| 摘要 |
PROBLEM TO BE SOLVED: To provide an injection device capable of suppressing whirling of a screw, and reducing friction between the screw and a cylinder.SOLUTION: An injection device comprises a cylinder for heating a molding material, and a screw disposed rotatably in the cylinder. The screw comprises a rotary shaft and spiral flights which protrude from an outer periphery of the rotary shaft, and the molding material is fed from an upstream side toward a downstream side along the rotary shaft, by rotation of the rotary shaft. The flights comprise: spiral first flight parts; and spiral second flight parts which are disposed on a downstream side relative to the first flight parts. The second flight parts are different diameter flight parts in which, height of a downstream side end part of an apex is lower than height of an upstream side end part of the apex, and a ratio of a flight width of the second flight part with respect to a pitch of the second flight part is larger than a ratio of a flight width of the first flight part to a pitch of the first flight part.SELECTED DRAWING: Figure 1 |
