Mazda Motor Corporation

Masatoshi Hidaka

Masanari Sueoka

Atsushi Inoue

Kazuhiro Nagatsu

Toshiaki Takahashi

Kota Matsumoto

Masahisa Yamakawa

Yusuke Kawai

Takashi Kaminaga

Tomonori Urushihara

Keiji Maruyama

Takuya Ohura

Tomohiro Nishida

Toru Miyamoto

Tatsuhiro Tokunaga

Toshiaki Nishimoto

Tomokuni Kusunoki

Keitaro Ezumi

Masami Nishida

Michiharu Kawano

Tetsuya Chikada

Akitomo Takagi

Naoya Watanabe

Kazuhiro Takemoto

Tota Tanii

Hiroaki Abe

Kazufumi Kumakura

Tadasu Hashiguchi

Tsubasa Ito

Tomohiro Hasegawa

An internal combustion engine is provided, which includes a variable phase mechanism configured to change rotational phases of intake and exhaust camshafts so that a valve overlap is made. An intake cam lobe is formed such that an open period of the intake valve is 210&#xb0; or larger and 330&#xb0; or smaller of a crank angle. The exhaust cam lobe is formed such that, during the overlap period with the rotational phase of the intake camshaft advanced to the maximum and the rotational phase of the exhaust camshaft retarded to the maximum, an effective valve lift amount (Lift(CA)) of the exhaust valve which is a function of a crank angle from the open timing (CA) of the intake valve to a middle timing (CA) of the overlap period, an inner circumferential length (L_ex) of a valve seat, and a swept volume (V) per cylinder satisfy the following formula: 

Internal combustion engine

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

When a specific condition requiring a rise in exhaust gas temperature is satisfied, a required fuel amount to be injected from an injector () is injected in a split manner, such that the fuel injection is divided to: a main injection (X) to be initiated a given period before a compression top dead center; an auxiliary injection (X) to be initiated after initiation of auto-ignited combustion of an air-fuel mixture consisting of air and the fuel injected by the main injection (X) and before an assumed peak timing (Pk') of a heat release rate (RH) from the combustion based on the main injection (X); and a post injection (X) to be initiated after the assumed peak timing (Pk&#x2032;) and before completion of combustion based on the main injection (X) and the auxiliary injection (X). This makes it possible to raise an exhaust gas temperature while sufficiently ensuring auto-ignitability and fuel economy performance.

Control system for gasoline engine

Disclosed is an engine control system which is designed to allow homogeneous-charge compression ignition combustion to be performed in an HCCI region (R) defined as an engine operating region including at least a partial-load range of an engine. In a low load zone (R) of the HCCI region (R), a lift amount of an intake valve () is set to a first predetermined value, and an exhaust valve () is allowed to start being opened during an intake stroke at a given timing later than an opening timing of the intake valve (). Further, in the medium load zone of the HCCI region, the lift amount of the intake valve () is gradually increased up to a second predetermined value greater than the first predetermined value, along with an increase in an engine load. The engine control system is capable of adequately controlling an amount of burned gas to be introduced into a cylinder, depending on the engine load to allow the HCCI combustion to be adequately performed in a wider engine load range.

Engine control system

There is provided a spark ignited internal combustion engine having a geometric compression ratio of 13.0 or greater. The engine comprises combustion chambers having a cylinder stroke volume of 0.3 liter or greater, with the spark plug in the chamber ceiling having its spark point in the combustion chamber, and a cavity being formed on the top surface of the piston. At least part of the cavity defines a spherical surface that a hypothetical sphere having its center at the spark point contacts when the piston is at top dead center. The cavity is formed so that V/V&#x2267;0.31, where Vis top-dead-center combustion chamber volume, and Vis the volume of the part of the hypothetical sphere not interfering with the combustion chamber floor or ceiling at top dead center. The flame thus spreads with less interference, shortening combustion duration and reducing fuel consumption.

Spark ignited internal combustion engine and manufacturing the same

Growing community of inventors

Higashihiroshima, Japan

Masatoshi Hidaka