| 摘要 |
<p>A core to be used in cooperation with a mold, for casting an engine cylinder block is made in a single piece. The single piece core comprises a main portion and at least one evaporative pattern (18). The main portion has a shape for forming one or more cylinder bore and a crank chamber (15) of a cylinder block. The evaporative pattern has the same shape as a main bearing portion which is to be formed in a cylinder block and includes a main bearing housing, ribs and lubricating oil passages. The evaporative pattern is embedded in the main body (16), and is made of a material such as foamed polystyrene. When heat is applied, the evaporative pattern dissipates and leaves a cavity in the main body of the core. When casting, this cavity is filled with a molten metal and the main bearing portion is formed in the casting.</p> |
