| 摘要 |
<P>PROBLEM TO BE SOLVED: To bore a mold with a small load while suppressing damage to the mold. <P>SOLUTION: A boring tool 15 is provided, which has a hollow structure to form a tool passage 19 for allowing air flow inside, and on whose outer periphery a plurality of slits 21 extending from a front end 15A of the boring tool 15 to a base end 15B thereof are formed in the peripheral direction. Further, edges 23 inclined inside are formed on the front ends of projecting parts 22 that are provided between the slits 21. The boring tool 15 is amounted on the front end of a support pipe 13. Boring of a mold 1 is performed, while pushing the boring tool 15 into sand 3 in the mold 1 by moving the support pipe 13 and the boring tool 15, making air flow from the support pipe 13 through the tool passage 19 of the boring tool 15, collapsing the sand 3 in the mold 1 to the inside of the boring tool 15 with the edges 23 of the boring tool 15, and discharging, to the outside of the mold 1 through the slits 21, the sand 3 that is collapsed with the edges 23 by action of the air flowing from the tool passage 19 into the slits 21. <P>COPYRIGHT: (C)2012,JPO&INPIT |
