| 摘要 |
<p>PURPOSE:To raise the filling efficiency and increase the output torque, by setting a lift control cam whose rotary motion is controlled according to the operating condition of an engine, and which variably controls the lift quantity of an intake valve, and setting a phase control means which controls the phase of rotation of a drive cam for an intake/exhaust valve. CONSTITUTION:An intake valve 11 is opened and closed, by the rotary motion of a drive cam 12 fixed on a cam shaft 13, through a rocker arm 14, and the lower surface 15A of a lever 15 is brought in point contact with the back surface 14B, which is curved upward as to be a convex surface, of said rocker arm 14. Then, a lift control cam 16 whose rotary motion is controlled according to the operating condition of an engine, is brought in contact with the upper surface 15B of said lever 15, and the lift of the intake valve 11 is controlled according to the position of the rotated lift control cam 16. On the other hand, a phase control device 22, which consists of a hydraulic piston 24, a slider 26 which is reciprocated by this piston 24, and in which a spiral female spline 26A engaged with a spiral male spline 13A of the cam shaft 13, is formed, and others, is assembled in the connecting part between the cam shaft 13 and a timing pulley 20 which is moved linking to a crankshaft.</p> |
