Fuel injection control device for internal combustion engine

A fuel injection control device for an internal combustion engine, comprising:

• a crank angle sensor for detecting a revolution cycle of a crank shaft;
• an intake pressure sensor for detecting an intake pressure of air taken into an intake pipe;
• a throttle sensor for detecting a throttle opening degree of the intake pipe;
• rpm calculating means for calculating a rpm of the crank shaft according to the revolution cycle of the crank angle detected by said crank angle sensor;
• first basic fuel injection volume calculating means for calculating a first basic fuel injection volume by using the rpm and the intake pressure as parameters;
• second basic fuel injection volume calculating means for calculating a second basic fuel injection volume by using the rpm and the throttle opening degree as parameters;
• ratio calculating means for calculating a mixture ratio between the first basic fuel injection volume and the second basic fuel injection volume when a fuel injection volume is switched between the first basic fuel injection volume and the second basic fuel injection volume, and for gradually changing the mixture ratio at regular time intervals;
• and
• injector drive means for driving injectors so as to achieve an injection volume calculated by said ratio calculating means.