| 摘要 |
PURPOSE:To draw a separating pattern to the side oppsite from a molding board quickly and easily in a vacuum molding method by opening a hole in each film on the top surface of the separating pattern and acting air pressure on the bottom surface of the separating pattern to blow the pattern upward. CONSTITUTION:A film 4 on the lower side is attracted to a pattern 3 and a separating pattern 2, sand grains 5 are packed in a casting mold, a film 6 on the upper side is deposited on the rear surface of the sand grains, and the casting mold is cured under the evacuation in a casting flask 12, according to an ordinary vacuum molding method. A hole 7 having a diameter D is opened in each of the films 4, 6 on the top surface of the pattern 2. Compressed air of about several kg/cm<2> is supplied in a suction box 11 to act the air pressure on the bottom surface of the pattern 2 through an air supply hole 15 and the expanded part 16 of the air supply hole. Then, the pattern 2 is blown upward and is exposed partly or wholly from the hole 7. The operator simply draws such pattern 2 manually. |
