| 摘要 |
PROBLEM TO BE SOLVED: To restrict vibration degradation accompanied by a crossing action of a crank shaft without modifying a shape of a crank shaft in particular.SOLUTION: A flat-type 4-cylinder engine 1 in which a first cylinder 11, a second cylinder 12, a third cylinder 13 and a fourth cylinder 14 are arranged in this order from one end side and a flywheel 15 is installed at the other end side is constituted such that there is provided a weight member 16 to which a centrifugal force generated by rotation of a crank shaft 10 acts against an axial center of a third pin 13b extending out toward the flywheel 15 over a direction passing through a rotation center Pc of the crank shaft 10 substantially crossing at a right angle with a linear line extending out of an axis center of a third pin 13b toward the flywheel 15 between the crank shaft 10 and the flywheel 15. |
