JP2019148216A - Exhaust emission control device - Google Patents

Abstract

To provide an exhaust emission control device that excels in productivity, is stable in quality, is compact, and excels in controlling emissions of exhaust gas.SOLUTION: An exhaust emission control device 1 includes a columnar honeycomb carrier 10, a cylindrical case 20 housing the honeycomb carrier 10, and a mat 30 that is provided so as to surround the outer periphery of the honeycomb carrier 10 between the honeycomb carrier 10 and the case 20. The honeycomb carrier 10 has at least one straight part 111, 112, 113, 114 in which the outline of the cross section intersecting the central axis thereof is linear, and R parts 121, 122, 123, 124 at the other locations. The R parts 121, 122, 123, 124 are formed with bulge portions 131, 132, 133, 134 that protrude in the outer diameter direction, and the straight parts 111, 112, 113, 114 are flat. The mat 30 is disposed so as to cover the bulge portions 131, 132, 133, 134.SELECTED DRAWING: Figure 2

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 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. In order to ensure the retention of the honeycomb carrier by the mat, a technique of providing a flange portion on the outer peripheral portion of the honeycomb carrier has been proposed (for example, see Patent Document 1).

  In addition, a technique is provided in which a hook portion is provided at both axial end portions of the honeycomb carrier, and the honeycomb carrier is fixed by a claw-shaped pressing portion that protrudes from the inner periphery of the end portion of the corresponding portion of the hook portion in the case that is a metal tube. Has been proposed (see, for example, Patent Document 2).

Japanese Patent No. 6174500 Japanese Utility Model Application No. 61-48913 (Microfilm of Japanese Utility Model Application No. 62-162329)

In the technique of Patent Document 1, since the flange portion protrudes from the outer peripheral portion of the honeycomb carrier, it is difficult to wind the mat and it is difficult to manage the surface pressure when pressing the mat with the case. For this reason, it is not suitable for mass production. Further, compaction is hindered by the protruding flange portion. Furthermore, quality may vary when the honeycomb carrier is compressed and fixed (canning) through a mat in the case.
On the other hand, in the technique of Patent Document 2, the structure is not based on the assumption that the mat is wound. However, if the mat is wound, the mat pressed by the claw-shaped pressing portion at the end portion extends over the inner peripheral side of the honeycomb carrier. There is a risk that the performance of purifying the exhaust gas is deteriorated due to the exhaust gas being blocked.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an exhaust emission control device that is excellent in productivity, stable in quality, compact, and excellent in purifying exhaust gas.

  (1) An exhaust purification device (for example, an exhaust purification device 1 described later) provided in an exhaust passage of an internal combustion engine for purifying exhaust gas of the internal combustion engine, and a columnar honeycomb carrier (for example, a honeycomb carrier 10 described later) And a cylindrical case (for example, case 20 described later) for housing the honeycomb carrier, and a mat (for example, described later) provided so as to surround the outer periphery of the honeycomb carrier between the honeycomb carrier and the case. The honeycomb carrier includes a straight portion (for example, straight portions 111, 112, and 113 to be described later) in which the outline of a cross section intersecting a central axis (for example, a central axis X to be described later) forms a linear shape. , 114) and at least one R portion (for example, R portions 121, 122, 123, and 124, which will be described later). A bulge portion (for example, bulge portions 131, 132, 133, and 134 to be described later) protruding in the outer diameter direction is formed, the straight portion is flat, and the mat is arranged to cover the bulge portion. An exhaust emission control device characterized by that.

  According to the exhaust purification device of (1) above, the bulge portion protruding in the outer diameter direction is formed in the R portion of the honeycomb carrier, and the straight portion is flat. In other words, since the bulge portion is provided in the R portion and the bulge portion is not provided in the straight portion, the honeycomb carrier can be made compact while sufficiently securing the cross-sectional area of the honeycomb carrier. The R portion of the honeycomb carrier has a high surface pressure applied to the mat, and the surface pressure can be easily managed as compared with the straight portion. For this reason, it is excellent in productivity and the quality at the time of mass production is stabilized. By the way, when the bulge portion is provided in the straight portion, it is difficult to align the mat when the mat is wound around the honeycomb carrier and accommodated in the case, which may make it difficult to manage the surface pressure. On the other hand, in the present invention, the bulge portion is formed only in the R portion and not formed in the straight portion, so that the alignment can be performed with high accuracy.

(2) The exhaust gas purification apparatus according to (1), wherein the honeycomb carrier has a plurality of R parts.

  According to the exhaust gas purification apparatus of (2) above, since a plurality of R parts having bulge parts are formed, the position of the honeycomb carrier by the mat is more reliably maintained.

(3) The honeycomb carrier has a rounded rectangular shape in a cross-sectional view perpendicular to the central axis, and the straight portion corresponds to a long diameter portion corresponding to both ends in the longitudinal direction and both ends in the short direction in the cross-sectional view. The exhaust purification device according to (1) or (2), wherein the exhaust gas purification device is formed in each of the short diameter portions.

  According to the exhaust purification device of (3) above, by forming a plurality of straight portions, a large cross-sectional area of the honeycomb carrier can be ensured, so that exhaust pressure loss can be reduced.

(4) The honeycomb carrier is configured by joining a plurality of square column shaped segments,
One said R part is formed by cutting one segment, The exhaust gas purification apparatus in any one of (1) to (3) characterized by the above-mentioned.

  According to the exhaust purification apparatus of (4) above, the honeycomb carrier is configured by joining a plurality of square column shaped segments, and further, one R portion is formed by cutting one segment. In a honeycomb carrier configured by joining a plurality of segments, the thermal expansion due to the heat of exhaust gas is particularly large at the joined portions of the segments. For this reason, when the R portion is formed across a plurality of segments, the R portion, and hence the bulge portion formed in the R portion, may break due to thermal expansion. On the other hand, in this invention, the crack of R part and a bulge part by thermal expansion can be prevented by forming one R part in one segment.

(5) In a cross-sectional view parallel to the central axis of the honeycomb carrier, both end faces of the bulge portion are formed on the center side along the central axis from the inflow end face and the outflow end face of the exhaust gas of the honeycomb carrier, respectively. The exhaust emission control device according to any one of (1) to (4).

  According to the exhaust purification device of (5) above, both end faces of the bulge portion are formed on the center side along the central axis from the inflow end face and the outflow end face of the honeycomb carrier. Thereby, both ends of the bulge portion can be covered with the mat while preventing the mat from being applied to the inflow end surface and the outflow end surface of the honeycomb carrier. Therefore, the honeycomb carrier can be effectively held in the case.

  According to the present invention, it is possible to provide an exhaust gas purification apparatus that is excellent in productivity, has stable quality, is compact, and has excellent performance for purifying exhaust gas.

It is a disassembled perspective view which shows the exhaust gas purification apparatus of this invention. FIG. 2 is a perspective view showing a honeycomb carrier of the exhaust emission control device of FIG. 1. FIG. 3 is a cross-sectional view in a direction intersecting with the axis of the honeycomb carrier of FIG. 2. It is a cross-sectional schematic diagram in the direction along the axis of the honeycomb carrier. It is a figure for demonstrating the manufacturing method of a honeycomb support | carrier. It is sectional drawing which shows the honeycomb support | carrier of the other aspect of this invention. It is sectional drawing of the direction which cross | intersects the axis | shaft of the honeycomb support | carrier in an example of the exhaust gas purification apparatus relevant to this invention. FIG. 6 is a cross-sectional view in a direction intersecting with an axis of a honeycomb carrier in another example of the exhaust emission control apparatus related to the present invention.

(Configuration of one embodiment of the present invention)
1, 2 and 3 are views showing an exhaust purification device 1 as an embodiment of the present invention.
FIG. 1 is an exploded perspective view of the exhaust purification device 1, and FIG. 2 is a perspective view of a honeycomb carrier 10 of the exhaust purification device 1.

  The exhaust purification device 1 is an exhaust purification filter called a DPF (Diesel Particulate Filter) that is provided in an exhaust pipe of a diesel internal combustion engine (not shown) and collects exhaust particulates flowing through the exhaust pipe. The exhaust purification device 1 includes a columnar honeycomb carrier 10, a cylindrical case 20 that houses the honeycomb carrier 10, and a mat that is provided between the honeycomb carrier 10 and the case 20 so as to surround the outer periphery of the honeycomb carrier 10. 30.

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. 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 is held in the case 20 by a mat 30 inserted in a compressed state between the outer peripheral surface thereof and the inner surface of the case 20. The case 20 is fitted with a female half 21 that is one half and a male half 22 that is the other half so that the female half 21 is outside the male half 22. Configured.

  The columnar honeycomb carrier 10 has at least one straight portion 111, 112, 113, 114 (four in this example) in which the contour C1 of the cross section S1 intersecting the central axis X forms a straight line, and at other locations. R portions 121, 122, 123, and 124 are included. In the R portions 121, 122, 123, and 124, bulge portions 131, 132, 133, and 134 protruding in the outer diameter direction are formed. On the other hand, the straight portions 111, 112, 113, and 114 are flat.

  FIG. 3 is a cross-sectional view in a direction intersecting with an axis of a portion including a bulge portion of the honeycomb carrier. As shown in FIG. 3, the honeycomb carrier 10 has a contour C1 of a cross section S1 in a rounded rectangular shape, long diameter portions LD1 and LD2 corresponding to both ends in the longitudinal direction LD, and both ends in the short direction SD. Straight portions 111, 112, 113, and 114 are respectively formed in the short diameter portions SD1 and SD2 corresponding to. 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. 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. As a result, when considering a virtual diagonal line connecting the intersections on the extensions of the straight portions 111 and 112 and the straight portions 113 and 114 diagonally, the bulge portions 131, 132, 133, and 134 It is located in a pair on the diagonal. By forming a plurality of straight portions in this way, 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 and the surface pressure is increased. Easy to manage.

FIG. 4 is a schematic diagram of a cross section S2 parallel to the central axis X of the honeycomb carrier 10. In particular, the cross section S2 is a cross section of a portion including the bulge portions 131, 133 (132, 134) and the central axis X described above. In other words, the cross section S2 is a cross section of a part including the central axis X and the virtual diagonal line described above.
As shown in FIG. 4, the cross section S2 parallel to the central axis X of the honeycomb carrier 10 has a substantially square outline C2 and the upper and lower sides of the outline C2 are on the exhaust inflow side and the exhaust outflow side of the honeycomb carrier 10. It corresponds. Moreover, it is a site | part applicable to the outer peripheral surface 11 of the honeycomb support | carrier 10 whose right and left sides of the outline C2 are columnar. The bulge portions 131 and 133 (132 and 134) protrude from portions corresponding to the outer peripheral surface 11.

  As shown in FIG. 4, the bulge portions 131 and 133 (132 and 134) are formed at intermediate positions from the exhaust inflow end surface to the outflow end surface of the honeycomb carrier 10. In other words, both end faces 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 face and the outflow end face of the honeycomb carrier 10, respectively. For this reason, when a mat (not shown in FIG. 4) is wound around the outer peripheral surface 11 of the honeycomb carrier 10, the bulge parts 131, 133 (132, 134) are entirely covered with the mat, including both end faces thereof. Position holding in the case of the carrier is sufficient.

Next, a method for manufacturing the honeycomb carrier 10 as described above will be described with reference to FIG.
FIG. 5 is a view for explaining a method for manufacturing the honeycomb carrier 10.

  First, as shown in (a), a plurality of segments 5 are prepared. The segment 5 is a member constituting a part of the honeycomb carrier 10 and has a large number of cells partitioned by partition walls, and both end faces of the cells are alternately sealed with adjacent end faces and one end face and the other end face. Has been. The segment 5 has a quadrangular prism shape, and its length along the axial direction is equal to the length along the central axis X of the honeycomb carrier 10. The number of segments 5 that can constitute the honeycomb carrier 10 is prepared.

  Next, the bonding material 6 is applied to the segment 5 as shown in FIG.

  Next, as shown in (c), the segments to which the bonding material 6 is applied are joined, and as shown in (e), the block 7 having a size that allows the honeycomb carrier 10 to be formed, that is, the joined segments are formed. As described above, the honeycomb carrier 10 has a rounded rectangular shape in sectional view. Therefore, the block 7 is configured by joining a total of 12 segments 5-1, 5-2,..., 5-12, three vertically and four horizontally as shown in FIG.

  Next, as shown in (e), the honeycomb carrier 10 is completed by performing cutting and skin coating on the block 7.

  As shown in (e), the cutting is performed at four corners of the 12 segments 5-1,..., 5-12 constituting the block 7, that is, four Rs in the honeycomb carrier 10 which is a finished product. This is performed only for the segments 5-1, 5-4, 5-9, and 5-12 that become the parts 121, 122, 123, and 124. That is, with respect to the segments 5-2, 5-3, 5-5, 5-8, 5-10, 5-11 which become the four straight portions 111, 112, 113, 114 in the honeycomb carrier 10 which is a finished product. Does not cut. That is, the straight portions 111,..., 114 having a flat surface in the honeycomb carrier 10 are formed by using the outer wall surface of the block 7 as they are.

  As shown in (e), in the cutting process, among the segments 5-1, 5-4, 5-9, and 5-12, the portions that become the bulge portions 131, 132, 133, and 134 are left in the honeycomb carrier 10. While rounding off the corners. Further, of each of the segments 5-1, 5-4, 5-9, 5-12, the honeycomb carrier 10 is completed by repainting the outer surface of the surface where the inside of the cell is exposed by cutting. To do. That is, in the honeycomb carrier 10, the portions to be the R portions 121, 122, 123, 124 and the bulge portions 131, 132, 133, 134 are the segments 5-1, 5-4, 5-9, 5- 12 is formed by cutting and coating the outer skin.

  Returning to FIG. 1, the mat 30 is wound around the outer peripheral surface 11 of the honeycomb carrier 10 so as to cover the bulge portions 131, 132, 133, and 134. That is, in the mat 30, the bulge portions 131, 132, 133, and 134 are formed around the straight portions 111, 112, 113, and 114 and the R portions 121, 122, 123, and 124 of the honeycomb carrier 10 in the circumferential direction. The outer periphery of the honeycomb carrier 10 is surrounded so as to cover the portion that is formed. The mat 30 is made of ceramic fibers such as alumina fibers, silica fibers, alumina silica fibers, and glass fibers having heat resistance, vibration resistance, sealing function, and vibration absorption capability.

(Operation and effect of one embodiment of the present invention)
Next, the operation and effect of the exhaust emission control device as one embodiment of the present invention described with reference to FIGS. 1 to 4 will be described.

(1) According to the exhaust emission control device 1, bulge portions 131, 132, 133, 134 protruding in the outer diameter direction are formed in the R portions 121, 122, 123, 124 of the honeycomb carrier 10, and the straight portions 111, 112 are formed. , 113 and 114 are flat. In other words, the R parts 121, 122, 123, and 124 have bulge parts 131, 132, 133, and 134, and the straight parts 111, 112, 113, and 114 have no bulge parts. The honeycomb carrier 10 can be made compact while sufficiently securing. The R portions 121, 122, 123, and 124 of the honeycomb carrier 10 have a high surface pressure applied to the mat 30, and the surface pressure can be easily managed as compared with the straight portions 111, 112, 113, and 114. For this reason, it is excellent in productivity and the quality at the time of mass production is stabilized. If a bulge portion is provided on the straight portions 111, 112, 113, 114, it is difficult to align the mat 30 when the mat 30 is wound around the honeycomb carrier 10 and accommodated in the case 20, and thus the surface pressure management is difficult. It may become. On the other hand, in the present invention, the bulge portion is formed only in the R portions 121, 122, 123, and 124, and is not formed in the straight portions 111, 112, 113, and 114, so that alignment can be performed with high accuracy.

(2) According to the exhaust emission control device 1, since the R parts 121, 122, 123, and 124 having the bulge parts 131, 132, 133, and 134 are formed in a plurality of places, the honeycomb carrier 10 can be more securely held by the mat 30. Certainty. Further, since the bulge portions 131, 132, 133, and 134 are positioned on the diagonal lines as described above, the position of the honeycomb carrier 10, that is, the relative position phase with respect to the case 20 can be easily managed.

(3) According to the exhaust gas purification apparatus 1, since the straight portions 111 and 112 and the straight portions 113 and 114 are provided, it is possible to secure a large effective cross-sectional area of the honeycomb carrier 10 and reduce the pressure loss of the exhaust flow.

(4) According to the exhaust emission control device 1, the honeycomb carrier 10 is configured by joining a plurality of square column-shaped segments, and one R portion 121 (122, 123, 124) is formed as one segment 5-1. It is formed by cutting (5-4, 5-12, 5-9). In a honeycomb carrier configured by joining a plurality of segments, the thermal expansion due to the heat of exhaust gas is particularly large at the joined portions of the segments. For this reason, when the R portion is formed across a plurality of segments, the R portion, and hence the bulge portion formed in the R portion, may break due to thermal expansion. On the other hand, in the present invention, one R portion 121 (122, 123, 124) is formed in one segment 5-1 (5-4, 5-12, 5-9), so that the R portion due to thermal expansion. 121 (122, 123, 124) and the bulge part 131 (132, 133, 134) can be prevented from cracking.

(5) According to the exhaust purification device 1, both end surfaces of the bulge portions 131, 133, 132, 134 are formed on the center side along the central axis X from the inflow end surface and the outflow end surface of the honeycomb carrier 10. Thereby, both ends of the bulge portions 131, 133, 132, and 134 can be covered with the mat 30 so that the mat 30 does not cover the inflow end surface and the outflow end surface of the honeycomb carrier 10. Therefore, the honeycomb carrier 10 can be effectively held in the case 20.

(Other aspects of the present invention)
FIG. 6 is a cross-sectional view showing a honeycomb carrier according to another embodiment of the present invention.
The honeycomb carrier 10a in FIG. 6 has a columnar shape, and the central axis X can be considered similarly to the honeycomb carrier 10 in the embodiments of FIGS. A cross section S3 of the honeycomb carrier 10a in FIG. 6 is a cross section in a direction intersecting the central axis X (in this case, a direction orthogonal), and the shape of the contour C3 is different from that in FIG. A case (not shown) that conforms to this shape is also provided for the honeycomb carrier 10a of FIG.
As shown in FIG. 6, the honeycomb carrier 10a has six straight portions 111a, 112a, 113a, 114a, 151, 152 in which the contour C3 of the cross section S3 forms a straight line, and R portions 121a, 123a in other places. Have The straight portions form pairs parallel to each other, and there are three pairs. That is, a pair of straight portions 111a and 112a, a pair of straight portions 113a and 114a, and a pair of straight portions 151 and 152. An R portion 121a is formed between the straight portion 111a and the straight portion 113a, and an R portion 123a is formed between the straight portion 112a and the straight portion 114a. A bulge portion 131a is formed in the R portion 121a, and a bulge portion 133a is formed in the R portion 123a. A mat (not shown in FIG. 6) is provided on the outer peripheral surface of the honeycomb carrier 10a so as to cover the bulge portions 131a and 133a.

  In the embodiment of FIG. 6 as well, since the bulge portions 131a and 133a are present in the R portions 121a and 123a and the bulge portions are not present in the straight portions 111a, 112a, 113a, 114a, 151 and 152, the sectional area of the honeycomb carrier 10a is sufficiently large. In addition, the honeycomb carrier 10a can be made compact. In addition, the surface pressure of the mat wound around the honeycomb carrier 10a is high in the R portions 121a and 123a, and the surface pressure can be easily managed as compared with the straight portions 111a, 112a, 113a, 114a, 151, and 152. For this reason, it is excellent in productivity and the quality at the time of mass production is stabilized.

Also in the embodiment of FIG. 6, the honeycomb carrier 10a is configured by joining a plurality of square pillar-shaped segments 1-1a,..., 1-2a, and one R portion 121a (123a) is formed as one segment 1- It is formed by cutting 1a (1-2a). That is, the R portion 121a is formed in one segment 1-1a, and is not formed across other segments. Similarly, the R portion 123a is formed in one segment 1-2a and is not formed across other segments.
For this reason, the crack of R part 121a (123a) and bulge part 131a (133a) by thermal expansion can be prevented.

  The positions of the bulge portions 131a and 133a in the central axis X direction are the same as those in FIG. Thereby, both ends of the bulge parts 131a and 133a can be covered with the mat while preventing the mat from covering the inflow end surface and the outflow end surface of the honeycomb carrier 10a. For this reason, the honeycomb carrier 10a can be effectively held in the case.

  In the exhaust gas purification apparatus described above, the bulge portions are formed one by one in the central axis X direction. However, the present invention is not limited to this, and a plurality of bulge portions may be formed separately in the central axis X direction. Also in this case, when viewed in a cross section in a direction intersecting the central axis X, it is preferable that the bulge portions are positioned so as to form a pair at the corresponding position on the virtual diagonal line in the cross section.

  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 apparatus of the present invention may be applied to an exhaust purification filter called a GPF (Gasoline Particulate Filter) provided in an exhaust pipe of a gasoline internal combustion engine and collecting exhaust particulates flowing through the exhaust pipe.

(Exhaust gas purification apparatus related to the present invention)
Next, an exhaust emission control device related to the present invention will be described.
FIG. 7 is a cross-sectional view in a direction intersecting with the axis of the honeycomb carrier in an example of the exhaust gas purification apparatus related to the present invention.
The honeycomb carrier 10b shown in FIG. 7 has a columnar shape, and the central axis X can be considered similarly to the honeycomb carrier 10 in the embodiments of FIGS. The cross section S4 of the honeycomb carrier 10b in FIG. 7 is a cross section in the direction intersecting the central axis X (in this case, the direction orthogonal), and the contour C4 is a perfect circle.
A case (not shown) that conforms to this shape is also provided for the honeycomb carrier 10b of FIG.

The honeycomb carrier 10b is configured by joining a plurality of columnar segments including a quadrangular columnar central segment 1-1b located at a core portion including the central axis X at adjacent side surface portions. The honeycomb carrier 10b in the illustrated example has segments 1-2b, 1-3b, 1-4b, 1-5b, 1-6b in order in which the outline C4 of the cross section S4 is rotated clockwise around the center segment 1-1b. , 1-7b, 1-8b, 1-9b are arranged. Of the plurality of segments, the four segments 1-3b, 1-5b, 1-7b, and 1-9b, each of which is in contact with the four side surfaces of the center segment 1-1b, do not have a bulge portion. On the other hand, the four segments 1-2b, 1-4b, 1-6b, and 1-8b other than the four segments 1-3b, 1-5b, 1-7b, and 1-9b described above are bulge portions 131b, 132b, and 133b. , 134b. In other words, segment 1-2b has a bulge 131b, segment 1-4b has a bulge 132b, segment 1-6b has a bulge 133b, and segment 1-8b has a bulge 134b. . That is, the bulge portions 131b, 132b, 133b, and 134b are formed in a single segment 1-2b, 1-4b, 1-6b, and 1-8b, respectively, and are not formed across a plurality of segments. .
On the other hand, the bulge portions 131b, 132b, 133b, 134b are formed at intermediate positions from the exhaust inflow end surface to the outflow end surface of the honeycomb carrier 10b. That is, both end surfaces of the bulge portions 131b, 132b, 133b, and 134b viewed in the direction of the central axis X 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 10b. This is the same as in the case of FIG. 4 described above.

In the honeycomb carrier 10b of FIG. 7, as described above, the bulge portions 131b, 132b, 133b, and 134b are formed into single segments 1-2b, 1-4b, 1-6b, and 1-8b, respectively. That is, each bulge part 131b, 132b, 133b, 134b is not formed over a plurality of segments.
For this reason, the crack of the bulge part 131b, 132b, 133b, 134b by thermal expansion can be prevented.

Further, in the honeycomb carrier 10b of FIG. 7, as described above, both end faces of the bulge portions 131b, 132b, 133b, and 134b viewed in the direction of the central axis X are more central axes than the exhaust inflow end face and the outflow end face of the honeycomb carrier 10b, respectively. It is formed on the center side along X.
For this reason, when the mat is wound around the outer peripheral surface of the honeycomb carrier 10b, the bulge portions 131b, 132b, 133b, and 134b are covered with the entire surface including their both end surfaces by the mat, Position maintenance is perfect.

FIG. 8 is a cross-sectional view in a direction intersecting with the axis of the honeycomb carrier in another example of the exhaust gas purification apparatus related to the present invention.
The honeycomb carrier 10c shown in FIG. 8 has a columnar shape, and the central axis X can be considered similarly to the honeycomb carrier 10 in the embodiments of FIGS. The cross section S5 of the honeycomb carrier 10c in FIG. 8 is a cross section in the direction intersecting the central axis X (in this case, the direction orthogonal thereto), and the outline C5 has a rounded rectangular shape. That is, the contour C5 has straight portions 111c, 112c, 113c, and 114c that are partially linear, and has R portions 121c, 122c, 123c, and 124c at other locations. In the honeycomb carrier 10c of FIG. 8, bulge portions 131c and 132c projecting in the outer diameter direction are formed on the pair of straight portions 111c and 112c, respectively. On the other hand, the other pair of straight portions 113c and 114c are flat.

Focusing on the fact that the cross section S5 of the honeycomb carrier 10c has a rounded rectangular shape, the long diameter portions LD1 and LD2 corresponding to both ends of the longitudinal direction LD and the short diameter portions SD1 and SD2 corresponding to both ends of the short direction SD, Are formed with straight portions 111c, 112c, 113c, and 114c, respectively. The orthogonal arrow lines LD and SD drawn below in FIG. 8 conceptually represent the longitudinal direction and the short direction of the rounded rectangular shape.
A case (not shown) that conforms to this shape is also provided for the honeycomb carrier 10c of FIG.

The honeycomb carrier 10c is formed by joining a plurality of columnar segments including a square columnar center segment 1-1c located at a core portion including the central axis X at adjacent side surface portions. The honeycomb carrier 10c in the illustrated example has segments 1-2c, 1-3c, 1-4c, 1-5c, 1-6c in the order around the contour C5 of the cross section S5 around the center segment 1-1c. 1-7c, 1-8c, 1-9c are arranged. Of these segments, bulge portions 131c and 132c are formed in the segments 1-9c and 1-5c having the pair of straight portions 111c and 112c, respectively. That is, the bulge portions 131c and 132c are formed in single segments 1-5c and 1-9c, respectively, and are not formed across a plurality of segments.
On the other hand, the bulge portions 131c and 132c are formed at intermediate positions from the exhaust inflow side end surface to the outflow side end surface of the honeycomb carrier 10c. That is, both end surfaces of the bulge portions 131c and 132c viewed in the direction of the central axis X are formed on the center side along the central axis X from the inflow end surface and outflow end surface of the exhaust gas of the honeycomb carrier 10c. This is the same as in the case of FIG. 4 described above.

In the honeycomb carrier 10c of FIG. 8, as described above, the bulge portions 131c and 132c are formed into single segments 11-5c and 1-9c, respectively. That is, the bulge portions 131c and 132c are not formed across a plurality of segments.
For this reason, the crack of the bulge parts 131c and 132c by thermal expansion can be prevented.

Further, in the honeycomb carrier 10c of FIG. 8, as described above, both end surfaces of the bulge portions 131c and 132c viewed in the direction of the central axis X are respectively along the central axis X rather than the exhaust inflow end surface and outflow end surface of the honeycomb carrier 10c. It is formed on the center side.
For this reason, when the mat is wound around the outer peripheral surface of the honeycomb carrier 10c, the bulge parts 131c and 132c are entirely covered by the mat including the both end surfaces thereof, and the position of the honeycomb carrier 10c in the case by the mat is sufficiently maintained. It will be everything.
Furthermore, as described above, since the honeycomb carrier 10c has a shape in which the contour C5 of the cross section S5 has a plurality of straight portions, a large cross-sectional area of the honeycomb carrier 10c can be secured, so that the exhaust pressure loss can be reduced.

The technology of the exhaust gas purification device described with reference to FIGS. 1 to 8 can be summarized as follows (Appendix 1).
(Appendix 1)
An exhaust purification device that is provided in an exhaust passage of an internal combustion engine and purifies exhaust of the internal combustion engine,
A columnar honeycomb carrier;
A cylindrical case for storing the honeycomb carrier;
A mat provided so as to surround the outer periphery of the honeycomb carrier between the honeycomb carrier and the case,
The honeycomb carrier is configured as an assembly in which a plurality of columnar segments are joined, and a bulge portion protruding in the outer diameter direction is formed on the peripheral surface thereof,
The bulge portion is formed in a single segment that is a component of the aggregate.

DESCRIPTION OF SYMBOLS 1 ... Exhaust gas purification device 1-1, 1-2, ..., 1-11, 1-12 ... Segment 10 ... Honeycomb carrier 11 ... Outer peripheral surface 20 ... Case 21 ... Female side half 22 ... Male side half 30 ... Mat 111, 112, 113, 114 ... straight part 121, 122, 123, 124 ... R part 131, 132, 133, 134 ... bulge part

Claims (5)

An exhaust purification device that is provided in an exhaust passage of an internal combustion engine and purifies exhaust of the internal combustion engine,
A columnar honeycomb carrier;
A cylindrical case for storing the honeycomb carrier;
A mat provided so as to surround the outer periphery of the honeycomb carrier between the honeycomb carrier and the case,
The honeycomb carrier has at least one straight portion in which the outline of a cross section intersecting the central axis thereof is linear, and has an R portion at the other location,
The R portion is formed with a bulge portion protruding in the outer diameter direction,
The straight portion is flat,
The exhaust purification apparatus according to claim 1, wherein the mat is disposed so as to cover the bulge portion.   The exhaust emission control device according to claim 1, wherein the honeycomb carrier has a plurality of the R portions. The honeycomb carrier has a rounded rectangular shape in a cross-sectional view perpendicular to the central axis,
3. The exhaust gas purification according to claim 1, wherein the straight portion is formed in a long diameter portion corresponding to both ends in the longitudinal direction in the sectional view and a short diameter portion corresponding to both ends in the short direction, respectively. apparatus. The honeycomb carrier is configured by joining a plurality of square column shaped segments,
The exhaust purification device according to any one of claims 1 to 3, wherein one R portion is formed by cutting one segment.   In a cross-sectional view parallel to the central axis of the honeycomb carrier, both end faces of the bulge portion are formed more centrally along the central axis than the exhaust inflow end face and outflow end face of the honeycomb carrier, respectively. The exhaust emission control device according to any one of claims 1 to 4, wherein

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