| 摘要 |
PROBLEM TO BE SOLVED: To provide a vacuum casting metal mold in which leakage from an insertion hole into which an extrusion pin is inserted, is suppressed.SOLUTION: There is provided a casting metal mold 1 which includes an insertion hole 23a having a first sliding part 231, a loosely fitting part 233 and a second sliding part 232. When assuming that a side opposite from a cavity C side is a back surface side, the first sliding part 231 is formed on the cavity C side and a projection-direction tip part of an extrusion pin 30 is slidably inserted into the first sliding part 231. The loosely fitting part 233 is formed on the back surface side of the first sliding part 231 and has a cross-sectional area larger than that of the first sliding part 231. The second sliding part 232 is formed on the back surface side of the loosely fitting part 233, has a diameter substantially same as that of the first sliding part 231 and the extrusion pin 30 is slidably inserted into the second sliding part 232. A decompression passage 24 communicating with the loosely fitting part 233 and decompressing the inside of the loosely fitting part 233 is formed inside a metal mold 100. The second sliding part 233 includes a cylindrical bush 232a, and the extrusion pin 30 is slidably held with an inner peripheral surface of the bush 232a, and an O ring 232b is provided on an outer peripheral surface of the bush 232a. |
