| 摘要 |
PURPOSE:To prevent the generation of casting defects of cylinder barrels and to improve the adhesiveness between the cylinder barrels and sleeves by providing respective annular bodies to the upper parts of the cylinder barrels, executing casting and cutting away these bodies after mold expanding. CONSTITUTION:The Siamese annular bodies R, r1-r4 are provided to a cylinder block stock Sm and casting is executed. The impurities such as oxides in the molten metal gather at the respective annular bodies r1-r4 in the upper parts of the cylinder barrels 11-14 in the stage of casting and the generation of the casting defects in the cylinder barrels 11-14 is prevented. Since the top end faces of the sleeves 4 are covered by the annular bodies r1-r4, the shrinking force on solidification in the axial line direction of the sleeves 4 generated in the cylinder barrels 11-14 is suppressed by the annular bodies r1-r4 detaining with the top end faces of the sleeves 4; at the same time, the shrinking force on solidification toward the inside in the radial direction of the sleeves 4 is generated in the annular bodies r1-r4, by which the adhesiveness of the top ends of the cylinder barrels 11-14 to the sleeves 4 is improved. The annular bodies r1-r4 are cut away from the cylinder barrels to remove the casting defect parts.
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