| 摘要 |
<p>A molding nozzle (10) controls the flow of material from a source of plastic melt to an outlet that communicates with a gate (30) to a mold cavity (12). The nozzle (10) contains a valve pin (38) that includes a guide section (40) and a valve end (42), and is movable toward and away from the gate (30) to open and close the gate (30) selectively. The valve pin (38) is guided for movement by guide surfaces (64) on inwardly-extending vanes (62) within the nozzle (10), such that the guide surfaces (64) engage the guide section (40) of the valve pin (38). The valve end (42) of the valve pin (38) has a smaller diameter than that of the guide section (40), so that the valve section (42) is free-floating to allow annular flow in the guide surface region to minimize the likelihood of formation of flow lines in the molded part.</p> |
