Mazda Motor Corporation

Mazda Motor Corporat Ion

Masayoshi Higashio

Kenko Ujihara

Yugou Sunagare

Yuto Matsushima

Yuta Masuda

Kensuke Ashikaga

Yuichiro Tsumura

Daisuke Tanaka

Hiroki Morimoto

Shinji Takayama

Michio Ito

Yukio Haizaki

Taiki Maiguma

Akira Tsuda

Kenichi Nakashima

Takafumi Nishio

Keitaro Ezumi

Ken Yoshida

Taketoshi Yamauchi

Mitsunori Wasada

Jiro Kato

Takuji Okumura

Ryo Yamamoto

Haruna Yanagida

Kenji Takami

An exhaust gas recirculation (EGR) passage is connected with an intake passage (a bypass passage bypassing a supercharger) of an engine. The EGR passage includes, in a position close to a connection port to the intake passage, an expanding portion in which a passage cross-sectional area expands and which lowers a flow speed of EGR gas so as to reduce an uneven flow, in the connection port, of the EGR gas flowing into the intake passage.

Air intake device for engine

A control system for a compression ignition engine is provided, which includes a combustion chamber, a throttle valve, an injector, an ignition plug, a sensor, and a controller. A changing module outputs a signal to the throttle valve so that an air amount increases more than before the change demand, outputs to the injector a signal to increase the fuel amount according to the increase in the air amount so that an air-fuel ratio of the mixture gas becomes a stoichiometric air-fuel ratio or a substantially stoichiometric air-fuel ratio, and performs a torque adjustment so that an increase of the engine torque caused by the increase in the fuel amount is reduced. When the air amount is determined to have reached a given amount, the changing module ends the increasing of the fuel amount and the torque adjustment, and permits that a second mode module starts the second mode.

Control system for compression ignition engine

A control system for a compression ignition engine includes a combustion chamber, a throttle valve, an injector, an ignition plug, an EGR system, a sensor device and a controller. The controller includes a first mode module, a second mode module and a changing module configured to change an engine mode from a first mode to a second mode in response to a change demand. The changing module outputs signals to the throttle valve and the injector in response to the demand so that an air-fuel ratio of mixture gas becomes a stoichiometric air-fuel ratio or a substantially stoichiometric air-fuel ratio, and outputs a signal to the EGR system so that an EGR gas amount decreases more than before the demand, and when the EGR gas amount is determined to be decreased to a given amount, the changing module permits that the second mode module starts the second mode.

A control system for a compression ignition engine is provided, which includes a combustion chamber, a throttle valve, an injector, an ignition plug, a sensor, and a controller. A changing module of the controller outputs a signal to the throttle valve so that an air amount increases more than before a demand of changing from a first mode to a second mode, and outputs to the injector a signal to increase a fuel amount according to the air amount increase so that an air-fuel ratio of mixture gas becomes at or substantially at a stoichiometric air-fuel ratio, and outputs to the ignition plug a signal to retard an ignition timing so that an engine torque increase caused by the fuel amount increase is reduced. The changing module reduces the retarding of the ignition timing when the ignition timing is determined to have reached a retard limit.

A control system for a compression ignition engine is provided, which includes a sensor and a cylinder count control module which changes between all-cylinder and reduced-cylinder operations when the compression ignition combustion is performed at a given lean air-fuel ratio. The cylinder count control module executes a preparation control to change from the all-cylinder operation to the reduced-cylinder operation when the change is demanded. In the preparation control, the cylinder count control module outputs a signal to a throttle valve to execute an air amount increase processing, outputs a signal to a fuel injection valve to execute a fuel amount increase processing, and outputs a signal to an ignition plug to execute a retard processing. The cylinder count control module ends the fuel amount increase processing and the retard processing when it is determined that an air-fuel ratio is in a given air-fuel ratio state, and starts the reduced-cylinder operation.

Control device for compression ignition engine

A control system for a compression ignition engine configured to start compression ignition combustion by igniting mixture gas formed by injecting fuel into combustion chambers is provided, which includes combustion chambers each defined in respective cylinders so that displacements of the combustion chambers change by respective pistons reciprocating, a throttle valve, ignition plugs, injectors, a sensor having measuring parts including an atmospheric-pressure detector configured to detect an atmospheric pressure, and configured to measure parameters related to operation of the engine, and a controller. The controller executes a lean compression ignition combustion control in which compression ignition combustion is performed at a given lean air-fuel ratio higher than a stoichiometric air-fuel ratio. The controller restricts the execution of the lean compression ignition combustion control when the controller determines that the atmospheric pressure is lower than a given threshold based on a signal outputted from the atmospheric-pressure detector.

A control device for a compression-ignition engine in which partial compression-ignition combustion including spark ignition (SI) combustion performed by combusting a portion of a mixture gas inside a cylinder by spark-ignition followed by compression ignition (CI) combustion performed by causing the remaining mixture gas to self-ignite is executed at least within a part of an engine operating range is provided, which includes a detector configured to detect a given parameter that changes as combustion progresses inside the cylinder, an A/F (air-fuel ratio) controller configured to change an air-fuel ratio of air to fuel introduced into the cylinder, and a combustion controller configured to determine combustion stability based on the detected parameter of the detector and control the A/F controller to reduce the air-fuel ratio when it is confirmed that during the partial compression-ignition combustion the combustion stability is low.

Control device for compression-ignition engine

A control system for a compression ignition engine is provided, which includes a combustion chamber, a throttle valve, an injector, an ignition, a swirl control valve, a sensor and a controller. The controller is configured to execute a first mode module, a second mode module, and a changing module to change an engine mode from a first mode to a second mode in response to a change demand. The changing module outputs signals to the throttle valve and the injector in response to the demand so that an air-fuel ratio of mixture gas becomes a stoichiometric air-fuel ratio, and outputs a signal to the swirl control valve so that an EGR gas amount decreases more than before the demand, and when the EGR gas amount is determined to be decreased to a given amount, the changing module causes the second mode module to start the second mode.

A control device for a compression-ignition (CI) engine in which partial CI combustion including spark ignition (SI) combustion performed by combusting a portion of mixture gas inside a cylinder by spark ignition followed by CI combustion performed by causing the rest of the mixture gas inside the cylinder to self-ignite is executed within a part of an engine operating range, is provided, including an EGR (exhaust gas recirculation) controller configured to change an EGR ratio, and a combustion controller configured to control the EGR controller during the partial compression-ignition combustion to switch a combustion mode between first and second modes in which the EGR ratio is higher than the first mode. After the first mode is switched to the second mode, if a condition is satisfied, the combustion controller causes the resumption to the first mode after a given period of time has elapsed from the switching.

A control device for a compression-ignition engine is provided, in which partial compression-ignition combustion including spark ignition (SI) combustion performed by combusting a portion of mixture gas inside a cylinder by spark-ignition followed by compression ignition (CI) combustion performed by causing the rest of the mixture gas inside the cylinder to self-ignite is executed within a part of an operating range of the engine. The device includes a detector configured to detect a parameter related to noise caused by the combustion inside the cylinder, an EGR (exhaust gas recirculation) controller configured to change an EGR ratio being a ratio of exhaust gas introduced into the cylinder, and a combustion controller configured to control the EGR controller to increase the EGR ratio when a noise index value specified based on the detected parameter of the detector is confirmed to exceed a given threshold during the partial compression-ignition combustion.

A control device for an engine in which partial compression-ignition combustion including SI combustion performed by forcibly combusting a portion of mixture gas inside a cylinder followed by CI combustion performed by causing the rest of the mixture gas inside the cylinder to self-ignite is executed within a part of an operating range of the engine, is provided. The device includes a detector configured to detect a parameter related to noise caused by the combustion inside the cylinder, a memory configured to store a characteristic defining a relationship between a start timing of the CI combustion and a combustion noise index, and a processor configured to specify a given combustion noise index value based on the detection value of the detector, and control the start timing of the CI combustion.

Control device for engine

An engine system includes: a hydraulic valve stop mechanism configured to switch states of an intake valve and exhaust valve of a same stopped cylinder; a hydraulic pressure changing device configured to change hydraulic pressure supplied to the valve stop mechanism; and a valve control portion configured to control the hydraulic pressure changing device. When a return from a reduced-cylinder operation to an all-cylinder operation is requested, and an engine revolution is less than a reference revolution, the hydraulic pressure is changed such that opening of one of the valves of the stopped cylinder able to restart at an earlier stage is first restarted. When the return is requested, and the engine revolution is not less than the reference revolution, the hydraulic pressure is changed such that opening of the exhaust valve of the stopped cylinder is restarted before opening of the intake valve.

Engine system with valve stop

A control method of a turbocharged engine includes: a bypass passage bypassing a compressor; and a bypass valve configured to open and close the bypass passage. The method includes: a compressor flow rate predicting step of predicting a flow rate of air flowing through the compressor after a predetermined time; a compressor pressure ratio detecting step of detecting a pressure ratio of the compressor; a surging determining step of determining whether or not surging occurs after the predetermined time, in reference to preliminary prepared surging determination data based on the compressor predicted flow rate and the compressor pressure ratio; and a bypass valve controlling step of opening the bypass valve when it is determined in the surging determining step that the surging occurs and closing the bypass valve when it is determined in the surging determining step that the surging does not occur.

Method of controlling turbocharged engine and control device of turbocharged engine

Provided are a valve stop mechanism capable of switching intake valves and exhaust valves of deactivated cylinders between an openable/closable state and a closed state, and an engine speed control unit which controls the engine speed. The engine speed control unit controls the engine speed in such a manner that the amount of change in the engine speed with respect to time is reduced, as compared with a case in which a specific condition is not satisfied, when the specific condition that switching by the valve stop mechanism is not completed, and that connection between an engine and a power transmission unit is released is satisfied after issuance of a switching request from one of a reduced-cylinder operation and an all-cylinder operation to the other thereof.

Engine control device

When a difference between a target intake air amount during the reduced-cylinder operation, which is greater than a target intake air amount during the all-cylinder operation in a normal state, and an actual intake air amount is greater than an allowable deficient intake air amount, a preparatory control for increasing the actual intake air amount and shifting an ignition timing toward a retard side with respect to an ignition timing during the all-cylinder operation in the normal state. Then, at a time when the difference between the target intake air amount and the actual intake air amount becomes equal to or less than the allowable deficient intake air amount, the reduced-cylinder operation is started, wherein the allowable deficient intake air amount is set to a larger value when a current speed stage is a high speed stage than when it is a low speed stage.

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Hiroshima, Japan

Masayoshi Higashio