Mazda Motor Corporation

Mazda Motor Corporat Ion

Michiharu Kawano

Yuya Honda

Yasushi Nakahara

Atsushi Inoue

Kota Matsumoto

Masaki Fukuma

Satoshi Imamura

Kento Onishi

Yoshiharu Ueki

Tota Tanii

Takuya Ohura

Tomohiro Nishida

Tsuyoshi Yamamoto

Yohei Suzuki

Futa Nishi

Masanari Sueoka

Tomonori Urushihara

Yusuke Kawai

Toru Miyamoto

Masatoshi Hidaka

Tsubasa Ito

An internal combustion engine is provided, which includes a variable phase mechanism configured to change rotational phases of intake and exhaust camshafts so that a valve overlap is made. An intake cam lobe is formed such that an open period of the intake valve is 210&#xb0; or larger and 330&#xb0; or smaller of a crank angle. The exhaust cam lobe is formed such that, during the overlap period with the rotational phase of the intake camshaft advanced to the maximum and the rotational phase of the exhaust camshaft retarded to the maximum, an effective valve lift amount (Lift(CA)) of the exhaust valve which is a function of a crank angle from the open timing (CA) of the intake valve to a middle timing (CA) of the overlap period, an inner circumferential length (L_ex) of a valve seat, and a swept volume (V) per cylinder satisfy the following formula: 

Internal combustion engine

A fuel injection control device for an engine is provided. A swirl generator generates a swirl flow inside a combustion chamber. A fuel injector with multiple nozzle holes injects fuel into the combustion chamber, and forms a lean mixture gas inside the combustion chamber. An spark plug ignites the lean mixture gas to cause the mixture gas to start combustion accompanied by flame propagation, and then combust by self-ignition. A first atomized fuel spray injected from a first nozzle hole and a second atomized fuel spray injected from a second nozzle hole separate from each other by the swirl flow. The fuel injector sequentially performs first and second injections in an intake stroke. A ratio of an injection amount of the second injection to the entire amount of fuel required per cycle is increased as an engine load increases.

Fuel injection control device for engine

A fuel injection control device for an engine is provided. A swirl generator generates a swirl flow inside a combustion chamber. A fuel injector with multiple nozzle holes injects fuel into the combustion chamber, and forms a lean mixture gas inside the combustion chamber. A spark plug ignites the lean mixture gas to cause a portion of the mixture gas to start combustion accompanied by flame propagation, and then combusts by self-ignition. The fuel injector has first and second nozzle holes, and a first atomized fuel spray injected from the first nozzle hole and a second atomized fuel spray injected from the second nozzle hole separate from each other by the swirl flow. The fuel injector performs the fuel injection in an intake stroke, and retards a start timing of the injection when an engine load is high compared to that when the load is low.

A structure of a combustion chamber for an engine includes a crown surface of a piston, a combustion chamber ceiling surface, an injector and an ignition plug provided on the combustion chamber ceiling surface, and an intake opening and an exhaust opening opened in the combustion chamber ceiling surface. A side where the intake opening is opened is defined as an intake port side, and a side where the exhaust opening is opened is defined as an exhaust port side. An ignition portion of the ignition plug is disposed on the intake port side. The ignition plug is ignited at a timing after the piston passes a compression top dead center. The injector is disposed on the center portion, and is configured to inject fuel toward the exhaust port side. A cavity is provided on the crown surface. A reverse squish flow generation portion is provided in the combustion chamber.

Combustion chamber structure for engines

A structure of a combustion chamber for an engine includes a crown surface of a piston, a combustion chamber ceiling surface formed on a cylinder head, an injector and an ignition plug provided on the combustion chamber ceiling surface, and an intake opening and an exhaust opening opened in the combustion chamber ceiling surface. A side where the intake opening is opened is defined as an intake port side, and a side where the exhaust opening is opened is defined as an exhaust port side, with respect to a position, as a reference, where an ignition portion of the ignition plug is disposed in a plan view from one side in a cylinder axis direction, the injector is configured to inject fuel toward the exhaust port side, and a reverse squish flow generation portion, which draws an air-fuel mixture toward the intake port side, is provided in the combustion chamber.

A fuel injection control device for an engine is provided. A fuel injector with multiple nozzle holes forms a lean mixture gas inside a combustion chamber, a spark plug ignites to cause the mixture gas to start combustion accompanied by flame propagation, then combust by self-ignition. A first atomized fuel spray injected from a first nozzle hole and a second atomized fuel spray injected from a second nozzle hole separate from each other by a swirl flow, and a third atomized fuel spray injected from a third nozzle hole and a fourth atomized fuel spray from a fourth nozzle hole approach each other by the swirl flow so that a first area and a second area where mixture gas is richer are formed inside the combustion chamber. The fuel injector sequentially performs first, second, and third injections with an injection interval therebetween in an intake stroke.

A structure of a combustion chamber for an engine includes a crown surface of a piston, a cylinder wall surface, a combustion chamber ceiling surface, and an ignition plug which includes an ignition portion. The crown surface of the piston includes: a cavity recessed in the cylinder axis direction; a parallel surface portion which is in parallel to a corresponding region on the combustion chamber ceiling surface at a position above the cylinder axis direction with a gap, when the piston is at a compression top dead center; and an inclined surface portion formed to continue to the parallel surface portion in such a way as to be directed to the ignition plug, when the piston is at a compression top dead center. The parallel surface portion and the corresponding region, in combination, constitute a squish flow generation portion generating a squish flow when the piston is lifted.

A structure of a combustion chamber for an engine includes: a crown surface of a piston; a combustion chamber ceiling surface formed on a cylinder head; and an ignition plug mounted on the combustion chamber ceiling surface, and including an ignition portion disposed in such a way as to face the combustion chamber. The crown surface of the piston includes a cavity which is recessed in a cylinder axis direction in a region including a position below the ignition portion of the ignition plug in a plan view from the cylinder axis direction. A rim portion of the cavity includes a guide portion, raised in the cylinder axis direction with respect to an inner region of the rim portion, interposing the ignition portion when the piston is at a compression top dead center, and configured to guide an air-fuel mixture within the combustion chamber to the ignition portion.

A combustion chamber structure for an engine includes a combustion chamber where SI combustion by spark ignition and CI combustion by self-ignition are conducted. A crown surface includes a cavity recessed to have a bowl-shape; a pair of first raised portions having a mound-shape along a pent roof shape; and a second raised portion provided to protrude at a position orthogonal to a ridge extending direction of the pair of first raised portions. With a height of the first raised portion relative to a height position of a deepest portion of the cavity being represented as H1 and a height of the second raised portion being represented as H2, H1/H2 as a ratio of the height H1 of the first raised portion to the height H2 of the second raised portion is set to be in a range of 1.92 or more and 2.75 or less.

Combustion chamber structure for engine

A combustion chamber structure for an engine includes a combustion chamber where SI combustion by spark ignition and CI combustion by self-ignition are conducted. A crown surface includes a cavity recessed to have a bowl-shape, and a pair of raised portions. The cavity includes a bottom portion which is a lower region of the recessed part, the bottom portion having an outer circumferential edge which is circular in a top view. With a height of the raised portion relative to a height position of a deepest portion of the cavity being represented as H1 and a diameter of an outer circumferential edge of the bottom portion of the cavity being represented as D, H1/D as a ratio of the height H1 of the raised portion to the diameter D of the cavity is set to be in a range of 0.05 or more and 0.36 or less.

In an engine (), an ignition plug () is arranged between a first intake port () and a second intake port (). In a case where a downstream end portion () of the second intake port () is divided into a first intake port () side and an opposite first intake port () side, an inner wall surface () of an opposite first intake port () side portion extends in a direction toward the first intake port () as extending from an upstream side to a downstream side of the second intake port ().

Intake port structure for internal combustion engine

In an engine (), when an intake valve () opens, a downstream end portion () of a first intake port () extends to direct to between a shade back () positioned on a cylinder axis (C) side with respect to a valve stem () and a ceiling surface () facing the shade back (). As viewed in a section perpendicular to a direction perpendicular to an intake air flow direction, a second intake port side inner wall surface () at the downstream end portion () of the first intake port () curves apart from a second intake port () in a direction from an exhaust side to an intake side as compared to the shape of an opposite second intake port side inner wall surface () mirror-reversed to a second intake port () side.

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Hiroshima, Japan

Michiharu Kawano