| 摘要 |
PURPOSE:To promote the simplification of casting work and the improvement of rigidity, by performing an internal chill of a frame structure, composed of iron system material, into a cylinder block main unit, composed of aluminum alloy, thereafter closing an opening part of the frame structure by a cover member of iron system molded material. CONSTITUTION:An engine main unit, when it is manufactured, first forms a channel into a framework and a frame structure. This frame structure 2 is formed so as to provide an external shape equal to the external shape around a bore 1c of a block main unit 1 while height a little smaller than the height of the bore 1c. Next the frame structure 2 is set to a cast mold, and the block main unit 1 is cast, in this way the frame structure 2 is placed in a condition that its internal chill is performed in the block main unit 1. Thereafter, cover members 3, 4, in which a steel plate is formed by drawing obtaining high rigidity, are forced to be fitted to opening parts 2b of the frame structure 2, and the engine main unit, welding a fitting peripheral part of the cover members 3, 4 to the frame structure 2, finishes a series of manufacturing processes. |
