Locally pressurizing type injection molding machine

Claim 1

A locally pressurizing injection molding machine comprising: a stationary die, a movable die disposed for movement relative to said stationary die, between open and closed positions, said movable die and said stationary die defining a mold cavity therebetween in said closed position, an ejector pin slidably mounted in said movable die and having a tip end facing said cavity and a trailing end opposite said tip end, an ejector plate fixed to the trailing end of said ejector pin, a vibrating/pressurizing pin slidably mounted in said movable die and said ejector plate and having a tip end facing a resin passage in communication with said mold cavity and a trailing end opposite said tip end, a vibrating/pressurizing plate fixed to the trailing end of said vibrating/pressurizing pin, vibrating/pressurizing actuator means for vibrating said vibrating/pressurizing pin by applying a pulsating pressure against said vibrating/pressurizing plate, for advancing said vibrating/pressurizing plate into contact with said ejector plate and for further advancing said vibrating/pressurizing plate and said ejector plate together toward said dies; and control means for controlling the frequency and amplitude of said pulsating pressure.