| 摘要 |
PROBLEM TO BE SOLVED: To easily and securely evaporate away moisture from the inside of a die without causing the evaporation of a tip lubricant. SOLUTION: In vacuum die casting where, while evacuating the inside of the cavity 2 of a die 1 by an evacuating apparatus 4, a molten metal M is injected to the cavity 2 by the progress of a plunger tip 15 in an injection sleeve 14, a die temperature sensor 20 detecting the surface temperature of the die 1 and a tip temperature sensor 21 detecting the surface temperature of the plunger tip 15 are provided. Before the injection of the molten metal M to the cavity 2, detected signals from the temperature sensors 20, 21 are taken into a controller 5, the upper limit of the objective vacuum degree is decided based on the correlation between the temperature of the die and the evaporation vacuum degree of water and the lower limit of the objective vacuum degree is decided based on the correlation between the temperature of the tip and the evaporation vacuum degree of a lubricant applied thereto, respectively, the pressure in the cavity 2 is reduced so as to be controlled to the ranges of the vacuum degrees in the upper and lower limits, and, while suppressing the evaporation of the tip lubricant, moisture remaining in the die is evaporated. COPYRIGHT: (C)2009,JPO&INPIT
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