| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an internal combustion engine which is excellent in the lubrication performance of oil in the internal combustion engine while suppressing the enlargement of the internal combustion engine.SOLUTION: In an internal combustion engine, upper and lower crank cases 50, 60 comprise: a crank chamber 45; a clutch chamber 105 which communicates with the crank chamber 45; and a cam chain chamber 46. The upper crank case 50 comprises: a second upper partitioning wall 52 which partitions the cam chain chamber 46 and the clutch chamber 105, and the lower crank case 60 comprises: a first lower partitioning wall 61 which partitions the cam chain chamber 46 and the crank chamber 45; and a second lower partitioning wall 62 which partitions the cam chain chamber 46 and the clutch chamber 105. An oil passage 64 which makes the cam chain chamber 46 and the crank chamber 45 communicate with each other is formed at the first lower partitioning wall 61, and first passages 53, 63 which make the cam chain chamber 46 and the clutch chamber 105 communicate with each other are formed at a lower face 52A of the second partitioning wall 52 and an upper face 62A of the second partitioning wall 62.</p> |
