Hydraulic circuit control device and molding machine

A molding machine comprising:

• a fixed portion to which a fixed mold is attached;
• a movable portion to which a movable mold is attached;
• and
• a hydraulic circuit control device provided in the movable portion and configured to move the movable portion relative to the fixed portion, wherein
• the hydraulic circuit control device includes
• a drive motor,
• a drive-side cylinder including a drive-side fluid chamber and a drive-side piston that is moved by the drive motor,
• a driven-side cylinder including a driven-side fluid chamber, a fluid path that connects the driven-side fluid chamber and the drive-side fluid chamber, and a driven-side piston that is moved by moving the drive-side piston to increase or reduce an amount of a working fluid in the driven-side fluid chamber through the fluid path, and
• a fluid path volume adjustment mechanism configured to increase or reduce a volume of the fluid path according to an increase or reduction in a volume of the working fluid, wherein
• the fluid path includes a main fluid path portion through which the working fluid flows between the driven-side fluid chamber and the drive-side fluid chamber, and an adjustment fluid path portion connected to the main fluid path portion, and
• the fluid path volume adjustment mechanism includes a volume adjustment motor configured to move an inner wall surface of the adjustment fluid path portion, and is configured to move the inner wall surface to increase or reduce a volume of the adjustment fluid path portion.