JPH02126942A - Metallic carrier base for carrying exhaust gas purifying catalyst - Google Patents

Abstract

PURPOSE:To prevent the release of the component member of a honeycomb core from the metallic case by sticking the core to the case by a brazing material held in the groove provided on the inner wall surface of the case. CONSTITUTION:The flat band material 3 of a thin metallic sheet and a corrugated band material 4 are laminated on one another so that both materials are closely attached to each other. The laminate is formed spirally or stepwise to produce the honeycomb core 2 having many reticular air-passage holes 5 in its axial direction. The core 2 is fixed in the cylindrical case 6. The core 2 is stuck to the case 6 by the brazing material 8 held in the groove 7 provided on the inner wall surface of the case 6. As a result, the release of the component member of the core from the case is prevented, and exhaust gas can be sufficiently purified.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention is directed to a method for supporting an exhaust gas purifying catalyst that is generally inserted in the middle of an exhaust pipe as a means for purifying automobile exhaust gas. The present invention relates to a metal supporting matrix.

More specifically, it relates to a metal support base for supporting an exhaust gas purification catalyst that has improved bonding strength between each constituent member of the metal support base and can withstand peeling between members due to thermal distortion, etc. It is.

(Prior Art) Conventionally, a metal support base for supporting this type of exhaust gas purification catalyst has been designed to increase the support surface area per unit volume, that is, to increase the support surface area per unit volume, that is, to In order to maximize the effective contact area with the oil converting catalyst and to reduce the weight of the metal carrier as much as possible, thin flat metal strips and corrugated metal strips are used. A structure in which the material and the material are layered in a Wi layer, or a structure in which both of these materials are wound and laminated together (hereinafter referred to as a honeycomb core body because they have a honeycomb-like structure) Are known.

For example, a flat strip made of a heat-resistant thin steel plate of 0.1 m/m or less and a corrugated strip made by forming the thin steel plate flat strip into a corrugated shape are connected to each other at the abutting portions. The honeycomb core body is stacked so as to have a plurality of gases, and is wound in a spiral shape to form a honeycomb core body having a large number of mesh-like vent passages for exhaust gas passages in the axial direction. The wound and laminated honeycomb core body is housed in a cylindrical metal case with both ends open, and is bonded to each other to form a vibration-resistant structure. That is, the abutting portions between the flat metal strip and the corrugated metal strip constituting the honeycomb core body and the abutting portions between the honeycomb core body and the metal case are joined by welding, brazing, or the like.

As these joining means, we pay particular attention to the joining means of the abutting portion between the honeycomb core body and the metal case. (1) JP-A-54-13482, JP-A-57-158
Electron beam welding, as disclosed in No. 5 and others.

By laser beam welding, arc welding, etc.

(ii) After loading the honeycomb core body into a metal case, as disclosed in Japanese Patent Application Laid-open No. 199574/1983,
Various methods have been proposed, such as applying brazing filler metal to areas near the ends of these composites by coating, spraying, etc., and brazing them by heat treatment.

(Problems to be Solved by the Invention) However, the conventional bonding method described above has the following manufacturing and quality problems.

In the above-mentioned joining means (i) such as electron beam welding or laser beam welding, special and expensive equipment must be used.

In addition, in the joining means that applies and sprays a brazing material to the open end of the metal case after the (eye) honeycomb core body is loaded into the metal case, the work of applying the brazing material is complicated. There is a problem in the bonding strength of the central part of the metal case among the abutting surfaces of the cam core body and the metal case.

Generally, this type of metal carrier is used in a harsh thermal environment, and therefore is required to have sufficient durability against damage, cracking, or peeling between component members. That is, -20 found in automobile exhaust gas systems.
Under severe cooling/heating cycles (heat alternating loads) of ℃ to ÷ 800℃, component members undergo strain (hereinafter referred to as "thermal strain") due to large thermal expansion (volume expansion, linear expansion), etc. Vibration from the vehicle body is also added, causing separation (separation) between component parts, damage to component parts, and cracks (cracks).

In particular, if different metal materials are used for the metal case in consideration of oxidation resistance and for the honeycomb core body in consideration of heat resistance (for example, austenitic stainless steel is used for the former and ferritic stainless steel for the latter). ),
Due to the difference in thermal expansion, the separation of the two becomes more rapid. When separation occurs in a small region of the joint surface between the metal case and the honeycomb core body, it expands one after another. In addition, vibrations from the car body are applied at the same time as the body is separated, which can cause peeling of the joints between the flat strip and corrugated strip, which are the constituent members of the honeycomb core body, and cracks and damage to these members. .

Therefore, in this type of metal support base, the contact surfaces between the inner wall surface of the metal case and the outer peripheral surface of the honeycomb core body must be reliably joined with sufficient strength, but as described above, effective joining methods are required. The current situation is that there is no.

The purpose of the present invention is to prevent separation (peeling) between the constituent members of the metal supporting body, that is, the cylindrical metal case and the honeycomb core body, over a long period of time, and to exhibit a sufficient exhaust gas purification function. do. An object of the present invention is to provide a metal support base for supporting an exhaust gas purifying catalyst.

[Structure of the invention]

(Means for Solving the Problems) To summarize the present invention, the present invention involves superimposing a flat strip and a corrugated strip of a thin metal plate so that they are in contact with each other, and forming a spiral or N A metal supporting body for supporting an exhaust gas purification catalyst, which is formed by fixing a honeycomb core body formed in layers and having a large number of mesh-like ventilation holes in the axial direction in a cylindrical metal case, For supporting an exhaust gas purifying catalyst, wherein the honeycomb core body is fixed to the cylindrical metal case by a brazing filler metal held in a brazing filler metal holding groove provided on an inner wall surface of the cylindrical metal case. The present invention relates to a metal supporting matrix.

Hereinafter, the configuration of the present invention will be explained in detail.

As described above, the present invention is characterized in that it improves the bonding strength between the constituent members of the metal supporting body, particularly the bonding strength between the inner wall surface of the cylindrical metal case, the outer peripheral surface of the henicum core body, and the entire contact surface. It is something that you have.

Furthermore, the present invention is characterized in that the bonding strength with the outer circumferential surface of the honeycomb core body is made sufficient, particularly in the central region of the inner wall surface of the cylindrical metal case and in the vicinity thereof.

Means for improving the bonding strength between the honeycomb core body and the cylindrical metal case will be explained based on the drawings.

FIGS. 1 and 2 are side views of a metal supporting body (1, 1') for supporting the exhaust gas purifying catalyst of the present invention. The honeycomb core body (2) in Fig. 1 is made by winding a flat metal strip (3) and a corrugated metal strip (4) in a spiral shape. The body (2') is composed of a flat metal strip (3') and a corrugated metal strip (4') layered in layers. The honeycomb core body (2,
2') is loaded into a cylindrical metal case (s, e') as shown in Figs. 1 and 2, and the honeycomb core body and the metal case are firmly fixed in the manner described later. . In addition, flat strip material (3, 3') and corrugated strip material (4, 4')
), a large number of mesh-like vent passages (5, 5') are formed in the axial direction by the winding or layered stacking.

In the present invention, as a means for improving the bonding strength of the honeycomb core body (2) and the H-shaped metal case (6), the inner wall surface of the cylindrical metal case is entirely covered or except for the areas near the openings at both ends thereof. A brazing material retaining groove (7) is provided in a portion (such as the center and a portion near the center).

The brazing material holding groove (7) is connected to the cylindrical metal case (8, 8'
) is formed in various forms as shown in FIGS. 3 to 15, but the present invention is not limited to what is shown in the drawings. From the viewpoint of improving the bonding strength, for example, when the brazing material holding groove is linear (straight or curved), the width is 0.
2 to 1.0 mm and a depth of 0.2 to 0.5 mm are sufficient, but are not limited thereto. In the present invention, the brazing material retaining groove (7) is provided by drilling a concave groove in the inner wall surface of the metal case (6) or by processing the wall of the metal case (6) to form concave and convex portions (plastic processing). It is fine, and there are no particular restrictions.

FIG. 3 is a longitudinal sectional view of the cylindrical metal case (6) of the present invention. The brazing metal holding tXII (7) is a cylindrical metal case (8
) are provided on the inner wall surface of the shaft in a direction perpendicular to the axial direction thereof and at desired intervals.

Note that FIG. 3 shows a state in which the brazing wire (8) is held in the brazing material holding groove (7).

FIG. 4 is a longitudinal sectional view of the metal case (6) in which the brazing material retaining groove (7) is formed in the second manner, and FIG. 5 is a plan view thereof.

As shown in FIGS. 4 and 5, the brazing metal holding vll(
7) are provided on the inner wall surface of the metal case (6) parallel to its axial direction and at desired intervals over the entire length.

FIG. 6 is a longitudinal sectional view of a metal case (6) in which a brazing material holding groove (7) is formed in a third manner.

As shown in FIG. 6, the brazing material holding groove (7) is a portion between the inner wall surfaces of the metal case (6), which is formed by plastic working, that is, by roughening the wall of the metal case (6).

Figure 7 shows the brazing metal holding til! (7) is a plan view of the metal case (6) formed in the fourth embodiment. The one shown in Fig. 7 is a modification of the one shown in Figs. 4 and 5, in which the brazing material holding groove (7) is formed in the axial direction of the metal case (6) by the uneven machining of the wall of the metal case (6). It is formed over the entire length.

FIGS. 8 to 11 are related views of the metal case (6) in which the brazing material holding* (7) is formed in the fifth embodiment.

8 is a longitudinal sectional view of the metal case (8), FIG. 9 is a front view, FIG. 1O is a sectional view taken along line A--A in FIG. 9, and FIG. 11 is a plan view. The metal case (6
) is characterized in that the brazing material retaining groove (7) is not provided over the entire length of the metal case in the axial direction, unlike those shown in FIGS. Configuring the brazing metal holding @ (7) in this way has the advantage that the brazing metal will not flow out of the metal support base (1) after the metal case (6) and honeycomb core body (2) are soldered together. This provides strong joint strength over a long period of time.

FIG. 12 is a longitudinal cross-sectional view of the metal case (6) in which the brazing material holding groove (7) is formed in the sixth embodiment, and the brazing material holding groove (7) is arranged in a desired direction in the axial direction of the metal case. It is provided in a curved shape that is discontinuous at an angle.

FIG. 13 is a longitudinal cross-sectional view of the metal case (8) in which the brazing material holding groove (7) is formed in the seventh embodiment, and the brazing material holding groove (7) is formed in the desired direction in the axial direction of the metal case. It is provided in a continuous curved shape with an angle of .

FIG. 14 is a longitudinal cross-sectional view of the metal case (8) in which the brazing material holding grooves (7) are formed in a manner similar to that shown in FIG. provided.

FIG. 15 is a sectional view of a part of the metal case (6) in which the brazing material holding groove (7) is formed in the ninth embodiment, and the brazing material holding groove (7) is provided in a block shape.

In order to manufacture the metal support base for supporting the exhaust gas purification catalyst of the present invention, the metal case (
For example, as shown in FIG. 3, a brazing wire (8) is buried in the brazing material holding groove (7) formed on the inner wall surface of the wire (6). In order to hold the brazing material in the brazing material holding groove (7), in addition to the wire, molten brazing material may be cooled and solidified in the brazing material holding groove, or a paste containing brazing material powder may be dried. In the present invention, the brazing filler metal used is preferably a high-temperature brazing filler metal, for example, a Ni-based brazing filler metal, in view of the usage conditions of this type of metal carrier.

Next, when the honeycomb core body is loaded and heated to a temperature higher than the melting temperature of the brazing material, both the metal case and the honeycomb core body are firmly joined by the brazing material. In particular, in the two aspects of the present invention, the drawback of insufficient bonding strength near the central portion of the inner wall surface of the metal case can be overcome, and both can be firmly and reliably joined at the central portion of the metal case.

In the present invention, the contact portion (flat plate-like The abutting portions of the metal strip and the peaks and valleys of the corrugated metal strip may be joined by a normal method.For example, first, the flat metal strip (3)
Then, the honeycomb core body (2) formed by winding the corrugated metal strip (4) in a spiral shape is loaded into the metal case holding the brazing wire in the brazing wire holding groove described above. Brazing material is applied, dipped or sprayed from the open end of the metal case, excess brazing material is removed, and then heat treatment is performed. With this method, both the honeycomb core body and the metal case can be joined together at the same time as the members constituting the honeycomb core body are joined. In this case, since the brazing material is also supplied from the open end of the metal case, the brazing material holding groove (7) is formed on the inner wall surface of the cylindrical metal case except for the areas near the openings at both ends of the cylindrical metal case. Case (6) can be preferably used.

In addition, when forming the honeycomb core body, at least one of the strips, for example, a corrugated strip whose protrusions and/or valleys may be coated with brazing material in advance, may be used. All that is required is to press-fit and stack a honeycomb core body manufactured using strip material into a metal case holding a brazing wire rod, and then heat-treat the honeycomb core body.

〔Example〕

Hereinafter, the present invention will be explained in more detail based on Examples, but the present invention is not limited to these Examples.

(j) Manufacture of honeycomb core body As a flat metal strip material, the thickness of ferritic stainless steel with Cr2O%, A, and t5% is 0.044mm/7mm width
A heat-resistant thin-walled steel strip of 4.5 cm/layer was used.

Next, the strip material is passed between forming gears and processed into a corrugated shape with a pitch width of 2.5 mm/h in the longitudinal direction,
It was made into a corrugated metal strip material.

Next, the flat metal strip material and the corrugated metal strip material are overlapped so that they have abutting portions, and are rolled up into a spiral shape and fixed at important points by spot welding, and then A Nicum core body with a diameter of 700 mm and a large number of mesh ventilation holes in the axial direction was manufactured.

(ii) Production of metal case A flat plate of austenitic stainless steel (SUS304) is made of +! A cylindrical metal case with an inner diameter of 7017 layers, a wall thickness of 1.2 layers, and a length of 800 layers is made from this by cutting a 1g layer, 0.5 layers deep, and a brazing wire holding groove. Manufactured. Note that six brazing wire holding grooves were formed at equal intervals around the center of the metal case.

(iii) Production of metal support base A 0-order honeycomb core body with a diameter of 0.4 layers of brazing wire embedded with a brazing wire (of Kkel type) was press-fitted into the brazing wire holding groove of the metal case, and then vacuumed. The honeycomb core was heat-treated at 1100° C. and the metal case and honeycomb core body were brazed together.

As a result, it was possible to manufacture a metal support base in which the metal case and honeycomb core body would not separate for a long period of time.

〔Effect of the invention〕

The present invention is for loading a honeycomb core body with a brazing material held in a brazing material holding groove previously provided on the inner wall surface of a cylindrical metal case, and performing heat treatment to braze the metal case and the honeycomb core body. , has the following excellent effects.

(i) Bonding strength between the metal case and the honeycomb core body,
In particular, the bonding strength near the central portion of the metal case can be significantly improved, and a metal support base with excellent durability can be obtained.

(ii) Since a brazing material such as a brazing wire is embedded in the brazing material holding groove and brazing is performed, uniform and reliable brazing can be achieved.

(iii) Expensive high-temperature brazing filler metal such as N+ type brazing filler metal is used to manufacture the metal support base, but in the present invention, the brazing filler metal is buried in the brazing filler metal holding structure, so the brazing filler metal is Easy to manage usage.

(1v) Compared to conventional methods of applying brazing filler metal by coating or dipping, drying steps etc. can be omitted;
Highly productive.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a rolled metal support base for supporting an exhaust gas purifying catalyst of the present invention, and FIG. 2 is a perspective view of a layered metal support base of the present invention. Figure m3 is a longitudinal sectional view of a metal case in which a brazing material holding groove is formed in the first embodiment of the present invention. FIG. 4 is a longitudinal cross-sectional view of a metal case in which a brazing material retaining groove is formed according to a second embodiment of the present invention, and FIG. 5 is a plan view thereof. FIG. 6 is a longitudinal sectional view of a metal case in which a brazing material retaining groove is formed according to a third embodiment of the present invention. FIG. 7 is a plan view of a metal case in which a brazing material retaining groove is formed according to a fourth embodiment of the present invention. 8 to 11 are related views of a metal case in which a brazing metal holding groove is formed according to the fifth r$ aspect of the present invention, in which FIG. 8 is a longitudinal sectional view, FIG. 9 is a front view, and FIG. 1O is a sectional view taken along line A-A in FIG. 9, and FIG. 11 is a plan view. FIG. 12 is a longitudinal sectional view of a metal case in which a brazing material retaining groove is formed according to a sixth embodiment of the present invention. FIG. 13 is a longitudinal sectional view of a metal case in which a brazing material retaining groove is formed according to a seventh embodiment of the present invention. FIG. 14 is a longitudinal sectional view of a metal case in which a brazing material retaining groove is formed according to a second aspect of the present invention. FIG. 15 is a partial vertical sectional view of a metal case in which a brazing material retaining groove is formed according to a ninth aspect of the present invention. l, 1'...Metal support base 2.2'...Honeycomb core body 3.3'...Flat metal strip material 4.4'...Corrugated metal strip material 5.5'...Mesh ventilation hole passage 6.6'...Metal case 7...Brazing metal holding groove 8...Brazing material Wire rod patent applicant Usui Kokusai Sangyo Co., Ltd. Agent Patent attorney Yoshio Kino 4-corrugated metal strip material

Claims (1)

[Claims] 1. A large number of axially formed strips made of thin metal plates are stacked one on top of the other so that they are in contact with each other, and formed into a spiral or layered shape. In a metal supporting body for supporting an exhaust gas purifying catalyst, the honeycomb core body having a mesh-like ventilation hole is fixed in a cylindrical metal case, wherein the honeycomb core body is attached to an inner wall surface of the cylindrical metal case. 1. A metal support base for supporting an exhaust gas purifying catalyst, characterized in that the support is fixed to a cylindrical metal case by a brazing material held in a brazing material holding groove provided in the cylindrical metal case. 2. The metal support base according to claim 1, wherein the brazing material holding groove is linear, curved, or block-shaped. 3. The metal support base according to claim 1, wherein the brazing material holding groove is provided at a desired angle with respect to the axial direction of the cylindrical metal case. 4. The brazing material holding groove provided on the inner wall surface of the metal case is
2. The metal support base according to claim 1, which is provided axially parallel to the inner wall surface of the cylindrical metal case and at a desired interval. 5. The brazing material holding groove provided on the inner wall surface of the metal case is
2. The metal support base according to claim 1, which is provided in a direction perpendicular to the axial direction of the cylindrical metal case and at a desired interval. 6. The brazing material holding groove provided on the inner wall surface of the metal case is
The metal support base according to claim 1, which is provided over the entire length of the metal case in the axial direction. 7. The brazing material holding groove provided on the inner wall surface of the metal case is
The metal support base according to claim 1, which is provided over a part of the entire length of the metal case in the axial direction. 8. The brazing material holding groove provided on the inner wall surface of the metal case is
Claim 1, which is a concave groove provided on the inner wall surface of a metal case.
The metal supporting matrix described in Section 1. 9. The brazing material holding groove provided on the inner wall surface of the metal case is
2. The metal support base according to claim 1, wherein the recess is formed by machining the wall of the metal case to have a concave and convex shape. 10. The metal support base according to claim 1, wherein the brazing material held in the brazing material holding groove is a brazing wire. 11. The metal support base according to claim 1, wherein the brazing material held in the brazing material holding groove is a block-shaped piece of brazing material. 12. The metal support base according to claim 1, wherein the brazing filler metal held in the brazing filler metal holding groove is obtained by cooling and solidifying molten brazing filler metal within the brazing filler metal holding groove. 13. The metal support base according to claim 1, wherein the brazing filler metal held in the brazing filler metal holding groove is a paste-like brazing filler metal that is dried and solidified within the brazing filler metal holding groove.