Injection molding apparatus and mold clamping device

An injection molding apparatus configured to perform injection molding of a molded article using a molding die configured with a fixed mold and a movable mold, the apparatus comprising:

• an injection unit configured to inject a material of the molded article into the molding die;
• a mold clamping unit to which the molding die is attached and which is configured to perform mold clamping of the molding die;
• and
• a controller configured to control the injection unit and the mold clamping unit, wherein
• the mold clamping unit includes
• a toggle fixing plate,
• a fixed mold attachment portion to which the fixed mold is attached,
• a movable mold attachment portion which is disposed between the toggle fixing plate and the fixed mold attachment portion so as to be movable forward and backward in a mold clamping direction, and to which the movable mold is attached,
• a motor,
• a ball screw attached to the toggle fixing plate and configured to rotate due to driving of the motor,
• a crosshead configured to move between the toggle fixing plate and the movable mold attachment portion due to rotation of the ball screw,
• a toggle section coupled to the toggle fixing plate, the movable mold attachment portion, and the crosshead and configured to move the movable mold attachment portion along the mold clamping direction due to a movement of the crosshead, and
• a position detector configured to detect a position of the crosshead, and
• the controller drives the motor to control the position of the crosshead based on a detection result of the position detector to thereby make the toggle section operate to perform the mold clamping of the fixed mold and the movable mold.