摘要:
A direct-injection spark-ignition engine in which a combustible mixture is produced around a spark plug at an ignition point by causing a tumble and a fuel spray to collide with each other in a combustion chamber during stratified charge combustion comprises a fuel pressure controller which controls fuel pressure such that penetration of the fuel spray from a fuel injector is progressively intensified with an increase in engine speed in a stratified charge combustion region and means for controlling fuel injection timing including an injection timing setter. The means for controlling fuel injection timing controls the injection timing in such a way that the interval between a fuel injection ending point and the ignition point becomes progressively shorter as engine speed increases under the same engine load conditions in the stratified charge combustion region.
摘要:
In a control system for an in-cylinder direct injection engine, an actual port intake air density ganmap is calculated based on the intake air temperature thae and the atmospheric pressure atp, a reference port intake air density ganmap* corresponding to the current operating conditions of the engine is read out of a map and compared with the actual port intake air density ganmap, and a target fuel pressure or fuel injection timing is compensatorily modified based on the comparison result. This prevents fuel spray and the tumble from being thrown out of balance due to a change in intake air temperature or atmospheric pressure thereby providing suitable mixture stratification.
摘要:
In a control system for an in-cylinder direct injection engine, during idling operation, the fuel injection timing is compensated to the advance side for each cylinder so that the rate of change in crank angular velocity becomes smaller than a preset criterion while the fuel injection pressure of an injector is gradually reduced from a reference target fuel pressure to a preset lower limit. If the rate of change in crank angular speed becomes smaller than the criterion as a result of the above compensation, the fuel injection timing is compensated to the retard side so that the rate of change in crank angular velocity becomes smaller while the fuel pressure is gradually increased to the preset upper limit. Consequently, the unbalance of fuel spray and tumble due to deviations of fuel spray penetration and the like can be eliminated thereby providing suitable mixture stratification.
摘要:
Upon refreshing a catalyst (25) in steps SA2 to SA6, the air-fuel ratio of each combustion chamber (4) of an engine (1) is dither-controlled to periodically vary to the rich and lean sides of a target value (A/F=15 to 16) in steps SA16 and SA17. In step SA15, an injector (7) divisionally injects fuel in two injections within the period from the intake stroke to the compression stroke of each cylinder, thus accomplishing weakly stratified combustion. In step SA18, the opening of an EGR valve (27) is controlled to recirculate a large amount of exhaust gas to an intake path (10) so as to achieve around 40% EGR ratio.
摘要翻译:在步骤SA2至SA6中更新催化剂(25)时,发动机(1)的每个燃烧室(4)的空燃比被抖动控制,以周期性地变化到目标值(A / F = 15〜16)。 在步骤SA15中,喷射器(7)在从进气冲程到每个气缸的压缩冲程的时段内分两次喷射燃料,从而完成弱分层燃烧。 在步骤SA18中,控制EGR阀(27)的开度使大量废气再循环到进气路径(10),以实现大约40%的EGR率。
摘要:
An air intake control system for an engine equipped with an exhaust gas recirculation feature controls an exhaust gas recirculation valve according to an amount of air charge dictated by an amount of intake air detected by an air flow sensor to deliver a target amount of air charge and control an amount of air charge meeting an estimated amount of air charge estimated under the condition that the control of exhaust gas recirculation valve according to an amount of air charge is interrupted.
摘要:
A fuel injection control system for a direct injection-spark ignition engine determines an injection pulse width corresponding to a given quantity of fuel with which an injector is kept open, controls the injector to spray a given quantity of fuel in a compression stroke while the engine operates in a zone of lower engine loads specified for lean stratified charge combustion so that the fuel is stratified around an ignition plug to cause lean stratified charge combustion so as thereby to provide an air-fuel ratio greater than a stoichiometric air-fuel ratio, executes fuel injection feedback control to control a quantity of fuel injection based on an air-fuel ratio detected by an oxygen sensor, causes the injector to spray a given quantity of fuel through a plurality of intake stroke split injection in a specified engine operating zone in which the fuel injection feedback control is performed to maintain at least a stoichiometric air-fuel ratio while the engine operates with lower loads, learns a fuel injection quantity characteristic of the injector with respect to injection pulse width for each intake stroke split injection based on a value controlled by the fuel injection feedback control during execution of the intake stroke split injection to determine a leaning correction value, and makes the learning correction value reflect on the control of the quantity of fuel in a minute injection zone specified within the specified engine operating zone for the lean stratified charge combustion.
摘要:
An engine control system for controlling operation of an engine of a type injecting fuel directly into a combustion chamber in different injection modes according to engine operating conditions has a map of engine control values with respect to specified engine operating conditions at intersection points of a grid pattern in which engine control values at extreme intersection points adjacent to a boundary between adjacent injection modes is discontinual. The engine control system calculates an engine control value for an engine operating condition by interpolation with the aid of engine control values at the intersection points and determines an engine control value for an engine operating condition at a point closer to the boundary than the extreme intersection point of one injection mode based on engine control values at intersection points of the one injection mode only.
摘要:
An engine control system for an automobile engine of, for example, the type which injects fuel directly into an combustion chamber (16) and executes a fuel-cut control under a specified engine operating condition establishes a stratified charge combustion mode and a homogeneous charge combustion mode selectively according to engine operating conditions following termination of the fuel-cut control and shuts off nearly completely an engine throttle valve (28) during execution of the fuel-cut control and opens the engine throttle valve (28) so as to variably control an amount of intake air passing through an intake passage (24) into the combustion chamber (16) before the stratified charge combustion mode is established following termination of the fuel-cut control.
摘要:
A control device for controlling a direct injection engine provided with an injector for injecting fuel directly into a combustion chamber in a cylinder thereof and a throttle valve is switchable between a stratified charge combustion mode and a uniform charge combustion mode. The control device predicts switching to the uniform charge combustion mode based on a change in the target load Piobj during engine acceleration in the stratified charge combustion mode, and corrects the target load Piobj so that the opening of the throttle valve approaches the opening suited for the uniform charge combustion mode prior to the switching to the uniform charge combustion mode when such combustion mode switching has been predicted. This control device prevents torque shock due to the combustion mode switching during engine acceleration without causing a deterioration in fuel economy or in vehicle acceleration performance.
摘要:
An engine control system for an engine equipped with a swirl control valve which is operative in operation modes different in fuel injection form according to engine operating conditions judges based on a change in an engine operating condition whether a mode shift to one operation mode to another is demanded and controls the swirl control valve so as to attain a target opening for the one engine operation mode while keeping a specific mode shift waiting until the swirl valve opening reaches a limit value permissible in one engine operation mode into which the specific mode shift is made when the swirl control valve is judged to be out of the limit value.