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 method of operating an internal combustion engine comprising a cylinder and a piston, the method including injecting into the cylinder, as a liquid, a fuel which has been condensed into its liquid phase via a refrigeration process, such that the fuel vaporises into its gaseous phase during a compression stroke of the piston and before combustion such that a rise in temperature caused by the compression stroke is limited by the absorption of heat by the fuel.

A liquid fuel injector such as for a dual fuel system in an internal combustion engine includes two-way injection control valves for controlling twin outlet checks. A first set of orifices are arranged in an A-F-Z pattern, and a second set of orifices are arranged in an A-F-Z pattern, within the fuel injector, among a high-pressure inlet passage, a low-pressure space, and first and second outlet check control chambers, respectively. A common nozzle supply cavity is fluidly connected to the high-pressure inlet passage and supplies each of two sets of nozzle outlets opened and closed by the twin outlet checks.

It is a challenge to reduce unburned hydrocarbon emissions for gaseous fuelled engines, especially at low engine load conditions, to meet demanding emission regulation targets. A method for reducing unburned hydrocarbon emissions in a lean-burn internal combustion engine that is fuelled with a gaseous fuel comprises adjusting the timing for closing of an intake valve as a function of engine operating conditions by one of advancing timing for closing of the intake valve and closing the intake valve earlier during an intake stroke; and retarding timing for closing of the intake valve and closing the intake valve later during a compression stroke. The volumetric efficiency of the internal combustion engine is reduced and unburned hydrocarbon emissions are maintained below a predetermined level.

An injector for introducing a gaseous fuel into a combustion chamber. A housing has an outflow opening that can be flowed through by the gaseous fuel. A valve element can be moved between a closed position in which the valve element sits on a valve seat to separate a first housing region from a second housing region and an open position in which the valve element is spaced apart from the valve seat. When moved out of the closed position into the open position, the valve element can be moved into the second housing region. The valve element has a valve body region that is disposed in the second housing region in both the closed position and the open position. The valve body region is domed at least in a partial region of the valve body region and/or is tapered in a direction pointing away from the valve seat.

Low-cost fuel injection systems for internal combustion engines, including vapor fuel engines are provided.

The present invention relates to an injector for injecting gas, in particular hydrogen, preferably for directly injecting hydrogen, comprising an injector housing for holding injector components, a valve needle movably arranged along its longitudinal axis in the injector housing and configured to selectively close or release an injection opening for the flow of hydrogen therethrough, and a valve, preferably a solenoid valve, which is adapted to transfer the valve needle into a closing or releasing state by a movement along its longitudinal axis. The injector is characterized in that the valve needle is a hollow needle adapted to pass a gas, in particular hydrogen, flowing through the injection port through the interior of the hollow needle.

A fuel injection device includes a fuel injection valve at a position corresponding to a portion between intake ports in an internal combustion engine. The fuel injection valve includes a body and a needle inside the body. The fuel injection valve is disposed closer to a piston of the internal combustion engine than the intake ports are to the piston. A single fuel injection passage for conducting gaseous fuel is present between a valve seat of the fuel injection valve and a combustion chamber of the internal combustion engine. The flow cross section of the gaseous fuel in the fuel injection passage is larger on a side closer to the piston of the internal combustion engine than on a side closer to an ignition plug of the internal combustion engine over a specified length in an extending direction of the fuel injection passage.

The invention relates to a gas valve (1), comprising: a valve body (2) which is hollow-cylindrical at least in parts and which forms a sealing seat (3) over which a gas flow path (4) is conducted, a reciprocating valve closure element (5) which is accommodated at least partly in the valve body (2) and which has a plate-like end portion (6) arranged outside the valve body, (2) which end portion interacts with the sealing seat (3), a sleeve (7) which at least partially surrounds the valve body (2) and the valve closure element (5) and which, together with the plate-like end portion (6) of the valve closure element (5), delimits an annular gap (8) which forms a throttle point in the gas flow path (4) downstream of the sealing seat (3).

Various aspects of the present disclosure are directed to a cylinder head for an internal combustion engine. In one example embodiment, the cylinder head includes at least one spark plug having at least one earth electrode, a precombustion chamber accommodating the at least one spark plug, and a fuel channel which leads into the precombustion chamber. The fuel channel having a flow axis at an outlet that is oriented in the direction of the at least one earth electrode. An axis of rotation of the at least one spark plug has an offset with respect to the flow axis between 0 and 15% of the greatest precombustion chamber diameter.