| 摘要 |
PURPOSE:To omit the stage of work after machining as well as to make improvements in production efficiency so high, by forming an oil passage between a main gallery and a main journal part with a molding hole, in case of a cylinder block of an engine. CONSTITUTION:Oil passages 7 and 8 leading to each main journal part 2 from a main galley 1 to which lubricating oil to be fed, with pressure, by a hydraulic pump are installed in a cylinder block. Each of molding holes 7 and 8 is formed by the molding pin installed in a mold at the time of casting. After casting, a residual part 10 of this molding hole is pierced through by a drill or the like, and such one requiring closure in the said molding hole closes its opening part 9. Thus, a process of pressure resisting tests is omissible and, what is more, production efficiency is improvable so high. |
