Mazda Motor Corporation

Yoshihisa Nou

Noriyuki Ota

Kazuaki Narahara

Kazuo Ichikawa

Fumihiko Saito

Yuji Harada

Kenji Uchida

Masahiko Fujimoto

Akira Kageyama

Yuma Miyauchi

Osamu Aoki

Tsuguhisa Miyamoto

Xiyao Ge

Masahisa Yamakawa

Keiji Araki

Kazuhiro Nagatsu

Naoyuki Yamagata

Kouhei Iwai

Tatsuya Koga

Takeshi Nagasawa

Shuji Oba

Kazutoyo Watanabe

Naoya Watanabe

Hiroyuki Kurita

A method of controlling an engine is provided, which includes, during motoring of the engine, injecting, by an injector, fuel for analysis into a cylinder of the engine at a specific timing after an intake valve of the cylinder is closed. The method includes acquiring, by a controller, a crank angle period from a start timing of the fuel injection to a timing of a pressure inside the cylinder reaching a reference pressure, in response to signals of a crank angle sensor and an in-cylinder pressure sensor. The method includes determining, by the controller, a property of the fuel injected by the injector by comparing the acquired crank angle period with a reference crank angle period, the reference crank angle period being from an injection start timing when a standard fuel is injected into the cylinder to a timing of the pressure inside the cylinder reaching the reference pressure.

Motoring an engine and injecting fuel to determine fuel properties by measuring cylinder pressure

A method of controlling an engine is provided, which includes the steps of, during motoring of the engine, injecting, by an injector, fuel for analysis into a cylinder at a specific timing after an intake valve of the cylinder of the engine is closed, outputting to a controller, by an in-cylinder pressure sensor, a signal corresponding to a pressure inside the cylinder at least at a timing when a specific crank angle period has passed from the fuel injection timing, and determining, by the controller, a property of the fuel injected by the injector, by comparing a pressure value measured by the in-cylinder pressure sensor with a reference pressure value inside the cylinder measured at a timing when the specific crank angle period has passed after a standard fuel is injected into the cylinder at the specific timing.

Engine controlling method and engine system

A method of controlling an engine is provided, which includes the steps of injecting main fuel by a fuel injector during an intake stroke or a compression stroke, providing a mixture gas containing fuel and air inside a cylinder, applying by an ignition device a high voltage between electrodes of a spark plug at a timing when the mixture gas is not ignited, detecting a parameter related to a current value of an electric-discharge channel generated between the electrodes, determining by a controller whether the detected parameter is within a range between a first threshold and a second threshold to determine a flowing state of a vortex inside the cylinder, operating the spark plug to carry out a supplemental ignition when the parameter is determined to be outside the range, and igniting the mixture gas by operation of the spark plug after the supplemental ignition.

Method of controlling engine, and engine system

An engine controlling method is provided, which includes, during motoring of the engine, outputting, by an in-cylinder pressure sensor, to a controller a signal indicative of a reference pressure corresponding to a pressure change after an intake valve of a cylinder of the engine is closed when not performing fuel injection, and then injecting, by an injector, fuel for analysis into the cylinder at a specific timing after the intake valve is closed. The method includes, by the controller, acquiring a crank angle period from the intake valve close timing, through the fuel injection, to a timing of the in-cylinder pressure reaching the reference pressure based on signals from the in-cylinder pressure sensor and a crank angle sensor, and determining a property of the injected fuel by comparing the acquired crank angle period with that of a standard fuel based on stored information on a property of the standard fuel.

A method of controlling an engine is provided, the method including the steps of injecting main fuel by a fuel injector during an intake stroke or a compression stroke, providing a mixture gas containing fuel and air inside a cylinder, applying by an ignition device a high voltage between electrodes of a spark plug at a timing when the mixture gas is not ignited, detecting a parameter related to a current value of an electric-discharge channel generated between the electrodes, determining whether the detected parameter is within a range between a first threshold and a second threshold to determine a flowing state of a vortex inside the cylinder, injecting supplemental fuel by the fuel injector after the main fuel injection when the parameter is determined to be outside the range, and igniting the mixture gas by the ignition device using the spark plug after the supplemental fuel injection.

A combustion chamber structure for an engine includes a combustion chamber that is defined by a cylinder block, a cylinder head, and a piston. The cylinder head includes: a head body that has a lower surface opposing the combustion chamber; and a coat layer that covers the lower surface. The coat layer includes: a heat-insulating layer that is arranged in a region, which opposes a cavity, in the lower surface and has a lower thermal conductivity than the head body; a heat-shielding layer that is arranged to cover the lower surface and has a lower thermal conductivity than the head body and the heat-insulating layer; and a heat diffusion layer that is arranged between the heat-insulating layer and the heat-shielding layer and has a higher thermal conductivity. The heat diffusion layer includes a side end edge and an extending portion, each of which abuts the head body.

Combustion chamber structure for engine

An engine includes an output shaft, a cylinder block, a cylinder head, a cap portion, and head bolts. The cylinder block, the cylinder head, and the cap portion are fastened together with the head bolts. The cylinder block includes a cylinder portion and a plurality of output shaft supporting portions. When an outer wall face of at least one of the plurality of output shaft supporting portions is viewed along an output shaft axial direction, the outer wall face includes a first rib diagonally extending from a supporting portion of the output shaft toward one of two head bolt holes.

Engine

An engine includes an output shaft, a cylinder head, a cylinder block, and a plurality of head bolts. The cylinder block includes three or more cylinder parts, a plurality of connecting portions, a plurality of output shaft supporting parts, and a plurality of head bolt holes. A side wall face of at least one cylinder part includes a first rib. The first rib diagonally extends from the connecting portion toward a head bolt hole base.

Multi-cylinder engine

A combustion-chamber structure of an engine comprises a combustion chamber which is partitioned by a cylinder block, a cylinder head, and a piston. The piston includes a piston body having an upper surface facing the combustion chamber, a heat-insulation layer provided at least in a central area, in a radial direction, of the upper surface and having smaller heat conductivity than the piston body, a heat-barrier layer provided to cover the upper surface and having smaller heat conductivity than the piston body and the heat-insulation layer, and a heat-diffusion layer provided between the heat-insulation layer and the heat-barrier layer and having larger heat conductivity than the heat-insulation layer and the heat-barrier layer. The heat-diffusion layer comprises a side end edge and an extension portion which contact with the piston body.

Combustion-chamber structure of engine

A cylinder block includes a body part where a cylinder is formed, an outer wall part made of fiber reinforced resin and surrounding an outer circumference of the body part, and a metal member attached to the outer wall part. The outer wall part is comprised of an inner layer surrounding the outer circumference of the body part, and an outer layer surrounding an outer circumference of the inner layer. A density of reinforcing fiber contained in the outer layer is higher than a density of reinforcing fiber contained in the inner layer. The metal member is attached to the outer wall part so as to contact the outer layer. The reinforcing fiber contained in the outer layer has an electric insulating property.

Cylinder block

A cylinder block includes a metal body part having a cylinder, and an outer wall part made of fiber reinforced resin, surrounding an outer circumference of the body part. A part of the outer wall part at BDC side in a cylinder axis direction contacts a bottom wall forming part. The outer wall part is comprised of an inner layer surrounding the outer circumference of the body part, and an outer layer surrounding an outer circumference of the inner layer. A density of reinforcing fiber contained in the outer layer is higher than that in the inner layer. A thickness of a part of the inner layer at BDC side in the cylinder axis direction is greater than that of the TDC-side inner layer. A thickness of a part of the outer layer at TDC side in the cylinder axis direction is greater than that of the BDC-side outer layer.

A direct injection engine includes a fuel injection valve configured to inject fuel into a cylinder, a water injection valve configured to inject water into the cylinder, and a valve variable mechanism configured to change an operation timing of each of an intake valve and an exhaust valve. During an operation in a low load range, a negative overlap period when both of the intake valve and the exhaust valve are closed across an exhaust top dead center is formed by the valve variable mechanism, and fuel is injected from the fuel injection valve and water is injected from the water injection valve respectively during the negative overlap period. This causes a steam reforming reaction such that at least a part of injected fuel and injected water turns to hydrogen and carbon monoxide within the cylinder during the negative overlap period.

Direct injection engine and control method thereof

A homogeneous charge compression ignition engine includes a cylinder configured to accommodate a piston to be reciprocally movable, a fuel injection valve configured to inject fuel into the cylinder, a water injection valve configured to inject water into the cylinder, a fuel injection control module configured to inject fuel from the fuel injection valve into the cylinder at such a timing that a mixture of fuel and air is self-ignited in a latter stage of a compression stroke or in an initial stage of an expansion stroke, and a water injection control module configured to perform at least a basic water injection of injecting water from the water injection valve into the cylinder during a predetermined period, which starts concurrently with or after start of combustion by the self-ignition and which overlaps a combustion period.

Homogeneous charge compression ignition 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 shifted, with respect to the bore center of a cylinder, toward one end of an engine's output shaft. A top surface of a piston has inclined surfaces, and is raised by the inclined surfaces. A cavity is formed by hollowing out portions of the inclined surfaces, and faces the injection axis of the fuel injection valve. In a vertical cross section taken along the plane passing through a particular location in an intake other-side region of a combustion chamber and the location of the fuel injection valve, the distance from an injection tip of the fuel injection valve to the wall surface of the cavity at the particular location is longer than that from the injection tip to the wall surface at a diametrically opposed location to the particular location.

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Aki-gun, Japan

Yoshihisa Nou