| 摘要 |
PROBLEM TO BE SOLVED: To provide an oil passage structure of an internal combustion engine superior in warming-up performance, having less influence on a flow rate of lubrication oil, and hardly deteriorating the oil even in sudden engine stop.SOLUTION: An oil passage structure 51 of an engine 11 includes an oil passage 56 disposed on a cylinder head 43 accommodating a crank case 41, a cylinder 42 and a valve mechanism 61, an oil pump 81 for supplying an oil in the crank case 41 to the oil passage 56, and an open valve 111 disposed on the oil passage 56. The oil passage 56c in the cylinder head 43 includes a second linear portion 102 as a lower passing portion to circulate the oil through a lower part of the valve mechanism 61, and the open valve 111 is disposed on a highest part of the second linear portion 102.SELECTED DRAWING: Figure 8 |
