| 摘要 |
PURPOSE:To make the maximum surface pressures of both valve opening and closing cams equal together to enhance the durability of the cams, by making the area of the cam slide section of a rocker arm which is in contact with the valve openig cam, larger than the area of the can slide section of a rocker arm which is in contact with the valve closing cam. CONSTITUTION:First rocker arms 33, 59 and second rocker arms 34, 60 contact with valve opening cams 30, 56 and valve closing cams 31, 57 which are fitted onto cam shafts 29, 55, and therefore, valves 13, 14 are forcively opened and closed. Each area of the slide parts 38 where the rocker arms 33, 59 contact with the valve opening cam 30, 50 is made larger than that of the slide parts 40 where the rocker arms 34, 60 contact with the valve closing cams 31, 57. With this arrangement, even though the valve opening cams 30, 56 are subjected to a large acceleration, the maximum surface pressures of both cams are made equal together. |
