JP3667811B2

JP3667811B2 - Metal carrier

Info

Publication number: JP3667811B2
Application number: JP07685395A
Authority: JP
Inventors: 泰石川; 忠幸大谷
Original assignee: Nippon Steel Corp
Current assignee: Nippon Steel Corp
Priority date: 1995-03-31
Filing date: 1995-03-31
Publication date: 2005-07-06
Anticipated expiration: 2020-07-06
Also published as: JPH08266905A

Description

【０００１】
【産業上の利用分野】
本発明は、自動車エンジン等の内燃機関から排出される排ガスを浄化するためのメタル担体に関するものである。
【０００２】
【従来の技術】
従来排気ガスを浄化するための触媒コンバータにはセラミックスメタル担体が使用されたが、耐熱性、低圧損および搭載性の点より最近はメタル担体の使用が増加している。
【０００３】
メタル担体は厚さ５０μｍ程度の耐熱性のあるフェライト系ステンレス鋼等の金属よりなる平箔と、この平箔をコルゲート加工した波箔とを渦巻状に巻回してハニカム体を形成し、これを同じく耐熱性のあるフェライト系ステンレス鋼等の耐蝕、耐熱性金属で製造された外筒に収納し、ロウ付け等により相互に接合して構成されている。
【０００４】
このメタル担体は白金、パラジウム、ロジウム等の排ガス浄化用の触媒を担持された後、例えば自動車エンジンの排ガス系に搭載使用される。
そのため、本メタル担体は運転状況の変化に伴う激しい温度変化、振動を受けるが、もし損傷すると浄化性能が落ちるばかりか、排気系の閉鎖あるいはエンジン損傷を引き起こすため特に高い耐久性が要求される。
【０００５】
メタル担体に作用する熱応力は、温度差の大きい外筒とハニカム体間では特に大きく従来からその応力を緩和するため、様々な接合構造が提案されている。
例えば、特開平４−１４８０１６号公報に示されるように、ハニカム体内部の接合構造およびハニカム体と外筒の接合箇所を特定し、熱変形に対する自由度を上げ、いわゆる柔構造とし、熱応力を下げる方法、あるいは、特開平３−１５７１３９号公報、特開平２−２９８６２０号公報に示されるように、筒状の中間体をハニカム体と外筒の間に配置し、内側でハニカム体と、外側で外筒と接合するが、その両接合箇所を軸方向に一致させないことにより、同じく熱変形に対する自由度を上げる方法がある。
【０００６】
従来の方法は、ハニカム体内部および外筒とハニカム体間の接合構造を合理化したり、また中間体を設けることにより、熱変形に対する自由度を高め、良好な耐久性を確保しているが、製造が複雑で生産性が低くなり、コスト高になる問題があった。またハニカム体を拡散接合する場合は、特別な対策を講じなければ平箔と波箔の接触箇所は全て接合されるが、このようにハニカム体が全体接合された場合は、外筒とハニカム体間の変形に対する自由度をさらに高める必要があるが、従来の方法では不足し、ハニカム体支持部が破損し終わりには、ずれてしまう問題があった。
【０００７】
【発明が解決しようとする課題】
本発明は、メタル担体のハニカム体が全体接合されたり、排気ガスの温度変化が大きく、従来の方法ではハニカム体と外筒間の変形に対する自由度が不足するため、高い耐久性が得られない場合、外筒とハニカム体間に中間を設けることにより高い自由度を簡便な方法で付与したメタル担体を提供するものである。
【０００８】
【課題を解決するための手段】
すなわち本発明は、耐久性のあるメタル担体として、
（１）平箔と波箔を交互に巻回あるいは積層したハニカム体を形成した後、その外側に箔と同じあるいはそれよりも厚い薄板を２回以上巻回して中間体を形成し、その中間体の内面とハニカム体外面とは連続的に一周しかも軸方向に全長接合し、中間体の外面においては外筒と一周以内しかも軸方向に全長接合し、さらに中間体内部においては一周以上の非接合層を設けたことを特徴とするメタル担体、
（２）ハニカム体内部を全体接合したことを特徴とする前（１）項記載のメタル担体、（３）中間体をコルゲート加工していない平板とすることを特徴とする前（１）あるいは（２）項記載のメタル担体、
（４）中間体をコルゲート加工した波板とすることを特徴とする前（１）あるいは（２）項記載のメタル担体、である。
【０００９】
以下本発明を詳細に説明する。
図１は本発明のメタル担体１の外観図である。平箔２と波箔３を巻回あるいは積層して形成されたハニカム体４の外側に、２回以上巻回した中間体５が、さらにその外側に外筒６が配置されている。同構成においてハニカム体４は中間体５の内面と接合し、また中間体５の外面は、外筒６の内面と接合されている。しかし、多重に巻回されている中間体５の内部は接合されていない。
【００１０】
また中間体５の板厚は、外筒６より薄く、ハニカム体を構成している平箔２、波箔３より厚く設定されている。
中間体５は、ハニカム体４とは連続的にあるいは間欠的に一周分で接合し、外筒６とは一周分以内で、連続的あるいは間欠的に接合されている。
【００１１】
従って、本発明のメタル担体１の中間体５は、熱応力的には内周でハニカム体４を保持し、その外面で外筒６に結合しているコイルバネのような役割を有し、半径方向の変位に対して容易に追従でき、また熱伝導的には、中間体５内部の非接合層が断熱層として作用し、ハニカム体４と中間体５の温度差が小さくなり、同時に中間体５と外筒６間の温度差も小さくなり、ハニカム体４と外筒６間で発生する応力を小さくできる。
【００１２】
ハニカム体４には、触媒が塗布されているので、その反応熱が発生し軸方向に熱応力が発生する。しかし、ハニカム体４が全体接合されているため、その軸方向の変位は、強制的に拘束されるので変位量が小さくなり、良好な耐久性を確保できる。
【００１３】
図２は本発明のメタル担体１の構成を示す図である。（ａ）図には平箔２と波箔３が巻回され形成されたハニカム体４の外観を示し、（ｂ）図にそのハニカム体４を巻き込み包む中間体５の外観を示すが、２回以上カールされている。また図２では中間体は平坦な薄板で示しているが、コルゲート加工した波箔を同様に２回以上カールしても良い。（ｃ）図にはハニカム体４と中間筒５を収納する外筒６の外観を示す。これらの接触面には、例えばロウ付けする場合は相互に接合するためのロウ材、あるいは拡散接合する場合は界面接合を清浄にし接合できる準備がなされ、また逆に接合しない部位については接合防止剤等が塗布された後、必要な加圧力が付加され密着するように組み立てられる。
【００１４】
以下本発明のメタル担体における各種の接合構造を示す。
図３から図５までは、メタル担体縦断面における接合構造の実施例を示し、図６から図９は各メタル担体横断面の接合構造を示す。なお、これらの縦断面の接合構造と横断面の接合構造は、特定の組み合わせはなく、適宜、組み合わせて使用できるものである。
【００１５】
図３は、ハニカム体４は斜線で示す範囲が例えば拡散接合あるいはロウ付けにより、平箔と波箔の全ての接点が、原則的に接合されている。５は中間体であるが、その内面のハニカム体４の外面と接するの部位７（点で示している範囲の部位）は軸方向に全長接合している。同様に中間体５の外面と外筒６の内面と接する部位８（点で示している範囲の部位）は軸方向に全長接合している。しかし、中間体５の内外面以外の、中間層９は接合されない。
【００１６】
図４は、例えば中間体５のハニカム体４および外筒６との接合部を、高温の排気ガスから保護する場合に採用するが、ハニカム体４は斜線で示す範囲が例えば拡散接合あるいはロウ付けにより、平箔と波箔の全ての接点が、原則的に接合されている。中間体５の内面のハニカム体４の外面と接する部位７は軸方向に、例えば排気ガスの出側の特定範囲を接合し、外筒６の内面と接する部位８は軸方向に、例えば排気ガス出側の特定範囲を接合している。しかし、同じく中間体５の内外面以外の、中間層９は接合されない。なお中間体５の長さは、図４では接合範囲に留めているが、接合長よりも長くしても支障ない。
【００１７】
図５は、例えばハニカム体５の長さが短いため、使用中に外筒６の中で傾くのを防止する場合に採用する。同図においてハニカム体４の長さは短いが、中間体５および外筒６は、ハニカム体４より長く、使用中に変形が発生しても、その姿勢を維持できる長さを有している。ハニカム体４は、上記と同様に斜線で示す範囲が例えば拡散接合あるいはロウ付けにより、平箔と波箔の全ての接点が、原則的に接合されている。中間体５の内面のハニカム体４の外面と接する部位７は軸方向に、例えば全長接合し、外筒６の内面と接する部位８は軸方向に、例えば全長接合している。しかし、同じく中間体５の内外面以外の中間層９は接合されない。
【００１８】
図６において、ハニカム体４は斜線で示す範囲の平箔と波箔の接点が全て接合され、中間体５の内面とは全周（点で示される範囲の部位）で接合され、また中間体５の外面は外筒６と全周（点で示される範囲の部位）で接合されている。しかし、中間体５の中間層９は接合されていない。
【００１９】
図７においては、中間体５と外筒６は、ハニカム体４の箔よりも厚いため全周接合する必要がない場合に採用する接合構造である。ハニカム体４内部の接合およびハニカム体４と中間体５との接合は図６の場合と同じであるが、中間体５の外面と外筒６の内面は全周でない、一部に留め、他の点で示していない範囲の部位は接合されていない。なおこの場合、中間体５の非接合部が１周以上必要ない場合は、本発明の応用として中間体５のカールする範囲を２周以下とし、中間体５を節約することができる。
【００２０】
図８は、中間体５と外筒６間の接合材を節約する場合に採用する構造を示す。すなわち中間体５と外筒６間の点で示す範囲の部位は接合し、点で示されない範囲の接合しない部位を交互に配置する。中間体５の内部の層を接合しないのは上記と同じである。
【００２１】
図９はさらにハニカム体４と中間体５間、および中間体５と外筒６間の接合材を節約する場合に採用する構造である。同図で点で示す範囲の部位は接合し、表示していない範囲の部位は接合しない。すなわちハニカム体４は全体的に接合し、ハニカム体４と中間体５とは間欠的に、また中間体５は外筒６とはその一部で接合している。
【００２２】
上記の応用として、公知の内部の特定箇所に非接合部を設けたハニカム体を、本発明のメタル担体に採用することは、耐久性をさらに向上し可能である。しかし製造コストから本発明のように、全体的に接合したハニカム体を採用した方が有利である。
【００２３】
本発明のメタル担体１は、従来の公知のメタル担体と同様に、例えば排気ガス浄化用の白金、パラジウム、ロジウム等の貴金属を担持された後、例えば自動車の排気系に取り付け使用される。同箇所ではメタル担体は激しい温度変化を受けるため、半径方向の大きい温度差が発生し、外筒６はハニカム体４に強い圧縮引張り力が作用する。
【００２４】
ハニカム体４は熱膨張により、中間体５を介して外筒６に押し付けられるが、１回目の熱膨張により、ハニカム体４は外層が若干押し潰され外径が小さくなり、以降の熱膨張では圧縮応力は殆ど作用しなくなる。一方熱収縮による引張り力は、熱膨張と熱収縮が熱サイクル毎に繰り返され発生する。しかし、内部の層が接合されていない中間体５が配設されているので、変形が吸収されハニカム体４に発生する応力が大幅に低減される。さらに同中間体５の非接合層により、外筒と断熱されるため、ハニカム体に発生する温度分布が改善され、耐久性が向上する。
次に本発明の実施例について述べる。
【００２５】
【実施例】
図３に本発明の実施例のメタル担体Ａを示す。横断面の接合構造を図６に示す。外筒６は１９Ｃｒ−０．４Ｎｂを合金成分とするフェライト系ステンレス鋼で、外径は１００mm、長さは１１０mm、厚さは１．５mmである。ハニカム体４は２０Ｃｒ−５Ａを合金成分とするフェライト系ステンレス鋼で、外径は９６．４で、厚さ５０μｍの平箔４と波箔５で構成されている。ハニカム体４のセル密度は、４００セル／平方インチである。中間体５は２０Ｃｒ−５Ａｌを合金成分とするフィライト系ステンレンス鋼で、その長さは１００mmで、２回カールされ外径は９７mmで、その厚さは１５０μｍである。
【００２６】
またハニカム体４の内部の接合はロウ付けあるいは拡散接合により、ハニカム体４と中間体５の接合および中間体５と外筒６の接合は、Ｎｉを主成分とするＮｉロウ材で接合されている。
【００２７】
図４は本発明の別の実施例のメタル担体Ｃを示す。その横断面の接合構造は図６に示す。外筒６、長さが５０mmとなった以外は中間体５も、ハニカム体４の材質、寸法および接合方法はメタル担体Ａと同じである。中間体５はメタル担体の中央より出側に配置され、ハニカム体４と中間体５は軸方向に全長、中間体５と外筒６は軸方向に全長ロウ付けされている。
【００２８】
図５は本発明の別の実施例のメタル担体Ｄを示す。その横断面の接合構造は図６に示す。外筒６、中間体５、ハニカム体４も長さが５０mmとなった以外は材質、寸法および接合方法はメタル担体Ａと同じである。ハニカム体４は担体の入側に配置され、ハニカム体４と中間体５は軸方向に全長、中間体５と外筒６は軸方向に全長ロウ付けされている。
【００２９】
図１０は、本発明のメタル担体と比較するための公知のメタル担体Ｅである。メタル担体各部の寸法、材質は同じであるが、ハニカム体４の外径は、中間体がないため、９７mmである。ハニカム体１０の内部は斜線の範囲がロウ付けで接合されている。ハニカム体１０と外筒６は、メタル担体の出側近傍の点で示される範囲の部位１１でロウ付けされており、温度変化の大きい排気ガスによる半径方向および軸方向の熱膨張収縮に対して、自由に変形できるので、ハニカム体１０と外筒６の間に大きい熱応力が発生することは殆どなく、高い耐久性が確保される。しかし、ハニカム体１０内部の接合を、図のようにパターン化するには複雑な製造工程が必要で、製造コストが掛かる問題がある。
【００３０】
図１１は、本発明のメタル担体と比較するための公知のメタル担体Ｆである。外筒６、ハニカム体４、中間体１２の材質は同じである。外筒６のサイズはメタル担体Ａと同じであるが、中間体１２は厚さは１５０μｍであるが、ハニカム体４の周りを一周しているのみである。ハニカム体４の内部は同様に斜線を施している範囲を拡散接合あるいはロウ付けで全体接合されているが、ハニカム体４と中間体１２は担体の入側近傍部１３で、中間体１１と外筒６は出側近傍部１４で接合されている。排気ガスの温度変化による、メタル担体Ｆのハニカム体４の半径方向の熱膨張収縮を、中間体１２の撓みで逃げる構造となっている。
【００３１】
これらの各種メタル担体の製造コストを相対比較すると共に、耐久性を評価するため排気量２０００ccの、４サイクルエンジンの出側に取付け、図１２のような熱サイクル試験を実施した。
同図で縦軸は温度、横軸は時間を表し、測温はメタル担体の上流側端面から２０mmの位置で行い、Temp1 ＝１５０℃、Temp2 ＝９００℃、Ｔ1 ＝１０min 、Ｔ2 ＝１０min である。達成すべき試験サイクル数は、１０００サイクルであるが、耐久性を相対評価するため試験サイクル数を１５００サイクルまで延長し評価した。
【００３２】
その製造コスト比較と耐久試験結果を表１に示す。
外筒からハニカム体が外れるまでのサイクル数を示す。なお、判定は１０００サイクル耐えれば合格とした。
【００３３】
【表１】

【００３４】
以上のように、本発明の各種メタル担体および比較の従来の各種メタル担体は何れも、耐久試験に合格したが、従来のメタル担体Ｆは中間体の変形自由度が不足し相対的に耐久度が低い。またメタル担体Ｅは良好な耐久性を示したが、製造プロセスが複雑なため、製造コストが高くなる短所がある。
それに比べ本発明のメタル担体Ａ，Ｃ，Ｄは、耐久性および製造コストのバランスがとれ、従来のメタル担体より総合的に優秀である。
【００３５】
【発明の効果】
以上説明したように、本発明によれば、メタル担体の構造を合理化することにより、低コストで耐久性の優れたメタル担体を供給できることが判明した。
【図面の簡単な説明】
【図１】本発明のメタル担体の外観を示す斜視図。
【図２】本発明のメタル担体の各構成要素の一例を示す外観斜視図。
【図３】本発明の実施例（メタル担体Ａ）を示す断面図。
【図４】本発明の実施例（メタル担体Ｃ）を示す断面図。
【図５】本発明の実施例（メタル担体Ｄ）を示す断面図。
【図６】本発明の実施例を示すメタル担体の横断面図。
【図７】本発明の実施例を示すメタル担体の横断面図。
【図８】本発明の実施例を示すメタル担体の横断面図。
【図９】本発明の実施例を示すメタル担体の横断面図。
【図１０】本発明のメタル担体と比較するための公知のメタル担体Ｅの縦断面図。
【図１１】本発明のメタル担体と比較するための公知のメタル担体Ｆの縦断面図。
【図１２】各種メタル担体の耐久性を評価するための熱サイクルパターンを示す図。
【符号の説明】
１メタル担体
２平箔
３波箔
４ハニカム体
５中間体
６外筒
７ハニカム体と中間体との接合部
８中間体と外筒の接合部
９中間体の非接合部
１０接合部位をパターン化したハニカム体
１１ハニカム体と外筒の接合部
１２中間体
１３ハニカム体と中間体の接合部
１４中間体と外筒の接合部[0001]
[Industrial application fields]
The present invention relates to a metal carrier for purifying exhaust gas discharged from an internal combustion engine such as an automobile engine.
[0002]
[Prior art]
Conventionally, a ceramic metal carrier has been used in a catalytic converter for purifying exhaust gas, but recently, the use of a metal carrier has been increased from the viewpoint of heat resistance, low pressure loss and mountability.
[0003]
A metal carrier is formed by winding a flat foil made of a metal such as ferritic stainless steel having a heat resistance of about 50 μm in thickness and a corrugated corrugated foil to form a honeycomb body. Similarly, they are housed in an outer tube made of corrosion-resistant and heat-resistant metal such as ferritic stainless steel having heat resistance, and are joined to each other by brazing or the like.
[0004]
This metal carrier is loaded and used, for example, in an exhaust system of an automobile engine after a catalyst for purifying exhaust gas such as platinum, palladium, rhodium, etc. is supported.
For this reason, the metal carrier is subjected to severe temperature changes and vibrations accompanying changes in operating conditions, but if it is damaged, not only the purification performance deteriorates but also the exhaust system is closed or the engine is damaged, so that particularly high durability is required.
[0005]
The thermal stress acting on the metal carrier is particularly large between the outer cylinder and the honeycomb body having a large temperature difference, and various joining structures have been proposed in order to alleviate the stress.
For example, as shown in Japanese Patent Laid-Open No. 4-148016, the joint structure inside the honeycomb body and the joint portion between the honeycomb body and the outer cylinder are specified, the degree of freedom with respect to thermal deformation is increased, and a so-called flexible structure is formed. A lowering method, or as disclosed in JP-A-3-157139 and JP-A-2-298620, a cylindrical intermediate body is disposed between the honeycomb body and the outer cylinder, and the honeycomb body and the outside However, there is a method of increasing the degree of freedom with respect to thermal deformation by not joining the two joints in the axial direction.
[0006]
The conventional method streamlines the joint structure between the honeycomb body and between the outer cylinder and the honeycomb body, or by providing an intermediate body, thereby increasing the degree of freedom against thermal deformation and ensuring good durability. There is a problem that the manufacturing is complicated, the productivity is low, and the cost is high. When the honeycomb body is diffusion-bonded, all the contact points between the flat foil and the corrugated foil are bonded unless special measures are taken. However, when the honeycomb body is bonded as a whole, the outer cylinder and the honeycomb body are bonded together. Although it is necessary to further increase the degree of freedom with respect to the deformation in the meantime, the conventional method is insufficient, and there has been a problem that the honeycomb body supporting portion is broken and shifted at the end.
[0007]
[Problems to be solved by the invention]
In the present invention, the entire honeycomb body of the metal carrier is joined or the temperature change of the exhaust gas is large, and in the conventional method, the degree of freedom in deformation between the honeycomb body and the outer cylinder is insufficient, so high durability cannot be obtained. In this case, a metal carrier provided with a high degree of freedom by a simple method by providing an intermediate between the outer cylinder and the honeycomb body is provided.
[0008]
[Means for Solving the Problems]
That is, the present invention is a durable metal carrier,
(1) After forming a honeycomb body in which flat foil and corrugated foil are alternately wound or laminated, an intermediate body is formed by winding a thin plate that is the same as or thicker than the foil twice or more on the outside. The inner surface of the body and the outer surface of the honeycomb body are continuously joined in a full length in the axial direction, and the outer surface of the intermediate body is joined in a full length in the axial direction with the outer cylinder within one turn. A metal carrier characterized by providing a bonding layer;
(2) The metal carrier as set forth in (1) above, wherein the inside of the honeycomb body is entirely joined, (3) Before (1) or (), wherein the intermediate body is a flat plate not corrugated. 2) the metal carrier according to
(4) The metal carrier according to (1) or (2) above , wherein the corrugated intermediate plate is used as the intermediate.
[0009]
The present invention will be described in detail below.
FIG. 1 is an external view of a metal carrier 1 of the present invention. An intermediate body 5 wound twice or more is disposed outside the honeycomb body 4 formed by winding or laminating the flat foil 2 and the corrugated foil 3, and an outer cylinder 6 is disposed outside the intermediate body 5. In the same configuration, the honeycomb body 4 is bonded to the inner surface of the intermediate body 5, and the outer surface of the intermediate body 5 is bonded to the inner surface of the outer cylinder 6. However, the inside of the intermediate body 5 wound in multiple is not joined.
[0010]
The plate thickness of the intermediate body 5 is set to be thinner than the outer cylinder 6 and thicker than the flat foil 2 and the corrugated foil 3 constituting the honeycomb body.
The intermediate body 5 is joined to the honeycomb body 4 continuously or intermittently for one round, and the outer body 6 is joined to the outer cylinder 6 continuously or intermittently within one round.
[0011]
Therefore, the intermediate body 5 of the metal carrier 1 of the present invention has a role like a coil spring that holds the honeycomb body 4 on the inner periphery and is coupled to the outer cylinder 6 on the outer surface in terms of thermal stress, and has a radius The non-bonding layer in the intermediate body 5 acts as a heat insulating layer, and the temperature difference between the honeycomb body 4 and the intermediate body 5 is reduced, and at the same time, the intermediate body The temperature difference between 5 and the outer cylinder 6 is also reduced, and the stress generated between the honeycomb body 4 and the outer cylinder 6 can be reduced.
[0012]
Since the honeycomb body 4 is coated with a catalyst, the reaction heat is generated and a thermal stress is generated in the axial direction. However, since the honeycomb bodies 4 are entirely joined, the displacement in the axial direction is forcibly restrained, so that the amount of displacement is reduced and good durability can be ensured.
[0013]
FIG. 2 is a diagram showing the configuration of the metal carrier 1 of the present invention. FIG. 2A shows the appearance of a honeycomb body 4 formed by winding a flat foil 2 and a corrugated foil 3, and FIG. 2B shows the appearance of an intermediate body 5 that wraps and wraps the honeycomb body 4. Has been curled more than once. In FIG. 2, the intermediate is shown as a flat thin plate, but the corrugated corrugated foil may be curled twice or more in the same manner. (C) The figure shows the external appearance of the outer cylinder 6 that houses the honeycomb body 4 and the intermediate cylinder 5. These contact surfaces are, for example, a brazing material for bonding to each other in the case of brazing, or in the case of diffusion bonding, the interface bonding is cleaned and prepared to be bonded, and on the contrary, a bonding inhibitor is used for a portion that is not bonded. Etc. are applied, and a necessary pressurizing force is applied and assembled so as to adhere.
[0014]
Hereinafter, various joining structures in the metal carrier of the present invention are shown.
FIGS. 3 to 5 show an example of the joining structure in the vertical cross section of the metal carrier, and FIGS. 6 to 9 show the joining structure of the cross section of each metal carrier. In addition, the joining structure of these vertical cross sections and the joining structure of a cross section do not have a specific combination, and can be used combining them suitably.
[0015]
In FIG. 3, the honeycomb body 4 has an area indicated by hatching in which all contact points of the flat foil and the corrugated foil are bonded in principle by, for example, diffusion bonding or brazing. Reference numeral 5 denotes an intermediate body, but a portion 7 (a portion in a range indicated by a dot) that is in contact with the outer surface of the honeycomb body 4 on the inner surface is joined to the entire length in the axial direction. Similarly, a portion 8 (a portion in a range indicated by a dot) in contact with the outer surface of the intermediate body 5 and the inner surface of the outer cylinder 6 is joined to the entire length in the axial direction. However, the intermediate layer 9 other than the inner and outer surfaces of the intermediate body 5 is not joined.
[0016]
FIG. 4 is employed when, for example, the joint between the honeycomb body 4 and the outer cylinder 6 of the intermediate body 5 is protected from high-temperature exhaust gas. The honeycomb body 4 has a range indicated by hatching, for example, diffusion bonding or brazing. As a result, all the contacts of the flat foil and the corrugated foil are joined in principle. A portion 7 in contact with the outer surface of the honeycomb body 4 on the inner surface of the intermediate body 5 is joined in the axial direction, for example, a specific range on the outlet side of the exhaust gas, and a portion 8 in contact with the inner surface of the outer cylinder 6 is in the axial direction, for example, the exhaust gas. The specific area on the exit side is joined. However, the intermediate layer 9 other than the inner and outer surfaces of the intermediate body 5 is not joined. In addition, although the length of the intermediate body 5 is stopped in the joining range in FIG. 4 , it does not interfere even if it is longer than the joining length.
[0017]
FIG. 5 is employed when, for example, the honeycomb body 5 is short in length, so that it is prevented from tilting in the outer cylinder 6 during use. Although the length of the honeycomb body 4 is short in the figure, the intermediate body 5 and the outer cylinder 6 are longer than the honeycomb body 4 and have a length that can maintain the posture even when deformation occurs during use. . In the honeycomb body 4, all the contact points of the flat foil and the corrugated foil are bonded in principle by the diffusion bonding or brazing, for example, in the range indicated by the oblique lines as described above. A portion 7 in contact with the outer surface of the honeycomb body 4 on the inner surface of the intermediate body 5 is joined in the axial direction, for example, full length, and a portion 8 in contact with the inner surface of the outer cylinder 6 is joined in the axial direction, for example, in the full length. However, the intermediate layers 9 other than the inner and outer surfaces of the intermediate body 5 are not joined.
[0018]
In FIG. 6 , the contact points of the flat foil and the corrugated foil in the range indicated by diagonal lines are all bonded to the honeycomb body 4, and the inner surface of the intermediate body 5 is bonded to the entire circumference (the part indicated by the points). The outer surface of 5 is joined to the outer cylinder 6 on the entire circumference (parts in a range indicated by dots). However, the intermediate layer 9 of the intermediate body 5 is not joined.
[0019]
In FIG. 7 , the intermediate body 5 and the outer cylinder 6 have a joining structure that is employed when it is not necessary to join the entire circumference since the intermediate body 5 and the outer cylinder 6 are thicker than the foil of the honeycomb body 4. The bonding inside the honeycomb body 4 and the bonding between the honeycomb body 4 and the intermediate body 5 are the same as in the case of FIG. 6 , but the outer surface of the intermediate body 5 and the inner surface of the outer cylinder 6 are not the entire circumference, but are limited to a part. The region in the range not indicated by the point is not joined. In this case, if the non-joined portion of the intermediate body 5 is not required one or more rounds, the intermediate body 5 can be saved by setting the curling range of the intermediate body 5 as two or less rounds as an application of the present invention.
[0020]
FIG. 8 shows a structure that is adopted when saving the bonding material between the intermediate body 5 and the outer cylinder 6. That is, the parts in the range indicated by the points between the intermediate body 5 and the outer cylinder 6 are joined, and the parts not joined in the range not indicated by the points are alternately arranged. It is the same as the above that the layers inside the intermediate body 5 are not joined.
[0021]
FIG. 9 shows a structure that is employed when the bonding material between the honeycomb body 4 and the intermediate body 5 and between the intermediate body 5 and the outer cylinder 6 is saved. Parts in the range indicated by dots in the figure are joined, and parts in a range not shown are not joined. That is, the honeycomb body 4 is joined as a whole, the honeycomb body 4 and the intermediate body 5 are joined intermittently, and the intermediate body 5 is joined with a part of the outer cylinder 6.
[0022]
As the above-mentioned application, it is possible to further improve the durability by adopting a known honeycomb body provided with a non-joined portion at a specific location inside the metal carrier of the present invention. However, from the manufacturing cost, it is more advantageous to adopt a honeycomb body bonded as a whole as in the present invention.
[0023]
The metal carrier 1 of the present invention is used, for example, after being loaded with a noble metal such as platinum, palladium or rhodium for purifying exhaust gas, for example, in the exhaust system of an automobile, in the same manner as a conventionally known metal carrier. At the same location, the metal carrier is subjected to a drastic temperature change, so that a large temperature difference occurs in the radial direction, and a strong compressive tensile force acts on the honeycomb body 4 in the outer cylinder 6.
[0024]
The honeycomb body 4 is pressed against the outer cylinder 6 via the intermediate body 5 due to thermal expansion. However, due to the first thermal expansion, the outer layer of the honeycomb body 4 is slightly crushed and the outer diameter is reduced. Compressive stress almost does not work. On the other hand, the tensile force due to thermal contraction is generated by repeating thermal expansion and thermal contraction every thermal cycle. However, since the intermediate body 5 in which the inner layers are not bonded is provided, the deformation is absorbed and the stress generated in the honeycomb body 4 is greatly reduced. Furthermore, since the non-bonding layer of the intermediate body 5 is thermally insulated from the outer cylinder, the temperature distribution generated in the honeycomb body is improved and the durability is improved.
Next, examples of the present invention will be described.
[0025]
【Example】
FIG. 3 shows a metal carrier A according to an embodiment of the present invention. FIG. 6 shows a cross-sectional joining structure. The outer cylinder 6 is ferritic stainless steel having 19Cr-0.4Nb as an alloy component, and has an outer diameter of 100 mm, a length of 110 mm, and a thickness of 1.5 mm. The honeycomb body 4 is a ferritic stainless steel having 20Cr-5A as an alloy component, and has an outer diameter of 96.4 and is composed of a flat foil 4 and a corrugated foil 5 having a thickness of 50 μm. The cell density of the honeycomb body 4 is 400 cells / square inch. The intermediate body 5 is a philitic stainless steel containing 20Cr-5Al as an alloy component, and its length is 100 mm, it is curled twice, its outer diameter is 97 mm, and its thickness is 150 μm.
[0026]
Also, the inside of the honeycomb body 4 is joined by brazing or diffusion joining, and the joining of the honeycomb body 4 and the intermediate body 5 and the joining of the intermediate body 5 and the outer cylinder 6 are joined by a Ni brazing material containing Ni as a main component. Yes.
[0027]
FIG. 4 shows a metal carrier C according to another embodiment of the present invention. The junction structure of the cross-section shown in FIG. Except for the outer cylinder 6 and the length of 50 mm, the intermediate body 5 is also the same as the metal carrier A in the material, dimensions and joining method of the honeycomb body 4. The intermediate body 5 is disposed on the outlet side from the center of the metal carrier, the honeycomb body 4 and the intermediate body 5 are full length in the axial direction, and the intermediate body 5 and the outer cylinder 6 are brazed in the full length in the axial direction.
[0028]
FIG. 5 shows a metal carrier D according to another embodiment of the present invention. The junction structure of the cross-section shown in FIG. The material, dimensions, and joining method are the same as those of the metal carrier A except that the length of the outer cylinder 6, the intermediate body 5, and the honeycomb body 4 is also 50 mm. The honeycomb body 4 is disposed on the inlet side of the carrier, the honeycomb body 4 and the intermediate body 5 are brazed in the full length in the axial direction, and the intermediate body 5 and the outer cylinder 6 are brazed in the full length in the axial direction.
[0029]
FIG. 10 shows a known metal carrier E for comparison with the metal carrier of the present invention. Although the dimensions and materials of the respective parts of the metal carrier are the same, the outer diameter of the honeycomb body 4 is 97 mm because there is no intermediate body. The inside of the honeycomb body 10 is joined by brazing in the shaded area. The honeycomb body 10 and the outer cylinder 6 are brazed at a portion 11 in a range indicated by a point near the exit side of the metal carrier, and against thermal expansion and contraction in the radial direction and the axial direction due to exhaust gas having a large temperature change. Since it can be freely deformed, a large thermal stress is hardly generated between the honeycomb body 10 and the outer cylinder 6, and high durability is ensured. However, in order to pattern the joints inside the honeycomb body 10 as shown in the figure, a complicated manufacturing process is required, and there is a problem that the manufacturing cost is increased.
[0030]
FIG. 11 shows a known metal carrier F for comparison with the metal carrier of the present invention. The materials of the outer cylinder 6, the honeycomb body 4, and the intermediate body 12 are the same. Although the size of the outer cylinder 6 is the same as that of the metal carrier A, the intermediate body 12 has a thickness of 150 μm, but only goes around the honeycomb body 4. Similarly, the inside of the honeycomb body 4 is entirely joined by diffusion bonding or brazing in a hatched area, but the honeycomb body 4 and the intermediate body 12 are in the vicinity 13 of the carrier entrance side, and the intermediate body 11 and the outer body 12 are joined together. The cylinder 6 is joined at the exit side vicinity 14. The structure is such that the thermal expansion and contraction in the radial direction of the honeycomb body 4 of the metal carrier F due to the temperature change of the exhaust gas escapes due to the bending of the intermediate body 12.
[0031]
The relative manufacturing costs of these various metal carriers were compared, and in order to evaluate the durability, they were mounted on the exit side of a 4-cycle engine with a displacement of 2000 cc, and a thermal cycle test as shown in FIG. 12 was performed.
In the figure, the vertical axis represents temperature, the horizontal axis represents time, and the temperature measurement is performed at a position 20 mm from the upstream end face of the metal carrier, Temp1 = 150 ° C., Temp2 = 900 ° C., T1 = 10 min, T2 = 10 min. . The number of test cycles to be achieved is 1000, but the test cycle number was extended to 1500 cycles for relative evaluation of durability.
[0032]
The production cost comparison and the durability test results are shown in Table 1.
The number of cycles until the honeycomb body is detached from the outer cylinder is shown. In addition, the determination was accepted if it could withstand 1000 cycles.
[0033]
[Table 1]

[0034]
As described above, each of the various metal carriers of the present invention and the conventional various metal carriers for comparison passed the durability test, but the conventional metal carrier F lacks the degree of freedom of deformation of the intermediate and is relatively durable. Is low. In addition, although the metal carrier E showed good durability, there is a disadvantage that the manufacturing cost is high because the manufacturing process is complicated.
In contrast, the metal carriers A 1 , C, and D of the present invention have a balance between durability and manufacturing cost, and are comprehensively superior to conventional metal carriers.
[0035]
【The invention's effect】
As described above, according to the present invention, it has been found that by rationalizing the structure of the metal carrier, it is possible to supply a metal carrier having excellent durability at low cost.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an appearance of a metal carrier of the present invention.
FIG. 2 is an external perspective view showing an example of each component of the metal carrier of the present invention.
FIG. 3 is a cross-sectional view showing an embodiment (metal carrier A) of the present invention.
FIG. 4 is a sectional view showing an example of the present invention (metal carrier C).
FIG. 5 is a sectional view showing an example of the present invention (metal carrier D).
FIG. 6 is a cross-sectional view of a metal carrier showing an embodiment of the present invention.
FIG. 7 is a cross-sectional view of a metal carrier showing an embodiment of the present invention.
FIG. 8 is a cross-sectional view of a metal carrier showing an embodiment of the present invention.
FIG. 9 is a cross-sectional view of a metal carrier showing an embodiment of the present invention.
FIG. 10 is a longitudinal sectional view of a known metal carrier E for comparison with the metal carrier of the present invention.
FIG. 11 is a longitudinal sectional view of a known metal carrier F for comparison with the metal carrier of the present invention.
FIG. 12 is a diagram showing a thermal cycle pattern for evaluating the durability of various metal carriers.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Metal carrier 2 Flat foil 3 Corrugated foil 4 Honeycomb body 5 Intermediate body 6 Outer cylinder 7 Junction part of a honeycomb body and an intermediate body 8 Junction part of an intermediate body and an outer cylinder 9 Non-joint part of an intermediate body 10 Patterning of joining part Honeycomb body 11 Junction part of honeycomb body and outer cylinder 12 Intermediate body 13 Junction part of honeycomb body and intermediate body 14 Junction part of intermediate body and outer cylinder

Claims

After forming a honeycomb body in which flat foil and corrugated foil are alternately wound or laminated, an intermediate body is formed by winding a thin plate that is the same as or thicker than the foil on the outer side twice or more. And the outer surface of the honeycomb body are continuously rounded and joined in the full length in the axial direction. A metal carrier characterized by being provided.

2. The metal carrier according to claim 1, wherein the whole inside of the honeycomb body is joined.

3. The metal carrier according to claim 1, wherein the intermediate body is a flat plate not corrugated.

The metal carrier according to claim 1 or 2 , wherein the corrugated intermediate plate is used.