JP2012005954A - Structure for holding support for use in cleaning exhaust - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for holding a support for use in cleaning exhaust, capable of improving the holding force of a support for use in cleaning exhaust.SOLUTION: There is disclosed a catalytic converter 1 that holds a column-shaped support 11 in a roughly cylindrical case 15 via a holder 13, which cylindrical case 15 is formed by jointing a pair of roughly half-cylindrical divided cases. The support 11 includes a pair of convex members 115, 115 each disposed on its outer circumferential face at symmetrical positions respectively, relative to the center axis X thereof to extend in the axial direction. The case 15 is formed by jointing a pair of divided cases with the vicinity of the joints protruding outward and includes a pair of protrusions 155, 155 having a width greater than that of the convex members 115, 115 and extending in the axial direction. The support 11 is held in the case 15 with the convex members 115, 115 each kept in a state of being pressed in the pair of corresponding protrusions 155, 155 respectively, via the holder 13.

Description

  The present invention relates to an exhaust purification support holding structure. More specifically, the present invention relates to a structure for holding an exhaust purification carrier used in a catalytic converter or an exhaust purification filter.

  Conventionally, in an exhaust system of an internal combustion engine, a catalytic converter and an exhaust purification filter for purifying exhaust are arranged. These catalytic converters and exhaust purification filters include an exhaust purification support and a case that accommodates and holds the exhaust purification support.

  For example, a catalytic converter is disclosed in which an exhaust purification carrier having a honeycomb structure is held via a holding material in a cylindrical case formed by joining a pair of semi-cylindrical divided cases. In this catalytic converter, the exhaust purification carrier is held in the case while being covered with the holding material.

No. 5-7454

  By the way, when the exhaust purification carrier is enlarged, or when the exhaust purification carrier is formed of a material having a high density such as SiC, the holding power of the exhaust purification carrier in the case is insufficient. A holding structure capable of improving the force is desired.

  The present invention has been made in view of the above, and an object thereof is to provide an exhaust purification carrier holding structure capable of improving the holding power of the exhaust purification carrier.

  In order to achieve the above object, in the present invention, a substantially cylindrical case (for example, described later) formed by joining a pair of substantially semi-cylindrical divided cases (for example, a first divided case 151 and a second divided case 152 to be described later). In the case 15), an exhaust purification carrier holding structure (for example, described later) that holds a columnar exhaust purification carrier (for example, later described carrier 11) via a retaining material (for example, a later described holding material 13). A catalytic converter 1) is provided. In the exhaust purification carrier holding structure, the exhaust purification carrier has a pair of protrusions extending along the axial direction on the outer circumferential surface thereof at positions symmetrical to a central axis (for example, a central axis X described later). And the case is formed by joining the pair of split cases projecting outward in the vicinity of the joint and larger than the width of the convex. With a pair of protrusions (e.g., protrusions 155 and 155 described later) extending in the axial direction with a width, in the state where the protrusions are sandwiched between the pair of protrusions via the holding material, The exhaust purification carrier is held in the case.

In the present invention, on the outer peripheral surface of the exhaust purification carrier, a pair of projecting portions extending along the axial direction are provided at positions symmetrical with respect to the central axis, and a pair of divided cases projecting outward in the vicinity of the joint portion As a result, a pair of protrusions extending in the axial direction with a width larger than the width of the protrusions was provided on the case. Further, the exhaust purifying carrier is held in the case in a state where the protruding portion is clamped via the holding member in the protruding portion.
As a result, the exhaust purification carrier can be held in the case in a state where the protruding portion formed by joining the divided cases strongly clamps the convex portion having high rigidity. Therefore, according to the present invention, the holding power of the exhaust gas purification carrier can be improved as compared with the prior art.

  In this case, it is preferable that the pair of projecting portions is provided only in a portion where the exhaust gas purification carrier is held in the axial direction of the case.

In the present invention, the protruding portion is provided only in the portion where the exhaust purification carrier is held in the axial direction of the case.
Thereby, it can avoid that exhaust flows into the upstream end part of the axial direction of the holding material which covers a convex part directly. For this reason, it can suppress that a particulate matter etc. accumulate in such an upstream side edge part, or a holding material is eroded, and can suppress the fall of the retention strength of the support | carrier for exhaust gas purification.

  ADVANTAGE OF THE INVENTION According to this invention, the holding structure of the exhaust gas purification carrier which can improve the retention strength of the exhaust gas purification carrier can be provided.

It is a perspective view which shows the structure of the catalytic converter which concerns on one Embodiment of this invention. It is the sectional view on the AA line of FIG. It is a figure for demonstrating the manufacturing method of the catalytic converter which concerns on the said embodiment, (a) is a cross-sectional view of the honeycomb structure used for formation of a support | carrier, (b) is a cross-sectional view of a support | carrier, (C) is a cross-sectional view when the outer peripheral surface of the carrier is covered with a holding material, (d) is a cross-sectional view showing a state when the carrier is accommodated in the case via the holding material, ( e) is a cross-sectional view of a catalytic converter completed by joining divided cases. It is a partial expanded sectional view of the catalytic converter which concerns on the modification 1 of the said embodiment. It is a partial expanded sectional view of the catalytic converter which concerns on the modification 2 of the said embodiment. It is a partial expanded sectional view of the catalytic converter which concerns on the modification 3 of the said embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view showing a configuration of a catalytic converter 1 to which an exhaust purification carrier holding structure according to the present invention is applied. 2 is a cross-sectional view taken along line AA perpendicular to the central axis X of the catalytic converter 1 shown in FIG. The catalytic converter 1 is a device that is disposed in the middle of an exhaust pipe 9 of an internal combustion engine (not shown) and purifies exhaust gas discharged from the internal combustion engine.

As shown in FIG. 1, the catalytic converter 1 includes a carrier 11, a holding material 13, and a case 15. An exhaust introduction cone 17 that expands from the upstream side to the downstream side is connected to the upstream end portion of the case 15, and the downstream end portion of the case 15 is contracted from the upstream side to the downstream side. A radiating exhaust outlet cone 19 is connected.
The catalytic converter 1 of the present embodiment is a horizontal type catalytic converter that holds the carrier 11 along the horizontal direction, but may be a vertical type catalytic converter that holds the carrier 11 along the vertical direction. .

  As shown in FIG. 2, the carrier 11 includes a cylindrical honeycomb structure 111 and an outer skin 113 provided so as to cover the outer periphery of the honeycomb structure 111. The honeycomb structure 111 is not limited to a cylindrical shape, and may be elliptical.

  The honeycomb structure 111 includes a plurality of substantially square cells. The honeycomb structure 111 is formed by joining the side surfaces of a plurality of columnar segments each having a plurality of cells formed therein to form a cylindrical aggregate. Alternatively, it is formed by integral molding such as extrusion molding.

  The outer skin 113 has a pair of convex portions 115 and 115 on its outer peripheral surface. The pair of convex portions 115 and 115 are provided at positions symmetrical with respect to the central axis X so as to extend along the axial direction.

As shown in FIG. 2, the height H of the pair of convex portions 115 and 115 is substantially the same, and is preferably 1 to 20% of the diameter of the honeycomb structure 111. Moreover, the dimension of the width W of a pair of convex parts 115 and 115 is substantially the same, and it is preferable that it is 3.5 to 30% of the diameter of the honeycomb structure 111. FIG. In addition, when the cross section perpendicular | vertical to the axial direction of the honeycomb structure 111 is elliptical, the short axis of an ellipse is made into a reference | standard.
In addition, the length in the axial direction of the pair of convex portions 115 and 115 is substantially the same, and is preferably 30 to 90% of the length in the axial direction of the honeycomb structure 111.

  When the heights H, widths W, and lengths of the projections 115, 115 are smaller than the above ranges, the projections 115, 115 are too small, resulting in an improvement in the holding force of the carrier 11. I can't. On the other hand, when each of the above dimensions is larger than the above range, as a result of the protrusions 115 and 115 being too large, the holding material 13 cannot be wound well around the outer periphery of the carrier 11, and the dimensions of the catalytic converter 1. This will cause problems in the layout of the exhaust system.

  The honeycomb structure 111 and the outer skin 113 constituting the support 11 are one or two selected from the group consisting of alumina, mullite, lithium aluminum silicate, silicon carbide (SiC), silicon nitride, alumina titanate (AT), and cordierite. It is preferable to be composed of more than one kind of material. The honeycomb structure 111 and the outer skin 113 may be made of the same material or different materials.

  The outer skin 113 is formed by installing a molding die on the outer periphery of the honeycomb structure 111 and filling the gaps between the honeycomb structure 111 and the molding die with the materials listed above that constitute the outer skin 113. Alternatively, it is formed by simultaneously extruding the honeycomb structure 111 and the outer skin 113.

  The carrier 11 carries a predetermined amount of various exhaust purification catalysts such as a conventionally known three-way catalyst, oxidation catalyst, NOx purification catalyst and the like. As the exhaust gas flows through the carrier 11 on which these exhaust purification catalysts are supported, HC, CO, NOx, etc. contained in the exhaust gas are purified.

  The method for supporting the exhaust purification catalyst on the carrier 11 is not particularly limited, and a conventionally known washcoat method or the like is employed. Specifically, a slurry containing the constituent material of the exhaust purification catalyst is prepared, the carrier 11 is immersed in this slurry, and then pulled up and dried, whereby the exhaust purification catalyst is supported on the carrier 11.

Returning to FIG. 1, the holding member 13 is wound around the outer periphery of the carrier 11 so as to cover the entire outer periphery of the carrier 11. The holding material 13 is provided only at the central portion of the carrier 11 in the axial direction, and the holding material 13 is not provided at the upstream end and the downstream end of the carrier 11 in the axial direction.
The holding member 13 is accommodated in the case 15 in a compressed state by a gap between the outer peripheral surface of the carrier 11 and the inner peripheral surface of the case 15, thereby holding the carrier 11 in the case 15.

  The holding material 13 is composed of one or more materials selected from the group consisting of metal wire materials such as SUS, glass fibers, alumina fibers, carbon fibers, and polyamide fibers.

In addition, it is preferable to put a polygonal line along the outer shape of the carrier 11 in the holding material 13 in advance. Thereby, when the holding material 13 is wound around the outer periphery of the carrier 11, the holding material 13 can be fitted to the outer peripheral surface of the carrier 11. Specifically, the holding material 13 can be wound following the outer shape of the carrier 11 by making a broken line corresponding to the shape of the pair of convex portions 115, 115 provided on the outer peripheral surface of the carrier 11. .
Further, when the holding material 13 is wound around the carrier 11, it is preferable that both end portions of the holding material 13 in the axial direction are fixed with a tape or the like in order to prevent the displacement of the holding material 13.

  As shown in FIGS. 1 and 2, the case 15 is a substantially cylindrical case formed by joining a pair of substantially semi-cylindrical divided cases. More specifically, the case 15 of the present embodiment includes the first divided case 151 and the second divided case 152 that are divided into two on a plane that includes the central axis X and that passes through protrusions 155 and 155 described later. Formed with.

As shown in FIG. 1, the case 15 has a pair of projecting portions 155 and 155 extending along the axial direction with a width larger than the width of the convex portions 115 and 115. The pair of projecting portions 155 and 155 are provided only in a portion where the carrier 11 is held in the axial direction of the case 15.
The pair of projecting portions 155 and 155 are formed by joining the first divided case 151 and the second divided case 152 formed so that the vicinity of the joint portion projects outward.

  The pair of protrusions 155 and 155 are provided corresponding to the shape and position of the pair of protrusions 115 and 115 formed on the outer peripheral surface of the carrier 11. The carrier 11 is held in the case 15 in a state where the projecting portions 115 and 115 are sandwiched between the projecting portions 155 and 155 via the holding material 13.

  The first divided case 151 and the second divided case 152 constituting the case 15 are made of the same material, specifically, a material such as SUS or Ni—Cr alloy. For this reason, joining of the 1st division | segmentation case 151 and the 2nd division | segmentation case 152 is performed by welding. Specifically, the joint portion 157 between the first split case 151 and the second split case 152 is formed by butt welding the flanges 159 and 159 provided at the joint portion of both split cases.

Next, a method for manufacturing the catalytic converter 1 according to this embodiment will be described.
First, as shown in FIG. 3A, a honeycomb structure 111 used for forming the carrier 11 is prepared. The honeycomb structure 111 is formed by joining the side surfaces of a plurality of columnar segments each having a plurality of cells formed therein to form a cylindrical aggregate.

  Next, as shown in FIG. 3B, the carrier 11 is formed which covers the outer peripheral surface of the honeycomb structure 111 and is provided with an outer skin 113 having a pair of convex portions 115 and 115 on the outer periphery. Specifically, a forming die is placed on the outer periphery of the honeycomb structure 111, and a material constituting the outer skin 113 is filled in a gap between the honeycomb structure 111 and the forming die.

  Next, as shown in FIG. 3C, the holding material 13 is wound so as to cover the outer peripheral surface of the carrier 11. At this time, the holding material 13 is wound so that the holding material 13 fits the outer surface of the carrier 11 by following the shape of the convex portions 115 and 115 of the carrier 11 while pressing the holding material 13.

  Next, as shown in FIG. 3D, the carrier 11 having the holding material 13 wound around the outer peripheral surface is sandwiched between the first divided case 151 and the second divided case 152, so that the carrier 11 is placed in the case 15. Housed inside. At this time, the outwardly projecting portion provided in the vicinity of the joint between the first split case 151 and the second split case 152 (the portion forming the pair of projecting portions 155 and 155 by the joint) is the convex portion of the carrier 11. The opposing flanges 159 and 159 of the two divided cases are brought into contact with each other so that the positions 115 and 115 are located.

  Finally, as shown in FIG. 3E, the case 15 is formed by welding the first divided case 151 and the second divided case 152 with the flanges 159 and 159 butt-welded to each other. As a result, the catalytic converter 1 in which the carrier 11 is held in the case 15 is manufactured in a state where the protrusions 115 and 115 of the carrier 11 are strongly clamped via the holding material 13 at the pair of protrusions 155 and 155. Is done.

The catalytic converter 1 according to this embodiment has the following effects.
In the present embodiment, a pair of convex portions 115, 115 extending along the axial direction are provided on the outer peripheral surface of the carrier 11 at positions symmetrical with respect to the central axis X. In addition, by joining the pair of first divided case 151 and second divided case 152 that protrude outward in the vicinity of the joint portion, a pair of portions extending along the axial direction with a width larger than the width of the convex portions 115 and 115. The protrusions 155 and 155 are provided on the case 15. Further, the carrier 11 is held in the case 15 with the protrusions 155 and 155 sandwiching the convex portions 115 and 115 via the holding member 13.
As a result, in the protruding portions 155 and 155 formed by joining the first divided case 151 and the second divided case 152, the carrier 11 is placed in the case 15 in a state where the convex portions 115 and 115 having high rigidity are strongly clamped. Can be kept inside. Therefore, according to the present embodiment, the holding force of the carrier 11 can be improved as compared with the conventional case.

In the present embodiment, the projecting portions 155 and 155 are provided only in the portion where the carrier 11 is held in the axial direction of the case 15.
Thereby, it is possible to avoid the exhaust directly flowing into the upstream end portion in the axial direction of the holding member 13 covering the convex portions 115 and 115. For this reason, it can suppress that the particulate matter etc. in exhaust_gas | exhaustion accumulate in such an upstream side edge part, or the holding material 13 is eroded, and can suppress the fall of the holding power of the support | carrier 11.

[Modification 1]
FIG. 4 is a partially enlarged cross-sectional view of the catalytic converter 2 according to the first modification of the embodiment. As shown in FIG. 4, the catalytic converter 2 according to the modified example 1 changes the shape of the convex portion 215 to a substantially isosceles trapezoidal shape in a cross-sectional view, and changes the shape of the protruding portion 255 and the like accordingly. Except for this, the configuration is the same as that of the above embodiment.
According to the first modification, the same effects as those of the above embodiment are achieved.

[Modification 2]
FIG. 5 is a partially enlarged cross-sectional view of the catalytic converter 3 according to Modification 2 of the above embodiment. As shown in FIG. 5, the catalytic converter 3 according to the modified example 2 except that the shape of the convex portion 315 is changed to a semicircular shape in a cross-sectional view, and the shape of the protruding portion 355 is changed accordingly. The configuration is the same as in the above embodiment.
According to the second modification, the same effect as in the above embodiment can be obtained.

[Modification 3]
FIG. 6 is a partially enlarged cross-sectional view of the catalytic converter 4 according to Modification 3 of the above embodiment. As shown in FIG. 6, the catalytic converter 4 according to the modified example 3 has the protruding portion 455 formed by joining the ends of the first divided case 451 and the second divided case 452 in a state of being overlapped with each other. Except for this, the configuration is the same as that of the above embodiment.
According to the third modification, in addition to the same effects as the above embodiment, the clamping pressure of the convex portion 415 is adjusted by adjusting the wrapping degree of the end portions of the first divided case 451 and the second divided case 452. Since the load can be adjusted, the holding force of the carrier can be freely adjusted. Further, since a flange extending outward from the protruding portion 455 is not necessary, space saving is possible.

It should be noted that the present invention is not limited to the above-described embodiment, and modifications and improvements within the scope that can achieve the object of the present invention are included in the present invention.
In the above embodiment, an example in which the structure for holding an exhaust gas purification carrier according to the present invention is applied to a catalytic converter has been described. However, the present invention is not limited to this. For example, the present invention can be applied to a DPF as an exhaust purification filter.

1, 2, 3, 4 ... catalytic converter (exhaust purification carrier holding structure)
11 ... Carrier (exhaust purification carrier)
DESCRIPTION OF SYMBOLS 13 ... Holding material 15, 25, 35, 45 ... Case 111 ... Honeycomb structure 113 ... Outer skin 115,215,315,415 ... convex part 151,251,351,451 ... 1st division | segmentation case (a pair of division | segmentation case)
152,252,352,452 ... 2nd division case (a pair of division cases)
155, 255, 355, 455 ... projecting portion

Claims (2)

An exhaust purification carrier holding structure for holding a columnar exhaust purification carrier via a holding material in a substantially cylindrical case formed by joining a pair of substantially semi-cylindrical divided cases,
The exhaust purification carrier has a pair of convex portions extending along the axial direction at a position symmetric with respect to the central axis on the outer peripheral surface thereof.
The case has a pair of projecting portions formed by joining the pair of split cases whose joint portions protrude outwardly and extending along the axial direction with a width larger than the width of the convex portion,
A structure for holding an exhaust gas purification carrier, wherein the exhaust gas purification carrier is held in the case in a state where the convex portion is sandwiched between the pair of protrusions via the holding material.   2. The structure for holding an exhaust purification carrier according to claim 1, wherein the pair of protrusions are provided only in a portion where the exhaust purification support is held in the axial direction of the case.

Images