JP2003214140A - Diesel exhaust gas purification filter - Google Patents
Diesel exhaust gas purification filterInfo
- Publication number
- JP2003214140A JP2003214140A JP2002009799A JP2002009799A JP2003214140A JP 2003214140 A JP2003214140 A JP 2003214140A JP 2002009799 A JP2002009799 A JP 2002009799A JP 2002009799 A JP2002009799 A JP 2002009799A JP 2003214140 A JP2003214140 A JP 2003214140A
- Authority
- JP
- Japan
- Prior art keywords
- partition wall
- outer peripheral
- exhaust gas
- peripheral portion
- inner peripheral
- 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.)
- Pending
Links
- 238000000746 purification Methods 0.000 title claims abstract description 17
- 238000005192 partition Methods 0.000 claims abstract description 161
- 230000002093 peripheral effect Effects 0.000 claims abstract description 156
- 239000002184 metal Substances 0.000 claims abstract description 22
- 229910052751 metal Inorganic materials 0.000 claims abstract description 22
- 239000003054 catalyst Substances 0.000 claims abstract description 21
- 239000000919 ceramic Substances 0.000 claims abstract description 7
- 239000011148 porous material Substances 0.000 claims description 92
- 239000000843 powder Substances 0.000 claims description 41
- 230000003197 catalytic effect Effects 0.000 claims description 13
- 230000000694 effects Effects 0.000 abstract description 7
- 230000000452 restraining effect Effects 0.000 abstract 1
- 239000010410 layer Substances 0.000 description 25
- 239000002002 slurry Substances 0.000 description 17
- 229910052878 cordierite Inorganic materials 0.000 description 13
- JSKIRARMQDRGJZ-UHFFFAOYSA-N dimagnesium dioxido-bis[(1-oxido-3-oxo-2,4,6,8,9-pentaoxa-1,3-disila-5,7-dialuminabicyclo[3.3.1]nonan-7-yl)oxy]silane Chemical compound [Mg++].[Mg++].[O-][Si]([O-])(O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2)O[Al]1O[Al]2O[Si](=O)O[Si]([O-])(O1)O2 JSKIRARMQDRGJZ-UHFFFAOYSA-N 0.000 description 13
- 230000000052 comparative effect Effects 0.000 description 11
- 239000002245 particle Substances 0.000 description 11
- 239000000203 mixture Substances 0.000 description 9
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 8
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 7
- 239000011247 coating layer Substances 0.000 description 6
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 239000013618 particulate matter Substances 0.000 description 5
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 4
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 239000002131 composite material Substances 0.000 description 4
- 230000033228 biological regulation Effects 0.000 description 3
- 238000006555 catalytic reaction Methods 0.000 description 3
- 239000010419 fine particle Substances 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 230000008034 disappearance Effects 0.000 description 2
- 238000001125 extrusion Methods 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- 238000011068 loading method Methods 0.000 description 2
- 239000000395 magnesium oxide Substances 0.000 description 2
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 2
- 229910052753 mercury Inorganic materials 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 230000008646 thermal stress Effects 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 229920002472 Starch Polymers 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 229910010413 TiO 2 Inorganic materials 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- IXSUHTFXKKBBJP-UHFFFAOYSA-L azanide;platinum(2+);dinitrite Chemical compound [NH2-].[NH2-].[Pt+2].[O-]N=O.[O-]N=O IXSUHTFXKKBBJP-UHFFFAOYSA-L 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000010485 coping Effects 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 229910001960 metal nitrate Inorganic materials 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 229910052763 palladium Inorganic materials 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 239000010970 precious metal Substances 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 229910052703 rhodium Inorganic materials 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000002791 soaking Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000000638 solvent extraction Methods 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- 239000008107 starch Substances 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
Landscapes
- Filtering Of Dispersed Particles In Gases (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Catalysts (AREA)
- Processes For Solid Components From Exhaust (AREA)
- Filtering Materials (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、ディーゼルエンジ
ンからの排ガス中に含まれるパティキュレート（粒子状
物質）を捕捉するとともに、捕捉した該パティキュレー
トを酸化させて除去するディーゼル排ガス浄化フィルタ
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diesel exhaust gas purification filter that traps particulates (particulate matter) contained in exhaust gas from a diesel engine and oxidizes and removes the trapped particulates.
【０００２】[0002]
【従来の技術】車両用エンジンのうち、ガソリンエンジ
ンにおいては、排ガスに対する厳しい規制とそれに対処
できる技術の進歩とにより、排ガス中の有害成分は確実
に減少されてきている。しかし、ディーゼルエンジンに
おいては、特異な事情から、規制も技術の進歩もガソリ
ンエンジンに比べて遅れている。特異な事情とは、有害
成分がパティキュレート（粒子状物質：炭素微粒子、サ
ルフェート等の硫黄系微粒子、高分子量炭化水素微粒子
等）として排ガスとともに排出されるということであ
る。2. Description of the Related Art Among vehicle engines, in a gasoline engine, harmful components in exhaust gas have been surely reduced due to strict regulations on exhaust gas and progress in technology capable of coping with the regulations. However, due to unique circumstances, the regulations and technological progress of diesel engines lag behind that of gasoline engines. The peculiar situation is that harmful components are discharged together with the exhaust gas as particulates (particulate matter: carbon fine particles, sulfur fine particles such as sulfate, high molecular weight hydrocarbon fine particles, etc.).
【０００３】現在までに開発されているディーゼルエン
ジン用排ガス浄化装置の一つにトラップ型のものがあ
り、セラミック製で目封じタイプのハニカム構造体（デ
ィーゼルパティキュレートフィルタ（以下必要に応じて
「ＤＰＦ」と略称する））がその主体を成す。One of the diesel engine exhaust gas purifying apparatuses that have been developed up to now is a trap type, which is a ceramic and plugged type honeycomb structure (diesel particulate filter (hereinafter referred to as "DPF" as necessary). Abbreviated as ")) forms the main body.
【０００４】このＤＰＦは、平行に伸びる複数の細長い
セルを流通する排ガスを、セルを区画形成する隔壁に形
成された細孔に通過させて濾過し、隔壁にパティキュレ
ートを捕集することにより、その排出を抑制する。しか
し、隔壁に堆積したパティキュレートにより排気系中の
圧力損失（圧損）が上昇し、エンジンの出力が低下する
ことがある。そのため、隔壁に堆積したパティキュレー
トを定期的に除去して再生する必要がある。In this DPF, exhaust gas flowing through a plurality of elongated cells extending in parallel is filtered by passing through the pores formed in the partition walls that define the cells, and the particulates are collected in the partition walls. Suppress its discharge. However, the particulate matter accumulated on the partition walls may increase the pressure loss (pressure loss) in the exhaust system, and the output of the engine may decrease. Therefore, it is necessary to periodically remove and regenerate the particulates deposited on the partition walls.
【０００５】そこで、例えば特開平４−１４８０１３号
公報に開示された排ガス微粒子補集用フィルタでは、圧
損が上昇した場合、隔壁上に堆積したパティキュレート
をフィルタの一端部に配置した電気ヒータにより加熱し
て燃焼させている。しかし、パティキュレートの堆積量
が多い場合はパティキュレートの燃焼量が多くなるの
で、フィルタの温度が大きく上昇し、それに基づく熱応
力によりフィルタが破損するおそれがある。Therefore, for example, in the exhaust gas particulate collection filter disclosed in Japanese Patent Laid-Open No. 4-148013, when the pressure loss increases, the particulate matter deposited on the partition walls is heated by an electric heater arranged at one end of the filter. And burn it. However, when the amount of accumulated particulates is large, the amount of particulates burned increases, so the temperature of the filter rises significantly, and there is a risk that the filter will be damaged by thermal stress due to this.
【０００６】そこで、例えば特開平９−２２０４２３号
公報に開示されたディーゼル排ガス浄化フィルタ即ちＤ
ＰＦでは、隔壁にアルミナ等から成るコート層を形成
し、該コート層に白金（Pt）等の触媒金属を担持してい
る。これにより、パティキュレートを隔壁に捕集すると
同時に触媒金属の触媒反応によって酸化させ、ＤＰＦの
再生を行なう。このＤＰＦでは、触媒反応は比較的低温
で起こり、しかもパティキュレートは捕集量が少ないう
ちに燃焼される。よって、ＤＰＦに作用する熱応力が小
さくなり、その破損が防止される。Therefore, for example, a diesel exhaust gas purifying filter disclosed in Japanese Patent Laid-Open No. 9-220423, that is, D
In the PF, a coating layer made of alumina or the like is formed on the partition walls, and a catalytic metal such as platinum (Pt) is carried on the coating layer. As a result, the particulates are collected on the partition walls and simultaneously oxidized by the catalytic reaction of the catalytic metal to regenerate the DPF. In this DPF, the catalytic reaction takes place at a relatively low temperature, and the particulates are burned while the trapped amount is small. Therefore, the thermal stress acting on the DPF is reduced, and the damage is prevented.
【０００７】しかし、この場合でも、ＤＰＦの外周部の
セル及び隔壁は、外気への放熱等により、内周部のセル
及び隔壁に比べて温度が低いため、外周部の隔壁におけ
る触媒金属の酸化能は内周部の隔壁におけるそれに比べ
て低い。そのため、外周部の隔壁ではパティキュレート
の燃残りが生じ、該燃残りが排ガスの円滑な流通を妨げ
て圧損が生ずる不具合があった。However, even in this case, since the cells and partition walls of the outer peripheral portion of the DPF have a lower temperature than the cells and partition walls of the inner peripheral portion due to heat radiation to the outside air, etc., oxidation of the catalyst metal in the outer peripheral partition walls is carried out. Noh is lower than that of the inner partition wall. For this reason, there is a problem that the unburned particulates are left unburned in the outer peripheral partition wall, and the unburned unburned burns hinder smooth flow of the exhaust gas, resulting in pressure loss.
【０００８】[0008]
【発明が解決しようとする課題】本発明は、上記事情に
鑑みてなされたもので、圧損が抑制されたディーゼル排
ガスフィルタを提供することを目的とする。SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a diesel exhaust gas filter with suppressed pressure loss.
【０００９】[0009]
【課題を解決するための手段】本発明のディーゼル排ガ
ス用フィルタは、セラミックハニカム構造体のセルの開
口部を交互に目封じしたフィルタ部材と、多孔質性酸化
物及び触媒金属から成り隔壁に形成された触媒層と、と
から成り、セルを流通する排ガスを隔壁の細孔に通過さ
せ、隔壁に捕集されたパティキュレートを触媒金属によ
り酸化燃焼させる排ガス浄化フィルタであって、外周部
における隔壁の排ガスの流通抵抗を、内周部における隔
壁の排ガスの流通抵抗よりも小さくしたことを特徴とす
る。DISCLOSURE OF THE INVENTION A diesel exhaust gas filter according to the present invention is formed on a partition wall made of a porous honeycomb oxide and a catalyst metal and a filter member in which openings of cells of a ceramic honeycomb structure are alternately plugged. An exhaust gas purifying filter comprising an exhaust gas flowing through cells through the pores of the partition wall and oxidizing and burning the particulates collected in the partition wall with a catalytic metal, the partition wall at the outer peripheral portion. The distribution resistance of the exhaust gas is smaller than the distribution resistance of the exhaust gas of the partition wall in the inner peripheral portion.
【００１０】[0010]
【発明の実施の形態】以下、発明の実施の形態につき説
明する。
＜フィルタ部材＞フィルタ部材は、セラミックハニカム
構造体の隔壁により区画形成されセルの開口部の両端を
交互に目封じしたものである。外周面側の外周部と、中
心側の内周部とを含む。フィルタ部材は、例えば低熱膨
張性を示すコーディエライト等の耐熱性セラミックスか
ら成ることができる。その場合、コーディエライト粉末
を主成分とする粘土状のスラリーを調製し、それを押出
成形等で成形し、焼成してハニカム構造体とする。尚、
コーディエライト粉末に代えて、アルミナ、マグネシア
及びシリカの各粉末をコーディエライト組成となるよう
に配合することもできる。BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. <Filter member> The filter member is formed by partitioning the partition walls of the ceramic honeycomb structure, and alternately seals both ends of the cell openings. It includes an outer peripheral portion on the outer peripheral surface side and an inner peripheral portion on the center side. The filter member can be made of heat-resistant ceramics such as cordierite having low thermal expansion. In that case, a clay-like slurry containing cordierite powder as a main component is prepared, and the slurry is molded by extrusion molding or the like and fired to obtain a honeycomb structure. still,
Instead of the cordierite powder, alumina, magnesia, and silica powders may be blended so as to have a cordierite composition.
【００１１】その後、ハニカム構造体の一端面の外周部
及び内周部のセルの開口を同様の粘土状のスラリー等で
目封じし、他端面の一端面で目封じされていない内周部
及び外周部のセルの開口を目封じする。その後、焼成等
して基材と同じ材質の目封じ材を形成することによりフ
ィルタ部材が完成する。After that, the openings of the cells at the outer peripheral portion and the inner peripheral portion of the one end face of the honeycomb structure are plugged with the same clay-like slurry, and the inner peripheral portion which is not plugged at the other end face and The cell openings at the outer periphery are plugged. After that, the filter member is completed by firing or the like to form a plugging material of the same material as the base material.
【００１２】隔壁には多数の細孔（気孔）が形成されて
いる。細孔は、上記スラリー中に混合しておいたカーボ
ン粉末、木粉、澱粉、樹脂粉末等の可燃物粉末が焼成時
に消失することにより形成される。
＜触媒層＞触媒層は多孔質酸化物及び触媒金属を含んで
成り、隔壁上に形成される。触媒層は、多孔質酸化物を
含むコート層上に触媒金属を担持して形成（前者）して
も良いし、多孔質酸化物に触媒金属を担持した触媒粉末
を用いてコート層を形成することにより形成（後者）し
ても良い。多孔質酸化物はAl2O3、ZrO2、CeO2、TiO2、S
iO2等の酸化物又はこれらの複数種から成る複合酸化物
から形成される。
コート層
前者では、コート層は隔壁上にコートされ触媒金属を担
持する担体となる。前者でも後者でも、コート層の形成
場所は隔壁の表面ばかりでなく、可燃物粉末の消失によ
って形成された細孔内の表面も含むことが望ましい。A large number of pores (pores) are formed in the partition wall. The pores are formed by the disappearance of combustible powder such as carbon powder, wood powder, starch, and resin powder mixed in the slurry during firing. <Catalyst Layer> The catalyst layer contains a porous oxide and a catalyst metal and is formed on the partition walls. The catalyst layer may be formed by supporting a catalyst metal on a coat layer containing a porous oxide (former), or forming a coat layer by using a catalyst powder in which a catalyst metal is supported on a porous oxide. It may be formed (the latter). Porous oxides are Al 2 O 3 , ZrO 2 , CeO 2 , TiO 2 , S
It is formed from an oxide such as iO 2 or a composite oxide composed of plural kinds of these. Coat layer In the former case, the coat layer is coated on the partition walls to serve as a carrier for supporting the catalytic metal. In both the former case and the latter case, it is desirable that the coating layer is formed not only on the surface of the partition wall but also on the surface in the pores formed by the disappearance of the combustible powder.
【００１３】酸化物又は複合酸化物を構成する粉末の粒
径に関し、隔壁の表面及び細孔の表面にコート層を形成
するには、隔壁の平均細孔径より小さい粒径の粉末が90
重量％以上を占める酸化物又は複合酸化物を用いること
が好ましい。平均細孔径より大きな粒径の粉末が１０重
量％より多くなると、細孔内の表面にコート層を形成す
ることひいては細孔内のパティキュレートを酸化燃焼す
ることが困難となる。Regarding the particle size of the powder constituting the oxide or the complex oxide, in order to form the coat layer on the surface of the partition wall and the surface of the pores, the powder having a particle size smaller than the average pore diameter of the partition wall is 90
It is preferable to use an oxide or a composite oxide that accounts for at least wt%. When the amount of the powder having a particle size larger than the average pore size is more than 10% by weight, it becomes difficult to form a coat layer on the surface in the pores and further to oxidize and burn the particulates in the pores.
【００１４】コート層の形成量（厚さ）は、セルの内径
にもよるが、厚さが１から１０μｍの範囲、又はフィル
タ部材の容積１リットルあたり６０ｇから200 ｇの範囲
とすることが好ましい。形成量がこの範囲より少なくな
ると、触媒金属が高密度に担持され過ぎ高温に晒される
と粒成長が生じて活性が低下する場合がある。一方、形
成量がこの範囲より多くなると、圧損が増大するととも
に、細孔の孔径及び開口面積が低下してしまう。The formation amount (thickness) of the coat layer depends on the inner diameter of the cell, but the thickness is preferably in the range of 1 to 10 μm or in the range of 60 g to 200 g per liter of the volume of the filter member. . If the amount formed is less than this range, the catalytic metal may be loaded too densely and exposed to high temperatures, which may cause grain growth and lower the activity. On the other hand, when the amount of formation is larger than this range, the pressure loss increases and the pore diameter and opening area of the pores decrease.
【００１５】コート層を形成するには、酸化物粉末又は
複合酸化物粉末をアルミナゾル等のバインダ成分及び水
とともに混合してスラリーとし、そのスラリーを隔壁に
付着させた後に焼成すれば良い。スラリーを付着させる
には、通常の浸漬法によることができ、その際エアブロ
ー又は吸引によって細孔内のスラリーのうち余分なもの
を除去することが望ましい。
触媒金属
触媒金属としては、触媒反応によってパティキュレート
の酸化を促進するものであれば特に制約はないが、Pt、
Rh、Pd等の白金族の貴金属から選ばれた一種又は複数種
であることが特に望ましい。To form the coat layer, the oxide powder or the composite oxide powder may be mixed with a binder component such as alumina sol and water to form a slurry, and the slurry may be adhered to the partition walls and then fired. To attach the slurry, a usual dipping method can be used, and it is desirable to remove excess slurry in the pores by air blow or suction. Catalytic metal The catalytic metal is not particularly limited as long as it promotes the oxidation of particulates by a catalytic reaction, Pt,
It is particularly desirable to be one or more selected from platinum group precious metals such as Rh and Pd.
【００１６】前者の場合、触媒金属の担持量は、フィル
タ部材１リットルあたり０．５ｇから１０ｇの範囲とす
ることが望ましい。担持量がこれより少ないと活性が低
すぎ、反対にこれより多く担持しても活性が飽和する。In the former case, it is desirable that the supported amount of the catalytic metal be in the range of 0.5 g to 10 g per liter of the filter member. If the loading amount is less than this, the activity is too low, and conversely, if the loading amount is more than this, the activity is saturated.
【００１７】前者の場合、触媒金属をコート層上に担持
させるには、触媒金属の硝酸塩等を溶解した溶液を用
い、吸着担持法、吸水担持法等によれば良い。また酸化
物粉末又は複合酸化物粉末に予め触媒金属を担持してお
き、その触媒粉末によりコート層を形成することもでき
る。
＜フィルタ部材の外周部・内周部、流通抵抗＞フィルタ
部材の断面積に対して、外周部の断面積が占める割合は
７０％から３０％とすることができる。一方、内周部と
はフィルタ部材のうち外周部以外の部分、即ち中心側の
部分である。フィルタ部材の断面積に対して内周部の断
面積が占める割合は、３０％から７０％とすることがで
きる。In the former case, in order to support the catalytic metal on the coating layer, a solution in which a catalytic metal nitrate or the like is dissolved may be used, and an adsorption supporting method, a water absorption supporting method or the like may be used. It is also possible to previously support a catalyst metal on the oxide powder or the composite oxide powder and form the coat layer with the catalyst powder. <Outer peripheral portion / inner peripheral portion of filter member, flow resistance> The ratio of the sectional area of the outer peripheral portion to the sectional area of the filter member can be 70% to 30%. On the other hand, the inner peripheral portion is a portion of the filter member other than the outer peripheral portion, that is, a portion on the center side. The ratio of the cross-sectional area of the inner peripheral portion to the cross-sectional area of the filter member can be 30% to 70%.
【００１８】排ガスの流通抵抗とは、外周部及び内周部
の隔壁及びセル内を排ガスが流通する際、流通を妨げる
作用であり、次述する気孔率及び平均細孔径により決ま
る。
＜気孔率＞「気孔率」とは、コート層の形成後に隔壁の
表面積に対して隔壁に形成された細孔の開口面積が占め
る割合であり、細孔の孔径と細孔の分布密度とにより決
まる。外周部の隔壁の気孔率は内周部の隔壁の気孔率よ
りも大きくされている。外周部の隔壁の気孔率を６０％
から８０％とし、内周部の隔壁の気孔率を５０％から６
０％とすることが望ましい。外周部の隔壁の気孔率を７
０％とし、内周部の隔壁の気孔率を５５％とすることが
特に望ましい。The flow resistance of the exhaust gas is an effect of hindering the flow of the exhaust gas when it flows through the partition walls and cells in the outer peripheral portion and the inner peripheral portion, and is determined by the porosity and the average pore diameter described below. <Porosity> The “porosity” is the ratio of the opening area of the pores formed in the partition walls to the surface area of the partition walls after the formation of the coating layer, and is defined by the pore size of the pores and the distribution density of the pores. Decided. The porosity of the partition wall in the outer peripheral portion is set to be higher than that of the partition wall in the inner peripheral portion. 60% porosity of the partition walls on the outer periphery
To 80%, and the porosity of the inner partition wall is 50% to 6%.
It is desirable to set it to 0%. The porosity of the outer partition wall is 7
It is particularly desirable to set the porosity of the partition walls in the inner peripheral portion to 0% and 55%.
【００１９】外周部の隔壁の気孔率が６０％以下にな
り、内周部の隔壁の気孔率が５０％以下になると、排ガ
スの流通抵抗が大き過ぎ、圧損が大きくなりエンジンの
出力の低下につながるので望ましくない。また、外周部
の隔壁の気孔率が８０％以上になり、内周部の隔壁の気
孔率が６０％以上になると、基材の強度が低下するので
望ましくない。When the porosity of the outer peripheral partition wall is less than 60% and the porosity of the inner peripheral partition wall is less than 50%, the flow resistance of the exhaust gas becomes too large and the pressure loss becomes large, resulting in a reduction in the engine output. It is not desirable because it will be connected. Further, if the porosity of the partition walls on the outer peripheral portion is 80% or more and the porosity of the partition walls on the inner peripheral portion is 60% or more, the strength of the base material is lowered, which is not desirable.
【００２０】気孔率を外周部の隔壁において大きく内周
部の隔壁において小さくするためには、例えばハニカム
構造体を形成するスラリーに混合するカーボン粉末等の
可燃物粉末の量を、外周部の隔壁において多く、内周部
の隔壁において少なくすれば良い。
＜平均細孔径＞外周部の隔壁の細孔の平均細孔径は、内
周部の隔壁の細孔の平均細孔径よりも大きくされてい
る。外周部の隔壁の平均細孔径を２０μｍから４０μｍ
とし、内周部の隔壁の平均細孔径を１０μｍから３０μ
ｍとすることが望ましい。外周部の隔壁の平均細孔径を
３０μｍとし、内周部の隔壁の平均細孔径を２０μｍと
することが特に望ましい。In order to make the porosity large in the outer peripheral partition wall and small in the inner peripheral partition wall, for example, the amount of combustible powder such as carbon powder mixed with the slurry forming the honeycomb structure is set to the outer peripheral partition wall. In the inner peripheral portion, and it may be reduced in the inner peripheral partition wall. <Average Pore Diameter> The average pore diameter of the pores of the partition walls on the outer peripheral portion is larger than the average pore diameter of the pores of the partition walls on the inner peripheral portion. The average pore diameter of the outer peripheral partition wall is 20 to 40 μm.
And the average pore diameter of the partition walls of the inner peripheral portion is 10 μm to 30 μm.
It is desirable to set m. It is particularly desirable to set the average pore diameter of the outer peripheral partition walls to 30 μm and the average pore diameter of the inner peripheral partition walls to 20 μm.
【００２１】尚、何れの場合も、外周部の隔壁の細孔の
平均細孔径は内周部の隔壁の細孔の平均細孔径よりも大
きくする。In any case, the average pore diameter of the pores of the partition wall in the outer peripheral portion is made larger than the average pore diameter of the pores of the partition wall in the inner peripheral portion.
【００２２】外周部の隔壁の平均細孔径が２０μｍ以下
になり、内周部の隔壁の平均細孔径が１０μｍ以下にな
ると、排ガスの流通抵抗が大き過ぎて圧損が大きくなる
ので望ましくない。外周部の隔壁の平均細孔径が４０μ
ｍ以上になり、内周部の隔壁の平均細孔径が３０μｍ以
上になると、ＰＭの捕集効果が低下するので望ましくな
い。If the average pore size of the partition walls in the outer peripheral portion is 20 μm or less and the average pore size of the partition walls in the inner peripheral portion is 10 μm or less, the flow resistance of the exhaust gas becomes too large and the pressure loss becomes large, which is not desirable. The average pore diameter of the partition walls on the outer periphery is 40μ
If the average pore diameter of the partition walls in the inner peripheral portion is 30 μm or more, the PM trapping effect decreases, which is not desirable.
【００２３】尚、細孔の平均細孔径を外周部の隔壁にお
いて大きく内周部の隔壁において小さくするためには、
スラリーに混合する可燃物粉末の大きさを、外周部の隔
壁において大きく、内周部の隔壁において小さくすれば
良い。
＜気孔率と平均細孔径との関係＞フィルタ部材の外周部
の隔壁の気孔率が内周部の隔壁の気孔率よりも大きくて
も良いし、外周部の隔壁の平均細径孔が内周部の隔壁の
平均細孔径よりも大きくても良い。前述したように、気
孔率は細孔の孔径と細孔の分布密度とにより決まる。よ
って、細孔が外周部の隔壁と内周部の隔壁とで同様に分
布していると仮定すれば、平均細孔径が大きい方が気孔
率が大きくなる。一方、細孔の平均細孔径が外周部の隔
壁と内周部の隔壁とで等しいと仮定すれば、分布密度が
大きい方が気孔率が大きくなる。なお、気孔率及び平均
細孔径の両方が外周部の隔壁の方が内周部の隔壁よりも
大きいことが、外周部のセル及び隔壁での流通抵抗を低
下させる上で最も望ましい。In order to make the average pore diameter of the pores large in the outer peripheral partition wall and small in the inner peripheral partition wall,
The size of the combustible powder to be mixed with the slurry may be large in the outer peripheral partition wall and small in the inner peripheral partition wall. <Relationship between Porosity and Average Pore Diameter> The porosity of the partition walls on the outer peripheral portion of the filter member may be larger than the porosity of the partition walls on the inner peripheral portion, or the average small diameter holes of the partition walls on the outer peripheral portion are the inner periphery. It may be larger than the average pore diameter of the partition walls. As described above, the porosity is determined by the pore size and the distribution density of the pores. Therefore, assuming that the pores are similarly distributed in the outer peripheral partition wall and the inner peripheral partition wall, the larger the average pore diameter, the larger the porosity. On the other hand, assuming that the average pore diameter of the pores is equal in the outer peripheral partition wall and the inner peripheral partition wall, the larger the distribution density, the larger the porosity. It is most desirable that both the porosity and the average pore diameter of the outer peripheral partition wall are larger than that of the inner peripheral partition wall in order to reduce the flow resistance in the outer peripheral cell and partition wall.
【００２４】[0024]
【作用】本発明のディーゼル排ガス用フィルタでは、外
周部のセル及び隔壁における排ガスの流通が促進され、
外周部のセル及び隔壁を流通する該ガスからの加熱によ
り外周部の隔壁に担持された触媒層の活性が高まる。In the diesel exhaust gas filter of the present invention, the circulation of exhaust gas in the cells and partition walls of the outer peripheral portion is promoted,
The activity of the catalyst layer carried on the partition walls of the outer peripheral portion is increased by heating from the gas flowing through the cells and the partition walls of the outer peripheral portion.
【００２５】[0025]
【実施例】以下、実施例及び比較例により本発明を具体
的に説明する。EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples.
【００２６】（実施例１）図１及び図２に、本発明の実
施例１によるディーゼル排ガス浄化フィルタ１０の断面
図を示す。このディーゼル排ガス浄化フィルタ１０は、
セラミックハニカム構造体の隔壁１４により区画される
セル１６の開口部を交互に目封じしたフィルタ部材１２
と、多孔質酸化物及び触媒金属を含み隔壁１４に形成さ
れた触媒層と、から成る。(Embodiment 1) FIGS. 1 and 2 are sectional views of a diesel exhaust gas purification filter 10 according to Embodiment 1 of the present invention. This diesel exhaust gas purification filter 10 is
Filter member 12 in which openings of cells 16 defined by partition walls 14 of the ceramic honeycomb structure are alternately plugged
And a catalyst layer formed on the partition wall 14 containing a porous oxide and a catalyst metal.
【００２７】詳述すると、フィルタ部材１０はコーディ
エライトから成り、複数の平行な隔壁１４により区画さ
れた複数の平行なセル１６を含み、ハニカム形状を持
つ。半径方向において外周面側の外周部１８と、中心側
の内周部１９とに二分される。隔壁１４は、外周部１８
の隔壁（以下「外周隔壁」と言う）１３ａと、内周部１
９の隔壁（以下「内周隔壁」と言う）１３ｂとを含み、
セル１６は外周部１８のセル（以下「外周セル」と言
う）１５ａと内周部１９のセル（以下「内周セル」と言
う）１５ｂとを含む。More specifically, the filter member 10 is made of cordierite, includes a plurality of parallel cells 16 partitioned by a plurality of parallel partition walls 14, and has a honeycomb shape. It is divided into an outer peripheral portion 18 on the outer peripheral surface side and an inner peripheral portion 19 on the center side in the radial direction. The partition wall 14 has an outer peripheral portion 18
Partition wall (hereinafter referred to as "outer peripheral partition wall") 13a and inner peripheral portion 1
9 partition walls (hereinafter referred to as "inner peripheral partition walls") 13b,
The cell 16 includes a cell of the outer peripheral portion 18 (hereinafter referred to as “outer peripheral cell”) 15a and a cell of the inner peripheral portion 19 (hereinafter referred to as “inner peripheral cell”) 15b.
【００２８】フィルタ部材１２の横断面積に対して、外
周隔壁１３ａ及び外周セル１５ａが占める横断面積が約
５０％で、内周隔壁１３ｂ及び内周セル１５ｂが占める
横断面積が約５０％である。フィルタ部材１２の両端で
は、外周セル１５ａ及び内周セル１５ｂの開口が目封じ
部１７により交互に市松状に目封じされている。The cross-sectional area occupied by the outer peripheral partition wall 13a and the outer peripheral cell 15a is about 50%, and the cross-sectional area occupied by the inner peripheral partition wall 13b and the inner peripheral cell 15b is about 50% of the cross-sectional area of the filter member 12. At both ends of the filter member 12, the openings of the outer peripheral cells 15a and the inner peripheral cells 15b are alternately plugged by the plugging portions 17 in a checkered pattern.
【００２９】触媒層は、Al2O3から成りフィルタ部材１
２の外周隔壁１３ａ及び内周隔壁１３ｂに形成されたコ
ート層２０と、Ptから成りコート層２０に担持された触
媒金属（不図示）とを含む。The catalyst layer is made of Al 2 O 3 and is a filter member 1.
2 includes an outer peripheral partition wall 13a and an inner peripheral partition wall 13b, and a catalyst metal (not shown) made of Pt and supported on the coat layer 20.
【００３０】以下、このディーゼル排ガス浄化フィルタ
１０の製造方法を説明し、構成の詳細な説明に代える。A method of manufacturing the diesel exhaust gas purification filter 10 will be described below, and will be replaced with a detailed description of the configuration.
【００３１】始めに、フィルタ部材１２の製作について
説明する。製作時は、外周隔壁１３ａと内周隔壁１３ｂ
とでコーディエライト（2MgO・2Al2O3・5SiO2 ）組成を
形成する粉末は同じであるが、該粉末に混合する可燃物
粉末の大きさは外周隔壁１３ａと内周隔壁１３ｂとで変
える。即ち、外周隔壁１３ａ及び内周隔壁１３ｂのコー
ディエライト組成を形成する粉末は、粒度を１０から１
５μｍに調整した Al2O3粉末、MgO粉末及びSiO2粉末を
所定の割合で配合して成る。First, the production of the filter member 12 will be described. Outer partition 13a and inner partition 13b during manufacture
Although cordierite powder forming the (2MgO · 2Al 2 O 3 · 5SiO 2) composition are the same, the size of the combustible powder to be mixed with the powder vary with the outer circumferential partition wall 13a and the inner circumferential partition wall 13b in the . That is, the powder forming the cordierite composition of the outer partition 13a and the inner partition 13b has a particle size of 10 to 1.
It is formed by mixing Al 2 O 3 powder, MgO powder and SiO 2 powder adjusted to 5 μm in a predetermined ratio.
【００３２】一方、表１に示すように、外周隔壁１３ａ
のコーディエライト組成を形成する粉末に混合される可
燃物粉末は、平均粒径２０μｍで５０体積％のカーボン
粉末から成る。これに対して、内周隔壁１３ｂのコーデ
ィエライト組成を形成する粉末に混合される可燃物粉末
は、平均粒径２０μｍで４０体積％のカーボン粉末から
成る。On the other hand, as shown in Table 1, the outer peripheral partition wall 13a
The combustible powder to be mixed with the powder forming the cordierite composition is composed of carbon powder having an average particle diameter of 20 μm and 50% by volume. On the other hand, the combustible powder mixed with the powder forming the cordierite composition of the inner peripheral partition wall 13b is made of carbon powder having an average particle size of 20 μm and 40% by volume.
【００３３】その後、上記各粉末及び上記各可燃物粉末
にそれぞれ水を加えて混練し、粘土状の外周隔壁１３ａ
用の第１スラリーと、内周隔壁１３ｂ用の第２スラリー
をそれぞれ調製した。この第１スラリー及び第２スラリ
ーを所定の押出金具を用いて同時に押出成形してハニカ
ム形状の成形体を形成し、乾燥後、約1400℃で焼成し
た。これにより、外周隔壁１３ａと内周隔壁１３ｂとで
異なる細孔構造を有するハニカム形状のフィルタ部材１
２を形成した。After that, water is added to each of the above powders and each of the above combustible powders and kneaded to form a clay-like outer peripheral partition wall 13a.
And a second slurry for the inner partition wall 13b were prepared. The first slurry and the second slurry were simultaneously extrusion-molded using a predetermined extrusion fitting to form a honeycomb-shaped molded body, which was dried and then fired at about 1400 ° C. Thereby, the honeycomb-shaped filter member 1 having different pore structures in the outer peripheral partition wall 13a and the inner peripheral partition wall 13b.
Formed 2.
【００３４】そして、基材のコーディエライト組成に対
応する組成のコーディエライト粉末を主成分とする粘土
状スラリーにより、フィルタ部材１２の外周隔壁１３ａ
の外周セル１５ａ、及び内周隔壁１３ｂの内周セル１５
ｂの開口を目封じした。その際、一端面の外周セル１５
ａ及び内周セル１５ｂの開口を市松状に目封じするとと
もに、他端面では一端面で目封じされていない外周セル
１５ａ及び内周セル１５ｂの開口を市松状に目封じし、
それを焼成した。これにより、目封じ部１７を持つフィ
ルタ部材１２を調製した。Then, the outer peripheral partition wall 13a of the filter member 12 is made of a clay-like slurry whose main component is cordierite powder having a composition corresponding to the cordierite composition of the base material.
Outer peripheral cells 15a and inner peripheral cells 15 of the inner peripheral partition wall 13b
The opening of b was plugged. At that time, the outer peripheral cell 15 on one end face
a and the openings of the inner peripheral cells 15b are checkered, and the openings of the outer peripheral cells 15a and the inner peripheral cells 15b, which are not closed at one end at the other end, are checkered.
It was fired. In this way, the filter member 12 having the plugging portion 17 was prepared.
【００３５】その結果、図２（ｂ）に示すように、外周
隔壁１３ａでは細孔の孔径が大きく、細孔の密度が粗で
ある。これに対して、図２（ａ）に示すように内周隔壁
１３ｂでは細孔の孔径が小さく、細孔の密度が密であ
る。As a result, as shown in FIG. 2B, in the outer peripheral partition wall 13a, the pore size of the pores is large and the density of the pores is coarse. On the other hand, as shown in FIG. 2A, in the inner peripheral partition wall 13b, the pore size of the pores is small and the density of the pores is high.
【００３６】次に、コート層２０の形成について説明す
る。コート層２０は、外周隔壁１３ａと内周隔壁１３ｂ
とに同様に形成する。即ち、平均粒径１μｍで４８重量
％のAl2O3粉末と、平均粒径０．５μｍで４０重量％のT
iO2粉末と、平均粒径０．５μｍで１０重量％のCeO2粉
末と、１０重量％のアルミナゾル（Al2 O3 が20重量
％）とを含むスラリーを調製した。上記フィルタ部材１
２をこのスラリーに浸漬後引き上げ、真空吸引して余分
なスラリーを除去した後、120 ℃で乾燥し 500℃で６０
分間焼成した。これにより、外周隔壁１３ａ及び内周隔
壁１３ｂ上にコート層２０を形成した処、コート層２０
はフィルタ部材１２の容積１リットルあたり約８０ｇ形
成された。Next, the formation of the coat layer 20 will be described. The coat layer 20 includes an outer peripheral partition wall 13a and an inner peripheral partition wall 13b.
And are formed similarly. That is, 48% by weight of Al 2 O 3 powder with an average particle size of 1 μm and 40% by weight of T with an average particle size of 0.5 μm.
and iO 2 powder, 10% by weight of CeO 2 powder with an average particle diameter of 0.5 [mu] m, 10 wt% of alumina sol (Al 2 O 3 is 20 wt%) to prepare a slurry containing the. The filter member 1
After soaking 2 in this slurry, pulling up, vacuum suction to remove excess slurry, dry at 120 ℃ and 60 at 500 ℃.
Bake for minutes. Thus, when the coat layer 20 is formed on the outer peripheral partition wall 13a and the inner peripheral partition wall 13b, the coat layer 20 is formed.
Was formed in a volume of the filter member 12 of about 80 g per liter.
【００３７】続いて、コート層２０に触媒金属（不図
示）を担持させる。触媒金属は、外周部隔壁１３ａのコ
ート層２０と内周隔壁１３ｂのコート層２０とに同様に
担持させる。即ち、所定濃度のジニトロジアンミン白金
水溶液の所定量だけコート層２０に吸水させ、120 ℃で
乾燥後、500 ℃で６０分間焼成した。これによりコート
層２０上にPtを担持した処、Ptはフィルタ部材１２の容
積１リットルあたり２ｇ担持された。Subsequently, a catalyst metal (not shown) is supported on the coat layer 20. The catalytic metal is similarly supported on the coat layer 20 of the outer peripheral partition wall 13a and the coat layer 20 of the inner peripheral partition wall 13b. That is, the coating layer 20 was made to absorb a predetermined amount of a dinitrodiammine platinum aqueous solution having a predetermined concentration, dried at 120 ° C., and then baked at 500 ° C. for 60 minutes. As a result, when Pt was carried on the coat layer 20, 2 g of Pt was carried per 1 liter of the volume of the filter member 12.
【００３８】以上の工程で製作された排ガス浄化フィル
タの外周隔壁１３ａ及び内周隔壁１３ｂの気孔率を水銀
ポロシメータで測定した。その結果、表２に示すよう
に、外周隔壁１３ａの気孔率は８０％で、内周隔壁１３
ｂの気孔率は６０％であった。The porosities of the outer peripheral partition wall 13a and the inner peripheral partition wall 13b of the exhaust gas purifying filter manufactured through the above steps were measured with a mercury porosimeter. As a result, as shown in Table 2, the outer peripheral partition wall 13a has a porosity of 80% and the inner peripheral partition wall 13 has a porosity of 80%.
The porosity of b was 60%.
【００３９】また、外周隔壁１３ａ及び内周隔壁１３ｂ
の細孔の平均細孔径を水銀ポロシメータで測定した。そ
の結果、表２に示すように、外周隔壁１３ａの細孔の平
均細孔径は３０μｍで、内周隔壁１３ｂの細孔の平均細
孔径は３０μｍであった。Further, the outer peripheral partition wall 13a and the inner peripheral partition wall 13b.
The average pore diameter of the pores was measured with a mercury porosimeter. As a result, as shown in Table 2, the average pore diameter of the pores of the outer peripheral partition wall 13a was 30 μm, and the average pore diameter of the pores of the inner peripheral partition wall 13b was 30 μm.
【００４０】（実施例２）実施例２は、外周隔壁１３ａ
の気孔率が実施例１のそれよりも小さく、外周隔壁１３
ａの細孔の平均細孔径が実施例１のそれよりも大きくな
っている。即ち、表２に示すように、外周隔壁１３ａの
気孔率は６０％で、外周隔壁１３ａの細孔の平均細孔径
は４０μｍである。(Embodiment 2) In Embodiment 2, an outer peripheral partition wall 13a is used.
Has a porosity smaller than that of Example 1,
The average pore diameter of the pores of a is larger than that of Example 1. That is, as shown in Table 2, the outer peripheral partition wall 13a has a porosity of 60%, and the outer peripheral partition wall 13a has an average pore diameter of 40 μm.
【００４１】実施例２の製作時、表１に示すように、外
周隔壁１３ａのコーディエライト組成を形成する粉末に
混合される可燃物粉末は平均粒径３０μｍで４０体積％
のカーボン粉末から成る。その他の点は実施例１と同じ
である。When manufacturing Example 2, as shown in Table 1, the combustible powder mixed with the powder forming the cordierite composition of the outer peripheral partition wall 13a has an average particle size of 30 μm and 40% by volume.
Composed of carbon powder. The other points are the same as in the first embodiment.
【００４２】（実施例３）実施例３は、外周隔壁１３ａ
の細孔の平均細孔径が実施例１のそれよりも大きく、表
２に示すように、平均細孔径は４０μｍになっている。(Third Embodiment) In the third embodiment, the outer peripheral partition wall 13a is formed.
The average pore diameter of the pores is larger than that of Example 1, and as shown in Table 2, the average pore diameter is 40 μm.
【００４３】実施例３の製作時、表１に示すように、外
周隔壁１３ａのコーディエライト組成を形成する粉末に
混合される可燃物粉末は平均粒径３０μｍで５０体積％
のカーボン粉末から成る。その他の点は実施例１と同じ
である。When manufacturing Example 3, as shown in Table 1, the combustible powder mixed with the powder forming the cordierite composition of the outer peripheral partition wall 13a has an average particle size of 30 μm and 50% by volume.
Composed of carbon powder. The other points are the same as in the first embodiment.
【００４４】（比較例）比較例は、表２に示すように、
外周隔壁１３ａの気孔率と内周隔壁１３ｂの気孔率とが
等しく、ともに６０％である。また、外周隔壁１３ａの
細孔の平均細孔径と内周隔壁１３ｂの細孔の平均細孔径
とが等しく、ともに３０μｍである。Comparative Example As shown in Table 2, the comparative example is as follows.
The porosity of the outer peripheral partition wall 13a is equal to the porosity of the inner peripheral partition wall 13b, both being 60%. Further, the average pore diameter of the pores of the outer peripheral partition wall 13a and the average pore diameter of the pores of the inner peripheral partition wall 13b are equal, and both are 30 μm.
【００４５】[0045]
【表１】 [Table 1]
【００４６】＜試験・評価＞次に、実施例１から３及び
比較例の各ディーゼル排ガス浄化フィルタをディーゼル
エンジンベンチの排気系にそれぞれ取付け、回転数1600
ｒｐｍ、負荷３０Ｎｍで運転した。そして、外周隔壁１
３ａ及び内周隔壁１３ｂの気孔率と、外周隔壁１３ａ及
び内周隔壁１３ｂの細孔の平均細孔径と、排気系中の圧
損との関係を調べた。その結果を表２を示す。<Test / Evaluation> Next, the diesel exhaust gas purification filters of Examples 1 to 3 and Comparative Example were attached to the exhaust system of the diesel engine bench, respectively, and the rotation speed was 1600.
It was operated at rpm and a load of 30 Nm. And the outer peripheral partition wall 1
The relationship between the porosity of 3a and the inner partition 13b, the average pore diameter of the pores of the outer partition 13a and the inner partition 13b, and the pressure loss in the exhaust system was investigated. The results are shown in Table 2.
【００４７】[0047]
【表２】 [Table 2]
【００４８】これから明らかなように、実施例１、実施
例２及び実施例３の何れにおいても、比較例と比べる
と、圧損の値が低下している。このうち、実施例１と実
施例２とでは圧損の低下の程度はほぼ同じである。実施
例１と比較例とは外周隔壁１３ａの気孔率が異なり（実
施例１の方が比較例よりも大きい）、実施例２と比較例
とは外周隔壁１３ａの細孔の平均細孔径が異なる（実施
例２の方が比較例よりも大きい）。これより、外周隔壁
１３ａの気孔率が増加しても、外周隔壁１３ａの細孔の
平均細孔径が増加しても、同様に圧損が低下することが
分かる。As is apparent from the above, in any of Examples 1, 2 and 3, the pressure loss value is lower than that of the comparative example. Among these, the degree of reduction in pressure loss is substantially the same in Example 1 and Example 2. The porosity of the outer peripheral partition wall 13a is different between Example 1 and the comparative example (Example 1 is larger than the comparative example), and the average pore diameter of the pores of the outer peripheral partition wall 13a is different between the Example 2 and the comparative example. (Example 2 is larger than the comparative example). From this, it can be seen that the pressure loss similarly decreases even if the porosity of the outer peripheral partition wall 13a increases or the average pore diameter of the pores of the outer peripheral partition wall 13a increases.
【００４９】これに対して、実施例３では圧損の値は大
きく低下している。実施例３と比較例とは外周隔壁１３
ａの気孔率及び外周隔壁１３ａの細孔の平均細孔径が異
なる（実施例３の方が比較例よりも共に大きい）。これ
より、外周隔壁１３ａの気孔率及び平均細孔径の両方が
増加することが圧損の大幅な低下につながり、圧損の抑
制の点からは実施例３が最も好ましいことが分かる。On the other hand, in Example 3, the value of pressure loss is greatly reduced. The outer peripheral partition wall 13 is used in the third embodiment and the comparative example.
The porosity of a and the average pore diameter of the pores of the outer peripheral partition wall 13a are different (both of Example 3 is larger than that of Comparative Example). From this, it can be understood that the increase in both the porosity and the average pore diameter of the outer peripheral partition wall 13a leads to a large decrease in pressure loss, and that Example 3 is the most preferable in terms of suppressing the pressure loss.
【００５０】[0050]
【発明の効果】本発明のディーゼル排ガス用フィルタに
よれば、外周部のパティキュレートが効率よく酸化さ
れ、圧損が抑制される。According to the diesel exhaust gas filter of the present invention, the particulate matter in the outer peripheral portion is efficiently oxidized and the pressure loss is suppressed.
【図１】本発明の一実施例（ディーゼル排ガス浄化フィ
ルタ）を示す正面断面図である。FIG. 1 is a front sectional view showing an embodiment (diesel exhaust gas purification filter) of the present invention.
【図２】（ａ）は図１におけるＡ部拡大図、（ｂ）は図
１におけるＢ部拡大図である。2A is an enlarged view of an A part in FIG. 1, and FIG. 2B is an enlarged view of a B part in FIG.
１０：排ガス浄化フィルタ １２：フィルタ部
材
１３ａ：外周隔壁 １３ｂ：内周隔壁
１５ａ：外周セル １５ｂ：内周セル
１６ａ：外周セル １５ｂ：内周セル
１７：目封じ部材 １８：外周部
１９：内周部 ２０：コート層10: Exhaust gas purification filter 12: Filter member 13a: Outer peripheral partition wall 13b: Inner peripheral partition wall 15a: Outer peripheral cell 15b: Inner peripheral cell 16a: Outer peripheral cell 15b: Inner peripheral cell 17: Sealing member 18: Outer peripheral portion 19: Inner peripheral portion 20: Coat layer
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｂ０１Ｄ 53/94 Ｂ０１Ｊ 35/04 ３０１Ｅ Ｂ０１Ｊ 21/16 Ｂ０１Ｄ 46/00 ３０２ 35/04 ３０１ 46/42 Ｂ // Ｂ０１Ｄ 46/00 ３０２ 53/36 １０４Ｂ 46/42 ＺＡＢ (72)発明者 垣花 大 愛知県豊田市トヨタ町１番地 トヨタ自動 車株式会社内 Ｆターム(参考） 3G090 AA03 BA01 4D019 AA01 BA05 BB06 BC07 BD01 CA01 CB04 CB09 4D048 AA14 AB01 BA03Y BA06Y BA07Y BA08Y BA10X BA19Y BA30Y BA31Y BA33Y BA41Y BB02 BB14 BB17 CC38 4D058 JA37 JB06 MA44 SA08 4G069 BA01A BA02A BA04A BA05A BA13A BA13B BB02A BB04A BC43A BC71A BC72A BC75A CA02 CA03 CA07 CA18 EA19 EA25 EA27 EB12X EB12Y EC17X EC17Y ED03 ─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. 7 Identification code FI theme code (reference) B01D 53/94 B01J 35/04 301E B01J 21/16 B01D 46/00 302 35/04 301 46/42 B / / B01D 46/00 302 53/36 104B 46/42 ZAB (72) Inventor Dai Hakihana 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation F-term (reference) 3G090 AA03 BA01 4D019 AA01 BA05 BB06 BC07 BD01 CA01 CB04 CB09 4D048 AA14 AB01 BA03Y BA06Y BA07Y BA08Y BA10X BA19Y BA30Y BA31Y BA33Y BA41Y BB02 BB14 BB17 CC38 4D058 JA37 JB06 MA44 SA08 4G069 CA17 BC17 CA17 BC17 CA25 BC25 CA17 EA17 BC17A25 BC17A17 BB17A17 BB17A17 BB17A17 BB17A17 BB17A17 BB17B17A02
Claims (7)
区画されるセルの開口部を交互に目封じしたフィルタ部
材と、多孔質酸化物及び触媒金属を含み前記隔壁に形成
された触媒層と、から成り、前記セルを流通する排ガス
を前記隔壁の細孔に通過させ、該隔壁に捕集されたパテ
ィキュレートを前記触媒金属により酸化させる排ガス浄
化フィルタであって、 前記フィルタ部材の外周部における前記隔壁の排ガスの
流通抵抗を、内周部における前記隔壁の排ガスの流通抵
抗よりも小さくしたことを特徴とするディーゼル排ガス
浄化フィルタ。1. A ceramic honeycomb structure comprising: a filter member in which openings of cells defined by partition walls are alternately plugged; and a catalyst layer containing porous oxide and catalytic metal and formed on the partition walls. An exhaust gas purifying filter that allows the exhaust gas flowing through the cells to pass through the pores of the partition wall and oxidize the particulates collected in the partition wall by the catalytic metal, wherein the partition wall of the outer peripheral portion of the filter member is A diesel exhaust gas purification filter characterized in that the flow resistance of the exhaust gas is made smaller than the flow resistance of the exhaust gas of the partition wall in the inner peripheral portion.
を、前記内周部における前記隔壁の気孔率よりも大きく
した請求項１に記載のディーゼル排ガス浄化フィルタ。2. The diesel exhaust gas purification filter according to claim 1, wherein a porosity of the partition wall in the outer peripheral portion is larger than a porosity of the partition wall in the inner peripheral portion.
から８０％であり、前記内周部の前記隔壁の気孔率は５
０％から６０％である請求項２に記載のディーゼル排ガ
ス浄化フィルタ。3. The porosity of the partition wall of the outer peripheral portion is 60%
To 80%, and the porosity of the partition walls in the inner peripheral portion is 5
The diesel exhaust gas purification filter according to claim 2, which is 0% to 60%.
周部の前記隔壁の気孔率を、前記フィルタ部材に混入さ
れる可燃物粉末の量を変えることにより異ならせている
請求項３に記載のディーゼル排ガス浄化フィルタ。4. The porosity of the partition wall at the outer peripheral portion and the porosity of the partition wall at the inner peripheral portion are made different by changing the amount of combustible powder mixed in the filter member. The diesel exhaust gas purification filter described in.
均細孔径を、前記内周部における前記隔壁の細孔の平均
細孔径よりも大きくした請求項１乃至４の何れか１つに
記載のディーゼル排ガス浄化フィルタ。5. The average pore diameter of the pores of the partition wall in the outer peripheral portion is larger than the average pore diameter of the pores of the partition wall in the inner peripheral portion. Diesel exhaust gas purification filter.
径は２０μｍから４０μｍであり、前記内周部の前記隔
壁の細孔の平均細孔径は１０μｍから３０μｍである請
求項５記載のディーゼル排ガス浄化フィルタ。6. The average pore diameter of the pores of the partition wall in the outer peripheral portion is 20 μm to 40 μm, and the average pore diameter of the pores of the partition wall in the inner peripheral portion is 10 μm to 30 μm. Diesel exhaust gas purification filter.
径と前記内周部の前記隔壁の細孔の平均細孔径を、前記
フィルタ部材に混入される可燃物粉末の大きさを変える
ことにより異ならせている請求項６に記載のディーゼル
排ガス浄化フィルタ。7. The size of the combustible powder mixed in the filter member is changed by changing the average pore diameter of the pores of the partition wall in the outer peripheral portion and the average pore diameter of the pores of the partition wall in the inner peripheral portion. The diesel exhaust gas purification filter according to claim 6, wherein the diesel exhaust gas purification filter is different.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002009799A JP2003214140A (en) | 2002-01-18 | 2002-01-18 | Diesel exhaust gas purification filter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002009799A JP2003214140A (en) | 2002-01-18 | 2002-01-18 | Diesel exhaust gas purification filter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2003214140A true JP2003214140A (en) | 2003-07-30 |
Family
ID=27647711
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2002009799A Pending JP2003214140A (en) | 2002-01-18 | 2002-01-18 | Diesel exhaust gas purification filter |
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| Country | Link |
|---|---|
| JP (1) | JP2003214140A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006231116A (en) * | 2005-02-22 | 2006-09-07 | Toyota Motor Corp | Exhaust gas-cleaning filter catalyst |
| JP2009255048A (en) * | 2008-03-19 | 2009-11-05 | Ngk Insulators Ltd | Honeycomb structure |
| DE102018008711A1 (en) | 2017-12-08 | 2019-06-13 | Ngk Insulators, Ltd. | filter |
| CN111749760A (en) * | 2019-03-29 | 2020-10-09 | 日本碍子株式会社 | Honeycomb filter |
| CN111749759A (en) * | 2019-03-29 | 2020-10-09 | 日本碍子株式会社 | Honeycomb filter |
| WO2021033541A1 (en) * | 2019-08-20 | 2021-02-25 | 株式会社デンソー | Exhaust gas purification filter |
| CN113508219A (en) * | 2019-07-29 | 2021-10-15 | 株式会社电装 | Exhaust gas purifying filter |
-
2002
- 2002-01-18 JP JP2002009799A patent/JP2003214140A/en active Pending
Cited By (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006231116A (en) * | 2005-02-22 | 2006-09-07 | Toyota Motor Corp | Exhaust gas-cleaning filter catalyst |
| JP2009255048A (en) * | 2008-03-19 | 2009-11-05 | Ngk Insulators Ltd | Honeycomb structure |
| US10830113B2 (en) | 2017-12-08 | 2020-11-10 | Ngk Insulators, Ltd. | Filter |
| DE102018008711A1 (en) | 2017-12-08 | 2019-06-13 | Ngk Insulators, Ltd. | filter |
| US11400441B2 (en) * | 2019-03-29 | 2022-08-02 | Ngk Insulators, Ltd. | Honeycomb filter |
| CN111749759A (en) * | 2019-03-29 | 2020-10-09 | 日本碍子株式会社 | Honeycomb filter |
| US11260384B2 (en) * | 2019-03-29 | 2022-03-01 | Ngk Insulators, Ltd. | Honeycomb filter |
| CN111749760A (en) * | 2019-03-29 | 2020-10-09 | 日本碍子株式会社 | Honeycomb filter |
| CN113508219A (en) * | 2019-07-29 | 2021-10-15 | 株式会社电装 | Exhaust gas purifying filter |
| CN113508219B (en) * | 2019-07-29 | 2024-03-26 | 株式会社电装 | Exhaust gas purifying filter |
| WO2021033541A1 (en) * | 2019-08-20 | 2021-02-25 | 株式会社デンソー | Exhaust gas purification filter |
| JP2021032096A (en) * | 2019-08-20 | 2021-03-01 | 株式会社デンソー | Exhaust emission control filter |
| CN113614338A (en) * | 2019-08-20 | 2021-11-05 | 株式会社电装 | Exhaust gas purifying filter |
| JP6992790B2 (en) | 2019-08-20 | 2022-02-03 | 株式会社デンソー | Exhaust gas purification filter |
| CN113614338B (en) * | 2019-08-20 | 2023-10-20 | 株式会社电装 | Exhaust gas purifying filter |
| US11845033B2 (en) | 2019-08-20 | 2023-12-19 | Denso Corporation | Exhaust gas purification filter |
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