| 摘要 |
PROBLEM TO BE SOLVED: To hold a best combustion condition by setting a proper intake/exhaust valve opening/closing angle in every load ranges and rotating speed. SOLUTION: This device is composed of a cam roller having an elliptical shaped cross section wherein a cam profile is continuously changed while holding a top point of a cam in a constant level, which is brought into correctly contact at every positions of the cam profile, and for transmitting cam lift force; and a cam shaft moving device for freely moving a cam shaft 2 in the axial direction. In the case where the cam is a low load, a valve opening angle is reduced. In the case where the cam is a high load, the valve opening angle is increased. The opening and closing positions of each intake and exhaust valve can be set to the optimal position, the lifting range of the valve is constantly held since the top point of the cam is constantly held, and unreasonable force is not applied on the valve and a valve seat. The cam is moved in the axial direction to a cam position corresponding to a load condition during operation of an engine by the cam shaft moving device.
|
