Mazda Motor Corporation

Hidetoshi Kudou

Hiroyuki Yamashita

Tsuyoshi Goto

Noriyuki Ota

Masami Nishida

Masashi Marubara

Yasushi Nakahara

Mikihito Fujii

Fumihiko Saito

Akira Kageyama

Masakazu Matsumoto

Provided is a spark-ignition internal combustion engine capable of ensuring engine output power while setting a geometric compression ratio of an engine body to a high value. In the spark-ignition internal combustion engine, each of a clearance between a top surface () of a piston () located at a top dead center position and a lower surface () of each of two intake valves () in a full-closed state, and a clearance between the top surface () of the piston () located at the top dead center position and a lower surface () of each of two exhaust valves () in a full-closed state, is set to 5 mm or more, and a stroke length S of the piston () is set to satisfy the following relation: S&#x2266;0.977&#xd7;B+18.2, where B is a bore diameter of a cylinder.

Spark-ignition internal combustion engine

There is provided, in one aspect of the present description, an internal combustion engine system. In one example, the system comprises a controller configured to control an intake valve closing timing varying mechanism to vary a closing timing of the intake valve to regulate air charged in a combustion chamber in accordance with engine operating conditions and, in a first engine operating condition where a least volume of air is required to be charged into the combustion chamber, retard a closing timing of the intake valve to a most retarded crank angle which is after bottom dead center during a cylinder cycle and satisfies the following formulas:&#x3b1;&#x2267;&#x2212;0.2685&#xd7;&#x3b5;0+10.723&#xd7;&#x3b5;0+15.815 and&#x3b5;0&#x2267;11.0,where &#x3b1; is the most retarded crank angle and &#x3b5;0 is a geometric compression ratio of the engine.

Spark ignited internal combustion engine system

A control device for a direct injection engine having a catalyst provided in an exhaust passage for converting exhaust gases and an injector for injecting fuel directly into a combustion chamber, includes a temperature state identifier for judging the temperature state of the catalyst, a load condition detector for sensing engine load conditions, and a fuel injection controller for controlling fuel injection from the injector. The fuel injection controller performs quick light-off control operation by causing the injector to inject fuel in one-time injection mode during a compression stroke in a specific low-load operating range of the engine when the catalyst is in its unheated state where its temperature is below its activation temperature, and switching the mode of fuel injection to intake-compression stroke split injection mode in a specific high-load operating range of the engine.

Control device for direct injection engine

A direct injection engine including an injector disposed in an upper portion of a combustion chamber defined above a piston disposed in a cylinder of the engine with a fuel injecting direction of the injector being provided so that a fuel being injected toward a top portion of the piston, an ignition plug disposed at an upper portion of the combustion chamber, an engine operating condition detector for detecting an engine operating condition. The fuel is injected in a compression stroke from the injector when it is detected by the engine operating condition detector that the engine is in a low engine load and speed zone so as to stratify an injected air fuel mixture around the ignition plug to accomplish a stratified combustion. The engine further includes a fuel controller for controlling an fuel injection so as to inject the fuel plural times into the combustion chamber in a compression stroke when at least one of an engine load and an engine speed is relatively high in an engine operating zone for accomplishing the stratified combustion. A stable combustion is accomplished to improve the fuel consumption efficiency.

Direct fuel injection engine

A direct injection ignition engine includes a piston with a cavity on a top surface thereof, an injector arranged at a peripheral portion of a combustion chamber to be faced to the combustion chamber for injecting a fuel directly into the combustion chamber, an ignition plug arranged to be projected to the combustion chamber for igniting the fuel introduced into the combustion chamber, an intake passage connected to the combustion chamber for introducing an intake air to the combustion chamber, intake air flow control valve arranged in the intake passage for controlling an intake air flow of an inclined vortex including a tumble component and swirl component produced in the combustion chamber, an actuator for driving the control valve, engine load detecting sensor for detecting an engine load, engine speed detecting sensor for detecting an engine speed, fuel supply controller, based on the output signals from the engine load detecting sensor and the engine speed detecting sensor, for producing control signals for the injector which include a fuel injection amount and fuel injection timing in a compression stroke for accomplishing a stratified combustion condition in which an air fuel mixture with an air fuel ratio greater than a theoretical one is concentrated around the ignition plug when an operating condition is in at least a low engine load and low engine speed condition, and, the fuel injection amount and fuel injection timing in an intake stroke for accomplishing a uniform combustion condition in which an air fuel mixture with an air fuel ratio greater than a theoretical one is uniformly and entirely dispersed in the combustion chamber when the operating condition is at least in a condition beyond said low engine load and engine speed condition with regard to the engine load and engine speed, and, producing control signals for the actuator to produce the inclined vortex of the air fuel mixture in the operating condition from the stratified combustion condition to the uniform combustion condition.

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Higashihiroshima, Japan

Hidetoshi Kudou