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US 6,192,857 B1Granted
Control apparatus of engine with electronically driven intake and exhaust valves
AssigneeHitachi, Ltd.
InventorKousaku Shimada
Life of this patent
Estimating the term…
Abstract
There is provided an engine control apparatus with electromagnetically driven intake and exhaust valves which can widen the dynamic range of engine brake torque. The valve open timing of the electromagnetic exhaust valve during fuel cut is made to be variable between the initial stage of expansion stroke and the late stage thereof so as to control the magnitude of engine brake torque.
Claims21
An engine control apparatus with electromagnetically driven intake and exhaust valves, comprising:
- valve control means including fuel injection timed valve controlling means, fuel cut timed valve controlling means and means for controlling drive of the intake and exhaust valves on the basis of output signals of said two means,
- wherein said fuel cut timed valve controlling means includes exhaust valve open/close timing calculating means for making the valve open timing of the exhaust valve earlier than the fuel injection timing during fuel cut.
A control apparatus for an engine with electromagnetically driven intake and exhaust valves, comprising:
- accelerator detecting means for detecting an accelerator operating amount Acc;
- air flow meter means for measuring intake air flow Qa sucked into cylinders of said engine;
- engine speed measuring means for measuring an engine speed Ne;
- basic fuel injection quantity deciding means for determining basic fuel injection quantity Tp1 as a basic fuel injection width per cylinder by dividing said intake air flow Qa by said engine speed Ne and multiplying the product by a coefficient which makes the air-fuel ratio a stoichiometric air-fuel ratio;
- reference fuel injection deciding means for determining target reference fuel injection quantity Tp2 which is on the same dimension as said basic fuel injection width and which is a criterion for target fuel injection quantity Tp3, from two variables of the accelerator operating amount Acc and engine speed Ne;
- target fuel injection calculating means for determining the target fuel injection quantity Tp3 by multiplying said reference fuel injection quantity Tp2 by a target air-fuel ratio and dividing the product by the stoichiometric air-fuel ratio;
- fuel injection width calculating means for calculating a fuel injection width Ti by adding to said reference fuel injection quantity Tp2 an invalid injection width Ts indicative of a delay relative to an injector signal;
- and
- valve control means including:
- fuel injection timed valve controlling means for controlling valve open operation of said intake valve by retrieving maps of control parameters for selection of optimum control parameters, comprising optimum ignition timing, air-fuel ratio, fuel injection timing and EGR rate, on axes representing engine speed and engine load in accordance with a running state of said engine, feedback-controlling said intake air flow Qa to cause said basic fuel injection quantity Tp1 to follow said target fuel injection quantity Tp3 and determining the valve open timing of said intake valve as an intermediate parameter in the feedback of said intake air flow Qa;
- fuel cut timed valve controlling means;
- and
- intake and exhaust valve drive controlling means.
10 more elements
Dependencies are inferred from the claim text.