Insert device for fuel injection

Abstract

An insert device for fuel injection, the body of which has an upper body portion coupled to a cylinder head of an engine cylinder, a lower body portion extending from the upper body portion toward a combustion chamber of the engine cylinder, and an inner surface extending around a central volume, the central volume being positioned to receive liquid fuel from a fuel injector. The body includes a plurality of gas inlet passages and a plurality of fuel gas mixture outlet passages. The gas inlet passages direct gas into the central volume. The fuel gas mixture outlet passages direct the fuel gas mixture into the combustion chamber. The inner surface includes a plurality of concave surface portions between the inlet passages and the outlet passages along a central axis of the body, the concave surface portions being shaped to direct the gas entering the central volume toward the liquid fuel in the central volume.

Description

Technical Field

[0001] The subject matter described herein relates to fuel injection insertion devices and methods for mixing fuel and gas into a fuel-gas mixture prior to injecting the mixture into engine cylinders. Background Art

[0002] In a compression ignition engine, fuel can be injected directly into compressed hot gases, such as air or a mixture of air and recirculated exhaust gas. The fuel mixes with these cylinder gases near the location where the fuel is injected into the cylinder of the engine. When the relatively cold fuel mixes with the higher temperature gases, the resulting mixture reaches a temperature sufficient to ignite. This can be a dynamic event, and the fuel can be ignited and can burn at the head of the fuel spray plume while fuel continues to be injected to the other end of the spray plume.

[0003] When the temperature of the gases entrained into the injected fuel is kept elevated, the delay between the injection of the fuel and the ignition of the fuel-air mixture in the cylinder can be reduced. This can result in the fuel spray plume having a suboptimal fuel-air mixture ratio prior to initial ignition, which can generate soot. The generation and subsequent accumulation of soot can reduce the performance of the engine and eventually require cleaning or other repairs to the engine. In addition, certain regulations or laws may limit how much particulate matter or other emissions an engine can generate.

[0004] Insert devices may be placed between a fuel injector and a combustion chamber of an engine cylinder to mix the fuel and air before the mixture is directed to the combustion chamber. These insert devices may be exposed to extreme temperatures, which may cause mechanical stress to the insert devices due to the fact that the devices have a different coefficient of thermal expansion (CTE) than the cylinder head to which the insert devices are coupled. Such stresses may damage or destroy the insert devices and / or the cylinder head.

[0005] Insert devices may include conduits through which gas and fuel are received. It may be desirable to control the characteristics of the gas and / or fuel within the insert device, as well as the flow of the fuel-gas mixture into the engine cylinders. Therefore, there is a need for insert devices that are capable of controlling fluids moving toward, within, and out of these insert devices. Summary of the invention

[0006] In one or more embodiments, an insert device includes a body having an upper body portion configured to be coupled to a cylinder head of an engine cylinder and a lower body portion extending from the upper body portion toward a combustion chamber of the engine cylinder when the upper body portion is coupled to the cylinder head. The body includes an inner surface extending around a central volume, the central volume being positioned to receive liquid fuel from a fuel injector when the upper body portion is coupled to the cylinder head. The body includes a gas inlet passage and a fuel gas mixture outlet passage. The gas inlet passage is positioned to receive gas from outside the body and guide the gas into the central volume, where the gas is mixed with the liquid fuel to form a fuel gas mixture. The fuel gas mixture outlet passage is positioned to guide the fuel gas mixture into the combustion chamber of the engine cylinder when the upper body portion is coupled to the cylinder head. The inner surface of the body includes a concave surface portion between the gas inlet passage and the fuel gas mixture outlet passage along the central axis of the body. The concave surface portion is shaped to guide the gas flow entering the central volume toward the liquid fuel in the central volume into the central volume.

[0007] In one or more embodiments, an insert device includes a body having an upper body portion configured to be coupled to a cylinder head of an engine cylinder and a lower body portion extending from the upper body portion toward a combustion chamber of the engine cylinder when the upper body portion is coupled to the cylinder head. The body includes an inner surface extending around a central volume, the central volume being positioned to receive liquid fuel from a fuel injector when the upper body portion is coupled to the cylinder head. The body includes a fuel gas mixture outlet passage, an upper group of gas inlet passages, and a lower group of gas inlet passages. The upper group of gas inlet passages and the lower group of gas inlet passages are positioned to receive gas from outside the body and guide the gas into the central volume, where the gas is mixed with the liquid fuel to form a fuel gas mixture. The fuel gas mixture outlet passage is positioned to guide the fuel gas mixture into the combustion chamber of the engine cylinder when the upper body portion is coupled to the cylinder head. The inner surface of the body includes a recess between the fuel gas mixture outlet passage and one or more of the upper group of gas inlet passages or the lower group of gas inlet passages. The dimples are shaped to direct a flow of gas entering the central volume toward the liquid fuel in the central volume.

[0008] In one or more embodiments, a method includes depositing a first layer onto a build surface, and sequentially depositing one or more additional layers on the first layer to form an additively manufactured body having an upper body portion configured to be coupled to a cylinder head of an engine cylinder and a lower body portion extending from the upper body portion toward a combustion chamber of the engine cylinder when the upper body portion is coupled to the cylinder head. The body is formed to have an inner surface extending around a central volume, the central volume being positioned to receive liquid fuel from a fuel injector when the upper body portion is coupled to the cylinder head. The body is formed to have a gas inlet channel and a fuel gas mixture outlet channel. The gas inlet channel is positioned to receive gas from outside the body and guide the gas into the central volume, where the gas is mixed with the liquid fuel to form a fuel gas mixture. The fuel gas mixture outlet channel is positioned to guide the fuel gas mixture into the combustion chamber of the engine cylinder when the upper body portion is coupled to the cylinder head. The inner surface of the body is formed to have a concave surface portion between the gas inlet channel and the fuel gas mixture outlet channel along the central axis of the body. The concave surface portion is shaped to direct a flow of gas entering the central volume toward the liquid fuel in the central volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The subject matter of the invention may be understood by reading the following description of non-limiting embodiments with reference to the accompanying drawings, in which:

[0010] Figure 1 depicts a cross-sectional view of one example of an insert device for a cylinder head coupled to an engine cylinder in an engine;

[0011] Figure 2 Draws Figure 1 An enlarged cross-sectional view of one example of an insertion device is shown;

[0012] Figure 3 Draws Figure 2 A cross-sectional view of the insertion device shown;

[0013] Figure 4 depicts a cross-sectional view of an insertion device according to one embodiment;

[0014] Figure 5 depicts a cross-sectional view of an insertion device according to one embodiment;

[0015] Figure 6 depicts a cross-sectional view of an insertion device according to one embodiment;

[0016] Figure 7 depicts a cross-sectional view of an insertion device according to one embodiment;

[0017] Figure 8depicts a cross-sectional view of an insertion device according to one embodiment; and

[0018] Fig. 9 A cross-sectional view of an insertion device according to one embodiment is depicted. DETAILED DESCRIPTION

[0019] Embodiments of the subject matter described herein relate to an insert device and method for mixing fuel and gas (e.g., air) into a fuel gas (or fuel air) mixture and then directing the fuel gas (or fuel air) mixture into an engine cylinder. The insert device may include an upper body portion coupled to a cylinder head of an engine, and a lower body portion extending from the upper body portion toward a combustion chamber of an engine cylinder. The insert device includes an inner surface extending around and defining a central volume, the central volume receiving liquid fuel from a fuel injector and receiving gas from one or more gas inlet channels. The gas is combined or mixed with the liquid fuel in the central volume and directed out of the central volume toward the combustion chamber via one or more fuel gas mixture outlet channels. The inner surface of the insert device may include one or more parts (e.g., recessed surface parts, protrusions, extensions, angle surfaces, etc.), which may be configured to control or change one or more features of a gas, liquid fuel, and / or fuel gas mixture within the device. For example, one or more parts may control or change the pressure, volume flow rate, rotational force, quantity, turbulence level, etc., of one or more fluids within the insert device.

[0020] Insertion devices can affect and / or control the ignition delay of the fuel (e.g., by delaying the ignition relative to the injection time). Ignition control can allow a different (e.g., leaner) fuel-air mixture to be obtained before the mixture reaches the combustion zone to ignite or burn. Several concepts that contribute to such modifications of the fuel combustion event are described herein. Although tubes and pipes can be used in some assemblies, other insertion devices define passages, flow paths, conduits, etc., and do not include tube structures or pipe structures in the combustion chamber of the cylinder. Some devices with tubes or pipes have been shown to suffer catastrophic failures, such as explosions occurring in the tubes.

[0021] With reference to some of these concepts, the insert device may be placed in the cylinder head between the fuel injector and the piston within the engine cylinder, or may be disposed on top of the piston. The insert device may control (e.g., reduce) the amount of hot gases entrained into the injected fuel stream. The fuel injector may inject fuel and may have nozzles that form multiple fuel streams. By adding in these insert devices, the fuel and air may have more time to mix before ignition in the engine cylinder. In addition, the ratio of fuel to gas / air may be controlled, which may reduce or eliminate the generation of certain exhaust products (e.g., soot, NOx) during the combustion process. The insert device of the present invention described herein may also be referred to as a mixing structure or mixing assembly.

[0022] By adding these insert devices to the engine, these devices can contact hot gases and air to act as heat sinks. In this way, the insert device can locally cool the previously hot gases / air as the gases / air are combined, entrained and / or swept together with the fuel flow plume within the insert device. The insert device can cool gases that may be entrained into the fuel flow injected into the cylinder. The cooler mixture can delay ignition and thereby reduce the amount of soot generated or prevent the generation of soot altogether. Various embodiments of the insert device may be referred to as soot reduction assemblies or engine assemblies. As used herein, the term gas (gas or gases) includes air, a combination of air and recirculated exhaust gas (EGR), a combination of air and other diluents (e.g., water vapor, CO2 and / or N2, etc.), air modified to change the oxygen concentration, and any of the foregoing in combination with aspirated natural gas.

[0023] As described herein, various embodiments of the insert device include features or designs that reduce or eliminate mechanical stresses caused by elevated temperatures to which the insert device is exposed. Reducing these stresses may increase the useful life of the insert device and / or cylinder head.

[0024] The insertion device can be additionally manufactured using three-dimensional printing, direct metal laser sintering, etc. The insertion device can be formed by the same material or a combination of materials. The insertion device can be a homogeneous body with a consistent formula and density throughout the body of the device. For example, the weight, volume, or relative amount or ratio of both weight and volume of the material used to form the insertion device can be the same throughout the insertion device, regardless of the size or shape of any part of the insertion device. Alternatively, the insertion device can be a non-homogeneous body, and the weight, volume, or relative amount or ratio of weight and volume of the material is different at different positions of the insertion device. The insertion device can be monolithic because the insertion device is formed as a single-piece body and is not produced by forming separate parts that are subsequently connected together to form the insertion device. The body of the monolithic insertion device can be formed integrally with each other as a single body. The overall aspects or properties of the insertion device can be identified or verified by the absence of any seams or interfaces between the different parts that are connected together to form the insertion device. Alternatively, the insertion device may not be a monolithic body because the insertion device is formed as a plurality of separate parts that are subsequently connected together to form the insertion device. Non-integral aspects or properties of the insertion device may be identified or verified through seams or interfaces between different components that are joined together to form the insertion device.

[0025] An additive manufacturing process for forming an insert device can include sequentially constructing the body of the device layer by layer. For example, an insert device can be formed by depositing a first layer onto a build surface and sequentially depositing one or more additional layers on the first layer to form an additively manufactured insert device. Suitable processes include, for example, selective laser melting (or sintering) and binder jets. Selective laser melting involves depositing a layer of powder on a build plate and melting selective portions of the power using an ytterbium fiber laser that scans a computer-aided design (CAD) pattern or file. Binder jets produce parts by embedding metal powders and a polymer binder that bonds the particles and layers together without the use of laser heating.

[0026] Different portions of the insert device may be additively manufactured from different materials. For example, a portion of the insert device that abuts or contacts a cylinder head of an engine cylinder may be formed from a first material (e.g., a metal or metal alloy, a polymer, a ceramic, etc.) having a CTE that is the same as or closer to the CTE of the cylinder head, while another portion of the insert device that does not abut or contact the cylinder head may be formed from another material having a CTE that is different from or further away from the CTE of the cylinder head (further away from the CTE of the cylinder head than the portion of the insert device that contacts the cylinder head).

[0027] Figure 1A cross-sectional view of one example of an insert device 100 coupled to a cylinder head 300 of an engine cylinder 302 in an engine is depicted. The insert device can be coupled to the cylinder head at a location between a fuel injector 304 and a crown 306 of a piston 308 in the cylinder. During engine operation, the piston moves toward and away from the fuel injector, or Figure 1 . In the illustrated embodiment, the insert device may be fixed, as the mixing structure may be mounted or otherwise secured to the cylinder head. The piston moves toward and away from the fuel injector and the fixed insert device. In one embodiment, the insert device may be secured or otherwise coupled or incorporated into the crown of the piston such that the insert device moves with the piston toward and away from the fuel injector.

[0028] In operation, the fuel injector injects one or more streams of fuel into the central volume of the body of the insert device. During operation, a stream of fuel flows from the fuel injector through the central volume of the insert device. The pressure supplied to the fuel injector may cause all or substantially all (e.g., at least 90%) of the fuel to pass through the conduit of the insert device (after mixing with the gas, as described herein).

[0029] As fuel flows into the interior volume of the insert device, the moving fuel draws gas through air passages in the device (e.g., openings along the top of the insert device, such as the side of the insert device facing away from the piston and generally in a direction toward the fuel injector; openings above the fuel passage; openings below the fuel passage; etc.) The gas, which may be relatively hot, may be pulled through the interior of the insert device such that the hot gas moves inward from the exterior of the insert device into the central volume of the insert device.

[0030] The insert device can cool the incoming air by operating as a radiator and / or increasing the residence time of the air (e.g., the duration that the air flows through the insert device, mixes with the fuel, and enters the engine cylinder). At least a portion of the cooled gas is then entrained in the fuel flow in the insert device to form a fuel-gas mixture within the insert device. The fuel-gas mixture can be formed before the fuel or gas enters the combustion chamber of the cylinder. The fuel and gas mix to form a fuel-gas mixture, which flows out of the insert device via one or more mixture conduits. The fuel-gas mixture then flows into the combustion chamber of the cylinder. The fuel-gas mixture can be cooler than a fuel-gas mixture that does not flow through the insert device or is not mixed within the insert device, which can delay ignition within the chamber of the cylinder and prevent or reduce smoke formation, as described herein.

[0031] Optionally, the conduit can be oriented to direct the fuel-gas mixture further into the combustion chamber of the cylinder such that the fuel-gas mixture penetrates further into the combustion chamber (e.g., compared to directing the fuel and gas into the combustion chamber using an insert device without mixing the fuel and gas). For example, mixing the fuel and gas in the insert device and then directing the fuel-gas mixture into the combustion chamber using the insert device can change the combined mass and velocity of the mixed jet relative to the mass and velocity that the fuel and gas jets would each have without premixing the fuel and gas in the insert device. For example, a jet with a mixing structure may be more restricted (e.g., narrower) than a jet without an insert device. . Additionally, the jet may have a lower initial mass entrainment but a higher velocity relative to a jet without an insert device. Without an insert device, the jet may entrain more gas earlier in the flow path, which will have a higher mass within the spray region and diffuse the spray, resulting in a lower velocity and lower penetration into the cylinder. The more concentrated, faster mixture passing through the insert device causes the mixture to travel farther into the combustion chamber to a location that may be farther from the insert device (relative to not using an insert device). As penetration of the mixture into the combustion chamber increases, soot oxidation within the combustion chamber may be enhanced, which may eliminate or reduce the amount of soot in the engine cylinder.

[0032] Figure 2 Draws Figure 1 An enlarged cross-sectional view of an example of an insert device 100 is shown. The insert device has a body 106, which includes an upper body portion 102 and a lower body portion 108 extending from the upper body portion toward a combustion chamber of an engine cylinder. The upper body portion is coupled to the cylinder head and receives a fuel injector. The lower body portion is coupled to the combustion chamber fluid. In one or more embodiments, the upper body portion has a substantially circular cross-sectional shape, and the lower body portion has a substantially circular cross-sectional shape larger than the upper body portion. In one embodiment, the upper body portion can be concentric and / or coaxial with the lower body portion. Optionally, the upper body portion and / or the lower body portion of the body can have an alternative cross-sectional shape, size or orientation relative to the other of the upper body portion or the lower body portion. The body of the insert device extends between the upper body portion and the lower body portion of the body along the central axis 104. The upper body portion includes an upper end 322, which is positioned away from the combustion chamber when the upper body portion is coupled to the cylinder head. For example, the upper end faces away from the lower body portion of the body. The upper end can represent an outer surface along the top side of the insert device.

[0033] Figure 3 Draws Figure 2 The insert device is shown in partial cross-section. The body includes an inner surface 312 extending around a central volume 314 of the insert device. The central volume is shaped and positioned to receive fuel from the fuel injector ( Figure 2) to receive liquid fuel. In one embodiment, the upper body portion may include an internal thread 316 disposed along a portion of the inner surface of the body. The internal thread may correspond to the thread of the fuel injector, and the insert device may be coupled to the fuel injector, or the insert device may be coupled to another portion of the cylinder head of the engine cylinder. In addition, the body includes a coupling part 332 that may be mated or coupled to a corresponding coupling part of the fuel injector. For example, in the illustrated embodiment, the coupling part protrudes away from the inner surface of the body toward the central axis. The fuel injector may include a coupling recess or a receiving recess in which the coupling part may be received. Optionally, the insert device may be coupled to the cylinder head by any alternative mating and / or coupling part (for example, but not limited to, a press fit, a snap-fit ​​part, an alignment assembly, etc.).

[0034] The insert device includes a plurality of gas inlet passages 318, 320 that receive gas from outside the body. For example, the gas inlet passages are passages, conduits, passages, etc. that direct gas into the central volume of the insert device. The gas received from within the central volume of the body is mixed with liquid fuel received from the fuel injector to form a fuel-gas mixture. The insert device also includes a fuel-gas mixture outlet passage 324 to direct the fuel-gas mixture out of the central volume toward the combustion chamber of the engine cylinder.

[0035] exist Figure 3 In the illustrated embodiment, the insertion device includes an upper group of gas inlet channels 318 and a lower group of gas inlet channels 320. The upper group of gas inlet channels may include a plurality of inlet channels arranged around the central axis of the body. The lower group of gas inlet channels may include the same number or a different number of inlet channels as the upper group. In addition, the lower group may include a plurality of inlet channels arranged around the central axis. In one or more embodiments, the upper group of gas inlet channels may have a shape, size, and / or orientation that is the same or different from the shape, size, and / or orientation of the lower group of gas inlet channels. For example, the upper group may have a size different from the size of the lower group to control the amount of gas directed into the central volume of the body via the upper group relative to the amount of gas directed into the central volume via the lower group. Optionally, the upper group may have an orientation such that the upper group of gas inlet channels directs gas to the central volume in a first radial direction relative to the central axis, and the lower group may have an orientation such that the lower group directs gas to the central volume in a different second radial direction relative to the central axis. Optionally, the upper and lower groups may direct gas into the central volume in substantially the same or similar radial directions (eg, within about a 2° difference, about a 5° difference, about a 15° difference, etc.).

[0036] The upper group of gas inlet channels is disposed in the upper body portion of the insert device and the lower group of gas inlet channels is disposed in the lower body portion of the insert device. Optionally, one or both groups may be disposed in the upper body portion or the lower body portion of the insert device. The upper group of gas inlet channels is disposed along the central axis between the upper end 322 of the upper body portion and the fuel gas mixture outlet channel. The fuel gas mixture outlet channel is disposed along the central axis between the upper group of gas inlet channels and the lower group of gas inlet channels.

[0037] exist Figure 3 In the illustrated embodiment, the cross-sectional dimensions of the fuel gas mixture outlet passage are smaller than the cross-sectional dimensions of the gas inlet passage. For example, the fuel gas mixture outlet passage may be shaped and dimensioned to control one or more flow characteristics (e.g., pressure, velocity, turbulence, volume, flow direction, etc.) of the fuel gas mixture directed out of the central volume of the body via the outlet passage. The fuel gas mixture outlet passage has a substantially circular cross-sectional shape, but may alternatively have any alternative shape to control the flow characteristics of the mixture.

[0038] The insert device includes a plurality of different recessed surface portions or dimples disposed at locations along the inner surface of the body. The recessed surface portions may protrude or extend into the inner surface of the body so as to form depressions, notches, dents, dimples, grooves, etc. along the inner surface. The recessed surface portions may be shaped, sized, and / or positioned within the body to control flow characteristics of gas, liquid fuel, and / or fuel gas mixture. For example, the recessed surface portions may be shaped, sized, and / or oriented, etc., to direct the gas flow entering the central volume of the body toward the liquid fuel in the central volume to mix with the liquid fuel to form a fuel gas mixture. Optionally, the recessed surface portions may be shaped, sized, oriented, etc., to direct the fuel gas mixture out of the insert device.

[0039] exist Figure 3 In the illustrated embodiment, the insert device includes an upper set of concave surface portions or dimples 326 and a lower set of concave surface portions or dimples 328. The upper set of concave surface portions are positioned along the central axis between the upper set of gas inlet channels and the fuel gas mixture outlet channels, and the lower set of concave surface portions are positioned along the central axis between the lower set of gas inlet channels and the fuel gas mixture outlet channels. For example, the upper set of concave surface portions are disposed above the fuel gas mixture outlet channels and the lower set of concave surface portions are disposed along the central axis below the fuel gas mixture outlet channels.

[0040] The upper group of concave surface portions and / or the lower group of concave surface portions can be positioned between adjacent channels of the fuel gas mixture outlet channel. For example, the upper group of concave surface portions can include a first concave surface portion 326A and a second concave surface portion 326B. The first and second concave surface portions 326A, 326B are located between adjacent channels of the outlet channel around the central axis. For example, the second concave surface portion 326B is arranged between the first outlet channel 324A and the second outlet channel 324B of the fuel gas mixture outlet channel. In addition, adjacent concave surface portions can intersect with each other. In the illustrated embodiment, the first concave surface portion 326A of the upper group can intersect with the adjacent second concave surface portion 326B of the upper group around the central axis. For example, a part of the groove, depression, etc. of the first concave surface portion can intersect, connect or merge, etc. with a part of the groove of the second concave surface portion.

[0041] In one or more embodiments, the concave surface portion may include an intermediate group of concave surface portions 334. Each portion within the intermediate group may be located between adjacent channels of the fuel gas mixture outlet channel. For example, the first surface 334A of the intermediate group of concave portions is disposed between the first outlet channel 324A and the third outlet channel 324C of the fuel gas mixture outlet channel. Optionally, the concave portion in the intermediate group may be merged with the upper group of concave surface portions and / or the lower group of concave surface portions in the position 330 between adjacent channels of the fuel gas mixture outlet channel. For example, the first surface 334A of the intermediate group may be merged, combined, similarly shaped, etc. with the first concave portion 326A of the upper group. Additionally or alternatively, the first surface of the intermediate group may be merged, combined, similarly shaped, etc. with the first concave portion 328A of the lower group of concave surface portions.

[0042] In one or more embodiments, the body of the insert device may include multiple material layers connected together to form the body. For example, part or all of the insert device may be additively manufactured using three-dimensional printing, direct material laser sintering, etc. For example, the insert device may be a single body or a single structure. The insert device may be formed of the same material or a combination of materials. Optionally, secondary forming or processing may be performed on a portion of the insert device. For example, the body may be additively formed into a single structure, and one or more inlets, outlets, recessed portions, etc. may be subsequently formed (e.g., drilled, machined, etched, etc.).

[0043] Figure 4An insert device 400 is depicted according to one or more embodiments. The insert device includes a body 406 having an upper body portion 402 and a lower body portion 408 extending from the upper body portion along a central axis 404. The body includes an inner surface 412 extending around a central volume of the body that is positioned to receive liquid fuel from a fuel injector. The insert device includes internal threads 416 that can be coupled with corresponding threads of a portion of a cylinder head to couple the upper body portion of the insert device to the cylinder head of an engine cylinder.

[0044] and Figure 3 Similar to the insert device shown, insert device 400 includes gas inlet passages 418, 420 and a fuel gas mixture outlet passage 424. The fuel gas mixture outlet passage is disposed along a central axis between the upper set of gas inlet passages 418 and the lower set of gas inlet passages 420. The gas inlet passage is shaped, sized and / or positioned to direct gas from a location external to the insert device toward a central volume of the insert device to mix or combine with the liquid fuel. The fuel gas mixture outlet passage is shaped, sized and / or positioned to direct the fuel gas mixture out of the central volume toward a combustion chamber of an engine cylinder.

[0045] In the illustrated embodiment, the insert device also includes a concave surface portion disposed along the central axis between the gas inlet channel and the fuel gas mixture outlet channel. For example, the upper group of concave surface portions 426 are disposed above the fuel gas mixture outlet channel, and the lower group of concave surface portions 428 are disposed along the central axis below the fuel gas mixture outlet channel. Figure 3 Unlike the illustrated insertion device, adjacent concave surface portions of the insertion device 400 do not intersect each other. For example, the first concave portion 426A does not intersect or merge with the adjacent second concave portion 426B around the central axis. The first and second concave portions of the upper group are separated by a portion of the inner surface of the body.

[0046] Figure 5 An insert device 500 is depicted according to one or more embodiments. The insert device includes an upper body portion 502 and a lower body portion 508 along a central axis 504. The device includes an inner surface 512 that defines and extends around a central volume of the body. The upper body portion of the insert device includes a coupling feature 516 that can mate or couple with a corresponding coupling feature of a fuel injector and / or another portion of a cylinder head. In the depicted embodiment, the coupling feature protrudes away from the inner surface of the body toward the central axis, but may alternatively extend into the inner surface and away from the central axis.

[0047] The insert device includes a plurality of gas inlet passages 518, 520 disposed about a central axis. The gas inlet passages direct gas from a location external to the insert device toward a central volume of the insert device. The device includes an upper group of gas inlet passages 518 and a lower group of gas inlet passages 520. A plurality of fuel gas mixture outlet passages 524 are disposed along the central axis between the upper group of gas inlet passages and the lower group of gas inlet passages. The fuel gas mixture outlet passages may be shaped, sized, and / or oriented to control one or more flow characteristics of the fuel gas mixture directed out of the insert device via the outlet passages. For example, Figure 5 The cross-sectional dimensions of the fuel gas mixture outlet passage shown are smaller than Figure 4 Cross-sectional dimensions of the fuel gas mixture outlet channels shown. Optionally, one or more of the outlet channels may have a shape and / or size that is different from the shape and / or size of another outlet channel.

[0048] The insert device includes a plurality of upper concave surface portions 526 and a plurality of lower concave surface portions 528 shaped to direct the flow of gas entering the central volume toward the liquid fuel in the central volume. Figure 5 In the illustrated embodiment, adjacent concave surface portions of the upper and lower groups do not intersect or merge with each other. Optionally, two adjacent concave portions may intersect or merge with each other, and other adjacent concave portions may not intersect or merge with each other. Optionally, the body of the insert device may have an alternative arrangement of parts (e.g., concave surfaces, grooves, protrusions, etc.) to control the flow of gas streams, liquid fuels, and / or fuel-gas mixtures into, within, and / or out of the device.

[0049] Figure 6 An insert device 600 is depicted according to one or more embodiments. The insert device includes a body having an inner surface 612 extending around and defining a central volume of the device. The device includes a fuel gas mixture outlet passage 624 disposed between a plurality of upper gas inlet passages 618 and lower gas inlet passages 620 along a central axis 604 of the device. The gas inlet passage directs gas to the central volume of the device, and the fuel gas mixture outlet passage directs the fuel gas mixture out of the device toward a combustion chamber of an engine cylinder.

[0050] The inner surface of the insert device may include recessed surface portions 626, 628 disposed at one or more locations along the central axis to control the flow characteristics of the gas, liquid fuel, and / or fuel gas mixture within the insert device. In one or more embodiments, the body of the insert device may be additionally formed as a unitary structure, and one or more of the inlet, outlet, recessed portion, etc. may be subsequently formed (e.g., drilled, machined, etched, etc.). For example, an insert device including a gas inlet passage, a recessed surface portion, and a coupling part 616 extending from the inner surface may be additionally formed via multiple material layers coupled together, and the fuel gas mixture outlet passage may be subsequently drilled, formed, etc.

[0051] Figure 7 An insert device 700 is depicted according to one or more embodiments. The insert device includes a body having an inner surface 712 extending around and defining a central volume. The device includes a fuel gas mixture outlet passage 724 disposed between an upper gas inlet passage 718 and a lower gas inlet passage 720 along a central axis 704. The gas inlet passage directs gas to the central volume of the device where it mixes with liquid fuel from a fuel injector (not shown). The fuel gas mixture outlet passage directs the fuel gas mixture out of the device and toward a combustion chamber of an engine cylinder.

[0052] The insert device includes a concave surface portion 728 disposed between the fuel gas mixture outlet passage and the lower gas inlet passage. The concave surface portion directs gas from the lower gas inlet passage within the device. Figure 3 Unlike the insert device shown, the insert device does not include a concave surface portion disposed between the upper gas inlet channel and the fuel gas mixture outlet channel. Instead, the insert device includes an inclined edge 726 surrounding the central axis. The inclined edge is disposed between the upper gas inlet channel and the fuel gas mixture outlet channel. For example, the concave surface portion is disposed on a first side of the fuel gas mixture outlet channel, and the inclined edge is disposed on a second side of the fuel gas mixture outlet channel opposite the first side.

[0053] The inclined edge has an inclined surface 730 oriented toward the fuel gas mixture outlet passage. For example, the inclined surface extends in a radial direction away from the central axis and is inclined between the upper gas inlet passage and the fuel gas mixture outlet passage. The inclined edge may be referred to as a chamfered surface, a chamfered feature, etc. The inclined surface is oriented to promote movement of gas from the upper gas inlet passage toward the central volume to mix or combine with the liquid fuel.

[0054] Figure 8 An insertion device 800 is shown according to one or more embodiments. Figures 3 to 7The insert device is similar to that shown and includes a body having an inner surface 812 defining a central volume of the device. The device includes a fuel gas mixture outlet passage 824 disposed along the central axis 804 between an upper gas inlet passage 818 and a lower gas inlet passage 820. The gas inlet passage directs gas to the central volume of the device where it mixes with liquid fuel from a fuel injector.

[0055] and Figure 7 The insert device shown is similar, and includes an inclined edge 830 disposed on one side of the fuel gas mixture outlet passage, and a concave surface portion 828 disposed on the opposite side of the fuel gas mixture outlet passage. The inner surface of the insert device including the inclined edge and the concave surface portion is configured to control one or more characteristics of the gas, liquid fuel and / or fuel gas mixture.

[0056] The inner surface of the body includes an annular extension 832 protruding inwardly, which extends from the inner surface toward the central axis of the insertion device. In the illustrated embodiment, the annular extension protruding inwardly is arranged or positioned around the fuel gas mixture outlet channel. For example, the extension can be coaxial with the fuel gas mixture outlet channel. The extension can be an extension of the fuel gas mixture outlet channel, which extends or protrudes into the central volume of the device. The extension can extend around a portion of one or more of the fuel gas mixture outlet channels to control one or more characteristics (e.g., pressure, volume, speed or flow rate, direction, rotational force, etc.) of the fuel gas mixture guided out of the device via the fuel gas mixture outlet channel. In one or more embodiments, one or more inwardly protruding extensions can be arranged around the upper and / or lower gas inlet channels, the fuel gas mixture outlet channels, around one or more recessed surface portions, etc.

[0057] Fig. 9 An insert device 900 is depicted according to one or more embodiments. The insert device includes an inner surface 912 extending about a central axis 904 and defining a central volume of the device. The device includes a fuel gas mixture outlet passage 924 disposed along the central axis between an upper gas inlet passage 918 and a lower gas inlet passage 920. The gas inlet passage directs gas to the central volume of the device where it mixes with liquid fuel from a fuel injector to form a fuel gas mixture.

[0058] The insert device includes an inclined edge 930 disposed between the upper gas inlet channel and the fuel gas mixture outlet channel. In the illustrated embodiment, the inclined edge includes a convex surface between the upper gas inlet channel and the fuel gas mixture outlet channel. For example, the convex surface protrudes or extends away from the inner surface of the device so that the inner surface includes a ridge, protrusion, ridge, extension, etc. between the gas inlet channel and the outlet channel. The inclined edge is shaped to control one or more features of the gas directed into the central volume via the gas inlet channel. In one or more embodiments, the insert device may include an inclined edge disposed between the fuel gas mixture outlet channel and the lower gas inlet channel.

[0059] and Figure 8 Similar to the insert device shown, the inner surface of the body includes an inwardly protruding annular extension 932 that extends from the inner surface toward the central axis of the device. The inwardly protruding annular extension is positioned around the fuel gas mixture outlet passage. Optionally, the extension can be positioned around a portion of one or more of the fuel gas mixture outlet passages, around a portion of one or more of the gas inlet passages, etc.

[0060] Figures 3 to 9 Various embodiments of insertion devices having one or more different parts are depicted. Optionally, the insertion device may include one or more parts from any of the different insertion devices depicted.

[0061] In one or more embodiments of the subject matter described herein, an insert device includes a body having an upper body portion configured to be coupled to a cylinder head of an engine cylinder and a lower body portion extending from the upper body portion toward a combustion chamber of the engine cylinder when the upper body portion is coupled to the cylinder head. The body includes an inner surface extending around a central volume, the central volume being positioned to receive liquid fuel from a fuel injector when the upper body portion is coupled to the cylinder head. The body includes a plurality of gas inlet channels and a plurality of fuel gas mixture outlet channels. The gas inlet channels are positioned to receive gas from outside the body and guide the gas into the central volume, where the gas is mixed with the liquid fuel to form a fuel gas mixture. The fuel gas mixture outlet channels are positioned to guide the fuel gas mixture into the combustion chamber of the engine cylinder when the upper body portion is coupled to the cylinder head. The inner surface of the body includes a plurality of concave surface portions between the gas inlet channels and the fuel gas mixture outlet channels along the central axis of the body. The concave surface portions are shaped to guide the gas flow entering the central volume toward the liquid fuel in the central volume.

[0062] Optionally, the upper body portion may include an upper end positioned to face away from a combustion chamber of an engine cylinder when the upper body portion is coupled to the cylinder head. The lower body portion may include a lower set of gas inlet channels and an upper set of gas inlet channels disposed between the upper end of the upper body portion and the fuel gas mixture outlet channels, wherein the fuel gas mixture outlet channels are disposed between the upper set of gas inlet channels and the lower set of gas inlet channels.

[0063] Optionally, an upper group of recessed surface portions of the inner surface of the body may be positioned along the central axis of the body between an upper group of gas inlet channels and a fuel gas mixture outlet channel, and a lower group of recessed surface portions of the inner surface of the body may be positioned along the central axis of the body between a lower group of gas inlet channels and a fuel gas mixture outlet channel.

[0064] Optionally, the concave surface portions may include an intermediate set of concave surface portions, each concave surface portion of the intermediate set of concave surface portions being located between adjacent channels of the fuel gas mixture outlet channel.

[0065] Optionally, the concave surface portion may include one or both of an upper group of concave surface portions and a lower group of concave surface portions. The upper group of concave surface portions may be disposed above the fuel gas mixture outlet channel along the central axis, and the lower group of concave surface portions may be disposed below the fuel gas mixture outlet channel along the central axis. The concave surface portions in the middle group may merge with one or both of the upper group of concave surface portions and the lower group of concave surface portions at a position between adjacent channels of the fuel gas mixture outlet channel.

[0066] Optionally, adjacent concave surface portions may not intersect each other.

[0067] Optionally, adjacent concave surface portions may intersect each other.

[0068] Optionally, the inner surface of the body may include a sloped edge surrounding the central axis and having an inclined surface oriented toward the fuel gas mixture outlet passage.

[0069] Optionally, the concave surface portion may be provided on a first side of the fuel gas mixture outlet channel and the beveled edge may be provided on a second side of the fuel gas mixture outlet channel opposite the first side.

[0070] Optionally, the inner surface of the body may include an inwardly projecting annular extension coaxial with the fuel gas mixture outlet passage.

[0071] Optionally, the body may include multiple layers of material coupled together to form the body.

[0072] In one or more embodiments of the subject matter described herein, an insert device includes a body having an upper body portion configured to be coupled to a cylinder head of an engine cylinder and a lower body portion extending from the upper body portion toward a combustion chamber of the engine cylinder when the upper body portion is coupled to the cylinder head. The body includes an inner surface extending around a central volume, the central volume being positioned to receive liquid fuel from a fuel injector when the upper body portion is coupled to the cylinder head. The body includes a plurality of fuel gas mixture outlet passages, an upper group of gas inlet passages, and a lower group of gas inlet passages. The upper group of gas inlet passages and the lower group of gas inlet passages are positioned to receive gas from outside the body and guide the gas into the central volume, where the gas is mixed with the liquid fuel to form a fuel gas mixture. The fuel gas mixture outlet passage is positioned to guide the fuel gas mixture into the combustion chamber of the engine cylinder when the upper body portion is coupled to the cylinder head. The inner surface of the body includes a plurality of dimples between the fuel gas mixture outlet passages and the upper group of gas inlet passages and / or the lower group of gas inlet passages. The plurality of dimples are shaped to direct a flow of gas entering the central volume toward the liquid fuel in the central volume.

[0073] Optionally, the plurality of dimples may include an intermediate group of dimples, each dimple in the intermediate group of dimples being located between adjacent channels of the fuel gas mixture outlet channel.

[0074] Optionally, the upper group of dimples may be disposed above the fuel gas mixture outlet passage along the central axis, and the lower group of dimples may be disposed below the fuel gas mixture outlet passage along the central axis. The middle group of dimples may merge with the upper group of dimples and / or the lower group of dimples at a location between adjacent passages of the fuel gas mixture outlet passage.

[0075] Optionally, adjacent dimples may not intersect each other.

[0076] Optionally, adjacent dimples may intersect one another.

[0077] Optionally, the inner surface of the body may include a sloped edge surrounding the central axis and including an inclined surface oriented toward the fuel gas mixture outlet passage.

[0078] Optionally, the dimple may be provided on a first side of the fuel gas mixture outlet channel and the sloped edge may be provided on a second side of the fuel gas mixture outlet channel opposite the first side.

[0079] Optionally, the inner surface of the body may include an inwardly projecting annular extension coaxial with the fuel gas mixture outlet passage.

[0080] In one or more embodiments of the subject matter described herein, a method includes depositing a first layer onto a build surface, and sequentially depositing one or more additional layers on the first layer to form an additively manufactured body having an upper body portion configured to be coupled to a cylinder head of an engine cylinder and a lower body portion extending from the upper body portion toward a combustion chamber of the engine cylinder when the upper body portion is coupled to the cylinder head. The body is formed to have an inner surface extending around a central volume, the central volume being positioned to receive liquid fuel from a fuel injector when the upper body portion is coupled to the cylinder head. The body is formed to have a gas inlet channel and a fuel gas mixture outlet channel. The gas inlet channel is positioned to receive gas from outside the body and guide the gas into the central volume, where the gas is mixed with the liquid fuel to form a fuel gas mixture. The fuel gas mixture outlet channel is positioned to guide the fuel gas mixture into the combustion chamber of the engine cylinder when the upper body portion is coupled to the cylinder head. The inner surface of the body is formed to have a concave surface portion between the gas inlet channel and the fuel gas mixture outlet channel along the central axis of the body. The concave surface portion is shaped to direct a flow of gas entering the central volume toward the liquid fuel in the central volume.

[0081] The singular forms "a", "an" and "the" include plural references unless the context clearly indicates otherwise. "Optional" or "optionally" means that the subsequent event or situation described may or may not occur, and the description may include situations where the event occurs and situations where it does not occur. The approximate language used throughout the specification and claims can be used to modify any quantitative representation that allows variation without causing a change in the basic function associated therewith. Therefore, the value modified by one or more terms such as "about", "substantially" and "approximately" may not be limited to the specified exact value. In at least some cases, the approximate language may correspond to the accuracy of the instrument used to measure the value. In this article and throughout the specification and claims, range limitations can be combined and / or interchanged, unless the context or language indicates otherwise, such ranges can be identified and include all sub-ranges contained therein.

[0082] This written description uses examples to disclose the embodiments, including the best mode, and to enable a person of ordinary skill in the art to practice the embodiments, including making and using any devices or systems and performing any incorporated methods. The claims define the patentable scope of the disclosure, and include other examples that occur to a person of ordinary skill in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

Claims

1. An insert device for fuel injection, comprising a body having: an upper body portion configured to couple with a cylinder head of an engine cylinder; a lower body portion extending from the upper body portion toward a combustion chamber of the engine cylinder when the upper body portion is coupled to the cylinder head; an inner surface extending about a central volume, the central volume being positioned to receive liquid fuel from a fuel injector when the upper body portion is coupled to the cylinder head; an upper set of gas inlet passages and a lower set of gas inlet passages and a fuel gas mixture outlet passage disposed therebetween, wherein the upper set of gas inlet passages and the lower set of gas inlet passages are positioned to receive gas from an exterior of the body and direct the gas into the central volume where the gas mixes with the liquid fuel to form a fuel gas mixture, the fuel gas mixture outlet passage being positioned to direct the fuel gas mixture into the combustion chamber of the engine cylinder when the upper body portion is coupled to the cylinder head, Wherein, the inner surface of the main body has an upper group of concave surface portions and a lower group of concave surface portions, the upper group of concave surface portions includes two or more concave surface portions between the upper group of gas inlet channels and the fuel gas mixture outlet channels along the central axis of the main body, the lower group of concave surface portions includes two or more concave surface portions between the fuel gas mixture outlet channels and the lower group of gas inlet channels along the central axis of the main body, the upper group of concave surface portions and the lower group of concave surface portions are formed to guide the gas flow entering the central volume toward the liquid fuel in the central volume.

2. The insert device of claim 1 further comprising an intermediate set of concave surface portions, each of the intermediate set of concave surface portions being located between adjacent channels of the fuel gas mixture outlet channels.

3. The insertion device according to claim 2, wherein: The middle group of concave surface portions merges with the upper group of concave surface portions and / or the lower group of concave surface portions at locations between adjacent channels of the fuel gas mixture outlet channels.

4. The insertion device according to claim 1, wherein: The upper group of concave surface portions do not merge or couple with each other, and the lower group of concave surface portions do not merge or couple with each other.

5. The insertion device according to claim 1, wherein: Adjacent concave surface portions of the upper group are merged or coupled to each other, and adjacent concave surface portions of the lower group are merged or coupled to each other.

6. The insertion device according to claim 1, wherein: The inner surface of the body includes an inwardly protruding annular extension that is coaxial with the fuel gas mixture outlet passage.

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