EXHAUST FUEL LEAKAGE MANAGEMENT

Abstract

Exhaust gas management arrangement (132) for an engine (10), comprising: an opening (134) arranged to collect an exhaust gas exiting from a movable section (146) of an exhaust gas flow guidance mechanism (99); and a channel (136) for directing the escaped exhaust gas to an engine crankcase (26), characterized by the fact that the movable section (146) is a rod (148) arranged for movement in a pair of spaced-apart bushings (150), wherein the channel (136) has a groove (152) which intersects the rod (148) between the bushings (150).

Description

[0001] The present invention relates to controlling and / or regulating possible exhaust gas leaks from various engine components and directing the exhaust gases to a crankcase ventilation system for more advantageous handling.

[0002] Internal combustion engines often incorporate techniques to improve various engine characteristics. However, a beneficial technique applied to one part of the engine can negatively impact other engine characteristics due to the introduction of complexity and / or additional components.

[0003] One exemplary technique for reducing nitrogen oxide (NOx) emissions from engine exhaust, which form when nitrogen and oxygen in the intake air are exposed to high combustion temperatures, is exhaust gas recirculation (EGR). This involves recirculating a portion of cooled exhaust gas back into the engine's combustion chamber(s) and mixing it with the intake air. Another technique for increasing power output is the addition of a turbocharger. This is achieved by capturing the power of exhaust gases to drive a compressor and increase intake air density. However, incorporating a turbocharger into an engine can make managing potential undesirable exhaust byproducts more challenging.

[0004] In US patent 6,263,672 B1, an exhaust gas management arrangement is described that includes an opening designed to collect exhaust gas exiting from a moving section of an exhaust gas stream via a widening mechanism, and a channel for directing the exiting exhaust gas to a test housing. Further relevant prior art relating to the background of the invention is provided in US patents 6,418,916 B1, US 2008 / 0083399 A1, US 4,171,936 A, and US 2011 / 0073082 A1.

[0005] US patent application US 6,089,019 A discloses an attempt to address the added complexity of combining a turbocharger with exhaust gas recirculation (EGR). Specifically, in a turbocharged engine, the intake gas is at a higher pressure than the exhaust gas. However, in order to recirculate exhaust gas back into the intake manifold, the exhaust gas must be at a higher pressure than the intake gas.

[0006] The present invention proposes arranging a throttle valve on the exhaust line upstream of the turbocharger to throttle the exhaust flow and increase the exhaust gas pressure. The exhaust gas at increased pressure is supplied to the inlet of an exhaust gas recirculation (EGR) valve, which can be actuated independently of the throttle valve's operation.

[0007] The inventors have identified several problems with this approach. Firstly, there are other areas in an engine where untreated exhaust gas can be released into the atmosphere, for example, areas in a turbocharged engine. Embodiments according to the present invention can provide a means of reducing emissions that would otherwise escape from various moving components or be released in other ways.

[0008] Embodiments according to the present invention can provide an exhaust gas management arrangement for an engine. The exhaust gas management arrangement can have an opening designed to collect exhaust gas that has escaped from a movable section of an exhaust flow guidance mechanism. The arrangement can also have a channel for directing the escaped exhaust gas to a crankcase of the engine. In this way, leaks can be controlled and subsequently treated according to preferred and / or established methods.

[0009] Some embodiments may provide a turbocharger boost control valve for an engine that has an encapsulation in sealing engagement with a potentially leaking section of the boost control valve. The boost control valve may also have a channel from the encapsulation to a crankcase ventilation (PCV) system to route exhaust gas escaping from the boost control valve to the engine's crankcase. The channel may include an oil return line for a turbocharger bearing. In this way, gases escaping from the boost control valve can be regulated and / or handled by the PCV system and are not released into the atmosphere.

[0010] It will be understood that the above summary is provided to offer, in simplified form, a selection of concepts that are described in more detail in the full description. It is not intended to identify any principal or essential features of the claimed subject matter, the scope of which is defined solely in the claims that follow the full description. Furthermore, the claimed subject matter is not limited to implementations that eliminate any potential disadvantages mentioned above or in any part of this disclosure.

[0011] The figures show: Fig. 1 a cross-sectional diagram of an exemplary engine according to the present disclosure; Fig. 2 A cross-sectional view of an exemplary turbocharger boost pressure control valve, in which the exemplary engine can be used, which is in Fig. 1 is shown; Fig. 3 A cross-sectional view of another exemplary turbocharger boost pressure control valve in which the exemplary engine can be used, which is in Fig. 1 is shown; Fig. 4 a cross-sectional view of another exemplary, but not inventive, turbocharger boost pressure control flap in which the exemplary engine can be used, which is in Fig. 1 is shown;

[0012] Fig. Figure 1 is a cross-sectional diagram showing a cross-section of a motor 10 according to the present invention. Various features of the motor may be omitted or simplified for ease of understanding of the present description. For example, certain areas may have continuous cross-hatching, which might otherwise indicate a solid; however, actual embodiments may include various motor components and / or hollow or empty sections of the motor with the cross-hatched areas.

[0013] Fig. Figure 1 is a cross-sectional view through a cylinder 12 of the engine 10. Various components of the engine 10 can be controlled, at least partially, by a control system that includes a control unit (not shown) and / or by input from a vehicle operator via an input device such as an accelerator pedal (not shown). The cylinder 12 can have a combustion chamber 14. A piston 16 can be arranged within the cylinder 12 for reciprocating motion. The piston 16 can be coupled to a crankshaft 18 via a connecting rod 20, a crankpin 21, and a crank throw 22, which is shown here with a counterweight 24. Some examples include a discrete crank throw 22 and a counterweight 24. The reciprocating motion of the piston 16 can be transmitted into a rotary motion of the crankshaft 18.The crankshaft 18, the connecting rod 20, the crankpin 21, the crank throw 22, and the counterweight 24, as well as possibly other elements not shown, can be housed in a crankcase 26. The crankcase 26 may contain oil. The crankshaft 18 can be coupled to at least one drive wheel of a vehicle via an intermediate transmission system. Furthermore, a starter motor can be coupled to the crankshaft 18 via a flywheel to initiate a starting process of the engine 10.

[0014] The combustion chamber 14 can draw in intake air from an intake duct 30. It can also expel combustion gases through the exhaust duct 32. The intake duct 30 and the exhaust duct 32 can communicate selectively with the combustion chamber 14 via a corresponding intake valve 34 and exhaust valve 36. A throttle valve 31 may be included to control the amount of air that can be directed through the intake duct 30. In some embodiments, the combustion chamber 14 may have two or more intake valves and / or two or more exhaust valves.

[0015] In this example, the intake valve 34 and the exhaust valve 36 can be controlled by cam actuation via the cam actuation systems 38 and 40, respectively. The cam actuation systems 38 and 40 can each have one or more cams 42 and utilize one or more cam profile switching (CPS), variable camshaft timing (VCT), variable valve timing (VVT), and / or variable valve lift (VVL) systems, which can be operated by the control unit to vary valve operation. The cams 42 can be configured to rotate on respective rotating camshafts 44. As shown, the camshafts 44 can be in a double overhead camshaft (DOHC) configuration, although alternative configurations are also possible. The position of the intake valve 34 and the exhaust valve 36 can be determined by position sensors (not shown).In alternative embodiments, the intake valve 34 and / or the exhaust valve 36 can be controlled by electric valve actuation. For example, the cylinder 16 can alternatively have an intake valve controlled by electric valve actuation and an exhaust valve controlled by cam actuation, including CPS and / or VCT systems.

[0016] In one embodiment, a double independent VCT can be used on each bank of a V-engine. For example, the cylinder in one bank of the V can have independently adjustable intake and exhaust cams, wherein the camshaft timing of each intake and exhaust cam can be set independently with respect to the crankshaft timing.

[0017] As shown, the fuel injector 50 is directly coupled to the combustion chamber 14 for the direct injection of fuel in proportion to the pulse width of a signal that can be received by the control unit. In this way, the fuel injector 50 provides so-called direct injection of fuel into the combustion chamber 14. The fuel injector 50 can be mounted, for example, on the side of the combustion chamber 14 or on the top of the combustion chamber 14. Fuel can be supplied to the fuel injector 50 via a fuel system (not shown) comprising a fuel tank, a fuel pump, and a fuel distributor.In some embodiments, the combustion chamber 14 may alternatively or additionally have a fuel injection nozzle arranged in the intake duct 30 in a configuration known as port fuel injection into the intake manifold upstream of the combustion chamber 14.

[0018] The ignition system 52 can provide a spark to the combustion chamber 14 via the spark plug 54 in response to an advance ignition signal from the control unit under selected operating modes. Although ignition components are shown in some embodiments, the combustion chamber 14 or one or more other combustion chambers of the engine 10 can be operated in a compression ignition mode with or without a spark.

[0019] The cylinder head 60 can be coupled to a cylinder block 62. The cylinder head 60 can be configured to accommodate and / or support the intake valve(s) 34, the exhaust valve(s) 36, the associated valve actuation systems 38 and 40, and the like. The cylinder head 60 can also support camshafts 44. A cam cover 64 can be coupled to and / or attached to the cylinder head 60 and can accommodate the associated valve actuation systems 38 and 40, and the like. Other components, such as the spark plug 54, can also be accommodated in and / or supported by the cylinder head 60. A cylinder block 62, or engine block, can be configured to accommodate the piston 16. In one example, the cylinder head 60 can correspond to a cylinder 12 located at a first end of the engine. Although Fig. 1 represents only one cylinder 12 of a multi-cylinder engine 10, each cylinder 12 can similarly have its own set of intake and exhaust valves, fuel injector, spark plug, etc.

[0020] Fig. Figure 1 also represents an oil separator 70, which may include an oil separation chamber 72 and a base plate 74 that may define a bottom surface of the oil separation chamber 72. The oil separator 70 may be contained within the cam cover 64, as shown, or may be located in another position within or connected to the engine 10. The base plate 74 and / or the oil separation chamber 72 may be attached to or supported in the cylinder head 64. The oil separator 70 may extend lengthwise along a section of the length of the engine bank, that is, in a direction substantially parallel to the axes of the camshafts 44. The oil separator 70 may contain the cam cover 64. One or more guide vanes (not shown) may be included in the oil separator 70.

[0021] The oil separator 70 may be included as part of an engine crankcase ventilation system 80. The engine crankcase ventilation system 80 may be a positive crankcase ventilation system or PCV system 80. The engine crankcase ventilation system 80 may be included in the engine 10 to reduce a quantity of unwanted exhaust gases emitted by the engine 10. During operation, certain leakage gases 82, such as those found in Fig. The leakage gases 82, shown with arrows, travel from the combustion chamber 14 to the crankcase 26. Some of the leakage gases 82 may be incompletely combusted and reintroduced into the combustion chamber 14 via a first crankcase ventilation line 84, a second crankcase ventilation line 86, and the intake duct 30 to attempt complete combustion. However, the leakage gases 82 may contain suspended oil, which is picked up in the gas stream from one or more locations in the engine, such as the crankcase 26. In an attempt to separate the suspended oil from the leakage gases 82, the mixture of oil and leakage gases 88, as indicated by an arrow, may first be passed through the oil separator 70.

[0022] The flow of crankcase ventilation gases through the engine crankcase ventilation system 80 can be controlled by one or more mechanisms, which may include a valve 90. In some cases, the valve 90 may be referred to as a positive crankcase ventilation (PCV) valve. In some cases, a vent pipe 92 or vent channel, or the like, may be included to introduce clean air into the crankcase 26 to purge or reduce the concentration of unwanted crankcase gases. In some cases, the vent pipe 92 may be fluidically coupled to the intake manifold and / or intake port 30 as a source of clean air.

[0023] A turbocharger 94 may be arranged on an induction air path 96 to compress an induction fluid before the induction fluid is directed into the intake port 30 of the engine 10. In some applications, an intercooler (not shown) may be included to cool the intake charge before it enters the engine. The turbocharger 94 may be driven by an exhaust turbine 98, which may be driven by exhaust gases exiting the outlet port 32. In some cases, the throttle valve 31 may be located downstream of the turbocharger 94 instead of upstream as shown. Although not shown, the engine 10 may have an exhaust gas recirculation (EGR) line and / or an EGR system.

[0024] The flow of exhaust gases can be regulated or controlled by one or more exhaust flow guidance mechanisms 99. For example, the engine 10 may have a boost pressure control valve 100 (“wastegate”) configured to divert exhaust gases away from the exhaust turbine 98 and into an exhaust pipe 102. Diverting the exhaust gases can help regulate the speed of the exhaust turbine 98, which in turn can regulate the speed of the turbocharger 94. The boost pressure control valve 100 can be configured as a valve. The boost pressure control valve 100 can be used to regulate, for example, a maximum boost pressure in the turbocharger system, which can help protect the engine and the turbocharger.

[0025] The exhaust pipe 102 can have one or more emission control devices 104, which can be mounted in a directly coupled position in the exhaust pipe 102. The one or more emission control devices 104 can include, for example, a three-way catalytic converter, a lean nitrogen separator, a diesel particulate filter, an oxidation catalyst, etc.

[0026] The engine 10 can have an engine lubrication system 106, for example, an oil lubrication system, which includes an oil pump 108 or other actuating means to pump and / or pressurize oil and move it to the lubrication system 106. The oil pump 108 can be configured to draw oil from an oil reservoir stored in an oil pan 110 through a supply channel 112. The lubrication system 106 can have various branches 114, 116, 118 to supply oil to different oil subsystems. The oil can be returned through one or more return paths, including a return channel 120, whereby the oil can flow or drip back into the oil pan 110. The oil can be filtered by the oil filter 122. The oil subsystems can use an oil flow to perform a certain function, such as lubrication, actuation of an actuator, etc.Example subsystems can include lubrication systems such as passages for delivering oil to moving components like camshafts, cylinder valves, etc. Other oil subsystems can include hydraulic systems such as hydraulic actuators and hydraulic control valves. There may be fewer or more oil subsystems than those shown in the example.

[0027] An oil subsystem can be a turbine bearing lubrication system 124, which can receive oil through a turbine oil supply branch 118. The turbo compressor 94 can be coupled to the exhaust turbine 98 for rotation via a turbine shaft 126. The turbine shaft 126 can be supported for rotation by the turbine bearings 128 and lubricated by the turbine bearing lubrication system 124. The oil can be returned to other parts of the engine 10 for recirculation, filtration, etc., via the oil return line 130.

[0028] As mentioned, the boost pressure control valve 100 can be an example of an exhaust flow guidance mechanism 99. The engine 10 may also have other exhaust flow guidance mechanisms that may be configured to control and / or direct the flow of exhaust gases in and / or around the engine 10. In some cases, the one or more exhaust flow guidance mechanisms 99 may allow varying amounts of untreated exhaust gas to escape due to small clearances between mating parts and / or a defective and / or worn seal. In many cases, the leak(s) may be small, yet still noticeable and / or detectable. As emission sources are increasingly scrutinized, relatively small leaks can become increasingly significant.

[0029] Embodiments according to the present invention provide an exhaust gas management arrangement 132 for an engine 10. The exhaust gas management arrangement 132 includes an opening 134 arranged to collect exhaust gas escaping from a movable section of an exhaust gas flow guide mechanism 99. The exhaust gas management arrangement 132 also has a channel 136 for directing the escaped exhaust gas to a crankcase 26 of the engine 10. In this way, even a relatively small leak can be controlled and instead treated according to preferred and / or established methods. The channel 136 can be fluidically coupled to a fluid-carrying body at one or more connection points 138. Exemplary fluid-carrying bodies that may be suitable elements for the one or more connection points 138 include, but are not limited to, the first crankcase ventilation line 84 and the vent pipe 92.The one or more connection points 138 can provide fluid access to the positive crankcase ventilation (PCT) system 80. In this way, gases that have escaped from the one or more exhaust flow control mechanisms 99 can be regulated or handled by the PCV system 80 and are not released into the atmosphere.

[0030] In some embodiments, the channel 136 can be fluidically coupled to the crankcase 26 via the oil return line 130 for a bearing 128 of the turbocharger. In some embodiments, the channel 136 can be fluidically coupled to the crankcase via the cam cover 64. In some embodiments, the channel 136 can be fluidically coupled to the crankcase 26 via the cylinder head 60. In some embodiments, the channel 136 can be fluidically coupled to the crankcase 26 via the vent channel 92 of the positive crankcase ventilation (PCV) system 80.

[0031] Fig. Figure 2 is a cross-sectional view of an exemplary exhaust flow guidance mechanism 99, which may be a turbocharger boost pressure control valve 100; Fig. Figure 3 is a cross-sectional view of another exemplary turbocharger boost pressure control valve 100; and Fig. Figure 4 is a cross-sectional view of another exemplary, but not invention-specific, turbocharger boost pressure control valve 100 according to the present disclosure. Each boost pressure control valve 100 can be combined with the exemplary engine in Fig. 1 or another engine. The illustrated boost pressure control flaps 100 may have similar features and some differences. Similar parts may be marked with similar reference numerals.

[0032] Each boost pressure control valve 100 can have an inlet 140 and an outlet 142. The flow through the boost pressure control valve 100 can be controlled by a valve 144. Each boost pressure control valve 100 can have an opening 134 arranged to collect exhaust gas exiting from a movable section 146 of the boost pressure control valve 100. Each boost pressure control valve 100 can also have a channel 136 to direct the exiting exhaust gas to a crankcase 26 of the engine 10.

[0033] The movable section 146 is a rod 148 arranged for movement within a pair of spaced-apart bushings 150. The rod 148 may be a valve stem. The channel 136 has a groove 152 that intersects with the rod between the bushings 150. In some cases, the opening 134 may be an encapsulation 156 that engages in a sealing manner with the exhaust flow guidance mechanism and defines a volume 158 around a potentially leaking section 154 of the exhaust flow guidance mechanism 99.

[0034] In some embodiments, the movable section 146 can be coupled to a diaphragm 160, which is movable in accordance with a pressure within a volume 162 defined between the diaphragm 160 and a casing 164. The pressure can be varied according to a fluid connection 166. The fluid connection 166 can be a boost pressure control orifice. A spring 168 can be included to bias the movable section 146, for example, into a closed position.

[0035] Various embodiments can provide a turbocharger boost pressure control valve 100 for an engine 10. The boost pressure control valve 100 has an encapsulation 156 that engages in a sealing manner with a potentially leaking section 154 of the boost pressure control valve 100. The boost pressure control valve 100 also has a channel 136 from the encapsulation 156 to a positive crankcase ventilation (PCV) system 80 to direct exhaust gas that has escaped from the boost pressure control valve 100 to a crankcase 26 of the engine 10. The channel 136 may include an oil return line 130 for a bearing 128 of the turbocharger.

[0036] The potentially leaking section 154 of the boost pressure control flap can be a rod 148 arranged in a bushing 150 to transmit movement from an actuator 170 to a valve 144. In some cases, the rod 148 can be actuated by a lever 172.

[0037] In some cases, the rod 148 can be actuated by a diaphragm 160. According to the invention, the channel 136 is a groove 152 arranged to intersect with the rod 148. The channel 136 has a gap or space 174 between two sections of the bushings 150. According to the invention, the turbocharger boost pressure control valve 100 has two bushings 150 with a space 174 between them. The rod 148 is arranged for translational movement within the two bushings 150. The channel 136 has a groove 152 in line with the space 174 between the bushings 150 and is arranged to intersect with the rod 148.

[0038] Various embodiments can provide a turbocharger boost pressure control valve 100 for an engine 10. The boost pressure control valve 100 has an encapsulation 156 that engages in a sealing manner with a potentially leaking section 154 of the boost pressure control valve 100 and is in fluid communication with a crankcase 26 of the engine 10. In some embodiments, the encapsulation 156 can be in fluid communication with the crankcase 26 via a positive crankcase ventilation system 80. In some embodiments, the encapsulation 156 can be in fluid communication with a positive crankcase ventilation system 80 via a turbocharger bearing oil return line 130.

[0039] It will be understood that the systems and procedures described here are exemplary and that these specific embodiments or examples are not to be understood in a restrictive sense, as numerous variations thereof are taken into account. Reference symbol list 10 Motor 12 cylinders 14 Combustion chamber 16 pistons 18 Crankshaft 20 Connecting rod 21 crank pins 22 crank offset 24 Counterweight 26 Crankcase 30 Intake channel 31 Throttle valve 32 Outlet channel 34 Intake valve 36 Exhaust valve 38 Cam actuation system 40 cam actuation system 42 cams 44 Camshaft 50 Fuel injector 52 Ignition system 54 Spark plug 60 cylinder head 62 cylinder block 64 cam covers 70 oil separators 72 Oil separation chamber 74 Base plate 80 Engine crankcase ventilation system 82 Leaking gases 84 first crankcase ventilation line 86 second crankcase ventilation line 88 Mixture of oil and leaking gases 90 valve 92 Vent pipe 94 Turbo compressor 96 Induction air path 98 Exhaust turbine 99 Exhaust gas flow guidance mechanism 100 Charge pressure control valve 102 Exhaust pipe 104 Emission control device 106 Engine lubrication system 108 Oil pump 110 Oil pan 112 Supply channel 114 Junction 116 Junction 118 Junction 120 feedback channel 122 Oil filters 124 Turbine bearing lubrication system 126 Turbine shaft 128 turbine bearings 130 Oil return line 132 Exhaust gas management system 134 Opening Channel 136 138 liaison point 140 Inlet of the boost pressure control flap 142 Outlet of the boost pressure control flap 144 Valve 146 movable section 148 bars 150 sockets 154 possibly leaking section 156 Encapsulation 158 volumes around a potentially leaking section 160 Membran 162 Volume between membrane and covering 164 Envelope 166 Fluid connection 168 spring 170 actuator 172 levers 174 Space between the sockets

Claims

[1] Exhaust gas management arrangement (132) for an engine (10), comprising: an opening (134) arranged to collect an exhaust gas exiting a movable portion (146) of an exhaust flow directing mechanism (99); and a channel (136) for directing the escaped exhaust gas to an engine crankcase (26), characterized by , that the movable portion (146) is a rod (148) arranged for movement in a pair of spaced-apart bushings (150), the channel (136) having a groove (152) intersecting the rod (148) between the bushings (150). [2] The exhaust gas management arrangement (132) of claim 1, wherein a gas leak originates from a turbocharger wastegate (100). [3] The exhaust gas management arrangement (132) of claim 1, wherein the exhaust gas flow directing mechanism (99) is a turbocharger wastegate (100). [4] The exhaust gas management arrangement (132) of claim 1, wherein the channel (136) is fluidly coupled to the crankcase (26) via an oil return line (130) for a bearing (128) of a turbocharger. [5] The exhaust management assembly (132) of claim 1, wherein the channel (136) is fluidly coupled to the crankcase (26) via a cam cover (64). [6] The exhaust management arrangement (132) of claim 1, wherein the channel (136) is fluidly coupled to the crankcase (26) via a cylinder head (60). [7] The exhaust management assembly (132) of claim 1, wherein the passage (136) is fluidly coupled to the crankcase (26) via a positive crankcase ventilation (PCV) system (80). [8] The exhaust management assembly (132) of claim 1, wherein the opening (134) is an encapsulation (156) sealingly engaged with the exhaust flow directing mechanism (99) and defining a volume around a potentially leaking portion (154) of the exhaust flow directing mechanism (99). [9] Turbocharger wastegate (100) for an engine, comprising: an encapsulation (156) sealingly engaging a potentially leaking portion (154) of the wastegate (100); and a channel (136) from the enclosure (156) to a positive crankcase ventilation (PCV) system (80) for moving exhaust gas exiting the wastegate (100) to a crankcase (26) of the engine (10), characterized by , that the turbocharger wastegate (100) comprises two bushings (150) with a space (174) therebetween and a rod (148) arranged for translational movement in the two bushings (150); wherein the channel (136) has a groove (152) aligned with the space (174) between the bushings (150) and arranged to intersect with the rod (148). [10] Turbocharger wastegate (100) according to claim 9, wherein the channel (136) comprises an oil return line (130) for a bearing (128) of the turbocharger. [11] A turbocharger wastegate (100) according to claim 9, wherein the potentially leaking portion (154) of the wastegate (100) is the rod (148) disposed in the two bushings (150) to transmit movement from an actuator (170) to a valve (144). [12] Turbocharger wastegate (100) according to claim 11, wherein the rod (148) is actuated by a lever (172). [13] Turbocharger wastegate (100) according to claim 11, wherein the rod (148) is actuated by a diaphragm (160). [14] Turbocharger wastegate (100) according to claim 11, wherein the channel (136) is a gap between two portions of the bushings (150).

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