JP2002233771A - Metal carrier for catalytic converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal carrier for a catalytic converter intended to prevent a honeycomb core part from falling off resulting from brazing the honeycomb core part with a metal outer cylinder. SOLUTION: This metal carrier for a catalytic converter is provided with a honeycomb core part formed of a roll cylinder of multiple alternate layers of a corrugated plate of and a flat plate of a metal sheet having a rolled flat plate of the metal sheet as the outermost layer and a metal outer cylinder surrounding the outer periphery of the honeycomb core part and bonded to the honeycomb core part with a brazing foil material. The honeycomb core part is characterized in that exhaust gas passages are formed by jointing the corrugated plates with the flat plates through diffusion bonding and by jointing the outermost flat plates together through diffusion bonding to form a zone protected from ingress of a brazing material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a metal carrier for a catalytic converter mounted on an exhaust system of an internal combustion engine or the like.

[0002]

2. Description of the Related Art Conventionally, a catalytic converter for purifying exhaust gas is mounted in an exhaust system of an internal combustion engine, and a Fe—Cr—Al ferrite stainless steel foil material (20Cr-5Al-La) is used as a catalyst carrier for this. -A metal carrier made of a thin metal plate such as Fe) is widely used.

This metal carrier is disclosed in, for example,
The one disclosed in Japanese Patent No. 31143 or the like is known.
FIG. 6 shows an example. The metal carrier 1 is as shown in FIG.
As shown in FIG. 1, a honeycomb core portion 2 having an infinite number of exhaust gas passages, and a Ni-low foil material 5 which is pressed into the honeycomb core portion 2 and wound around the exhaust gas outflow side of the honeycomb core portion 2 or the outer periphery of a central portion thereof. The corrugated plate 3 and the flat plate 4 are joined by diffusion bonding, and the honeycomb core portion 5 is joined to the metal outer cylinder 6 by brazing and joining. Have been.

[0004] The metal carrier 1 is manufactured, for example, as follows. First, as shown in FIG. 6 (a), strip-shaped corrugated sheets 3 and flat plates 4 made of a thin metal plate are alternately overlapped, and these are wound in multiple layers to form a honeycomb core portion 2 having a circular cross section or a racing track cross section. To form Next, as shown in FIG. 6 (b), the Ni low foil material 5 is wound around the exhaust gas outflow side of the honeycomb core portion 2 or the outer periphery of the central portion thereof.

[0005] Next, the honeycomb core 2 around which the Ni low foil material 5 is wound is pressed into a metal outer cylinder 6 and heated (heat treated) in a vacuum state. By this heat treatment, the corrugated plate 3 and the flat plate 4 are joined by diffusion bonding, and the honeycomb core portion 5 is joined to the metal outer cylinder 6 by brazing.
Note that the above-mentioned racing track shape is a substantially elliptical shape similar to the track shape in athletics, comprising two opposing linear portions and two opposing semi-circular portions connecting these.

[0006]

However, in the conventional metal carrier 1, when the honeycomb core portion 2 and the metal outer cylinder 6 are brazed, as shown in FIG.
Melts into the corrugated sheet 3 located on the outer peripheral side of the honeycomb core portion 2, and the Ni sheet foil material 5 restrains the corrugated sheet 3. For this reason, when thermal contraction occurs in the metal carrier 1 due to the use of the catalytic converter, there is a difference in thermal expansion between the honeycomb core portion 2 and the metal outer cylinder 6, so that the corrugated plate 3 cannot follow the contraction. The cell 7 formed by the above may be broken.

Further, when vibration such as running vibration is input during use of the catalytic converter, stress concentrates on the end portion 8a of the brazing portion 8 due to a frequency difference between the honeycomb core portion 2 and the metal outer cylinder 6. The flat plate 4 at the outermost periphery of the end 8a may be broken. As a result, as shown in FIG.
There is a possibility that the joint portion between the metal core and the metal outer cylinder 6 disappears in the region indicated by the thick arrow, and the honeycomb core portion 2 falls off.

The present invention has been made in order to solve the conventional problems, and an object of the present invention is to prevent a catalyst from falling off of a honeycomb core portion due to brazing of the honeycomb core portion and a metal outer cylinder. It is an object to provide a metal carrier for a converter.

[0009]

According to the first aspect of the present invention,
A honeycomb core portion formed by alternately stacking corrugated plates and flat plates made of a thin metal plate, winding these multiple times, and further winding the flat plate a plurality of times to form an outermost layer made of the flat plates; And a metal outer cylinder joined to the honeycomb core portion through a low foil material while surrounding the outer periphery of the portion, the honeycomb core portion, the corrugated plate and the flat plate are joined by diffusion bonding, exhaust gas A passage is formed, and the flat plates of the outermost layer are joined by diffusion bonding to form a brazing material non-entry area.

According to a second aspect of the present invention, in the metal carrier for a catalytic converter according to the first aspect, a brazing portion between the honeycomb core portion and the metal outer cylinder is provided with an exhaust gas from an exhaust gas outflow end of the exhaust gas passage. It is characterized by being formed with a predetermined width toward the inflow end. Claim 3
The invention according to claim 1, wherein, in the metal carrier of the catalytic converter according to claim 1, a brazing portion between the honeycomb core portion and the metal outer cylinder is configured such that the brazing portion extends from an exhaust gas outflow end of an exhaust gas passage toward an exhaust gas inflow end. It is characterized by being formed with a predetermined width starting from a position separated from the exhaust gas outflow end.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show a metal carrier A of a catalytic converter according to a first embodiment of the present invention (corresponding to claims 1 and 2). The metal carrier A of the catalytic converter according to the present embodiment has a honeycomb core portion 10 having an infinite number of exhaust gas passages 14 and having a circular cross section or a racing track cross section formed by forming a brazing material non-entry area 15 in the outermost layer. And a metal outer cylinder 20 that is press-fitted with the honeycomb core portion 10 and joined to the honeycomb core portion 10 by a Ni low foil material 17 wound around the outer periphery of the honeycomb core portion 10 on the exhaust gas outflow end portion 10a side. .

The honeycomb core portion 10 is formed by alternately stacking strip-shaped corrugated plates 11 made of a thin metal plate and flat plates 12, winding these multiple times, and further winding the flat plates 12 about 2 to 5 times. Is heated in a vacuum according to a standard method, whereby the corrugated sheet 11 and the flat plate 12 are joined by diffusion bonding to form an exhaust gas passage 14 and the outermost flat plates 12 are joined by diffusion bonding to prevent the brazing material from entering. The region 15 is formed.

On the other hand, the metal outer cylinder 20 is a cylindrical outer cylinder formed of SUS430 ferritic stainless steel. The inner diameter of the metal outer cylinder 20 is smaller than the outer diameter of the honeycomb core portion 10 that is press-fitted therein.

The honeycomb core portion 10 and the metal outer tube 20 are formed in such a manner that the Ni low foil material 17 wound on the outer periphery on the exhaust gas outflow end portion 10a side melts during the above-mentioned heat treatment, and the low material non-entry area. 15 and the inner surface of the metal outer cylinder 20 are brazed to join the portions where the Ni low foil material 17 is wound to be integrated. At the time of this brazing, the molten Ni raw foil material 17 tends to melt in the direction of the corrugated sheet 11 as in the prior art, but is melted by the brazing material non-entry area 15 in which the flat plate 12 is wound about two to five times. Is prevented.

Therefore, the molten Ni low foil material 17 is reliably filled between the honeycomb core portion 10 and the metal outer cylinder 20 and both can be reliably joined. For this reason, in the metal carrier A of the catalytic converter according to the present embodiment, the corrugated plate 11 of the honeycomb core portion 10 follows the contraction in the center direction as shown in FIG. Can be.

Therefore, it is possible to prevent cell breakage caused by heat shrinkage as in the conventional case. When vibration is input during use of the catalytic converter, since the brazing layer is reliably filled between the honeycomb core portion 10 and the metal outer cylinder 20, stress concentrates on the end portion 17a. Also, it is possible to exhibit much higher proof stress than the conventional brazing portion.

FIG. 5 shows a metal carrier B of a catalytic converter according to a second embodiment of the present invention (corresponding to claims 1 and 3). Metal carrier B of catalytic converter according to the present embodiment
Is different from the first embodiment in that the winding position of the Ni low foil material 17 is shifted to the exhaust gas inflow end portion 10b side as compared with the first embodiment.

In the metal carrier B of the catalytic converter according to the present embodiment, the winding position of the Ni low foil material 17 is displaced from the exhaust gas outflow end 10a to the exhaust gas inflow end 10b. If there is a vibration input during the use of, the locations where the stress is concentrated are located at both ends 17c and 17c.
d, and the generated stress can be reduced.

Other functions and effects are the same as those of the first embodiment. In each of the above embodiments, the honeycomb core 1
Although the flat plate 12 forming the 0 is a flat band-shaped thin metal plate, the flat plate 12 may be a flat plate with ripples whose crest height is sufficiently smaller than the corrugated plate 11. Since the winding width of the raw foil material 17 is determined by the bonding strength between the honeycomb core portion 10 and the metal outer cylinder 20, it is appropriately determined according to the size of the metal carrier 17, the operating temperature conditions, and the like.

[0020]

As described above, according to the metal carrier of the catalytic converter according to the first and second aspects of the present invention, the non-penetrating region of the brazing material made of a flat wound layer is formed on the outermost layer of the honeycomb core. Therefore, when the honeycomb core portion and the metal outer cylinder are integrated by heat treatment, the brazing material does not melt into the honeycomb core portion side, and cracks in the brazing portion can be prevented.

According to the metal carrier of the catalytic converter according to the first and third aspects, in addition to the effect of the metal carrier of the catalytic converter according to the first and second aspects, the brazing position moves to the exhaust gas inflow end side. In addition, there are two concentrated portions of the thermal stress, and the thermal stress can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a metal carrier of a catalytic converter according to a first embodiment of the present invention.

FIG. 2 is a front view of a metal carrier of the catalytic converter of FIG.

FIG. 3 is an enlarged front view of a metal carrier of the catalytic converter of FIG. 1;

FIG. 4 is an enlarged sectional view of a metal carrier of the catalytic converter of FIG.

FIG. 5 is a perspective view showing a metal carrier of a catalytic converter according to a second embodiment of the present invention.

FIG. 6 is a perspective view showing a manufacturing process of a metal carrier of a conventional catalytic converter.

FIG. 7 is an enlarged front view of the metal carrier of the conventional catalytic converter of FIG.

FIG. 8 is an enlarged sectional view of a metal carrier of the conventional catalytic converter of FIG.

[Explanation of symbols]

 A, B Metal carrier of catalytic converter 10 Honeycomb core 10a Exhaust gas outflow end 10b Exhaust gas inflow end 11 Corrugated plate 12 Flat plate 14 Exhaust gas passage 15 Low material non-entry area 17 Low foil material 7-1 Low material 20 Metal outer Pipe

. Of the front page Continued (51) Int.Cl ⁷ identification mark FI theme Court Bu (Reference) F01N 3/28 301 F01N 3/28 301U B23K 101: 02 // B23K 101: 02 B01D 53/36 ZABC F -term (reference) 3G091 BA21 BA39 GA08 GA12 GB01X HA31 4D048 BB02 CA08 4E067 BA00 DA17 DB01 DC04 EA07 EB00 EC09 4G069 AA01 AA08 BA17 CA03 DA05 EA21 EA24 FB66

Claims (3)

[Claims] 1. A honeycomb core portion formed by alternately stacking corrugated plates made of a thin metal plate and flat plates, winding these multiple times, and further winding the flat plates a plurality of times to form an outermost layer made of the flat plates. And a metal outer cylinder surrounding the outer periphery of the honeycomb core portion and joined to the honeycomb core portion via a low foil material, wherein the honeycomb core portion is formed by diffusion bonding of the corrugated plate and the flat plate. A metal carrier of the catalytic converter, wherein the flat plates of the outermost layer are bonded by diffusion bonding to form a non-penetrating region of the brazing material. 2. The metal carrier of the catalytic converter according to claim 1, wherein a portion where the honeycomb core portion and the metal outer cylinder are brazed from an exhaust gas outflow end of the exhaust gas passage toward an exhaust gas inflow end. A metal carrier for a catalytic converter, which is formed with a predetermined width. 3. The metal carrier of a catalytic converter according to claim 1, wherein a portion where the honeycomb core portion and the metal outer cylinder are brazed is arranged such that a portion from an exhaust gas outflow end to an exhaust gas inflow end of an exhaust gas passage. A metal carrier for a catalytic converter, which is formed with a predetermined width starting from a position separated from an exhaust gas outflow end.