| 摘要 |
<p>PURPOSE:To improve combustibility of mixture by changing the lift of exhaust and intake valves of an internal combustion engine, through employment of an arrangement in which a cam formed with cam surfaces having different contact areas is held in contact with the exhaust or intake valve by the intermeidary of rocker arm, and the rocker arm is shifted in respeonse to the engine speed. CONSTITUTION:Top member 4 at the top of shaft 5 of an intake or exhaust valve is held in contact with rocker arm 3. Cam shaft 2 rotated with operation of engine is held in contact with rocker arm 3 at its top at one end portion thereof, and the rocker arm 3 is connected at the other end to support member 7 which is arranged to be slidable in guide member 6, by means of pin 8. Further, a shift cam 9 turned in response to the engine speed is held in contact with support member 7 for shifting rocker arm 3. Cam shaft 2 is formed with cam 2m having a relatively large lift and cams 2a having a relatively small lift which are disposed on the opposite sides of cam 2m. Further, sloped surface 3b to be held in contact with cam 2m and flat surfaces 3f to be held in contact with cams 2s are formed at the top of arm 3, so that the valve lift is changed by selecting their contact.</p> |
