Molding machine and control method of molding machine

A method for controlling a molding machine,

• the molding machine including:
• a mold opening/closing mechanism configured to move a movable platen to be attached with a movable mold to a stationary platen to be attached with a stationary mold;
• and
• a clamping mechanism including four tie bars and being independent of the mold opening/closing mechanism, the clamping mechanism being configured to perform a clamping process,
• wherein the mold opening/closing mechanism includes:
• at least two ball screws separate from the tie bars;
• at least four servomotors that are configured to drive the ball screws;
• and
• at least two ball screw nuts into which the respective ball screws are inserted,
• wherein each of the at least two ball screws is driven by at least two of the four servomotors at the same time,
• wherein the two servomotors drive the ball screw by a driving force transmission
• the method comprising:
• using an encoder of any one of the servomotors to provide a detection value, and
• using the detection value as a position of the movable platen to perform control.