| 摘要 |
PURPOSE:To increase rigidity of a cylinder block and reduce a noise emitted from its skirt part, by supporting a crankshaft with a main journal part, continuously locating a skirt part to the lower of a bore part, providing plural vertical wall parts connecting said main journal part and skirt part and forming a box shaped structural unit. CONSTITUTION:A cylinder block is constituted by a bore part 1, having a water jacket 2 in its external wall, skirt part 3, successively provided to the lower part of said bore part and spread to circular arc shape, and a main journal part 4, supporting a crankshaft. Here the skirt part 3 and the periphery of the main journal part 4 are connected by two sheets of vertical wall parts 5a, 5b, and a box shaped structural member of high rigidity is constituted by these members 3, 4, 5a, 5b. In this case, outside surfaces of each vertical wall part 5a, 5b are formed to dimensions continued to thickness (width) of the main journal part 4, and air gap parts 7 are formed between each vertical wall part 5a, 5b. In this way, the skirt part 3 is suppressed its vibration, and a level of noise emitted from the skirt part 3 can be decreased. |
