Insert device for fuel injection

Abstract

An insert device for fuel injection is disclosed, comprising a first coupling body inserted into an engine cylinder head. The first coupling body extends around a central axis to define a first internal volume of the first coupling body, the first internal volume being shaped to receive a distal end of a fuel injector. The insert device comprises a second mixing body coupled to the first coupling body and extending around the central axis. The second mixing body comprises a conduit that receives fuel from the fuel injector and air from a combustion chamber, mixes the fuel with the air, and directs the fuel-air mixture into the combustion chamber. The first coupling body has a first end face positioned to face the cylinder head, and the first coupling body is tapered so that an outer diameter of the first coupling body toward the first end face is greater than an outer diameter toward the second mixing body.

Description

Technical Field

[0001] The subject matter described herein relates to apparatus and methods for mixing fuel and air into a fuel-air mixture and then 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 engine cylinder. 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] As the temperature of the gases entrained into the injected fuel remains elevated, the delay between the injection of the fuel and the ignition of the fuel-air mixture in the cylinder may decrease. This may result in the fuel spray plume having a suboptimal fuel-air mixture ratio prior to initial ignition, which may generate soot. The generation and subsequent accumulation of soot may reduce engine performance and eventually require cleaning or other repairs to the engine. Additionally, certain regulations or laws may limit how much particulate matter or other emissions an engine may generate.

[0004] Insert devices may be disposed between a fuel injector and a combustion chamber of an engine cylinder to mix fuel and air before the fuel-air mixture is introduced into the combustion chamber. These insert devices may be exposed to extreme temperatures, which may introduce mechanical stresses into the insert devices due to the fact that these devices have a different coefficient of thermal expansion (CTE) than the cylinder head to which the insert devices are connected. Such stresses may damage or destroy the insert devices and / or the cylinder head. Therefore, there is a need for insert devices that can reduce or eliminate these stresses to extend the useful life of the insert devices.

[0005] Additionally, the insert device may include a conduit for receiving fuel from a fuel injector. Due to the small distance between the fuel injector and the insert device, the conduit may be difficult to align with the hole in the fuel injector for injecting fuel. Misalignment of the conduit of the insert device and the hole in the fuel injector may interfere with the flow of fuel into the engine cylinder and may be detrimental to the operation of the cylinder. Therefore, a method of aligning the conduit of the insert device with the hole in the fuel injector is also needed. Summary of the invention

[0006] In one example, an insertion device is provided, which includes a first coupling body, which is shaped to be inserted into a receiving portion of a cylinder head of an engine cylinder. The first coupling body extends around a central axis to define a first internal volume of the first coupling body, and the first internal volume is shaped to receive one or more distal ends of a fuel injector. The insertion device also includes a second mixing body, which is connected to the first coupling body and extends around the central axis. The second mixing body includes a conduit, which is configured to receive fuel output by the fuel injector and air from a combustion chamber, combine the fuel and air into the fuel-air mixture, and guide the fuel-air mixture into the combustion chamber of the engine cylinder. The first coupling body has a first end face positioned to face the cylinder head, and the first coupling body is tapered so that the outer diameter of the first coupling body toward the first end face is greater than the outer diameter toward the second mixing body.

[0007] In another example, an insert device is provided, the insert device including a first body, the first body being shaped to mate with a cylinder head receiving portion. The first body is shaped to receive a tip of a fuel injector, from which fuel is ejected. The insert device also includes a second body formed integrally with the first body. The second body may include a body configured to receive fuel ejected by the fuel injector, mix the fuel with air into a fuel-air mixture, and direct the fuel-air mixture into an engine cylinder combustion chamber. The first body may include one or more internal chambers that allow the first body to flex and reduce thermal stresses in the first body when the first body thermally expands.

[0008] In another example, another insertion device is provided. The insertion device includes a first body and a second body, the first body being shaped to be inserted into a receiving portion of a cylinder head of an engine cylinder, the second body being coupled to the first body and including a conduit, the conduit being configured to receive fuel output by a fuel injector, mix the fuel with air drawn into the second body into a fuel-air mixture, and direct the fuel-air mixture into a combustion chamber of the engine cylinder. The first body and / or the second body includes an internal flat surface, the internal flat surface being positioned to mate with a corresponding flat portion of the fuel injector to align the fuel output from the fuel injector with the conduit in the second body. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

[0011] Figure 2 Shows Figure 1 A top perspective view of one example of an insertion device is shown;

[0012] Figure 3 Shows Figure 2 A bottom perspective view of the insertion device is shown;

[0013] Figure 4 Shows Figure 2 A side view of the insertion device is shown;

[0014] Figure 5 Shows Figure 2 A top view of the insertion device shown;

[0015] Figure 6 Shows Figure 2 a bottom plan view of the insertion device shown;

[0016] Figure 7 Shows Figure 2 A cross-sectional view of one example of an insert device is shown coupled to a cylinder head of an engine cylinder;

[0017] Figure 8 The cylinder head coupled to the engine cylinder is shown Figure 2 Another cross-sectional view of one example of an insertion device is shown;

[0018] Fig. 9 Shown along Figure 4 A cross-sectional view of the insertion device shown along line 8-8;

[0019] Fig.10 shows a top perspective view of another example of an insertion device;

[0020] Fig.11 Shows Fig.10 A bottom perspective view of the insertion device is shown;

[0021] Fig.12 Shows Fig.10 A side view of the insertion device is shown;

[0022] Fig.13 Shows Fig.10 A top view of the insertion device shown;

[0023] Fig.14 Shows Fig.10 a bottom plan view of the insertion device shown;

[0024] Fig.15 Shows Fig.10 A cross-sectional view of one example of an insert device is shown coupled to a cylinder head of an engine cylinder;

[0025] Fig.16 shows a top perspective view of another example of an insertion device;

[0026] Fig.17 Shows Fig.16 A bottom perspective view of the insertion device is shown;

[0027] Fig.18 Shows Fig.16 A side view of the insertion device is shown;

[0028] Fig.19 Shows Fig.16 A top view of the insertion device shown;

[0029] Fig. 20 Shows Fig.16 a bottom plan view of the insertion device shown;

[0030] Fig.21 Another example of an insertion device is shown; and

[0031] Fig. 22 Shows Fig.21 A cross-sectional view of an insert device coupled to a cylinder head is shown in FIG. DETAILED DESCRIPTION

[0032] Embodiments of the subject matter described herein relate to insert devices and methods for mixing fuel and gas (e.g., air) into a fuel-gas (or fuel-air) mixture and then directing the mixture into an engine cylinder. The insert device 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 different (e.g., leaner) fuel-air mixtures to be achieved before the mixture reaches the combustion zone to ignite or burn. Several concepts that contribute to modifying fuel combustion events are described herein. Although tubes and pipes can be used in some assemblies, other insert 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 experience catastrophic failures, such as explosions that occur in the pipe.

[0033] 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 placed 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 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 devices of the present disclosure described herein may also be referred to as mixing structures or mixing assemblies.

[0034] By adding these insert devices to the engine, these devices can contact the hot gas and air to act as a heat sink. In this way, the insert device can locally cool the previously hot gas / air as the gas / air is incorporated, entrained and / or swept along with the fuel flow plume within the insert device. The insert device can cool the gas that may be entrained into the fuel flow injected into the cylinder. The cooler mixture can delay ignition, thereby reducing the amount of soot generated or preventing the generation of soot altogether. Various embodiments of the insert device may be referred to as a soot reduction assembly or an engine assembly. As used herein, the term gas or gas 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 air-breathing natural gas.

[0035] Alternatively, one or more embodiments of the insert device may include a conduit aligned with an outlet of a fuel injector to form a ducted fuel injector. The fuel injector outlet may be aligned with a conduit inside the insert device and extending through the insert device (from an interior volume to an exterior surface of the insert device).

[0036] As described herein, various embodiments of the insert device include features or designs that reduce or eliminate mechanical stresses caused by exposure of the insert device to high temperatures. Reducing these stresses can extend the useful life of the insert device and / or the cylinder head.

[0037] The insert device can be manufactured using additive manufacturing methods such as three-dimensional printing, direct metal laser sintering, etc. The insert device can be formed by the same material or a combination of multiple materials. The insert device can be a homogeneous body with a consistent formula and density throughout the device body. For example, the weight, volume, or relative amount or ratio of both weight and volume of the material used to form the insert device can be the same throughout the insert device, regardless of the size or shape of any part of the insert device. Alternatively, the insert device can be a non-homogeneous body, in which the weight, volume, or relative amount or ratio of both weight and volume of the material is different in different positions of the insert device. The insert device can be integral, that is, the insert device is formed as a single piece, rather than being produced by forming separate parts and then connecting these separate parts together to form the insert device. The body of the integral insert device can be formed integrally with each other as a single body. The integrity of the insert device can be identified or verified by the absence of any seams or joints between the different parts connected together to form the insert device. Alternatively, the insert device may not be a monolithic body, that is, the insert device is formed as a plurality of separate parts, which are then connected together to form the insert device. The non-integral nature of the insert device may be identified or verified by seams or joins between the different components joined together to form the insert device.

[0038] Additive manufacturing processes for forming insert devices can involve sequentially constructing the body of the device layer by layer. Suitable processes include, for example, selective laser melting (or sintering) and binder jetting. Selective laser melting involves depositing layers of powder on a build plate and melting selected portions of the powder using an ytterbium fiber laser that scans a computer-aided design (CAD) pattern or file. Binder jetting creates parts by sandwiching metal powders with a polymer binder that binds the particles and layers together without the use of laser heating.

[0039] 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 that has a different CTE than the cylinder head or has a greater CTE difference than the portion of the insert device that contacts the cylinder head.

[0040] The insert device may be formed to have a shape that provides an interference fit between the insert device and the cylinder head. The shape of the insert device that provides an interference fit may have a taper to control the amount of interference (e.g., the force applied by the insert device on the cylinder head). For example, the tapered shape of the insert device may provide less pressure or force on the cylinder head at a location closer to the combustion chamber (where the temperature may be higher) and provide more pressure or force on the cylinder head at a location farther from the combustion chamber (where the temperature may be slightly lower).

[0041] The insert device can be formed with an internal cutout or recess that allows the insert device to flex at the interference fit area (e.g., at a location laterally between the cylinder head and the interior volume of the insert device). When the insert device becomes hot, the insert device can thermally expand, and the flexure of the insert device can be absorbed by the internal cutout or recess to reduce stress from the thermal expansion of the insert device.

[0042] A sleeve made of a ductile material may be placed (e.g., pressed) between the insert device and the cylinder head. The sleeve may reduce thermal expansion stresses in the cylinder head caused by the CTE difference between the insert device and the cylinder head. The sleeve may optionally be screwed onto or into the insert device and abut against a shoulder on the cylinder head. The sleeve may support the fuel injector and hold the insert device in place relative to the fuel injector.

[0043] The fuel injector may have flat surfaces on the outer periphery of the fuel injector. The insert device may be formed with mating flat surfaces on the outer surface. These flat surfaces of the fuel injector and the insert device may mate with each other to align the holes or conduits in the insert device (through which the fuel-air mixture passes and exits the insert device) with the holes in the fuel injector through which the fuel is injected from the fuel injector into the insert device.

[0044] Figure 1 A 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 shown. 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 embodiment shown, the insert device can be stationary because the mixing structure can be mounted or otherwise attached 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 can be fixed or otherwise coupled to or incorporated into the crown of the piston so that the insert device moves with the piston toward and away from the fuel injector.

[0045] 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, the fuel stream flows from the fuel injector through the central volume of the insert device. The pressure supplied to the fuel injector can cause all or substantially all of the fuel (e.g., at least 90%) to pass through the conduit of the insert device (after mixing with the gas, as described herein).

[0046] As fuel flows into the interior volume of the insert, the moving fuel draws gas through air passages in the device (e.g., openings along the top of the insert, such as the side of the insert facing away from the piston and generally in the direction of the fuel injector; openings above the fuel passages; openings below the fuel passages; etc.) Gases, which may be relatively hot, may be pulled through the interior of the insert such that the hot gas moves inward from the exterior of the insert to the central volume of the insert.

[0047] 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 of time 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, forming 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 soot formation, as described herein.

[0048] Optionally, the conduit can be oriented to direct the fuel-gas mixture further into the combustion chamber of the cylinder so that the fuel-gas mixture penetrates further into the combustion chamber (e.g., compared to directing the fuel and gas into the combustion chamber without using an insert device to mix 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 combination of mass and velocity of the mixture jet relative to the mass and velocity that the fuel and gas jets would have individually without premixing the fuel and gas in the insert device. For example, the jet with the mixing structure can be more restricted (e.g., narrower) than the jet without the insert device. In addition, the jet can have a lower initial mass entrainment, but a higher velocity, relative to the jet without the insert device. In the absence of the insert device, the jet may entrain more gas earlier in the flow path, which will have a high mass within the spray region and cause the spray to spread, resulting in a lower velocity and lower penetration into the cylinder. The more concentrated and faster mixture through the insertion device may cause the mixture to enter a further location in the combustion chamber, which may be further away from the insertion device (relative to not using the insertion device). As the mixture increasingly penetrates into the combustion chamber, soot oxidation within the combustion chamber may be enhanced, which may eliminate or reduce the amount of soot in the engine cylinder.

[0049] Figure 2 Shows Figure 1 A top perspective view of one example of an insertion device 100 is shown. Figure 3 Shows Figure 2 A bottom perspective view of the insertion device is shown. Figure 4 Shows Figure 2 A side view of the insertion device is shown. Figure 5 Shows Figure 2 A top view of the insertion device is shown. Figure 6 Shows Figure 2 A bottom plan view of the insertion device is shown. Figure 7 The cylinder head 602 coupled to the engine cylinder 604 is shown. Figure 2 A cross-sectional view of one example of an insertion device is shown. Figure 8 The cylinder head coupled to the engine cylinder is shown Figure 2 Another cross-sectional view of one example of an insertion device is shown.

[0050] The insertion device comprises a first coupling body 102 which is shaped to be inserted into a receiving portion 600 (at Figure 7The first coupling body may have a generally cylindrical shape with a taper, as described below. The first coupling body extends about the central axis 104 of the insert device. The central axis may extend along or parallel to the length of the fuel injector 304 (eg, Figure 7 ). The first coupling body extends around the first interior volume 106 of the insertion device and defines the first interior volume 106 of the insertion device. For example, the first coupling body can be an annular body surrounding the first interior volume. Although the first coupling body is shown as having a circular shape, alternatively, the first coupling body may not have a circular shape. For example, the first coupling body may include one or more linear sides.

[0051] The first interior volume is shaped to receive the distal end 606 ( Figure 7 As shown in Figure 7 As shown, the first internal volume can be large enough to receive the distal end and sleeve 616 (described below) without additional volume or space within the first internal volume. Alternatively, the first internal volume can be larger so that one or more open volumes or gaps are disposed between any two or more of the first coupling body, the sleeve, and the fuel injector.

[0052] The insertion device also includes a second mixing body 108 coupled to the first coupling body. The second mixing body may optionally be referred to as a second guiding body. The first body and the second body of the insertion device may be different parts of a single integral body, or may be separate components formed separately but then joined together. The second mixing body extends around the central axis of the insertion device. The second mixing body may have a flared shape or a dovetail shape extending outwardly so that the second mixing body transitions from the smaller outer diameter of the first coupling body to the larger outer diameter of the second mixing body.

[0053] The second mixing body includes a conduit 110 configured (e.g., shaped and / or positioned) to receive fuel output by the fuel injector. The conduit may be referred to as a mixture conduit. The conduit may extend from an inner surface 114 of the insert device to an outer surface 108 of the insert device. The inner surface of the insert body may extend around or otherwise around and face the central axis of the insert device. The conduit may be connected to the fuel injection hole 612 ( Figure 7 The insert device may be aligned with the orifice so that the fuel injected from the orifice is directed into a conduit in the second mixing body. The conduit and orifice may be aligned so that the direction or trajectory of the fuel does not need to be changed so that the fuel flows into and through the conduit and out of the insert device.

[0054] The conduit can also receive gas (e.g., air) from outside the insert device. For example, air can flow through the second end face 301 of the insert device and enter the internal volume of the insert device. The second end face faces the combustion chamber and is opposite to the first end face 112 (the first end face 112 is generally away from the combustion chamber and in the direction of the fuel injector). Air can be sucked into the first internal volume by the fuel flow entering and passing through the conduit of the insert device. The conduit can be shaped to mix the fuel and air in the conduit into a fuel-air mixture. For example, each conduit can have a size (e.g., inner diameter) that is reduced relative to the internal volume of the insert device. This reduced size helps to mix the fuel and air into the fuel-air mixture at a desired or specified fuel-air ratio. Changing the length of the conduit, the inner diameter of the conduit, etc. can change the ratio.

[0055] Optionally, one or more of these conduits may receive gas (e.g., air) from outside the insert device, which then flows into the interior volume of the insert device and then flows out of the insert device via one or more other conduits. There may be more conduits around the periphery of the second mixing body than the number of holes of the fuel injector through which the fuel is injected. Conduits that are not aligned with the holes of the fuel injector may receive air from outside the insert device and direct the air into the interior volume of the insert device.

[0056] The conduits may be angled in a downward direction from the inner surface or volume of the insert toward the outer surface of the insert. This angled direction may direct the fuel-air mixture in the conduits to the engine cylinders 604 ( Figure 7 Combustion chamber 610 (shown) Figure 7 Optionally, the conduit may not be inclined downward.

[0057] like Figure 8 As shown, the first coupling body may have a tapered shape to control stress between the insert device and the cylinder head. The first coupling body may be tapered because the first coupling body is wider at the first end face than at the interface between the first coupling body and the second mixing body, as shown in FIG. Figure 7As shown. The outer diameter 300 of the first coupling body can be different at different positions along the length of the first coupling body to provide the tapered shape. For example, the outer diameter can be the largest at a position closer to the first end face along the length of the first coupling body, and can be shorter at a position farther away from the first end face and closer to the second mixing body along the length of the first coupling body. The tapered shape can make the pressure generated by the interference fit between the first coupling body and the cylinder head larger along the outer surface of the first coupling body (which engages or contacts the cylinder head) at a position closer to the first end face and smaller at a position farther away from the first end face (and closer to the second mixing body). For example, during the operation of the engine cylinder, the first coupling body can be heated to a hotter temperature at a position closer to the combustion chamber of the engine cylinder relative to a position farther away from the combustion chamber. As a result, the first coupling body can thermally expand more at a position closer to the second mixing body than at a position farther away from the second mixing body, and the outer diameter of the first coupling body can increase more. Although one or more embodiments shown and described herein relate to the insertion device being mounted on the cylinder head or installed with the cylinder head, not all embodiments are limited in this way. At least one embodiment of the insert device may be installed in a liner of an engine cylinder.

[0058] The tapered shape provides a transition from (a) a clearance fit between the first coupling body and the cylinder head at or closer to the interface between the first coupling body and the second mixing body to (b) an interference fit or transition fit between the first coupling body and the cylinder head at or closer to the first end face of the first coupling body. Tapering the first coupling body can allow such thermal expansion to occur without generating excessive pressure or stress between the first coupling body and the cylinder head that could cause the cylinder head or the first coupling body to rupture or otherwise damage. The tapered shape can allow the first end of the first coupling body to maintain an interference fit or transition fit connection between the insert device and the cylinder head without damaging the insert device and the cylinder head, while the second end of the first coupling body is able to expand without contacting the cylinder head (or, if contact is made, the stress or pressure generated is reduced relative to the first coupling body that is not tapered).

[0059] In the example shown, the sleeve 616 is arranged around the fuel injector, wherein the distal end of the fuel injector extends from the second end of the sleeve (eg, Figure 7 617. The sleeve may be formed of a ductile material, such as one or more metals or metal alloys. Alternatively, the sleeve may be formed of other types of materials. The sleeve includes a curved portion forming a shoulder 617 that rests on a step 619 in the cylinder head.

[0060] The sleeve can retain a coolant (e.g., water or other cooling medium) outside the fuel injector and between the fuel injector and the inner surface of the sleeve. The second end of the sleeve is disposed between the first coupling body of the insert device and the cylinder head. The second end of the sleeve can reduce thermal expansion stress in the cylinder head caused by the CTE difference between the insert device and the cylinder head. For example, the sleeve can be compressed to absorb the expansion of the insert device.

[0061] like Figure 7 As shown, the second end of the sleeve includes external threads 614. These external threads protrude outwardly from the sleeve in a direction away from the central axis of the insertion device. Figure 2 , 3 As shown in Figures 1 and 7, the inner surface of the first coupling body of the insert device includes internal threads 118. Alternatively, the inner surface of the second mixing body of the insert device may include internal threads. These internal threads protrude inwardly from the inner surface of the first coupling body in the direction toward the central axis of the insert device. The internal threads and the external threads are formed to match each other. The sleeve and the insert device can be connected to each other and fixed to each other by screwing the insert device onto the sleeve and / or screwing the sleeve into the insert device. The sleeve can support the fuel injector and use this threaded connection to keep the insert device in a suitable position relative to the fuel injector.

[0062] Continue to refer to Figures 2 to 8 The insertion device shown, Fig. 9 Shown along Figure 4 8. The inner surface of the insertion device may include a locating plane 116. A locating plane is a portion of the inner surface that is planar or flatter than one or more other portions (or the entire remaining portion) of the inner surface. The inner surface may form a circular shape or path 801 at different distances along the central axis of the insertion device along the circumference of the inner surface. Fig. 9 As shown, the positioning plane may be a plane formed by an inner surface that is not curved like a circular shape or path.

[0063] The locating plane can be located at a position along the circumference of the inner surface, the position of which is based on the position of the conduit in the insert body. The fuel injector may include a complementary locating plane 800, the position of which is based on the position of the hole through which the fuel is injected from the fuel injector. The locating planes of the insert device and the fuel injector can be matched to each other to align the rotational position of the first coupling body with a specified orientation in the cylinder head. The specified orientation can align the mixture conduit of the insert device with the hole of the fuel injector. For example, when the locating plane of the insert device matches the locating plane of the fuel injector, the conduit of the insert device is aligned with the hole of the fuel injector. During the installation process of the insert device, the fit of the locating planes against each other can be detected or felt to ensure that the insert device is properly aligned with the fuel injector.

[0064] Fig.10 A top perspective view of another example of an insertion device 900 is shown. The insertion device 900 may represent Figure 1 Insertion device 100 is shown. Fig.11 Shows Fig.10 A bottom perspective view of the insertion device is shown. Fig.12 Shows Fig.10 A side view of the insertion device is shown. Fig.13 Shows Fig.10 A top view of the insertion device is shown. Fig.14 Shows Fig.10 A bottom plan view of the insertion device is shown. Fig.15 The cylinder head 1402 coupled to the engine cylinder 1404 is shown. Fig.10 A cross-sectional view of one example of an insertion device is shown.

[0065] Insert device 900 can be similar to insert device 100. For example, insert device 900 can include a first coupling body 902 having an end surface 112 and a second mixing body 908 having a conduit 110. The first coupling body and the second mixing body can extend about a central axis 904 and define a central interior volume 906. The first coupling body includes an inner surface 914 that can have the internal threads 118 described above. As described below, the insert device can be coupled to a cylinder head to receive and mix fuel and air before introducing the fuel-air mixture into a combustion chamber of an engine cylinder.

[0066] One difference between the insertion devices 100 and 900 is the presence of external threads 918 along the outer surface of the first coupling body of the insertion device 900. The external threads may protrude outwardly from the first coupling body in a direction away from the central axis. Fig.15 As shown, the insert device is received in the receiving portion 1400 of the cylinder head 1402. Figure 7 Compared to the illustrated cylinder head 602, the cylinder head 1402 may include internal threads 1406 that protrude inwardly (eg, toward the insert device and toward each other). The external threads of the insert device may mate with the internal threads of the cylinder head to secure the insert device to the cylinder head.

[0067] Fig.16 A top perspective view of another example of an insertion device 1500 is shown. The insertion device 1500 may represent Figure 1 Insertion device 100 is shown. Fig.17 Shows Fig.16 A bottom perspective view of the insertion device is shown. Fig.18 Shows Fig.16 A side view of the insertion device is shown. Fig.19 Shows Fig.16A top view of the insertion device is shown. Fig. 20 Shows Fig.16 A bottom plan view of the insertion device is shown.

[0068] Similar to the insertion device 100, Figures 16 to 21 The insert device shown in includes a tapered first coupling body 1502 that is shaped to be inserted into a receiving portion of a cylinder head of an engine cylinder. The first coupling body extends around a central axis 1504 of the insert device. When the insert device is coupled to the cylinder head, the central axis may extend along or parallel to the length of the fuel injector. Similar to the first coupling body 102 and the first internal volume 106, the first coupling body extends around and defines a first internal volume 1506 of the insert device. The first internal volume is shaped to accommodate the distal end of the fuel injector. As shown in FIG. Fig.21 As shown, similar to the insertion device 100, the first internal volume can be large enough to accommodate the distal end and the sleeve of the fuel injector. Alternatively, the first internal volume can be larger so that one or more open volumes or gaps are disposed between any two or more of the first coupling body, the sleeve, and the fuel injector.

[0069] The insertion device 1500 also includes a second mixing body 1508 coupled to the first coupling body. The second mixing body may optionally be referred to as a second guiding body. The first body and the second body of the insertion device may be different parts of a single integral body, or may be separate components formed separately but then joined together. The second mixing body extends around the central axis of the insertion device. The second mixing body has a flared shape or dovetail shape extending outwardly, so that the second mixing body transitions from the smaller outer diameter of the first coupling body to the larger outer diameter of the second mixing body.

[0070] The second mixing body includes the above-mentioned conduit 110 and an additional conduit 1510. In one embodiment, the conduit 1510 is an air or gas conduit through which air is received from outside the insert device. The air flows through the air conduit into the interior volume of the insert device, entrains the fuel injected by the fuel injector, and exits the insert device as a fuel-air mixture through the conduit 110 (which may be referred to as a mixture conduit). Similar to the mixture conduit, the air conduit may extend from the inner surface 1514 of the insert device to the outer surface 1508 of the insert device. The inner surface of the insert body may extend around the central axis of the insert device or otherwise around the central axis of the insert device and face the central axis. The mixture conduit may be aligned with the orifice of the fuel injector so that the fuel injected from the orifice is directed into the mixture conduit in the second mixing body, as described above.

[0071] like Fig.16 and 19As shown, the insert device may include a locating flat 1516 that is similar or identical to the locating flat. As described above, the locating flat may engage or mate with a complementary locating flat of the fuel injector to align the mixture conduit of the insert device with the bore of the fuel injector.

[0072] The insertion device may include an internal recess or cutout 1518 defining an internal chamber in the insertion device. Fig.16 and 19 As shown, the recesses or cutouts can be voids extending inwardly from the first end face 1512 of the insert device into the insert device. The first end face can face upward in the direction of the fuel injector. Internal recesses or cutouts are voids in the first coupling body that can extend from the first end face into the insert device, but do not extend all the way to the second mixing body. Alternatively, these internal recesses or cutouts can be voids in the first coupling body that extend from the first end face all the way into the insert device to the second mixing body. In another embodiment, the internal recesses or cutouts can be voids in the first coupling body that are located between the first end face and the second mixing body, but do not open along the first end face (with the first end face opening being the same as the second mixing body). Fig.16 and 19 The embodiment shown is the opposite).

[0073] The internal recess or cutout allows the first coupling body to bend inwardly and / or around the internal recess or cutout. This can reduce thermal stresses in the first coupling body when the first coupling body expands thermally. For example, the thermal expansion of the insert device can be greater than the thermal expansion of the cylinder head. The increasing size of the insert device can be absorbed by bending the insert device inwardly into the gap created by the internal recess or cutout.

[0074] Fig.21 Another example of an insertion device 2100 is shown. Fig. 22 The cylinder head 2202 is shown connected to the Fig.21 A cross-sectional view of the insertion device shown. Similar to other insertion devices described herein, Fig.21 and Fig. 22 The insert device shown in comprises a first coupling body 2102 configured to receive the distal end of a fuel injector and a second mixing body 2104 having a mixture conduit 110 through which a fuel-air mixture is directed into a combustion chamber of an engine cylinder.

[0075] The insert device includes an alignment receiver 2106 in which an alignment pin or key 2108 is disposed. Alternatively, the alignment pin or key may be additively formed with the insert device so that the insert device and the alignment pin or key are a single, monolithic body. The cylinder head may include a complementary alignment receiver 2110. The alignment receivers of the insert device and the cylinder head may receive opposite ends of the same elongated alignment pin or key to align the rotational position of the first coupling body to a specified orientation within the cylinder head. The specified orientation may align the mixture conduit of the insert device with the bore of the fuel injector.

[0076] For example, the receiving portion in the insert device may be located at a position on the second mixing body that is based on the position of the conduit in the insert body. The receiving portion in the cylinder head may also be located at a position that is based on the position of the fuel injector hole. An alignment pin or key may be received in both receiving portions (or may be received in the receiving portion of the cylinder head) to align the conduit of the insert device with the hole of the fuel injector.

[0077] The method for forming one or more insertion devices described herein may include depositing or printing a first layer of material on a build surface. The method may also include sequentially depositing or printing a layer of material or multiple successive layers of material on the first layer and / or on top of each other. The process may continue until the formation of the insertion device is complete.

[0078] In one example, an insertion device is provided, which includes a first coupling body, which is shaped to be inserted into a receiving portion of a cylinder head of an engine cylinder. The first coupling body extends around a central axis to define a first internal volume of the first coupling body, and the first internal volume is shaped to receive a distal end of a fuel injector. The insertion device also includes a second mixing body, which is coupled to the first coupling body and extends around the central axis. The second mixing body includes a conduit, which is configured to receive fuel output by the fuel injector and air from a combustion chamber, combine the fuel and air into the fuel-air mixture, and guide the fuel-air mixture into the combustion chamber of the engine cylinder. The first coupling body has a first end face positioned to face the cylinder head, and the first coupling body is tapered so that the outer diameter of the first coupling body toward the first end face is greater than the outer diameter toward the second mixing body.

[0079] Optionally, the first coupling body is shaped to provide an interference fit between the first coupling body and the cylinder head. The first coupling body can be shaped to provide an interference fit between the first coupling body and the cylinder head, with a lower interference pressure at a position closer to the combustion chamber than at other positions closer to the first end face. The first coupling body and the second guide body can be different parts of a single body without a seam or joint between the first coupling body and the second guide body. The first coupling body may include one or more inner chambers. The first coupling body can be configured to bend around one or more inner chambers and reduce thermal stress in the first coupling body when the first coupling body thermally expands.

[0080] The first coupling body and / or the second mixing body may include an inner surface extending around the central axis. The inner surface may include a positioning plane, which is positioned to match the corresponding flat surface of the fuel injector. The positioning plane can be positioned relative to the conduit in the second guide body so that the conduit is aligned with the fuel injection hole of the fuel injector, and the positioning plane matches the flat surface of the fuel injector. The first coupling body and / or the second mixing body may include an internal threaded surface, which is shaped to match the external threaded surface of the sleeve in which the fuel injector is disposed. The first coupling body may include an external threaded surface, which is shaped to match the internal threaded surface of the cylinder head.

[0081] In another example, an insert device is provided, the insert device including a first body, the first body being shaped to mate with a cylinder head receiving portion. The first body is shaped to receive a tip of a fuel injector, from which fuel is ejected. The insert device also includes a second body formed integrally with the first body. The second body may include a body configured to receive fuel ejected by the fuel injector, mix the fuel with air into a fuel-air mixture, and direct the fuel-air mixture into an engine cylinder combustion chamber. The first body may include one or more internal chambers that allow the first body to flex and reduce thermal stresses in the first body when the first body thermally expands.

[0082] Optionally, the first body has a tapered shape such that an outer diameter of the first body is greater at a location farther from the second body than at a first location closer to the second body. The tapered shape of the first body can provide an interference fit between the first body and the engine cylinder head, wherein an interference pressure between the first body and the engine cylinder head at a location farther from the second body is lower than an interference pressure between the first body and the engine cylinder head at a location closer to the second body. The first body and the second body can be different parts of a single additively manufactured body without a seam or joint between the first body and the second body.

[0083] In another example, another insertion device is provided. The insertion device includes a first body and a second body, the first body being shaped to be inserted into a receiving portion of a cylinder head of an engine cylinder, the second body being coupled to the first body and including a conduit, the conduit being configured to receive fuel output by a fuel injector, mix the fuel with air drawn into the second body into a fuel-air mixture, and direct the fuel-air mixture into a combustion chamber of the engine cylinder. The first body and / or the second body includes an internal flat surface, the internal flat surface being positioned to mate with a corresponding flat portion of the fuel injector to align the fuel output from the fuel injector with the conduit in the second body.

[0084] Optionally, the first body may have a tapered shape having an outer diameter at a first position farther from the second body that is greater than an outer diameter at a position closer to the second body. The first body and the second body may be different parts of a single additively manufactured body, with no seam or joint between the first body and the second body. The first body may include one or more internal cutouts or recesses that allow the first body to bend and reduce thermal stresses in the first body when the first body expands thermally. The first body and / or the second body may include an internal threaded surface that is shaped to match an external threaded surface of a sleeve in which a fuel injector is disposed. The first body may include an external threaded surface that is shaped to match an internal threaded surface of a cylinder head.

[0085] In one embodiment, different bodies described in conjunction with different embodiments or figures can be combined with each other. For example, the first body 102 can be combined with one or more second bodies 108, 908, 1508, 2104 to form an insertion device, the first body 902 can be combined with one or more second bodies 108, 908, 1508, 2104 to form an insertion device, the first body 1502 can be combined with one or more second bodies 108, 908, 1508, 2104 to form an insertion device, or the first body 2102 can be combined with one or more second bodies 108, 908, 1508, 2104 to form an insertion device. Optionally, the relative positions of the first and second bodies can be switched. For example, the second body 108 can be at the position of the first body 102 and the first body 102 can be at the position of the second body 108, the second body 908 can be at the position of the first body 902 and the first body 902 can be at the position of the second body 908, and so on. In addition, the first body of one embodiment may be combined with the second body of another embodiment, and the positions of the first body and the second body may be switched with each other.

[0086] Unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" include plural references. "Optional" or "optionally" means that the event or situation described subsequently may or may not occur, and this specification may include instances where the event occurs and instances where the event does not occur. As used herein throughout the specification and claims, approximate language may be used to modify any quantitative representation that may allow variation without causing a change in the basic function to which it may relate. 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 instances, approximate language may correspond to the accuracy of the instrument used to measure the value. Here and throughout the specification and claims, range limitations may be combined and / or interchanged, unless otherwise indicated by the context or language, such ranges may be identified and include all sub-ranges included therein.

[0087] This written description uses examples to disclose embodiments, including the best mode, and to enable persons skilled 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 persons skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that are the same as the literal language of the appended claims, or if they include equivalent structural elements that are insubstantially different from the literal language of the claims.

Claims

1. An insert device for fuel injection, comprising: a first coupling body shaped to be inserted into a receiving portion of a cylinder head of an engine cylinder, the first coupling body having a first inner surface about and extending about a central axis to define a first interior volume of the first coupling body, the first interior volume being shaped to receive a distal end of a fuel injector; and a second mixing body coupled to the first coupling body and extending about the central axis, the second mixing body having a second inner surface surrounding and extending about the central axis to define a second interior volume of the second mixing body, the second mixing body including a conduit extending from the second inner surface through the second mixing body, the conduit being configured to receive fuel output by the fuel injector and air from a combustion chamber of the engine cylinder, combine the fuel with the air into a fuel-air mixture, and direct the fuel-air mixture into the combustion chamber of the engine cylinder, The first coupling body has a first end surface positioned to face the cylinder head, and the first coupling body is tapered so that an outer diameter of the first coupling body toward the first end surface is larger than an outer diameter toward the second mixing body. 2 . The insert device of claim 1 , wherein the first coupling body is shaped to provide an interference fit between the first coupling body and the cylinder head.

3. An insertion device according to claim 2, wherein the first connecting body is formed to provide an interference fit between the first connecting body and the cylinder head, wherein the interference pressure between the first connecting body and the cylinder head at a second position toward the combustion chamber is lower than the interference pressure between the first connecting body and the cylinder head at a first position toward the first end face.

4. The insertion device of claim 1, wherein the first coupling body and the second hybrid body are different parts of a single body without a seam or joint between the first coupling body and the second hybrid body.

5. The insertion device of claim 1, wherein the first coupling body includes one or more internal chambers extending from the first end surface of the first coupling body to the first coupling body.

6. The insertion device of claim 5, wherein the first coupling body is configured to bend around the one or more internal chambers and reduce thermal stress in the first coupling body when the first coupling body thermally expands.

7. The insert device of claim 1, the first inner surface or the second inner surface includes a locating flat surface positioned to mate with a corresponding flat surface of the fuel injector.

8. The insert device of claim 7, wherein the locating plane is positioned relative to the conduit in the second mixing body such that the conduit is aligned with a fuel injection hole of the fuel injector while the locating plane matches the planar surface of the fuel injector.

9. The insert device of claim 1, wherein one or more of the first coupling body or the second mixing body includes an internal threaded surface shaped to mate with an external threaded surface of a sleeve in which the fuel injector is seated.

10. The insert device of claim 1, wherein the first coupling body includes an external threaded surface shaped to mate with an internal threaded surface of the cylinder head.

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