| 摘要 |
<p>PURPOSE:To eliminate torque fluctuation in a cam shaft so as to eliminate a braking contact phenomenon and gear rattling sound (gear noise) in a gear train by giving cancel torque fluctuation to a cam shaft which is driven from a crank shaft via the gear train and opens/closed an intake/exhaust valve. CONSTITUTION:An approximately elliptic dummy cam 10 is coaxially installed in the end part of a cam shaft 2, and on the outer circumferential face of the dummy cam 10, a roller tappet 7 is arranged at an interval of 90 deg. in the circumference direction so that it can be freely moved in the radius direction and can be brought into contact with the outer circumferential face of the dummy cam 10 by elastic force. The cam profile of the dummy cam 10 is set so as to generate cancel torque fluctuation, whose cycle and change in an amplitude is substantially equal to those of driving torque fluctuation of the cam shaft 2, in the cam shaft 2, and a relative position between the dummy cam 10 and a pair of roller tappets 7 set apart, from each other at an interval of 180 deg. is set so that the cancel torque whose phase is reverse to that of the driving torque is added to the cam shaft 2.</p> |
