Mazda Motor Corporation

Toshiaki Takahashi

Masanari Sueoka

Masatoshi Hidaka

Atsushi Inoue

Junichi Taga

Kouhei Iwai

Kota Matsumoto

Keiji Maruyama

Takuya Ohura

Yusuke Kawai

Tomohiro Nishida

Tatsuhiro Tokunaga

Tomokuni Kusunoki

Keitaro Ezumi

Masami Nishida

Tetsuya Chikada

Akitomo Takagi

Kazuhiro Takemoto

Kazufumi Kumakura

Tadasu Hashiguchi

Tomohiro Hasegawa

A method of implementing control logic of a compression-ignition engine is provided. A controller outputs a signal to a injector and a variable valve operating mechanism so that a gas-fuel ratio (G/F) becomes leaner than a stoichiometric air fuel ratio, and an air-fuel ratio (A/F) becomes equal to or richer than the stoichiometric air fuel ratio, and to an ignition plug so that unburnt mixture gas combusts by self-ignition after the ignition plug ignites mixture gas inside a combustion chamber. The method includes steps of determining a geometric compression ratio and determining the control logic defining an intake valve close timing IVC. IVC (deg.aBDC) is determined so that the following expression is satisfied: if the geometric compression ratio &#x3b5; is 10&#x2264;&#x3b5;&#x3c;17,0.4234&#x3b5;&#x2212;22.926&#x3b5;+207.84++22.926&#x3b5;&#x2212;167.84+where C is a correction term according to an engine speed NE (rpm),&#x2212;1.0&#xd7;10+7.0&#xd7;10

Method of implementing control logic of compression-ignition engine

Disclosed is a control device for a multi-cylinder engine having a combustion chamber () to which an intake port () and an exhaust port () are connected. The control device comprises: an intake-side variable valve operating mechanism () for controlling a lift timing of two intake valves () of the intake port (); an exhaust-side variable valve operating mechanism () for controlling a lift timing of an exhaust valve (); and an exhaust-side valve operating mechanism () for driving an exhaust valve () at a fixed timing. The control device is operable, when executing cylinder deactivation in a low engine load and low engine speed operating range, to cause the exhaust-side variable valve operating mechanism () to open the exhaust valve () during downward movement of a piston () in a cylinder () being subjected to the cylinder deactivation.

Controller for multi-cylinder engine

A PCM () selects one of a CI mode or an SI mode based on the operating conditions of the engine (). In the CI mode, the engine () is operated by compression ignition combustion. In the SI mode, the engine () is operated by spark ignition combustion. if, while the engine () is being operated in the CI mode, a determination is made that an estimated value (Tc) of the catalyst temperature is lower than or equal to a warming start temperature (Ts), the PCM () further performs first warming control to assign four cylinders () as CI and SI cylinders, which perform the compression ignition combustion and the spark ignition combustion, respectively, such that the four cylinders () alternately perform the compression ignition combustion and the spark ignition combustion in accordance with the order of combustion of the cylinders.

Engine control device

A control device of a spark-ignition engine is provided. The control device includes a main body of the engine, a fuel injection valve, an ignition plug, and a controller. According to an operating state of the engine, the controller switches an ignition mode between a compression-ignition mode in which compression-ignition combustion is performed by causing the mixture gas to self-ignite and combust, and a spark-ignition mode in which spark-ignition combustion is performed by igniting the mixture gas with the ignition plug to combust. The controller switches the ignition mode from the spark-ignition mode to the compression-ignition mode by performing a transition mode in which a temperature inside the cylinder is forcibly decreased and combustion is performed.

Control device of spark-ignition engine

A control device of a spark-ignition engine is provided. The control device includes a main body of the engine, a fuel injection valve, an ignition plug, and a controller. According to an engine operating state, the controller switches between a compression-ignition mode in which compression-ignition combustion is performed, and a spark-ignition mode in which spark-ignition combustion is performed. The controller switches from the spark-ignition mode to the compression-ignition mode by performing in order, a first stage where an air-fuel ratio of mixture gas is set to a predetermined value and the spark-ignition combustion is performed, a second stage where the air-fuel ratio of the mixture gas is set leaner than the first stage and the compression-ignition combustion is performed, and a third stage where the air-fuel ratio of the mixture gas is set richer than the second stage and the compression-ignition combustion is performed.

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Hiroshima, Japan

Toshiaki Takahashi