CN112922710B

CN112922710B - Exhaust system

Info

Publication number: CN112922710B
Application number: CN202011126510.5A
Authority: CN
Inventors: 阿希舍克·米什拉; 舒罕·杜贝
Original assignee: Shangyinuo Motorcycle Co ltd
Current assignee: Shangyinuo Motorcycle Co ltd
Priority date: 2019-12-05
Filing date: 2020-10-20
Publication date: 2023-03-14
Anticipated expiration: 2040-10-20
Also published as: CN112922710A

Abstract

In one aspect of the invention, a vehicle (100) is provided. A vehicle (100) includes: a frame (200); an internal combustion engine (300) swingably mounted to the frame (200) by an engine mounting system (400); an engine cooling fan unit (316) mounted to the internal combustion engine (300); and an exhaust system (500) mounted on the frame (200). The exhaust system (500) comprises: an exhaust pipe (301) including a first bent portion (302), a second bent portion (303), and a tail pipe (330); a second exhaust gas purification device (304 a) located on a downstream end of the tail pipe (330); a muffler device (307) connected to the second exhaust gas purification device (304 a). A second exhaust gas purification device (304 a). The tail pipe (330) is located a predetermined distance below the engine cooling fan unit (316).

Description

Exhaust system

Technical Field

The present disclosure relates to vehicles, and more particularly, to exhaust systems of vehicles.

Background

Vehicles, particularly vehicles configured for riding, such as scooters, motorcycles, tricycles, and quadricycles such as all terrain vehicles), include an internal combustion engine and an exhaust system. Generally, exhaust systems are used to clean the exhaust gases emitted by an internal combustion engine during its operation. The cleaned exhaust gas from the exhaust system is then discharged to the atmosphere.

The exhaust system includes one or more exhaust emission purification devices, such as a first exhaust purification device and a second exhaust purification device. The first exhaust gas purification device is arranged upstream of the muffler, preferably close to the combustion chamber, so that the catalyst contained therein can be activated quickly, while the second exhaust gas purification device extends along the side of the vehicle. In this arrangement, that is, when the first exhaust gas purification apparatus is arranged near the combustion chamber, the catalyst unit is located below or near the engine main body.

Various constraints exist in such positioning of the first exhaust gas purification device. For example, in order to properly clean exhaust gas (exhaust gas), the exhaust gas purification apparatus needs to have a necessary length and/or a sufficient cross-sectional area. An increase in the length of the first exhaust gas purification device leads to an increase in the width of the vehicle and/or to the components of the exhaust system protruding to such an extent that their probability of touching the user and causing combustion problems is greatly increased.

On the other hand, the positioning and routing of the muffler device and the second exhaust gas purification device also largely depend on the length of the first exhaust gas purification device. Therefore, as the length of the first exhaust gas purification device increases, the exhaust pipe, the muffler device and the second exhaust gas purification device need to be routed so that the exhaust pipe, the muffler device and the first exhaust gas purification device are kept away from the engine cooling fan unit, which would otherwise eventually draw in hot air, which is clearly disadvantageous for the engine operation.

Further, the muffler device and the second exhaust gas purification device are routed so that the exhaust pipe, the muffler device, and the second exhaust gas purification device are held in positions where they are unlikely to contact a user and cause a combustion problem.

Disclosure of Invention

In one aspect of the present invention, a vehicle is provided. The vehicle includes: a frame; an engine mounting system; an internal combustion engine, said; the internal combustion engine is swingably mounted to the frame by an engine mounting system; an engine cooling fan unit mounted to an internal combustion engine; and an exhaust system mounted on the frame, the exhaust system comprising: an exhaust pipe including a first bend, a second bend, and a tail pipe, a downstream end of the second bend being fluidly connected to an upstream end of the tail pipe; a first exhaust gas purification device connected between the first bent portion and the second bent portion; a second exhaust gas purification device located on a downstream end of the tail pipe; a muffler device connected to the second exhaust gas purification device, wherein the second exhaust gas purification device. The tail pipe is located at a predetermined distance below the engine cooling fan unit.

The present invention thus provides a second bend in the exhaust pipe that ensures that the tail pipe is located a predetermined distance below the engine cooling fan unit. Therefore, the possibility that the air flowing into the engine cooling fan unit is heated by the exhaust system is eliminated.

The vehicle further comprises a swing arm for mounting the exhaust system on the frame, wherein the swing arm comprises a body portion, a first protrusion, a second protrusion positioned offset with respect to the first protrusion, and a main component, wherein each of the first protrusion and the second protrusion is connected to the muffler device. The first protrusion is longer in length than the second protrusion such that the muffler device is located at a predetermined distance from the main body portion of the swing arm. The second bent portion of the exhaust pipe includes a first half and a second half joined to the first half. The second bent portion of the exhaust pipe has a small bend in such a manner that the exhaust pipe is held toward the frame. The second bend of the exhaust pipe ensures that the maximum inclination angle of the vehicle is allowed.

The present invention thus provides a second bend of the exhaust pipe which ensures that the maximum angle of inclination of the vehicle is allowed. At the same time, the second curved portion of the exhaust duct ensures that the user's body part (L) and the engine cooling fan unit are sufficiently spaced from the exhaust duct. Further, even when the overall layout of the exhaust system is tiltable, the difference in length between the first projection and the second projection allows the muffler device to be located at a desired position or a straight position with respect to the side body cover of the vehicle.

In another aspect of the present invention, a vehicle is provided. The vehicle includes: a frame; an internal combustion engine; an engine mounting system for swingably mounting the internal combustion engine to the frame, the engine mounting system including a right link arm, a left link arm, a pivot, and an engine support; and an exhaust system mounted on the frame, the exhaust system including an exhaust pipe, a first exhaust gas purification device, a second exhaust gas purification device, a muffler device, and a swing arm. The exhaust pipe includes a first bent portion, a second bent portion, and a tail pipe. The downstream end of the second bend is fluidly connected to the upstream end of the tailpipe. The second bent portion of the exhaust pipe includes a first half and a second half joined to the first half. The first exhaust gas purification device is connected between the first bend and the second bend. The first exhaust gas purification device is located on the exhaust pipe between the first curved portion and the second curved portion and above the left link arm of the engine mount system in a direction substantially along the width direction of the frame. The second exhaust gas purification device is located on the downstream end of the tail pipe. The muffler device is connected to the second exhaust gas purification device. Wherein the second exhaust gas purification device. The swing arm is for mounting the exhaust system on the frame, wherein the swing arm includes a body portion, a first protrusion, a second protrusion positioned offset from the first protrusion, and a main component. The first protrusion is longer in length than the second protrusion such that the muffler device is located at a predetermined distance from the main body portion of the swing arm. The tail pipe is located at a predetermined distance below the engine cooling fan unit.

Accordingly, the present invention provides a vehicle having a second bend of an exhaust pipe that ensures that a tail pipe is located at a predetermined distance below an engine cooling fan unit. Therefore, the possibility that the air flowing into the engine cooling fan unit is heated by the exhaust system is eliminated.

Drawings

The invention itself, together with further features and attendant advantages, will be best understood by reference to the following detailed description, taken in conjunction with the accompanying drawings. One or more embodiments of the present invention will now be described, by way of example only, with like reference numerals indicating like elements, and in which:

FIG. 1 is a side view of an exemplary vehicle according to an embodiment of the present invention;

FIG. 2 is a view of a body frame of a vehicle according to an embodiment of the invention;

FIG. 3 is a bottom view of the vehicle according to an embodiment of the present invention;

FIG. 4 is a bottom view of a power unit of a vehicle along with an exhaust system according to an embodiment of the present invention;

FIG. 5 is a view of an exhaust system of a vehicle according to an embodiment of the invention;

FIG. 6 is a side view of an exhaust system of a vehicle according to an embodiment of the present invention;

FIG. 7 is a view of an exhaust system of a vehicle according to yet another embodiment of the invention; and

fig. 8 is an exploded view of an exhaust system of a vehicle according to still another embodiment of the present invention.

Unless specifically noted, the drawings referred to in this description are not to be understood as being drawn to scale, and such drawings are merely exemplary in nature.

Detailed Description

While the invention is susceptible to various modifications and alternative forms, embodiments thereof have been shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that an arrangement, structure, or method that comprises a list of elements or steps does not include only those elements or steps, but may include other elements or steps not expressly listed or inherent to such arrangement, structure, or method. In other words, without further constraints, one or more elements beginning with "\8230;" does not preclude the presence of other or additional elements in the system or device.

For a better understanding of the present invention, reference will now be made to the embodiments illustrated in the drawings and described herein below, and in addition, in the following drawings, like numerals are used to identify like components in the various views.

Although the present invention is illustrated in the context of a vehicle, the exhaust system and aspects and features thereof may also be used with other types of vehicles. Throughout the specification, the terms "vehicle", "two-wheeled vehicle" and "motorcycle" have been used interchangeably. The term "vehicle" includes vehicles such as motorcycles, scooters, bicycles, mopeds, scooter-type vehicles, all Terrain Vehicles (ATVs), and the like.

The terms "forward/forward", "rearward/rearward", "upper/above/top", "lower/below/downward, bottom", "left/left", "right/right" used herein denote directions as seen by a straddle-seated vehicle driver, and these directions are represented in the drawings by arrows Fr, rr, U, lr, L, R.

Referring to fig. 1, a vehicle (100) according to an embodiment of the invention is depicted. The vehicle (100) referred to herein is realized as a motorcycle. Alternatively, without limiting the scope of the invention, the vehicle (100) may be embodied as any other cycling vehicle such as a scooter, tricycle, all-terrain vehicle (ATV), and the like.

As shown in fig. 1, the vehicle (100) includes a main body frame (200), a pair of front forks, a front cover (109), a rear cover (111), front wheels (108), a steering handle (107), an oil tank (not shown) disposed below a seat (106), a utility tank, an engine unit (300), an exhaust system (500), an engine cooling fan unit (316), a side body cover (104), a front cover (126), a leg shield (leg shield) (103), a lower front cover (102), tail lights (139), headlights (123), a foot pedal (128), a rear suspension (rear suspension) (not shown in the drawings), a rear grip (141), and rear wheels (127).

As shown in fig. 2, a vehicle body frame (200), also referred to as a "frame (200)", includes a head pipe (110), a main frame (112), and a pair of rear seat sub-frames (114 a), (114 b), and one or more cross frames (116), (120), and (124). The main frame (112) extends downward and rearward from the head pipe (110) and then extends substantially horizontally. The main frame (112) is provided with a cross member (124), and the cross member (124) is connected to the rear end of the main frame (112). The cross frame member (124) extends in the lateral direction of the vehicle (100). The cross frame member (124) supports an engine unit (300), the engine unit (300 is also referred to as an "internal combustion engine (300)", "power unit (300)", or "engine (300)", a pair of left and right rear seat sub-frames (114 a) and (114 b) extend rearward and upward from an end of the cross member (124) and then extend substantially horizontally, rear portions of the rear seat sub-frames (114 a) and (114 b) are bent at rear ends and connected by a bracket (not shown in the drawings), a front side cross frame (120) configured in a "U" shape is provided on front portions of the rear seat sub-frames (114 a) and (114 b), a rear side cross frame (116) is configured on a substantially middle portion of the rear sub-frames (114 a) and (114 b).

On the upper surface of the front part of the substantially horizontal portion of the main pipe (112), a cross pipe (122) is provided in the lateral direction, and paired left and right sub frames (117 a) and (117 b) extend rearward from both end sides of the cross pipe (122). In a side view, these left and right subframes (117 a) and (117 b) extend from the front to the rear in their slightly inclined state, and these left and right subframes (117 a) and (117 b) are welded to a cross member (124) forming a stepped floor structure (125).

As shown in fig. 1, the footrest (128) is disposed above the stepped floor structure (125). The footrest (128) is a part on which the rider puts his/her feet. Further, a first U-shaped frame tube (118 a) extends obliquely downward and rearward, and a front end of the first U-shaped frame tube (118 a) is welded to the left rear seat sub-frame (114 a) at a position close to the front side cross frame (120). Similarly, a second U-shaped frame tube (not shown) extends obliquely downward and rearward, and the front end of the second U-shaped frame tube is welded to the right sub-frame (114 b) at a position close to the front side cross frame (120). The first and second U-shaped frame tubes (118 a ) are used to mount the foot peg.

Referring to fig. 1 and 2, the head tube (110) is operatively connected to the front fork (121), and the front wheel (108) is attached to the lower end of the front fork. A handle (107) is attached to the upper end of the head tube (110). The headlight (123) is arranged in front of the handle (107). A front cover (109) is provided to cover an upper portion of the front wheel (108). The rear seat sub-frames (114 a) and (114 b) support a seat (106) on which a rider straddles.

A leg shield (103) for protecting the rider's legs is provided on the front side. A center frame cover is provided behind the leg shield plate (103). A tail lamp 139 and a rear cover 111 are provided at the rear of the side body cover 104. A fuel tank (not shown) is disposed inside the side body cover (104) below the seat (106). The front cover (126) and the lower front cover (102) form a front cover portion of the vehicle (100).

As shown in fig. 2, a fuel tank (not shown) is mounted in a space between the rear end portions of the rear seat sub-frames (114 a, 114 b) and the rear side cross frame (116). The rear cross frame (116) has one or more mounting devices, such as brackets or the like, for mounting the fuel tank. The engine unit (300) is disposed downward in front of the fuel tank.

In one embodiment, the engine unit (300) is a single cylinder, four-stroke cycle, and forced air cooled internal combustion engine. The engine unit (300) includes: a crankcase; a cylinder block attached to a front end of the crankcase; a cylinder top (cylinder head) attached to the cylinder block; and a head cover for covering a front opening in the cylinder top. The power unit (300) is disposed in a substantially horizontal position in the vehicle (100), and the roof is positioned toward the front wheels of the vehicle (100).

The crankcase includes a crankshaft (not shown) extending in the left-right direction of the vehicle (100). The crankshaft is connected to the piston. A generator/alternator (not shown in the drawings) is provided on the right end of the crankshaft. An engine cooling fan unit (316) is mounted to the right side of the crankshaft. The engine cooling fan unit (316) includes an outer peripheral edge and a fan cover having a plurality of fins covering a right side portion of the engine cooling fan. Air in the power unit (300) is drawn in by an engine cooling fan unit (316) driven by the crankshaft. The engine cooling fan unit (316) is adapted to take in air from the outside and send the air into the power unit (300) to cool the cylinder block and other components in the engine unit (300).

The cylinder top includes an intake port (not visible in the drawings) and an exhaust port (321). An exhaust port (321) is provided in a cylinder head wall that faces the ground in the vehicle layout. The intake port is provided in the other wall of the cylinder top opposite to the exhaust port (321). As shown in fig. 5, the engine unit (300) has an air cleaner mounted on the upper surface side of the transmission chamber (204) on the rear side of the vehicle (100), and the engine unit (300) has a throttle device joined to the front of the air cleaner. An intake pipe (not shown in the drawings) extends forward from the throttle body, and the mixed air is supplied to the engine unit (300) through the intake pipe. The transmission chamber (204) comprises: a V-belt wrapped around a drive pulley mounted to a left end of the crankshaft; and a driven pulley mounted to the driven shaft. The engine unit (300) rotatably supports the rear wheels (127) on the rear side of the vehicle (100) via the transmission chamber (204) and the reduction chamber.

Further, as shown in fig. 3, 4 and 5, the engine unit (300) includes an exhaust system (500), the exhaust system (500) including an exhaust pipe (301), a muffler device (307) and an oxygen detector. An exhaust pipe (301) is connected to the downstream end of the exhaust port (321). The muffler device 307 is provided with a discharge port (324) exposed to the atmosphere. A muffler device (307) is connected to the exhaust pipe (301), and allows exhaust gas to flow from a downstream end of the exhaust pipe (301) to the discharge port (324). The muffler device (307) is configured to suppress sound generated by the exhaust gas. In an embodiment, the exhaust system (500) further comprises an exhaust gas cleaning device (304), also referred to as first exhaust gas cleaning device (304). The oxygen detector is disposed upstream of a first exhaust gas purification device (304), such as a catalyst.

The engine unit (300) is swingably supported by the main body frame (200) by an engine mount system (400), and this engine mount system (400) is also referred to as a swing support system (400). The swing support system (400) includes a right link arm (133R) and a left link arm (133L). The swing support system (400) further includes a pivot (132). In one embodiment, the pivot (132) includes: two first pivots, namely a first pivot (132R) and a first pivot (132L), collectively referred to as first pivots (132R), (132L); and an engine support device (131) comprising a right engine support device (131R) and a left engine support device (131L). The engine unit (300) and the rear wheel (127) integrally swing about the first pivot shafts (132R) and (132L).

Thus, the right link arm (133R) and the left link arm (133L) are swingably supported by the main body frame (200). In one embodiment, the right engine support (131R) and the left engine support (131L) are left and right ends of a single shaft with a bolt at each end. In one embodiment, the right engine support (131R) and the left engine support (131L) are separate shafts, each of which includes a bolt. The first pivots (132R) and (132L) extend in the left-right direction. The first pivot (132R) and the first pivot (132L) are disposed coaxially. In one embodiment, the first pivot (132R) and the first pivot (132L) form a single axis.

The right link arm (133R) includes a curved profile. In one embodiment, the curved profile may be semi-circular. The curved profile of the right link arm (133R) includes a concave portion and a convex portion opposite to the concave portion. In one embodiment, the right engine support (131R) and the left engine support (131L) form a single shaft. A right engine support (131R) and a left engine support (131L) are disposed rearward of the first pivots (132R) and (132L). In one embodiment, the right link arm (133R), the left link arm (133L), the first pivot 132R, (132L), and the right engine support (131R) and the left engine support (131L) together form an integral unit. As shown in fig. 3 and 4, the exhaust port (321) is located between the right link arm (133R) and the left link arm (133L) when viewed from the bottom side. An exhaust pipe (301) is connected to the downstream end of the exhaust port (321).

The exhaust pipe (301) includes a first bent portion (302), a second bent portion (303), and a tail pipe (330). The first exhaust gas purification device (304) connects the first curved section (302) and the second curved section (303). In an embodiment, the first exhaust gas purification device (304) is realized as a linear section connecting the first bend (302) and the second bend (303). The upstream end of the first curved portion (302) has a flange (not numbered) that is communicatively connected to the exhaust port (321). The first curved portion (302) extends downward and to the side from the exhaust port (321) substantially in the width direction of the vehicle (100). A first curved portion (302) is connected to an upstream end of the linear portion. A first curved portion (302) of the exhaust pipe (301) is disposed in between the exhaust port (321) and the right link arm (133R) and the left link arm (133L) when viewed in the up-down direction of the vehicle (100). In an embodiment, both the first curved portion (302) of the exhaust pipe (301) and the first exhaust gas purification device (304) may be disposed in between the exhaust port (321) and the right link arm (133R) and the left link arm (133L) when viewed in the up-down direction of the vehicle (100).

The linear portion of the exhaust pipe (301) extends substantially in the width direction of the vehicle (100). A first exhaust gas purification device (304) is provided in a linear portion of the exhaust pipe (301). In an embodiment, the first exhaust gas purification device (304) is realized as a linear part of the exhaust pipe (301). As shown in fig. 3, the first bent portion (302) of the exhaust pipe (301) is disposed in between the first pivot shafts (132R), (132L) and the right and left engine support devices (131R, 131L) when viewed in the front-rear direction of the vehicle (100). In one embodiment, the first bent portion (302) of the exhaust pipe (301) and the first exhaust gas purification device (304) are disposed in between the first pivot shafts (132R), (132L) and the right and left engine support devices (131R, 131L) when viewed in the front-rear direction of the vehicle (100). A first exhaust gas purification device (304) of the exhaust pipe (301) extends at an angle to the longitudinal direction of the vehicle (100). In one embodiment, the first exhaust gas purification device (304) of the exhaust pipe (301) extends substantially in the width direction of the vehicle (100).

The upstream end of the second curved portion (303) is connected to the downstream end of the first exhaust gas purification device (304). Further, an upstream end of the second curved portion (303) extends in a rearward direction while being curved, so that a downstream end of the tail pipe (330) is connected to the muffler device (307). The muffler device (307) is arranged almost in the front-rear direction of the vehicle (100) in the longitudinal direction thereof. The second curved portion (303) includes a first half portion (303 a) and a second half portion (303 b) joined to the first half portion (303 a). Due to such a configuration, the second bent portion (303) of the exhaust pipe (301) has a small bend in such a manner that the exhaust pipe (301) is held toward the frame (200). A small bend as used herein refers to a bend having a small diameter. Thus, the second bend (303) of the exhaust pipe (301) ensures that the maximum inclination angle of the vehicle (100) is allowed. At the same time, the second bent portion (303) of the exhaust pipe (301) ensures a sufficient clearance from the exhaust pipe (301).

As shown in fig. 3, 4 and 5, the exhaust system (500) further includes a second exhaust gas purification device (304 a). The second exhaust gas purification device (304 a) is located on the downstream end of the tail pipe (330). The second exhaust gas purification device (304 a) and the muffler device (307) are positioned along the linear axis of the tail pipe (330). The tail pipe (330) is located a predetermined distance below the engine cooling fan unit (316).

Referring now to fig. 7 and 8, the exhaust system (500) further includes a swing arm (600), the swing arm (600) for mounting the exhaust system (500) on the frame (200). The swing arm (600) includes a main body portion (602), a first protrusion (604), a second protrusion (606) positioned offset from the first protrusion (604), and a main component (main vision) (608). Each of the first protrusion (604) and the second protrusion (606) is connected to the muffler device (307). In an embodiment, the first protrusion (604) and the second protrusion (606) are connected to a bracket (308 a) and a bracket (308 b), respectively, of the muffler device (307). Specifically, the swing arm (600) is used to mount a muffler device (307) of the exhaust system (500) on the frame (200).

As shown in fig. 8, the first protrusion (604) is longer in length than the second protrusion (606) so that the muffler device (307) is located at a predetermined distance from the main body portion (602) of the swing arm (600). In one embodiment, the first protrusion (604) has a length L1 and the second protrusion (606) has a length L2. In such an example, length L1 is different from length L2. In another example, length L1 is greater than length L2.

In an embodiment, the first exhaust gas purification device (304) and/or the second exhaust gas purification device (304 a) may be a catalytic converter. In one example, the first exhaust gas purification device (304) may be a three-way catalyst. The three-way catalyst may be a honeycomb structure, or any other suitable structure of catalyst having a coating of a metal such as platinum, palladium, rhodium, and similar combinations of metals. For example, the configurations are not limited thereto, and other configurations are possible.

At least a part of the first exhaust gas purification device (304) overlaps with one of the right link arm (133R) and the left link arm (133L) when viewed from the bottom side of the vehicle (100). In this arrangement, the first exhaust gas purification device (304) is arranged near the engine unit (300) and closer to the exhaust port (321), and therefore, the temperature of the first exhaust gas purification device (304) can easily reach the activation temperature due to the heat from the exhaust gas coming out of the exhaust port (321) of the engine unit (300), and for example, even in a cold state immediately after starting traveling, the exhaust gas mixture is heated in a relatively short time, thereby quickly activating the first exhaust gas purification device (304). The first exhaust gas purification device (304) is provided at a position lower than the right link arm (133R) of the swing support system (400) or at a position below the right link arm (133R) of the swing support system (400).

During the course of operation of the vehicle (100), when the power unit (300) is started, exhaust gas is discharged from the exhaust pipe (301) via the exhaust port (321) from the combustion chamber in the cylinder head. The exhaust gas flows into a first exhaust gas purification device (304) provided in the exhaust pipe (301) through the inside of a first bent section (302) of the exhaust pipe (301). The exhaust gas further passes through the second bend (303) of the exhaust pipe (301), and then passes through the second exhaust gas purification device (304 a) and the muffler device (307) to be discharged from the outlet (324) of the muffler device (307) to the atmosphere.

In view of the above, the present invention provides a vehicle (100) that allows a first exhaust gas purification device (304) to be positioned close to an engine unit (300) and an exhaust port (321), thereby allowing the temperature of the first exhaust gas purification device (304) to quickly reach an activation temperature due to heat from exhaust gas coming out from the exhaust port (321) of the engine unit (300).

Further, the present invention allows the first exhaust gas purification device (304) to be positioned below the right link arm (133R) of the engine mount system (400). Such positioning of the first exhaust gas purification device (304) below the right link arm (133R) allows accommodation of various sizes of exhaust gas purification devices. Specifically, a first exhaust gas purification apparatus 304 of a larger diameter may be provided in the exhaust pipe (301). Further, since the right link arm (133R) is located above the first exhaust gas purification device (304), the size of the first exhaust gas purification device (304) does not cause a requirement to move the right link arm 133R closer to the ground surface (S).

The second curved portion (303) includes a first half portion (303 a) and a second half portion (303 b). Due to such a configuration, the second bent portion (303) of the exhaust pipe (301) has a small bend. The second bend (303) of the exhaust pipe (301) ensures that the maximum inclination angle of the vehicle (100) is allowed. At the same time, the second curved portion (303) of the exhaust duct (301) ensures a sufficient clearance between the user's body part (L) and the engine cooling fan unit (316) and the exhaust duct (301). The second bend (303) of the exhaust pipe (301) also ensures that the tail pipe (330) is located at a predetermined distance below the engine cooling fan unit (316). Thus, the possibility that the air flowing into the engine cooling fan unit (316) is heated by the exhaust system (500) is eliminated.

Further, a swing arm (600) that mounts the exhaust system (500) on the frame (200) has a first protrusion (604) as follows: the first protrusion (604) is longer than the second protrusion (606) in length so that the muffler device (307) is located at a predetermined distance from the main body portion (602) of the swing arm (600). The difference in length between the first projection (604) and the second projection (606) allows the muffler device (307) to be located at a desired position or a linear position with respect to the side body cover (104) of the vehicle (100) even when the overall layout of the exhaust system (500) may be inclined. Further, the first protrusion (604) and the second protrusion (606) allow the exhaust system (500) to be positioned at a predetermined offset relative to the side body cover (104) of the vehicle (100), thereby substantially eliminating the possibility of the exhaust system (500) contacting the user's body (L) and causing combustion problems.

Although several embodiments of the present invention have been described above, it will be understood that the present invention is not limited to the above embodiments, and may be appropriately modified within the spirit and scope of the present invention.

While considerable emphasis has been placed herein on the particular features of the invention, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the invention. These and other modifications in the nature of the invention or preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be clearly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

Claims

1. A vehicle, comprising:

a frame (200);

an internal combustion engine (300);

an engine mounting system (400) for swingably mounting the internal combustion engine (300) to the frame, the engine mounting system (400) comprising:

a right link arm (133R);

a left link arm (133L);

a pivot (132); and

an engine support device (131); and

an exhaust system (500) mounted on the frame (200), the exhaust system (500) comprising:

an exhaust pipe (301) comprising a first bend (302), a second bend (303), and a tailpipe (330), a downstream end of the second bend (303) being fluidly connected to an upstream end of the tailpipe (330), the second bend (303) of the exhaust pipe (301) comprising a first half (303 a) and a second half (303 b) joined to the first half (303 a);

a first exhaust gas purification device (304) connected between the first curved portion (302) and the second curved portion (303), the first exhaust gas purification device (304) being located on the exhaust pipe (301), between the first curved portion (302) and the second curved portion (303), and above the left link arm (133L) of the engine mount system (400) in a direction substantially along a width direction of the frame (200);

a second exhaust gas purification device (304 a) located on a downstream end of the tail pipe (330);

-a muffler device (307) connected to the second exhaust gas purification device (304 a); and

a swing arm (600) for mounting the exhaust system (500) on the frame (200), wherein the swing arm (600) comprises a body portion (602), a first protrusion (604), a second protrusion (606) positioned offset with respect to the first protrusion (604), and a main part (608), wherein the first protrusion (604) has a different length than the second protrusion (606).

2. The vehicle (100) of claim 1, characterized in that the first protrusion (604) is longer in length than the second protrusion (606) such that the muffler device (307) is located at a predetermined distance from the main body portion (602) of the swing arm (600), and wherein the tail pipe (330) is located at a predetermined distance below the engine cooling fan unit (316).

3. A vehicle (100) comprising:

a frame (200);

an engine mount system (400);

an internal combustion engine (300) swingably mounted to the frame (200) by the engine mounting system (400);

an engine cooling fan unit (316) mounted to the internal combustion engine (300); and

an exhaust pipe (301) comprising a first bend (302), a second bend (303), and a tailpipe (330), a downstream end of the second bend (303) being fluidly connected to an upstream end of the tailpipe (330),

a first exhaust gas purification device (304) connected between the first curved portion (302) and the second curved portion (303),

a second exhaust gas purification device (304 a) located on a downstream end of the tail pipe (330),

a muffler device (307) connected to the second exhaust gas purification device (304 a),

wherein the tail pipe (330) of the exhaust pipe (301) is located at a predetermined distance below the engine cooling fan unit (316).

4. The vehicle (100) of claim 3, further comprising a swing arm (600), the swing arm (600) for mounting the exhaust system (500) on the frame (200), wherein the swing arm (600) comprises a body portion (602), a first protrusion (604), a second protrusion (606) positioned offset with respect to the first protrusion (604), and a main component (608), wherein each of the first protrusion (604) and the second protrusion (606) is connected to the muffler device (307).

5. The vehicle (100) of claim 4, characterized in that the first protrusion (604) is longer in length than the second protrusion (606) such that the muffler device (307) is located at a predetermined distance from the main body portion (602) of the swing arm (600).

6. The vehicle (100) according to claim 3, characterized in that the second bent portion (303) of the exhaust pipe (301) includes a first half (303 a) and a second half (303 b) joined to the first half (303 a).

7. The vehicle (100) according to claim 6, characterized in that the second bent portion (303) of the exhaust pipe (301) has a small bend in such a manner that the exhaust pipe (301) is held toward the frame (200).

8. Vehicle (100) according to claim 7, characterised in that the second bend (303) of the exhaust pipe (301) ensures that a maximum inclination angle of the vehicle (100) is allowed.