A method for activating an injector for injecting fuel into an internal combustion engine, in which a nozzle needle of the injector moves from a closed position in the direction of an open position as long as an activation signal is applied to the injector. The nozzle needle of the injector moves from the open position into the closed position when the activation signal is absent. The duration of the activation signal is selected in such a way that the nozzle needle does not reach its completely open position. In specific operating states, a second activation signal is applied to the injector before reaching the closed position of the injector, which has the result that the nozzle needle of the injector moves back in the direction of the open position.

A gas injector for injecting a gaseous fuel directly into a combustion chamber of an internal combustion engine includes a valve-closing element for releasing and sealing a through opening at a sealing seat; a shielding element, which is situated at an end of the valve-closing element on a side of the combustion chamber and which shields the valve-closing element and the sealing seat with respect to the combustion chamber; and a cooling ring having a first contact area designed for direct contact with the shielding element and a second contact area designed for direct contact with a component of the internal combustion engine, in particular with a cylinder head.

A gas injector for injecting a gaseous fuel, in particular directly into a combustion chamber of an internal combustion engine, including: a valve closing element for opening or closing a pass-through opening, a valve body, and a sealing seat between the valve body and the valve closing element, in the case of a maximum lift of the valve closing element a flow cross section between the valve body and the valve closing element being smaller in the flow direction upstream from the sealing seat than a flow cross section between the valve closing element and the sealing seat and being smaller than a flow cross section in the flow direction downstream from the sealing seat.

A valve for injecting fuel in an internal combustion engine includes a housing having an inflow section and an outflow section for the fuel and a drive section situated between the inflow section and the outflow section. A first control element is provided which is assigned to the inflow section and which enables or prevents the supply of the fuel in a manner dependent on a switching position of the first control element. A second control element is provided which is assigned to the outflow section and which enables or prevents the discharge of the fuel in a manner dependent on a switching position of the second control element. An actuating drive is provided which is arranged in the drive section and which is coupled to both control elements such that the control elements can be moved into an open position independently of one another.

A method for operating an internal combustion engine including feeding a pilot quantity of gas fuel, into a prechamber before a piston reaches a top dead center position. The method comprises autoignition of the pilot quantity of gas fuel in the prechamber, feeding a main quantity of gas fuel into the prechamber after the autoignition, and ignition of the main quantity of gas fuel by the conditions in the prechamber that are brought about by the autoignited pilot quantity. The method makes it possible to operate an internal combustion engine purely with methane or some other gaseous fuel, by means of compression autoignition of the pilot quantity.

An ignition device with a pre-combustion chamber for an internal combustion engine is disclosed. The internal combustion engine may have a plurality of cylinders. Each cylinder may define a main combustion chamber. The ignition device may have a first pre-combustion chamber part configured to at least partially accommodate a spark plug. The ignition device may also have a second pre-combustion chamber part defining at least a portion of the pre-combustion chamber. The second pre-combustion chamber part may include at least one orifice configured to be fluidly connected to the main combustion chamber. The second pre-combustion chamber part may be detachably mountable to the first pre-combustion chamber part, such that the first and second pre-combustion chamber parts are axially secured to one another and rotatable with respect to one another.

Systems and methods for improving engine torque response are presented. In one example, engine idle speed is increased to shorten engine torque response based on engine operating conditions. The methods and systems may be useful for operating an engine that is supplied a gaseous fuel.

An object is to improve a trap effect to trap ignition fuel gas supplied to a pre-combustion chamber and reduce an amount of non-combusted ignition fuel gas flowing out of the pre-combustion chamber to suppress a decrease in combustion efficiency. A pre-combustion-chamber type gas engine includes: a pre-combustion chamber Sr disposed on a cylinder head portion 10; a spark plug 20 disposed on an upper part of the pre-combustion chamber Sr; a pre-combustion-chamber gas supply mechanism configured to supply ignition fuel gas “g” to the pre-combustion chamber Sr via gas supply channels for the pre-combustion chamber 22a and 22b with an opening on an upper part of the pre-combustion chamber Sr; and a check valve 24 disposed in the gas supply channel 22b for the pre-combustion chamber. The opening of the gas supply channel 22a for the pre-combustion chamber is disposed on a lower surface of a cover member 16 forming the pre-combustion chamber Sr or on an upper section of a side wall of a pre-combustion-chamber member 14, the opening facing in a tangent direction of a side-wall inner peripheral surface 14a of the pre-combustion-chamber member 14. The ignition fuel gas “g” supplied to the pre-combustion chamber Sr forms a swirl flow s1 which swirls about a longitudinal axis x of the pre-combustion chamber Sr inside the pre-combustion chamber Sr.

A gas injector for directly injecting a gaseous fuel into a combustion chamber of an internal combustion engine, including a valve closure element for releasing and closing a passage opening, the valve closure element opening in the direction of a flow direction of the gas injector, a sealing seat between the valve closure element and a valve body, a flow-guiding element being situated downstream of the sealing seat in the flow direction of the gas injector and configured to form a gas jet to be injected into the combustion chamber.

A uniflow-scavenging-type two-cycle engine includes: a cylinder; a piston that slides in the cylinder; an exhaust port that is provided at a first end of the cylinder; an exhaust valve that opens and closes the exhaust port; a scavenging port that is provided in an inner circumferential surface of a second end of the cylinder in the stroke direction of the piston and inhales an active gas into a combustion chamber in accordance with a sliding movement of the piston; a plurality of fuel injection valves that inject a fuel gas to the active gas, which has been drawn in from the scavenging port to the combustion chamber, to thereby generate a premixed gas; and a fuel injection control unit that varies injection directions of fuel gas injected from a part or all of the fuel injection valves.