JP3315742B2 - Manufacturing method of metal carrier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A metal carrier is made of a heat-resistant stainless steel having a thickness of about 50 .mu.m and a flat or micro-corrugated metal foil (hereinafter referred to as a flat foil) and a metal foil obtained by corrugating a flat metal foil. (Hereinafter referred to as a corrugated foil)) and wound in a spiral shape or alternately stacked to form a honeycomb body, and this honeycomb body is housed and fixed in an outer cylinder made of a corrosion-resistant and heat-resistant metal such as stainless steel. It is configured.

[0003] After supporting a catalyst for purifying exhaust gas, this metal carrier is used, for example, mounted and fixed in an exhaust gas path of an automobile engine, due to a heat cycle of heating and cooling and a temperature distribution difference inside the honeycomb body. It is required to withstand thermal stress and thermal fatigue. For this purpose, it is essential to have a contact portion between the flat foil and the corrugated foil inside the honeycomb body and a rational connection between the honeycomb body and a metal outer cylinder that houses the honeycomb body.

[0004] A specific portion inside the honeycomb body or between the honeycomb body and the outer cylinder must be firmly joined. Stress is generated, and the joint between the outer cylinder and the honeycomb body is destroyed due to thermal fatigue, or the inside of the honeycomb body is destroyed and the honeycomb body falls off the outer cylinder, causing problems such as engine trouble or reduced exhaust gas purification ability. appear.

[0005] In order to prevent this, the contact portion between the flat foil and the corrugated foil of the honeycomb body is not entirely joined.
As disclosed in Japanese Patent Application Laid-Open No. 3,312,944, a method of brazing only at least one end face of at least one end face of a honeycomb body as disclosed in Japanese Patent No. 41466,
A structure in which a part of a corrugated foil and a flat foil are made to have a flexible bonding structure, or a structure in which a honeycomb body and an outer cylinder are locally bonded, as disclosed in Japanese Utility Model Application Laid-Open No. 62-194436, has been proposed. I have.

However, in each of these examples, the specific joining portion between the flat foil and the corrugated foil is joined by brazing. In the brazing joining method, in addition to the cost problem of the brazing agent,
There is a problem that the brazing component diffuses into the flat foil or corrugated foil and deteriorates the high-temperature strength and the oxidation resistance, or a problem that the flat foil or corrugated foil is corroded (brazed) if the brazing agent is supplied too much. is there.

[0007] Therefore, as a method without using a brazing agent,
Japanese Patent Application Laid-Open Nos. 54-13462 and 63-36843 disclose bonding using high-density energy such as an electron beam or a laser.
As disclosed in Japanese Patent No. 3462, it is proposed to join a flat foil and a corrugated foil by resistance welding, but the joining rate is rate-determining in any of these, and there is a limit in increasing productivity and reducing costs.

Further, Japanese Patent Application Laid-Open No. 56-85514 discloses a method of sintering the contact portion.
No. 8636 describes a method based on solid phase diffusion bonding. According to such a sintering method or a solid phase diffusion bonding method,
Although it is possible to temporarily solve the problem in terms of characteristics or work involved in brazing as described above, in order to obtain sufficient strength of the joint by these treatments, heating at high temperature for a long time It is necessary to perform the treatment and to apply a considerably large pressure to the contact portion between the flat foil and the corrugated foil.

Japanese Patent Laid-Open No. 2-147 for satisfying this requirement
No. 47 discloses that the outer cylinder containing the honeycomb body is squeezed and reduced in diameter to improve the contact between the flat foil and the corrugated foil and the adhesion (surface pressure) between the honeycomb body and the outer cylinder. Diffusion bonding is proposed but not sufficient.

Furthermore, Japanese Patent Publication No. 60-28592 discloses a method of manufacturing a honeycomb body made of titanium or a titanium-based alloy by laminating copper and nickel on a bonding interface and lowering the melting point by a eutectic reaction. Liquid phase diffusion bonding has been proposed in which bonding is performed via the liquid phase, and then these elements are diffused into the base material to make the components uniform. There is a drawback that it takes a long time for the heat diffusion treatment for the formation of the film.

[0011] Furthermore, the joining of the outer cylinder and the honeycomb body also has the same problem as the joining of the contact portion between the flat foil and the corrugated foil in the case of the brazing method. When a mechanical means such as a retainer is used, there is a problem that the honeycomb body is damaged by being bitten by the retainer.

[0012]

As described above, many proposals have been made for solid-phase or liquid-phase diffusion bonding. However, long-time heat treatment at a high temperature impairs productivity as well as manufacturing cost, and Also, the improvement of the adhesion by reducing the diameter of the outer cylinder containing the honeycomb body by narrowing the outer cylinder tends to be effective only in the vicinity of the outer periphery of the honeycomb body and insufficient at other locations.

The purpose of reducing the outer cylinder is to increase the pressing force between the flat foil and the corrugated foil, thereby increasing the contact surface pressure and performing good solid-phase diffusion bonding.
m, and is easily deformed, so that the contact surface pressure does not substantially increase, and the contact becomes microscopic point contact due to irregularities on the surface of the metal foil. For this reason, the joint does not become a continuous linear solid-state diffusion bonding along the contact line between the flat foil and the corrugated foil, but becomes a discontinuous point-like solid-phase diffusion bonding. When the battery is mounted on a test piece and tested for durability, problems such as partial loss of the flat foil or corrugated foil and delamination occur due to insufficient bonding. Further, destruction at the junction between the honeycomb body and the outer cylinder directly leads to troubles such as detachment of the honeycomb body from the outer cylinder.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems in the honeycomb body and the joining of the honeycomb body and the outer cylinder. The present invention is directed to a contact portion of a flat foil and a corrugated foil constituting the honeycomb body or an outer cylinder. The present invention provides a method for manufacturing a metal carrier in which a bonding portion between a honeycomb structure and a honeycomb body has necessary and sufficient strength.

[0015]

In order to achieve the above object, the present invention has the following constitution. That is, (1) carbon, boron, a halogen element or a compound thereof.
A honeycomb body is formed by adhering a bonding promoter comprising at least one compound to a predetermined portion of a flat foil or a corrugated foil, and the honeycomb body is incorporated in an outer cylinder, or only the honeycomb body is placed in a non-oxidizing atmosphere. It is a method of manufacturing a metal carrier, characterized in that a flat foil and a corrugated foil are joined by heat treatment at,
(2) After forming the honeycomb body, carbon, boron, halogen
Element or at least one of these compounds
The adhesion promoting agent is adhered to a predetermined site within the honeycomb body that, to the said honeycomb body on the outer tube into systems or the honeycomb body only, bonding the heat treatment to the flat foil and corrugated foil in a non-oxidizing atmosphere (3) A method for manufacturing a metal carrier comprising the steps of: (3) forming a charcoal on an outer surface of a joined honeycomb body or an unjoined honeycomb body,
Elemental, boron, halogen elements or their compounds
At least one kind of bonding promoter is attached, and then the outer cylinder is inserted. The outer cylinder and the honeycomb body are joined by heat treatment in a non-oxidizing atmosphere to be integrated. It is a manufacturing method.

[0016]

The reason why the bonding promoter is applied to the predetermined portion corresponding to the bonding portion of the corrugated foil or the flat foil as described above is to obtain a continuous good linear bonding portion. A bonding promoter is attached to the contact portion, and by a heat treatment in a non-oxidizing atmosphere, the oxide film on the surface of the flat foil and the corrugated foil that interferes with bonding is reduced and decomposed by the action of the bonding promoter, or In addition, the melting point of the bonding agent-applied part is lowered, and a liquid phase part in the form of a film is exposed at the bonding interface to obtain a reliable diffusion bonding part through this liquid phase. Various conditions required for joining such as application of surface pressure can be relaxed.

In addition to solid-phase diffusion bonding, a liquid phase is made to appear at the bonding interface as described in the above-mentioned Japanese Patent Application Laid-Open No. 60-28592. And then heat-treated to diffuse the joining elements and homogenize the components. Liquid phase diffusion bonding, or bonding without performing diffusion heat treatment to homogenize the components after bonding in the liquid phase diffusion bonding process ( Hereinafter, it is referred to as liquid phase bonding.)

The bonding promoter used in the present invention has an action of reacting with the oxide film of the base material to reduce and decompose or a function of lowering the melting point. The above three types of bonding can be performed by selecting the conditions of the amount of the agent, the heat treatment temperature, and the time.

That is, when performing solid phase diffusion bonding, the amount of the bonding promoter used is reduced, the reduction of the oxide film at the bonding interface is stopped, and thereafter solid phase diffusion bonding is controlled by controlling the surface pressure, heat treatment temperature and time. Let me know. In the case of performing liquid phase bonding, the amount of the bonding promoter used is slightly increased, a liquid phase portion is surely formed at the bonding interface, and then the solidification is performed by cooling and solidifying. Further, when performing liquid phase diffusion bonding, the liquid phase portion is maintained at a high temperature, so that the liquid phase portion is diffused and disappeared in the base material and bonded.

In the case of solid solution diffusion bonding, the amount of foreign components penetrated is small and there is little problem such as material deterioration. However, it is strongly affected by the properties of the bonding interface, and requires processing at high temperature and high vacuum. There is a disadvantage that it requires. On the other hand, in the case of liquid phase bonding, since a heterogeneous phase is formed at the bonding interface, it may be disadvantageous in terms of strength or corrosion resistance, but the influence of the properties of the bonding interface is small, and the heat treatment time is short. Excellent productivity. In the case of the liquid phase diffusion bonding, since the liquid phase part is finally diffused and disappeared in the base material, a bonded part with less influence of the foreign component can be obtained, but there is a problem that the processing requires a long time. As described above, according to the present invention, three types of joining modes can be achieved by setting conditions, and thus the setting may be made in consideration of required joint characteristics or productivity.

The bonding promoters include carbon, boron and halogen
Motoa Rui is effective these compounds, a method for coating deposited by blending the other liquid coating agent is excellent in workability surface, such as using by processing used or tape-like in powder form Is also possible.

As a method of joining the inside of the honeycomb body or a specific portion of the honeycomb body and the outer cylinder, a method of applying a joining accelerator to a portion to be joined may be used.
There is a method in which a bonding inhibitor is applied to a portion where bonding is to be avoided, and only a portion other than the application position is bonded, and a method of using these in combination. After blending with a liquid coating agent, for example, a method of applying to a predetermined site by a roll coater method disclosed in JP-A-1-242020, or, after applying a liquid coating agent to a predetermined site, a powdery bonding accelerator or It is also possible to use a method in which a blocking agent is sprayed and adhered and adhered, or a tape-shaped product is used.

When the joining promoting portion is near the end of the honeycomb body, when the joining unnecessary portion is treated to prevent joining inside the honeycomb body, or when the whole body is joined, the joining promoting agent is blended. It is also possible to apply the liquid coating agent after forming the honeycomb body by a dipping method or the like.

The outer cylinder and the honeycomb body are joined by brazing or mechanical joining by a retainer. However, the joining method according to the present invention not only reduces the brazing agent cost but also simultaneously joins the honeycomb body. Can be joined,
Excellent productivity.

Hereinafter, the present invention will be described in detail with reference to examples. FIG. 1 is an example showing a schematic view of the manufacturing process of the present invention.
A liquid coating material 2 blended with a bonding promoter 1 is placed in a container 3, and a sink roll 4 is immersed in the liquid coating material 2. The coating material 2 attached to the surface of the sink roll 4 is transferred and synchronized with the movement of the corrugated foil 5. The application roll 6 is rotated and has a coating material 7 attached to a part of its surface so that the liquid application agent 2 can be applied to a predetermined portion of the corrugated foil 5 in advance. The corrugated foil 5 to which the liquid coating agent 2 has been applied is wound around or laminated with the flat foil 8 to form a honeycomb body 9.

Next, as shown in FIGS. 2 (a) to 2 (c), a liquid coating material 2 blended with a bonding promoter 1 is applied to a predetermined portion on the outer surface of the honeycomb body 9 (FIG. 2A). 10 (FIG. B), and then the honeycomb body 9 by the contractor 11
Is reduced (FIG. 3c), and the degree of adhesion between the flat foil 8 and the corrugated foil 5 and the honeycomb body 9 and the outer cylinder 10 in the honeycomb body 9 is increased.

The contraction machine 11 is disclosed, for example, in Japanese Unexamined Patent Publication No.
As shown in Japanese Patent Application Laid-Open No. 4 (1999) -2012, the outer cylinder 10 is surrounded and stored by a large number of segments 12 configured to be able to enter and exit the die 14, and the segments 12 are
Although there is a method of reducing the diameter of the outer cylinder 10 by drawing it into the inner surface of the above, the method is not limited to this method, and a method of press-fitting the formed honeycomb body into the outer cylinder is also effective.

As the liquid coating agent 2, for example, PVA (polyvinyl alcohol), dextrin, various adhesives and the like can be used.
Particulate carbon, boron, halogen, Oh Rui can choose from these compounds, the carbon to promote solid phase diffusion bonding,
Boron compounds, c androgenic compound, the liquid phase diffusion bonding and <br/> liquid phase bonding is effective carbon, especially if the graphite powder, the promotion of solid phase diffusion bonding and liquid phase diffusion bonding or liquid-phase bonding Can also be used. The flat foil 8 and the corrugated foil 5 are mainly made of ferrite alloy foil such as 20Cr-5Al from the viewpoint of heat resistance and oxidation resistance.

[0029]

[Embodiment] As shown in FIG. 3A, the diameter (outer diameter) D1 =
84mm, height B1 = 100mm metal carrier (a1), thickness
t1 = 2mm, diameter (outer diameter) D1 = 84mm, height B1 = 100mm
And a 20Cr-5Al-based alloy foil having a width of
B2 = 100 mm, thickness t2 = 50 μm flat foil 8 (a2), 2
0Cr-5Al alloy foil, width B2 = 100 mm, thickness t2 = 50 μm, wave height h1 = 1.2 mm, wave pitch p1 =
The honeycomb body 9 is composed of a 2.4 mm corrugated foil 5 (a3), and the inside of the honeycomb body 9 has a diameter D2 = 73.
1 shows a method for producing a carrier having a portion which does not promote bonding with a height of B3 = 80 mm.

The length L1 = 4.2 m and the width B2 shown in FIG.
= 100mm, on both sides of corrugated foil 5, length L2 = 3.5m, width B3
= 3 mm by roll coater method except for the area 15 of 80 mm
A liquid coating agent mainly containing a water-soluble thermosetting polymer containing 5% of scale-like graphite having a particle size of about 5 μm is applied.
Next, this corrugated foil 5 is placed on the end of FIG.
As shown in (c), a flat foil 8 is wound around the honeycomb body 9 having a diameter D3 = 80 mm, and the same liquid coating material 2 is applied to the outer surface of the honeycomb body 9 (c1) in the lower half B4 = 50 mm range. Diameter D4
= 85 mm, height B1 = 100 mm, inserted into an outer cylinder 10 (c2), reduced in outer diameter to 84 mm, and 1250 ° C x 60 in a vacuum furnace.
The carrier A was manufactured by heat treatment for one minute.

On the other hand, a carrier B was produced in the same manner except that the carrier having the same dimensions was not coated on the corrugated foil 5 with the liquid coating material 2 containing the bonding promoter 1.

As a result of subjecting the above carriers A and B to the following tests, the carrier according to the present invention was superior to the carrier according to the conventional method as follows.

[0033]

[Table 1]

[0034]

As described above, according to the present invention, a metal carrier having a sufficient bonding strength without heating for a long time at a high temperature or performing an extreme diameter reduction operation by using a bonding promoter. In addition to adopting a pattern joining structure that partially joins only predetermined positions in joining of the honeycomb body, extremely high quality is achieved by optimizing the joining position between the outer cylinder and the honeycomb body, etc. A metal carrier can be obtained efficiently.

[Brief description of the drawings]

FIG. 1 is a view showing a step of applying a liquid coating agent containing a bonding promoter of the present invention.

FIGS. 2A, 2B, and 2C are diagrams schematically showing a process of incorporating a honeycomb body of the present invention into an outer cylinder.

FIGS. 3A, 3B, and 3C are diagrams schematically illustrating a manufacturing process according to an embodiment of the present invention.

[Description of Signs] 1 Joining promoter 2 Liquid coating agent 3 Container 4 Sink roll 5 Corrugated foil 6 Coating roll 7 Coating material 8 Flat foil 9 Honeycomb body 10 Outer cylinder 11 Contractor 12 Segment 13 Hydraulic cylinder 14 Dice 15 Liquid Area where the coating agent is not applied 16 Rolling center

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masao Yatsushiro 5-3 Tokaicho, Tokai City, Aichi Prefecture Nippon Steel Corporation Nagoya Works (72) Inventor Hitoshi Ota 5-3 Tokaicho, Tokai City, Aichi Prefecture New Nippon Steel Corporation Nagoya Works (56) References JP-A-2-86848 (JP, A) JP-A-62-282644 (JP, A) JP-A-62-250950 (JP, A) 5-103994 (JP, A) JP-A-3-278815 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01J 21/00-37/36 B01D 53/86 F01N 3 / 28

Claims (3)

(57) [Claims] In a manufacturing process of a metal honeycomb body formed by laminating or winding a flat metal foil and a corrugated metal foil, carbon, boron, a halogen element or a carbon element.
A bonding body comprising at least one of these compounds is attached to a predetermined portion of a flat metal foil or a corrugated metal foil to form a honeycomb body, and the formed honeycomb body or the honeycomb body is formed of metal. A method for producing a metal carrier, comprising: incorporating a flat metal foil and a corrugated metal foil in a non-oxidizing atmosphere after being assembled into a metal outer cylinder; 2. In a manufacturing process of a metal honeycomb body formed by laminating or winding a flat metal foil and a corrugated metal foil, after forming the honeycomb body, carbon,
Element, halogen element or at least one of these compounds
One type of a bonding accelerator is attached to a predetermined portion of the inside of the honeycomb body, and the honeycomb body or the honeycomb body is incorporated in a metal outer cylinder, and then heated in a non-oxidizing atmosphere to obtain a flat surface. A method for producing a metal carrier, comprising joining a contact portion between a metal foil and a corrugated metal foil. 3. A method in which a bonded honeycomb body or a non-bonded processed honeycomb body is assembled into a metal outer cylinder and heated in a non-oxidizing atmosphere to perform bonding with the outer cylinder.
Carbon, boron, halogen elements or their compounds
After adhering at least one type of the adhesion promoter to a predetermined portion of the outer surface of the honeycomb body or the inner surface of the outer cylinder, the honeycomb body is incorporated into the outer cylinder, and the honeycomb body and the outer cylinder are subjected to heat treatment in a non-oxidizing atmosphere. A method for producing a metal carrier, comprising joining.