Mazda Motor Corporation

Denso Corporation

Kazuhiro Nagatsu

Takashi Youso

Masahisa Yamakawa

Kouhei Iwai

Takashi Kaminaga

Atsushi Inoue

Kenji Uchida

Takaaki Nagano

Yuji Harada

Ryohei Ono

Keiji Araki

Toru Miyamoto

Tatsuya Fujikawa

Mitsunori Wasada

Naoya Watanabe

Hiroyuki Kurita

Masayuki Kidokoro

Kota Matsumoto

Noriyuki Ota

Masatoshi Hidaka

Shuji Oba

Tomonori Urushihara

Junichi Taga

Toshifumi Hayami

Kazutoyo Watanabe

Takayuki Hikita

Hiroaki Abe

Yuuki Kawai

Hiroyuki Yamashita

Toshiaki Nishimoto

Yasushi Nakahara

Yoshihisa Nou

Tatsuya Koga

Tsuyoshi Yamamoto

Tadatomo Toda

Tadasu Hashiguchi

Daisuke Asaji

Hirotaka Suzuki

Mingzhao Xie

To effectively suppress strong knock that occurs in the operating region of high load and high rotation in a specific engine having a pre-chamber in a combustion chamber, the engine includes a piston that defines a combustion chamber together with a cylinder block and a cylinder head. The combustion chamber includes a sub-chamber and a main chamber separated from the sub-chamber by a pre-chamber. The specific ratio obtained by dividing a bore/stroke ratio of a cylinder by the volume of the sub-chamber is greater than or equal to 6.6 cmand less than or equal to 57.6 cm.

Engine

To meet both a request to improve the thermal efficiency in the medium load operation of an engine and a request to suppress knocking in the high load and high rotation operation of the engine, the engine includes a main combustion chamber including a cylinder block, a cylinder head, and a piston; a pre-chamber having a plurality of injection holes that are open into the main combustion chamber; and a spark plug that ignites an air-fuel mixture in the pre-chamber. A compression ratio of the main combustion chamber is not less than 14 and not more than 24. A second index that is a product between a volume of the pre-chamber and the compression ratio is not less than 1.03 cmand not more than 5.92 cm.

To meet both a request to improve the thermal efficiency in the medium load operation of an engine and a request to suppress knocking in the high load and high rotation operation of the engine, the engine includes a main combustion chamber comprising a cylinder block, a cylinder head, and a piston; a pre-chamber having a plurality of injection holes that open into the main combustion chamber; and a spark plug that ignites an air-fuel mixture in the pre-chamber. A compression ratio of the main combustion chamber is not less than 14 and not more than 24. A first index, which is the product between a total cross-sectional area of the plurality of injection holes and the compression ratio, is not less than 0.1496 cmand not more than 0.8449 cm.

To effectively suppress strong knock that occurs in the operating region of high load and high rotation in a specific engine having a pre-chamber in a combustion chamber, the engine includes a piston that defines a combustion chamber together with a cylinder block and a cylinder head. The combustion chamber includes a sub-chamber and a main chamber separated from the sub-chamber by a pre-chamber. The specific ratio obtained by dividing a volume of the sub-chamber by a stroke volume of a cylinder is greater than or equal to 0.00005 and less than or equal to 0.00045.

An engine system includes an engine, a main combustion chamber formed by a cylinder head and a piston, an auxiliary chamber formed with a communicating hole communicating with the main combustion chamber, an injector configured to inject fuel into the main combustion chamber, an ignition plug provided to the auxiliary chamber and configured to ignite a mixture gas inside the auxiliary chamber, an accelerator opening sensor, and a control device. The control device controls the injector so that an air-fuel ratio of the mixture gas inside the auxiliary chamber becomes a first air-fuel ratio when an engine load range is a first range, and the air-fuel ratio of the mixture gas inside the auxiliary chamber becomes a second air-fuel ratio leaner than the first air-fuel ratio when the engine load range is a second range where the engine load is higher than in the first range.

Engine system

A control device for a compression self-ignition combustion engine is provided, which includes a variable valve operating system configured to introduce internal exhaust gas recirculation (EGR) gas into a combustion chamber, a boosting system configured to boost intake air, a controller configured to control the valve operating system, and a sensor connected to the controller and configured to detect a parameter related to an operating state of the engine. An operation mode of the valve operating system is switchable between first and second modes. The boosting system boosts the intake air when an engine load is higher than a given load, and does not boost when lower than the given load. When the engine load is high, the controller controls the valve operating system to operate in the first mode, and when the load is low, the controller controls the valve operating system to operate in the second mode.

Control device of 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.

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.

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

A controller injects fuel into a cylinder at a high fuel pressure of 30 MPa or higher, at least in a period between a terminal stage of a compression stroke and an initial stage of an expansion stroke when an operating mode of an engine body is at least in a first specified sub-range of a low load range, and at least in a second specified sub-range of a high load range. The controller sets an EGR ratio in the first specified sub-range to be higher than an EGR ratio in the second specified sub-range, and advances start of fuel injection in the first specified sub-range to start of fuel injection in the second specified sub-range.

Spark-ignition direct-injection engine

A control device of a compression-ignition engine is provided. The device includes an engine having a cylinder, a fuel injection valve for injecting a fuel, an exhaust valve mechanism for switching an operation mode of an exhaust valve between a normal mode and an open-twice mode, a throttle valve disposed on an intake passage, and a controller for operating the engine by compression-ignition combustion of mixture gas inside the cylinder at least within a low engine load range. The controller suspends the fuel injection by the fuel injection valve when a predetermined fuel cut condition is met while the engine decelerates, and the controller fully closes the throttle valve and controls the exhaust valve mechanism to operate in the open-twice mode during the fuel cut. When a predetermined fuel resuming condition is met, the controller restarts the fuel injection, opens the throttle valve, and causes the compression-ignition combustion.

Control device of compression-ignition engine

A control device for a compression ignition engine includes a controller configured to operate an engine body by compression ignition combustion when the engine body operates in a compression ignition range. When the engine body operates in a low load range with a load lower than a predetermined load in the compression ignition range, the controller sets a time of fuel injection with the fuel injection valve in a first half of a compression stroke or earlier, and allows the ozonator to introduce the ozone into the cylinder. When the engine body operates in the low load range, the controller controls an ozone concentration to be lower at a higher speed than at a low speed.

Control device for compression ignition-type engine

A control device of an engine is provided. The engine is operated at a high compression ratio, a geometric compression ratio of the engine being 14:1 or higher. The control device includes a fuel injection controller for controlling a fuel injector of the engine to start a fuel injection in a latter half of a compression stroke within an engine operating range where an engine speed is below a predetermined value and an engine load is above a predetermined value, and an ignition controller for controlling an ignition plug of the engine to retard an ignition timing when a timing for the fuel injection controller to start the fuel injection is on a retarding side of a predetermined timing, the ignition timing being retarded based on a retarding amount of the fuel injection start timing from the predetermined timing.

Control device of engine

A control device for a compression ignition engine includes a controller configured to operate an engine body by compression ignition combustion when the engine body operates in a predetermined compression ignition range. When the engine body operates in a predetermined high load range of the compression ignition range, the controller maximizes a filling amount of the cylinder using a gas state adjustment system, and lowers an EGR ratio so that the air-fuel mixture in the cylinder is lean with an excess air ratio &#x3bb; higher than 1 in a lower speed range, and maximizes the filling amount of the cylinder, and increases the EGR ratio so that the air-fuel mixture in the cylinder has the excess air ratio &#x3bb; of 1 or lower in a higher speed range than the lower speed range.

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.

Growing community of inventors

Hiroshima, Japan

Kazuhiro Nagatsu