Patent ID: 7029258

Claim:
An injection molding machine system comprising: a motor-driven injection molding machine body including an injection mechanism and a mold clamping mechanism that are driven by servo-motors; a control device giving a command to said servo-motors to drive said injection mechanism and said mold clamping mechanism in accordance with predetermined program commands; and an electric power supply device for supplying said motor-driven injection molding machine body with the electric power required for operating said motor-driven injection molding machine body, said electric power supply device including: a first electric power supply unit for supplying the electric power from a commercial power source; a second electric power supply unit having an electric power accumulation unit dedicated to said motor-driven injection molding machine; an electric power comparator for comparing outputs of said first and second electric power supply units; and a switching device for switching over a supply of the electric power given to said second electric power supply unit from said first electric power supply unit in response to a result of the comparison by said electric power comparator under predetermined conditions.