Patent ID: 8523558

Claim:
An injection mold for forming a molded product that has a size of hundreds of micrometers to several millimeters and a molded portion having an aspect ratio of 5 to 20 consists of the following: an outer block that is mounted and fixed to an injection molding machine and divided into an upper mold and a lower mold; cooling water ports that are formed at the outer block and through which cold water or hot water supplied from the outside circulates inside the outer block and controls the temperature of the outer block; an inner block that is replaceably coupled to the upper mold and the lower mold and composed of an upper block and a lower block; a metal core that is detachably mounted in the inner block and has a cavity for forming a molded product having a molded portion having a size of tens to hundreds of micrometers; an ejector that is disposed under the inner block and removes the molded product in the cavity by moving straight; and a driving unit that is disposed under the ejector, moved up/down by hydraulic pressure or pneumatic pressure supplied from the outside, and drives the ejector, wherein the outer block includes: an upper plate that is mounted on the injection molding machine; an upper frame that forms the lower portion of the upper mold by being combined with the upper plate and has the bottom repressed to accommodate the upper block; a lower frame that forms the upper portion of the lower mold and has the top recessed to accommodate the lower block and the ejector; and a lower plate that is composed of a base mounted and fixed to the injection molding machine and an extender extending upward from both sides of the base plate and coupled to the bottom of the lower frame, so that a space accommodating the driving unit is formed between the lower frame and the base plate, the ejector includes: an ejecting plate that is disposed between the lower block and the upper mold to move up/down; an ejecting pin that is mounted on the ejecting plate and pushes up the molded product while moving up/down with the ejecting plate; a plurality of sub-ejecting pins that is disposed on the ejecting plate around the ejecting pin and pushes up the outer side of the molded product through the metal core; and elastic members that are disposed between the lower block and the ejecting plate and provide elastic force to the ejecting plate, and the driving unit includes: a driving unit plate that is moved up/down by hydraulic pressure or pneumatic pressure supplied from the outside; a push rod that is mounted and fixed to the center of the driving unit and is extended to selectively push the bottom of the ejector; a stroking block that is replaceably disposed on the top of the driving unit plate and limits upward movement of the driving unit plate in contact with the lower frame when the driving unit moves up; and the driving unit elastic members that are disposed between the driving unit plate and the lower frame and provide elastic force to the driving unit plate.