JPH11276909A - Method for producing metal catalyst carrier and metal catalyst carrier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure effective welding length by making the butting part of an outer cylinder coincident to the winding end part of a honeycomb part when the depth of a recessed part exceeds a prescribed value based on the depth of the recessed part of the winding end part as a reference and intentionally shifting the winding end part when the depth of the recessed part is within the prescribed value to limit a welding place to only one place. SOLUTION: In the production of a metal made catalyst carrier 20, the outer cylinder 25 formed by welding the butting part 26 from the outside and the honeycomb part 23 formed by laminating a corrugated plate 22 on a flat plat 21 and winding into a roll like state are prepared, the depth of the recessed part in the winding end part 28 of the honeycomb part 23 is measured and in the case that the depth of the recessed part exceeds the prescribed value, the honeycomb part 23 is inserted in the outer cylinder 25 in a state of making the winding end part 28 coincident to the butting part 26 and is fillet-welded to the outer cylinder 25. On the other hand, in the case that the depth of the recessed part is within the prescribed value, the honeycomb part 23 is inserted to the outer cylinder 25 in a state of shifting the winding end part 28 from the butting part 26 and is fillet-welded to the outer cylinder 25. As a result, the length of the unwelded part is shortened to secure the effective welding length.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a metal catalyst carrier and a metal catalyst carrier.

[0002]

2. Description of the Related Art As one method for purifying exhaust gas,
BACKGROUND ART A metal catalyst carrier (metal catalyzer) is known, and a specific structure is described in, for example, JP-A-4-29750, “Metal carrier for exhaust gas purification catalyst”. That is, in FIG. 3 of the publication, band-shaped brazing members 2A and 2B are wound around a honeycomb portion 1 formed by laminating a flat plate 10 and a corrugated plate 11 and winding them in a roll shape. The honeycomb member 1 is inserted into the outer tube 3 with the brazing members 2A and 2B.

In the above brazing method, the brazing member 2 is used.
A work for winding A and 2B and a heating device for heating and melting the wax are required, which increases the number of processing steps.

Therefore, a welding method is considered as an alternative joining method. FIG. 6 is a diagram illustrating the principle of a conventional welding method, in which a honeycomb portion 102 is inserted into an outer cylinder 101 and a laser beam 10 is inserted.
The two are joined by fillet welding at 3. Since the beam spot of the laser beam 103 is very small, the bead width becomes narrow and thermal distortion can be suppressed.
4 is suitable for welding.

FIGS. 7 (a) to 7 (d) are explanatory views when a metal catalyst carrier is manufactured by a conventional laser welding method.
(A) is a perspective view of the honeycomb portion 102. Since the honeycomb portion 102 is wound in a roll shape in a state where the flat plate 104 and the corrugated plate 105 are overlapped, a winding final portion 106 is inevitably generated on the outermost peripheral surface. (B) is an enlarged view of the winding final part 106,
In the winding final part 106, the end of the flat plate 104 is hung on the flat plate 104a one turn before.

FIG. 2C is a partially enlarged view of the honeycomb portion 102 after the honeycomb portion 102 has been inserted into the outer cylinder 101.
, The substantially triangular recess 107 remains in the winding final part 106 even if it is attempted to adhere the inner surface of the outer cylinder 101 to the inner surface of the outer cylinder 101.
(D) shows a state where the flat plates 104 and 104a are welded to the outer cylinder 101, and 108 is a weld bead, and
At position 06, an unwelded portion having a length B appears.

Although the above unwelded portion is not preferable,
In order to completely eliminate the unwelded portion, the shape of the final winding portion 106 must be improved. Specifically, the shape improvement requires secondary processing such as gradually reducing the wave of the corrugated plate 105, which causes an increase in cost. Therefore, the design is made so that the required joining strength can be obtained only by the weld bead 108 from which the unwelded portion is subtracted.

[0008]

Although an unwelded portion is allowed, it has been found that the following problems still occur. If the inner surface of the outer cylinder 101 has irregularities, an unwelded portion may also appear at that portion (see B2 in FIG. 4B described later).
If the unwelded portion is added to the unwelded portion, there is a possibility that a predetermined joining strength cannot be obtained. As a countermeasure, it is conceivable to take measures such as obtaining an outer cylinder 101 with a flat inner surface such as a seamless pipe, or adding a secondary process to flatten the inner surface, but all of these measures increase costs. Leads to. Since the size of the concave portion 107 of the winding final portion 106 changes according to the plate thickness of the flat plate 104 and the corrugated plate 105, if the depth of the concave portion 107 is a certain size or more, the unwelded portion is reduced. However, when the depth of the recess 107 is small, the unwelded portion does not appear. Of course, the absence of unwelded portions is preferable in terms of joining strength.

[0009]

Means for Solving the Problems The present inventors have improved the joint strength of a conventional inexpensive outer cylinder having irregularities on the inner surface and a honeycomb portion in which a gap is likely to be formed at the end of the winding. We decided to develop a manufacturing method that could be secured. During the development, the depth of the dent at the end of the winding varies depending on the thickness of the flat plate and corrugated sheet used, the height of the corrugated sheet, and the pitch. If the depth of this dent is small, the laser beam However, it was found that if it was too large, the laser beam would pass and welding would not be possible.

In view of the above, according to the present invention, there is provided an outer cylinder formed by winding a flat plate into a cylindrical shape and welding a butt portion from the outside, and a honeycomb portion formed by laminating a corrugated plate on the flat plate and winding the roll into a roll.
The depth of the dent at the winding end of the honeycomb portion is measured or predicted, and when the depth of the dent exceeds a predetermined value, the honeycomb portion is fitted to the outer cylinder in a state where the winding end matches the butt portion. Insert, fillet weld the honeycomb portion to the outer cylinder, when the depth of the dent is within a predetermined value, insert the honeycomb portion into the outer cylinder in a state where the winding final part is displaced from the butt portion, It is characterized in that the honeycomb portion is fillet welded.

That is, based on the depth of the dent at the end of the winding, when the depth of the dent exceeds a predetermined value, the end of the winding of the honeycomb portion is intentionally made to match the abutting portion of the outer cylinder. Alternatively, when the depth of the depression is within a predetermined value, the winding end portion of the honeycomb portion is intentionally shifted with respect to the abutting portion of the outer cylinder.

According to a second aspect of the present invention, a honeycomb portion formed by laminating a corrugated plate on a flat plate and winding it into a roll is inserted into an outer cylinder formed by winding a flat plate into a tubular shape and welding a butt portion from the outside. In the metal catalyst carrier in which the honeycomb portion is fillet-welded, a winding end portion of the honeycomb portion is matched with a butt portion of the outer cylinder.

The length of the unwelded portion is reduced by superimposing the unwelded portion caused by the butted portion of the outer cylinder and the unwelded portion caused by the winding end portion, and the effective weld length is secured.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of reference numerals. FIG. 1 is a side view of an exhaust device according to the present invention. The exhaust device 1 includes an exhaust pipe 2 for guiding exhaust gas generated by an internal combustion engine, a silencer 10 as a silencer, and the exhaust pipe 2 and the silencer 10 mounted on a vehicle body. And a bracket 5 for attachment to the frame 4.

FIG. 2 is a sectional view of a main part of a silencer according to the present invention.
(... denotes a plurality; the same applies hereinafter), a sound absorbing material holding cylinder 13 ..., a partition plate 14, a first inner tube 15 and a second inner tube 16 penetrating the partition plate 14, An example of arrangement of a conical tube 17 formed at the outlet end of the first inner tube 15 and a metal catalyst carrier 20 attached to the outlet end of the conical tube 17 is shown.

FIG. 3 is a front view of the metal catalyst carrier according to the present invention. The metal catalyst carrier 20 comprises a flat plate 21 and a corrugated plate 22.
The honeycomb portion 23 formed by superposing the honeycomb portion and wound in a roll is inserted into the outer tube 25, and the outermost peripheral portion of the honeycomb portion 23 is fixed to the outer tube 25 by fillet welding with a laser beam. The flat plate 21 is a stainless steel plate of about 0.1 mm (100 μm), and the corrugated plate 22 is 0.1 mm (100 μm).
m) and a stainless steel plate of about 1.5 mm was used for the outer cylinder 25. The honeycomb portion 23 supports a metal catalyst typified by platinum rhodium. The metal catalyst acts on unburned components in the exhaust gas to oxidize (combust) the metal catalyst. Call.

Next, a method for manufacturing the metal catalyst carrier having the above-described structure will be described. First, the outer cylinder 25 and the honeycomb portion 23 in FIG. 3 are manufactured. The outer cylinder 25 is formed by bending a flat plate, and the butting portion 26 is externally formed by, for example, TIG (tungsten).
(Inert gas) Joining by welding method. Deformation is caused by welding heat and heat shrinkage, and the butted portion 26 becomes convex outward. The amount of protrusion at this time changes depending on welding conditions and the like. When the butt portion 26 is welded from the inside, the bead projects inward and hinders the honeycomb portion 23 from being inserted. Therefore, welding was performed from outside.

The honeycomb portion 23 is formed by spirally winding the flat plate 21 and the corrugated plate 23 from the center, and suitably stopping them by spot welding in the middle thereof.
Is simply applied to the adjacent flat plate 21a, and since the corrugated plate 23 is missing in the winding final portion 28, a "heavy" or V-shaped recess 29 is generated.

Then, the honeycomb portion 23 is inserted into the outer tube 25, and the outer peripheral portion of the honeycomb portion 23 is welded to the inner surface of the outer tube 25 with a laser beam. (See also FIG. 6) Since the laser beam has a small laser spot, it is suitable for joining extremely thin metal plates. However, if the root gap is large because the laser spot is small, a laser beam blow-through phenomenon occurs, resulting in poor welding.

Therefore, an outer cylinder formed by winding a flat plate into a tubular shape and welding a butt portion from the outside, and a honeycomb portion formed by laminating a corrugated plate on the flat plate and winding the roll into a roll are prepared. Measure or predict the depth of the depression in the final part. "Forecast" refers to the material (thickness, thickness,
Once the shape, wave height and pitch of the corrugated sheet, total number of windings, winding method, and spot welding procedure are determined, it is empirically known that the depth of the hollow in the rod falls within a certain control value. Means to adopt. The root gap that can be welded can be determined empirically or experimentally according to the material at that time. The value is "predetermined value"
And

A specific example of claim 1 will be described with reference to FIGS. FIGS. 4A and 4B are diagrams showing examples / comparative examples of a metal catalyst carrier. (A) is an embodiment, and when the depth D of the dent exceeds a predetermined value, the honeycomb portion 23 is inserted into the outer cylinder 25 with the winding final portion 28 aligned with the butted portion 26, and the outer cylinder 25 is inserted into the outer cylinder 25. The honeycomb portion 23 is fillet welded. The winding end portion 28 is not welded, and if this unwelded length is B1, the effective weld length L1 is the value obtained by removing B1 from the 360 ° circumference. In order to make the winding end portion 28 coincide with the butting portion 26, the center of the concave portion 29 only needs to substantially coincide with the butting portion 26.

(B) is a comparative example, in which when the depth D of the dent exceeds a predetermined value, the winding end portion 28 is not made to match the butting portion 26 (for example, it is swung clockwise approximately 80 ° with respect to the butting portion 26). The winding final part 28 is positioned at the position
In this state, the honeycomb portion 23 is inserted into the outer cylinder 25,
If the honeycomb portion 23 is fillet-welded, an unwelded portion having a length B2 due to the butted portion 26 is added in addition to B1, and the effective weld length (L2 + L3) is (B1 + B2) from the 360 ° circumference. Is excluded. Accordingly, the effective welding length (L2 + L3) <the effective welding length L1, and the comparative example has a small strength margin, which is not preferable.

FIG. 5 is a view showing another embodiment of the metal catalyst carrier. When the depth D of the dent is within a predetermined value, the honeycomb is attached to the outer cylinder 25 with the wound final part 28 shifted from the butted part 26. 5 shows a metal catalyst carrier in which the honeycomb portion 23 is fillet-welded to the outer cylinder 25 with the portion 23 inserted. That is, since the depth D of the depression is small in the winding final portion 28, the outer cylinder 2
5 can be welded. Also, the butting portion 2 of the outer cylinder 25
When the protrusion amount of No. 6 is small, welding with the honeycomb part 23 may be possible, and in this case, the 360 ° circumference is the effective welding length.

The reason for intentionally displacing the winding end portion 28 from the butting portion 26 will be described. Even if the depth D of the depression is within a predetermined value, if the winding end portion 28 matches the butting portion 26, the following problem may occur. If the depth t of the recess inside the butting portion 26 of the outer cylinder 25 is added to the depth D of the recess within the predetermined value, the added value (D + t) may exceed the predetermined value. If the specified value is exceeded, welding failure will occur.
The state shown in FIG. When this is compared with FIG. 5 (360 ° full circumference welding is possible), the effective welding length is reduced, which is not preferable.

As described above, when the depth D of the dent exceeds the predetermined value with reference to the depth D of the dent of the final winding portion 28, the final winding portion 2 of the honeycomb portion is intentionally added to the butting portion 26 of the outer cylinder.
FIG. 4 (a) is obtained by matching 8 and FIG. 5 is obtained by intentionally displacing the final winding portion 28 of the honeycomb portion with respect to the butting portion 26 of the outer cylinder when the value is within a predetermined value. It is characterized by.

Although the above-described manufacturing method (claim 1) is useful in securing the effective welding length, it requires a step of measuring or predicting the depth of the depression, so that it is a little troublesome. is there. Therefore, a specific example of claim 2 for the purpose of reducing the manufacturing cost will be described below.

As the cost of the metal catalyst carrier is reduced,
The depth D of the depression tends to increase, and the depth of the depression inside the butted portion 26 tends to increase. In view of this, in claim 2, the structure of the metal catalyst carrier in which the winding end portion 28 matches the butting portion 26 as shown in FIG.

This is because, if this structure is adopted, the trouble of measuring or predicting the depth of the depression can be saved, and the productivity can be improved. That is, since the unwelded portion caused by the butted portion of the outer cylinder and the unwelded portion caused by the final winding portion are overlapped, the number of unwelded portions is not two, and the number of unwelded portions is one.
And the effective welding length can be secured. Since welding is performed in a state where the final part is wound around the butted part, the setup is facilitated, and the productivity can be easily increased.

In the present invention, a laser beam method is suitable as a method for welding the honeycomb portion to the outer cylinder, but other welding methods such as electron beam welding may be used.

[0030]

According to the present invention, the following effects are exhibited by the above configuration. Claim 1 is based on the depth of the dent of the final winding portion, and when the depth of the dent exceeds a predetermined value, the final winding portion of the honeycomb portion is intentionally made to match the abutting portion of the outer cylinder. When the depth is within a predetermined value, the winding end portion of the honeycomb portion is intentionally shifted with respect to the abutting portion of the outer cylinder. Therefore, the number of unwelded portions is not two, and the number of unwelded portions is one.
It becomes a point or 0 (zero), and the effective welding length can be secured.

According to the second aspect, the unwelded portion caused by the butted portion of the outer cylinder and the unwelded portion caused by the winding end portion are overlapped. Becomes one place, and an effective welding length can be secured.
Since welding is performed in a state where the final part is wound around the butted part, the setup is facilitated, and the productivity can be easily increased.

[Brief description of the drawings]

FIG. 1 is a side view of an exhaust device according to the present invention.

FIG. 2 is a sectional view of a main part of a silencer according to the present invention.

FIG. 3 is a front view of the metal catalyst carrier according to the present invention.

FIG. 4 shows an example / comparative example of a metal catalyst carrier.

FIG. 5 is a view showing another embodiment of the metal catalyst carrier.

FIG. 6 is a diagram showing the principle of a conventional welding method.

FIG. 7 is an explanatory view when a metal catalyst carrier is manufactured by a conventional laser welding method.

[Explanation of symbols]

Reference numeral 20: metal catalyst carrier, 21: flat plate, 22: corrugated plate, 2
3. Honeycomb part, 25 ... outer cylinder, 26 ... butting part, 28 ...
Winding final part, 29: depression, B, B1, B2: length of unwelded part, D: depth of depression, L1 to L3: effective welding length.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Mitsunori Takekawa 508-1 Toyocho, Hamamatsu-shi, Shizuoka Prefecture Inside Yutaka Giken (72) Inventor Kogo Kanada 508-1 Toyocho, Hamamatsu-shi, Shizuoka 1 Corporation Yutaka Giken (72) Inventor Toshiaki Okada 508-1 Toyocho, Hamamatsu City, Shizuoka Prefecture Yutaka Giken Co., Ltd.

Claims (2)

[Claims] 1. An outer cylinder formed by winding a flat plate into a tubular shape and welding a butt portion from the outside, and a honeycomb portion formed by laminating a corrugated plate on a flat plate and winding in a roll form are prepared. Measure or predict the depth of the depression in the final part, and when the depth of the depression exceeds a predetermined value, insert the honeycomb part into the outer cylinder in a state where the winding final part is matched with the butting part, and When the depth of the dent is within a predetermined value, the honeycomb portion is inserted into the outer cylinder while the final winding portion is shifted from the butt portion, and the honeycomb portion is filled with the outer cylinder. A method for producing a metal catalyst carrier, characterized by welding. 2. A honeycomb portion formed by winding a flat plate into a cylindrical shape and welding a butt portion from outside to the outer tube is inserted into a honeycomb portion formed by laminating a corrugated plate on the flat plate and winding in a roll shape. A metal catalyst carrier having a fillet weld, wherein a winding end portion of a honeycomb portion is matched with a butt portion of an outer cylinder.