Exhaust device for internal combustion engine

Abstract

To provide an exhaust device for an internal combustion engine capable of separating condensation water from exhaust gas flowing in an exhaust pipe and reducing flowing noise of the condensation water caused by a gas-liquid two-phase flow.SOLUTION: An exhaust device 10 for an engine 1 includes: a downstream side exhaust pipe 14 having an exhaust passage 14a in which exhaust gas discharged from an engine 1 flows and a discharge port for releasing exhaust gas to the atmosphere; and a muffler mounted to the downstream side exhaust pipe 14 and muffling exhaust noise. A reception member 15 that can store condensation water is mounted to a lower side of the downstream side exhaust pipe 14. The downstream side exhaust pipe 14 includes a through hole 16 for communicating the exhaust passage 14a and the reception member 15.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an exhaust system for an internal combustion engine. [Background technology]

[0002] 2. Description of the Related Art A vehicle exhaust system structure shown in Patent Document 1 is known as an exhaust device for an internal combustion engine that discharges exhaust gas emitted from the internal combustion engine into the atmosphere.

[0003] This vehicle exhaust system structure has a first catalytic converter, a second catalytic converter, an exhaust heat recovery device, and a muffler, which are arranged in this order from the upstream side in the flow direction of exhaust gas.

[0004] In addition, the vehicle exhaust system structure includes a first exhaust pipe connecting the second catalytic device and the exhaust heat recovery device, a second exhaust pipe connecting the exhaust heat recovery device and the silencer, and a downstream exhaust pipe provided downstream of the silencer, and the downstream exhaust pipe is inclined upward from the upstream side to the downstream side.

[0005] Meanwhile, unburned hydrocarbons contained in exhaust gas generated during the engine's combustion stroke are oxidized by the first and second catalytic devices to produce water. However, because the exhaust gas temperature is high, the water evaporates and is discharged as water vapor from the open-to-atmosphere section.

[0006] However, in hybrid vehicles and the like in which the engine is shut off during operation, the temperature of the exhaust system structure, including the exhaust pipe, muffler, and exhaust heat recovery device, tends to drop, resulting in an increase in the amount of condensed water generated in the exhaust system structure.

[0007] Here, the condensed water is carried to the downstream exhaust pipe by the exhaust gas flow and is finally discharged from a portion of the downstream exhaust pipe that is open to the atmosphere. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2008-169710 A Summary of the Invention [Problem to be solved by the invention]

[0009] However, in conventional vehicle exhaust system structures, the exhaust pipe slopes upward from the upstream side to the downstream side, so that condensed water that is unable to climb the slope due to the flow of exhaust gas tends to accumulate upstream of the slope.

[0010] As a result, a two-phase gas-liquid flow occurs in which the gas and liquid phases are mixed upstream of the inclined portion, and there is a risk that the exhaust gas will collide with the condensed water, generating the noise of the condensed water flowing.

[0011] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide an exhaust device for an internal combustion engine that can separate condensed water from exhaust gas flowing through an exhaust pipe and reduce the flow noise of condensed water caused by a two-phase gas-liquid flow. [Means for solving the problem]

[0012] The present invention is an exhaust system for an internal combustion engine comprising an exhaust pipe having an exhaust passage through which exhaust gas discharged from the internal combustion engine flows and an exhaust port for releasing the exhaust gas into the atmosphere, and an exhaust member attached to the exhaust pipe and having a muffler for silencing exhaust noise, wherein a receiving member capable of storing water is provided at least in a lower portion of the exhaust pipe, and the exhaust pipe has a through hole connecting the exhaust passage and the receiving member. Effect of the Invention

[0013] As described above, according to the present invention, the condensed water can be separated from the exhaust gas flowing through the exhaust pipe, thereby reducing the flow noise of the condensed water due to a gas-liquid two-phase flow. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a side view of an exhaust system for an internal combustion engine according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view taken along the line II-II of FIG. [Diagram 3] FIG. 3 is a side view of an exhaust system for an internal combustion engine according to a second embodiment of the present invention. [Figure 4] 4 is a cross-sectional view taken along the line IV-IV in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] An exhaust system for an internal combustion engine according to one embodiment of the present invention is an exhaust system for an internal combustion engine comprising an exhaust pipe having an exhaust passage through which exhaust gas discharged from the internal combustion engine flows and an exhaust port for releasing the exhaust gas into the atmosphere, and an exhaust member attached to the exhaust pipe and having a silencer for silencing exhaust noise, wherein a receiving member capable of storing water is provided in at least the lower part of the exhaust pipe, and the exhaust pipe has a through hole connecting the exhaust passage and the receiving member.

[0016] As a result, the exhaust system for an internal combustion engine according to one embodiment of the present invention can separate the condensed water from the exhaust gas flowing through the exhaust pipe, thereby reducing the flow noise of the condensed water due to a gas-liquid two-phase flow. EXAMPLES

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an exhaust system for an internal combustion engine according to the present invention will now be described with reference to the drawings. 1 and 2 are diagrams showing an exhaust system for an internal combustion engine according to a first embodiment of the present invention.

[0018] In Figures 1 and 2, the up, down, front, back, left and right directions are defined as follows. The direction along the crankshaft is defined as the left-right direction of the engine. The direction perpendicular to the crankshaft in the horizontal plane is defined as the front-rear direction of the engine. The side of the engine where the catalytic converter is located is defined as the front, and the opposite side is defined as the rear.

[0019] The direction along the central axis of the cylinder is defined as the up-down direction of the engine, with the cylinder head side being the top and the oil pan side being the bottom.

[0020] First, the configuration will be described. In FIG. 1, engine 1 as an internal combustion engine mounted on a hybrid vehicle constitutes a drive source together with a motor (not shown). Engine 1 has a cylinder block 2, a cylinder head 3, a cylinder head cover 4 and an oil pan 5.

[0021] A plurality of cylinders (not shown) are provided in the cylinder block 2, and the cylinders are arranged side by side in the left-right direction of the engine 1. The engine 1 is installed so that a central axis 2C of the cylinder extends in the vertical direction.

[0022] Each cylinder houses a piston (not shown), and the pistons are connected to a crankshaft 6 via a connecting rod (not shown). The crankshaft 6 has a rotation center axis 6a extending in the left-right direction, and rotates around the rotation center axis 6a.

[0023] The piston reciprocates within the cylinder, thereby rotating the crankshaft 6 via the connecting rod.

[0024] On the other hand, a hybrid vehicle is provided with a motor. The motor is connected to the crankshaft 6 via a reduction gear mechanism (not shown), and the driving force of the motor is transmitted to the crankshaft 6 by connecting a clutch mechanism (not shown). In this way, the vehicle is driven by the engine 1 and by the motor.

[0025] The cylinder head 3 is provided with a plurality of intake ports (not shown) that are connected to the respective cylinders, and an intake manifold (not shown) that is provided upstream of the intake ports and is connected to the plurality of intake ports.

[0026] The air drawn into the intake manifold is distributed to each cylinder through the intake ports.

[0027] The cylinder head 3 is provided with a plurality of exhaust ports (not shown) that are connected to the respective cylinders, and an exhaust manifold that is provided downstream of the exhaust ports and is connected to the plurality of exhaust ports.

[0028] The exhaust gas combusted in the cylinder is collected in the exhaust manifold and discharged from the exhaust port, and then discharged from the exhaust manifold to the outside of the cylinder head 3 .

[0029] An exhaust system 10 is connected to the cylinder head 3, and the exhaust system 10 includes a catalytic converter 11, an upstream exhaust pipe 12, a silencer 13, and a downstream exhaust pipe 14.

[0030] An upstream end of the catalytic converter 11 is connected to the cylinder head 3. The catalytic converter 11 has an exhaust passage 11a communicating with the exhaust manifold, and a three-way catalyst 11A provided in the exhaust passage 11a.

[0031] The catalytic converter 11 purifies air pollutants such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen compounds (NOx) in the exhaust gas by using a three-way catalyst 11A.

[0032] The upstream exhaust pipe 12 is connected to the downstream end of the catalytic converter 11. The upstream exhaust pipe 12 has an exhaust passage 12a that communicates with the exhaust passage 11a and through which exhaust gas discharged from the exhaust passage 11a flows.

[0033] A recess 5a is formed in the oil pan 5, and the upstream exhaust pipe 12 passes through the recess 5a and is disposed above the lower end of the oil pan 5.

[0034] The silencer 13 is connected to the downstream end of the upstream exhaust pipe 12 , and silences the exhaust noise (pulsation noise) of the exhaust gas discharged from the cylinder head 3 .

[0035] The upstream exhaust pipe 12 and the silencer 13 are arranged in a horizontal direction, and the exhaust gas flows in the horizontal direction through the upstream exhaust pipe 12 and the silencer 13. Note that the upstream exhaust pipe 12 and the silencer 13 are not limited to being arranged in a horizontal direction.

[0036] The downstream exhaust pipe 14 is connected to the downstream end of the silencer 13, and an exhaust passage 14a is formed in the downstream exhaust pipe 14, through which the exhaust gas discharged from the silencer 13 flows.

[0037] An exhaust port 14b is provided at the downstream end of the downstream exhaust pipe 14, and the exhaust gas flowing through the exhaust passage 14a is discharged from the exhaust port 14b into the atmosphere.

[0038] Here, upstream and downstream refer to the upstream and downstream with respect to the flow direction of exhaust gas and intake air, and for example, the upstream exhaust pipe 12 is located upstream of the silencer 13, and the silencer 13 is located downstream of the upstream exhaust pipe 12. In this embodiment, the upstream exhaust pipe 12 and the downstream exhaust pipe 14 constitute an exhaust pipe.

[0039] A horizontal exhaust pipe section 14A and an inclined exhaust pipe section 14B are formed in the downstream exhaust pipe 14. The horizontal exhaust pipe section 14A extends linearly from the silencer 13 in the horizontal direction.

[0040] The inclined exhaust pipe section 14B is located downstream of the muffler 13, and is inclined upward and rearward from an upstream end 14c that is connected to the downstream end of the horizontal exhaust pipe section 14A.

[0041] That is, the inclined exhaust pipe section 14B is inclined upward from the upstream end 14c toward the downstream end 14d, and the downstream end 14d is located above the upstream end 14c. The inclined exhaust pipe section 14B of this embodiment forms an inclined portion.

[0042] As shown in Figures 1 and 2, a half-shaped receiving member 15 is attached to the lower part of the downstream exhaust pipe 14, and the receiving member 15 covers the entire horizontal exhaust pipe section 14A and the upstream side of the inclined exhaust pipe section 14B from below.

[0043] Specifically, the receiving member 15 has a horizontal half portion 15A that is attached to the horizontal exhaust pipe section 14A so as to cover the lower side of the horizontal exhaust pipe section 14A and extends along the horizontal exhaust pipe section 14A, and an inclined half portion 15B that is attached to the inclined exhaust pipe section 14B so as to cover the lower side of the inclined exhaust pipe section 14B and extends along the inclined exhaust pipe section 14B.

[0044] The receiving member 15 includes the upstream end 14c of the inclined exhaust pipe section 14B, and is arranged from the upstream end 14c of the inclined exhaust pipe section 14B to the entire horizontal exhaust pipe section 14A, and from the upstream end 14c of the inclined exhaust pipe section 14B to the upstream side of the inclined exhaust pipe section 14B.

[0045] More specifically, the receiving member 15 has an upstream end 15c (upstream end 15c of the horizontal half portion 15A) connected to the muffler 13, and a downstream end 15d (downstream end 15d of the inclined half portion 15B) extending to the downstream side of the inclined exhaust pipe portion 14B.

[0046] A lower end 15e of the horizontal half section 15A is inclined downward from the upstream end 14c of the inclined exhaust pipe section 14B toward the muffler 13.

[0047] The receiving member 15 is attached to the silencer 13 and the downstream exhaust pipe 14 by having the upper left end 15a, the upper right end 15b, and the downstream end 15d in the circumferential direction fixed to the downstream exhaust pipe 14, and the upstream end 15c fixed to the silencer 13.

[0048] Through holes 16 (see FIG. 2) are formed throughout the horizontal exhaust pipe section 14A and on the upstream side of the inclined exhaust pipe section 14B. The through holes 16 are formed on the circumferential lower sides of the horizontal exhaust pipe section 14A and the inclined exhaust pipe section 14B, and face the receiving member 15 in the up-down direction.

[0049] In other words, the through holes 16 are formed at a predetermined interval within the range in which the receiving member 15 is disposed in the extension direction (front-to-back direction) and circumferential direction of the horizontal exhaust pipe section 14A and the inclined exhaust pipe section 14B, and the through holes 16 connect the exhaust passage 14a and the receiving member 15.

[0050] Gaps 17 are formed between the horizontal exhaust pipe section 14A and the inclined exhaust pipe section 14B and the receiving member 15, and condensed water accumulated in the exhaust passage 14a is discharged from the through holes 16 to the receiving member 15. In other words, the gaps 17 form a space that receives the condensed water discharged from the through holes 16.

[0051] In addition, the receiving member 15 has an upstream end 15c fixed to the muffler 13, and an upper left end 15a, an upper right end 15b, and a downstream end 15d fixed to the downstream exhaust pipe 14 at its circumferential upper left end 15a, upper right end 15b, and downstream end 15d, so that the upstream end 15c and downstream end 15d seal the gap 17. This prevents condensed water from leaking out from the upstream end 15c and downstream end 15d of the receiving member 15.

[0052] Next, the operation will be described. Unburned hydrocarbons contained in exhaust gas produced during the engine's combustion stroke are oxidized by catalytic converter 11 to produce water. In a hybrid vehicle, however, engine 1 is shut down during operation, so the temperature of exhaust device 10 tends to drop and the amount of condensed water produced in exhaust device 10 increases.

[0053] During motor driving, the rotation of the motor rotates the crankshaft 6 and exhaust gas is discharged into the exhaust device 10. However, since the exhaust gas is at a low temperature, condensed water is difficult to discharge from the downstream exhaust pipe 14 and remains in the downstream exhaust pipe 14.

[0054] In other words, condensed water generated inside the upstream exhaust pipe 12 or the muffler 13 tends to flow to the downstream exhaust pipe 14, but since the flow speed of the exhaust gas slows down the further downstream it goes, the condensed water tends to remain in the downstream exhaust pipe 14.

[0055] In the exhaust device 10 of the engine 1 of this embodiment, a receiving member 15 capable of storing condensed water (water) is attached below the downstream exhaust pipe 14, and the downstream exhaust pipe 14 has a through hole 16 that connects the exhaust passage 14a and the receiving member 15.

[0056] As a result, the condensed water that has passed through the catalytic converter 11 and is generated inside the downstream exhaust pipe 14 can be discharged to the receiving member 15 through the through hole 16. As a result, the condensed water can be separated from the exhaust gas flowing through the downstream exhaust pipe 14, suppressing the generation of a gas-liquid two-phase flow, and reducing the flow noise of the condensed water due to the gas-liquid two-phase flow.

[0057] Here, when condensation water is generated inside the upstream exhaust pipe 12, the muffler 13, and the downstream exhaust pipe 14, if the upstream exhaust pipe 12, the muffler 13, and the downstream exhaust pipe 14 are arranged horizontally or inclined toward the downstream side, the condensed water is likely to be discharged from the exhaust outlet 14b of the downstream exhaust pipe 14 by the exhaust gas flow, and the accumulation of condensed water that could cause flow noise is likely to be suppressed.

[0058] In other words, the condensed water is likely to accumulate in front of (on the upstream side of) the inclined portion where the exhaust passage slopes upward toward the downstream side.

[0059] According to the exhaust device 10 of this embodiment, the downstream exhaust pipe 14 has an inclined exhaust pipe section 14B that inclines upward from the upstream end 14c to the downstream end 14d, and the receiving member 15 includes the upstream end 14c of the inclined exhaust pipe section 14B and is arranged from the upstream end 14c of the inclined exhaust pipe section 14B to the entire horizontal exhaust pipe section 14A, and from the upstream end 14c of the inclined exhaust pipe section 14B to the upstream side of the inclined exhaust pipe section 14B.

[0060] This allows the condensed water to be discharged into the receiving member 15 upstream of the upstream end 14c of the inclined exhaust pipe section 14B, where condensed water is likely to accumulate, and more effectively separates the condensed water from the exhaust gas flowing through the downstream exhaust pipe 14, more effectively suppressing the generation of a two-phase gas-liquid flow, and more effectively reducing the flow noise of the condensed water caused by the two-phase gas-liquid flow.

[0061] In addition, since the receiving member 15 of this embodiment is a half-split receiving member 15 attached to the lower part of the downstream exhaust pipe 14, it is possible to shorten the installation range of the receiving member 15 in the circumferential direction of the downstream exhaust pipe 14. This prevents the weight of the receiving member 15 from increasing, and therefore makes it possible to suppress an increase in the weight of the exhaust device 10.

[0062] Here, when the receiving member 15 is provided upstream of the muffler 13, the flow noise of the condensed water generated upstream of the muffler 13 can be reduced by the muffler 13. As a result, the effect of reducing the flow noise of the condensed water by providing the receiving member 15 is small.

[0063] According to the exhaust device 10 of this embodiment, the inclined exhaust pipe section 14B is formed downstream of the silencer 13. As a result, the exhaust noise generated after passing through the silencer 13 is basically difficult to reduce, so the effect of reducing the flow noise of condensed water accumulated downstream of the silencer 13 is small.

[0064] In the exhaust device 10 of the present embodiment, the inclined exhaust pipe section 14B is formed downstream of the muffler 13, and receiving members 15 are provided on the inclined exhaust pipe section 14B and the horizontal exhaust pipe section 14A. This makes it possible to more effectively separate condensed water from the exhaust gas flowing through the downstream exhaust pipe 14 and more effectively suppress the generation of a two-phase gas-liquid flow, thereby more effectively reducing the flow noise of the condensed water due to the two-phase gas-liquid flow.

[0065] Furthermore, since the receiving member 15 is provided downstream of the muffler 13, the exhaust noise radiated downward from the downstream exhaust pipe 14 can be muffled by the receiving member 15.

[0066] Furthermore, according to the exhaust device 10 of this embodiment, the upstream end 15c of the receiving member 15 is connected to the muffler 13, and the lower end 15e of the receiving member 15 is inclined downward as it moves from the upstream end 14c of the inclined exhaust pipe section 14B toward the muffler 13.

[0067] This allows condensed water that cannot be discharged from outlet 14b to flow down from inclined half 15B to horizontal half 15A, and then to be collected on the muffler 13 side along the bottom surface of horizontal half 15A.

[0068] Therefore, after the engine 1 is started, the condensed water can be efficiently evaporated by the heat of the exhaust gas on the upstream side where the temperature of the exhaust gas is higher than on the downstream side.

[0069] 3 and 4 are diagrams showing an exhaust system for an internal combustion engine according to a second embodiment of the present invention, in which the same components as those in the first embodiment are given the same reference numerals and their explanation will be omitted.

[0070] As shown in Figures 3 and 4, a cylindrical receiving member 21 is attached to the lower part of the downstream exhaust pipe 14, and the receiving member 21 circumferentially covers the entire horizontal exhaust pipe section 14A and the upstream side of the inclined exhaust pipe section 14B.

[0071] Specifically, the receiving member 21 has a horizontal cylindrical portion 21A that covers the entire circumferential direction and extension direction of the horizontal exhaust pipe section 14A and extends along the horizontal exhaust pipe section 14A, and an inclined cylindrical portion 21B that covers the entire circumferential direction of the inclined exhaust pipe section 14B upstream of the inclined exhaust pipe section 14B and extends along the inclined exhaust pipe section 14B.

[0072] The receiving member 21 includes the upstream end 14c of the inclined exhaust pipe section 14B, and is arranged from the upstream end 14c of the inclined exhaust pipe section 14B to the entire horizontal exhaust pipe section 14A, and from the upstream end 14c of the inclined exhaust pipe section 14B to the upstream side of the inclined exhaust pipe section 14B.

[0073] More specifically, the receiving member 21 has an upstream end 21b (upstream end 21b of the horizontal cylindrical portion 21A) connected to the muffler 13, and a downstream end 21c (downstream end 21c of the inclined cylindrical portion 21B) extending to the downstream side of the inclined exhaust pipe portion 14B.

[0074] A lower end 21d of the horizontal cylindrical portion 21A is inclined downward from the upstream end 14c of the inclined exhaust pipe portion 14B toward the muffler 13.

[0075] 4, through holes 22 are formed throughout the horizontal exhaust pipe section 14A and on the upstream side of the inclined exhaust pipe section 14B. The through holes 22 face the receiving member 21 in the circumferential direction and in the front-rear direction of the horizontal exhaust pipe section 14A and the inclined exhaust pipe section 14B.

[0076] In other words, the through holes 22 are formed at a predetermined interval within the range in which the receiving member 21 is disposed in the extension direction and circumferential direction of the horizontal exhaust pipe section 14A and the inclined exhaust pipe section 14B, and the through holes 22 connect the exhaust passage 14a and the receiving member 21.

[0077] Gaps 23 are formed between the horizontal exhaust pipe section 14A and the inclined exhaust pipe section 14B and the receiving member 21, and condensed water accumulated in the exhaust passage 14a is discharged from the through holes 22 to the receiving member 21. In other words, the gaps 23 form a space that receives the condensed water discharged from the through holes 22.

[0078] In addition, the receiving member 21 is attached to the silencer 13 and the downstream exhaust pipe 14 by having the upstream end 21b fixed to the silencer 13 and the downstream end 21c fixed to the downstream exhaust pipe 14 so as to form a gap 23 of a certain size.

[0079] Furthermore, the receiving member 21 seals the gap 23 with the upstream end 21b and the downstream end 21c, so that condensed water does not leak from the upstream end 21b and the downstream end 21c of the receiving member 21.

[0080] Next, the operation will be described. In the exhaust device 10 of the engine 1 of this embodiment, a receiving member 21 capable of storing condensed water (water) is attached below the downstream exhaust pipe 14, and the downstream exhaust pipe 14 has a through hole 22 that connects the exhaust passage 14a and the receiving member 21.

[0081] As a result, the condensed water that has passed through the catalytic converter 11 and is generated inside the downstream exhaust pipe 14 can be discharged to the receiving member 21 through the through hole 22. As a result, the condensed water can be separated from the exhaust gas flowing through the downstream exhaust pipe 14, suppressing the generation of a gas-liquid two-phase flow, and reducing the flow noise of the condensed water due to the gas-liquid two-phase flow.

[0082] Furthermore, according to the exhaust device 10 of this embodiment, the downstream exhaust pipe 14 has an inclined exhaust pipe section 14B that inclines upward from the upstream end 14c to the downstream end 14d, and the receiving member 21 includes the upstream end 14c of the inclined exhaust pipe section 14B and is arranged from the upstream end 14c of the inclined exhaust pipe section 14B to the entire horizontal exhaust pipe section 14A, and from the upstream end 14c of the inclined exhaust pipe section 14B to the upstream side of the inclined exhaust pipe section 14B.

[0083] This allows the condensed water to be discharged into the receiving member 21 upstream of the upstream end 14c of the inclined exhaust pipe section 14B, where condensed water is likely to accumulate, and more effectively separates the condensed water from the exhaust gas flowing through the downstream exhaust pipe 14, more effectively suppressing the generation of a two-phase gas-liquid flow, and more effectively reducing the flow noise of the condensed water caused by the two-phase gas-liquid flow.

[0084] Furthermore, since the exhaust device 10 of this embodiment is provided with a receiving member 21 downstream of the muffler 13, which covers the entire circumferential direction of the downstream exhaust pipe 14, the exhaust sound radiated from the downstream exhaust pipe 14 can be more effectively muffled by the receiving member 21.

[0085] Furthermore, according to the exhaust device 10 of this embodiment, the upstream end 21b of the receiving member 21 is connected to the muffler 13, and the lower end 21d of the receiving member 21 is inclined downward as it moves from the upstream end 14c of the inclined exhaust pipe section 14B toward the muffler 13.

[0086] As a result, the condensed water that cannot be discharged from the discharge port 14b can flow down from the inclined cylindrical portion 21B to the horizontal cylindrical portion 21A, and then can be collected on the silencer 13 side along the bottom surface of the horizontal cylindrical portion 21A.

[0087] Therefore, after the engine 1 is started, the condensed water can be efficiently evaporated by the heat of the exhaust gas on the upstream side where the temperature of the exhaust gas is higher than on the downstream side.

[0088] It should be noted that the receiving members 15, 21 in each of the above embodiments include the upstream end 14c of the inclined exhaust pipe section 14B, and are arranged from the upstream end 14c of the inclined exhaust pipe section 14B to the entire horizontal exhaust pipe section 14A, and from the upstream end 14c of the inclined exhaust pipe section 14B to the upstream side of the inclined exhaust pipe section 14B; however, it is sufficient that the receiving members 15, 21 include the upstream end 14c of the inclined exhaust pipe section 14B and are arranged at least from the upstream end 14c of the inclined exhaust pipe section 14B to the downstream side of the horizontal exhaust pipe section 14A (downstream exhaust pipe 14).

[0089] Furthermore, the layout of the components of the exhaust device 10 is not limited to those in the above-described embodiments. It is sufficient that the exhaust device 10 has the inclined exhaust pipe section 14B and the receiving members 15 and 21 disposed at least downstream of the silencer 13.

[0090] Although an embodiment of the invention has been disclosed, it will be apparent to one skilled in the art that modifications may be made without departing from the spirit and scope of the invention, and all such modifications and equivalents are intended to be encompassed by the following claims. [Explanation of symbols]

[0091] 1...engine (internal combustion engine), 12...upstream exhaust pipe (exhaust pipe), 13...muffler, 14...downstream exhaust pipe (exhaust pipe), 14a...exhaust passage, 14B...inclined exhaust pipe section (inclined section), 14b...exhaust port, 14c...upstream end (upstream end of inclined section), 15, 21...receiving member, 15e, 21d...lower end (lower end of receiving member), 16, 22...through hole

Claims

1. an exhaust pipe having an exhaust passage through which exhaust gas discharged from the internal combustion engine flows and an exhaust port through which the exhaust gas is discharged into the atmosphere; and an exhaust member having a muffler attached to the exhaust pipe for silencing exhaust noise, a receiving member capable of storing water is provided at least in a lower portion of the exhaust pipe, 2 is a perspective view of an exhaust pipe according to an embodiment of the present invention; FIG. 3 is a perspective view of an exhaust pipe according to an embodiment of the present invention;

2. the exhaust pipe has an inclined portion that inclines upward from an upstream end to a downstream end in a flow direction of exhaust gas, 2. The exhaust system for an internal combustion engine according to claim 1, wherein the receiving member includes an upstream end of the inclined portion and is disposed at least upstream of the upstream end of the inclined portion on the exhaust pipe.

3. 3. The exhaust system for an internal combustion engine according to claim 2, wherein the inclined portion is formed downstream of the muffler.

4. The upstream end of the receiving member is connected to the muffler, 4. The exhaust system for an internal combustion engine according to claim 3, wherein the lower end of the receiving member is inclined downward from the upstream end of the inclined portion toward the muffler.

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