| 摘要 |
PROBLEM TO BE SOLVED: To provide a variable valve system capable of accurately controlling the maximum rotational position of a control shaft without being affected by the maximum movement position of a ball nut. SOLUTION: This variable valve system is provided with a variable mechanism 4 for changing an opening/closing operational condition of an intake valve 2 by performing rotational control of the control shaft 32 by means of a stopper mechanism 29 within a predetermined range, and with an actuator 6 for transmitting rotational force to the control shaft 32 via a ball screw transmitting mechanism 37. The actuator 6 is equipped with the ball nut 46 provided movably in the axial direction along with rotation of a ball screw shaft 45. In the position where the maximum rotation in one direction of the control shaft 32 is regulated by the stopper mechanism 29 (minimum lift control), by regulating the maximum movement position of the ball nut 46 in the axial direction by an adjusting bolt beforehand, a gap is formed between the ball nut 46 and a ball bearing 50. COPYRIGHT: (C)2006,JPO&NCIPI
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