Exhaust device for internal combustion engine

Abstract

Provided is an exhaust device for an internal combustion engine in which an exhaust manifold and an exhaust purification device are integrally configured near a lateral portion of the internal combustion engine to achieve miniaturization. The entire inflow port for exhaust from the internal combustion engine that flows in an air gap between an inner cylinder retaining an exhaust purification catalyst therein and an outer cylinder is configured to be opposed to an outer peripheral surface of the inner cylinder. More preferably, the exhaust purification catalyst retained inside the inner cylinder and the inflow port are configured to be at least partially opposed to each other. Thus, uniformization of inflow of exhaust into an exhaust purification member is promoted, and an improvement in warming-up performance and miniaturization can be achieved.

Description

Technical Field

[0001] The present invention relates to an exhaust device for an internal combustion engine. More specifically, the present invention relates to an exhaust device for an internal combustion engine capable of achieving improvement in warm-up performance and miniaturization while equalizing the inflow of exhaust gas into an exhaust purification member.

Background Art

[0002] Exhaust gas discharged from internal combustion engines such as gasoline engines and diesel engines contains specific substances such as particulate matter (PM) composed of, for example, soot, carbon monoxide (CO), unburned hydrocarbons (HC: HydroCarbon), and nitrogen oxides (NOx). Therefore, from the viewpoint of protecting the global environment, for example, filters such as gasoline particulate filters (GPF) and diesel particulate filters (DPF) that collect PM, as well as exhaust purification catalysts such as oxidation catalysts (OC), three-way catalysts (TWC), selective catalytic reduction denitration devices (SCR), and ammonia slip catalysts (ASC) are installed in the exhaust flow path of the internal combustion engine. Widely used to remove these specific substances.

[0003] In recent vehicles, a plurality of exhaust purification members (for example, catalytic converters and filters) are built into the exhaust purification device, and each exhaust purification member tends to have a larger capacity (become larger). For this reason, it has become increasingly difficult to accommodate the exhaust purification device in the limited space in the engine mounting compartment (engine compartment). Therefore, in this technical field, a layout in which an exhaust device (manifold) in which an exhaust manifold and an exhaust purification device are integrated is arranged near the side portion of the internal combustion engine in the engine mounting compartment has been widely adopted.

[0004] For example, in Patent Document 1 (Japanese Patent Application Laid-Open No. 2007-146681), an exhaust device for an internal combustion engine is disclosed in which a long cylindrical exhaust purification device incorporating a plurality of exhaust purification members is arranged substantially parallel to the crankshaft, and an exhaust manifold is integrally provided above the exhaust purification device. According to this, it is said that the space efficiency in the engine mounting chamber can be improved by miniaturizing the exhaust device, and a crushable zone in the front-rear direction of the engine can be secured when mounted so as to have a transverse rear exhaust.

[0005] Further, in Patent Document 2 (Japanese Patent No. 6444183), an exhaust gas collecting device for an internal combustion engine having a configuration in which an exhaust manifold portion is wound around the outer peripheral surface of a cylindrical housing of an exhaust purification member in the same layout as described above is disclosed. According to this, it is said that the length of the branch pipe (branch length) from each exhaust port and the length of the introduction pipe from the collecting portion of the branch pipes to the expansion chamber provided at the upstream end of the exhaust purification member can be ensured to be large, so that both the effective utilization of exhaust pulsation and the heat insulation of the catalyst carrier can be achieved.

[0006] However, in the above-described conventional technology, since the exhaust gas is made to flow into the expansion chamber provided upstream of the most upstream exhaust purification member through a single introduction pipe, a swirling flow and / or a non-uniform flow is likely to occur inside the expansion chamber. For this reason, it is difficult for the flow velocity and / or pressure of the exhaust gas flowing into the upstream end face of the exhaust purification member to become uniform, and the degree of uniformity of the flow velocity and / or pressure of the exhaust gas flowing into the upstream end face of the most upstream exhaust purification member is low (not uniform per unit area). As a result, there is a problem that the original exhaust purification function of the exhaust purification member cannot be sufficiently exerted.

[0007] On the other hand, in Patent Document 3 (Japanese Utility Model Publication No. 52-94512), although the structure of the exhaust manifold is not disclosed, an exhaust purification device disposed near the side portion of the internal combustion engine as described above is disclosed. In the exhaust purification device, exhaust gas flows into an end portion opposite to the expansion chamber formed at the upstream end of the exhaust purification catalyst, and the exhaust gas is guided from the inlet to the expansion chamber via a gap between the inner cylinder and the outer cylinder that holds the exhaust purification catalyst inside. At this time, by guiding the exhaust gas in the tangential direction of the outer cylinder with the positional relationship between the central axis of the inlet and the central axis of the outer cylinder being a so-called "twisted position" (in a view perpendicular to the axis), a swirling flow is generated and maintained in the exhaust gas flowing from the above gap to the expansion chamber, and the exhaust gas reaches the upstream end face of the exhaust purification catalyst.

[0008] However, as described above, from the viewpoint of sufficiently exerting the original exhaust purification function of the exhaust purification member, it is preferable that the uniformity of the flow velocity and / or pressure of the exhaust gas flowing into the upstream end face of the most upstream exhaust purification member is high (the exhaust gas per unit area hitting the upstream end face of the exhaust purification member is uniform). Therefore, although the above device can exert the effect of creating an insulating layer with the exhaust gas before purification to prevent abnormal temperature rise of the exhaust purification catalyst, it has an adverse effect on the exertion of the original exhaust purification function of the entire exhaust purification member. In addition, by intentionally generating and maintaining a swirling flow as described above, there also arises a problem that the flow path resistance increases (the back pressure rises).

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0010] As is apparent from the foregoing, in this technical field, there is a continuous demand for an exhaust device of an internal combustion engine that can achieve improvement and miniaturization of warm-up performance while equalizing the inflow of exhaust gas into an exhaust purification member.

Means for Solving the Problem

[0011] Therefore, as a result of intensive research, the inventor has found that, in an exhaust device of an internal combustion engine that achieves miniaturization by integrally forming an exhaust manifold and an exhaust purification device in the vicinity of the side portion of the internal combustion engine, by configuring the entire inflow port of the exhaust gas from the internal combustion engine flowing into the gap between the inner cylinder holding the exhaust purification catalyst inside and the outer cylinder so as to face the outer peripheral surface of the inner cylinder, the above problems can be solved.

[0012] Specifically, an exhaust device of an internal combustion engine according to the present invention (hereinafter, may be referred to as "the device of the present invention") is an exhaust device of an internal combustion engine including an exhaust purification device including a casing and one or more exhaust purification members housed inside the casing, and an exhaust manifold. The casing includes an inner cylinder that is a cylindrical member that holds the exhaust purification member inside, and an outer cylinder that has a bottomed cylindrical shape and whose end portion on the opening side is externally fitted to the inner cylinder so as to cover at least a part of the exhaust purification member.

[0013] Also, inside the casing, a first space that is a gap between the outer peripheral surface of the inner cylinder and the inner peripheral surface of the outer cylinder, and a second space that is a space between the end portion of the inner cylinder and the bottom portion of the outer cylinder are formed. Further, the casing and the exhaust manifold are connected so that the internal space of the collecting pipe of the exhaust manifold and the first space communicate with each other through an inflow port that is an opening formed on the side surface of the outer cylinder. In addition, in a first projection view that is a projection view in the flow direction of the exhaust gas flowing from the internal space of the collecting pipe into the first space through the inflow port, the entire inflow port overlaps with the inner cylinder.

Advantages of the Invention

[0014] As described above, in the apparatus of the present invention, inside the casing, a first space which is a gap between the inner peripheral surface of the outer cylinder and the outer peripheral surface of the inner cylinder, and a second space which is a space between the bottom of the outer cylinder and the end of the inner cylinder are formed. Further, the internal space of the collecting pipe of the exhaust manifold and the first space communicate with each other through an inlet which is an opening formed on the side surface of the outer cylinder. Therefore, compared with a structure in which an expansion chamber is provided separately, although it has a more compact structure, by expanding the exhaust gas flowing into the casing from the internal space of the collecting pipe through the inlet from the first space to the second space, the flow velocity of the exhaust gas can be effectively reduced. As a result, the inflow of the exhaust gas to the exhaust purification member can be made uniform.

[0015] In addition, the apparatus of the present invention is configured such that in a first projection view which is a projection view in the flow direction of the exhaust gas flowing from the internal space of the collecting pipe toward the first space through the inlet, the entire inlet overlaps with the inner cylinder. Therefore, the exhaust gas flowing into the first space from the internal space of the collecting pipe through the inlet can be surely made to collide with the outer peripheral surface of the inner cylinder. As a result, the influence of pulsating flow in the exhaust gas flow can be reduced, and the inflow of the exhaust gas to the exhaust purification member can be made more uniform. Further, with the above configuration, the ratio of the exhaust gas that expands so as to surround the inner cylinder and then expands to the second space among the exhaust gas flowing into the first space can be increased, so that the heat insulation effect of the exhaust purification member held inside the inner cylinder and the warm-up effect during cold operation are also enhanced. These effects are particularly effective when the exhaust purification member is an exhaust purification catalyst.

[0016] As described above, according to the apparatus of the present invention, it is possible to achieve improvement in warm-up performance and miniaturization while making the inflow of the exhaust gas to the exhaust purification member uniform.

[0017] Other objects, other features and attendant advantages of the present invention will be easily understood from the description of each embodiment of the present invention described with reference to the following drawings.

Brief Description of the Drawings

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Mode for Carrying Out the Invention

[0021] 《First Embodiment》 Hereinafter, an exhaust device for an internal combustion engine according to the first embodiment of the present invention (hereinafter, may be referred to as "the first device") will be described with reference to the drawings. However, the following description is merely illustrative, and the present invention is not limited to the embodiments described below. The present invention can be implemented in any form without departing from the scope of the technical idea described in the specification, claims, and drawings attached to the application.

[0022] 〈Configuration〉 FIG. 1 is a schematic cross-sectional view showing an example of the configuration of the first device. In FIG. 1, a schematic cross-sectional view taken along a plane passing through the central axis of the exhaust purification member provided in the first device and the central axis of the collecting pipe of the exhaust manifold is shown on the left side facing the drawing, and a schematic cross-sectional view taken along a plane perpendicular to the central axis of the exhaust purification member and passing through the central axis of the collecting pipe of the exhaust manifold is shown on the right side facing the drawing. In addition, in this specification, the term "collecting pipe" does not refer only to a tubular member such as a general collecting pipe of an exhaust manifold, but widely includes a member that defines a space in which the exhaust flowing inside the branch pipes in the exhaust manifold converges (merges) into one body (specifically, it will be described later in the description of Example 1 of the present invention).

[0023] The exhaust gas purification device 100 shown in Fig. 1 is an exhaust gas device of an internal combustion engine composed of an exhaust gas purification device 100 including a casing 110 and one or more exhaust gas purification members 120 housed inside the casing 110, and an exhaust manifold 200. The casing 110 includes an inner cylinder 111 which is a cylindrical member that holds the exhaust gas purification member 120 inside, and an outer cylinder 112 which has a bottomed cylindrical shape and the end on the opening side is externally fitted to the inner cylinder 111 so as to cover at least a part of the exhaust gas purification member 120.

[0024] The specific configurations of the inner cylinder 111 and the outer cylinder 112 that make up the casing 110 are not particularly limited as long as they satisfy the above-mentioned requirements and can withstand the usage environment and conditions as an exhaust gas purification device. Specifically, the inner cylinder 111 and the outer cylinder 112 may be composed of a cylindrical member made of a metal material such as stainless steel, or may be composed by a manufacturing method of stacking a plurality of press-molded members (so-called "Monaka manufacturing method"). The size and shape of the inner cylinder 111 can be appropriately determined according to, for example, the size and shape of the exhaust gas purification member 120 held inside. The size and shape of the outer cylinder 112 can be appropriately determined according to, for example, the size and shape of the inner cylinder 111 held inside, and the size and shape of the spatial margin in the engine mounting chamber.

[0025] The exhaust gas purification member 120 is a member that purifies exhaust gas. Specifically, the exhaust gas purification member 120 is a member that has a function of purifying the exhaust gas by removing and / or detoxifying the specific substances as described above contained in the exhaust gas discharged from an internal combustion engine (not shown). Specific examples of such members include exhaust gas purification catalysts such as oxidation catalysts (OC), three-way catalysts (TWC), selective catalytic reduction denitration devices (SCR), and ammonia slip catalysts (ASC), and filters such as gasoline particulate filters (GPF) and diesel particulate filters (DPF) that collect PM.

[0026] When the first device 1001 includes an exhaust gas purification member 120 that requires an additive such as a reducing agent in removing and / or detoxifying a specific substance, the first device 1001 may include a device for supplying the additive to the exhaust gas flow path upstream of the member that requires the additive. Further, the exhaust gas purification member 120 may be, for example, an electrically heated catalyst (EHC) which is a purification member including a heating element that generates heat by being energized through a pair of electrodes to heat an exhaust gas purification catalyst and / or the heating element.

[0027] The number of exhaust gas purification members 120 held inside the inner cylinder 111 may be one or two or more. In the latter case, all of the plurality of exhaust gas purification members 120 may be of the same type or different types.

[0028] The specific method for holding the exhaust gas purification member 120 inside the inner cylinder 111 is not particularly limited as long as the exhaust gas purification member 120 can be fixed at a predetermined position inside the inner cylinder 111 and can withstand the usage environment and conditions of the exhaust gas purification device. For example, in the first device 1001, a holding member (mat) 130 which is a buffer material made of a material capable of exerting a restoring force as a reaction to compression and having sufficient heat resistance is sandwiched and held between the exhaust gas purification member 120 and the inner cylinder 111, and the exhaust gas purification member 120 can be held at a predetermined position inside the inner cylinder 111 by the restoring force of the holding member 130.

[0029] As a specific example of the method for sandwiching and holding the holding member 130 between the exhaust gas purification member 120 and the inner cylinder 111 as described above and holding the exhaust gas purification member 120 at a predetermined position inside the inner cylinder 111 by the restoring force of the holding member 130, for example, methods using a press-fitting method and a sizing method can be mentioned. Since the details of the press-fitting method and the sizing method are well known to those skilled in the art, the description here is omitted.

[0030] Furthermore, as a specific example of the material constituting the holding member 130 as described above, for example, inorganic fibers such as alumina-based fibers and alumina-silica-based fibers, and those obtained by adding a resin as a binder to such inorganic fibers can be mentioned. Specific examples of the resin used as the binder include, for example, acrylic rubber, nitrile rubber, polyvinyl alcohol, and acrylic resin.

[0031] Also, inside the casing 110, a first space S1, which is a gap between the outer peripheral surface of the inner cylinder 111 and the inner peripheral surface of the outer cylinder 112, and a second space S2, which is a space between the end of the inner cylinder 111 and the bottom of the outer cylinder 112, are formed. Furthermore, the casing 110 and the exhaust manifold 200 are connected such that the internal space SC of the collecting pipe of the exhaust manifold 200 and the first space S1 communicate with each other through an inlet AE, which is an opening formed on the side surface of the outer cylinder 112.

[0032] FIG. 2 is a schematic cross-sectional view showing an example of the exhaust flow in the first apparatus 1001 illustrated in FIG. 1. In FIGS. 1 and 2, a third space S3 exists on the downstream side (opposite to the second space S2) of the exhaust purification member 120 inside the inner cylinder 111, but such a downstream space is not an essential component of the first apparatus 1001. Also, in FIG. 2, for the purpose of easily illustrating the exhaust flow in the first apparatus 1001, reference numerals are attached only to a part of the components of the first apparatus 1001. Therefore, in the following description, not only FIG. 2 but also FIG. 1 should be referred to as necessary.

[0033] As illustrated in FIG. 2, the exhaust gas discharged from an internal combustion engine (not shown) and gathered into the internal space SC of the header pipe of the exhaust manifold 200 through an exhaust port (not shown) in the cylinder head 210 first flows from the internal space SC into the first space S1 through the inlet AE (see the thick dashed arrow F1). At least a part of the exhaust gas flowing into the first space S1 spreads so as to surround the inner cylinder 111 (see the thick dashed arrow F2). Thereby, the heat retaining effect of the exhaust gas purification member 120 held inside the inner cylinder 111 and the warm-up effect during cold times can be enhanced. The exhaust gas further flows into the second space S2 (see the thick dashed arrow F3).

[0034] By expanding the exhaust gas flowing from the internal space SC of the header pipe into the inside of the casing 110 through the inlet AE as described above from the first space S1 to the second space S2, the flow velocity of the exhaust gas can be effectively reduced. As a result, the inflow of the exhaust gas flowing from the second space S2 into the inside of the inner cylinder 111 and reaching the end on the upstream side (the second space S2 side) of the exhaust gas purification member 120 can be made uniform.

[0035] In addition, the size and shape of the internal space SC of the header pipe of the exhaust manifold 200, the inlet AE formed on the side surface of the outer cylinder 112, and the first space S1 and the second space S2 inside the casing 110 can be appropriately determined according to, for example, the magnitude of the effect of reducing the flow velocity of the exhaust gas described above and / or the magnitude of the flow path resistance.

[0036] In addition, the first device 1001 is configured such that the entire inlet AE overlaps with the inner cylinder 111 in a first projection view which is a projection view in the flow direction of the exhaust gas flowing from the internal space SC of the header pipe into the first space S1 through the inlet AE.

[0037] FIG. 3 is a schematic diagram showing an example of a vertical projection view (first projection view) in the direction of the exhaust flow direction (arrow F1 in FIG. 2) flowing from the internal space SC of the collecting pipe toward the first space S1 through the inlet AE in the first device 1001 illustrated in FIGS. 1 and 2. However, in FIG. 3, only the inlet AE and the inner cylinder 111 in the first projection view are drawn for the purpose of easily illustrating the positional relationship between the inlet AE and the inner cylinder 111 in the first device 1001.

[0038] As illustrated in FIG. 3, in the first device 1001, in the first projection view which is a projection view in the direction of the exhaust flow direction flowing from the internal space SC of the collecting pipe toward the first space S1 through the inlet AE, the entire inlet AE (refer to the black circle) overlaps with the inner cylinder 111.

[0039] Therefore, in the first device 1001, the exhaust flowing from the internal space SC of the collecting pipe of the exhaust manifold 200 into the first space S1 through the inlet AE can surely collide with the outer peripheral surface of the inner cylinder 111. As a result, according to the first device 1001, the influence of pulsating flow in the exhaust flow can be reduced, and the inflow of exhaust into the exhaust purification member 120 can be further made uniform. Further, with the above configuration, the ratio of the exhaust that expands to surround the inner cylinder 111 and then expands to the second space S2 among the exhaust flowing into the first space S1 can be increased, so that the heat insulation effect of the exhaust purification member 120 held inside the inner cylinder 111 and the warm-up effect during cold operation are also enhanced. These effects are particularly effective when the exhaust purification member 120 is an exhaust purification catalyst.

[0040] <Effect> As described above, according to the first device, it is possible to achieve improvement in warm-up performance and miniaturization while making the inflow of exhaust into the exhaust purification member uniform.

[0041] (Modification 1-1) In the above-described first device 1001, the internal space SC of the collecting pipe of the exhaust manifold 200 and the first space S1 were communicated with each other by the inflow port AE, which is one opening formed on the side surface of the outer cylinder 112. However, the number of the inflow ports AE is not limited to one, and any number of two or more inflow ports AE may be formed on the side surface of the outer cylinder 112.

[0042] FIG. 4 is a schematic cross-sectional view showing an example of the internal structure of the exhaust purification device included in the first device according to Modification 1-1. Specifically, FIG. 4(a) is a schematic cross-sectional view by a plane perpendicular to the central axis of the exhaust purification member and passing through the central axis of the collecting pipe of the exhaust manifold connected to the inflow port, and the branch pipes of the exhaust manifold are omitted. FIG. 4(b) is a schematic view showing an example of a vertical projection view (first projection view) in the flow direction of the exhaust flowing from the internal space of the collecting pipe toward the first space S1 through the inflow ports AE1 and AE2 in the first device 1001a according to Modification 1-1 illustrated in FIG. 4(a). However, also in FIG. 4(b), for the purpose of easily illustrating the positional relationship between the inflow ports AE1 and AE2 and the inner cylinder 111 in the first device 1001a, only the inflow ports AE1 and AE2 and the inner cylinder 111 in the first projection view are drawn, similar to FIG. 3.

[0043] In the first device 1001a according to Modification 1-1 illustrated in FIG. 4(a), two inflow ports AE1 and AE2 are formed on the side surface of the outer cylinder 112, and the collecting pipes of the exhaust manifold are connected to each of them. Incidentally, the two collecting pipes connected to the two inflow ports AE1 and AE2 may be those branched into two after all the branch pipes included in the exhaust manifold are collected (merged). Alternatively, a part of the plurality of branch pipes may be collected into one collecting pipe, and the remaining branch pipes may be collected into the other collecting pipe.

[0044] As illustrated in FIG. 4(b), also in the first device 1001a according to the first modification example 1-1, in the projection view (first projection view) of the exhaust flow direction flowing from the internal space of the collecting pipe toward the first space S1 through the inlets AE1 and AE2, the entire inlets AE1 and AE2 overlap with the inner cylinder 111. Therefore, similar to the first device 1001 described above, it is possible to achieve improvement in warm-up performance and miniaturization while equalizing the inflow of exhaust into the exhaust purification member.

[0045] In addition, in the first device 1001a illustrated in FIG. 4, two inlets AE1 and AE2 were formed at the same position in the central axis direction of the exhaust purification member (not shown). However, in the first device according to the first modification example 1-1, for example, as in the first device 1001b illustrated in FIG. 5, two inlets AE1 and AE2 may be formed at different positions in the central axis direction of the exhaust purification member. Furthermore, the number of inlets formed on the side surface of the outer cylinder is not limited to one or two, and may be any number of three or more. In this case, a plurality of inlets may be formed at different positions in the central axis direction of the exhaust purification member.

[0046] (First modification example 1-2) In the first device 1001 illustrated in FIGS. 1 to 3 and the first device 1001a according to the first modification example 1-1 illustrated in FIGS. 4 and 5, the flow direction of the exhaust flowing from the internal space of the collecting pipe toward the first space S1 through one inlet AE and the two inlets AE1 and AE2 formed on the side surface of the outer cylinder 112 is perpendicular to the central axis direction of the exhaust purification member 120. However, in the first device, as long as the entire inlet overlaps with the inner cylinder in the first projection view, the flow direction of the exhaust flowing from the internal space of the collecting pipe toward the first space through the inlet does not necessarily have to be perpendicular to the central axis direction of the exhaust purification member. For example, as illustrated in FIG. 6, the flow direction of the exhaust flowing from the internal space of the collecting pipe toward the first space through the inlet may be inclined at a predetermined angle with respect to the central axis direction of the exhaust purification member.

[0047] FIG. 6 is a schematic cross-sectional view showing an example of the internal structure of an exhaust gas purification device provided in the first device according to Modification 1-2. Specifically, FIG. 6(a) is a schematic cross-sectional view by a plane passing through the central axis of the exhaust gas purification member and the central axis of the inlet, and the branch pipe of the exhaust manifold is omitted. FIG. 6(b) is a schematic view showing an example of a projection view (second projection view) onto a plane passing through the diameter of the exhaust gas purification member 120 and the central axis AX of the exhaust gas purification member 120, which is orthogonal to the flow direction of the exhaust gas flowing from the internal space of the collecting pipe into the first space S1 through the inlet AE in the first device 1001b according to Modification 1-2 illustrated in FIG. 6(a). However, in FIG. 6(b), only the inlet AE and the inner cylinder 111 in the second projection view are drawn for the purpose of easily illustrating the positional relationship between the inlet AE and the inner cylinder 111 in the first device 1001b.

[0048] As illustrated in FIG. 6(a), in the first device 1001b, the angle formed by the flow direction of the exhaust gas flowing from the internal space of the collecting pipe into the first space S1 through the inlet AE and the direction of the central axis AX of the exhaust gas purification member 120 is not perpendicular, but is inclined at a predetermined angle θ. As a result, in the second projection view illustrated in FIG. 6(b), the inlet AE has an elliptical shape instead of a perfect circular shape, but the entire inlet AE overlaps with the inner cylinder 111. Although not shown, even when the flow direction of the exhaust gas and the direction of the central axis AX of the exhaust gas purification member 120 are inclined as illustrated in FIG. 6(a), in the first projection view, which is a projection view in the flow direction of the exhaust gas flowing from the internal space of the collecting pipe into the first space S1 through the inlet AE, the entire inlet AE overlaps with the inner cylinder 111.

[0049] 《Second Embodiment》 Hereinafter, an exhaust device for an internal combustion engine according to the second embodiment of the present invention (hereinafter, may be referred to as the "second device") will be described with reference to the drawings.

[0050] As described above, in the first projection view, which is a projection view in the flow direction of the exhaust gas flowing from the internal space of the collecting pipe of the exhaust manifold toward the first space of the exhaust gas purification device, the entire inlet is configured to overlap with the inner cylinder. Therefore, the exhaust gas flowing from the internal space of the collecting pipe into the first space through the inlet can surely collide with the outer peripheral surface of the inner cylinder. As a result, the influence of pulsating flow in the exhaust gas flow can be reduced, and the inflow of the exhaust gas into the exhaust gas purification member can be further equalized. Further, with the above configuration, the ratio of the exhaust gas that expands to surround the inner cylinder and then expands into the second space among the exhaust gas flowing into the first space can be increased. Therefore, the heat insulation effect of the exhaust gas purification member held inside the inner cylinder and the warm-up effect during cold operation are also enhanced.

[0051] However, from the viewpoint of enhancing the heat insulation effect of the exhaust gas purification member held inside the inner cylinder and the warm-up effect during cold operation, it is preferable that the exhaust gas flowing from the internal space of the collecting pipe into the first space through the inlet collides with the region facing the exhaust gas purification member of the inner cylinder. Further, when a plurality of exhaust gas purification members are accommodated inside the inner cylinder constituting the casing, if the exhaust gas purification member located on the most upstream side in the exhaust gas flow is activated, the downstream exhaust gas purification member can be activated by the high-temperature exhaust gas discharged from the exhaust gas purification member. Therefore, when the exhaust gas flowing from the internal space of the collecting pipe into the first space collides with the outer peripheral surface of the inner cylinder, it is preferable that the exhaust gas collides with the region facing the exhaust gas purification member located on the most upstream side of the inner cylinder.

[0052] <Configuration> Therefore, the second device is the above-described first device, and is an exhaust device for an internal combustion engine, characterized in that in the above-described first projection view, the exhaust gas purification member closest to the second space and the inlet at least partially overlap.

[0053] FIG. 7 is a schematic diagram showing some examples of a vertical projection view (first projection view) in the flow direction of exhaust gas flowing from the internal space of the collecting pipe toward the first space through the inlet in the second device, and is a drawing corresponding to FIG. 3 referred to in the description regarding the first device 1001 described above. However, in FIG. 7, only the inlet, the inner cylinder, and the exhaust gas purification member in the first projection view are drawn for the purpose of easily illustrating the positional relationship among the inlet, the inner cylinder, and the exhaust gas purification member in the second device.

[0054] In the example shown in FIG. 7(a), the entire inlet AE (see the black circle) overlaps both the inner cylinder 111 and the exhaust gas purification member 120. In this case, the heat preservation effect of the exhaust gas purification member 120 held inside the inner cylinder 111 by the high-temperature exhaust gas flowing from the internal space of the collecting pipe (not shown) toward the first space through the inlet AE and the warm-up effect during cold operation can be extremely effectively enhanced. On the other hand, in the examples shown in FIGS. 7(b) and 7(c), although the entire inlet AE (see the black circle) overlaps the inner cylinder 111, the inlet AE and the exhaust gas purification member 120 only partially overlap in the vicinity of the upstream and downstream ends of the exhaust gas purification member 120, respectively. However, even in these cases, compared with the case where the inlet AE and the exhaust gas purification member 120 do not overlap at all in the first projection view, the heat preservation effect of the exhaust gas purification member 120 held inside the inner cylinder 111 and the warm-up effect during cold operation can be more effectively enhanced.

[0055] <Effect> As described above, in the second device, since high-temperature exhaust gas can be made to collide with the region facing the exhaust gas purification member located on the most upstream side of the inner cylinder, the exhaust gas purification member located on the most upstream side can be activated more reliably and quickly. Therefore, even when a plurality of exhaust gas purification members are accommodated inside the inner cylinder constituting the casing, the exhaust gas purification member located on the downstream side can be activated by the high-temperature exhaust gas discharged from the exhaust gas purification member located on the most upstream side. As a result, according to the second device, while equalizing the inflow of exhaust gas to the exhaust gas purification member, improvement in warm-up performance and miniaturization are achieved, and the heat retention effect of the exhaust gas purification member held inside the inner cylinder and the warm-up effect during cold times can be enhanced more effectively.

[0056] (Modification Example 2-1) In the above description of the second device, a configuration in which one exhaust gas purification member is accommodated inside the inner cylinder constituting the casing provided in the exhaust gas purification device has been exemplified. However, as described in the above description regarding the first device, two or more exhaust gas purification members can also be accommodated inside the inner cylinder constituting the casing provided in the exhaust gas purification device. Even when a plurality of exhaust gas purification members are accommodated inside the inner cylinder in this way, the second device is configured such that the exhaust gas purification member closest to the second space in the first projection view and the inlet overlap at least partially.

[0057] FIG. 8 is a schematic diagram showing an example of the configuration of the second device according to Modification Example 2-1. Specifically, FIG. 8(a) is a schematic cross-sectional view taken along a plane passing through the central axis of the exhaust gas purification member and the central axis of the collecting pipe of the exhaust manifold provided in the second device according to Modification Example 2-1. FIG. 8(b) is a schematic diagram showing an example of a vertical projection view (first projection view) in the flow direction of the exhaust gas flowing from the internal space of the collecting pipe toward the first space S1 through the inlet AE in the second device 1002a according to Modification Example 2-1 illustrated in (a). Also in FIG. 8, for the purpose of easily illustrating the positional relationship among the inlet, the inner cylinder, and the exhaust gas purification member in the second device, only the inlet, the inner cylinder, and the exhaust gas purification member in the first projection view are drawn.

[0058] In the second device 1002a illustrated in FIG. 8, an exhaust gas purification member 121 disposed on the upstream side and an exhaust gas purification member 122 disposed on the downstream side are held at predetermined positions inside the inner cylinder 111 by holding members (mats) 131 and 132, respectively. That is, the second device 1002a includes two exhaust gas purification members 121 and 122. And, as illustrated in FIG. 8(b), in the second device 1002a, in the first projection view, each of the two exhaust gas purification members 121 and 122 and the inlet AE partially overlap. Thus, in the second device, a mode in which an exhaust gas purification member other than the exhaust gas purification member closest to the second space S2 (i.e., the most upstream side) in the first projection view overlaps with the inlet is not excluded.

[0059] Next, FIG. 9 is a schematic diagram showing another example of the configuration of the second device according to Modification 2-1. FIGS. 9(a) and 9(b) are drawings corresponding to FIGS. 8(a) and 8(b), respectively, which were referred to in the description of the second device 1002a described above.

[0060] Also in the second device 1002b illustrated in FIG. 9, similar to the second device 1002a described above, an exhaust gas purification member 121 disposed on the upstream side and an exhaust gas purification member 122 disposed on the downstream side are held at predetermined positions inside the inner cylinder 111 by holding members (mats) 131 and 132, respectively. That is, the second device 1002b also includes two exhaust gas purification members 121 and 122. However, as illustrated in FIG. 9(b), in the second device 1002b, in the first projection view, the entire inlet AE overlaps with the most upstream exhaust gas purification member 121, and the downstream exhaust gas purification member 122 and the inlet AE do not overlap at all. Thus, in the second device, a mode in which the inlet overlaps with the exhaust gas purification member closest to the second space S2 (i.e., the most upstream side) in the first projection view but does not overlap with an exhaust gas purification member other than the exhaust gas purification member is not excluded. Also, even in such a mode, as described above with reference to FIGS. 7(b) and 7(c), the most upstream exhaust gas purification member 121 and the inlet AE may partially overlap in the first projection view.

[0061] In the second devices 1002a and 1002b illustrated in FIGS. 8 and 9, both the exhaust purification member 121 disposed on the upstream side and the exhaust purification member 122 disposed on the downstream side are covered not only by the inner cylinder 111 but also by the outer cylinder 112. That is, the first space S1, which is the space between the outer peripheral surface of the inner cylinder 111 and the inner peripheral surface of the outer cylinder 112, is formed not only around the exhaust purification member 121 disposed on the upstream side but also around the exhaust purification member 122 disposed on the downstream side. Such a configuration is preferable from the viewpoint of enhancing the heat retention effect of the exhaust purification member 122 disposed on the downstream side and the warm-up effect during cold operation.

[0062] However, for example, depending on the size of the spatial margin in the engine mounting compartment and / or the type of the exhaust purification member disposed on the downstream side, etc., only the exhaust purification member 121 disposed on the upstream side may be covered by both the inner cylinder 111 and the outer cylinder 112. FIG. 10 is a schematic diagram showing still another example of the configuration of the second device according to Modification 2-1. FIGS. 10(a) and 10(b) are drawings corresponding to FIGS. 9(a) and 9(b), respectively, which were referred to in the description of the above-described second device 1002b. However, in the second device 1002c illustrated in FIG. 10, only the exhaust purification member 121 disposed on the upstream side is covered by both the inner cylinder 111 and the outer cylinder 112, and the exhaust purification member 122 disposed on the downstream side is covered by the inner cylinder 111 but not by the outer cylinder 112. That is, the first space S1, which is the space between the outer peripheral surface of the inner cylinder 111 and the inner peripheral surface of the outer cylinder 112, is formed only around the exhaust purification member 121 disposed on the upstream side and is not formed around the exhaust purification member 122 disposed on the downstream side. Thus, in the second device, a mode in which the exhaust purification members other than the exhaust purification member closest to (i.e., the most upstream side) the second space S2 in the first projection view are not covered by the outer cylinder is not excluded.

[0063] As described above, also in the second apparatuses 1002a to 1002c according to Modification Example 2-1 in which a plurality of exhaust purification members are accommodated inside the inner cylinder, the exhaust purification member closest to the second space in the first projection view and the inlet are configured to at least partially overlap. That is, since the high-temperature exhaust can be made to collide with the region facing the exhaust purification member located on the most upstream side of the inner cylinder, the exhaust purification member located on the most upstream side can be activated more reliably and quickly. Therefore, the exhaust purification member located on the downstream side can be activated by the high-temperature exhaust discharged from the exhaust purification member located on the most upstream side. As a result, while equalizing the inflow of exhaust into the exhaust purification member, improvement in warm-up performance and miniaturization are achieved, and the heat retention effect of the exhaust purification member held inside the inner cylinder and the warm-up effect during cold times can be enhanced more effectively.

[0064] <<Third Embodiment>> Hereinafter, an exhaust device for an internal combustion engine according to the third embodiment of the present invention (hereinafter, may be referred to as the "third device") will be described with reference to the drawings.

[0065] <Configuration> The third device is the first device or the second device described above, and is an exhaust device for an internal combustion engine, characterized in that an outlet portion having an opening formed coaxially with the inner cylinder is provided at an end portion of the inner cylinder on the side opposite to the second space.

[0066] FIG. 11 is a schematic cross-sectional view showing an example of the configuration of the third device. As illustrated in FIG. 11(a), in the third device 1003, an outlet portion 140 having an opening formed coaxially with the inner cylinder 111 is provided at an end portion of the inner cylinder 111 on the side opposite to the second space S2. Moreover, the downstream opening of the outlet portion 140 is formed coaxially with the inner cylinder 111.

[0067] <Effect> As described above, in the third device 1003, an outlet portion 140 formed coaxially with the inner cylinder 111 is provided at the end of the inner cylinder 111 on the side opposite to the second space S2. Therefore, in the third device 1003, uniform discharge of the exhaust gas from the exhaust gas purification member located on the most downstream side can be achieved without disturbing the flow of the exhaust gas from the exhaust gas purification member located on the most downstream side adjacent to the upstream side of the outlet portion 140. As a result, according to the third device 1003, further uniform inflow of the exhaust gas from the second space S2 into the exhaust gas purification member located on the most upstream side is achieved. That is, according to the third device 1003, the inflow of the exhaust gas into the exhaust gas purification member can be made more reliably uniform.

[0068] In addition, as illustrated in FIG. 11(b), a tapered portion that is a portion where the inner diameter gradually decreases from the upstream side to the downstream side may be provided between the small-diameter portion formed at the downstream end of the outlet portion 140 and the portion that houses the exhaust gas purification member 120 of the inner cylinder 111 inside. By providing the tapered portion in this way, the effect of achieving uniform discharge of the exhaust gas from the exhaust gas purification member located on the most downstream side can be further enhanced without disturbing the flow of the exhaust gas from the exhaust gas purification member located on the most downstream side adjacent to the upstream side of the outlet portion 140.

[0069] <<Fourth Embodiment>> Hereinafter, an exhaust device for an internal combustion engine according to a fourth embodiment of the present invention (hereinafter, may be referred to as the "fourth device") will be described with reference to the drawings.

[0070] <Configuration> The fourth device is the aforementioned first device or second device, and the casing further includes a second outer cylinder. The second outer cylinder is a member having a bottomed cylindrical shape and configured to cover the end portion on the side opposite to the second space of the inner cylinder with the bottom side end portion and to externally fit the end portion on the opening side to the outer peripheral surface of the outer cylinder. Alternatively, the second outer cylinder is a member having a container-like shape that houses the exhaust purification member, the inner cylinder, and the outer cylinder therein. Further, inside the casing, a fourth space, which is a gap between the outer peripheral surface of the outer cylinder and the inner peripheral surface of the second outer cylinder, is formed. In addition, an outlet, which is an opening that communicates the fourth space with the outside of the second outer cylinder, is formed at a predetermined position of the second outer cylinder.

[0071] FIGS. 12 and 13 are schematic cross-sectional views illustrating the configuration of the fourth device. Specifically, FIGS. 12 and 13 are schematic cross-sectional views taken along a plane passing through the central axis of the exhaust purification member included in the fourth device and the central axis of the collecting pipe of the exhaust manifold, and illustrate two types of configurations of the fourth device, respectively.

[0072] The second outer cylinder 113 included in the fourth device 1004a illustrated in FIG. 12 has a bottomed cylindrical shape and is configured to cover the end portion on the side opposite to the second space S2 of the inner cylinder 111 with the bottom side end portion and to externally fit the end portion on the opening side to the outer peripheral surface of the outer cylinder 112. On the other hand, the second outer cylinder 113 included in the fourth device 1004b illustrated in FIG. 13 has a container-like shape that houses the exhaust purification member 120, the inner cylinder 111, and the outer cylinder 112 therein.

[0073] The specific configuration of the second outer cylinder 113 is not particularly limited as long as it satisfies the above-described requirements and can withstand the usage environment and usage conditions as an exhaust purification device. Specifically, similar to the inner cylinder 111 and the outer cylinder 112, the second outer cylinder 113 may be configured by a cylindrical member made of a metal material such as stainless steel, or may be configured by a manufacturing method of overlapping a plurality of press-molded members (so-called "mocha manufacturing method"). The size and shape of the second outer cylinder 113 can be appropriately determined according to, for example, the size and shape of the outer cylinder 112 held therein, and the size and shape of the spatial margin in the engine mounting chamber.

[0074] In any configuration, inside the casing 110, a third space S3 is formed between the end portion on the downstream side of the exhaust purification member 120 (the side opposite to the second space S2) and the second outer cylinder 113, and a fourth space S4 is formed between the outer peripheral surface of the outer cylinder 112 and the inner peripheral surface of the second outer cylinder 113. As a result, the exhaust gas that has flowed into the inside of the casing 110 from the internal space SC of the manifold (not shown) through the inlet AE expands from the first space S1 into the second space S2, decelerates, and then flows into the exhaust purification member 120, and flows from the exhaust purification member 120 into the fourth space S4 through the third space S3.

[0075] As described above, at least a part of the casing 110 included in the exhaust purification device 100 that constitutes the fourth devices 1004a and 1004b has a triple structure including the inner cylinder 111, the outer cylinder 112, and the second outer cylinder 113. In the portion having such a triple structure, the fourth space through which the exhaust gas having a relatively low temperature flows covers the outside of the first space S1 or the second space S2 through which the exhaust gas having a relatively high temperature flows. Therefore, for example, effects such as reduction of heat damage to other devices and / or members disposed around the fourth devices 1004a and 1004b can be achieved.

[0076] In addition, an outlet AO, which is an opening that communicates the fourth space S4 with the outside of the second outer cylinder 113, is formed at a predetermined position of the second outer cylinder 113. That is, in the fourth devices 1004a and 1004b, by forming an opening at a desired position of the second outer cylinder 113, an exhaust outlet AO can be formed at the desired position. For example, in the fourth device 1004a illustrated in FIG. 12, the outlet AO is formed on the opposite side of the inlet AE with the exhaust purification member 120 interposed therebetween, and in the fourth device 1004b illustrated in FIG. 13, the outlet AO is formed at a position facing the upstream side (the second space S2 side) end of the exhaust purification member 120. Thus, in the fourth devices 1004a and 1004b, by further providing the casing 110 with the second outer cylinder 113, the degree of freedom in design regarding at least the position of the exhaust outlet AO is increased. Note that although it is also possible to provide an opening so as to communicate the third space S3 with the outside of the second outer cylinder 113 and use it as the outlet AO, from the viewpoint of effectively achieving the effects such as reduction of the above-described heat damage by allowing the exhaust to flow into the fourth space S4, it is preferable to form the outlet AO so as to communicate the fourth space S4 with the outside of the second outer cylinder 113.

[0077] <Effect> As described above, the fourth device further includes a second outer cylinder having a shape configured such that the bottom-side end covers the end of the inner cylinder on the side opposite to the second space and the opening-side end is externally fitted to the outer peripheral surface of the outer cylinder, or having a container-like shape that houses the exhaust purification member, the inner cylinder, and the outer cylinder therein. As a result, a third space is formed between the downstream end of the exhaust purification member and the second outer cylinder, and a fourth space is formed between the outer peripheral surface of the outer cylinder and the inner peripheral surface of the second outer cylinder. Consequently, since at least a part of the casing included in the exhaust purification device has a triple structure composed of the cylinder, the outer cylinder, and the second outer cylinder, it is possible to achieve effects such as reduction of heat damage to other devices and / or members disposed around the fourth device. Further, since an opening can be formed at a desired position of the second outer cylinder to serve as an exhaust outlet, the degree of freedom in design regarding the position of the exhaust outlet is increased.

[0078] <<Fifth Embodiment>> Hereinafter, an exhaust device for an internal combustion engine according to a fifth embodiment of the present invention (hereinafter, may be referred to as the "fifth device") will be described with reference to the drawings.

[0079] As described above, the exhaust device for an internal combustion engine according to the present invention including the first device to the fourth device (the present invention device) is configured such that the entire inlet overlaps with the inner cylinder in a first projection view which is a projection view in the flow direction of the exhaust flowing from the internal space of the collecting pipe toward the first space through the inlet. Therefore, since the ratio of the exhaust that expands to surround the inner cylinder and then expands into the second space among the exhaust flowing into the first space can be increased, the heat retention effect of the exhaust purification member held inside the inner cylinder and the warm-up effect during cold times are enhanced.

[0080] On the other hand, as is well known to those skilled in the art, by disposing a separate exhaust purification device having a relatively small heat capacity upstream of the main exhaust purification device, it is possible to ensure the exhaust purification action during the period until the activation of the main exhaust purification device is completed. However, when such a separate exhaust purification device is added in this way, the size of the entire exhaust device becomes large, and it becomes difficult to accommodate the exhaust device in the limited space in the engine mounting chamber (engine compartment).

[0081] <Configuration> Therefore, the fifth device is any one of the first device to the fourth device described above, and is an exhaust device for an internal combustion engine, characterized in that it further includes a start catalyst which is an exhaust purification member in which a complex of metal fibers carrying an exhaust purification catalyst is wound around the outer peripheral surface of the inner cylinder.

[0082] As the exhaust purification catalyst constituting the start catalyst, an exhaust purification catalyst suitable for removing and / or detoxifying specific substances contained in the exhaust discharged from the internal combustion engine during the period until the activation of the exhaust purification member held inside the inner cylinder is completed is appropriately selected. Specific examples of such an exhaust purification catalyst include, for example, a hydrocarbon trap catalyst and a NOx storage and release catalyst, but are not limited thereto. Further, as the metal fiber constituting the complex carrying the exhaust purification catalyst, a metal fiber capable of withstanding the use environment of the fifth device is appropriately selected. Since the heat capacity of the complex of the metal fibers is sufficiently smaller than the heat capacity of the exhaust purification member held inside the inner cylinder, the start catalyst can be rapidly heated by the exhaust flowing into the first space through the inlet. Specific examples of such a complex include, for example, a wire mesh made of metal having high thermal conductivity, but are not limited thereto. The start catalyst is preferably at least partially fixed to the outer peripheral surface of the inner cylinder by means such as welding so as not to fall off from the outer peripheral surface of the inner cylinder during use.

[0083] FIG. 14 is a schematic cross-sectional view illustrating the configuration of the fifth device. Specifically, FIG. 14 is a schematic cross-sectional view taken along a plane passing through the central axis of the exhaust purification member provided in the fifth device and the central axis of the collecting pipe of the exhaust manifold.

[0084] The fifth device 1005 illustrated in FIG. 14 has the same configuration as the exhaust device (first device) of the internal combustion engine according to the first embodiment of the present invention described with reference to FIGS. 1 to 3, except that it further includes a start catalyst 300 which is an exhaust purification member in which a complex of metal fibers carrying an exhaust purification catalyst (not shown) is wound around the outer peripheral surface of the inner cylinder 111. Therefore, similar to the first device, the exhaust that has gathered into the internal space of the collecting pipe of the exhaust manifold through the exhaust port of the internal combustion engine (not shown) flows from the internal space into the first space S1 through the inlet AE. At least a part of the exhaust flowing into the first space S1 spreads so as to surround the inner cylinder 111, heats the inner cylinder 111 itself, and can enhance the heat retention effect of the exhaust purification member 120 held inside the inner cylinder 111 and the warm-up effect during cold start.

[0085] In the fifth device 1005, as described above, since the start catalyst 300, which is an exhaust purification member composed of a complex of metal fibers supporting an exhaust purification catalyst, is wound around the outer peripheral surface of the inner cylinder 111, the start catalyst 300 is rapidly heated by heat conduction from the heated inner cylinder 111 as described above. That is, the start catalyst 300 can be activated before the activation of the exhaust purification member 120 held inside the inner cylinder 111 is completed.

[0086] In addition, from the viewpoint of activating the start catalyst 300 more rapidly, as illustrated in FIG. 14, in the first projection view, which is a projection view in the flow direction of the exhaust flowing from the internal space of the collecting pipe toward the first space S1 through the inlet AE, it is preferable that at least a part of the inlet AE overlaps with the start catalyst 300. Thereby, since at least a part of the exhaust flowing from the internal space of the collecting pipe toward the first space S1 through the inlet AE directly touches the portion of the start catalyst 300 facing the inlet AE, the start catalyst 300 can be activated more rapidly.

[0087] <Effect> As described above, the fifth device further includes a start catalyst, which is an exhaust purification member in which a complex of metal fibers supporting an exhaust purification catalyst is wound around the outer peripheral surface of the inner cylinder. Thereby, the start catalyst can be activated earlier than the exhaust purification member held inside the inner cylinder. As a result, it is possible to surely remove and / or detoxify specific substances (initial emissions) contained in the exhaust discharged from the internal combustion engine during the period until the activation of the exhaust purification member held inside the inner cylinder is completed. Needless to say, after the activation of the exhaust purification member held inside the inner cylinder is completed, the exhaust purification member held inside the inner cylinder can remove and / or detoxify specific substances contained in the exhaust.

Example

[0088] The exhaust device of an internal combustion engine according to the first embodiment of the present invention (hereinafter sometimes referred to as the "first embodiment device") will be described in detail below with reference to the drawings.

[0089] FIG. 15 is a schematic perspective view of the first embodiment device, FIG. 16 is a schematic top view of the first embodiment device, FIG. 17 is a schematic right side view of the first embodiment device, and FIG. 18 is a schematic front view of the first embodiment device. Further, FIG. 19 is a schematic view when observing the first embodiment device from the flow direction of the exhaust flowing from the internal space of the collecting pipe toward the first space through the inlet, and FIG. 20 is a schematic left side view of the first embodiment device.

[0090] As illustrated in FIGS. 15 to 20, the first embodiment device 1011 is an exhaust manifold integrated exhaust purification device (exhaust treatment unit) integrally configured with an exhaust manifold (hereinafter sometimes abbreviated as "exhaust mani"). Such an exhaust purification device is also referred to as a "maniverter". The first embodiment device 1011 is attached to the side surface of a cylinder head of an in-line four-cylinder internal combustion engine (not shown) via a head flange of the exhaust manifold 200. However, of course, the type of the internal combustion engine to which the exhaust device of the internal combustion engine according to the present invention (the present invention device) is applied is not limited to the in-line four-cylinder type, and the present invention device can be applied to internal combustion engines having various numbers of cylinders and cylinder layouts, such as two cylinders, in-line six cylinders, and V-type six cylinders.

[0091] Also, in the exhaust manifold 200 provided in the first embodiment apparatus 1011, a portion corresponding to the collecting pipe of the exhaust manifold 200 is constituted by a collecting chamber 230 and a connecting pipe 240. The collecting chamber 230 is a member that defines a space where the exhaust flowing in from the four branch pipes 220 collects (merges). The connecting pipe 240 is a member that connects the collecting chamber 230 to an inlet formed in an outer cylinder that constitutes the casing 110 of the exhaust purification apparatus 100. As described in the explanation regarding the exhaust apparatus (first apparatus) of the internal combustion engine according to the first embodiment of the present invention, in this specification, the term "collecting pipe" does not refer only to a tubular member such as the collecting pipe of a general exhaust manifold, but widely includes a member that defines a space where the exhaust flowing inside the branch pipes in the exhaust manifold collects (merges) and becomes integrated. For example, when an internal combustion engine is provided with a supercharger such as a turbocharger or the like on the downstream side of the collecting pipe of the exhaust manifold, the outlet portion of the exhaust from the supercharger is regarded as the collecting pipe, and the casing and the outlet portion can be connected so that the internal space of the outlet portion and the first space communicate with each other through an inlet, which is an opening formed in the side surface of the outer cylinder.

[0092] In the exhaust manifold 200 included in the first embodiment apparatus 1011, a so-called "4-1" layout in which all four branch pipes 220 are directly connected to the collector chamber 230 was adopted. However, the layout of the portion corresponding to the collecting pipe of the exhaust manifold 200 is not limited to the above. Although not shown, for example, a layout in which a plurality of branch pipes partially merge and finally merge into one, such as a so-called "4-2-1" layout in which two of the four branch pipes 220 merge into two merged pipes formed by merging two by two and then these two merged pipes further merge into one, may be adopted. Alternatively, two merged pipes formed by merging two of the four branch pipes 220 into one each may be connected to two inlets AE1 and AE2 formed at different positions, for example, as in the first apparatus 1001a or the first apparatus 1001b illustrated in FIG. 4 or FIG. 5. Furthermore, in this specification, the term "exhaust manifold" is not limited to a general exhaust manifold connected to the outside of the internal combustion engine. For example, a so-called "collecting port" in which exhaust ports from a plurality of cylinders merge inside the engine head is also included in the exhaust manifold constituting the apparatus of the present invention.

[0093] As described above, the casing 110 includes an inner cylinder which is a cylindrical member that holds an exhaust purification member (not shown) inside, and an outer cylinder which has a bottomed cylindrical shape and the end portion on the opening side is externally fitted to the inner cylinder so as to cover at least a part of the exhaust purification member. In the exhaust purification apparatus 100 included in the first embodiment apparatus 1011, the exhaust purification member has a cylindrical shape, the inner cylinder and the outer cylinder have a substantially cylindrical shape, and these three components are arranged coaxially. Also, in the first embodiment apparatus 1011, the crankshaft of the internal combustion engine and the central axis of the exhaust purification member are arranged so as to be substantially parallel to each other.

[0094] Furthermore, as shown in FIGS. 16 and 19, the axial direction of the exhaust pipe 160, which is a member defining a flow path for guiding the exhaust discharged from the exhaust purification device 100 to another device or the like located on the downstream side, is perpendicular to the axial direction of the exhaust purification member in a plan view. Such an arrangement is suitable, for example, in a layout where the internal combustion engine is arranged in a so-called "transverse" manner in an FF (front engine · front drive) vehicle and the exhaust is guided rearward of the vehicle. In addition, as shown in FIGS. 17 and 20, the exhaust pipe 160 is configured to incline downward by a predetermined angle (θ) with respect to the horizontal.

[0095] However, the arrangement of the exhaust purification member and the exhaust pipe with respect to the internal combustion engine can be appropriately determined according to the layout of the internal combustion engine, the exhaust system, etc. in the vehicle on which the exhaust device (the device of the present invention) according to the present invention is mounted. For example, the direction of the crankshaft of the internal combustion engine and the axial direction of the exhaust purification member may not be parallel, and the angle formed by the two may be a predetermined angle such as a right angle. Also, the angles formed by the axial direction of the exhaust purification member and the horizontal direction in a plan view and the axial direction of the exhaust pipe 160 can also be appropriately determined.

[0096] FIG. 21 is a schematic view showing the first embodiment device 1011 cut by a plane passing through the straight line A - A drawn in FIG. 19 and the straight line B - B drawn in FIG. 20. As shown in FIG. 21, inside the casing 110, a first space S1, which is a gap between the outer peripheral surface of the inner cylinder 111 and the inner peripheral surface of the outer cylinder 112, and a second space S2, which is a space between the end of the inner cylinder 111 and the bottom of the outer cylinder 112, are formed. Furthermore, the casing 110 and the exhaust manifold 200 are connected so that the internal space SC of the collecting pipe of the exhaust manifold 200 and the first space S1 communicate with each other through an inlet AE, which is an opening formed on the side surface of the outer cylinder 112.

[0097] With the above configuration, in the apparatus 1011 of the first embodiment, by expanding the exhaust gas that has flowed into the interior of the casing 110 from the internal space SC of the collecting pipe through the inlet AE from the first space S1 to the second space S2, the flow velocity of the exhaust gas can be effectively reduced. As a result, the inflow of the exhaust gas that flows into the interior of the inner cylinder 111 from the second space S2 and reaches the end on the upstream side (the first space S1 side) of the exhaust gas purification member 120 can be made uniform (the surface contact per unit area of the exhaust gas against the end face on the upstream side of the exhaust gas purification member 120 is made uniform to improve the uniformity of the flow velocity and / or pressure of the exhaust gas).

[0098] In addition, in the first projection view, which is a projection view in the flow direction of the exhaust gas flowing into the first space S1 from the internal space SC of the collecting pipe of the exhaust manifold 200 through the inlet AE, the entire inlet AE is configured to overlap with the inner cylinder 111 in the apparatus 1011 of the first embodiment.

[0099] Therefore, in the apparatus 1011 of the first embodiment, as can be seen from FIG. 21, the exhaust gas that has flowed into the first space S1 from the internal space SC of the collecting pipe of the exhaust manifold 200 through the inlet AE can be surely made to collide with the outer peripheral surface of the inner cylinder 111. As a result, according to the apparatus 1011 of the first embodiment, the influence of pulsating flow in the exhaust gas flow can be reduced, and the inflow of the exhaust gas into the exhaust gas purification member 120 can be made even more uniform. Further, with the above configuration, as described with reference to FIG. 2, the ratio of the exhaust gas that expands so as to surround the inner cylinder 111 among the exhaust gas that has flowed into the first space S1 and then expands into the second space 112 can be increased, so that the heat insulation effect of the exhaust gas purification member 120 held inside the inner cylinder 111 and the warm-up effect during cold operation are also enhanced. These effects are particularly effective when the exhaust gas purification member 120 is an exhaust gas purification catalyst.

[0100] As described above, according to the apparatus of the first embodiment, it is possible to achieve improvement and miniaturization of warm-up performance while equalizing the inflow of exhaust gas into the exhaust purification member. Note that the apparatus 1011 of the first embodiment illustrated in FIGS. 15 to 21 includes the EGR pipe 150, but the EGR pipe is not an essential component in the exhaust apparatus (the apparatus of the present invention) of the internal combustion engine according to the present invention, and whether or not to adopt the EGR pipe is determined according to the specifications of the vehicle on which the apparatus of the present invention is mounted.

Embodiment

[0101] Next, an exhaust apparatus for an internal combustion engine according to a second embodiment of the present invention (hereinafter sometimes referred to as the "apparatus of the second embodiment") will be described in detail below with reference to the drawings.

[0102] FIG. 22 is a schematic perspective view of the apparatus of the second embodiment, FIG. 23 is a schematic top view of the apparatus of the second embodiment, FIG. 24 is a schematic left side view of the apparatus of the second embodiment, and FIG. 25 is a schematic front view of the apparatus of the second embodiment. Further, FIG. 26 is a schematic view showing the apparatus of the second embodiment cut by a plane passing through the straight line C-C drawn in FIG. 25.

[0103] As illustrated in FIGS. 22 to 26, the apparatus 1012 of the second embodiment has the same configuration as the apparatus 1011 of the first embodiment described above, except that the angle formed by the direction of the crankshaft of the internal combustion engine and the axial direction of the exhaust purification member is substantially a right angle, and the outlet portion 140 having an opening formed coaxially with the inner cylinder 111 is provided at the end portion of the inner cylinder 111 on the side opposite to the second space S2.

[0104] Therefore, also in the second embodiment apparatus 1012, similar to the first embodiment apparatus 1011 described above, by expanding the exhaust gas that has flowed into the interior of the casing 110 from the internal space SC of the collecting pipe through the inlet AE from the first space S1 to the second space S2, the flow velocity of the exhaust gas can be effectively reduced. As a result, the inflow of the exhaust gas that has flowed into the interior of the inner cylinder 111 from the second space S2 and reached the end on the upstream side (the first space S1 side) of the exhaust gas purification member 120 can be made uniform (the surface contact of the exhaust gas with the upstream end face of the exhaust gas purification member 120 is made uniform to improve the flow velocity and / or the degree of pressure of the exhaust gas).

[0105] Further, as can be seen from FIG. 26, in the second embodiment apparatus 1012, the exhaust gas that has flowed into the first space S1 from the internal space SC of the collecting pipe of the exhaust manifold 200 through the inlet AE can be surely made to collide with the outer peripheral surface of the inner cylinder 111. As a result, according to the second embodiment apparatus 1012, the influence of pulsating flow in the exhaust gas flow can be reduced, and the inflow of the exhaust gas to the exhaust gas purification member 120 can be made even more uniform. Further, with the above configuration, as described with reference to FIG. 2, the ratio of the exhaust gas that expands so as to surround the inner cylinder 111 among the exhaust gas that has flowed into the first space S1 and then expands to the second space S2 can be increased. Therefore, the heat insulation effect of the exhaust gas purification member 120 held inside the inner cylinder 111 and the warm-up effect during cold operation are also enhanced. These effects are particularly effective when the exhaust gas purification member 120 is an exhaust gas purification catalyst.

[0106] As described with reference to FIG. 6 in the description of Modification 1-2 of the first embodiment of the present invention, the angle formed by the exhaust flow direction flowing from the internal space SC of the collecting pipe toward the first space S1 through the inlet AE and the axial direction of the exhaust purification member 120 does not necessarily have to be perpendicular, and may be inclined at a predetermined angle θ. As shown in FIGS. 24 and 26, in the second embodiment apparatus 1012, unlike the above-described first embodiment apparatus 1011, the angle formed by the exhaust flow direction flowing from the internal space SC of the collecting pipe (collecting chamber 230 and connecting pipe 240) toward the first space S1 through the inlet AE and the axial direction of the exhaust purification member 120 is an obtuse angle. Thus, the angle formed by the exhaust flow direction flowing from the internal space SC toward the first space S1 and the axial direction of the exhaust purification member 120 can also be appropriately determined according to the layout of the internal combustion engine and the exhaust system, etc. in the vehicle on which the apparatus of the present invention is mounted, as long as the predetermined positional relationship between the inlet and the inner cylinder in the first projection view or the inlet, the inner cylinder, and the exhaust purification member located most upstream is satisfied.

[0107] As described above, also in the second embodiment apparatus 1012, similar to the above-described first embodiment apparatus 1011, it is possible to achieve improvement in warm-up performance and miniaturization while equalizing the inflow of exhaust gas into the exhaust purification member. The second embodiment apparatus 1012 illustrated in FIGS. 22 to 26 also includes the EGR pipe 150 in the same manner as the above-described first embodiment apparatus 1011. However, as described above, the EGR pipe is not an essential component in the apparatus of the present invention, and whether or not to include the EGR pipe is determined according to the specifications of the vehicle on which the apparatus of the present invention is mounted.

[0108] Also, in the exhaust manifold 200 provided in the second embodiment apparatus 1012, similar to the first embodiment apparatus 1011 described above, a so-called "4-1" layout in which all four branch pipes 220 are directly connected to the collecting chamber 230 was adopted. However, the layout of the portion corresponding to the collecting pipe of the exhaust manifold 200 is not limited to the above. For example, as in the second embodiment apparatus 1012a illustrated in FIG. 27(a), a layout in which the four branch pipes 220 merge sequentially one by one and finally become one merging pipe 250 may be used. In this case, the merging pipe 250 also functions as the collecting chamber 230 and the connecting pipe 240.

[0109] Also, although not shown, for example, a layout in which a plurality of branch pipes partially merge and finally become one merging pipe, such as a so-called "4-2-1" layout in which two of the four branch pipes 220 merge into one respectively and then the two resulting merging pipes further merge into one, may be adopted. Alternatively, for example, as in the second embodiment apparatus 1012b illustrated in FIG. 27(b), the two merging pipes 250 formed by merging two of the four branch pipes 220 into one respectively may be connected to two inlets AE1 and AE2 formed at different positions, as in the first apparatus 1001a or the first apparatus 1001b illustrated in FIG. 4 or FIG. 5.

Embodiment

[0110] In the description of the exhaust devices (the first device to the fourth device) of the internal combustion engine according to the first to fourth embodiments of the present invention described above, and the exhaust devices (the first embodiment device and the second embodiment device) of the internal combustion engine according to the first and second embodiments of the present invention, the case where each exhaust device of the internal combustion engine includes one exhaust purification device 100 has been described. However, the number of exhaust purification devices included in the exhaust device of the internal combustion engine according to the present invention (the present invention device) is not limited to one, and the present invention device can include two or more exhaust purification devices. Also, when the present invention device includes two or more exhaust purification devices, these exhaust purification devices can be arranged in various positional relationships.

[0111] Therefore, several specific examples of the exhaust device of the internal combustion engine according to the third embodiment of the present invention (hereinafter may be referred to as the "third embodiment device") will be described in detail below with reference to the drawings.

[0112] FIG. 28 is a schematic perspective view showing an example of the configuration of a third embodiment device according to one aspect of the third embodiment of the present invention. Further, FIG. 29(a) is a schematic front view of the third embodiment device illustrated in FIG. 28, (b) is a schematic top view, and (c) is a schematic right side view.

[0113] As illustrated in FIGS. 28 and 29, the third embodiment device 1013a is an exhaust device of an internal combustion engine configured by two exhaust purification devices 101 and 102 connected in series and an exhaust manifold 200. The portion from the exhaust manifold 200 to the exhaust purification device 101 disposed upstream in the third embodiment device 1013a has the same configuration as the portion from the exhaust manifold 200 to the exhaust purification device 100 in the first embodiment device 1011 described with reference to FIGS. 15 to 21. That is, the exhaust purification device 101 disposed upstream is arranged such that the crankshaft of the internal combustion engine (not shown) and the central axis of the exhaust purification member are substantially parallel to each other. Hereinafter, such an arrangement of the exhaust purification device is referred to as "horizontally placed".

[0114] On the other hand, in the portion downstream of the exhaust purification device 101, the third embodiment device 1013a has a configuration different from that of the first embodiment device 1011. In the first embodiment device 1011, the discharge pipe 160, which is a member defining a flow path for guiding the exhaust discharged from the exhaust purification device 100 to other devices or the like located downstream, is provided so as to extend perpendicular to the axial direction of the exhaust purification member. In contrast, in the third embodiment device 1013a, another exhaust purification device 102 is disposed downstream of the exhaust purification device 101, and a connection portion 170, which is a member defining a flow path for guiding the exhaust discharged from the exhaust purification device 101 to the exhaust purification device 102, is provided between the exhaust purification device 101 and the exhaust purification device 102.

[0115] Unlike the upstream exhaust purification device 101, the downstream exhaust purification device 102 is arranged such that the angle formed by the direction of the crankshaft of the internal combustion engine (not shown) and the axial direction of the exhaust purification member is substantially a right angle. Hereinafter, such an arrangement of the exhaust purification device will be referred to as "vertically installed". That is, in the third embodiment device 1013a, the upstream exhaust purification device 101 is arranged "horizontally installed", and the downstream exhaust purification device 102 is arranged "vertically installed".

[0116] Next, FIG. 30 is a schematic perspective view showing an example of the configuration of a third embodiment device according to another aspect of the third embodiment of the present invention. Also, FIG. 31(a) is a schematic front view of the third embodiment device illustrated in FIG. 30, (b) is a schematic top view, (c) is a schematic right side view, and (d) is a schematic cross-sectional view taken along the straight line A-A drawn in (a) and a plane passing through the central axis of the exhaust purification member provided in the third embodiment device.

[0117] As illustrated in FIGS. 30 and 31, the third embodiment device 1013b is also an exhaust device of an internal combustion engine configured by two exhaust purification devices 101 and 102 connected in series and an exhaust manifold 200, similar to the above-described third embodiment device 1013a. However, the portion from the exhaust manifold 200 to the upstream exhaust purification device 101 disposed in the third embodiment device 1013b has the same configuration as the portion from the exhaust manifold 200 to the exhaust purification device 100 in the second embodiment device 1012 described with reference to FIGS. 22 to 26, unlike the third embodiment device 1013a. That is, the upstream exhaust purification device 101 is arranged such that the angle formed by the direction of the crankshaft of the internal combustion engine (not shown) and the axial direction of the exhaust purification member is substantially a right angle, i.e., "vertically installed".

[0118] However, as described above, the portion corresponding to the header pipe of the exhaust manifold 200 that constitutes the second embodiment apparatus 1012 is constituted by the collecting chamber 230 and the connecting pipe 240, whereas the portion corresponding to the header pipe of the exhaust manifold 200 that constitutes the third embodiment apparatus 1013b is configured such that the four branch pipes 220 merge one by one sequentially and finally form one merging pipe 250.

[0119] On the other hand, in the portion downstream of the exhaust purification apparatus 101, the third embodiment apparatus 1013b has a configuration different from that of the second embodiment apparatus 1012. In the second embodiment apparatus 1012, an outlet portion 140 having an opening formed coaxially with the inner cylinder 111 of the exhaust purification apparatus 100 was provided downstream of the exhaust purification apparatus 100. In contrast, in the third embodiment apparatus 1013b, another exhaust purification apparatus 102 is directly connected downstream of the exhaust purification apparatus 101, and an outlet portion 140 having an opening formed coaxially with an inner cylinder (not shown) of the exhaust purification apparatus 102 is provided downstream of the exhaust purification apparatus 102.

[0120] Note that the downstream exhaust purification apparatus 102 is arranged in the same manner as the upstream exhaust purification apparatus 101 such that the angle formed by the direction of the crankshaft of the internal combustion engine (not shown) and the axial direction of the exhaust purification member is substantially a right angle, i.e., in a "vertically arranged" state. That is, in the third embodiment apparatus 1013b, both the upstream exhaust purification apparatus 101 and the downstream exhaust purification apparatus 102 are arranged in a "vertically arranged" state.

[0121] However, the arrangement of each exhaust purification device in the device of the present invention equipped with two or more exhaust purification devices is not limited to the above-described third embodiment devices 1013a and 1013b. Although not shown, for example, both the upstream exhaust purification device 101 and the downstream exhaust purification device 102 may be arranged "horizontally". Alternatively, the upstream exhaust purification device 101 may be arranged "vertically" and the downstream exhaust purification device 102 may be arranged "horizontally". Furthermore, the device of the present invention may be equipped with three or more exhaust purification devices, and each exhaust purification device may be configured to be selected from the group consisting of "horizontal", "vertical", and other arrangements that are neither "horizontal" nor "vertical".

[0122] As described above, for the purpose of explaining the present invention, several embodiments, modifications, and examples having specific configurations have been described with reference to the accompanying drawings at times. However, the scope of the present invention should not be construed as being limited to these exemplary embodiments, modifications, and examples, and it goes without saying that appropriate modifications can be made within the scope of the matters described in the claims and the specification.

[0123] In addition, when the exhaust device of the internal combustion engine according to the present invention is applied to an internal combustion engine mounted on a vehicle, the mounting position of the internal combustion engine in the vehicle is not particularly limited, and it may be, for example, near the front wheels, near the rear wheels, or anywhere between the front wheels and the rear wheels. Also, the fuel used in the internal combustion engine is not particularly limited either, and it may be, for example, gasoline, light oil, hydrogen, or other alternative fuels. Furthermore, the power source of the vehicle does not necessarily have to be an internal combustion engine alone, and it may be, for example, an internal combustion engine combined with an electric device (motor / generator).

Explanation of Reference Numerals

[0124] 1001, 1001a, 1001b, 1002a, 1002b, 1002c, 1003, 1004a, 1004b, 1005, 1011, 1012, 1013a, 1013b... Exhaust devices of internal combustion engines 100... Exhaust purification devices 110... Casing 111…Inner cylinder 112…Outer cylinder 113…Second outer cylinder 120, 121, 122…Exhaust purification member 130, 131, 132…Holding member 140…Outlet part 150…EGR pipe 160…Exhaust pipe 170…Connection part 200…Exhaust manifold 210…Cylinder head 220…Branch pipe 230…Collecting chamber 240…Connecting pipe 250…Confluence pipe 300…Start catalyst SC…Internal space of the collecting pipe of the exhaust manifold S1…First space S2…Second space S3…Third space S4…Fourth space AE, AE1, AE2…Inlet AO…Outlet F1, F2, F3…Exhaust flow

Claims

1. An exhaust gas purification device including a casing and one or more exhaust gas purification members housed inside the casing, and an exhaust manifold, which constitutes an exhaust device of an internal combustion engine, The exhaust manifold has a collecting pipe which is a member that defines a space where the exhaust gases flowing inside the branch pipes merge and become integrated, The casing includes an inner cylinder which is a cylindrical member that holds the exhaust gas purification member inside, and an outer cylinder which has a bottomed cylindrical shape and whose end on the opening side is externally fitted to the inner cylinder so as to cover at least a part of the exhaust gas purification member, Inside the casing, A first space which is a gap between the outer peripheral surface of the inner cylinder and the inner peripheral surface of the outer cylinder, A second space which is a space between the end of the inner cylinder and the bottom of the outer cylinder, are formed, The casing and the exhaust manifold are connected such that the internal space of the collecting pipe and the first space communicate with each other through an inlet which is an opening formed on the side surface of the outer cylinder, In a first projection view which is a perpendicular projection view of the exhaust gas flowing from the internal space of the collecting pipe toward the first space through the inlet, the entire inlet overlaps with the outer peripheral surface of the inner cylinder, In the first projection view, the exhaust gas purification member closest to the second space and the inlet at least partially overlap, The casing is a member having a bottomed cylindrical shape and configured such that the end on the side opposite to the second space of the inner cylinder is covered by the end on the bottom side and the end on the opening side is externally fitted to the outer peripheral surface of the outer cylinder, or further includes a second outer cylinder which is a member having a container-like shape that houses the exhaust gas purification member, the inner cylinder, and the outer cylinder inside, Inside the casing, a fourth space which is a gap between the outer peripheral surface of the outer cylinder and the inner peripheral surface of the second outer cylinder is formed, An outlet which is an opening that communicates the fourth space and the outside of the second outer cylinder is formed at a predetermined position of the second outer cylinder, An exhaust device for an internal combustion engine, characterized by the following.

2. An exhaust device for an internal combustion engine, comprising an exhaust purification device including a casing and one or more exhaust purification members housed inside the casing, and an exhaust manifold, wherein: the exhaust manifold has a collecting pipe which is a member that defines a space where the exhaust flowing inside the branch pipes merges and becomes integrated; the casing includes an inner cylinder which is a cylindrical member that holds the exhaust purification member inside, and an outer cylinder which has a bottomed cylindrical shape and whose end on the opening side is externally fitted to the inner cylinder so as to cover at least a part of the exhaust purification member; inside the casing, a first space which is a gap between the outer peripheral surface of the inner cylinder and the inner peripheral surface of the outer cylinder, and a second space which is a space between the end of the inner cylinder and the bottom of the outer cylinder, are formed; the casing and the exhaust manifold are connected such that the internal space of the collecting pipe and the first space communicate with each other through an inlet which is an opening formed on the side surface of the outer cylinder; in a first projection view which is a vertical projection view of the exhaust flow direction from the internal space of the collecting pipe toward the first space through the inlet, the entire inlet overlaps with the outer peripheral surface of the inner cylinder; in the first projection view, the exhaust purification member closest to the second space and the inlet at least partially overlap; further comprising a start catalyst which is an exhaust purification member in which a complex of metal fibers carrying an exhaust purification catalyst is wound around the outer peripheral surface of the inner cylinder. An exhaust device for an internal combustion engine, characterized by the above.

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