JP2019218924A - Exhaust emission control device - Google Patents

Exhaust emission control device Download PDF

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JP2019218924A
JP2019218924A JP2018118205A JP2018118205A JP2019218924A JP 2019218924 A JP2019218924 A JP 2019218924A JP 2018118205 A JP2018118205 A JP 2018118205A JP 2018118205 A JP2018118205 A JP 2018118205A JP 2019218924 A JP2019218924 A JP 2019218924A
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exhaust gas
injector
exhaust pipe
exhaust
mixing
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英明 大賀
Hideaki Oga
英明 大賀
雅之 片渕
Masayuki Katabuchi
雅之 片渕
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Mitsubishi Fuso Truck and Bus Corp
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Mitsubishi Fuso Truck and Bus Corp
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
    • Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters

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Abstract

To promote mixing of an exhaust gas and an additive while enhancing a degree of freedom of layout.SOLUTION: An exhaust emission control device includes: an exhaust pipe 2 in which an exhaust gas from an engine mounted to a vehicle flows; and an injector 3 for injecting an additive for purifying the exhaust gas into the exhaust pipe 2. The exhaust pipe 2 includes: a boss part 4 to which the injector 3 is mounted; and a cylindrical mixing part 15 for mixing the additive injected from the injector 3 with the exhaust gas. The boss part 4 has a bottomed cylindrical shape recessed toward the inner side of the exhaust pipe 2, and includes a bottom part 5 in which a through hole 7 having a tip of the injector 3 arranged therein is formed and a peripheral wall part 6 extended from an outer edge of the bottom part 5 toward the outer side of the exhaust pipe 2. The mixing part 15 includes a plurality of holes 15h for taking in the exhaust gas thereto and extends from the bottom part 5 in the direction separating from the peripheral wall part 6. Spaces S1, S2 in which the exhaust gas can flow are provided on outer peripheries of the peripheral wall part 6 and the mixing part 15, respectively.SELECTED DRAWING: Figure 2

Description

本発明は、車両に搭載されたエンジンの排気が流通する排気管と、この排気管のボス部に取り付けられたインジェクタとを備えた排気浄化装置に関する。   The present invention relates to an exhaust gas purification device including an exhaust pipe through which exhaust gas of an engine mounted on a vehicle flows, and an injector attached to a boss of the exhaust pipe.

従来、車両に搭載されたエンジンの排気を浄化する排気浄化装置として、排気管内に添加剤を噴射するインジェクタを備えたものが知られている。例えば、インジェクタにより排気管内に尿素水を噴射し、この尿素水の熱分解によって生成されるアンモニア（NH3）を利用して、排気中の窒素酸化物（NOx）を窒素（N2）に還元するものが普及している。   2. Description of the Related Art Conventionally, as an exhaust gas purification device that purifies exhaust gas of an engine mounted on a vehicle, a device provided with an injector that injects an additive into an exhaust pipe is known. For example, urea water is injected into the exhaust pipe by an injector, and ammonia (NH3) generated by thermal decomposition of the urea water is used to reduce nitrogen oxides (NOx) in the exhaust gas to nitrogen (N2). Is widespread.

ところで、前述したようなインジェクタが排気管の外側に突出して設けられると、インジェクタと排気管の近傍に配置される他の機器との干渉が問題となりうる。そこで、排気管においてインジェクタが取り付けられるボス部を、排気管の内側に向けて凹ませた形状とすることが提案されている（例えば特許文献１参照）。このようにボス部を凹ませれば、インジェクタの突出量が低減されることから、排気浄化装置及びその周辺機器のレイアウトの自由度が向上しうる。   Incidentally, if the injector as described above is provided to protrude outside the exhaust pipe, interference between the injector and other devices arranged near the exhaust pipe may be a problem. Therefore, it has been proposed that a boss portion of the exhaust pipe to which the injector is attached is formed to be concave toward the inside of the exhaust pipe (for example, see Patent Document 1). When the boss portion is recessed in this manner, the amount of projection of the injector is reduced, so that the degree of freedom in the layout of the exhaust gas purification device and its peripheral devices can be improved.

米国特許出願公開第２０１１／００７９００３号明細書US Patent Application Publication No. 2011/0079903

しかしながら、前述したようにボス部を凹ませた構成とすると、インジェクタの突出量は低減されるものの、ボス部が凹む分だけ排気通路が短くなる。これにより、排気が添加剤と混ざり合いながら流れる距離が短縮されることから、排気と添加剤との混合が十分に行われないおそれがある。   However, when the boss is recessed as described above, the amount of protrusion of the injector is reduced, but the exhaust passage is shortened by the recess of the boss. As a result, the distance that the exhaust gas flows while mixing with the additive is shortened, and there is a possibility that the exhaust gas and the additive are not sufficiently mixed.

本件の排気浄化装置は、前述したような課題に鑑み創案されたものであり、レイアウトの自由度を高めつつ、排気と添加剤との混合を促進することを目的の一つとする。   The exhaust gas purifying device of the present invention has been made in view of the above-described problems, and has as its object to promote mixing of exhaust gas and additives while increasing the degree of freedom in layout.

ここで開示する排気浄化装置は、車両に搭載されたエンジンの排気が内部を流通する排気管と、前記排気管内に排気浄化用の添加剤を噴射するインジェクタと、を備え、前記排気管は、前記インジェクタが取り付けられるボス部と前記インジェクタから噴射された前記添加剤を前記排気と混合させる筒状の混合部とを有し、前記ボス部は、前記排気管の内側に向かって凹んだ有底筒状であり、前記インジェクタの先端が配置される貫通孔が形成された底部と前記底部の外縁から前記排気管の外側に向かって延設された周壁部とを有し、前記混合部は、前記排気を内部に取り入れるための複数の孔部を有するとともに前記底部から前記周壁部と離隔する方向に延在し、前記周壁部及び前記混合部の各外周には、前記排気が流通可能な空間が設けられている。
これにより、インジェクタの突出量が低減されるとともに、周壁部及び混合部の各外周に設けられた空間に排気が回り込むことで混合部内の排気に乱流が生じやすくなる。 The exhaust purification device disclosed herein includes: an exhaust pipe through which the exhaust of an engine mounted on a vehicle flows, and an injector that injects an exhaust purification additive into the exhaust pipe. A boss portion to which the injector is attached, and a cylindrical mixing portion that mixes the additive injected from the injector with the exhaust gas, wherein the boss portion has a bottom with a concave portion toward the inside of the exhaust pipe. It is cylindrical, and has a bottom part in which a through hole in which the tip of the injector is arranged is formed, and a peripheral wall part extending toward the outside of the exhaust pipe from an outer edge of the bottom part. A space having a plurality of holes for taking the exhaust gas therein and extending from the bottom in a direction away from the peripheral wall portion, and a space through which the exhaust gas can flow around each of the peripheral wall portion and the mixing section. Provided It has been.
Accordingly, the amount of protrusion of the injector is reduced, and turbulence is easily generated in the exhaust gas in the mixing unit by the exhaust gas flowing into the space provided on each of the peripheral wall and the outer periphery of the mixing unit.

開示の排気浄化装置によれば、レイアウトの自由度を高めつつ、排気と添加剤との混合を促進することができる。   ADVANTAGE OF THE INVENTION According to the exhaust gas purification device of this indication, mixing of exhaust gas and an additive can be promoted, increasing the freedom of layout.

実施形態に係る排気浄化装置の上面図である。It is a top view of the exhaust gas purification device concerning an embodiment. 図１の排気浄化装置における要部の断面図（図１のＡ−Ａ矢視断面図）である。FIG. 2 is a cross-sectional view (a cross-sectional view taken along the line AA of FIG. 1) of a main part of the exhaust gas purification device of FIG.

図面を参照して、実施形態としての排気浄化装置について説明する。以下に示す実施形態はあくまでも例示に過ぎず、以下の実施形態で明示しない種々の変形や技術の適用を排除する意図はない。本実施形態の各構成は、それらの趣旨を逸脱しない範囲で種々変形して実施することができる。また、必要に応じて取捨選択することができ、あるいは適宜組み合わせることができる。   An exhaust gas purifying apparatus as an embodiment will be described with reference to the drawings. The embodiments described below are merely examples, and there is no intention to exclude various modifications and application of techniques not explicitly described in the following embodiments. Each configuration of the present embodiment can be variously modified and implemented without departing from the spirit thereof. Further, they can be selected as needed, or can be appropriately combined.

［１．構成］
［１−１．全体構成］
本実施形態に係る排気浄化装置１は、エンジンを搭載した車両に設けられ、このエンジンの排気を浄化するものである。本実施形態では、排気浄化装置１がディーゼルエンジンの排気を浄化する場合について説明する。以下の説明では、排気浄化装置１が適用された車両を基準にして、前後方向及び左右方向を定める。また、重力が作用する方向を下方とし、この逆方向を上方とする。なお、排気浄化装置１が適用された車両は水平な路面上にあるものとする。 [1. Constitution]
[1-1. overall structure]
The exhaust gas purification device 1 according to the present embodiment is provided in a vehicle equipped with an engine, and purifies exhaust gas from the engine. In the present embodiment, a case where the exhaust gas purification device 1 purifies exhaust gas from a diesel engine will be described. In the following description, the front-rear direction and the left-right direction are determined based on the vehicle to which the exhaust emission control device 1 is applied. Further, the direction in which gravity acts is defined as a downward direction, and the opposite direction is defined as an upward direction. It is assumed that the vehicle to which the exhaust emission control device 1 is applied is on a horizontal road surface.

図１に示すように、排気浄化装置１は、車両に搭載されたエンジンの排気が流通する排気管２と、排気管２内に添加剤を噴射するインジェクタ３とを備えている。インジェクタ３は、排気管２に設けられたボス部４に取り付けられている。以下、排気管２，インジェクタ３，ボス部４について順に説明する。   As shown in FIG. 1, the exhaust gas purification device 1 includes an exhaust pipe 2 through which exhaust of an engine mounted on a vehicle flows, and an injector 3 that injects an additive into the exhaust pipe 2. The injector 3 is attached to a boss 4 provided on the exhaust pipe 2. Hereinafter, the exhaust pipe 2, the injector 3, and the boss 4 will be described in order.

［１−２．排気管］
排気管２は、エンジンの気筒から車両の外部へと排気を導くためのものである。ここでは、排気の流れ方向を基準として上流及び下流を定める。排気管２は、前段酸化触媒５１及びＤＰＦ（Diesel Particulate Filter）５２が設けられた第一ユニット１０と、ＳＣＲ（Selective Catalytic Reduction）５３及び後段酸化触媒５４が設けられた第二ユニット２０とを含んで構成される。本実施形態では、第一ユニット１０が第二ユニット２０の左方に隣接して配置される場合を例示する。また、第一ユニット１０の左方には、前後方向に延びるプロペラシャフト（図示略）が隣接して配置される。 [1-2. Exhaust pipe]
The exhaust pipe 2 is for guiding exhaust gas from the engine cylinder to the outside of the vehicle. Here, upstream and downstream are determined based on the flow direction of exhaust gas. The exhaust pipe 2 includes a first unit 10 provided with a first-stage oxidation catalyst 51 and a DPF (Diesel Particulate Filter) 52, and a second unit 20 provided with an SCR (Selective Catalytic Reduction) 53 and a second-stage oxidation catalyst 54. It consists of. In the present embodiment, a case where the first unit 10 is arranged adjacent to the left of the second unit 20 will be exemplified. A propeller shaft (not shown) extending in the front-rear direction is disposed adjacent to the left of the first unit 10.

第一ユニット１０は、第二ユニット２０の直上流に設けられる。第一ユニット１０は、前段酸化触媒５１に排気を送り込む第一入口部１１と、前段酸化触媒５１を収容する前段ケース部１２と、ＤＰＦ５２を収容するＤＰＦケース部１３と、ＤＰＦ５２を通過した排気を受ける第一出口部１４と、排気に乱流を生じさせる混合部１５とで構成される。   The first unit 10 is provided immediately upstream of the second unit 20. The first unit 10 includes a first inlet portion 11 for sending exhaust gas to the pre-stage oxidation catalyst 51, a front case portion 12 for housing the pre-stage oxidation catalyst 51, a DPF case portion 13 for housing the DPF 52, and an exhaust gas passing through the DPF 52. It comprises a first outlet section 14 for receiving the gas and a mixing section 15 for generating a turbulent flow in the exhaust gas.

第一入口部１１，前段ケース部１２，ＤＰＦケース部１３及び混合部１５は何れも、両端の開口が互いに逆方向を向く略円筒状に形成される。一方、第一出口部１４は、下流側の端部が略平板状の端壁部１４ａで塞がれた略有底円筒状に形成される。第一入口部１１，前段ケース部１２，ＤＰＦケース部１３及び第一出口部１４は、何れも軸心が前後方向に沿う姿勢とされ、前方から後方に向かってこの順に配置される。   Each of the first inlet part 11, the front case part 12, the DPF case part 13, and the mixing part 15 is formed in a substantially cylindrical shape with openings at both ends facing in opposite directions. On the other hand, the first outlet portion 14 is formed in a substantially bottomed cylindrical shape whose downstream end is closed by a substantially flat end wall portion 14a. The first inlet part 11, the front case part 12, the DPF case part 13, and the first outlet part 14 are all arranged so that their axes are aligned in the front-rear direction, and are arranged in this order from front to rear.

これに対し、混合部１５は、軸心が左右方向に沿う姿勢とされ、その左側の部分が第一出口部１４に入り込んだ状態で配置される。混合部１５のうち、第一出口部１４内に配置される部分には、排気を混合部１５の内部に取り入れるための複数の孔部１５ｈが形成される。混合部１５は、孔部１５ｈから流入した排気と、インジェクタ３から噴射された添加剤との混合を促進する機能をもつ。   On the other hand, the mixing section 15 is arranged such that the axis is in the left-right direction, and the left portion thereof enters the first outlet section 14. A plurality of holes 15h for taking in exhaust gas into the inside of the mixing section 15 are formed in a portion of the mixing section 15 arranged inside the first outlet section 14. The mixing section 15 has a function of promoting mixing of the exhaust gas flowing from the hole 15h and the additive injected from the injector 3.

第二ユニット２０は、ＳＣＲ５３に排気を送り込む第二入口部２１と、ＳＣＲ５３及び後段酸化触媒５４を収容するＳＣＲケース部２２と、ＳＣＲ５３及び後段酸化触媒５４を通過した排気を下流側へ送る第二出口部２３とで構成される。第二入口部２１及び第二下口部２３は何れも、緩やかに湾曲した略円筒状に形成される。第二入口部２１の上流端は、混合部１５の下流端に接続される。   The second unit 20 includes a second inlet 21 for sending exhaust gas to the SCR 53, an SCR case 22 for storing the SCR 53 and the second-stage oxidation catalyst 54, and a second second unit for sending exhaust gas that has passed through the SCR 53 and the second-stage oxidation catalyst 54 to the downstream side. An outlet 23 is provided. Both the second inlet 21 and the second lower outlet 23 are formed in a gently curved substantially cylindrical shape. The upstream end of the second inlet 21 is connected to the downstream end of the mixing section 15.

ＳＣＲケース部２２は、ＳＣＲ５３及び後段酸化触媒５４を収容する部位が略円筒状に形成され、その軸心が前後方向に沿う姿勢とされる。第二入口部２１，ＳＣＲケース部２２及び第二出口部２３は、後方から前方に向かってこの順に配置される。なお、ＳＣＲケース部２２内では、ＳＣＲ５３が後段酸化触媒５４よりも上流側に配置される。   The SCR case portion 22 has a substantially cylindrical shape for accommodating the SCR 53 and the second-stage oxidation catalyst 54, and has an axial center along the front-rear direction. The second inlet 21, the SCR case 22, and the second outlet 23 are arranged in this order from rear to front. In the SCR case 22, the SCR 53 is disposed on the upstream side of the post-stage oxidation catalyst 54.

エンジンの排気は、第一入口部１１を通って前段ケース部１２に流入し、前段酸化触媒５１を通過した後にＤＰＦケース部１３内のＤＰＦ５２を通過して第一出口部１４に流れる。そして、この排気は、混合部１５の孔部１５ｈから混合部１５内に流れ、インジェクタ３から噴射された添加剤と混ざり合いながら第二入口部２１に流れる。このように、排気は、第一出口部１４の内部で混合部１５に流れ込むことで、その流れ方向が後方へ向かう方向から右方へ向かう方向へと略９０°変更されて、第二入口部２１へと到達する。続いて、この排気は、ＳＣＲケース部２２に流入し、ＳＣＲ５３及び後段酸化触媒５４を順に通過した後に第二出口部２３から下流側へと流れる。   The exhaust gas of the engine flows into the former case part 12 through the first inlet part 11, passes through the former oxidation catalyst 51, passes through the DPF 52 in the DPF case part 13, and flows to the first outlet part 14. Then, the exhaust gas flows from the hole 15 h of the mixing section 15 into the mixing section 15, and flows into the second inlet section 21 while being mixed with the additive injected from the injector 3. As described above, the exhaust gas flows into the mixing section 15 inside the first outlet section 14, so that the flow direction is changed by approximately 90 ° from the backward direction to the right direction, and the second inlet section Reaching 21 Subsequently, the exhaust gas flows into the SCR case portion 22, flows through the SCR 53 and the post-stage oxidation catalyst 54 in order, and then flows downstream from the second outlet portion 23.

ここで、第一出口部１４の詳細な構成について説明する。
本実施形態の第一出口部１４は、その内側に向かって凹んだ凹部１４ｂと、凹部１４ｂから更に内側に向かって凹んだボス部４とを有する。本実施形態では、凹部１４ｂ及びボス部４が、第一出口部１４の左側の部位に形成されている場合を例示する。すなわち、凹部１４ｂ及びボス部４は何れも、第一出口部１４において、プロペラシャフトから離隔する方向（右方）に向かって凹んだ部位である。 Here, a detailed configuration of the first outlet section 14 will be described.
The first outlet portion 14 of the present embodiment has a concave portion 14b recessed inward and a boss portion 4 recessed further inward from the concave portion 14b. In the present embodiment, a case where the concave portion 14b and the boss portion 4 are formed in a portion on the left side of the first outlet portion 14 is exemplified. That is, both the concave portion 14b and the boss portion 4 are concave portions in the first outlet portion 14 in the direction away from the propeller shaft (rightward).

凹部１４ｂ及びボス部４は、インジェクタ３の突出量（第一ユニット１０の左側面から左側へ突出する長さ）を低減する機能をもつ。具体的には、凹部１４ｂ及びボス部４のそれぞれが凹むことによって形成される空間にインジェクタ３が配置されることで、インジェクタ３の左方への突出量が低減され、インジェクタ３とプロペラシャフトとの干渉が抑制される。   The concave portion 14b and the boss portion 4 have a function of reducing the amount of projection of the injector 3 (the length of the first unit 10 projecting leftward from the left side). Specifically, by disposing the injector 3 in a space formed by recessing each of the concave portion 14b and the boss portion 4, the amount of projection of the injector 3 to the left is reduced, and the injector 3 and the propeller shaft Interference is suppressed.

第一出口部１４は、ボス部４を除く部分が二重の構造とされている。具体的には図２に示すように、第一出口部１４は、内壁材４１と、内壁材４１よりも一回り大きく形成されて内壁材４１の外側に配置された外壁材４２とを有する。内壁材４１及び外壁材４２は何れも、前述した凹部１４ｂを構成するように略筒状に形成されている。   The first exit portion 14 has a double structure except for the boss portion 4. Specifically, as shown in FIG. 2, the first outlet portion 14 includes an inner wall member 41 and an outer wall member 42 which is formed to be slightly larger than the inner wall member 41 and is disposed outside the inner wall member 41. Each of the inner wall material 41 and the outer wall material 42 is formed in a substantially cylindrical shape so as to form the above-described concave portion 14b.

内壁材４１は、ボス部４が配置される空間（孔部）を囲む環状の第一縁部４３と、混合部１５が配置される空間（孔部）を囲む環状の第二縁部４４とを有する。第一縁部４３にはボス部４が固定され、第二縁部４４には混合部１５の外周面が固定される。なお、図示は省略するが、第一出口部１４の端壁部１４ａも同様に、内壁材と外壁材とで二重の構造とされている。   The inner wall material 41 includes an annular first edge 43 surrounding a space (hole) in which the boss 4 is arranged, an annular second edge 44 surrounding a space (hole) in which the mixing unit 15 is arranged. Having. The boss 4 is fixed to the first edge 43, and the outer peripheral surface of the mixing unit 15 is fixed to the second edge 44. Although not shown, the end wall portion 14a of the first outlet portion 14 also has a double structure of the inner wall material and the outer wall material.

［１−３．インジェクタ］
図２に示すように、インジェクタ３は、その基端に設けられた供給孔３１に供給される添加剤を、その先端に設けられた噴射孔３２から混合部１５内に噴射するものである。本実施形態のインジェクタ３は、添加剤の単位時間当たりの噴射量を所定量に調整したうえで、混合部１５の軸心Ｃ１に沿って添加剤を噴射する。また、本実施形態では、インジェクタ３が圧縮空気を用いない所謂エアレス式のものであるとともに、水冷式の構造をもつ場合について説明する。なお、図２には、インジェクタ３の断面を簡素化して示している。 [1-3. Injector]
As shown in FIG. 2, the injector 3 is configured to inject an additive supplied to a supply hole 31 provided at a base end thereof into a mixing unit 15 from an injection hole 32 provided at a tip end thereof. The injector 3 of the present embodiment injects the additive along the axis C <b> 1 of the mixing unit 15 after adjusting the injection amount of the additive per unit time to a predetermined amount. In the present embodiment, a case will be described in which the injector 3 is of a so-called airless type that does not use compressed air and has a water-cooled structure. FIG. 2 shows a simplified cross section of the injector 3.

インジェクタ３が噴射する添加剤としては、尿素水，アンモニア水，無水アンモニア（NH3）が挙げられる。インジェクタ３が尿素水を噴射する場合、排気管２内では、尿素水の熱分解によってNH3が生成される。また、インジェクタ３がアンモニア水を噴射する場合、排気管２内では、アンモニア水の加水分解によってNH3が生成される。すなわち、インジェクタ３が尿素水，アンモニア水，無水アンモニアの何れを噴射する場合も、排気管２内ではNH3が排気と混ざり合って流れる。排気と混ざり合ったNH3は、ＳＣＲ５３で還元剤として機能し、排気中の窒素酸化物（NOx）を窒素（N2）に還元する。   Examples of additives injected by the injector 3 include urea water, aqueous ammonia, and anhydrous ammonia (NH3). When the injector 3 injects urea water, NH3 is generated in the exhaust pipe 2 by thermal decomposition of the urea water. When the injector 3 injects the ammonia water, NH3 is generated in the exhaust pipe 2 by hydrolysis of the ammonia water. That is, regardless of whether the injector 3 injects urea water, ammonia water, or anhydrous ammonia, NH3 flows in the exhaust pipe 2 in a manner mixed with the exhaust gas. The NH3 mixed with the exhaust gas functions as a reducing agent in the SCR 53, and reduces nitrogen oxides (NOx) in the exhaust gas to nitrogen (N2).

供給孔３１と噴射孔３２とは、同一の軸心Ｃ２上に設けられる。インジェクタ３は、この軸心Ｃ２に沿って添加剤を噴射する。以下、この軸心Ｃ２を「インジェクタ３の軸心Ｃ２」ともいい、供給孔３１から噴射孔３２に向かう方向（すなわち、インジェクタ３が添加剤を噴射する方向）を噴射方向Ｄともいう。   The supply hole 31 and the injection hole 32 are provided on the same axis C2. The injector 3 injects the additive along the axis C2. Hereinafter, the axis C2 is also referred to as “the axis C2 of the injector 3”, and the direction from the supply hole 31 toward the injection hole 32 (that is, the direction in which the injector 3 injects the additive) is also referred to as the injection direction D.

インジェクタ３の軸心Ｃ２は、インジェクタ３がボス部４に取り付けられた状態で、混合部１５の軸心Ｃ１上に位置する。言い換えると、インジェクタ３は、混合部１５と同一軸心上に位置する（すなわち、インジェクタ３の軸心Ｃ２が混合部１５の軸心Ｃ１と重なる）ように、ボス部４に対して位置決めされる。また、本実施形態のインジェクタ３は、噴射方向Ｄが水平方向に対して下降傾斜する姿勢でボス部４に取り付けられている。より具体的には、本実施形態の噴射方向Ｄは、左方から右方に向かって下降傾斜する方向である。なお、インジェクタ３は、ボス部４に取り付けられた状態で、ボス部４よりも第一出口部１４の外側（本実施形態では左方）に突出する。   The axis C2 of the injector 3 is located on the axis C1 of the mixing section 15 with the injector 3 attached to the boss section 4. In other words, the injector 3 is positioned with respect to the boss 4 so that the injector 3 is located on the same axis as the mixing section 15 (that is, the axis C2 of the injector 3 overlaps the axis C1 of the mixing section 15). . Further, the injector 3 of the present embodiment is attached to the boss portion 4 in a posture in which the injection direction D is inclined downward with respect to the horizontal direction. More specifically, the injection direction D of the present embodiment is a direction in which the injection direction D is inclined downward from left to right. The injector 3 projects outside the first outlet 14 (leftward in the present embodiment) from the boss 4 when attached to the boss 4.

［１−４．ボス部］
ボス部４は、第一出口部１４の内側へ向かって凹んだ有底筒状に形成される。本実施形態のボス部４は、鋳造により、第一出口部１４の他の部位とは別体で形成されている。ボス部４は、略平板状に形成された底部５と、略円筒状に形成された周壁部６とを有する。 [1-4. Boss]
The boss portion 4 is formed in a bottomed cylindrical shape that is concave toward the inside of the first outlet portion 14. The boss portion 4 of the present embodiment is formed separately from other portions of the first outlet portion 14 by casting. The boss part 4 has a bottom part 5 formed in a substantially flat plate shape and a peripheral wall part 6 formed in a substantially cylindrical shape.

底部５は、その法線が左方から右方に向かって下降傾斜する姿勢で、内壁材４１の第一縁部４３よりも第一出口部１４の内側（右方）に配置される。底部５の外周面は、円柱面状に形成される。底部５の外周面には、混合部１５の左端部が例えば溶接により固定される。なお、混合部１５は、このように底部５に固定された状態では、底部５から周壁部６と離隔する方向に延在する。   The bottom portion 5 is disposed on the inner side (right side) of the first outlet portion 14 with respect to the first edge portion 43 of the inner wall material 41 in a posture in which the normal line is inclined downward from left to right. The outer peripheral surface of the bottom portion 5 is formed in a cylindrical shape. The left end of the mixing section 15 is fixed to the outer peripheral surface of the bottom 5 by, for example, welding. When the mixing section 15 is fixed to the bottom section 5 in this manner, the mixing section 15 extends in a direction away from the bottom section 5 and the peripheral wall section 6.

底部５には、インジェクタ３の噴射孔３２が配置される貫通孔７が形成される。貫通孔７は、底部５の略中心に設けられ、その軸心Ｃ３は、底部５の法線と平行に延び、混合部１５及びインジェクタ３のそれぞれがボス部４に取り付けられた状態では混合部１５及びインジェクタ３の各軸心Ｃ１，Ｃ２と重なる（一致する）。   In the bottom part 5, a through hole 7 in which the injection hole 32 of the injector 3 is arranged is formed. The through hole 7 is provided substantially at the center of the bottom 5, and its axis C 3 extends in parallel with the normal line of the bottom 5, and when the mixing section 15 and the injector 3 are each attached to the boss section 4, the mixing section 15 and each axis C1 and C2 of the injector 3 overlap (coincide).

周壁部６は、底部５の外縁から第一出口部１４の外側に向かって延設される。本実施形態の周壁部６は、その縁部６ａが斜め上方を向く開口をなす。すなわち、周壁部６の縁部６ａがなす開口の軸心は、第一出口部１４の外側に向かって上り傾斜している。また、周壁部６の縁部６ａの外周面は、円柱面状に形成される。周壁部６の縁部６ａの外周面は、内壁材４１の第一縁部４３に固定される。ボス部４は、このように周壁部６の縁部６ａが内壁材４１の第一縁部４３に固定されることで、第一出口部１４の他の部位（ボス部４以外の部位）と一体化される。   The peripheral wall portion 6 extends from the outer edge of the bottom portion 5 toward the outside of the first outlet portion 14. The peripheral wall 6 of the present embodiment has an opening whose edge 6a faces obliquely upward. That is, the axis of the opening formed by the edge 6 a of the peripheral wall 6 is inclined upward toward the outside of the first outlet 14. The outer peripheral surface of the edge 6a of the peripheral wall 6 is formed in a cylindrical shape. The outer peripheral surface of the edge 6 a of the peripheral wall 6 is fixed to the first edge 43 of the inner wall material 41. The boss portion 4 is fixed to the first edge portion 43 of the inner wall member 41 with the edge 6a of the peripheral wall portion 6 in this manner, so that the boss portion 4 and other portions of the first outlet portion 14 (portions other than the boss portion 4) can be formed. Integrated.

本実施形態の周壁部６の縁部６ａは、円形状に形成され、混合部１５，インジェクタ３，貫通孔７のそれぞれと同一軸心上に配置されている。すなわち、周壁部６の縁部６ａがなす円の中心は、混合部１５とインジェクタ３と貫通孔７とのそれぞれの軸心Ｃ１，Ｃ２，Ｃ３上に位置する。なお、周壁部６の縁部６ａは、周壁部６の端面から内壁材４１の第一縁部４３が固定される部位までを含む端部を指す。   The edge 6a of the peripheral wall 6 of the present embodiment is formed in a circular shape, and is arranged on the same axis as the mixing section 15, the injector 3, and the through hole 7. That is, the center of the circle formed by the edge 6a of the peripheral wall 6 is located on the respective axes C1, C2, C3 of the mixing section 15, the injector 3, and the through hole 7. In addition, the edge 6 a of the peripheral wall 6 refers to an end including a portion from an end surface of the peripheral wall 6 to a portion where the first edge 43 of the inner wall material 41 is fixed.

周壁部６は、縁部６ａを除く部位が内壁材４１と非接触に設けられる。すなわち、ボス部４が内壁材４１に固定された状態で、周壁部６の外周には排気が流通可能な空間Ｓ１が設けられる。また、底部５に固定された混合部１５の外周にも同様に、排気が流通可能な空間Ｓ２が設けられる。空間Ｓ１，Ｓ２は、周壁部６及び混合部１５をそれぞれ囲むように、周壁部６及び混合部１５の全周にわたって設けられている。   The peripheral wall portion 6 is provided so that a portion other than the edge portion 6 a is not in contact with the inner wall material 41. That is, a space S1 through which exhaust gas can flow is provided on the outer periphery of the peripheral wall portion 6 in a state where the boss portion 4 is fixed to the inner wall material 41. Similarly, a space S2 through which exhaust gas can flow is provided on the outer periphery of the mixing section 15 fixed to the bottom section 5. The spaces S1 and S2 are provided over the entire periphery of the peripheral wall 6 and the mixing unit 15 so as to surround the peripheral wall 6 and the mixing unit 15, respectively.

［２．作用，効果］
排気浄化装置１によれば、ボス部４が排気管２の内側に向かって窪んだ有底筒状であるため、ボス部４に取り付けられたインジェクタ３の突出量を低減することができる。これにより、排気浄化装置１とその近傍に配置される機器（例えば前述したプロペラシャフト）との干渉を防止しやすくすることができる。よって、排気浄化装置１及びその周辺機器のレイアウトの自由度を向上させることができる。 [2. Action, effect]
According to the exhaust gas purification device 1, since the boss portion 4 has a bottomed cylindrical shape depressed toward the inside of the exhaust pipe 2, the amount of protrusion of the injector 3 attached to the boss portion 4 can be reduced. Accordingly, it is possible to easily prevent interference between the exhaust gas purification device 1 and a device (for example, the above-described propeller shaft) arranged in the vicinity thereof. Therefore, the degree of freedom of the layout of the exhaust gas purification device 1 and its peripheral devices can be improved.

また、排気管２にはボス部４の底部５から周壁部６と離隔する方向に延在する筒状の混合部１５が設けられており、周壁部６及び混合部１５の各外周には排気が流通可能な空間Ｓ１，Ｓ２が設けられているため、排気管２内で空間Ｓ１，Ｓ２に排気を回り込ませることができる。排気が周壁部６の外周の空間Ｓ１に回り込んでから混合部１５の外周の空間Ｓ２へと流れることで、混合部１５に流入する排気に乱流が生じやすくなる。また、排気が混合部１５の外周の空間Ｓ２に回り込むことで、混合部１５の全周から混合部１５内に排気が取り入れられるため、混合部１５内で排気に乱流が生じやすくなる。これらより、インジェクタ３から噴射された添加剤と排気との混合を促進することができ、排気浄化性能の向上に寄与することができる。以上のように、排気浄化装置１によれば、レイアウトの自由度を向上させつつ、排気と添加剤との混合を促進することができる。   Further, the exhaust pipe 2 is provided with a cylindrical mixing section 15 extending in a direction away from the bottom 5 of the boss section 4 and the peripheral wall section 6, and an exhaust gas is provided on each outer periphery of the peripheral wall section 6 and the mixing section 15. Since the spaces S1 and S2 through which the gas can flow are provided, the exhaust gas can flow around the spaces S1 and S2 in the exhaust pipe 2. Since the exhaust flows into the space S1 on the outer periphery of the peripheral wall portion 6 and then flows to the space S2 on the outer periphery of the mixing section 15, turbulence is likely to occur in the exhaust gas flowing into the mixing section 15. In addition, since the exhaust gas enters the mixing unit 15 from the entire circumference of the mixing unit 15 by flowing into the space S2 on the outer periphery of the mixing unit 15, turbulence is easily generated in the exhaust gas in the mixing unit 15. Thus, mixing of the additive injected from the injector 3 with the exhaust gas can be promoted, which can contribute to improvement in exhaust gas purification performance. As described above, according to the exhaust gas purification device 1, it is possible to promote the mixing of the exhaust gas and the additive while improving the degree of freedom of the layout.

［３．変形例］
排気管２の形状，配置は前述したものに限定されない。例えば、排気管２の第一出口部１４は凹部１４ｂが省略された形状であってもよいし、第一ユニット１０は第二ユニット２０の右方に配置されてもよい。また、ボス部４の周壁部６は角筒状であってもよいし、周壁部６の縁部６ａがなす開口は斜め上方以外を向いていてもよい。 [3. Modification]
The shape and arrangement of the exhaust pipe 2 are not limited to those described above. For example, the first outlet portion 14 of the exhaust pipe 2 may have a shape in which the concave portion 14b is omitted, or the first unit 10 may be arranged on the right side of the second unit 20. Further, the peripheral wall portion 6 of the boss portion 4 may be in the shape of a rectangular tube, and the opening formed by the edge portion 6a of the peripheral wall portion 6 may be directed to a position other than diagonally upward.

前述したインジェクタ３の構成，配置は一例である。インジェクタ３は、圧縮空気を用いて添加剤を噴射する方式のものであってもよいし、水冷式の構造が省略されてもよい。また、インジェクタ３は、その噴射方向Ｄが下降傾斜する姿勢とされてなくてもよい。
前述した前段酸化触媒５１，ＤＰＦ５２，ＳＣＲ５３及び後段酸化触媒５４は、排気浄化装置１で浄化する排気の成分に応じて適宜設けられればよく、これらの一部が省略されてもよい。また、排気管２内には、これら以外の触媒やフィルタが更に設けられてもよい。 The configuration and arrangement of the injector 3 described above is an example. The injector 3 may be of a type in which an additive is injected using compressed air, or a water-cooled structure may be omitted. Further, the injector 3 does not have to be in a posture in which the injection direction D is inclined downward.
The above-described first-stage oxidation catalyst 51, DPF 52, SCR 53, and second-stage oxidation catalyst 54 may be appropriately provided according to the components of the exhaust gas to be purified by the exhaust gas purification device 1, and some of them may be omitted. Further, a catalyst or a filter other than these may be further provided in the exhaust pipe 2.

なお、インジェクタ３の下流に酸化触媒及びフィルタを設けるとともに、インジェクタ３によって噴射する添加剤として未燃燃料を採用してもよい。この場合、インジェクタ３から噴射された未燃燃料が酸化触媒において酸化することで排気温度が上昇するため、フィルタに捕集された排気中のPM（Particulate Matter；粒子状物質）を燃焼させることができる。よって、排気の浄化を促進することができる。   Note that an oxidation catalyst and a filter may be provided downstream of the injector 3, and unburned fuel may be used as an additive to be injected by the injector 3. In this case, since the unburned fuel injected from the injector 3 is oxidized by the oxidation catalyst and the exhaust gas temperature rises, PM (Particulate Matter) in the exhaust gas collected by the filter may be burned. it can. Therefore, purification of exhaust gas can be promoted.

１ 排気浄化装置
２ 排気管
３ インジェクタ
４ ボス部
５ 底部
６ 周壁部
７ 貫通孔
１５ 混合部
１５ｈ 孔部
Ｓ１，Ｓ２ 空間 DESCRIPTION OF SYMBOLS 1 Exhaust purification device 2 Exhaust pipe 3 Injector 4 Boss part 5 Bottom part 6 Peripheral wall part 7 Through hole 15 Mixing part 15h Hole parts S1, S2 Space

Claims (1)

車両に搭載されたエンジンの排気が内部を流通する排気管と、
前記排気管内に排気浄化用の添加剤を噴射するインジェクタと、を備え、
前記排気管は、前記インジェクタが取り付けられるボス部と前記インジェクタから噴射された前記添加剤を前記排気と混合させる筒状の混合部とを有し、
前記ボス部は、前記排気管の内側に向かって凹んだ有底筒状であり、前記インジェクタの先端が配置される貫通孔が形成された底部と前記底部の外縁から前記排気管の外側に向かって延設された周壁部とを有し、
前記混合部は、前記排気を内部に取り入れるための複数の孔部を有するとともに前記底部から前記周壁部と離隔する方向に延在し、
前記周壁部及び前記混合部の各外周には、前記排気が流通可能な空間が設けられていることを特徴とする、排気浄化装置。 An exhaust pipe through which the exhaust of the engine mounted on the vehicle flows,
An injector for injecting an exhaust gas purification additive into the exhaust pipe,
The exhaust pipe has a boss portion to which the injector is attached and a cylindrical mixing portion that mixes the additive ejected from the injector with the exhaust gas,
The boss portion is a bottomed cylindrical shape that is recessed toward the inside of the exhaust pipe, and a bottom portion having a through hole in which a tip of the injector is disposed and an outer edge of the bottom portion, which extends outward from the exhaust pipe. Having a peripheral wall portion extended
The mixing section has a plurality of holes for taking the exhaust gas therein and extends in a direction away from the peripheral wall from the bottom,
An exhaust gas purification device, wherein a space through which the exhaust gas can flow is provided on each outer periphery of the peripheral wall portion and the mixing portion.
JP2018118205A 2018-06-21 2018-06-21 Exhaust emission control device Pending JP2019218924A (en)

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Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015086816A (en) * 2013-10-31 2015-05-07 日野自動車株式会社 Exhaust emission control device

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015086816A (en) * 2013-10-31 2015-05-07 日野自動車株式会社 Exhaust emission control device

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