Die casting machine with reduced static injection pressure

A method of die casting parts comprising the steps of:

• injecting a molten alloy having the characteristics of minimal volumetric contraction during solidification into a die cavity during a filling stage;
• monitoring at least one of the pressure of a shot cylinder for injecting the molten alloy into the die cavity or the position of a plunger rod for injecting the molten metal into the die cavity;
• and
• reducing the injection pressure applied by the shot cylinder and plunger rod during a final stage of filling of the die mold for reducing the die separating force near the end of a molding cycle.

A die casting machine comprising:

• a pair of dies defining at least one die cavity for a part to be molded;
• a clamping system for clamping said dies together during the injection of a molten alloy into said die cavity;
• a shot cylinder having a plunger rod and a hydraulic fluid inlet for receiving pressurized hydraulic fluid for moving said plunger rod;
• a cold chamber with an inlet for receiving a molten alloy having a low shrinkage characteristic and an outlet coupled to said die cavity, said plunger rod extending into said cold chamber for injecting a molten alloy into said die cavity;
• a source of hydraulic pressure for coupling to said inlet of said shot cylinder;
• and
• a control system in communication with said source of hydraulic pressure for reducing the injection pressure applied by said plunger rod near the end of an injection cycle.