| 摘要 |
PURPOSE:To balance primary inertia force of an engine by setting angles formed by respective cylinders, crank pins of said respective cylinders, and a balance weight such that said angles satisfy a prescribed expression, in the engine including three or more of cylinders. CONSTITUTION:A reference cylinder is designated as 3a and an i-th cylinder from said reference cylinder 3a as 3i. Further, an angle between a crank pin 7 of the reference cylinder 3a and a crank pin 7 of the cylinder 3i is designated as alphai with respect to a rotary center 16 of a crank shaft 6. Likewise, an angle between the both cylinders 3a, 3i is designated as 3i with respect to the rotary center 16. In addition, when an angle between the crank pin 7 of the reference cylinder 3a and a balance weight 17 is designated as alpha with respect to the rotary center 16, each numeral is set to satisfy four specific expressions. Here, k in the expressions is of a value of W/m where reciprocating mass of each cylinder is m, and mass of the balance weight W. |
