FUEL PUMP DRIVING DEVICE FOR ENGINE

PROBLEM TO BE SOLVED: To reduce a peak value of rotational load when a cam shaft and a fuel pump connected to the cam shaft are driven, in an engine for driving the fuel pump by the cam shaft. SOLUTION: When the cam shaft is rotated, periodic rotational load (reference to a thin slid line) is generated when a valve gear cam drives an intake valve and an exhaust valve. When a pump shaft of the fuel pump driven by the cam shaft is rotated, periodic rotational load (reference to a broken line) is generated. When a phase for coupling both of the cam shaft and the pump shaft is set so that a peak valve Fa of composed rotational load (reference to a thick solid line) of rotational load of the cam shaft and rotational load of the pump shaft may be decreased or minimum [refer to (A)], the peak value Fa can be made smaller than a peak value Fb when the phase is improperly set [refer to (B)].