| 摘要 |
<p>PURPOSE:To reduce working force by displacing a roller in the direction perpendicular to a cam axis, while keeping a tappet clearance at the valve top, by means of an eccentric shaft through a support arm so that the valve opening time is changed by one cam. CONSTITUTION:An exhaust cam 1 fixed to a cam shaft 16 lifts an exhaust valve through a roller 2, roller pin 3, support arm 4, and push rod 7. The center of a shock-absorbing metal 5 is deviated from the center of the cam 1 toward a pin 8a by a distance l. The pin 8a is displaced by the piston rotation of an oil hydraulic motor, and the roller 2 is moved to a position symmetrical relative to the center of the cam 1 so as to eliminate the thrust-up of an exhaust valve. The exhaust valve force applied to the upper face of the arm 4 from the rod 7 is dissociated into forces FR and FV applied respectively to the roller 2 and the pin 8a; the force FV goves a torque to an eccentric shaft 8 so as to reduce the support torque of the piston generated by pressure oil.</p> |
