JP2000045762A - Catalyst converter and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To securely hold the catalyst carrier with a catalyst holding part while smoothly inserting the catalyst carrier by adjusting the inner diameter of a front part or a rear part of the catalyst holding part to the outer diameter dimension of the catalyst carrier of the catalyst holding part provided at a central part of a catalyst holding cylinder. SOLUTION: A catalyst part 3 formed by winding a holding material such as a non-expansion mat around a catalyst carrier is prepared. The catalyst part 3 is inserted into a catalyst holding cylinder 4 made of stainless steel and formed with a circumferential recessed part 6 at an exhaust gas flow-in side 5 from an exhaust gas flow-out side 10 and made to abut on the circumferential recessed part 6 for positioning. At this stage, thickness of the catalyst holding cylinder 4 is set so as to have the inner diameter capable of smoothly inserting the catalyst body 3. Thereafter, the exhaust gas flow-in side 5 and the exhaust gas flow-out side 10 are shrunken by spinning or the like so as to form diffusers 9, 11, and finally, the inner diameter of the catalyst holding part 8 of the holding cylinder 4 is shrunken by the spinning or the like so as to securely hold the catalyst body 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalytic converter mounted on a vehicle exhaust system and the like, and a method of manufacturing the same.

[0002]

2. Description of the Related Art This type of catalytic converter is also known from the disclosure of, for example, Japanese Patent Application Laid-Open No. Hei 9-112259. The catalytic converter disclosed in this publication is a monolith catalytic converter including a catalyst container connected to an exhaust gas pipe and a monolith catalyst held in the catalyst container, and the catalyst container includes the monolith catalyst. A cylindrical portion held inside and a pair of cone portions connected to the exhaust gas pipe at both ends of the cylindrical portion are integrally formed.

[0003] However, there are actually technical problems described below.

[0004]

That is, in the above-described conventional catalytic converter, a holding member having a thermal expansion property is wound around the outer periphery of the catalyst carrier around a cylindrical portion holding the monolith catalyst inside. And a pair of cone portions connected to the exhaust gas pipe at both ends of the cylindrical portion are integrally formed.

[0005] In recent years, in order to improve the performance of the catalyst and the reaction speed of the catalyst, the walls of the cells constituting the catalyst carrier are formed as ultra-thin walls to increase the geometric surface area, and to reduce exhaust gas and exhaust gas. In order to increase the number of contacts and increase the temperature rise of the cell wall to increase the reaction rate, there is a demand for holding an ultra-thin walled catalyst support in the cylindrical portion.

However, this ultra-thin wall catalyst support is
When simply inserted into the cylindrical portion by the conventional method, the catalyst carrier is a monolith, so it is difficult to finish the outer diameter accurately, so if it is forcibly inserted, it may be damaged, or a heat-expandable holding material may be used. When used, the catalyst carrier is compressed and broken by thermal expansion. If the ultra-thin walled catalyst carrier is not held tightly in the cylindrical portion than before, the catalyst carrier may be damaged by vibration or the like. Therefore, it is necessary to securely hold and protect the catalyst carrier.

[0007] The present invention solves the above-mentioned problems. After measuring the outer diameter of the catalyst carrier, the non-expandable holding material is wound around the catalyst carrier, and then the cylindrical shape is easily applied. And a method for manufacturing the catalyst converter, wherein the catalyst carrier is securely held by adjusting the inner diameter of the catalyst holder in accordance with the outer diameter of the catalyst carrier after inserting the catalyst carrier therein. The purpose is to provide.

[0008]

(1) In order to achieve the above object, the invention according to claim 1 provides a catalyst in which a center of one catalyst holding tube is a catalyst holding portion and a holding member is arranged on an outer periphery. In a catalytic converter in which a carrier is mounted in the catalyst holding unit and the diameter of the catalyst holding cylinders in front of and behind the catalyst holding unit is reduced to form a diffuser, the outside of the catalyst carrier is held so as to securely hold the catalyst carrier. The inside diameter of at least one of the front part and the rear part of the catalyst holding part is adjusted according to the diameter.

According to the above arrangement, the inner diameter of the catalyst holder is adjusted according to the outer diameter of the catalyst carrier, so that the catalyst carrier can be inserted into the catalyst holder without difficulty. It was possible to provide a catalytic converter that can reliably hold the catalyst carrier by adjusting the inner diameter of the catalyst holding unit later according to the outer diameter dimension of the catalyst carrier.

(2) The invention according to claim 2 is based on claim 1
Wherein the portion for adjusting the inner diameter of the catalyst holding portion is a central portion excluding a portion where the diameter of the catalyst holding cylinder at the front and rear of the catalyst holding portion is reduced. .

According to the above construction, the inner diameter of the catalyst holding portion is adjusted in accordance with the outer diameter of the catalyst carrier at the central portion where the end surface where the catalyst carrier is easily damaged is avoided and the inner diameter is relatively easy to adjust. Therefore, it was possible to provide a catalytic converter whose inner diameter was easily adjusted.

(3) The invention according to claim 3 is the invention according to claim 1.
In the catalytic converter according to claim 1, in the catalytic converter according to claim 1, one of the front and rear catalyst holding cylinders of the catalyst holding unit has an inner diameter adjusted to match the outer diameter of the catalyst carrier, and It is characterized in that the catalyst holding cylinder is inclined so as to have the inner diameter of the catalyst holding cylinder before adjustment.

According to the above construction, the inside diameter of the front or rear catalyst holding tube of the catalyst holding unit is adjusted according to the outside diameter of the catalyst carrier to ensure the positioning and the holding of the catalyst carrier at the same time. Can provide a catalyst converter in which the rear catalyst holding cylinder is inclined to reduce the number of adjustment portions as the inner diameter of the catalyst holding cylinder before adjustment, thereby facilitating the adjustment.

(4) The invention according to claim 4 is a measuring step for measuring the outer diameter of the catalyst carrier, an inserting step for inserting the catalyst carrier into a cylindrical pipe material, and an opening at both ends in the pipe material. Having a drawing step of performing a diffuser process by reducing the diameter of the pipe, and an adjusting step of adjusting an inner diameter of the catalyst holding section in accordance with an outer diameter dimension of the catalyst carrier, using a central portion of the pipe material as a catalyst holding section. Features.

According to the above configuration, the inner diameter of the catalyst holding portion is adjusted according to the outer diameter of the catalyst carrier. Therefore, when the catalyst carrier is inserted into the catalyst holding portion, the catalyst carrier can be inserted without difficulty. After the above, a catalyst converter capable of reliably holding the catalyst carrier by adjusting the inner diameter of the catalyst holding portion in accordance with the outer diameter dimension of the catalyst carrier could be provided.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

=== First Embodiment === First, the outer diameter is measured by performing image processing on the appearance of the catalyst carrier 1 as shown in FIG. Next, as shown in FIG. 2, a holding member 2 such as a non-expansion mat is wound around a catalyst carrier 1 to form a catalyst portion 3, and then, as shown in FIG. A circumferential recess 6 is formed on the exhaust gas inflow side 5 of the holding cylinder 4 for positioning when the catalyst body 3 is inserted.

Next, as shown in FIG. 4, one catalyst body 3 is inserted into the catalyst holding cylinder 4 up to the circumferential recess 6 (see (a)), or two catalyst bodies 3 (( (See b)) The catalyst holding tube 4 is inserted, but the thickness of the catalyst holding tube 4 is set to an inner diameter that allows the catalyst body 3 to be smoothly inserted.

Thereafter, as shown in FIG. 5, the exhaust gas inflow side 5 is reduced in diameter by spinning or the like to form a diffuser 9, and as shown in FIG. 6, the exhaust gas outflow side 10 is reduced in diameter by spinning or the like to obtain a diffuser. It is assumed to be 11.

Finally, as shown in FIG. 7, by adjusting the inner diameter of the catalyst holder 8 by spinning or the like in accordance with the outer diameter of the catalyst carrier 1, the outer diameter 12 of the catalyst holder 8 (two-dot chain line) is adjusted. (Shown) becomes 13 (shown by a solid line) so that the catalyst body 3 can be securely held.

In the above configuration, since the non-expandable holding material 2 is wound around the catalyst carrier 1, the thickness of the catalyst support 1 is such that it can smoothly enter the catalyst holding pipe material 4.
Mill, thin-walled catalyst carrier 1 such as 900 cells,
The catalyst carrier 1 can be inserted into the catalyst holding tube 4 without causing any trouble such as damage to the catalyst carrier 1. Since the catalyst carrier 1 is made of a monolith, it is difficult to accurately form the outer diameter. Therefore, the catalyst holder 8 of the pipe material 4 is adjusted to the diameter whose outer diameter has been measured in advance.
By adjusting the diameter of the catalyst support 1 by spinning or the like, the catalyst support 1 wrapped with the non-expandable holding material 2 is securely held, and even if heated, the catalyst support 1 is not subjected to excessive pressure, and the thin-walled catalyst support 1 Even if it is 1, it can be held tightly in the catalyst holding unit 4 without difficulty.

Embodiment 2 In Embodiment 2, as shown in FIG. 6 of Embodiment 1, after the exhaust gas outlet side 10 is reduced in diameter and reduced by spinning or the like to form a diffuser 11, As shown in FIG. 8, a central portion 1 excluding portions 14 and 15 where the diameter reduction before and after the catalyst holding portion 8 starts is reduced.
6 is adjusted to the outer diameter of the catalyst carrier 1 to adjust the diameter of the catalyst holding section 6, and the outer diameter 17 of the catalyst holding section 8 (shown by a two-dot chain line)
Is 18 (shown by a solid line) so as to reduce the diameter so that the catalyst body 3 can be securely held, and the catalyst carrier 1 is securely held.

According to the above configuration, the diameter of the catalyst holding portion 8 is adjusted by adjusting the central portion 16 of the catalyst holding portion 8 except for the portions 14 and 15 where the diameter reduction is started before and after the catalyst holding portion 8 to the outer diameter of the catalyst carrier 1. Since the catalyst carrier 1 is adjusted, both end faces 19 and 2 where the catalyst carrier 1 is easily damaged are provided.
0, and avoiding the portions 14 and 15 where the diameter reduction starts before and after the catalyst holding portion 8 where the diameter adjustment is difficult.
A catalytic converter in which the diameter of the catalyst holding section 6 can be easily adjusted in accordance with the outer diameter of the catalyst carrier 1 can be provided.

=== Embodiment 3 === In Embodiment 3, as shown in FIG. 9 of Embodiment 1, the exhaust gas outlet side 10 is reduced in diameter by spinning or the like to form a diffuser 11, and then The diameter of the front part 21 of the catalyst holding part 8 is reduced according to the outer diameter of the catalyst carrier 1 to adjust the inner diameter, and thereafter, the diameter of the catalyst holding cylinder 8 is changed from the front part 21 to the rear part 2.
2 so that the outer diameter 23 (shown by a two-dot chain line) of the catalyst holding portion 8 is 2 mm.
4 (shown in the actual battle) to reduce the diameter and securely hold the catalyst carrier. In the present embodiment, the front part 2
Although the form in which it is inclined from 1 to the rear part 22 is shown, it may be inclined from the rear part 22 to the front part 21.

According to the above configuration, the number of portions for adjusting the inner diameter by reducing the diameter is small, and the efficiency is improved.

=== Embodiment 4 === As shown in FIG. 10 of the embodiment 1, the exhaust gas outlet side 10 is reduced in diameter by spinning or the like to form a diffuser 8, and then the catalyst holding portion 8 The inner diameter is adjusted by reducing the diameter of the catalyst holding cylinder 8 of the front part 25 according to the outer diameter of the catalyst carrier 1, and the outer diameter 26 (shown by a two-dot chain line) of the catalyst holding part 27 is 27 (shown in a practical battle).
The catalyst carrier 1 is securely held by reducing the diameter so that In the present embodiment, the inner diameter is adjusted by reducing the diameter of the front portion 25. However, the inner diameter may be adjusted by reducing the diameter of the rear portion 28.

According to the above configuration, similarly to the third embodiment, the number of portions for adjusting the inner diameter by reducing the diameter is small, and the efficiency is improved.

[0028]

According to the above configuration, as described above,
Since the invention described in each claim employs the means described in each claim, the following effects can be obtained. In the catalytic converter of claim 1, the non-expandable holding material is wound around the catalyst carrier. Insert the catalyst carrier into the pipe material without causing any obstacles such as breakage of the catalyst carrier even if it is a thin-walled catalyst carrier because the thickness relationship is such that it can be smoothly inserted into the pipe material in the folded state. be able to. And since the catalyst carrier is made of monolith and it is difficult to make the outside diameter accurately, the diameter of the catalyst holding part of the pipe material is adjusted by spinning etc. according to the diameter whose outside diameter has been measured in advance. Adjustment ensures that the catalyst carrier with the non-expandable holding material wound around it is securely held, and no excessive pressure is applied to the catalyst carrier even when heated. It can be held by the holding section.

In the catalytic converter according to the second aspect, the catalyst carrier is prevented from being easily damaged at both ends, and the portion where the diameter of the catalyst carrier is difficult to adjust is avoided before and after the catalyst holding portion. There is an effect that the diameter of the catalyst holding portion can be easily adjusted according to the outer diameter.

In the catalytic converter according to the third aspect, the catalyst carrier can be reliably held, and the number of portions for reducing the diameter and adjusting the inner diameter is small, and the efficiency is high.

The method for manufacturing a catalytic converter according to claim 4 can be a manufacturing method capable of easily and tightly holding a thin wall catalyst carrier in a catalyst holding section.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a catalyst carrier of a catalytic converter according to the present invention.

FIG. 2 is a cross-sectional view of the catalytic converter in which a holding material is wound around a catalyst carrier.

FIG. 3 is a cross-sectional view of the catalytic converter in which a circumferential concave portion is added to a pipe material.

FIG. 4 is a cross-sectional view of the catalytic converter in which a catalytic body is inserted into a pipe material.

FIG. 5 is a sectional view in which a diffuser is added to an exhaust gas inflow side of the catalytic converter.

FIG. 6 is a cross-sectional view in which a diffuser is added to an exhaust gas inflow side and an exhaust gas outflow side of the catalytic converter.

FIG. 7 is a sectional view showing an adjustment state of a catalyst holding unit of the catalytic converter.

FIG. 8 is a cross-sectional view showing another adjustment state of the catalyst holding unit of the catalytic converter.

FIG. 9 is a cross-sectional view showing another adjustment state of the catalyst holding unit of the catalytic converter.

FIG. 10 is a sectional view showing still another adjustment state of the catalyst holding unit of the catalytic converter.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 catalyst carrier 2 holding material 4 catalyst holding cylinder pipe material 6 circumferential recess 8 catalyst holding portion 9, 11 diffuser

 ────────────────────────────────────────────────── ─── Continued on the front page F term (reference) 3G091 AA02 AB01 BA09 BA10 BA39 GA06 GB01Z HA27 HA28 HA29 HA31 HA32 HA47 4G069 AA01 AA08 CA03 EA06 EA19 EA30 EB01 ED03 EE01 FB66 FB70 FB73 FB74

Claims (4)

[Claims] 1. A catalyst carrier having a holding member disposed on an outer periphery thereof is mounted in the catalyst holding portion with a center of one catalyst holding tube as a catalyst holding portion, and a catalyst holding tube in front of and behind the catalyst holding portion is mounted. In a catalytic converter having a reduced diameter and a diffuser, at least one of an inner diameter of a front portion and a rear portion of the catalyst holding portion is adjusted in accordance with an outer diameter of the catalyst carrier so as to securely hold the catalyst carrier. A catalytic converter, characterized in that: 2. The catalyst converter according to claim 1, wherein the portion for adjusting the inner diameter of the catalyst holding portion is a center excluding a portion where the diameter of the catalyst holding cylinder at the front and rear of the catalyst holding portion starts to be reduced. A catalytic converter, characterized by being a part. 3. The catalyst converter according to claim 1, wherein one of the front and rear catalyst holding cylinders of the catalyst holding section has an inner diameter adjusted to match an outer diameter dimension of the catalyst carrier.
A catalytic converter characterized in that the other catalyst holding cylinder is inclined so as to have the inner diameter of the catalyst holding cylinder before adjustment. 4. A measuring step for measuring the outer diameter of the catalyst carrier,
An insertion step of inserting the catalyst carrier into a tubular pipe material, a drawing step of reducing the diameter of both ends of the pipe material and performing a diffuser process, and a catalyst holding portion having a central portion of the pipe material as a catalyst holding portion. Adjusting the inner diameter of the catalyst holding portion in accordance with the outer diameter of the carrier.