Nissei Plastic Industrial Co., Ltd.

Takahiro Kobayashi

Mamoru Miyagawa

Toshiyasu Koda

Masashi Suganuma

Yasuhiko Takeuchi

Yuji Hayashi

Kazutoshi Takayama

An injection molding method of a metal material in a liquid phase state, by which the material can be transferred, metered, and deaerated smoothly by operating the movement and rotation of the screw. After injection, retraction resistance made of the metal material that went into a clearance between the heating cylinder and screw flights is removed in advance by rotating the screw for a set number of times at a forward position. Then, the metal material in the liquid phase state is accumulated in a front chamber by forcing the screw to retract for a set distance, and applying a back pressure to the screw rotating at a retraction position, thereby starting transfer of the metal material. Subsequently, the rotation of the screw is stopped, whereupon the accumulation is completed. Then, the accumulated metal material is pressed by moving the screw forward. Injection is effected only when a material pressure reaches a set pressure within a preset forward distance of the screw, whereupon metering is assumed to have been completed.

Injection molding method of metal material

A method of metering a metal material in a liquid phase in molding injection provides accurate and reliable transfer of the metal material. A heating cylinder housing a rotatable and axially movable screw, is inclined with its head pointing downward, so that the metal material in the liquid phase state flows down into a front chamber due to self-weight. At the forward position after injection, the screw is forced to retract to a set position, whereby a predetermined quantity of a liquid phase material primarily stored on the periphery of the head portion of the screw is accumulated by suction due to a negative pressure in the front chamber of the heating cylinder. Further, a constant quantity of the liquid phase material can be metered each time in the front chamber by stopping and then rotating the screw at a retraction position.

Metering method of metal material in injection molding

A mold clamping method for a straight hydraulic mold clamping apparatus, wherein supply of mold clamping oil to the rear oil chamber of the mold clamping cylinder starts immediately before completion of slowing down of the mold closing process using rapid-moving cylinders, and raising the mold clamping force successively starts simultaneously with completion of the mold closing.

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Nagano-ken, Japan

Takahiro Kobayashi