JPH0716013Y2 - Catalytic converter - Google Patents
Catalytic converterInfo
- Publication number
- JPH0716013Y2 JPH0716013Y2 JP1988111253U JP11125388U JPH0716013Y2 JP H0716013 Y2 JPH0716013 Y2 JP H0716013Y2 JP 1988111253 U JP1988111253 U JP 1988111253U JP 11125388 U JP11125388 U JP 11125388U JP H0716013 Y2 JPH0716013 Y2 JP H0716013Y2
- Authority
- JP
- Japan
- Prior art keywords
- monolith catalyst
- catalyst carrier
- catalytic converter
- aperture ratio
- upstream
- 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 - Lifetime
Links
Landscapes
- Exhaust Gas After Treatment (AREA)
Description
【考案の詳細な説明】 〔産業上の利用分野〕 本考案は、自動車の排気系に設置される触媒コンバータ
に関し、とくにコンバータケース内に複数のモノリス触
媒担体を有する触媒コンバータに関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a catalytic converter installed in an exhaust system of an automobile, and more particularly to a catalytic converter having a plurality of monolith catalyst carriers in a converter case.
コンバータケース内にモノリス触媒担体を設けた触媒コ
ンバータは、通常１箇のモノリス触媒担体を備えている
が、排気ガス浄化性能を向上させるために、第２図に示
すように、複数のモノリス触媒担体12、13をコンバータ
ケース11内に直列に設置することがある。A catalytic converter in which a monolith catalyst carrier is provided in a converter case usually has one monolith catalyst carrier. However, in order to improve exhaust gas purification performance, as shown in FIG. 12 and 13 may be installed in series in the converter case 11.
直列設置のモノリス触媒担体12、13は通常は同一構造で
あるが、特開昭63-113112号公報は、排気系の背圧抵抗
を減少させるとともに触媒のウォーミングアップ性能を
向上させる目的をもって、上流側モノリス触媒担体の触
媒担体のセル開口の大きさを下流側モノリス触媒担体の
それより小さくすることを提案している。The monolith catalyst carriers 12 and 13 installed in series usually have the same structure, but JP-A-63-113112 discloses that the upstream side has the purpose of reducing the back pressure resistance of the exhaust system and improving the warming-up performance of the catalyst. It is proposed that the size of the cell opening of the catalyst carrier of the monolith catalyst carrier be smaller than that of the downstream side monolith catalyst carrier.
しかし、従来技術においては、上流側モノリス触媒担体
のセル開口の大きさを小さくしても、所期の目的がほと
んど達成されず、場合によっては、同構造のモノリス触
媒担体が直列に並べた場合よりも、上流側担体の開口の
大きさを小さくしたものの方が圧力損失が増大し、背圧
が上がってしまうこともある。However, in the prior art, even if the size of the cell opening of the upstream side monolith catalyst carrier is reduced, the intended purpose is hardly achieved, and in some cases, when the monolith catalyst carriers having the same structure are arranged in series. Rather than having a smaller opening size on the upstream side carrier, the pressure loss may increase and the back pressure may increase.
本考案の目的は、コールドスタート時排気ガス浄化性能
向上と圧力損失低下との両方を安定して満足させること
ができる触媒コンバータを提供することにある。An object of the present invention is to provide a catalytic converter capable of stably satisfying both improvement of exhaust gas purification performance at cold start and reduction of pressure loss.
上記目的を達成する、本考案の触媒コンバータは、次の
通りである。The catalytic converter of the present invention that achieves the above object is as follows.
コンバータケース内に、排気ガスの流れ方向に複数のモ
ノリス触媒担体を直列に配設した触媒コンバータにおい
て、上流側のモノリス触媒担体の開口率を下流側のモノ
リス触媒担体の開口率よりも小さくし、下流側のモノリ
ス触媒担体の上流側のモノリス触媒担体に対する開口率
比を1.2〜1.35の範囲に設定したことを特徴とする触媒
コンバータ。In a converter case, in a catalytic converter in which a plurality of monolith catalyst carriers are arranged in series in the exhaust gas flow direction, the aperture ratio of the upstream monolith catalyst carrier is smaller than the aperture ratio of the downstream monolith catalyst carrier, A catalytic converter characterized in that the opening ratio of the downstream monolith catalyst carrier to the upstream monolith catalyst carrier is set in the range of 1.2 to 1.35.
本考案では、開口の大きさではなく開口率を基準にし、
上流側モノリス触媒担体と下流側モノリス触媒担体の開
口率の比でデータを整理し、コールドスタート時排気ガ
ス浄化性能向上と圧力損失低下の両方が得られる領域に
開口率比を設定したので、安定して両方の性能な改善が
得られる。In the present invention, the aperture ratio is used as a reference, not the size of the aperture,
Data is organized by the ratio of the opening ratios of the upstream monolith catalyst carrier and the downstream monolith catalyst carrier, and the opening ratio is set in the region where both improvement of exhaust gas purification performance and pressure loss reduction at cold start are obtained, so it is stable. Both performance improvements are obtained.
以下に、本考案の望ましい実施例を、図面を参照して説
明する。Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
第１図は、本考案の一実施例に係るアンダフロアタイプ
の触媒コンバータを示しており、第２図は、比較のため
に、上流側モノリス触媒担体と下流側モノリス触媒担体
が同じ開口率の触媒コンバータを示している。FIG. 1 shows an underfloor type catalytic converter according to an embodiment of the present invention, and FIG. 2 shows, for comparison, an upstream monolith catalyst carrier and a downstream monolith catalyst carrier having the same opening ratio. 1 shows a catalytic converter.
第１図において、１はコンバータケースを示しており、
矢印は排気ガスの流れ方向を示している。コンバータケ
ース１内には、本実施例では２個のモノリス触媒担体
２、３が、排気ガスの流れ方向に直列に配設、収納され
ている。上流側のモノリス触媒担体２の開口率Ａは、下
流側のモノリス触媒担体３の開口率Ｂよりも小さくさ
れ、ＢのＡに対する開口率比B/Aは、1.2〜1.35の範囲内
に設定されている。ここで、開口率はセルのピッチをp,
壁厚をｔとすれば、開口率は｛（ｐ−ｔ）2/p2｝×100
％として計算される。In FIG. 1, 1 indicates a converter case,
The arrow indicates the flow direction of the exhaust gas. In the present embodiment, two monolith catalyst carriers 2, 3 are arranged and housed in the converter case 1 in series in the exhaust gas flow direction. The aperture ratio A of the upstream monolith catalyst carrier 2 is made smaller than the aperture ratio B of the downstream monolith catalyst carrier 3, and the aperture ratio B / A of B to A is set within the range of 1.2 to 1.35. ing. Where the aperture ratio is the cell pitch p,
If the wall thickness is t, the aperture ratio is {(p−t) 2 / p 2 } × 100
Calculated as a percentage.
モノリス触媒担体２、３のセル形状については、たとえ
ば第３図および第４図に示すように、格子目形状のもの
４、三角形状のもの５が適用できるが、断面内全面にわ
たって均一な形状であれば蜂の巣（六角形）形状などの
多数形形状のものでもよい。As for the cell shape of the monolith catalyst supports 2 and 3, for example, as shown in FIGS. 3 and 4, lattice-shaped ones 4 and triangular-shaped ones 5 can be applied. If there is a honeycomb shape (hexagonal shape) or the like, it may have a multi-shape.
本考案における上記開口率比B/Aの最適範囲は、次のよ
うに試験によって求められた。The optimum range of the aperture ratio B / A in the present invention was determined by the following test.
セル板厚については、通常0.10〜0.30mmであるが、本検
討では標準的な0.15mmのものを用い、第２図に示したコ
ンバータケース11内の上流側モノリス触媒担体12の開口
率と下流側モノリス触媒担体13の開口率とが同じ場合に
比べ、排気ガスの浄化性能の向上の度合と圧力損失の低
減の度合を、上記開口率比B/Aを基準に最適範囲を求め
た。The cell plate thickness is usually 0.10 to 0.30 mm, but in this study, a standard 0.15 mm plate was used, and the aperture ratio and downstream of the upstream monolith catalyst carrier 12 in the converter case 11 shown in FIG. 2 were used. As compared with the case where the opening ratio of the side monolith catalyst carrier 13 is the same, the degree of improvement in exhaust gas purification performance and the degree of reduction in pressure loss were determined to be the optimum range based on the opening ratio B / A.
試験に使用した触媒コンバータは、第１表に示すとおり
である。The catalytic converter used in the test is as shown in Table 1.
なお、使用触媒は全て下記条件にて台上耐久を実施した
ものである。 In addition, all the catalysts used were mounted on a bench under the following conditions.
エンジン:2lEFIエンジン 回転数 :3600rpm 吸気圧 ：−240mmHg 空気比 ：ストイキ、酸素センサからのフィードバック
有 触媒入ガス温度:720℃ 耐久時間:200時間 さらに、排気ガス浄化性能と圧力損失の試験条件は次の
とおりである。Engine: 2lEFI Engine speed: 3600rpm Intake pressure: −240mmHg Air ratio: With stoichiometric feedback from oxygen sensor Catalyst inlet gas temperature: 720 ℃ Endurance time: 200 hours Furthermore, the test conditions for exhaust gas purification performance and pressure loss are as follows: It is as follows.
エンジン:2lEFIエンジン 回転数 :2400rpm 吸気圧 ：−300mmHg 空気比 ：ストイキ 触媒入ガス温度:400℃ この条件にて、HC、CO、NOXの浄化率、圧力損失を測定
した。第５図に結果を示す。第５図は、NOXについての
浄化性能向上率を示したが、HC、COについても略同じ傾
向であり、最適範囲も略一致している。Engine: 2LEFI engine speed: 2400 rpm intake pressure: -300 mmHg air ratio: stoichiometric catalyst inflow gas temperature: 400 ° C. under these conditions was measured HC, CO, purification rate of NO X, the pressure loss. The results are shown in FIG. FIG. 5 shows the purification performance improvement rate for NO X , but HC and CO show substantially the same tendency, and the optimum ranges are also substantially the same.
第５図に示すように、第２図に示した触媒コンバータに
比べ、排気ガス浄化性能については、開口率比が1.2ま
では浄化性能向上率は増加するが、それ以上では低下
し、1.35を越すと開口率比1.0よりも悪化する。As shown in Fig. 5, in comparison with the catalytic converter shown in Fig. 2, in the exhaust gas purification performance, the purification performance improvement rate increases up to an aperture ratio of 1.2, but decreases above that, and becomes 1.35. If it exceeds, the aperture ratio will be worse than 1.0.
圧力損失については、開口率比B/Aが1.2までは開口率比
1.0よりも悪いが、1.2以上では圧力損失低下率が向上す
る。Regarding the pressure loss, the aperture ratio B / A is up to 1.2.
It is worse than 1.0, but if it is 1.2 or higher, the pressure loss decrease rate improves.
したがって、開口率比B/Aが1.2〜1.35の範囲では、浄化
性能の向上、圧力損失の低減が共に得られる。Therefore, when the aperture ratio B / A is in the range of 1.2 to 1.35, both improvement of purification performance and reduction of pressure loss can be obtained.
なお、本実施例ではコンバータケース１内に２つのモノ
リス触媒担体２、３を配設する場合について説明した
が、３個以上のモノリス触媒担体を直列に配設すること
も可能である。その場合には、最上流側のモノリス触媒
担体の開口率と最下流側のモノリス触媒担体の開口率と
の比を上記最適範囲内とすることで、同様の効果が得ら
れる。In this embodiment, the case where the two monolith catalyst carriers 2 and 3 are arranged in the converter case 1 has been described, but it is also possible to arrange three or more monolith catalyst carriers in series. In that case, the same effect can be obtained by setting the ratio of the opening ratio of the most upstream monolith catalyst carrier to the most downstream of the downstream monolith catalyst carrier within the optimum range.
本考案の触媒コンバータによれば、上流側モノリス触媒
担体の開口率Ａを下流側モノリス触媒担体の開口率Ｂよ
りも小さくし、開口率比B/Aを1.2〜1.35に設定すること
により、単に同一開口率の触媒担体を直列に配列する場
合や特開昭63-113112号のように開口の大きさを設定し
た場合に比べ、排気ガスの浄化性能の向上および圧力損
失の低減を同時に達成することができる。また、上流側
のモノリス触媒担体の開口率を小さくしたため、コール
ドスタート時にも十分な排気ガス浄化性能を得る。According to the catalytic converter of the present invention, the aperture ratio A of the upstream monolith catalyst carrier is made smaller than the aperture ratio B of the downstream monolith catalyst carrier, and the aperture ratio B / A is set to 1.2 to 1.35. Compared to the case of arranging catalyst carriers with the same opening ratio in series and the case of setting the size of the opening as in JP-A-63-113112, improvement of exhaust gas purification performance and reduction of pressure loss are achieved at the same time. be able to. Further, since the opening ratio of the upstream monolith catalyst carrier is reduced, sufficient exhaust gas purification performance can be obtained even at cold start.
第１図は本考案の一実施例に係る触媒コンバータの断面
図、 第２図は上流側モノリス触媒担体の下流側モノリス触媒
担体の開口率が同じである触媒コンバータの断面図、 第３図は第１図のモノリス触媒担体に適用可能なセル形
状の一例を示す正面図、 第４図は第１図のモノリス触媒担体に適用可能なセル形
状の他の例を示す正面図、第５図は本考案における開口
率比の最適範囲を示す開口率比と浄化性能向上率および
圧力損失低下率との関係図、 である。 １……コンバータケース ２……上流側モノリス触媒担体 ３……下流側モノリス触媒担体FIG. 1 is a cross-sectional view of a catalytic converter according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of a catalytic converter in which the upstream monolith catalyst carrier has the same downstream monolith catalyst carrier aperture ratio, and FIG. 1 is a front view showing an example of a cell shape applicable to the monolith catalyst carrier of FIG. 1, FIG. 4 is a front view showing another example of a cell shape applicable to the monolith catalyst carrier of FIG. 1, and FIG. FIG. 3 is a diagram showing the relationship between the aperture ratio, which shows the optimum range of the aperture ratio in the present invention, and the purification performance improvement rate and pressure loss reduction rate. 1 ... Converter case 2 ... Upstream side monolith catalyst carrier 3 ... Downstream side monolith catalyst carrier
Claims (1)
向に複数のモノリス触媒担体を直列に配設した触媒コン
バータにおいて、上流側のモノリス触媒担体の開口率を
下流側のモノリス触媒担体の開口率よりも小さくし、下
流側のモノリス触媒担体の上流側のモノリス触媒担体に
対する開口率比を1.2〜1.35の範囲に設定したことを特
徴とする触媒コンバータ。1. In a catalytic converter in which a plurality of monolith catalyst carriers are arranged in series in a converter case in a flow direction of exhaust gas, an opening ratio of an upstream monolith catalyst carrier is set to an opening ratio of a downstream monolith catalyst carrier. The catalytic converter is characterized in that the opening ratio of the downstream monolith catalyst carrier to the upstream monolith catalyst carrier is set in the range of 1.2 to 1.35.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1988111253U JPH0716013Y2 (en) | 1988-08-26 | 1988-08-26 | Catalytic converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1988111253U JPH0716013Y2 (en) | 1988-08-26 | 1988-08-26 | Catalytic converter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0235919U JPH0235919U (en) | 1990-03-08 |
| JPH0716013Y2 true JPH0716013Y2 (en) | 1995-04-12 |
Family
ID=31349145
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1988111253U Expired - Lifetime JPH0716013Y2 (en) | 1988-08-26 | 1988-08-26 | Catalytic converter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0716013Y2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3366914B2 (en) | 1991-07-04 | 2003-01-14 | 松本鋼管株式会社 | Catalytic metal carrier and method for producing the same |
| US10087800B2 (en) * | 2014-04-04 | 2018-10-02 | Nissan Motor Co., Ltd. | Engine exhaust apparatus |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH086582B2 (en) * | 1986-10-31 | 1996-01-24 | マツダ株式会社 | Engine exhaust gas purification catalytic device |
-
1988
- 1988-08-26 JP JP1988111253U patent/JPH0716013Y2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0235919U (en) | 1990-03-08 |
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