chamber 5 at the top head advances the bottomed bylindrical 2nd booster ram 4 which advances the main ram 2 by a stepped spigot 17 at a high-speed when said oil is fed in a high-speed oil supply hole 10a. A pilot check valve I18 is closed when the oil is fed in a middle-speed oil supply hole 12b. The main ram 2 advances and the speed thereof decreases to the middle-speed in inverse proportion to the sectional area of the ram 3 and the ram 4 when the oil is filled in a middle-speed operating chamber 6. The oil in a pressurizing chamber 8 sucked therein by the advance of the main ram 2 generates the low-speed total pressure by the pressure oil of a pump 24, by which dies are clamped. The retreat of the ram 2 is executed by the oil pressure of a back chamber 7 when the oil is fed into a back pressure supply hole 13c. The machine safely operated by varying the advance speed of the main ram 2 to the high middle low speeds. The dies are thus safely maintained.