The present disclosure relates to exhaust aftertreatment systems for treating exhaust gases produced in automotive applications, and particularly to an aftertreatment system for reducing or removing nitrogen oxides (NOx) from exhaust gases.
A vehicle in accordance with the present disclosure includes an engine and an exhaust aftertreatment system in accordance with the present disclosure. The engine combusts fuel and discharges exhaust gases through an interior space. The exhaust aftertreatment system is configured to reduce various undesired effluents in the exhaust gases, for example, NOx, before the exhaust gases are released to the atmosphere.
In illustrative embodiments, the exhaust aftertreatment system includes an exhaust housing and one or more exhaust aftertreatment devices coupled to the exhaust housing. The exhaust aftertreatment devices includes a selective catalytic reduction unit (SCR) and a doser mounted upstream of the SCR for injecting a reagent exhaust gases passing through an exhaust passageway defined by the exhaust housing. Chemical reaction of the reagent with the exhaust gases with the reagent occurs downstream of the doser in the SCR to transform the NOx into molecular nitrogen and water vapor which are not harmful to the environment.
In illustrative embodiments, the SCR includes a catalyst arranged to lie within the exhaust passageway and configured to encourage the chemical reaction between the exhaust gases and the reagent. In some situations, an efficiency of the chemical reaction can be improved by increasing a temperature of at least one of the catalyst or the exhaust gases and reagent passing therethrough. The SCR further includes an electrical conductor assembly coupled to the catalyst or a heater included in the catalyst and an electrical connector coupled between a power source and the electrical conductor assembly. The electrical conductor assembly and the electrical connector cooperate to supply electrical power from the power source to the catalyst or the heater to heat at least one of the catalyst or the exhaust gases and the reagent passing therethrough.
In illustrative embodiments, the electrical conductor assembly is mounted on the exhaust housing and insulates the electrical power from the exhaust housing. The electrical conductor assembly includes an outer mount sleeve coupled to the exhaust housing, an electrical conductor coupled between the electrical connector and the catalyst or the heater, and an insulative sleeve arranged between the outer mount sleeve and the electrical conductor. In some embodiments, axial forces are applied on the outer mount sleeve and radial forces are applied on the electrical conductor to retain the electrical conductor in place relative to the catalyst and the exhaust housing.
In illustrative embodiments, the electrical conductor is threadless and the electrical connector is attached to or removed from the electrical conductor by translating the electrical connector in only one direction. The electrical connector may be free to pivot relative to the electrical conductor so as not to impart substantial torque forced on the electrical conductor.
Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of illustrative embodiments exemplifying the best mode of carrying out the disclosure as presently perceived.
The detailed description particularly refers to the accompanying figures in which:
An illustrative over-the-road vehicle 10 includes an engine 12 and an exhaust aftertreatment system 14 in accordance with the present disclosure as shown in
In the illustrative embodiment, the exhaust aftertreatment system 14 includes an exhaust housing 15 and one or more exhaust aftertreatment devices 17 such as a diesel oxidation catalyst (DOC) 18, a diesel particulate filter (DPF) 20, a mixer 22, a doser 24 coupled to the mixer 22, and a selective catalytic reduction unit (SCR) 26. The exhaust housing 15 defines the interior space 16. Each of the exhaust aftertreatment devices 17 is coupled to the exhaust housing 15 and/or located within the interior space 16 and is configured to interact with the exhaust gases produced by the engine 12 to remove or reduce different effluents from the exhaust gases prior to being released to the atmosphere.
The mixer 22, doser 24, and SCR 26 cooperate to reduce or remove NOx effluents from the exhaust gases. The doser 24 is coupled to the mixer 22 and is configured to inject a reagent into the exhaust gases upstream of the SCR 26. The reagent is, illustratively, a urea solution (i.e. Diesel Emission Fluid), however in other embodiments the reagent may be gaseous ammonia or other suitable chemicals. The mixer 22 is configured to induce mixing of the exhaust gases and the reagent upstream of the SCR 26. Chemical reaction of the reagent with the exhaust gases occurs downstream of the mixer 22 and the doser 24 in the SCR 26.
The SCR 26 includes a catalyst 28 that encourages chemical reaction of the reagent and the exhaust gases to transform the NOx effluents into molecular nitrogen and water vapor. In the illustrative embodiment, the exhaust aftertreatment system 14 further includes a control system 100 that controls operation of the doser 24 and to selectively heat the catalyst 28 in certain situations. The control system 100 includes a power source 102, a sensor 104, and a controller 106 as shown in
The catalyst 28 is selectively heatable by the control system 100 to increase an efficiency of the chemical reaction in low-temperature situations, such as start-up conditions of the engine 12 and until a temperature of the exhaust gases and/or the catalyst 28 reaches a predetermined temperature. The catalyst 28 includes catalyst media 108, a heater 110, and a conductive ring 112 surrounding the catalyst media 108. The catalyst media 108 is configured to encourage the chemical reaction between the exhaust gases and the reagent. The heater 110 is coupled to and/or integrated with the catalyst media 108 and increases in temperature when the electrical power passes through the heater 110 to heat the catalyst media 108 (i.e. by resistive heating). In some embodiments, the catalyst media 108 is conductive and is directly heated when the electrical power passes through the catalyst media 108. The conductive ring 112 is coupled to the heater 110 and receives electrical power and distributes the electrical power to the heater 110.
The SCR 26 further includes an electrical conductor assembly 30 coupled to the exhaust housing 15 and the catalyst 28 and an electrical connector 32 removably coupled to the electrical conductor assembly 30 as shown in
Together, the electrical conductor assembly 30 and the electrical connector 32 may be included in an electrical connection system that is configured to interconnect the power source 102 to one or more electrical components or devices. The electrical connection system is configured to transfer and deliver the electrical power to the one or more electrical components for consumption by the electrical component or device. The electrical conductor assembly 30 may be fixed to a non-electrical component (i.e. exhaust housing 15) relative to the electrical component or device while insulating other the non-electrical component from the electrical power provided by the power source 102.
The electrical conductor assembly 30 includes an outer mount sleeve 34, an electrical conductor 36, and an insulative sleeve 38 as shown in
The outer mount sleeve 34 is illustratively embodied as a cylindrical tube as shown in
The electrical conductor 36 is illustratively embodied as a cylindrical rod to match a shape of the outer mount sleeve 34 and the insulative sleeve 38, however, in some embodiments, any suitable polygonal shape may be used. The electrical conductor 36 is threadless but is formed to include an annular channel 37 at an outer end 46 of the electrical conductor 36 that is configured to receive the electrical connector 32. An inner end 48 of the electrical conductor 36 is engaged with the conductive ring 112 of the catalyst 28. The electrical connector 32 includes at least one connector retainer 33 that extends into the annular channel 37 to retain the electrical connector 32 to the electrical conductor 36. The at least one connector retainer 33 is free to slide through the annular channel 37 such that the electrical connector 32 is free to pivot relative to the electrical conductor 36 without imparting substantial torque on the electrical conductor 36.
The insulative sleeve 38 includes a sleeve body 50, a first insulative ring 52 coupled to an inner end of the sleeve body 50, and a second insulative ring 54 coupled to an opposite, outer end of the sleeve body 50 as shown in
At least one of the sleeve body 50, the first insulative ring 52, and the second insulative ring 54 may be sized so as to be press-fit with the electrical conductor 36 when the electrical conductor assembly 30 is fully assembled. The first and second insulative rings 52, 54 may engage the outer mount sleeve 34 and impart opposing inward forces 90, 92 on the inner and outer ends 42, 44 of the outer mount sleeve 34. The opposing inward forces 90, 92 may provide a compressive load on the outer mount sleeve 34. The insulative sleeve 38 may also impart a radial force 94 toward and on the electrical conductor 36 so as to frictionally engage the electrical conductor 36 and block movement of the electrical conductor 36 relative to the outer mount sleeve 34 and the exhaust housing 15. Accordingly, an outer diameter of the electrical conductor 36 may be slightly larger than an inner diameter of the insulative sleeve 38 so as to provide a friction-interference fit therebetween. In some embodiments, the radially inward force 94 is provided by the outer mount sleeve 34 to the electrical conductor 36 through the insulative sleeve 38 such that a friction-interference is provided between the outer mount sleeve 34 and the insulative sleeve 38 and between the insulative sleeve 38 and the electrical conductor 36.
In some embodiments, the sleeve body 50 includes a first sleeve-body section 60 and a second sleeve-body section 62 separate from the first sleeve-body section 60 as shown in
During installation and assembly of the electrical conductor assembly 30, the first sleeve-body section 60 is inserted into the outer mount sleeve 34 from the inner end 42 until the first insulative ring 52 engages the inner end 42 of the outer mount sleeve 34. The second sleeve-body section 62 is inserted into the outer mount sleeve 34 from the outer end 44 until the second insulative ring 54 engages the outer end 44 of the outer mount sleeve 34. The electrical conductor 36 may then be inserted into the insulative sleeve 38 from either direction to complete assembly of the electrical conductor assembly 30. The outer mount sleeve 34 may then be secured to the exhaust housing 15.
In some embodiments, the electrical conductor assembly 30 further includes a first retainer 70 and a second retainer 72 as shown in
The first insulative ring 52 is located between the inner end 42 of the outer mount sleeve 34 and the first retainer 70. The second insulative ring 54 is located between the outer end 44 of the outer mount sleeve 34 and the second retainer 72. In this way, the retainers 70, 72 are insulated from the exhaust housing 15 to disrupt any electrical path from the electrical conductor 36, through the retainers 70, 72, and to the exhaust housing 15.
The first and second retainers 70, 72, when included, apply radial forces 94 on the electrical conductor 36 and the inward forces 90, 92 through the insulative rings 52, 54 to the outer mount sleeve 34. In this arrangement, the retainers 70, 72 apply the forces 90, 92 on the outer mount sleeve 34 and the insulative sleeve 38. The insulative rings 52, 54 provide the forces 90, 92 on the outer mount sleeve 38, but when the first and second retainers 70, 72 are included, the insulative rings 52, 54 may not be the cause of the forces 90, 92. The first and second retainers 70, 72 may have an inner diameter that is slightly less than the outer diameter of the electrical conductor 36 to provide a friction-interference fit therebetween.
The electrical connector 32 includes a cable 80, a connector head 82 coupled to the cable 80, and an insulative connector sleeve 84 as shown in
The insulative connector sleeve 84 includes a sleeve tube 86 and a sleeve head 88 as shown in
Another embodiment of an electrical conductor assembly 230 is shown in
The electrical conductor assembly 230 includes a conductor 236 that has an outer end 244 that is curved as shown in
The following numbered clauses include embodiments that are contemplated and non-limiting:
Clause 1. An exhaust aftertreatment system for an over-the-road vehicle, the exhaust aftertreatment system comprising
Clause 2. The aftertreatment system of clause 1, any other clause or any suitable combination of clauses, wherein the sleeve-body includes a first sleeve-body section and a second sleeve-body section separate from the first sleeve-body section, and wherein the first sleeve-body section is integral with the first insulative ring and the second sleeve-body section is integral with the second insulative ring.
Clause 3. The aftertreatment system of clause 2, any other clause or any suitable combination of clauses, wherein the first sleeve-body section and the second sleeve-body section are press-fit with the electrical conductor so that the first insulative ring and the second insulative ring apply a compressive load on the outer mount sleeve.
Clause 4. The aftertreatment system of clause 2, any other clause or any suitable combination of clauses, wherein the electrical-conductor assembly further includes: (iv) a first retainer coupled to the electrical conductor and the first insulative ring to locate the first insulative ring between the inner end of the outer mount sleeve and the first retainer and (v) a second retainer coupled to the electrical conductor and the second insulative ring to locate the second insulative ring between the outer end of the outer mount sleeve and the second retainer.
Clause 5. The aftertreatment system of clause 4, any other clause or any suitable combination of clauses, wherein first and second retainers are press-fit with the electrical conductor and cooperate to provide a compressive load through the first insulative ring and the second insulative ring to the outer mount sleeve.
Clause 6. The aftertreatment system of clause 1, any other clause or any suitable combination of clauses, further comprising a control system including the power source, a temperature sensor configured to measure a temperature of at least one of the catalyst and the exhaust gases, and a controller configured to selectively provide power from the power source to the catalyst to heat the catalyst when the temperature is below a predetermined threshold.
Clause 7. The aftertreatment system of clause 1, any other clause or any suitable combination of clauses, wherein the electrical conductor includes an outer end arranged outside of the interior space and an inner end arranged within the interior space, and wherein the outer end is formed without threads and includes an annular channel that is configured to engage one or more connector retainers that extend into the annular channel such that the electrical connector is free to pivot about the outer end of the electrical conductor.
Clause 8. A selective catalytic reduction unit for an exhaust aftertreatment system having an exhaust housing defining an interior space, the aftertreatment system comprising
Clause 9. The selective catalytic reduction unit of clause 8, any other clause or any suitable combination of clauses, wherein the sleeve body includes a first sleeve-body section and a second sleeve-body section separate from the first sleeve-body section, and wherein the first sleeve-body section is integral with the first insulative ring and the second sleeve-body section is integral with the second insulative ring.
Clause 10. The selective catalytic reduction unit of clause 9, any other clause or any suitable combination of clauses, wherein the first sleeve-body section and the second sleeve-body section are press-fit with the electrical conductor and the first insulative ring and the second insulative ring apply the compressive load on opposing ends of the outer mount sleeve.
Clause 11. The selective catalytic reduction unit of clause 10, any other clause or any suitable combination of clauses, wherein the electrical-conductor assembly further includes: (iv) a first retainer coupled to the electrical conductor and the first insulative ring to locate the first insulative ring between the inner end of the outer mount sleeve and the first retainer and (v) a second retainer coupled to the electrical conductor and the second insulative ring to locate the second insulative ring between the outer end of the outer mount sleeve and the second retainer.
Clause 12. The selective catalytic reduction unit of clause 11, any other clause or any suitable combination of clauses, wherein first and second retainers are press-fit with the electrical conductor and cooperate to provide the compressive load through the first insulative ring and the second insulative ring to the outer mount sleeve.
Clause 13. The selective catalytic reduction unit of clause 8, any other clause or any suitable combination of clauses, wherein the electrical conductor includes an outer end arranged outside of the interior space and an inner end arranged within the interior space, and wherein the outer end is formed without threads and includes an annular channel that is configured to engage one or more connector retainers that extend into the annular channel such that the electrical connector is free to pivot about the outer end of the electrical conductor.
Clause 14. An electrical connection system configured to interconnect a power source and an electrical component, the electrical connection system comprising
Clause 15. The electrical connection system of clause 14, any other clause or any suitable combination of clauses, wherein a first force is provided on the first end of the outer mount sleeve and an opposite, second force is provided on the second end of the outer mount sleeve such that a compressive load is applied on the outer mount sleeve through the first and second insulative rings to retain the electrical conductor and the insulative sleeve in place relative to the exhaust housing.
Clause 16. The electrical connection system of clause 15, any other clause or any suitable combination of clauses, wherein the sleeve body includes a first sleeve-body section and a second sleeve-body section separate from the first sleeve-body section, and wherein the first sleeve-body section is integral with the first insulative ring and the second sleeve-body section is integral with the second insulative ring.
Clause 17. The electrical connection system of clause 16, any other clause or any suitable combination of clauses, wherein first insulative ring and the second insulative ring are press-fit with the electrical conductor such that the first insulative ring and the second insulative ring apply the compressive load on the outer mount sleeve.
Clause 18. The electrical connection system of clause 14, any other clause or any suitable combination of clauses, wherein the electrical-conductor assembly further includes: (iv) a first retainer coupled to the electrical conductor and the first insulative ring to locate the first insulative ring between the first end of the outer mount sleeve and the first retainer and (v) a second retainer coupled to the electrical conductor and the second insulative ring to locate the second insulative ring between the second end of the outer mount sleeve and the second retainer.
Clause 19. The electrical connection system of clause 18, any other clause or any suitable combination of clauses, wherein first and second retainers are press-fit with the electrical conductor and cooperate to provide the compressive load through the first insulative ring and the second insulative ring to the outer mount sleeve.
Clause 20. The electrical connection system of clause 14, any other clause or any suitable combination of clauses, wherein the electrical conductor includes an outer end configured to couple with the electrical connector and an inner end configured to couple with the electrical component and wherein the outer end is formed without threads and includes an annular channel that is configured to engage one or more connector retainers of the electrical connector that extend into the annular channel such that the electrical connector is free to pivot about the outer end of the electrical conductor.