JP2010196523A - Support structure of exhaust emission control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a support structure of an exhaust emission control device, easily removing only a casing for a particulate filter while a casing for a selective reduction catalyst is left on the side of a vehicle body in a stable support state. <P>SOLUTION: In this support structure of the exhaust emission control device, the particulate filter 5 and the selective reduction catalyst 6 downstream of the particulate filter are respectively held by the casings 7, 8, and the casings 7, 8 are fastened one by one to lower surfaces of hangers 16, 17 through rubber mounts 18, 19. A bracket part 22 for fastening the casing 8 for the selective reduction catalyst 6 to the lower surface of one hanger 17 is provided with an extension part 23 extending outward in the arrangement direction of both the cases 7, 8 beyond a part fastened to one hanger 17. A stopper means 24 interposed between the extension part 23 and the lower surface of one hanger 17 and stably maintaining a distance between the extension part and the lower surface of the hanger is detachably attached to the extension part 23. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a support structure for an exhaust emission control device.

  2. Description of the Related Art In recent years, a selective reduction catalyst that includes a particulate filter that collects particulates in exhaust gas in the middle of an exhaust pipe, and that can selectively react NOx with ammonia even in the presence of oxygen on the downstream side of the particulate filter. It is proposed that urea water is added as a reducing agent between the selective reduction catalyst and the particulate filter to simultaneously reduce particulates and NOx.

  In this case, since the urea water is added to the selective reduction catalyst between the particulate filter and the selective reduction catalyst, the urea water added in the exhaust gas is heated to ammonia and carbon dioxide. In order to secure sufficient reaction time until decomposition, it is necessary to increase the distance from the urea water addition position to the selective catalytic reduction catalyst. However, there is a sufficient distance between the particulate filter and the selective catalytic reduction catalyst. If they are spaced apart from each other, the mountability on the vehicle is significantly impaired.

  For this reason, a compact exhaust purification device (see Patent Document 1) as shown in FIG. 4 has already been proposed by the same applicant as the present invention. In the exhaust purification device shown here, exhaust gas from the diesel engine 1 is exhausted. In the middle of the exhaust pipe 4 through which the exhaust gas 3 exhausted through the manifold 2 flows, a particulate filter 5 that collects particulates in the exhaust gas 3 and the downstream side of the particulate filter 5 in the presence of oxygen. However, the selective reduction catalyst 6 having the property of allowing NOx to selectively react with ammonia is held in parallel by the casings 7 and 8, and the outlet side end portion of the particulate filter 5 and the selective reduction catalyst are selectively reduced. An S-shaped connecting flow path 9 having a urea water addition means 10 is provided on the upstream side thereof and connected to the inlet side end of the type catalyst 6. The exhaust gas 3 discharged from the outlet side end of the particulate filter 5 is folded in the reverse direction and introduced into the inlet side end of the adjacent selective catalytic reduction catalyst 6.

  In addition, an oxidation catalyst 11 that oxidizes the unburned fuel in the exhaust gas 3 is provided in the front stage in the casing 7 in which the particulate filter 5 is held, and the selective reduction catalyst 6 is provided. An ammonia reduction catalyst 12 that oxidizes surplus ammonia is provided in the rear stage in the casing 8 that is held.

  If such a configuration is employed, particulates in the exhaust gas 3 are collected by the particulate filter 5, and urea water from the urea water addition means 10 is exhausted from the exhaust gas 3 on the upstream side of the communication channel 9. As a result of being decomposed into ammonia and carbon dioxide gas and NOx in the exhaust gas 3 being reduced and purified well by ammonia on the selective catalytic reduction catalyst 6, simultaneous reduction of particulates and NOx in the exhaust gas 3 is achieved. It will be illustrated.

  At this time, the exhaust gas 3 discharged from the outlet end portion of the particulate filter 5 is folded in the reverse direction by the connecting flow path 9 and then introduced into the inlet end portion of the adjacent selective catalytic reduction catalyst 6. Therefore, a long distance from the urea water addition position by the urea water addition means 10 to the selective catalytic reduction catalyst 6 is ensured, and the flow of the exhaust gas 3 is turned back to turbulently flow to form urea water and exhaust gas. As a result of promoting the mixing with the gas 3, a sufficient reaction time is secured for the generation of ammonia from the urea water.

  In addition, the particulate filter 5 and the selective catalytic reduction catalyst 6 are arranged in parallel, and the connecting flow path 9 is arranged between the particulate filter 5 and the selective catalytic reduction catalyst 6, so that the whole The configuration becomes compact, and the mountability to the vehicle is greatly improved.

  Further, in such a structure in which the particulate filter 5 and the selective reduction catalyst 6 which are heavy objects are arranged in parallel and connected by the connecting flow path 9 having an S-shaped structure, the particulate filter 5 and the selective reduction catalyst 6 are combined. As shown in FIG. 5, the particulate filter 5 is liable to cause relative twisting between the two, and there is a possibility that stress is concentrated on the connecting portion or the bent portion of the connecting flow path 9 connecting them. In addition, the casings 7 and 8 of the selective catalytic reduction catalyst 6 are connected to each other via connecting portions 13 and 14 at a plurality of vertical positions in the axial direction so that no relative twist occurs between them. The casings 7 and 8 are arranged in parallel between a pair of hangers 16 and 17 attached to the side frame 15 and are supported by the hangers 16 and 17 one by one.

  More specifically, the casings 7 and 8 are fastened to the lower surfaces of the hangers 16 and 17 with fasteners 20 and 21 via rubber mounts 18 and 19, respectively. The rubber mounts 18 and 19 are elastically deformed to insulate vibration and relax thermal stress.

  5 denotes a bracket portion for fastening the casing 8 of the selective catalytic reduction catalyst 6 to the lower surface of one hanger 17.

JP 2007-29923 A

  However, since the ash generated by in-cylinder combustion due to the lubricating oil gradually accumulates in the particulate filter 5, the particulate filter 5 may be directly cleaned by air washing or water washing. The casing 7 needs to be attached and detached so that it can be replaced with a new particulate filter 5. However, in the support type as shown in FIG. 5 described above, the selective reduction type can be achieved by removing the casing 7 of the particulate filter 5. Since the casing 8 of the catalyst 6 is cantilevered and is tilted by its own weight and cannot maintain a stable support state, the entire unit of the exhaust gas purification apparatus including both the casings 7 and 8 must be removed together. In other words, it takes a lot of labor to perform maintenance of the particulate filter 5. There was a problem.

  The present invention has been made in view of the above circumstances, and is an exhaust purification device that can easily remove only the casing of the particulate filter while leaving the casing of the selective catalytic reduction catalyst on the vehicle body side in a stable support state. It is intended to provide a support structure.

  The present invention includes a particulate filter and a selective reduction catalyst that is provided on the downstream side of the particulate filter and selectively reacts with NOx in the presence of oxygen in a coexistence with a reducing agent. In a support structure of an exhaust emission control apparatus in which the casings are connected in parallel between the hangers and the casings are fastened to the lower surfaces of the hangers one by one via rubber mounts, the selective reduction catalyst casing is connected to one of the hangers. An extension portion is provided on the bracket portion for fastening to the lower surface of the first hanger so as to protrude outward in the arrangement direction of the casings from the fastening portion with the one hanger, and is interposed between the extension portion and the lower surface of the one hanger. The stopper means for keeping the distance between the two constant can be detachably attached to the extension portion.

  Thus, when removing the particulate filter casing for maintenance, prior to this, stopper means is temporarily attached to the extension part and interposed between the extension part and the lower surface of one hanger. If the distance between the two is kept constant, even if the particulate filter casing is removed for maintenance, the stopper means is interposed between the extension and the lower surface of one hanger, The inclination due to the weight of the casing of the selective catalytic reduction catalyst is prevented, and the casing of the selective catalytic reduction catalyst can be maintained in a stable support state.

  That is, when the casing of the selective catalytic reduction catalyst is tilted by its own weight, the distance between the extension portion of the bracket portion and the lower surface of the one hanger is reduced with the fastening portion between the bracket portion and the one hanger as a fulcrum. Therefore, in the state where the stopper means is interposed between the extension portion and the lower surface of one hanger and the distance between the two is kept constant, the inclination due to the weight of the casing of the selective catalytic reduction catalyst is reduced. Will be blocked.

  Further, in carrying out the present invention more specifically, a bolt hole drilled at an appropriate position of the extension portion so as to face the lower surface of one hanger, and the one of the ones inserted through the bolt hole from below. A stopper means is constituted by a bolt that abuts on the lower surface of the hanger and a nut that is screwed to a threaded portion of the bolt that projects above the extension, and defines the projecting amount of the bolt, or a lower surface of one hanger A bolt hole that is drilled at an appropriate position of the extension so as to face each other and has an internal thread engraved on its inner peripheral surface, and a bolt that is tightened into the bolt hole from below and hits the lower surface of the one hanger. It is possible to constitute stopper means.

  According to the support structure for an exhaust emission control device of the present invention described above, various excellent effects as described below can be obtained.

  (I) According to the invention described in claim 1 of the present invention, the casing of the selective reduction catalyst can be easily removed by leaving only the casing of the particulate filter while leaving the casing of the selective reduction catalyst in a stable support state. The labor required for the maintenance of the particulate filter can be greatly reduced compared to the case where the entire unit of the exhaust gas purification device is removed together as in the prior art.

  (II) According to the invention described in claims 2 and 3 of the present invention, the bolt can be easily placed between the extension and the lower surface of one hanger only by adjusting the protruding amount of the bolt protruding upward from the extension. Since the distance between the two can be kept constant, the operation for applying the stopper means can be performed very easily, and it can be easily performed at a designated factory where the particulate filter is maintained. Since general-purpose bolts and nuts that can be obtained can be used, the stopper means can be realized at a relatively low cost.

It is a front view which shows an example of the form which implements this invention. It is an enlarged view which shows the detail of the principal part of FIG. It is an enlarged view which shows another example of a form of this invention. It is the schematic which shows a prior art example. It is the front view which looked at the exhaust gas purification apparatus of FIG. 4 from the axial center direction of each casing.

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

  1 to 2 show an example of an embodiment for carrying out the present invention, and the portions denoted by the same reference numerals as those in FIGS. 4 and 5 represent the same items.

  As shown in FIG. 1, in the present embodiment, the particulate filter 5 and the selective catalytic reduction catalyst 6 are held by the casings 7 and 8 in the same manner as in the case of FIG. The casings 7 and 8 are arranged in parallel between a pair of attached hangers 16 and 17 and are connected to each other via connecting portions 13 and 14, respectively. The casings 7 and 8 are respectively connected to the hangers 16 and 17 one by one. A type in which a rubber mount 18 or 19 is fastened to and supported by fasteners 20 or 21 on the lower surface of the steel plate is employed.

  Further, when arranging the casings 7 and 8 in parallel between the hangers 16 and 17, the casings 7 and 8 are arranged in parallel so that the entrance end portions of the casings 7 and 8 face in the same direction. There is provided a communication channel 9 having an S-shaped structure for folding the exhaust gas 3 discharged from the outlet side end of the filter 5 in the reverse direction and introducing it into the inlet side end of the adjacent selective catalytic reduction catalyst 6. 9 is provided with urea water adding means 10 for adding urea water.

  However, in the case of this embodiment, both the casings 7 and 8 are connected to the bracket portion 22 for fastening the casing 8 of the selective catalytic reduction catalyst 6 to the lower surface of the one hanger 17 rather than the fastening portion with the one hanger 17. The extension portion 23 is provided with an extension portion 23 that protrudes outward in the direction of the arrangement, and is interposed between the extension portion 23 and the lower surface of the one hanger 17 so as to maintain a constant distance therebetween. It is configured so that it can be detachably attached.

  That is, as shown in an enlarged view in FIG. 2, a bolt hole 25 drilled at an appropriate position of the extension 23 facing the lower surface of one hanger 17, and the one hanger inserted through the bolt hole 25 from below. The stopper means 24 is constituted by a bolt 26 that abuts on the lower surface of 17 and a nut 27 that is screwed onto a threaded portion 26 a of the bolt 26 that projects above the extension 23 to define the amount of projection of the bolt 26. .

  Thus, when it is desired to remove the casing 7 so that the particulate filter 5 can be directly cleaned by air washing or water washing, or can be replaced with a new particulate filter 5. First, the bolt 26 is inserted into the bolt hole 25 of the extension portion 23 from below, and a nut 27 is screwed onto the screw portion 26a of the bolt 26 protruding above the extension portion 23. When the amount of protrusion is defined so as to abut against the lower surface of one hanger 17, a portion of the bolt 26 protruding above the extension 23 is interposed between the extension 23 and the lower surface of the one hanger 17. Thus, the distance between 23 and the lower surface of one hanger 17 is kept constant.

  As a result, even if the casing 7 of the particulate filter 5 is removed for maintenance and the casing 8 of the selective catalytic reduction catalyst 6 is cantilevered, the portion protruding above the extension 23 of the bolt 26 is the extension 23. By being interposed between the lower surface of one hanger 17, the inclination of the selective reduction catalyst 6 due to its own weight is prevented, and the casing 8 of the selective reduction catalyst 6 can be kept in a stable support state. It becomes possible.

  That is, when the casing 8 of the selective catalytic reduction catalyst 6 is inclined by its own weight, the extension portion 23 of the bracket portion 22 and the lower surface of the one hanger 17 are used with the fastening portion between the bracket portion 22 and the one hanger 17 as a fulcrum. Since the bolt 26 is interposed between the extension 23 and the lower surface of the one hanger 17 and the distance between the two is kept constant, the selective reduction is performed. The inclination by the dead weight of the casing 8 of the type catalyst 6 is prevented.

  Therefore, according to the above embodiment, the casing 8 of the selective catalytic reduction catalyst 6 can be easily removed by leaving only the casing 7 of the particulate filter 5 while leaving the casing 8 of the selective catalytic reduction catalyst 6 in the stable support state. In addition, the labor required for maintenance of the particulate filter 5 can be greatly reduced as compared with the case where the entire unit of the exhaust gas purification device is removed together.

  In addition, the bolt 26 can be easily interposed between the extension 23 and the lower surface of one hanger 17 by adjusting the protruding amount of the bolt 26 protruding upward from the extension 23 to keep the distance between the two constant. Therefore, a general-purpose bolt 26 that can be operated very simply to make the stopper means 24 effective, and that can be easily obtained at a designated factory or the like where the particulate filter 5 is maintained. Since the nut 27 can be diverted, the stopper means 24 can be realized at a relatively low cost.

  FIG. 3 shows another embodiment of the present invention. A female screw 25a is formed on the inner peripheral surface of the bolt hole 25 of the extension 23 in the embodiment shown in FIGS. The bolt 26 is tightened and screwed into the hole 25 from below so that the nut 27 is not required. Even in this case, the bolt 26 is inserted into the bolt hole 25 from below. The inclination of the selective catalytic reduction catalyst 6 due to its own weight can be prevented by tightening and making it abut against the lower surface of the one hanger 17.

  The support structure of the exhaust emission control device of the present invention is not limited to the above-described embodiment. In the illustrated example, the particulate filter and the selective reduction catalyst casing are arranged in the same direction and are connected to each other by a communication channel. Explains the form of flowing exhaust gas in the shape of a letter, but it is also possible to arrange the casings of the particulate filter and the selective reduction catalyst in opposite directions and flow the exhaust gas in a U-shape through the communication channel, If necessary, the particulate filter side may be provided with the same extension and stopper means as the selective catalytic reduction catalyst side, and the selective catalytic reduction catalyst is not necessarily limited to urea water as a reducing agent. Needless to say, the present invention is not limited, and various modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 3 Exhaust gas 5 Particulate filter 6 Selective reduction type catalyst 7 Casing 8 Casing 15 Frame 16 Hanger 17 Hanger 18 Rubber mount 19 Rubber mount 20 Fastening tool 21 Fastening tool 22 Bracket part 23 Extension part 24 Stopper means 25 Bolt hole 25a Female screw 26 Bolt 26a Screw part 27 Nut

Claims (3)

  A particulate filter and a selective reduction catalyst that is provided downstream of the NOx and selectively reacts with a reducing agent even in the presence of oxygen are held in a casing, and both casings are arranged in parallel between a pair of hangers on the vehicle body side. The selective reduction catalyst casing is fastened to the lower surface of one hanger in the support structure of the exhaust gas purification device in which the casings are connected to each other and the casings are fastened to the lower surfaces of the hangers one by one via rubber mounts. The bracket portion is provided with an extension portion that protrudes outward in the arrangement direction of the two casings from the fastening portion with the one hanger, and is interposed between the extension portion and the lower surface of the one hanger. A support structure for an exhaust emission control device, characterized in that a stopper means for maintaining a constant distance can be detachably attached to the extension portion.   A bolt hole drilled at an appropriate position of the extension so as to face the lower surface of one hanger, a bolt inserted into the bolt hole from below and hitting the lower surface of the one hanger, and above the extension 2. A support structure for an exhaust emission control device according to claim 1, wherein the stopper means is constituted by a nut that is screwed into a threaded portion of the projecting bolt to define the projecting amount of the bolt.   A bolt hole drilled at an appropriate position of the extension so as to face the lower surface of one hanger and having an internal thread engraved on the inner peripheral surface thereof, and tightened into the bolt hole from below, The support structure of the exhaust emission control device according to claim 1, wherein the stopper means is constituted by a bolt that abuts on the lower surface.

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