JP6533461B2 - Exhaust system structure of swinging vehicle - Google Patents

Description

  The present invention relates to an exhaust system structure of a rocking vehicle.

  Conventionally, in the exhaust system structure of a swing vehicle provided with an exhaust pipe and an expansion chamber disposed below the internal combustion engine, a plurality of expansion chambers provided side by side in the front-rear direction straddle the center in the vehicle width direction and It is known to arrange them so as to overlap each other (see, for example, Patent Document 1).

Japanese Patent Application Publication No. 2007-118900

By arranging a plurality of expansion chambers in the front-rear direction as in the above-described conventional exhaust device structure, the expansion chambers can be provided by effectively utilizing the front and rear spaces, but depending on the layout of parts of the vehicle In some cases, the weight balance of the vehicle in the vehicle width direction is biased. In particular, in a swing vehicle in which the vehicle body swings and is banked, it is desirable to improve the weight balance.
The present invention has been made in view of the above-described circumstances, and it is an object of the present invention to improve the weight balance between the left and right of a vehicle in the exhaust system structure of a rocking vehicle.

In order to achieve the above object, the present invention provides an internal combustion engine (10) mounted between a front wheel (2) and a rear wheel (3), and an exhaust system for silencing exhaust gas from the internal combustion engine (10) And an exhaust pipe (71, 100) having an upstream end connected to the exhaust port (52L, 52R, 53L, 53R) of the internal combustion engine (10). 101) and an expansion chamber (72, 102) connected to the downstream end of the exhaust pipe (71, 101), wherein the expansion chamber (72, 102) is disposed near the lower part of the vehicle In the exhaust system of the present invention, the expansion chambers (72, 102) are a first silencer (72) and a second silencer (102) separated from each other in the longitudinal direction of the vehicle, and the first silencer (72) And the second silencer (102) is left with respect to the vehicle center (C) The exhaust pipes (71, 101) of the exhaust device (70, 100) are disposed apart from each other in a direction, and are constituted of a pair of exhaust pipes (71, 101) independent of each other, and the first silencer (72 And the second silencer (102) are divided into a pair of the exhaust pipes (71, 101), and the exhaust port (78a) of the first silencer (72) and the second silencer (102). the exhaust port (102d) of) the longitudinal direction of the vehicle, and, while being spaced apart in the lateral direction, are spaced from each other in the vertical direction so as not to overlap each other in the vertical direction of the vehicle, said first The second silencer (102) is a front silencer (102) disposed on the front side in the longitudinal direction of the vehicle, and the front silencer (102) is disposed below the internal combustion engine (10); 1 silencer (72) is in front of the vehicle Of the rear side silencer (72) disposed on the rear side of the direction, and the rear side silencer (72) is a swing arm (swingably supporting the rear wheel (3) on the vehicle body frame (F) 30), and the front side silencer (102) disposed below the internal combustion engine (10) avoids an oil pan (44) bulging from the lower part of the internal combustion engine (10) The exhaust pipe (71) of the rear silencer (72) is disposed on the side, and is disposed to pass through one side of the oil pan (44), and the internal combustion engine (10) is a pair of cylinder parts The V-type internal combustion engine is arranged in a V-shape in which (42, 43) are arranged in the front and rear direction, and the front silencer (102) and the rear silencer (72) are each of the cylinder portions (42, 43) Divided into a plurality of exhaust pipes (71, 101) independently connected to the The V-type internal combustion engine (10) has a plurality of parallel cylinders in one cylinder portion (42), and a collecting portion where the exhaust pipes (71) extended from the cylinders merge (75) is disposed on the lower side of the V-type internal combustion engine (10) and opposite to the front silencer (102) with the oil pan (44) in front of the rear silencer (72) It is characterized by being.
According to the present invention, an exhaust system for muffling exhaust gas from an internal combustion engine includes an exhaust pipe whose upstream end is connected to an exhaust port of the internal combustion engine, and an expansion chamber connected to the downstream end of the exhaust pipe The expansion chamber is disposed closer to the lower portion of the vehicle, the expansion chamber includes a plurality of expansion chambers separated from each other in the front-rear direction of the vehicle, and the plurality of expansion chambers are disposed separately in the left-right direction with respect to the vehicle center There is. Thus, the plurality of expansion chambers are disposed apart from each other in the front-rear direction of the vehicle and are mutually separated from each other in the left-right direction with respect to the center of the vehicle. Even in the configuration in which the expansion chambers are arranged in the vehicle width direction, the left-right weight balance of the vehicle can be improved. Further, the exhaust pipe of the exhaust system is constituted of a plurality of exhaust pipes independent of each other, and the plurality of expansion chambers are silencers which are divided into a plurality of exhaust pipes independent of each other. Thus, since the exhaust pipes are independent of each other, the silencers can be easily disposed apart from each other in the left-right direction with respect to the center of the vehicle. Further, since the expansion chambers are silencers that increase in weight, the left and right weight balances can be effectively improved by arranging them separately in the left-right direction.
In addition, since the front silencer is disposed below the internal combustion engine and the rear silencer is disposed below a swing arm that pivotally supports the rear wheel on the vehicle body frame, the space below the internal combustion engine and the swing The space under the arms can be used effectively to arrange the front and rear silencers separately in the front and rear and left and right. Further, the front silencer disposed below the internal combustion engine is disposed on the other side avoiding the oil pan bulging out from the lower portion of the internal combustion engine, and the exhaust pipe of the rear silencer passes through one side of the oil pan Because of the arrangement, the space under the internal combustion engine can be divided into the arrangement of the front side silencer on the other side of the oil pan and the exhaust pipe on the one side of the oil pan, increasing the volume of the front side silencer. it can. Further, the internal combustion engine is a V-shaped internal combustion engine arranged in a V-shape in which paired cylinder portions are arranged back and forth, and a plurality of front and rear silencers are connected independently to each cylinder portion. It is divided into exhaust pipes and arranged. Thus, since the plurality of exhaust pipes are independently connected to the cylinder sections of the V-type internal combustion engine, the degree of freedom in the arrangement of the exhaust pipes is high, and the muffle provided in the exhaust pipes is at the vehicle center It is easy to arrange separately in the left and right direction. Further, the front silencer and the rear silencer can be efficiently spaced apart in the front-rear direction corresponding to the positions of the cylinder portions arranged in the front-rear direction. Further, the V-type internal combustion engine has a plurality of parallel cylinders in one cylinder portion, and a collective portion where exhaust pipes extending from the cylinders merge is a lower and front silencer of the V-type internal combustion engine Is located on the front side of the rear silencer opposite to the oil pan. As a result, the collection portion of the exhaust pipe can be disposed at a position below the V-type internal combustion engine and at a different position from the front and rear silencers, and the exhaust pipe can be efficiently utilized by utilizing the space below the V-type internal combustion engine. It can be arranged.

Furthermore, the present invention is, before SL front silencer (102), said curved surface portion along the side surface of the bulging portion (87) of the oil pan (44) side face has the oil pan (44) and (102f) It is characterized by having.
According to the present invention, since the front side muffler is provided with a curved surface portion along a side surface of the bulging portion of the oil pan, it can increase the capacity of the front muffler.
Further, according to the present invention, an exhaust valve (112) for controlling the opening and closing of an exhaust pipe line in the exhaust pipe (101) located in front of the rear side silencer (72) and below the internal combustion engine (10) And a drive pulley portion (112c) for driving the exhaust valve (112) is provided on an exhaust pipe side surface facing the internal combustion engine (10).
According to the present invention, the exhaust pipe located in the lower part of the internal combustion engine in front of the rear silencer is provided with an exhaust valve for controlling the opening and closing of the exhaust pipe, and the drive pulley for driving the exhaust valve is an internal combustion engine. It is provided on the side of the exhaust pipe facing the engine. Thus, the drive pulley portion can be compactly provided on the outer side and the lower side, and the clearance between the exhaust valve and the road surface can be secured.

Et al of the present invention, the V-type internal combustion engine (10) includes a plurality of parallel cylinders each cylinder portion (42, 43), said exhaust pipe extending from each said cylinder (71,101 The exhaust pipe (71, 101) is provided with a collecting part (75, 105) where each of the cylinder parts (42, 43) merges, and extends from each cylinder part (42, 43). 10) extending oppositely, said collecting part (75, 105) being arranged to pass by front and back below said V-type internal combustion engine (10) and characterized by not overlapping in front and back .
According to the present invention, the V-type internal combustion engine has a plurality of parallel cylinders in each of the cylinder portions, and includes, for each cylinder portion, a collective portion where exhaust pipes extended from the cylinders merge, and extends from each cylinder portion The exhaust pipe extends opposite to the lower part of the V-type internal combustion engine, and the collecting part is disposed to pass by the front and rear of the V-type internal combustion engine and does not overlap in the front-rear direction. As a result, it is possible to compactly arrange, in the space below the V-type internal combustion engine, a collection of exhaust pipes in which a plurality of exhaust pipes extend for each cylinder.
Further, according to the present invention, an internal combustion engine (10) mounted between a front wheel (2) and a rear wheel (3) and an exhaust system (70, 100) for muffling exhaust gas from the internal combustion engine (10) And an exhaust pipe (71, 101) whose upstream end is connected to an exhaust port (52L, 52R, 53L, 53R) of the internal combustion engine (10), and the exhaust system (70, 100); And an expansion chamber (72, 102) connected to the downstream end of the exhaust pipe (71, 101), wherein the expansion chamber (72, 102) is disposed closer to the lower portion of the vehicle. The expansion chamber (72, 102) includes a plurality of expansion chambers (72, 102) separated from each other in the longitudinal direction of the vehicle, and the plurality of expansion chambers (72, 102) with respect to the vehicle center (C) Are disposed apart from each other in the left and right direction, The exhaust pipe (71, 101) of (70, 100) is composed of a plurality of exhaust pipes (71, 101) independent of each other, and the plurality of expansion chambers (72, 102) are a plurality of the above independent of each other. A front silencer (102), which is a silencer separately disposed in the exhaust pipe (71, 101) and disposed on the front side in the front-rear direction of the vehicle, is disposed below the internal combustion engine (10). A rear silencer (72) disposed on the rear side in the front-rear direction is disposed below a swing arm (30) that swingably supports the rear wheel (3) on the vehicle body frame (F), and the internal combustion engine The front silencer (102) disposed below the engine (10) is disposed on the other side avoiding the oil pan (44) bulging out from the lower part of the internal combustion engine (10), and the rear silencer The exhaust pipe (71) of (72) is the oil pan Are arranged to pass through one side of 44), the internal combustion engine (10) is a V-type internal combustion engine arranged in a V-shape cylinder portion forming a pair (42, 43) is arranged in the front and rear, the front silencer (102) and the rear side silencer (72) are divided into a plurality of the exhaust pipes (71, 101) independently connected to the respective cylinder parts (42, 43), and the V type The internal combustion engine (10) has a plurality of parallel cylinders in one cylinder portion (42), and a collecting portion (75) where the exhaust pipes (71) extended from the cylinders merge is the above-mentioned The lower part of the V-type internal combustion engine (10) and the front side silencer (102) are disposed opposite to each other across the oil pan (44) and are disposed forward of the rear side silencer (72) I assume.
Further, according to the present invention, an internal combustion engine (10) mounted between a front wheel (2) and a rear wheel (3) and an exhaust system (70, 100) for muffling exhaust gas from the internal combustion engine (10) And an exhaust pipe (71, 101) whose upstream end is connected to an exhaust port (52L, 52R, 53L, 53R) of the internal combustion engine (10), and the exhaust system (70, 100); And an expansion chamber (72, 102) connected to the downstream end of the exhaust pipe (71, 101), wherein the expansion chamber (72, 102) is disposed closer to the lower portion of the vehicle. The expansion chamber (72, 102) includes a plurality of expansion chambers (72, 102) separated from each other in the longitudinal direction of the vehicle, and the plurality of expansion chambers (72, 102) with respect to the vehicle center (C) Are disposed apart from each other in the left and right direction, The exhaust pipe (71, 101) of (70, 100) is composed of a plurality of exhaust pipes (71, 101) independent of each other, and the plurality of expansion chambers (72, 102) are a plurality of the above independent of each other. A front silencer (102), which is a silencer separately disposed in the exhaust pipe (71, 101) and disposed on the front side in the front-rear direction of the vehicle, is disposed below the internal combustion engine (10). A rear silencer (72) disposed on the rear side in the front-rear direction is disposed below a swing arm (30) that swingably supports the rear wheel (3) on the vehicle body frame (F), and the internal combustion engine The engine (10) is a V-type internal combustion engine arranged in a V-shape in which cylinder portions (42, 43) forming a pair are arranged in the front and rear direction, and the front silencer (102) and the rear silencer (72) , Independently connected to each of the cylinder portions (42, 43) The V-type internal combustion engine (10) has a plurality of parallel cylinders in each cylinder portion (42, 43) and is extended from each of the cylinders. The exhaust pipe (71, 101) is provided with a collecting part (75, 105) where the exhaust pipe (71, 101) to be joined merges for each of the cylinder parts (42, 43) and extends from each cylinder part (42, 43). Extends oppositely below the V-type internal combustion engine (10), and the collecting portions (75, 105) are disposed to pass by the V-type internal combustion engine back and forth below the V-type internal combustion engine (10) It is characterized by not overlapping.

In the exhaust system structure of the rocking vehicle according to the present invention, the expansion chamber can be disposed by effectively utilizing the front and rear spaces, and the left and right weights of the vehicle can be arranged even if the expansion chamber is disposed close to the vehicle width direction. Balance can be improved.
In addition, since the exhaust pipes are independent of each other, the silencers can be easily disposed separately in the left-right direction with respect to the center of the vehicle.
In addition, the front silencer and the rear silencer can be spaced apart longitudinally and laterally by effectively utilizing the space under the internal combustion engine and the space under the swing arm.
Furthermore, the capacity of the front muffler can be increased.
In addition, the clearance between the exhaust valve and the road surface can be secured.
Further, the degree of freedom in the arrangement of the exhaust pipe is high, and the muffles provided on the exhaust pipe can be easily arranged separately in the lateral direction with respect to the center of the vehicle.
In addition, the collecting portion of the exhaust pipe can be disposed compactly.
In addition, it is possible to compactly arrange the collecting portion of the exhaust pipe in which a plurality of extending portions are extended for each cylinder portion.

FIG. 1 is a left side view of a motorcycle according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the motorcycle 1 taken along a vertical plane along a center line in the vehicle width direction. It is the III-III sectional view of FIG. It is the top view which looked at the front side exhaust device and the rear side exhaust device from upper side. It is a left view of the front side exhaust device and the rear side exhaust device. It is the front view which looked at the front side exhaust device and the rear side exhaust device from the front side. It is the top view seen from the downward side of the front side exhaust device and the rear side exhaust device. It is VIII-VIII sectional drawing of FIG. It is IX-IX sectional drawing of FIG. It is the top view which looked at the peripheral part of the engine from the downward direction. It is a right view of a peripheral part of the lower part of an engine. It is a left view of a peripheral part of a lower part of an engine. It is a XIII-XIII sectional view of FIG. It is XIV-XIV sectional drawing of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description, the directions such as front, rear, left, right and up and down are the same as the directions with respect to the vehicle body unless otherwise specified. Further, a symbol FR shown in each drawing indicates the front of the vehicle body, a symbol UP indicates the upper portion of the vehicle body, and a symbol LH indicates the left side of the vehicle body. Further, in the drawings, the right side of the vehicle body may be indicated by a symbol RH.

FIG. 1 is a left side view of a motorcycle according to an embodiment of the present invention. In addition, in FIG. 1, only the left side is illustrated in the left and right pair.
In the motorcycle 1, an engine 10 (internal combustion engine, V-type internal combustion engine) as a power unit is supported on a vehicle body frame F, and a front fork 11 supporting the front wheel 2 is steerably supported on the front end of the vehicle body frame F. A suspension system 12 supporting the vehicle 3 is a vehicle provided on the rear side of a vehicle body frame F. The motorcycle 1 is a saddle-ride type vehicle in which a seat 13 on which an occupant sits is provided above the rear of the vehicle body frame F. The motorcycle 1 is a rocking vehicle in which the vehicle body swings (banks) to the left and right when it turns.

The body frame F has a head pipe 14 provided at the front end and pivotally supporting the front fork 11, a pair of left and right main frames 15, 15 extending obliquely downward and backward from the head pipe 14, and a main frame 15. , 15 and a pair of left and right seat frames 16 and 16 extending upward from the rear end to the rear end of the vehicle, and a pair of left and right pivot frames 17 and 17 extending downward from the front of the seat frames 16 and 16.
The main frames 15, 15 are formed such that the distance between the left and right becomes wider as it goes to the rear side in plan view. The main frames 15, 15 have an upper engine hanger 15a at the rear end. The main frames 15, 15 are provided with a front engine hanger portion 15b at the lower end portion of the lower extension portion extending downward from the front and rear middle portions.
The pivot frames 17 and 17 are provided with Vibot support holes 17a at upper and lower intermediate portions, and a pivot shaft 18 connecting the left and right pivot frames 17 and 17 in the vehicle width direction is supported by the Vibot support holes 17a. .
The pivot frames 17, 17 are provided with rear engine hangers 17b, 17c at the top and bottom of the front edge.

The driver sitting on the seat 13 steers the front wheel 2 via the handle 19 attached to the upper end of the front fork 11. The front wheel 2 is pivotally supported by a front wheel axle 2 a provided between lower ends of left and right fork tubes of the front fork 11.
The suspension device 12 includes a swing arm 30 that swingably supports the rear wheel 3 and a cushion device 31 that buffers the swing of the swing arm 30. The swing arm 30 has a front end pivotally supported by the pivot shaft 18 and swings up and down about the pivot shaft 18. The rear wheel 3 is pivotally supported by a rear wheel axle 3 a inserted into the rear end portion of the swing arm 30.

The seat 13 is provided above the front of the seat frames 16, 16.
At the lower part of the left and right pivot frames 17, 17, a pair of left and right step holders 20, 20 are provided. A pair of left and right main steps 20a, 20a on which the driver puts his / her foot is attached to the step holders 20, 20 and positioned behind the pivot frames 17, 17.
The side stand 21 is attached to the lower end portion of the left pivot frame 17.

The motorcycle 1 includes a vehicle body cover 22. The vehicle body cover 22 includes a front cover 23 that covers the periphery of the head pipe 14 from the front side, a front side cover 24 that covers the front of the vehicle body frame F from the side, and an under cover 25 that covers the engine 10 and the like from below. And a rear cover 26 covering the rear of the vehicle body frame F. A front fender 27 is provided on the front fork 11.
Above the rear portions of the main frames 15, 15, an air cleaner box 29 for purifying the air supplied to the engine 10 is provided.

FIG. 2 is a cross-sectional view of the motorcycle 1 taken along the vertical plane along the center line in the vehicle width direction. FIG. 3 is a cross-sectional view taken along line III-III of FIG. In FIG. 3, a blower fan 55a, an oil cooler 56 and the like described later are not shown.
Referring to FIGS. 1 to 3, engine 10 is a V-type engine in which a pair of front cylinder portions 42 (cylinder portions) and rear cylinder portions 43 (cylinder portions) are arranged in a V shape in the front and rear. . In the present embodiment, engine 10 is a V-type 4-cylinder engine.
The engine 10 includes a crankcase 41 accommodating a crankshaft 40 extending in the vehicle width direction, a front cylinder portion 42 obliquely extending forward and upward from an upper portion of a front portion of the crankcase 41, and a crank behind the front cylinder portion 42. A rear cylinder portion 43 obliquely extending from the top of the case 41 to the rear upper side, and an oil pan 44 attached to the lower surface of the crankcase 41 are provided.
At the rear of the crankcase 41, a transmission 45 provided with a plurality of gears is accommodated. The output of the engine 10 is transmitted to the rear wheel 3 by a drive chain 47 which is bridged between a drive sprocket 46 (FIG. 1) provided on the output shaft of the transmission 45 and the rear wheel 3.

The front cylinder portion 42 includes a front cylinder block 42a integrally formed on a front upper portion of the crankcase 41, a front cylinder head 42b coupled to an upper end of the front cylinder block 42a, and a front head cover covering an upper surface of the front cylinder head 42b. And 42c. The cylinder axis 42d of the front cylinder portion 42 is inclined forward. The front cylinder portion 42 projects further forward than the front surface of the crankcase 41. The front cylinder portion 42 includes a plurality of (two) parallel cylinders aligned in the vehicle width direction.
The rear cylinder portion 43 has a rear cylinder block 43a integrally formed on the upper portion of the crankcase 41, a rear cylinder head 43b coupled to the upper end of the rear cylinder block 43a, and a rear head cover 43c covering the upper surface of the rear cylinder head 43b. And The cylinder axis 43 d of the rear cylinder portion 43 is inclined rearward. The rear cylinder portion 43 extends to the upper side of the transmission 45. The rear cylinder portion 43 includes a plurality of (two) parallel cylinders aligned in the vehicle width direction.

The engine 10 is disposed between the left and right main frames 15, 15, between the front portions of the left and right seat frames 16, 16, and between the left and right pivot frames 17, 17, and suspended from the vehicle body frame F Supported by
Specifically, as shown in FIG. 1, the engine 10 is supported at the front of the crankcase 41 by the front engine hanger 15b and at the upper front of the rear cylinder head 43b by the upper engine hanger 15a. The rear portion of the crankcase 41 is supported by the rear engine hangers 17 b and 17 c and the pivot shaft 18.
The front cylinder portion 42 is covered from the outside in the vehicle width direction by the left and right main frames 15, 15.

As shown in FIG. 2, on the rear surface of the front cylinder head 42b, a pair of left and right front intake ports 50, 50 aligned in the vehicle width direction are provided corresponding to the two front cylinders.
A pair of left and right rear intake ports 51, 51 aligned in the vehicle width direction are provided on the front surface of the rear cylinder head 43b corresponding to the two rear cylinders.
The front throttle body 48 and the rear throttle body 49 connected to the front intake ports 50, 50 and the rear intake ports 51, 51 are disposed utilizing a space between the front cylinder portion 42 and the rear cylinder portion 43. .

A pair of left and right front exhaust ports 52L and 52R (exhaust ports) aligned in the vehicle width direction are provided corresponding to the two front cylinders on the front upper surface of the front cylinder head 42b. The front exhaust ports 52L, 52R are disposed on the left and right across the vehicle center C in the vehicle width direction. Here, the vehicle center C includes a straight line passing through the center of the front wheel 2 and the rear wheel 3 in the vehicle width direction.
A cylindrical oil filter cartridge 41a for filtering engine oil is attached to the front of the crankcase 41 below the left front exhaust port 52L.

  A pair of left and right rear exhaust ports 53L, 53R (exhaust ports, see FIG. 9) aligned in the vehicle width direction are provided corresponding to the two rear cylinders on the rear rear surface of the rear cylinder head 43b. . The rear exhaust ports 53L, 53R are disposed on the left and right across the vehicle center C in the vehicle width direction. In the vehicle width direction, the front exhaust port 52L on the left side (other side) and the rear exhaust port 53L are provided so as to substantially overlap with each other. Further, in the vehicle width direction, the front exhaust port 52R on the right side (one side) and the rear exhaust port 53R are provided at substantially overlapping positions.

A front side exhaust device 70 (exhaust device) through which the exhaust of the front cylinder head 42b passes is connected to the front exhaust ports 52L and 52R.
A rear exhaust device 100 (exhaust device) through which the exhaust of the rear cylinder head 43b passes is connected to the rear exhaust ports 53L, 53R.
Between the front cylinder portion 42 and the front wheel 2, a plate-shaped radiator 55 for radiating the cooling water of the engine 10 is provided. The radiator 55 is provided with a blower fan 55a on the rear side. An oil cooler 56 for radiating the oil of the engine 10 is provided below the radiator 55 and in front of the front exhaust device 70.

Referring to FIGS. 1 and 2, the swing arm 30 is provided on one side (right side) arm 30 a and the other side (left side) arm 30 b respectively provided on the left and right sides of the rear wheel 3 and one in front of the rear wheel 3. A cross member 30c is provided that connects the side arm 30a and the other side arm 30b in the vehicle width direction.
The swing arms 30 are pivotally supported by pivot shafts 18 which are disposed on the left and right pivot frames 17 and 17 at the front end portions 30d of the one side arm 30a and the other side arm 30b and are inserted into the front end portions 30d.
The cross member 30 c includes a link connecting portion 57 that protrudes below the lower surfaces of the one side arm 30 a and the other side arm 30 b.

The cushion device 31 includes a cylindrical suspension 58 that strokes in the axial direction, and a link mechanism 59 that connects the lower end portion 58 a of the suspension 58 and the swing arm 30. The suspension 58 is internally provided with oil or gas that damps the stroke of the suspension 58.
An upper end portion 58 b of the suspension 58 is connected to the vehicle body frame F at the rear of the crankcase 41 and below the rear exhaust ports 53 L, 53 R. The suspension 58 is vertically passed through the space between the cross member 30 c and the pivot shaft 18.
The link mechanism 59 includes a link plate 60 having a substantially triangular shape in a side view, the link plate 60, and a pair of left and right link arms 61 and 61 extending rearward from the link plate 60 and coupled to the swing arm 30.
The vehicle body frame F includes a lower cross frame 62 connecting lower ends of the left and right pivot frames 17 and 17 in the vehicle width direction.

The link plate 60 is disposed in a direction in which one apex of a triangle protrudes downward in a side view.
Specifically, the link plate 60 has a frame connecting portion 60a connected to the lower cross frame 62 at the front end, and a suspension connecting portion 60b connected to the lower end 58a of the suspension 58 at the rear end, and the link arm A link arm connection portion 60c connected to the front end portions 61, 61 is provided at the lower end portion.
The link arms 61 and 61 are formed in a rod shape extending linearly in the back and forth direction, and are disposed on the left and right sides of the link plate 60, respectively.

The link arms 61 and 61 have a plate connecting portion 61a connected to the link arm connecting portion 60c of the link plate 60 at the front end, and a swing arm connecting portion 61b connected to the link connecting portion 57 of the swing arm 30 at the rear end. Prepare for the department.
The link connecting portion 57 is located rearward of the suspension connecting portion 60b and the link arm connecting portion 60c and is located above the link arm connecting portion 60c in a side view. For this reason, the link arms 61 and 61 extending linearly extend in a rearward and upward direction and extend rearward in a side view.
The oil pan 44 is formed so as to bulge downward so as to be able to store oil.

FIG. 4 is a plan view of the front exhaust device 70 and the rear exhaust device 100 as viewed from above. FIG. 5 is a left side view of the front side exhaust device 70 and the rear side exhaust device 100. FIG. 6 is a front view of the front exhaust device 70 and the rear exhaust device 100 as viewed from the front side. FIG. 7 is a plan view of the front exhaust device 70 and the rear exhaust device 100 as viewed from below. 8 is a cross-sectional view taken along line VIII-VIII of FIG. In the following description, the right side in the vehicle width direction may be called one side, and the left side in the vehicle width direction may be called the other side.
4 to 8, the front side exhaust device 70 has a front side exhaust pipe 71 (exhaust pipe) whose upstream end is connected to the front exhaust ports 52L and 52R (FIG. 3), and a downstream end of the front side exhaust pipe 71 And a first silencer 72 (muffler, expansion chamber, rear silencer) connected to the The front exhaust device 70 is an exhaust device connected independently to the front cylinder portion 42, and the exhaust of the rear cylinder portion 43 does not flow through the front exhaust device 70.

  The front exhaust pipe 71 includes a front first exhaust pipe 73 whose upstream end 73a is connected to the left front exhaust port 52L, and a front second exhaust pipe 74 whose upstream end 74a is connected to the right front exhaust port 52R. The first front exhaust pipe 73 and the second front exhaust pipe 74 join together to form a single front collecting portion 75 (collecting portion), and one front extending portion 75 extends from the first collecting portion 75, and the downstream end 76a thereof is the first muffling And a front collecting pipe 76 connected to the housing 72.

  The first silencer 72 has a front muffling portion 77 connected to the downstream end 76 a of the front collective pipe 76, a rear muffling portion 78 provided downstream of the front muffling portion 77, a front muffling portion 77 and a rear muffler And a connecting pipe 79 for connecting with the part 78.

Referring to FIGS. 3 and 6, the front first exhaust pipe 73 extends downward from the left front exhaust port 52L to avoid the oil filter cartridge 41a (FIG. 3) in front of the crankcase 41 in the vehicle width direction. After being bent (one side), an upper bent portion 73b is bent toward the lower side of the oil filter cartridge 41a in the vehicle width direction (the other side), and extends downward inward in the vehicle width direction in front of the oil pan 44 And a lower bent portion 73c. The upper bending portion 73 b once overlaps the vehicle center C and returns to the left side.
The lower end portion of the lower bent portion 73c is located on the right side (one side) of the vehicle body across the vehicle center C, that is, on the opposite side of the vehicle center C to the front exhaust port 52L.
Further, referring to FIGS. 4, 6 and 7, the front first exhaust pipe 73 is bent backward at the lower end of the lower bent portion 73c, and extends rearward substantially straightly on the right side of the vehicle body. Equipped with The rear extension portion 73 d includes a rear end portion 73 e (FIG. 7) bent inward in the vehicle width direction so as to overlap the vehicle center C.

With reference to FIGS. 3 and 6, the front second exhaust pipe 74 extends downward from the front exhaust port 52R on the right side, and bends along the upper bend 73b of the front first exhaust pipe 73 and an upper bending portion 74b and And a lower bent portion 74c bent along the lower bent portion 73c in front of the oil pan 44. The lower bending portion 74c once straddles the vehicle center C to the left (other side) and returns to the right.
The lower end portion of the lower bending portion 74c extends outward along the upper surface of the lower bending portion 73c of the front first exhaust pipe 73 in the vehicle width direction, and is lower than the lower end portion of the lower bending portion 73c in the vehicle width direction Located outside (one side) and forward.

Further, referring to FIGS. 4, 6 and 7, the front second exhaust pipe 74 is provided with a rear extending portion 74d which is bent backward at the lower end of the lower bent portion 74c and extends rearward on the right side of the vehicle body. The rear extension 74d includes an extension front portion 74e extending rearward through an outer side and an upper portion of the rear extension 73d, and an extension rear portion 74f bent toward the vehicle center C and obliquely extending rearward. Equipped with
The rear end portion of the extension rear portion 74 f extends rearward through the upper side of the rear end portion 73 e of the front first exhaust pipe 73 and is connected to the front collective portion 75 at a position overlapping the vehicle center C.
The rear end portion 73e of the rear extension portion 73d of the front first exhaust pipe 73 is connected to the front collecting portion 75 below the extension rear portion 74f.
That is, the front first exhaust pipe 73 and the front second exhaust pipe 74 are arranged vertically at a portion immediately in front of the front collecting portion 75 so as to be compact in the vehicle width direction.

The front collective pipe 76 of the front first exhaust pipe 73 has a rear extension 76b that obliquely extends from the front collective 75 toward the rear left (rear on the other side), and a rear extension 76b located on the other side of the vehicle body And a straight portion 76d linearly extending in the vehicle width direction from an end of the rear bent portion 76c.
The straight portion 76 d straddles the vehicle center C so as to be substantially orthogonal to the vehicle center C, and is connected to a first silencer 72 located on the right side (one side) of the vehicle body.

The front muffling portion 77 of the first silencer 72 is an expansion chamber formed in a box shape, and is formed larger than the straight portion 76 d in a side view.
The downstream end of the straight portion 76 d of the front first exhaust pipe 73 is inserted into and connected to the rear portion of the side wall portion 77 a on the inner side in the vehicle width direction of the front muffling portion 77. The straight portion 76d is formed to have a large diameter at a portion connected to the side wall portion 77a, and a cylindrical catalyst device 80 is provided inside the large diameter portion. The straight portion 76 d has an end extending into the front muffling portion 77, and a part of the catalyst device 80 is disposed in the front muffling portion 77.
The connecting pipe 79 extends from the upper wall 77 b (upper surface) of the front muffling section 77 outward and rearward and upward in the vehicle width direction, and is connected to the front end of the rear muffing section 78.
The rear muffling section 78 is a cylindrical expansion chamber which is formed to have a diameter larger than the diameter of the connection pipe 79 and which is long in the front-rear direction. The exhaust port 78a of the rear muffling section 78 is directed rearward and upward.

The front side exhaust device 70 includes an exhaust gas sensor 81 and an exhaust valve 82 that controls the opening and closing of the exhaust pipe.
The exhaust gas sensor 81 is provided at the front end of the rear extension 76 b of the front collecting pipe 76. The exhaust gas sensor 81 is formed in a rod-like shape, and is provided so as to be inserted into the upper portion of the rear extension portion 76b. The detection portion of the exhaust gas sensor 81 is located in the rear extension portion 76 b and detects the oxygen concentration of the exhaust gas exhausted from the front cylinder portion 42.
The exhaust valve 82 is disposed between the exhaust gas sensor 81 and the rear bend 76c in the rear extension 76b.
The front exhaust system 70 further includes stays 83, 84, 85 for fixing the front exhaust system 70 to the vehicle body side. The stay 83 extends upward from the front collecting portion 75. The stay 84 extends forward from the front wall 77 c of the front muffling section 77. The stay 85 extends upward from the front end of the rear muffling section 78.

  4 to 8, the rear exhaust device 100 has a rear exhaust pipe 101 (exhaust pipe) whose upstream end is connected to the rear exhaust ports 53L and 53R (FIG. 9), and a rear exhaust pipe 101. And a second muffler 102 (muffler, expansion chamber, front silencer) connected to the downstream end of the The rear side exhaust device 100 is an exhaust device connected independently to the rear cylinder portion 43, and the exhaust of the front cylinder portion 42 does not flow through the rear side exhaust device 100.

  The rear exhaust pipe 101 has a first rear exhaust pipe 103 whose upstream end 103a is connected to the rear exhaust port 53L on the left, and a rear second exhaust pipe whose upstream end 104a is connected to the rear exhaust port 53R on the right 104, the rear first exhaust pipe 103 and the rear second exhaust pipe 104 join together to form a single rear collective portion 105 (collective portion), and a single rear extension portion 105 extending from the rear collective portion 105 The downstream end 106 a is provided with a rear collecting pipe 106 connected to the second silencer 102.

  4 to 8, the rear first exhaust pipe 103 extends diagonally from the rear exhaust port 53L (not shown) on the left side to the right rear (one side rear) in plan view across the vehicle center C from the rear exhaust port 53L (not shown) An extending portion 103b, a lower extending portion 103c bent downward at the rear end of the rear extending portion 103b and extending downward to the front muffling portion 77 side of the first silencer 72, and a lower end of the lower extending portion 103c And a forward extension 103d extending forward through the right side (one side) of the vehicle body.

The rear second exhaust pipe 104 is bent downward at the rear end of the rear extension portion 104b, and a first muffler by the rear extension portion 104b obliquely extending to the right rear in plan view from the rear exhaust port 53R on the right side A lower extension portion 104c which extends downward to the front muffling portion 77 side of 72 and a front extension portion 104d which is bent forward at the lower end of the lower extension portion 104c and which extends forward through the right side (one side) of the vehicle body And
The rear extension portion 104 b extends rearward through the lower widthwise inner side of the rear extension portion 103 b of the rear first exhaust pipe 103 and the inside in the vehicle width direction of the lower extension portion 103 c.

The lower extending portion 104 c extends along the lower extending portion 103 c rearward and inward in the vehicle width direction with respect to the lower extending portion 103 c of the rear first exhaust pipe 103. Lower end portions of the lower extending portion 103 c and the lower extending portion 104 c are bent to the front side at a position along the front wall portion 77 c of the front muffling portion 77.
The front extension portion 104d extends along the front extension portion 103d below the front extension portion 103d of the rear first exhaust pipe 103 and inside the vehicle width direction.
The front extension 103 d and the front extension 104 d extend forward through the outer side (right side) of the front collecting pipe 76 and the front collecting portion 75 of the front exhaust pipe 71.

The front extending portion 103 d and the front extending portion 104 d merge at the rear side collecting portion 105. The rear collecting portion 105 is located forward and outward (rightward) with respect to the front collecting portion 75 of the front exhaust pipe 71.
The rear collecting pipe 106 includes a front extending portion 106b extending forward from the rear collecting portion 105, a front bent portion 106c bent inward in the vehicle width direction at the front end of the front extending portion 106b, and a vehicle from the front bent portion 106c. And a side extending portion 106d extending in the vehicle width direction to the left side (the other side) of the vehicle body across the center C.
The side extension part 106d extends in the vehicle width direction above the extension part front part 74e and the rear extension part 73d of the front side exhaust pipe 71, and the downstream end 106a is connected to the second silencer 102. .

The second silencer 102 is an expansion chamber formed in a box shape longer in the front-rear direction than the vehicle width direction, and includes an expansion chamber main body portion 102a including a plurality of expansion chambers partitioned by partition walls, and an expansion chamber main body portion And a tail pipe portion 102b extending rearward from the rear end of the The tail pipe portion 102 b is a portion through which a tail pipe 102 c (FIG. 8) for discharging exhaust air from the expansion chamber main portion 102 a to the outside air passes. The exhaust port 102d of the tail pipe portion 102b is directed rearward.
The second silencer 102 is disposed on the left side (the other side) of the vehicle body with respect to the vehicle center C, and passes rearward through the other side of the rear extension portion 74 d and the rear extension portion 73 d of the front exhaust pipe 71. Extend to
The side extension portion 106 d of the rear exhaust pipe 101 is inserted into and connected to the front end portion of the side wall portion 102 e on the inner side in the vehicle width direction of the second silencer 102. The side extension portion 106d is formed with a large diameter at a portion connected to the side wall portion 102e, and a tubular catalyst device 110 (FIG. 8) is provided inside the large diameter portion. An end of the side extension 106 d extends into the second silencer 102, and a part of the catalyst device 110 is disposed in the second silencer 102.

The rear exhaust device 100 includes an exhaust gas sensor 111 and an exhaust valve 112 that controls the opening and closing of an exhaust pipe.
The exhaust gas sensor 111 is provided in the rear side collecting unit 105. The exhaust gas sensor 111 is formed in a rod-like shape, and is provided so as to be inserted into the upper portion of the rear side collecting portion 105. The detection unit of the exhaust gas sensor 111 is located in the rear side collecting unit 105, and detects the oxygen concentration of the exhaust gas exhausted from the rear cylinder unit 43.
The exhaust valve 112 is disposed between the exhaust gas sensor 111 and the front bent portion 106 c in the rear collecting pipe 106.
In addition, the rear exhaust system 100 is provided with stays 113, 114 and 115 for fixing the rear exhaust system 100 to the vehicle body side. The stay 113 is provided at the lower end portion of the lower extending portion 103 c of the rear first exhaust pipe 103. The stay 114 is provided at the front end of the second silencer 102. The stay 115 is provided at the rear end of the second silencer 102.

Next, the positional relationship and the like of the front exhaust device 70 and the rear exhaust device 100 with respect to the vehicle body will be described in detail.
As shown in FIG. 3, the front first exhaust pipe 73 and the front second exhaust pipe 74 of the front exhaust device 70 extend downward through the front of the crankcase 41 and the oil pan 44.
The front first exhaust pipe 73 and the front second exhaust pipe 74 are bent rearward from the right side of the vehicle body and pass under the engine 10.

FIG. 9 is a cross-sectional view taken along line IX-IX of FIG.
With reference to FIGS. 2, 5 and 9, in the rear first exhaust pipe 103 and the rear second exhaust pipe 104 of the rear exhaust device 100, the rear extension portions 103 b and 104 b are rearward from the rear cylinder portion 43. It is pulled out and passes above the swing arm 30.
The lower extension portions 103c and 104c of the rear first exhaust pipe 103 and the rear second exhaust pipe 104 are disposed behind the pivot frame 17 on the right side (one side) between the one side arm 30a and the right step holder 20. Extend downward. That is, the lower extending portions 103c and 104c are passed through the outside of the one side arm 30a in the vehicle width direction.

In the rear first exhaust pipe 103 and the rear second exhaust pipe 104, the lower extending portions 103c and 104c are bent forward on the front side of the first silencer 72, and the front extending portions 103d and 104d are from the right side of the vehicle body It extends forward and is passed below the engine 10.
The suspension 58 and the link mechanism 59 are provided at a position overlapping the vehicle center C in the vehicle width direction, but are offset to the left (other side) with respect to the vehicle center C.

FIG. 10 is a plan view of the periphery of the engine 10 as viewed from below. FIG. 11 is a right side view of the lower peripheral portion of the engine 10. FIG. 12 is a left side view of the lower peripheral portion of the engine 10. 13 is a cross-sectional view taken along line XIII-XIII of FIG.
Referring to FIGS. 10 to 13, the oil pan 44 is attached to the lower surface of the crankcase 41. The oil pan 44 includes a bulging portion 87 that bulges downward at a central portion in the vehicle width direction.
The bulging portion 87 is provided rearward of the front end of the crankcase 41 and is provided forward of the rear end of the crankcase 41.

The bulging portion 87 includes a bottom wall portion 87a constituting the bottom of the oil pan 44, and a peripheral wall portion 87b extending upward from the periphery of the bottom wall portion 87a to constitute a side wall of the bulging portion. The peripheral wall portion 87b is formed to be tapered from the upper end toward the bottom wall portion 87a.
In detail, the bulging portion 87 is disposed near the other side (left side) with respect to the vehicle center C. Further, the other side wall 87c of the peripheral wall 87b extends upward substantially vertically, but the one side wall 87d of the peripheral wall 87b is inclined so as to be located on the outer side in the vehicle width direction toward the upper side.
The position of the bottom wall 87a of the oil pan 44 substantially coincides with the position of the lower end of the link mechanism 59 in the vertical direction.

The front muffling portion 77 of the first silencer 72 of the front exhaust device 70 is disposed below one side arm 30 a of the swing arm 30 and on one side (right side) of the link mechanism 59. The front muffling section 77 is located on one side of the vehicle center C, and is disposed close to one side of the vehicle body. In addition, the front muffling section 77 is disposed in front of the rear wheel 3 and behind the engine 10.
The second muffler 102 of the rear exhaust device 100 is disposed below the engine 10 and on the other side (left side) of the bulging portion 87 of the oil pan 44. The second silencer 102 is located on the other side of the vehicle center C, and is disposed close to the other side of the vehicle body. The second silencer 102 extends from near the front end of the crankcase 41 to near the link mechanism 59 in the front-rear direction.

Specifically, the expansion chamber main body portion 102 a of the second silencer 102 is disposed in front of the first silencer 72 so as not to overlap with the front silencer portion 77 of the first silencer 72 in the front-rear direction. There is.
As described above, the first silencer 72 of the front side exhaust device 70 of the front cylinder portion 42 and the second silencer 102 of the rear side exhaust device 100 of the rear cylinder portion 43 are provided at mutually separated positions in the front-rear direction. By disposing the first silencer 72 and the second silencer 102 effectively utilizing the arrangement spaces of the lower part of the motorcycle 1 by disposing the first silencer 72 and the second silencer 102 in the vehicle width direction separately from each other with respect to the vehicle center C. While being able to do, bias of the weight balance on either side by a silencer can be made small, and the weight balance on either side can be improved.

Referring to FIGS. 10 to 13, the rear first exhaust pipe 103 and the rear second exhaust pipe 104 of the rear exhaust pipe 101 pass the front side of the first silencer 72 and forward the lower part of the crankcase 41. Extend to
Specifically, the rear exhaust pipe 101 has a front extending portion 103 d, 104 d extending forward through one side of the vehicle body below the crankcase 41 and positioned to one side of the bulging portion 87. The side collecting portion 105 forms one rear collecting pipe 106.
The rear collecting pipe 106 is bent inward in the vehicle width direction at the front bending portion 106c, and the side extension portion 106d extends to the other side of the vehicle body through the front of the bulging portion 87 and is connected to the second silencer 102 Be done. In detail, the side extension part 106d is passed between the bulging part 87 and the lower side bending parts 73c and 74c and above the rear extension part 73d and the rear extension part 74d.

The second silencer 102 extends rearward through the other side of the bulging portion 87 below the crankcase 41, and an exhaust port 102d at the rear end opens rearward at a position on the other side of the link mechanism 59.
That is, in the rear exhaust device 100, the rear exhaust pipe 101 extends downward from the rear cylinder portion 43, bends forward at one side of the link mechanism 59, and passes through one side of the vehicle body below the crankcase 41. It extends forward and bends to the other side of the vehicle body through the front of the bulging portion 87 and is connected to the second silencer 102, and the second silencer 102 extends rearward through the other side of the vehicle body, and the exhaust port 102d Open on the other side of the link mechanism 59. Therefore, a long exhaust pipe length of the rear side exhaust device 100 can be secured.

As shown in FIGS. 4 and 10, the side wall 102e of the expansion chamber main body 102a of the second silencer 102 includes a curved surface 102f that is recessed along the outer shape of the bulging portion 87. Thus, the expansion chamber main body portion 102a can be disposed along the bulging portion 87, and the capacity of the second silencer 102 can be increased.
As shown in FIGS. 10, 11 and 13, the exhaust valve 112 of the rear exhaust device 100 is provided in the rear collecting pipe 106 and is located on one side of the bulging portion 87. Therefore, the exhaust of the rear cylinder portion 43 provided with the two rear exhaust ports 53L, 53R can be controlled by one exhaust valve 112.
The exhaust valve 112 includes a valve body 112a provided in the front extension portion 106b of the rear side collective pipe 106, a drive shaft 112b for pivotally supporting the valve body 112a, and a disc connected to the drive shaft 112b. And a drive pulley portion 112c. In the exhaust valve 112, when the pulley 112c is rotated by a drive source such as a motor, the valve body 112a rotates around the drive shaft 112b, and opens and closes a pipe line in the rear collecting pipe 106.

As shown in FIG. 13, the drive shaft 112b is inclined and disposed so as to be slightly inward in the vehicle width direction than the vertical in a front view. The drive pulley portion 112 c is provided on the upper end portion of the drive shaft 112 b that protrudes outward from the upper surface of the rear side collecting pipe 106, and is thus located on the upper side surface of the rear side collecting pipe 106.
By disposing the drive shaft 112 b in an inclined manner, the drive pulley portion 112 c is provided to substantially face the inclined one side wall 87 d of the bulging portion 87. That is, the drive pulley portion 112 c is provided on the upper side surface (exhaust pipe side surface) of the rear side collective pipe 106 so as to face the oil pan 44 in the lower part of the engine 10 from below. As a result, the drive pulley portion 112c can be compactly provided so as not to protrude outward and downward. Therefore, the drive pulley portion 112c can be disposed apart from the road surface, and the clearance between the road surface and the drive pulley portion 112c can be secured even in a state where the motorcycle 1 is banked at the time of turning.

Referring to FIGS. 10 to 13, the rear extension 73 d and the rear extension 74 d of the front exhaust pipe 71 extend rearward on the right side of the vehicle body below the oil pan 44. Specifically, the rear extension 73 d and the rear extension 74 d extend rearward through the outer side of the one side wall 87 d of the bulging portion 87 and the inner side in the vehicle width direction than the rear collecting pipe 106 and bulging. It joins in the front side gathering part 75 of the back of the part 87. FIG.
As shown in FIG. 13, in the side portion of the bulging portion 87, the pipes located on the lower side of the rear collective pipe 106, the rear extending portion 74 d and the rear extending portion 73 d are more in the vehicle width direction It is arranged to be located inside. Therefore, the clearance between the road surface and the exhaust pipe when the motorcycle 1 is banked can be secured.

FIG. 14 is a cross-sectional view taken along line XIV-XIV of FIG.
Referring to FIGS. 10, 12 and 14, the front collecting pipe 76 of the front exhaust pipe 71 passes between the front extending portions 103 d and 104 d of the rear exhaust device 100 and the second silencer 102 to the rear. Extend.
The front collecting pipe 76 extends rearward from the front collecting portion 75 to the other side (left side) of the vehicle body, passes through the front of the link mechanism 59, and then extends rearward through the other side of the link mechanism 59.
Next, the front collecting pipe 76 is bent inward in the vehicle width direction at the rear bending portion 76c at the rear of the link mechanism 59, and the straight portion 76d extends to the one side (right side) of the vehicle body through the rear of the link mechanism 59 It is connected to the front muffling portion 77 of the first muffler 72 disposed on one side of the link mechanism 59 on one side.

  That is, in the front side exhaust device 70, the front side exhaust pipe 71 extends downward from the front cylinder portion 42, extends from the other side of the vehicle body to one side of the vehicle body across the vehicle center C, and below the crankcase 41 And is bent to the other side of the vehicle body, and is connected to the front muffling section 77 on one side of the link mechanism 59 through the other side and the rear of the link mechanism 59. Therefore, a long exhaust pipe length of the front side exhaust device 70 can be secured.

As shown in FIGS. 11 and 12, the link arms 61 and 61 of the link mechanism 59 are inclined rearward and inclined rearward and extend rearward in a side view, and the straight portion 76 d of the front exhaust pipe 71 is the link arm 61. , 61 and extends in the vehicle width direction through the space under the rear. That is, the straight portion 76d extends in the vehicle width direction below the space on the swing arm connecting portion 61b, 61b side, which is the upper end side (rear end side) of the link arms 61, 61. Therefore, the front exhaust pipe 71 can be compactly arranged in the front-rear direction by effectively using the space under the link mechanism 59.
Further, the upper wall 77b (FIG. 11) of the front muffling section 77 of the first silencer 72 is located below the one side arm 30a of the swing arm 30, and the swing arm 30 swings downward. , Close to the lower surface of the one side arm 30a. In the present embodiment, the upper wall portion 77 b of the first silencer 72 is provided in a rear-down manner in a side view so that the rear portion is lower than the front portion in accordance with the swing angle of the swing arm 30. Therefore, the front muffling section 77 can be compactly arranged while securing the swing angle of the swing arm 30.

Referring to FIGS. 9, 10, 12 and 14, the exhaust valve 82 of the front exhaust device 70 is provided in the front collecting pipe 76. For this reason, the exhaust of the front cylinder portion 42 provided with the two front exhaust ports 52L, 52R can be controlled by one exhaust valve 82.
The exhaust valve 82 is disposed on the other side of the link mechanism 59. The exhaust valve 82 includes a valve body 82a provided in the rear extension portion 76b of the front side collecting pipe 76, a drive shaft 82b for pivotally supporting the valve body 82a, and a disk shape connected to the drive shaft 82b. And a drive pulley portion 82c. In the exhaust valve 82, when the drive pulley portion 82c is rotated by a drive source such as a motor, the valve body 82a is rotated about the drive shaft 82b to open and close the pipeline in the front collecting pipe 76.

The drive shaft 82b extends substantially vertically along the axis 58c (FIG. 14) of the suspension 58 in a front view. The drive pulley portion 82 c is provided on the upper end portion of the drive shaft 82 b that protrudes outward from the upper surface of the front collecting pipe 76, and is thus located on the upper side surface of the front collecting pipe 76. As described above, by providing the drive shaft 82b substantially vertically, the exhaust valve 82 can be made compact in the vehicle width direction, so the exhaust valve 82 can be disposed on the side of the link mechanism 59.
Further, as shown in FIG. 12, the rear extension portion 76b is disposed at the rear end along the lower surface of the one side arm 30a. The drive shaft 82b is inclined rearward relative to the vertical side in a side view, and the drive pulley portion 82c is disposed rearward and downward along the lower surface of the one side arm 30a. Therefore, a large clearance can be secured between the one side arm 30a and the drive pulley portion 82c.

Referring to FIGS. 2, 9 and 10, the exhaust gas sensor 81 of the front side exhaust device 70 is provided on the rear extension portion 76 b of the front side collecting pipe 76 at a position below the swing arm 30. And the front extension portion 104 d of the rear second exhaust pipe 104.
The exhaust gas sensor 81 obliquely extends outward and upward in the vehicle width direction toward the front extension portion 104 d in a front view.
The exhaust gas sensor 81 is disposed in front of the link mechanism 59, and overlaps the link mechanism 59 in a front view. Therefore, the exhaust gas sensor 81 can be compactly provided by utilizing the space in front of the link mechanism 59 below the swing arm 30.

  Referring to FIGS. 10 to 12 and 14, the front exhaust device 70 is provided to surround the link mechanism 59 from the periphery by the exhaust gas sensor 81, the exhaust valve 112, the straight portion 76 d and the front muffling portion 77. ing. Therefore, the exhaust gas sensor 81, the exhaust valve 112, the linear portion 76d, and the front muffling portion 77 can be compactly provided by utilizing the space around the link mechanism 59, and the front exhaust pipe 71 can be provided with the link mechanism 59. Can be provided to surround the exhaust pipe, and a long exhaust pipe can be secured.

As shown in FIG. 10, the front gathering portion 75 of the front exhaust device 70 is located on the opposite side of the second silencer 102 with the bulging portion 87 interposed below the crankcase 41 and from the front muffling portion 77. Is also located forward. Therefore, the front collecting portion 75 can be disposed below the crankcase 41 at a position different from that of the second silencer 102 and the front muffling portion 77, and a front exhaust system can be effectively utilized by utilizing the space below the crankcase 41. 70 can be arranged.
Further, below the crankcase 41, the front exhaust pipe 71 extends rearward from the front side, the rear exhaust pipe 101 extends from the rear side to the front, and the front exhaust pipe 71 and the rear exhaust pipe 101 It extends in the front-rear direction so as to be opposed below.

Specifically, the front collecting portion 75 of the front exhaust pipe 71 is located rearward of the rear collecting portion 105 of the rear exhaust pipe 101, and the front extending portions 103d and 104d of the rear exhaust pipe 101 in the vehicle width direction. It is arranged side by side.
Further, the rear side collecting portion 105 of the rear side exhaust pipe 101 is located forward of the front side collecting portion 75 of the front side exhaust pipe 71 and is aligned with the rear extension portions 73 d and 74 d of the front side exhaust pipe 71 in the vehicle width direction. It is arranged.
That is, the front side collecting portion 75 and the rear side collecting portion 105 are disposed to pass each other in the front and back direction below the crankcase 41. Therefore, the front collecting portion 75 and the rear collecting portion 105 of the front exhaust pipe 71 and the rear exhaust pipe 101 independently extended from the front cylinder portion 42 and the rear cylinder portion 43 are provided compactly below the crankcase 41. be able to.

  As described above, according to the embodiment to which the present invention is applied, the exhaust system structure of the motorcycle 1 is provided between the front wheel 2 and the rear wheel 3 and the engine 10 mounted on the vehicle body frame F , A front exhaust device 70 for muffling exhaust gas from the engine 10, and a suspension system 12 for swingably supporting the rear wheel 3, and the front exhaust device 70 is provided at the front exhaust ports 52L, 53R of the engine 10. The swing arm 30 supports the rear wheel 3 so as to swingably support the rear wheel 3. The swing arm 30 includes a front exhaust pipe 71 to which the upstream end is connected, and a first silencer 72 connected to the downstream end of the front exhaust pipe 71. And the cushion device 31 that buffers the swing of the swing arm 30, the first silencer 72 is disposed below the swing arm 30 and to one side of the cushion device 31, and the front exhaust pipe 71 is First silencer 7 Of extending from the front side, and is connected from the other side of the cushion device 31 in the first muffler 72 is bent so as to pass through the rear of the cushion device 31. As a result, since the first silencer 72 is disposed below the swing arm 30 and to one side of the cushion device 31, the clearance between the first silencer 72 and the cushion device 31 of the suspension device 12 can be secured. Furthermore, since the first silencer 72 can be disposed at the center of the vehicle width direction at a low position of the vehicle body, the clearance between the first silencer 72 and the road surface can be secured even when the motorcycle 1 is banked. Further, the front exhaust pipe 71 extends from the front side of the first silencer 72, is bent to pass from the other side of the cushion device 31 to the rear of the cushion device 31, and is connected to the first silencer 72. The exhaust pipe length from the front exhaust ports 52L, 53R to the first silencer 72 can be lengthened.

The cushion device 31 further includes a suspension 58, and a link mechanism 59 connected to the suspension 58 and positioned below the lower surface of the swing arm 30, and the first silencer 72 is disposed on the side of the link mechanism 59. ing. In the cushion device 31, the link mechanism 59 is a portion that is less susceptible to heat than the suspension 58, so the first silencer 72 can be disposed closer to the link mechanism 59. Therefore, the first silencer 72 can be disposed compactly.
Further, the link mechanism 59 is provided obliquely in a side view, and the front exhaust pipe 71 is connected to the first silencer 72 through the lower side of the upper end side of the link arms 61, 61 of the link mechanism 59. Therefore, the front exhaust pipe 71 can be compactly arranged in the front-rear direction by effectively using the space under the link mechanism 59.

Furthermore, the front side exhaust pipe 71 is provided with a straight portion 76d that linearly extends in the left-right direction of the vehicle after bending so as to pass from the other side of the cushion device 31 to the rear of the cushion device 31. An apparatus 80 is provided. As a result, the catalyst device 80 can be provided by utilizing the straight part 76 d passing behind the cushion device 31, and there is no need to provide a straight pipe for providing the catalyst device 80 in the front-rear direction. The front and back length of can be made compact.
In addition, since the exhaust gas sensor 81 is provided in the front exhaust pipe 71 and the exhaust gas sensor 81 is disposed just in front of the cushion device 31, a space in front of the cushion device 31 below the swing arm 30 is used. Thus, the exhaust gas sensor 81 can be provided compactly.

In the front exhaust pipe 71, an exhaust valve 82 for controlling the opening and closing of the exhaust pipe is provided at a side position of the link mechanism 59 in the front exhaust pipe 71, and a drive shaft 82b serving as a rotation center of the exhaust valve 82 is provided. They are disposed along the direction of the axis 58c of the cushion device 31 in a front view. Therefore, the exhaust valve 82 can be made compact in the vehicle width direction, and the exhaust valve 82 can be made compact at the side position of the link mechanism 59.
Also, as viewed from the bottom of the vehicle as shown in FIG. 10, the front exhaust pipe 71 is wrapped around the cushion device 31 so that the cushion device 31 is surrounded by the exhaust gas sensor 81, the straight portion 76d and the exhaust valve 82; One side of the cushion device 31 is covered with a first silencer 72. Thus, the exhaust gas sensor 81, the linear portion 76d provided with the catalyst device 80, the exhaust valve 82 and the first silencer 72 can be compactly provided so as to surround the cushion device 31.

  Furthermore, in the side view of the vehicle, the upper wall 77 b of the first silencer 72 is inclined so that the rear portion is lower than its front portion in accordance with the swing angle of the swing arm 30. The first silencer 72 can be compactly arranged while securing the swing angle of.

  Further, according to the embodiment to which the present invention is applied, the exhaust system structure of the motorcycle 1 has an engine 10 mounted between the front wheel 2 and the rear wheel 3 and a front side for muffling exhaust gas from the engine 10 A front side provided with an exhaust system 70 and a rear side exhaust system 100, the front side exhaust system 70 and the rear side exhaust system 100 being connected to the front exhaust ports 52L, 52R and the rear exhaust ports 53L, 53R of the engine 10 An exhaust pipe 71 and a rear exhaust pipe 101; and a plurality of first and second silencers 72 and 102 as expansion chambers connected to the downstream ends of the front exhaust pipe 71 and the rear exhaust pipe 101, The first silencer 72 and the second silencer 102 are disposed closer to the lower portion of the motorcycle 1, and the first silencer 72 and the second silencer 102 are disposed apart from each other in the front-rear direction. And the second mute 102 and are spaced apart on the left and right direction with respect to the vehicle center C is a vehicle center. Thus, the plurality of expansion chambers are disposed apart from each other in the front-rear direction of the vehicle and are mutually separated from each other in the left-right direction with respect to the center of the vehicle. The two silencers 102 can be disposed, and even if the first silencer 72 and the second silencer 102 are disposed close to each other in the vehicle width direction, the left-right weight balance of the motorcycle 1 can be improved.

  Further, the front exhaust pipe 71 and the front exhaust pipe 71 and the rear exhaust pipe 101 of the rear exhaust apparatus 100 are exhaust pipes independent of each other, and the first silencer 72 and the second silencer 102 are independent of each other. It is a silencer divided into the front exhaust pipe 71 and the rear exhaust pipe 101. Thus, the front exhaust pipe 71 and the rear exhaust pipe 101 are independent of each other, so the degree of freedom of the exhaust pipe management is high, and the first silencer 72 and the second silencer 102 with respect to the vehicle center C. It is easy to arrange separately in the left and right direction. Further, since the expansion chambers are the first silencer 72 and the second silencer 102 which are heavy in weight, the left and right weight balance can be effectively improved by arranging them separately in the left-right direction.

  Further, since the second silencer 102 is disposed below the engine 10 and the first silencer 72 is disposed below the swing arm 30 that supports the rear wheel 3 to the vehicle body frame F so as to be able to pivot, the engine 10 The second silencer 102 and the first silencer 72 can be spaced apart in the front-rear direction and in the left-right direction by effectively utilizing the space below and the space below the swing arm 30.

Furthermore, the second silencer 102 disposed below the engine 10 is disposed on the other side avoiding the oil pan 44 bulging out from the lower portion of the engine 10, and the front exhaust pipe 71 of the first silencer 72 is oil The second silencer 102 is provided with a curved portion 102 f along the side surface of the bulging portion 87 of the oil pan 44 so as to pass through one side of the pan 44. As a result, the space under the engine 10 can be divided into the second silencer 102 on the other side of the oil pan 44 and the front exhaust pipe 71 on one side of the oil pan 44. Capacity can be increased. In addition, since the second silencer 102 includes the curved surface portion 102 f along the side surface of the bulging portion 87 of the oil pan 44, the capacity of the second silencer 102 can be increased.
In addition, an exhaust valve 112 for controlling the opening and closing of the exhaust pipe is provided in the rear exhaust pipe 101 located in front of the first silencer 72 and below the engine 10, and a drive pulley portion 112c for driving the exhaust valve 112 is provided. , Provided on the side of the exhaust pipe facing the engine 10. Thus, the drive pulley portion 112c can be compactly provided on the outer side and the lower side, and the clearance between the exhaust valve 112 and the road surface can be secured.

  The engine 10 is a V-type internal combustion engine in which a pair of front cylinder portions 42 and rear cylinder portions 43 are arranged in a V-shape, and the first silencer 72 and the second silencer 102 are front The front exhaust pipe 71 and the rear exhaust pipe 101 independently connected to the cylinder portion 42 and the rear cylinder portion 43 are separately disposed. The front exhaust pipe 71 and the rear exhaust pipe 101 are connected independently to the front cylinder portion 42 and the rear cylinder portion 43 of the V-type internal combustion engine, so the degree of freedom of the exhaust pipe arrangement is high. The second silencer 102 and the first silencer 72 provided on the pipe can be easily disposed separately in the left-right direction with respect to the vehicle center C. Further, the first silencer 72 and the second silencer 102 can be efficiently spaced apart in the front-rear direction corresponding to the positions of the front cylinder portion 42 and the rear cylinder portion 43 arranged in the front-rear direction, and the exhaust pipe length can be secured in a balanced manner.

Further, the engine 10 has a plurality of parallel cylinders in the front cylinder portion 42, and the front side collective portion 75 where the front side first exhaust pipe 73 and the front side second exhaust pipe 74 extended from the cylinders merge is The lower side of the engine 10 and the second silencer 102 are disposed on the front side of the first silencer 72 on the opposite side of the oil pan 44. As a result, the front collecting portion 75 of the front exhaust pipe 71 can be disposed below the engine 10 at a different position from the second silencer 102 and the first silencer 72, and the space below the engine 10 is effectively utilized. The front side exhaust pipe 71 can be disposed.
Furthermore, the engine 10 has a plurality of parallel cylinders in the front cylinder portion 42 and a plurality of parallel cylinders in the rear cylinder portion 43, and the front first exhaust gas extended from each cylinder of the front cylinder portion 42 A front assembly portion 75 where the pipe 73 and the front second exhaust pipe 74 merge, and a rear assembly where the rear first exhaust pipe 103 and the rear second exhaust pipe 104 extended from each cylinder of the rear cylinder portion 43 merge A front exhaust pipe 71 and a rear exhaust pipe 101 extending from the front cylinder portion 42 and the rear cylinder portion 43 are provided to face each other below the engine 10, and a front collecting portion 75 and a rear collecting portion are provided. The reference numeral 105 is arranged below the engine 10 so as to pass each other back and forth. Thus, the front collecting portion 75 and the rear collecting portion 105 of the front exhaust pipe 71 and the rear exhaust pipe 101, in which a plurality of exhaust pipes are extended for each of the front and rear cylinder portions 42 and 43, are It can be arranged compactly.

The above embodiment shows one aspect to which the present invention is applied, and the present invention is not limited to the above embodiment.
In the above embodiment, the first silencer 72 and the second silencer 102 are separately disposed in the front exhaust pipe 71 and the rear exhaust pipe 101 independently connected to the front cylinder portion 42 and the rear cylinder portion 43. However, the present invention is not limited to this. For example, a single exhaust pipe extending from the cylinder portion may be provided with a plurality of silencers, and these silencers may be disposed apart from each other in the front-rear direction and in the left-right direction with respect to the vehicle center C.
In the above embodiment, the motorcycle 1 has been described as an example of the rocking vehicle, but the present invention is not limited to this. For example, three wheels including two front wheels or two rear wheels The present invention may be applied to a saddle-ride type vehicle or a rocking vehicle having four or more wheels.

1 Motorcycle (rocking vehicle)
2 front wheel 3 rear wheel 10 engine (internal combustion engine, V-type internal combustion engine)
30 Swing arm 42 Front cylinder part (cylinder part)
43 Rear cylinder part (cylinder part)
44 Oil pan 52L, 52R Front exhaust port (exhaust port)
53L, 53R Rear exhaust port (exhaust port)
70 Front exhaust system (exhaust system)
71 Front exhaust pipe (exhaust pipe)
72 First silencer (expansion chamber, rear silencer)
75 Front Assembly (Assembly)
87 bulging part 100 Rear exhaust device (exhaust device)
101 Rear exhaust pipe (exhaust pipe)
102 Second silencer (expansion chamber, front silencer)
102f Curved surface portion 105 Rear side collecting portion (collecting portion)
112 exhaust valve 112 c drive pulley portion C vehicle center F body frame

Claims (6)

An internal combustion engine (10) mounted between a front wheel (2) and a rear wheel (3); and an exhaust system (70, 100) for muffling exhaust gas from the internal combustion engine (10); An exhaust pipe (71, 101) having an upstream end connected to an exhaust port (52L, 52R, 53L, 53R) of the internal combustion engine (10), and an exhaust pipe (71, 101) And an expansion chamber (72, 102) connected to the downstream end of the exhaust system, wherein the expansion chamber (72, 102) is disposed closer to the lower portion of the vehicle.
The expansion chambers (72, 102) are a first silencer (72) and a second silencer (102) separated from each other in the longitudinal direction of the vehicle, and the first silencer (72) and the second silencer (102) are disposed apart from each other in the left-right direction with respect to the vehicle center (C),
The exhaust pipe (71, 101) of the exhaust device (70, 100) is composed of a pair of exhaust pipes (71, 101) independent of each other, and the first silencer (72) and the second silencer ( 102) are disposed separately in the pair of exhaust pipes (71, 101),
The exhaust port (78a) of the first silencer (72) and the exhaust port (102d) of the second silencer (102) are disposed separately in the front-rear direction and in the left-right direction of the vehicle, Vertically spaced from each other so as not to overlap each other in the vertical direction of the vehicle ,
The second silencer (102) is a front silencer (102) disposed on the front side in the front-rear direction of the vehicle, and the front silencer (102) is disposed below the internal combustion engine (10).
The first silencer (72) is a rear silencer (72) disposed on the rear side in the front-rear direction of the vehicle, and the rear silencer (72) is a vehicle body frame of the rear wheel (3). (F) is disposed below a swing arm (30) that supports swingably,
The front silencer (102) disposed below the internal combustion engine (10) is disposed on the other side, avoiding the oil pan (44) bulging from the lower part of the internal combustion engine (10), and the rear side The exhaust pipe (71) of the silencer (72) is disposed to pass through one side of the oil pan (44);
The internal combustion engine (10) is a V-type internal combustion engine in which a pair of cylinder parts (42, 43) are arranged in the front and back in a V-shape, and the front silencer (102) and the rear silencer (72) Is divided into a plurality of the exhaust pipes (71, 101) independently connected to the respective cylinder parts (42, 43),
The V-type internal combustion engine (10) has a plurality of parallel cylinders in one cylinder portion (42), and a collecting portion (75) where the exhaust pipes (71) extended from the cylinders merge Is disposed opposite to the lower side of the V-type internal combustion engine (10) and the front side silencer (102) with respect to the oil pan (44) in front of the rear side silencer (72). An exhaust system structure of a swing vehicle characterized in that Before SL front silencer (102), characterized in that it comprises a curved portion along the side surface of the bulging portion (87) and (102f) of said oil pan (44) side face has the oil pan (44) The exhaust system structure of a swing vehicle according to claim 1 . An exhaust valve (112) for controlling the opening and closing of an exhaust pipe line is provided in the exhaust pipe (101) located below the internal combustion engine (10) in front of the rear side silencer (72), the exhaust 3. The exhaust system according to claim 1, wherein a drive pulley (112c) for driving the valve (112) is provided on the side of the exhaust pipe facing the internal combustion engine (10). The V-type internal combustion engine (10) has a plurality of parallel cylinders in each cylinder portion (42, 43), and a collecting portion (75) where the exhaust pipes (71, 101) extended from the cylinders merge. 105) for each of the cylinder portions (42, 43), and the exhaust pipes (71, 101) extending from the respective cylinder portions (42, 43) are opposed below the V-type internal combustion engine (10) Extend to
The said assembly part (75,105) is arrange | positioned so that it may pass by the front and back below the said V-type internal combustion engine (10), and does not overlap in the front and back, It is characterized by the above-mentioned. Exhaust system structure of the swinging vehicle. An internal combustion engine (10) mounted between a front wheel (2) and a rear wheel (3); and an exhaust system (70, 100) for muffling exhaust gas from the internal combustion engine (10); An exhaust pipe (71, 101) having an upstream end connected to an exhaust port (52L, 52R, 53L, 53R) of the internal combustion engine (10), and an exhaust pipe (71, 101) And an expansion chamber (72, 102) connected to the downstream end of the exhaust system, wherein the expansion chamber (72, 102) is disposed closer to the lower portion of the vehicle.
The expansion chamber (72, 102) includes a plurality of expansion chambers (72, 102) separated from each other in the front-rear direction of the vehicle, and the plurality of expansion chambers (72, 102) with respect to the vehicle center (C) Placed apart from each other in the left-right direction,
The exhaust pipe (71, 101) of the exhaust device (70, 100) is composed of a plurality of exhaust pipes (71, 101) independent of each other, and the plurality of expansion chambers (72, 102) are independent of each other It is a silencer divided and disposed in a plurality of the exhaust pipes (71, 101),
A front silencer (102) disposed on the front side in the front-rear direction of the vehicle is disposed below the internal combustion engine (10).
A rear silencer (72) disposed on the rear side in the front-rear direction of the vehicle is disposed below a swing arm (30) that swingably supports the rear wheel (3) on the vehicle body frame (F),
The front silencer (102) disposed below the internal combustion engine (10) is disposed on the other side, avoiding the oil pan (44) bulging from the lower part of the internal combustion engine (10), and the rear side The exhaust pipe (71) of the silencer (72) is disposed to pass through one side of the oil pan (44);
The internal combustion engine (10) is a V-type internal combustion engine in which a pair of cylinder parts (42, 43) are arranged in the front and back in a V-shape, and the front silencer (102) and the rear silencer (72) Is divided into a plurality of the exhaust pipes (71, 101) independently connected to the respective cylinder parts (42, 43),
The V-type internal combustion engine (10) has a plurality of parallel cylinders in one cylinder portion (42), and a collecting portion (75) where the exhaust pipes (71) extended from the cylinders merge The lower side of the V-type internal combustion engine (10) and the front side silencer (102) are disposed in front of the rear side silencer (72) at an opposite side of the oil pan (44). An exhaust system structure of a swing vehicle characterized in that An internal combustion engine (10) mounted between a front wheel (2) and a rear wheel (3); and an exhaust system (70, 100) for muffling exhaust gas from the internal combustion engine (10); An exhaust pipe (71, 101) having an upstream end connected to an exhaust port (52L, 52R, 53L, 53R) of the internal combustion engine (10), and an exhaust pipe (71, 101) And an expansion chamber (72, 102) connected to the downstream end of the exhaust system, wherein the expansion chamber (72, 102) is disposed closer to the lower portion of the vehicle.
The expansion chamber (72, 102) includes a plurality of expansion chambers (72, 102) separated from each other in the front-rear direction of the vehicle, and the plurality of expansion chambers (72, 102) with respect to the vehicle center (C) Placed apart from each other in the left-right direction,
The exhaust pipe (71, 101) of the exhaust device (70, 100) is composed of a plurality of exhaust pipes (71, 101) independent of each other, and the plurality of expansion chambers (72, 102) are independent of each other It is a silencer divided and disposed in a plurality of the exhaust pipes (71, 101),
A front silencer (102) disposed on the front side in the front-rear direction of the vehicle is disposed below the internal combustion engine (10).
A rear silencer (72) disposed on the rear side in the front-rear direction of the vehicle is disposed below a swing arm (30) that swingably supports the rear wheel (3) on the vehicle body frame (F),
The internal combustion engine (10) is a V-type internal combustion engine in which a pair of cylinder parts (42, 43) are arranged in the front and back in a V-shape, and the front silencer (102) and the rear silencer (72) Is divided into a plurality of the exhaust pipes (71, 101) independently connected to the respective cylinder parts (42, 43),
The V-type internal combustion engine (10) has a plurality of parallel cylinders in each cylinder portion (42, 43), and a collecting portion (75) where the exhaust pipes (71, 101) extended from the cylinders merge. 105) for each of the cylinder portions (42, 43), and the exhaust pipes (71, 101) extending from the respective cylinder portions (42, 43) are opposed below the V-type internal combustion engine (10) Extend to
The exhaust system structure of a rocking vehicle according to the present invention, wherein the collecting portion (75, 105) is disposed below and behind the V-type internal combustion engine (10) so as to pass each other back and forth.

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