An injection mold ( 1 ) may include: an outer block ( 100 ) that is mounted and fixed to an injection molding machine and divided into an upper mold ( 110 ) and a lower mold ( 120 ), an inner block ( 200 ) composed of an upper block ( 230 ) and a lower block ( 220 ) that are replaceably mounted on the upper mold ( 110 ) and the lower mold ( 120 ), respectively; a metal core ( 300 ) mounted in the inner block ( 200 ) and has a cavity ( 310 ) for forming a molded product ( 10 ) with a molded portion having a size of tens to hundreds of micrometers; an ejector ( 400 ) coupled to the inner block ( 200 ) and removes the molded product ( 10 ) in the cavity ( 310 ) by moving straight; a driving unit ( 500 ) disposed inside the lower mold ( 120 ) is moved up/down by hydraulic pressure or pneumatic pressure supplied from the outside, and drives the ejector ( 400 ).
1. 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.
2. The injection mold according to claim 1 , wherein the metal core is replaceably mounted on the top of the lower block.
3. The injection mold according to claim 1 , wherein a cutting member that cuts the complete molded product by moving up/down is disposed in the inner block.
4. The injection mold according to claim 3 , wherein the cutting member is elastically supported by a first elastic member between the upper mold and the inner block.
5. The injection mold according to claim 1 , wherein a first injection channel and a second injection channel that form a channel for a material injected from the outside of the inner block in contact with each other are formed on the upper block and the lower block, respectively.
6. The injection mold according to claim 5 , wherein the second injection channel is repressed at the edge of the top of the lower block and at the metal core, and
the first injection channel is formed on the bottom of the upper block and repressed to connect the second injection channels.
7. The injection mold according to claim 1 , wherein the ejector further has an ejector guide that is fastened to the lower block through the ejecting plate and guides movement of the ejecting plate.
8. The injection mold according to claim 1 , wherein the ejecting pin is inserted in the cavity of the metal core and pushes up the molded product in the cavity.
9. The injection mold according to claim 1 , wherein the lower frame further has a through hole through which a portion of the driving unit moves in/out.
10. The injection mold according to claim 1 , wherein the push rod passes through the stroking block.
11. The injection mold according to claim 1 , wherein the driving unit plate includes:
a first plate disposed at the lower portion, supporting the push rod; and
a second plate disposed on the top of the first plate, fixing the push rod that passes through the second plate.
12. The injection mold according to claim 11 , wherein the first plate and the second plate are separable so that the push rod can be replaced.