An engine system is provided, which includes a vehicle-mounted engine having an injector, a spark plug, an intake valve operating mechanism, and an exhaust valve operating mechanism, an accelerator opening sensor, and a controller. The engine is configured to execute flame propagation combustion and compressed self-ignition combustion. The controller performs a combustion control so that a target torque set based on an accelerator opening is realized in a specific cycle in the future from a present time by a given delay time. The controller sets beforehand the combustion mode based on a target load, estimates an in-cylinder property when the intake valve is closed in the present cycle, sets a target in-cylinder property so that the set combustion mode is realized in the specific cycle, and sets a target operating amount of each of the intake and exhaust valve operating mechanisms based on the set target in-cylinder property.

An engine system is provided, which includes a vehicle-mounted engine having an injector, a spark plug, an intake valve operating mechanism, and an exhaust valve operating mechanism, an accelerator opening sensor, and a controller. The controller sets beforehand a combustion mode so that a target torque set based on an accelerator opening is realized in a specific cycle in the future from a present time by a given delay time, sets an in-cylinder property when an intake valve is closed in the specific cycle so that the set combustion mode is realized in the specific cycle, estimates the actual in-cylinder property when the intake valve is closed in the specific cycle, when the delay time passes and the cycle becomes the specific cycle, and adjusts an operating amount of at least one of the injector and the spark plug, when the estimated in-cylinder property deviates from the target in-cylinder property.

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.

An electronic control unit of an internal combustion engine is configured to control the fuel injection valve and to control a spark plug if necessary such that fuel is combusted by pre-mixture compression ignition combustion or flame propagation combustion. The electronic control unit is configured to perform homogeneous combustion in a flame ignition operation range when switching failure has not occurred, the homogeneous combustion being combustion in which fuel homogeneously diffused into the combustion chamber is ignited using the spark plug and is combusted by flame propagation combustion. The electronic control unit is configured to perform spray-guided stratified combustion in a second operation range when the switching failure has occurred, the spray-guided stratified combustion being combustion in which fuel in the fuel injection path is ignited using the spark plug and is combusted by the flame propagation combustion.

An engine system is provided, which includes a cylinder block, a cylinder head, a piston, a main combustion chamber, a subchamber, an injector that injects fuel into the main combustion chamber, a main spark plug that ignites a mixture gas inside the main combustion chamber, a subspark plug that ignites the mixture gas inside the subchamber, and a control device. In a low-speed high-load range, a fuel injection timing is set in compression stroke and the main ignition and the subignition are performed after the fuel injection timing, and the fuel injection timing under a low-speed condition becomes later than that under a high-speed condition, and the ignition devices are controlled so that the subignition timing is retarded from the main ignition timing and an ignition phase difference that is the retard amount of the subignition timing becomes larger under the low-speed condition than under the high-speed condition.

Provided are a work machine, a power unit, and a diesel engine of a work machine that make it possible to reduce emitted noxious substances to levels below reference values stipulated by exhaust gas regulations in advanced countries and regions while also omitting or simplifying a post-treatment device. A hydraulic pump is driven by a diesel engine that limits maximum output torque in a low revolution speed region lower than a high revolution speed region including a rated revolution speed in such a manner that the maximum output torque has a characteristic of intermediate torque lower than torque of a maximum output horsepower point at the rated revolution speed, and a hydraulic actuator is driven by hydraulic fluid delivered from the hydraulic pump.

Embodiments described herein relate to systems and methods of cylinder deactivation in compression-ignition engines. An engine described herein can include N cylinders, with N being an integer of at least 2, with each cylinder including an inner surface, a piston disposed and configured to move in each cylinder of the N cylinders, an intake port, an exhaust port, and a fuel injector. The piston and the inner surface define a combustion chamber. A method of operating the compression ignition engine includes injecting a fuel into each of the combustion chambers, combusting substantially all of the fuel in the compression ignition engine, monitoring engine load of the compression ignition engine, and deactivating a cylinder of the N cylinders upon a decrease in load to less than (N−1)/N×FL, wherein FL is a full load at a given engine speed.

An internal combustion engine includes a combustion chamber with a cylinder head, a cylinder, and a piston. The internal combustion engine also includes at least one intake valve and at least one exhaust valve that are connected to the combustion chamber, a fuel injector that injects fuel into the combustion chamber, at least two ignition devices arranged in the combustion chamber, and control means that control the valves, the injector, and the ignition means. The control means operate the engine according to different combustion modes including a controlled ignition combustion mode, a compression ignition combustion mode, and an assisted compression ignition combustion mode. The control means activate the ignition means in the assisted compression ignition combustion mode.

An action of injection of the main injection fuel (QM) from the fuel injector (3) is started within a range of crank angle from 10 degree before the compression top dead center to 10 degree after the compression top dead center. A smaller amount of the auxiliary injection fuel (QN) than the main injection fuel (QM) is made to be injected from the fuel injector (3) before the main injection fuel (QM) so as to make the auxiliary injection fuel (QN) ignite by the premixed charge compression ignition. The injection timing of the auxiliary injection fuel (QN) is controlled to a timing whereby a heat generated by the premixed charge compression ignition of the auxiliary injection fuel (QN) causes the premixed charge compression ignition of the main injection fuel (QM) after the start of injection of the main injection fuel (QM).

Methods and systems are provided for controlling a vehicle engine to reduce engine knock and increase fuel efficiency by reducing hydrocarbon breakthrough. In one example, a method may include adjusting a compression ratio of a variable compression engine in response to hydrocarbon breakthrough above a threshold from a fuel vapor canister of an evaporative emissions system.