JP6845879B2 - Exhaust structure of saddle-riding vehicle - Google Patents

Description

The present invention relates to an exhaust structure of a saddle-mounted vehicle.

Conventionally, an exhaust structure of a saddle-riding vehicle including an exhaust pipe connected to an internal combustion engine and a catalyst provided in the exhaust pipe is known (see, for example, Patent Document 1). In Patent Document 1, in an exhaust pipe provided with a catalyst, another exhaust pipe joins a portion upstream of the tubular portion accommodating the catalyst so as to be substantially orthogonal to the exhaust pipe. This confluence is located away from the catalyst, and near the catalyst, the exhaust flows in the axial direction of the exhaust pipe.

Special Publication No. 60-17220

By the way, in the exhaust structure of a saddle-riding vehicle, in order for the catalyst to function efficiently, it is desirable that the exhaust flows as uniformly as possible to the catalyst.
The present invention has been made in view of the above circumstances, and an object of the present invention is to enable uniform exhaust flow to a catalyst in an exhaust structure of a saddle-riding vehicle.

The exhaust structure of the saddle-mounted vehicle includes an exhaust pipe (33) connected to the internal combustion engine (11) and a catalyst (52) provided in the exhaust pipe (33). In the exhaust structure of a saddle-mounted vehicle including a catalyst case portion (51) for accommodating the catalyst (52) and upstream exhaust pipes (50L, 50R) provided on the upstream side of the catalyst case portion (51). The catalyst case portion (51) has a larger diameter than the upstream exhaust pipe (50L, 50R), and the upstream exhaust pipe (50L, 50R) is upstream of the catalyst (52) in the exhaust flow. A connecting portion (60) located on the side is connected to the catalyst case portion (51), and at the connecting portion (60), the axis lines (50L1, 50R1) of the upstream exhaust pipes (50L, 50R) and the catalyst case. Ri positional relationship near the substantially right angle to the axis (51a) of the section (51), the upstream exhaust pipe (50L, 50R), the catalyst case section in a plurality of said connecting portion (60) to (51) Connected, the plurality of upstream exhaust pipes (50L, 50R) are arranged side by side substantially in parallel at the connection portion (60), and the plurality of upstream exhaust pipes (50L, 50R) are arranged at the connection portion (60). ), The inner extension pipe portions (61L, 61R) extending inward of the catalyst case portion (51) are provided, and the upstream side in the axial view of the axis (51a) of the catalyst case portion (51). The axis (50L1, 50R1) of the upstream exhaust pipe (50L, 50R) and the inner surface (51d) of the catalyst case portion (51) in the direction orthogonal to the axis (50L1, 50R1) of the exhaust pipe (50L, 50R). The upstream exhaust pipe (50R) having a closer distance to the catalyst case portion (61R) has a catalyst case portion (61R) than the upstream exhaust pipe (50L) having a longer distance from the catalyst case portion (61R). to the inside of the 51) and deeply extending said Rukoto.

In addition, the above-described configuration, the upstream-side exhaust pipe (50L, 50R), said extending exhaust port of an internal combustion engine (11) from (31b, 31c) until the catalyst case portion (51), wherein the catalyst case portion ( 51) may be arranged outside the vehicle width direction with respect to the exhaust ports (31b, 31c).

Further, in the above configuration, a reinforcing member (58) for reinforcing the upstream exhaust pipe (50L, 50R) is provided, and the reinforcing member (58) is a plurality of the upstream exhaust pipes (50L, 50R). An inner reinforcing member (70) that connects a plurality of the upstream exhaust pipes (50L, 50R) to each other at an intermediate position, and an upstream exhaust pipe (50R) outside the inner reinforcing member (70). The outer reinforcing member (71) is provided, and the plate thickness (t1) of the outer reinforcing member (71) may be smaller than the plate thickness (t2, t3) of the inner reinforcing member (70).
Further, in the above configuration, the inner reinforcing member (70) may be separately provided on the front side and the rear side of the saddle-riding vehicle in the upstream exhaust pipes (50L, 50R).

Further, in the above configuration, the upstream exhaust pipes (50L, 50R) are formed from the downward extending portions (55L, 55R) extending downward from the exhaust port and the lower ends of the downward extending portions (55L, 55R). A lateral extension portion (56L, 56R) extending outward in the vehicle width direction is provided, and the lateral extension portion (56L, 56R) is connected to the catalyst case portion (51) by the connection portion (60). You may.
Further, in the above configuration, the catalyst case portion (51) is arranged downward in the rear view from the side view of the vehicle, and the connection portion (60) is provided at the front end portion (51b) of the catalyst case portion (51). Is also good.

Further, in the above configuration, the body frame (10) of the saddle-riding vehicle includes a head pipe (16) that supports the steering system (12) and a down frame (19) that extends downward from the head pipe (16). And a lower frame (20) extending rearward from the down frame (19) below the internal combustion engine (11), and the upstream exhaust pipes (50L, 50R) are on the front surface of the internal combustion engine (11). At least a part of the connection portion (60) extends downward from the exhaust port (31b, 31c) of the vehicle through the side of the down frame (19), and the down frame (19) It may be provided in front of the lower frame (20).
Further, in the above configuration, the axis (51a) of the catalyst case (51) extends in the front-rear direction of the vehicle, and the axis (51a) of the catalyst case (51) extends from above the catalyst case (51). When the axis (51a) and the axis (50L1, 50R1) of the upstream exhaust pipe (50L, 50R) are viewed in a direction orthogonal to), the axis (50L, 50R) of the upstream exhaust pipe (50L, 50R) The 50L1, 50R1) and the axis (51a) of the catalyst case portion (51) may be in a substantially orthogonal positional relationship.

The exhaust structure of the saddle-mounted vehicle includes an exhaust pipe connected to the internal combustion engine and a catalyst provided in the exhaust pipe, and the exhaust pipe is provided in the catalyst case portion for accommodating the catalyst and on the upstream side of the catalyst case portion. The catalyst case part has a larger diameter than the upstream side exhaust pipe, and the upstream side exhaust pipe is a connection part located on the upstream side of the catalyst in the exhaust flow to the catalyst case part. In the connected portion, the axis of the upstream exhaust pipe and the axis of the catalyst case are substantially perpendicular to each other.
According to this configuration, at the connection portion where the upstream exhaust pipe is connected to the catalyst case portion, the exhaust gas from the upstream exhaust pipe flows into the catalyst case portion in a direction substantially perpendicular to the axis of the catalyst case portion. As a result, in the catalyst case portion, the flow of the exhaust gas is disturbed on the upstream side of the catalyst and the exhaust gas is dispersed, so that the exhaust gas can flow uniformly to the catalyst.

Further, in the above configuration, a plurality of upstream exhaust pipes may be connected to the catalyst case portion at the connecting portion.
According to this configuration, exhaust gas flows into the catalyst case portion from a plurality of upstream exhaust pipes in a direction substantially perpendicular to the axis of the catalyst case portion. As a result, the flow of exhaust gas is disturbed on the upstream side of the catalyst, so that the exhaust gas can flow uniformly through the catalyst.
Further, in the above configuration, the plurality of upstream exhaust pipes may be arranged side by side substantially in parallel at the connection portion.
According to this configuration, the exhaust gas flows from the plurality of upstream exhaust pipes substantially at right angles to the axes of the catalyst case portion and substantially parallel to each other, and flows into the catalyst case portion. As a result, the flow of exhaust gas is disturbed on the upstream side of the catalyst, so that the exhaust gas can flow uniformly through the catalyst. In addition, a plurality of upstream exhaust pipes can be arranged compactly.

Further, in the above configuration, the plurality of upstream exhaust pipes are provided with an inner extension pipe portion extending inward of the catalyst case portion at the connection portion, and the upstream exhaust pipe portion is provided in the axial direction of the axis of the catalyst case portion. The upstream exhaust pipe on the side where the distance between the axis of the upstream exhaust pipe and the inner surface of the catalyst case in the direction orthogonal to the axis of the catalyst case is short is the inner extension pipe part than the upstream exhaust pipe on the far side. May extend deep into the inside of the catalyst case.
According to this configuration, the exhaust gas that enters the inside of the catalyst case portion from the upstream exhaust pipe that is closer to the distance generates a flow that rotates along the inner peripheral surface of the catalyst case portion, and the exhaust gas that is farther away is generated. The exhaust gas entering the inside of the catalyst case portion from the upstream exhaust pipe joins the above-mentioned rotating flow. As a result, the turbulence of the exhaust flow can be efficiently generated on the upstream side of the catalyst, and the exhaust can be uniformly flowed to the catalyst.
Further, in the above configuration, the upstream exhaust pipe may extend from the exhaust port of the internal combustion engine to the catalyst case portion, and the catalyst case portion may be arranged outside the vehicle width direction with respect to the exhaust port.
According to this configuration, since the catalyst case portion is arranged on the outer side in the vehicle width direction with respect to the exhaust port, it is easy to secure a space in the portion located above and below the exhaust port.

Further, in the above configuration, a reinforcing member for reinforcing the upstream exhaust pipe is provided, and the reinforcing member includes an inner reinforcing member for connecting the plurality of upstream exhaust pipes to each other at a position between the plurality of upstream exhaust pipes. It is provided with an outer reinforcing member provided on the upstream exhaust pipe outside the inner reinforcing member, and the plate thickness of the outer reinforcing member may be smaller than the plate thickness of the inner reinforcing member.
According to this configuration, the strength of the upstream exhaust pipe can be effectively increased by the inner reinforcing member that connects the plurality of upstream exhaust pipes to each other at the position between the plurality of upstream exhaust pipes. Further, since the plate thickness of the outer reinforcing member provided outside the inner reinforcing member is smaller than the plate thickness of the inner reinforcing member, it is possible to reduce the weight while increasing the strength of the upstream exhaust pipe. Further, by providing the inner reinforcing member, it is possible to prevent foreign matter such as grass from being caught between the plurality of upstream exhaust pipes, and the exhaust structure can be easily cleaned.
Further, in the above configuration, the inner reinforcing member may be separately provided on the front side and the rear side of the saddle-riding vehicle in the upstream exhaust pipe.
According to this configuration, it is easy to provide an inner reinforcing member in the upstream exhaust pipe at the time of manufacturing.

Further, in the above configuration, the plurality of upstream exhaust pipes include a downward extending portion extending downward from the exhaust port and a lateral extending portion extending outward in the vehicle width direction from the lower end of the downward extending portion. The extending portion may be connected to the catalyst case portion at the connecting portion.
According to this configuration, the lateral extension portion extending outward in the vehicle width direction from the lower end of the downward extension portion is connected to the catalyst case portion at the connection portion, so that the exhaust structure is compact in the vertical direction in the vicinity of the catalyst case portion. Can be converted.
Further, in the above configuration, the catalyst case portion may be arranged downward in the rear view from the side view of the vehicle, and the connecting portion may be provided at the front end portion of the catalyst case portion.
According to this configuration, since the catalyst case portion is arranged downward in the rear view from the side view of the vehicle, the front portion of the catalyst case portion can be arranged at a high position, and the front portion of the catalyst case portion can be arranged at a position far from the road surface. In addition, the length of the upstream exhaust pipe can be shortened.

Further, in the above configuration, the body frame of the saddle-riding vehicle includes a head pipe that supports the steering system, a down frame that extends downward from the head pipe, and a lower frame that extends rearward from the down frame below the internal combustion engine. The upstream exhaust pipe extends downward from the front exhaust port of the internal combustion engine through the side of the down frame, and at least a part of the connection part is in front of the down frame and the lower frame in the vehicle side view. It may be provided.
According to this configuration, since the connecting portion is provided in front of the down frame and the lower frame when viewed from the side of the vehicle, the upstream exhaust pipe can be easily extended outward in the vehicle width direction, and the axis of the upstream exhaust pipe and the catalyst case portion can be easily extended. It is easy to provide the axis at a substantially right angle. In addition, the upstream exhaust pipe can be shortened.
Further, in the above configuration, when the axis of the catalyst case portion extends in the front-rear direction of the vehicle and the axis of the catalyst case and the axis of the upstream exhaust pipe are viewed from above the catalyst case in a direction orthogonal to the axis of the catalyst case. , The axis of the upstream exhaust pipe and the axis of the catalyst case may be in a substantially orthogonal positional relationship.
According to this configuration, the connection portion and the catalyst case portion can be arranged compactly.

It is a right side view of the motorcycle which concerns on embodiment of this invention. FIG. 2 is a sectional view taken along line II-II of FIG. It is a right side view of an exhaust pipe. It is a front view which looked at the peripheral part of the catalyst case part from the front side. It is a right side view of the peripheral part of an engine and an exhaust pipe. It is a front view which looked at the exhaust pipe from the front side. It is the figure which looked at the exhaust pipe from the front side in the axial direction of the axis. It is a perspective view which looked at the exhaust pipe from the left rear side. FIG. 7 is a cross-sectional view taken along the line IX-IX of FIG. FIG. 6 is a cross-sectional view taken along the line XX of FIG. It is a figure which shows typically the internal structure of a muffler. It is the figure which looked at the rear end part of a muffler from the rear side. It is a perspective view which looked at the rear end part of a muffler from the rear side side. It is a perspective view which shows the state which attached the exhaust port cover different from the exhaust port cover to a muffler.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the explanation, the directions such as front / rear / left / right and up / down are the same as the directions with respect to the vehicle body unless otherwise specified. Further, the reference numeral FR shown in each figure indicates the front of the vehicle body, the reference numeral UP indicates the upper part of the vehicle body, and the reference numeral LH indicates the left side of the vehicle body.

FIG. 1 is a right side view of a motorcycle according to an embodiment of the present invention.
In the motorcycle 1, the engine 11 (internal combustion engine) as a power unit is supported by the body frame 10, and the steering system 12 that steerably supports the front wheels 2 is steerably supported by the front end of the body frame 10, and the rear wheels 3 are supported. A vehicle in which a supporting swing arm 13 is provided at the rear of the vehicle body frame 10.
The motorcycle 1 is a saddle-riding vehicle in which an occupant sits so as to straddle the seat 14, and the seat 14 is provided above the rear portion of the vehicle body frame 10.

The vehicle body frame 10 includes a head pipe 16, a pair of left and right main frames 17, a pair of left and right pivot frames 18, a down frame 19, a pair of left and right lower frames 20, and a pair of left and right seat frames 21.

Specifically, the head pipe 16 is provided at the front end of the vehicle body frame 10 and is located at the center of the vehicle width.
The left and right main frames 17 extend rearward from the head pipe 16 downward.
The left and right pivot frames 18 extend downward from the rear end of the main frame 17.
The down frame 19 extends downward by one from the position below the main frame 17 in the head pipe 16 and is located at the center of the vehicle width.
The left and right lower frames 20 branch left and right from the lower end of the down frame 19 and extend rearward, respectively, and are connected to the lower end of the pivot frame 18.
The left and right seat frames 21 extend rearward and upward from the upper part of the pivot frame 18.

The steering system 12 includes a pair of left and right front forks 25 that are rotatably provided via a steering shaft (not shown) pivotally supported by the head pipe 16, and a handle 26 that is attached to the upper end of the front fork 25. The front wheel 2 is pivotally supported at the lower end of the front fork 25.

The front end of the swing arm 13 is pivotally supported by a pivot shaft 27 that connects the left and right pivot frames 18 in the vehicle width direction, and the swing arm 13 swings up and down about the pivot shaft 27. The rear wheel 3 is pivotally supported at the rear end of the swing arm 13.

The engine 11 is arranged between the main frame 17 and the lower frame 20 and between the down frame 19 and the pivot frame 18 in a vehicle side view, and is supported by the vehicle body frame 10.
The engine 11 includes a crankcase 30 that supports a crankshaft 29 that extends horizontally in the vehicle width direction (left-right direction), and a cylinder portion 31 that extends upward from the front portion of the crankcase 30. The cylinder axis 31a of the cylinder portion 31 tilts forward with respect to the vertical direction.

The intake device (not shown) of the engine 11 is connected to the intake port on the rear surface of the cylinder portion 31.
The exhaust device 32 of the engine 11 includes an exhaust pipe 33 connected to the front surface of the cylinder portion 31 and a muffler 34 connected to the downstream end of the exhaust pipe 33.
The exhaust pipe 33 extends downward from the front surface of the cylinder portion 31, passes under the engine 11, and extends rearward. The muffler 34 is arranged on the outer side of the rear wheel 3.
The rear portion of the crankcase 30 is a transmission case portion 30b that houses the transmission. The output of the engine 11 is transmitted to the rear wheels 3 by a drive chain 35 that connects the output shaft of the transmission and the rear wheels 3.

The seat 14 is supported from below by the seat frame 21.
The fuel tank 36 is arranged between the head pipe 16 and the seat 14, and is supported by the main frame 17 above the engine 11.
Step 37 on which the driver puts his / her foot is provided on the lower end of the pivot frame 18 in pairs on the left and right.

The motorcycle 1 includes a vehicle body cover that covers a vehicle body such as a vehicle body frame 10 and an engine 11. The vehicle body cover includes a front cover 38 that covers the upper part of the head pipe 16 and the steering system 12 from the front and sides, a rear side cover 39 that covers the seat frame 21 below the seat 14, and a rear portion of the seat 14 from above. A tail cover 40 that covers the engine 11 and an undercover 41 that covers the lower portion of the engine 11 from the front are provided.
Further, the motorcycle 1 includes a front fender 42 that covers the front wheels 2 from above and a rear fender 43 that covers the rear wheels 3 from above.

FIG. 2 is a sectional view taken along line II-II of FIG.
A pair of left and right plate-shaped radiators 45 of the engine 11 are provided on the left and right sides of the down frame 19. The radiator 45 is covered from the side by the left and right side portions of the front cover 38.
A plurality of exhaust ports 31b and 31c are provided side by side in the vehicle width direction on the front surface of the cylinder head of the cylinder portion 31 of the engine 11. A pair of left and right exhaust ports 31b and 31c are provided on the left and right sides of the down frame 19. The exhaust ports 31b and 31c are located below the radiator 45.
A horn 46 is arranged between the radiator 45 on the right side and the down frame 19 above the exhaust port 31c.

FIG. 3 is a right side view of the exhaust pipe 33.
With reference to FIGS. 1 to 3, the exhaust pipe 33 is connected to one upstream exhaust pipe 50L connected to one of the left and right (left side) exhaust ports 31b and to the left and right other (right side) exhaust port 31c. The other upstream exhaust pipe 50R, the catalyst case 51 connected to the downstream ends of the upstream exhaust pipes 50L and 50R (plural exhaust pipes extending from the exhaust port of the internal combustion engine), and the catalyst case 51 are housed in the catalyst case 51. The catalyst 52 is provided, and a downstream exhaust pipe 53 extending from the catalyst case portion 51 toward the muffler 34 is provided.

FIG. 4 is a front view of the peripheral portion of the catalyst case portion 51 as viewed from the front side. FIG. 5 is a right side view of the peripheral portion of the engine 11 and the exhaust pipe 33. In FIGS. 4 and 5, the undercover 41 is not shown.
With reference to FIGS. 2 to 5, the catalyst case portion 51 is a cylindrical tube that extends long in the front-rear direction of the vehicle. The catalyst case portion 51 is a portion of the exhaust pipe 33 whose diameter is larger than that of the upstream exhaust pipes 50L and 50R, and the outer diameter of the catalyst case portion 51 is the outer diameter of the upstream exhaust pipes 50L and 50R. Greater than.
The catalyst case portion 51 is arranged offset to one side (right side) in the vehicle width direction with respect to the center of the vehicle width. The catalyst case portion 51 is arranged below the exhaust ports 31b and 31c and outside in the vehicle width direction. The catalyst case portion 51 is located outside the vehicle width direction with respect to the virtual straight line 31d extending downward from the outer end in the vehicle width direction at the exhaust ports 31b and 31c.

The catalyst case portion 51 is arranged below the end portion 30a of the crankcase 30 in the vehicle width direction and on the outer side of the front portion of the lower frame 20.
Specifically, the left and right lower frames 20 are inclined so as to be located outside and rearward in the vehicle width direction from the lower end of the down frame 19 downward, and substantially horizontally from the lower end of the inclined portion 20a to the rear. It is provided with an extending rear extension portion 20b.
The catalyst case portion 51 overlaps the inclined portion 20a of the front end portion of the lower frame 20 from the outside in the vehicle width direction when viewed from the side of the vehicle. The catalyst case portion 51 is arranged above the rear extending portion 20b.
The catalyst case portion 51 is arranged in a rear-down (front-up) posture along the inclined portion 20a when viewed from the side of the vehicle. The axis 51a of the catalyst case portion 51 inclines downward. Further, the catalyst case portion 51 is hardly inclined in the left-right direction, and extends straight in the front-rear direction of the vehicle. That is, when the catalyst case portion 51 is viewed from above the vehicle, the axis 51a extends straight in the vehicle front-rear direction.

Since the catalyst case portion 51 is raised forward, the front end portion 51b is at the highest position. The downstream ends of the upstream exhaust pipes 50L and 50R are connected to the front end portion 51b.
The upstream end of the downstream exhaust pipe 53 is connected to the rear end 51c of the catalyst case 51, and extends rearward from the rear end 51c. The rear end portion 51c of the catalyst case portion 51 is the lower end portion of the catalyst case portion 51, and is located forward and below the crankshaft 29.
Like the catalyst case portion 51, the muffler 34 is offset to one side (right side) in the vehicle width direction with respect to the center of the vehicle width. The downstream exhaust pipe 53 extends substantially straight rearward from the rear end portion 51c of the catalyst case portion 51 and is connected to the muffler 34. Therefore, the downstream exhaust pipe 53 can be shortened.

The catalyst 52 is a honeycomb-shaped porous structure having a large number of pores extending in the axial direction inside the cylindrical outer shell. A catalytic substance (for example, platinum, rhodium and palladium) that decomposes an exhaust gas component is supported on the wall of each of the pores.
The catalyst 52 is fixed to the catalyst case portion 51 by fitting the outer peripheral portion of the catalyst 52 to the inner peripheral portion of the catalyst case portion 51. The catalyst 52 fits into the inner peripheral portion of the catalyst case portion 51 via a holding cylinder (not shown) that surrounds the outer periphery of the catalyst 52.
As shown in FIGS. 1 and 2, the catalyst 52 is covered by the side portions of the undercover 41 from the front, the bottom, and the outside.

FIG. 6 is a front view of the exhaust pipe 33 as viewed from the front side. FIG. 7 is a view of the exhaust pipe 33 viewed from the front side in the axial direction of the axis 51a. FIG. 8 is a perspective view of the exhaust pipe 33 as viewed from the left rear side. In FIG. 7, the front surface portion of the catalyst case portion 51 is cut out so that the inside of the catalyst case portion 51 can be seen.
With reference to FIGS. 2 and 6 to 8, the upstream exhaust pipe 50L on the left side has a downward extension portion 55L extending downward from the left exhaust port 31b (FIG. 2) of the cylinder portion 31 and a downward extension portion. A lateral extension portion 56L extending from the lower end of the 55L in the vehicle width direction and connected to the catalyst case portion 51 is provided.
Further, the upstream exhaust pipe 50R on the right side extends downward from the exhaust port 31c (FIG. 2) on the right side of the cylinder portion 31 and extends outward from the lower end of the downward extending portion 55R in the vehicle width direction. A side extension portion 56R connected to the catalyst case portion 51 is provided.

The downward extending portions 55L and 55R are separately arranged on the left and right sides of the down frame 19, and extend downward along the down frame 19.
The downward extending portion 55R on the right side is located on the same side as the catalyst case portion 51 when the left and right sides are divided with respect to the down frame 19. The lower extension portion 55L on the left side is located on the opposite side of the catalyst case portion 51 when the left and right sides are divided with respect to the down frame 19, and is closer to the lower extension portion 55R on the right side with respect to the catalyst case portion 51. It is in a distant position.

The lateral extension portion 56L has a curved portion 56L1 that bends in an arc shape from the lower end of the downward extension portion 55L toward the catalyst case portion 51, and a curved portion 56L1 that extends linearly from the curved portion 56L1 in the vehicle width direction to the catalyst case portion 51. It includes a straight portion 56L2 to be connected. The straight portion 56L2 extends in front of the down frame 19 to the catalyst case portion 51 across the down frame 19 in the vehicle width direction.

The lateral extension portion 56R has a curved portion 56R1 that bends in an arc shape from the lower end of the downward extension portion 55R toward the catalyst case portion 51, and a curved portion 56R1 that extends linearly from the curved portion 56R1 in the vehicle width direction to the catalyst case portion 51. It includes a straight portion 56R2 to be connected.

The exhaust pipe 33 includes a gathering portion 57 in which the left and right upstream exhaust pipes 50L and 50R are gathered.
The gathering portion 57 is a portion where the left and right lateral extending portions 56L and 56R are gathered so as to be close to each other.
Specifically, in the gathering portion 57, the curved portion 56R1 and the straight portion 56R2 of the lateral extending portion 56R and the straight portion 56L2 of the lateral extending portion 56L are close to each other. The side extension portion 56R and the side extension portion 56L may come into contact with each other.
The straight portion 56L2 is provided side by side below the straight portion 56R2, and extends outward in the vehicle width direction substantially parallel to the straight portion 56R2.

The exhaust pipe 33 includes a reinforcing member 58 that connects and reinforces the upstream exhaust pipe 50L and the upstream exhaust pipe 50R. The reinforcing member 58 is provided at the gathering portion 57.
The exhaust pipe 33 includes sensors 78 for detecting the oxygen concentration of the exhaust gas of the upstream exhaust pipes 50L and 50R in the upstream exhaust pipes 50L and 50R, respectively.
The sensor 78 has a rod shape, and the sensor support hole 55a on the outer surface of the downward extending portions 55L, 55R in the vehicle width direction so that the detecting portion at the tip of the sensor 78 is exposed in the downward extending portions 55L, 55R ( It is inserted into FIG. 8) from the side. In the front view of FIG. 6, the sensor 78 extends obliquely outward and upward in the vehicle width direction from the downward extending portions 55L and 55R.
Further, the exhaust pipe 33 includes sensor guards 79 covering the sensor 78 in the upstream exhaust pipes 50L and 50R, respectively.
The sensor guard 79 extends obliquely outward and upward in the vehicle width direction along the sensor 78 from the outer surfaces of the downward extending portions 55L and 55R.
The sensor guard 79 is a plate member integrally including a front surface portion 79a that covers the sensor 78 from the front and a lower surface portion 79b that covers the sensor 78 from below. The base end of the sensor guard 79 is welded to the downward extending portions 55L and 55R.

FIG. 9 is a cross-sectional view taken along the line IX-IX of FIG.
With reference to FIGS. 6, 7 and 9, in the catalyst case portion 51, between the front surface of the front end portion 51b of the catalyst case portion 51 and the front end surface 52a of the catalyst 52, the upstream exhaust pipes 50L and 50R An exhaust inflow space 59 into which the exhaust from the air flows in is provided.
The upstream exhaust pipes 50L and 50R are connected to the catalyst case 51 by a connecting portion 60 located upstream of the catalyst 52 in the exhaust flow. The connecting portion 60 is an end portion of the gathering portion 57 on the outer side in the vehicle width direction, and is a part of the gathering portion 57.

The upstream exhaust pipe 50L includes an inner extending pipe portion 61L extending inward of the catalyst case portion 51 at the connecting portion 60 at the downstream end of the straight portion 56L2.
The upstream exhaust pipe 50R includes an inner extending pipe portion 61R extending inward of the catalyst case portion 51 at the connecting portion 60 at the downstream end of the straight portion 56R2.
The inner extension pipe portion 61L and the inner extension pipe portion 61R extend substantially parallel to each other in the vehicle width direction and communicate with the exhaust inflow space 59.
The inner extending pipe portion 61L and the inner extending pipe portion 61R penetrate the inner side surface in the vehicle width direction of the front end portion 51b of the catalyst case portion 51 and enter the exhaust inflow space 59.

As shown in FIG. 9, in the connection portion 60, the axis line 50L1 extending in the vehicle width direction of the upstream exhaust pipe 50L and the axis line 51a extending in the vehicle front-rear direction of the catalyst case portion 51 are in a substantially right-angled positional relationship with each other. The angle A formed by 50L1 and the axis 51a is approximately 90 °.
In the present embodiment, when the axis 51a and the axis 50L1 are viewed from above the catalyst case portion 51 in the direction orthogonal to the axis 51a as shown in FIG. 9, the angle A formed by the axis 50L1 and the axis 51a is approximately 90 °. Is. In this embodiment, the angle A is 97.1 °.
Further, the axis 50L1 of the upstream exhaust pipe 50L on the left side and the axis 50R1 (FIG. 7) of the upstream exhaust pipe 50R on the right side are substantially parallel to each other. The axis line 50R1 and the axis line 51a of the catalyst case portion 51 are in a substantially right-angled positional relationship. In the present embodiment, when the axis 51a and the axis 50R1 are viewed from above the catalyst case portion 51 in the direction orthogonal to the axis 51a, the angle A formed by the axis 50R1 and the axis 51a is approximately 90 °.
That is, the upstream exhaust pipes 50L and 50R are inserted from the vehicle width direction so as to be substantially orthogonal to the tubular catalyst case portion 51 extending in the vehicle front-rear direction.

With reference to FIG. 7, the inner extension pipe portion 61R is provided in the upper part of the exhaust inflow space 59 and opens outward in the vehicle width direction. The inner extension pipe portion 61L is provided in the upper and lower intermediate portions in the exhaust inflow space 59, and opens outward in the vehicle width direction below the inner extension pipe portion 61R.

In the exhaust inflow space 59, the lengths of the inner extension pipe portion 61L and the inner extension pipe portion 61R are different.
Specifically, as shown in FIG. 7, the distance between the axis 50R1 and the inner surface 51d of the catalyst case 51 in the direction orthogonal to the axis 50R1 of the upstream exhaust pipe 50R in the axial view of the axis 51a of the catalyst case 51. D1 is smaller than the distance D2 between the axis 50L1 and the inner surface 51d of the catalyst case portion 51 in the direction orthogonal to the axis 50L1 of the upstream exhaust pipe 50L. Therefore, the upstream exhaust pipe 50R is closer to the inner surface 51d than the upstream exhaust pipe 50L.
In the upstream exhaust pipe 50R, which is closer to the inner surface 51d than the upstream exhaust pipe 50L, the inner extension pipe portion 61R extends deeper than the inner extension pipe portion 61L to the inside of the catalyst case portion 51.
That is, the tip of the inner extending pipe portion 61R protrudes in the axial direction by a length H from the tip of the inner extending pipe portion 61L.

The upstream exhaust pipe 50R is shorter than the upstream exhaust pipe 50L, and the exhaust path from the exhaust port 31c to the downstream end of the upstream exhaust pipe 50R is downstream from the exhaust port 31b to the upstream exhaust pipe 50L. Shorter than the exhaust path to the end.
The upstream exhaust pipe 50R having a shorter exhaust path extends deeper into the catalyst case portion 51 than the upstream exhaust pipe 50L having a longer exhaust path.

With reference to FIG. 5, the upstream exhaust pipes 50L and 50R extend downward from the exhaust ports 31b and 31c through the side of the down frame 19 and are connected to the front end portion 51b of the catalyst case portion 51 via the connecting portion 60. Will be done.
The front end portion 51b of the catalyst case portion 51 is located in front of the down frame 19 and the lower frame 20 in the vehicle side view, and the connecting portion 60 is located behind the front wheel 2 and in front of the down frame 19 and the lower frame 20. Provided. Therefore, the connecting portion 60 can be easily connected to the catalyst case portion 51 extending in the front-rear direction at a substantially right angle from the vehicle width direction, and the upstream exhaust pipes 50L and 50R can be shortened. Further, since the upstream exhaust pipes 50L and 50R are shortened, the high temperature exhaust gas flows to the catalyst case portion 51, so that the catalyst 52 can be activated quickly and the exhaust gas can be efficiently purified.
Here, in FIG. 5, dots are added to the portion of the connecting portion 60 in the side view of the vehicle for distinction. In the present embodiment, most of the connecting portion 60 is located in front of the down frame 19, and the rear end portion of the connecting portion 60 overlaps the down frame 19 when viewed from the side of the vehicle. At least a part of the connecting portion 60 may be located in front of the down frame 19 and the lower frame 20, and the connecting portion 60 may be entirely located in front of the down frame 19 and the lower frame 20.

With reference to FIG. 7, the exhaust gas of the engine 11 passes through the upstream exhaust pipe 50L and the upstream exhaust pipe 50R, respectively, and flows into the exhaust inflow space 59 of the catalyst case portion 51. The exhaust gas flowing into the exhaust inflow space 59 flows rearward through the catalyst 52, flows into the muffler 34 through the downstream exhaust pipe 53, and is discharged to the outside from the muffler 34.
Since the upstream exhaust pipes 50L and 50R are provided so as to be substantially orthogonal to the catalyst case portion 51, the exhaust of the upstream exhaust pipes 50L and 50R is exhausted in a direction substantially perpendicular to the axis 51a of the catalyst case portion 51. It flows into the inflow space 59. As a result, the flow of the exhaust gas is disturbed in the exhaust gas inflow space 59 and the exhaust gas is dispersed, so that the exhaust gas can be uniformly flowed from the exhaust gas inflow space 59 to the catalyst 52.

Further, since the inner extension pipe portion 61R of the upstream side exhaust pipe 50R provided above the catalyst case portion 51 is close to the inner surface 51d of the catalyst case portion 51, the exhaust gas flowing into the exhaust inflow space 59 from the upstream side exhaust pipe 50R. G1 rotates along the inner peripheral surface of the catalyst case portion 51. As a result, the flow of the exhaust gas is disturbed in the exhaust inflow space 59, so that the exhaust gas can flow uniformly to the catalyst 52.
Further, the exhaust G2 flowing into the exhaust inflow space 59 from the inner extension pipe portion 61L of the upstream side exhaust pipe 50L provided in the upper and lower intermediate portions of the catalyst case portion 51 joins the exhaust G1 from the central side of the catalyst case portion 51. To do. As a result, the flow of the exhaust gas is disturbed in the exhaust inflow space 59, so that the exhaust gas can flow uniformly to the catalyst 52. Here, since the tip of the inner extension pipe portion 61R protrudes in the axial direction by a length H from the tip of the inner extension pipe portion 61L, a rotating flow due to the exhaust G1 can be efficiently generated. Exhaust turbulence can be satisfactorily generated.

With reference to FIGS. 6 to 8, in the collecting portion 57, the distance between the upstream exhaust pipe 50L and the upstream exhaust pipe 50R becomes smaller toward the connecting portion 60 side (downstream side). The reinforcing member 58 connects the upstream exhaust pipe 50L and the upstream exhaust pipe 50R at the gathering portion 57.
The reinforcing member 58 is more than the inner reinforcing member 70 that connects the upstream exhaust pipe 50L and the upstream exhaust pipe 50R to each other at a position between the upstream exhaust pipe 50L and the upstream exhaust pipe 50R, and the inner reinforcing member 70. An outer reinforcing member 71 provided on the upstream exhaust pipe 50R at an outer position is provided.
The reinforcing member 58 is provided on the upstream side of the connecting portion 60 in the flow of exhaust gas.

The outer reinforcing member 71 is a plate material that is joined so as to be attached to the surface of the upstream exhaust pipe 50R. The outer reinforcing member 71 is provided on the curved portion 56R1 of the lateral extending portion 56R of the upstream exhaust pipe 50R.
The outer reinforcing member 71 is provided on the curved inner peripheral surface 72a of the curved portion 56R1. The inner peripheral surface 72a is the outer surface of the curved portion 56R1 in the vehicle width direction in the front view of FIG.
The outer reinforcing member 71 is a plate material that curves along the inner peripheral surface 72a, and is provided over the substantially overall length of the curved portion 56R1 in the axial direction of the upstream exhaust pipe 50R. The outer reinforcing member 71 is provided in a substantially half portion located outside in the vehicle width direction in the circumferential direction of the upstream exhaust pipe 50R.
The outer reinforcing member 71 extends upward to the vicinity of the lower end portion of the sensor guard 79 on the right side. The sensor guard 79 functions as a member for reinforcing the upstream exhaust pipe 50R together with the outer reinforcing member 71.
The outer reinforcing member 71 is connected to the curved portion 56R1 by welding, for example.

The inner reinforcing member 70 is a plate material that is bonded so as to be attached to the surfaces of the upstream exhaust pipes 50L and 50R. The inner reinforcing member 70 is provided below the outer reinforcing member 71. The inner reinforcing member 70 is connected to the upstream exhaust pipes 50L and 50R by welding, for example.
The inner reinforcing member 70 extends from the joint portion 73 to the upstream side of the upstream exhaust pipe 50R along the lateral extension portion 56R and the joint portion 73 that connects the lateral extension portions 56L and 56R vertically in the gathering portion 57. A first extending portion 74 to be extended and a second extending portion 75 extending from the coupling portion 73 to the upstream side of the upstream exhaust pipe 50L along the lateral extending portion 56L are provided.

Specifically, the connecting portion 73 includes a front reinforcing portion 73a that connects the front portions of the lateral extending portions 56L and 56R vertically and a rear reinforcing portion 73b that connects the rear surface portions of the lateral extending portions 56L and 56R vertically. And a front-rear connecting portion 73c that connects the front-side reinforcing portion 73a and the rear-side reinforcing portion 73b in the front-rear direction.
The front reinforcing portion 73a connects the lower half of the front surface of the curved portion 56R1 and the upper half of the front surface of the straight portion 56L2 below the downstream end portion 71a of the outer reinforcing member 71.
The rear reinforcing portion 73b connects the lower half of the rear surface of the curved portion 56R1 and the upper half of the rear surface of the straight portion 56L2 below the end portion 71a on the downstream side of the outer reinforcing member 71.
The front-rear connecting portion 73c connects the inner edge portion of the front side reinforcing portion 73a in the vehicle width direction and the inner edge portion of the rear side reinforcing portion 73b in the vehicle width direction.

The first extending portion 74 extends upward from the front-rear connecting portion 73c along the curved portion 56R1. The first extending portion 74 is provided on the outer peripheral surface 72b of the bend of the curved portion 56R1. The outer peripheral surface 72b is the inner surface of the curved portion 56R1 in the vehicle width direction in the front view of FIG.
The first extending portion 74 is a plate material that curves along the outer peripheral surface 72b, and is provided over substantially the entire length of the curved portion 56R1 in the axial direction of the upstream exhaust pipe 50R. The first extending portion 74 is provided in a substantially half portion located inside in the vehicle width direction in the circumferential direction of the upstream exhaust pipe 50R.

The second extending portion 75 is a plate material extending inward in the vehicle width direction from the front-rear connecting portion 73c along the straight portion 56L2. The second extending portion 75 is provided in substantially half of the upper surface side of the straight portion 56L2 in the circumferential direction of the upstream exhaust pipe 50L.

FIG. 10 is a cross-sectional view taken along the line XX of FIG.
With reference to FIGS. 6 to 8 and 10, the inner reinforcing member 70 is a front reinforcing member 76 provided on the front side of the motorcycle 1 in the upstream exhaust pipes 50L and 50R, and the upstream exhaust pipes 50L and 50R. It is divided into two front and rear parts with a rear side reinforcing member 77 provided on the rear side of the motorcycle 1.
The front reinforcing member 76 constitutes substantially half of the front side of the connecting portion 73, the first extending portion 74, and the second extending portion 75.
The rear reinforcing member 77 constitutes substantially half of the rear side of the connecting portion 73, the first extending portion 74, and the second extending portion 75.
In this way, since the inner reinforcing member 70 is separately provided as the front reinforcing member 76 and the rear reinforcing member 77, the front reinforcing member 76 and the rear reinforcing member 77 can be individually assembled to the gathering portion 57. The inner reinforcing member 70 can be easily connected to the upstream exhaust pipes 50L and 50R.

Since the inner reinforcing member 70 connects the upstream exhaust pipe 50L and the upstream exhaust pipe 50R, the strength and rigidity of the upstream exhaust pipes 50L and 50R can be effectively increased. Further, the outer reinforcing member 71 is provided on the curved portion 56R1 and can increase the strength and rigidity of the upstream exhaust pipe 50R.
Here, referring to FIG. 10, the plate thickness t1 of the outer reinforcing member 71 is based on the plate thickness t2 of the front side reinforcing member 76 which is the inner reinforcing member 70 and the plate thickness t3 of the rear side reinforcing member 77 which is the inner reinforcing member 70. Is also small. In the present embodiment, the thicknesses of the front reinforcing member 76 and the rear reinforcing member 77 are the same, and the plate thickness t2 and the plate thickness t3 are the same.
That is, the plate thicknesses t2 and t3 of the inner reinforcing member 70 connecting the upstream exhaust pipes 50L and 50R are larger than the plate thickness t1 of the outer reinforcing member 71. Therefore, the inner reinforcing member 70 and the outer reinforcing member 71 can increase the strength and rigidity of the upstream exhaust pipes 50L and 50R, and can reduce the weight of the reinforcing member 58.
In the reinforcing member 58, the plate thickness t1 of the outer reinforcing member 71 may be smaller than the plate thicknesses t2 and t3 of the inner reinforcing member 70, and the plate thickness t2 and the plate thickness t3 may be different in size. For example, the plate thickness t2 may be made smaller than the plate thickness t3, or the plate thickness t3 may be made smaller than the plate thickness t2.

As shown in FIG. 5, the gathering portion 57 is located in front of the down frame 19 in the side view of the vehicle, and the reinforcing member 58 is provided in the gathering portion 57 in front of the down frame 19. Therefore, the gathering portion 57 located in front of the down frame 19 can be effectively protected by covering it with the reinforcing member 58.
Specifically, when viewed from the side of the vehicle, the front portion of the reinforcing member 58 is located in front of the down frame 19, and the rear portion of the down frame 19 overlaps the down frame 19. At least a part of the reinforcing member 58 may be arranged in front of the down frame 19 in a side view of the vehicle, and all of the reinforcing members 58 may be arranged in front of the down frame 19.

FIG. 11 is a diagram schematically showing the internal structure of the muffler 34.
The muffler 34 includes a tubular muffler case 80 in which the front end and the rear end are closed, and a partition wall 81 that partitions the inside of the muffler case 80 back and forth. The space inside the muffler case 80 is divided into a first expansion chamber 82 and a second expansion chamber 83 behind the first expansion chamber 82 by the partition wall 81.
The muffler 34 includes a main pipe 84 that penetrates from the front end of the muffler case 80 through the partition wall 81 to the rear end, and a communication pipe 85 that penetrates the partition wall 81 and communicates the first expansion chamber 82 and the second expansion chamber 83. A tail pipe 86 is provided behind the communication pipe 85 so as to penetrate the rear end of the muffler case 80 and communicate the second expansion chamber 83 to the outside.

The muffler 34 includes an exhaust valve 87 at a portion of the main pipe 84 that passes through the first expansion chamber 82. The exhaust valve 87 is controlled by the control unit of the motorcycle 1 to open and close the exhaust flow path of the main pipe 84.
The main pipe 84 is provided with communication ports 84a and 84b for communicating the main pipe 84 with the first expansion chamber 82 in a portion located in the first expansion chamber 82. The communication port 84a is provided upstream of the exhaust valve 87, and the communication port 84b is provided downstream of the exhaust valve 87.
The front end of the main pipe 84 is connected to the rear end of the downstream exhaust pipe 53.

As shown by the solid line in FIG. 11, when the exhaust valve 87 is closed, the exhaust gas flowing from the exhaust pipe 33 into the main pipe 84 flows into the first expansion chamber 82 from the communication port 84a.
The exhaust gas that has flowed into the first expansion chamber 82 is divided into an exhaust gas that flows into the main pipe 84 again from the communication port 84b and an exhaust gas that flows into the second expansion chamber 83 from the communication pipe 85.
The exhaust gas that has flowed into the main pipe 84 from the communication port 84b is discharged to the outside from the muffler exhaust port 84c at the rear end of the main pipe 84. The exhaust gas that has flowed into the second expansion chamber 83 is discharged to the outside from the muffler exhaust port 86a at the rear end of the tail pipe 86.

As shown by a virtual line in FIG. 11, when the exhaust valve 87 is opened, most of the exhaust gas flowing from the exhaust pipe 33 into the main pipe 84 flows backward through the main pipe 84, and the main pipe 84 It is discharged from the rear end to the outside.

FIG. 12 is a view of the rear end portion of the muffler 34 as viewed from the rear side. FIG. 13 is a perspective view of the rear end portion of the muffler 34 as viewed from the rear side.
Exhaust port covers 88 are attached to the muffler exhaust port 84c and the muffler exhaust port 86a, respectively.
The exhaust port cover 88 covers the muffler exhaust ports 84c and 86a from the outside rear.
The exhaust port cover 88 includes a linear cover portion 88a (linear portion) formed in a cross shape and a mounting portion 88b extending from each tip of the cross of the linear cover portion 88a to the outer peripheral portions of the muffler exhaust ports 84c and 86a. To be equipped.

The exhaust port cover 88 is arranged so that the center of the cross of the linear cover portion 88a substantially overlaps the center of the muffler exhaust ports 84c and 86a, and covers a part of the muffler exhaust ports 84c and 86a from the downstream side of the exhaust. The linear cover portion 88a extends radially outward from the center of the muffler exhaust ports 84c and 86a.
The mounting portion 88b has a linear shape extending in the axial direction of the muffler exhaust ports 84c and 86a. In the exhaust port cover 88, four mounting portions 88b are coupled to the outer peripheral portions of the muffler exhaust ports 84c and 86a.
The exhaust port cover 88 is a linear body having a bent linear portion 89 bent in a V shape at an angle of approximately 90 ° and a pair of mounting portions 88b extending from the V-shaped tip of the bent linear portion 89. By combining two 90s, it is formed in a cross shape.

The exhaust gas discharged from the muffler exhaust ports 84c and 86a is diffused by hitting the exhaust port cover 88. Thereby, by adjusting the size and the mounting state of the exhaust port cover 88, the flow velocity of the exhaust gas discharged from the muffler exhaust ports 84c and 86a can be adjusted to an arbitrary flow velocity.

FIG. 14 is a perspective view showing a state in which an exhaust port cover 188 different from the exhaust port cover 88 is attached to the muffler 34.
The exhaust port cover 188 includes a linear cover portion 188a that covers a part of the muffler exhaust ports 84c and 86a from the downstream side of the exhaust, and a frame portion 188b that is provided so as to surround the outer peripheral portion of the linear cover portion 188a.
The linear cover portion 188a is supported by the frame portion 188b and is attached to the muffler 34 via the frame portion 188b.

The linear cover portion 188a includes a plurality of linear portions 188c extending radially outward from the center of each muffler exhaust port 84c, 86a. Specifically, in each of the muffler exhaust ports 84c and 86a, three linear portions 188c are provided, and the linear portions 188c are provided at intervals of approximately 120 ° from each other.
The linear portion 188c on the muffler exhaust port 84c side and the linear portion 188c on the muffler exhaust port 86a side are connected by a linear connecting portion 188d.
By providing the exhaust port cover 188, the flow velocity of the exhaust can be adjusted to an arbitrary flow velocity.

As described above, according to the embodiment to which the present invention is applied, the exhaust structure of the motorcycle 1 includes an exhaust pipe 33 connected to the engine 11 and a catalyst 52 provided in the exhaust pipe 33, and exhausts the gas. The pipe 33 includes a catalyst case portion 51 for accommodating the catalyst 52 and upstream exhaust pipes 50L and 50R provided on the upstream side of the catalyst case 51, and the catalyst case 51 is provided from the upstream exhaust pipes 50L and 50R. The upstream exhaust pipes 50L and 50R are connected to the catalyst case 51 by a connecting portion 60 located upstream of the catalyst 52 in the exhaust flow, and the upstream exhaust pipes 50L and 50L are connected to the connecting portion 60. , 50R axes 50L1, 50R1 and the catalyst case 51 axis 51a are in a substantially perpendicular positional relationship.
According to this configuration, in the connection portion 60 in which the upstream exhaust pipes 50L and 50R are connected to the catalyst case portion 51, the exhaust of the upstream exhaust pipes 50L and 50R is substantially perpendicular to the axis 51a of the catalyst case portion 51. It flows into the catalyst case portion 51 in the direction. As a result, in the catalyst case portion 51, the flow of the exhaust gas is disturbed on the upstream side of the catalyst 52 and the exhaust gas is dispersed, so that the exhaust gas can flow uniformly to the catalyst 52.
Here, the degree of substantially right angle between the axis lines 50L1, 50R1 of the flow side exhaust pipes 50L and 50R and the axis line 51a of the catalyst case portion 51 may effectively cause turbulence in the exhaust flow on the upstream side of the catalyst 52. It may be as long as possible, for example, a substantially right angle is in the range of 70 ° to 110 °.

Further, a plurality of upstream exhaust pipes 50L and 50R are connected to the catalyst case portion 51 by the connecting portion 60.
According to this configuration, exhaust gas flows from the plurality of upstream exhaust pipes 50L and 50R into the catalyst case portion 51 in a direction substantially perpendicular to the axis 51a of the catalyst case portion 51. As a result, the flow of the exhaust gas is disturbed on the upstream side of the catalyst 52, so that the exhaust gas can flow uniformly to the catalyst 52.
Further, the plurality of upstream exhaust pipes 50L and 50R are arranged side by side in substantially parallel at the connecting portion 60.
According to this configuration, the exhaust gas flows from the plurality of upstream exhaust pipes 50L and 50R substantially at right angles to the axis 51a of the catalyst case portion 51 and substantially parallel to each other, and flows into the catalyst case portion 51. As a result, the flow of the exhaust gas is disturbed on the upstream side of the catalyst 52, so that the exhaust gas can flow uniformly to the catalyst 52. Further, a plurality of upstream exhaust pipes 50L and 50R can be arranged compactly.

Further, the plurality of upstream exhaust pipes 50L and 50R include inner extension pipes 61L and 61R extending inward of the catalyst case 51 at the connection portion 60, and in the axial view of the axis 51a of the catalyst case 51. , The upstream exhaust pipe 50R, which is closer to the upstream exhaust pipe 50L, 50R axis 50L1, 50R1 and the inner surface 51d of the catalyst case portion 51 in the direction orthogonal to the upstream exhaust pipes 50L, 50R axes 50L1, 50R1. The inner extension pipe portion 61R extends deeper to the inside of the catalyst case portion 51 than the upstream exhaust pipe 50L which is farther away.
According to this configuration, the exhaust G1 entering the inside of the catalyst case portion 51 from the upstream exhaust pipe 50R having the closer distance generates a flow that rotates along the inner peripheral surface of the catalyst case portion 51, and the above distance. The exhaust G2 that enters the inside of the catalyst case portion 51 from the upstream exhaust pipe 50L that is far away joins the above-mentioned rotating flow. As a result, the turbulence of the exhaust flow can be efficiently generated on the upstream side of the catalyst 52, and the exhaust can be uniformly flowed to the catalyst 52.
Further, the upstream exhaust pipes 50L and 50R extend from the exhaust ports 31b and 31c of the engine 11 to the catalyst case portion 51, and the catalyst case portion 51 is arranged outside the vehicle width direction with respect to the exhaust ports 31b and 31c.
According to this configuration, since the catalyst case portion 51 is arranged on the outer side in the vehicle width direction with respect to the exhaust ports 31b and 31c, it is easy to secure a space in the portions located above and below the exhaust ports 31b and 31c.

Further, a reinforcing member 58 for reinforcing the upstream exhaust pipes 50L and 50R is provided, and the reinforcing member 58 connects the plurality of upstream exhaust pipes 50L and 50R to each other at a position between the plurality of upstream exhaust pipes 50L and 50R. The inner reinforcing member 70 and the outer reinforcing member 71 provided on the upstream exhaust pipe 50R outside the inner reinforcing member 70 are provided, and the plate thickness t1 of the outer reinforcing member 71 is the plate thickness t2 of the inner reinforcing member 70. It is smaller than t3.
According to this configuration, the strength of the upstream exhaust pipes 50L and 50R is effective by the inner reinforcing member 70 that connects the plurality of upstream exhaust pipes 50L and 50R to each other at the position between the plurality of upstream exhaust pipes 50L and 50R. Can be increased. Further, since the plate thickness t1 of the outer reinforcing member 71 provided outside the inner reinforcing member 70 is smaller than the plate thicknesses t2 and t3 of the inner reinforcing member 70, the strength of the upstream exhaust pipes 50L and 50R is increased. , Weight reduction can be achieved. Further, by providing the inner reinforcing member 70, it is possible to prevent foreign matter such as grass from being caught between the plurality of upstream exhaust pipes 50L and 50R, and the exhaust structure can be easily cleaned.
Further, the inner reinforcing member 70 is separately provided in the upstream exhaust pipes 50L and 50R by the front reinforcing member 76 on the front side of the motorcycle and the rear reinforcing member 77 on the rear side.
According to this configuration, it is easy to provide the inner reinforcing member 70 in the upstream exhaust pipes 50L and 50R at the time of manufacturing.

Further, the plurality of upstream exhaust pipes 50L and 50R have a downward extension portion 55L and 55R extending downward from the exhaust ports 31b and 31c and a lateral extension extending outward from the lower end of the downward extension portion 55L and 55R in the vehicle width direction. The protrusions 56L and 56R are provided, and the lateral extension portions 56L and 56R are connected to the catalyst case portion 51 by the connection portion 60.
According to this configuration, the lateral extension portions 56L and 56R extending outward in the vehicle width direction from the lower ends of the downward extension portions 55L and 55R are connected to the catalyst case portion 51 by the connection portion 60, so that the catalyst case portion 51 The exhaust structure can be made compact in the vertical direction in the vicinity.
Further, the catalyst case portion 51 is arranged downward in the rear view from the side view of the vehicle, and the connecting portion 60 is provided at the front end portion 51b of the catalyst case portion 51.
According to this configuration, since the catalyst case portion 51 is arranged downward in the rear view from the side view of the vehicle, the front portion of the catalyst case portion 51 can be arranged at a high position, and the front portion of the catalyst case portion 51 can be arranged at a position far from the road surface. It can be arranged and the ground clearance of the motorcycle 1 can be secured. Further, the lengths of the upstream exhaust pipes 50L and 50R can be shortened.

Further, the body frame 10 of the motorcycle 1 includes a head pipe 16 that supports the steering system 12, a down frame 19 that extends downward from the head pipe 16, and a lower frame 20 that extends rearward from the down frame 19 below the engine 11. The upstream exhaust pipes 50L and 50R extend downward from the exhaust ports 31b and 31c on the front surface of the engine 11 through the side of the down frame 19, and the connection portion 60 is a vehicle side view of the down frame 19 and It is provided in front of the lower frame 20.
According to this configuration, since the connecting portion 60 is provided in front of the down frame 19 and the lower frame 20 when viewed from the side of the vehicle, the upstream exhaust pipes 50L and 50R can be easily extended outward in the vehicle width direction, and the upstream exhaust pipe 50L can be easily extended. , 50R axis lines 50L1, 50R1 and the axis line 51a of the catalyst case portion 51 can be easily provided at a substantially right angle. Further, the upstream exhaust pipes 50L and 50R can be shortened.
Further, the axis 51a of the catalyst case portion 51 extends in the front-rear direction of the vehicle, and the axis 51a and the axis 50L1 of the upstream exhaust pipes 50L and 50R are oriented in the direction orthogonal to the axis 51a of the catalyst case 51 from above the catalyst case 51. When looking at 50R1, the axial lines 50L1, 50R1 of the upstream exhaust pipes 50L and 50R and the axis 51a of the catalyst case portion 51 are in a substantially right-angled positional relationship.
According to this configuration, the connection portion 60 and the catalyst case portion 51 can be arranged compactly.

Further, according to the embodiment to which the present invention is applied, the exhaust structure of the motorcycle 1 includes a plurality of upstream exhaust pipes 50L and 50R extending from the exhaust ports 31b and 31c of the engine 11 and upstream exhaust pipes 50L and 50R. A gathering portion 57 in which a plurality of upstream exhaust pipes 50L and 50R are gathered is arranged outside in the vehicle width direction with respect to the exhaust ports 31b and 31c, and the reinforcing member 58 is provided in the gathering portion 57. The reinforcing member 58 is provided at a position between the plurality of upstream exhaust pipes 50L and 50R, the inner reinforcing member 70 connecting the plurality of upstream exhaust pipes 50L and 50R to each other, and a position outside the inner reinforcing member 70. The outer reinforcing member 71 provided in the upstream exhaust pipe 50R is provided, and the plate thickness t1 of the outer reinforcing member 71 is smaller than the plate thicknesses t2 and t3 of the inner reinforcing member 70.
According to this configuration, the gathering portion 57 and the reinforcing member 58 in which the plurality of upstream exhaust pipes 50L and 50R are gathered are arranged outside the exhaust ports 31b and 31c in the vehicle width direction, so that the minimum ground clearance of the motorcycle 1 is reached. Is easy to secure. Further, the strength of the upstream exhaust pipes 50L and 50R is increased by a simple structure by the inner reinforcing member 70 that connects the plurality of upstream exhaust pipes 50L and 50R to each other at the position between the plurality of upstream exhaust pipes 50L and 50R. Can be made to. Further, since the plate thickness t1 of the outer reinforcing member 71 provided outside the inner reinforcing member 70 is smaller than the plate thicknesses t2 and t3 of the inner reinforcing member 70, the strength of the upstream exhaust pipes 50L and 50R is increased. , Weight reduction can be achieved.

Further, the inner reinforcing member 70 is separately provided on the front side and the rear side of the motorcycle 1 in the upstream exhaust pipes 50L and 50R.
According to this configuration, it is easy to provide the inner reinforcing member 70 in the upstream exhaust pipes 50L and 50R at the time of manufacturing.
Further, the catalyst 52 is housed in the catalyst case portion 51 having a diameter larger than that of the upstream exhaust pipes 50L and 50R, and the collecting portion 57 is connected to the upstream side of the catalyst 52 in the catalyst case portion 51, and a plurality of upstream exhaust pipes are connected. The 50L and 50R are arranged side by side in the gathering portion 57.
According to this configuration, since the exhaust gas flows into the catalyst case portion 51 from the plurality of upstream exhaust pipes 50L and 50R, the exhaust flow can be disturbed by the catalyst case portion 51 to disperse the exhaust gas, and the exhaust gas can be catalyzed. It can be uniformly flowed to 52. Further, since the upstream exhaust pipes 50L and 50R are arranged side by side in the gathering portion 57, the upstream exhaust pipes 50L and 50R can be compactly arranged.

Further, in the plurality of upstream exhaust pipes 50L and 50R, the collecting portion 57 is connected to the catalyst case portion 51, and the axes 50L1 and 50R1 of the upstream exhaust pipes 50L and 50R and the axis 51a of the catalyst case 51 in the collecting portion 57 Are in a substantially right-angled positional relationship.
According to this configuration, in the collecting portion 57, the exhaust of the upstream exhaust pipes 50L and 50R flows into the catalyst case portion 51 in a direction substantially perpendicular to the axis 51a of the catalyst case portion 51. As a result, the flow of the exhaust gas is disturbed in the catalyst case portion 51 and the exhaust gas is dispersed, so that the exhaust gas can flow uniformly to the catalyst 52.
Further, the plurality of upstream exhaust pipes 50L and 50R include inner extension pipes 61L and 61R extending inward of the catalyst case 51 at the gathering portion 57, and in the axial view of the axis 51a of the catalyst case 51. , The upstream exhaust pipe 50R, which is closer to the upstream exhaust pipe 50L, 50R axis 50L1, 50R1 and the inner surface 51d of the catalyst case portion 51 in the direction orthogonal to the upstream exhaust pipes 50L, 50R axes 50L1, 50R1. The inner extension pipe portion 61R extends deeper to the inside of the catalyst case portion 51 than the upstream exhaust pipe 50L which is farther away.
According to this configuration, the exhaust G1 entering the inside of the catalyst case portion 51 from the upstream exhaust pipe 50R having the closer distance generates a flow that rotates along the inner peripheral surface of the catalyst case portion 51, and the above distance. The exhaust G2 that enters the inside of the catalyst case portion 51 from the upstream exhaust pipe 50L that is far away joins the above-mentioned rotating flow. As a result, the turbulence of the exhaust flow can be efficiently generated on the upstream side of the catalyst 52, and the exhaust can be uniformly flowed to the catalyst 52.

Further, a muffler 34 is provided on the downstream side of the upstream exhaust pipes 50L and 50R, the muffler 34 is provided with muffler exhaust ports 84c and 86a for exhausting exhaust to the outside, and an exhaust port cover 88 covering the muffler exhaust ports 84c and 86a is provided. The exhaust port cover 88 is provided and includes a linear cover portion 88a that covers a part of the muffler exhaust ports 84c and 86a.
According to this configuration, the exhaust gas can be diffused by the linear cover portion 88a of the exhaust port cover 88, and the flow velocity of the exhaust gas can be adjusted.
Further, the muffler exhaust ports 84c and 86a may be covered with the linear portion 188c of the exhaust port cover 188. According to this configuration, the exhaust gas can be diffused by the linear portion 188c, and the flow velocity of the exhaust gas can be adjusted.
Further, the plurality of upstream exhaust pipes 50L and 50R extend downward from the exhaust ports 31b and 31c and extend downward from the lower ends of the downward extending portions 55L and 55R in the vehicle width direction to the outside of the catalyst case. The side extending portions 56L and 56R connected to the portion 51 are provided, and the gathering portion 57 is a portion where a plurality of lateral extending portions 56L and 56R are gathered.
According to this configuration, the lateral extension portions 56L and 56R extending outward in the vehicle width direction from the lower ends of the downward extension portions 55L and 55R are connected to the catalyst case portion 51 by the gathering portion 57, so that the catalyst case portion 51 The exhaust structure can be made compact in the vertical direction in the vicinity.

Further, the catalyst case portion 51 is arranged downward in the rear view from the side view of the vehicle, and the gathering portion 57 is connected to the front end portion 51b of the catalyst case portion 51.
According to this configuration, since the catalyst case portion 51 is arranged downward in the rear view from the side view of the vehicle, the front portion of the catalyst case portion 51 can be arranged at a high position, and the front portion of the catalyst case portion 51 can be arranged at a position far from the road surface. Can be placed. Further, the lengths of the upstream exhaust pipes 50L and 50R can be shortened.
Further, the body frame 10 of the motorcycle 1 includes a head pipe 16 that supports the steering system 12, a down frame 19 that extends downward from the head pipe 16, and a lower frame 20 that extends rearward from the down frame 19 below the engine 11. The reinforcing member 58 is provided in the upstream exhaust pipes 50L and 50R at a position in front of the down frame 19 and the lower frame 20 when viewed from the side of the vehicle.
According to this configuration, the upstream exhaust pipes 50L and 50R located in front of the down frame 19 and the lower frame 20 can be effectively protected by the reinforcing member 58.

It should be noted that 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 axes 50L1, 50R1 of the plurality of upstream exhaust pipes 50L and 50R have been described as having a positional relationship substantially perpendicular to the axis 51a of the catalyst case portion 51, but the present invention is limited thereto. It's not something. For example, at least one upstream exhaust pipe (for example, only the upstream exhaust pipe 50L) among the plurality of upstream exhaust pipes 50L and 50R may be in a substantially right-angled positional relationship as described above. Further, only one upstream exhaust pipe may be provided, and the upstream exhaust pipe may have a positional relationship substantially perpendicular to the axis 51a of the catalyst case portion 51 as described above.
Further, in the above embodiment, a plurality of upstream exhaust pipes 50L and 50R have been described as being arranged side by side substantially in parallel at the connection portion 60, but the present invention is not limited to this, and the upstream exhaust pipe 50L and the upstream exhaust are not limited to this. The pipe 50L and the pipe 50L may be arranged at different angles at the connection portion 60.
Further, in the above embodiment, the outer reinforcing member 71 has been described as being provided in the upstream exhaust pipe 50R, but the present invention is not limited thereto. For example, the outer reinforcing member may be provided on both the upstream exhaust pipes 50L and 50R, or only on the upstream exhaust pipe 50L.
In the above embodiment, the motorcycle 1 as a saddle-riding vehicle has been described as an example, but the present invention is not limited to this, and the present invention is a three-wheeled vehicle including two front wheels or two rear wheels. It is applicable to saddle-riding vehicles and saddle-riding vehicles having four or more wheels.

1 Motorcycle (saddle-riding vehicle)
10 Body frame 11 Engine (internal combustion engine)
12 Steering system 16 Head pipe 19 Down frame 20 Lower frame 31b, 31c Exhaust port 33 Exhaust pipe 50L, 50R Upstream side exhaust pipe 50L1, 50R1 Axis line (upstream side exhaust pipe axis)
51 Catalyst case section 51a Axis line (Catalyst case section axis line)
51b Front end 51d Inner surface 52 Catalyst 55L, 55R Downward extension 56L, 56R Side extension 58 Reinforcement member 60 Connection part 61L, 61R Inner extension pipe 70 Inner reinforcement 71 Outer reinforcement t1 Plate thickness (outer reinforcement) Member plate thickness)
t2, t3 plate thickness (thickness of inner reinforcing member)

Claims (8)

A catalyst (33) connected to the internal combustion engine (11) and a catalyst (52) provided in the exhaust pipe (33), and the exhaust pipe (33) houses the catalyst (52). In the exhaust structure of a saddle-mounted vehicle including a case portion (51) and upstream exhaust pipes (50L, 50R) provided on the upstream side of the catalyst case portion (51).
The catalyst case portion (51) has a larger diameter than the upstream exhaust pipes (50L, 50R).
The upstream exhaust pipes (50L, 50R) are connected to the catalyst case (51) by a connecting portion (60) located upstream of the catalyst (52) in the exhaust flow.
In the connecting portion (60), Ri positional relationship near the substantially right angle to the axis (51a) of said upstream exhaust pipes (50L, 50R) axis of (50L1,50R1) and the catalyst casing portion (51),
A plurality of the upstream exhaust pipes (50L, 50R) are connected to the catalyst case portion (51) by the connecting portion (60).
The plurality of upstream exhaust pipes (50L, 50R) are arranged side by side in substantially parallel at the connection portion (60).
The plurality of upstream exhaust pipes (50L, 50R) include an inner extension pipe portion (61L, 61R) extending inward of the catalyst case portion (51) at the connection portion (60).
In the axial view of the axis (51a) of the catalyst case portion (51), the upstream exhaust pipe (50L, 50R) in a direction orthogonal to the axis (50L1, 50R1) of the upstream exhaust pipe (50L, 50R). The upstream exhaust pipe (50R) having a short distance between the axis (50L1, 50R1) of the 50R) and the inner surface (51d) of the catalyst case portion (51) has the upstream exhaust having a long distance. than the pipe (50L), the exhaust structure for a saddle type vehicle which deeply extends characterized Rukoto to the inside of the inner extension outflow tract portion (61R) is the catalyst case portion (51). The upstream exhaust pipes (50L, 50R) extend from the exhaust ports (31b, 31c) of the internal combustion engine (11) to the catalyst case portion (51).
The catalyst case portion (51), the relative exhaust port (31b, 31c), an exhaust structure for a saddle type vehicle according to claim 1 Symbol mounting, characterized in that it is arranged on the outside in the vehicle width direction. A reinforcing member (58) for reinforcing the upstream exhaust pipes (50L, 50R) is provided.
The reinforcing member (58) includes an inner reinforcing member (70) that connects a plurality of the upstream exhaust pipes (50L, 50R) to each other at a position between the plurality of upstream exhaust pipes (50L, 50R). It is provided with an outer reinforcing member (71) provided on the upstream exhaust pipe (50R) outside the inner reinforcing member (70).
The saddle-riding vehicle according to claim 1 or 2 , wherein the plate thickness (t1) of the outer reinforcing member (71) is smaller than the plate thickness (t2, t3) of the inner reinforcing member (70). Exhaust structure. The saddle riding according to claim 3, wherein the inner reinforcing member (70) is separately provided on the front side and the rear surface side of the saddle riding type vehicle in the upstream exhaust pipes (50L, 50R). Exhaust structure of type vehicle. The upstream exhaust pipes (50L, 50R) are a side extending downward from the exhaust port (55L, 55R) and a side extending outward from the lower end of the downward extending portion (55L, 55R) in the vehicle width direction. Equipped with a direction extension (56L, 56R)
The exhaust structure for a saddle-riding vehicle according to claim 2 , wherein the lateral extension portions (56L, 56R) are connected to the catalyst case portion (51) at the connection portion (60). The catalyst case portion (51) is disposed in the rear edge when viewed from the side of the vehicle, the connecting portion (60), according to claim 5, characterized in that provided on the front end of the catalyst case portion (51) (51b) Exhaust structure of the saddle-riding vehicle described. The body frame (10) of the saddle-riding vehicle includes a head pipe (16) that supports the steering system (12), a down frame (19) that extends downward from the head pipe (16), and the down frame (19). ) To the lower frame (20) extending rearward below the internal combustion engine (11).
The upstream exhaust pipes (50L, 50R) extend downward from the exhaust ports (31b, 31c) on the front surface of the internal combustion engine (11) through the side of the down frame (19).
The saddle according to claim 5 or 6 , wherein at least a part of the connecting portion (60) is provided in front of the down frame (19) and the lower frame (20) in a vehicle side view. Exhaust structure of a riding vehicle. The axis (51a) of the catalyst case portion (51) extends in the front-rear direction of the vehicle.
The axis (51a) and the axis (50L1,) of the upstream exhaust pipe (50L, 50R) in a direction orthogonal to the axis (51a) of the catalyst case (51) from above the catalyst case (51). When looking at 50R1), the axis (50L1, 50R1) of the upstream exhaust pipes (50L, 50R) and the axis (51a) of the catalyst case portion (51) are in a substantially right-angled positional relationship. The exhaust structure of a saddle-mounted vehicle according to any one of claims 1 to 7, wherein the exhaust structure is characterized by.

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