JP5915762B2 - Exhaust gas purification device - Google Patents

Description

  The present invention relates to an exhaust gas purifying apparatus that purifies exhaust gas discharged from an internal combustion engine and having a heating unit disposed at a place where heating is required.

  Vehicle exhaust gas purifiers disperse a catalyst and a reducing agent added to the catalyst in the exhaust pipe to purify environmental pollutants (HC, CO, NOx, etc.) contained in the exhaust gas exhausted from the engine A device or the like is provided. The catalyst has an optimum temperature (activation temperature) for activating the purification capacity, but when the engine is started, the temperature of the exhaust gas is low and it takes time to reach the activation temperature. Therefore, some exhaust gas purification devices warm up the catalyst by a heating device. Patent Document 1 discloses a catalyst warm-up device that warms up a catalyst by a heat storage device using reaction heat of a chemical reaction. In addition, when urea water is used as the reducing agent, some exhaust gas purification devices heat the dispersion device with a heating device in order to increase the hydrolyzability of urea water.

JP 59-208118 A

  Although the heating unit of the heating device as described above is provided on the outer peripheral surface of the exhaust pipe or the like, the adhesion between the heating unit and the outer peripheral surface of the exhaust pipe or the like may decrease due to thermal expansion, vibration, aging deterioration, or the like. In such a case, the heat transfer efficiency from the heating unit is lowered, the heating efficiency is lowered, and the heat from the heating unit is lost.

  Then, this invention makes it a subject to provide the exhaust gas purification apparatus which prevents the fall of the heat transfer efficiency from a heating part.

  An exhaust gas purification apparatus according to the present invention is an exhaust gas purification apparatus that purifies exhaust gas exhausted from an internal combustion engine, and includes a heating unit disposed at a location where heating is required in the exhaust gas purification apparatus, and heating. It is provided with the contact | adherence material provided between the required location and the said heating part.

  In this exhaust gas purification device, a heating unit is disposed at a place where heating is necessary. Examples of the places where heating is required include various catalysts arranged in the exhaust pipe, places upstream of the exhaust pipe where the various catalysts are arranged, and places of the exhaust pipe where the dispersing device is arranged. And in this exhaust gas purification apparatus, the contact | adherence material is provided between the location which needs the heating, and a heating part. Due to this adhesive material, the portion that needs to be heated and the heating part are always in close contact with each other via the adhesive material. For this reason, even if a location or heating portion that requires heating is thermally expanded, vibrated, aged, or the like, the location that requires heating and the heating portion can be maintained in close contact with each other through the adhesive material. As a result, the heat transfer efficiency from the heating part to the place where heating is required does not decrease. Thus, this exhaust gas purification apparatus can prevent a decrease in heat transfer efficiency from the heating unit by providing an adhesion material between the portion that needs to be heated and the heating unit. As a result, the heating efficiency by the heating unit is not lowered, and heat loss can be prevented.

  In the exhaust gas purifying apparatus of the present invention, it is preferable that the adhesion material is provided on the entire circumference along the outer circumferential surface of the portion that needs to be heated. As described above, in this exhaust gas purifying apparatus, the heat transfer efficiency from the heating part to the place where heating is required is improved by providing the contact material on the entire circumference along the outer peripheral surface of the place where heating is required. The assembly structure of the material becomes simple, and the assembly work becomes easy.

  In the exhaust gas purifying apparatus of the present invention, it is preferable that the surface on the adhesion material side in the heating portion and the surface on the adhesion material side in a portion where heating is necessary have an uneven shape that is engaged through the adhesion material.

  The surface on the adhesion material side in the heating unit has an uneven shape. In addition, the surface on the adhesion material side in the place where heating is necessary also has an uneven shape. Then, an adhesive material is provided between the uneven surface of the heating part and the uneven surface of the part that needs to be heated, and the heating part and the part that needs to be heated are related to the uneven part via the adhesive material. Match. Examples of the uneven shape include a rectangular uneven shape, a triangular uneven shape, and a wavy uneven shape. Thus, by making it an uneven | corrugated shape, since the contact area of a heating part and the location which needs a heating becomes large via a contact | adherence material, heat transfer efficiency improves. Moreover, by setting it as an uneven | corrugated shape, the position shift of the heating part with respect to the location which needs heating can be prevented, and the location which needs heating with a heating part can be heated reliably. Thus, this exhaust gas purifying device can improve the heat transfer effect by making the location where the adhesion material is provided uneven.

  The exhaust gas purifying apparatus of the present invention may be configured such that the entire surface of the case of the heating unit or a part of the surface including at least a surface on the side of the case where heating is required is formed with an adhesive material.

  The heating unit is housed in a case, and the entire surface of the case or a part of the surface including the surface on the side where heating is required is formed of an adhesive material. By forming the heating part in this way, the contact part is provided by a part of the heating part between the part that needs heating by disposing the heating part in the part that needs heating. As described above, this exhaust gas purifying apparatus improves the adhesion by forming the entire surface or a part of the surface of the case of the heating unit with an adhesion material, and also transfers heat from the heating unit to a place where heating is necessary. The distance can be shortened.

  ADVANTAGE OF THE INVENTION According to this invention, the fall of the heat transfer efficiency from a heating part can be prevented by providing a contact | adherence material between the location which needs a heating, and a heating part, and a heat loss can be prevented.

1 is a schematic configuration diagram of an exhaust gas purification device according to the present embodiment. It is an enlarged view of a dispersion device periphery, (a) is a sectional side view, (b) is a front view. 2A is an enlarged view of the vicinity of the adhesive material in the side sectional view of FIG. 2A, FIG. 2A is a case where the contact surface is a planar shape, and FIG. 2B is a case where the contact surface is a rectangular uneven shape, c) is the case where the heating part case is formed of a contact material and the contact surface is a flat shape, and (d) is the case where the heating part case is formed of a contact material and the contact surface is a rectangular uneven shape. (E) is a case where the case of the heating part is formed of an adhesive material and a vacuum double tube, and the contact surface is planar. It is the figure which showed the heating part arrange | positioned at the oxidation catalyst, (a) is a sectional side view, (b) is a front view. It is the figure which showed the heating part arrange | positioned at the exhaust pipe of the location where the gas warming-up member is arrange | positioned, (a) is a sectional side view, (b) is a front view.

  Hereinafter, an embodiment of an exhaust gas purifying apparatus according to the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected about the element which is the same or it corresponds in each figure, and the overlapping description is abbreviate | omitted.

  In the present embodiment, the exhaust gas purification apparatus according to the present invention is applied to an exhaust gas purification apparatus provided in an exhaust system of a vehicle engine (internal combustion engine). The exhaust gas purifying apparatus according to the present embodiment is an apparatus that purifies harmful substances (environmental pollutants) contained in exhaust gas discharged from an engine (particularly a diesel engine). The exhaust gas purification apparatus according to the present embodiment includes a catalyst oxidation catalyst, an SCR [Selective Catalytic Reduction], an NH3 slip catalyst, and a filter DPF [Diesel Particulate Filter]. The exhaust gas purifying apparatus according to the present embodiment also includes a reducing agent supply device that supplies a reducing agent (urea water) and a dispersing device that disperses the reducing agent, where the SCR is urea SCR. Furthermore, the exhaust gas purification apparatus according to the present embodiment also includes a heating device that heats the dispersion device disposed in the exhaust pipe.

  With reference to FIG.1 and FIG.2, the exhaust gas purification apparatus 1 which concerns on this Embodiment is demonstrated. FIG. 1 is a schematic configuration diagram of an exhaust gas purifying apparatus according to the present embodiment. 2A and 2B are enlarged views of the periphery of the dispersing device, where FIG. 2A is a side sectional view (note that only the upstream side of the SCR is a sectional view), and FIG. 2B is a front view.

  The exhaust gas purification device 1 includes an oxidation catalyst 4, a diesel exhaust particulate removal filter (DPF) 5, a selective reduction catalyst (SCR) 6 from the upstream side to the downstream side of the exhaust pipe 3 connected to the exhaust side of the engine 2. And a NH 3 slip catalyst 7, and a reducing agent supply device 8 and a dispersion device 9 for SCR 6.

The oxidation catalyst 4 is a catalyst that oxidizes HC, CO and the like contained in the exhaust gas. The DPF 5 is a filter that collects and removes PM contained in the exhaust gas. The SCR 6 is a catalyst that reduces and purifies NOx by chemically reacting ammonia (NH ₃ ) hydrolyzed from urea water as a reducing agent and NOx contained in the exhaust gas. The NH3 slip catalyst 7 is a catalyst that oxidizes ammonia that has passed through the SCR 6 and has flowed downstream.

  The reducing agent supply device 8 is a device for supplying urea water (reducing agent) to the upstream side of the SCR 6 in the exhaust pipe 3 (particularly, the upstream side of the dispersing device 9). Specifically, the reducing agent supply device 8 includes a pump (not shown), a reducing agent tank 8a, a reducing agent introduction pipe 8b, an injector 8c, and the like. The reducing agent tank 8a is a tank that stores urea water as a reducing agent. When the pump is activated, urea water is sent from the reducing agent tank 8a to the reducing agent introduction pipe 8b. The reducing agent introduction pipe 8b is a pipe that connects the reducing agent tank 8a and the injector 8c and moves urea water from the reducing agent tank 8a to the injector 8c. The injector 8 c is disposed between the DPF 5 and the SCR 6 in the exhaust pipe 3 (particularly on the upstream side of the dispersion device 9), and injects urea water into the exhaust pipe 3. The urea water injected into the exhaust pipe 3 is uniformly dispersed by the dispersing device 9 and hydrolyzed at a high temperature to become ammonia.

The dispersion device 9 is a device for dispersing urea water (particularly, hydrolyzed ammonia) supplied into the exhaust pipe 3 by the reducing agent supply device 8 and uniformly introducing it into the SCR 6. The dispersing device 9 is disposed between the DPF 5 and the SCR 6 in the exhaust pipe 3 (particularly, downstream of the injector 8c). As shown in FIG. 2, the dispersing device 9 has a disk shape having a predetermined thickness, and is disposed in a state of being fitted in the exhaust pipe 3. The structure for dispersing the urea water in the dispersion device 9 is a conventionally known structure such as a mixer or a swirler. In order to promote the hydrolysis of urea water, a dispersion promoting material such as Al ₂ O ₃ , SiO ₃ , TiO ₂ or polysilazane may be added to the dispersing device 9. Moreover, in order to improve the thermal conductivity of the heat from the heating unit 10, the dispersion device 9 is preferably formed of a metal with good thermal conductivity.

  Urea water becomes highly hydrolyzable at high temperatures and tends to be ammonia. However, immediately after the engine 2 is started, the temperature of the exhaust gas immediately after being discharged from the engine 2 is a relatively low temperature of about 100 ° C. Even after the engine 2 is started, it is necessary to increase the temperature of the urea water injected into the exhaust gas in the exhaust pipe 3 in order to increase the hydrolyzability of the urea water. Therefore, the exhaust gas purification device 1 is provided with a heating device (heating device in FIG. 1 or the like) at an outer peripheral portion (a portion where heating is required) of the exhaust pipe 3 where the dispersion device 9 is disposed in order to heat the dispersion device 9. Only the heating unit 10 is shown). The exhaust gas purification device 1 is provided with a temperature sensor that detects the temperature of the exhaust gas discharged from the engine 2.

  The heating device is a device that heats the dispersion device 9 via the exhaust pipe 3. As the heating device, any heating device can be applied as long as it can be heated through the exhaust pipe 3, for example, a heat storage device using reaction heat of a chemical reaction. The heating device includes a heating unit 10 and the like. As shown in FIG. 2, the heating unit 10 has an annular shape (annular shape in which the diameter of the inner peripheral surface is slightly longer than the diameter of the outer peripheral surface of the exhaust pipe 3) having a predetermined thickness, and the dispersing device 9 is disposed. The exhaust pipe 3 is disposed on the entire circumference along the outer peripheral surface of the portion. There is a gap between the inner peripheral surface of the heating unit 10 and the outer peripheral surface of the exhaust pipe 3. The heating unit 10 generates heat and heats the dispersion device 9 from the outside of the exhaust pipe 3.

For example, when the heating device is a chemical heat storage device, a storage unit that stores a reaction medium of a chemical reaction such as ammonia or water, a reaction unit that has a reaction material that chemically reacts with the reaction medium, and a reaction medium that includes a storage unit and a reaction unit. It has a supply part etc. to move between. This reaction unit corresponds to the heating unit 10 described above, and a reaction material such as MgCl ₂ or CaCl ₂ is accommodated in a case formed of stainless steel or the like. When the temperature of the exhaust gas detected by the temperature sensor described above is lower than a predetermined temperature (for example, immediately after starting the engine 2), the reaction medium in the storage unit is supplied to the reaction unit by the supply unit, and the reaction unit (heating unit 10) ), The supplied reaction medium and the reaction material chemically react to generate heat.

  In addition, when arrange | positioning in the state which made the heating part contact the outer peripheral surface of an exhaust pipe directly, the adhesiveness of a heating part and an exhaust pipe falls by thermal expansion, a vibration, aged deterioration, etc. Therefore, the heat transfer efficiency of the heat generated in the heating unit to the exhaust pipe (and thus the dispersion device) decreases, and the dispersion device cannot be efficiently heated. Therefore, in the exhaust gas purification device 1, in order to prevent the heat transfer efficiency from the heating unit 10 to the exhaust pipe 3 (and thus the dispersion device 9) from being lowered, the exhaust gas purification device 1 is closely attached between the exhaust pipe 3 and the heating unit 10. A material 11 is provided.

  The adhesion material 11 is a member that is provided in a gap between the heating unit 10 and the exhaust pipe 3 and that causes the heating unit 10 and the exhaust pipe 3 to adhere to each other. As shown in FIG. 2, the adhesion material 11 is sandwiched between the inner peripheral surface of the heating unit 10 and the outer peripheral surface of the exhaust pipe 3, and is disposed at the location of the exhaust pipe 3 where the dispersing device 9 is disposed. It is provided on the entire circumference along the outer peripheral surface. Therefore, the adhesion material 11 also has a very thin annular shape. As described above, the contact material 11 is interposed between the heating unit 10 and the exhaust pipe 3, so that the heating unit 10, the exhaust pipe 3, and the dispersing device 9 can be in close contact with each other even if there is thermal expansion, vibration, aging, etc. Since the adhesion between the heating unit 10 and the exhaust pipe 3 can be maintained via the material 11, the heat transfer efficiency from the heating unit 10 to the exhaust pipe 3 (and thus the dispersion device 9) does not decrease. As a result, the heating efficiency with respect to the dispersing device 9 by the heating unit 10 does not decrease, and heat loss can be prevented.

As the material of the adhesive 11, a material having superelasticity and capable of easily changing its shape is used, for example, a shape memory alloy or a shape memory polymer having a shape memory effect. Examples of such materials include titanium-nickel alloy, iron-manganese, Ag-Cd 44/49 at.% Cd, and Ag-Cd 46.5 / 50.
at.% Cd, Cu-Al-Ni 14 / 14.5 wt.% Al and 3 / 4.5 wt.% Ni, Cu-Snapprox.
15at.% Sn, Cu-Zn 38.5 / 41.5 wt.% Zn, Cu-Zn-X (X = Si, Al, Sn), Fe-Pt approx.
25 at.% Pt, Mn-Cu 5/35 at.% Cu, Fe-Mn-Si, Fe-Ni-Co-Al, Pt alloys, Co-Ni-Al, Co-Ni-Ga, Ni-Fe- The mixing ratio of Ga and Ti-Pd is variable and there is Ni-Ti (~ 55% Ni). Among such materials, a material having high thermal conductivity is desirable. For example, in the case of Ni—Ti (˜55% Ni), the thermal conductivity is 12.1 W / m / K.

  With reference to FIG. 3, the shape of the outer peripheral surface of the contact | adherence material 11 and the exhaust pipe 3 around this contact | adherence material 11 and the internal peripheral surface of the heating part 10, and the variation of the structure of the heating part 10 are demonstrated. Here, the heating unit 10 is a reaction unit of the chemical heat storage device, and is made of a case and a reaction material accommodated in the case. 3A and 3B are enlarged views of the vicinity of the adhesion material in the side sectional view of FIG. 2A, where FIG. 3A is a case where the contact surface is a planar shape, and FIG. 3B is a case where the contact surface is a rectangular uneven shape. (C) is a case where the case of the heating part is formed of an adhesive material and the contact surface is a flat shape, and (d) is a case where the case of the heating part is formed of an adhesive material and the contact surface is a rectangular uneven shape. (E) is a case where the case of the heating part is formed of an adhesive material and a vacuum double tube, and the contact surface has a planar shape.

  With reference to Fig.3 (a), the case where a contact surface is planar shape (basic shape) is demonstrated. The heating unit 10A houses a reaction material in the case 10Aa. Case 10Aa is formed with stainless steel etc., and the surface (inner peripheral surface) by the side of adhesion material 11A is a plane shape. The exhaust pipe 3A around the place where the dispersing device 9 is disposed has a flat surface on the surface (outer peripheral surface) on the adhesion material 11A side. Therefore, the contact material 11A sandwiched in the gap between the inner peripheral surface of the case 10Aa and the outer peripheral surface of the exhaust pipe 3A has a rectangular shape with a long and narrow cross-sectional shape along the longitudinal direction of the exhaust pipe 3A.

  With reference to FIG. 3B, a case where the contact surface has a rectangular uneven shape will be described. The heating unit 10B houses the reaction material in the case 10Ba. The case 10Ba is made of stainless steel or the like, and has a concave-convex shape (comb shape) whose surface (inner peripheral surface) on the adhesion material 11B side is rectangular. The exhaust pipe 3B around the place where the dispersing device 9 is disposed has a rectangular uneven shape in which the surface (outer peripheral surface) on the contact material 11B side engages with the rectangular uneven shape of the case 10Ba via the contact material 11B. is there. Therefore, the contact material 11B sandwiched in the gap between the inner peripheral surface of the case 10Ba and the outer peripheral surface of the exhaust pipe 3B has a thin concavo-convex shape with a rectangular cross-sectional shape along the longitudinal direction of the exhaust pipe 3B. By setting it as such a rectangular uneven | corrugated shape, while the contact area of the heating part 10B and the exhaust pipe 3B via the contact | adherence material 11B increases, the heating part 10B does not shift in the longitudinal direction of the exhaust pipe 3B.

  With reference to FIG.3 (c), the case where the case of a heating part is formed with a contact | adherence material and a contact surface is planar shape is demonstrated. 10C of heating parts have accommodated the reactive material in case 10Ca. The case 10Ca is entirely formed of a shape memory alloy or a shape memory polymer, and the exhaust pipe 3C side surface (inner peripheral surface) has a planar shape. As for the exhaust pipe 3C around the location where the dispersing device 9 is disposed, the surface (outer peripheral surface) on the heating unit 10C side has a planar shape. Since the case 10Ca of the heating unit 10C is formed of a shape memory alloy or a shape memory polymer, the surface (inner peripheral surface) on the exhaust pipe 3C side of the case 10Ca functions as the adhesion material 11C. The adhesion material 11C has a rectangular shape with a long and narrow cross-sectional shape along the longitudinal direction of the exhaust pipe 3C. Thus, by making the case 10Ca function as the adhesion material 11C, the adhesion is improved and the heat transfer distance from the heating unit 10C to the exhaust pipe 3C (and thus the dispersion device 9) is shortened.

  With reference to FIG.3 (d), the case where the case of a heating part is formed with a contact | adherence material and a contact surface is a rectangular uneven | corrugated shape is demonstrated. The heating unit 10D stores a reaction material in the case 10Da. The entire case 10Da is formed of a shape memory alloy or a shape memory polymer, and the exhaust pipe 3D side surface (inner peripheral surface) has a rectangular uneven shape. The exhaust pipe 3D around the location where the dispersing device 9 is disposed has a rectangular uneven shape in which the surface (outer peripheral surface) on the heating unit 10D side engages with the rectangular uneven shape of the case 10Da. The surface (inner peripheral surface) on the exhaust pipe 3D side of the case 10Da also functions as the adhesion material 11D. The adhesion material 11D has a thin uneven shape with a rectangular cross-sectional shape along the longitudinal direction of the exhaust pipe 3D. As described above, by making the case 10Da function as the adhesion material 11D and having the rectangular uneven shape, the adhesion is improved, the heat transfer distance is shortened, the contact area is increased, and the heating unit is increased. 10D is not displaced in the longitudinal direction of the exhaust pipe 3D.

  With reference to FIG.3 (e), the case where the case of a heating part is formed with a contact material and a vacuum double tube, and a contact surface is planar shape is demonstrated. The heating unit 10E stores a reaction material in the case 10Ea. In the case 10Ea, only the surface (inner peripheral surface) on the exhaust pipe 3E side is formed of a shape memory alloy or a shape memory polymer, and the other surface is formed of a vacuum double pipe. The circumferential surface is a planar shape. The exhaust pipe 3E around the location where the dispersing device 9 is disposed has a planar shape on the heating unit 10E side (outer peripheral surface). Since the surface (inner peripheral surface) on the exhaust pipe 3E side of the case 10Ea of the heating unit 10E is formed of a shape memory alloy or a shape memory polymer, the surface (inner peripheral surface) on the exhaust pipe 3E side serves as the adhesion material 11E. Function. The adhesion material 11E has a rectangular shape with a long and narrow cross-sectional shape along the longitudinal direction of the exhaust pipe 3E. Thus, by making the case 10Ea function as the adhesion material 11E, as described above, the adhesion is improved and the heat transfer distance is shortened. Furthermore, by using a vacuum double pipe for the surface of the case 10Ea that does not come into contact with the exhaust pipe 3E, the heat generated in the heating unit 10E can be concentrated in the direction of the exhaust pipe 3E (and thus the dispersion device 9). Transmission efficiency is further improved. In addition, you may form with a heat insulating material etc. instead of the vacuum double tube in case 10Ea. Further, each shape around the contact material 11E may be a rectangular uneven shape instead of a planar shape.

  According to the exhaust gas purifying apparatus 1, the contact material 11 is provided between the exhaust pipe 3 and the heating unit 10 where the dispersing device 9 is disposed, thereby causing thermal expansion, vibration, deterioration over time, and the like. Even so, it is possible to prevent a decrease in heat transfer efficiency from the heating unit 10 to the exhaust pipe 3 (and thus the dispersion device 9), and to efficiently transfer the heat generated in the heating unit 10 to the dispersion device 9. As a result, the heating efficiency with respect to the dispersing device 9 by the heating unit 10 does not decrease, and heat loss can be prevented. Therefore, the hydrolyzability of urea water can be improved from when the exhaust gas temperature is low, such as immediately after the engine 2 is started. As a result, the NOx purification rate in the SCR 6 can be increased, and the NOx purification performance is improved.

  Moreover, according to the exhaust gas purification apparatus 1, since the contact | adherence material 11 is provided in the perimeter along the outer peripheral surface of the exhaust pipe 3, adhesiveness improves and heat transfer efficiency can be improved. Furthermore, the assembly structure of the adhesive material 11 is simplified, and the assembly work is facilitated.

  Moreover, according to the exhaust gas purification apparatus 1, the contact area can be increased and the heat transfer effect can be improved by making the portion where the adhesion material 11 is provided into a rectangular uneven shape. As a result, the heating efficiency for the dispersing device 9 by the heating unit 10 is improved, and heat loss can be further prevented. Furthermore, according to the exhaust gas purifying apparatus 1, the rectangular uneven shape is provided along the longitudinal direction of the exhaust pipe 3, so that the heating unit 10 is displaced from the disposition position of the dispersing device 9 in the longitudinal direction of the exhaust pipe 3. Therefore, the dispersing device 9 can be reliably heated by the heating unit 10.

  In this embodiment, in order to heat the dispersion device 9, the heating unit 10 is disposed along the outer periphery of the exhaust pipe 3 where the dispersion device 9 is disposed. Other locations such as various catalysts and locations upstream of the various catalysts in the exhaust pipe may be used as the locations to be heated in the apparatus 1.

  That is, the heating unit 10 may be disposed on at least one of the oxidation catalyst 4, the SCR 6, and the NH3 slip catalyst 7 shown in FIG. For example, FIG. 4 shows an example in which the heating unit 10 is disposed on the oxidation catalyst 4. As shown in FIG. 4, the oxidation catalyst 4 is provided with a disk-shaped oxidation catalyst 9 </ b> A having a predetermined thickness in a state of being fitted in the exhaust pipe 3. And in order to heat 9A of disk shaped oxidation catalysts, the heating part 10 of the structure same or equivalent to the heating part mentioned above is arrange | positioned in the outer peripheral location of the exhaust pipe 3. FIG. Then, the above-described adhesion material 11 is provided between the exhaust pipe 3 and the heating unit 10. Therefore, the adhesion between the heating unit 10 and the exhaust pipe 3 is maintained via the adhesion material 11, and a reduction in the efficiency of heat transfer from the heating unit 10 to the exhaust pipe 3 (and thus the disc-shaped oxidation catalyst 9 </ b> A) is prevented. Is done. In addition, by disposing the heating unit 10 on the oxidation catalyst 4, the oxidation catalyst 4 can be heated to the activation temperature at an early stage when the engine is started. Note that the same effect can be obtained when the heating unit 10 is provided in the SCR 6 or the NH 3 slip catalyst 7.

  Moreover, you may arrange | position the heating part 10 to the exhaust pipe of the location in which the gas warming-up member which performs heat exchange with exhaust gas is arrange | positioned. For example, an example in which the heating unit 10 is disposed on the gas warm-up member 9B of the exhaust pipe 3 upstream of the oxidation catalyst 4 is shown in FIG. As shown in FIG. 5, the gas warm-up member 9 </ b> B has a disk shape having a predetermined thickness, and is disposed in a state of being fitted in the exhaust pipe 3. As the gas warm-up member 9B, a honeycomb (metal honeycomb, metalized honeycomb, ceramic honeycomb, etc.) can be used. And in order to heat the gas warming-up member 9B, the heating part 10 of the structure same or equivalent to the heating part mentioned above is arrange | positioned in the outer peripheral location of the exhaust pipe 3. FIG. Then, the above-described adhesion material 11 is provided between the exhaust pipe 3 and the heating unit 10. Therefore, the adhesion between the heating unit 10 and the exhaust pipe 3 is maintained via the adhesion material 11, and a reduction in heat transfer efficiency from the heating unit 10 to the exhaust pipe 3 (and hence the gas warm-up member 9B) is prevented. Is done. In addition, by disposing the heating unit 10 in the exhaust pipe 3 in which the gas warm-up member 9B is disposed, the catalyst (oxidation catalyst 4) disposed downstream of the gas warm-up member 9B at the time of engine start or the like. Etc.) can be heated to the activation temperature early. The gas warm-up member 9B heated by the heating unit 10 is provided in the exhaust pipe 3 upstream of the oxidation catalyst 4, so that the temperature of the catalyst other than the oxidation catalyst 4 (DPF5, SCR6, NH3 slip catalyst 7) can be increased. However, if necessary, it may be provided in the exhaust pipe 3 immediately upstream of the SCR 6 or the NH 3 slip catalyst 7.

  As mentioned above, although embodiment which concerns on this invention was described, this invention is implemented in various forms, without being limited to the said embodiment.

  For example, in the present embodiment, the present invention is applied to an exhaust gas purification apparatus including an oxidation catalyst as a catalyst, an SCR and NH3 slip catalyst, and a DPF as a filter. However, the present invention can be applied to various other exhaust gas purification apparatuses.

  Further, in the present embodiment, the heating unit and the adhesion material are arranged along the outer circumferential surface of the exhaust pipe along the entire circumference (annular). However, depending on the structure of the heating target, the heating unit and the adhesion material are arranged along the outer circumferential surface. It does not have to be the entire circumference, such as being arranged at a predetermined interval or arranged on a part of the outer peripheral surface.

  In the present embodiment, the concave / convex shape around the adhesion material is a rectangular concave / convex shape, but may be another concave / convex shape such as a triangular shape or a wave shape. In the present embodiment, the uneven shape is provided along the longitudinal direction of the exhaust pipe. However, the uneven shape may be provided along the circumferential direction of the exhaust pipe. Thus, when uneven | corrugated shape is provided, the rotation of the circumferential direction of a heating part can be prevented.

  In this embodiment, the shape memory alloy or shape memory polymer is used as the material of the adhesion material. However, an elastic body having thermal conductivity such as silicon rubber is used, or the thermal conductivity such as silicon grease is used together with the shape memory alloy. It is also possible to use additional grease.

DESCRIPTION OF SYMBOLS 1 Exhaust gas purification device 2 Engine 3, 3A, 3B, 3C, 3D, 3E Exhaust pipe 4 Oxidation catalyst 5 Diesel exhaust particulate removal filter (DPF)
6 Selective reduction catalyst (SCR)
7 NH3 slip catalyst 8 reducing agent supply device 8a reducing agent tank 8b reducing agent introduction pipe 8c injector 9 dispersing device 10, 10A, 10B, 10C, 10D, 10E heating unit 10Aa, 10Ba, 10Ca, 10Da, 10Ea case 10Eb vacuum double Tube 11, 11A, 11B, 11C, 11D, 11E Adhesive material

Claims (4)

An exhaust gas purification device for purifying exhaust gas discharged from an internal combustion engine,
A heating unit disposed on an outer periphery of a place where heating is required in the exhaust gas purification device;
A contact member provided between gap between the outer peripheral surface and the heating portion of the heating part that needs,
An exhaust gas purification apparatus comprising:   The exhaust gas purifying apparatus according to claim 1, wherein the adhesion material is provided on the entire circumference along an outer circumferential surface of a portion where the heating is required.   The surface on the adhesion material side in the heating part and the surface on the adhesion material side in a place where the heating is necessary have a concavo-convex shape engaged through the adhesion material. Item 3. The exhaust gas purifying device according to Item 2.   4. The method according to claim 1, wherein the entire surface of the case of the heating unit or a part of the surface including at least a surface of the case where the heating is required is formed of an adhesive material. 5. The exhaust gas purification apparatus as described.

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