| 摘要 |
A casted cylinder block having: a cylinder bore wall part; a water jacket groove arranged on the outer periphery of the cylinder bore wall part; and a water jacket external wall part defining the water jacket groove together with the cylinder bore wall part. The water jacket groove includes a shallow groove part in which the groove depth becomes shallower towards the end portion of the cylinder bore wall part. When the direction that the groove becomes deeper is taken to be the downward direction, the portion of the cylinder bore wall part where the shallow groove part is arranged includes a second outside wall surface facing the water jacket groove, and a third outside wall surface constituting the outer wall surface of the cylinder block and arranged in the downward direction from the groove bottom of the shallow groove part. The third outside wall surface is depressed towards a cylinder bore. |
