A vehicular fuel system with onboard fuel characterization including an onboard combustion modifier source capable of supplying a combustion modifier agent, such as hydrogen, and a fuel tank capable of storing a fuel. An injector-igniter is operative to direct inject the fuel and a proportionate amount of the modifier agent into a cylinder of an internal combustion engine. An engine control unit is operatively connectable to the combustion modifier source and the injector. The system may further comprise a mixing valve operative to proportionately mix the fuel and modifier agent. The combustion modifier source may be a tank containing hydrogen or a thermo-chemical reactor, for example.

A fuel injection device includes a coil, a stator provided on an inner side of the coil, a housing including an injection hole at an end opposite to a stator side in an axial direction, a movable element including a movable element main body that generates a first gap with the stator and a stopper portion provided to an injection hole side of the movable element main body, and provided inside the housing in a reciprocable manner, a main valve including a lock portion that generates a second gap smaller than the first gap together with an end face of the stopper portion on the stator side, and provided to open and close the injection hole, a first pushing portion constantly pushing the movable element to the injection hole side, and a second pushing portion constantly pushing the main valve to the stator side.

A gas fuel injector of an electromagnetic drive type includes a cylindrical main body in which a fuel passage is formed, an opening/closing valve configured to open and close the fuel passage, a solenoid configured to open the opening/closing valve, and a nozzle provided at a distal end portion of the main body. The opening/closing valve includes a valve body configured to reciprocate together with a plunger constituting the solenoid and a valve seat configured to come into contact with and be separated from the valve body. The plunger is fixed to a retainer provided on an upstream side of the opening/closing valve. The retainer is installed between a closing spring configured to bias the plunger in a valve closing direction and an adjustment spring configured to bias the plunger in a valve opening direction.

A fuel injector for injecting gaseous fuels into a combustion chamber, comprising an injection nozzle including a nozzle cap, and an outward opening injection needle. The injection nozzle has a longitudinal injector axis and a tip region that is shaped to define a valve seat that extends about a central outlet opening for gaseous fuel. The outward opening injection needle is slidably received in the injection nozzle and is engageable with the valve seat to control a flow of gaseous fuel into a sac volume of the fuel injector. The nozzle cap is received over the tip region to define the sac volume, and is provided with a plurality of openings to enable the flow of gaseous fuel to pass from the sac volume into the combustion chamber when the injection needle is moved away from the valve seat.

A fuel injection arrangement admits a flow of hydrogen into a combustion chamber of hydrogen internal combustion engine. The fuel injection arrangement has a nozzle cap and an inlet valve arrangement. An inner surface of the nozzle cap comprises a nozzle protrusion protruding radially towards an envelope surface of a flow guiding portion of the inlet valve arrangement. The nozzle protrusion is arranged axially between a valve protrusion of the inlet valve arrangement and an outlet of the nozzle cap. The valve protrusion and the nozzle protrusion at least partly overlap in a radial direction.

A supplemental fuel system for a machine with an engine is configured to monitor a voltage of a power supply of the machine based on voltage data acquired by a voltage sensor where the power supply is configured to receive power from an alternator driven by the engine, compare the voltage to a voltage threshold, and control an electronic lock off valve positioned between a supplemental fuel tank and an air supply system for the engine such that the electronic lock off valve is (i) closed to prevent a supplemental fuel from being provided from the supplemental fuel tank to the to the air supply system in response to the voltage being less than the voltage threshold and (ii) open or openable to permit the supplemental fuel to be provided to the air supply system in response to the voltage being greater than the voltage threshold.

A fuel system for a machine with an engine is configured to monitor a voltage of a power supply of the machine based on voltage data acquired by a voltage sensor where the power supply is configured to receive power from an alternator driven by the engine, compare the voltage to a voltage threshold, and control an electronic lock off valve associated with a fuel tank such that the electronic lock off valve is (i) closed to prevent a fuel from being provided from the fuel tank to the to the engine in response to the voltage being less than the voltage threshold and (ii) open or openable to permit the fuel to be provided to the engine in response to the voltage being greater than the voltage threshold.