Mazda Motor Corporation

Naoya Ito

Masahisa Yamakawa

Tatsuya Fujikawa

Takashi Kaminaga

Mitsuhiro Muto

Takuma Fujii

Junki Hori

Ryohei Matsuo

Yuta Sasaki

Takashi Youso

Kenji Uchida

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.

Growing community of inventors

Aki-gun, Japan

Naoya Ito