A two cycle-opposed piston, two cycle, homogenous charge compression ignition engine with cylinder sets, each cylinder set having a first cylinder with an intake port; a second cylinder coaxially aligned with the first cylinder and having an exhaust port; a first piston engaged within the first cylinder; a second piston engaged within the second cylinder; a combustion chamber formed between the first piston and the second piston; a first cam mechanically engaged with the first piston; a mechanical device to convert reciprocating motion to rotational motion connected to the second piston; and a charge pump connected to the intake port by an intake passage.

A two cycle-opposed piston, two cycle, homogenous charge compression ignition engine with cylinder sets, each cylinder set having a first cylinder with an intake port; a second cylinder coaxially aligned with the first cylinder and having an exhaust port; a first piston engaged within the first cylinder; a second piston engaged within the second cylinder; a combustion chamber formed between the first piston and the second piston; a first cam mechanically engaged with the first piston; a mechanical device to convert reciprocating motion to rotational motion connected to the second piston; and a charge pump connected to the intake port by an intake passage.

A method of operating a hydrogen-fueled internal combustion engine. The engine is determined to have a mode control value, which represents a threshold torque. During operation of the engine, a demanded torque of the internal combustion engine is determined and compared to the threshold torque. If the demanded torque is less than the threshold torque, the engine is operated in a low load mode that uses spark ignition and pre-mixed combustion. If the demanded torque is greater than the threshold torque, the engine is operated in a high load mode that uses compression ignition and diffusion combustion.

A method of operating a hydrogen-fueled internal combustion engine. The engine is determined to have a mode control value, which represents a threshold torque. During operation of the engine, a demanded torque of the internal combustion engine is determined and compared to the threshold torque. If the demanded torque is less than the threshold torque, the engine is operated in a low load mode that uses spark ignition and pre-mixed combustion. If the demanded torque is greater than the threshold torque, the engine is operated in a high load mode that uses compression ignition and diffusion combustion.

A fuel injection control device for an engine is provided. A swirl generator generates a swirl flow inside a combustion chamber. A fuel injector with multiple nozzle holes injects fuel into the combustion chamber, and forms a lean mixture gas inside the combustion chamber. An spark plug ignites the lean mixture gas to cause a portion of the mixture gas to start combustion accompanied by flame propagation, and then combusts by self-ignition. The fuel injector has first and second nozzle holes, and a first atomized fuel spray injected from the first nozzle hole and a second atomized fuel spray injected from the second nozzle hole separate from each other by the swirl flow. The fuel injector sequentially performs a first injection and a second injection in an intake stroke. The controller makes an injection amount of the second injection greater than that of the first injection.

An intake-air temperature controlling device for an engine is provided, which includes an engine body, an intake passage, an air intake part, an intake air temperature adjuster configured to adjust air temperature taken in through the air intake part to the passage, and a controller. An operating range in which the CI combustion is performed has a lean operating range in which A/F of mixture gas formed inside the cylinder, or G/F that is a relationship between the total weight G of gas inside the cylinder and a weight F of fuel fed to the cylinder is relatively low, and a rich operating range in which the A/F or G/F is relatively high. When the engine is in the lean operating range, the controller outputs a control signal to the intake air temperature adjuster so that the air temperature is increased, as compared in the rich operating range.

A method for operating an internal combustion engine having an engine with a first number of cylinders and a second number of cylinders and a supercharger arrangement, wherein a charge air flow supplied to the engine is compressed by means of at least one compressor and at least one turbine is acted on by an exhaust gas flow discharged from the engine. In a main operating mode, the engine operates the first number of cylinders in two-stroke operation and the second number of cylinders in four-stroke operation. A scavenging gradient of the engine is greater for the cylinders operated in the two-stroke operation than for the cylinders operated in the four-stroke operation.

Provided is an ignition control section and an injection control section. When partial compression ignition combustion is carried out, the ignition control section causes an ignition plug to carry out: main ignition in which a spark is generated in a late period of a compression stroke or an initial period of an expansion stroke to initiate SI combustion; and preceding ignition in which the spark is generated at earlier timing than the main ignition. Also, when the partial compression ignition combustion is carried out, the injection control section causes an injector to inject fuel at such timing that the fuel exists in a cylinder at an earlier time point than the preceding ignition. Ignition timing of the preceding ignition is set to be more retarded when an in-cylinder pressure specified by an in-cylinder pressure specification section is high than when the in-cylinder pressure is low.

An engine control apparatus includes an ignition control section and an injection control section. When partial compression ignition combustion is carried out, the ignition control section causes an ignition plug to carry out: main ignition in which a spark is generated in a late period of a compression stroke or an initial period of a expansion stroke to initiate the SI combustion; and preceding ignition in which the spark is generated at earlier timing than the main ignition. Also, when the partial compression ignition combustion is carried out, the injection control section causes the injector to inject fuel at such timing that the fuel exists in a cylinder at an earlier time point than the preceding ignition. Energy of the preceding ignition is set to be lower when an in-cylinder temperature specified by an in-cylinder temperature specification section is high than when the in-cylinder temperature is low.

Provided is an ignition control section and an injection control section. When partial compression ignition combustion is carried out, the ignition control section causes an ignition plug to carry out: main ignition in which a spark is generated in a late period of a compression stroke or an initial period of an expansion stroke to initiate SI combustion; and preceding ignition in which the spark is generated at earlier timing than the main ignition. Also, when the partial compression ignition combustion is carried out, the injection control section causes an injector to inject fuel at such timing that the fuel exists in a cylinder at an earlier time point than the preceding ignition. Ignition timing of the preceding ignition is set to be more advanced when an in-cylinder temperature specified by an in-cylinder temperature specification section is high than when the in-cylinder temperature is low.