Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
  • F02M26/65—Constructional details of EGR valves
  • F02M26/72—Housings
  • F02M26/73—Housings with means for heating or cooling the EGR valve
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D9/00—Controlling engines by throttling air or fuel-and-air induction conduits or exhaust conduits
  • F02D9/08—Throttle valves specially adapted therefor; Arrangements of such valves in conduits
  • F02D9/10—Throttle valves specially adapted therefor; Arrangements of such valves in conduits having pivotally-mounted flaps
  • F02D9/1065—Mechanical control linkage between an actuator and the flap, e.g. including levers, gears, springs, clutches, limit stops of the like
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
  • F02M26/52—Systems for actuating EGR valves
  • F02M26/53—Systems for actuating EGR valves using electric actuators, e.g. solenoids
  • F02M26/54—Rotary actuators, e.g. step motors
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M26/00—Engine-pertinent apparatus for adding exhaust gases to combustion-air, main fuel or fuel-air mixture, e.g. by exhaust gas recirculation [EGR] systems
  • F02M26/65—Constructional details of EGR valves
  • F02M26/70—Flap valves; Rotary valves; Sliding valves; Resilient valves

Definitions

• EGR systems have been used to reduce the NOx emissions of engine exhaust by recycling inert exhaust gas.
• EGR systems may be internal, i.e., by trapping exhaust gas within the cylinder by not fully expelling it during the exhaust stroke, or external, e.g., by piping it from the exhaust manifold to the inlet manifold.
• EGR systems may be high pressure, such as for forced induction applications, or low pressure, such as for naturally aspirated engines.
• Control valves may be used as part of the EGR system to modulate and time the recirculated gas flow. Depending on the location of the modulating valve and the coupling of the driver mechanism, valves and actuators used as part of EGR systems may be exposed to high temperatures transmitted via conduction, convection or radiation.
• an exhaust gas recirculation valve has a cast metal body having at least one cooling circuit that is cast in to the cast metal body.
• the cooling circuit includes a coolant inlet, a coolant outlet, and passage between the inlet and the outlet.
• a device has a cast metal body, and electronics cooling circuit cast into the metal body, and a valve cooling circuit cast into the metal body.
• the electronics cooling circuit cools at least one of a circuit board and a motor.
• the valve cooling circuit cools at least one of a valve shaft and a gear train.
• a method of manufacturing an exhaust gas recirculation valve includes providing a mold having a cast pattern comprising at least one cooling circuit in the mold.
• the cooling circuit includes a coolant inlet, a coolant outlet, and a coolant passage between the inlet and outlet. The method further involves introducing molten metal or alloy to the mold, and cooling the molten metal or alloy, to form a cast metal device having the pattern of the mold including the cooling circuit.
• FIG. 1 is a perspective view of an EGR valve, in accordance with an exemplary embodiment.
• FIG. 2 is a sectional view of an EGR valve, in accordance with an exemplary embodiment.
• FIG. 3 is a sectional view of an electronics portion of an EGR valve, in accordance with an exemplary embodiment.
• FIG. 4 is a sectional view of an EGR valve, in accordance with an exemplary embodiment.
• FIG. 5 is a sectional view of a valve portion of an EGR valve, in accordance with an exemplary embodiment.
• FIG. 6 is a sectional view of a valve portion of an EGR valve, in accordance with an exemplary embodiment.
• FIG. 7 is a sectional view of an EGR valve, in accordance with an exemplary embodiment.
• FIG. 8 is a perspective view of an EGR valve, in accordance with an exemplary embodiment.
• FIG. 9 is a sectional view of an EGR valve, in accordance with an exemplary embodiment.
• FIG. 10 is a sectional view of an electronics portion of an EGR valve, in accordance with an exemplary embodiment.
• FIG. 11 is a sectional view of an EGR valve, in accordance with an exemplary embodiment.
• FIG. 12 is a sectional view of a shaft, in accordance with an exemplary embodiment.
• EGR valves to modulate and time the recirculated gas flow.
• valves and actuators used in EGR systems may be exposed to high temperatures transmitted via conduction, convection or radiation.
• the EGR valves of the exemplary embodiments provide a cooling methodology and the means of achieving it via novel manufacturing processes and design features.
• valves and methods of the exemplary embodiments provide an improvement over other known devices and cooling techniques.
• a metal or alloy actuator flange or valve housing or mechanism is not cast using the exemplary method, it requires several parts and seals to conform to specifications such as for leakage and robustness.
• the exemplary method simplifies the manufacture of these devices, by reducing or eliminating several machining, processing and assembly steps, also reducing the cost of processing these devices.
• an exemplary EGR valve 100 may have a housing or body 110, a valve portion 150, and an electronics portion 140.
• Valve portion 150 and electronics portion 140 may be formed as a unitary part, or may be formed as a plurality of parts fastened together.
• the valve portion 150 may include any valve type suitable for the embodiments described herein.
• the valve can be a low pressure or high pressure type and can be of the internal (in cylinder) or external type.
• low pressure EGR systems are generally for naturally aspirated engines while the high pressure EGR systems are for forced induction engine application.
• the valve may use any suitable modulation means.
• the modulation of the re-circulated gases can be accomplished by poppet valves, flapper valves, butterfly valves, gate valves, etc., and they can be pressure balanced or pressure biased according to their operation.
• actuation of the valve can be accomplished by any suitable means.
• an exemplary valve may be actuated manually, pneumatically, hydraulically or electrically and directly coupled, magnetically coupled or driven via levers and pushrods, etc.
• Exemplary valves and actuators are described in U.S. Patent Nos. 7,591,245, and
• valve portion 150 may be an electronic closed coupled actuator two barrel butterfly EGR valve configured for a high pressure application.
• the valve portion 150 includes a gas passage 152, and a rotatable plate 154 coupled with a shaft 156.
• the rotatable plate 154 rotates between an open position, and a closed position in which the plate 154 provides a seal against a portion of the inner surface of the passage 152, so that there is substantially no gas flow past the plate 154.
• the valve portion 150 may have other various features, as necessary or desired.
• the electronics portion 140 of the EGR valve 100 includes the electronic controls for the valve.
• the electronics portion 140 may include, for example, a circuit board 142, and a motor 144, such as a brushless DC (BLDC) motor.
• the electronics portion 140 may have other various features, as necessary or desired.
• the EGR valve 100 may be cooled by any known or later developed cooling methodology. Exemplary cooling methods include those used for single or multi-barrel valves or stand-alone actuators that require cooling due to high temperature environmental exposure.
• a coolant medium may be circulated through the EGR valve 100, to facilitate heat transfer.
• the EGR valve 100 may have at least one cooling passage 200 formed within the valve housing/body 110, to provide a means for communicating the coolant medium through the valve body 110.
• the cooling passage 200 may have an inlet 210 and a outlet 220, for a coolant medium.
• the passage 200, inlet 210, and outlet 220 may be provided in any part of the valve body 110, as necessary or desired. For example, referring to FIGS.
• the inlet 210 and/or outlet 220 may be provided on the valve portion 150 of the valve 100, or referring to FIG. 8, the inlet 210 and/or outlet 220 may be provided in the electronics portion 140 of the valve 100, or any combination of the foregoing.
• the valve 100 may have a plurality of passages 200, inlets 210, and/or outlets 220.
• cooling passage(s) 200 are provided in close proximity to the mechanism(s) being cooled, thereby improving the cooling efficiency of the device.
• cooling medium refers to any suitable coolant or refrigerant, including gases, liquids, nanofluids, and mixtures thereof.
• the coolant medium may be a gas such as air, hydrogen, helium, nitrogen, carbon dioxide, etc.
• the coolant medium may be a liquid such as water, polyalkylene glycols, ethylene glycol, diethylene glycol, propylene glycol, betaine, oils, fuels, molten metals (e.g., sodium or a sodium-potassium alloy), etc.
• molten metals e.g., sodium or a sodium-potassium alloy
• the coolant medium may be introduced to the cooling passage 200 by any suitable mechanism including pumps, etc.
• the cooling passage(s) 200 may provide one or more major cooling circuits, including an electronic/electric cooling circuit 240 (see FIGS. 1-4 and 8-10) and/or a valve cooling circuit 250 (see FIGS. 5-7 and 11).
• the valve cooling circuit 250 provides a cooling passage 200 through the valve body 110, in and about the valve portion 150, and the parts provided therein.
• the valve cooling circuit 250 may provide a cooling passage 200 about the shaft and motor flange. The valve cooling circuit 250 may reject the heat conducted through the shaft into the gear train 158 and shield the BLDC motor flange from heat conduction transmitted from the exhaust gases.
• the electronics/electric cooling circuit 240 provides a cooling passage 200 through the valve body 110, in and about the electronics/electric portion 140, and the parts provided therein.
• the electronics/electric cooling circuit 240 may provide a cooling passage 200 about the motor 144, and/or, referring to FIG. 4, about the electronic board 144.
• the electronic/electric cooling circuit 240 of the exemplary embodiments may reject heat generated at the circuit board and BLDC motor 144 as well as shield the circuit board 142 and the motor 144 from the engine underhood high temperatures.
• the one or more cooling circuits 240 and 250 may be formed by providing cooling passages 200 in the valve body/housing 210, or in the mechanism of valve portion 150, or a combination thereof.
• valve 100 has both an electronic cooling circuit 240 and a valve cooling circuit 250.
• the electronic cooling circuit 240 is in fluid communication with the valve cooling circuit 250.
• a cooling passage 200 may be configured so that the coolant medium enters via the coolant medium inlet 210 and flows through the electronic cooling circuit 240 and then through the valve cooling circuit 250 (see FIG. 4), and then exits via the coolant medium outlet 220.
• the cooling passage 200 may be configured so that the coolant medium enters via the coolant medium inlet 210 and flows through the valve cooling circuit 250 and then through the electronic cooling circuit 240 and then exits via the coolant medium outlet 220.
• separate cooling passages 200 may be provided for the electronic cooling circuit 240 and the valve cooling circuit 250, each circuit having its own cooling medium inlet 210 and outlet 220.
• additional heat path reduction features may be designed into the shaft 156 between the high temperature exposure and the shaft seal 160.
• a hollow shaft portion 170 may be provided to reduce the heat transfer path, or, referring to FIG. 11, the shaft 156 may be cross drilled with shaft holes 172 to reduce the heat transfer path.
• a non-contact heat transfer configuration minimizes the gap between the shaft housing and its integrated cooling passage to achieve shaft heat rejection.
• the shaft heat rejection may be achieved with a contact heat transfer design.
• the coolant passage 200 may direct the coolant medium the shaft 156 so that it is exposed to the coolant and two shaft seals 160a and 160b contain the coolant, segregating it from the valve passage 152.
• a shaft cooling passage 164 may be provided through the shaft 156.
• the shaft cooling passage 164 may be in fluid communication with the valve cooling circuit 150 and/or the electronic cooling circuit 240.
• the hollow shaft (FIG. 7) may be a sodium-filled shaft, or may be a flow-through chamber.
• brush contacts 162 may be spring loaded between the housing 110 and the shaft 156, whereby the brushes 162 carry the heat from the shaft to the adjacent cooled surface of the housing 110.
• the brushes 162 may be connected to the shaft 156 (as shown) or to the adjacent housing 110.
• Spring loading of the brushes 162 may be accomplished by any suitable means such as, for example, compression, tension, or torsional springs 174 as well as sponge type brushes with spring properties, may be connected to the shaft 156 (as shown) or to the adjacent housing 110.
• a method for cooling may be provided.
• the EGR valve 100 includes one or more cast parts, and a cooling method involves providing cooling passages 200 that are "cast in" to the cast parts, such as by using a lost foam casting process, a lost core investment casting process, a salt core casting process, or the like. While the embodiments are described in more detail below with respect to a lost foam casting process, one of ordinary skill in the art would recognize from this description how to adapt other suitable processes to make a similar device.
• Lost foam casting processes generally involve providing a lost foam embedded in sand mold, where the foam is formed into the desired shape of the finished cast part; and pouring molten metal or alloy material onto the vaporizable foam material so that the molten metal vaporizes and displaces the foam, forming a cast part in the shape of the lost foam.
• This casting process allows a reduction in assembly complexity, parts count and the potential leak points generally encountered in a multi seal assembly. Seals have also the properties in reducing the heat transfer causing poor heat rejection via the coolant and/or heat and/or fluid compatibility issues.
• Any suitable metal and/or alloy material may be used in the various embodiments including, for example, aluminum or cast iron.
• the lost foam and sand mold may be configured to provide one or more cooling passages 200 in the cast part to provide one or more cooling circuits having a coolant medium inlet 210 and a coolant medium outlet 220.
• the method of the exemplary embodiments provides advantages over known processes because it can provide cooling passages in closer proximity to the mechanism(s) being cooled, thereby improving the cooling efficiency of the device.
• the lost foam material may be any foam material that is vaporizable by the molten metal or alloy to form voids therein.
• the lost foam may be polystyrene foam. Other suitable materials for the lost foam may be used as necessary and/or desired.
• a single piece lost foam casting process may be utilized to maximize the coolant flow and heat rejection and minimize the part count assembly complexity and leak potential.
• Other variants of this process that are suitable for the embodiments described herein may be used as necessary and/or desired.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Exhaust-Gas Circulating Devices (AREA)
• Details Of Valves (AREA)

Applications Claiming Priority (3)

Publications (2)

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Family Applications (1)

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Citations (6)

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• 2010
  • 2010-04-20 BR BRPI1013738A patent/BRPI1013738A2/pt not_active IP Right Cessation
  • 2010-04-20 EP EP10767639.7A patent/EP2422069A4/de not_active Withdrawn
  • 2010-04-20 WO PCT/US2010/031752 patent/WO2010123899A1/en active Application Filing
  • 2010-04-20 CN CN2010800250651A patent/CN102449296A/zh active Pending
  • 2010-04-20 JP JP2012507314A patent/JP2012524212A/ja active Pending

Patent Citations (6)

Non-Patent Citations (1)

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