| 摘要 |
PURPOSE:To prevent a pressure loss and heat generation by constituting a valve gate device of an extruding metal die by making an opening and closing positions of a valve pin, which is capable of opening and closing at free timing, provided on each gate into three positions such as a closed, fully opened and half-opened positions. CONSTITUTION:When injection is started, molten resin is injected into a metal die from an extruder through an inlet 2a of the resin and the molten resin is streamed into a cavity 23 for a molded article from each gate 24 through a duct 2b of the resin. Each age 24 is provided with a valve pin 5 which is capable of opening and closing at three positions such as a closed, fully opened and half- opened positions, through which a gate opening having a necessary opening at necessary timing can be obtained. A leak of the resin can be prevented from leaking through the gate 24 by closing a valve pin 5, and a pressure loss and heating of inflow resin from the gate can be prevented through the fully open position valve pin 5. Then the excessive pressure being applied in the vicinity of the gate for the molded article can be prevented through the half-opened position valve pin 5. |
