Patent ID: 7011137
Filing Date: 2006-03-14
Classification: B22D

Abstract:
1. A molding device comprising: a first mold unit; a second mold unit arranged to face the first mold unit, wherein the first mold unit and the second mold unit relatively approach and are separated from each other, and wherein, when the first mold unit and the second mold unit approach each other to be closed, a molding cavity is defined between the first mold unit and the second mold unit; a storing chamber arranged in at least one of the first mold unit and the second mold unit, wherein the storing chamber is communicated with the molding cavity and stores molten material; a pushing mechanism, wherein the pushing mechanism pushes out the molten material in the storing chamber to the molding cavity when the molding cavity is defined between the first mold unit and the second mold unit, wherein the pushing mechanism includes a pushing rod that is inserted to the storing chamber, the pushing rod having an end surface that forms a bottom of the storing chamber, wherein one of the first and second mold units has an insertion hole that is communicated with the storing chamber and receives the pushing rod, wherein a predetermined second space is defined between an outer circumferential surface of the pushing rod and an inner circumferential surface of the insertion hole; a first pressure-decreasing mechanism for decreasing pressure in the molding cavity prior to pushing out the molten material in the storing chamber to molding cavity; and a second pressure-decreasing mechanism for decreasing pressure on a side of the molten material that is opposite to the molding cavity substantially at the same time that the pressure in the molding cavity is decreased, wherein the second pressure-decreasing mechanism includes a second seal member and a second pressure-decreasing passage, wherein the second seal member seals a space between the outer circumferential surface of the rushing rod and the inner circumferential surface of the insertion hole, and wherein the second pressure-decreasing passage is communicated with a part of the second space between the second seal member and the storing chamber.