JP2019148221A - Exhaust emission control device - Google Patents

Abstract

To provide an exhaust emission control device for eliminating the possibility of extruding a mat when mating the half bodies of a case storing a honeycomb carrier.SOLUTION: The exhaust emission control device includes a base material 10, a mat 30, and a case 20, the case 20 being split in two, namely, into a first half body 21 and a second half body 22 in the radial direction of the base material 10, the first half body and the second half body being joined to each other at their ends 211, 212, 221, 222 extending in parallel to a center axis X of the base material in the peripheral direction of the base material to form joint parts 251, 252, the joint parts being formed on the side of the first half body further than an intersection point NP between a virtual straight line HL which is perpendicular to a direction of connecting middle points MP1, MP2 in the cross directions of the first half body and the second half body and intersects with the center axis X in the cross section intersecting with the center axis X of the base material, and a cross-sectional contour C1, the second half body having extention parts 223, 224 extending in the tangential direction of the peripheral face of the base material so that their extending edges are ends as parts of the joint parts 251, 252.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an exhaust emission control device.

  Conventionally, an exhaust emission control device provided in an exhaust passage of an internal combustion engine has a structure in which a columnar honeycomb carrier is accommodated in a cylindrical case. The honeycomb carrier is held in the case by a mat inserted in a compressed state between the outer peripheral surface of the honeycomb carrier and the inner surface of the case. A technology has been proposed in which each half of the cylindrical case is joined in the circumferential direction, and a deformable mechanism is provided at the joint so that the dimensional tolerance of the honeycomb carrier and each half can be absorbed. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 10-47046

  However, in the technique of Patent Document 1, when joining two halves together, the joining portion may bite the mat and may protrude from the joining portion.

  The present invention has been made in view of the above circumstances, and provides an exhaust emission control device that does not cause a mat to bite at a joint portion of the half body when the half body of the case housing the base material is joined. For the purpose.

(1) A columnar substrate (for example, a honeycomb carrier 10 described later) carrying an exhaust gas treatment catalyst, a mat (for example, a mat 30 described later) wound around the outer peripheral surface of the substrate, and the mat is compressed. An exhaust purification device (for example, an exhaust purification device 1 to be described later) having a case (for example, a case 20 to be described later) that holds the base material in a state in which the case is placed in the radial direction of the base material. The first half and the second half are divided into one half (for example, a first half 21 described later) and a second half (for example, a second half 22 described later). Are joined in the circumferential direction of the substrate at respective end portions (for example, end portions 211, 212, 221, 222 described later) extending in parallel to the center axis (for example, center axis X described later) of the substrate. Form joints (for example, joints 251 and 252 described later) The joint portion has respective midpoints in the width direction of the first half and the second half (for example, midpoints MP1 and MP2 described later) in a cross section intersecting the central axis of the base material. ) Formed on the first half body side from an intersection (for example, an intersection point NP to be described later) of an imaginary straight line (for example, an imaginary line HL to be described later) that intersects the central axis and intersects the central axis. The second half has an extending portion (for example, an extending portion 223 described later) that extends in a tangential direction of the peripheral surface of the base material and has an extended edge that forms an end portion that forms the joint portion. An exhaust purification device characterized by that.

  In the exhaust emission control device according to (1), the joining portion connects the respective midpoints in the width direction of the first half and the second half in a cross section intersecting the central axis of the base material. Is formed on the first half side with respect to the intersection of the virtual straight line intersecting the central axis and the cross-sectional contour. Furthermore, the second half has an extending portion that extends in a tangential direction of the peripheral surface of the base material, and an extended edge of which forms an end portion that forms the joint portion. With such a configuration, the extended portion of the second half has a gap with the mat disposed on the peripheral surface of the base material. Because of this gap, there is no risk of biting the mat when joining the first half and the second half together at their corresponding ends. As a result, there is no change in the contact pressure of the case caused by biting the mat. Therefore, the surface pressure of the case can be made uniform regardless of the portion.

(2) The exhaust emission control device according to (1), wherein the base material includes a plurality of cells surrounded by a partition wall, and the outline of the cross section includes a plurality of straight portions parallel to the partition wall.

  In the exhaust purification apparatus of (2), since the base material has a straight portion, a large cross-sectional area of the base material can be secured, and exhaust pressure loss can be reduced.

(3) The exhaust emission control device according to (2), wherein the joining portion is formed closer to the first half body side than an end portion of the straight portion on the first half body side.

  In the exhaust purification apparatus of (3) above, since the joining portion is formed on the first half side of the straight portion of the base material on the first half side, the mat tangent toward the joining portion The extending part of the second half extending in the direction is sufficiently separated from the peripheral surface of the mat. That is, the joint portion is sufficiently separated from the mat. Therefore, the risk of biting the mat when the first half and the second half are joined together at their corresponding ends is further reduced.

  According to the present invention, when mating the half of the case containing the base material, there is no risk of biting the mat at the joining portion of the half, and the surface pressure of the case can be made uniform regardless of the portion. An exhaust emission control device that can be provided can be provided.

1 is an exploded perspective view of an exhaust emission control device according to an embodiment of the present invention. It is a perspective view which shows the honeycomb support | carrier as a base material. It is an exploded sectional view of an exhaust emission control device. It is the elements on larger scale which looked at the exhaust emission control device from the end face.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
1, FIG. 2, FIG. 3 and FIG. 4 are views showing an exhaust emission control device 1 as an embodiment of the present invention.
FIG. 1 is an exploded perspective view of an exhaust purification device 1 according to the present embodiment, and FIG. 2 is a perspective view of a honeycomb carrier 10 as a base material applied to the exhaust purification device 1. 3 is an exploded cross-sectional view of the exhaust purification device 1, and FIG. 4 is a partial enlarged view of the exhaust purification device 1 as viewed from the end.

  The exhaust purification device 1 is an exhaust purification filter called a DPF (Diesel Particulate Filter) that is provided in an exhaust passage of a diesel internal combustion engine (not shown) and collects particulates in exhaust flowing through the exhaust passage. The exhaust purification device 1 includes a columnar honeycomb carrier 10, a mat 30 wound around the outer peripheral surface 11 of the honeycomb carrier 10, and a case 20 that holds the honeycomb carrier 10 in a compressed state. .

  Next, the honeycomb carrier 10, the mat 30, and the case 20 that constitute the exhaust purification device 1 will be sequentially described in detail.

The honeycomb carrier 10 is a wall-through type for collecting exhaust particulates, and is made of, for example, silicon carbide.
The honeycomb carrier 10 has a large number of cells partitioned by partition walls in the exhaust flow direction, and both end surfaces of the cells are sealed with one end surface and the other end surface alternately with adjacent cells. Columnar segments 150 and 150 are configured as an aggregate of a large number of cells partitioned by partition walls, and the honeycomb carrier 10 is configured as an aggregate of a plurality of segments 150 and 150. The segments 150 and 150 constituting the honeycomb carrier 10 are bonded to each other by a bonding agent on their peripheral surfaces. On the end face of the honeycomb carrier 10, the joint portions SP1 and SP2 of the segments 150 and 150 are visually recognized in a lattice shape. In the honeycomb carrier 10, exhaust gas flows in from the cells opened upstream in the exhaust flow direction in the columnar shape, and exhaust particulates are collected when the exhaust gas passes through the partition walls between adjacent cells. The removed exhaust gas flows out from the cell that is open downstream in the exhaust flow direction in the cylindrical shape.

The honeycomb carrier 10 has a columnar shape as a whole, and the central axis X can be considered.
As shown in FIG. 2, the columnar honeycomb carrier 10 has bulge portions 131, 132, 133, and 134 that protrude from the peripheral surface at intermediate positions in the central axis X direction of the honeycomb carrier 10.
The outline C1 of the cross section that intersects the central axis X of the honeycomb carrier 10 has a rounded rectangular shape as shown in FIG. A contour C1 in FIG. 3 is a cross section orthogonal to the central axis X, and is in a portion closer to the end than the bulge portions 131, 132, 133, and 134.
Straight portions 111, 112, 113, and 114 are formed in the long diameter portions LD1 and LD2 corresponding to both ends in the longitudinal direction LD of the contour C1 and the short diameter portions SD1 and SD2 corresponding to both ends in the short direction SD, respectively. .

  The orthogonal arrow lines LD and SD drawn below in FIG. 3 conceptually represent the longitudinal direction and the short direction of the rounded rectangular shape of the contour C1.

  Straight portions 111 and 112 are formed corresponding to the long diameter portions LD1 and LD2, respectively, and straight portions 113 and 114 are formed corresponding to the short diameter portions SD1 and SD2, respectively. The straight portions 111, 112, 113, 114 are flat. As a result, when considering a virtual diagonal line connecting the intersections on the extensions of the straight parts 111 and 112 and the straight parts 113 and 114 diagonally, the bulge parts 131, 132, 133, and 134 are on the corresponding virtual diagonal line. Located in pairs.

  In other words, focusing on the configuration of the above-described honeycomb carrier 10, in other words, the honeycomb carrier 10 is composed of a plurality of cells (segments 150 and 150 that are aggregates of cells) surrounded by partition walls, and the outline C1 is a cell. The plurality of straight portions 111, 112, 113, 114 are parallel to the partition walls.

By forming a plurality of straight portions as described above, a large cross-sectional area of the honeycomb carrier 10 can be ensured, so that exhaust pressure loss can be reduced.
Further, since the bulge portions 131, 132, 133, and 134 are positioned in pairs on the above-described virtual diagonal line, the surface pressure applied to the mat 30 at the R portions 121, 122, 123, and 124 is effectively increased. Is easy to manage.
Furthermore, both end surfaces of the bulge portions 131 and 133 (132 and 134) are formed on the center side along the central axis X from the exhaust inflow end surface and outflow end surface of the honeycomb carrier 10 respectively. For this reason, when the mat 30 is wound around the outer peripheral surface 11 of the honeycomb carrier 10, the bulge portions 131 and 133 (132 and 134) are covered with the mat 30 on the entire surface including both end surfaces thereof. Position retention in the case is complete.

  A member made of a material having heat resistance, vibration resistance, a sealing function, and a vibration absorbing ability is applied to the mat 30. Specifically, for example, ceramic fibers such as alumina fibers, silica fibers, alumina silica fibers, and glass fibers are used.

  The case 20 is configured by joining two halves divided into a first half 21 and a second half 22 in the radial direction of the honeycomb carrier 10. The case 20 has a tubular shape as a whole in a state where the first half 21 and the second half 22 are joined, and shares the central axis X with the honeycomb carrier 10. The first half 21 and the second half 22 are formed of, for example, a metal plate. As shown in FIGS. 1 and 3, an exhaust circulation hole 25 is formed in the first half 21.

The cross-sectional view in FIG. 3 is a position closer to the exhaust circulation hole 25 than the bulge parts 131, 132, 133, 134 on the central axis X of the honeycomb carrier 10.
The first half 21 of the case 20 has circumferential ends 211 and 212 extending along the central axis X. The second half 22 has circumferential ends 221 and 222 extending along the central axis X. The end portion 211 of the first half body 21 and the end portion 221 of the second half body 22 are joined to form a joint portion 251. Similarly, the end portion 212 of the first half 21 and the end portion 222 of the second half 22 are joined to form a joined portion 252. The end portions 211 and 212 of the first half body 21 and the end portions 221 and 222 of the second half body 22 form a jockle that protrudes with a step in a direction away from the central axis X.

3, in the cross section of FIG. 3 intersecting the central axis X, the direction connecting the midpoint MP1 of the width direction WD1 of the first half 21 and the midpoint MP2 of the width direction WD2 of the second half 22 Is formed closer to the first half 21 than the intersection of the imaginary straight line HL intersecting the central axis X and the contour C1 (in FIG. 3, the intersection NP in the straight portion 111 is shown).
The second half 33 has extending portions 223 and 224 that extend in the tangential direction of the outer peripheral surface 11 of the honeycomb carrier 10 and whose extended end edges become end portions 221 and 222 that form the joint portions 251 and 252.

Next, the configuration around the joint 251 will be described in more detail with reference to FIG. 4 and FIG.
FIG. 4 is a partially enlarged view around the joint 251 in the end view of the exhaust emission control device 1. In FIG. 4, the honeycomb carrier 10 is viewed from the side opposite to the exhaust circulation hole 25 of the first half body 21 in the direction of the central axis X. From such a viewpoint of FIG. 4, it can be seen that the mat 30 covering the bulge portions 131 and 132 of the honeycomb carrier 10 protrudes in accordance with the protrusion of the bulge portions 131 and 132. 4 shows a partial configuration around the joint 251 among the above-described joints 251 and 252, the same configuration is also applied to the portion around the joint 252.
The straight portion 111 in the contour C1 of the honeycomb carrier 10 extends flat in the SD direction, and one end E1 and the other end E2 are equidistant from the intersection NP. The end E1 is an end of the straight portion 111 on the first half body 21 side.

  As shown in FIGS. 3 and 4, in the present embodiment, the joining portion 251 is formed at a position closer to the first half body 21 than the end E1 of the straight portion 111 on the first half body 21 side. In other words, the extending portion 223 of the second half 22 extends to this position, and the extended end is the end 221 on the second half 22 side of the joint portion 251. As shown in FIG. 3, the extending portion 223 of the second half 22 extends a distance d from the intersection NP in the tangential TL direction of the outer peripheral surface 11 of the honeycomb carrier 10. For this reason, a portion of the extending portion 223 from the portion along the peripheral surface of the mat 30 surrounding the honeycomb carrier 10 toward the end 221 has a gap with the peripheral surface of the mat 30. Therefore, the end portion 211 of the first half body 21 that is joined to the end portion 221 of the second half body 22 to form the joint portion 251 also creates a gap with the peripheral surface of the mat 30. In other words, the portion of the joint portion 251 is separated from the peripheral surface of the mat 30 at the gap portion. As described above, the configuration around the joint 251 is the same as the configuration around the joint 252. For this reason, in the exhaust emission control device 1 of the present embodiment, when the first half body 21 and the second half body 22 are joined by the joint portions 251 and 252, the mat 30 is inserted between the half halves 21 and 22. There is no fear. As a result of not mating the mat 30, the surface pressure of the case 20 can be made uniform regardless of the portion.

In the exhaust purification device 1 described above, the honeycomb carrier 10 has a rounded rectangular shape C1 in the cross section, and has flat straight portions 111, 112, 113, 114. Not limited to this. The present invention may have various shapes such as a case where the shape of the outline of the honeycomb carrier in a cross-sectional view is a perfect circle, or a non-circular shape in which the short direction and the long direction are defined. In any case, the positions of the joints of the two halves constituting the case are the respective midpoints in the width direction of one half and the other half in the cross section intersecting the central axis of the honeycomb carrier. It is formed at a position that is biased toward one half of the intersection of the virtual straight line that intersects the central axis and intersects with the central axis and the cross-sectional contour of the honeycomb carrier. Further, in this case, the end portion forming the joining portion of the other half is configured so that the other half becomes the edge of the extending portion extending in the tangential direction of the peripheral surface of the honeycomb carrier.
In this configuration, a gap is formed between the extending portion extending in the tangential direction toward the joint portion of the other halves and the mat disposed on the peripheral surface of the honeycomb carrier. Therefore, there is no possibility of biting the mat when the two halves are joined, and the surface pressure of the case is made uniform regardless of the portion.

  In the above embodiment, the exhaust purification apparatus of the present invention has been described by taking the DPF used in a diesel internal combustion engine as an example, but the present invention is not limited to this. The exhaust purification device of the present invention is applied to an exhaust purification filter called GPF (Gasoline Particulate Filter) that is provided in an exhaust pipe of a gasoline internal combustion engine and collects particulate matter in exhaust gas flowing through the exhaust pipe. Also good.

C1 ... contour HL ... virtual straight line MP1, MP2 ... mid point NP ... intersection TL ... tangent X ... center axis 1 ... exhaust gas purification device 10 ... honeycomb carrier (base material)
DESCRIPTION OF SYMBOLS 11 ... Outer peripheral surface 20 ... Case 21 ... 1st half 22 ... 2nd half 30 ... Mat 251,252 ... Junction part 211,212,221,222 ... End part 223,224 ... Extension part

Claims (3)

An exhaust purification apparatus comprising a columnar base material carrying an exhaust gas treatment catalyst, a mat wound around an outer peripheral surface of the base material, and a case for holding the base material in a compressed state of the mat,
The case is divided into a first half and a second half in the radial direction of the base material,
The first half and the second half are joined in the circumferential direction of the base at each end extending parallel to the central axis of the base to form a joint,
The joint is perpendicular to the direction connecting the respective midpoints in the width direction of the first half and the second half in a cross section intersecting the central axis of the base material, and intersects the central axis Is formed on the first half side from the intersection of the virtual straight line and the cross-sectional contour,
2. The exhaust emission control device according to claim 1, wherein the second half has an extending portion that extends in a tangential direction of the peripheral surface of the base material and has an extended end edge serving as an end portion that forms the joint portion.   2. The exhaust emission control device according to claim 1, wherein the base material includes a plurality of cells surrounded by a partition wall, and an outline of the cross section includes a plurality of straight portions parallel to the partition wall.   3. The exhaust emission control device according to claim 2, wherein the joint portion is formed closer to the first half body side than an end portion of the straight portion on the first half body side.

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