JPH09108576A - Metal carrier of catalyst converter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal carrier of a catalyst converter in which an inner cylinder can be easily mounted into an outer cylinder and which can be manufactured more easily than a conventional one by improving the metal carrier whose shell having therein a core is of double-wall structure comprising an inner and outer cylinders. SOLUTION: In a metal carrier of a catalyst converter in which a shell 19 including a core 17 formed from corrugated metal plates and flat metal plates is of double-wall structure comprising an outer cylinder 21 and an inner cylinder 23, a portion 25 of the outer cylinder 21, having a reduced diameter, is formed on the side of an end 21a of the cylinder 21 so that the outer periphery of one end 23a of the cylinder 23 can be brought into contact with the portion 25, and a portion 27 of the cylinder 23, having an enlarged diameter, is formed on the side of the other end 23b of the cylinder 23 so as to be brought into contact with the inner periphery of the cylinder 21, so that the cylinder 21 and cylinder 23 can be joined together through at least any one of the portions 25, 27.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a metal carrier of a catalytic converter mounted in an exhaust system of an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, for example, a vehicle exhaust system has been equipped with a catalytic converter for purifying exhaust gas discharged from an engine, but these days, as a catalyst carrier, a corrugated plate and a flat plate made of metal are used. A metal carrier composed of a core and a shell containing the core is widely used, and a catalytic converter is formed by attaching a noble metal catalyst to the core and then attaching diffusers before and after the shell.

By the way, these days, as disclosed in Japanese Patent Laid-Open No. 6-47285, for the purpose of enhancing the temperature rising characteristic of the catalytic converter to enhance the activity of the catalyst and to shield the heat to reduce the thermal influence on the surroundings. Japanese Patent Application Laid-Open No. 2003-242242 discloses a metal carrier having a shell having a core and having a double structure including an inner cylinder and an outer cylinder. 6 and 7 show the metal carrier disclosed in the above publications, in which 1 is a core formed by winding a corrugated plate 3 and a flat plate 5 made of metal in multiple layers, and 7 is a core 1. The shell 7 is composed of an inner cylinder 11 and an outer cylinder 13 made of a metal whose both ends are airtightly joined to each other and the inside 9 of which is formed into a vacuum. Tube 1
The outer cylinder 1 and the outer cylinder 13 are brazed with a brazing material.

After the noble metal catalyst is loaded on the core 1 as described above, diffusers (not shown) are attached to the front and rear of the shell 7 to form a catalytic converter using the metal carrier 15. . Incidentally, as the supporting treatment of the noble metal catalyst, a washcoat solution containing a noble metal catalyst such as platinum on the surfaces of the corrugated plate 3 and the flat plate 5 constituting the core 1 (a solution containing γ-alumina, an additive and a noble metal catalyst) Is widely used to form a thin coating film called a washcoat layer.

[0005]

However, in the metal carrier 15 described above, the openings 11a, 1 at both ends of the inner cylinder 11 are formed.
Due to the structure in which 1b is expanded and joined to the inner circumference 13a of the outer cylinder 13, strict dimensional accuracy is required for the inner cylinder 11 and the outer cylinder 13, but by expanding both ends of the inner cylinder 11 in this way, If so, it has been pointed out that it is difficult to insert the inner cylinder 11 into the outer cylinder 13 and the workability in manufacturing the metal carrier 15 is poor.

The present invention has been devised in view of the above circumstances, and an improvement has been made to the metal carrier of a catalytic converter in which the shell for housing the core has a double structure of an inner cylinder and an outer cylinder, and An object of the present invention is to provide a metal carrier for a catalytic converter which is easier to assemble than the conventional one by facilitating the assembling of the inner cylinder.

[0007]

In order to achieve such an object, the invention according to claim 1 provides a shell in which a core formed of a metal corrugated plate and a flat plate is mounted, an outer cylinder and an inner cylinder. In a metal carrier of a catalytic converter having a double structure of an inner cylinder inserted in the inner cylinder, a reduced diameter portion is formed on one end side of the outer cylinder to which an outer periphery of one end side of the inner cylinder contacts, and A large diameter portion that contacts the inner circumference of the outer cylinder is formed on the other end side of the outer cylinder, and the outer cylinder and the inner cylinder are joined at at least one of the reduced diameter portion and the large diameter portion. To do.

[0008] The invention according to claim 2 is based on claim 1.
The metal carrier according to claim 3 is characterized in that a diffuser is extended to the reduced diameter portion of the outer cylinder, and the invention according to claim 3 is the metal carrier according to claim 1 or 2, wherein To
The diffuser that extends through the reduced diameter portion of the outer cylinder is extended.

[0009]

According to the metal carrier of each claim, the catalytic converter is formed by mounting the noble metal catalyst on the core and then attaching the diffuser to the shell, and
By mounting such a catalytic converter on the vehicle exhaust system, exhaust gas can be purified.

A shell consisting of an outer cylinder and an inner cylinder joined to at least one of the reduced diameter portion and the large diameter portion,
The catalytic converter's temperature rising characteristics are enhanced to enhance the catalyst's activity, and the exhaust gas is shielded to reduce the thermal influence on the surroundings.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an embodiment of the metal carrier according to claim 1. In the figure, 17 is a corrugated plate made of a thin metal plate such as Fe--Cr alloy and a flat plate, which are wound in multiple layers and rolled. Shaped core, 19 is a metal shell that contains the core 17, and the shell 19 is a metal (for example, SUS430) outer cylinder 21 and inner cylinder 2 formed in a circular cross section.
3 and has a structure in which the core 17 is brazed in the inner cylinder 23 with a brazing material.

On the one end 21a side of the outer cylinder 21, there is formed a reduced diameter portion 25 with which the outer circumference of the one end 23a side of the inner cylinder 23 abuts, and on the other end 23b side of the inner cylinder 23, the outer cylinder 21 is formed.
Of the outer cylinder 21 and the inner cylinder 23, the large diameter portion 27 is formed so as to come into contact with the inner circumference of the other end 21b of the outer cylinder 21 and the inner cylinder 23.
Each is spot-welded and joined together.

The metal carrier 29 according to the present embodiment is constructed in this way. To manufacture the metal carrier 29, first, the other end 23b side of the cylindrical inner cylinder 23 is formed by, for example, a molding die. While expanding to form the large diameter portion 27,
Similarly, the one end 21a side of the outer cylinder 21 which is also cylindrically shaped is squeezed by a molding die to form the reduced diameter portion 25. Next, the core 17 formed by winding the corrugated plate and the flat plate in multiple layers is inserted into the inner cylinder 23 from the large diameter portion 27 side, and the contact portion between the corrugated plate and the flat plate and the outer periphery of the core 17 and the inner cylinder 23 is inserted. Braze.

Then, as shown in FIG. 2, one end 23a of the inner cylinder 23 incorporating the core 17 is inserted from the other end 21b side of the outer cylinder 21, and its outer circumference is brought into contact with the inner circumference of the reduced diameter portion 25. As shown by the chain double-dashed line, the one end 23a side of the inner cylinder 23 may be projected from the reduced diameter portion 25 by a predetermined amount, and thus the one end 23a side of the inner cylinder 23 may be extended from the reduced diameter portion 25 by a predetermined amount. When projected, the large diameter portion 27 of the inner cylinder 23 comes into contact with the inner circumference of the outer cylinder 21 on the other end 21b side.

Thereafter, the outer cylinder 21 and the inner cylinder 23 are connected to each other by the reduced diameter portion 25.
The inner and outer cylinders 21 and 23 are joined to each other by spot welding with the large-diameter portion 27 and the large-diameter portion 27 to manufacture the metal carrier 29 according to the present embodiment, and the noble metal catalyst is carried on the core 17 as in the conventional case. After that, the diffusers 31 and 33 are attached to the front and rear of the shell 19 to form the catalytic converter.

By mounting such a catalytic converter on the vehicle exhaust system, exhaust gas is purified, and
The shell 19 composed of the outer cylinder 21 and the inner cylinder 23 enhances the temperature rising characteristic of the catalytic converter to enhance the activity of the catalyst, and the shell 19 shields the exhaust gas to reduce the thermal influence on the surroundings. Become. As described above, in the metal carrier 29 according to the present embodiment, the reduced diameter portion 25 with which the outer circumference of the one end 23a of the inner cylinder 23 abuts is formed on the one end 21a side of the outer cylinder 21, and the other end of the inner cylinder 23 is also formed. Since the large diameter portion 27 that comes into contact with the inner circumference of the outer cylinder 21 is formed on the 23b side, in manufacturing, from the other end 21b side of the outer cylinder 21 that is largely opened,
The one end 23a side of the inner cylinder 23 having a smaller diameter than that of the other end 21b is inserted, and the outer circumference thereof is brought into contact with the reduced diameter portion 25.
Since it suffices to bring the large-diameter portion 27 of No. 3 into contact with the inner circumference of the outer cylinder 21, it is extremely easy to insert the inner cylinder 23 into the outer cylinder 21 as compared with the conventional example shown in FIG. Compared with the conventional example, it is possible to easily manufacture the metal carrier 29 in which the shell 19 has a double structure of the outer cylinder 21 and the inner cylinder 23.

FIG. 3 shows an embodiment of the metal carrier according to any one of claims 1 to 3, in which reference numeral 35 denotes a metal shell containing the core 17 therein, and the shell 35 is also formed into a circular cross section. The outer cylinder 37 and the inner cylinder 39 are made of metal, and the core 17 is brazed in the inner cylinder 39. The outer cylinder 37 includes the outer cylinder 2 of the above embodiment.
Similar to 1, the reduced diameter portion 41 with which the outer circumference on one end side of the inner cylinder 39 abuts
Is formed on one end side, but the outer cylinder 3 in this embodiment is
In addition to such a configuration, 7 has a diffuser 43 in the reduced diameter portion 41.
Is further extended integrally.

On the other hand, the inner cylinder 39 also has a large-diameter portion 45 which is in contact with the inner circumference of the outer cylinder 37 on the other end side and is spot-welded to the outer cylinder 37 at the large-diameter portion 45. Although it has a structure, the reduced diameter portion 41 is further inserted into one end side of the inner cylinder 39 that abuts the reduced diameter portion 41, and the diffuser 47 is formed.
Is extended integrally with the diffuser 43 on the outer cylinder 37 side with a gap 49 therebetween, and its tip 47a slidably contacts the inner circumference of a tubular portion 43a provided at the tip of the diffuser 43. It has a contact structure.

The metal carrier 51 according to this embodiment is constructed in this way. To manufacture the metal carrier 51, after the outer cylinder 37 and the inner cylinder 39 having the above-mentioned structures are respectively molded by a molding die or the like. , The core 17 from the large diameter portion 45 side to the inner cylinder 39
Inserted inside, corrugated plate and flat plate, outer periphery of core 17 and inner cylinder 3
Brazing the abutting part with 9. Then, as shown in FIG. 4, the diffuser 47 of the inner cylinder 39 in which the core 17 is incorporated is used.
Side is inserted into the outer cylinder 37, and the outer circumference of the inner cylinder 39 is reduced to the reduced diameter portion 4
1, the tip 47 of the diffuser 47 is brought into contact with the inner circumference of the diffuser 47.
It suffices to bring a into contact with the inner circumference of the cylindrical portion 43a. When the tip 47a of the diffuser 47 is brought into contact with the inner circumference of the cylindrical portion 43a in this manner, the large diameter portion 45 of the inner cylinder 39 becomes the outer cylinder. It comes into contact with the inner circumference of 37.

Thereafter, the outer cylinder 37 and the inner cylinder 39 are connected to the large diameter portion 4
The other end sides of the inner and outer cylinders 37, 39 are joined to each other by spot welding at 5, and the metal carrier 5 according to the present embodiment.
1 will be manufactured. Then, after supporting the precious metal catalyst on the core 17, the diffuser 3 is provided on the rear portion of the shell 35.
The catalytic converter is formed by mounting the catalytic converter 3, and the exhaust gas is purified by mounting the catalytic converter in the vehicle exhaust system.

The shell 35 consisting of the outer cylinder 37 and the inner cylinder 39 enhances the temperature rise characteristic of the catalytic converter to enhance the activity of the catalyst and shields heat to reduce the thermal influence on the surroundings. Since the tip 47a of the diffuser 47 is slidable with respect to the outer cylinder 37, the inner cylinder 39 that is directly exposed to the exhaust gas is absorbed by the difference in thermal expansion between the outer cylinder 37 and the inner cylinder 39. Becomes

As described above, the metal carrier 5 according to this embodiment
The outer cylinder 37 that has a large opening in manufacturing even if it is 1.
From the other end side of the inner cylinder 39, the diffuser 47 side of the inner cylinder 39 is inserted, and the outer circumference of the inner cylinder 39 is brought into contact with the reduced diameter portion 41.
If the tip 47a is brought into contact with the inner circumference of the cylindrical portion 43a of the diffuser 43 on the outer cylinder 37 side, the large diameter portion 45 of the inner cylinder 39 is formed.
Since it contacts the inner circumference of the outer cylinder 37, insertion of the inner cylinder 39 into the outer cylinder 37 becomes extremely easy as compared with the conventional example shown in FIG. 6, and as a result, the metal carrier 51 is attached more easily than the conventional example. It became possible to manufacture easily.

However, according to the present embodiment, since it is not necessary to attach the diffuser 31 of FIG. 1 separately, the working man-hours can be further reduced as compared with such a metal carrier 29, and in the present embodiment, the diffuser is also provided. Since the diffuser 43 has a double structure by opening the gap 49 between 43 and 47, by using the diffuser 43 and 47 side on the upstream side of the exhaust gas, it is possible to enhance the temperature rising characteristic of the catalytic converter and enhance the activity of the catalyst. It has the advantage that it can.

In addition, according to the present embodiment, the inner cylinder 39 which is directly exposed to the high temperature exhaust gas is the tip 4 of the diffuser 47.
Since 7a is slidable with respect to the outer cylinder 37, the difference in the coefficient of thermal expansion between the outer cylinder 37 and the inner cylinder 39 can be absorbed at the relevant portion, and therefore the stress concentration on the inner cylinder 39 is alleviated. Have the advantage of FIG. 5 shows an embodiment of the metal carrier according to claims 1 and 3, and in this embodiment, a diffuser is extended in an inner cylinder forming a shell.

That is, in the figure, reference numeral 53 denotes a metal shell that houses the core 17, and the shell 53 is also composed of a metal outer cylinder 55 and an inner cylinder 57 that are formed in a circular cross section.
A diffuser 59 that can be inserted into the outer cylinder 55 is integrally extended to one end of the inner cylinder 57, and a large diameter portion 61 that contacts the inner circumference of the outer cylinder 55 is formed on the other end. The core 17 is brazed inside.

A reduced diameter portion 63 through which the diffuser 59 is inserted is formed on one end side of the outer cylinder 55. The reduced diameter portion 63 is in contact with the outer circumference of the diffuser 59, and the outer cylinder 55 and the inner cylinder 57 are spot-welded by the large diameter portion 61 and the reduced diameter portion 63, respectively. There is. The metal carrier 65 according to this embodiment is configured in this way, and like the above-described embodiments, the catalytic converter is formed by mounting the noble metal catalyst on the core 17 and then attaching the diffuser 33 to the shell 53. However, in order to manufacture the metal carrier 65, after molding the outer cylinder 55 and the inner cylinder 57 having the above-mentioned configurations with a molding die or the like, the core 17 is inserted from the large diameter portion 61 side into the inner cylinder 57, The corrugated plate, the flat plate, the outer periphery of the core 17, and the contact portion of the inner cylinder 57 are brazed.

Then, the diffuser 59 side of the inner cylinder 57 incorporating the core 17 is inserted into the outer cylinder 55, and the inner cylinder 57 is inserted.
The outer periphery of the diffuser 59 provided at the inner periphery of the outer diameter of the outer cylinder 55 is made to contact the inner periphery of the reduced diameter portion 63 by inserting the diffuser 59 from the reduced diameter portion 63 by a predetermined amount. It comes into contact with the inner circumference. After that, the outer cylinder 55 and the inner cylinder 5
By spot-welding 7 at the large-diameter portion 61 and the reduced-diameter portion 63, the inner and outer cylinders 55 and 57 are joined to each other to manufacture the metal carrier 65 according to the present embodiment.

Thus, the metal carrier 6 according to this embodiment
5, the outer cylinder 55 having a large opening in manufacturing
From the other end side, the diffuser 59 side of the inner cylinder 57 having a small diameter is inserted, the outer periphery of the diffuser 59 is brought into contact with the inner periphery of the reduced diameter portion 63, and the diffuser 59 is inserted from the reduced diameter portion 63 by a predetermined amount. By doing so, the large-diameter portion 61 of the inner cylinder 57 becomes the outer cylinder 55.
Since it contacts the inner circumference of the outer cylinder 5,
It is extremely easy to insert the inner cylinder 57 into the inner cylinder 5, and as a result, the metal carrier 65 can be manufactured more easily than in the conventional example.

Of course, this embodiment also has an advantage that the number of working steps can be further reduced as compared with such a metal carrier 29, since it is not necessary to separately attach the diffuser 31 of FIG. In each of the above embodiments, the core 17 and the inner cylinders 23, 3
9 and 57 were brazed by brazing filler metal, respectively, but it goes without saying that they may be joined by diffusion joining, and instead of spot welding, the outer cylinders 21, 37, 55 and the inner cylinders 23, 39 are joined. , 57 may be welded all around, or may be brazed or diffusion-bonded together with the core 17, and the joining method is not limited to the above embodiment.

[0031]

As described above, according to the inventions according to each of the claims, it is much easier to insert the inner cylinder into the outer cylinder as compared with the conventional example, so that the shell is formed between the outer cylinder and the inner cylinder. It has become possible to easily manufacture a metal carrier for a catalytic converter having a double structure. Further, according to the inventions according to claims 2 and 3, the number of man-hours for attaching the diffuser can be reduced as compared with the conventional case, and therefore, there is an advantage that the manufacturing of the metal carrier is further improved.

[Brief description of the drawings]

1 is a cross-sectional view of an embodiment of a metal carrier according to claim 1. FIG.

FIG. 2 is an explanatory diagram of a method for manufacturing the metal carrier shown in FIG.

FIG. 3 is a sectional view of an embodiment of a metal carrier according to claims 1 to 3.

FIG. 4 is an explanatory view of a method for manufacturing the metal carrier shown in FIG.

FIG. 5 is a sectional view of an embodiment of the metal carrier according to claims 1 and 3.

FIG. 6 is a cross-sectional view of a conventional metal carrier.

FIG. 7 is a sectional view taken along line VII-VII of FIG. 6;

[Explanation of symbols]

 17 core 19,35,53 shell 21,37,55 outer cylinder 23,39,57 inner cylinder 25,41,63 reduced diameter portion 27,45,61 large diameter portion 29,51,65 metal carrier 31,33,43 , 47,59 Diffuser

Claims (3)

[Claims] 1. A shell (19, 35, 53) containing a core (17) formed of a metal corrugated plate and a flat plate, an outer cylinder (21, 37, 55) and the outer cylinder (21, 37). , 5
5) In a metal carrier of a catalytic converter having a double structure of an inner cylinder (23, 39, 57) inserted in the inner cylinder (23, 39, 57), at one end (21a) side of the outer cylinder (21, 37, 55),
While forming a reduced diameter portion (25, 41, 63) with which the outer periphery on the one end (23a) side of the inner cylinder (23, 39, 57) abuts,
On the other end (21b) side of the inner cylinder (23, 39, 57),
Large diameter part (2) that contacts the inner circumference of the outer cylinder (21, 37, 55)
7, 45, 61) to form an outer cylinder (21, 37, 55)
And the inner cylinder (23, 39, 57) to the reduced diameter portion (25, 4
1, 63) or at least one of the large diameter portions (27, 45, 61) is joined to the metal carrier of the catalytic converter. 2. A metal carrier for a catalytic converter according to claim 1, wherein a diffuser (43) is extended to the reduced diameter portion (41) of the outer cylinder (37). 3. The outer cylinder (37, 37) is attached to the inner cylinder (39, 57).
55. The metal carrier for a catalytic converter according to claim 1 or 2, further comprising a diffuser (47, 59) which extends through the reduced diameter portion (41, 63) of (55).