Mazda Motor Corporation

Kotaro Takahashi

Nobuo Yunoki

Masahiro Naito

Hiromu Sugano

Toru Kobayashi

Masahiro Tateishi

Kanae Fuki

Ryohei Karatsu

Takamitsu Miyahigashi

Jiro Yamasaki

Hiroshi Minamoto

Kenjiro Konomi

Atsushi Yamada

A system for controlling a compression ignition engine includes: a speed obtaining section which detects or estimates an engine speed achieved by combustion in an n-th cycle; and an injection amount setting section which sets, in a start period after the start of cranking, a fuel injection amount to be injected by injectors in an (n+1)-th cycle. If the engine speed achieved by the combustion in the n-th cycle falls in the resonance range, the injection amount setting section sets the fuel injection amount for an (n+1)-th cycle to be larger than the fuel injection amount injected when the engine speed is higher than or equal to an upper limit of the resonance range.

Method and device for controlling compression ignition engine

At start of an engine, a fuel injection amount is set to a jump-over injection amount if the engine speed obtained in each cycle is higher than or equal to a determination threshold value, which is set lower than a lower limit of a resonance speed range of powertrain by a predetermined reference value. If the engine speed is lower than the value, the fuel injection amount is set to a step-over injection amount that is smaller than the jump-over injection amount. This setting makes it possible to increase the engine speed such that the engine speed approaches the lower limit of the resonance speed range causing resonance in the powertrain, up to a predetermined range, and then causes the engine speed to jump straight to an engine speed which exceeds the resonance speed range, while in the process of increasing the engine speed by executing the combustion cycles.

Method and device for controlling starting of engine

A system for controlling a compression ignition engine includes: a speed obtaining section which obtains an engine speed; and an injection amount setting section which sets, in a start period after the start of cranking, a fuel injection amount to be injected by injectors in next and subsequent cycles. If an engine speed achieved by combustion in an (n&#x2212;1)-th cycle is higher than or equal to a determination threshold value and lower than a lower limit of the resonance range, the injection amount setting section sets the fuel injection amount for the n-th cycle to a jump-over injection amount, and sets the fuel injection amount for the (n+1)-th cycle to a resonance induction reducing amount, which is smaller than the jump-over injection amount.

An exhaust gas recirculation control device for an engine is provided. The device includes an EGR passage connecting an exhaust passage of the engine with an intake passage of the engine, an EGR amount adjustor for adjusting an EGR amount that is a recirculation amount of exhaust gas of the engine through the EGR passage, an adjustor controller for controlling the EGR adjustor to adjust the EGR amount, and a gear position detector for detecting a gear position of a transmission of a vehicle on which the engine is mounted. When the gear position detected by the gear position detector during an idle operation of the engine is a non-travel position, the adjustor controller performs an EGR amount increase control in which the EGR amount adjustor is controlled to increase the EGR amount to be higher than when the gear position is a travel position.

Exhaust gas recirculation (EGR) control device for engine including an EGR amount increase control

A cooling system for an engine is provided. The cooling system includes coolant flow paths including a first flow path and a second flow path and where coolant circulates, a coolant pump for circulating coolant within the coolant flow paths, a flow rate control valve for adjusting a flow rate of the coolant through the second flow path, a temperature detector for detecting a temperature of the coolant within the first flow path, and a valve controller for adjusting an opening of the flow rate control valve based on the temperature detected by the temperature detector. The first flow path passes through a cylinder head of the engine, and the second flow path branches from the first flow path and passes through auxiliary machinery of the engine.

Cooling system for engine

A cooling system for an engine is provided. The cooling system includes coolant flow paths including a first flow path and a second flow path and where coolant circulates, a coolant pump for circulating the coolant within the coolant flow paths, a flow rate control valve for adjusting a flow rate of the coolant through the second flow path, a temperature detector for detecting a temperature of the coolant within the first flow path, a valve controller for adjusting an opening of the flow rate control valve based on the temperature detected by the temperature detector, and an output level determiner for determining an output level of the engine based on at least one of a fuel injection amount for the engine and an engine speed.

An exhaust control apparatus for an engine is provided. The apparatus includes a turbocharger, a high-pressure exhaust gas recirculation (EGR) device, a low-pressure EGR device, and a flap controller. The turbocharger includes a turbine, a compressor, and movable flaps, and rotates the turbine by exhaust gas to drive the compressor so as to boost intake air. The high-pressure EGR device recirculates, within a first engine operating range, the exhaust gas from a position of an exhaust passage upstream of the turbine to a position of an intake passage downstream of the compressor. The low-pressure EGR device recirculates, within a second engine operating range, the exhaust gas from a position of the exhaust passage downstream of the turbine to a position of the intake passage upstream of the compressor. The flap controller controls flap openings.

Exhaust control apparatus for engine

A cooling system for an engine is provided. The cooling system includes an EGR device including an EGR passage for recirculating exhaust gas into an intake passage, an EGR valve for adjusting a flow rate of the recirculating exhaust gas, and an EGR cooler for cooling the recirculating exhaust gas, an EGR valve controller for controlling the EGR valve, coolant flow paths including a first flow path and a second flow path and where coolant circulates, a coolant pump for circulating coolant within the coolant flow paths, a flow rate control valve for adjusting a flow rate of the coolant through the second flow path, a temperature detector for detecting a coolant temperature within the first flow path, and a valve controller for adjusting a flow rate control valve opening based on the detected temperature.

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Hiroshima, Japan

Kotaro Takahashi