JP4529904B2 - Exhaust gas purification device for internal combustion engine - Google Patents

Description

  The present invention relates to an exhaust emission control device for an internal combustion engine, and more particularly, to measures for smoothly guiding particulate components such as manganese oxide contained in the exhaust of the engine to a catalyst device upstream of the exhaust passage.

Conventionally, as an exhaust purification device for an internal combustion engine having a plurality of cylinders, a catalyst device for purifying particulate components contained in exhaust gas is provided downstream of an exhaust collecting portion of the internal combustion engine. It is known that a rectifying plate for rectifying the flow of exhaust gas flowing into the catalyst device is provided immediately upstream (see, for example, Patent Document 1).
JP-A-9-68032

  By the way, lead-free MMT (methylcyclopentadienyl manganese tricarbonyl) or the like is used as an additive for gasoline. This MMT has high anti-knock properties but is related to environmental problems because it is an organic metal. It is considered a chemical substance and its use requires caution.

  In that case, the MMT is burned in a combustion chamber of each cylinder of an internal combustion engine such as a gasoline engine to generate manganese oxide. Therefore, manganese oxide contained in the exhaust gas is removed from the exhaust collecting portion of the internal combustion engine. Purification is performed by a catalyst device provided on the upstream side of the exhaust passage located near the downstream.

  However, manganese oxide in the exhaust gas adheres to and accumulates on the rectifying plate that rectifies the flow of the exhaust gas immediately upstream of the catalyst device, and the rectifying plate may be clogged. This is because the flow of exhaust gas guided from the plurality of cylinders to the exhaust assembly portion on the upstream side of the exhaust passage located in the vicinity of the downstream side of the exhaust assembly portion is inclined with respect to the joint of the rectifying plate, so that the rectifying plate is evenly distributed. It is thought that it is because it can be sprayed only on the biased position of the current plate without being guided.

  The present invention has been made in view of the above points, and the object of the present invention is to evenly guide the current plate to the current plate even if the flow of exhaust gas is inclined with respect to the joint of the current plate. An object of the present invention is to provide an exhaust emission control device for an internal combustion engine which can effectively prevent clogging of a rectifying plate by eliminating deposition due to adhesion of manganese oxide to the above.

  In order to achieve the above object, in the present invention, as an exhaust gas purification device for an internal combustion engine, a catalyst device provided downstream of an exhaust collecting portion of an internal combustion engine having a plurality of cylinders, and an upstream side of the catalyst device, A rectifying plate that rectifies the flow of the exhaust gas flowing into the catalyst device. And the said baffle plate is attached to the exhaust passage through the elastic body so that the baffle plate may be moved in the direction of contact with and away from the inner peripheral surface of the exhaust passage by vibration.

  Because of this specific matter, the rectifying plate is attached to the exhaust passage through the elastic body so as to move in a direction of contact with and away from the inner peripheral surface of the exhaust passage due to vibration generated by an internal combustion engine or the like. The exhaust flow discharged from a plurality of cylinders on the downstream side of the exhaust gas and combined into one at the exhaust collecting portion is inclined with respect to the joint of the rectifying plate, but the rectifying plate is in relation to the inner peripheral surface of the exhaust passage. Since it moves in the direction of contact and separation, it can only be sprayed on the biased position of the current plate, and it can be sprayed evenly. As a result, manganese oxide can be smoothly guided to the catalyst device without adhering to and depositing on the biased position of the rectifying plate, and clogging of the rectifying plate due to manganese oxide can be effectively prevented. Become.

  In particular, when a leaf spring-like urging member that urges the rectifying plate in the direction of moving away from the inner peripheral surface of the exhaust passage is applied as the elastic body, the rectifying plate is , The vibrations generated by the internal combustion engine are urged toward and away from each other in the direction of contact with and away from the inner peripheral surface of the exhaust passage, and the exhaust flow that is inclined with respect to the joint of the rectifying plate is smoothly moved. It is sprayed evenly without spraying to the biased position.

  Moreover, the leaf spring-like urging member can be easily set to a spring constant corresponding to the vibration generated by the internal combustion engine, and can be easily tuned according to the flow of the exhaust gas.

  In short, the flow of the exhaust gas inclined with respect to the joints of the rectifying plate can be obtained by attaching the rectifying plate to the exhaust passage through the elastic body so that the rectifying plate is moved in the direction of contact with and away from the inner peripheral surface of the exhaust passage by vibration. The current plate can be sprayed evenly, and deposition due to adhesion of manganese oxide to the current plate can be eliminated, and clogging of the current plate by manganese oxide can be effectively prevented.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a basic configuration of an exhaust emission control device of a gasoline engine (internal combustion engine) in which unleaded MMT (methylcyclopentadienyl manganese tricarbonyl) or the like is used as an additive for gasoline. Each of the exhaust ports has an upstream end of an exhaust manifold 11 as an upstream portion of the exhaust passage. The exhaust manifold 11 has an exhaust collecting portion 11a that collects exhaust from each cylinder into one upstream, and has an exhaust purification device 2 on the downstream side formed in a substantially cylindrical shape. Further, an exhaust pipe 12 as a downstream side of the exhaust passage is connected to the downstream end of the exhaust manifold 11. The exhaust manifold 11 is bent from a combined exhaust collecting portion 11a extending in a substantially horizontal direction from the exhaust port of the gasoline engine 1 and extending downward in a substantially vertical direction. In this case, the MMT added to the gasoline is burned in the combustion chamber of the gasoline engine 1 to produce manganese oxide, which becomes manganese oxide and is contained in the exhaust gas.

  The exhaust purification device 2 is provided in a three-way catalytic converter 21 (catalyst device) that purifies particulate components such as manganese oxide contained in exhaust gas, and an exhaust manifold 11 immediately upstream of the three-way catalytic converter 21. And a rectifying plate 22 that rectifies the flow of the exhaust gas flowing into the three-way catalytic converter 21.

  As shown in FIG. 2, the three-way catalytic converter 21 is held on the inner wall surface on the downstream side of the exhaust manifold 11 via the mat 13. The three-way catalytic converter 21 is provided in the exhaust manifold 11 close to the exhaust port of the gasoline engine 1, and includes a filter 21a for collecting manganese oxide and the like contained in the exhaust gas on the upstream side. ing. The filter 21a is formed in a lattice shape so as to divide the flow of exhaust gas into a plurality of spaces within a substantially cylindrical frame, and downstream of the exhaust manifold 11 from the upstream end of the three-way catalytic converter 21 to the vicinity of the downstream. It extends in parallel to the central axis. In the three-way catalytic converter 21, the manganese oxide collected by the filter 21 a is purified, and the exhaust gas containing impurities generated in the purification process is disposed downstream of the exhaust pipe 12. It leads to the main converter which is another catalyst device provided. The exhaust gas led to the main converter is further purified by the main converter and then discharged to the atmosphere. In this case, the exhaust emission control device 2 is configured as a manifold type in which an exhaust manifold 11 is integrally provided with a three-way catalytic converter 21.

  The rectifying plate 22 is elastic so as to move in a direction (radial direction with respect to the central axis on the downstream side of the exhaust manifold 11) to and away from the inner wall surface (inner peripheral surface) of the exhaust manifold 11 due to vibration generated by the gasoline engine 1. It is attached to the inner wall surface of the exhaust manifold 11 via the body 23. Further, as shown in FIG. 3, the rectifying plate 22 is formed in a lattice shape so as to divide the flow of exhaust gas into a plurality of spaces in a substantially cylindrical frame, and from the upstream end to the downstream end in the rectifying plate 22. Extending parallel to the central axis on the downstream side of the exhaust manifold 11. As the elastic body 23, four leaf spring-like urging members 24 are applied. Each of the urging members 24 is provided at a position 90 degrees apart in the circumferential direction of the inner wall surface of the exhaust manifold 11, and the rectifying plates 22 are arranged so as to be separated from each other in a direction contacting and separating from the inner wall surface of the exhaust manifold 11. Is to be energized. In this case, the exhaust gas discharged to the exhaust manifold 11 is changed from a substantially horizontal direction to an obliquely downward direction in the exhaust collecting portion 11a, and is inclined with respect to the grid-shaped joint of the rectifying plate 22 as shown by a wavy arrow in FIG. It has been introduced in the state.

  Therefore, in the above-described embodiment, the rectifying plate 22 is moved so as to move in a direction in which the rectifying plate 22 contacts and separates from the inner wall surface of the exhaust manifold 11 due to vibration generated by the gasoline engine 1 (radial direction with respect to the central axis on the downstream side of the exhaust manifold 11). Since the exhaust manifold 11 is attached to the exhaust manifold 11 via the spring-like biasing member 24 (elastic body 23), the exhaust gas changed from the substantially horizontal direction to the obliquely downward direction in the exhaust manifold 11a of the exhaust manifold 11 is shown in FIG. As shown by the wavy arrows in FIG. 4, the four rectifying plates 22 are inclined with respect to the grid-like joints of the rectifying plate 22, but are separated from each other in the direction in which the rectifying plate 22 contacts and separates from the inner wall surface of the exhaust manifold 11. Since it is energized and moved by the energizing member 24, it can be sprayed only on the biased position of the rectifying plate 22 and sprayed evenly. It will be used. As a result, the manganese oxide in the exhaust gas is smoothly guided along the joints of the filter 21a of the three-way catalytic converter 21 without adhering to and depositing on the uneven position of the rectifying plate 22, and the manganese oxide Clogging of the current plate 22 can be effectively prevented.

  In addition, each urging member 24 can be easily set to a spring constant corresponding to the vibration generated by the gasoline engine 1 and can be easily tuned according to the flow of the exhaust gas.

  In addition, this invention is not limited to the said embodiment, The other various modifications are included. For example, in the above-described embodiment, the filter 21a and the rectifying plate 22 are formed in a lattice shape, but the present invention is not limited to this, and may be formed in a honeycomb shape or the like.

  In the above-described embodiment, the exhaust gas purification device 2 of the maniverter type in which the three-way catalytic converter 21 is provided in the exhaust manifold 11 has been described. However, manganese oxidation is performed in a pipe interposed between the exhaust manifold and the exhaust pipe. It may be a start catalyst type exhaust gas purification device provided with a three-way catalytic converter for purifying an object.

It is sectional drawing of the exhaust manifold provided with the exhaust gas purification apparatus of the internal combustion engine concerning embodiment of this invention. FIG. 2 is a cross-sectional view of the vicinity of a current plate cut along line AA in FIG. 1. It is the top view which looked at the baffle plate in an exhaust manifold from upper direction.

Explanation of symbols

1 Gasoline engine (internal combustion engine)
11 Exhaust manifold (upstream side of exhaust passage)
11a Exhaust gas collection pipe 2 Exhaust gas purification device 21 Three-way catalytic converter (catalyst device)
22 Current plate 23 Elastic body 24 Biasing member

Claims (2)

A catalyst device provided downstream of an exhaust collecting portion of an internal combustion engine having a plurality of cylinders;
A rectifying plate provided on the upstream side of the catalyst device and rectifying the flow of exhaust gas flowing into the catalyst device;
The exhaust gas purification apparatus for an internal combustion engine, wherein the current plate is attached to the exhaust passage through an elastic body so as to move the current plate in a direction in which the current plate is moved toward and away from the inner peripheral surface of the exhaust passage by vibration. . The exhaust gas purification apparatus for an internal combustion engine according to claim 1,
As the elastic body, a leaf spring-like urging member that urges the rectifying plate in a direction in which the rectifying plates are separated from each other in a direction in which they are in contact with or away from the inner peripheral surface of the exhaust passage is applied. An exhaust purification device for an internal combustion engine.

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