Hitachi Automotive Systems, Ltd.

Kenichiroh Ogata

Yoshinobu Arihara

Takashi Okamoto

Yoshihiro Sukegawa

Kengo Kumano

Takaki Itaya

Hisahiro Ooba

Takuya Shiraishi

Kenichi Machida

Yoshihiko Akagi

Daisuke Watanabe

In an internal combustion engine which performs a homogeneous lean combustion mode and a stratified lean combustion mode, there is provided a new internal combustion engine control device capable of obtaining a stable combustion state by decreasing influences of delay of an air flow and a degree of change of a transient state and smoothly performing switching between the homogeneous lean combustion mode and the stratified lean combustion mode. Accordingly, in the present invention, when switching between the stratified lean mode in which a compression stroke injection is performed by a direct injection injectorand the homogeneous lean combustion mode in which an intake stroke injection is performed by the direct injection injectoris performed, a predetermined delay time &#x394;t is provided from at least a switching operation of a tumble control valve, a switching operation between the compression stroke injection and the intake stroke injection is performed, and the delay time &#x394;t is set so as to correspond to a magnitude of the degree of change &#x394;L of the transient state. A switching timing between the compression stroke injection and the intake stroke injection is controlled according to the flow delay of an air control system such as the tumble control valveand the degree of change &#x394;L of the transient state, and thus, it is possible to improve combustion stability in a combustion chamber.

Internal combustion engine control device

Provided is an engine control device capable of suppressing deterioration of combustion stability due to a change in engine temperature in an engine which performs lean combustion or EGR combustion. When lean combustion in which an air-fuel mixture leaner than a stoichiometric air-fuel ratio is burned or exhaust gas recirculation combustion in which a diluted air-fuel mixture is burned by re-suctioning exhaust gas discharged from the combustion chamber into the combustion chamber is performed, a ratio of a fuel injection amount during a compression stroke to a total fuel injection amount during one combustion cycle is increased as a temperature of an engine decreases.

Engine control device

An engine control device sets a target value for the engine oil temperature appropriately in an engine that uses gasoline as a fuel, even when the fuel does not have a single boiling point because the gasoline is a mixed composition, or when the fuel property changes (for example, when the vaporization property changes due to deterioration). In other words, the engine control device prevents excessive heating or insufficient heating by changing the oil temperature to the high side in a condition wherein the fuel being used does not easily vaporize, and changing the oil temperature to the low side in a condition wherein the fuel being used easily vaporizes. This engine control device includes an oil temperature controller that controls the temperature of oil lubricating the interior of the engine; a fuel supply device that supplies fuel to the engine; and a detector for detecting the property of the fuel. The temperature of the oil is controlled on the basis of a signal from the detector.

The purpose of the present invention is to provide an engine control system that is capable of promoting mixing of fuel and air during exhaust gas recirculation, thereby suppressing combustion fluctuation of a gasoline engine, such that efficiency and exhaust gas purification can be simultaneously achieved. The engine control system controls an engine and is equipped with an injection device for injecting fuel directly into a cylinder and a recirculation device for recirculating exhaust gas to the intake side. When the temperature of the recirculating exhaust gas recirculated by the recirculation device is high as opposed to when the temperature is low, or when the amount of the recirculating exhaust gas recirculated by the recirculation device is large as opposed to when the amount is small, at least one of the following is executed: advancing of the fuel injection timing (IT_SP (n&#x2212;2) of the injection device; increasing of the fuel pressure (FP) to be supplied to the injection device; reducing the frequency (n) of divided multi-stage injection to be performed by the injection device during the period between intake top dead center and compression top dead center; and reducing of the interval of divided multi-stage injection (IT_RE (n&#x2212;2)).

Engine control system

In order to solve a problem that in an internal combustion engine in which abnormal combustion (knocking or an accidental fire) of an engine is detected from an ion signal, the setting of an abnormal combustion determination threshold value under a transient condition in which an engine operating state abruptly changes is difficult to thereby cause erroneous determination, the present invention is an engine control device provided with an ion signal detection means for detecting ions generated during combustion, and provided with an abnormal combustion determination means for determining knocking or an accidental fire according to an ion signal detected by the detection means, the engine control device being characterized by being provided with an in-cylinder temperature estimation means for estimating the in-cylinder temperature in a normal combustion cycle under a current operating condition of the engine, and by setting the knocking determination threshold value or accidental fire determination threshold value of the ion signal on the basis of the estimated in-cylinder temperature information. Consequently, it becomes possible to accurately detect abnormal combustion even under a transient operating condition.

Although a method for changing a combustion method taking place in an internal combustion engine depending on running condition is proposed, it can be considered that conditions under which a combustion noise occurs naturally differ with different methods. A detection method of prior art is not compatible with different combustion methods and the accuracy of combustion noise detection was low. Accurate combustion noise detection is enabled by identifying a combustion mode taking place in the internal combustion engine, selecting a sensed frequency or frequency band of a combustion noise sensor that detects a combustion noise in a combustion chamber of the internal combustion engine according to the combustion mode, and detecting a combustion noise.

Method for detecting combustion noise in internal combustion engine, combustion noise detection device, and device for controlling internal combustion engine

An object of the present invention is to obtain a control apparatus of an internal combustion engine capable of respectively accurately detecting a combustion change in a plurality of combustion modes. In the present invention, the control apparatus of the internal combustion engine operable upon switching the combustion mode sets a detection time and a detection duration to detect a sensor signal of a crank angle sensorin accordance with the combustion mode, and determines whether or not there is the combustion change based on the sensor signal detected by the crank angle sensorat the detection time and for the detection duration set by the control apparatus.

Control apparatus of internal combustion engine

When a direct injection type internal combustion engine is in an operating state, a fuel is split and jetted into a cylinder of the internal combustion engine and split injections are performed in a manner to make a ratio of a piston travel and an injection pulse width of split injection constant in a cycle whereby a rich mixture is not locally generated and a mixture in a cylinder of the internal combustion engine is put in a condition near stoichiometry. Also, when the internal combustion engine is in cold condition, a fuel is split and jetted and split injections are performed so that the ratio of the piston travel and the injection pulse width of split injections monotonously increases in a cycle.

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Hitachinaka, Japan

Kenichiroh Ogata