Mazda Motor Corporation

Denso Corporation

Tatsuya Fujikawa

Masahisa Yamakawa

Takashi Youso

Takashi Kaminaga

Kazuhiro Nagatsu

Toshiaki Nishimoto

Mitsuhiro Muto

Takuma Fujii

Takaaki Nagano

Junki Hori

Naoya Ito

Yuta Sasaki

Ryohei Matsuo

Atsushi Inoue

Tomonori Urushihara

Kenji Uchida

Kouhei Iwai

Toshifumi Hayami

Takayuki Hikita

Yuuki Kawai

Noriyuki Ota

Noriyuki Iwata

Tomomi Watanabe

Yasushi Nakahara

Naohiro Yamaguchi

Masatoshi Seto

Kouji Shishime

Mitsunori Wasada

Tatsuya Koga

Tsuyoshi Yamamoto

Shuji Oba

Naoya Watanabe

Naoya Matsuo

Hiroyuki Kurita

Mikinori Ohashi

Takashi Yohso

Kiyotaka Sato

Hiroaki Abe

Shigeyuki Hirashita

Yoshiteru Nakayama

Daisuke Asaji

Takeaki Kudo

A control system for an engine including intake and exhaust valve phase variable devices and a control device is provided. At an engine temperature below a first determination temperature, the control is performed so that an exhaust valve close timing is at or retarded from the exhaust top dead center, an intake valve open timing is retarded from the exhaust valve close timing, and the fuel supply to the combustion chamber starts in an intake stroke on a retarding side of the exhaust valve close timing. At the engine temperature above the first determination temperature and below a second determination temperature, the control is performed so that a negative overlap with both the exhaust and intake valves closed during a period including the exhaust top dead center, or a positive overlap with both the exhaust and intake valves opened during a period including the exhaust top dead center, occurs.

Engine control system

An engine system is provided, including a controller which controls devices of an engine at a given engine speed so that, when a demanded engine load is a first load, a mass ratio (G/F) of intake air inside a cylinder (containing fresh air and burnt gas) to fuel is a first G/F and mixture gas inside the cylinder combusts by flame-propagation, when the demanded load is a second load (&#x3c;the first load), the G/F is a second G/F (&#x3e;the first G/F) and an injection center-of-gravity is at a timing such that the entire mixture gas combusts by CI combustion, and when the demanded load is between the first and second loads, the G/F is at a third G/F (between the first and second G/Fs) and the injection center-of-gravity is at a later timing such that at least part of the mixture gas combusts by the CI combustion.

Engine system

An engine system is provided, including a controller which estimates an intake-valve-closing temperature inside a cylinder. When an engine operates at a given speed and a demanded engine load is a first load or a second load (&#x3e;the first load), the controller controls so that a mixture gas inside the cylinder combusts by compression ignition, and controls so that, at the first load, the entire mixture gas combusts by compression ignition when the intake-valve-closing temperature is above a first temperature, and at least part of the mixture gas combusts by flame propagation when the intake-valve-closing temperature is below the first temperature, whereas at the second load, the entire mixture gas combusts by compression ignition when the intake-valve-closing temperature is above a second temperature (&#x3c;the first temperature), and at least part of the mixture gas combusts by flame propagation when the intake-valve-closing temperature is below the second temperature.

An engine system is provided, including a controller which estimates a mass ratio (G/F) of intake air inside a cylinder (containing fresh air and burnt gas) to fuel, and controls devices of an engine at a given engine speed so that, while a demanded engine load is a first load, at least part of a mixture gas inside the cylinder combusts by flame-propagation when the estimated G/F is below a first G/F, and the entire mixture gas combusts by compression ignition when the estimated G/F is above the first G/F, whereas while the demanded load is a second load (&#x3e;the first load), at least part of the mixture gas combusts by flame-propagation when the estimated G/F is below a second G/F (&#x3c;the first G/F), and the entire mixture gas combusts by compression ignition when the estimated G/F is above the second G/F.

A control device for a compression self-ignition engine includes a fuel injection system and an injection controller. While the engine is operated by CI combustion under a given first condition, a first injection is carried out in which fuel is injected at a first timing in a compression stroke and at which the fuel goes toward a part radially outward of a cavity formed in a crown surface of a piston, and a second injection is suspended. While the engine is operated by the CI combustion under a second condition in which a temperature inside a combustion chamber at a close timing of an intake valve becomes lower than the first condition, at least the second injection is carried out in which the fuel is injected at a second timing later than the first timing in the compression stroke and at which the fuel goes toward the cavity.

Control device for compression self-ignition engine

An engine includes: a piston including a cavity; a cylinder head configured so as to form a combustion chamber having a pent roof shape; a fuel injection valve configured to inject fuel from a second half of a compression stroke until a first half of an expansion stroke; and a spark plug arranged at a position corresponding to an upper side of the cavity. Injection openings which are arranged in a circumferential direction surrounding a longitudinal axis of the valve and through each of which the fuel is injected in a direction inclined relative to the longitudinal axis by a predetermined angle is formed such that when a height of a ceiling of the combustion chamber at a position corresponding to an edge end portion of the cavity in an injection direction of the injection opening is large, the injection angle of the injection opening is large.

Engine

An engine includes: a piston including a cavity; a cylinder head configured to form a combustion chamber having a pent roof shape; a fuel injection valve configured to inject fuel from a second half of a compression stroke until a first half of an expansion stroke; and a spark plug arranged at a position corresponding to an upper side of the cavity. Injection openings are arranged in a circumferential direction surrounding a longitudinal axis of the valve. The combustion chamber at a compression top dead center is divided into a plurality of fuel injection regions, located in respective injection directions of the injection openings, by vertical surfaces extending radially from the longitudinal axis through a middle between adjacent injection openings. When a volume of the fuel injection region located in the injection direction of the injection opening is large, an opening area of the injection opening is large.

A controller of a laser ignition engine configured to perform ignition by using a laser ignition device configured to emit a laser beam condensed by a lens includes: a combustion state related value acquiring portion configured to acquire a combustion state related value related to a combustion state of the engine; and a contamination determining portion configured to compare the combustion state related value acquired by the combustion state related value acquiring portion with a combustion state determining value to determine whether or not the laser ignition device is contaminated, the combustion state determining value being defined based on the combustion state of the engine when the laser ignition device is not contaminated.

Controller of laser ignition engine

Injection of the fuel by the injectorcreates a gas flow in the combustion chamber. The gas expands in a radial fashion from an axis of a cylinder toward a radial outside of the cylinder, and then flows from the radial outside along the cylinder head bottom facetoward the axis of the cylinder. The spark plughas a gap positioned away from the axis of the cylinder toward the radial outside of the cylinder at a predetermined distance, and placed radially inwardly from a position opposite a rim of an opening of the cavityA side electrode extends to be oriented in a direction perpendicular to the flow of the gas along the cylinder head bottom face. The gap has a center positioned near the cylinder head bottom face, and closer to an interior of a combustion chamber than to the cylinder head bottom face.

Internal combustion engine

An engine body includes a cylinder with a geometrical compression ratio of 15 or higher, and is supplied with fuel containing at least gasoline. When an operating mode of the engine body is in a high load range, a controller (i.e., a PCM) drives a fuel injection valve (i.e., an injector)to inject the fuel at a time within a retarded period between a terminal stage of a compression stroke and an initial stage of an expansion stroke in a low speed range. The controller drives the fuel injection valve to inject the fuel in an intake stroke until an intake valveis closed in a high-load high-speed range.

Control system and control method of spark ignition gasoline engine

The disclosure provides a control device of a spark-ignition gasoline engine. When an operating state of an engine body is within a low engine speed range, a controller controls a fuel pressure variable mechanism so that a fuel pressure is higher within a high engine load range compared to a low engine load range, the controller operates, within the high engine load range, a fuel injection valve to perform a fuel injection at least at a timing that is more retarded than an injection timing of a fuel within the low engine load range and is within a retard period from a late stage of a compression stroke to an early stage of an expansion stroke, and the controller operates, within the high engine load range, an ignition plug to ignite at a timing within the retard period and further after the fuel injection.

Control device of spark-ignition gasoline engine

A multi-hole injector directly injects fuel into a combustion chamber. Intake air is introduced into the combustion chamber through intake ports to provide tumble flow in the combustion chamber. A cavity is formed in a part of the top surface of a piston which is eccentric to the exhaust side. In the intake stroke, fuel injection ends in a downstroke of a piston. When the crank angle is 100 degrees after the top dead center in the intake stroke at which the fuel injection ends, a most downward lower spray collides with a part of the top surface of the piston which ranges on the intake side from the edge on the exhaust side of the cavity. A most upward upper spray does not come into contact with a spark plug. Thus, the fuel injection can enhance the tumble flow to promote homogeneous dispersion of fuel-air mixture in the combustion chamber.

Internal combustion engine of spark-ignition direct-injection type and fuel injecting method thereof

Disclosed is an internal combustion engine (A), which has a valve overlap period (T) during which an intake valve () and an exhaust valve () are opened, and a geometric compression ratio of 13.0 or greater. The engine (A) is designed to satisfy, at a center timing (Tc) of the valve overlap period (T), a conditional expression: S&#x2267;Swhere Sis a cross-sectional area of a combustion chamber () taken along any selected one of a plurality of mutually parallel hypothetical cutting-planes (IP) each of which extends parallel to a linear reciprocating direction (dor d) of at least one of the intake and exhaust valves () and passes through a valve head (or) of the at least one of the valves (), and Sis an effective opening area defined between the valve head (or) and a corresponding valve seat (or) in a region on an outward side of the combustion chamber () relative to the selected hypothetical cutting-plane (IP). The present invention can reliably improve combusted-gas scavenging efficiency and intake-air charging efficiency.

Disclosed is a direct-injection spark-ignition engine designed to promote catalyst activation during cold engine operation. A fuel injection timing for a fuel injection period in an compression stroke (second fuel injection period F2) is set to allow a first fuel spray Ga injected from a first spray holeto enter a cavityin a piston crown surface, and allow a second fuel spray Gb to impinge against a region of the piston crown surfacelocated closer to an injector than the cavity, so as to cause the second fuel spray Gb having a lowered penetration force due to the impingement to be pulled toward the cavityby a negative pressure generated in the cavityas a result of passing of the first fuel spray Ga therethrough. The direct-injection spark-ignition engine can maximally hold an injected fuel spray around a spark plug to reliably stabilize a combustion state in a combustion mode for promoting catalyst activation during cold engine operation, while enhancing combustion efficiency in a homogenous combustion mode during normal engine operation.

Direct-injection spark-ignition engine

Disclosed is an internal combustion engine, which has a geometric compression ratio of 13.0 or greater, and a combustion chamber () configured to satisfy a condition of S/V&#x2266;0.12 (mm) when a radius r of a hypothetical sphere (IS) with its center at an ignition point (CP) of a spark plug () is set to satisfy a condition of V=0.15&#xd7;V, where: S (mm) is an area of an interference surface between the hypothetical sphere (IS) and an inner wall of the combustion chamber () in a state when a piston () is at its top dead center position; V(mm) is a volume of the combustion chamberin the state when the piston () is at the top dead center position; and V(mm) is a volume of a non-interference part of the hypothetical sphere (IS) which is free of interference with the inner wall of the combustion chamber () when the piston () is at the top dead center position. The internal combustion engine of the present invention can more reliably improve fuel economy.

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Aki-gun, Japan

Tatsuya Fujikawa