| 摘要 |
<p>Injection moulding device includes a mould and an injection section movable bodily to and from the mould. The injection section comprises an outer cylinder, having a valved outlet cooperable with the inlet sprue of the mould, and an inner cylinder reciprocable within the outer cylinder to define a variable volume chamber. The inner cylinder is provided with a screw to force working material through its valved end into the variable volume chamber. Means are also provided to move the inner cylinder through the chamber, after it has been filled with material, and the valved outlet of the outer cylinder has been contacted with the mould sprue passage to force the material from the chamber into the mould. During filling of the chamber there is a gap between the front ends of the screw and the inner cylinder. The movement of the injection section onto the mould only during injection reduces the heat exchange between the mould and the injection section. Also the gap between the inner cylinder and the screw prevents breakage of any fibrous reinforcement that is being used.</p> |
