| 摘要 |
PROBLEM TO BE SOLVED: To accurately mold by metering a raw material by retracting a screw plunger to a suck-back position decided from a forwarding limiting position, then rotating the plunger, metering the material, storing forward, and hence finishing the step at a metering completing position rear of the suck-back position. SOLUTION: A screw plunger 12 for next injecting is retracted from a forwarding limiting position A in the case of completing an injecting step. When a limit switch 23 set at a suck-back position B of a metering starting position is hit by a dog 21 of the plunger 12, the retracting is stopped. Then, a metering step is started, the plunger 12 is rotated by a motor 19 at the position B, a raw material from a hopper 18 is continuously metered and filled in a forward air gap 25 of the plunger 12, the plunger 12 is pushed by the increased metered resin and retarded. This rotating and retracting are continued until the switch 24 of the metering step completing position is hit by the dot 22 of the plunger 12. Thus, accurate metering can be conducted, a molten state of the resin is made uniform, and hence a molding of high quality can be obtained.
|
