Method and system for a fuel injector

Abstract

Methods and systems for a duct fuel injector are provided. In one example, the method may include adjusting a temperature of combustion chamber gases in a combustion chamber and / or adjusting a fuel rail pressure in response to an amount of light sensed by a photodiode of the duct.

Description

Technical Field

[0001] The present description generally relates to methods and systems for a fuel injector including an air entrainment feature.

[0002] Background technology / invention content

[0003] In a diesel engine, during the intake stroke, air is drawn into the combustion chamber by opening one or more intake valves. Then, during the subsequent compression stroke, the intake valve closes, and the reciprocating piston of the combustion chamber compresses the gas that entered during the intake stroke, thereby raising the temperature of the gas in the combustion chamber. Fuel is then injected into the hot, compressed gas mixture in the combustion chamber, causing the fuel to burn. Therefore, in a diesel engine, due to the high temperature of the air, the fuel may burn with the air in the combustion chamber and may not ignite via the spark plug as in a gasoline engine. The burning air-fuel mixture pushes against the piston, driving the piston's motion, which is then converted into rotational energy of the crankshaft.

[0004] However, the inventors have recognized potential problems with such diesel engines. As an example, diesel fuel may not mix evenly with the air in the combustion chamber, resulting in the formation of dense bubbles of fuel vapor in the combustion chamber. When the fuel burns, these dense fuel areas may produce soot. Therefore, conventional diesel engines include particulate filters for reducing the amount of soot and other particulate matter in their emissions. However, such particulate filters result in increased costs and increased fuel consumption.

[0005] Modern technology for mitigating engine soot output includes features for entraining the fuel with air prior to injection. This can include passages located in the injector body inserted as an insert into the engine cylinder head plate surface or into the engine cylinder head. Ambient air mixes with the fuel, cooling the injection temperature before delivering the mixture to the compressed air in the cylinder. By entraining the fuel with cooling air prior to injection, the lift-off length is extended and the start of combustion is delayed. This limits soot generation through a range of engine operating conditions, reducing the need for particulate filters.

[0006] However, the inventors herein have recognized potential problems with such injectors. As an example, in accordance with increasingly stringent emission standards, the previously described fuel injectors may no longer be sufficient to prevent soot generation to a desired level. Therefore, a particulate filter may be positioned in the exhaust passage, thereby increasing the manufacturing cost and packaging constraints of the vehicle.

[0007] In one example, the above problem can be solved by a system including a combustion chamber, the combustion chamber including a conduit, the conduit including at least one flow passage, the flow passage being configured to receive a fuel injection and combustion chamber gases, the flow passage including a first diameter upstream that is greater than a second diameter, a second diameter upstream that is greater than a third diameter, and wherein a first difference between the first diameter and the second diameter is greater than a second difference between the second diameter and the third diameter. In this way, when pre-ignition is detected in the passage, soot generation is limited or prevented.

[0008] As an example, the circulation channel is integrated into one or more of a conduit and a nozzle tip of a fuel injector. The first diameter corresponds to an inlet of the circulation channel and the third diameter corresponds to an outlet of the circulation channel. Additionally or alternatively, the first diameter may be a maximum diameter of the circulation channel and the third diameter may be a minimum diameter of the circulation channel. This may provide a circulation channel having a generally trumpet shape. By doing so, the duration that a fuel injection resides in the circulation channel may be reduced relative to a circulation channel having a fixed diameter. In this way, particulate matter output may be mitigated and / or prevented.

[0009] It should be understood that the above summary is provided to introduce some concepts further described in the detailed description in a simplified form. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is solely defined by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages described above or in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A schematic diagram of an exemplary engine system including conduits for entraining air with fuel is shown.

[0011] Figure 2A A side cross-sectional view of the injector and conduit is shown.

[0012] Figure 2B A detailed view of a single channel of the pipeline is shown.

[0013] Figure 2C A perspective view of the pipeline is shown.

[0014] Figure 2A , Figure 2B and Figure 2C Shown approximately to scale.

[0015] Figure 3 A method of adjusting cylinder operating conditions in response to emissions output is shown.

[0016] Figure 4 Shown based on Figure 1 Implementation Figure 3 The operating sequence of the engine system of the method shown in FIG. DETAILED DESCRIPTION

[0017] The following description relates to systems and methods for injecting fuel into engine cylinders. In particular, the following description relates to systems and methods for injecting diesel fuel. Figure 1 The engine system shown may include one or more engine cylinders, each engine cylinder including at least one fuel injector. The fuel injector may be a direct injector, which injects fuel directly into the engine cylinder. However, when injected directly into the cylinder, the diesel fuel may not mix evenly with the air in the cylinder, resulting in a denser and / or low oxygen fuel vapor bubble in the cylinder, wherein soot may be generated during the combustion cycle.

[0018] In order to reduce the amount of soot produced by the engine, an air passage may be included in the engine. Specifically, the air passage may be positioned in a portion of a nozzle of a fuel injector that is in fluid communication with and within a combustion chamber. In this manner, gas from the combustion chamber may flow through the air passage, where the gas may be mixed with the fuel injection prior to combustion. This may improve air-fuel mixing and reduce the likelihood of fuel vapor bubble formation.

[0019] To further reduce the amount of soot produced by the engine, one or more conduits may be associated with each fuel injector of the engine. The conduits may include one or more air entrainment features configured to mix the cylinder air with the fuel injection prior to injection. In one example, the air entrainment feature corresponds to the outlet of the cooling air passage. This may prevent pre-ignition of the fuel injection while extending the lift-off length and delaying the start of ignition. Thus, the uniformity of the air-fuel mixture is increased and the formation of fuel vapor bubbles in the cylinder is mitigated.

[0020] In some instances, such as Figure 2A In the example described in , the air passage can be included in a duct that is coupled to the fuel injector and protrudes into the cylinder space below the cylinder head. The duct is configured to increase air-fuel mixing via surface features located therein. The air passage of the duct is Figure 2B is shown in a more detailed view. Figure 2C The duct is shown in more detail in FIG. 1 , including the outlet of its air passage.

[0021] In some examples, methods and systems include adjusting engine operating parameters based on in-cylinder and / or in-nozzle or in-duct conditions. For example, a photodiode may monitor light emitted in a duct and / or nozzle to indicate combustion in the duct and / or nozzle. Figure 3 A method for adjusting engine operating parameters based on emitted light is shown in FIG. Figure 4 The Figure 3 An exemplary timeline for adjusting an engine operating parameter of a method.

[0022] Figures 1 to 2C Exemplary configurations under the relative positioning of various components are shown. If shown as directly contacting each other or directly connected, then at least in one example, these elements can be referred to as directly contacting or directly connected respectively. Similarly, at least in one example, the elements shown as being adjacent to each other or adjacent to each other can be adjacent to each other or adjacent to each other respectively. As an example, the components placed in coplanar contact with each other can be referred to as coplanar contact. As another example, in at least one example, the elements positioned to be separated from each other with only intervals therebetween and without other components can be referred to as such. As another example, the elements shown as above / below each other, on the sides opposite to each other or on the left / right sides of each other can be referred to as such relative to each other. In addition, as shown in the figure, in at least one example, the topmost element or the topmost point of an element can be referred to as the "top" of a component, and the bottommost element or the bottommost point of an element can be referred to as the "bottom" of a component. As used herein, top / bottom, upper / lower, above / below can be relative to the vertical axis of the accompanying drawings, and are used to describe the positioning of the elements in the accompanying drawings relative to each other. Thus, in one example, elements shown as being above other elements are positioned vertically above other elements. As yet another example, the shapes of the elements depicted in the drawings may be referred to as having those shapes (e.g., such as circular, straight, flat, curved, rounded, chamfered, angled, etc.). In addition, in at least one example, elements shown as intersecting each other may be referred to as intersecting elements or intersecting each other. In addition, in one example, elements shown as being within another element or elements shown as being outside another element may be referred to as such. It should be understood that one or more components referred to as "substantially similar and / or identical" differ from one another according to manufacturing tolerances (e.g., within a deviation of 1%-5%).

[0023] Notice, Figure 2A and Figure 2B Arrows are shown indicating where there is space for gas flow, and solid lines of device walls show where flow is blocked and communication is not possible due to the lack of fluid communication created by the device walls spanning from one point to another. The walls create separations between areas except for openings in the walls that allow for said fluid communication.

[0024] The air in the combustion chamber can pass through the air passages, and a more thorough and uniform mixing of the fuel and air can be achieved before combustion. Specifically, the flotation length, which is a term commonly used by those skilled in the art to describe the distance between the fuel spray and the combustion flame, can be increased. Therefore, the fuel may entrain more air before combustion. Therefore, combustion can be delayed and air entrainment of the fuel can be increased, resulting in a more complete and soot-free combustion.

[0025] Figure 1 An engine system 100 for a vehicle is depicted. The vehicle may be a road vehicle having drive wheels in contact with a road surface. The engine system 100 includes an engine 10 including a plurality of cylinders. Figure 1 One such cylinder or combustion chamber is illustrated in detail. The various components of engine 10 may be controlled by electronic engine controller 12 .

[0026] The engine 10 includes a cylinder block 14 including at least one cylinder bore 20 and a cylinder head 16 including an intake valve 152 and an exhaust valve 154. In other examples, in examples where the engine 10 is configured as a two-stroke engine, the cylinder head 16 may include one or more intake and / or exhaust passages. The cylinder block 14 includes a cylinder wall 32, wherein a piston 36 is located in the cylinder wall 32 and connected to a crankshaft 40. The cylinder bore 20 may be defined as a volume surrounded by the cylinder wall 32. The cylinder head 16 may be coupled to the cylinder block 14 to surround the cylinder bore 20. Thus, when coupled together, the cylinder head 16 and the cylinder block 14 may form one or more combustion chambers. Specifically, the combustion chamber 30 may be a volume included between the top surface 17 of the piston 36 and the fire plate 19 of the cylinder head 16. Thus, the volume of the combustion chamber 30 is adjusted based on the swing of the piston 36. Combustion chamber 30 may also be referred to herein as cylinder 30. Combustion chamber 30 is shown communicating with intake manifold 144 and exhaust manifold 148 via respective intake valve 152 and exhaust valve 154. Each intake valve and exhaust valve may be operated by an intake cam 51 and an exhaust cam 53. Alternatively, one or more of the intake and exhaust valves may be operated by an electromechanically controlled valve coil and armature assembly. The position of intake cam 51 may be determined by intake cam sensor 55. The position of exhaust cam 53 may be determined by exhaust cam sensor 57. Thus, when valves 152 and 154 are closed, combustion chamber 30 and cylinder bore 20 may be fluidly sealed such that gas does not enter or leave combustion chamber 30.

[0027] Combustion chamber 30 may be formed by cylinder wall 32, piston 36, and cylinder head 16 of cylinder block 14. Cylinder block 14 may include cylinder wall 32, piston 36, crankshaft 40, etc. Cylinder head 16 may include one or more fuel injectors (such as fuel injector 66), one or more intake valves 152, and one or more exhaust valves (such as exhaust valve 154). Cylinder head 16 may be coupled to cylinder block 14 via fasteners (such as bolts and / or screws). Specifically, when coupled, cylinder block 14 and cylinder head 16 may be in sealing contact with each other via gaskets, and thus cylinder block 14 and cylinder head 16 may seal combustion chamber 30 so that only gas can flow into and / or out of combustion chamber 30 via intake manifold 144 when intake valve 152 is open, and / or flow into and / or out of combustion chamber 30 via exhaust manifold 148 when exhaust valve 154 is open. In some examples, each combustion chamber 30 may include only one intake valve and one exhaust valve. However, in other examples, engine 10 may include more than one intake valve and / or more than one exhaust valve in each combustion chamber 30 .

[0028] The conduit 18 is located below the cylinder head 16 in the combustion chamber 30. Specifically, the conduit 18 is located entirely within the volume of the combustion chamber 30. Alternatively, the conduit 18 is located partially within the combustion chamber 30 and within the cylinder head 16. The portion of the conduit 18 located in the combustion chamber 30 may be configured with one or more air passages for mixing fuel from the fuel injector 66 with the combustion chamber gases, as described below. Figure 2A , Figure 2B and Figure 2C In some examples, additionally or alternatively, conduit 18 may be omitted and injector 66 may extend through cylinder head 16 and into combustion chamber 30. The portion of injector 66 located in combustion chamber 30 below cylinder head 16 may be machined with air passages for mixing fuel from fuel injector 66 with combustion chamber gases, as will be described below. Figure 3 As described in.

[0029] Thus, the cylinder wall 32, the piston 36, and the cylinder head 16 may form a combustion chamber 30, wherein the top surface 17 of the piston 36 serves as a bottom wall of the combustion chamber 30, and the opposing surface or the fire shield 19 of the cylinder head 16 forms a top wall of the combustion chamber 30. Thus, the combustion chamber 30 may be a volume included within the top surface 17 of the piston 36, the cylinder wall 32, and the fire shield 19 of the cylinder head 16.

[0030] Fuel injector 66 may be positioned to inject fuel directly into combustion chamber 30, which is known as direct injection to those skilled in the art. Specifically, fuel injector 66 is positioned to inject fuel directly into a portion of conduit 18 located in combustion chamber 30. Therefore, fuel may flow from injector 66 through conduit 18 and then into combustion chamber 30. Fuel injector 66 delivers liquid fuel in proportion to the pulse width FPW of a signal from controller 12. Fuel is delivered to fuel injector 66 by a fuel system (not shown) including a fuel tank, a fuel pump, and a fuel rail. Operating current is supplied to fuel injector 66 from driver 68, which responds to controller 12. In some examples, engine 10 may be a diesel engine, and the fuel tank may include diesel fuel, which may be injected into combustion chamber 30 by injector 66. However, in other examples, engine 10 may be a gasoline engine, and the fuel tank may include gasoline fuel, which may be injected into the combustion chamber by injector 66. Further, in the example where engine 10 is configured as a gasoline engine, engine 10 may include a spark plug to initiate combustion in combustion chamber 30 .

[0031] In some examples, duct 18 may be included to reduce the temperature of air entrained by the fuel injected from injector 66. Specifically, when the fuel leaves injector 66 during fuel injection, the fuel may travel a distance while mixing with the air in duct 18 before combustion. In the description herein, the distance traveled by the fuel spray before combustion may be referred to as a "floatation length." Specifically, the floatation length may refer to the distance traveled by the injected fuel before the combustion process begins. Thus, the floatation length may be the distance between the orifice of injector 66, from which the fuel leaves injector 66, and the point in the combustion chamber 30 where fuel combustion occurs.

[0032] The conduit 18 can reduce the temperature of the gas mixed with the fuel before combustion in the combustion chamber 30. In addition, the conduit 18 can achieve a higher axial spray velocity for injecting fuel from the injector 66 in and at the outlet of the conduit 18, thereby increasing air entrainment with fuel injection and fuel penetration into the combustion chamber 30. In this way, the flotation length of the fuel spray can be increased and / or the amount of air entrainment in the fuel spray can be increased. The conduit 18 can be positioned inside the combustion chamber 30 and in fluid communication with the combustion chamber 30 so that the gas in the combustion chamber 30 can enter one or more flow channels of the conduit 18 and recirculate back into the combustion chamber 30. As an example, the intake air introduced into the combustion chamber 30 during the intake stroke can be pushed into the conduit 18 during all or a portion of the compression stroke. In other examples, the conduit 18 can be partially positioned outside the combustion chamber 30, so that at least a portion of the conduit 18 can be positioned inside the combustion chamber 30, and the remaining portion can be positioned in the cylinder head 16 outside the combustion chamber 30.

[0033] In some instances, such as in Figure 1 In some examples, when coupled in a road vehicle, the duct 18 can be positioned vertically below the cylinder head 16 relative to the ground. In some examples, substantially all of the duct 18 can be positioned outside of the cylinder head 16, such that no portion of the duct 18 extends into the cylinder head 16. However, in other examples, a portion of the duct 18 can extend into the cylinder head 16.

[0034] In some instances, such as Figure 1 In the example shown in FIG. 1 , the conduit 18 may be positioned between one or more outlets of the fuel injector 66 and the combustion chamber 30. Thus, the fuel injected by the injector 66 may pass through the conduit 18 before entering the combustion chamber 30. Specifically, the injector 66 may be coupled to the top of the conduit 18, wherein the flow passage of the conduit 18 is open to the combustion chamber 30. For example, as described below with reference to Figure 2A As depicted, the top and / or upper portion of conduit 18 may be pressed against fire shield 19 of cylinder head 16, and / or may be integrally formed as a portion of fire shield 19. Thus, fuel may be injected from injector 66 and may exit injector 66 from a location vertically above combustion chamber 30 and cylinder block 14, and vertically above fire shield 19 of cylinder head 16.

[0035] A glow plug may additionally be included to heat the fuel injected by fuel injector 66 to increase combustion during, for example, engine starting or engine cold start. In some examples, such as examples where conduit 18 is included between fuel injector 66 and combustion chamber 30, the glow plug may be coupled to conduit 18 and may extend into conduit 18. In other examples, the glow plug may be coupled to combustion chamber 30 and may extend into combustion chamber 30.

[0036] Intake manifold 144 is shown communicating with optional electronic throttle 62, which adjusts a position of throttle plate 64 to control air flow to engine cylinders 30. This may include controlling the air flow of pressurized air from intake boost chamber 146. In some embodiments, throttle 62 may be omitted, and air flow to the engine may be controlled via a single intake system throttle (AIS throttle) 82 coupled to intake passage 42 and located upstream of intake boost chamber 146. In other examples, throttle 82 may be omitted, and air flow to the engine may be controlled utilizing throttle 62.

[0037] In some embodiments, engine 10 is configured to provide exhaust gas recirculation or EGR. When EGR is included, EGR can be provided as high pressure EGR and / or low pressure EGR. In an example where engine 10 includes low pressure EGR, low pressure EGR can be provided to the engine intake system via EGR passage 135 and EGR valve 138 at a position downstream of air intake system (AIS) throttle 82 and upstream of compressor 162 from a position in the exhaust system downstream of turbine 164. When there is a pressure difference of the driving flow, EGR can be sucked from the exhaust system to the intake system. A pressure difference can be generated by partially closing the AIS throttle 82. Throttle 84 controls the pressure at the inlet of compressor 162. The AIS can be electrically controlled, and its position can be adjusted based on an optional position sensor 88.

[0038] Ambient air is drawn into combustion chamber 30 via intake passage 42, which includes air filter 156. Therefore, air first passes through air filter 156 and enters intake passage 42. Compressor 162 then draws air from intake passage 42 to be discharged through compressor outlet pipe ( Figure 1 164) supplies compressed air to the boost chamber 146. In some examples, the intake passage 42 may include an air box (not shown) having a filter. In one example, the compressor 162 may be a turbocharger, wherein the power of the compressor 162 is sucked from the exhaust flow through the turbine 164. Specifically, the exhaust gas may rotate the turbine 164, which is coupled to the compressor 162 via the shaft 161. The wastegate 72 allows the exhaust gas to bypass the turbine 164, so that the boost pressure can be controlled under varying operating conditions. The wastegate 72 may be closed (or the opening of the wastegate may be reduced) in response to an increased boost demand, such as during the driver's depressing of the accelerator pedal. By closing the wastegate, the exhaust pressure upstream of the turbine may be increased, thereby increasing the turbine speed and peak power output. This allows the boost pressure to be increased. In addition, when the compressor recirculation valve is partially open, the wastegate may be moved toward a closed position to maintain a desired boost pressure. In another example, wastegate 72 may be opened (or the opening of the wastegate may be increased) in response to a reduced boost demand, such as during a driver's release of the accelerator pedal. By opening the wastegate, exhaust pressure may be reduced, reducing turbine speed and turbine power. This allows for a reduction in boost pressure.

[0039] However, in alternative embodiments, compressor 162 may be a supercharger, wherein power to compressor 162 is drawn from crankshaft 40. Thus, compressor 162 may be coupled to crankshaft 40 via a mechanical linkage, such as a belt. Thus, a portion of the rotational energy output by crankshaft 40 may be transferred to compressor 162 to power compressor 162.

[0040] A compressor recirculation valve 158 (CRV) may be disposed in a compressor recirculation path 159 about compressor 162 so that air may be moved from the compressor outlet to the compressor inlet in order to reduce pressure that may be generated on compressor 162. A charge air cooler 157 may be positioned in plenum 146 downstream of compressor 162 for cooling the charge air delivered to the engine intake. Figure 1 In other examples shown, charge air cooler 157 may be positioned downstream of electronic throttle 62 in intake manifold 144. In some examples, charge air cooler 157 may be an air-to-air charge air cooler. However, in other examples, charge air cooler 157 may be a liquid-to-air cooler.

[0041] In the depicted example, compressor recirculation path 159 is configured to recirculate cooled compressed air from downstream of charge air cooler 157 to the compressor inlet. In an alternative example, compressor recirculation path 159 may be configured to recirculate compressed air from downstream of the compressor and upstream of charge air cooler 157 to the compressor inlet. CRV 158 may be opened and closed via an electrical signal from controller 12. CRV 158 may be configured as a three-state valve having a default half-open position, from which CRV 158 may be moved to a fully open position or a fully closed position.

[0042] Universal Exhaust Gas Oxygen (UEGO) sensor 126 is shown as being coupled to exhaust manifold 148 upstream of emission control device 70. The emission control device may be a catalytic converter, and therefore may also be referred to herein as catalytic converter 70. Alternatively, a two-state exhaust gas oxygen sensor may be replaced with UEGO sensor 126. In one example, converter 70 may include multiple catalyst bricks. In another example, multiple emission control devices may be used, each having multiple bricks. In one example, converter 70 may be a three-way type catalyst. Although the depicted example shows UEGO sensor 126 upstream of turbine 164, it should be understood that in alternative embodiments, the UEGO sensor may be positioned in the exhaust manifold downstream of turbine 164 and upstream of converter 70. Additionally or alternatively, converter 70 may include a diesel oxidation catalyst (DOC) and / or a diesel cold start catalyst.

[0043] In some examples, a diesel particulate filter (DPF) 74 may be coupled downstream of emission control device 70 to capture soot in the direction of exhaust gas flow. In some examples, a selective catalytic reduction device and / or a lean NOx filter may be present between converter 70 and DPF 74. xTrap. DPF 74 can be made of a variety of materials, including cordierite, silicon carbide and other high temperature oxide ceramics. DPF 74 can be periodically regenerated to reduce soot deposits in the filter against the exhaust flow. Filter regeneration can be accomplished by heating the filter to a temperature that will burn soot particles at a faster rate than new soot particles are deposited, such as 400°C-600°C.

[0044] However, in other examples, DPF 74 may not be included in engine 10 due to the inclusion of conduit 18 and / or flow passages in the nozzle of fuel injector 66. Therefore, by including conduit 18, the amount of air entrained by the fuel in conduit 18 prior to combustion in combustion chamber 30 is increased. Therefore, soot generation during the combustion cycle can be reduced. In some examples, due to the increased mixing of fuel and air prior to combustion / ignition of the mixture in combustion chamber 30, soot levels can be reduced to approximately zero. Therefore, in some examples, engine 10 may produce substantially no soot (e.g., zero soot) during the combustion cycle. In other examples, due to the inclusion of conduit 18, soot generation can be reduced, and therefore, DPF 74 can be regenerated less frequently, thereby reducing fuel consumption.

[0045] During the combustion cycle, each cylinder in the engine 10 may undergo a four-stroke cycle, including: an intake stroke, a compression stroke, a power stroke, and an exhaust stroke. During the intake stroke and the power stroke, the piston 36 moves away from the cylinder head 16 toward the bottom of the cylinder, increasing the volume between the top of the piston 36 and the fire shield 19. The position of the piston 36 near the bottom of the cylinder and at the end of its intake stroke and / or power stroke (e.g., when the combustion chamber 30 is at its maximum volume) is generally referred to as the bottom dead center (BDC) by those skilled in the art. Conversely, during the compression stroke and the exhaust stroke, the piston 36 moves away from the BDC toward the top of the cylinder (e.g., the fire shield 19), thereby reducing the volume between the top of the piston 36 and the fire shield 19. The position of the piston 36 near the top of the cylinder and at the end of its compression stroke and / or exhaust stroke (e.g., when the combustion chamber 30 is at its minimum volume) is generally referred to as the top dead center (TDC) by those skilled in the art. Thus, during the intake stroke and the power stroke, the piston moves from TDC to BDC, and during the compression stroke and the exhaust stroke, the piston moves from BDC to TDC.

[0046] Furthermore, during the intake stroke, typically, exhaust valve 154 is closed and intake valve 152 is opened to allow intake air to enter combustion chamber 30. During the compression stroke, both valves 152 and 154 may remain closed as piston 36 compresses the gas mixture entering during the intake stroke. During the compression stroke, gases in combustion chamber 30 may be pushed into conduit 18 due to the positive pressure created by piston 36 as it travels toward conduit 18. Gases from combustion chamber 30 may dissipate heat through one or more of cylinder head 16 and ambient air via conduction and / or conventional means. As a result, the temperature of gases in conduit 18 may be reduced relative to the temperature of gases in combustion chamber 30.

[0047] When piston 36 is near or at TDC during the compression stroke and / or the power stroke, fuel is injected into combustion chamber 30 via injector 66. During the subsequent power stroke, valves 152 and 154 remain closed as the expanding and burning fuel and air mixture pushes piston 36 toward BDC. In some examples, fuel may be injected during the compression stroke before piston 36 reaches TDC. However, in other examples, fuel may be injected when piston 36 reaches TDC. In other examples, fuel may be injected after piston 36 reaches TDC and begins to translate back toward BDC during the power stroke. In other examples, fuel may be injected during the compression stroke and the power stroke.

[0048] The fuel may be injected over a period of time. The amount of fuel injected and / or the duration of the injection of the fuel may be varied via pulse width modulation (PWM) according to one or more linear or nonlinear equations. In addition, the injector 66 may include multiple injection orifices, and the amount of fuel injected from each orifice may be varied as desired.

[0049] The injected fuel travels through the volume of the conduit 18 before entering the combustion chamber 30. In other words, the conduit 18 includes air and fuel passages for entraining air and fuel, wherein the passages are located within the combustion chamber 30. However, the passages are defined by the surface of the conduit 18, and the fuel and air flow flows through these passages before flowing outside the conduit 18 and entering the combustion chamber 30 to mix with the unmixed combustion chamber gases. The flow of air and fuel through the conduit 18 will be described in more detail below. It should be understood that the same phenomenon may occur if the conduit is omitted and the passages are instead integrated into the nozzle of the fuel injector 66.

[0050] During the exhaust stroke, exhaust valve 154 may open to release the combusted air-fuel mixture to exhaust manifold 148, and piston 36 returns to TDC. Exhaust gases may continue to flow from exhaust manifold 148 to turbine 164 via exhaust passage 180. Both exhaust valve 154 and intake valve 152 may be adjusted between a respective closed first position and an open second position. In addition, the positions of valves 154 and 152 may be adjusted to any position between their respective first and second positions. In the closed first position of intake valve 152, air and / or air / fuel mixture does not flow between intake manifold 144 and combustion chamber 30. In the open second position of intake valve 152, air and / or air / fuel mixture flows between intake manifold 144 and combustion chamber 30. In the closed second position of exhaust valve 154, air and / or air-fuel mixture does not flow between combustion chamber 30 and exhaust manifold 148. However, when exhaust valve 154 is in the open second position, air and / or air-fuel mixture can flow between combustion chamber 30 and exhaust manifold 148 .

[0051] Note that the above valve opening and closing schedules are described only as examples, and that the intake and exhaust valve opening and / or closing timings may be varied, such as to provide positive or negative valve overlap, late intake valve closing, or various other examples.

[0052] Figure 1Controller 12 is shown as a microcomputer including a microprocessor unit 102, input / output ports 104, read-only memory 106, random access memory 108, keep alive memory 110, and a conventional data bus. Controller 12 is shown receiving various signals from sensors coupled to engine 10 in addition to those signals previously discussed, including: engine coolant temperature (ECT) from temperature sensor 112 coupled to cooling jacket 114; position sensor 134 coupled to input device 130 for sensing input device pedal position (PP) adjusted by vehicle operator 132; knock sensor (not shown) for determining end gas ignition; measurement of engine manifold pressure (MAP) from pressure sensor 121 coupled to intake manifold 144; measurement of boost pressure from pressure sensor 122 coupled to boost chamber 146; engine position sensor from Hall effect sensor 118 sensing position of crankshaft 40; measurement of air mass entering the engine from sensor 120 (e.g., hot wire air flow meter); and measurement of throttle position from sensor 58. Barometric pressure may also be sensed (sensor not shown) for processing by controller 12. Premature combustion may be sensed by photodiode 92 measuring lumens in conduit 18 for processing by controller 12. In a preferred aspect of the present specification, the Hall Effect sensor 118 generates a predetermined number of equally spaced pulses per revolution of the crankshaft, from which the engine speed (RPM) can be determined. The input device 130 may include an accelerator pedal and / or a brake pedal. Thus, the output from the position sensor 134 can be used to determine the position of the accelerator pedal and / or the brake pedal of the input device 130, and thus determine the desired engine torque. Therefore, the desired engine torque requested by the vehicle driver 132 can be estimated based on the pedal position of the input device 130.

[0053] The controller 12 is Figure 1 Various sensors receive signals and use Figure 1 Various actuators may be activated to adjust engine operation based on received signals and instructions stored on a memory of the controller. For example, adjusting cylinder temperature based on sensed light being greater than a threshold light may include adjusting an amount of EGR flowing to engine 10. For example, EGR valve 138 may be moved closer to a fully open position. In one example, the threshold light is based on an amount of light corresponding to pre-ignition in conduit 18. As a result, the mixture of fuel and air in conduit 18 is too hot and is able to ignite before flowing to the combustion chamber. In this way, soot formation may be greater than desired. Adjusting the EGR injection amount may include increasing the amount of EGR to reduce the combustion chamber temperature, which may mitigate pre-ignition in conduit 18.

[0054] In some examples, the vehicle 5 may be a hybrid vehicle with multiple torque sources available for one or more wheels 59. In other examples, the vehicle 5 is a conventional vehicle with only an engine, or an electric vehicle with only a motor. In the example shown, the vehicle 5 includes an engine 10 and a motor 61. The motor 61 may be a motor or a motor / generator. When one or more clutches 56 are engaged, the crankshaft 40 of the engine 10 and the motor 61 are connected to the wheels 59 via the transmission 54. In the depicted example, the first clutch 56 is disposed between the crankshaft 40 and the motor 61, and the second clutch 56 is disposed between the motor 61 and the transmission 54. The controller 12 may send a signal to the actuator of each clutch 56 to engage or disengage the clutch so as to connect or disconnect the crankshaft 40 with the motor 61 and the components connected thereto, and / or connect or disconnect the motor 61 with the transmission 54 and the components connected thereto. The transmission 54 may be a gearbox, a planetary gear system, or another type of transmission. The powertrain may be configured in various ways, including, for example, a parallel, series, or series-parallel hybrid vehicle.

[0055] The electric machine 61 receives power from the traction battery 58 to provide torque to the wheels 59. The electric machine 61 may also operate as a generator to provide power to charge the battery 58, such as during a braking operation.

[0056] Reference now Figure 2A , which shows the above reference Figure 1 A side cross-sectional view 200 of an injector 66 of engine 10 is depicted. Accordingly, previously introduced components may be similarly numbered in subsequent figures. Figure 2A Also included is an axis system 290 that can be used to describe the relative positioning of components of the engine system. The axis system 290 can include a vertical axis 292 that is parallel to a gravity direction 299 and a lateral axis 294 that is parallel to a horizontal direction 296, with the gravity direction 299 being perpendicular to the horizontal direction 296. The axes 292 and 294 can be orthogonal to each other, thereby defining a two-dimensional axis system. However, it should be understood that the conduit 18 described in more detail herein is three-dimensional, and that features of the conduit 18 can be continued and / or repeated in a three-dimensional manner, as will be described in more detail herein, such as in Figure 2CAs used herein, "top / bottom," "upper / lower," "above / below" may be relative to the vertical axis 292, and may be used to describe the positioning of elements of the drawings relative to each other along the vertical axis 292. Thus, a first component described as "vertically above a second component" may be positioned vertically above and / or higher than the second component relative to the vertical axis 292 (e.g., in a positive direction relative to the second component along the axis 292). Similarly, "left / right side" and "side" may be used to describe the positioning of elements of the drawings relative to each other along the transverse axis 294, and may be used to describe the positioning of elements of the drawings relative to each other along the transverse axis 294.

[0057] like Figure 2A , the conduit 18 can be physically coupled to a nozzle 212 extending from an injector body 210 of the fuel injector 66. The portion of the conduit 18 above the cylinder head 16 can be coupled to the cylinder head via a boss, a press fit, screws, a clip, fusion, and / or welding. The physical coupling can hermetically seal the conduit 18 to the cylinder head 16 so that the pressurized contents in the cylinder do not flow through the coupling. In this way, the portion of the conduit 18 outside the combustion chamber 30 and in the cylinder head 16 can not receive combustion chamber gases.

[0058] Additionally or alternatively, the conduit 18 may be completely located below the cylinder head 16. Thus, the top of the conduit 18 may be flush with the fire plate 19 of the cylinder head 16. It should be understood that the conduit 18 may be physically coupled to the fire plate 19 via any of the coupling elements described above. Additionally, portions of the conduit 18 may be pressed against the fire plate 19 to form an airtight seal, preventing gas and / or liquid from passing therebetween. This may prevent particles and / or air / fuel mixture from accumulating between the conduit 18 and the fire plate 19.

[0059] Fire shield 19 represents the lowest portion of cylinder head 16 relative to vertical axis 292. Thus, fire shield 19 is the surface of cylinder head 16 that faces combustion chamber 30. In addition, combustion chamber gases may come into contact with fire shield 19. As described above, the volume of combustion chamber 30 is affected by cylinder head 16, piston (e.g., Figure 1 of the piston 36) and the cylinder sidewall (e.g., Figure 1 The volume of combustion chamber 30 includes at least a portion of conduit 18, if not all of conduit 18. However, while the volume of combustion chamber 30 is adjustable via the piston, the volume of conduit 18 is fixed and does not change. Thus, when the piston is in the TDC position, it is closest to conduit 18 and combustion chamber 30 is at its smallest volume. Alternatively, when the piston is in the BDC position, it is farthest from conduit 18 and combustion chamber 30 is at its largest volume. Thus, conduit 18 is vertically positioned above the piston (e.g., Figure 1 The pipe 18 is positioned vertically above the piston 36 of the piston 36 such that the pipe 18 is vertically located above the piston at TDC and BDC, and any position therebetween. Thus, the pipe 18 is vertically located above the piston and does not contact the piston at TDC, BDC, and any position therebetween. In one example, the pipe 18 is fixed and does not move. Thus, the pipe 18 may not be electric, hydraulically powered, mechanically powered, and / or pneumatically powered.

[0060] The central axis 298 may represent the central axis of both the conduit 18 and the fuel injector 66, with the central axis 298 being parallel to the vertical axis 292 and the direction of movement of the piston. In this manner, the central axis 298 may pass through the geometric centers of the piston, the fuel injector 66, and the conduit 18. It should be appreciated that in some embodiments, the fuel injector 66 and the conduit 18 may not be aligned with the central axis 298, such that the conduit 18 and the injector 66 are angled with the central axis 298 and / or are not radially aligned with the central axis 298. For example, in some embodiments, the conduit 18 may be angled relative to the vertical axis 292.

[0061] The conduit 18 may include a circular cross-section along the transverse axis 294 and a rectangular cross-section along the vertical axis 292. Thus, in one example, the conduit 18 is cylindrical, such as in Figure 2C In the example shown. Those skilled in the art will appreciate that the duct 18 may be other shapes without departing from the scope of the present disclosure. For example, the duct 18 may be frustoconical, cubic, triangular pyramidal, etc.

[0062] The conduit 18 can include various materials suitable for residing in a combustion environment. For example, the conduit 18 can include iron, aluminum, carbon fiber, magnesium, steel, ceramic, etc. In one example, the conduit 18 mimics the material of the combustion chamber 30 or the cylinder head 16. Additionally or alternatively, the conduit 18 can include a coating configured to prevent particles from impacting the surface of the conduit 18.

[0063] The conduit 18 may include a plurality of flow passages 230 beneath the cylinder head 16. The number of flow passages 230 included in the conduit 18 may be equal to the number of fuel injections that the nozzle tip 214 is configured to inject. The flow passages 230 may be formed between the upper portion 202 and the lower portion 204 of the conduit 18. The upper portion 202 and the lower portion 204 of the conduit 18 may be continuous and uniform, such as Figure 2C However, in Figure 2A and Figure 2B In the cross-section of FIG. 2 , the upper portion 202 and the lower portion 204 are depicted as being separated to illustrate the flow channel 230 .

[0064] exist Figure 2AIn the cross-section of FIG. 2 , the nozzle tip 214 is shown as ejecting two jets 242. Thus, two flow channels 230 are shown. In one example, there are exactly six flow channels 230. In this way, combustion chamber gases can flow into and out of the flow channels without flowing out of the combustion chamber 30. The duct 18 can include an opening 232 disposed in a portion of the flow channel 230 located above the lowest point of the nozzle tip 214. That is, the opening 232 can be disposed so that air can flow through the opening 232 and into the duct 18 above the start of the jet 242.

[0065] Optional secondary air passages are shown via conduit 252, which may extend in a direction parallel to central axis 298. Conduit 252 may be configured to allow combustion chamber gases to enter duct 18 and merge with jet 242 in flow passage 230. Thus, conduit 252 may be functionally similar to opening 232.

[0066] As shown, the trajectory 282 of the jet 242 can be angled relative to the fire plate 19. The angle formed between the jet 242 and the fire plate 19 can be between 5-60°. In one example, the angle formed between each jet 242 and the fire plate 19 is equal to 20°. In addition, the trajectory 282 can be aligned with the center of each flow channel 230. This can prevent and / or reduce contact between the jet 242 and the surface of the flow channel 230 and the pipe 18.

[0067] In this manner, the flow channel 230 may be an angled channel disposed across the entire surface of the conduit 18. The flow channel 230 is aligned with the spray orifice of the nozzle tip 214 so that the spray 242 ejected from the spray orifice may pass through the flow channel 230 uninterruptedly.

[0068] Reference now Figure 2B , which shows a detailed view of the circulation channel 231, the circulation channel 231 and Figure 2A Each flow channel 230 in is substantially identical.

[0069] The opening 233, which is identical to each opening 232, may be a single continuous opening extending along the entire circumference of the upper portion 202 of the duct 18, fluidly coupling the flow passage 230 to the combustion chamber 30. The number of openings 232 may be substantially equal to the number of flow passages 230. Thus, each flow passage may be configured to entrain air with a jet of jet 242.

[0070] The circulation channel 231 may extend from its inlet 234 to its outlet 236, wherein the outlet 236 is disposed near the lower portion of the duct 18. The circulation channel 231 may follow the shape of the inner surface 224 of the upper portion 202 and the lower portion 204 of the duct 18. In one example, the circulation channel 231 is symmetrical, and the inner surfaces 224 of the upper portion 202 and the lower portion 204 are substantially the same. Specifically, the inner surface 224 is a single surface of the duct corresponding to the circulation channel 231, and the inner surface 224 is physically connected to each of the outer surface 222 and the bottom surface 226. The outer surface 222 may extend around the maximum circumference of the duct 18 corresponding to the circulation channel 231. The bottom surface 226 may extend from the outer surface 222 to the inner surface 224 near the outlet 236 of the circulation channel 231. In one example, the outer surface 222 is linear and parallel to the central axis 298, and the bottom surface 226 is linear and perpendicular to the central axis 298.

[0071] The circulation channel 231 may include a first diameter at the inlet 234. The profile of the inner surface 224 may be such that the circulation channel 231 includes a second diameter at the section 238 and a third diameter at the outlet 236. In one example, the first diameter is the maximum diameter of the circulation channel 231, the second diameter is less than the first diameter, and the third diameter is less than the second diameter. Therefore, the third diameter may be the minimum diameter of the circulation channel 231. Additionally or alternatively, the difference between the second diameter and the third diameter is less than the difference between the first diameter and the second diameter. In this way, the profile of the inner surface 224 is more extreme from the inlet 234 to the section 238 than from the section 238 to the outlet 236. In other words, the radius of curvature of the conduit 18 decreases from the inlet section 234 to the outlet section 236. In one example, the radius of curvature between the section 238 and the outlet 236 is substantially equal to zero (e.g., the inner surface 224 is linear between the section 238 and the outlet 236). Herein, the portion of the flow passage 231 between the inlet 234 and the section 238 may be referred to as a horn section, and the portion of the flow passage 231 between the section 238 and the outlet 236 may be referred to as a nozzle section.

[0072] Specifically, the inner surface 224 can extend inwardly from the outer surface 222 toward the central axis 298 between the inlet 234 and the section 238. Thus, the inner surface 224 can bulge toward the trajectory 283 of the jet 243 between the inlet 234 and the section 238. This inward extension can narrow the flow channel 231 so that its second diameter at the section 238 is between 60%-75% of the first diameter at the inlet 234. From the section 238 to the outlet 236 (e.g., the nozzle section), the inner surface 224 continues to compress and / or narrow the flow channel 231. However, the compression between the section 238 and the outlet 236 is not as severe as the compression between the inlet 234 and the section 238. The third diameter at the outlet 236 can be similar to 50% of the first diameter. In this way, the flow channel 231 can include a trumpet shape having a circular cross-section taken along the transverse axis 294, wherein the diameter of the cross-section decreases from the inlet 234 to the outlet 236. It should be understood that other dimensions (eg, diameters and angles) may be used without departing from the scope of the present disclosure.

[0073] As shown, the inner surface 224 is smooth without indentations or protrusions extending therefrom along the flow passage 231. However, one of ordinary skill in the art will appreciate that the inner surface 224 may include indentations and / or protrusions without departing from the scope of the present disclosure.

[0074] As an example, the first diameter decreases at a first rate of change toward the second diameter in the horn section, and the second diameter decreases at a second rate of change toward the third diameter. The first rate of change can be two to five times the second rate of change. This, combined with the horn section being shorter than the nozzle section along the vertical axis 292, results in an uneven narrowing of the flow channel. Additionally or alternatively, the second rate of change can be zero, and the first rate of change can decay so that the radius of curvature of the flow channel 231 decreases from the inlet 234 to the section 238 to produce a convex shape of curvature.

[0075] By compacting the flow passage 231, the amount of time that the fuel jet 243 from the nozzle tip 214 of the injector 66 resides in the flow passage 231 is reduced relative to a passage having a uniform width and / or diameter. Thus, the reduced diameter of the flow passage 231 increases the jet velocity at the outlet 236 of the conduit 18, thereby increasing air entrainment at the outlet 236. The trumpet shape can also allow combustion chamber gases (shown by arrows 244) to flow through the opening 232 and into the flow passage 230, where the combustion chamber gases can mix and / or merge and / or combine with the fuel jet 242. Thus, the fuel jet 242 can entrain the combustion chamber gases 244 before flowing through the outlet 236 of the flow passage 230 and entering the combustion chamber 30. In one example, the conduit 18 can allow the fuel jet 242 to penetrate deeper into the combustion chamber 30 compared to a fuel injector without the conduit 18.

[0076] exist Figure 2A In the context of embodiments of the present invention, the combustion chamber 30 may depict the volume of the combustion chamber 30 in addition to the flow passage 230 and other portions of the conduit 18. Thus, even though portions of the conduit 18 are disposed in the combustion chamber 30, the gases flowing through these portions (e.g., the flow passage 230 and the opening 232) are described separately. For example, the fuel jet 242 and the combustion chamber gases 244 in the flow passage 230 may not come into contact with other combustion chamber gases in the combustion chamber 30 and outside of the flow passage 230 until the fuel jet 242 and the combustion chamber gases 244 flow through the outlet 236 of the flow passage 230. As another example, the combustion chamber gases flowing through the opening 232 may flow from the combustion chamber 30 to the flow passage 230.

[0077] By entraining the fuel spray 242 and combustion chamber gases 244 in the conduit 18, bubbles of unburned fuel vapor may not form in the combustion chamber, which may improve fuel economy and reduce particulate matter output.

[0078] In other words, the duct 18 includes a flow channel 230 disposed below the fire plate 19 of the cylinder head 16. The opening 232 is disposed between the inlet 234 of the flow channel 230 and the fire plate 19. The nozzle tip 214 can be positioned to spray below the opening 232 and into the flow channel 230. Therefore, the nozzle tip 214 and the flow channel 230 can be aligned along the central axis 298. The fuel jet 242 can pass through the flow channel 230, wherein the flow rate of the fuel jet 242 is increased due to the compression and / or narrowing of the flow channel 230. This increase in flow rate can cause the combustion chamber gas 244 to flow through the opening 232 and into the flow channel 230.

[0079] Reference now Figure 2C, which shows a three-dimensional view of the pipe 18. As shown, the opening 232 and the circulation channel 230 extend through the entire thickness of the pipe 18. In addition, the opening 232 is parallel to the transverse axis 294, and the circulation channel 230 is angled with the transverse axis 294 and the vertical axis 292. In addition, the opening 232 and the circulation channel 230 are coaxial about the axis 284, wherein the axis 284 can be parallel to the vertical axis 292. The opening of the opening 232 can be directly arranged above the circulation channel 230, wherein the opening 232 is arranged vertically above the lowest point of the nozzle tip 214. As shown, the diameter of the opening 232 is less than the diameter of the outlet 236 of the circulation channel 230. In other examples, additionally or alternatively, the size of the opening 232 can be similar to the outlet of the circulation channel.

[0080] Reference now Figure 3 , which shows a method 300 for adjusting engine operating parameters in response to engine soot output. Instructions for executing method 300 may be provided by a controller based on instructions stored in a memory of the controller and in conjunction with sensors of the engine system (such as those described above). Figure 1 According to the method described below, the controller can use the engine actuators of the engine system to adjust the engine operation.

[0081] At 302, method 300 includes determining, estimating and / or measuring current engine operating parameters. Current engine operating parameters may include, but are not limited to, one or more of: manifold pressure, manifold temperature, throttle position, engine speed, engine temperature, coolant temperature, vehicle speed, EGR flow rate, and air / fuel ratio.

[0082] At 304, method 300 may include measuring light transmitted from a flow channel, wherein the flow channel is a pipe (eg, Figure 2A The flow channel 230 of the conduit 18 in the fuel tank is shown in FIG. 2 ). As described above, the channel can be configured with a photodiode adapted to measure the amount of light transmitted from the conduit. The amount of light measured can indicate the extent of pre-ignition. Thus, as the amount of light increases, the extent of pre-ignition increases and may result in less than the desired amount of gas / fuel mixing. This may result in increased soot formation compared to when no pre-ignition occurs.

[0083] At 306, method 300 includes determining whether the light sensed by the photodiode is greater than a threshold light amount. In one example, the threshold light is equal to the amount of light emitted from the conduit corresponding to the engine soot output, which is greater than the threshold soot output. In one example, the threshold soot output is equal to the emission standard. In another example, the threshold soot output is equal to zero. If the sensed light is less than the threshold light, the engine soot output is less than the threshold soot output, and method 300 proceeds to 308 to maintain the current engine operating parameters. In this way, the engine soot output is relatively low and / or zero, and the engine operating parameters are not adjusted to reduce the engine soot output.

[0084] If the light is greater than the threshold light, then too much pre-ignition is occurring and the engine soot output is greater than the threshold soot output. Method 300 may proceed to 310 to adjust engine operating parameters.

[0085] In some embodiments, additionally or alternatively, the degree of pre-ignition is calculated based on feedback from one or more of a pressure transducer and a strain gauge in the duct. Additionally or alternatively, the calculation may also include feedback from an exhaust gas sensor located in the exhaust system. If too much pressure (e.g., pressure greater than a threshold pressure), too much strain (e.g., strain greater than a threshold strain), and / or too much soot (e.g., soot greater than a threshold soot output) is detected, too much pre-ignition may be occurring, and the method may proceed to 310. Each of the threshold pressure and the threshold strain may correspond to the same degree of pre-ignition as the threshold light.

[0086] At 310, method 300 includes one or more of: increasing EGR at 312, decreasing manifold pressure at 314, decreasing intake air temperature at 316, increasing cooling in the duct area at 318, and increasing water injection at 320. Increasing EGR at 312 may include adjusting the EGR valve to a more open position to allow a greater amount of EGR to flow into the intake passage. Decreasing manifold pressure may include moving the throttle valve to a less open position. Additionally, EGR flow into the intake manifold may be reduced to further reduce intake manifold pressure. Additionally or alternatively, directing intake air through a charge air cooler (e.g., Figure 1CAC 157) to further reduce manifold pressure. Therefore, EGR can still be increased at 312, but the EGR is directed through an EGR cooler before flowing to the intake manifold. Lowering the intake air temperature can include spraying water into the intake passage and / or manifold upstream of the combustion chamber. Increasing cooling in the conduit area includes flowing coolant to a portion of the cylinder cooling jacket near the conduit and / or nozzle tip. Increasing the water injection can include signaling an actuator of a fuel injector located in the cylinder to notify the injector of a larger amount of water. Additionally or alternatively, the injection pressure can be increased in response to the measured light being greater than a threshold light. In this way, the injection can flow into the combustion chamber faster than a lower injection pressure, thereby reducing the possibility of pre-ignition. In some examples, the injection pressure can be reduced in response to the measured light being greater than a threshold light.

[0087] In one example, the method can apply one or more adjustments at 310 based on the difference between the transmitted duct light and the threshold light. For example, if the difference is relatively high and therefore the transmitted duct light is much higher than the threshold light, one or more adjustments can be applied. Additionally or alternatively, the magnitude of the adjustment is increased in response to the difference being relatively high. For example, the amount of water injection is increased. Alternatively, if the difference is relatively low (e.g., less than the relatively high difference), less adjustments can be applied. Additionally or alternatively, the magnitude of the adjustment can be slightly reduced or not increased. For example, the amount of water injection is a baseline (e.g., minimum) amount. In this manner, the combustion chamber gases can include one or more of air, water, and / or EGR.

[0088] In this manner, method 300 can adjust engine operating parameters in response to the transmitted light being greater than a threshold light. The engine operating parameters can be adjusted to mitigate pre-ignition in the duct, which reduces the transmitted duct light. By doing so, fewer particles, if any, are expelled through the exhaust valve of the combustion chamber to the exhaust manifold.

[0089] Multiple photodiodes may be included in the conduit and / or nozzle tip. Thus, adjustments may be implemented based on exceeding one or more of a plurality of threshold lights and the magnitude of each threshold light being exceeded. For example, if the measured amount of light exceeds a first threshold light and a second threshold light but does not exceed a third threshold light, method 400 may inject water and reduce EGR flow. However, in one example, if the amount of light exceeds each of the first, second, and third threshold lights, method 400 may inject water, reduce EGR flow, and increase injection pressure.

[0090] At 322, method 300 includes flowing the combustion chamber gases to a flow passage located in the conduit. Prior to injection, the combustion chamber gases may flow through the flow passage located in the conduit. However, due to the nature of fuel injection, the combustion chamber gases flow through the opening of the conduit, through the inlet of the flow passage, and into the flow passage, where the combustion chamber gases may mix with the fuel injection. After the adjustment at 310 described above, the combustion chamber gases may be cooler than the combustion chamber gas temperature before pre-ignition. In this manner, pre-ignition in the conduit may be less likely to occur.

[0091] At 324, method 300 includes injecting fuel and mixing the fuel with the combustion chamber gases in the pipeline. As described above, the fuel injection flows through the fuel pipeline of the fuel injector before flowing out of one or more injection orifices aligned with one or more outlet passages. The combustion chamber gases from the combustion chamber flow through the opening and flow into the circulation passage, wherein the combustion chamber gases are mixed with the fuel injection before leaving the outlet passage. This mixing can limit or prevent particulate matter from escaping from the cylinder. Specifically, the amount of fuel to be injected can be determined based on one or more of the driver's demand torque, the desired air / fuel ratio, the mass airflow rate of change, etc. In addition, the injection timing can be adjusted based on the engine operating conditions. Specifically, the fuel can be injected toward the combustion chamber. In some examples, the fuel can be substantially parallel to the fuel spray pipeline of the circulation passage and / or injected in unison with the fuel spray pipeline. Therefore, method 300 includes mixing the injected fuel with the combustion chamber gases in the circulation passage inside the combustion chamber.

[0092] At 326, method 300 includes directing a mixture including a fuel injection and combustion chamber gases to mix with unmixed combustion chamber gases. Unmixed combustion chamber gases may be defined as combustion chamber gases that are not mixed with fuel. The fuel / air mixture may flow into the combustion chamber during one or more of a compression stroke and / or a power stroke.

[0093] At 328, method 300 includes igniting the fuel / air mixture in the combustion chamber. In some examples, the fuel / air mixture may spontaneously combust due to the temperature and pressure in the combustion chamber. In other examples, the fuel / air mixture may be ignited by a glow plug.

[0094] At 330, method 300 includes injecting gases in the combustion chamber during the exhaust stroke. Specifically, method 300 may include opening one or more exhaust valves (e.g., Figure 1 154) and injects the combustion chamber gases into the exhaust manifold (e.g., as described above in Figure 1 The method 300 may include injecting gases in the combustion chamber into the exhaust manifold only during the exhaust stroke of the piston.

[0095] In some examples, the fuel rail pressure may be proportional to the amount of particulate matter produced in the combustion chamber. Therefore, the fuel rail pressure may increase as the amount of particulate matter increases. Conversely, as the amount of particulate matter produced decreases, the fuel rail pressure may decrease. In one example, increasing the fuel rail pressure may reduce the amount of time the fuel injection resides in the flow passage 230. Increasing the fuel rail pressure may also increase the amount of combustion chamber gas that flows into the flow passage to mix with the fuel injection. Therefore, reducing the fuel rail pressure may increase the amount of time the fuel injection resides in the flow passage 230. For example, if the transmitted pipe light is greater than the threshold light, the amount of particulate matter produced may be higher than the desired amount, and the fuel rail pressure may be increased. This adjustment may occur simultaneously with one or more adjustments at 310. Additionally or alternatively, the adjustment of the fuel rail pressure may occur independently of the adjustment at 310.

[0096] Reference now Figure 4 , which shows an operational sequence 400, which shows an operational sequence 400 having an implementation Figure 4 The controller of the method 400 (eg, Figure 1 Example results for an engine of the engine 10 and controller 12 of FIG. 4. Line 410 represents combustion chamber gas temperature, line 420 represents PM output temperature, line 422 represents threshold PM output, line 430 represents injection lift length, and line 432 represents threshold injection lift length, line 440 represents measured light quantity, and line 442 represents measured threshold light quantity, line 450 represents EGR flow rate, line 460 represents whether water injection occurs in the combustion chamber, and line 470 represents fuel rail pressure. The horizontal axis of each graph represents time and time increases from the left side of the graph to the right side of the graph.

[0097] Prior to t1, the combustion chamber gas temperature and / or the combustion chamber gas temperature is relatively low, as shown by line 410. However, the combustion chamber gas temperature increases toward a high temperature. In one example, this is due to an increase in engine load. Therefore, the injection lift begins to decrease from a relatively high length toward a threshold lift length, as shown by lines 430 and 432, respectively. As the combustion gas temperature increases, the lift length decreases, which may result in earlier combustion than expected. Therefore, the PM output also begins to increase from a relatively low amount toward a threshold PM output, as shown by lines 420 and 422, respectively. As the lift length decreases, the amount of light measured by the optical sensor in the conduit and / or flow channel increases toward the measured threshold amount of light, as shown by lines 440 and 442, respectively. In one example, Figure 1 The optical sensor 92 is positioned at Figure 2A The measured threshold light quantity is substantially similar to Figure 3The threshold light described at 306 of method 300 is shown in FIG. 4. Thus, when the measured light is greater than the threshold light amount, combustion may occur in the conduit or flow passage prior to the fuel / combustion chamber gas mixture flowing into the combustion chamber. The EGR flow rate is relatively low, as shown by line 450. Water injection is stopped, as shown by line 460. The fuel rail pressure is relatively low, as shown by line 470.

[0098] At t1, the combustion chamber gas temperature reaches a relatively high temperature. As a result, the PM output increases to a PM output greater than a threshold PM output. In addition, the injection lift is reduced to a lift length less than a threshold lift length. Therefore, the light measured by the light sensor is greater than the threshold light amount. Therefore, the combustion chamber temperature is too high, causing the fuel to burn (e.g., ignite) prematurely in the circulation channel of the pipeline. In order to reduce the PM output and increase the injection lift length, the EGR flow rate is increased and water injection is activated. The fuel rail pressure is increased to reduce the possibility of pre-combustion in the circulation channel.

[0099] After t1 and before t2, water injection continues and the EGR flow rate continues to increase toward a relatively higher EGR flow rate to help reduce combustion chamber gas temperature. By doing so, combustion chamber gas temperature decreases, and therefore injection float rises back toward a threshold float, PM output decreases toward a threshold PM output, and measured light decreases toward a measured threshold light amount. Fuel rail pressure continues to increase until the fuel rail pressure reaches a relatively higher pressure.

[0100] At t2, the combustion chamber gas temperature has been sufficiently reduced so that the PM output is reduced to a PM output below a threshold PM output, the injection lift is increased to an injection lift length greater than the threshold injection lift, and the measured light is reduced to an amount of light less than the measured threshold amount of light. Therefore, the water injection is terminated and the EGR flow rate is reduced. The water injection can be performed by an injector positioned to inject water into the combustion chamber outside the pipe or nozzle tip and / or in an area spaced apart from the pipe or nozzle tip. In some examples, in addition or alternatively, one or more of the water injection and EGR flow rate are maintained to keep the combustion chamber gas temperature relatively low. This can be based on combustion stability, EGR demand, and / or the amount of water available from a water reservoir, which is fluidly connected to an injector configured to inject into the cylinder. In response to the PM output decreasing below the threshold PM output, the fuel rail pressure may begin to decrease.

[0101] After t2, the combustion chamber gas temperature decreases to a relatively low temperature. The PM output is less than a threshold PM output. The injection lift is greater than a threshold injection lift. The measured lift is less than a measured threshold lift. The EGR flow rate continues to decrease and water injection remains deactivated. The fuel rail pressure returns to a relatively low pressure.

[0102] In this way, a fuel injector can be equipped with a conduit including a circulation passage. The diameter of the circulation passage decreases from its inlet adjacent to the fuel injector nozzle to its outlet distal to the fuel injector nozzle. By doing so, the fuel injection can reside in the circulation passage for a shorter amount of time while still being fully mixed with the combustion chamber gases to reduce particulate matter output. The technical effect of mixing the combustion gases with the fuel injection within the circulation passage before the fuel injection flows into the combustion chamber is to reduce particulate matter output. By premixing the fuel and the combustion gases, bubbles of unburned fuel vapor may not be formed in the combustion chamber, which may not only improve fuel economy but also prevent particulate matter output.

[0103] The system includes a combustion chamber, the combustion chamber includes a conduit, the conduit includes at least one circulation channel, the circulation channel is configured to receive a fuel injection and a combustion chamber gas, the circulation channel includes a first diameter upstream and greater than the second diameter, a second diameter upstream and greater than the third diameter, and wherein the first difference between the first diameter and the second diameter is greater than the second difference between the second diameter and the third diameter. The first instance of the system also includes: wherein the first diameter corresponds to an inlet of the circulation channel, and the third diameter corresponds to an outlet of the circulation channel. The second instance of the system (optionally, including the first instance) also includes: wherein the circulation channel is arranged below a fireproof plate of a cylinder head of the combustion chamber, and wherein the conduit also includes at least one opening between the circulation channel and the fireproof plate, and the at least one opening connects the circulation channel fluid to the combustion chamber. The third instance of the system (optionally including the first and / or second instance) also includes: wherein the circulation channel receives a fuel injection through its first diameter from a fuel injector of the combustion chamber, and wherein the combustion chamber gas flows through the at least one opening and mixes with the fuel injection in the circulation channel. A fourth example of the system (optionally including one or more of the first to third examples) also includes: wherein the conduit further includes a photodiode configured to measure an amount of light transmitted from the conduit.

[0104] A method includes measuring an amount of light sensed in a passageway that fluidly couples a fuel injector to a combustion chamber via a photodiode; comparing the amount of light to a threshold light; and adjusting a fuel rail pressure in response to the comparison. A first example of the method also includes wherein the threshold light is based on light released in the passageway when particulate matter produced exceeds a desired amount. A second example of the method (optionally including the first example) also includes wherein adjusting the fuel rail pressure includes increasing the fuel rail pressure in response to the measured amount of light being greater than the threshold light. A third example of the method (optionally including the first and / or second example) also includes wherein the increasing further includes adjusting a magnitude of the increase in response to a difference between the measured amount of light and the threshold light, wherein the magnitude increases as the difference increases. A fourth example of the method (optionally including one or more of the first to third examples) also includes wherein an EGR flow rate, a manifold pressure, a manifold temperature, and an amount of water injection are adjusted in response to the comparison. A fifth example of the method (optionally including one or more of the first to fourth examples) also includes wherein the passageway is disposed below a cylinder head of a combustion chamber and aligned with a central axis of a fuel injector of the combustion chamber.

[0105] The engine system includes a fuel injector positioned to inject into a pipe through an opening, wherein the diameter of the pipe is largest at a first end near the injector, the diameter decreases at a first rate of change in a trumpet section, and wherein the diameter decreases at a second rate of change in a nozzle section located downstream of the trumpet section, and wherein the second rate of change is less than the first rate of change. The first instance of the engine system also includes: wherein the first rate of change is two to five times the second rate of change. The second instance of the engine system (optionally including the first instance) also includes: wherein the trumpet section corresponds to an inlet of a flow channel of the pipe, and wherein the nozzle section corresponds to an outlet of the flow channel, and wherein the inlet is fluidly coupled to the combustion chamber via the opening, and the outlet is directly fluidly coupled to the combustion chamber. The third instance of the engine system (optionally including the first and / or second instance) also includes: wherein the diameter decreases along the direction in which the fuel injection flows through the pipe. A fourth example of an engine system (optionally including one or more of the first to third examples) further includes: wherein the controller has computer readable instructions stored on its non-transitory memory, the computer readable instructions when executed allowing the controller to reduce the combustion chamber temperature in response to the amount of light measured by the light sensor in the conduit when the measured amount of light is greater than a threshold light. A fifth example of an engine system (optionally including one or more of the first to fourth examples) further includes: wherein the conduit includes a flow passage aligned with the nozzle of the fuel injector along the central axis, and wherein the conduit also includes a molded inner surface in coplanar contact with the flow passage. A sixth example of an engine system (optionally including one or more of the first to fifth examples) further includes: wherein the inner surface includes a first angle relative to the central axis in the horn section, and wherein the inner surface includes a second angle relative to the central axis in the nozzle section, and wherein the first angle is greater than the second angle. A seventh example of an engine system (optionally including one or more of the first to sixth examples) further includes: wherein the first angle is between 45 degrees and 80 degrees and wherein the second angle is between 5 degrees and 30 degrees. The eighth example of the engine system (optionally including one or more of the first to seventh examples) also includes: wherein the conduit includes no other inlets or additional outlets other than the opening and the outlet of the nozzle section.

[0106] Note that the exemplary control and estimation routines included herein can be used with various engine and / or vehicle system configurations. The control methods and routines disclosed herein can be stored as executable instructions in a non-transitory memory and can be executed by a control system including a combination of a controller and various sensors, actuators, and other engine hardware. The specific routines described herein can represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multi-tasking, multi-threading, etc. Therefore, the various actions, operations, and / or functions described can be omitted in the described sequence, in parallel, or in some cases. Similarly, the processing order is not necessarily required to achieve the features and advantages of the exemplary embodiments described herein, but is provided for the ease of description and description. One or more of the described actions, operations, and / or functions can be repeatedly performed according to the specific strategy used. In addition, the described actions, operations, and / or functions can clearly represent the code in the non-transitory memory of the computer-readable storage medium to be programmed into the engine control system, wherein the described actions are implemented by executing instructions in a system including a combination of various engine hardware components and an electronic controller.

[0107] It will be appreciated that the configurations and routines disclosed herein are exemplary in nature, and these specific embodiments should not be viewed in a limiting sense, as numerous variations are possible. For example, the above-described techniques may be applied to V-6, I-4, I-6, V-12, opposed 4, and other engine types. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations and other features, functions, and / or properties disclosed herein.

[0108] The accompanying claims particularly point out certain combinations and subcombinations regarded as novel and non-obvious. These claims may refer to "an" element or "a first" element or the equivalent thereof. Such claims should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements, and / or properties may be claimed by amendment of the present claims or by presentation of new claims in this or a related application. Such claims, whether broader, narrower, the same, or different in scope than the original claims, are also deemed to be included within the subject matter of the present disclosure.

[0109] According to the present invention, a system is provided, the system having a combustion chamber, the combustion chamber including a conduit, the conduit including at least one flow channel, the flow channel being configured to receive a fuel injection and combustion chamber gases, the flow channel including a first diameter upstream and larger than a second diameter, a second diameter upstream and larger than a third diameter, and wherein a first difference between the first diameter and the second diameter is larger than a second difference between the second diameter and the third diameter.

[0110] According to one embodiment, the first diameter corresponds to an inlet of the flow channel and the third diameter corresponds to an outlet of the flow channel, wherein the first diameter corresponds to a bulge of the conduit.

[0111] According to one embodiment, the flow channel is arranged below a fire shield of a cylinder head of the combustion chamber, and the duct further comprises at least one opening between the flow channel and the fire shield, the at least one opening fluidly coupling the flow channel to the combustion chamber.

[0112] According to one embodiment, the flow passage receives a fuel spray from a fuel injector of the combustion chamber through a first diameter thereof, and wherein combustion chamber gases flow through the at least one opening and mix with the fuel spray in the flow passage.

[0113] According to one embodiment, the conduit further comprises a photodiode configured to measure an amount of light transmitted from the conduit.

[0114] According to the present invention, a method includes measuring an amount of light sensed in a passage fluidly coupling a fuel injector to a combustion chamber via a photodiode, comparing the amount of light to a threshold light, and adjusting a fuel rail pressure in response to the comparison.

[0115] According to one embodiment, the threshold light is based on light released in the channel when the generated particulate matter exceeds a desired amount.

[0116] According to one embodiment, adjusting the fuel rail pressure includes increasing the fuel rail pressure in response to the measured amount of light being greater than a threshold light.

[0117] According to one embodiment, the increasing further comprises adjusting a magnitude of the increase in response to a difference between the measured amount of light and the threshold light, wherein the magnitude increases as the difference increases.

[0118] According to one embodiment, the invention is further characterized by adjusting the EGR flow rate, the manifold pressure, the manifold temperature, and the water injection amount in response to the comparison.

[0119] According to one embodiment, the channel is arranged below the cylinder head of the combustion chamber and is aligned with the central axis of the fuel injector of the combustion chamber.

[0120] According to the present invention, an engine system is provided, having: a fuel injector, the fuel injector being positioned to inject into a conduit through an opening, wherein the diameter of the conduit is largest at a first end near the injector, the diameter decreases at a first rate in a flare section, and wherein the diameter decreases at a second rate in a nozzle section located downstream of the flare section, and wherein the second rate is less than the first rate.

[0121] According to one embodiment, the first rate of change is two to five times greater than the second rate of change.

[0122] According to one embodiment, the trumpet section corresponds to an inlet of the flow channel of the duct, and wherein the nozzle section corresponds to an outlet of the flow channel, and wherein the inlet is fluidly coupled to the combustion chamber via the opening, and the outlet is fluidly coupled directly to the combustion chamber.

[0123] According to one embodiment, the diameter decreases in the direction of the fuel jet flow through the duct.

[0124] According to one embodiment, the invention is also characterized by a controller having computer-readable instructions stored on its non-transitory memory, which when executed allow the controller to reduce the combustion chamber temperature in response to the amount of light measured by the light sensor in the conduit when the measured amount of light is greater than a threshold light.

[0125] According to one embodiment, the conduit includes a flow passage aligned with a nozzle of a fuel injector along a central axis, and wherein the conduit further includes a contoured inner surface in coplanar contact with the flow passage.

[0126] According to one embodiment, the inner surface comprises a first angle relative to the central axis in the horn section, and wherein the inner surface comprises a second angle relative to the central axis in the nozzle section, and wherein the first angle is greater than the second angle.

[0127] According to one embodiment, the first angle is between 45 degrees and 80 degrees, and wherein the second angle is between 5 degrees and 30 degrees.

[0128] According to one embodiment, the duct comprises no other inlets or further outlets than the opening and the outlet of the nozzle section.

Claims

1. A method comprising: measuring an amount of light sensed in a passage fluidly coupling the fuel injector to the combustion chamber via a photodiode; comparing the amount of light to a threshold amount of light to estimate engine soot output; as well as Fuel rail pressure is adjusted in response to the comparison to reduce the engine soot output. 2 . The method of claim 1 , wherein the threshold amount of light is based on light released in the channel when particulate matter generated exceeds a desired amount. 3 . The method of claim 1 , wherein adjusting the fuel rail pressure comprises increasing the fuel rail pressure in response to the measured amount of light being greater than the threshold amount of light. 4 . The method of claim 3 , wherein the increasing further comprises adjusting a magnitude of the increase in response to a difference between the measured amount of light and the threshold amount of light, wherein the magnitude increases as the difference increases. 5 . The method of claim 1 , further comprising adjusting EGR flow rate, manifold pressure, manifold temperature, and water injection amount in response to the comparison. 6 . The method of claim 1 , wherein the passage is disposed below a cylinder head of the combustion chamber and is aligned with a central axis of a fuel injector of the combustion chamber.

7. An engine system comprising: A fuel injector positioned to inject through an opening into a conduit, wherein the conduit has a largest diameter at a first end near the injector, the diameter decreases at a first rate in a trumpet-shaped section, and wherein the diameter decreases at a second rate in a nozzle section downstream of the trumpet-shaped section, and wherein the second rate is less than the first rate. 8 . The engine system of claim 7 , wherein the first change rate is two to five times the second change rate.

9. The engine system of claim 7, wherein the trumpet-shaped section corresponds to an inlet of a flow passage of the conduit, and wherein the nozzle section corresponds to an outlet of the flow passage, and wherein the inlet is fluidly coupled to a combustion chamber via the opening, and the outlet is directly fluidly coupled to the combustion chamber.

10. The engine system of claim 7, wherein the diameter of the conduit decreases in a direction of fuel spray flow through the conduit.

11. The engine system of claim 7 further comprising a controller having computer readable instructions stored on a non-transitory memory thereof, the computer readable instructions when executed allowing the controller to adjust an engine operating parameter to reduce a combustion chamber temperature in response to an amount of light measured by the light sensor in the conduit when the measured amount of light is greater than a threshold amount of light.

12. The engine system of claim 7, wherein the conduit includes a flow passage aligned along a central axis with a nozzle of a fuel injector, and wherein the conduit further includes a contoured inner surface in coplanar contact with the flow passage.

13. The engine system of claim 12, wherein the inner surface includes a first angle relative to a central axis in the trumpet-shaped section, and wherein the inner surface includes a second angle relative to a central axis in the nozzle section, and wherein the first angle is greater than the second angle.

14. The engine system of claim 13, wherein the first angle is between 45 degrees and 80 degrees, and the second angle is between 5 degrees and 30 degrees.

15. The engine system of claim 7, wherein the conduit includes no inlets or additional outlets other than the opening and the outlet of the nozzle segment.

Images