JP2000102830A - Metal honeycomb compact for exhaust gas purification catalyzer and, manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To relax a thermal stress being distributed in a radius direction of a metal honeycomb compact by forming a non-joining part of a flat foil and a corrugated foil in the metal honeycomb compact at more than two positions and, by specifying the positions thereof in a given range. SOLUTION: This metal honeycomb compact 2 is formed by laminating a flat foil of a ferritic heat resistant high-alloy steel and a corrugated foil thereof alternately or by enfolding them together. For one round starting from a gas discharge side as a start to a point in the honeycomb compact 2 as an end point, a non-joining part 11 of the flat foil, the corrugated foil contacting part is formed in the compact 2 at more than two positions. At least one of the non-joining parts 11 is made to be located in a scope within 1/2 or less of a radius from the core shaft S of the honeycomb compact 2. In addition, at least one of the non-joining part 11 is made to be positioned apart from the core shaft S at 1/2 or more of the radius, and, at inside of the periphery. Other contacting part of the flat foil and the corrugated foil is made to be a solid diffusion jointed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal honeycomb body for supporting a catalyst for purifying exhaust gas discharged from an internal combustion engine such as an automobile engine and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, metal catalysts having excellent initial purification capability of exhaust gas and low exhaust resistance have been often used in catalytic devices for automobiles. Conventionally, as a metal carrier of this type, a metal flat foil and a metal corrugated foil obtained by plastically processing a metal flat foil into a corrugated shape in the length direction are superimposed and wound, for example, in a spiral shape to form a cylindrical honeycomb. It has been known that a body, or a flat foil and a corrugated foil are alternately laminated on a plane to form a honeycomb body, and the metal honeycomb body is assembled into a casing such as a metal outer cylinder and joined to each other, A catalyst is carried on the metal honeycomb body and used as an automobile exhaust gas purifying apparatus.

For example, as shown in FIG. 1, a conventional metal carrier 1 is manufactured by incorporating a metal honeycomb body 2 made of a heat-resistant stainless steel foil into a metal outer cylinder 3.
As shown in FIG. 2, the metal honeycomb body 2 mainly includes a strip-shaped flat foil 5 having a thickness of about 50 μm and a strip-shaped corrugated foil 6 obtained by corrugating the flat foil 5, Arrow B
And spirally manufactured. A ridge line 7 of each wave is formed in the band-shaped corrugated foil 6 in the width direction, and the spirally wound cylindrical metal honeycomb body 2 has a large number of ventilation holes 4 in the axial direction of the cylinder. ing. Then, a catalyst is supported on the vent holes to form a catalytic converter.

[0004] The catalyst carrier is required to have excellent durability to withstand severe thermal cycling due to high temperature exhaust gas from the engine and to withstand severe vibration from the engine. For this reason, the conventional metal carrier 1 includes a contact portion between the flat foil 5 and the corrugated foil 6 of the metal honeycomb body 2 and the metal honeycomb body 2.
And the inner circumference of the outer cylinder 3 are joined.

In general, a high heat-resistant ferritic stainless steel made of Cr-Al-Fe is often used as a metal foil constituting a metal honeycomb body. This is because Al in the foil is selectively oxidized on the surface and Al ₂ O is formed. _This is because the formation of ₃ improves the oxidation resistance. Therefore, the amount of Al in the metal foil has an important effect on the durability of the metal carrier.

[0006] The bonding inside the metal honeycomb body is made of N
It is performed by fixing an i-type powder brazing agent to a contact portion of a metal flat foil or a metal corrugated foil with an organic substance such as a binder interposed therebetween and performing a brazing treatment in a vacuum furnace. In this case, Al in the metal foil tends to bond very strongly with Ni in the brazing agent, and Al segregates near the brazing portion. On the other hand, Al around the segregation site is conversely depleted, and the oxidation resistance is locally deteriorated, which may cause a problem in durability.
Further, from the viewpoint of manufacturing cost, the brazing agent is very expensive, which hinders supply of inexpensive metal carriers to users.

Therefore, as a method of manufacturing a metal carrier without using a brazing agent, there is known a method of performing a heat treatment in a high-temperature vacuum atmosphere to bond a contact portion between a metal flat foil and a corrugated foil by solid diffusion bonding. I have.

When the catalyst carrier is used while being mounted and fixed on an exhaust gas system of an automobile engine, the engine is vibrated during the operation of the engine and is heated by the exhaust gas and a catalytic reaction. When the engine is started or accelerated, it is rapidly heated, and when it is braked or stopped, it is rapidly cooled, and a rapid heating-cooling heat cycle is repeated during traveling. With such a heat cycle, the metal carrier repeats expansion and contraction.

When the metal carrier is rapidly heated, the central portion of the metal honeycomb body where the flow rate of the exhaust gas is large is heated most rapidly, and the outer cylinder exposed to the outside air and the outer peripheral part of the metal honeycomb body in contact with the outer cylinder are heated. , The stress due to the difference in thermal expansion is concentrated on the entire inside of the metal honeycomb body or on the joint between the metal honeycomb body and the outer cylinder, causing breakage, buckling or peeling. In addition, during rapid cooling, the temperature of the metal honeycomb body decreases due to the temperature difference between the central part of the metal honeycomb body, whose temperature decreases rapidly with the decrease in exhaust gas temperature, and the outer peripheral part of the metal honeycomb body, whose temperature decreases slowly. The stress due to the difference in thermal expansion is concentrated on a steep portion, and similarly, breakage, buckling, peeling, and the like occur.

[0010] As a countermeasure, by joining only a part of the contact portion between the flat foil and the corrugated foil of the metal honeycomb body or by leaving a part thereof, the stress concentration due to the difference in thermal expansion is reduced, and the durability is improved. Techniques for improving the performance are known. Japanese Patent Laid-Open No. 5-
In JP-A-131144, a bonding inhibitor is applied to a predetermined portion of a corrugated foil having a parallel portion having a width equal to or greater than the foil thickness at the top and the valley, and the foil is overlapped with a flat foil and wound to form a desired foil. There is disclosed a method of firmly performing diffusion bonding only at a site. Further, Japanese Patent Application Laid-Open No. 7-328778 discloses a method in which a diffusion inhibitor is attached to a predetermined portion of a flat foil, and the resultant is overlapped with a corrugated foil and wound to diffuse and bond only a predetermined portion of both foils. . In addition, Japanese Patent Application Laid-Open No. H8-80204 discloses a method for reducing stress concentration by partially joining a metal honeycomb body and an outer cylinder.
No. 229411.

Further, as another measure for preventing breakage buckling, peeling, etc. of the metal carrier due to expansion and contraction in the metal honeycomb body caused by the rapid heat-quench heat cycle,
Japanese Utility Model Laid-Open No. 3-61113 discloses that a flat foil constituting a metal honeycomb body as described above is extended, and is wound around the honeycomb body to form a multilayered flat foil, and the tip portion is formed into an outer cylinder. By welding, the expansion and contraction due to the thermal cycle as described above is absorbed by the multiple layers, the adhesive strength with the outer cylinder is increased, and the occurrence of voids and cracks at or near the outermost peripheral portion of the metal honeycomb body can be prevented. Proposed.

Japanese Utility Model Laid-Open No. 5-9638 discloses that at least one sheet forming a layer member is formed on a metal carrier obtained by bending a layer member formed by alternately stacking flat plates and corrugated plates into an S shape. A technique has been proposed in which a corrugated plate or flat plate is made longer than other corrugated plates or flat plates, and the extra length is wound around the outermost periphery to improve the outer shape accuracy.

[0013]

A metal carrier for joining a contact portion between a flat foil and a corrugated foil by solid-phase diffusion bonding is disclosed in Japanese Patent Application Laid-Open No. 5-131144. The metal carrier disclosed in Japanese Patent Application Laid-Open No. 8-229411 can be confirmed to have excellent durability in a cold endurance test by a normal rapid heat-quench cycle, but under more severe conditions, for example, 950
In a cold endurance test between a high temperature of 150 ° C. or higher and 150 ° C., the durability was not always satisfactory. Also, the technique disclosed in Japanese Patent Application Laid-Open No. 7-328778 shows that attaching a diffusion inhibitor to flat foil rather than attaching it to corrugated foil can surely prevent joining at the joined portion. The specific structure of the portion where the joined portion is formed is not shown.

Further, the catalytic converter exerts an action on a reaction for detoxifying harmful gas in exhaust gas only when the temperature becomes equal to or higher than the activation temperature of the catalyst. Therefore, it is desired that the temperature be raised quickly when the engine is started. To this end, it is advantageous to mount the exhaust gas at a high temperature near the engine and rapidly heat it to a higher temperature. However, the above-mentioned problem due to the difference in thermal expansion becomes more remarkable due to the rapid heating at a high temperature. JP-A-3-61113 and JP-A-5-963.
In the technology disclosed in Japanese Patent Application Publication No. 8 (1994), the flat foil or corrugated foil layer wound around the metal honeycomb body is not joined to each other. For this reason, the durability was not always satisfactory under severe conditions such as being heated to a higher temperature and more rapidly, such as when mounted near an engine.

The present invention solves these problems in a metal carrier in which a contact portion between a flat foil and a corrugated foil is joined by solid-phase diffusion bonding. An object of the present invention is to provide a metal carrier capable of withstanding severe conditions and a method for producing the same.

[0016]

That is, the gist of the present invention is as follows. (1) A flat foil made of a heat-resistant high-alloy steel of ferrite series and a corrugated foil obtained by corrugating the flat foil are alternately laminated. Alternatively, in the metal honeycomb body formed by wrapping together and joining the flat foil and the corrugated foil, one end on the gas outlet side is used as a starting point, and from the starting point, 9/20 to the entire length of the metal honeycomb body in the central axis direction.
A non-joined portion where the contact portion between the flat foil and the corrugated foil is not joined to the metal honeycomb for at least one round over the entire circumference, ending with a point located within the metal honeycomb body by a length in a range of 9/10 in the metal honeycomb Two or more locations are formed in the body, at least one location of the non-bonded portion is within a range of less than 1/2 of a radius from a central axis of the metal honeycomb body, and at least one location of the non-bonded portion is the metal. An exhaust gas purifying catalyst, wherein the flat foil and the corrugated foil are in contact with each other at a position apart from the central axis of the honeycomb body by at least 1/2 of the radius and inside the outer periphery by solid diffusion bonding. Metal honeycomb body. (2) Between one non-joining part of the non-joining parts and an adjacent non-joining part, there is provided a joining part in which at least one flat foil and a corrugated foil are joined. The above (1)
2. A metal honeycomb body for an exhaust gas purifying catalyst according to item 1. (3) The average value of the distance from the starting point to the end point of the non-joined portion within a range of less than 1/2 of the radius from the central axis of the metal honeycomb body in the non-joined portion is the central axis of the metal honeycomb body. The exhaust gas purification according to the above (1) or (2), characterized in that the exhaust gas purification is larger than the average value of the distance from the starting point to the ending point of the non-joined portion located at a position which is at least 1/2 of the radius and located inside the outer periphery from the outside. Metal honeycomb body for catalyst. (4) The starting point of the non-joined portion is located at a point located within the metal honeycomb body from the one end on the gas outlet side by a length of less than 1/10 of the entire axial length of the metal honeycomb body. The metal honeycomb body for an exhaust gas purifying catalyst according to any one of the above (1) to (3). (5) Between the outer periphery of the metal honeycomb body and the outer cylinder into which the metal honeycomb body is inserted, the gas outlet side from the one end on the gas inlet side by a length equal to or more than １ ／ of the total length of the metal honeycomb body. Starting from a point located toward the other end
The joining portion is formed in a range from the starting point to the other end serving as the gas outlet side in a range ending with a length equal to or less than １ ／ of the entire length of the metal honeycomb body in the central axis direction. The metal honeycomb body for an exhaust gas purifying catalyst according to any one of (1) to (4). (6) The above-mentioned (1) to (4), wherein a flat foil or a corrugated foil is further wrapped around the outer periphery of the metal honeycomb body one or more times to form a shell, and the outer periphery is joined to the shell and the shells. The metal honeycomb body for an exhaust gas purifying catalyst according to any one of the above items. (7) The exhaust gas purifying catalyst according to the above (6), wherein the shell is a metal foil in which the flat or corrugated foil forming the metal honeycomb body is elongated by the length of the shell. Metal honeycomb body. (8) The metal honeycomb body for an exhaust gas purifying catalyst according to the above (6), wherein the shell is a flat foil or a corrugated foil different from the metal foil forming the metal honeycomb body. (9) The metal honeycomb body for an exhaust gas purifying catalyst according to the above (6), wherein the shell has a thickness of 100 to 500 µm. (10) The metal honeycomb body for an exhaust gas purifying catalyst according to the above (6), wherein the outer periphery of the metal honeycomb body, the shell, and the shells are solid-phase diffusion bonded. (11) The metal honeycomb for an exhaust gas purifying catalyst according to the above (6), wherein a gap is provided between the outer periphery of the metal honeycomb body having the shell on the outer circumference and an outer cylinder into which the metal honeycomb body is inserted. body. (12) A gap is provided between a metal honeycomb body having the shell on the outer periphery and an outer cylinder into which the metal honeycomb body is inserted, and between a part of the outer periphery of the shell and the outer cylinder. The metal honeycomb body for an exhaust gas purifying catalyst according to the above (6). (13) A flat honeycomb and a corrugated foil are wound while supplying a diffusion inhibitor to a position corresponding to the non-joined portion to form a metal honeycomb body, and the obtained metal honeycomb body is processed at a processing temperature of 1100 ° C.
熱処理 1250 ° C., heat treatment time of 30 minutes to 90 minutes, and ultimate vacuum degree of 3 × 10 ^{-4 to} 5 × 10 ^-5 Torr. The method for producing a metal honeycomb body for an exhaust gas purifying catalyst according to any one of the above (1) to (5), wherein the contact portion is solid-state diffusion bonded. (14) A flat foil and a corrugated foil are wound while supplying a diffusion inhibitor to a position corresponding to the non-joined portion to form a metal honeycomb body, and the metal honeycomb body is formed around the outer periphery of the metal honeycomb body. A flat or corrugated foil is wound one or more turns to form a shell, and the obtained metal honeycomb body is thereafter processed at a processing temperature of 1100 ° C. to 1250 ° C., a processing time of 30 minutes to 90 minutes, and an ultimate vacuum of 3 × 10 ^{-4 to} 5 (6) to (12), wherein a heat treatment is performed under a processing condition of × 10 ^-5 Torr, and a contact portion between the flat foil and the corrugated foil other than the position corresponding to the non-joined portion is subjected to solid diffusion bonding. A method for producing a metal honeycomb body for an exhaust gas purifying catalyst according to any one of the above. (15) The method for producing a metal honeycomb body for an exhaust gas purifying catalyst according to the above (14), wherein the shell is a flat foil or a corrugated foil different from the metal foil forming the metal honeycomb body. (16) In forming the metal honeycomb body, a brazing material is attached to an outer peripheral surface of a shell provided on an outer periphery of the metal honeycomb body, and diffusion is prevented on an outer peripheral surface of the metal honeycomb body having no shell. The method for producing a metal honeycomb body for an exhaust gas purifying catalyst according to the above (14), wherein the metal honeycomb body is assembled into an outer cylinder after the agent is attached, and heat treatment is performed. (17) The metal honeycomb for an exhaust gas purifying catalyst according to the above (14), wherein a brazing material is attached to a part of the outer peripheral surface of the shell, and a diffusion inhibitor is attached to the remaining part of the outer peripheral surface. How to make the body. (18) The solid-phase diffusion bonding is performed using the foil thickness t (μ) of the metal foil.
The method for producing a metal honeycomb body for an exhaust gas purifying catalyst according to the above (13) or (14), wherein the vacuum heat treatment is performed at a temperature T (° C.) in the following formula according to m).

1100 ≦ T ≦ 1.7 × t + 1165

At the time of rapid heating and rapid cooling, a large temperature difference occurs between the central portion and the peripheral portion of the metal honeycomb body 2, and a thermal stress is generated in the axial direction of the metal honeycomb body 2. According to the present invention, the metal honeycomb body 2 has two or more non-joined portions 11 where the contact portions 9 of the flat foil 5 and the corrugated foil 6 are not joined at least one turn over the entire circumference. The high temperature side can extend to the gas outlet side without being restricted by the low temperature side with respect to the part 11, thereby releasing the thermal stress.

Since the temperature gradient in the radial direction in the metal honeycomb body exists at any part from the central part to the outer peripheral part, a sufficient effect can be obtained if the non-joined part 11 is unevenly distributed in the radial direction. I can't raise it. In the present invention, at least one portion of the non-joined portion 11 is within a range of less than の of a radius from a center axis of the metal honeycomb body, and at least one portion of the non-joined portion 11 is the metal honeycomb. Since it is located at a position apart from the center axis of the body by 以上 or more of the radius and inside the outer periphery, the thermal stress distributed in the radial direction of the metal honeycomb body can be sufficiently reduced.

The non-joined portion 11 has a starting point at one end on the gas outlet side of the metal honeycomb body 2 and has a range of 9/20 to 9/10 of the entire length of the metal honeycomb body 2 in the direction of the central axis S from the starting point. A point located within the metal honeycomb body by the length is provided as an end point. On the gas-incoming side of the metal honeycomb body, there is a portion where the temperature becomes particularly high locally, and local thermal stress is severely applied. Therefore, when the starting point of the non-joined portion 11 is provided from the gas-incoming side end of the metal honeycomb body, Honeycomb defects called chips are likely to occur around the non-joined portion 11. Further, if the length of the non-joined portion 11 is less than 9/20 of the entire length of the metal honeycomb body 2, the expansion and contraction on the center axis side due to the above-described temperature difference increases the binding force, and the thermal stress is not easily reduced. Become.
The length of the non-joined portion 11 is 9/1 of the entire length of the metal honeycomb body
If it exceeds 0, the non-joined portion 11
Cracks occur in the upper metal honeycomb body, and if severe, the central shaft side may fall.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIG. 1, a metal carrier 1 of the present invention has a metal honeycomb body 2 incorporated in a metal outer cylinder 3. As shown in FIG. 2, the metal honeycomb body 2 includes a band-shaped flat foil 5 made of heat-resistant stainless steel,
A band-shaped corrugated foil 6 obtained by corrugating the flat foil 5 is superposed and wound to form a spiral. A ridge line 7 of each wave is formed in the band-shaped corrugated foil 6 in the width direction, and the spirally wound cylindrical metal honeycomb body 2 has a large number of ventilation holes 4 in the axial direction of the cylinder. ing.

The material of the metal honeycomb body 2 is a ferritic stainless steel containing 3 to 10% of Al and 15 to 25% of Cr as a heat-resistant alloy element, for example, 20% Cr.
-5% Al-Fe steel is adopted. Further, as a material for the outer tube 3, since heat resistance is not required as much as that of the metal honeycomb body 2, stainless steel containing no heat-resistant alloy element such as Al may be used.

In the case of solid-phase diffusion bonding of a metal flat foil and a metal corrugated foil forming such a metal honeycomb body, it is necessary to select a vacuum processing condition in which Al in the metal foil is not significantly reduced. Foil (thickness: 50 μm) made of a high heat-resistant ferritic stainless steel of 20% Cr-5% Al-Fe.
m), the diffusion bonding of the flat foil and the corrugated foil is performed by heating at a high temperature in a non-oxidizing atmosphere such as a vacuum furnace. In case of vacuum heating, 3 × 10 ^-4
Degree of vacuum in the range of 5 × 10 ⁻⁵ Torr, 1100 ° C. to 12
It can be performed at a temperature of 50 ° C. and a holding time of 30 minutes to 90 minutes. If the processing temperature is high, the holding time is long, and the degree of vacuum is high, scattering of Al in the foil during the heat treatment is promoted. If Al in the foil disappears by 1% or more due to the heat treatment, the oxidation resistance of the foil decreases, and the durability of the metal honeycomb body deteriorates. Conversely, if the processing temperature is low, the holding time is short, and the degree of vacuum is low, the strength of diffusion bonding cannot be sufficiently obtained.
If the processing temperature, the holding time, and the degree of vacuum are within the above ranges, the deterioration of durability due to the scattering of Al does not occur, and diffusion bonding with sufficient strength can be realized.

During use of the metal carrier 1 of the present invention for purifying engine exhaust gas from an automobile or the like, the temperature in the metal honeycomb body 2 continuously changes in the radial direction. In addition, the location of the heat spot where the temperature rises and the thermal stress is concentrated is affected by the drift of the gas flow flowing into the metal honeycomb body 2, and it is not possible to specify where the heat spot is generated. . Since the thermal stress is present at all radial positions in the metal honeycomb body corresponding to the temperature continuously changing in the radial direction, the number of the non-joined portions 11 formed in the metal honeycomb body 2 is two or more. The greater the number, the more effective. FIG.
FIG. 4 shows a cross section of the metal carrier 1 when the non-joined portions are provided at four locations. In FIG. 3, the upper side of the metal honeycomb body 2 in the figure is the gas inlet side, the lower side is the gas outlet side, and the white arrows indicate the gas inflow direction. The same applies to the following figures. By disposing a large number of non-joined portions 11 in a radially dispersed manner, it is possible to reduce the thermal stress at each portion. FIG. 5 shows a situation where the thermal stress is relaxed when four non-joined portions are provided. The temperature of the metal honeycomb body 2 is higher toward the center, and the thermal stress is relaxed at each non-joined portion 11, and it is apparent that the metal honeycomb body 11 extends to the exhaust gas outlet side according to the temperature of the portion. It is. In addition, by disposing the non-joined portions 11 in each part, even if a heat spot corresponding to the gas drift occurs at any position, the thermal stress caused by the heat spot can be effectively reduced. Can be.

Although the thermal stress can be effectively reduced by the presence of the non-joined portion 11, the non-joined portion 11 has an end point in the metal honeycomb body, and stress concentration occurs in the metal honeycomb body at the end point. By arranging a large number of non-joined portions 11, it is possible to arrange a number of end points within a close range.
If there is only one end point of the non-joined portion 11 in the close range, a large stress concentration occurs at this end point,
By arranging a large number of non-joined portions 11 and arranging a plurality of end points in a close range, it is possible to reduce the concentrated stress per one end point. Therefore, as the number of the non-joined portions 11 increases, the concentrated stress at the end point of the non-joined portion 11 is alleviated, and damage to the metal honeycomb body due to stress concentration can be prevented.

When the number of the non-joined portions 11 in the metal honeycomb body is increased, the distance between the adjacent non-joined portions 11 is inevitably narrowed. There are no places, and a wide area becomes a non-bonding area. When the non-joining area is widened, the rigidity of the metal honeycomb body in that area is reduced, which causes a reduction in the life of the metal honeycomb body. Non-joined part 11 and non-joined part 1
There is no problem if there is only a small portion where the joint portion does not exist between the non-joined portion and the non-joined portion adjacent to one of the non-joined portions 11 as shown in FIG. By securing at least one joining portion 10 in which the flat foil and the corrugated foil are joined, the rigidity of the metal honeycomb body can be secured.

More preferably, as shown in FIG. 7, a joining portion where at least two flat foils and two corrugated foils are continuously joined between adjacent non-joining portions is secured. When the gas flow in the metal honeycomb body has a deviated flow, the foil oscillates due to the pulsation of the gas flowing in the cell, and the metal honeycomb body may cause fatigue failure at the site. By securing a joining portion where at least two flat foils and two corrugated foils are continuously joined between non-joining portions, the bending rigidity of the joining portion is improved, and fatigue fracture due to vibration is prevented. Can be. Usually, about 30 to 50 layers of flat foil are present between the central axis and the outer periphery of the metal honeycomb body. For this reason, the number of non-joined portions 11 is limited to 15 to 30 at most.

The length of the non-joined portion 11 in the axial direction is preferably longer from the viewpoint of relaxation of thermal stress. On the other hand, it is necessary to secure a joint length necessary to prevent the central axis side of the metal honeycomb body 2 from dropping off at the joint portion from the end point of the non-joined portion 11 to the gas entry side end. In one round of the non-joined portion 11 existing at a certain radius, the axial force acting in the direction of dropping off the central axis side is proportional to the cross-sectional area on the central axis side. Therefore, the load applied to the joining portion from the end point to the gas entry side becomes greater toward the outer peripheral side of the metal honeycomb body, so that the length of the non-joining portion 11 on the outer peripheral side is smaller than that on the center side. Must be shorter. In addition, since the temperature change is greater at the outer peripheral portion than at the central portion of the metal honeycomb body, the reason that the outer peripheral portion needs to have a larger joint area to withstand the axial stress than the central portion. It depends.

More specifically, the end position of the non-joined portion 11 is formed in an arch shape in the cross section of the metal honeycomb body as shown in FIG. Shapes that are shorter are preferred. Regarding the relationship between the adjacent non-joined portions, it is not always the case that the length of the non-joined portion must be shorter on the outer peripheral side.
Non-joined portion 11 within a range of less than 1/2 of the radius R
The average value of the distance from the starting point to the end point is the average value of the distance from the starting point to the end point of the non-joined portion 11 which is located at least 1/2 of the radius from the central axis of the metal honeycomb body 2 and located inside the outer periphery. The effect can be exhibited by increasing the value of.

As for the joining between the outer periphery of the metal honeycomb body of the present invention and the inner periphery of the outer cylinder, a non-joining portion 12 and a joining portion 13 having a predetermined length are formed as shown in FIGS. Is preferred. The joining portion 13 has, as a starting point, a point located from one end on the gas inlet side to the other end on the gas outlet side by a length equal to or more than の of the entire length of the metal honeycomb body,
From the starting point to the other end on the gas outlet side, the metal honeycomb body is formed over a range ending in a length equal to or less than の of the entire length in the central axis direction of the metal honeycomb body. It is. That is, in FIGS. 8 and 9, L ₁ >
L / 3, L ₂ ≦ L / 2. L ₃ may be 0, as shown in FIG. 9, the embodiment joint 13 is formed as a starting point one end a gas exit side metal honeycomb body 2 is also within the scope of the present invention.

By providing the non-joined portion 12 and the joined portion 13 thus defined at the boundary between the metal honeycomb body 2 and the outer cylinder 3, when mounted on an engine exhaust gas system of an automobile or the like,
Superior durability against rapid heat cycles and rapid cooling due to exhaust gas is exhibited. That is, even if the central portion of the metal honeycomb body 2 is rapidly heated or rapidly cooled to increase the temperature difference from the outer peripheral portion, for example, in the case of the metal carrier of FIG. The center axis side extends or contracts toward the gas outlet side from the boundary, and the entire metal honeycomb body 2 expands and contracts toward the gas inlet side, so that the thermal stress is further reduced.

8 and 9, the non-joined portion on the gas entry side
Length L₁ Is less than 1/3 of the total length L of the metal honeycomb body
And the expansion and contraction of the entire metal honeycomb body to the gas-filled side.
To be restrained, further reducing thermal stress
It is difficult to show the effect. Also the length L of the joint_Two Is Metal Ha
If it exceeds 1/2 of the total length L of the honeycomb body, the
To be restrained by the expansion and contraction of the entire Tal honeycomb body
Therefore, the effect of further reducing the thermal stress is hardly exhibited. Moth
Length L_Three Is not limited. L ₁ And L
_Two Is within the above range, the entire metal honeycomb body is filled with gas.
Because it expands and contracts to the_Three Even if is 0
Good.

The upper limit of L ₁ and the lower limit of L ₂ are not limited.
It is sufficient metallic honeycomb body is joined to the outer tube, the length L ₂ of the bonded portion can be shortened. However, when the junction 13 is at risk of the metal honeycomb body is falling damaged is 1/20 the lower limit of L ₂ of the overall length L of the metal honeycomb body
It is desirable that When the lower limit of L ₂ is set in this way,
The upper limit of L ₁ is the 19/20 of L.

As shown in FIG. 11, the metal carrier of the present invention may be formed such that the joined portions are both inside the metal honeycomb body at both ends. The length range of the non-joined portion is 1/10 of the entire length L of the metal honeycomb body from one end on the gas outlet side.
Starting from a position separated by a length D less than or equal to 9/20 or more 9/9 of the total length L of the metal honeycomb body from one end on the gas outlet side
The end point is a position separated by a length of / 10 or less. Others are the same as the metal carrier of the embodiment of FIG. That is, in FIG. 11, D <L / 10 and 9L / 20
≦ H ₁ ≦ 9L / 10 and 9L / 20 ≦ H ₂ ≦ 9L / 10.

In the case of the metal carrier of the above embodiment, FIG.
As shown in 2, it is preferable that a non-joined portion and a joined portion having a predetermined length are formed at a boundary between the outer periphery of the metal honeycomb body and the inner periphery of the outer cylinder. The position and length of the joint are shown in FIG.
This is the same as the case of the metal carrier of the embodiment. That is, in FIG. 12, L ₁ > L / 3 and L ₂ ≦ L / 2. L
₃ may be 0. The operation is the same as that of the metal carrier of the embodiment shown in FIG.

When manufacturing the metal carrier 1 of the present invention,
As shown in FIG. 13, when the band-shaped flat foil 5 and the band-shaped corrugated foil 6 are superposed and wound, a diffusion preventing agent 14 is interposed at a predetermined portion. Then, after the metal honeycomb body 2 obtained after the winding is incorporated into the outer cylinder 3, a diffusion bonding process is performed. As a result, of the contact portion 9 between the flat foil 5 and the corrugated foil 6, the diffusion preventing agent 14
6 and 7 are not joined, the non-joined portions 11 as shown in FIGS. 6 and 7 are formed, and the other portions are diffusion-joined to form the joined portions 10.

As the diffusion inhibitor 14, a material which is thermally stable at the heating temperature for diffusion bonding, for example, TiO.
₂ , metal oxides such as Al ₂ O ₃ and ceramics such as SiC and BN can be employed. In order to interpose these between the flat foil 5 and the corrugated foil 6, a powder mixed with, for example, water is applied to the flat foil 5 or the corrugated foil 6, and a sheet-like material is attached or sandwiched. , Etc. can be adopted.

FIG. 13 shows an example in which the diffusion preventing agent 14 obtained by mixing the above-mentioned powder with water is applied to the corrugated foil 6 by a coating apparatus 15 by a roll transfer method. The diffusion preventing agent 14 is applied to the ridge line 7 of the corrugated foil 6 and wound, and is interposed in the contact portion 9 with the flat foil 5. The application of the diffusion preventing agent 14 only to a predetermined site can be performed by moving a transfer roll or a corrugated foil of the application device 15.

As shown in FIGS. 8 and 9, means for forming the joint portion 13 and the non-joint portion 12 between the metal honeycomb body 2 and the outer cylinder 3 are as follows. Before assembling into the metal honeycomb body 2 serving as the joining portion 13
The brazing material 16 is adhered to one or both of the outer peripheral surface portion of the metal honeycomb body 2 and the inner peripheral surface portion of the outer cylinder 3 serving as the joining portion 13, and the outer peripheral surface of the metal honeycomb body 2 serving as the non-joining portion 12. The bonding preventing agent 14 is adhered to one or both of the above-mentioned part and the part of the inner peripheral surface of the outer cylinder 3 to be the non-joining part 12.

As described above, the brazing material 16 and the diffusion preventing material 1
After the bonding, the non-bonding portion 11 is formed on the metal honeycomb body 2 by performing the diffusion bonding process by incorporating the brazing material 4 and the brazing material 16 is bonded on the boundary between the metal honeycomb body 2 and the outer cylinder 3. Joint 13
Is formed, and the non-joined portion 12 is formed without joining the portion where the diffusion preventing material 14 is attached.

As the brazing material 16, those used in ordinary brazing can be employed. In order to adhere this to the outer peripheral surface of the metal honeycomb body 2 or the inner peripheral surface of the outer cylinder 3, a powdery brazing material 16 is mixed with a binder and applied. Means such as sprinkling the brazing material 16 to shake off the brazing material at a portion other than the predetermined portion, or attaching a sheet-like brazing material 16 can be adopted.

As the diffusion preventing material 14, the same material as that interposed between the flat foil 5 and the corrugated foil 6 can be adopted, and as a means for attaching the same, coating or pasting can be adopted. . FIG. 14 shows an example in which a sheet-like brazing material 16 is adhered to the outer peripheral surface of the metal honeycomb body 2 and the diffusion preventing material 14 is applied to the other outer peripheral surface.

In the present invention, after assembling the metal honeycomb body 2 into the outer cylinder 3, a diameter reduction process can be performed to bring the outer cylinder 3 and the metal honeycomb body 2 into close contact with each other. The diffusion bonding is performed by heating at a high temperature in a non-oxidizing atmosphere such as a vacuum furnace. In the case of vacuum heating, 3 × 10 ^{-4 to} 5
A degree of vacuum in the range of ^10-5 Torr, 1100C to 125
The reaction can be performed at a temperature of 0 ° C. and a holding time of 30 minutes to 90 minutes.

Next, the invention in which the shell 19 is wound around the outer periphery of the metal honeycomb body 2 as shown in FIG. 15 will be described. In the figure, shell 19 is flat foil 5 or corrugated foil 6.
Are wound one or more times, and flat foils or corrugated foils forming the shell 19 are joined. FIG.
In 5, S is the central axis of the metal honeycomb body 2, and the exhaust gas is introduced in the direction of the white arrow.

Flat foil 5 or corrugated foil 6 forming shell 19
May be integrated with the flat foil 5 or the corrugated foil 6 forming the metal honeycomb body 2 or may be separate. In the former case, when forming the metal honeycomb body 2 as shown in FIG. 17, one of the flat foil 5 and the corrugated foil 6 is made long by the length of the shell 19, and this is additionally wound. It is formed. In the latter case,
After the metal honeycomb body 2 is formed, it is formed by additionally winding another flat foil 5 or corrugated foil 6.

Metal honeycomb body 2 before being additionally wound
When the outermost periphery of the flat foil 5 is a flat foil, the shell 19 adds one flat foil.
It is formed by wrapping around the circumference or wrapping the corrugated foil two or more times. When the outermost periphery of the metal honeycomb body 2 before being additionally wound is corrugated, the shell 1
9 is formed by additionally wrapping the corrugated foil one or more times, or by additionally wrapping the flat foil two or more times.

Then, after assembling the metal honeycomb body 2 having the shell 19 into the outer cylinder 3, the metal honeycomb body 2
The flat foil 5 and the corrugated foil 6 forming the shell 19 are joined together, the flat foils or the corrugated foils forming the shell 19 are joined together, and the outer peripheral surface of the shell 19 and the inner peripheral surface of the outer cylinder 3 are joined together. Joined to form the metal carrier of the present invention.

Since the metal carrier of the present invention has the above-described shell 19 formed on the outer periphery of the metal honeycomb body 2, when used as a catalytic converter, it is heated to a higher temperature and more rapidly than before, and is heated and cooled. Has excellent durability when repeated. In other words, even if stress concentrates near the boundary due to the temperature difference between the metal honeycomb body 2 and the outer cylinder 3, the strong shell 19 in which the flat foils or the corrugated foils are joined and integrated becomes hard to be damaged. Excellent durability against displacement of the metal carrier in the axial direction.

Next, a preferred embodiment of the metal carrier of the present invention is shown in the sectional view of FIG. In this embodiment, the joining portion 13 and the boundary non-joining portion 20 are provided at the boundary between the shell 19 and the outer cylinder 3.
Are formed. The boundary non-joining part 20 is formed by the shell 1
9 are formed starting from the gas-filled end of
Are formed starting from the gas outlet side.

Since the boundary non-joining portion 20 is formed between the shell 19 and the outer cylinder 3 as described above, the thermal stress concentration between the shell 19 and the outer cylinder 3 is reduced, and the durability is further improved. improves. At this time, since the metal honeycomb body 2 expands and contracts to the gas inlet side with respect to the outer sleeve 3 due to the gap between the shell 19 and the outer sleeve 3, it is better that the boundary non-joined portion 20 is formed on the gas inlet side. Works more effectively.

The diffusion bonding of the present invention is the same as that of the above-described technique.
Vacuum processing in a temperature range of 0 to 1250 ° C., for example, 10 ⁻⁴ T
Although the treatment is performed at a degree of vacuum of about orr, it is preferable that the diffusion bonding is performed by a vacuum heat treatment at a temperature T (° C.) in the range of Expression (1) according to the foil thickness t (μm) of the metal honeycomb body 2. . That is, as shown in FIG. 19, the upper limit of the vacuum heat treatment temperature is allowed to be higher when the foil thickness is large, and is limited to a lower temperature when the foil thickness is small. According to the condition of the expression (1), the metal honeycomb body 2 becomes a metal carrier with more stable heat resistance and oxidation resistance. Under the condition of the expression (2), the metal carrier is further improved in stability.

1100 ≦ T ≦ 1.7 × t + 1165 (1) 1100 ≦ T ≦ 1.9 × t + 1117 (2) FIG. 17 shows a specific example in which the shell 19 is provided on the outer periphery of the metal honeycomb body 2 in the present invention. explain. In this example, a flat foil integral with the flat foil 5 forming the metal honeycomb body 2 is used. Contact part 9
A non-bonding portion 11 of the honeycomb body is formed by interposing a diffusion preventing agent 14 in a predetermined portion of the shell, and the flat foil 5 is elongated by the shell forming portion 19, and the width of the shell 19 is reduced by notching the gas entry side. Is formed. By making the corrugated foil 6 similarly long by the amount of the shell formation, the corrugated foil can be wound to form the shell 19.

As a further preferred embodiment of the present invention, before assembling the metal honeycomb body 2 on which the shell 19 is formed into the outer cylinder 3, a predetermined portion of the outer peripheral surface of the shell 19 and the inner peripheral surface of the outer cylinder 3 are formed. By adhering the diffusion preventing agent to one or both of the predetermined portions and the brazing material to one or both of the other predetermined portions of the shell 19, as shown in the example of FIG. 20 is formed.

FIG. 18 shows a specific example. The shell 19 is formed on the gas outlet side of the metal honeycomb body 2, the diffusion inhibitor 14 is provided on the gas inlet side of the shell 19, and the brazing material 16 is provided on the gas outlet side.
Is attached to the outer cylinder 3 and then diffusion-bonded, whereby the boundary non-bonded portion 20 is bonded to the portion where the diffusion preventing agent 14 is bonded, and the bonding portion is bonded to the portion where the brazing material 16 is bonded. 13 are formed respectively. In addition, the diffusion preventing agent 14 and the brazing material 16 may be attached to the inner surface of the outer cylinder 3, or may be attached to both the outer surface of the shell 19 and the inner surface of the outer cylinder 3.

In the method of the present invention, the thickness of the shell 19 is 50 μm or more, preferably 100 μm or more and 500 μm or less.
It is preferable that the number of times of winding is adjusted according to the thickness of the flat foil or corrugated foil on which the metal foil forming the honeycomb body is extended or another metal foil is wound. Further, it is preferable to join the flat foils or the corrugated foils forming the shell 19 by solid phase diffusion bonding.
Is assembled in an outer cylinder, and then heated at a high temperature in a non-oxidizing atmosphere such as a vacuum furnace, so that the flat foil and the corrugated foil forming the metal honeycomb body 2 and the flat foils forming the shell 19 or corrugated foil are formed. They can be joined by solid phase diffusion bonding. At this time, the brazing of the shell 19 and the outer cylinder 3 is performed simultaneously.

[0056]

EXAMPLE A metal carrier 1 having an outer diameter of 100 mm and a length of 100 mm was manufactured and subjected to a durability test. Metal honeycomb body 2
20Cr with a thickness of 30 μm and a width of 100 mm as a flat foil 5 of
A -5 Al-Fe ferritic stainless steel foil was used, and as the corrugated foil 6, the flat foil 5 obtained by corrugating with a wave height of 1.25 mm and a pitch of 2.54 mm was used. The outer cylinder 3 has a thickness of 1.5 mm, a length of 100 mm, and an outer diameter of 102 m.
A 19Cr-Fe heat-resistant stainless steel tube of m m was used.

The flat foil 5 is applied with a back tension of 5 kgf.
While winding with a corrugated foil 6
Tal honeycomb body 2 was produced. Non-joined part 1 when wound
A diffusion inhibitor 14 is applied to the corrugated foil 6 at the position where
Applied. Al is used as the diffusion inhibitor 14_Two O_Three Using powder
Was. L of the inner circumference of the outer cylinder 3_Two Apply brazing material to the position of ₁ 
Position and L_Three Al as a diffusion inhibitor 14_Two 
O_Three After applying, the metal honeycomb body 2 is assembled
Then 1200 ° C, 1 × 10^-FourTorr high temperature
It was manufactured by performing a diffusion bonding process of heating for 90 minutes under air.

Table 1 shows the conditions for installing the non-joined portion of the metal honeycomb body 2 and the joining conditions with the outer cylinder 3 in this embodiment. Of the non-joined portions 11, the height of the non-joined portion 11 closest to the outer periphery is H
₁ , the distance from the center was R ₁ , the height of the non-bonded portion 11 closest to the center was H ₂ , and the distance from the center was R ₂ .

[0059]

[Table 1] A catalyst is supported on the metal carrier thus produced,
Installed in the exhaust system of a gasoline engine and heated to 950 ° C1
A severe cold endurance test was performed in which the cooling was performed at 150 ° C. for 10 minutes as one cycle for 0 minute. First, whether or not the metal honeycomb body was damaged after the completion of 900 cycles was evaluated.
Here, ○: no damage such as chipping occurred on both the entrance side and the exit side of the metal honeycomb body after 900 cycles,
In addition, there was no deviation at the boundary surface between the metal honeycomb body and the outer cylinder, and the test was passed.

X: Failure occurred due to damage such as breakage or displacement of the metal honeycomb body.

Next, as a limit durability test, the number of cycles leading to breakage was measured. The results are shown in Table 1.

No. 1 in Table 1. 1 to 6 are examples of the present invention. N
o. 1 and 2 have two non-joined portions. No. Nos. 3 and 4 have the number of non-joined portions of 4, the distance between the non-joined portions is 10 mm, and the height of the non-joined portions is no. 3 is 80, 80, 6 from the center side
0, 60 mm, No. 4 is 80, 70, 6 from the center side
0, 50 mm. No. In Nos. 5 and 6, the number of non-joined portions is 7, the interval between the non-joined portions is 5 mm, and the height of the non-joined portions is uniformly lower by 5 mm from the center side. For joining with the outer cylinder, only 25 mm on the gas outlet side was joined. N
o. 6 further has a shell. 150 μm in thickness and 40 mm in length on the outer periphery corresponding to the gas outlet side of the metal honeycomb body 2
Was wound once around the 20Cr-5Al-Fe ferritic stainless steel plate to form a shell 19, and a brazing material 16 having a width of 25 mm was adhered to the outer periphery thereof for one round. Furthermore, outer cylinder 3
75 mm from the gas entering side on the inner peripheral surface of
Then, the above-mentioned metal honeycomb body 2 was assembled.

In all the measurements after the completion of 900 cycles, no damage such as breakage or displacement of the honeycomb body occurred. In the limit durability test, as the number of non-joined portions increases, the number of cycles until breakage increases. No. having a shell. 6 had the highest durability.

No. 7 to 9 are comparative examples. No. 7,
No. 8 has no non-joined part. 9 has only one non-joined portion. No. to the outer cylinder No. 7 was joined over the entire length of the honeycomb body. In Nos. 8 and 9, only 25 mm on the gas outlet side was joined. In each of the measurements after the completion of 900 cycles, damage such as breakage or displacement of the metal honeycomb body occurred. In particular, no. In Nos. 7 and 8, the displacement of the honeycomb body occurred in a very short cycle.

[0065]

According to the present invention, there is provided a metal carrier in which a contact portion between a flat foil and a corrugated foil is joined by solid phase diffusion bonding, wherein the contact portion between the flat foil and the corrugated foil is joined at least one round over the entire circumference. Two or more non-bonded portions are formed in the metal honeycomb body, and at least one of the non-bonded portions is within a range of less than 1/2 of a radius from a center axis of the metal honeycomb body. Since at least one joint portion is located at a position apart from the central axis of the metal honeycomb body by at least one-half of the radius and inside the outer periphery, thermal stress distributed in the metal honeycomb body radial direction can be sufficiently reduced. it can.

According to the present invention, at least one flat foil and a corrugated foil are bonded between one non-bonded portion and an adjacent non-bonded portion. Thus, the rigidity of the metal honeycomb body can be secured.

The present invention further employs a shape in which the end position of the non-joined portion has an arch shape in the cross section of the metal honeycomb body, and the length of the non-joined portion gradually decreases toward the outer periphery. Thereby, the rigidity of the metal honeycomb body can be increased.

According to the present invention, by forming a non-joining portion and a joining portion in joining the metal honeycomb body and the outer cylinder, thermal stress during rapid heating and rapid cooling is reduced, and the durability of the metal honeycomb body is improved. can do.

Further, according to the present invention, by forming a shell on the outer periphery of the metal honeycomb body, the metal honeycomb body is heated to a higher temperature and more rapidly than in the past, and has excellent durability when heating and cooling are repeated.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of a metal carrier.

FIG. 2 is a schematic view showing a state of forming a metal honeycomb body.

FIG. 3 is a cross-sectional view of the metal carrier of the present invention.

FIG. 4 is a cross-sectional view of the metal carrier of the present invention.

FIG. 5 is a cross-sectional view showing thermal stress relaxation of the metal honeycomb body of the present invention.

FIG. 6 is a partial cross-sectional view of the metal honeycomb body of the present invention.

FIG. 7 is a partial cross-sectional view of the metal honeycomb body of the present invention.

FIG. 8 is a cross-sectional view of the metal carrier of the present invention.

FIG. 9 is a cross-sectional view of the metal carrier of the present invention.

FIG. 10 is a sectional view showing thermal stress relaxation of the metal honeycomb body of the present invention.

FIG. 11 is a cross-sectional view of the metal carrier of the present invention.

FIG. 12 is a cross-sectional view of the metal carrier of the present invention.

FIG. 13 is a conceptual diagram showing a manufacturing state of the metal honeycomb body of the present invention.

FIG. 14 is a conceptual diagram showing a manufacturing state of the metal honeycomb body of the present invention.

FIG. 15 is a cross-sectional view of the metal carrier of the present invention.

FIG. 16 is a sectional view of the metal carrier of the present invention.

FIG. 17 is a conceptual diagram showing a manufacturing state of the metal honeycomb body of the present invention.

FIG. 18 is a conceptual diagram showing a manufacturing state of the metal honeycomb body of the present invention.

FIG. 19 is a graph for explaining the relationship between the vacuum heat treatment temperature and the foil thickness in the metal carrier of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal carrier 2 Metal honeycomb body 3 Outer cylinder 4 Vent hole 5 Flat foil 6 Corrugated foil 7 Ridge line 9 Contact part 10 Joining part 11 Non-joining part 12 Non-joining part 13 Joining part 14 Diffusion inhibitor 15 Coating device 16 Brazing material 19 Shell 20 Boundary non-joint S center axis

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takuzo Kako 5-3 Tokai-cho, Tokai-shi F-term in Nagoya Works, Nippon Steel Corporation (reference) 3G091 AA02 AB01 BA08 BA10 BA39 FB03 FC08 GA08 GA12 GA13 GB01X GB01Z HA27 HA31 4D048 AA06 AA13 AA18 AB01 AB05 BA39X BB02 4G069 AA01 AA08 BA17 CA03 CA09 DA06 EA18 EA24 EA27

Claims (18)

[Claims] 1. A metal honeycomb formed by alternately laminating or winding together flat foils made of ferritic heat-resistant high alloy steel and corrugated foils obtained by corrugating the flat foils, and joining the flat foils and the corrugated foils. In the body, starting from one end that is the gas outlet side,
The flat foil is provided for at least one round over the entire circumference with a point located in the metal honeycomb within a range of 9/20 to 9/10 of the entire length of the metal honeycomb body in the central axis direction from the starting point as an end point. Two or more non-joined portions where the contact portions of the metal foil and the corrugated foil are not joined are formed in the metal honeycomb body, and at least one of the non-joined portions has a radius less than １ ／ of a radius from a central axis of the metal honeycomb body. Within the range,
Further, at least one portion of the non-joined portion is located at a position separated from the central axis of the metal honeycomb body by at least a half of the radius and inside the outer periphery, and the other contact portion of the flat foil and the corrugated foil is solid-state diffusion bonded. A metal honeycomb body for an exhaust gas purifying catalyst, characterized by being made. 2. A method according to claim 1, wherein at least one flat foil and a corrugated foil are joined between one of the non-joined portions and an adjacent non-joined portion. The metal honeycomb body for an exhaust gas purifying catalyst according to claim 1, characterized in that: 3. An average value of a distance from a starting point to an end point of a non-joined portion of the non-joined portion within a range of less than 1/2 of a radius from a central axis of the metal honeycomb body is equal to or smaller than a radius of the metal honeycomb body. The exhaust gas purifying catalyst according to claim 1 or 2, wherein the catalyst is larger than an average value of a distance from a starting point to an end point of a non-joined portion located at a position which is at least 1/2 of a radius from the center axis and located inside the outer periphery. For metal honeycomb body. 4. The starting point of the non-joined portion is 1/10 of the axial length of the metal honeycomb body from one end on the gas outlet side.
The metal honeycomb body for an exhaust gas purifying catalyst according to any one of claims 1 to 3, wherein the metal honeycomb body is located at a point located within the metal honeycomb body by a length shorter than the length. 5. A gas between an outer periphery of the metal honeycomb body and an outer cylinder into which the metal honeycomb body is inserted, from one end on a gas-incoming side to a length of at least ３ of a total length of the metal honeycomb body. A point located toward the other end serving as the outlet side is defined as a starting point, and an end point having a length equal to or less than の of the total length of the metal honeycomb body in the central axis direction from the starting point toward the other end serving as the gas outlet side is referred to as an end point. The metal honeycomb body for an exhaust gas purifying catalyst according to any one of claims 1 to 4, wherein the joining portion is formed over a range defined as follows. 6. A shell is formed by further winding one or more rounds of flat foil or corrugated foil around the outer periphery of the metal honeycomb body, and joining the outer periphery to the shell and the shells. The metal honeycomb body for an exhaust gas purifying catalyst according to any one of the above. 7. The exhaust gas purifying catalyst according to claim 6, wherein the shell is a metal foil in which a flat foil or a corrugated foil forming the metal honeycomb body is elongated by the length of the shell. For metal honeycomb body. 8. The metal honeycomb body for an exhaust gas purifying catalyst according to claim 6, wherein the shell is a flat foil or a corrugated foil different from the metal foil forming the metal honeycomb body. 9. The shell has a thickness of 100 to 500 μm.
The metal honeycomb body for an exhaust gas purifying catalyst according to claim 6, wherein: 10. The metal honeycomb body for an exhaust gas purification catalyst according to claim 6, wherein the outer periphery of the metal honeycomb body, the shell, and the shells are solid-phase diffusion bonded. 11. The exhaust gas purifying catalyst metal according to claim 6, wherein a gap is provided between an outer periphery of the metal honeycomb body having the shell on the outer periphery and an outer cylinder into which the metal honeycomb body is inserted. Honeycomb body. 12. A gap is provided between a metal honeycomb body having the shell on the outer periphery and an outer cylinder into which the metal honeycomb body is inserted, and between a part of the outer periphery of the shell and the outer cylinder. The metal honeycomb body for an exhaust gas purifying catalyst according to claim 6, wherein 13. A metal honeycomb body is formed by winding a flat foil and a corrugated foil while supplying a diffusion inhibitor to a position corresponding to the non-joined portion, and forming the obtained metal honeycomb body at a processing temperature of 1.
100 ° C. to 1250 ° C., a heat treatment time of 30 minutes to 90 minutes and a final vacuum degree of 3 × 10 ^{−4 to} 5 × 10 ⁻⁵ Torr, and a flat foil other than the position corresponding to the non-bonded portion. The method for producing a metal honeycomb body for an exhaust gas purifying catalyst according to any one of claims 1 to 5, wherein a contact portion of the corrugated foil is subjected to solid diffusion bonding. 14. A metal honeycomb body is formed by winding a flat foil and a corrugated foil while supplying a diffusion inhibitor to a position corresponding to the non-joined portion, and forming the metal honeycomb body around the outer periphery of the metal honeycomb body. The flat or corrugated foil to be formed is wound one or more rounds to form a shell, and then the obtained metal honeycomb body is processed at a processing temperature of 1100 ° C to 1250 ° C and a processing time of 30 minutes to 9 minutes.
Heat-treating under the processing conditions of 0 minute and ultimate vacuum degree of 3 × 10 ^{-4 to} 5 × 10 ^-5 Torr, and solid diffusion bonding of the contact portion between the flat foil and the corrugated foil other than the position corresponding to the non-bonded portion. The method for producing a metal honeycomb body for an exhaust gas purifying catalyst according to any one of claims 6 to 12, wherein: 15. The method for producing a metal honeycomb body for an exhaust gas purifying catalyst according to claim 14, wherein the shell is a flat foil or a corrugated foil different from the metal foil forming the metal honeycomb body. 16. When forming the metal honeycomb body, a brazing material is adhered to an outer peripheral surface of a shell provided on an outer periphery of the metal honeycomb body, and is attached to an outer peripheral surface of the metal honeycomb body having no shell. The method for producing a metal honeycomb body for an exhaust gas purifying catalyst according to claim 14, wherein the metal honeycomb body is assembled into an outer cylinder after the diffusion inhibitor is attached, and heat treatment is performed. 17. The metal for an exhaust gas purifying catalyst according to claim 14, wherein a brazing material is attached to a part of the outer peripheral surface of the shell, and a diffusion inhibitor is attached to the remaining part of the outer peripheral surface. A method for manufacturing a honeycomb body. 18. The method according to claim 13, wherein the solid-phase diffusion bonding is performed by performing a vacuum heat treatment at a temperature T (° C.) in the following formula according to the thickness t (μm) of the metal foil. A method for producing a metal honeycomb body for an exhaust gas purifying catalyst of the present invention. 1100 ≦ T ≦ 1.7 × t + 1165