JP3395234B2 - Electrically heated metal catalyst carrier structure - Google Patents
Electrically heated metal catalyst carrier structureInfo
- Publication number
- JP3395234B2 JP3395234B2 JP04123993A JP4123993A JP3395234B2 JP 3395234 B2 JP3395234 B2 JP 3395234B2 JP 04123993 A JP04123993 A JP 04123993A JP 4123993 A JP4123993 A JP 4123993A JP 3395234 B2 JP3395234 B2 JP 3395234B2
- Authority
- JP
- Japan
- Prior art keywords
- catalyst carrier
- short
- catalyst
- metal
- carrier structure
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 239000003054 catalyst Substances 0.000 title claims description 56
- 239000002184 metal Substances 0.000 title claims description 32
- 239000011888 foil Substances 0.000 claims description 29
- 238000011144 upstream manufacturing Methods 0.000 claims description 9
- 239000003863 metallic catalyst Substances 0.000 claims description 2
- 238000010438 heat treatment Methods 0.000 description 8
- 238000000034 method Methods 0.000 description 7
- 230000004913 activation Effects 0.000 description 4
- 238000005219 brazing Methods 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 231100000572 poisoning Toxicity 0.000 description 3
- 230000000607 poisoning effect Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 230000007774 longterm Effects 0.000 description 2
- 230000000873 masking effect Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Landscapes
- Exhaust Gas After Treatment (AREA)
- Catalysts (AREA)
Description
【発明の詳細な説明】
【０００１】
【産業上の利用分野】本発明は、自動車等に装着される
排気ガス触媒に関し、特に触媒を担持させた複数の金属
箔を中心電極周りに巻回すことにより形成される通電加
熱式の金属触媒担体構造に関する。
【０００２】
【従来の技術】一般に、自動車等の排気ガスを浄化する
ために用いられる触媒は、その触媒作用を充分に発揮す
るためには所定温度以上に昇温していることが必要であ
り、このため、エンジン温度が低く排気ガスの温度では
触媒が充分に加熱されないような機関始動時において
は、触媒に通電することでこれを積極的に加熱し、以て
その触媒の活性化を早めるようにした通電加熱式金属触
媒担体が知られている。
【０００３】また、このような通電加熱式の金属触媒担
体には、暖機時間の短縮かつ低電力化を目的として、絶
縁関係にある金属箔同士を部分的に短絡させ、この部分
に電流を集中させることにより局部加熱して昇温効率を
高めようとした触媒担体構造を出願人らは特願平５−９
３４４号にて出願している。
【０００４】
【発明が解決しようとする課題】ところで、一般に、触
媒は使用に伴う熱劣化や被毒劣化により徐々に排気上流
側の端面から約数mm程度、触媒としての性能が低下して
いく傾向にある。そして、上述したような局部加熱式の
触媒担体では、通常その端面側に加熱部となる短絡部が
形成されるため、長期間の使用後は加熱しても効率良く
触媒活性化できないという問題がある。
【０００５】本発明は、かかる問題点に鑑みなされるも
のであって、金属箔同士を短絡させた加熱式触媒担体に
おいて、長期間の使用でも活性化を効率良く行うことが
できるような触媒担体構造を提供することを目的とする
ものである。
【０００６】
【課題を解決するための手段】上記目的を達成するため
本発明によれば、両端を電極に接続した複数の金属箔を
一軸線周りに積層・巻き回しして成る金属触媒担体の上
記金属箔同士を電気的に絶縁すると共に、局部的に短絡
させた通電加熱式金属触媒担体構造において、上記金属
箔同士の短絡部を、金属箔の排気流れ方向上流側端部領
域を除く下流側の領域に設けたことを特徴とする通電加
熱式金属触媒担体構造が提供される。
【０００７】
【作用】短絡部が排気流れ方向上流側端部より下流側の
奥まった所に位置するため、短絡部、即ち触媒加熱部に
おける触媒自体が熱劣化や被毒しにくくなる。
【０００８】
【実施例】本発明による金属触媒担体構造を説明するに
先立ち、まず基本的な触媒担体構造について図面を参照
しながら説明する。図１は一般的な本発明適用対象とし
ての触媒担体を示すものであって、その担体を排気上流
側より見た平面図である。
【０００９】この触媒担体は、図中部分的に拡大したよ
うに平箔１と波箔２とから成る金属箔のペアを５層に亙
って積層し、さらにこの積層体を中心電極３の周りで２
条に巻き付けることにより提供されるものであり、５層
金属箔は他の５層金属箔に対し、例えばアルミナ・ガラ
ス層に代表されるような酸化被膜の絶縁層４によって電
気的に絶縁されている。
【００１０】従って、この触媒担体は、通電時において
中心電極３（＋側）から２系統で矢印の方向に電流が流
れ、そのコア全体が発熱するタイプのものとなる。尚、
本図において、５は以上のように構成された触媒本体６
を収納する外筒（−側）であって、その内周面には一端
を中心電極３に電気的に接続した多数金属箔の他端が接
合されることになる。
【００１１】以上がコア全体を発熱させるタイプの触媒
担体の一構造例であるが、本発明では、このような触媒
担体通電時の昇温速度を迅速化しつつ低電力化を図るた
め、例えば上記絶縁層４の酸化被膜を局部的に除去し、
この除去部を短絡部としてここに電流を集中させること
により局部加熱型の触媒担体構造を提供する。しかし
て、本実施例によれば、この短絡部は触媒担体の排気流
れ上流側端面（以下、フロント端面と呼ぶ）に設けるの
ではなく、触媒軸方向においてそのフロント端面よりも
若干、排気下流側にシフトされた位置に、短絡面が形成
される。
【００１２】図２は、上記絶縁層４上に形成される短絡
面の位置を斜線Ａで示した図であって、触媒担体組立状
態における絶縁層４を部分的に、その触媒側面方向から
見た概略図である。尚、本図はその左側が排気流れ上流
側となる触媒担体フロント側、右側が排気下流側となる
リア側になる。この図からも明らかなように、本実施例
によればこの短絡面Ａは、触媒の長期使用に伴って熱劣
化（又は被毒劣化）すると想定される斜線Ｂの部位（通
常、フロント端面６ａより約数mm程度リア側までの範
囲）を避けるように、予めフロント端面６ａよりもリア
側に移動される。
【００１３】この結果、触媒担体通電時においては、絶
縁層４で絶縁されていた各金属箔がこの短絡面Ａを介し
て電気的に接続されることとなり、電流はこの短絡面Ａ
に集中して、この集中部において局所加熱することにな
る。従って、図１に示すパターンの絶縁層全体に亙って
上述した短絡面形成をした場合、その発熱部位は絶縁層
配置パターンに対応した螺旋状となり、以上のようにし
て部分加熱であるが発せられた熱が全体に行き渡る低電
力型の触媒担体が提供されることになる。
【００１４】加えて、本実施例によれば、上述した短絡
面形成位置により、熱や被毒の影響が小さく、長期的な
使用においても触媒担体昇温速度が低下せずその活性化
を効率良く行うことが可能な触媒担体構造が提供される
ことになる。図３は、上述したようにフロント端面６ａ
より奥まった所定部位に金属箔同士の短絡面Ａを形成す
る方法を示したものである。尚、この方法はあくまで短
絡面形成のための一例であって、実際にはこの方法に限
定されるものではない。
【００１５】しかして、その具体的手順は、まず絶縁層
が欠落することになる平箔１の特定表面部位にマスキン
グシール７を貼り付け（図３−ａ参照）、次いでこの平
箔表面全域に亙って、例えばアルミナ・ガラス混合材に
代表されるような絶縁層４をコーティングする（図３−
ｂ参照）。そして絶縁層４が形成された後、図３の
（ｃ）に示すように上記マスキングシール７を剥がす。
この結果、平箔１の表面には絶縁層４で被覆されない部
分が現出することになり、次いでこの絶縁層欠落部分に
対してろう材８を仮留めし（図３−ｄ）、その後この金
属箔を他の金属箔と共に巻き込み、この仮留め部分を介
して絶縁層を持たない他の金属箔に対してろう付けし、
絶縁処理された金属箔の短絡部を形成して局部加熱型の
触媒担体が提供されることになる。
【００１６】以上、図１の絶縁層配置パターンに一致し
た短絡パターンを持つ触媒担体に例をとり、本発明の触
媒担体構造を説明したが、その他の短絡パターンとして
は触媒担体を構成する総ての金属箔に絶縁層を被覆さ
せ、その上で上述したような短絡面を金属箔全長に亙っ
て形成するような、所謂触媒全域が発熱部位となる図４
の（ａ）に示すような短絡パターンも可能である。
【００１７】尚、その他の短絡パターンとしては、図４
（ｂ）、（ｃ）、（ｄ）に夫々示したようなものが考え
られるが、このような短絡パターンを形成するにあたっ
ては、各パターンに対応したろう付け位置を予め求め、
その部位の絶縁層を図３に示したような方法でろう材に
置き換えた後、巻き込んでろう付けすれば良い。
【００１８】
【発明の効果】以上説明したように本発明によれば、短
絡部が排気流れ方向上流側端部より下流側の奥まった所
に位置するため、短絡部、即ち触媒加熱部における触媒
自体が熱劣化や被毒しにくくなり、長期間使用された触
媒担体でも迅速な加熱が達成され触媒活性化を効率良く
行うことができる。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust gas catalyst mounted on an automobile or the like, and more particularly, to winding a plurality of metal foils carrying the catalyst around a center electrode. And a current-carrying metal catalyst carrier structure formed by the method. 2. Description of the Related Art Generally, a catalyst used for purifying exhaust gas of an automobile or the like needs to be heated to a predetermined temperature or higher in order to sufficiently exert its catalytic action. Therefore, when the engine is started such that the catalyst is not sufficiently heated at a low exhaust gas temperature due to a low engine temperature, the catalyst is energized to actively heat the catalyst, thereby accelerating the activation of the catalyst. Such an electrically heated metal catalyst carrier is known. [0003] Further, in order to shorten the warm-up time and reduce the power consumption, such an electrically heated metal catalyst carrier is partially short-circuited between metal foils having an insulating relationship, and current is applied to this portion. Applicants have disclosed a catalyst carrier structure in which local heating is performed by concentrating to increase the temperature raising efficiency.
No. 344. [0004] Generally, the performance of the catalyst gradually decreases by about several mm from the end face on the exhaust upstream side due to thermal deterioration and poisoning deterioration accompanying use. There is a tendency. In the case of the locally heated catalyst carrier as described above, since a short-circuited portion serving as a heating portion is usually formed on the end face side, there is a problem that the catalyst cannot be efficiently activated even after heating for a long period of use. is there. [0005] The present invention has been made in view of the above problems, and is intended to provide a heating type catalyst carrier in which metal foils are short-circuited such that activation can be efficiently performed even when used for a long time. It is intended to provide a structure. According to the present invention, there is provided a metal catalyst carrier comprising a plurality of metal foils, both ends of which are connected to electrodes, laminated and wound around one axis. with electrically isolating the metal foil each other, in locally shorted allowed energization heated metallic catalyst support structure, the short-circuit portion between the metal foil, the exhaust flow direction upstream end territory of the metal foil
And a current-carrying metal catalyst carrier structure provided in a downstream region other than the region . Since the short-circuit portion is located deeper downstream of the upstream end in the exhaust gas flow direction, the short-circuit portion, that is, the catalyst itself in the catalyst heating portion is less likely to be thermally deteriorated or poisoned. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing the structure of a metal catalyst carrier according to the present invention, a basic catalyst carrier structure will be described with reference to the drawings. FIG. 1 shows a general catalyst carrier to which the present invention is applied, and is a plan view of the carrier viewed from an exhaust upstream side. This catalyst carrier is formed by laminating a pair of metal foils consisting of a flat foil 1 and a corrugated foil 2 in five layers as shown partially enlarged in the figure. Around 2
The five-layered metal foil is electrically insulated from other five-layered metal foils by an insulating layer 4 of an oxide film represented by, for example, an alumina glass layer. I have. Therefore, this catalyst carrier is of a type in which current flows in two directions from the center electrode 3 (+ side) in the direction of the arrow when energized, and the entire core generates heat. still,
In this drawing, reference numeral 5 denotes a catalyst body 6 configured as described above.
The other end of a multi-metal foil having one end electrically connected to the center electrode 3 is joined to the inner peripheral surface of the outer cylinder (-side). The above is an example of the structure of the catalyst carrier of the type in which the entire core is heated. In the present invention, in order to reduce the power while increasing the temperature rising rate when the catalyst carrier is energized, for example, The oxide film of the insulating layer 4 is locally removed,
The removal portion is used as a short-circuit portion and the current is concentrated here to provide a locally heated catalyst carrier structure. According to the present embodiment, the short-circuit portion is not provided on the exhaust flow upstream end surface (hereinafter, referred to as a front end surface) of the catalyst carrier, but is slightly downstream of the front end surface in the catalyst axial direction. A short-circuit surface is formed at the position shifted to. FIG. 2 is a diagram in which the position of the short-circuit surface formed on the insulating layer 4 is indicated by oblique lines A, and the insulating layer 4 in a catalyst carrier assembled state is partially viewed from the side of the catalyst. FIG. In this figure, the left side is the catalyst carrier front side which is the exhaust gas upstream side, and the right side is the rear side which is the exhaust downstream side. As is clear from this figure, according to the present embodiment, the short-circuited surface A is a portion of the hatched line B (normally, the front end surface 6a) which is assumed to be thermally deteriorated (or poisoned) with the long-term use of the catalyst. (The range of about several mm to the rear side) is moved in advance to the rear side from the front end face 6a. As a result, when the catalyst carrier is energized, the respective metal foils insulated by the insulating layer 4 are electrically connected via the short-circuit surface A, and the current is applied to the short-circuit surface A.
And local heating is performed in this concentrated portion. Therefore, when the above-described short-circuit surface is formed over the entire insulating layer of the pattern shown in FIG. Thus, a low-power catalyst carrier in which the generated heat is distributed throughout is provided. In addition, according to this embodiment, the influence of heat and poisoning is small due to the above-mentioned short-circuit surface formation position, and the catalyst carrier temperature rising rate does not decrease even in long-term use, and the activation of the catalyst carrier is efficient. A catalyst support structure that can be performed well will be provided. FIG. 3 shows the front end surface 6a as described above.
It shows a method of forming a short-circuit surface A between metal foils at a predetermined deeper portion. Note that this method is merely an example for forming a short-circuit surface, and is not actually limited to this method. The specific procedure is as follows. First, a masking seal 7 is attached to a specific surface portion of the flat foil 1 where the insulating layer is to be removed (see FIG. 3A). Over this, an insulating layer 4 typified by, for example, an alumina-glass mixture is coated (FIG. 3).
b). After the insulating layer 4 is formed, the masking seal 7 is peeled off as shown in FIG.
As a result, a portion not covered with the insulating layer 4 appears on the surface of the flat foil 1, and then the brazing material 8 is temporarily fastened to the insulating layer missing portion (FIG. 3D). Wrap the metal foil together with the other metal foil, braze it through this temporary fixing part to the other metal foil without the insulating layer,
A short-circuit portion of the insulated metal foil is formed to provide a locally heated catalyst carrier. In the above, the structure of the catalyst carrier of the present invention has been described by taking the example of the catalyst carrier having a short-circuit pattern corresponding to the arrangement pattern of the insulating layers in FIG. 1. However, all other short-circuit patterns constitute the catalyst carrier. In FIG. 4, the so-called entire region of the catalyst is a heat generating portion in which the metal foil is covered with an insulating layer and the short-circuit surface as described above is formed over the entire length of the metal foil.
A short circuit pattern as shown in FIG. As another short-circuit pattern, FIG.
(B), (c), and (d) can be considered. In forming such a short-circuit pattern, a brazing position corresponding to each pattern is obtained in advance.
After replacing the insulating layer at that portion with a brazing material by the method shown in FIG. 3, it may be wound around and brazed. As described above, according to the present invention, since the short-circuit portion is located deeper downstream from the upstream end in the exhaust flow direction, the short-circuit portion, that is, the catalyst in the catalyst heating portion, is provided. The catalyst itself is less susceptible to thermal deterioration and poisoning, and rapid heating can be achieved even with a catalyst carrier used for a long period of time, so that catalyst activation can be performed efficiently.
【図面の簡単な説明】
【図１】本発明の適用対象となる一般的触媒担体構造の
平面図である。
【図２】本発明による短絡面形成位置を示す触媒担体構
造の側面図である。
【図３】本発明による触媒担体構造の短絡面形成手順を
示す図である。
【図４】各種短絡パターンを示す担体構造平面図であ
る。
【符号の説明】
１…平箔
２…波箔
３…中心電極
４…絶縁層
５…外筒
６…触媒担体本体
６ａ…フロント端面（排気流れ上流側端面）
Ａ…短絡面BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a general catalyst carrier structure to which the present invention is applied. FIG. 2 is a side view of a catalyst carrier structure showing a short-circuit surface forming position according to the present invention. FIG. 3 is a view showing a procedure for forming a short-circuit surface of a catalyst carrier structure according to the present invention. FIG. 4 is a plan view of a carrier structure showing various short-circuit patterns. [Description of Signs] 1 ... Flat foil 2 ... Corrugated foil 3 ... Central electrode 4 ... Insulating layer 5 ... Outer cylinder 6 ... Catalyst carrier body 6a ... Front end face (end face on the upstream side of exhaust gas flow)
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平５−138042（ＪＰ，Ａ) 特開 平６−23278（ＪＰ，Ａ) 特開 平３−254836（ＪＰ，Ａ) 特表 平３−500911（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) B01J 21/00 - 38/74 B01D 53/86,53/94 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-138042 (JP, A) JP-A-6-23278 (JP, A) JP-A-3-254836 (JP, A) 500911 (JP, A) (58) Field surveyed (Int. Cl. 7 , DB name) B01J 21/00-38/74 B01D 53 / 86,53 / 94
Claims (1)
軸線周りに積層・巻き回しして成る金属触媒担体の上記
金属箔同士を電気的に絶縁すると共に、局部的に短絡さ
せた通電加熱式金属触媒担体構造において、 上記金属箔同士の短絡部を、金属箔の排気流れ方向上流
側端部領域を除く下流側の領域に設けたことを特徴とす
る通電加熱式金属触媒担体構造。(57) Claims 1. A plurality of metal foils, both ends of which are connected to electrodes, are laminated and wound around one axis, and the metal foils of a metal catalyst carrier are electrically insulated from each other. together, the locally shorted allowed energization heated metallic catalyst support structure, and characterized in that the short-circuit portion between the metal foil, is provided on the downstream side of the area except for the exhaust gas flow upstream side end region of the metal foils Energized and heated metal catalyst carrier structure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04123993A JP3395234B2 (en) | 1993-03-02 | 1993-03-02 | Electrically heated metal catalyst carrier structure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04123993A JP3395234B2 (en) | 1993-03-02 | 1993-03-02 | Electrically heated metal catalyst carrier structure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06254405A JPH06254405A (en) | 1994-09-13 |
| JP3395234B2 true JP3395234B2 (en) | 2003-04-07 |
Family
ID=12602882
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP04123993A Expired - Fee Related JP3395234B2 (en) | 1993-03-02 | 1993-03-02 | Electrically heated metal catalyst carrier structure |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3395234B2 (en) |
-
1993
- 1993-03-02 JP JP04123993A patent/JP3395234B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06254405A (en) | 1994-09-13 |
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