| 摘要 |
PROBLEM TO BE SOLVED: To provide a variable valve gear having a torsion coil spring biasing a rocker arm in a return direction, capable of lessening spring force in the maximum deformation of the torsion coil spring and advantageous to miniaturization. SOLUTION: The variable valve gear 10 is for varying an working angle of a valve 12 and includes the rocker arm 18 supported for rocking motion about a control shaft 16 and rocking with rotation of a cam 14, a variable mechanism varying a rocking range of the rocker arm 18 by rotating the control shaft 16 and the torsion coil spring 32 imparting moment of force to the rocker arm 18 in a direction of bringing the rocker arm 18 close to the cam 14. The variable valve gear is constructed so that concerning a change rate of a torsion angle of the torsion coil spring 32 to the change of a cam angle, the change rate of the torsion angle on a cam angle side in which valve lift is maximized is smaller than the change rate of the torsion angle on a cam angle side in which the valve lift becomes zero. COPYRIGHT: (C)2009,JPO&INPIT
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