Method of and apparatus for determining separating force of molded product from mold

An apparatus to determine a separating force of a molded product from a mold in an injection molding machine having a ejection mechanism, comprising:

• load determining means for determining a load exerted on the ejector mechanism at predetermined periods or predetermined positions in driving the ejector mechanism;
• storing means for storing the determined load;
• means for driving the ejector mechanism in a molding operation without injection of resin and storing a load exerted on the ejector mechanism determined by said load determining means in driving the ejector mechanism in said storing means;
• and
• means for driving an ejector mechanism in a molding operation with injection of resin to produce a molded product in the mold;
• and
• means for obtaining a difference between the load on the ejector mechanism determined by said load determining means in driving the ejector mechanism with the molded product and the stored load determined by said load determining means in driving the ejector mechanism without the molded product, as a separating force of the molded product at the predetermined periods or predetermined positions of the ejector mechanism.

An apparatus to determine a separating force of a molded product from a mold using an ejection mechanism, comprising:

• a load determining unit to determine a load exerted on the ejector mechanism at predetermined periods or predetermined positions in driving the ejector mechanism;
• a storing unit to store the determined load;
• a driving unit to drive the ejector mechanism in a molding operation without injection of resin and storing a load exerted on the ejector mechanism determined by said load determining unit in driving the ejector mechanism in said storing unit and to drive the ejector mechanism in a molding operation with injection of resin to produce a molded product in the mold;
• and
• a difference determining unit to determine a difference between the load on the ejector mechanism determined by said load determining unit in driving the ejector mechanism with the molded product and the stored load determined by said load determining unit in driving the ejector mechanism without the molded product, as a separating force of the molded product at the predetermined periods or predetermined positions of the ejector mechanism.