JP2021076023A - Exhaust system - Google Patents

Abstract

To provide a technology that can suppress generation of deposit that is generated from a low-temperature exhaust gas by mixing the low-temperature exhaust gas with a high-temperature exhaust gas.SOLUTION: An exhaust system (10) includes: a heat exchanger (20) including a first pipe (50) for evacuating a low-temperature exhaust gas cooled by a cooling medium; a second pipe (60) for evacuating a high-temperature exhaust gas; and a merging part (40) including a merging space (70) where the low-temperature exhaust gas merges with the high-temperature exhaust gas. The merging space (70) is provided with: an obstruction part (80) for obstructing a flow of the low-temperature exhaust gas and a flow of the high-temperature exhaust gas; and a mixing space (71) for mixing the low-temperature exhaust gas and the high-temperature exhaust gas, which are stagnated by the obstruction part (80), with each other.SELECTED DRAWING: Figure 4

Description

The present invention relates to an exhaust device in which exhaust gas flows inside.

Regarding heat exchangers in which exhaust gas flows inside, an exhaust recirculation device is known as a technique for reducing NOx of exhaust gas of an internal combustion engine and improving fuel efficiency by taking out a part of exhaust gas and reintroducing it into intake air. ..

7 (a) and 7 (b) are obtained by schematically reprinting the figure of Patent Document 1 and reassigning the reference numerals. The exhaust gas recirculation device 100 (exhaust device) is an EGR (Exhaust) that divides the exhaust gas flowing from the upstream into two and flows the exhaust gas to the downstream, and connects to the branch pipe 101 to cool the exhaust gas passing through the inside. Gas Recirculation) The cooler 102, the bypass pipe 103 that connects to the branch pipe 101 and diverts the exhaust gas passing through the inside from the EGR gas cooler 102, the flow of the exhaust gas that has passed through the EGR cooler 102, and the exhaust gas that has passed through the bypass pipe 103. It has a switching mechanism 104 that switches the flow of gas.

See FIG. 7 (b). The switching mechanism 104 includes a first inlet 105 communicating with the downstream end of the EGR cooler 102, a second inlet 106 communicating with the downstream end of the bypass pipe 103, and a valve rotating about the rotation shaft 104a. It has 104b and an outlet 107.

The flow of the exhaust gas is switched according to the opening degree of the valve 104b. Specifically, the switching mechanism 104 has an exclusive form in which either the exhaust gas cooled by passing through the EGR cooler 102 or the high-temperature exhaust gas passing through the bypass pipe 103 flows downstream, and the EGR cooler. It includes a confluence form in which both the exhaust gas that has passed through the 102 and the exhaust gas that has passed through the bypass pipe 103 flow to the downstream side.

Patent Document 2 discloses that when exhaust gas cooled to a predetermined temperature or lower recirculates, components such as particulate matter and unburned hydrocarbons contained in the exhaust are deposited in a solid state in the exhaust device. Has been done. If the amount of deposits increases in the exhaust system, the flow of exhaust gas deteriorates and the sealing performance of the valve 104b deteriorates. However, the formation of deposits can be suppressed by increasing the temperature of the exhaust gas.

Japanese Unexamined Patent Publication No. 2010-31707 Patent No. 5896955

When the switching mechanism 104 of Patent Document 1 is in the confluence form, the exhaust gas that has passed through the EGR cooler 102 and cooled and the exhaust gas that has passed through the bypass pipe 103 and remains at a high temperature are on the downstream side of the switching mechanism 104. They merge in the confluence space 108 and mix with each other. Of the low-temperature exhaust gas, the region near the boundary with the high-temperature exhaust gas is heated, but other parts are difficult to heat. If the high-temperature exhaust gas and the low-temperature exhaust gas are surely mixed with each other, the formation of deposits can be suppressed.

An object of the present invention is to provide a technique capable of suppressing the formation of deposits generated from low-temperature exhaust gas by mixing low-temperature exhaust gas and high-temperature exhaust gas.

A first aspect of the present invention includes a heat exchanger including a first pipe for discharging the low-temperature exhaust gas cooled by the cooling medium.
A second pipe that discharges a high-temperature exhaust gas that is hotter than the low-temperature exhaust gas,
In an exhaust device having a confluence portion including a confluence space in which the low-temperature exhaust gas and the high-temperature exhaust gas merge, and a discharge port for discharging the merged low-temperature exhaust gas and the high-temperature exhaust to the outside.
The confluence space is provided with an obstacle portion that obstructs the flow of the low temperature exhaust gas and the flow of the high temperature exhaust gas, and a mixing space in which the low temperature exhaust gas and the high temperature exhaust gas retained by the obstacle portion are mixed with each other. It is an exhaust system characterized by being used.

As described in claim 2, preferably, the confluence space is provided with an induction portion that guides either the low-temperature exhaust gas or the high-temperature exhaust gas toward the other gas.

As described in claim 3, the obstacle portion is a plate-shaped member, and a part of the obstacle portion is overlapped with the inner surface of the confluence portion.

As described in claim 4, the center line of the first pipe is set as the first center line, the center line of the second pipe is set as the second center line, and the first center line and the second center line are set. If the center line at the same distance from the center line of is the third center line,
With reference to the third center line, the outlet of the mixing space is offset to the second pipe side, and the discharge port of the merging portion is offset to the second pipe side.

According to claim 1, the exhaust device includes a first pipe for discharging low-temperature exhaust gas, a second pipe for discharging high-temperature exhaust gas, and a confluence space where low-temperature exhaust gas and high-temperature exhaust gas merge. The confluence space is provided with an obstacle portion that obstructs the flow of the low-temperature exhaust gas and the high-temperature exhaust gas, and a mixing space in which the low-temperature exhaust gas and the high-temperature exhaust gas retained by the obstacle portion are mixed with each other. That is, the low-temperature exhaust gas that has flowed into the confluence space and the high-temperature exhaust gas are mixed with each other by being blocked by an obstacle and staying in the mixing space before being discharged from the exhaust port of the exhaust device. The low temperature gas is easily heated by the high temperature gas. The formation of sediments generated from cold gas can be suppressed.

In claim 2, the confluence space is provided with an induction portion that guides either the low-temperature exhaust gas or the high-temperature exhaust gas toward the other. Therefore, both gases are further mixed with each other. Since the cold gas is further heated, the formation of deposits can be suppressed.

In claim 3, the obstacle portion is a plate-shaped member. Further, a part of the obstacle portion is overlapped with respect to the inner surface of the confluence portion. Compared with the case where the end faces (faces indicating the thickness) of the obstacles are joined, the area to be joined to each other is larger. Obstacles can be reliably joined to the confluence. As a result, the obstacle portion can be accurately arranged at a predetermined position in the confluence space.

In claim 4, the low-temperature exhaust gas and the high-temperature exhaust gas mixed in the mixing space pass through the outlet of the mixing space and are discharged from the discharge port of the confluence. The outlet of the mixing space and the discharge port of the confluence are both offset toward the second pipe side with respect to the third center line. Compared with the case where either the outlet of the mixing space or the discharge port of the confluence is offset to the first pipe side and the other is offset to the second pipe side, the outlet of the mixing space and the discharge of the confluence are discharged. The distance from the exit can be shortened. As a result, the size of the confluence can be shortened in the flow direction of the exhaust gas.

It is a perspective view of the exhaust device according to Example 1. FIG. It is sectional drawing of the exhaust system shown in FIG. FIG. 3A is a perspective view of a confluence portion and an obstacle portion of the exhaust device shown in FIG. FIG. 3B is a diagram illustrating an exhaust device viewed from the downstream side. It is a figure explaining the obstacle part and the mixing space of the exhaust system shown in FIG. FIG. 5A is a diagram illustrating an obstacle portion of the exhaust device according to the second embodiment. FIG. 5B is a diagram illustrating an obstacle portion and a mixing space of the exhaust device according to the second embodiment. FIG. 6A is a diagram illustrating an obstacle portion of the exhaust device according to the third embodiment. FIG. 6B is a diagram illustrating an obstacle portion and a mixing space of the exhaust device according to the third embodiment. FIG. 7A is a diagram illustrating an exhaust device according to a conventional technique. FIG. 7B is a diagram illustrating a configuration around a confluence space of the exhaust device shown in FIG. 7A.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

<Example 1>
See FIG. The EGR cooler 10 (exhaust device) passes through a heat exchanger 20 in which exhaust gas and cooling water (cooling medium) exchange heat, an introduction member 30 for introducing exhaust gas into the heat exchanger 20, and a heat exchanger 20. It is composed of a discharge member 40 (merging portion) for discharging the exhaust gas.

Refer to FIGS. 1 and 2. The heat exchanger 20 includes a tubular core case 21, a flat first heat exchange tube 50 (first tube) housed in the core case 21, and a cylindrical second heat exchange tube 60 (a cylindrical second heat exchange tube 60). A second tube), a first end plate 22 that closes one end of the core case 21, and a second end plate 23 that closes the other end of the core case 21.

Fins 50a are built in the first heat exchange tube 50. The number of the first heat exchange tubes 50 in this embodiment is 6, but it may be at least one or more. The second heat exchange tube 60 is a tube that can exchange heat, but may be a tube that does not exchange heat, such as a so-called bypass tube. That is, a pipe in which cooling water does not flow to the outer periphery may be used as the second pipe.

The core case 21 is composed of a U-shaped groove-shaped first case half body 24 and a second case half body 25. The second case half body 25 is formed with a water introduction hole 26 for introducing water inside the core case 21 and a water discharge hole 27 for discharging water to the outside of the core case 21.

The first end plate 22 is formed with a gas introduction hole 22a for introducing an exhaust gas inside the core case 21. The inlet 51 of the first heat exchange tube 50 and the inlet 61 of the second heat exchange tube 60 are fitted in the gas introduction hole 22a.

The second end plate 23 is formed with a gas discharge hole 23a for discharging exhaust gas from the inside of the core case 21. The outlet 52 of the first heat exchange tube 50 and the outlet 62 of the second heat exchange tube 60 are fitted in the gas discharge hole 23a.

The introduction member 30 has a tubular shape as a whole, and has an introduction port 31 for introducing exhaust gas and an introduction side attachment port 32 attached to the first end plate 22.

The discharge member 40 has a tubular shape as a whole, and has a discharge side mounting port 41 attached to the second end plate 23 and a discharge port 42 for discharging exhaust gas.

The space between the discharge side mounting port 41 and the discharge port 42 is a confluence space 70 where the exhaust gases that have passed through the heat exchange tubes 50 and 60 merge with each other.

The operation of the EGR cooler 10 will be described. The exhaust gas discharged from the engine is introduced into the core case 21 from the introduction port 31 of the introduction member 30. The introduced exhaust gas passes through the first heat exchange tube 50 and the second heat exchange tube 60. On the other hand, cooling water introduced into the core case 21 flows from the water introduction holes 26 on the outer circumferences of the heat exchange tubes 50 and 60, respectively. The exhaust gas passing through the heat exchange tubes 50 and 60 is cooled by the cooling water flowing on the outer circumference. The cooled exhaust gas passes through the confluence space 70, is discharged from the discharge port 42 of the discharge member 40, and is returned to the engine. On the other hand, the cooling water that has absorbed the heat of the exhaust gas is discharged to the outside of the core case 21 from the water discharge hole 27.

See FIG. 3 (a). The discharge member 40 has a rectangular frame portion 43 constituting the discharge side mounting port 41, and four inclined portions 44 to 46 extending from the end portion of the frame portion 43 toward the discharge port 42 side. ing.

All of the four inclined portions 44 to 46 are inclined inward in the radial direction of the discharge port 42. Of the four inclined portions 44 to 46, the one having the largest inclination angle α (see FIG. 4) is designated as the first inclined portion 44, and the one extending upward from both ends of the first inclined portion 44 is a pair. The second inclined portions 45 and 45, and the one having the smallest inclination angle β (see FIG. 4) is referred to as a third inclined portion 46.

The discharge member 40 is provided with an obstacle wall 80 (obstacle portion) that obstructs the flow of exhaust gas that has passed through the heat exchange tubes 50 and 60. The obstacle wall 80 is a substantially trapezoidal plate material. In Examples 1 to 3, the obstacle portion is made of a plate material, but the obstacle portion is not limited to the plate material as long as it obstructs the flow of exhaust gas.

A part of the end surface 80a (the surface indicating the thickness of the plate material) of the obstacle wall 80 is joined to the inner surface 40a of the exhaust member 40. Well-known techniques such as brazing can be adopted as the joining method. The end face 80a has a first end face 81 that can be joined to the inner surface 44a of the first inclined portion 44, and two second end faces 82 that can be joined to the inner surface 45a of the second inclined portion 45. ing.

See FIG. In a state where the discharge member 40 is attached to the second end plate 23, the first inclined portion 44 is located on the lower side (the first heat exchange tube 50 side), and the third inclined portion 46 is on the upper side (the first). It is located on the heat exchange tube 60 side of 2. Further, the direction in which the outlet 52 of the first heat exchange tube 50 and the outlet 62 of the second heat exchange tube 60 are facing is the downstream side in the exhaust gas flow direction, and the opposite side is the upstream side in the exhaust gas flow direction. Be on the side.

With reference to the direction orthogonal to the exhaust gas flow direction, the obstacle wall 80 is inclined to the upstream side in the exhaust gas flow direction with the first end surface 81 as a base point (inclination angle θ1).

The amount of heat exchanged by the single first heat exchange tube 50 is larger than the amount of heat exchanged by the second heat exchange tube 60. That is, the temperature of the exhaust gas that has passed through the first heat exchange tube 50 is lower than the temperature of the exhaust gas that has passed through the second heat exchange tube 60. Hereinafter, the exhaust gas that has passed through the first heat exchange tube 50 is referred to as a low temperature gas (low temperature exhaust gas). The exhaust gas that has passed through the second heat exchange tube 60 is designated as a high temperature gas (high temperature exhaust gas).

The merging space 70 is a mixing space 71 on the upstream side where low-temperature gas and high-temperature gas are mixed, and a downstream side where gas (hereinafter referred to as mixed gas) in which low-temperature gas and high-temperature gas are mixed flows toward the discharge port 42. It is partitioned into a mixing flow path 72 and.

A gap is formed between the inner surface 46a of the third inclined portion 46 and the third end surface 83 of the obstacle wall 80. This gap is also an outlet 73 of the mixing space 71 (a continuous passage between the mixing space 71 and the mixing flow path 72).

The entire center line of the six first heat exchange tubes 50 is defined as the first center line C1. The center line of the second heat exchange tube 60 is defined as the second center line C2. Further, the center line at the same distance from the first center line C1 and the second center line C2 is referred to as the third center line C3.

The outlet 73 of the mixing space 71 is offset to the upper side (the second heat exchange tube 60 side) with respect to the third center line C3. With reference to the third center line C3, the center line C4 of the discharge port 42 is offset to the upper side (the second heat exchange tube 60 side).

The first barrier portion 84 in the obstacle wall 80 overlaps the outlets 52 of the upper three first heat exchange tubes 50 in the exhaust gas flow direction. The second barrier portion 85 (induction portion) in the obstacle wall 80 overlaps the outlet 62 of the second heat exchange tube 60 in the exhaust gas flow direction.

See FIG. The cold gas discharged from the second heat exchange tube 60 flows along the second barrier portion 85 (see arrow a) toward the lower end portion 80c of the obstacle wall 80. The hot gas discharged from the upper three first heat exchange tubes 50 flows along the first barrier portion 84 (see arrow b) toward the lower end portion 80c. The hot gas discharged from the lower three first heat exchange tubes 50 flows along the first inclined portion 44 (see arrow c) toward the lower end portion 80c.

The low temperature gas and the high temperature gas are mixed at the lower end 80c. The mixed gas passes through the outlet 73 of the mixing space 71 (see arrow d), the mixing flow path 72 (see arrow e), and is discharged from the discharge port 42 (see arrow f).

See FIG. 3 (b). Looking from the downstream side to the upstream side in the flow direction of the exhaust gas, only the outer surface 80b of the obstacle wall 80 can be visually recognized inside the exhaust port 42. The obstacle wall 80 has a symmetrical configuration in the width direction (left-right direction on the paper surface). The obstacle walls 90 and 90A of Examples 2 and 3 described later also have a configuration symmetrical in the width direction.

The effect of Example 1 will be described.

See FIG. The confluence space 70 is provided with an obstacle wall 80 that obstructs the flow of low-temperature gas and high-temperature gas, and a mixing space 71 in which the low-temperature gas and high-temperature gas retained by the obstacle wall 80 are mixed with each other. That is, the low-temperature gas and the high-temperature gas that have flowed into the merging space 70 are mixed with each other by being blocked by the obstacle wall 80 and staying in the mixing space 71 before being discharged from the discharge port 42 of the exhaust device. Fit. The low temperature gas is easily heated by the high temperature gas. The formation of sediments generated from cold gas can be suppressed.

In addition, the cold gas flows along the second barrier 85 (see arrow (a)) towards the lower end 80c of the obstruction wall 80. The hot gas flows along the first inclined portion 44 (see arrow (c)) toward the lower end portion 80c. The low temperature gas and the high temperature gas gather at the lower end 80c and mix with each other. Since the cold gas is further heated, the formation of deposits can be further suppressed.

In this embodiment, a part of the obstacle wall 80 is a second barrier portion 85 (guidance portion), but the guide portion may be separate from the obstacle wall 80. The shape and position of the member are not limited to those of the present embodiment as long as the guiding portion guides either the low temperature gas or the high temperature gas toward the other.

In addition, the outlet 73 of the mixing space 71 and the discharge port 42 of the discharge member 40 are both offset to the upper side (second heat exchange tube 60 side) with reference to the center line C3 of the heat exchange tubes 50 and 60. doing.

If either the outlet 73 of the mixing space 71 or the discharge port 42 of the discharge member 40 is offset downward and the other is offset upward, the exhaust gas in the merging space 70 meanders and flows greatly. It will be. In order to suppress the pressure loss, it is necessary to set the dimension of the exhaust member 40 to be long in the flow direction of the exhaust gas. On the other hand, if the outlet 73 and the discharge port 42 of the mixing space 71 are offset in the same direction, the meandering can be reduced, so that the dimension Le of the confluence can be shortened.

<Example 2>
See FIG. 5 (a). The barrier portion 90 is made of a plate material formed by press working. Specifically, the barrier portion 90 is dish-shaped as a whole and comprises a rectangular bottom portion 91 and four side wall portions 92 to 94 extending from the peripheral edge of the bottom portion 91.

Of the four side wall portions 92 to 94, the one that is overlapped with the inner surface 44a of the first inclined portion 44 of the discharge member 40 is referred to as the first side wall portion 92, and the inner surfaces 45a of the second inclined portions 45 and 45, respectively. , 45a is referred to as the second side wall portions 93 and 93, and the one that forms a gap with the third inclined portion 46 is referred to as the third side wall portion 94.

The edge 92a of the first side wall portion 92 and the edges 93a, 93a of the second side wall portion 93 are overlapped with the frame portion 43. The edge 94a of the third side wall portion 94 is lacking in meat.

See FIG. 5 (b). The bottom portion 91 of the barrier portion 90 overlaps with the outlets 52 of the upper three first heat exchange tubes 50 in the flow direction of the exhaust gas. The normal direction of the bottom 91 coincides with the flow direction of the exhaust gas.

The third side wall portion 94 is inclined to the upstream side in the exhaust gas flow direction with the boundary 91a with the bottom portion 91 as a base point (inclination angle θ2). The third side wall portion 94 overlaps with the outlet 62 of the second heat exchange tube 60 in the flow direction of the exhaust gas.

In the confluence space 70, the space on the upstream side of the barrier portion 90 is the mixed space 97. The missing portion of the edge 94a of the third side wall portion 94 becomes the outlet 95 of the mixing space 97. The gap between the third inclined portion 46 and the third side wall portion 94 constitutes the mixing flow path 96 of the mixed gas.

The barrier portion 90 has a dish shape. Therefore, the high-temperature gas and the low-temperature gas flowing toward the barrier portion 90 gather at the bottom portion 91. Specifically, the hot gas flows along the third side wall 94 towards the bottom 91 (see arrow (g)). A portion of the cold gas flows directly toward the bottom 91 (see arrow (h)). A portion of the cold gas flows along the first side wall 44 towards the bottom 91 (see arrow (i)). The cold gas and the hot gas mix at the bottom 91. The mixed gas passes through the mixing flow path 96 at the outlet 95 of the mixing space 97 (see arrow (j)) and is discharged from the discharge port (see arrow (k)).

The effect of Example 2 will be described. Example 2 has the following effects in addition to the effects of Example 1.

See FIG. 5 (a). The first side wall portion 92 of the barrier portion 90 is overlapped with the inner surface 44a of the first inclined portion 44. The second side wall portions 93, 93 are overlapped with the inner surfaces 45a, 45a of the second inclined portions 45, 45. The edge 92a of the first side wall portion 92 and the edge 93a of the second side wall portion 93 are overlapped with the frame portion 43.

Compared with the case where the end surface 80a of the barrier portion 80 (see FIG. 3) of the first embodiment is joined to the inner surface 40a of the discharge member 40, the area to be joined to each other is larger. The barrier portion 90 can be reliably joined to the discharge member 40. As a result, the barrier portion 90 can be reliably arranged at a predetermined position in the confluence space 70.

<Example 3>
See FIG. 6 (a). The barrier portion 90A of the third embodiment has the same basic configuration as the barrier portion 90 of the second embodiment. The barrier portion 90A is made of a plate material formed in a dish shape by press working. Compared with the barrier portion 90 of the second embodiment, the barrier portion 90A is largely lacking in meat.

The barrier portion 90A includes a rectangular bottom portion 91A and four side wall portions 92A to 94A extending from the peripheral edge of the bottom portion 91A. Of the four side wall portions 92A to 94A, the one that is overlapped with the inner surface 44a of the first inclined portion 44 is the first side wall portion 92A, and the one that is overlapped with the inner surface 45a of the second inclined portion 45 is the second. The side wall portion 93A of the above, and the one that forms a gap together with the third inclined portion 46 is referred to as the third side wall portion 94A. The edge 92Aa of the first side wall portion 92A and the edge 93Aa of the second side wall portion 93A are overlapped with the frame portion 43.

The third side wall portion 94A is partially lacking in meat and has a semicircular shape as a whole.

See FIG. 6 (b). The normal direction of the bottom 91A coincides with the flow direction of the exhaust gas. The bottom portion 91A overlaps with the outlets 52 of the upper three first heat exchange tubes 50 in the flow direction of the exhaust gas. The third side wall portion 94A is inclined to the upstream side in the exhaust gas flow direction with the boundary 91Aa with the bottom portion 91A as a base point (inclination angle θ3). The third side wall portion 94A overlaps the outlet 62 of the second heat exchange tube 60 in the exhaust gas flow direction.

Similar to Example 2, the barrier portion 90A has a dish shape. Therefore, the high-temperature gas and the low-temperature gas flowing toward the barrier portion 90A gather at the bottom portion 91A. Specifically, the hot gas flows along the third side wall 94A towards the bottom 91A (see arrow (l)). A portion of the cold gas flows directly toward the bottom 91A (see arrow (m)). A portion of the cold gas flows along the first inclined portion 44 toward the bottom 91A (see arrow (n)). The cold gas and the hot gas mix at the bottom 91A.

In the confluence space 70, the space on the upstream side of the barrier portion 90A becomes the mixing space 97A. The third side wall portion 94A is partially lacking in meat and has a semicircular shape as a whole (see FIG. 6A). The arc of the semicircle is divided into two equal parts, one of which is the first arc 94Aa and the other of which is the second arc 94Ab. The mixed gas passes lateral to the first arc 94Aa (see arrow (o)). Similarly, the mixed gas passes laterally to the second arc 94Ab (see arrow (o)). That is, the missing portion becomes the outlets 95A and 95A of the mixing space 97A. The mixed gas passes through the outlet 95A and the mixing flow path 96A, and is discharged from the discharge port (see arrow (p)).

The effect of Example 3 will be described. Example 3 has the following effects in addition to the effects of Example 2.

Compared with the outlet of the mixed space of Example 2 (see FIG. 5A), the outlets 95A and 95A of the mixed space 97A are wider. Therefore, the pressure loss of the mixed gas flowing in the confluence space 70 can be reduced.

Although an EGR cooler is used as an example of the exhaust device of the present invention, it can be applied to other devices as long as it includes a heat exchanger in which the exhaust gas is cooled. That is, the present invention is not limited to the examples as long as it exerts an action and an effect.

The exhaust device of the present invention is suitable for a four-wheeled vehicle.

10 ... EGR cooler (exhaust device)
20 ... Heat exchanger 40 ... Discharge member (merging portion), 40a ... Inner surface of confluence 42 ... Discharge port 50 ... First heat exchange tube (first tube)
60 ... Second heat exchange tube (second tube)
70 ... Confluence space 71 ... Mixed space 73 ... Exit of mixed space 80 ... Barrier part (obstacle part)
85 ... Second barrier part (guidance part)
90, 90A ... Barrier portion C1 ... First center line C2 ... Second center line C3 ... Third center line

Claims (4)

A heat exchanger that includes a first tube that exhausts the cold exhaust gas cooled by the cooling medium.
A second pipe that discharges a high-temperature exhaust gas that is hotter than the low-temperature exhaust gas,
In an exhaust device having a confluence portion including a confluence space in which the low-temperature exhaust gas and the high-temperature exhaust gas merge, and a discharge port for discharging the merged low-temperature exhaust gas and the high-temperature exhaust to the outside.
The confluence space is provided with an obstacle portion that obstructs the flow of the low temperature exhaust gas and the flow of the high temperature exhaust gas, and a mixing space in which the low temperature exhaust gas and the high temperature exhaust gas retained by the obstacle portion are mixed with each other. An exhaust system characterized by being. The exhaust device according to claim 1, wherein the merging space is provided with an induction portion that guides either the low-temperature exhaust gas or the high-temperature exhaust gas toward the other gas. .. The exhaust according to claim 1 or 2, wherein the obstacle portion is a plate-shaped member, and a part of the obstacle portion is overlapped with the inner surface of the confluence portion. apparatus. The center line of the first pipe is set as the first center line, and the center line of the second pipe is set as the second center line.
Assuming that the center line at the same distance from the first center line and the second center line is the third center line,
With reference to the third center line, the outlet of the mixing space is offset to the second pipe side, and the exhaust port of the merging portion is offset to the second pipe side. The exhaust device according to any one of claims 1 to 3.

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