Mazda Motor Corporation

Akira Kageyama

Noriyuki Ota

Hiroyuki Yamashita

Hiroyuki Oda

Yoshihisa Nou

Takeshi Nagasawa

Hiroyuki Yamamoto

Hirofumi Nishimura

Naoyuki Yamagata

Yasuyuki Morita

Hiroyasu Uchida

Masashi Marubara

Shigeru Sakurai

Masayuki Kuroki

Kazuaki Narahara

Hidetoshi Kudou

Takehiko Yasuoka

Xiyao Ge

Hidetoshi Kudo

Ryo Kiyosue

An engine system includes a combustion chamber including a cylinder formed in an engine and a piston configured to reciprocate inside the cylinder, a spark plug disposed in a ceiling part of the combustion chamber, and a water injection device configured to inject water into the combustion chamber through a plurality of nozzle holes facing the inside of the combustion chamber. The piston has a cavity in an upper surface thereof. The water injection device injects water into the cavity in a compression stroke at a timing when an extension of axes of at least some of the nozzle holes intersects the cavity. The cavity has a bottom part where the water injected by the water injection device collides, and a raising part configured to raise the water spreading along the bottom part toward the water injection device.

Combustion chamber structure of engine

A fuel injection valve is provided for a ceiling portion of a cylinder head. A tip of an ignition electrode is arranged in the vicinity of an injection tip of the fuel injection valve. A recess is provided for the ceiling portion. A center of a cavity is shifted with respect to a bore center of the cylinder. In a vertical cross-section of the inside of a combustion chamber taken along a plane passing through the injection tip of the fuel injection valve and the tip of the ignition electrode, a distance from the injection tip to a wall surface of the cavity at a side at which the ignition electrode is provided is longer than a distance from the injection tip to a wall surface of the cavity at an opposite side.

Combustion chamber structure for direct injection engine

A fuel injection valve is caused to inject fuel in a latter half of a compression stroke in such a manner that a fuel concentration immediately before start of combustion is higher in a middle portion of a combustion chamber than in an outer peripheral portion thereof in a low load range where the engine load is lower than a predetermined set reference load. An intake valve driving device is controlled in such a manner that an intake valve closing timing in the low load range is advanced on a retard side with respect to an intake bottom dead center in a case where the engine speed is high, as compared with a case where the engine speed is low, and intake air within a cylinder is blown back toward an intake port at least in a range where the engine speed is low.

Direct injection engine

Provided is an exhaust system of a multi-cylinder engine capable of increasing the air-intake and thereby increasing the engine output with a simple configuration. The exhaust system is provided with low velocity-side passages, high velocity-side passages, a low velocity-side collection part, a high velocity-side collection part, and a flow passage area variable valvecapable of changing the flow passage area of the respective high velocity-side passages. The relationship of a diameter aof a true circle with a same area as the flow passage area of the downstream end of the low velocity-side passages, a diameter Dof a true circle with a same area as the flow passage area of the downstream end of the low velocity-side collection part, a diameter aof a true circle with a same area as the flow passage area of the downstream end of the high velocity-side passages, and a diameter Dof a true circle with a same area as the flow passage area of the downstream end of the high velocity-side collection partis made to be a/D&#x2267;a/D. In a low velocity region R, an exhaust valveis opened during the overlap period of an intake valveand the exhaust valveand the flow passage area of the high velocity-side passagesis narrowed, and, in a high velocity region R, the flow passage area of the high velocity-side passagesis set to be a maximum area.

Exhaust system of multi-cylinder engine

A direct injection engine provided with an injector at a peripheral portion of a combustion chamber to inject at least at a latter stage of a compression stroke in at least in a low engine load and low engine speed condition, wherein a distance from the tip end of the injector to an opposite end the combustion chamber is determined greater than a traveling distance of an injected fuel for a time period from a start of a fuel injection at the latter stage of the compression stroke to the ignition timing, wherein; an ignition plug is arranged that an ignition gap is disposed within an injection area of the injector; and, wherein a distance from the tip end of the injector to the ignition gap is determined smaller than said traveling distance of the injected fuel. An ignitability and combustion stability can be improved to thereby improve a 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.

Direct fuel injection ignition engine

A V-type two cycle, supercharged engine having scavenging ports for said cylinders includes a mechanical supercharger and a surge tank. A pair of rotors of the supercharger are horizontally arranged in parallel with each other with one positioned directly below the other and them supercharger is offset laterally toward one of the left and right banks from the center of the V-shaped space defined between the left and right banks. An air expulsion opening is formed in the supercharger housing on its side nearest to the other bank. The surge tank is disposed below the supercharger and is partly expanded upward on the side nearest the other bank.

V-type two cycle supercharged engine

The block construction of an engine and more particularly the passage construction of the cooling water in an engine having the block integrally cast, the block being provided with a head portion and a cylinder portion. The cooling operation with respect to the peripheral portion of the combustion chamber is properly performed to improve the knocking resistance and the heat load resistance of the engine, the uniform cooling effect for each cylinder in the multiple cylinder engine is retained and the cooling property with respect to the portion between the adjacent cylinders is improved.

Block construction of engine

In a four-valve engine having a pair of intake ports and a pair of exhaust ports, the hole for inserting the spark plug or the fuel injection nozzle is obliquely formed between the exhaust ports so that one end of the hole opens in the lower surface of the cylinder head at the center of the combustion chamber and the other end of the hole opens between the spring seat portions for the exhaust valve springs and the opening of the exhaust ports in the side face of the cylinder head.

Internal combustion engine

In a spark-ignited engine in which a spark plug is supported so that its igniting tip is centrally located in the combustion chamber, a bore for forming a coolant passage is provided in the wall of the cylinder head defining the combustion chamber to extend between an exhaust port and a threaded bore into which the spark plug is screwed. The bore is formed to extend from a cooland inlet formed in the lower side of the cylinder head through which coolant from the cylinder block enters the cylinder head to the water jacket formed in the cylinder head so that the coolant from the cylinder block flows through the bore under the pressure difference between the coolant inlet and the water jacket.

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Hiroshima, Japan

Akira Kageyama