Patent ID: 6634338
Filing Date: 2003-10-21
Classification: F02D

Abstract:
A fuel injection apparatus comprising an electromagnetic fuel injection valve and a driving circuit driving said electromagnetic fuel injection valve, wherein said electromagnetic fuel injection valve is provided with a first coil having a large rate of change in time of magnetomotive force and a second coil having a smaller rate of change in time of magnetomotive force than said first coil, and wherein one end of said first coil is connected to a plus side of a power supply of said driving circuit, the other end of said first coil is connected to one end of said second coil and to a minus side of said power supply via a first switching circuit controlling current passage, the other end of said second coil is connected to the minus side of the power supply of said driving circuit via a second switching circuit provided with a surge absorbed diode and controlling current passage, and said first and second coils are arranged so that magnetomotive force in a reverse direction due to mutual inductance could be generated in said second coil when current in said first coil rises, whereby at an initial stage of opening operation of said valve, at least said first switching circuit is turned on to cause a first current to flow into at least said first coil, after which only said second switching circuit is turned on, thereby causing a second current to flow into both said first and second coils, said driving circuit including a diode that allows current to flow only in a direction from said second coil to said second switching circuit, said diode provided between said second coil and said second switching circuit or between said second switching circuit and the minus side of the power supply so as to substantially prevent said magnetomotive force in a reverse direction.