Patent ID: 7399178
Filing Date: 2008-07-15
Classification: B29C

Abstract:
1. An injection device having a heating cylinder, the device comprising: a plunger reciprocably inserted into the heating cylinder, and disposed such that a molten material supplied into a storage portion disposed at a front end of the plunger is injected by the plunger via a nozzle into a die, said plunger comprising: a base connected to a reciprocating drive unit; a cylindrical sealing portion secured to an end portion of said base on the side of the nozzle and disposed so that the molten material is prevented from easily entering a gap between the plunger and an inner wall of the heating cylinder; and a cylinder core keeping portion formed on an end portion of said sealing portion on the side of the nozzle provided such that an annular space is defined between a front portion of the plunger and the inner wall of the heating cylinder, and the annular space is connected to the storage portion.