| 摘要 |
<p>PURPOSE:To pack molding sand uniformly in a pattern box without requiring any clamping device by sucking and evacuating the cavity part of the pattern box from the lower part and packing the molding sand from the upper part. CONSTITUTION:A pattern plate 1 provided with an evacuating chamber 2 and vent holes 3 is provided in the lower part of a pattern box 12, and a cavity part 12a and the holes 3 are communicated. A hopper 16 contg. molding sand 15 is placed on the upper part. The box 12 consists of a left mold 10 and a right mold 11. The inside of a tank 7 is evacuating by closing a stop valve 5 and operating a vacuum pump 8, after which the valve 5 is opened and the cavity part 12a of the box 12 is evacuated to negative pressure through a conduit 4, the chamber 2 and the holes 3. Thereby, the molding sand 15 in the hopper 16 can be sucked and packed to all corners of the cavity part 12a. Thereafter, a hardening gas is passed through the sand 15 in the box 12, whereby the sand is hardened and molded. Thereby, the satisfactory use of a woode mold for the box 12 is made possible.</p> |
