JP2003120277A - Exhaust gas purification device for internal combustion engine - Google Patents

Abstract

(57) [Object] To provide an exhaust gas purifying device for an internal combustion engine, which can prevent damage to an exhaust aftertreatment device. SOLUTION: In the exhaust gas purifying apparatus 1, the center side of a ring-shaped member 24 of a tubular member 20 is formed thick, and U bolts 52 are tightened at the portion to fix the exhaust gas purifying apparatus 1 to a bracket. Since the ring-shaped member 24 is thick, the amount of deformation of the cylindrical member 20 due to the tightening force of the U bolt 52 can be reduced. Thus, the external force applied to the exhaust post-processing device 10 can be made very small due to the deformation of the cylindrical member 20, and thus the exhaust post-processing device 10 can be prevented from being damaged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas purifying apparatus for an internal combustion engine, and more particularly, to an exhaust gas purifying apparatus for exhaust gas of an internal combustion engine provided in an exhaust passage of the internal combustion engine and provided with an exhaust aftertreatment device for purifying exhaust gas. The present invention relates to a gas purification device.

[0002]

2. Description of the Related Art Conventionally, in order to collect particulate matter (particulate matter) in exhaust gas discharged from an internal combustion engine such as a diesel engine or to reduce the amount of NOx, exhaust gas is exhausted in an exhaust passage of the internal combustion engine. It is known to provide a purification device.

As an exhaust gas purifying device for collecting particulates, a device equipped with an exhaust after-treatment device composed of a diesel particulate filter (hereinafter referred to as DPF (Diesel Particulate Filter)) has been developed. As an exhaust gas purifying device for reducing the NOx amount, a NOx reduction catalyst (DeNOx catalyst) or NOx is used.
A device equipped with an exhaust aftertreatment device composed of an occlusion reduction catalyst has been developed.

In any of the exhaust aftertreatment devices of these exhaust gas purifying devices, a ceramic carrier such as cordierite or silicon carbide or a metal-made, for example, columnar carrier (core) is used. This carrier has a structure in which a large number of small holes penetrate in the axial direction like a honeycomb. DP
In the exhaust aftertreatment device provided with F, the carrier has a function as a filter, and the exhaust gas is a porous material that separates the small holes of the carrier while the exhaust gas flows in from one end surface of the carrier and flows out from the other end surface. Particulates are collected on the partition wall (boundary wall). Further, in the exhaust aftertreatment device equipped with the NOx reduction catalyst and the NOx storage reduction catalyst, various catalysts are preliminarily carried on the carrier, and NOx is reduced while the exhaust gas flows in the carrier.

An exhaust gas purifying apparatus having such an exhaust aftertreatment device is interposed between a sheet metal cylindrical member holding the exhaust aftertreatment device therein and the exhaust aftertreatment device and the cylindrical member. And a cushioning member. Then, an exhaust pipe for guiding the exhaust gas to the carrier is connected to one end of the cylindrical member of the exhaust gas purifying device, and an exhaust pipe for guiding the exhaust gas flowing out of the carrier to the outside is connected to the other end of the exhaust gas purifying device. Will be provided in the middle of the exhaust passage of the internal combustion engine. At this time, the exhaust gas purification device is attached to the 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]

However, in the exhaust gas purifying apparatus as described above, when it is attempted to mount it on the floor or the internal combustion engine with the fastening member, the sheet metal cylindrical member is deformed by the fastening force of the fastening member. When the amount of deformation is large, the cushioning member cannot absorb it completely, 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 are axially penetrated in a honeycomb shape and is relatively weak against external force, the carrier may be damaged in such a case. In particular,
In a vehicle such as a construction machine, an exhaust emission control device is often mounted on an engine due to a problem of installation space. In this case, the engine vibration when the construction machine is operating is directly transmitted to the exhaust gas purification device, so 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.

An object of the present invention is to provide an exhaust gas purifying device for an internal combustion engine, which can prevent damage to the exhaust aftertreatment device.

[0008]

An exhaust gas purifying apparatus for an internal combustion engine according to the present invention is provided in an exhaust passage of the internal combustion engine and is provided with an exhaust aftertreatment device for purifying inflowing exhaust gas. An exhaust gas purification device of
In order to achieve the above object, a tubular member that holds the exhaust aftertreatment device inside, and a cushioning member interposed between the outer peripheral surface of the exhaust aftertreatment device and the inner peripheral surface of the tubular member are provided. It is characterized in that at least a part of the tubular member is configured to have higher rigidity than other parts, and that the highly rigid part of the tubular member is supported by a supporting means.

Here, the exhaust aftertreatment device is provided with a carrier, and such an exhaust aftertreatment device is a DPF.
Exhaust aftertreatment device consisting of NOx reduction catalyst, exhaust aftertreatment device consisting of NOx reduction catalyst, exhaust aftertreatment device consisting of NOx storage reduction catalyst, exhaust aftertreatment device consisting of oxidation catalyst, exhaust aftertreatment device consisting of three-way catalyst it can. The tubular member is formed by rolling a plate member such as a metal plate.
Any of the tubular bodies that are formed into a tubular shape in advance at the time of molding can be used. As a method of forming at least a portion of the tubular member with high rigidity, a method of molding the portion into a thick wall, a method of winding a thick member around the outer periphery of the portion, a method of performing a hardening treatment on the portion, the portion It is possible to apply a method of forming a high-rigidity material. When the entire tubular member is configured to have high rigidity, the other portion means a portion other than the tubular member of the exhaust gas purifying device, that is, an upstream pipe or a downstream pipe in an embodiment described later. Refers to. The high rigidity means that the cylindrical member has such a rigidity that the carrier inside is not damaged when being used by being supported by the supporting means. The supporting means may be a bracket that is welded or adhesively fixed to the outer periphery of the tubular member, and the bracket that receives and supports the outer peripheral surface of the tubular member and the tubular member on the bracket side. The supporting means may include a tightening member (U bolt, band, etc.) that biases (tightens) the member.

According to the present invention, since the high-rigidity portion of the tubular member is attached to the supporting means, even if an external force from the supporting means is applied to the tubular member, the deformation of the portion can be minimized. it can. In this way, since the deformation amount of the tubular member can be made minute, it is possible to avoid applying a large external force to the exhaust aftertreatment device and prevent damage to the exhaust aftertreatment device. Moreover, in the present invention, since the cushioning member is interposed between the tubular member and the exhaust aftertreatment device, even if vibration or the like due to the operation of the internal combustion engine occurs, the cushioning member can tolerate it and Damage to the processing equipment can also be prevented.

In the exhaust gas purifying apparatus for an internal combustion engine according to the present invention, it is preferable that the high rigidity portion of the tubular member is both end portions of the tubular member. In this way, if both ends of the tubular member are configured to have high rigidity, it becomes easier to obtain the shape and dimensions at both ends of the tubular member, and it is possible to facilitate the connection work when connecting with another tubular body and It is possible to reduce rattling between the tubular member and the other tubular body.

In such a case, the high-rigidity portion of the tubular member is in contact with the end portion of the cushioning member to define the position of the exhaust aftertreatment device in the axial direction of the tubular member. It is desirable that a section is provided. Since the positioning portions are provided at both ends (highly rigid portion) of the tubular member in this manner, after the cushioning member is attached to the outer periphery of the exhaust aftertreatment device over substantially the entire circumference, the exhaust gas is exhausted into the tubular member. Since the position of the exhaust aftertreatment device with respect to the tubular member can be determined by inserting the aftertreatment device and pushing it in until the cushioning member comes into contact with the positioning portion, the assembling work of the exhaust gas purification device according to the present invention can be performed. It will be easy. Further, since the exhaust aftertreatment device can be installed at a predetermined position with respect to the tubular member by pushing the cushioning member until it comes into contact with the positioning portion, for example, the exhaust aftertreatment device is pushed too much into the tubular 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.

In the exhaust gas purifying apparatus for an internal combustion engine according to the present invention, the tubular member includes a first tubular member in which the buffer member is in contact with an inner peripheral surface, and a second tubular member holding the first tubular member therein. When,
It is preferable that the first cylinder member is configured to include an outer peripheral surface and a heat insulating material interposed between the inner peripheral surface of the second cylinder member. 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 reducing action is promoted. It is possible to maximize the capacity of the processing device.

In the exhaust gas purifying apparatus for an internal combustion engine of the present invention, an upstream pipe connected to the upstream end of the tubular member and a downstream pipe connected to the downstream end of the tubular member. Flanges are formed at both end portions of the tubular member, an end portion of the upstream pipe connected to the tubular member, and an end portion of the downstream pipe connected to the tubular member. It is desirable that the tubular member and the upstream pipe and the tubular member and the downstream pipe are connected to each other by the flanges and the spigot. Here, the upstream pipe and the downstream pipe may be simple pipe bodies, or may be pipe bodies in which devices such as an exhaust aftertreatment device and a silencer are housed. The spigot connection refers to a connection made by inserting one end of the tubular member and the upstream pipe (the tubular member and the downstream pipe) into the other end.

With such a structure, when the flanges are connected to each other, the tubular member and the upstream pipe, and the tubular member and the downstream pipe are already connected by the spigot and are in a state of being positioned relative to each other. Connection work becomes easy. Further, since the tubular member, the upstream pipe, and the downstream pipe are connected to each other by both the flange and the spigot, even if a stress is generated by engine vibration, this stress is applied to both the connecting parts by the flange and the spigot. Distributed. Therefore, it is possible to avoid excessive stress concentration on the connecting portion due to the flange, and it is possible to prevent the tubular member and the upstream side pipe and the downstream side pipe from coming off.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an exhaust gas purification device 1 according to an embodiment of the present invention. This exhaust gas purifying apparatus 1 includes a diesel engine 2 as an internal combustion engine.
The exhaust gas is purified from the exhaust gas and is provided in the middle of the exhaust passage 2A of the diesel engine 2. Specifically, the exhaust gas purifying apparatus 1 includes a columnar exhaust post-treatment device 10, a tubular member 20 having a role as a housing that houses the exhaust post-treatment device 10 therein,
The tubular member 20 includes an upstream pipe 30 and a downstream pipe 40, which are connected to both ends of the tubular member 20, respectively.

As shown in FIG. 2, the exhaust post-treatment device 10 comprises a substantially columnar carrier 11, which has a honeycomb-like structure having a large number of small holes 111. The small hole 111 extends from the inflow side end surface 11A to the outflow side end surface 1
They communicate with each other toward the 1B side, that is, along the axial direction of the carrier 11, and their cross sections are formed in a polygonal shape (hexagonal shape in this embodiment). The carrier 11 is made of cordierite, ceramics such as silicon carbide, or metal such as stainless steel and aluminum, and the material is appropriately determined according to the use of the carrier 11.

When the exhaust aftertreatment device 10 is a DPF, the numerous small holes 111 of the carrier 11 are formed on the outflow side end surface 11B.
The small side is divided into a small hole 111 having a role as an inflow side flow path by being plugged, and a small hole 111 having a role as an outflow side flow path by being closed on the inflow side end face 11A side. The channels are arranged in a staggered pattern. And
Boundary wall portions of the respective flow paths (small holes 111) are made randomly porous, and particulates (for example, soot, unburned fuel and lubricating oil mist and sulfate () in the exhaust gas flowing in from the inflow side flow path are formed. A complex composed of (such as sulfuric acid mist)) is collected at the boundary wall and accumulated in the inflow side flow path, and clean exhaust gas without particulates passes through the outflow side flow path. Is discharged.

On the other hand, when a catalyst is used in the exhaust post-treatment 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 by the action of the catalyst and becomes clean. The catalyst carried on the carrier 11 is a NOx storage reduction catalyst for removing NOx (nitrogen oxide), a NOx storage catalyst, HC or CO (carbon monoxide).
It is possible to employ an oxidation catalyst for oxidizing and removing hydrogen, a three-way catalyst for removing hydrocarbons, carbon monoxide, and nitrogen oxides.

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. There is. Here, the tubular member 20 is
Both ends are fastened to the bracket 51 side by two U bolts 52 attached to the bracket 51 with nuts 521. As a result, even when the diesel engine 2 is operating, the exhaust gas purification device 1 is prevented from coming off the diesel engine 2 due to vibration. The bracket 51 and the U bolt 52 are the supporting means according to the present invention. The exhaust aftertreatment device 10 is housed inside the tubular member 20, and the exhaust aftertreatment device 10 (carrier 1
Between the outer peripheral surface of 1) and the inner peripheral surface of the tubular member 20, a cushioning member 60 is interposed over substantially the entire circumference. The cushioning member 60 is a cushioning material for softening the collision between the exhaust aftertreatment device 10 and the tubular member 20 and absorbing the deformation of the tubular member 20 so as not to affect the exhaust aftertreatment device 10. is there. In the present embodiment, the cushioning member 60 is
It is formed of vermiculite, alumina fiber, and silica, and is attached to the outer peripheral surface of the exhaust post-treatment device 10 by an organic binder (not shown). The detailed structure of the tubular member 20 itself will be described later.

As shown in FIG. 4, one end of the upstream pipe 30 is connected to the upstream end (exhaust gas inflow end) of the tubular member 20, and the other end is closed by a wall 30A. There is.
A flange 30B 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 its axial direction.

The inlet pipe 31 has one open end connected to the exhaust passage 2A of the diesel engine 2 and the other closed end projecting into the upstream pipe 30. In part, it is connected to the upstream pipe 30. An innumerable small hole 31A is formed over the entire circumference in a portion of the inlet pipe 31 disposed inside the upstream pipe 30, and two resistance plates 311 and 312 are provided inside the inlet pipe 31. Are spaced apart in the axial direction. Resistor plate 311,
Round holes 311A and 312A are formed in 312, respectively. The diameter of the round hole 311A of the resistance plate 311 near the other end of the inlet pipe 31 is smaller than the diameter of the round hole 312A of the resistance plate 312, and the flow rate of exhaust gas passing through the resistance plates 311 and 312 is appropriately regulated. It is supposed to be done. In the inlet pipe 31 having such a configuration, when the exhaust gas discharged from the cylinder (not shown) of the diesel engine 2 flows in through the exhaust passage 2A, the exhaust gas tries to flow from one end side to the other end side. Resistor plates 311, 31
Due to 2, the flow of the exhaust gas in the inlet pipe 31 is appropriately blocked. As a result, the exhaust gas is discharged into the small holes 3 of the inlet pipe 31.
1A, flows out into the upstream pipe 30 substantially uniformly, and then flows into the exhaust aftertreatment device 10 in a uniformed state.

One end of the downstream pipe 40 has a tubular member 20.
Is connected to the downstream side end portion (exhaust gas outflow side end portion) and the other end is closed by a wall portion 40A. A flange 40 for connecting to the tubular member 20 is provided at one end of the downstream pipe 40.
B is formed. An outlet pipe 41 is provided in the downstream pipe 40 substantially orthogonal to its axial direction. Outlet pipe 4
1 has one end connected to the downstream pipe 40 and the other end connected to the exhaust passage 2A of the diesel engine 2. In addition,
In the present embodiment, one end of the outlet pipe 41 does not project inside the downstream pipe 40, but like the inlet pipe 31, it may project inside the downstream pipe 40 if necessary.

Next, the structure of the tubular member 20 will be described in detail. 3 to 5, a tubular member 20 includes a first tubular member 21 having a cushioning member 60 in contact with an inner peripheral surface thereof, and a first tubular member 21.
A second tubular member 22 that holds the tubular member 21 therein, and a first tubular member 2
1. The heat insulating material 23 interposed between the outer peripheral surface of No. 1 and the inner peripheral surface of the second tubular member 22 over substantially the entire circumference, the first tubular member 21 and the second tubular member 21.
A pair of ring-shaped members 24, which are connected to both ends of the tubular member 22 and configure both ends of the tubular member 20, are provided.

The first tubular member 21 and the second tubular member 22 are formed by rolling a sheet metal. The heat insulating material 23 covers substantially the entire exhaust aftertreatment device 10, whereby the exhaust aftertreatment device 10 is kept 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. Further, by using the heat insulating material 23, there is no fear that the outer surface of the tubular member 20 becomes hot, and safety can be improved.

In each ring-shaped member 24 forming the end portion of the tubular member 20, a flange 241 is provided at the substantially center of the outer peripheral surface.
Are formed on both sides of the flange 241, that is, the center side 24A of the center side 24A and the tip side 24B.
A stepped portion 242 is formed at the end of the substantially entire circumference. As shown in FIG. 4, the outer diameter dimension D1 of the step portion 242 is the outer diameter dimension D of the center side 24A of the ring-shaped member 24.
It is formed slightly smaller than 2, and the end portion of the first tubular member 21 is wound around the outer peripheral surface of the step portion 242. Also,
The end of the second tubular member 22 is wound around the outer peripheral surface of the ring-shaped member 24 on the center side 24A. Here, a gap at a predetermined interval for interposing the heat insulating material 23 is formed by the step portion 242 between the first tubular material 21 and the second tubular material 22. That is, assuming that 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 step portion 242, and the outer diameter dimension D2 of the center side 24A of the ring-shaped member 24 is as follows. , Is expressed by the following equation. (D2-D1) -2 * T1> 0 Further, the tubular member 20 is the center side 24 of the ring-shaped member 24.
A (specifically, the flange 241 on the center side 24A)
Between the step portion 242 and the step portion 242) is the U bolt 5 described above.
It is attached to the bracket 51 by being tightened with 2. Such a center side 2 of the ring-shaped member 24
4A is formed thicker than the thickness dimension of the first tubular member 21 and the second tubular member 22 so that a large deformation does not occur due to the tightening force of the U bolt 52. That is, it has a high rigidity.

On the other hand, the tip side 24B of the ring-shaped member 24
An insertion portion 243 that is inserted into the upstream pipe 30 or the downstream pipe 40 is formed on substantially the entire circumference. Figure 4
As shown in FIG. 7, the outer diameter dimension D3 of the insertion portion 243 is the inner diameter dimension D4 of one end of the upstream pipe 30 (the end portion where the flange 30B is formed) or the one end of the downstream pipe 40 (the flange 40B).
Is formed so as to substantially match the inner diameter dimension D4 of the end portion formed with. Accordingly, when the insertion portion 243 of the ring-shaped member 24 is inserted into the upstream pipe 30 or the downstream pipe 40, so-called spigot connection is made, and the flange 241 of the ring-shaped member 24 and the upstream pipe 3 are connected.
0 flange 30B or downstream pipe 40 flange 40
B comes into contact, and the flanges can be connected to each other. That is, in the present embodiment, the connection between the tubular member 20 and the upstream pipe 30 and the downstream pipe 40 is made by both a flange connection and a spigot connection. In this embodiment, the flanges are connected to each other by the ring-shaped member 2
No. 4 flange 241 and the upstream pipe 30 flange 30B
Alternatively, the packing 53 is interposed between the downstream side pipe 40 and the flange 40B, and then the flanges are connected to each other by the V clamp 54.
It is performed by tightening (also called V coupling). The packing 53 prevents exhaust gas leakage between the tubular member 20 and the upstream pipe 30 and the downstream pipe 40.

Next, the manufacturing procedure of the exhaust gas purifying apparatus 1 will be described below. First, the first tubular member 21 made of sheet metal is attached to one of the pair of ring-shaped members 24 of the tubular member 20 by welding. After that, the heat insulating material 23 is provided over substantially the entire circumference of the outer peripheral surface of the first tubular material 21, and the second tubular material 22 is wound from above the heat insulating material 23 and attached to one ring-shaped member 24 by welding.

Next, the exhaust aftertreatment device 10 having the cushioning member 60 wound around the outer peripheral surface thereof is inserted into the first tubular member 21 from right to left as shown by the chain double-dashed line in FIG. 5, for example. . Here, as shown in FIG. 4, the exhaust aftertreatment device 10
The outer diameter dimension D5 of the (carrier 11) is smaller than the inner diameter dimension D6 of the center side 24A of the ring-shaped member 24, and the outer peripheral surface of the exhaust aftertreatment device 10 and the inner peripheral surface of the center side 24A of the ring-shaped member 24. A predetermined gap is formed between them. Due to this gap, when the exhaust aftertreatment device 10 is inserted into the first tubular member 21, it is possible to prevent a collision between the end portion of the exhaust aftertreatment device 10 and the ring-shaped member 24. In addition, after the exhaust aftertreatment device 10 is inserted into the center side 24A of the ring-shaped member 24, the ring-shaped member 24 is allowed to deform in the center side 24A of the ring-shaped member 24.
It is possible to prevent mechanical interference with the exhaust aftertreatment device 10. Further, the exhaust aftertreatment device 10 is inserted into the first tubular member 21, and the end portion of the cushioning member 60 has the ring-shaped member 2.
When contacting the vertical surface 242A (see FIG. 5) of the stepped portion 242 of No. 4, the exhaust post-treatment device 10 cannot be pushed into the first tubular member 21 any more. As a result, the exhaust aftertreatment device 10 is positioned in the axial direction of the tubular member 20. The vertical surface 242A of the step portion 242 has the function of the positioning portion of the present invention.

In this way, after the exhaust aftertreatment device 10 is installed in the first tubular member 21, the other ring-shaped member 24 is attached to the first tubular member 21 and the second tubular member 22 by welding. . And the upstream pipe 3 with the inlet pipe 31 attached
0 and the downstream side pipe 40 to which the outlet pipe 41 is attached, with the insertion portions 243 of the ring-shaped member 24 inserted and positioned with respect to each other, the flanges are V-clamped 5
Then, the exhaust gas purifying apparatus 1 is completely manufactured.
After that, the exhaust gas purification device 1 is mounted on the diesel engine 2 by the U bolt 52 and the bracket 51.

According to this embodiment as described above, the following effects can be obtained. In the present embodiment, the U-bolt 52 is fastened at a portion (thickness formed portion) of the ring-shaped member 24 of the tubular member 20 on the center side 24A. The amount of deformation of 20 can be made minute. As a result, the external force applied to the exhaust aftertreatment device 10 due to the deformation of the tubular member 20 can be made extremely small, so that the exhaust aftertreatment device 10 can be prevented from being damaged. Further, 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 in the gap. Can be absorbed, 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.

First of the exhaust aftertreatment device 10 and the tubular member 20
Since the cushioning member 60 is interposed between the tubular member 21 and the tubular member 21, even if vibrations due to the operation of the diesel engine 2 occur, the exhaust aftertreatment device 10 and the first tubular member 21 collide,
The cushioning member 60 can absorb and allow the deformation of the first tubular member 21. As a result, even when the exhaust gas purification device 1 is installed on the diesel engine 2 which has a large vibration during operation,
The exhaust aftertreatment device 10 can be prevented from being damaged.

Since both ends of the tubular member 20 are constituted by the pair of thick-walled ring-shaped members 24, it becomes easy to obtain the shape and dimension at both ends of the tubular member 20, and the upstream pipe 30 and the downstream pipe 40. It is possible to easily perform the connecting work when connecting with, and to reduce rattling between the tubular member 20 and the upstream pipe 30 and the downstream pipe 40.

At the time of assembling the exhaust gas purifying device 1, the exhaust aftertreatment device 10 is inserted into the first tubular member 21, and the end portion of the buffer member 60 contacts the vertical surface 242A of the step portion 242 of the ring-shaped member 24. By doing so, since the exhaust aftertreatment device 10 is positioned in the axial direction of the tubular member 20, the assembling work can be facilitated. In addition, the cushioning member 60
The end of the vertical surface 24 of the step 242 of the ring-shaped member 24.
2A, the exhaust aftertreatment device 10 is further
Since the exhaust post-treatment device 10 cannot be pushed into the tubular member 21, it is possible to prevent the exhaust post-treatment device 10 from being excessively pushed into the tubular member 20 and damaging the exhaust post-treatment device 10 by applying an excessive external force. As a result, the yield in the production process of the exhaust gas purification device 1 can be improved.

Since the exhaust aftertreatment device 10 is entirely covered with the heat insulating material 23, the exhaust aftertreatment device 10 can be kept warm. Accordingly, when the exhaust aftertreatment device 10 is a DPF, combustion of particulates such as soot can be promoted, and when the exhaust aftertreatment device 10 uses a catalyst,
The action of the catalyst can be promoted, and the capability of the exhaust aftertreatment device 10 can be maximized.

When the tubular member 20 is connected to the upstream pipe 30 and the downstream pipe 40, the upstream pipe 30 and the downstream pipe 4 are connected.
By inserting the insertion portions 243 of the ring-shaped member 24 into the cylindrical member 20, the tubular member 20, the upstream pipe 30, and the tubular member 20 respectively.
Since the flanges are clamped with the V clamp 54 while the downstream pipe 40 and the downstream pipe 40 are positioned with respect to each other, the connection work can be facilitated.

Further, since the tubular member 20, the upstream pipe 30, and the downstream pipe 40 are connected to each other by both the flange and the spigot, even if stress occurs due to engine vibration, this stress is It is distributed to both connection parts by spigot. Therefore, it is possible to avoid excessive stress concentration on the connection portion due to the flange.

The present invention is not limited to the above-described embodiment, and modifications and improvements within the range in which the object of the present invention can be achieved are included in the present invention. For example,
In each connection structure of the tubular member and the upstream pipe, and the tubular member and the downstream pipe, the connection between the flanges is not limited to the V clamp 54, but a plurality of bolts 55 as shown in FIG.
Alternatively, the flanges may be tightened with the nut 56. In addition, 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 larger 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 the connection with the spigot. Therefore, the insertion portion 243 of the tubular member is unnecessary. May be (Fig. 7
reference).

The tubular member is not limited to one having a heat insulating material, but may be one having no second tubular material or heat insulating material. That is, the tubular member may have a single-layer structure including only the first tubular member, and in such a case, the stepped portion of the ring-shaped member is not necessary. In the tubular member, the first tubular material and the second tubular material
The tubular member and the ring-shaped member may be integrally molded, and when the tubular member is composed of only the first tubular member and the ring-shaped member, the integral molding becomes easy. It should be noted that when the tubular member is integrally molded, it is not necessary to form all the members integrally. For example, one of the two ring-shaped members and the first
The tubular material may be integrally molded, the exhaust aftertreatment device may be set in the first tubular material, and then the other ring-shaped member may be attached to the first tubular material by welding.

The positioning portion may be provided at a portion other than the highly rigid portion of the tubular member, or may be a separate member that is not provided integrally with the tubular member. May be. When the positioning portion is formed of a separate member, the positioning portion can be formed by fixing a ring-shaped member to the inner peripheral surface of the tubular member, for example. Further, the tubular member may be a tubular member provided with no positioning portion, and such a case is also included in the present invention.

The high-rigidity portion of the tubular member is not limited to both end portions of the tubular member, and for example, as shown in FIG. Good. In this case, the entire tubular member 20 is configured to have higher rigidity than the upstream pipe 30, the downstream pipe 40, and the like. With such a shape, the exhaust aftertreatment device 10 can be prevented from being damaged and the tubular member 20 can be easily integrally molded, as compared with the case where the upstream pipe 30 and the downstream pipe 40 are supported. Further, in the modified example shown in FIG. 7, since the structure does not have a heat insulating material, the positioning portion is not provided, and the spigot is not connected, the tubular member 20 has an extremely simple shape with a constant cross-sectional shape, Integral molding becomes easier.

The portion of the tubular member having a high rigidity is not limited to the both ends of the tubular member, and for example, FIG.
As shown in, the substantially central portion of the tubular member may be made highly rigid over substantially the entire circumference. In the modification shown in FIG. 8, one exhaust post-treatment device is used in the above-described embodiment, but two exhaust post-treatment devices are used. In FIG. 8, the exhaust gas purification device 3 is provided with two tubular members 70 each holding the exhaust aftertreatment device 10 inside via a cushioning member 60. Two tubular members 7
0s are connected in series with the upstream pipe 80 interposed therebetween. The upstream pipe 80 has the same structure as the upstream pipe 30 of the above-described embodiment, except that the other end is closed by the wall portion 30A. The tubular member 70 can be connected to both ends.

The tubular member 70 has a first tubular member 71, a second tubular member 22 and a first tubular member 71, of which the buffer member 60 is in contact with the inner peripheral surface thereof.
The heat insulating material 23 is interposed between the outer peripheral surface of the second cylindrical member 22 and the inner peripheral surface of the second cylindrical member 22, and the ring-shaped member 74 attached to the outer peripheral surface of the second cylindrical member 22 substantially at the center. The second tubular material 22 and the heat insulating material 23 are substantially the same as those in the above-mentioned embodiment, and therefore their explanations are omitted. The first tubular member 71 is formed in a substantially cylindrical shape, and flanges 71A are formed at both ends thereof so that it 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 cylinder member 71 and the second cylinder member 22, and is attached to the second cylinder member 22 by a fixing means such as welding. Such a cylindrical member 70 is attached to a bracket (not shown) (a bracket similar to the bracket 51 of the embodiment) by fastening the outer peripheral surface of the ring-shaped member 74 with the U bolt 52.

Also 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 due to the tightening force of the U-bolt 52. It will prevent damage. Further, in the exhaust gas purifying device 3 including the two exhaust aftertreatment devices 10 arranged in series, the exhaust aftertreatment devices 10 are fastened to the brackets with the U bolts 52 at substantially the center of each exhaust aftertreatment device 10. The number of U bolts 52 can be reduced as compared with the case where both end portions of U are fastened to the bracket with U bolts 52.

The supporting means is not limited to the supporting means composed of the bracket and the U-bolt, but may be the supporting means composed of only the bracket as shown in FIGS. 9 and 10. 9 and 10, the exhaust gas purification device 1
The bracket 57 as a support means for supporting the receiving member 571, which receives lower portions of the outer peripheral surfaces of both end portions of the tubular member 20,
The diesel engine 2 has a mounting portion 572 that is mounted by a bolt or the like, and these receiving portion 571 and mounting portion 5 are provided.
72 is integrally formed. The receiving portion 571 of the bracket 57 is an outer periphery of both ends of the tubular member 20, that is, the center side 24A of the ring-shaped member 24 (specifically, the portion between the flange 241 and the step portion 242 on the center side 24A). It is attached to the surface by welding. Even in such a case, the exhaust gas purifying device 1 is installed in the diesel engine 2
Can be reliably supported on top.

The exhaust gas purifying device is not limited to one installed on a diesel engine, but may be one installed on the floor (including the floor of a vehicle) or one suspended from the ceiling. . Further, the internal combustion engine is not limited to the diesel engine, but may be a gasoline engine, an internal combustion turbine, a jet engine, or the like.

[Brief description of drawings]

FIG. 1 is an overall side view showing an exhaust gas purification device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an exhaust aftertreatment device in FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

4 is a sectional view taken along line IV-IV of FIG.

5 is a cross-sectional view showing an enlarged main part of FIG.

FIG. 6 is a cross-sectional view showing a modified example of each connection structure of the tubular member and the upper and lower side tubes of the present invention.

FIG. 7 is a cross-sectional view showing a modified example of a highly rigid portion of the tubular 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 configured to have high rigidity.

FIG. 9 is a side view showing a modified example of the supporting means of the present invention.

10 is a cross-sectional view taken along the line XX of FIG.

[Explanation of symbols]

1, 3 ... Exhaust gas purifying device, 2 ... Diesel engine which is an internal combustion engine, 2A ... Exhaust passage, 10 ... Exhaust aftertreatment device, 20 ... Cylindrical member, 21, 71 ... First tubular material, 22 ... Second tubular Material, 23 ... Insulating material, 24, 74 ... Ring member that is a high-rigidity portion, 30, 80 ... Upstream side pipe, 30B ... Flange, 40 ... Downstream side pipe, 51 ... Bracket (supporting means), 52 ... U Bolts (supporting means), 57 ... Brackets that are supporting means, 60 ... Buffer members, 71A ... Flange,
241 ... Flange, 242A ... Vertical surface as a positioning portion

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3G090 AA02                 3G091 AA18 AB01 BA07 GA06 GB01Z                       GB17Y GB17Z HA25 HA27                 4D048 AA06 AA13 AA14 AA18 BA10X                       BA39X BB02 BB18 CA01                       CC02 CC04 CC08 CC10 CC63

Claims (5)

[Claims] 1. An exhaust gas purifying device (1) for an internal combustion engine (2), which is provided in an exhaust passage (2A) of an internal combustion engine (2) and includes an exhaust aftertreatment device (10) for purifying inflowing exhaust gas. , 3), wherein the tubular member (20, 70) holds the exhaust aftertreatment device (10) therein, the outer peripheral surface of the exhaust aftertreatment device (10) and the tubular member (20, 70). ) The cushioning member (6
0) and at least a part of the tubular member (20, 70) is configured to have higher rigidity than other parts, and the high-rigidity part of the tubular member (20, 70) is supported. An exhaust gas purification device (1, 3) for an internal combustion engine (2), characterized in that it is supported by means (51, 52, 57). 2. The exhaust gas purifying apparatus (1) for an internal combustion engine (2) according to claim 1, wherein the highly rigid portion of the tubular member (20) has both ends (24) of the tubular member. An exhaust gas purifying device (1) for an internal combustion engine (2), characterized in that 3. The exhaust gas purifying apparatus (1) for an internal combustion engine (2) according to claim 2, wherein the high rigidity portion of the tubular member (20) has an end portion of the cushioning member (60). Of the internal combustion engine (2), which is provided with a positioning portion (242A) that is in contact with the tubular member (20) and defines the position of the exhaust aftertreatment device (10) in the axial direction. Exhaust gas purification device (1). 4. The exhaust gas purifying device (1, 3) for an internal combustion engine (2) according to any one of claims 1 to 3, wherein the tubular member (20, 70) is the shock absorbing member ( 60)
A first tubular member (21, 71) in contact with the inner peripheral surface, a second tubular member (22) holding the first tubular member (21, 71) inside, and a first tubular member (21, 71) Internal combustion engine (2) characterized by including a heat insulating material (23) interposed between the outer peripheral surface of (1) and the inner peripheral surface of the second tubular material (22).
Exhaust gas purification device (1, 3). 5. The exhaust gas purifying device (1) for an internal combustion engine (2) according to any one of claims 1 to 4, wherein an upstream end connected to an upstream end of the tubular member (20). A side pipe (30) and a downstream pipe (40) connected to a downstream end of the tubular member (20) are provided, and both ends of the tubular member (20), the upstream pipe (30). )
Flanges (241, 30B, 40) on the end of the downstream pipe (40) connected to the tubular member (20) and the end of the downstream pipe (40) connected to the tubular member (20), respectively.
B) is formed, the tubular member (20) and the upstream pipe (30), and the tubular member (20) and the downstream pipe (40) are the flanges (241, 30B, 40B). And an exhaust gas purifying apparatus (1) for an internal combustion engine (2).