| 摘要 |
<p>PROBLEM TO BE SOLVED: To uniformly pack core sand into a cavity with high packing density by sucking the air in a blow head for supplying the core sand and in a core box to reduce the pressure therein and thereafter, repeating the operation of blowing and packing the core sand into the core box while dividing the core sand into the suitable quantity. SOLUTION: A valve 6 is opened and the air in the cavity 2 and the blow head 11 are sucked to reduce the pressure therein and after closing the valve 6, valves 13B, 14B, 15B are opened and also, a main valve 18 are opened so as to blow and pack the core sand S into the lower part from the air supplying hole 15 in the blow head 11 by the necessary sand quantity to fill the part between a contracting part 2A and a contracting part 2B in the cavity 2. By this method, compressed air is supplied into the blow head 11 from air supplying holes 13, 14, 15 and the core sand S at the part above the air supplying hole 15 is blown upward, and the core sand S below the air supplying hole 15 is divided and blown and packed into the cavity 2 together with the compressed air and at this time, the lower part than the contracting part 2A difficult to be filled is filled with high density, too.</p> |
