JP2013209904A - Exhaust emission control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem of local contact of an exhaust gas to a catalyst carrier in the case a manifold converter is provided eccentrically in the engine longitudinal direction.SOLUTION: An exhaust emission control device comprises a catalyst converter arranged downstream of an exhaust manifold assembly part, and a branch plate provided halfway of an exhaust passage from the assembly part to the catalyst converter. The branch plate has a projection shape with a mainstream point or a mainstream line located in the mainstream of the exhaust gas flow. At least one flow rate adjusting part is provided on a side surface of the branch plate for adjusting the flow rate of the exhaust gas to pass by. The flow rate adjusting part allows passage of the exhaust gas easier in a part farther from the mainstream.

Description

  The present invention relates to an exhaust emission control device having a flow dividing plate disposed at an inlet portion of a catalytic converter provided downstream of an exhaust manifold, and in particular, exhaust gas when a maniverter is provided offset in the engine longitudinal direction. Provided is an exhaust emission control device having a flow dividing plate for controlling exhaust gas so that it does not come into contact with a catalyst.

  The exhaust system of the engine contains exhaust gas, particularly soot, unburned hydrocarbons and NOx, and in order to further completely purify this, a catalytic converter is disposed immediately below the collecting part of the exhaust manifold. Are known. This is also called a manipulator. A catalyst is disposed in the catalytic converter.

  The catalyst is a porous ceramic filter on which a catalyst material is supported, and has a substantially cylindrical shape. This substantially cylindrical filter is also called a catalyst carrier. Then, exhaust gas enters from one bottom surface portion on the cylindrical shape of the catalyst carrier, and exhaust gas is discharged from the other bottom surface portion. This bottom portion is called the exhaust inlet of the catalyst carrier, and the opposite bottom portion is called the exhaust outlet.

  At this time, unnecessary components in the exhaust gas are converted into harmless components by the catalytic effect. However, when a catalytic converter is connected to the collective portion of the exhaust manifold, the flow of exhaust gas flowing into the catalytic converter tends to be uneven. For this reason, exhaust gas is biased and passes through the catalyst carrier, which causes problems such as deterioration in exhaust purification performance and partial disparity in catalyst temperature resulting in spalling cracks.

  In order to solve this problem, Patent Document 1 discloses an engine exhaust gas purification apparatus in which a catalytic converter is connected to a collection portion of an exhaust manifold, and a bulge is formed in the exhaust manifold between the collection portion of the exhaust manifold and the catalytic converter. An exhaust guide plate having a hemispherical portion that forms an exhaust passage around the periphery of the hemispherical portion is provided, and a plurality of exhaust passage small holes are formed in the hemispherical portion.

Japanese Utility Model Publication No. 3-127020

  As vehicles become smaller, there is less room in the engine compartment. Therefore, restrictions are also imposed on the shape of the mounted engine. Under such restrictions, the maniverter may be provided with a bias in the longitudinal direction of the engine. In such a case, the flow of exhaust from the far side from the maniverter and the flow of exhaust from the side close to the maniverter are not uniform when viewed from the maniverter, so the exhaust gas hits the catalyst carrier locally. There is a problem.

  When a hemispherical part having an exhaust circulation small hole disclosed in Patent Document 1 is used in such an engine, the area per local area can be reduced. However, the exhaust gas cannot be uniformly applied to the exhaust inlet of the catalyst carrier.

  The present invention has been conceived in view of the above problems, and provides an exhaust emission control device that allows exhaust gas to uniformly strike an exhaust inlet of a catalyst carrier when a maniverter is arranged in the engine longitudinal direction. To do.

More specifically, the exhaust emission control device of the present invention includes:
A catalytic converter is installed downstream of the exhaust manifold assembly,
In the exhaust emission control device provided with a flow dividing plate in the middle of the exhaust passage from the collecting portion to the catalytic converter,
The flow dividing plate has a convex shape having a main flow point or a main flow line in the main flow of the exhaust gas flow,
At least one or more flow rate adjusting parts for adjusting the flow rate of the exhaust gas passing through are provided on the side surface of the flow dividing plate,
The flow rate adjusting unit is characterized in that the exhaust gas is more easily passed as the distance from the main stream increases.

  The exhaust purification apparatus of the present invention exhausts the flow of exhaust gas by facilitating the passage of the exhaust gas through the flow rate control unit as the distance from the main flow point (main flow line), which is the point (line) where the main flow of exhaust gas flows, is increased. It is guided to the entire connection port (connection passage) between the manifold and the catalytic converter, and the exhaust gas can pass through the entire passage without being biased. As a result, problems such as catalyst performance degradation and spalling cracking can be suppressed.

  Further, as a result, the exhaust purification performance is improved, so that the catalyst (catalytic converter) can be reduced in size, and the fuel efficiency is improved.

It is a figure which shows the structure of the conventional exhaust gas purification apparatus. It is a figure which shows the flow dividing plate used for the exhaust gas purification apparatus which concerns on this invention. It is a figure which shows the structure of the exhaust gas purification apparatus which concerns on this invention. It is a figure which shows the other form of the flow dividing plate which concerns on this invention.

  The present invention will be described below with reference to the drawings. The following description exemplifies an embodiment of the present invention, and the following embodiment may be modified without departing from the gist of the present invention.

  FIG. 1 shows a conceptual diagram of an exhaust purification device 1 and an exhaust manifold 90 portion. Although the engine will be described with respect to three cylinders (reference numerals 91, 92, and 93, respectively), it is not particularly necessary to have three cylinders. If there are a plurality of cylinders and the catalytic converter 11 is arranged along the cylinder in a one-way direction, the exhaust emission control device according to the present invention can be used.

  The maniverter 10 is assumed to have a connection port 10 i connected to the collecting portion 95 of the exhaust manifold 90 between the second cylinder 92 and the third cylinder 93. In the present embodiment, since the catalytic converter 11 is arranged immediately downstream of the exhaust manifold 90, the maniverter 10 and the catalytic converter 11 may be synonymous.

  The position of the manipulator 10 is not limited to this, and may be any position as long as the position from each cylinder is asymmetric. In the maniverter 10, a catalyst carrier 14 carrying the above-described catalyst is disposed from the connection port 10i of the maniverter 10 through the exhaust passage 10p. The exhaust port 10x of the manipulator 10 is connected to a muffler tube (not shown).

  When viewed from the connection port 10i of the manipulator 10, there are one cylinder on the right side (third cylinder 93) and two cylinders on the left side (first cylinder 91 and second cylinder 92). Then, the exhaust gas coming from the connection port 10i toward the exhaust inlet 14in of the catalyst carrier 14 is more exhaust gas hitting the right side. A flow in which a large amount of exhaust gas flows when viewed from the exhaust inlet 14 in of the catalyst carrier 14 is referred to as an exhaust gas main flow 16.

  In the case of three cylinders as in the present embodiment, since the three cylinders sequentially perform the combustion / exhaust process, exhaust gases from a plurality of cylinders do not collide with each other at the exhaust inlet 14in of the catalyst carrier 14. However, a flow having a large amount of gas passing through for a certain time is defined as a main flow 16.

  Referring to FIG. 3, in the exhaust purification apparatus 1 of the present invention, the flow dividing plate 20 having a convex shape centered on a point or line through which the main flow 16 passes (referred to as a main flow point 16 p and a main flow line 16 L). Is provided. FIG. 2 shows a plan view (FIG. 2A) and a side view (FIG. 2B) of the flow dividing plate 20. The flow dividing plate 20 has a conical shape with the apex 21 shifted. The bottom 22 portion is not closed. Further, a through hole 26 is formed in the side surface 23 as a flow rate adjusting portion 24.

  That is, it has a hollow eccentric conical shape and has a shape in which the through hole 26 is formed in the side surface 23. Therefore, the exhaust gas entering from the through hole 26 passes through the bottom surface 22. The diameter of the bottom 22 portion is approximately the same as the exhaust inlet 14 in of the catalyst carrier 14. A bracket 27 with a through hole for supporting in the catalytic converter 11 is provided around the periphery.

  The vertex 21 is provided at a point where the main flow of exhaust gas flows (referred to as the main flow point 16p) when viewed from the exhaust inlet 14in of the catalyst carrier 14. That is, the flow dividing plate 20 is formed in accordance with the main flow 16 that changes depending on the position of the maniverter 10 arranged for a plurality of cylinders. Actually, the main flow 16 is a flow of airflow having a certain thickness, so that it can be said to be the main flow point 16p if it is almost in the center.

  At least one or more through holes 26 on the side surface 23 are provided. The position and size of the through hole 26 are formed such that the exhaust gas easily passes as the distance from the main flow point 16p increases. That is, as the distance from the main flow point 16p increases, the opening of the through hole 26 increases. It may be arranged concentrically for each size of the through hole 26, or the size may be changed for each position. As a result, the exhaust gas becomes easier to flow away from the main flow 16. Although the height from the bottom face 22 of the flow dividing plate 20 is not specifically limited, Since the flow velocity is quick, the pointed shape is preferable.

  Referring to FIG. 3, when the flow dividing plate 20 formed in this way is attached between the collecting portion 95 of the exhaust manifold 90 and the connection port 10 i of the catalytic converter 11, the first cylinder 91 and the second cylinder Since the exhaust gas from 92 almost enters the catalytic converter 11 as the main flow 16, it is distributed to the periphery at the apex 21 of the flow dividing plate 20. On the right side from the main flow 16, since the number of through holes 26 is small and the diameter of the through holes 26 is small, the exhaust gas hardly flows. On the other hand, on the left side from the main flow 16, the number of through holes 26 is large and the diameter of the through holes 26 is large, so that the exhaust gas easily flows. Note that the convex shape may be directed not only to the upstream side with respect to the flow of the exhaust gas but also to the downstream side as indicated by a dotted line in FIG.

  Since the exhaust gas from the third cylinder 93 mainly flows from the main flow 16 to the left side, it tends to flow to the left side of the exhaust inlet 14in. From the above, the exhaust gas from the three cylinders flows evenly into the exhaust inlet 14in of the catalyst carrier 14 and can eliminate the local area.

  The flow dividing plate 20 is not particularly limited to the shape shown in FIG. FIG. 4 shows another shape of the flow dividing plate 40. The main flow 16 does not necessarily form a circle due to the flow of the exhaust gas, and the exhaust port 14 in part of the catalyst carrier 14 may be elliptical. In such a case, the main flow point 16p is not a point but a main flow line 16L.

  In such a case, a flow dividing plate 40 as shown in FIG. 4 can be used. The flow dividing plate 40 of FIG. 4 is a convex-shaped body that connects the apexes of cones having the same bottom surface and has a top ridge 41. As in the case of FIG. 2, a through hole 46 is formed in the side surface 43, and the diameter of the through hole 46 increases as the distance from the top ridge 41 increases, and the exhaust gas easily passes. A bracket 47 with a through hole is also provided.

  In addition to these shapes, any structure may be used as long as the exhaust gas is more easily passed away from the main flow point 16p or the main flow line 16L. Further, in the exhaust emission control device 1 of the present invention, the flow dividing plate has a convex shape. However, as shown by the dotted line in FIG. 3, not only the convex portion is directed upstream but also downstream of the exhaust gas flow. You may turn to the side. When the height from the bottom surface of the flow dividing plate to the vertex 21 (or the top edge 41) is relatively low, the flow resistance against the flow of exhaust gas increases, so it is better to direct the convex shape to the downstream side. This is because there are cases.

  As described above, the exhaust gas purification apparatus 1 according to the present invention is provided with the flow dividing plate 20 in which the eccentric vertex 21 or apex edge 41 is aligned with the main flow 16 of the exhaust gas at the exhaust inlet 14 in of the catalyst carrier 14. Exhaust gas hits all the way to 14 inches and can avoid the local area. As a result, the life of the catalyst can be extended and the exhaust purification performance can be improved.

  The exhaust emission control device of the present invention can be suitably used not only for gasoline vehicles but also for diesel vehicles.

DESCRIPTION OF SYMBOLS 1 Exhaust purification device 10 Maniverter 10i Connection port 10p Exhaust passage 10x Exhaust port 11 Catalytic converter 14 Catalyst support body 14in Exhaust inlet 16 Main flow 16p Main flow point 16L Main flow line 20 Diverging plate 21 Vertex 22 Bottom surface 23 Side surface 24 Flow rate adjustment part 26 Through hole 27 Bracket with through hole 40 Flow dividing plate 41 Top ridge 43 Side surface 44 Flow rate adjusting part 46 Through hole 47 Bracket with through hole 90 Exhaust manifold 91, 92, 93 Cylinder 95 Collecting part

Claims (1)

A catalytic converter is installed downstream of the exhaust manifold assembly,
In the exhaust emission control device provided with a flow dividing plate in the middle of the exhaust passage from the collecting portion to the catalytic converter,
The flow dividing plate has a convex shape having a main flow point or a main flow line in the main flow of the exhaust gas flow,
At least one or more flow rate adjusting parts for adjusting the flow rate of the exhaust gas passing through are provided on the side surface of the flow dividing plate,
The exhaust gas purifying apparatus according to claim 1, wherein the flow rate adjusting unit is configured to facilitate passage of exhaust gas as the distance from the mainstream increases.