The present disclosure is directed toward an engine system and a multi-mode combustion method for an internal combustion engine using hydrogen as a fuel. The engine system comprises a combustion system including a step-lipped piston bowl, a cover opposing the piston bowl, a hydrogen direct injector, and a radially asymmetrical pre-chamber partially opposite the lip of the piston bowl. The multi-mode combustion method includes injecting hydrogen and air a first time into the combustion system through the hydrogen direct injector, and jet igniting the fuel-air mixture in the combustion system. The injecting occurs during an intake stroke at low loads, and during a compression stroke at medium and high loads, Injecting hydrogen and air into the combustion system a second time via the hydrogen direct injector occurs either during or after jet-igniting, the hydrogen and air being at least partially ignited by compression.

An electronic fuel injection type diesel engine enables reduction in engine size. The electronic fuel injection type diesel engine is provided with: a combustion chamber inside a cylinder; a fuel injection chamber inside a cylinder head; a fuel injector that injects liquid fuel into the fuel injection chamber; a fuel accumulation unit that accumulates the liquid fuel injected from the fuel injector; and an electronic control unit that controls a timing and an amount of injection of the liquid fuel.

An electronic fuel injection type diesel engine enables reduction in engine size. The electronic fuel injection type diesel engine is provided with: a combustion chamber inside a cylinder; a fuel injection chamber inside a cylinder head; a fuel injector that injects liquid fuel into the fuel injection chamber; a fuel accumulation unit that accumulates the liquid fuel injected from the fuel injector; and an electronic control unit that controls a timing and an amount of injection of the liquid fuel.

A combustion system includes a cylinder having a main chamber and a fuel injector positioned to inject fuel into the main chamber. A cylinder head is disposed at a top of the cylinder and forms an upper end of the main chamber. A prechamber adapter has a prechamber volume and a nozzle with a plurality of orifices for communication between the prechamber volume and an external environment. The prechamber adapter is threaded into a bore in the cylinder head and positioned to expose the nozzle to the main chamber. A spark plug is positioned within the prechamber adapter with a spark emitting end exposed to the prechamber volume. A piston movably disposed within the cylinder has a piston head forming a lower end of the main chamber. The piston head has a dome shape and a bowl formed in a top center of the dome shape.

A combustion system includes a cylinder having a main chamber and a fuel injector positioned to inject fuel into the main chamber. A cylinder head is disposed at a top of the cylinder and forms an upper end of the main chamber. A prechamber adapter has a prechamber volume and a nozzle with a plurality of orifices for communication between the prechamber volume and an external environment. The prechamber adapter is threaded into a bore in the cylinder head and positioned to expose the nozzle to the main chamber. A spark plug is positioned within the prechamber adapter with a spark emitting end exposed to the prechamber volume. A piston movably disposed within the cylinder has a piston head forming a lower end of the main chamber. The piston head has a dome shape and a bowl formed in a top center of the dome shape.

An engine system comprising an internal combustion engine and a turbocharger, where a diameter of the at least one intake valve is greater than a diameter of the at least one exhaust valve, the salient angle of the piston bowl is at least 10 degrees, the ratio between the piston bowl opening diameter and the piston bowl depth is approximately 0.5 to 2.0, the intake valve opens before top dead center on an exhaust stroke of the internal combustion engine and closes before bottom dead center of an intake stroke of the internal combustion engine, and the turbocharger has a combined efficiency of more than 50%.

In one aspect, an engine ignition apparatus for a natural gas engine may include a housing including a drive piston, a floating piston, a controllable hydraulic fluid chamber located between the drive piston and the floating piston, and an ignition chamber acted on by the floating piston, the ignition chamber having an outlet formed by a plurality of orifices, the outlet being in direct communication with a combustion chamber of the engine. In another aspect, an engine ignition apparatus for a natural gas engine may include, among other features, a controllable valve connected to a hydraulic fluid chamber, and configured to open and release a hydraulic fluid from the hydraulic fluid chamber, and to close. In still another aspect, a method for controlling an engine ignition apparatus for an engine includes, among other features, controlling a volume of a hydraulic fluid chamber of an ignition apparatus.

A precombustion chamber gas engine includes a main-chamber forming portion forming a main combustion chamber, a precombustion-chamber forming portion forming a precombustion chamber including a small-diameter cylinder chamber communicating with the main combustion chamber via a plurality of nozzle holes and a large-diameter cylinder chamber, an ignition device disposed in the large-diameter cylinder chamber of the precombustion chamber, and a precombustion-chamber-gas supply device for supplying a precombustion-chamber fuel gas to the precombustion chamber not via the main combustion chamber. The nozzle hole is formed so that a precombustion-chamber-side straight line passing through a central position of a precombustion-chamber-side opening of the nozzle hole and parallel to an extending direction of a central line of the precombustion-chamber-side opening of the nozzle hole intersects with a main-chamber-side straight line passing through a central position of a main-chamber-side opening of the nozzle hole and parallel to an extending direction of a central line of the main-chamber-side opening of the nozzle hole, and an acute angle between a precombustion chamber central axis of the precombustion chamber and the precombustion-chamber-side straight line is smaller than an acute angle between the precombustion chamber central axis and the main-chamber-side straight line.

An ignition system for a gaseous fuel engine includes an igniter and an actuator structured to apply an actuating force to a piston within the igniter, to autoignite an ignition charge of fuel and air within the igniter. A housing of the igniter includes a gas orifice having a flow area that is increased between a combustion pre-chamber in the igniter and a main combustion chamber in the engine, to limit velocity of outgoing combustion gases to below a threshold velocity for engine mis-fire.

An ignition system for a gaseous fuel engine includes an igniter and an actuator structured to apply an actuating force to a piston within the igniter, to autoignite an ignition charge of fuel and air within the igniter. A housing of the igniter includes a gas orifice having a flow area that is increased between a combustion pre-chamber in the igniter and a main combustion chamber in the engine, to limit velocity of outgoing combustion gases to below a threshold velocity for engine mis-fire.