JPH08173823A - Method for producing metal carrier for exhaust gas purification - Google Patents

Abstract

(57) [Abstract] [Purpose] Exhaust gas purification with a catalyst carrier matrix for carrying a catalyst coat layer for exhaust gas purification interposed in the middle of an exhaust pipe as a main component as means for purifying exhaust gas of automobiles To provide a method for producing a metal carrier for use. In the method for producing an exhaust gas purifying metal carrier, the heat-resistant metal foil is processed into a flat plate shape and a corrugated plate shape, and a portion to which the catalyst coat layer is adhered is rolled up. A step of winding a flat plate and a corrugated plate alternately on the core to be extracted from the core to obtain a honeycomb body having cells in which exhaust gas flows, a step of forming a honeycomb body having a space at the center where the core is pulled out, and the center When a honeycomb body having the space is compressed and deformed so as to eliminate the space, and the cross-sections are in contact with each other when viewed in a cross section perpendicular to the cell penetrating direction, the shape of the line is at least three lines. Is formed into a honeycomb body having a shape including at least one portion radially extending from one center, and a step of inserting the compressed honeycomb body into a casing. A method for producing a metal carrier for purification.

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 purifying exhaust gas, and in particular, it carries a catalyst coat layer for purifying exhaust gas, which is generally provided in the middle of an exhaust pipe as a means for purifying exhaust gas of an automobile. The present invention relates to a method for producing a metal carrier for purifying exhaust gas, which has a catalyst carrier matrix as a main component.

[0002]

2. Description of the Related Art A metal carrier for purifying exhaust gas has a cell wall as thin as 1/3 to 1/4 of cordierite, so that the ventilation resistance can be reduced and the thermal conductivity is good. Since it can be warmed, it has a feature that the catalytic activity can be expressed quickly when the temperature of exhaust gas is low, and its adoption is expanding.

This metal carrier is often used especially as a carrier for a catalyst installed near the manifold. Therefore, since it is exposed to high temperature, durability at high temperature is an important evaluation item of the carrier.

Further, the shape of the carrier is such that the distribution of the flow velocity of the exhaust gas is improved, the heat radiation from the side surface of the carrier is reduced, and the side surface is made as small as possible in order to suppress heat damage. The shape is desirable.

The following methods are known as methods for producing a metal carrier on which a metal foil is wound. The heat-resistant metal foil is processed into the shape of a flat plate and a corrugated plate, and the metal foil is rolled up at the same time to form the catalyst coat layer supporting portion, and then inserted into a round casing to change the shape of the casing and the catalyst coat layer supporting portion. A method of brazing so as to hold it (Fig. 21)
(See Japanese Patent Laid-Open No. 61-199574). As another method, a method of forming a hook on a heat-resistant metal foil and winding it up to form a catalyst coat layer supporting portion has been proposed (JP-A-6-182221).

[0006]

However, the carrier produced by the method disclosed in Japanese Patent Laid-Open No. 61-1995574 has a tension from the direction perpendicular to the metal foil when the structure is round, for example. Since it is a structure that does not take, it is difficult to press the flat plate and the corrugated plate to make sufficient contact, and thus it is difficult to manufacture a carrier having high rigidity.

When the carrier has a round shape, a core is used to wind up the metal foil, and when the core is removed, a space 14 is formed at the center.
However, there was a drawback that it could occur (see FIG. 21).

In the winding method disclosed in Japanese Unexamined Patent Publication No. 6-182221, usually, a core for winding in advance is used as shown in FIG. Adopting a method of winding it around a core while pulling it so that it does not sag, and cutting it after winding the metal foil into a predetermined length,
5B, 5C, 5D) (see Figures 5, 6, 7, and 8)

However, this method has a drawback in that when the film is wound up without using a core, the metal foil is bent so that a gap is likely to be formed and the preparation thereof is difficult.

On the other hand, even when the core is made of the same material as the foil and the cross-sectional area is the same as that of the cell (4A) and the core is wound up to leave the core as it is on the carrier, a small core having a diameter of about 1 mm is produced. Is difficult to manufacture.

On the other hand, in the case of the so-called racing track-shaped carrier 16 which is a carrier shape that is widely used at present, like the round shape, after winding the foil around the core, a straight line is formed from the outer circumference in order to obtain the shape. The part 15 is compressed and tension is applied to the straight part in a direction perpendicular to the foil (see FIG. 22). Therefore, the flat plate 2F and the corrugated plate 3F are always in contact with each other in the compressed straight line portion, and a carrier having high rigidity can be obtained.

However, the carrier produced by the above method 2 has the disadvantage that it is difficult to secure the rigidity because there are not as many places where the foils can be joined as the winding of the flat plate and the corrugated plate. there were.

Therefore, according to the present invention, a honeycomb body obtained by rolling up a heat-resistant metal foil using a core is compressed, and is deformed into a shape such that a flat plate and a corrugated plate of the honeycomb body are sufficiently brought into contact with each other, and then a casing or a shell. It is an object of the present invention to provide a method for producing an exhaust gas purifying metal carrier, which can easily produce a round metal carrier having high rigidity and excellent heat resistance by inserting the metal carrier into the exhaust gas.

[0014]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventor has found that when a racing track shape is used, the flat plate 2F and the corrugated plate 3F are surely brought into contact with each other and have excellent heat resistance. The inventors have found a method of applying the knowledge that a carrier having the same can be applied to a carrier having a round shape and a shape close to that, and have arrived at the present invention.

The above object of the present invention is to provide a method for producing a metal carrier for purifying exhaust gas, which comprises processing a heat-resistant metal foil into a flat plate shape and a corrugated plate shape and rolling up the metal foil to form a portion to which the catalyst coat layer is attached. A step of winding a flat plate and a corrugated plate alternately on a core extracted from the center of the exhaust gas purifying metal carrier to obtain a honeycomb body having cells in which exhaust gas flows, and a honeycomb having a space at the center by extracting the core. A line formed by the steps of forming a body and the honeycomb body having the space at the center compressed and deformed so as to eliminate the space, and the cross-sections of which are in contact when viewed in a cross section perpendicular to the cell penetration direction. Forming a honeycomb body having a shape including at least one portion where at least three lines radially extend from one center, and inserting the compressed honeycomb body into a casing. It was achieved by method of manufacturing the exhaust gas purifying metal carrier which comprises a degree.

The present invention will be described in more detail below. In the present invention, the flat plate 2F and the corrugated plate 3 are formed by the racing track-shaped carrier by compressing the flat plate and the corrugated plate from the direction perpendicular to the metal foil so that the flat plate and the corrugated plate contact each other during the production process.
The contact with F can be reliably performed.

Also, in the case of a round type carrier and a shape close to it, the honeycomb body (5A, 5B, 5C, 5
The same effect can be obtained if the effect can be maintained through the compression step of the flat plate and the corrugated plate of D) from the direction perpendicular to the metal foil.

In the manufacturing method of the present invention, first, the flat plate (2A, 2B, 2C, 2D) and the corrugated plate (3A, 3B, 3) are first attached to the core (1A, 1B, 1C, 1D) extracted from the center of the metal carrier.
C, 3D) are wound up so as to be alternately overlapped with each other to produce a honeycomb body (5A, 5B, 5C, 5D) having cells (4A, 4B, 4C, 4D) through which exhaust gas flows.

Then, the obtained honeycomb body (5A, 5A
B, 5C, 5D), the core (1A, 1B, 1C, 1D) is pulled out to obtain a honeycomb body (5A, 5B, 5C, 5D) having a space (6A, 6B, 6C, 6D) in the center. The honeycomb body is compressed and deformed.

This compression is performed by the portions (8A, 8B, 8) where at least three points on the surface of the honeycomb body space portion are in contact at the same time.
C, 8D, 8E-1, 8E-2, 8F-1, 8F-2,
8F-3) is carried out so as to have at least one, and from a direction perpendicular to the metal foil. That is, FIG. 9 to FIG.
4, the compressed honeycomb body (9A, 9B, 9C,
9D, 9E, 9F), the lines formed by the contact of the cross-sections when viewed in a cross section perpendicular to the cell penetration direction (7A, 7F)
B, 7C, 7D, 7E, 7F) has a shape of at least 3
Where the lines of the book extend radially from one center (8A, 8
B, 8C, 8D, 8E-1, 8E-2, 8F-1, 8F
-2,8F-3) is included at least one.

The reason why three or more portions of the surface of the hollow portion of the honeycomb body are in contact at the same time is to make the overall shape of the honeycomb body as close to a round shape as possible. The part where three or more parts of the surface of the hollow part of the honeycomb body are in contact at the same time does not have to be limited to one part, and does not necessarily exist in the center of the cross section.

Compressed honeycomb body (9A, 9B, 9
The cross-sectional area of C, 9D, 9E, 9F) is preferably in the range of 100 to 110% of the cross-sectional area of the casing. By setting the cross-sectional area within this range, the honeycomb body is appropriately compressed during insertion, and the rigidity of the carrier can be increased. The cross-sectional area of the honeycomb body is 100 times that of the casing.
When it is less than%, a gap is formed between the casing or shell and the honeycomb body, which is not desirable. On the other hand, when it exceeds 110%, the honeycomb body is largely crushed, which is not convenient for carrying the catalyst coat layer.

The cross-sectional shape of the compressed honeycomb body is preferably as close to a round shape as possible in order to reduce the portion that is compressed or deformed when it is inserted into the casing. The compressed honeycomb body is further divided into casings (10A, 10A
B, 10C, 10D) (11A, 11B, 11C,
11D) (Figs. 15, 16, 17, 18)
Alternatively, two or more shells (12A, 12A) having a shape capable of containing a honeycomb body inside when combined.
It is sandwiched by B) (Fig. 19).

Brazing involves depositing the brazing material as the honeycomb body is placed in the casing or shell. The method can be appropriately selected from known methods, and examples thereof include attaching powder of a brazing material, or spreading a brazing foil. It is also possible to use a procedure in which the brazing material is applied to the foil during the winding of the foil.

The foil used for the metal carrier is C, which has excellent heat resistance.
Stainless steel foil containing r and Al, for example Fe-20% by weight
A foil having a composition such as Cr-5 wt% Al, or Fe-18 wt% Cr-3 wt% Al can be used. The thickness of the foil is preferably in the range of 30 to 100 μm, and particularly preferably 50 μm in terms of oxidation resistance and cost.

Cores (1A, 1B, 1 used for winding up
C, 1D) can adopt any cross-sectional shape.
As an example, the shapes shown in FIGS. 1 to 4 can be used. However, it is preferable that the shape of the core has no corners so that the cell is not crushed when tension is applied in the direction opposite to the winding direction when the flat plate and the corrugated plate are wound.

The cell density of the carrier is preferably in the range of 31 to 121 per square cm of cross section. The cell density can be adjusted by changing the wavelength and frequency of the corrugated plate.

[0028]

EXAMPLES The present invention will now be described in more detail by way of examples, which should not be construed as limiting the invention.

Example 1 A metal foil having a thickness of 50 μm of Fe-20 wt% Cr-5 wt% Al stainless steel foil is processed into a flat plate 2A and a corrugated plate 3A, wound around a core 1A, and has a cell 4A through which exhaust gas flows. A honeycomb body 5A was obtained. At this time, tension was applied in the directions 18 and 19 opposite to the winding direction 17 around the foil (see FIG. 1). This tension is 0.5 to 10 kg on a flat plate
/ Cm, 5Kg / cm so as not to loosen the corrugated sheet
It is desirable to make the following. It is desirable that the tension be strong at the beginning of the winding and weak at the end of the winding. This is to maintain the shape of the cell formed by the flat plate and the corrugated plate and ensure the contact between the flat plate and the corrugated plate.

When the foil was wound so that the inner volume and the volume of the casing 10A were the same, the core was removed to obtain a honeycomb body 5A having a space portion 6A (FIG. 5). Honeycomb body 5A from outside of 5 to 100 kg / mm ² range, preferably under a pressure of 40 Kg / mm ^2, first, and the further portions of the cross bar after its sectional shape was set to cross A swastika type honeycomb body 9 is formed by bending under the same pressure.
It was set to C (FIG. 11).

A foil-shaped brazing material [J
Ni braze and Ni-Al specified in ISZ-3265
BNi-5 equivalent product (Cr: 18.
0 to 19.5 wt%, Si: 9.75 to 10.5 wt%, C: <0.10 wt%, B: <0.03 wt%,
P: <0.02% by weight, Ni: balance)], and insert the powdered brazing filler metal into the inside 11A of the casing 10A, and carry out a joining process [as a joining process, in air. After heating to 100-600 ° C, in vacuum (10 ^-
4 Torr) and heating was performed at 1180 to 1230 ° C. for 2 hours or less] to obtain a metal carrier 13 (see FIG. 20).

Example 2 A metal carrier 13 was obtained in the same manner as in Example 1 except that the casing 10B (see FIG. 16) was used instead of the casing 10A.

Example 3 A metal carrier 13 was obtained in the same manner as in Example 1 except that the casing 10D (see FIG. 18) was used instead of the casing 10A.

Example 4 A metal carrier 13 was obtained in exactly the same manner as in Example 1 except that the core 1B (see FIG. 2) was used in place of the core 1A.

Example 5 A metal carrier 13 was obtained in the same manner as in Example 1 except that the core 1C (see FIG. 3) was used instead of the core 1A.

Example 6 The volume of the honeycomb body 5A was set to 5 from the internal volume of the casing 10.
A metal carrier 13 was obtained in exactly the same manner as in Example 1 except that the percentage was increased.

Embodiment 7 Shells 12A and 12B (see FIG.
9) was used in the same manner as in Example 1 to obtain a metal carrier 13.

Example 8 A metal carrier 13 was obtained in the same manner as in Example 1 except that the core 1A was replaced with the core 1B and the honeycomb body obtained by further compression had a shape of 9A (see FIG. 9). .

Example 9 A metal carrier 13 was obtained in the same manner as in Example 8 except that the casing was changed to 10C (see FIG. 17).

Example 10 A metal carrier 13 was obtained in exactly the same manner as in Example 1 except that the core 1A was replaced with the core 1B and the honeycomb body obtained by further compression had a shape of 9D (see FIG. 12). .

Example 11 A metal carrier 13 was obtained in the same manner as in Example 10 except that the casing was 10B (see FIG. 16).

Example 12 A metal carrier 13 was obtained in the same manner as in Example 1 except that the core was changed from 1A to 1B and the shape of the honeycomb body obtained by compression was 9E (see FIG. 13).

Example 13 A metal carrier 13 was obtained in exactly the same manner as in Example 1 except that the core was changed from 1A to 1B and the shape of the honeycomb body obtained by compression was 9F (see FIG. 14).

Example 14 A metal carrier 13 was obtained in exactly the same manner as in Example 10 except that the shape of the honeycomb body obtained by compression was 9E (see FIG. 13).

Example 15 A metal carrier 13 was obtained in the same manner as in Example 10 except that the honeycomb body obtained by compression had a shape of 9F (see FIG. 14).

Example 16 Except that the shape of the casing was changed to 10D (see FIG. 18),
A metal carrier 13 was obtained in exactly the same manner as in Example 14.

[0047]

EFFECTS OF THE INVENTION According to the present invention, a honeycomb body formed by winding a heat-resistant metal foil using a core is compressed and deformed into a shape that allows a flat plate and a corrugated plate of the honeycomb body to come into sufficient contact with each other. Since it is later inserted into the casing or shell, a round metal carrier for exhaust gas purification having high rigidity and excellent heat resistance can be easily manufactured.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state in which a flat plate and a corrugated plate forming a catalyst coat layer supporting portion of a metal carrier according to the present invention are wound up.

FIG. 2 is a cross-sectional view showing a state in which a flat plate and a corrugated plate forming a catalyst coat layer supporting portion of a metal carrier according to the present invention are wound up.

FIG. 3 is a cross-sectional view showing a state in which a flat plate and a corrugated plate forming a catalyst coat layer supporting portion of the metal carrier according to the present invention are wound up.

FIG. 4 is a cross-sectional view showing a state in which a flat plate and a corrugated plate forming a catalyst coat layer supporting portion of the metal carrier according to the present invention are wound up.

FIG. 5 is a cross-sectional view of the honeycomb body with the core 1A removed from the honeycomb body of FIG.

FIG. 6 is a cross-sectional view of the honeycomb body in a state where the core 1B is removed from the honeycomb body of FIG.

FIG. 7 is a cross-sectional view of the honeycomb body with the core 1C removed from the honeycomb body of FIG.

FIG. 8 is a cross-sectional view of the honeycomb body with the core 1D removed from the honeycomb body of FIG.

FIG. 9 shows a honeycomb body (5A, 5B,
5C, 5D) to compress the internal space (6A, 6B, 6C,
6D) is a cross-sectional view of a compressed honeycomb body in a state where 6D) is lost.

FIG. 10 shows a honeycomb body (5A, 5
B, 5C, 5D) to compress the internal space (6A, 6B, 6
FIG. 6C is a cross-sectional view of a compressed honeycomb body without C, 6D).

FIG. 11 shows a honeycomb body (5A, 5
B, 5C, 5D) to compress the internal space (6A, 6B, 6
FIG. 6C is a cross-sectional view of a compressed honeycomb body without C, 6D).

FIG. 12 shows a honeycomb body (5A, 5
B, 5C, 5D) to compress the internal space (6A, 6B, 6
FIG. 6C is a cross-sectional view of a compressed honeycomb body without C, 6D).

FIG. 13 shows a honeycomb body (5A, 5
B, 5C, 5D) to compress the internal space (6A, 6B, 6
FIG. 6C is a cross-sectional view of a compressed honeycomb body without C, 6D).

[Fig. 14] Fig. 14 shows a honeycomb body (5A, 5
B, 5C, 5D) to compress the internal space (6A, 6B, 6
FIG. 6C is a cross-sectional view of a compressed honeycomb body without C, 6D).

FIG. 15 is a sectional shape view of a casing into which a honeycomb body is inserted.

FIG. 16 is a cross-sectional view of a casing into which a honeycomb body is inserted.

FIG. 17 is a sectional shape view of a casing into which a honeycomb body is inserted.

FIG. 18 is a sectional shape view of a casing into which a honeycomb body is inserted.

FIG. 19 is a sectional shape view of a shell surrounding a honeycomb body.

FIG. 20 shows a metal carrier having a honeycomb body inserted in a casing.

FIG. 21 shows a carrier having a round cross-sectional shape according to a conventional manufacturing method.

FIG. 22 is a cross-sectional structural view of a racing track-shaped metal carrier.

[Explanation of symbols]

1A, 1B, 1C and 1D core 2A, 2B, 2C and 2D flat plate 3A, 3B, 3C and 3D corrugated plate 4A, 4B, 4C and 4D cells 5A, 5B, 5C and 5D honeycomb body 6A, 6B, 6C and 6D space 7A, 7B, 7C, 7D, 7E and 7F Lines formed by cross-section contact 8A, 8B, 8C, 8D, 8E-1, 8E-2, 8F-
1, 8F-2 and 8F-3 at least 3 lines are 1
Radiation extending from one center to radiation 9A, 9B, 9C, 9D, 9E, 9F Compressed honeycomb body 10A, 10B, 10C and 10D Casing 11A, 11B, 11C and 11D Internal space 12A and 12B Shell 13 Metal carrier 14 Centered Space that can be created 15 Compression direction 16 Carrier 17 Direction to roll up 18 and 19 Direction to apply tension to flat plate

Claims (3)

[Claims] 1. A method for producing an exhaust gas-purifying metal carrier, which comprises processing a heat-resistant metal foil into a flat plate shape and a corrugated plate shape, and winding the rolled metal foil to form a portion to which a catalyst coating layer is attached. Of the core to be extracted from the center of the flat plate and corrugated plate so as to alternately overlap, to obtain a honeycomb body having cells in which exhaust gas flows, a step of forming a honeycomb body having a space at the center where the core is pulled out, A honeycomb body having the space at the center is compressed and deformed so as to eliminate the space, and when viewed in a cross section perpendicular to the cell penetrating direction, at least three line shapes are formed when the cross sections are in contact with each other. A step of forming a honeycomb body having a shape including at least one portion where the line of FIG. 1 radially extends from one center, and a step of inserting the compressed honeycomb body into a casing. The method of manufacturing the exhaust gas purifying metal carrier. 2. The method for producing a metal carrier for exhaust gas purification according to claim 1, wherein the cross-sectional area of the honeycomb body having no internal cavity is 100 to 110% of the cross-sectional area of the space in which the casing catalyst coat layer supporting portion is inserted. And a method for producing a metal carrier for purifying exhaust gas, wherein the metal carrier is compressed when inserted. 3. The method for producing a metal carrier for exhaust gas purification according to claim 1, wherein a honeycomb body having no internal cavity is inserted into a concave portion of a shell made up of at least two parts, instead of the round casing. Then, the shell is stopped, and a method for producing a metal carrier for purifying exhaust gas, comprising: