JP2018184923A - Exhaust emission control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust emission control device enabling easy fixation of components installed around the exhaust emission control device to the exhaust emission control device.SOLUTION: An exhaust emission control device includes a reducing agent addition device 9 provided in the middle of an exhaust flow passage in which exhaust gas 1 flows to add a reducing agent to the exhaust gas 1. A fixed potion 13b for fixing a component other than the reducing agent addition device 9 is additionally provided on a bearing surface 12 for installing the reducing agent addition device 9. A support bracket 15 for supporting reducing agent piping 11 for supplying the reducing agent to the reducing agent addition device 9 and an insulator 14 disposed between the reducing agent addition device 9 and the exhaust flow passage to insulate heat transfer from the exhaust flow passage to the reducing agent addition device 9 can be fixed to the fixed portion 13b.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an exhaust emission control device.

  The exhaust gas exhausted from the engine contains particulate matter (Particulate Matter), NOx, etc., so the particulate filter, oxidation catalyst, selective reduction catalyst, etc. in the middle of the exhaust pipe through which the exhaust gas flows It has been practiced to purify exhaust gas with a purifying material.

  4 and 5 show an example of such an exhaust purification device. In the middle of the exhaust pipe 2 through which the exhaust gas 1 discharged from the engine circulates, the particulate filter 3 that collects the particulates in the exhaust gas 1, and NOx reacts with the reducing agent downstream of the particulate filter 3. The selective catalytic reduction catalyst 4 having the property of being able to be held is respectively held in parallel by the casings 5 and 6, and between the rear end portion of the particulate filter 3 and the front end portion of the selective catalytic reduction catalyst 4. The exhaust gas 1 discharged from the rear end portion of the particulate filter 3 is connected to the front end portion of the adjacent selective catalytic reduction catalyst 4 by being connected by the S-shaped connecting flow path 7 and folded forward. Yes. In addition to the two purification materials (the particulate filter 3 and the selective reduction catalyst 4), an unburned fuel in the exhaust gas 1 is disposed in the first stage in the first casing 5 in which the particulate filter 3 is held. An oxidation catalyst 8 for oxidizing the portion is provided.

  The communication channel 7 surrounds the rear end portion of the particulate filter 3 and causes the exhaust gas 1 immediately after exiting from the rear end portion to collide with the wall surface and collect the gas collecting chamber while changing the direction in a substantially perpendicular direction. 7A, a mixing pipe 7B for extracting the exhaust gas 1 collected in the gas collecting chamber 7A toward the front, and the exhaust gas 1 guided forward by the mixing pipe 7B to collide with the wall surface in a substantially perpendicular direction. A gas dispersion chamber 7C surrounding the front end portion is configured to form an S-shape so that the exhaust gas 1 can be dispersed while changing its direction and the dispersed exhaust gas 1 can be introduced into the front end portion of the selective catalytic reduction catalyst 4. .

  The gas collecting chamber 7A is equipped with a reducing agent addition device 9 for adding a reducing agent in a direction in which the exhaust gas 1 emitted from the outlet end of the particulate filter 3 is turned in a substantially perpendicular direction. . As shown in FIGS. 4 and 5, the reducing agent addition device 9 has a circumferential direction from a position directly above the gas collecting chamber 7 </ b> A that forms an exhaust passage on the downstream side of the particulate filter 3 to the side opposite to the second casing 6. The reductant is jetted toward the inlet side of the mixing pipe 7B from diagonally downward toward the second casing 6 side. A reducing agent pipe 11 for supplying a reducing agent to the reducing agent adding device 9 is connected to the reducing agent adding device 9.

  The exhaust purification device as described above is attached to the frame 10 as shown in FIGS. The first casing 5 is fixed to the frame 10 so as to be located inside the frame 10 in the left-right direction of the vehicle body, and the second casing 6 is fixed to the outside of the frame 10.

  If such a configuration is adopted, particulates in the exhaust gas 1 are collected by the particulate filter 3, and the reducing agent is exhausted from the reducing agent addition device 9 in the middle of the connecting flow path 7 on the downstream side. As a result of being added to 1 and reacting with NOx in the exhaust gas 1 on the selective catalytic reduction catalyst 4, simultaneous reduction of particulates and NOx in the exhaust gas 1 is achieved.

  At this time, the exhaust gas 1 discharged from the rear end portion of the particulate filter 3 is folded forward by the connecting flow path 7 and then introduced into the front end portion of the adjacent selective catalytic reduction catalyst 4. The distance from the addition position of the reducing agent in the middle of the communication flow path 7 to the selective catalytic reduction catalyst 4 is ensured long, and the flow of the exhaust gas 1 is turned back to promote the mixing of the reducing agent and the exhaust gas 1. Figured.

  In addition, the particulate filter 3 and the selective catalytic reduction catalyst 4 are arranged in parallel, and the communication flow path 7 is arranged between the particulate filter 3 and the selective catalytic reduction catalyst 4, so that the whole The configuration becomes compact, and the mountability to the vehicle is greatly improved.

  Incidentally, as a prior art document related to an exhaust gas purification apparatus provided with a reducing agent addition device for adding this type of reducing agent, there is, for example, the following Patent Document 1.

JP 2015-48715

  In the exhaust purification apparatus as shown in FIGS. 4 and 5 described above, it is necessary to fix the reducing agent pipe 11 connected to the reducing agent addition device 9 somewhere. If the reducing agent pipe 11 in the vicinity of the reducing agent adding device 9 is greatly displaced due to engine vibration or the like, it is impossible to connect the connecting portion between the reducing agent pipe 11 and the reducing agent adding device 9 or the components of the reducing agent adding device 9. This is because a load may be applied.

  As a target for fixing the reducing agent pipe 11, any member constituting the exhaust purification device can be selected. For example, a support bracket may be installed on a member such as the gas collecting chamber 7A or the first casing 5 in the vicinity of the part to which the reducing agent adding device 9 is attached, and the reducing agent pipe 11 may be fixed to the supporting bracket. In this case, since the reducing agent pipe 11 and the reducing agent addition device 9 belong to the same vibration system, it is preferable for preventing displacement between the reducing agent pipe 11 and the reducing agent addition device 9.

  Here, regarding the fixed position of the reducing agent pipe 11, it is necessary to consider temperature in addition to vibration. The exhaust gas purification apparatus is heated by the high-temperature exhaust gas 1 that circulates in the interior. If the reducing agent pipe 11 is located in the vicinity of the high temperature portion, the reducing agent pipe 11 is affected by heat. However, the durability of the material may be reduced, or the resin material of the fixed portion may be melted. For this reason, the fixed position of the reducing agent pipe 11 needs to be separated to some extent from the portion through which the exhaust gas 1 flows.

  That is, when installing the reducing agent pipe 11, there is a request to arrange the reducing agent pipe 11 so as to belong to the same vibration system as the reducing agent addition device 9, while the fixed position is located at some distance from the exhaust flow path. Must be set to In order to achieve both of these, for example, the support bracket attached to the gas collecting chamber 7A or the first casing 5 is enlarged to greatly protrude out of the exhaust flow path constituting the exhaust purification device, and returned to the tip of the support bracket. Measures such as fixing the agent pipe 11 are taken. However, when the size of the support bracket is increased, the overall size of the exhaust emission control device including the support bracket is increased, and the mountability is impaired. There is a problem that errors are likely to occur when attaching.

  In addition to the reducing agent pipe 11, the exhaust purification device is equipped with various parts such as an insulator for blocking heat transfer and a cover for protecting each part from flying stones. These parts are not necessarily the ones that need to take into account the effects of vibration and heat, such as the above-described reducing agent piping 11, but some seating surfaces etc. are installed for installation. They are common in what they should do. Thus, in designing the exhaust purification device, it is essential to install a fixing structure for arranging these parts and devices installed around the exhaust purification device in an appropriate place.

  In view of such circumstances, the present invention intends to provide an exhaust purification device that can easily fix components installed around the exhaust purification device to the exhaust purification device.

  The present invention is an exhaust emission control device provided with a reducing agent addition device for adding a reducing agent to exhaust gas in the middle of an exhaust passage through which the exhaust gas flows, for installing the reducing agent addition device. This invention relates to an exhaust emission control device characterized in that a fixed portion for fixing components other than the reducing agent addition device is additionally provided on the seat surface.

  Thus, in this way, when installing the parts around the exhaust purification device, there is no need to newly set a seating surface for each part, and the parts are placed in the vicinity of the reducing agent adding device. It can be conveniently arranged at a low cost.

  In the exhaust emission control device of the present invention, a support bracket that supports a reducing agent pipe for supplying a reducing agent to the reducing agent adding device can be fixed to the fixed portion. 11 can be fixed at a suitable position in the vicinity of the exhaust purification device main body.

  In the exhaust emission control device of the present invention, a heat shielding material having a lower thermal conductivity than the support bracket can be provided between the support bracket and the seating surface. Heat conduction through the support bracket to the agent pipe can be reduced.

  In the exhaust emission control device according to the present invention, an insulator that is disposed between the reducing agent addition device and the exhaust passage and that blocks heat transfer from the exhaust passage to the reducing agent addition device is fixed to the fixed portion. In this way, the insulator can be easily installed in the vicinity of the reducing agent adding device.

  According to the exhaust emission control device of the present invention, the following various excellent effects can be obtained.

  (I) According to the first aspect of the present invention, components installed around the exhaust purification device can be easily fixed to the exhaust purification device.

  (II) According to the invention described in claim 2 of the present invention, since the reducing agent pipe is fixed in the vicinity of the main body of the exhaust gas purification device, the reducing agent adding device, the reducing agent pipe, Can be fixed to the exhaust gas purification device in the same vibration system, and the reducing agent pipe can be protected from heat.

  (III) According to the invention described in claim 3 of the present invention, since heat conduction through the support bracket from the exhaust passage to the reducing agent pipe is reduced, the influence of heat on the reducing agent pipe is further reduced. can do.

  (IV) According to the invention described in claim 4 of the present invention, by installing an insulator in the vicinity of the reducing agent addition device, heat conduction from the exhaust gas to the reducing agent addition device is prevented, and the reducing agent addition device The reducing agent can be added to the high temperature region while suppressing the influence of heat on the surface.

It is a disassembled perspective view which shows the principal part of the Example of this invention. It is a perspective view which shows the state which attached components regarding the Example of FIG. It is a perspective view which shows the reference example of this invention. It is a top view which shows an example of the exhaust gas purification apparatus provided with the reducing agent addition apparatus. FIG. 5 is a side view of the exhaust purification device of FIG. 4.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  1 and 2 show an example of a form of an exhaust emission control device according to an embodiment of the present invention. Here, the case where the present invention is applied to the exhaust purification apparatus having the same configuration as the example shown in FIGS. 4 and 5 is illustrated, and this embodiment particularly reduces the exhaust flow path. It has a feature in the structure of the seat surface for installing the agent addition device 9. Hereinafter, description will be made with reference to FIGS. 4 and 5 as necessary.

  As shown in FIGS. 4 and 5, the exhaust purification apparatus of the present embodiment places the particulate filter 3 and the selective reduction catalyst 4 in the first casing in the middle of the exhaust pipe 2 through which the exhaust gas 1 discharged from the engine flows. 5 and the second casing 6 are respectively held in parallel, and the rear end portion of the particulate filter 3 and the front end portion of the selective catalytic reduction catalyst 4 are connected by a communication channel 7 having an S-shaped structure. The exhaust flow path is configured. An oxidation catalyst 8 is provided in the previous stage in the first casing 5 in which the particulate filter 3 is held.

  The communication flow path 7 has an S-shaped structure composed of a gas collecting chamber 7A, a mixing pipe 7B, and a gas dispersion chamber 7C, and the gas collecting chamber 7A exits from the outlet end of the particulate filter 3. A reducing agent addition device 9 is provided for adding a reducing agent in a direction in which the exhaust gas 1 is turned in a substantially perpendicular direction. The reducing agent addition device 9 is located at a position obliquely above that is shifted by a predetermined distance in the circumferential direction from the position directly above the gas collecting chamber 7A forming the flow path on the downstream side of the particulate filter 3 to the side opposite to the second casing 6. The reducing agent is injected toward the inlet side of the mixing pipe 7 </ b> B obliquely downward toward the second casing 6 side. A reducing agent pipe 11 for supplying a reducing agent to the reducing agent adding device 9 is connected to the reducing agent adding device 9.

  The first casing 5 is fixed to the frame 10 so as to be located inside the frame 10 in the left-right direction of the vehicle body, and the second casing 6 is fixed to the outside of the frame 10.

  In the case of this embodiment, as shown in FIGS. 1 and 2, the reducing agent addition device 9 is provided on the seating surface 12 for installing the reducing agent addition device 9 in the gas collecting chamber 7A constituting the exhaust passage. It is characterized by the fact that other parts can be attached. 2 shows a state in which the reducing agent addition device 9 and other parts are attached to the seating surface 12 shown in FIG.

  As shown in FIG. 1, the seat surface 12 forms a home base pentagon as a whole, and includes a fixed portion 13 to which a fastener can be assembled in the vicinity of each vertex of the pentagon. Of the fixed parts 13 provided in total on the seating surface 12, three fixed parts 13 a arranged so as to form the vertices of substantially equilateral triangles are structures for installing the reducing agent adding device 9. The remaining two fixed portions 13b have a structure for fixing components other than the reducing agent adding device 9 (here, the insulator 14 and the support bracket 15 for supporting the reducing agent pipe 11). .

  As shown in FIG. 1, the reducing agent adding device 9 includes an injector main body 16 that performs injection of the reducing agent, and an injector holder 17 that accommodates the injector main body 16 and is attached to the seat surface 12. The injector holder 17 is provided with a pocket 18 for receiving the injector body 16 by fitting the distal end portion 16 a so that the distal end portion 16 a of the injector body 16 faces the seat surface 12. A water jacket 19 having a flow path (not shown) for cooling the injector main body 16 by circulating the cooling water supplied from the cooling water pipe 19a is formed. A reducing agent pipe 11 is connected to the rear end portion 16 b of the injector body 16.

  A mounting portion 20 that forms a surface along the seating surface 12 is formed in the lower portion of the injector holder 17. The front surface side of the pocket 18 is open (not shown) on the surface (the surface not shown in the figure) facing the seat surface 12 of the mounting portion 20, and the center of the seat surface 12 corresponds to the opening. A communication hole 12a penetrating the inside and outside of the gas collecting chamber 7A is opened at the position. And in the state which attached the reducing agent addition apparatus 9 to the seat surface, the front-end | tip part 16a of the injector main body 16 accommodated in the pocket 18 is exposed to the internal space of the gas collecting chamber 7A.

  The reducing agent addition device 9 includes, in addition to those shown in FIGS. 1 and 2, for example, a pressure gauge for detecting the pressure of the reducing agent, a member for attaching the pressure gauge to the flow path of the reducing agent, Although it is configured to include various parts such as an elastic body for securely fixing the injector body 16 to the injector holder 17, it is not directly related to the gist of the present invention. ing.

  A flange projecting around the injector holder 17 is formed in the mounting portion 20, and a fixing hole 20 a is opened at a position corresponding to the three fixed portions 13 a provided on the seat surface 12. ing. As shown in FIG. 2, the fixing hole 20 a can be fixed to the seating surface 12 by being fastened by a fixed portion 13 a of the seating surface 12 and a fastener 21.

  In the case of the present embodiment, the fixed portion 13a is configured such that a bolt shaft protrudes from the seating surface 12 as shown in FIG. 1, and the shaft is passed through the fixing hole 20a of the mounting portion 20 to be a nut. By attaching and tightening the tool 21, the mounting portion 20 is fastened to the seat surface 12 as shown in FIG. In addition, although the structure which the axis | shaft of the volt | bolt protruded from the seat surface 12 was illustrated as the to-be-fixed part 13a here, various structures can be employ | adopted as the to-be-fixed part 13a. For example, the shaft of the bolt may be fixed to the seat surface 12 side, or the bolt may be inserted into the hole provided in the seat surface 12 from the inside of the gas collecting chamber 7A. Alternatively, the fixed portion 13a is a hole provided in the seat surface 12, and the hole and the fixing hole 20a of the attachment portion 20 are passed through and fastened with a fastener from the opposite side of the attachment surface 20 to the seat surface 12. May be. In addition, the configuration of the fixed portion 13a can be variously changed as long as the attachment portion 20 of the injector holder 17 can be suitably attached.

  Of the fixed parts 13 provided on the seating surface 12, two fixed parts 13b that are not related to the fixing of the reducing agent adding device 9 are provided on the same seating surface 12 as the fixed part 13a. It arrange | positions on the outer side of the triangle which makes the to-be-fixed part 13a a vertex. Then, in a state where the reducing agent adding device 9 is fixed to the seat surface 12 as shown in FIG. 2, the fixed portion 13 b is located outside the region covered with the flange formed on the mounting portion 20.

  That is, if the seat surface 12 is designed as a structure for simply fixing the reducing agent adding device 9, as shown in FIG. 3 as a reference example, the seat has a shape corresponding to the mounting portion 20 (see FIG. 1) of the injector holder 17. In the case of the present embodiment, the range of the seating surface 12 is extended to the outside of the mounting portion 20, and a part other than the reducing agent adding device 9 is attached to the expanded region. A fixing portion 13b is provided.

  In the case of this embodiment, the insulator 14 and the support bracket 15 are attached to the two fixed portions 13b as shown in FIGS. One of the fixed parts 13b is provided on the first casing 5 side (left side in the figure; see also FIG. 4) from the attachment position of the injector holder 17 on the seat surface 12, and here the attachment part of the insulator 14 is provided. 14a is fastened by a fastener 23 which is a bolt. The insulator 14 includes a first casing 5 (see FIG. 4) in which a main body (not shown) made of a metal plate forms an exhaust passage, and an exhaust flow formed by the first casing 5 and the communication passage 7. It arrange | positions so that it may space between the reducing agent addition apparatus 9 installed in the outer side of a path | route, and may protect the reducing agent addition apparatus 9 from the heat | fever radiated | emitted from the 1st casing 5 through which the high temperature exhaust gas 1 distribute | circulates. It has become.

  The remaining fixed portion 13b is provided on the side opposite to the first casing 5 (right side in the figure; see also FIG. 4) of the mounting position of the injector holder 17 on the seat surface 12, and includes a support bracket. The 15 attachment portions 15a are fastened by a fastener 23 that is a bolt. The support bracket 15 is a member formed by bending a metal plate, and includes a mounting portion 15a that forms a surface along the seating surface 12, and a main body portion 15b that rises to the side of the reducing agent adding device 9 from the mounting portion 15a. And a support portion 15c provided on the distal end side of the main body portion 15b located at the height of the connection portion of the reducing agent pipe 11.

  The support portion 15 c extends while bending from the main body portion 15 b at the tip of the main body portion 15 b, and forms a surface along the reducing agent pipe 11 connected to the reducing agent adding device 9. In the case of the present embodiment, the reducing agent pipe 11 is attached to the reducing agent adding device 9 in a direction substantially orthogonal to the injector body 16, and the support bracket 15 is attached to the seating surface 12 in the state where the attachment portion 15 a is attached. The angles of the surfaces formed by the mounting portion 15a and the support portion 15c are adjusted so that the support portion 15c forms a surface substantially orthogonal to the injector body 16.

  As shown in FIG. 1, a support hole 15d is opened at the center of the support portion 15c. By attaching a fixture 24 such as a clamp to the support hole 15d, the fixture 24 is shown in FIG. Thus, the reducing agent pipe 11 can be fixed to the support bracket 15.

  In this way, if the fixed portion 13b for fixing components other than the reducing agent adding device 9 is added to the seat surface 12 provided with the fixed portion 13a for fixing the reducing agent adding device 9, exhaust purification is performed. Parts to be installed around the apparatus can be arranged at a suitable position in the vicinity of the reducing agent adding apparatus 9. That is, in installing the parts, as a structure for fixing the parts, the seating surface 12 for installing the reducing agent adding device 9 may be expanded and the fixed part 13b may be provided. There is no need to newly set a seating surface for each part, and the parts can be supported easily and at low cost.

  In particular, in the case of the present embodiment, a support bracket 15 for supporting the reducing agent pipe 11 is attached to one of the fixed portions 13b. In this way, the reducing agent addition device 9 and the reducing agent pipe 11 are fixed to the exhaust purification device in the same vibration system, but at the same time, the influence of heat on the reducing agent pipe 11 can be avoided.

  Since the reducing agent addition device 9 is configured to include relatively heat-sensitive components such as a resin O-ring, when installing the exhaust gas in the exhaust purification device, the exhaust gas 1 flowing through the exhaust purification device It is necessary to take measures to reduce the influence of heat, and the arrangement of the reducing agent addition device 9 so as to project outside the gas collecting chamber 7A is also part of such heat countermeasures. That is, as the place where the reducing agent addition device 9 is installed, an area where the influence of heat by the exhaust gas 1 is small is originally selected. Therefore, if the reducing agent pipe 11 is fixed in the vicinity of the reducing agent addition device 9, the reduction agent is added. This also reduces the influence of heat on the agent pipe 11.

  Moreover, in the present embodiment, the support bracket 15 that supports the reducing agent pipe 11 is located on the opposite side of the first casing 5 with respect to the reducing agent addition device 9. That is, since the reducing agent pipe 11 and the first casing 5 through which the exhaust gas 1 flows are opposed to each other with the reducing agent addition device 9 interposed therebetween, the reducing agent addition device 9 moves from the first casing 5 to the reducing agent pipe 11. It also cuts off the transmitted heat to some extent.

  If the reducing agent pipe 11 is fixed in the vicinity of the reducing agent adding device 9 in this way, the fixing position of the reducing agent pipe 11 is in the vicinity of the exhaust purification device main body, so that the support bracket 15 is made as small as possible. Is possible. Therefore, the overall size of the exhaust emission control device can be reduced and the mountability can be improved, and the influence of errors due to variations in the support bracket 15 can be minimized.

  When the support bracket 15 is fixed to the fixed portion 13b, a washer 25 as a heat shield may be sandwiched between the attachment portion 15a and the seat surface 12, as shown in FIG. The washer 25 is made of a material having a lower thermal conductivity than the support bracket 15, thereby blocking the heat transmitted from the gas collecting chamber 7 </ b> A to the reductant pipe 11 through the support bracket 15 to some extent, thereby reducing the reductant pipe 11. The influence of heat on can be further reduced. Although illustration is omitted, depending on the shape and dimensions of the support portion 15a and the seating surface 12, the surface formed by the support portion 15a may extend to a portion covered by the mounting portion 20 of the injector holder 17. In that case, a heat shielding material is inserted between the mounting portion 20 and the support portion 15a, or a washer is interposed between the support portion 15a and the seat surface 12 between the mounting portion 20 and the support portion 15a. It is sufficient to make it extend to.

  Furthermore, in the present embodiment, the insulator 14 is attached to the fixed portion 13b that is closer to the first casing 5 than the reducing agent adding device 9, and heat is transferred from the first casing 5 to the reducing agent adding device 9. I try to prevent it. In this way, the reducing agent adding device 9 can be protected from heat, and the influence of heat on the reducing agent pipe 11 fixed at a position farther from the first casing 5 than the reducing agent adding device 9 is reduced. Is done.

  Further, the reducing agent addition device 9 needs to consider the installation position so as to avoid the influence of heat as described above. On the other hand, from the viewpoint of NOx purification efficiency by the reducing agent, the reducing agent is supplied to the exhaust passage. Among these, it is preferable to add to a region having as high a temperature as possible. Also in this respect, the arrangement of the insulator 14 as described above is effective. This is because the heat transfer from the exhaust gas 1 is prevented by the insulator 14 so that the reducing agent can be added to a high temperature region while suppressing the influence of heat on the reducing agent adding device 9. At this time, as described above, if the insulator 14 is fixed to the fixed portion 13b provided on the seating surface 12 where the reducing agent adding device 9 is installed, the insulator 14 is placed in the vicinity of the reducing agent adding device 9. It can be installed easily. This is the most convenient arrangement for the function of the insulator 14 to protect the reducing agent addition device 9 from heat.

  In addition, although the present Example demonstrated the case where the insulator 14 and the support bracket 15 were fixed to the additional to-be-fixed part 13b, the components attached to the to-be-fixed part 13b are not limited to this. Any component or device that needs to be arranged in the vicinity of the exhaust purification device may be attached.

  Moreover, although the present Example demonstrated the case where three to-be-fixed parts 13a and two additional to-be-fixed parts 13b were provided with respect to the seat surface 12 for fixation of the reducing agent addition apparatus 9, it was fixed The number of parts 13a and 13b is not limited to this. The number and arrangement of the fixed parts 13a may be determined according to the specifications of the attachment part on the reducing agent addition device side, and the number of fixed parts 13b is increased or decreased according to the number or type of parts to be installed in the vicinity. be able to. In addition, one component can be fixed by the plurality of fixed portions 13b. What is necessary is just to design the shape of the seat surface 12, and arrangement | positioning of the to-be-fixed parts 13a and 13b with respect to this seat surface 12 according to the shape and arrangement | positioning of components to fix.

  In the above description, the case where the reducing agent addition device 9 is provided on the upper surface of the gas collecting chamber 7A has been described. Instead, as shown by the broken line in FIG. 4, the mixing pipe is provided from the upstream side of the mixing pipe 7B. You may provide the reducing agent addition apparatus 9 and the reducing agent piping 11 so that a reducing agent may be injected toward the inside of 7B. In addition, the reducing agent addition device 9 can be installed at various positions in the exhaust passage as required. In this case, the seating surface can be expanded as shown in the examples shown in FIGS. The same effect can be obtained.

  As described above, in this embodiment, the exhaust gas purification apparatus includes the reducing agent addition device 9 for adding the reducing agent to the exhaust gas 1 in the middle of the exhaust passage through which the exhaust gas 1 flows. In addition, the seating surface 12 for installing the reducing agent adding device 9 is additionally provided with a fixed portion 13b for fixing components other than the reducing agent adding device 9, so that parts are arranged around the exhaust purification device. When installing, there is no need to newly set a seating surface for each component, and the components can be conveniently arranged in the vicinity of the reducing agent adding device 9 at a low cost.

  Further, in the present embodiment, the support bracket 15 that supports the reducing agent pipe 11 that supplies the reducing agent to the reducing agent addition device 9 is fixed to the fixed portion 13b. It can be fixed at a suitable position in the vicinity of the main body. Therefore, while reducing the support bracket 15 as much as possible, the reducing agent addition device 9 and the reducing agent pipe 11 can be fixed to the exhaust purification device in the same vibration system, and the reducing agent pipe 11 can be protected from heat.

  Further, in this embodiment, since the heat shield 25 having a lower thermal conductivity than the support bracket is provided between the support bracket 15 and the seat surface 12, the support from the exhaust passage to the reducing agent pipe 11 is provided. The conduction of heat through the bracket 15 can be reduced, and the influence of heat on the reducing agent pipe 11 can be further reduced.

  Further, in the present embodiment, the insulator 14 that is disposed between the reducing agent addition device 9 and the exhaust passage and that blocks heat transfer from the exhaust passage to the reducing agent addition device 9 is fixed to the fixed portion 13b. Therefore, by providing the insulator 14 in the vicinity of the reducing agent adding device 9, heat conduction from the exhaust gas 1 to the reducing agent adding device 9 is prevented, and the influence of heat on the reducing agent adding device 9 is suppressed. The reducing agent can be added to the high temperature region.

  Therefore, according to this embodiment, the components installed around the exhaust purification device can be easily fixed to the exhaust purification device.

  The exhaust purification apparatus of the present invention is not limited to the above-described embodiment. For example, when a selective reduction catalyst having a property of reacting NOx with ammonia is installed as a purification material, the reduction is performed. Of course, urea may be used as the agent, and various modifications may be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Exhaust gas 9 Reducing agent addition apparatus 12 Seat surface 13b Fixed part 14 Insulator 15 Support bracket 25 Heat shield

Claims (4)

  An exhaust purification device comprising a reducing agent addition device for adding a reducing agent to the exhaust gas in the middle of an exhaust passage through which the exhaust gas circulates, on a seating surface for installing the reducing agent addition device An exhaust emission control device further comprising a fixed portion for fixing components other than the reducing agent addition device.   The exhaust purification device according to claim 1, wherein a support bracket that supports a reducing agent pipe that supplies a reducing agent to the reducing agent addition device is fixed to the fixed portion.   The exhaust emission control device according to claim 2, further comprising a heat shield having a lower thermal conductivity than the support bracket between the support bracket and the seat surface.   The insulator to be disposed between the reducing agent addition device and the exhaust passage and to block heat transfer from the exhaust passage to the reducing agent addition device is fixed to the fixed portion. The exhaust emission control device according to any one of?

Images