JP4115120B2 - Exhaust gas purification device for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exhaust gas purification device for an internal combustion engine, and more particularly to an exhaust gas purification device for an internal combustion engine that is provided in an exhaust passage of the internal combustion engine and includes an exhaust aftertreatment device that purifies the exhaust gas.
[0002]
[Background]
Conventionally, in order to collect particulates (particulate matter) in exhaust gas discharged from an internal combustion engine such as a diesel engine or to reduce the amount of NOx, an exhaust gas purification device is provided in the exhaust passage of the internal combustion engine. It is known.
[0003]
As an exhaust gas purifying device for collecting particulates, an exhaust gas purifying device comprising a diesel particulate filter (hereinafter referred to as DPF (Diesel Particulate Filter)) has been developed.
As an exhaust gas purification device for reducing the amount of NOx, an exhaust gas purification device having an exhaust aftertreatment device including a NOx reduction catalyst (DeNOx catalyst) and a NOx storage reduction catalyst has been developed.
[0004]
In any of the exhaust aftertreatment devices of these exhaust gas purification devices, for example, a columnar carrier (core) made of ceramic or metal such as cordierite or silicon carbide is used. This carrier has a structure in which a large number of small holes penetrate in the axial direction in a honeycomb shape.
In the exhaust aftertreatment device provided with the DPF, the carrier has a function as a filter, and the exhaust gas flows from one end surface of the carrier and flows out from the other end surface, so that the pores of the carrier are separated from each other. Particulates are collected on the partition walls (boundary walls).
Further, in an exhaust aftertreatment device equipped with a NOx reduction catalyst or NOx occlusion reduction catalyst, various catalysts are supported in advance on the carrier, and NOx is reduced while exhaust gas flows through the carrier.
[0005]
An exhaust gas purifying apparatus equipped with such an exhaust aftertreatment device includes a sheet metal cylindrical member that holds the exhaust aftertreatment device therein, and a buffer member interposed between the exhaust aftertreatment device and the cylindrical member, It is comprised including.
Then, an exhaust pipe that guides exhaust gas to the carrier is connected to one end of the cylindrical member of the exhaust gas purification apparatus, and an exhaust pipe that guides exhaust gas that has flowed out of the carrier to the outside is connected to the other end. Is provided in the middle of the exhaust passage of the internal combustion engine.
At this time, the exhaust gas purification device is mounted on a floor or an internal combustion engine equipped with the exhaust gas purification device by a fastening member such as a U bolt or a band.
[0006]
[Problems to be solved by the invention]
However, in the exhaust gas purification apparatus as described above, when the fastening member is used to attach the exhaust gas purification device to the floor or the internal combustion engine, the sheet metal cylindrical member is deformed by the fastening force of the fastening member. When the amount of deformation is large, it cannot be absorbed by the buffer member, and a large external force is applied to the exhaust aftertreatment device. Since the carrier of the exhaust aftertreatment device has a structure in which a large number of small holes penetrate in the axial direction in a honeycomb shape and is relatively weak against external force, the carrier may be damaged in such a case.
In particular, in vehicles such as construction machines, an exhaust purification device is often mounted on the engine due to the problem of installation space. In such a case, since the engine vibration during construction machine operation is directly transmitted to the exhaust gas purification device, it is necessary to firmly attach the exhaust gas purification device to the engine with a larger tightening force, and the carrier may be damaged. large.
[0007]
An object of the present invention is to provide an exhaust gas purification device for an internal combustion engine that can prevent damage to an exhaust aftertreatment device.
[0008]
[Means for solving the problems and effects]
  An exhaust gas purification apparatus for an internal combustion engine according to the present invention is an exhaust gas purification apparatus for an internal combustion engine, which is provided in an exhaust passage of an internal combustion engine mounted on a vehicle and includes an exhaust aftertreatment device that purifies inflowing exhaust gas. In order to achieve the above object, a cylindrical member that holds the exhaust aftertreatment device therein, and a buffer member that is interposed between the outer peripheral surface of the exhaust aftertreatment device and the inner peripheral surface of the cylindrical member Comprising the tubular memberAxialAt least partlyOver the entire circumferenceIt is configured with higher rigidity than other parts, and the high rigidity part of the cylindrical member is the high rigidity part.Outer peripheral surfaceIt is characterized in that it is supported by a supporting means that includes a fastening member for fastening the screw.
[0009]
  Here, the exhaust aftertreatment device includes a carrier, and such an exhaust aftertreatment device includes an exhaust aftertreatment device made of DPF, an exhaust aftertreatment device made of NOx reduction catalyst, and a NOx occlusion reduction catalyst. Any of an exhaust aftertreatment device, an exhaust aftertreatment device comprising an oxidation catalyst, and an exhaust aftertreatment device comprising a three-way catalyst can be employed.
  Further, as the cylindrical member, any one formed by rolling a plate-like member such as a sheet metal or one previously formed into a cylindrical shape at the time of molding such as a tubular body can be adopted.
  As a method of configuring at least a part of the cylindrical member with high rigidity, a method of forming the part thickly, a method of winding a thick member around the outer periphery of the part, a method of performing a curing process on the part, the part For example, a method of forming a material from a highly rigid material can be applied.
  In addition, when the whole cylindrical member is comprised with high rigidity, other parts are parts other than the cylindrical member of an exhaust-gas purification apparatus, ie, the upstream pipe | tube in the embodiment mentioned later, a downstream pipe | tube, etc. Point to.
  Further, the high rigidity means that the cylindrical member has a rigidity that does not damage the carrier when it is used by being supported by the support means.
  As the support means, the outer peripheral surface of the cylindrical memberAnd a support means configured to include a bracket for receiving and supporting, and a tightening member (such as a U bolt or a band) that urges (tightens) the cylindrical member toward the bracket.
[0010]
According to this invention, since the highly rigid part of the cylindrical member is attached to the support means, even if an external force from the support means is applied to the cylindrical member, the deformation at the part can be minimized. Thus, since the amount of deformation of the cylindrical member can be made minute, it is possible to avoid applying a large external force to the exhaust aftertreatment device and to prevent damage to the exhaust aftertreatment device.
In addition, in the present invention, since the buffer member is interposed between the cylindrical member and the exhaust aftertreatment device, even if vibration or the like due to the operation of the internal combustion engine occurs, the buffer member can tolerate and after exhaust due to vibration It is also possible to prevent damage to the processing apparatus.
[0011]
In the exhaust gas purifying apparatus for an internal combustion engine of the present invention, it is desirable that the highly rigid portions of the cylindrical member are both end portions of the cylindrical member.
Thus, if both ends of the tubular member are configured with high rigidity, the shape and dimensions at both ends of the tubular member can be easily obtained, and connection work when connecting to other tubular bodies can be facilitated. It becomes possible to reduce rattling between the member and the other tube.
[0012]
In such a case, the highly rigid portion of the cylindrical member is provided with a positioning portion that contacts the end of the buffer member and defines the position of the exhaust aftertreatment device in the axial direction of the cylindrical member. It is desirable that
Thus, since the positioning part was provided in the both ends (highly rigid part) of the cylindrical member, after attaching the buffer member to the outer periphery of the exhaust aftertreatment device over substantially the entire circumference, the exhaust is discharged into the cylindrical member. Since the position of the exhaust aftertreatment device relative to the tubular member can be determined by inserting the aftertreatment device and pushing it in until the buffer member contacts the positioning portion, the assembly work of the exhaust gas purification device according to the present invention is performed. It becomes easy.
Further, since the exhaust aftertreatment device can be installed at a predetermined position with respect to the cylindrical member by pushing the buffer member until it contacts the positioning portion, for example, the exhaust aftertreatment device is pushed too much into the cylindrical member. The exhaust aftertreatment device can be prevented from being damaged by applying an excessive external force, and the yield in the production process of the exhaust gas purification device can be improved.
[0013]
In the exhaust gas purifying apparatus for an internal combustion engine of the present invention, the cylindrical member includes a first cylindrical material in which the buffer member is in contact with an inner peripheral surface, a second cylindrical material that holds the first cylindrical material therein, It is desirable to include a heat insulating material interposed between the outer peripheral surface of the first cylindrical material and the inner peripheral surface of the second cylindrical material.
In this way, since the entire exhaust aftertreatment device is covered with the heat insulating material, the exhaust aftertreatment device is kept warm. Thus, when the exhaust aftertreatment device is a DPF, combustion of particulates such as soot is promoted, and when the exhaust aftertreatment device uses a catalyst, the reduction action is promoted. It is possible to maximize the capacity of the processing device.
[0014]
The exhaust gas purification apparatus for an internal combustion engine of the present invention comprises an upstream pipe connected to the upstream end of the cylindrical member, and a downstream pipe connected to the downstream end of the cylindrical member, At both ends of the cylindrical member, ends connected to the cylindrical member of the upstream pipe, and ends connected to the cylindrical member of the downstream pipe, flanges are formed, respectively, It is desirable that the cylindrical member and the upstream side pipe, and the cylindrical member and the downstream side pipe are connected by an inlay while the flanges are connected to each other.
Here, the upstream side pipe and the downstream side pipe may be simple pipes, or may be pipes in which devices such as an exhaust aftertreatment device and a silencer are accommodated.
Moreover, the connection by an inlay shows the connection performed by inserting one edge part of a cylindrical member and an upstream pipe | tube (a cylindrical member and a downstream pipe | tube) in the other edge part.
[0015]
In such a configuration, when connecting the flanges, the tubular member and the upstream pipe, and the tubular member and the downstream pipe are already connected by the inlay and are in a state of being positioned with respect to each other. It becomes easy.
In addition, since the cylindrical member, the upstream side pipe, and the downstream side pipe are connected to each other by both the flange and the inlay, even if a stress is generated by engine vibration, the stress is applied to both the connecting portions by the flange and the inlay. Distributed. Accordingly, it is possible to avoid excessive stress concentration on the connection portion by the flange, and it is possible to prevent the tubular member and the upstream side pipe and the downstream side pipe from being detached.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an exhaust gas purification device 1 according to an embodiment of the present invention. The exhaust gas purification device 1 purifies exhaust gas discharged from a diesel engine 2 as an internal combustion engine, and is provided in the middle of an exhaust passage 2A of the diesel engine 2.
Specifically, the exhaust gas purification device 1 includes a columnar exhaust aftertreatment device 10, a tubular member 20 serving as a housing that houses the exhaust aftertreatment device 10, and the tubular member 20. An upstream pipe 30 and a downstream pipe 40 are connected to both ends, respectively.
[0017]
As shown in FIG. 2, the exhaust aftertreatment device 10 includes a substantially cylindrical carrier 11, and this carrier 11 has a structure having a large number of small holes 111 in a honeycomb shape. The small hole 111 communicates from the inflow side end surface 11A toward the outflow side end surface 11B, that is, along the axial direction of the carrier 11, and its cross section is formed in a polygonal shape (in this embodiment, a hexagonal shape). Yes.
The carrier 11 is formed of ceramics such as cordierite and silicon carbide, or metal such as stainless steel and aluminum, and the material is appropriately determined according to the use of the carrier 11.
[0018]
When the exhaust aftertreatment device 10 is a DPF, the large number of small holes 111 of the carrier 11 is sealed with the small holes 111 serving as an inflow side flow path by sealing the outflow side end surface 11B side, and the inflow side By sealing the end face 11A side, it is divided into small holes 111 having a role as an outflow side flow path, and these flow paths are arranged in a staggered manner. And the boundary wall part of each flow path (small hole 111) is made into a random porous shape, and the particulates (for example, soot, mist of unburned fuel and lubricating oil in the exhaust gas flowing in from the inflow side flow path, and Complexes composed of sulfate (sulfate mist, etc.) are collected at the boundary wall and accumulated in the inflow channel, and clean exhaust gas from which particulates have been removed flows into the outflow channel. Discharged through.
[0019]
On the other hand, when a catalyst is used in the exhaust aftertreatment device 10, the catalyst is supported on the carrier 11 by a known method such as impregnation by immersion, wash coating, or ion exchange. Then, while the exhaust gas passes through the flow path (small hole 111), the exhaust gas is purified and cleaned by the action of the catalyst. The catalyst supported on the carrier 11 includes a NOx occlusion / reduction catalyst for removing NOx (nitrogen oxide), a NOx occlusion catalyst, an oxidation catalyst for oxidizing and removing HC and CO (carbon monoxide), and carbonization. A three-way catalyst for removing hydrogen, carbon monoxide, and nitrogen oxides can be employed.
[0020]
As shown in FIG. 3, the tubular member 20 is formed in a substantially cylindrical shape, and is mounted on the diesel engine 2 via a bracket 51 that receives a lower portion of the outer peripheral surface of the tubular member 20.
Here, both ends of the cylindrical member 20 are fastened to the bracket 51 side by two U bolts 52 attached to the bracket 51 with nuts 521. Thereby, even when the diesel engine 2 is in operation, the exhaust gas purification device 1 is prevented from being detached from the diesel engine 2 due to vibration. The bracket 51 and the U bolt 52 are support means according to the present invention.
The exhaust aftertreatment device 10 is accommodated inside the cylindrical member 20, and the entire circumference is between the outer peripheral surface of the exhaust aftertreatment device 10 (carrier 11) and the inner peripheral surface of the cylindrical member 20. A buffer member 60 is interposed.
The buffer member 60 is a cushioning material that softens the collision between the exhaust aftertreatment device 10 and the tubular member 20 or absorbs deformation of the tubular member 20 so as not to affect the exhaust aftertreatment device 10. is there. In the present embodiment, the buffer member 60 is made of vermiculite, alumina fiber, and silica, and is attached to the outer peripheral surface of the exhaust aftertreatment device 10 by an organic binder (not shown).
The detailed structure of the cylindrical member 20 itself will be described later.
[0021]
As shown in FIG. 4, the upstream pipe 30 has one end connected to the upstream end (exhaust gas inflow end) of the tubular member 20 and the other end closed with a wall 30A. A flange 30 </ b> B for connecting to the tubular member 20 is formed at one end of the upstream pipe 30. The upstream pipe 30 is provided with an inlet pipe 31 substantially orthogonal to the axial direction thereof.
[0022]
The inlet pipe 31 has one open end connected to the exhaust passage 2A of the diesel engine 2 and the other closed end protruding into the upstream pipe 30 and is upstream at a portion between the one end and the other end. It is connected to the side tube 30. An infinite number of small holes 31A are formed on the entire circumference of the portion of the inlet pipe 31 arranged in the upstream side pipe 30, and two resistance plates 311 and 312 are formed inside the pipe. Are arranged at intervals in the axial direction. The resistance plates 311 and 312 are formed with round holes 311A and 312A, respectively. The diameter dimension of the round hole 311A of the resistance plate 311 near the other end of the inlet pipe 31 is smaller than the diameter dimension of the round hole 312A of the resistance plate 312, and the flow rate of the exhaust gas passing through the resistance plates 311 and 312 is appropriately regulated. It has come to be.
In the inlet pipe 31 having such a configuration, when exhaust gas discharged from a cylinder (not shown) of the diesel engine 2 flows in through the exhaust passage 2A, it tends to flow from one end side toward the other end side. The resistance plates 311 and 312 appropriately block the flow of exhaust gas in the inlet pipe 31. As a result, the exhaust gas flows out from the small holes 31A of the inlet pipe 31 into the upstream pipe 30 substantially uniformly, and then flows into the exhaust aftertreatment device 10 in a uniform state.
[0023]
One end of the downstream side pipe 40 is connected to the downstream side end (exhaust gas outflow side end) of the cylindrical member 20, and the other end is closed by the wall 40A. A flange 40 </ b> B for connecting to the tubular member 20 is formed at one end of the downstream pipe 40. The downstream pipe 40 is provided with an outlet pipe 41 substantially orthogonal to the axial direction.
The outlet pipe 41 has one end connected to the downstream pipe 40 and the other end connected to the exhaust passage 2 </ b> A of the diesel engine 2. In the present embodiment, one end of the outlet pipe 41 does not protrude into the downstream pipe 40, but may protrude into the downstream pipe 40 as necessary, similarly to the inlet pipe 31.
[0024]
Next, the structure of the cylindrical member 20 will be described in detail.
3 to 5, the cylindrical member 20 includes a first tubular member 21 in which the buffer member 60 is in contact with the inner peripheral surface, a second tubular member 22 that holds the first tubular member 21 inside, and a first tube. The heat insulating material 23 interposed between the outer peripheral surface of the material 21 and the inner peripheral surface of the second cylindrical material 22 over almost the entire circumference, and both ends of the first cylindrical material 21 and the second cylindrical material 22 are respectively connected. A pair of ring-shaped members 24 constituting both ends of the cylindrical member 20 are provided.
[0025]
The 1st cylinder material 21 and the 2nd cylinder material 22 are formed by rolling a sheet metal.
The heat insulating material 23 covers substantially the entire exhaust aftertreatment device 10, thereby keeping the exhaust aftertreatment device 10 warm, and when the exhaust aftertreatment device 10 is a DPF, soot combustion is promoted, When the exhaust aftertreatment device 10 uses a catalyst, the action of the catalyst is promoted. Moreover, there is no possibility that the outer surface of the cylindrical member 20 becomes hot by using the heat insulating material 23, and safety can be improved.
[0026]
In each ring-shaped member 24 constituting the end portion of the cylindrical member 20, a flange 241 is formed at substantially the center of the outer peripheral surface, and the center side of both sides sandwiching the flange 241, that is, the center side 24A and the tip side 24B. At the end of 24A, a stepped portion 242 is formed over substantially the entire circumference.
As shown in FIG. 4, the outer diameter D1 of the stepped portion 242 is formed slightly smaller than the outer diameter D2 of the center side 24A of the ring-shaped member 24, and the first cylinder is formed on the outer peripheral surface of the stepped portion 242. The end of the material 21 is wound. Further, the end portion of the second tubular member 22 is wound around the outer peripheral surface of the center side 24 </ b> A of the ring-shaped member 24.
Here, a gap of a predetermined interval for interposing the heat insulating material 23 is formed between the first cylindrical material 21 and the second cylindrical material 22 by the step portion 242. That is, when the thickness dimension of the first tubular member 21 is T1, the relationship between the thickness dimension T1 of the first tubular member 21, the outer diameter dimension D1 of the stepped portion 242 and the outer diameter dimension D2 of the central side 24A of the ring-shaped member 24 is Is represented by the following equation.
(D2-D1) -2 × T1> 0
In addition, the cylindrical member 20 is formed by tightening the central side 24A of the ring-shaped member 24 (specifically, the portion between the flange 241 and the stepped portion 242 on the central side 24A) with the U-bolt 52 described above. The bracket 51 is attached. Such a central side 24A of the ring-shaped member 24 is formed thicker than the thickness dimensions of the first cylindrical member 21 and the second cylindrical member 22 so that large deformation does not occur due to the tightening force of the U-bolt 52. Has been. That is, it is configured with high rigidity.
[0027]
On the other hand, an insertion portion 243 to be inserted into the upstream side tube 30 or the downstream side tube 40 is formed on the distal end side 24B of the ring-shaped member 24 over substantially the entire circumference.
As shown in FIG. 4, the outer diameter D3 of the insertion portion 243 is equal to the inner diameter D4 of one end of the upstream pipe 30 (the end where the flange 30B is formed) or one end of the downstream pipe 40 (the flange 40B is formed). And the inner diameter D4 of the end portion).
As a result, when the insertion portion 243 of the ring-shaped member 24 is inserted into the upstream pipe 30 or the downstream pipe 40, a connection by so-called inlay is made, and the flange 241 of the ring-shaped member 24 and the upstream pipe 30 are connected. The flange 30 </ b> B or the flange 40 </ b> B of the downstream pipe 40 comes into contact, and the flanges can be connected to each other. That is, in this embodiment, the connection between the tubular member 20 and the upstream side pipe 30 and the downstream side pipe 40 is made by both the connection by the flange and the connection by the inlay.
In the present embodiment, the flanges are connected to each other after the packing 53 is interposed between the flange 241 of the ring-shaped member 24 and the flange 30B of the upstream pipe 30 or the flange 40B of the downstream pipe 40. This is done by tightening the flanges with a V clamp 54 (also called a V coupling). The packing 53 prevents exhaust gas leakage between the tubular member 20 and the upstream side pipe 30 and the downstream side pipe 40.
[0028]
Next, the manufacturing procedure of the exhaust gas purification apparatus 1 will be described below.
First, of the pair of ring-shaped members 24 of the tubular member 20, the first tubular member 21 formed from sheet metal is attached to one ring-shaped member 24 by welding. Thereafter, a heat insulating material 23 is provided over substantially the entire outer peripheral surface of the first cylindrical material 21, and the second cylindrical material 22 is wound from above the heat insulating material 23 and attached to one ring-shaped member 24 by welding.
[0029]
Next, the exhaust aftertreatment device 10 with the buffer member 60 wound around the outer peripheral surface is inserted into the first tubular member 21 from the right to the left as shown by a two-dot chain line in FIG. 5, for example.
Here, as shown in FIG. 4, the outer diameter D5 of the exhaust aftertreatment device 10 (carrier 11) is smaller than the inner diameter D6 of the central side 24A of the ring-shaped member 24, and the outer peripheral surface of the exhaust aftertreatment device 10 And a predetermined gap is formed between the inner peripheral surface of the center side 24A of the ring-shaped member 24. Due to this gap, when the exhaust aftertreatment device 10 is inserted into the first tubular member 21, collision between the end of the exhaust aftertreatment device 10 and the ring-shaped member 24 can be prevented. In addition, after the exhaust aftertreatment device 10 is inserted into the central side 24A of the ring-shaped member 24, the deformation of the central side 24A of the ring-shaped member 24 is allowed by the gap so that the ring-shaped member 24 and the post-exhaust device are exhausted. Mechanical interference with the processing apparatus 10 can be prevented.
Further, when the exhaust aftertreatment device 10 is inserted into the first tubular member 21 and the end of the buffer member 60 comes into contact with the vertical surface 242A (see FIG. 5) of the stepped portion 242 of the ring-shaped member 24, the exhaust aftertreatment device. 10 can no longer be pushed into the first tubular member 21. Thereby, the exhaust aftertreatment device 10 is positioned with respect to the axial direction of the tubular member 20. Note that the vertical surface 242A of the stepped portion 242 has the function of the positioning portion of the present invention.
[0030]
In this way, after the exhaust aftertreatment device 10 is installed in the first tubular member 21, the remaining other ring-shaped member 24 is attached to the first tubular member 21 and the second tubular member 22 by welding.
Then, in the state where the insertion portion 243 of the ring-shaped member 24 is inserted into the upstream side pipe 30 to which the inlet pipe 31 is attached and the downstream side pipe 40 to which the outlet pipe 41 is attached, respectively, the flanges are connected to each other. Tightening with the clamp 54 completes the manufacture of the exhaust gas purification device 1.
Thereafter, the exhaust gas purification device 1 is mounted on the diesel engine 2 by the U bolt 52 and the bracket 51.
[0031]
According to this embodiment as described above, the following effects are obtained.
In the present embodiment, the U-bolt 52 is tightened at the central side 24A portion (thickly formed portion) of the ring-shaped member 24 of the tubular member 20, so that the tubular member is caused by the tightening force of the U-bolt 52. The amount of deformation of 20 can be made minute. As a result, the external force applied to the exhaust aftertreatment device 10 can be made very small due to the deformation of the cylindrical member 20, and thus the exhaust aftertreatment device 10 can be prevented from being damaged.
Furthermore, in the present embodiment, since a predetermined gap is formed between the inner peripheral surface of the center side 24A of the ring-shaped member 24 and the outer peripheral surface of the exhaust aftertreatment device 10, the ring-shaped member 24 is formed by the gap. Therefore, mechanical interference between the exhaust aftertreatment device 10 and the ring-shaped member 24 can be prevented, and damage to the exhaust aftertreatment device 10 can be reliably prevented.
[0032]
Since the buffer member 60 is interposed between the exhaust aftertreatment device 10 and the first tubular member 21 of the tubular member 20, even if vibration or the like due to operation of the diesel engine 2 occurs, the exhaust aftertreatment at that time The shocks between the device 10 and the first tubular member 21 and the deformation of the first tubular member 21 can be absorbed and allowed by the buffer member 60. Thereby, even when the exhaust gas purification device 1 is installed on the diesel engine 2 with large vibration during operation, damage to the exhaust aftertreatment device 10 can be prevented.
[0033]
Since both end portions of the cylindrical member 20 are constituted by a pair of thick ring-shaped members 24, the shape and dimensions at the both end portions of the cylindrical member 20 are easily obtained, and are connected to the upstream side tube 30 and the downstream side tube 40. The connection work at the time can be facilitated, and rattling between the tubular member 20 and the upstream side pipe 30 and the downstream side pipe 40 can be reduced.
[0034]
At the time of assembling the exhaust gas purification device 1, the exhaust aftertreatment device 10 is inserted into the first tubular member 21, and the end of the buffer member 60 is brought into contact with the vertical surface 242 </ b> A of the stepped portion 242 of the ring-shaped member 24. Since the exhaust aftertreatment device 10 is positioned with respect to the axial direction of the cylindrical member 20, assembly work can be facilitated.
Further, if the end of the buffer member 60 comes into contact with the vertical surface 242A of the stepped portion 242 of the ring-shaped member 24, the exhaust aftertreatment device 10 cannot be pushed further into the first tubular member 21, so that the exhaust aftertreatment It is possible to prevent the apparatus 10 from being pushed too much into the cylindrical member 20 and applying excessive external force to the exhaust aftertreatment apparatus 10 to damage it. Thereby, the yield in the production process of the exhaust gas purification apparatus 1 can be improved.
[0035]
Since the exhaust aftertreatment device 10 is entirely covered with the heat insulating material 23, the exhaust aftertreatment device 10 can be kept warm. Thereby, when the exhaust aftertreatment device 10 is a DPF, combustion of particulates such as soot can be promoted. When the exhaust aftertreatment device 10 uses a catalyst, the action of the catalyst can be promoted, The ability of the post-processing apparatus 10 can be maximized.
[0036]
When the tubular member 20 is connected to the upstream side pipe 30 and the downstream side pipe 40, the insertion part 243 of the ring-shaped member 24 is inserted into the upstream side pipe 30 and the downstream side pipe 40, respectively. Since the flanges are fastened with the V clamp 54 in a state where the upstream pipe 30, the cylindrical member 20 and the downstream pipe 40 are positioned with respect to each other, the connection work can be facilitated.
[0037]
Further, since the cylindrical member 20, the upstream pipe 30, and the downstream pipe 40 are connected to each other by both the flange and the inlay, even if a stress is generated by engine vibration, the stress is generated by both the flange and the inlay. Distributed to connected parts. Therefore, excessive stress concentration on the connection portion by the flange can be avoided.
[0038]
It should be noted that the present invention is not limited to the above-described embodiment, and modifications and improvements within a scope that can achieve the object of the present invention are included in the present invention.
For example, in each connection structure of the cylindrical member and the upstream side pipe and between the cylindrical member and the downstream side pipe, the connection between the flanges is not limited to that by the V clamp 54, but as shown in FIG. The nuts 56 may be used to tighten the flanges. The plurality of bolts 55 and nuts 56 are arranged at predetermined intervals over the entire circumference of the flange. In such a case, a greater connection strength can be obtained than the connection between the flanges by the V clamp 54, and a sufficient connection strength can be obtained without performing the connection by the inlay, thus eliminating the need for the insertion portion 243 of the cylindrical member. (See FIG. 7).
[0039]
The cylindrical member is not limited to the one having a heat insulating material, and may be a member not having the second cylindrical material and the heat insulating material. That is, the cylindrical member may be a single-layer structure composed of only the first cylindrical material. In such a case, the step portion of the ring-shaped member is not necessary. Further, in the tubular member, the first tubular member, the second tubular member, and the ring-shaped member may be integrally molded. When the tubular member is composed of only the first tubular member and the ring-shaped member, the tubular member is integrated. Molding becomes easy. In addition, when molding the cylindrical member into a single body, it is not necessary to form all of the cylindrical members. For example, one of the two ring-shaped members and the first cylindrical material are integrally molded, and after exhausting After the processing apparatus is set in the first tubular member, the other ring-shaped member may be attached to the first tubular member by welding.
[0040]
As a positioning part, what was provided in parts other than the highly rigid part of a cylindrical member may be sufficient, and it may be comprised by another member, without providing integrally with a cylindrical member. . In the case where the positioning part is constituted by another member, for example, the positioning part can be constituted by fixing a ring-shaped member to the inner peripheral surface of the cylindrical member.
Furthermore, the cylindrical member may be a cylindrical member that is not provided with a positioning portion, and such a case is also included in the present invention.
[0041]
As a part comprised with high rigidity of a cylindrical member, you may comprise not only the both ends of a cylindrical member but highly rigid over the whole cylindrical member 20, for example, as shown in FIG. In this case, the entire tubular member 20 is configured to have higher rigidity than the upstream pipe 30 and the downstream pipe 40. With such a shape, damage to the exhaust aftertreatment device 10 can be prevented and integral molding of the tubular member 20 is facilitated as compared with the case where the upstream tube 30 and the downstream tube 40 are supported.
Furthermore, in the modified example shown in FIG. 7, since it has a structure without a heat insulating material, no positioning part is provided, and no connection is made by an inlay, the cylindrical member 20 has a very simple shape with a constant cross-sectional shape, Integrated molding becomes easier.
[0042]
Further, the highly rigid portion of the cylindrical member is not limited to the both end portions of the cylindrical member. For example, as shown in FIG. It may be configured to be rigid.
The modified example shown in FIG. 8 uses two exhaust aftertreatment devices instead of one exhaust aftertreatment device in the above-described embodiment.
In FIG. 8, the exhaust gas purification device 3 includes two cylindrical members 70 each holding the exhaust aftertreatment device 10 via a buffer member 60.
The two cylindrical members 70 are connected in series with the upstream pipe 80 interposed therebetween. The upstream pipe 80 is different from the upstream pipe 30 of the above embodiment in that the other end is closed by the wall 30A, but the other end is not provided with the wall 30A but is provided with a flange 30B similar to the one end. Thus, the cylindrical member 70 can be connected to both ends.
[0043]
The tubular member 70 includes a first tubular member 71, a second tubular member 22, and an outer peripheral surface of the first tubular member 71 and an inner peripheral surface of the second tubular member 22, the buffer member 60 being in contact with the inner peripheral surface. And a ring-shaped member 74 attached to the approximate center of the outer peripheral surface of the second tubular member 22. In addition, since the 2nd cylinder material 22 and the heat insulating material 23 are substantially the same as the said embodiment, the description is abbreviate | omitted.
The first tubular member 71 is formed in a substantially cylindrical shape, and flanges 71A are formed at both ends thereof, and can be connected to the upstream pipe 80 and a downstream pipe (not shown).
The ring-shaped member 74 is formed thicker than the first tubular member 71 and the second tubular member 22, and is attached to the second tubular member 22 by fixing means such as welding.
The cylindrical member 70 is attached to a bracket (not shown) (the same bracket as the bracket 51 of the above embodiment) by tightening the outer peripheral surface of the ring-shaped member 74 with the U bolt 52.
[0044]
Even in the exhaust gas purifying apparatus 3 having such a configuration, the thick ring-shaped member 74 can prevent the tubular member 70 from being deformed by the tightening force of the U bolt 52, so that the exhaust aftertreatment device 10 can be prevented from being damaged. become able to. Further, in the exhaust gas purifying device 3 including the two exhaust aftertreatment devices 10 arranged in series, the substantially center of each exhaust aftertreatment device 10 is fastened to the bracket by the U bolt 52. The number of U bolts 52 can be reduced as compared with the case where both ends of the bolts are fastened to the bracket by the U bolts 52.
[0045]
  FIGS. 9 and 10 show a supporting means which is not included in the present invention but is composed of only a bracket as a reference.
  9 and 10, a bracket 57 as a support means for supporting the exhaust gas purification device 1 is attached to the lower part of the outer peripheral surface of both ends of the cylindrical member 20 and to the diesel engine 2 with bolts or the like. The receiving part 571 and the attaching part 572 are integrally formed.
  The receiving portion 571 of the bracket 57 is the outer periphery of both ends of the cylindrical member 20, that is, the central side 24A of the ring-shaped member 24 (specifically, the portion between the flange 241 and the stepped portion 242 on the central side 24A). It is attached to the surface by welding. Even in such a case, the exhaust gas purification device 1 can be reliably supported on the diesel engine 2.
[0046]
The exhaust gas purification device is not limited to one installed on a diesel engine, but may be one installed on a floor (including a vehicle floor) or one suspended from a ceiling.
The internal combustion engine is not limited to a diesel engine, and may be a gasoline engine, an internal combustion turbine, a jet engine, or the like.
[Brief description of the drawings]
FIG. 1 is an overall side view showing an exhaust gas purification apparatus according to an embodiment of the present invention.
2 is a perspective view showing an exhaust aftertreatment device in FIG. 1; FIG.
3 is a cross-sectional view taken along line III-III in FIG.
4 is a cross-sectional view taken along line IV-IV in FIG.
5 is an enlarged cross-sectional view showing a main part of FIG.
FIG. 6 is a cross-sectional view showing a modified example of each connection structure between the tubular member and the upper and lower pipes of the present invention.
FIG. 7 is a cross-sectional view showing a modified example of a highly rigid portion of the cylindrical member of the present invention.
FIG. 8 is a side view showing another modification of the portion of the tubular member of the present invention that is configured with high rigidity.
FIG. 9 is a side view showing a modification of the support means of the present invention.
10 is a cross-sectional view taken along line XX in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1,3 ... Exhaust gas purification apparatus, 2 ... Diesel engine which is an internal combustion engine, 2A ... Exhaust passage, 10 ... Exhaust after-treatment device, 20 ... Cylindrical member, 21, 71 ... First cylinder material, 22 ... Second cylinder 23, heat insulating material, 24, 74 ... ring-shaped member which is a highly rigid part, 30, 80 ... upstream pipe, 30B ... flange, 40 ... downstream pipe, 51 ... bracket (support means), 52 ... U Bolt (support means), 57... Bracket as support means, 60... Shock absorbing member, 71 A. Flange, 241... Flange, 242 A.

Claims (5)

An exhaust gas purification device (1) for an internal combustion engine (2) provided in an exhaust passage (2A) of an internal combustion engine (2) mounted on a vehicle and provided with an exhaust aftertreatment device (10) for purifying inflowing exhaust gas. , 3)
A cylindrical member (20, 70) for holding the exhaust aftertreatment device (10) inside;
A buffer member (60) interposed between the outer peripheral surface of the exhaust aftertreatment device (10) and the inner peripheral surface of the cylindrical member (20, 70);
At least a portion of the cylindrical member (20, 70) in the axial direction is configured to be more rigid than the other portions over the entire circumference in the circumferential direction ,
The high-rigidity portion of the cylindrical member (20, 70) is supported by support means (51, 52) including a fastening member (52) for fastening the outer peripheral surface of the high-rigidity portion. An exhaust gas purification device (1, 3) for an internal combustion engine (2). In the exhaust gas purification device (1) of the internal combustion engine (2) according to claim 1,
The exhaust gas purifying device (1) for an internal combustion engine (2), wherein the highly rigid portions of the cylindrical member (20) are both end portions (24) of the cylindrical member. In the exhaust gas purification device (1) of the internal combustion engine (2) according to claim 2,
The position of the exhaust aftertreatment device (10) in the axial direction of the cylindrical member (20) is in contact with the end of the buffer member (60) at the highly rigid portion of the cylindrical member (20). An exhaust gas purifying device (1) for an internal combustion engine (2), characterized in that a positioning portion (242A) that defines In the exhaust gas purification device (1, 3) of the internal combustion engine (2) according to any one of claims 1 to 3,
The cylindrical member (20, 70) includes a first cylindrical member (21, 71) in which the buffer member (60) is in contact with an inner peripheral surface,
A second tubular member (22) for holding the first tubular member (21, 71) therein;
It is comprised including the heat insulating material (23) interposed between the outer peripheral surface of the said 1st cylindrical material (21,71) and the internal peripheral surface of the said 2nd cylindrical material (22), It is characterized by the above-mentioned. An exhaust gas purification device (1, 3) for an internal combustion engine (2). In the exhaust gas purification device (1) of the internal combustion engine (2) according to any one of claims 1 to 4,
An upstream pipe (30) connected to the upstream end of the tubular member (20);
A downstream pipe (40) connected to the downstream end of the tubular member (20),
Both ends of the tubular member (20), ends connected to the tubular member (20) of the upstream pipe (30), and the tubular member (20) of the downstream pipe (40) A flange (241, 30B, 40B) is formed at each end to be connected, and the tubular member (20) and the upstream pipe (30), and the tubular member (20) and the downstream pipe. (40) is an exhaust gas purification device (1) for an internal combustion engine (2), characterized in that the flanges (241, 30B, 40B) are connected to each other and are connected by an inlay.

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