| 摘要 |
PURPOSE:To adjust the rate of rise in a riser hole and to improve and stabilize the quality of a cast article by protruding a guide wall on the upper part of an external periphery-forming mold comprising an internal periphery-forming mold and a cavity, moving the external wall member of a sectional sprue hole and adjusting the opening of the riser gate. CONSTITUTION:Sectional external periphery-forming molds 4, 5 combined with an internal periphery-forming mold 3 provides an annular body-casting cavity 10. A sprue hole 15 and a gate 16 are comprised of the external wall members 11, 12 of the sectional sprue hole along two parallel guide walls 4a, 5a protruded to both top end parts of the external periphery-forming molds 4, 5. The external wall members 11, 12 of this sectional sprue hole is moved to adjust the opening of the gate 16 and the rate of rise in the riser corresponding to the pouring rate is controlled to protect impurities from being caught in the cavity 10. Accordingly, the cast article is improved and stabilized in quality by this annular body-casting mold. |
