JP2017198097A - Exhaust emission control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust emission control device for an internal combustion engine, in which going upstream of additive to the upstream side and the pressure loss of exhaust gas can be suppressed.SOLUTION: The exhaust emission control device for an internal combustion engine is provided that comprises an exhaust passage in which a catalyst is provided, an additive injection valve which is provided upstream from the catalyst in the exhaust passage and injects additive to the upstream side of the exhaust passage, and a plate member provided upstream from the additive injection valve in the exhaust passage. When the flow velocity of gas in the exhaust passage is lower than a predetermined value, the plate member rises from the inner wall side of the exhaust passage to the inside of the exhaust passage, and when the flow velocity of the gas in the exhaust passage is the predetermined value or higher, the plate member falls from the inside of the exhaust passage to the inner wall side.SELECTED DRAWING: Figure 1

Description

本発明は内燃機関の排気ガス浄化装置に関する。   The present invention relates to an exhaust gas purification device for an internal combustion engine.

内燃機関の排気ガス中に含まれるＣＯ（一酸化炭素）、ＨＣ（炭化水素）、ＮＯｘ（窒素酸化物）などの有害物質を浄化するため、排気経路の途中に触媒を設ける。触媒により有害物質を無害化し、浄化された排気ガスが車両の外に排出される。触媒における反応のための添加剤を触媒に噴射することがある（例えば特許文献１）。   In order to purify harmful substances such as CO (carbon monoxide), HC (hydrocarbon), NOx (nitrogen oxide) contained in the exhaust gas of the internal combustion engine, a catalyst is provided in the middle of the exhaust path. Hazardous substances are rendered harmless by the catalyst, and the purified exhaust gas is discharged out of the vehicle. An additive for reaction in the catalyst may be injected onto the catalyst (for example, Patent Document 1).

特開２００９−１５６０６６号公報JP 2009-156066 A

触媒での反応を効果的に行うためには、添加剤を微粒化させればよい。添加剤を排気経路の上流側に噴射し、排気ガス流の中に拡散させることで、添加剤を微粒化することができる。しかし、排気ガスの流速が小さい場合、添加剤が排気経路の上流側に遡上し、上流側の部品などに付着する。この結果、局所的な冷却およびデポジットの発生などが引き起こされる。添加剤を遮蔽する板を排気経路に設けることで、添加剤の上流側への遡上を抑制することができる。しかし板により排気ガスの圧力損失が大きくなってしまう。   In order to effectively carry out the reaction with the catalyst, the additive may be atomized. The additive can be atomized by spraying the additive upstream of the exhaust path and diffusing it into the exhaust gas flow. However, when the flow rate of the exhaust gas is small, the additive goes up to the upstream side of the exhaust path and adheres to upstream parts and the like. As a result, local cooling and generation of deposits are caused. By providing a plate that shields the additive in the exhaust path, the upstream of the additive can be suppressed. However, the pressure loss of the exhaust gas increases due to the plate.

そこで、添加剤の上流側への遡上および排気ガスの圧力損失を抑制することが可能な内燃機関の排気ガス浄化装置を提供することを目的とする。   Accordingly, an object of the present invention is to provide an exhaust gas purification device for an internal combustion engine that can suppress the upstream of the additive to the upstream side and the pressure loss of the exhaust gas.

上記目的は、触媒が設けられた排気経路と、前記排気経路の前記触媒より上流側に設けられ、前記排気経路の上流側に添加剤を噴射する添加剤噴射弁と、前記排気経路の前記添加剤噴射弁より上流側に設けられた板部材と、を具備し、前記排気経路内のガスの流速が所定値未満の場合、前記板部材は前記排気経路の内壁側から前記排気経路の内側に向けて立ち上がり、前記排気経路内のガスの流速が所定値以上の場合、前記板部材は前記排気経路の内側から前記内壁側に向けて倒れる内燃機関の排気ガス浄化装置によって達成できる。   The object is to provide an exhaust path provided with a catalyst, an additive injection valve provided upstream of the catalyst in the exhaust path and injecting an additive upstream of the exhaust path, and the addition of the exhaust path. A plate member provided on the upstream side of the agent injection valve, and when the flow velocity of the gas in the exhaust path is less than a predetermined value, the plate member extends from the inner wall side of the exhaust path to the inside of the exhaust path. The plate member can be achieved by an exhaust gas purifying apparatus for an internal combustion engine that rises toward the inner wall and falls toward the inner wall from the inside of the exhaust path when the flow velocity of the gas in the exhaust path is a predetermined value or more.

添加剤の上流側への遡上および排気ガスの圧力損失を抑制することが可能な内燃機関の排気ガス浄化装置を提供できる。   It is possible to provide an exhaust gas purification device for an internal combustion engine capable of suppressing the upstream of the additive to the upstream side and the pressure loss of the exhaust gas.

図１（ａ）は内燃機関の排気ガス浄化装置を例示する断面図である。図１（ｂ）は図１（ａ）の線Ａ−Ａに沿った断面図である。FIG. 1A is a cross-sectional view illustrating an exhaust gas purification device for an internal combustion engine. FIG.1 (b) is sectional drawing along line AA of Fig.1 (a). 図２（ａ）は図１（ｂ）の線Ｂ−Ｂに沿った断面図である。図２（ｂ）は板部が倒れた例を示す断面図である。FIG. 2A is a cross-sectional view taken along line BB in FIG. FIG. 2B is a cross-sectional view showing an example in which the plate portion falls down.

以下、図面を参照して本実施例の内燃機関の排気ガス浄化装置１００について説明する。図１（ａ）は内燃機関の排気ガス浄化装置１００を例示する断面図である。排気ガス浄化装置１００は例えば自動車に搭載される。自動車は例えばディーゼル車、ガソリン車、およびハイブリッド車などである。   Hereinafter, an exhaust gas purification apparatus 100 for an internal combustion engine according to this embodiment will be described with reference to the drawings. FIG. 1A is a cross-sectional view illustrating an exhaust gas purification device 100 for an internal combustion engine. The exhaust gas purification device 100 is mounted on, for example, an automobile. Examples of automobiles include diesel cars, gasoline cars, and hybrid cars.

図１（ａ）に示すように、排気ガス浄化装置１００は、排気経路１０に配置され、添加剤噴射弁１２、触媒１４および可動部材２０を備える。排気経路１０は不図示のエンジンに接続されている。エンジンから排出される排気ガスは、図１（ａ）に矢印で示すように排気経路１０を流れ、車両の外部に排出される。排気経路１０には、上流側から順に可動部材２０、添加剤噴射弁１２および触媒１４が設けられている。触媒１４は、例えば排気ガス中の有害物質を吸蔵し、ＣＯおよびＨＣの酸化ならびにＮＯｘの還元などを行い、排気ガスを浄化する三元触媒である。   As shown in FIG. 1A, the exhaust gas purification device 100 is disposed in the exhaust path 10 and includes an additive injection valve 12, a catalyst 14, and a movable member 20. The exhaust path 10 is connected to an engine (not shown). The exhaust gas discharged from the engine flows through the exhaust path 10 as indicated by an arrow in FIG. 1A and is discharged outside the vehicle. The exhaust path 10 is provided with a movable member 20, an additive injection valve 12, and a catalyst 14 in order from the upstream side. The catalyst 14 is a three-way catalyst that purifies the exhaust gas by storing, for example, harmful substances in the exhaust gas, oxidizing CO and HC, reducing NOx, and the like.

添加剤噴射弁１２は、触媒１４における反応のための添加剤１３（例えば燃料および尿素など）を、排気経路１０の上流側に噴射する。上流から流れてくる排気ガスにより添加剤１３が微粒化され、下流側の触媒１４に到達する。これにより触媒１４における反応が促進される。例えば燃料はＣＯおよびＨＣの酸化に用いられ、尿素はＮＯｘの還元に用いられる。   The additive injection valve 12 injects an additive 13 (for example, fuel and urea) for reaction in the catalyst 14 to the upstream side of the exhaust path 10. The additive 13 is atomized by the exhaust gas flowing from the upstream and reaches the catalyst 14 on the downstream side. Thereby, the reaction in the catalyst 14 is promoted. For example, fuel is used for CO and HC oxidation, and urea is used for NOx reduction.

図１（ｂ）は図１（ａ）の線Ａ−Ａに沿った断面図である。図１（ｂ）に示すように、排気経路１０の径方向に沿って対向する２つの可動部材２０が設けられている。可動部材２０は、板部材２２および蝶番２４を備える。図１（ｂ）に矢印で示すように、板部材２２は蝶番２４を軸として、排気経路１０の内壁側と排気経路１０の内側との間で回転可能である。蝶番２４はバネ蝶番であり、板部材２２が排気経路１０の内側に向けて立ち上がるように、板部材２２を付勢する。   FIG.1 (b) is sectional drawing along line AA of Fig.1 (a). As shown in FIG. 1B, two movable members 20 that are opposed along the radial direction of the exhaust path 10 are provided. The movable member 20 includes a plate member 22 and a hinge 24. As shown by an arrow in FIG. 1B, the plate member 22 can rotate between the inner wall side of the exhaust path 10 and the inside of the exhaust path 10 with the hinge 24 as an axis. The hinge 24 is a spring hinge and biases the plate member 22 so that the plate member 22 rises toward the inside of the exhaust path 10.

図２（ａ）は図１（ｂ）の線Ｂ−Ｂに沿った断面図である。図２（ａ）のブロック矢印は排気ガスの流れを示す。排気ガスの流速は所定値未満であり、蝶番２４の付勢力は排気ガスの圧力より大きい。このため板部材２２は排気経路１０の内側に向けて立ち上がる。添加剤１３は板部材２２によって遮られるため、上流側への遡上が抑制される。この結果、添加剤１３の付着が抑制され、付着による部品などの冷却が発生しにくい。またデポジットも抑制される。   FIG. 2A is a cross-sectional view taken along line BB in FIG. The block arrows in FIG. 2 (a) indicate the flow of exhaust gas. The flow rate of the exhaust gas is less than a predetermined value, and the biasing force of the hinge 24 is greater than the pressure of the exhaust gas. Therefore, the plate member 22 rises toward the inside of the exhaust path 10. Since the additive 13 is blocked by the plate member 22, the upstream run-up is suppressed. As a result, the adhesion of the additive 13 is suppressed, and cooling of parts and the like due to the adhesion hardly occurs. Deposits are also suppressed.

図２（ｂ）は板部材２２が倒れた例を示す断面図である。図２（ｂ）の例における排気ガスの流速は、図２（ａ）の例より大きく、所定値以上である。排気ガスの圧力が蝶番２４の付勢力より大きいため、図２（ｂ）に矢印で示すように板部材２２は排気経路１０の内壁側に倒れる。このため排気ガスは板部材２２に遮られずに下流側に流れる。したがって、排気ガスの圧力損失が小さくなる。また、排気ガスの圧力が大きいため、添加剤１３は上流側に遡上しにくく、排気ガスとともに下流側に流れる。このため添加剤１３の付着およびデポジットが抑制される。さらに添加剤１３が排気ガス中に拡散することで、添加剤１３の微粒化も促進される。なおガス流速の所定値とは、排気ガスの圧力が蝶番２４の付勢力より大きくなる速度である。   FIG. 2B is a cross-sectional view showing an example in which the plate member 22 falls. The flow rate of the exhaust gas in the example of FIG. 2B is larger than the example of FIG. Since the pressure of the exhaust gas is larger than the urging force of the hinge 24, the plate member 22 falls to the inner wall side of the exhaust path 10 as shown by an arrow in FIG. Therefore, the exhaust gas flows downstream without being blocked by the plate member 22. Therefore, the pressure loss of the exhaust gas is reduced. Further, since the pressure of the exhaust gas is large, the additive 13 does not easily go upstream, and flows downstream with the exhaust gas. For this reason, adhesion and deposit of additive 13 are suppressed. Furthermore, since the additive 13 diffuses into the exhaust gas, atomization of the additive 13 is also promoted. The predetermined value of the gas flow rate is a speed at which the pressure of the exhaust gas becomes larger than the urging force of the hinge 24.

本実施例によれば、添加剤１３の遡上および排気ガスの圧力損失を抑制することが可能である。すなわち、図２（ａ）のように排気ガスの流速が所定値未満の場合、可動部材２０の板部材２２が排気経路１０の内側に向けて立ち上がるため、添加剤１３の遡上が抑制され、上流側の部品などに付着しにくくなる。図２（ｂ）のように排気ガスの流速が所定値より大きい場合、板部材２２が排気経路１０の内壁側に倒れるため、圧力損失が抑制される。   According to the present embodiment, it is possible to suppress the upstream of the additive 13 and the pressure loss of the exhaust gas. That is, when the flow rate of the exhaust gas is less than a predetermined value as shown in FIG. 2A, the plate member 22 of the movable member 20 rises toward the inside of the exhaust path 10, so that the upstream of the additive 13 is suppressed, It becomes difficult to adhere to parts on the upstream side. When the flow rate of the exhaust gas is larger than a predetermined value as shown in FIG. 2 (b), the plate member 22 falls to the inner wall side of the exhaust path 10, so that pressure loss is suppressed.

可動部材２０の板部材２２は、バネ蝶番である蝶番２４により回転可能である。可動部材２０は、ガス流速が小さいときに排気経路１０の流路面積を小さくし、ガス流速が大きいときに流路面積を大きくするものであればよい。例えば油圧などを用いたメカ式の可動部材２０でもよい。また、可動部材２０を例えば電動式として、ＥＣＵ（Engine Control Unit）により駆動するモータなどを用いて板部材２２を移動させてもよい。ＥＣＵは排気経路１０に設けられたエアフローメータからガスの流量を取得し、ガスの流量が所定値より小さい場合に板部材２２を立ち上げ、ガスの流量が所定値より大きい場合に板部材２２を倒せばよい。また、可動部材２０の数は１つでもよいし、３つ以上でもよい。   The plate member 22 of the movable member 20 can be rotated by a hinge 24 that is a spring hinge. The movable member 20 only needs to reduce the flow path area of the exhaust passage 10 when the gas flow rate is low and increase the flow path area when the gas flow rate is high. For example, a mechanical movable member 20 using hydraulic pressure or the like may be used. Alternatively, the movable member 20 may be electrically operated, for example, and the plate member 22 may be moved using a motor driven by an ECU (Engine Control Unit). The ECU acquires the gas flow rate from an air flow meter provided in the exhaust path 10, and starts up the plate member 22 when the gas flow rate is smaller than a predetermined value, and moves the plate member 22 when the gas flow rate is larger than the predetermined value. Defeat it. Further, the number of movable members 20 may be one, or three or more.

排気経路１０のＬ字型に屈曲している部分に添加剤噴射弁１２を設け、添加剤噴射弁１２より上流側に可動部材２０、下流側に触媒１４を設けることが好ましい。これにより添加剤１３を上流側の可動部材２０に向けて噴射することができる。また添加剤１３が排気ガスとともに触媒１４に向けて流れる。触媒１４は、三元触媒、酸化触媒およびＮＯｘ吸蔵触媒などとすることができる。   It is preferable that the additive injection valve 12 is provided in a portion of the exhaust path 10 bent in an L shape, the movable member 20 is provided upstream from the additive injection valve 12, and the catalyst 14 is provided downstream. Thereby, the additive 13 can be injected toward the movable member 20 on the upstream side. The additive 13 flows toward the catalyst 14 together with the exhaust gas. The catalyst 14 can be a three-way catalyst, an oxidation catalyst, a NOx storage catalyst, or the like.

以上本発明の好ましい実施形態について詳述したが、本発明は係る特定の実施形態に限定されるものではなく、特許請求の範囲に記載された本発明の要旨の範囲内において、種々の変形・変更が可能である。   Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. It can be changed.

１０ 排気経路
１２ 添加剤噴射弁
１３ 添加剤
１４ 触媒
２０ 可動部材
２２ 板部材
２４ 蝶番
１００ 排気ガス浄化装置 DESCRIPTION OF SYMBOLS 10 Exhaust path 12 Additive injection valve 13 Additive 14 Catalyst 20 Movable member 22 Plate member 24 Hinge 100 Exhaust gas purification apparatus

Claims (1)

触媒が設けられた排気経路と、
前記排気経路の前記触媒より上流側に設けられ、前記排気経路の上流側に添加剤を噴射する添加剤噴射弁と、
前記排気経路の前記添加剤噴射弁より上流側に設けられた板部材と、を具備し、
前記排気経路内のガスの流速が所定値未満の場合、前記板部材は前記排気経路の内壁側から前記排気経路の内側に向けて立ち上がり、
前記排気経路内のガスの流速が所定値以上の場合、前記板部材は前記排気経路の内側から前記内壁側に向けて倒れる内燃機関の排気ガス浄化装置。

An exhaust path provided with a catalyst;
An additive injection valve that is provided upstream of the catalyst in the exhaust path and injects an additive upstream of the exhaust path;
A plate member provided upstream of the additive injection valve in the exhaust path,
When the flow velocity of the gas in the exhaust path is less than a predetermined value, the plate member rises from the inner wall side of the exhaust path toward the inside of the exhaust path,
The exhaust gas purifying apparatus for an internal combustion engine, wherein the plate member falls from the inside of the exhaust path toward the inner wall when the flow velocity of the gas in the exhaust path is a predetermined value or more.

Images