Patent ID: 7497679
Filing Date: 2009-03-03
Classification: B29C,Y10S

Abstract:
1. A mold for injection molding, the mold having a cavity formed by a stationary mold half and a movable mold half, wherein the stationary mold half has an exhaust section communicating with a vacuum exhaust means for evacuating air from the cavity, a switching valve provided in the exhaust section performs switching between an open position that allows the vacuum exhaust means and the cavity to communicate with each other through a gate part used to inject molten resin into the cavity and a closed position that does not allow the vacuum exhaust means and the cavity to communicate with each other therethrough, wherein the switching valve comprises: a main body having an actuation space formed to intersect with a sprue provided in the stationary mold half; and a valve element capable of performing switching between the open position and the closed position while airtightly moving back and forth inside the actuation space, wherein the valve element has a first hole that constitutes a part of the sprue in the closed position and a second hole one end of which leads to the gate part through the sprue and an opposite end of which leads to the vacuum exhaust means in the open position.