| 摘要 |
PURPOSE:To increase the amount of heat transferred from a barrel to material and consequently perform metering and injection processes in a short time by a structure wherein recessed parts or projected parts to enhanced the shifting speed of the material to the peripheral direction of a plunger are provided at least on a part ahead of a material feeding port in the outer peripheral surface of the plunger. CONSTITUTION:Under the condition that plunger 24 is rotated at a required rotation 1 frequency, material is changed in a stuffer 27 and pushed down with a stuffer plunger 30. The material is sent forward through the outer peripheral part of a plunger 24, passed through a check ring 23 part and successively stored in a barrel 22. After the above-mentioned metering process, injection is performed by advancing the plunger 24. And, since recessed parts or projected parts are provided on the peripheral surface of the plunger 24, the shifting speed of the material to the peripheral direction of the plunger becomes greater. As a result, the heat transfer coefficient from the inner peripheral surface of the barrel to the material increases and the temperature of the material rises quickly. Thus, the viscosity of the material lowers and consequently the time required for metering process and injection process is shortened. |
