Control system for two cycle direct injection engine and the method thereof

A control method for a two cycle fuel injection engine having a fuel injector for injecting an amount of fuel into a cylinder of said engine, an igniter electrically connected to a spark plug via an ignition coil for igniting said fuel in said cylinder, a throttle sensor mounted on said engine for detecting an opening degree of a throttle valve and for generating a throttle signal indicative thereof, a fuel properties sensor provided on a fuel delivery line for detecting fuel properties of said fuel and for generating a fuel properties signal indicative thereof, and engine r.p.m. calculating means responsive to a crank angle signal from a crank angle sensor attached near a crank shaft of said engine for calculating an engine speed and for generating an engine speed signal indicative thereof, comprising:

• calculating a target load required by a driver in response to said throttle signal and said engine speed signal;
• judging whether said target load is within a suspending region;
• determining a frequency of suspending fuel injection and fuel ignition in accordance with said target load when judged within said suspending region;
• varying said frequency according to a change of target load which remains within said suspending region;
• controling fuel injection and fuel ignition according to said frequency;
• and
• varying said suspending region in accordance with a change in said fuel properties signal.

A control system for a two cycle fuel injection engine having a fuel injector for injecting an amount of fuel into a cylinder of said engine, an igniter electrically connected to a spark plug via an ignition coil for igniting said fuel in said cylinder, a throttle sensor mounted on said engine for detecting an opening degree of a throttle valve and for generating a throttle signal indicative thereof and engine r.p.m. calculating means responsive to a crank angle signal from a crank angle sensor attached near a crankshaft of said engine for calculating an engine speed and for producing an engine speed signal indicative thereof, comprising:

• target load detecting means, responsive to said throttle signal and said engine speed signal, for calculating a target load required by a driver and for producing a load signal indicative thereof;
• suspending decision means, responsive to said engine speed signal and said load signal, for judging whether said target load is within a suspending region and, when said target load is within said suspending region, for generating a suspending signal indicative thereof;
• suspending frequency determing means, responsive to said suspending signal, for determing a frequency of suspending fuel injection and fuel ignition in accordance with said target load in said suspending region and for generating a control signal indicative thereof;
• suspension counting means for counting a number of suspensions and for generating a count signal indicative thereof;
• air fuel ratio adjusting means for determining an adjustment to an air fuel ratio in accordance with said count signal and for generating a correction signal indicative thereof;
• and
• control means responsive to said control signal and said correction signal for controlling said fuel injector and said igniter.

A control method for a two cycle fuel injection engine having a fuel injector for injecting an amount of fuel into a cylinder of said engine, an igniter electrically connected to a spark plug via an ignition coil for igniting said fuel in said cylinder, a throttle sensor mounted on said engine for detecting an opening degree of a throttle valve and for generating a throttle signal indicative thereof and engine r.p.m. calculating means responsive to a crank angle signal from a crank angle sensor attached near a crankshaft of said engine for calculating an engine speed and for generating an engine speed signal indicative thereof, comprising:

• calculating a target load required by a driver in response to said throttle signal and said engine speed signal;
• judging whether said target load is within a suspending region;
• determining a frequency of suspending fuel injection and fuel ignition in accordance with said target load when judged within said suspending region;
• varying said frequency according to a change of target load which remains within said suspending region;
• counting a number of suspension;
• calculating a correction parameter for an air fuel ratio based on said number of suspensions;
• and
• controlling fuel injection and fuel ignition according to said frequency and said correction parameter.