Patent ID: 7540146

Claim:
A fuel supply system for an exhaust purifying catalyst device in an internal combustion engine, the engine including; a plurality of cylinders each having an exhaust port; at least one exhaust manifold, each exhaust manifold being connected to the exhaust ports of the cylinders; an exhaust passage connected to the exhaust manifold; and a catalyst device having a catalyst provided in the middle of the exhaust passage, wherein in the exhaust manifold, there exists a non-exhaust period in which none of the cylinders corresponding to the exhaust manifold is in an exhaust stroke, whereby exhaust gas does not flow out to the exhaust passage from the exhaust manifold when the engine is in operation, and wherein the fuel supply system comprises: an addition nozzle injecting a fuel to the exhaust manifold for activating the catalyst; and a control section controlling the addition nozzle so as to add the fuel to the exhaust manifold in a period other than the non-exhaust period, wherein the control section sets a fuel adding period of the addition nozzle so as to divide the fuel adding period into a first half portion and a second half portion so that the period exits before and after the non-exhaust period, and controls the addition nozzle in such a manner as to add the fuel in the first half portion and the second half portion.