| 摘要 |
<p>The present invention relates to an injection mold having a core extraction device, comprising a guide mold through which an ejector pin is penetrated and which has an undercut withdrawing device installed therein. The undercut withdrawing device, comprises: an inserting groove which is embedded in the guide mold, has a bottom flange for supporting the lower end of the spring provided on an outer circumferential surface, and a lower end of a molding core inserted thereinto; a spring bracket which is penetrated through the lower part of the inserting groove and has a coupling hole into which a coupling means is inserted; a withdrawing unit which is coupled to the upper part of the spring bracket and moves vertically according to the operation of the spring bracket so as to enable withdrawal of an undercut part of a mold product; a molding core which has a stopper limiting the range of vertical movement of the molding core, and a taper part enabling the upper end part to be escaped from the undercut part; a guide holder which is fixed into the guide mold such that the molding core penetrates and moves vertically, has the upper part which controls the operation of the molding core by being in contact with the stopper, and prevents the collision between the spring bracket and an ejecting plate; a coupling means for coupling the molding core with the spring bracket by being inserted into the coupling hole of the spring bracket; and a supporting bush which supports the head part of the coupling means, allows the double coupling between the coupling means and the spring bracket, and absorbs the vibration delivered from the molding core so as to prevent the decline of the coupling force between the molding core and the spring bracket.</p> |
