| 摘要 |
PURPOSE:To make an engine compact by shortening a cylinder head distance by arranging a fixing bolt symetrical to a plane which contains a cylinder axial line and is slanting by a certain degree with respect to a crank axis line. CONSTITUTION:Six bolts 12 which are used for fixing a cylinder head 11 to a crank case, are arranged on a concentric circle centering around the cylinder axis line with a pitch of 55-65 degrees with a near equi-distance. They are also arranged symetrically with respect to a plane which contains the cylinder axis line and is slanting by a certain degree of angle smaller than the half of the pitch angle of the bolt 12 with respect to the crank axis line. An air intake passage way 13 and an exhast gas passageway 14 are arranged parallel to the crank axis line in the same direction. Accordingly, the arrangement of the bolts 12 becomes asymetry with respect to the crank axis line, leading to an enalrgement of the mutual distance between bolts 12', hence the distance between the cylinder heads 11 can be shortened. |
