Injection molding apparatus and method

摘要

The present invention is directed to an injection molding apparatus and method capable of preventing the occurrence of over-packing. The apparatus includes a pair of dies for forming a plurality of cavities therebetween; die closing devices for closing the pair of dies under a prescribed pressure; an injection device for injecting a molten resin into respective cavities under a prescribed pressure; and, a control device for controlling the die closing devices and the injection device. Further, the apparatus comprises a plurality of pressure sensors for detecting respective pressures in respective cavities and a control device that controls the injection device and/or the die closing devices to reduce the rate of injection of the molten resin and/or the force of closing the dies and, otherwise, stops the injection and/or the die closing operation when the pressure difference between cavities is found to be greater than a prescribed value on the basis of sensed values from the respective pressure sensors.