Mazda Motor Corporation

Mazda Motor Corporat Ion

Satoshi Imamura

Masaki Fukuma

Atsushi Inoue

Kota Matsumoto

Yasushi Nakahara

Yuya Honda

Michiharu Kawano

Yoshiharu Ueki

Kento Onishi

Naohiro Yamaguchi

Mitsunori Wasada

Toshimasa Kotani

Futa Nishi

Ichiro Hirose

Yoshitaka Wada

Akihiro Noda

Masaaki Sato

Masayuki Kidokoro

Sakumi Haseto

Kazuo Isayama

Hisashi Kajikawa

Shohei Kimura

Yasuyuki Imano

Toshinobu Yoneya

Ryoko Motohiro

Yuichi Someno

Takahiro Iwai

Hiroyuki Hamamoto

Nobuhiko Tanaka

Takumi Uemura

Masaaki Okagawa

Keisuke Yamamoto

An engine is provided, which includes an engine body including a cylinder provided with intake and exhaust ports and intake and exhaust valves, intake and exhaust passages, a turbocharger including a turbine provided to the exhaust passage and a compressor provided to the intake passage, and a variable phase mechanism configured to change open/close timings of the intake valve while maintaining an open period of the intake valve at a 270&#xb0; C.A or larger. A geometric compression ratio of the cylinder is 11:1 or higher. In a high-load range, the variable phase mechanism sets the intake valve close timing to be after an intake BDC and to make a ratio of a retarded amount of the intake closing to the geometric compression ratio be 4.58 or above and 6.67 or below, and sets the intake valve open timing to be before a close timing of the exhaust valve.

Engine

An engine is provided, which includes an engine body including a plurality of cylinders, each of the cylinders being provided with an intake port, an exhaust port, an intake valve, and an exhaust valve, an intake passage and an exhaust passage connected to the engine body, and a turbocharger including a turbine provided to the exhaust passage and a compressor provided to the intake passage. A geometric compression ratio of the cylinder is 11:1 or higher. An open period of the intake valve is a range of 270&#xb0; or larger by a crank angle. The exhaust passage includes a plurality of independent exhaust passages, each communicating with the exhaust port of one cylinder or with the exhaust ports of two or more cylinders of which timings of exhaust strokes are discontinuous from each other, and connecting the engine body to the turbine.

An engine is provided, which includes a combustion chamber defined by a piston crown surface, an inner wall surface of a cylinder, and a pentroof ceiling surface formed in a cylinder head, and an ignition part of a spark plug disposed at the ceiling surface to achieve flame propagation combustion inside the combustion chamber. A cavity recessed in a spherical cap shape is formed in a central area of the crown surface. An opening of an intake port is formed in the ceiling surface (intake side) and an opening of an exhaust port is formed in the ceiling surface (exhaust side). When seen in a cross-sectional view taken along a cylinder axis, the ignition part is located above the cavity to be offset toward the exhaust side with respect to a cylinder axial line whereas a cavity center point is located to be offset toward the intake side.

Engine with combustion chamber

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 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.

Disclosed herein is a support structure for a rotary part of an engine (). The support structure includes crank journal bearing metals () and crank pin bearing metals (). Each crank journal bearing metal () includes chamfers () and crowned portions (). On the other hand, each crank pin bearing metal () includes chamfers () and no crowned portion or crowned portions () on its inner peripheral surface. The crowned portions () are inclined at a smaller angle than the crowned portions ().

Rotating part supporting structure for engine

A counterweight forms a crankshaft of an engine, and includes: an arm connecting a crank journal and crank pin of the crankshaft; a neck extending from a first connection face of the arm in a direction opposite to the crank pin; and a substantially fan-shaped weight continuous with a portion of the neck opposite to the crank journal. The weight has left and right shoulders continuous with the neck, and each of the shoulders is tilted to be away from the neck at an angle with respect to a horizontal line orthogonal to a crankshaft center when viewed along the crankshaft center, the angle being 15&#xb0; or more and 22.5&#xb0; or less.

Counterweight, and crankshaft with the counterweight

A connecting rod includes a rod having the form of a bar, a smaller end part, and a larger end part. The rod is provided with a friction generation portion at which friction is generated due to deformation of the rod.

Connecting rod of engine

A first balancer shaft includes a shaft extension portion extending forward, to which a driven sprocket is attached. A case member includes a first bearing portion supporting the balancer shaft near its weight portions and rotational gear and a second bearing portion supporting the same near its driven sprocket. The case member includes an upper case coupled to a cylinder block and a lower case facing to the upper case, and there is provided a case extension portion extending forward at the upper case. The first bearing portion is configured of a hole formed by half-split portions of the both cases and the second bearing portion is configured of a hole formed integrally at the case extension portion.

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Hiroshima, Japan

Satoshi Imamura