Control system for two cycle direct injection engine and the method thereof
First Claim
1. 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, 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 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 determining means, responsive to said suspending signal, for determining 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; and
control means responsive to said control signal for controlling said fuel injector and said igniter, p1 wherein said suspending region is varied in accordance with a change in said fuel properties signal.
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Accused Products
Abstract
Disclosed is a control system and method of a two cycle direct fuel injection engine capable of smoothly suspending combustions in the cylinder during light load operation of the engine. Based on a map parameterizing the engine speed and the target engine load, it is judged whether or not, when the engine load is in the light load condition, the target engine load is located in a suspending area in which misfires tend to occur. If the target engine load is not in the suspending area, since there is no possibility of misfire, the normal combustion cycle continues to operate. On the other hand, if the target engine load enters into the suspending area, the control system instructs the fuel injection and ignition apparatuses so as to suspend fuel injection and spark ignition with a frequency determined according to the magnitude of the engine load. The frequency is determined by a predetermined formula such that it is reduced as the engine load becomes high and is increased as the engine load becomes low.
174 Citations
16 Claims
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1. 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, 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 crankshaft of said engine for calculating an engine speed and for producing an engine speed signal indicative thereof, comprising:
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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 determining means, responsive to said suspending signal, for determining 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; and control means responsive to said control signal for controlling said fuel injector and said igniter, p1 wherein said suspending region is varied in accordance with a change in said fuel properties signal. - View Dependent Claims (2, 3, 4)
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5. 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:
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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. - View Dependent Claims (6, 7, 8)
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9. 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:
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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. - View Dependent Claims (10, 11, 12)
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13. 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:
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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. - View Dependent Claims (14, 15, 16)
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Specification