Mazda Motor Corporation

Masatoshi Seto

Hiroyuki Yamashita

Yuji Harada

Masahiko Fujimoto

Hiroyuki Yoshida

Keiji Araki

Fumihiko Saito

Tatsuya Tanaka

Noriyuki Ohta

Takehiko Yasuoka

Masakazu Matsumoto

Masahisa Yamakawa

Yusuke Kawai

Noriyuki Ota

Tatsuya Fujikawa

Takeo Yamauchi

Masashi Marubara

Kazuaki Narahara

Kazuo Ichikawa

Hidefumi Fujimoto

Takashi Ikai

Tsugio Fukube

Junki Hori

Yoshio Tanita

Susumu Masuyama

Yoshitomo Takahashi

Hirokazu Nakahashi

Shingo Kai

Yusuke Nakao

Takeaki Kudo

A control system for an engine including intake and exhaust valve phase variable devices and a control device is provided. At an engine temperature below a first determination temperature, the control is performed so that an exhaust valve close timing is at or retarded from the exhaust top dead center, an intake valve open timing is retarded from the exhaust valve close timing, and the fuel supply to the combustion chamber starts in an intake stroke on a retarding side of the exhaust valve close timing. At the engine temperature above the first determination temperature and below a second determination temperature, the control is performed so that a negative overlap with both the exhaust and intake valves closed during a period including the exhaust top dead center, or a positive overlap with both the exhaust and intake valves opened during a period including the exhaust top dead center, occurs.

Engine control system

An engine has an engine body, an injector, and a control section which controls a fuel injection amount and an injection state of the injector. The control section predicts a state of temperature in the combustion chamber, and controls the injector such that a volume of an air-fuel mixture layer formed in the combustion chamber is larger when the predicted temperature is high, than when the predicted temperature is low, even when same fuel amounts are injected.

Control device for direct injection gasoline engine

A gasoline direct-injection engine is provided. The engine performs compression self-ignition combustion, and includes a cylinder, an injector, intake and exhaust ports, intake and exhaust valves, and an ozone generating system for generating ozone inside the cylinder. The system includes an electrode projecting into the cylinder while being partially electrically insulated from walls of the cylinder, and a high-voltage control device for applying a controlled pulse-shaped voltage to the electrode. When the voltage is applied, electric discharge occurs between the non-insulated part of the electrode and the walls of the cylinder, and ozone is generated inside the cylinder due to an effect of the electric discharge. A combustion pattern is provided, in which a compression stroke injection is performed and mixture gas formed by the fuel injection self-ignites to combust. When the combustion pattern is applied, the high-voltage control device is operated on intake stroke or the compression stroke.

Gasoline direct-injection engine

A control device for direct injection gasoline engines includes a fuel injection control part (engine control device) composed to control a fuel injection aspect of an injector. The fuel injection control part changes an injection mode of the injector by changing the lift amount of the injector and the injection interval of the fuel respectively. The fuel injection control part switches between a first injection mode, which includes multiple times of the fuel injection with the small lift amount of the injector and the small interval of the fuel injection, and a second injection mode, which includes multiple times of the fuel injection with the bigger lift amount of the injector and the larger interval of the fuel injection than those of the first injection mode, according to an operating state of the engine body.

Control device for direct injection gasoline engines

A control device of a gasoline direct-injection engine is provided. The control device includes an engine body, an injector, and a controller. Within a high load operating range, the controller causes the injector to perform a pre-injection and a post injection. In the pre-injection, the fuel is injected to cause a fuel concentration within an in-cylinder radially peripheral section to be higher than a fuel concentration within an in-cylinder radially central section at a timing for the fuel to ignite. In the post injection, the fuel is injected to cause the fuel concentration within the radially central section to be higher than the fuel concentration within the radially peripheral section at a timing for the fuel to ignite. The timing for the fuel injected in the post injection to ignite is after an oxidative reaction of the fuel injected in the pre-injection occurs and after a compression top dead center.

Control device of gasoline direct-injection engine

A control device of a direct-injection engine is provided. The control device includes an engine body having a piston provided inside a cylinder and a combustion chamber formed by the cylinder and the piston, an injector for injecting fuel into the combustion chamber, an ozone generator for generating ozone inside the combustion chamber, and a controller for controlling the injector and the ozone generator. The controller controls the injector to inject a first amount of the fuel and, after this fuel is ignited, to inject a second amount of the fuel, and the controller controls the ozone generator to generate ozone in synchronization with the fuel injection that is performed by the injector after the fuel ignition.

Control device of direct-injection engine

A direct injection engine includes an ignition assistance section applying energy to fuel injected into a cylinder using an injector to assist auto-ignition combustion of the fuel when the engine is within an auto-ignition combustion operation range. A start time of fuel injection is set within a period from a terminal stage of a compression stroke to a compression top dead center. The energy is applied to the fuel injected into the cylinder in a period from start of the fuel injection to an initial stage of an expansion stroke such that a time of a specific crank angle when an increase rate of in-cylinder pressure, which is a ratio of a change in the in-cylinder pressure to a change in a crank angle in motoring the engine, reaches a negative maximum value overlaps a combustion period when a combustion mass percentage of the fuel ranges from 10% to 90%.

Direct injection gasoline engine and method of controlling the direct injection gasoline engine

When it is determined that an engine operating condition is in a high-engine load HCCI range (A) where an engine load is higher than a specified load Xwithin a HCCI range A where a compression self combustion is performed, an after-TDC injection Fis executed at a point Twhen an internal pressure of a combustion chamber drops below a specified pressure Y after the top dead center of an exhaust stroke during a minus valve overlap period NVO during which intake and exhaust valves are both closed. Then, a main injection Fas a main injection is executed. Accordingly, any improper detonation or deterioration of NOx emission which may be caused by the compression self-ignition combustion in the range where the engine load is relatively high can be prevented.

Control method and system of engine

A method of controlling an internal combustion engine and system including the engine is provided. The method may include closing an exhaust valve of a combustion chamber of said engine during a cylinder cycle prior to opening an intake valve of said combustion chamber. The method may include, when a desired engine torque is a predetermined torque or greater, supplying a first pilot fuel into said combustion chamber after said exhaust valve closing and supplying a first main fuel into said combustion chamber after the combustion of said first preliminary fuel during the cylinder cycle. The method may include, when a desired engine torque is less than said predetermined torque, supplying a second pilot fuel into said combustion chamber after said exhaust valve closing during the cylinder cycle and supplying a second main fuel into said combustion chamber after the supplying of said second pilot fuel into said combustion chamber.

Method of controlling an internal combustion engine and system including the engine

A direct injection spark ignition engine comprises a cylinder, a piston, a fuel injector arranged at one side of a center axis of the cylinder for directly injecting fuel into the combustion chamber, and a smoothly continuous lowered recess formed on a top surface of the piston surface. The recess has a first cross section along a first plane including the cylinder center axis and a nozzle end of the injector. The first and second lower contours are smoothly connected with each other through a lowest point of the first cross section. The first lower contour is located at the one side of the cylinder center axis. The second lower contour is at the other side. The first contour has a larger radius than a radius of the second contour. Accordingly, the fuel spray having greater movement energy may impinge the recess at a regulated impinging angle.

Direct injection spark ignition engine

A fuel spray and a tumble collide with each other from approximately opposite directions in a cavity formed in a piston head so that a combustible mixture stays around a spark plug for an extended period of time. An upper opening of the cavity is elongated to both the left and right sides of a cylinder axis. The distance between a ceiling of the combustion chamber and a bottom surface of the cavity is smaller on the right side of the cylinder axis than on the left side thereof and largest at least at a point where the cylinder axis crosses the bottom surface of the cavity, and a portion of the cavity to the left of the cylinder axis has a larger volumetric capacity than a portion of the cavity to the right of the cylinder axis, whereby a strong tumble is maintained up to a fuel injection point.

Direct-injection spark-ignition engine

During stratified-charge combustion operation of a direct-injection spark ignition engine, at the cylinder compression stroke, a tumble is generated which flows between a spark plug electrode and a piston crown surface toward an injector. A fuel is injected from the injector in correspondence with the cylinder ignition timing by controlling the penetration of fuel spray from the injector to correspond to the tumble flow rate so that the fuel spray may go against the tumble, become a flammable mixture at the cylinder ignition timing and stay near the spark plug electrode. In the late stage of the compression stroke, diffusion of the flammable mixture is suppressed with squishes. Thus, fuel spray behavior in the combustion chamber is controlled to allow suitable mixture stratification over a wide engine operating condition range. This improves combustion quality and extends a stratified-charge combustion zone thereby providing enhanced fuel economy and power output.

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Hatsukaichi, Japan

Masatoshi Seto