Abstract: A method of implementing control logic of a compression ignition engine is provided. The engine includes an injector, a variable valve operating mechanism, an ignition plug, at least one sensor, and a processor. The processor outputs the signal to the ignition plug in a specific operating state so that unburnt mixture gas combusts by self ignition after the ignition plug ignites the mixture gas inside a combustion chamber. The method includes determining a geometric compression ratio ? of the engine, and determining control logic defining a valve opening angle CA of an intake valve. The valve opening angle CA (deg) is determined so that the following expression is satisfied, if the geometric compression ratio ? is ?<14, ?40?+800+D?CA?60??550+D. Here, D is a correction term according to the engine speed NE (rpm), D=3.3×10?10NE3?1.0×10?6NE2+7.0×10?4NE.

Abstract: A control device is provided for an engine in which premixed compression ignition combustion is carried out. The device includes an air amount adjusting mechanism, a variable valve mechanism, an exhaust choke valve, a water temperature sensor, and a processor. The processor controls the variable valve mechanism so that a valve overlap period of a given amount or more is formed in a low-load range where the engine load is low, and controls an injector, the air amount adjusting mechanism, and the exhaust choke valve so that A/F lean mixture gas is formed inside a combustion chamber, and premixed compression ignition combustion of the mixture gas is carried out. During the operation in the low-load range, the combustion controlling module makes an opening of the exhaust choke valve when a temperature parameter is low, smaller than that when the temperature parameter is high.

Abstract: A control device is provided for an engine in which SPCCI combustion is carried out in which SI combustion of a portion of a mixture gas is performed by jump-spark ignition, and CI combustion of the remaining mixture gas is performed by self-ignition. When the engine is low load and a temperature is less than a given value, an early injection in which fuel is injected during an intake stroke and a retarded injection in which fuel is injected during the second half of a compression stroke are performed, and SPCCI combustion of A/F-lean mixture gas is performed. When the engine is low load and the temperature is greater than or equal to the given value, an injection amount ratio of the early injection is increased and the ratio of the retarded injection is decreased, and SPCCI combustion of A/F-lean mixture gas is performed.

Abstract: A control device for a compression-ignition engine is provided, which includes an engine having a plurality of cylinders, spark plug, a fuel injector, and a control unit connected to the spark plug and the fuel injector. The control unit causes the engine to perform an all-cylinder operation when the engine operates at a load above a given load, and perform a reduced-cylinder operation at a load below the given load. In the reduced-cylinder operation, the fuel injector injects fuel to one or some of the cylinders to generate mixture gas, the spark plug ignites the mixture gas, and the engine starts, at an air-fuel ratio larger than a stoichiometric air-fuel ratio and a large compression ratio, SI combustion in which the mixture gas is ignited to combust by flame propagation, and then perform CI combustion in which unburned mixture gas ignites by self-ignition.

Abstract: A combustion control device for an engine includes a plurality of cylinders, a surge tank disposed in an intake path to the cylinders, an independent intake passage connecting the surge tank and an intake port of each of the cylinders, a fuel injection valve that is disposed for each of the cylinders and that supplies fuel into each of the cylinders, and a control unit that controls a fuel injection amount of each of the fuel injection valves according to an engine operating state. The control unit corrects a target fuel injection amount of each of the cylinders, the target fuel injection amount being determined according to the engine operating state, based on a re-intake correction amount set in each of the cylinders according to a re-intake amount of intake air from the intake port in internal EGR in each of the cylinders.

Abstract: The control apparatus for a compression ignition type engine includes a plurality of cylinder inner pressure sensors that detect pressure in each cylinder, and a combustion control unit. The combustion control unit corrects a target fuel injection amount of each cylinder by an injector based on a deviation between a predicted combustion period that is a period from an ignition timing by an ignition plug to a predetermined mass combustion timing and that is obtained based on a preset combustion model, and an actual combustion period that is a period from the ignition timing by the ignition plug to an actual combustion timing and that is obtained based on cylinder inner pressure, such that the period from the ignition timing by the ignition plug to the predetermined mass combustion timing, which is the timing when fuel having a predetermined mass ratio combusts, is equalized in each cylinder.

Abstract: A compression-ignition engine control system is provided, which includes an intake phase-variable mechanism and a controller. The controller controls the intake phase-variable mechanism to form a gas-fuel ratio (G/F) lean environment in which burnt gas remains inside a cylinder and an air-fuel ratio is near a stoichiometric air-fuel ratio, and controls the spark plug to spark-ignite the mixture gas to combust in a partial compression-ignition combustion. The controller controls the intake phase-variable mechanism to retard, as an engine speed increases at a constant engine load, an intake valve close timing on a retarding side of BDC of intake stroke and an intake valve open timing on an advancing side of TDC of exhaust stroke, and controls the intake phase-variable mechanism so that a change rate in the intake valve open timing according to the engine speed becomes larger in a high engine speed range.

Abstract: A compression-ignition engine control system is provided, which includes an intake variable mechanism and a controller. Within a first operating range and a second operating range on a higher engine load side, the controller controls the variable mechanism to form a gas-fuel ratio (G/F) lean environment in which an air-fuel ratio inside a cylinder is near a stoichiometric air-fuel ratio and burnt gas remains inside the cylinder, and controls a spark plug to spark-ignite mixture gas inside the cylinder to combust in a partial compression-ignition combustion. The controller controls the variable mechanism to advance the intake valve open timing on an advancing side of a TDC of the exhaust stroke, as the engine load increases within the first range, and retard the intake valve open timing on the advancing side of the TDC of the exhaust stroke, as the engine load increases within the second range.

Abstract: 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 ? is 10??<17, 0.4234?2?22.926?+207.84+C?IVC??0.4234?2+22.926??167.84+C where C is a correction term according to an engine speed NE (rpm), C=3.3×10?10NE3?1.0×10?6NE2+7.0×10?4NE.

Abstract: A method of implementing control logic of a compression-ignition engine is provided. A control part of the engine performs a calculation according to the control logic corresponding to an engine operating state in response to a measurement of a measurement part, controls a fuel injection part, a variable valve operating mechanism, an ignition part and a supercharger so that a G/F becomes leaner than a stoichiometric air fuel ratio and a A/F becomes equal to or richer than the stoichiometric air fuel ratio, while causing the supercharger to boost, and controls the ignition part so that unburnt mixture gas combusts by self-ignition after the ignition. The method includes determining a supercharging pressure P, and determining control logic defining a close timing IVC of an intake valve. When determining the control logic, the close timing IVC (deg.aBDC) is determined so that the supercharging pressure P (kPa) satisfies the following expression: P?8.0×10?11IVC6?1.0×10?8IVC5+3.0×10?7IVC4?4.0×10?6IVC3+0.

Abstract: A compression-ignition engine control system is provided, which includes an intake phase-variable mechanism and a controller. Within a first operating range and a second operating range on a higher engine load side, the controller controls the variable mechanism to form a gas-fuel ratio (G/F) lean environment in which an air-fuel ratio inside a cylinder is near a stoichiometric air-fuel ratio and burnt gas remains inside the cylinder, and controls a spark plug to spark-ignite mixture gas inside the cylinder to combust in a partial compression-ignition combustion. The controller controls the variable mechanism to retard the intake valve open timing on an advancing side of TDC of an exhaust stroke, as the engine load increases within the first range, and advance the intake valve close timing on a retarding side of TDC of intake stroke, as the engine load increases within the second range.

Abstract: A control device for an engine is provided, which includes a combustion controlling module, and an ignition retard determining module configured to determine whether there is a request for an ignition retard for retarding an ignition timing of an ignition plug. When the controlling module controls the ignition plug and an injector so that the SPCCI combustion is performed and there is not the ignition retard request, the controlling module executes a control in which the entire fuel to be injected in one cycle is injected in an intake stroke and a jump-spark ignition is carried out at a basic ignition timing, and when there is the ignition retard request, the controlling module executes a control in which an injection is performed in an intake stroke, a portion of the entire fuel is injected in a compression stroke, and the ignition timing is retarded from the basic ignition timing.

Abstract: A control device for an engine is provided, which includes a fuel injector attached to the engine, a spark plug disposed to be oriented into a combustion chamber, a swirl control valve provided in an intake passage, and a controller connected to the fuel injector, the spark plug, and the swirl control valve and configured to control the fuel injector, the spark plug, and the swirl control valve. The swirl control valve closes in a given operating state of the engine. The fuel injector injects fuel after the swirl control valve is closed, between intake stroke and an intermediate stage of compression stroke. The fuel injector injects the fuel after the first fuel injection. The spark plug performs the ignition after the second fuel injection so that the mixture gas starts combustion by flame propagation and then unburned mixture gas self-ignites.

Abstract: A control system of a compression-ignition engine includes an intake variable mechanism and a controller. In a second operating range, the controller controls the intake variable mechanism so that, while partial compression-ignition combustion is performed under an air-fuel ratio (A/F) lean environment, an intake valve open timing takes timing at an advanced side of an exhaust TDC. In a first operating range on a lower load side, the controller controls the intake variable mechanism so that, while the partial compression-ignition combustion is performed under the A/F lean environment, under the same engine speed condition, the intake valve close timing is more retarded within a range on a retarded side of an intake BDC as the engine load decreases, and an absolute value of a change rate of the intake valve close timing to the engine load becomes larger than in the second range.

Abstract: A control system of a compression-ignition engine which performs SPCCI combustion in which mixture gas is ignited with a spark plug to be partially combusted by SI combustion and the rest of mixture gas self-ignites to be combusted by CI combustion, is provided. When the engine is operated at least in a given first operating range, a controller of the device controls a variable intake mechanism so that an A/F lean environment where an air-fuel ratio in a cylinder becomes higher than a stoichiometric air-fuel ratio is formed, while causing the spark plug to perform spark ignition at a given timing so that the mixture gas combusts by SPCCI combustion, and controls so that, under the same engine load condition, an intake valve close timing is more retarded as the engine speed decreases, within a range where an amount of air inside the cylinder decreases by retarding the close timing.

Abstract: A control system for a compression-ignition engine is provided, which includes an engine having a combustion chamber, an injector, a spark plug, a swirl valve provided to an intake passage of the engine, and a controller connected to the injector, the spark plug, and the swirl valve to control them. The controller includes a processor configured to execute a swirl adjusting module to control an opening of the swirl valve so as to make the opening of the swirl valve smaller as an engine speed decreases and output a control signal to the injector to inject the fuel after the control of the swirl valve, and a combustion controlling module to output an ignition instruction to the spark plug so as to ignite at a given ignition timing after the EGR ratio adjustment, so that partial compression-ignition combustion is performed.

Abstract: When the geometric compression ratio of an engine body is set to 13:1 or more and the engine body operates in a preset high load region, the effective compression ratio of the engine body is set to 12:1 or more with a difference from the geometric compression ratio being within 2, a gas to be introduced into a combustion chamber is supercharged by a supercharging system, fuel is injected at least in a compression stroke by an injector, and after the fuel injection is finished, an air-fuel mixture in the combustion chamber is ignited by an ignition device before the compression top dead center and is thus burned by flame propagation in the engine body, and then the unburned air-fuel mixture is burned by compression ignition.

Abstract: A control apparatus for an engine includes an engine, an EGR system, a spark plug, a controller, and a supercharging system. While a supercharging system is performing supercharging and the EGR system is introducing burned gas into a combustion chamber, in response to a control signal from the controller, the spark plug ignites air-fuel mixture at predetermined timing so that unburned air-fuel mixture combusts by autoignition after the air-fuel mixture starts to combust by the ignition.

Abstract: A control apparatus for a compression autoignition engine includes an engine, a spark plug, a controller, and sensors. After the spark plug ignites air-fuel mixture to start combustion, unburned air-fuel mixture is combusted by autoignition. The controller changes an SI rate in accordance with an operation state of the engine. Furthermore, the controller adjusts the SI rate when determining that the SI rate needs to be adjusted.

Abstract: A control apparatus for a compression autoignition engine includes an engine, a state quantity setting device, a spark plug, and a controller. After the spark plug ignites air-fuel mixture to start combustion, unburned air-fuel mixture is combusted by autoignition. The controller changes, according to an operation state of the engine, a heat amount ratio that represents an index associated with a ratio of an amount of heat generated by air-fuel mixture being combusted by flame propagation, to a total amount of heat generated by air-fuel mixture in the combustion chamber being combusted.