JP4532841B2

JP4532841B2 - Catalytic converter

Info

Publication number: JP4532841B2
Application number: JP2003081790A
Authority: JP
Inventors: 彰広遠藤; 拓也小野; 淳哉川原
Original assignee: SAKAMOTO INDUSTRY CO.,LTD.
Current assignee: SAKAMOTO INDUSTRY CO.,LTD.
Priority date: 2003-03-25
Filing date: 2003-03-25
Publication date: 2010-08-25
Anticipated expiration: 2023-03-25
Also published as: JP2004285970A

Description

【０００１】
【発明の属する技術分野】
この発明は、エンジンの排気ガスに含まれるＮＯｘ等の有害な物質を無害化したり、少なくしたりするための触媒コンバータに関する。
【０００２】
【従来の技術】
一般に、この種の触媒コンバータは、シェルと、このシェルの内部に挿入された触媒担体とを有している。シェルは、全体が筒状をなしており、触媒担体が挿入固定される胴部と、この胴部の両端部に形成された第１、第２縮径筒部とから構成されている。第１、第２縮径筒部は、胴部から離れるにしたがって縮径しており、第１、第２縮径筒部の各大径側端部と胴部との各交差部は屈曲している。そして、この二つの屈曲部によって触媒担体が胴部に対してその軸線方向へ移動不能に固定されている（特許文献１参照）。
【０００３】
【特許文献１】
特許第２９５７１５４号公報（第５頁第９欄、図６）
【０００４】
【発明が解決しようとする問題点】
上記従来の触媒コンバータにおいては、第１、第２縮径筒部と胴部とのなす角度が鈍角であり、しかも大径側端部と胴部との間の屈曲部は触媒担体の両端部外周に環状に接触しているものの、ほとんど線接触している。このため、第１、第２縮径筒部と胴部との交差部は、触媒担体に対する固定強度が小さいという問題があった。特に、上記特許文献１に記載のもののように、第１、第２縮径筒部の軸線が胴部の軸線に対して傾斜している場合には、例えば第１縮径筒部のテーパ半角をαとし、第１縮径筒部の軸線の胴部の軸線に対する傾斜角をθとすると、第１縮径筒部の一方の側部では胴部とのなす角度が最大（＝α＋θ）となり（以下、胴部とのなす角度が最大になる側部を外側側部という。）、他方の側部では胴部とのなす角度が最小（＝α−θ）になる（以下、胴部とのなす角度が最小になる側部を内側側部という。）。このように、内側側部では、胴部と第１縮径筒部とのなす角度が小さくなってそれらが直線に近づくため、交差部による触媒担体に対する固定強度がより一層小さくなってしまう。これは、第２縮径筒部の内側側部における交差部についても同様である。
【０００５】
そこで、この出願の発明者は、胴部にその径方向内側へ向かってほぼ直角に屈曲する一対の当接段部を形成し、各当接段部を触媒担体の両端面に突き当てることにより、触媒担体に対する固定強度の向上を図ることを考えた。なお、このようにした場合には、第１、第２縮径筒部が当接段部の内側の端部に続いて形成される。
【０００６】
このような触媒コンバータは、次のようにして製造される。まず、一定の内径を有するストレートな素管の中央部（胴部）に触媒担体を挿入する。次に、スピニング加工により、素管の軸線方向に離れた所定の２箇所を径方向内側に向かってほぼ直角に折り曲げて一対の当接段部を形成する。この場合、各当接段部は触媒担体の両端面にそれぞれ突き当たるように形成されており、両当接段部によって触媒単体が素管の中央部に固定される。その後、当接段部から素管の端縁までの間をスピニング加工して第１、第２縮径筒部を形成する。
【０００７】
ところが、第１、第２縮径筒部の軸線が胴部の軸線に対して傾斜した触媒コンバータにおいては、第１、第２縮径筒部をスピニング加工した場合、当接段部による触媒担体の固定強度を期待するほど大きくすることができないという問題があった。すなわち、第１、第２縮径筒部をスピニング加工するに際しては、スピニング用のローラの公転軸線を素管の軸線に対し第１、第２縮径筒部の軸線が胴部の軸線に対して傾斜している角度の分だけ傾斜させる。このようにしてスピニング加工すると、第１、第２縮径筒部となるべき部分のうちの外側側部が、ローラを素管の中央側から端部側へ移動させるときにローラによりその移動方向と同方向に引っ張られる。この引っ張り力により、当接段部の外側側部に対応する部分が同方向に引き伸ばされる。この結果、当接段部の外側側部に対応する箇所においては、径方向内側への突出量が小さくなるとともに、胴部とのなす角度が直角より小さくなってしまう。このため、当接段部による触媒担体に対する固定強度が期待するほどには向上させることができなかったのである。
【０００８】
【課題を解決するための手段】
この発明は、上記事情を考慮してなされたもので、シェルと、このシェルの内部に挿入された触媒担体とを備え、上記シェルが、一定の内径を有し、かつ内部に上記触媒担体が挿入された胴部、この胴部の両端部にそれぞれ設けられ、胴部から離れるにしたがって小径となる第１、第２縮径筒部を有し、上記第１、第２縮径筒部の少なくとも一方の軸線が上記胴部の軸線に対して傾斜した触媒コンバータにおいて、上記胴部の両端部に、径方向内側へ向かってほぼ直角に折り曲がり、上記触媒担体の両端面にそれぞれ突き当たることによって上記触媒担体を上記胴部に対しその軸線方向へ移動不能に固定する当接段部がそれぞれ環状に形成され、上記第１、第２縮径部のうちの、軸線が上記胴部の軸線に対して傾斜した上記一方が上記胴部と別体に形成され、
上記一方側の当接段部の内周部に、一定の直径を有し、軸線を上記胴部の軸線と一致させて上記胴部から離れる方向へ向かって延びる支持筒部が形成され、上記胴部と別体に形成された上記一方の大径側端部に、軸線が上記一方の軸線に対し当該一方の軸線と上記胴部の軸線との間の角度と同一角度だけ傾斜した嵌合筒部が形成され、この嵌合筒部が上記支持筒部に嵌合固定されることによって上記一方が上記胴部に固定され、上記第１、第２縮径筒部のうちの他方の大径側端部が上記他方側の当接段部に連結されていることを特徴としている。
この場合、上記第１、第２縮径筒部の各軸線を上記胴部に対してそれぞれ傾斜させてもよく、そのようにする場合には、各当接段部の内周部に上記支持筒部がそれぞれ形成され、上記他方が上記胴部と別体に形成され、この他方の大径側端部に、軸線が上記他方の軸線に対し当該他方の軸線と上記胴部の軸線との間の角度と同一角度だけ傾斜した嵌合筒部が形成され、この嵌合筒部が上記他方側の支持筒部に嵌合固定されることにより、上記他方が上記胴部に固定されていることが望ましい。
【０００９】
【発明の実施の形態】
以下、この発明の一実施の形態について図１及び図２を参照して説明する。図１及び図２は、この発明に係る触媒コンバータ１を示す断面図である。これらの図に示すように、触媒コンバータ１は、シェル２及び触媒担体３を主な構成要素としている。
【００１０】
シェル２は、胴部２１と、この胴部２１と別体に形成された第１、第２筒部２２，２３とを有している。胴部２１及び第１、第２筒部２２，２３は、いずれも耐熱性に富んだ耐熱鋼等の金属によって構成されている。第１筒部２２は、胴部２１の一端部（図１，２において左端部）に連結固定され、第２筒部２３は、胴部２１の他端部に連結固定されている。
【００１１】
胴部２１は、内外径が一定で、両端が開口したストレートな筒体として形成された本体部２１ａを有している。本体部２１ａの断面形状は、この実施の形態では円形であるが、他の形状、例えば楕円形等にしてもよい。本体部２１ａの内周には、触媒担体３が無膨張マット等からなる保持材４を介して圧入状態で嵌合されている。本体部２１ａの軸線方向の長さは、触媒担体３より長く設定されており、その両端部は触媒担体３から外側に突出している。触媒担体３から突出した本体部２１ａの両端部には、当該両端部が本体部２１ａに対しほぼ直角に屈曲されることにより、径方向内側へ向かって突出する環状の当接段部２１ｂがそれぞれ形成されている。当接段部２１ｂは、例えばスピニング加工によって形成することができる。各当接段部２１ｂは、触媒担体３の一端面と他端面とに金属メッシュ５を介してそれぞれ押圧接触している。この結果、触媒担体３の両端面が一対の当接段部２１ｂ，２１ｂによって本体部２１ａの軸線方向に挟持され、それによって触媒担体３が胴部２１内に固定されている。金属メッシュ５の一部は、本体部２１ａの内周面の端部と触媒担体３の外周面の端部との間に介在している。換言すれば、触媒担体３の両端部が本体部２１ａの両端部に金属メッシュ５，５を介して圧入状態で嵌合されている。
【００１２】
各当接段部２１ｂの内周側の端部には、支持筒部２１ｃが一体に連設されている。支持筒部２１ｃは、一定の外径を有するストレートな筒部として形成されており、その軸線を胴部２１の軸線と一致させている。支持筒部２１ｃは、本体部２１ａの両端部を当接段部２１ｂに続けてスピニング加工することによって形成することができる。
【００１３】
第１筒部２２は、胴部２１から離れるにしたがって縮径するテーパ部（第１縮径筒部）２２ａを有している。テーパ部２２ａは、大径側端部から小径側端部まで一定の割合で縮径しているが、縮径割合を大径側と小径側とで異なる大きさにしてもよい。テーパ部２２ａの大径側端部には、嵌合筒部２２ｂが形成されている。この嵌合筒部２２ｂは、一定の内径を有するストレートな筒部として形成されている。嵌合筒部２２ｂは、その内径が支持筒部２１ｃの外径とほぼ同一に設定されており、支持筒部２１ｃの外周に嵌合され、溶接等によって固定されている。嵌合筒部２２ｂは、支持筒部２１ｃの内周に嵌合固定してもよい。嵌合筒部２２ｂの軸線は、テーパ部２２ａの軸線に対して予め定められた所定の角度だけ傾斜させられている。したがって、嵌合筒部２２ｂを支持筒部２１ｃに嵌合固定すると、テーパ部２２ａの軸線が胴部２１の軸線に対して所定の角度だけ傾斜することになる。テーパ部２２ａの小径側端部には、接続筒部２２ｃが一体に連設されている。接続筒部２２ｃは、一定の内外径を有する筒部として形成されており、その軸線をテーパ部２２ａの軸線と一致させて形成されている。接続筒部２２ｃには、エンジン（図示せず）に接続された排気管（図示せず）が接続される。
【００１４】
このように構成された第１筒部２２は、スピニング加工によって製造することも可能であるが、通常は、ストレートな素管に第１筒部２２の内周面と同一形状の外周面を有する芯金を挿入し、その芯金の外周面に素管の内周面が押圧接触させることによって成形することができる。
【００１５】
第２筒部２３は、テーパ部（第２縮径筒部）２３ａ、このテーパ部２３ａの大径側端部に軸線をテーパ部２３ａの軸線と所定の角度だけ傾斜させた状態で一体に連設された嵌合筒部２３ｂ、及びテーパ部２３ａの小径側端部に軸線をテーパ部２３ａの軸線と一致させた状態で一体に連設された接続筒部２３ｃとを有している。この場合、第２筒部２３は、テーパ部２３ａのテーパ度、胴部２１に対する傾斜角度及び傾斜方向が第１筒部２２のテーパ部２２ａのそれらと異なるだけであり、他の部分は第１筒部２２と同様に構成されている。そこで、第２筒部２３の構成についてはその説明を省略する。なお、テーパ部２３ａのテーパ度、胴部２１に対する傾斜角度及び傾斜方向については、第１筒部２２のテーパ部２２ａのそれらと同一にしてもよい。これとは逆に、第２筒部２３の他の部分を第１筒部２２の対応する部分と異なるように構成してもよい。例えば、嵌合筒部２３ｂを嵌合筒部２２ｂと異なる直径にしてもよい。勿論、その場合には、嵌合筒部２３ｂが嵌合する支持筒部２１ｃの外径が、嵌合筒部２２ｂが嵌合する支持筒部２１ｃの外径と異なる大きさにされる。さらに、接続筒部２２ｃには、外気に開放された排気管（図示せず）が接続される。第２筒部２３は、第１筒部２２と同様にして製造することができる。
【００１６】
上記構成の触媒コンバータ１においては、胴部２１の両端部に形成された支持筒部２１ｃ，２１ｃに第１、第２筒部２２，２３の嵌合筒部２２ｂ，２３ｂを嵌合固定しているから、当接段部２１ｂ，２１ｂが伸びたり、胴部２１の本体部２１ａとのなす角度が直角から小さくなったりすることがない。したがって、当接段部２１ｂ，２１ｂによる触媒担体３に対する固定強度を大きくすることができる。
【００１７】
なお、この発明は、上記の実施の形態に限定されるものでなく、適宜変更可能である。
例えば、上記の実施の形態においては、テーパ部２２ａ，２３ａのいずれもがその軸線を胴部２１の軸線に対して傾斜させているために、シェル２を胴部２１及び第１、第２筒部２２，２３の三つの部分に分割しているが、テーパ部２２ａ，２３ａのいずれか一方の軸線だけが胴部２１の軸線に対して傾斜し、他方の軸線が胴部２１の軸線と一致ないしは平行である場合には、第１、第２筒部２２，２３のうち、軸線が傾斜した一方２２（２３）だけを胴部２１と別体に形成し、他方２３（２２）についてはそのテーパ部２２ａを胴部２１の当接段部２１ｂの内周側の端部に連設してもよい。勿論、その場合には、他方２３（２２）の連結筒部２３ｂ（２２ｂ）及びこの連結筒部２３ｂ（２２ｂ）が嵌合固定される支持筒部２１ｂが不要になる。
【００１８】
【発明の効果】
以上説明したように、この発明によれば、当接段部による触媒担体に対する固定強度を大きくすることができるという効果が得られる。
【図面の簡単な説明】
【図１】この発明の一実施の形態を示す図であって、図２のＹ−Ｙ線に沿う断面図である。
【図２】図１のＸ−Ｘ線に沿う断面図である。
【符号の説明】
１触媒コンバータ
２シェル
３触媒担体
２１胴部
２１ｂ当接段部
２１ｃ支持筒部
２２第１筒部
２２ａテーパ部（第１縮径筒部）
２２ｂ嵌合筒部
２３第２筒部
２３ａテーパ部（第２縮径筒部）
２３ｂ嵌合筒部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a catalytic converter for detoxifying or reducing harmful substances such as NOx contained in engine exhaust gas.
[0002]
[Prior art]
In general, this type of catalytic converter has a shell and a catalyst carrier inserted into the shell. The shell has a cylindrical shape as a whole, and is composed of a barrel portion into which the catalyst carrier is inserted and fixed, and first and second reduced-diameter cylindrical portions formed at both ends of the barrel portion. The first and second reduced diameter cylindrical portions are reduced in diameter as they are separated from the trunk portion, and the intersections between the large diameter side ends of the first and second reduced diameter cylindrical portions and the trunk portion are bent. ing. And the catalyst support | carrier is fixed with respect to the trunk | drum so that it cannot move to the axial direction with these two bending parts (refer patent document 1).
[0003]
[Patent Document 1]
Japanese Patent No. 2957154 (page 9, column 9, FIG. 6)
[0004]
[Problems to be solved by the invention]
In the above conventional catalytic converter, the angle formed between the first and second reduced diameter cylindrical portions and the trunk portion is an obtuse angle, and the bent portion between the large diameter side end portion and the trunk portion is at both end portions of the catalyst carrier. Although it is in annular contact with the outer periphery, it is almost in line contact. For this reason, the intersection of the first and second reduced diameter cylindrical portions and the body portion has a problem that the fixing strength to the catalyst carrier is small. In particular, when the axes of the first and second reduced diameter cylindrical portions are inclined with respect to the axis of the trunk portion, as in the above-described Patent Document 1, for example, the taper half angle of the first reduced diameter cylindrical portion. Is α and the inclination angle of the axis of the first reduced diameter cylindrical portion with respect to the axis of the barrel is θ, the angle formed with the barrel on one side of the first reduced diameter cylindrical portion is the maximum (= α + θ). (Hereinafter, the side part with the maximum angle with the body part is referred to as the outer side part.) On the other side part, the angle with the body part is the minimum (= α−θ) (hereinafter referred to as the body part). The side where the angle between the two is the smallest is called the inner side.) In this way, at the inner side portion, the angle formed by the body portion and the first reduced diameter cylindrical portion becomes small and approaches a straight line, so that the fixing strength to the catalyst carrier by the intersecting portion is further reduced. The same applies to the intersecting portion at the inner side portion of the second reduced diameter cylindrical portion.
[0005]
Therefore, the inventor of this application forms a pair of contact step portions that bend substantially perpendicularly toward the inside in the radial direction in the body portion, and abuts each contact step portion against both end faces of the catalyst carrier. Therefore, it was considered to improve the fixing strength with respect to the catalyst carrier. In this case, the first and second reduced diameter cylindrical portions are formed following the inner end of the contact step portion.
[0006]
Such a catalytic converter is manufactured as follows. First, a catalyst carrier is inserted into the central part (body part) of a straight blank having a constant inner diameter. Next, a pair of abutting steps are formed by bending two predetermined portions apart from each other in the axial direction of the raw tube substantially at right angles toward the inside in the radial direction by spinning. In this case, each contact step is formed so as to abut against both end faces of the catalyst carrier, and the single catalyst is fixed to the central portion of the raw tube by both contact steps. Thereafter, the first and second reduced diameter cylindrical portions are formed by spinning between the contact step portion and the edge of the raw tube.
[0007]
However, in the catalytic converter in which the axes of the first and second reduced diameter cylindrical portions are inclined with respect to the axis of the body portion, when the first and second reduced diameter cylindrical portions are subjected to spinning processing, the catalyst carrier by the contact step portion There was a problem that it was not possible to increase the fixing strength as expected. That is, when spinning the first and second reduced diameter cylindrical portions, the axis of revolution of the spinning roller is set to the axis of the raw tube, and the axis of the first and second reduced diameter cylindrical portions is set to the axis of the barrel. Inclined by the angle of inclination. When spinning is performed in this manner, the outer side portion of the portions to be the first and second reduced diameter cylindrical portions moves in the direction of movement by the roller when the roller is moved from the center side to the end side of the raw tube. Is pulled in the same direction. By this pulling force, a portion corresponding to the outer side portion of the contact step portion is stretched in the same direction. As a result, in the portion corresponding to the outer side portion of the contact step portion, the amount of protrusion inward in the radial direction is reduced, and the angle formed with the body portion is smaller than a right angle. For this reason, the fixing strength to the catalyst carrier by the contact step portion could not be improved as expected.
[0008]
[Means for Solving the Problems]
The present invention has been made in consideration of the above circumstances, and includes a shell and a catalyst carrier inserted into the shell, the shell having a constant inner diameter, and the catalyst carrier is contained therein. The first and second diameter-reduced tube portions are provided at both ends of the inserted body portion and the body portion, and have first and second diameter-reduced tube portions that become smaller in diameter as they move away from the body portion. In the catalytic converter in which at least one axis is inclined with respect to the axis of the body part, the both ends of the body part are bent substantially perpendicularly toward the inner side in the radial direction, and are respectively brought into contact with both end surfaces of the catalyst carrier. Abutting step portions for fixing the catalyst carrier to the barrel portion so as to be immovable in the axial direction are respectively formed in an annular shape, and the axis of the first and second reduced diameter portions is the axis of the barrel portion. The one side inclined with respect to the trunk is It is formed in the body,
A support cylinder portion having a constant diameter and extending in a direction away from the body portion with an axis line aligned with the axis of the body portion is formed on the inner peripheral portion of the one-side contact step portion, A fitting in which the axis is inclined at the same angle as the angle between the one axis and the axis of the trunk at the one large-diameter side end formed separately from the trunk A tube portion is formed, and the fitting tube portion is fitted and fixed to the support tube portion, whereby the one is fixed to the body portion, and the other large one of the first and second reduced diameter tube portions. The radial end is connected to the contact step on the other side.
In this case, the axes of the first and second reduced diameter cylindrical portions may be inclined with respect to the body portion. In such a case, the support is provided on the inner peripheral portion of each contact stepped portion. A cylindrical part is formed, and the other is formed separately from the body part. At the other large-diameter side end, an axis is formed between the other axis and the axis of the body part with respect to the other axis. A fitting cylinder part inclined by the same angle as the angle between them is formed, and the fitting cylinder part is fitted and fixed to the support cylinder part on the other side, whereby the other is fixed to the trunk part. It is desirable.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2 are sectional views showing a catalytic converter 1 according to the present invention. As shown in these drawings, the catalytic converter 1 includes a shell 2 and a catalyst carrier 3 as main components.
[0010]
The shell 2 includes a body portion 21 and first and second tube portions 22 and 23 formed separately from the body portion 21. The trunk | drum 21 and the 1st, 2nd cylinder parts 22 and 23 are all comprised with metals, such as heat resistant steel which was rich in heat resistance. The first tube portion 22 is connected and fixed to one end portion (left end portion in FIGS. 1 and 2) of the body portion 21, and the second tube portion 23 is connected and fixed to the other end portion of the body portion 21.
[0011]
The body portion 21 has a main body portion 21a formed as a straight cylindrical body having a constant inner and outer diameter and open at both ends. The cross-sectional shape of the main body 21a is circular in this embodiment, but may be other shapes such as an ellipse. The catalyst carrier 3 is fitted into the inner periphery of the main body 21a in a press-fitted state via a holding material 4 made of a non-expandable mat or the like. The length of the main body portion 21 a in the axial direction is set to be longer than that of the catalyst carrier 3, and both end portions thereof protrude outward from the catalyst carrier 3. At both end portions of the main body portion 21a protruding from the catalyst carrier 3, the both end portions are bent at substantially right angles to the main body portion 21a, so that annular contact step portions 21b protruding radially inward are respectively provided. Is formed. The contact step 21b can be formed by, for example, spinning. Each contact step 21 b is in press contact with one end surface and the other end surface of the catalyst carrier 3 via the metal mesh 5. As a result, both end faces of the catalyst carrier 3 are sandwiched in the axial direction of the main body 21 a by the pair of contact step portions 21 b and 21 b, thereby fixing the catalyst carrier 3 in the body portion 21. A part of the metal mesh 5 is interposed between the end of the inner peripheral surface of the main body 21 a and the end of the outer peripheral surface of the catalyst carrier 3. In other words, both end portions of the catalyst carrier 3 are fitted into both end portions of the main body portion 21a through the metal meshes 5 and 5 in a press-fitted state.
[0012]
A support cylinder portion 21c is integrally connected to the inner peripheral end of each contact step portion 21b. The support cylinder part 21 c is formed as a straight cylinder part having a constant outer diameter, and its axis is made to coincide with the axis of the body part 21. The support cylinder portion 21c can be formed by spinning both ends of the main body portion 21a following the contact step portion 21b.
[0013]
The first cylindrical portion 22 has a tapered portion (first reduced diameter cylindrical portion) 22 a that is reduced in diameter as it is separated from the body portion 21. The tapered portion 22a is reduced in diameter from the large-diameter side end to the small-diameter side end at a constant rate, but the reduced diameter ratio may be different between the large-diameter side and the small-diameter side. A fitting tube portion 22b is formed at the large-diameter end of the taper portion 22a. This fitting cylinder part 22b is formed as a straight cylinder part which has a fixed internal diameter. The fitting cylinder part 22b has an inner diameter set to be substantially the same as the outer diameter of the support cylinder part 21c, is fitted to the outer periphery of the support cylinder part 21c, and is fixed by welding or the like. The fitting cylinder part 22b may be fitted and fixed to the inner periphery of the support cylinder part 21c. The axis of the fitting cylinder 22b is inclined by a predetermined angle with respect to the axis of the taper 22a. Therefore, when the fitting cylinder portion 22b is fitted and fixed to the support cylinder portion 21c, the axis of the taper portion 22a is inclined with respect to the axis of the trunk portion 21 by a predetermined angle. A connecting tube portion 22c is integrally connected to the small diameter side end portion of the tapered portion 22a. The connection cylinder part 22c is formed as a cylinder part having a constant inner and outer diameter, and its axis is made to coincide with the axis of the taper part 22a. An exhaust pipe (not shown) connected to an engine (not shown) is connected to the connection cylinder portion 22c.
[0014]
The first cylindrical portion 22 configured in this way can be manufactured by spinning, but normally, the straight tube has an outer peripheral surface having the same shape as the inner peripheral surface of the first cylindrical portion 22. It can be formed by inserting a cored bar and pressing the inner peripheral surface of the base tube into the outer peripheral surface of the cored bar.
[0015]
The second cylindrical portion 23 is integrally connected to the tapered portion (second reduced diameter cylindrical portion) 23a and the large diameter side end portion of the tapered portion 23a in a state where the axis is inclined with respect to the axis of the tapered portion 23a by a predetermined angle. The fitting tube portion 23b is provided, and the connecting tube portion 23c is integrally connected to the small diameter side end portion of the taper portion 23a in a state where the axis line coincides with the axis line of the taper portion 23a. In this case, the second cylinder part 23 is different from the taper part 22a of the first cylinder part 22 only in the taper degree of the taper part 23a, the inclination angle and the inclination direction with respect to the body part 21, and the other parts are the first part. The configuration is the same as the cylindrical portion 22. Therefore, the description of the configuration of the second cylinder portion 23 is omitted. Note that the taper degree of the taper portion 23 a, the inclination angle and the inclination direction with respect to the body portion 21 may be the same as those of the taper portion 22 a of the first tube portion 22. On the contrary, the other part of the second cylinder part 23 may be configured to be different from the corresponding part of the first cylinder part 22. For example, the fitting cylinder part 23b may have a diameter different from that of the fitting cylinder part 22b. Of course, in that case, the outer diameter of the support cylinder part 21c into which the fitting cylinder part 23b is fitted is made different from the outer diameter of the support cylinder part 21c into which the fitting cylinder part 22b is fitted. Further, an exhaust pipe (not shown) that is open to the outside air is connected to the connection cylinder portion 22c. The second cylinder portion 23 can be manufactured in the same manner as the first cylinder portion 22.
[0016]
In the catalytic converter 1 configured as described above, the fitting cylinder portions 22b and 23b of the first and second cylinder portions 22 and 23 are fitted and fixed to the support cylinder portions 21c and 21c formed at both ends of the trunk portion 21. Therefore, the contact step portions 21b and 21b do not extend, and the angle between the body portion 21a and the main body portion 21a does not decrease from a right angle. Therefore, the fixing strength with respect to the catalyst carrier 3 by the contact step portions 21b and 21b can be increased.
[0017]
In addition, this invention is not limited to said embodiment, It can change suitably.
For example, in the above-described embodiment, since both the taper portions 22a and 23a have the axis thereof inclined with respect to the axis of the body portion 21, the shell 2 is formed with the body portion 21 and the first and second cylinders. It is divided into three parts 22 and 23, but only one of the taper parts 22a and 23a is inclined with respect to the axis of the body part 21, and the other axis coincides with the axis of the body part 21. In the case of being parallel to each other, only one of the first and second cylindrical portions 22 and 23 having an inclined axis 22 (23) is formed separately from the body portion 21, and the other 23 (22) The tapered portion 22a may be provided continuously with the inner peripheral end of the contact step portion 21b of the body portion 21. Of course, in that case, the connecting cylinder part 23b (22b) of the other 23 (22) and the support cylinder part 21b to which the connecting cylinder part 23b (22b) is fitted and fixed are not necessary.
[0018]
【The invention's effect】
As described above, according to the present invention, it is possible to increase the fixing strength of the contact step portion with respect to the catalyst carrier.
[Brief description of the drawings]
FIG. 1 is a view showing an embodiment of the present invention, and is a cross-sectional view taken along line YY of FIG.
FIG. 2 is a cross-sectional view taken along line XX in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Catalytic converter 2 Shell 3 Catalyst support body 21 Body part 21b Contacting step part 21c Support cylinder part 22 1st cylinder part 22a Tapered part (1st reduced diameter cylinder part)
22b Fitting cylinder part 23 Second cylinder part 23a Taper part (second reduced diameter cylinder part)
23b Fitting cylinder part

Claims

A shell and a catalyst carrier inserted into the shell, the shell having a constant inner diameter and having the catalyst carrier inserted therein, provided at both ends of the barrel And having first and second reduced diameter cylindrical portions that become smaller in diameter as they move away from the trunk portion, and at least one axis of the first and second reduced diameter cylindrical portions is inclined with respect to the axis of the trunk portion. In catalytic converter,
The catalyst support is fixed to the barrel so as to be immovable in the axial direction by bending at substantially right angles toward both ends of the barrel toward the inner side in the radial direction and abutting against both ends of the catalyst carrier. The stepped parts are each formed in an annular shape,
Of the first and second reduced diameter portions, the one whose axis is inclined with respect to the axis of the body is formed separately from the body.
On the inner peripheral portion of the one-side contact step portion, a support cylinder portion having a constant diameter and extending in a direction away from the barrel portion with the axis line aligned with the axis of the barrel portion is formed.
In the one large-diameter side end formed separately from the body part, the axis is inclined with respect to the one axis by the same angle as the angle between the one axis and the body axis. A mating tube portion is formed, and the fitting tube portion is fitted and fixed to the support tube portion, whereby the one is fixed to the body portion,
The catalytic converter characterized in that the other large-diameter side end portion of the first and second reduced-diameter cylindrical portions is connected to the abutting step portion on the other side.

Each axis of the first and second diameter-reduced cylindrical portions is inclined with respect to the axis of the trunk portion, and the support cylindrical portion is formed on the inner peripheral portion of each contact step portion, and the other Is formed separately from the body portion, and at the other large-diameter side end, the axis is inclined with respect to the other axis by the same angle as the angle between the other axis and the body axis. The fitting cylinder portion is formed, and the fitting cylinder portion is fitted and fixed to the support cylinder portion on the other side, whereby the other is fixed to the trunk portion. The catalytic converter described.