System and method for controlling ignition timing for internal combustion engine in which alcohol is mixed with gasoline
First Claim
1. A system for controlling an ignition timing for an internal combustion engine, comprising:
- a) first means for detecting engine driving conditions, the engine being driven with a particular fuel containing an alternative fuel, the engine having a lean air/fuel mixture ratio;
b) second means for detecting an inner cylinder pressure of the engine;
c) third means for detecting whether the engine operating conditions fall in a predetermined transient operating state;
d) fourth means for setting a basic ignition timing for the particular fuel on the basis of the engine operating conditions;
e) fifth means for detecting a crank angular position at which the inner cylinder pressure becomes maximum on the basis of an output signal derived from the second means;
f) sixth means for calculating an ignition timing feedback correction quantity Δ
1 for the ignition timing for avoiding occurrence of engine knock and/or generating a maximum torque as derived from the signal of the second means;
g) seventh means for comparing the crank angular position at which the inner cylinder pressure becomes maximum with the current ignition timing to estimate a percentage of alternative fuel to the particular fuel and hating the estimation when the engine is transferred into the predetermined transient condition;
h) eighth means or calculating a second correction quantity Δ
2 for the ignition timing according to the estimated percentage of mixture of the alternative fuel;
i) ninth means for correcting the basic ignition timing using the first and second correction quantities to determine a final ignition timing; and
j) tenth means for igniting the air/fuel mixture supplied to the engine at a time derived by the ninth means.
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Accused Products
Abstract
A system and method for controlling ignition timing for a lean burn type internal combustion engine in which alcohol is mixed with gasoline. A final ignition timing value ADV is determined from a basic ignition timing value BASE, a feedback correction quantity Δ1, plus a second correction quantity Δ2, the basic ignition timing value being derived for conventional fuel (gasoline) on the basis of the operating conditions of an engine having a driving region in which the engine is driven with a lean air/fuel mixture ratio. The second correction quantity, Δ2, is derived according to an estimated value of a percentage R of mixture of an alternative fuel (alcohol) to the conventional fuel (gasoline).
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Citations
11 Claims
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1. A system for controlling an ignition timing for an internal combustion engine, comprising:
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a) first means for detecting engine driving conditions, the engine being driven with a particular fuel containing an alternative fuel, the engine having a lean air/fuel mixture ratio; b) second means for detecting an inner cylinder pressure of the engine; c) third means for detecting whether the engine operating conditions fall in a predetermined transient operating state; d) fourth means for setting a basic ignition timing for the particular fuel on the basis of the engine operating conditions; e) fifth means for detecting a crank angular position at which the inner cylinder pressure becomes maximum on the basis of an output signal derived from the second means; f) sixth means for calculating an ignition timing feedback correction quantity Δ
1 for the ignition timing for avoiding occurrence of engine knock and/or generating a maximum torque as derived from the signal of the second means;g) seventh means for comparing the crank angular position at which the inner cylinder pressure becomes maximum with the current ignition timing to estimate a percentage of alternative fuel to the particular fuel and hating the estimation when the engine is transferred into the predetermined transient condition; h) eighth means or calculating a second correction quantity Δ
2 for the ignition timing according to the estimated percentage of mixture of the alternative fuel;i) ninth means for correcting the basic ignition timing using the first and second correction quantities to determine a final ignition timing; and j) tenth means for igniting the air/fuel mixture supplied to the engine at a time derived by the ninth means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for controlling ignition timing for an internal combustion engine, comprising the steps of:
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a) detecting driving conditions, the engine being driven with a fuel containing a particular fuel and alternative fuel and the engine driving conditions including a range in which the engine is at least driven with a lean air/fuel mixture ratio; b) detecting an inner cylinder pressure of the engine; c) detecting whether the engine operating conditions fall in a transient operating state; d) setting a basic ignition timing for conventional fuel on the basis of the engine operating conditions; e) detecting a crank angular position at which the inner cylinder pressure becomes maximum on the basis of an output signal derived in the step b); f) calculating an ignition timing feedback correction quantity for the ignition timing for at least avoiding occurrence of at least one of engine knock or generating maximum torque as derived from the signal of step b); g) comparing the crank angular position at which the inner cylinder pressure becomes maximum with the current ignition timing to estimate the percentage of alternative fuel to particular fuel and halting the estimation when the engine is transferred into the predetermined transient driving condition; h) calculating a second correction quantity for the ignition timing according to the estimated percentage of mixture; i) correcting the basic ignition timing using the first and second correction quantities to determine a final ignition timing; and j) igniting the air/fuel mixture supplied to the engine on the basis of the determination made in the step i).
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Specification