| 摘要 |
The invention relates to a needle-sealed nozzle ( 10 ) for an injection mould whose injection nozzle ( 20 ) for introducing a fluid molten material (S) into a mould cavity ( 50 ) can be sealed on the end thereof by a closing needle ( 30 ). Said closing needle is provided with an injection channel ( 60 ) extending to an outlet orifice ( 62 ) for injecting a fluid (F) into the molten material (s) which is introduced into the mould cavity. Said outlet orifice is formed on the end face ( 34 ) of the closing needle for the molten material and can be closed by a fluid closing needle ( 64 ) which is axially displaceable in the closing needle for the molten material ( 30 ) can be moved from an opening position to a first and second closing position by a drive ( 40 ) For this purpose, the cylindrical closing part ( 33 ) of the closing needle ( 30 ) enters, in an accurately adjusted manner, a sealing seat (D) which is preferably formed in the injection nozzle ( 20 ) or in the end bit ( 23 ) of the nozzle. In order to inject a fluid, theclosing needle for the molten material ( 30 ) is placed in the first closing position and extends by the end thereof on the nozzle side towards the mould cavity ( 50 ) in such a way that the outlet orifice ( 62 ) for fluid (F) reaches the molten material (S) introduced in the mould cavity ( 50 ). The fluid being injected, the molten material (S) is extracted from the injection nozzle ( 20 ), if necessary and introduced in an injection hole (I) created by the fluid injection. For this purpose, the closing needle for the molten material ( 30 ) is displaced to the second closing position, the injection hole (I) being closed with the supplied molten material (s).
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