The invention relates to a mixture formation device for an internal combustion engine that is operated with a combustible gas, preferably compressed natural gas (CNG). The mixture formation device comprises a combination of a quantity regulator, a gas mixer, a flow guide element to recover pressure as well as a connection capability for recirculating the exhaust gas of the internal combustion engine. Owing to the mixture formation device according to the invention, a gas tank can be emptied down to a relatively low pressure of approximately 2 bar, whereby an excellent mixture formation is achieved over the entire speed and load ranges of the internal combustion engine. It is provided that, owing to the mixture formation device according to the invention, the installation space requirements as well as the production costs can be reduced in comparison to prior-art solutions. Moreover, an internal combustion engine operated with a combustible gas, especially natural gas (CNG), is being put forward which has such a mixture formation device in its intake tract.

Methods and systems are provided for a compressed natural gas fuel rail. In one example, a system comprises a device having a first volume for housing compressed natural gas and a second volume for housing lubricant, the first and second volumes arranged in a single housing and separated by a barrier. Lubricant flow from the second volume to the first volume may be adjusted by adjusting a pressure of the second volume so that a pressure difference between the second and first volumes is increased to increase lubricant flow or decreased to decrease lubricant flow.

The present invention pertains to a gas mixer for an internal combustion engine for mixing air with at least one admix gas, comprising a first duct segment having a first tube section and a first cone section, and a second duct segment having a second tube section and a second cone section. The first and second duct segments are stackable such that in a stacked state, a main gas conduit is formed by the first and second tube sections and an admix gas conduit is formed between the first cone section and the second duct segment. The present disclosure also pertains to a method for producing a gas mixer, comprising the steps of: for a predetermined mass flow of a gas to be admixed to air, calculating a flow cross section; machining at least one inner surface of an admix gas conduit such that at any position, the admix gas conduit comprises at least the calculated flow cross section; stacking two duct segments to provide the gas mixer. The present disclosure also pertains to a duct segment for being used in the gas mixer.

Various methods and systems are provided for an intake manifold for an engine. In one example, the intake manifold comprises a first passage for supplying intake air to a plurality of cylinders of the engine and a second passage for supplying gaseous fuel to the plurality of cylinders.

An insert for engine intake gaseous fuel mixing device. A body defines a longitudinal axis, leading end, trailing end, and exterior surface profile from the leading to the trailing end. Supports extend radially from the body, each support extending parallel to the axis to define separate longitudinal intake passages. The exterior surface profile of the body includes a nose section in which diameter increases from a minimum value at the leading end to a maximum value at a downstream end of the nose section. The nose section is followed by a flat section and a curved tapering section in which the profile converges toward the axis at an increasing rate from the flat section in a direction of the axis toward the trailing end. The diameter at the trailing end is at least 15 percent less than a maximum diameter of the body.

A gaseous fuel engine system includes an engine housing forming a plurality of intake ports, and a plurality of fuel admission tubes oriented to admit a gaseous fuel into the plurality of intake ports. The fuel admission tubes include mixers having flow-impinged surfaces exposed to at least one of a flow of gaseous fuel or a flow of intake air and each including a detachment edge. The mixers may include fins, wedge structures, and/or a contoured outer surface of the fuel admission tube. Related apparatus and methodology is also disclosed.

A mixing device for introducing gaseous fuel into an intake airflow of an engine, the mixing device including an inlet, an outlet, an intake passage extending between the inlet and the outlet, an annular channel, and a plurality of fuel supply manifolds, each coupled to a main gaseous fuel inlet of the mixing device, and a separate plurality of gaseous fuel injectors coupled to each one of the plurality of fuel supply manifolds to receive gaseous fuel from the corresponding fuel supply manifold. The annular channel is configured to receive gaseous fuel injected from all of the separate pluralities of gaseous fuel injectors. The mixing device includes a diffuser, the diffuser arranged to receive gaseous fuel from the annular channel and operable to diffuse gaseous fuel from the annular channel into the intake airflow.

A cylinder head for an internal combustion engine is configured to be operated with fuel, such as gaseous or liquid fuel, to provide a more complete combustion of the fuel/air mixture. The cylinder head has at least one fuel guiding section, which includes a fuel inlet valve casing for accommodating a fuel inlet valve configured to control a fuel flow rate, a fuel/air mixing chamber for mixing the fuel with air, and a fuel guiding portion connecting the fuel inlet valve casing to the fuel/air mixture chamber. The fuel guiding portion is integrally formed with the cylinder head and defines at least a first fuel feeding passage and at least a second fuel feeding passage. The first fuel feeding passage and the second fuel feeding passage extend from the fuel inlet valve casing to the fuel/air mixing chamber.

A mixing device for introducing gaseous fuel and recirculated exhaust gas into an intake passage of an engine, the mixing device including a body, an annular channel, the body defining a fuel inlet opening, and a plurality of gaseous fuel injectors fluidly coupled to the fuel inlet opening such that gaseous fuel from the plurality of gaseous fuel injectors is conveyed into the annular channel through the fuel inlet opening. The mixing device further includes a diffuser at a position of the annular channel to diffuse gaseous fuel from the annular channel into the intake airflow in the intake passage, an exhaust gas recirculation (EGR) inlet opening defined by the body and in fluid communication with the intake passage, and an exhaust gas recirculation supply pipe coupled to the EGR inlet opening and configured to direct recirculated exhaust gas from the engine into the intake passage.

A method for equipping an engine with a mixing device for introducing gaseous fuel into an intake passage of the engine comprising the steps of providing a body through which the intake passage extends, wherein an annular channel encircles the intake passage, providing a fuel inlet manifold with injector receiving ports, each injector receiving port configured to receive a discharge end of a fuel injector, with each injector receiving port in fluid communication with the annular channel, and providing a fuel supply manifold including fuel injector ports, wherein each fuel injector port is configured to receive an upstream end of a fuel injector. The method further includes blocking at least one injector receiving port such that fluid communication through the injector receiving port is prevented, removably coupling fuel injectors between the fuel supply manifold and the unblocked injector receiving ports, and providing the mixing device to the engine.