JP2010216366A - Exhaust emission control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device capable of allowing an end of an exhaust passage connected to a cone part to be brought close to an end of a cylindrical body. <P>SOLUTION: The exhaust emission control device includes the cylindrical body 2 storing a catalyst body A, a large diameter end 3a fitted over an end of the cylindrical body 2 and connected to the cylindrical body 2, a small diameter end 3b connected to an upstream side flange 5, and an upstream side cone part 3 comprising a connecting part 3c connecting the large diameter end 3a to the small diameter end 3b. The small diameter end 3b is brought close to the large diameter end 3a by curving the connecting part 3c, a portion of the large diameter end 3a brought close to the small diameter end 3b is extended, and an enlarged part 3d having a portion fitted over the end of the cylindrical body 2 is provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an exhaust purification device installed in an exhaust system of an engine.

  In order to purify nitrogen oxides, sulfur oxides and the like contained in the exhaust gas, an exhaust purification device is installed in the exhaust system. The exhaust purification device includes a cylindrical body that accommodates the catalyst main body and a cone portion connected to the exhaust passage.

  Conventionally, in order to ensure a large capacity of the catalyst body, a large-diameter end portion of a cone portion is externally fitted to an end portion of a cylindrical body, and a joint portion is welded over the entire circumference (for example, Patent Document 1). reference).

JP-A-9-170429

  However, the conventional exhaust purification device does not consider the layout of the exhaust system including other devices. The direct layout, in which the exhaust purification device is disposed in the immediate vicinity of the engine exhaust port, has an advantage that the catalyst can be warmed up quickly because the temperature atmosphere is increased by warm exhaust. However, in the direct layout, it is necessary to accommodate the exhaust purification device in the engine room where a large number of various auxiliary machines are arranged. Therefore, compared with the underfloor layout in which the exhaust purification device is disposed under the vehicle floor, The restrictions regarding the shape of the purification device, particularly the cone portion, are increased.

  In order to improve the exhaust purification performance, it is desirable that the volume of the catalyst body is large. From this point as well, there are large restrictions on the shape of the cone portion located between the cylindrical body that houses the catalyst body and the exhaust passage. Become.

  In particular, if the exhaust passage in the cone portion is sharply bent and the end of the exhaust passage connected to the cone portion can be brought close to the end portion of the cylindrical body, the direct type that has particularly great restrictions in the vertical direction Although advantageous in the layout, the conventional exhaust gas purification apparatus cannot secure a welding point.

  In view of the above, an object of the present invention is to provide an exhaust purification device capable of bringing an end of an exhaust passage connected to a cone portion close to an end of a cylindrical body.

  The exhaust emission control device of the present invention includes a cylindrical body that houses a catalyst body, a large-diameter end that is externally fitted to the end of the cylindrical body and joined to the cylindrical body, and a small-diameter end that is connected to the exhaust passage. And a cone portion comprising a connecting portion connecting between the large-diameter end portion and the small-diameter end portion, and the connecting portion is curved so that the large-diameter end portion is connected to the connecting portion or the small-diameter end. An enlarged portion is provided in which the portion is close, the portion of the large-diameter end portion that is close to the small-diameter end portion is extended, and the portion that is externally fitted to the end portion of the cylindrical body is enlarged.

  According to the exhaust emission control device of the present invention, an enlarged portion is provided by extending a portion close to the connection portion or the small diameter end portion of the large diameter end portion of the cone portion and enlarging the portion fitted on the end portion of the cylindrical body. ing. Thereby, since the welding location in the part close | similar to the connection part of a large diameter end part or a small diameter end part leaves | separates from a connection part or a small diameter end part, it becomes possible to perform welding with a cylindrical body and a cone part favorably. . Note that the cone portion does not mean a conical shape.

1 is a perspective view showing an exhaust emission control device according to an embodiment of the present invention. The perspective view which shows the upper part of an exhaust gas purification apparatus. The fragmentary sectional view which shows the upper part of an exhaust gas purification apparatus.

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

  Referring to FIG. 1, an exhaust purification device 1 includes a cylindrical body 2 that holds a catalyst body A (see FIG. 3) inside, an upstream cone portion 3 that is joined to the upstream side and the downstream side thereof, and a downstream side. Metal cone flange 4, metal upstream flange 5 connected to the engine side upstream exhaust pipe (not shown), metal downstream flange connected to the downstream exhaust pipe (not shown) 6 and.

  The exhaust purification device 1 is disposed immediately below the exhaust system of the engine, here the exhaust port. However, the exhaust purification device 1 may be arranged in the exhaust system under the vehicle floor.

  The cylindrical body 2 is a cylindrical casing that accommodates the catalyst main body A inside, and is formed of, for example, a metal material such as stainless steel, steel, or a magnesium alloy. The catalyst body A is, for example, a ceramic or metal monolith catalyst carrier, a DPF (diesel particulate filter) that traps PM (particulate matter) discharged from a diesel engine, or the like.

  The upstream cone portion 3 has an enlarged diameter in the exhaust flow direction, and is joined to the upstream flange 5 by welding. The downstream cone part 4 has a small diameter in the exhaust flow direction and is joined to the downstream flange 6 by welding.

  Referring to FIGS. 2 and 3, the upstream cone portion 3 is composed of a first half 7 and a second half 8. Both the first half 7 and the second half 8 are formed by pressing a metal plate such as stainless steel or steel. The first half body 7 and the second half body 8 are joined by welding after being fitted at the fitting portions 9.

  The upstream cone portion 3 includes a downstream large-diameter end portion 3a, an upstream small-diameter end portion 3b, and a connecting portion 3c that connects the large-diameter end portion 3a and the small-diameter end portion 3b. . The small-diameter end 3b is connected to the upstream flange 5 by welding. The large-diameter end 3 a is formed so that its inner diameter matches the outer diameter of the cylindrical body 2. With the upstream end portion of the cylindrical body 2 fitted in the large diameter end portion 3a of the upstream cone portion 3, welding is performed over the entire circumference of the step, and the cylindrical body 2 and the upstream cone Part 3 is joined.

  By the way, the angle formed by the axial direction at the large-diameter end portion 3a of the upstream cone portion 3 and the axial direction at the small-diameter end portion 3b is an acute angle, and the exhaust passage in the connection portion 3c is sharply curved. And the small diameter end part 3b protrudes so that it may adjoin to the large diameter end part 3a. On the other hand, welding between the cylindrical body 2 and the upstream cone portion 3 is performed by electric resistance welding, semi-automatic welding (MIG welding), tungsten electrode welding (TIG welding), etc. It is necessary to consider the interference.

  Therefore, an enlarged portion 3d is provided in which a portion of the large diameter end portion 3a adjacent to the small diameter end portion 3b is expanded downstream. In other words, the area of the overlapping portion where the large-diameter end portion 3a is fitted on the end portion of the cylindrical body 2 is larger in the vicinity of the small-diameter end portion 3b than in the other portions. Thereby, in the part which adjoins the small diameter edge part 3b, the level | step difference which is a welding location moves to the downstream side, and is separated. That is, the downstream end face of the large-diameter end 3a to be welded to the outer peripheral surface of the cylindrical body 2 has a portion close to the small-diameter end 3b positioned on the downstream side compared to the other portions. Therefore, it becomes possible to perform welding satisfactorily without interference between the welding apparatus and the upstream flange 5 or the like.

  Further, the portion other than the vicinity of the small-diameter end portion 3b of the large-diameter end portion 3a is not expanded downstream, and the increase in heat capacity is suppressed as much as possible, so that the temperature rise performance (warm-up performance) of the catalyst body A is ensured. be able to.

  The position of the small-diameter end 3b with respect to the large-diameter end 3a is determined according to the layout of auxiliary equipment and the like arranged around the exhaust purification device 1, and the bending of the connecting portion 3c is also determined accordingly. May be determined as appropriate.

  In addition, this invention is not limited to what was mentioned above. For example, in the embodiment, the case where the small diameter end portion 3b is close to the large diameter end portion 3a has been described. However, the same applies when a part of the connecting portion 3b is close to the large-diameter end portion 3a.

  Moreover, in embodiment, the case where the enlarged part 3d was provided in the large diameter edge part 3a of the upstream cone part 3 was demonstrated. However, an enlarged portion may be provided at the large diameter end portion of the downstream cone portion 4.

  Moreover, the case where the flanges 5 and 6 were joined to the cone parts 3 and 4 was demonstrated. However, members other than the flanges 5 and 6, for example, connecting pipes may be joined to the cone portions 3 and 4. Moreover, the case where it joined by welding was demonstrated. However, it may be joined by brazing.

  DESCRIPTION OF SYMBOLS 1 ... Exhaust gas purification apparatus, 2 ... Cylindrical body, 3 ... Upstream cone part (cone part), 3a ... Large diameter end part, 3b ... Small diameter end part, 3c ... Connection part, 3d ... Expansion part, 5 ... Upstream side Flange, A ... Catalyst body.

Claims (1)

A cylindrical body for storing the catalyst body;
A large-diameter end that is externally fitted to the end of the cylindrical body and joined to the cylindrical body, a small-diameter end connected to the exhaust passage, and a gap between the large-diameter end and the small-diameter end. With a cone part consisting of connecting parts to be connected,
The connecting portion is curved, the connecting portion or the small-diameter end portion is close to the large-diameter end portion, the portion of the large-diameter end portion that is close to the small-diameter end portion is extended, and the end portion of the cylindrical body An exhaust emission control device is provided, which is provided with an enlarged portion in which a portion to be externally fitted is enlarged.

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