Patent ID: 7568457

Claim:
A valve driving device for a multi-cylinder combustion engine, that converts rotational motion outputted from a valve-driving source to linear motion through motion-converting devices provided to respective cylinders and that drives valves in respective cylinders through the linear motion, the valve driving device comprising: an electric motor that is shared as the valve-driving source in a group of cylinders comprising a plurality of cylinders, in which open-valve periods of the valves do not overlap; a control device that controls operating characteristics of respective valves in the group of cylinders by varying at least one of rotation speed and rotation direction of the electric motor; and cam mechanisms that convert rotational motion outputted from the electric motor into linear motion of the valves, wherein each of the groups of cylinders consists of two cylinders, and the control device drives the electric motor such that the electric motor swings in opposite two directions within a range between a position where maximum lift amount is given by a cam in the cam mechanism of a cylinder in a group of cylinders and a position where maximum lift amount is given by a cam in the cam mechanism of another cylinder in the same group of cylinders, while varying the amount of swings.