Fuji Jukogyo Kabushiki Kaisha

Akira Akimoto

Koji Morikawa

Shinya Kudo

Takashi Matsuura

Fujio Takimoto

Toshio Yamaji

Keiichi Kakizaki

Atsushi Nanba

Nobuhiro Hakura

The in-cylinder fuel injection engine is characterized in that fuel is injected into the combustion chamber in two directions. When the homogeneous charge combustion is performed, a first spray block of fuel is injected inside of the cavity and a second spray block of fuel is injected outside of the cavity. When the stratified charge combustion is performed, both spray blocks are injected inside of the cavity.

In-cylinder fuel injection engine and the method of controlling the engine

A combustion chamber of an in-cylinder direct fuel injection spark ignition engine having a pentroof composed of an intake side roof and an exhaust side roof, a piston, and a cylinder. The combustion chamber has a fuel injector provided between the intake side roof and the exhaust side roof inclined toward the exhaust side port, an intake port provided on the intake port side roof at an acute angle with respect to an extended line from the exhaust side roof so as to form a tumble flow of intake air along the exhaust side roof, a piston cavity with a curved surface formed on the top surface of the piston so as to reflect a fuel spray injected from the fuel injector together with that tumble flow in the direction of the intake side roof, and an electrode of a spark plug projected from the intake side roof so as just to collide with the tumble flow. The thus constituted combustion chamber is able to establish fuel injection finishing timing over a wide range according to the fuel injection amount, when stratified charge combustion is applied.

Combustion chamber of in-cylinder direct fuel injection engine

The EGR gas flow is established based on the difference between an assumed value and a control target value of non-air components partial pressure calculated from target control values such as engine torque and at the same time the intake air flow passing through a throttle valve is established based on the difference between an assumed value and a control target value of air components partial pressure and based on the air components within EGR gas. Further, based on thus established EGR gas flow and the intake manifold pressure, the operating amount of an EGR actuator is calculated and based on thus established air flow passing through the throttle valve, the operating amount of an throttle actuator is obtained. Further, based on an estimated value of air components partial pressure, a final basic fuel injection amount is determined. An object of the present invention is to provide an engine control system and method capable of improving a drive feel and emissions simultaneously by integrally controlling fuel injection, induction air and EGR.

Engine control system and the method thereof

In an in-cylinder fuel injection engine capable of selectively switching a combustion strategy from a stratified charge combustion to a homogeneous charge combustion and vice versa, when a coolant temperature at engine start is lower than a specified temperature, the combustion strategy is established to be a homogeneous charge combustion mode and this homogeneous charge combustion mode is held until the coolant temperature reaches the specified temperature. While the coolant temperature is higher than the specified temperature and lower than a warm-up completion temperature, the combustion strategy is switched from homogeneous to stratified by lowering the engine load from a high load area to a low load area so as to improve emissions and fuel economy. On the other hand, when the engine is restarted at the coolant temperature higher than the specified temperature, the combustion strategy is established to be homogeneous until the fuel pressure reaches a specified value and is switched from homogeneous to stratified after the fuel pressure reaches the specified value.

Combustion control system for in-cylinder fuel injection engine and the

A combustion control system and method of a four cycle direct injection engine includes an igniter for igniting simultaneously in two cylinders, a firing cylinder and an off-firing cylinder. In the combustion control system, it is judged whether or not the spark discharge period following the ignition timing overlaps with the fuel injection period following the fuel injection starting timing. If it is judged not to overlap, the fuel injection starting timing determined based on the engine speed and the fuel injection amount is let be a final fuel injection starting timing. If it is judged to overlap, the spark discharge ending timing is obtained from the ignition timing and the spark discharge period and this spark discharge ending timing is let be a final fuel injection starting timing. By delaying the fuel injection starting timing until the final fuel injection starting timing, it is possible to prevent the off-firing cylinder from being fired when the igniter ignites simultaneously in the firing and off-firing cylinders.

Combustion control system for four cycle direct injection engine and the

In a catalyst activation control system for a direct fuel injection engine for igniting primary fuel injected into each cylinder, an additional fuel is injected at least once into each cylinder from an early period to a middle period of an expansion stroke of the primary fuel combustion in accordance with the engine operating conditions, to fire the additional injection fuel by flame propagation of the preceding fuel combustion (without re-ignition) for eliminating misfire, so that an exhaust gas temperature can be raised stably to activate catalyst for purification of exhaust gas. Further, any one of the additional fuel injection method and an ignition timing retarding method can be appropriately selected in accordance with the engine operating conditions for economization of fuel. Further, whenever a quantity of heat generated by the primary fuel combustion is not large enough to fire the additional injection fuel, any one of a method of changing a stratification combustion to a uniform combustion, a method of increasing the first fuel injection amount, and a method of interrupting the additional fuel injection can be selected appropriately for protectiing the catalyst.

Control system and method for direct fuel injection engine

When a damage in a high pressure line of a fuel pressure control system for a high pressure fuel injection engine is detected the fuel pressure is reduced to prevent fuel from blowing out of the damaged part. An acceleration detected by the acceleration sensor is compared with a set value. When the detected acceleration exceeds the set value, the system determines that such an emergency as a collision has happened, fully opens a solenoid type high pressure regulator provided downstream of the high pressure line of fuel system and stops the operation of a feed pump provided in a low pressure delivery line. Thereupon, the feed pump stops delivering the fuel to a high pressure fuel pump. On the other hand, the high pressure regulator is in a fully opened position. Thus, the fuel pressure in the high pressure line is relieved to a fuel tank. Therefore, even if a strong impact due to a collision gives damages to the high pressure line, the system can prevent the fuel from blowing out of the damaged part since the fuel pressure in the high pressure line has been already reduced.

Fuel pressure control system for high pressure fuel injection engine

Based on the output signal of the fuel sensor, it is judged whether or not the fuel (liquid fuel) is detected in the high pressure fuel system. When the fuel is detected, the count value for counting the detecting time is compared with the predetermined value. If the count value is equal to or larger than the predetermined value, the electromagnetic type high pressure fuel regulator is rendered closed and the starter motor prohibition flag is cleared to admit energizing the starter motor. As a result of this, the engine is permitted to be started and thus the high pressure fuel pump starts to produce the high pressure in the high pressure fuel system, whereby a sticking or a scuffing in the fuel pump due to poor lubrication can be prevented and an overshoot of the fuel pressure or a void injection in the fuel injector can be avoided.

Fuel pressure control method and system for direct fuel injection engine

The quantity of air passing a throttle valve of an engine is calculated and a weight for a weighted average is derived from a map in accordance with throttle valve position and engine speed. Engine load data is obtained by adding a last engine load data at a last program and a quotient calculated by dividing the difference between the throttle passing air quantity per revolution of the engine and the last engine load data by a present weight provided at a present program. Ignition timing is derived from a memory storing a plurality of ignition timings arranged in accordance with present engine load data and present engine speed.

Ignition timing control system for automotive engine

The quantity of intake air passing a throttle valve of an engine is calculated and a weight for a weighted mean is derived from a map in accordance with the throttle valve position and engine speed. The quantity of the intake air is calculated by multiplying the ratio of a weight at a last time to a weight at a present time by an intake air quantity produced at the last time to provide a product, by dividing a throttle passing air quantity produce by the throttle passing air calculator at the present time by a weight at the present time to provide a quotient, and by adding the product and the quotient.

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Tokyo, Japan

Akira Akimoto