JP2020186707A - Exhaust structure for engine - Google Patents

Abstract

To provide an exhaust structure for an engine where an exhaust noise suppressor is arranged on the vehicle rear, for suppressing the contact of the exhaust noise suppressor with mounted components during rear collision.SOLUTION: An exhaust structure A for the engine includes a main exhaust noise suppressor 13 arranged on the vehicle rear, a fuel tank 5 arranged on the vehicle front beyond the main noise suppressor 13, and an exhaust pipe 20 passing near the fuel tank 5 and extending from an engine 1 to the main exhaust noise suppressor 13 for delivering exhaust gas exhausted from the engine 1 to the main exhaust noise suppressor 13. On the vehicle rear beyond the fuel tank 5, the exhaust pipe 20 has a curved part 45 curved from the vehicle front side toward the vehicle downside and then curved toward the vehicle upside for promoting the rise of the main exhaust noise suppressor 13 up to the vehicle upside when receiving a load from the vehicle rear. The vehicle front beyond the curved part 45 and the vehicle rear beyond the fuel tank 5 each have higher rigidity than the curved part 45.SELECTED DRAWING: Figure 2

Description

The present invention relates to an engine exhaust structure.

There is an engine exhaust structure in which an exhaust silencer is arranged at the rear of the vehicle. For example, Patent Document 1 discloses an invention relating to a silencer (exhaust silencer). This silencer is arranged on the lower surface side of the rear part of the vehicle. A plurality of pipes communicating with the expansion chamber inside the silencer are arranged so as to extend in the front-rear direction of the vehicle. At least one of the plurality of pipes is held with its rear end protruding rearward from the rear end of the silencer. When an impact force exceeding a predetermined value toward the front end of the vehicle is applied to the rear end of the pipe, the pipe displaces the inside of the silencer toward the front of the vehicle, and the front end abuts on the front end of the silencer. It is pressed and contracts and deforms in the axial direction. This makes it possible to provide an automobile silencer that does not interfere with the uniform diffusion and absorption of the impact force applied to the vehicle in the event of a rear collision.

Japanese Unexamined Patent Publication No. 2001-323809

By the way, in the exhaust structure of an engine, on-board parts such as a fuel tank may be arranged in front of the vehicle from the exhaust silencer. In such a configuration, in the event of a collision from the rear of the vehicle (hereinafter referred to as "rear collision"), the exhaust silencer may be pushed forward of the vehicle and come into contact with the mounted parts.

The present invention has been made in view of these points, and a main object thereof is to install an exhaust silencer in an engine exhaust structure in which an exhaust silencer is arranged at the rear of the vehicle. The purpose is to prevent contact.

The exhaust structure of the engine disclosed herein includes an exhaust muffling device arranged at the rear of the vehicle, a mounted component arranged at the front of the vehicle with respect to the exhaust muffling device, and an exhaust muffling device from the engine through the vicinity of the mounted component. The exhaust pipe is provided with an exhaust pipe for leading the exhaust gas discharged from the engine to the exhaust muffling device, and the exhaust pipe is directed toward the rear of the vehicle from the mounted parts and from the front side of the vehicle to the lower side of the vehicle. It has a curved portion that is curved toward the upper side of the vehicle after being curved and promotes the rise of the exhaust muffling device upward of the vehicle when a load is received from the rear of the vehicle, and is mounted in front of the vehicle and mounted above the curved portion. The rear of the vehicle is more rigid than the parts and is more rigid than the curved portion.

According to this configuration, the curved portion has a "dogleg shape" that protrudes downward from the vehicle, so that when a load is applied from the rear of the vehicle, the curved portion is bent so as to be lowered downward from the vehicle. As a result, the exhaust pipe is likely to bend at the curved portion, so that the exhaust muffler is likely to rise upward in the vehicle at the curved portion.

Further, since the exhaust pipe is provided with a portion having a higher rigidity than the curved portion, the exhaust pipe is less likely to be deformed in the portion, and is more easily deformed in the curved portion. Further, since the portion that is hard to be deformed is provided in front of the vehicle and behind the mounted component of the curved portion, it is difficult for the exhaust pipe to bend or compress between the curved portion and the mounted component. That is, the movement of the exhaust silencer to the front of the vehicle is suppressed behind the mounted parts.

Therefore, the moving distance of the exhaust muffling device to the front of the vehicle is reduced, and it is possible to prevent the exhaust muffling device from coming into contact with the mounted parts.

In one embodiment, the exhaust pipe includes a first exhaust pipe that passes near the mounted component and extends to the rear of the vehicle from the mounted component, and a second exhaust pipe that extends from the first exhaust pipe to the rear of the vehicle and includes the curved portion. The first exhaust pipe has an exhaust pipe, and the first exhaust pipe has a higher rigidity than the second exhaust pipe.

According to this configuration, the first exhaust pipe has higher rigidity than the second exhaust pipe having a curved portion, and the first exhaust pipe and the second exhaust pipe are separate bodies, so that the second exhaust pipe is separated. Is more likely to bend into a "dogleg" shape. Therefore, it is possible to suppress the movement of the exhaust muffling device to the front of the vehicle.

Further, the above effect can be obtained only by connecting the first exhaust pipe and the second exhaust pipe having different rigidity to each other, so that a simple structure can be obtained.

In one embodiment, the first exhaust pipe is thicker than the second exhaust pipe.

According to such a configuration, the rigidity of the first exhaust pipe and the second exhaust pipe is adjusted by the wall thickness, and the structure is further simple.

In one embodiment, the exhaust silencer has a substantially box-shaped shape with the vehicle width direction as the longitudinal direction, and the exhaust pipe is connected to a substantially central portion of the exhaust silencer in the vehicle width direction.

According to such a configuration, the exhaust silencer is more likely to stand up above the vehicle than when the exhaust pipe is connected to the exhaust silencer at the end in the vehicle width direction. Further, since the distance between the exhaust silencer and the mounted parts can be increased, it is difficult for the exhaust silencer to come into contact with the mounted parts when the exhaust silencer stands up above the vehicle at the time of a rear collision.

In one embodiment, in the vehicle front-rear direction, a rear cross member extending in the vehicle width direction is arranged between the mounted component and the exhaust silencer.

According to this configuration, the rear cross member acts as a stopper to suppress the movement of the exhaust muffling device to the front of the vehicle, so that the exhaust muffling device is more reliably suppressed from coming into contact with the mounted parts at the time of a rear collision. Can be done.

In one embodiment, the mounted component is a fuel tank.

According to such a configuration, it is possible to suppress the leakage of the fuel stored in the fuel tank by suppressing the contact with the mounted parts of the exhaust muffling device.

According to the present invention, in the exhaust structure of an engine in which an exhaust silencer is arranged at the rear of the vehicle, it is possible to prevent the exhaust silencer from coming into contact with mounted parts at the time of a rear collision.

FIG. 1 is a bottom view of the exhaust structure of the engine according to the embodiment of the present invention as viewed from the lower side of the vehicle. FIG. 2 is a left side view of the exhaust structure of the engine as viewed from the left side of the vehicle. FIG. 3 is an enlarged view of Part III in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description of preferred embodiments is merely exemplary and is not intended to limit the present invention, its applications or its uses. In the present specification, the forward / backward direction of the vehicle is referred to as "front-rear direction", the forward side is referred to as "front side", and the backward side is referred to as "rear side". The vehicle width direction is "left-right direction", the right side is "right side" and the left side is "left side" when viewed from the rear side of the vehicle. The vehicle height direction is the "vertical direction", the upper side is the "upper side", and the lower side is the "lower side". Further, "upstream" and "downstream" are based on the flow direction of the exhaust gas.

FIG. 1 is a bottom view of the exhaust structure A of the engine according to the embodiment of the present invention as viewed from the lower side of the vehicle. FIG. 2 is a left side view of the exhaust structure A of the engine as viewed from the left side of the vehicle. FIG. 3 is an enlarged view of Part III in FIG. In FIGS. 2 and 3, the exhaust structure A of the engine is shown by a solid line, and the other parts are shown by a two-dot chain line or omitted. As shown in FIG. 1, an engine 1 is provided in front of the vehicle. The engine 1 is housed in the engine room 2 in front of the vehicle. The engine 1 is hidden behind the lower wall portion 2a of the engine room 2 and cannot be seen from the lower side of the vehicle. The engine 1 is provided with an intake device (not shown) on the front side of the vehicle and an exhaust device 10 on the rear side. That is, the engine 1 is a front intake and rear exhaust engine. The exhaust device 10 is connected to the engine 1 and extends rearward along the lower surface of the vehicle body floor 3.

The exhaust device 10 includes an exhaust manifold (not shown), an exhaust pipe 20, a catalyst device 11, a pre-exhaust silencer 12, and a main exhaust silencer 13. Here, on the lower surface of the vehicle body floor 3, a housing portion 4 recessed upward is provided. Since the exhaust device 10 is housed in the housing unit 4, the exhaust device 10 does not protrude below the lower surface of the vehicle body floor 3.

The upstream end of the exhaust manifold is a branch end connected to the exhaust port of each cylinder head of the engine 1. In the exhaust manifold, the exhaust gas discharged from each exhaust port is collected in one passage on the way, and the downstream end is connected to the exhaust pipe 20.

The exhaust pipe 20 is a pipe line that serves as a passage for exhaust gas, is connected to the downstream end of the exhaust manifold, and extends to the rear of the vehicle. A catalyst device 11 and a pre-exhaust gas silencer 12 are incorporated in the exhaust pipe 20 in order from the upstream side, and a main exhaust gas silencer 13 is connected to the end. The exhaust pipe 20 is composed of a plurality of exhaust pipes, the details of which will be described later.

The catalyst device 11 purifies harmful components in the exhaust gas discharged from the engine 1. The pre-exhaust muffling device 12 and the main exhaust muffling device 13 are incorporated in the exhaust system of the engine 1 in order to reduce the exhaust noise. The pre-exhaust silencer 12 arranged on the upstream side mainly reduces high-frequency components in the exhaust noise. As the pre-exhaust silencer 12, for example, a sound absorbing type silencer is adopted.

The main exhaust silencer 13 arranged on the downstream side mainly reduces low and medium frequency components of the exhaust noise. The main exhaust silencer 13 is arranged behind the vehicle. The main exhaust silencer 13 has a casing 13a. The casing 13a forms a muffling space (not shown) inside. The casing 13a (main exhaust silencer 13) has a substantially box-shaped shape that is flat and rounded as a whole, and the vertical and front-rear directions of the vehicle are the lateral directions, and the left-right direction (the vehicle width direction) is the longitudinal direction. An exhaust introduction pipe 13b is provided at a substantially central portion in the vehicle width direction on the front wall portion of the casing 13a. Exhaust outlet pipes 13c are provided on the side walls of the casing 13a on both sides in the vehicle width direction. The exhaust outlet pipe 13c extends outward in the vehicle width direction from the side wall portion of the casing 13a and then extends to the rear of the vehicle. The rear end portion of the exhaust outlet pipe 13c is composed of a tail pipe 13d having a diameter larger than that of other portions of the exhaust outlet pipe 13c. A discharge port 13e is provided at the rear end of the tail pipe 13d, and the sound deadening space is communicated with the atmosphere outside the casing 13a. By introducing the exhaust gas flowing through the exhaust pipe 20 from the exhaust introduction pipe 13b into the muffling space in the casing 13a, the specific frequency component of the exhaust sound is reduced. Then, the exhaust gas is introduced into the exhaust outlet pipe 13c and discharged from the exhaust port 13e to the atmosphere outside the casing 13a. The exhaust introduction pipe 13b and the two exhaust outlet pipes 13c and 13c are independent pipes.

As shown in FIG. 3, two support hooks 13f are provided on the side wall portions on both sides of the main exhaust silencer 13 in the vehicle width direction at intervals in the vehicle front-rear direction. Here, at the center of the two rear side frames 6 (shown by the alternate long and short dash line in FIG. 3) extending in the vehicle front-rear direction at intervals in the vehicle width direction, a bracket 6a extending outward in the vehicle width direction (shown in FIG. (Shown by a two-dot chain line in FIG. 3) is provided. The rear side frame 6 is a member constituting the vehicle body, and increases the rigidity of the vehicle body rear side (rear side). Each of the brackets 6a is provided with two support hooks 6b (shown by an alternate long and short dash line in FIG. 3) at intervals in the front-rear direction of the vehicle. The support hook 13f is inserted into the hole on the lower side of the vehicle in the rubber mount 7 from the inside to the outside in the vehicle width direction. The support hook 6b is inserted into the hole on the upper side of the vehicle in the rubber mount 7 from the inside to the outside in the vehicle width direction. That is, the main exhaust silencer 13 is supported by the support hooks 13f and 6b and the rubber mount 7 so as to be suspended from the rear side frame 6 (bracket 6a) on both outer sides in the vehicle width direction.

A fuel tank 5 as an on-board component is arranged in front of the main exhaust silencer 13. The fuel tank 5 has a flat, substantially box-shaped shape, and the vertical and front-rear directions of the vehicle are the lateral directions, and the left-right direction (the vehicle width direction) is the longitudinal direction. Here, the tank accommodating portion 4a is provided in the accommodating portion 4 provided on the lower surface of the vehicle body floor 3. The tank accommodating portion 4a has substantially the same shape as the outer shape of the fuel tank 5, and the vertical and front-rear directions of the vehicle are the lateral directions, and the horizontal direction (the vehicle width direction) is the longitudinal direction. Since the fuel tank 5 is housed in the tank housing portion 4a, the fuel tank 5 does not protrude below the lower surface of the vehicle body floor 3.

As shown in FIG. 1, a rear cross member 8 extending in the vehicle width direction is arranged between the fuel tank 5 and the main exhaust silencer 13 in the vehicle front-rear direction. The rear cross members 8 are fixed to the vehicle body on both sides in the vehicle width direction. The rear cross member 8 is a member constituting the vehicle body, and increases the rigidity of the vehicle body rear side (rear side).

Hereinafter, the configuration of the exhaust pipe 20 will be described in detail. As shown in FIG. 1, the exhaust pipe 20 extends from the engine 1 to the main exhaust silencer 13 through the vicinity of the fuel tank 5. The exhaust pipe 20 leads the exhaust gas discharged from the engine 1 to the main exhaust silencer 13. The exhaust pipe 20 is composed of connecting exhaust pipes 21, 22, a first exhaust pipe 30, and a second exhaust pipe 40.

The connection exhaust pipe 21 connects the exhaust manifold and the catalyst device 11. The downstream end of the connecting exhaust pipe 21 is flange-joined to the upstream end of the introduction pipe 11a provided in front of the catalyst device 11. The connection exhaust pipe 22 connects the catalyst device 11 and the pre-exhaust silencer device 12. As shown in FIG. 1, the connection exhaust pipe 21 and the connection exhaust pipe 22 extend in the front-rear direction at a substantially central portion in the vehicle width direction.

The first exhaust pipe 30 extends from the pre-exhaust silencer 12 to the rear of the vehicle from the fuel tank 5 through the vicinity of the fuel tank 5. Specifically, the first exhaust pipe 30 extends below the fuel tank 5 in the front-rear direction, and is located at a position overlapping the fuel tank 5 when viewed from the lower side of the vehicle. As shown in FIG. 1, the first exhaust pipe 30 extends rearward from the rear end of the pre-exhaust silencer 12 to the vicinity of the front end of the fuel tank 5 in the upstream portion 31 when viewed from the lower side of the vehicle. After that, the song touches diagonally backward to the right. The first exhaust pipe 30 extends diagonally rearward to the right in the middle stream portion 32 and then bends rearward. The first exhaust pipe 30 extends rearward in the downstream portion 33, and then bends diagonally rearward to the left at the rear of the vehicle with respect to the rear end of the fuel tank 5. The first exhaust pipe 30 is connected to the second exhaust pipe 40 at a connecting portion 34 provided at a downstream end located behind the fuel tank 5. As shown in FIG. 1, the downstream portion 33 is located outside in the vehicle width direction with respect to the upstream portion 31. Further, on the lower surface of the fuel tank 5, a housing portion 5a recessed upward is provided. The portion of the first exhaust pipe 30 that overlaps with the fuel tank 5 is accommodated in the accommodating portion 5a. As a result, the first exhaust pipe 30 does not protrude below the lower surface of the fuel tank 5.

As shown in FIG. 1, the second exhaust pipe 40 extends rearward from the first exhaust pipe 30. The second exhaust pipe 40 is connected to the connection portion 34 of the first exhaust pipe 30 at the connection portion 41 provided at the upstream end. The connection portion 34 of the first exhaust pipe 30 and the connection portion 41 of the second exhaust pipe 40 are connected by welding. On the other hand, the second exhaust pipe 40 is connected to the exhaust introduction pipe 13b located at the substantially central portion in the vehicle width direction of the main exhaust silencer 13 at the connecting portion 42 provided at the downstream end. The connection portion 42 of the second exhaust pipe 40 and the exhaust introduction pipe 13b of the main exhaust silencer 13 are connected by flange joining.

As shown in FIG. 1, the second exhaust pipe 40 extends diagonally rearward to the left from the connecting portion 41 at the upstream portion 43 when viewed from the lower side of the vehicle, and then bends rearward. On the other hand, as shown in FIG. 2, the second exhaust pipe 40 extends diagonally forward and downward from the connecting portion 42 at the downstream portion 44 when viewed from the vehicle side. The upstream portion 43 and the downstream portion 44 are connected by a curved portion 45. As shown in FIG. 1, the downstream portion 44 is located outside the upstream portion 31 of the first exhaust pipe 30 in the vehicle width direction and inside the downstream portion 33 in the vehicle width direction.

Hereinafter, the curved portion 45 will be described in detail with reference to FIG. As described above, a curved portion 45 is provided between the upstream portion 43 and the downstream portion 44 of the second exhaust pipe 40. That is, the curved portion 45 is located behind the vehicle from the fuel tank 5 and in front of the main exhaust silencer 13. The curved portion 45 promotes the main exhaust muffling device 13 to rise upward in the vehicle when a load is received from the rear of the vehicle. The curved portion 45 is curved from the front side of the vehicle toward the lower side of the vehicle, then folded back at the turning point 46, and is curved toward the upper side of the vehicle. That is, the curved portion 45 has a "dogleg shape" protruding downward from the vehicle. The turn-back point 46 is located at the lower end of the curved portion 45 of the vehicle. The turn-back point 46 is a starting point (hereinafter, referred to as “starting point 46”) of the rise of the main exhaust muffling device 13. H shown in FIG. 3 is the distance between the starting point 46 and the main exhaust silencer 13 in the vertical direction of the vehicle. As shown by the alternate long and short dash line in FIG. 3, the main exhaust silencer 13 stands above the vehicle at the curved portion 45 due to the rear collision. Here, M shown in FIG. 3 is a moment for raising the main exhaust muffling device 13 above the vehicle at the time of a rear collision, and L is a moving distance of the main exhaust muffling device 13 to the front of the vehicle due to the rear collision.

The first exhaust pipe 30 has higher rigidity than the second exhaust pipe 40. As described above, the first exhaust pipe 30 extends beyond the fuel tank 5 to the rear of the vehicle. Further, the second exhaust pipe 40 extends to the rear of the vehicle from the first exhaust pipe 30. That is, the exhaust pipe 20 has higher rigidity than the curved portion 45 at the front of the vehicle and at the rear of the vehicle than the fuel tank 5. Specifically, the first exhaust pipe 30 has a higher rigidity by increasing the wall thickness than the second exhaust pipe 40. For example, the wall thickness of the second exhaust pipe 40 is 0.5 to 0.5 to higher. While it is 1 mm, the wall thickness of the first exhaust pipe 30 is 1 to 2 mm. As the evaluation of "rigidity", at least one of compressive rigidity, tensile rigidity, flexural rigidity, shear rigidity, torsional rigidity, and the like may be used, but it is preferable to use compressive rigidity.

According to this configuration, the curved portion 45 has a “dogleg shape” that protrudes downward from the vehicle, so that when a load is applied from the rear of the vehicle, the curved portion 45 is lowered downward from the vehicle as shown in FIG. It breaks. As a result, the exhaust pipe 20 (second exhaust pipe 40) is likely to bend at the curved portion 45, so that the main exhaust muffler 13 is likely to rise upward at the curved portion 45.

Further, since the exhaust pipe 20 is provided with a portion having a higher rigidity (first exhaust pipe 30) than the curved portion 45, the exhaust pipe 20 is curved because it is less likely to be deformed in the portion (first exhaust pipe 30). The portion 45 is more easily deformed. Further, since the portion (first exhaust pipe 30) that is not easily deformed is provided in front of the vehicle and behind the fuel tank 5 of the curved portion 45, the exhaust pipe 20 is provided between the curved portion 45 and the fuel tank 5. It becomes difficult to bend or compress with. That is, the movement of the main exhaust muffling device 13 to the front of the vehicle is suppressed behind the fuel tank 5.

Further, since the starting point (turning point) 46 of the rise of the main exhaust silencer 13 is located at the lower end of the vehicle in the curved portion 45, the distance H between the starting point 46 and the main exhaust silencer 13 is large in the vertical direction of the vehicle. Become. As a result, the moment M that causes the main exhaust muffling device 13 to rise above the vehicle at the time of a rear collision increases, and the main exhaust muffling device 13 easily rises above the vehicle at the curved portion 45.

Therefore, the moving distance L of the main exhaust muffling device 13 to the front of the vehicle becomes small, and it is possible to prevent the main exhaust muffling device 13 from coming into contact with the fuel tank 5.

The first exhaust pipe 30 has higher rigidity than the second exhaust pipe 40 having the curved portion 45, and since the first exhaust pipe 30 and the second exhaust pipe 40 are separate bodies, the second exhaust pipe 40 Is more likely to bend into a "dogleg" shape. Therefore, the movement of the main exhaust muffling device 13 to the front of the vehicle can be suppressed.

Since the above effect can be obtained only by connecting the first exhaust pipe 30 and the second exhaust pipe 40 having different rigidity to each other, a simple structure can be obtained.

The rigidity of the first exhaust pipe 30 and the second exhaust pipe 40 is adjusted by the wall thickness, and the structure is further simple.

Compared with the case where the exhaust pipe 20 (second exhaust pipe 40) is connected to the main exhaust silencer 13 at the end in the vehicle width direction, the main exhaust silencer 13 is more likely to stand up above the vehicle. Further, since the distance between the main exhaust silencer 13 and the fuel tank 5 can be increased, when the main exhaust silencer 13 stands up above the vehicle at the time of a rear collision, the main exhaust silencer 13 comes into contact with the fuel tank 5. Hateful.

Since the rear cross member 8 serves as a stopper and the movement of the main exhaust muffling device 13 to the front of the vehicle is suppressed, it is possible to more reliably prevent the main exhaust muffling device 13 from coming into contact with the fuel tank 5 at the time of a rear collision. Can be done.

By suppressing the contact of the main exhaust silencer 13 with the fuel tank 5, it is possible to suppress the leakage of the fuel stored in the fuel tank 5.

Further, the main exhaust silencer 13 is supported by the support hooks 13f and 6b and the rubber mount 7 so as to be suspended from the rear side frame 6 (bracket 6a) on both outer sides in the vehicle width direction. That is, since the main exhaust silencer 13 is not completely fixed to the rear side frame 6 (bracket 6a), the movement upward of the vehicle is not restricted. Therefore, the main exhaust silencer 13 can stand up above the vehicle at the time of a rear collision, away from the rear side frame 6 (bracket 6a).

Although the present invention has been described above in terms of preferred embodiments, such a description is not a limitation, and of course, various modifications can be made.

In the present embodiment, the first exhaust pipe 30 (exhaust pipe 20) extends below the fuel tank 5 in the front-rear direction, and is located at a position overlapping the fuel tank 5 when viewed from the lower side of the vehicle. Not limited to this. For example, the first exhaust pipe 30 (exhaust pipe 20) may extend in the front-rear direction so as to bypass the outside of the fuel tank 5 in the vehicle width direction, as shown by the alternate long and short dash line in FIG. At this time, the first exhaust pipe 30 (exhaust pipe 20) is not located at a position overlapping the fuel tank 5 when viewed from the lower side of the vehicle. That is, the first exhaust pipe 30 (exhaust pipe 20) may have any configuration as long as it passes near the fuel tank 5.

In the present embodiment, the rigidity of the first exhaust pipe 30 and the second exhaust pipe 40 is adjusted by the wall thickness, but the present invention is not limited to this, and may be adjusted by, for example, a material. At this time, a material having a higher rigidity than the second exhaust pipe 40 may be used for the first exhaust pipe 30.

In the present embodiment, the exhaust pipe 20 is composed of the connecting exhaust pipes 21 and 22, the first exhaust pipe 30, and the second exhaust pipe 40, but is not limited thereto. That is, any configuration may be used as long as the front of the vehicle and the rear of the fuel tank 5 of the exhaust pipe 20 are more rigid than the curved portion 45. For example, the rigidity may be increased by reinforcing the front of the vehicle from the curved portion 45 of the exhaust pipe 20 and the rear of the vehicle from the fuel tank 5 with a reinforcing material.

The mounted parts are not limited to the fuel tank, and may be, for example, a battery or the like.

Since the present invention can be applied to the exhaust structure of an engine, it is extremely useful and has high industrial applicability.

A Engine exhaust structure 1 Engine 3 Body floor 5 Fuel tank (mounted parts)
8 Rear cross member 13 Main exhaust silencer (exhaust silencer)
20 Exhaust pipe 30 1st exhaust pipe 40 2nd exhaust pipe 45 Curved part

Claims (6)

Exhaust silencer located at the rear of the vehicle and
On-board parts placed in front of the vehicle from the exhaust silencer,
It is provided with an exhaust pipe that extends from the engine to the exhaust muffler through the vicinity of the mounted component and leads the exhaust gas discharged from the engine to the exhaust muffler.
The exhaust pipe
The exhaust muffling device rises upward from the vehicle when a load is applied from the rear of the vehicle by bending toward the rear of the vehicle from the front side of the vehicle toward the lower side of the vehicle and then toward the upper side of the vehicle. Has a curved part that promotes
An engine exhaust structure in which the front of the vehicle is higher than the curved portion and the rear of the vehicle is higher than the curved portion of the mounted parts. In claim 1,
The exhaust pipe
A first exhaust pipe that passes near the mounted component and extends to the rear of the vehicle from the mounted component.
It has a second exhaust pipe extending rearward from the first exhaust pipe and including the curved portion.
The first exhaust pipe has an engine exhaust structure having higher rigidity than the second exhaust pipe. In claim 2,
The first exhaust pipe has an engine exhaust structure having a larger wall thickness than the second exhaust pipe. In any one of claims 1 to 3,
The exhaust silencer has a substantially box-shaped shape with the vehicle width direction as the longitudinal direction.
The exhaust pipe is an engine exhaust structure connected to a substantially central portion of the exhaust silencer in the vehicle width direction. In any one of claims 1 to 4,
An engine exhaust structure in which a rear cross member extending in the vehicle width direction is arranged between the mounted component and the exhaust silencer in the front-rear direction of the vehicle. In any one of claims 1 to 5,
The mounted component is an engine exhaust structure, which is a fuel tank.

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