| 摘要 |
PURPOSE:To provide a satisfactory feeling of rapid acceleration when it is demanded for driving of a vehicle by selecting a for-high-speed valve timing at the time of driving at a low speed and then selecting an inherent valve timing as an engine speed is increased. CONSTITUTION:Idlers 28 and 30 in contact with a timing belt 24 which transmits revolution of a crankshaft 12 to both an intake cam shaft 14 and an exhaust cam shaft 16 are disposed via a timing change-over plate 32 in front of and at the rear of a pulley 20. The change-over plate 32 is swing by a step motor 36 through the center of the cam shaft 14 so that a valve timing may be varied. Operating condition of a vehicle is determined by the detective means 42, 43 and 44 concerning throttle valve opening, transmission gear position and engine speed. When a vehicle drives at a low speed, however, a driver demands a feeling as if it may be given when a gear is in a second or a third position, a valve timing used for high speed drive is selected to satisfy said acceleration feeling. |
