JP5993902B2 - Exhaust device for scooter type vehicle - Google Patents

Description

  The present invention relates to an exhaust device for a scooter type vehicle.

  In a scooter type vehicle in which the power unit is swingably supported on the body frame, the rear wheel is cantilevered on the rear wheel axle provided at the rear of the power transmission mechanism that extends rearward from the internal combustion engine of the power unit. A configuration in which an exhaust muffler is disposed on the side opposite to the power transmission mechanism disposed on one side of the wheel is conventionally known.

When the rear wheel is attached to the rear wheel axle that protrudes toward the exhaust muffler at the rear of the power transmission mechanism and the rear wheel hub is fitted and fastened with a nut, etc. Is released, the rear wheel is moved to the exhaust muffler side in the axle direction, the hub is removed from the rear wheel axle, and the rear wheel is removed.
At that time, by removing the exhaust muffler first, you can easily remove the exhaust wheel by moving the rear wheel to the vacant side except for the exhaust muffler. What has to be done every time is extremely cumbersome.

  Therefore, without removing the exhaust muffler, the inner side of the exhaust muffler on the rear wheel side is secured so that there is enough space for the rear wheel to pass between the rear wheel attached to the rear axle and the exhaust muffler on its side. The width of the vehicle width direction (left and right width) is reduced by bringing the wall closer to the outer wall, and the vertical width is increased accordingly to ensure the capacity, and the part of the inner wall facing the axle is used for rear wheel escape. A muffler-shaped exhaust device provided with a recess has been proposed (see Patent Document 1).

Japanese Utility Model Publication No. 63-17819

  By the way, in recent years, in order to detoxify harmful substances contained in exhaust gas, a catalytic converter has been provided in the exhaust system, and in order to arrange the catalytic converter in a space efficient manner, the catalytic converter is disposed in the exhaust muffler. However, since the catalytic converter is a relatively large member, the area occupied by the catalyst in the exhaust muffler tends to be large.

  Therefore, if the exhaust muffler is formed with a recess for escaping the rear wheel as in Patent Document 1, the shape of the recess is likely to be limited due to the catalytic converter, and a sufficient size and depth to avoid the rear wheel. There is a problem that it becomes difficult to form the recess.

  Therefore, in order to secure the necessary space between the rear wheel and the exhaust muffler without removing the exhaust muffler, it is conceivable to move the exhaust muffler outward in the vehicle width direction and away from the rear wheel. When the vehicle is viewed from the rear, the distance between the rear wheel and the exhaust muffler is widened to reduce the appearance, and there is a problem that the exhaust muffler bulges outward in the vehicle width direction to increase the size of the vehicle body. there is a possibility.

  The present invention has been made in view of such a point, and the target process is that the catalytic converter in the exhaust muffler is disposed avoiding the recessed portion for escape of the rear wheel having a required size and depth. A scooter-type vehicle exhaust system that can replace the rear wheel without removing the exhaust muffler while maintaining good appearance and avoiding an increase in the size of the vehicle body is provided.

In order to achieve the above object, the invention according to claim 1
A rear wheel is cantilevered on a rear wheel axle provided at a rear portion of a power transmission mechanism that extends rearward from an internal combustion engine of a power unit that is swingably supported on a body frame,
An exhaust muffler having a catalytic converter therein is disposed on the side opposite to the power transmission mechanism disposed on one side of the rear wheel,
In the exhaust device for a scooter type vehicle, a rear wheel escape recess is formed in a portion of the inner wall on the rear wheel side of the exhaust muffler facing the rear wheel axle.
The catalytic converter is disposed in front of the rear wheel escape recess in the exhaust muffler,
A second rear wheel escape recess is formed around the rear wheel escape recess on the inner wall on the rear wheel side of the exhaust muffler,
In the center of the second rear wheel escape recess recessed inside the exhaust muffler, the rear wheel escape recess is further recessed than the second rear wheel escape recess,
The catalytic converter is an exhaust device for a scooter type vehicle, which is disposed in front of the second rear wheel escape recess .

The invention according to claim 2
The exhaust device for a scooter type vehicle according to claim 1,
The exhaust muffler is characterized in that the maximum projecting position to the rear wheel side in the vehicle width direction is farther from the rear wheel than the front side with respect to the axis of the rear wheel axle.

The invention described in claim 3
The scooter type vehicle exhaust device according to claim 1 or 2,
The exhaust muffler is formed so that the vertical width is larger than the width in the vehicle width direction, and is disposed so as to completely cover the rear wheel axle in a vehicle side view,
The catalytic converter is arranged to be biased downward with respect to a virtual horizontal plane including an axis of the rear wheel axle.

The invention according to claim 4
The exhaust device for a scooter type vehicle according to claim 3,
The catalytic converter is disposed in a posture inclined forward and downward such that a front portion of the catalytic converter is separated from the virtual horizontal plane with respect to a rear portion of the catalytic converter.

The invention according to claim 5
The scooter type vehicle exhaust device according to claim 3 or 4,
The exhaust muffler is disposed such that the upper end edge of the exhaust muffler is positioned below the upper end of the wheel rim of the rear wheel,
A reserve tank is disposed above the exhaust muffler and at a position overlapping the rear wheel in a side view of the vehicle.

The invention described in claim 6
A rear wheel is cantilevered on a rear wheel axle provided at a rear portion of a power transmission mechanism that extends rearward from an internal combustion engine of a power unit that is swingably supported on a body frame,
An exhaust muffler having a catalytic converter therein is disposed on the side opposite to the power transmission mechanism disposed on one side of the rear wheel,
In the exhaust device for a scooter type vehicle, a rear wheel escape recess is formed in a portion of the inner wall on the rear wheel side of the exhaust muffler facing the rear wheel axle.
The catalytic converter is disposed in front of the rear wheel escape recess in the exhaust muffler,
A separator that partitions the inside of the exhaust muffler into a plurality of expansion chambers is provided in front of the rear wheel escape recess,
The exhaust system for a scooter type vehicle , wherein the catalytic converter is supported by the separator .
The invention according to claim 7 is the exhaust device for a scooter type vehicle according to claim 6,
The exhaust muffler is characterized in that the maximum projecting position to the rear wheel side in the vehicle width direction is farther from the rear wheel than the front side with respect to the axis of the rear wheel axle.
The invention according to claim 8 is the exhaust device for a scooter type vehicle according to claim 6 or 7,
The exhaust muffler is formed so that the vertical width is larger than the width in the vehicle width direction, and is disposed so as to completely cover the rear wheel axle in a vehicle side view,
The catalytic converter is arranged to be biased downward with respect to a virtual horizontal plane including an axis of the rear wheel axle.
The invention according to claim 9 is the exhaust system for a scooter type vehicle according to claim 8,
The catalytic converter is disposed in a posture inclined forward and downward such that a front portion of the catalytic converter is separated from the virtual horizontal plane with respect to a rear portion of the catalytic converter.
A tenth aspect of the present invention is the scooter type vehicle exhaust device according to the eighth or ninth aspect,
The exhaust muffler is disposed such that the upper end edge of the exhaust muffler is positioned below the upper end of the wheel rim of the rear wheel,
A reserve tank is disposed above the exhaust muffler and at a position overlapping the rear wheel in a side view of the vehicle.

The invention according to claim 12
The exhaust system for a scooter type vehicle according to claim 11 ,
The exhaust muffler is a muffler case configured by combining an inner case half disposed inside on the rear wheel side in the vehicle width direction and an outer case half disposed outside.
The exhaust muffler is supported by the internal combustion engine by a muffler support stay,
The muffler support stay is welded to an outer surface of an attachment portion to which the separator in the muffler case is attached.

The invention according to claim 13
The scooter type vehicle exhaust device according to claim 12 ,
The muffler support stay includes a first welding arm portion welded to an outer surface of the attachment portion to which the separator of the muffler case is attached, and a second weld welded to an outer surface of the rear portion from the attachment portion to which the separator is attached. An arm portion, and a third welding arm portion welded on an outer surface of a front portion from an attachment portion to which the separator is attached,
The second welding arm portion, characterized in that it is welded in front than the rear wheel relief recess.

The invention according to claim 14
The exhaust system for a scooter type vehicle according to claim 13 ,
The first, second, and third welding arm portions of the muffler support stay are dispersedly welded to any one of an upper end portion, a lower end portion, and a vertical middle portion of the muffler case. .

According to the exhaust apparatus for a scooter type vehicle of the first aspect, the catalytic converter provided in the exhaust muffler has a rear wheel escape recess formed at a portion of the inner wall of the exhaust muffler facing the rear wheel axle. Since the rear wheel escape recess formed on the inner wall of the exhaust muffler avoids interference with the catalytic converter, a large degree of freedom in the recess shape is ensured.
Therefore, for the rear wheel escape of the size and depth necessary to remove and replace the rear wheel without removing the exhaust muffler, while suppressing the exhaust muffler from expanding and protruding outward in the vehicle width direction. The recess can be easily formed.

By forming such a rear wheel escape recess, it is possible to easily replace the rear wheel without removing the exhaust muffler while maintaining good appearance and avoiding increasing the size of the vehicle body.
In addition, since the catalytic converter is not arranged on the rear side in the exhaust muffler, the width in the vehicle width direction of the exhaust muffler on the rear side can be kept small, and a large space for removing the rear wheel is secured on the rear side. The rear wheel can be easily removed and attached to the rear of the vehicle.
On the inner wall of the exhaust muffler on the rear wheel side, a second rear wheel escape recess is formed around the rear wheel escape recess, and in the center of the second rear wheel escape recess recessed inside the exhaust muffler, Since the rear wheel escape recess is formed further recessed than the second rear wheel escape recess, and the catalytic converter is disposed in front of the second rear wheel escape recess, in addition to the rear wheel escape recess, Furthermore, the formed second rear wheel escape recess can avoid interference with the catalytic converter and can ensure a large degree of freedom in the shape of the recess, making it easier for the second rear wheel escape recess of the required size and depth. The rear wheel can be removed and attached more easily without removing the exhaust muffler, and the exhaust muffler is arranged closer to the rear wheel side by the second rear wheel escape recess. To reduce the size in the vehicle width direction, It is possible to achieve the improvement of the human resistance, improved bicycle parking property.
Further, the inner wall of the exhaust muffler on the rear wheel side is recessed from the outer periphery to form a second rear wheel escape recess, and the center of the second rear wheel escape recess is further recessed and the rear wheel escape recess. The exhaust muffler is formed by a bent portion formed at the outer peripheral edge of the second rear wheel escape recess and a bent portion formed at the boundary between the center rear wheel escape recess and the second rear wheel escape recess. The rigidity of the inner wall can be increased.

  According to the exhaust system for a scooter type vehicle according to claim 2, the exhaust muffler has a rearward maximum rearward position on the rear wheel side in the vehicle width direction from the front side with respect to the axis of the rear wheel axle. Since it is far from the wheel, the rear wheel can be easily removed by moving it backward with sufficient space without removing the exhaust muffler, and the rear wheel can be easily attached from the rear.

  According to the exhaust system for a scooter type vehicle according to claim 3, since the exhaust muffler is formed so that the vertical width is larger than the width in the vehicle width direction, the rear side of the exhaust muffler is secured while ensuring the capacity of the exhaust muffler. By keeping the inner wall of the vehicle closer to the outer wall and narrowing the width in the vehicle width direction to a flat shape in the vehicle width direction, maintaining a good appearance, the rear wheel and the exhaust muffler on its side In addition, a space for allowing the rear wheels to pass through can be easily secured.

  Further, the exhaust muffler is disposed so as to completely cover the rear wheel axle in a side view of the vehicle, and the catalytic converter is disposed downwardly with respect to a virtual horizontal plane including the axis of the rear wheel axle. This makes it possible to lower the center of gravity of the exhaust muffler including the catalytic converter, and to improve the steering stability of the scooter type vehicle.

  When removing the rear wheel to the rear of the vehicle body, it is necessary to secure a virtual horizontal plane including the axis of the rear wheel axle and a rear wheel removal space in the vicinity thereof. Therefore, the rear wheel removal space can be easily secured.

  According to the exhaust system for a scooter type vehicle according to claim 4, the catalytic converter arranged to be deviated downward relative to the virtual horizontal plane including the axis of the rear wheel axle is such that the front part is separated from the virtual horizontal plane with respect to the rear part. Therefore, the catalytic converter moves away from the virtual horizontal plane toward the front side, and the front part of the rear wheel interferes with the catalytic converter when removing the rear wheel while tilting left and right. The rear wheel can be removed and attached more and more easily.

According to the exhaust device for a scooter type vehicle according to claim 5, the exhaust muffler is kept low so that the upper end edge of the exhaust muffler is positioned below the upper end of the wheel rim of the rear wheel. The reserve tank can be placed in a space-efficient manner in a position that overlaps the rear wheel in a side view of the vehicle that is easy to visually recognize, and the amount of liquid inside the reserve tank can be easily confirmed from the outside, improving maintainability. .
Further, since the catalytic converter is provided so as to be biased downward with respect to the virtual horizontal plane including the axis of the rear wheel axle, the reserve tank is located above the exhaust muffler even when the reserve tank is disposed close to the exhaust muffler. Therefore, it is difficult to be affected by the heat from the catalytic converter.

According to the exhaust device for a scooter type vehicle according to claim 6 , since the catalytic converter is supported by the separator provided in front of the rear wheel escape recess, the separator can be provided without interfering with the rear wheel escape recess. In addition, the degree of freedom of the recess shape of the rear wheel escape recess can be further ensured, and the rear wheel escape recess of the required size and depth can be easily formed.
Further, the catalytic converter can be firmly supported by the separator.

According to the exhaust apparatus for a scooter type vehicle according to claim 12, the exhaust muffler including the muffler case configured by combining the inner case half and the outer case half is supported by the internal combustion engine by the muffler support stay. Since the support stay is welded to the outer surface of the attachment portion where the separator is attached in the muffler case, the exhaust muffler is welded to the outer surface of the attachment portion of the separator in the muffler case whose rigidity is increased by the separator. Is firmly supported by the internal combustion engine.

According to the exhaust apparatus for a scooter type vehicle according to claim 13 , the muffler support stay includes a first welding arm portion welded to an outer surface of the attachment portion to which the separator of the muffler case is attached, and an attachment portion to which the separator is attached. Since the second welding arm part welded on the outer surface of the rear part and the third welding arm part welded on the outer surface of the front part from the attachment part to which the separator is attached, the muffler is provided at the position of the separator and the front and rear positions thereof. The first, second, and third welding arm portions of the support stay are welded, and the exhaust muffler can be firmly supported by the internal combustion engine.

  And since the 2nd welding arm part welded to a muffler case behind a separator is welded ahead of the recessed part for rear wheel escape, the 1st, 3rd welding arm part is also ahead of the recessed part for rear wheel escape. The rear wheel escape recess will be able to avoid interference with the muffler support stay and improve the flexibility of the recess shape, and the optimal recess shape will allow the rear wheel to be removed without removing the exhaust muffler. It is possible to remove and attach the exhaust muffler, and to suppress the exhaust muffler from protruding outward in the vehicle width direction.

According to the exhaust system for a scooter type vehicle according to claim 14 , the first, second, and third welding arm portions of the muffler support stay are respectively disposed at one of an upper end portion, a lower end portion, and an up-down direction intermediate portion of the muffler case. Are dispersed and welded, so that the exhaust muffler can be supported more firmly by the internal combustion engine.

1 is an overall side view of a scooter type vehicle according to an embodiment of the present invention. It is a principal part side view of the scooter type vehicle which removed a protector, a tank cover, a vehicle body cover, etc. It is the same rear view. It is a principal part top view which removed the tank cover, the vehicle body cover, etc. It is a VV arrow sectional view in FIG. It is a perspective view of an exhaust muffler and a muffler support stay. It is the same side view. It is a longitudinal cross-sectional view of the exhaust muffler. It is IX-IX arrow sectional drawing in FIG. It is sectional drawing equivalent to the VV arrow sectional drawing in FIG. 2 which shows 1 process of the operation | work which removes a rear wheel. It is the same sectional view showing the next process. It is the same sectional view showing the next process further.

Hereinafter, an embodiment according to the present invention will be described with reference to FIGS.
FIG. 1 is a side view of a scooter type motorcycle 1 according to an embodiment to which the present invention is applied.
In the description and claims of the present specification, the front-rear and left-right orientations follow a normal standard in which the rectilinear direction of the scooter type motorcycle 1 according to the present embodiment is the forward direction.
In the figure, arrow FR indicates the front of the vehicle, LH indicates the left side of the vehicle, RH indicates the right side of the vehicle, and UP indicates the upper side of the vehicle.

The vehicle body front portion 1f and the vehicle body rear portion 1r are connected via a low floor portion 1c, and the vehicle body frame forming the skeleton of the vehicle body is generally composed of the down tube 3 and the main pipe 4.
That is, the down tube 3 extends downward from the head pipe 2 at the front part 1f of the vehicle body, the down tube 3 is bent horizontally at the lower end and extends rearward under the floor 1c, and a pair of left and right main pipes 4 at the rear end. The main pipe 4 rises obliquely rearward from the connecting portion, bends horizontally at a predetermined height, and extends rearward.

A fuel tank 5 is supported on the rising inclined portion of the main pipe 4, a carrier 6 is provided on a horizontal portion extending further rearward, and a seat 7 is disposed on the fuel tank 5.
On the other hand, in the vehicle body front portion 1f, a handle 8 is provided on the upper side and is pivotally supported by the head pipe 2. A front fork 9 extends downward and a front wheel 10 is pivotally supported at the lower end thereof.

Referring to FIGS. 1 and 2, a bracket 4b protrudes from a rising portion of the main pipe 4, and a power unit 20 is swingably connected to the bracket 4b via a link member 11.
The front of the power unit 20 is a single-cylinder four-stroke water-cooled internal combustion engine 21, and a cylinder block 23, a cylinder head 24, and a cylinder head cover 25 are sequentially stacked and connected from the crankcase 22 to the front. The posture is largely forward tilted to near horizontal.

An end of a hanger bracket 22b that protrudes forward from the lower front portion of the crankcase 22 is connected to the link member 11 via a pivot shaft (pivot) 11p.
Note that the main stand 13 swings and is pivotably supported at the rear lower end of the crankcase 22 so that it can be raised and lowered, and when it falls down, it is stored substantially horizontally so as to straddle the rear wheel 40 from the front.

Referring to FIG. 5, the power unit 20 includes a belt-type continuously variable transmission 31 that is biased to the left and rearward from the internal combustion engine 21, and a rear wheel that is an output shaft of a speed reduction mechanism 33 provided at a rear portion thereof. An axle 35 projects rightward, and a rear wheel 40 is cantilevered on the rear axle 35.
The belt type continuously variable transmission 31 and the speed reduction mechanism 33 are power transmission mechanisms that extend rearward from the internal combustion engine 21.

  The crankcase 22 is configured by combining a left crankcase 22L and a right crankcase 22R which are divided into left and right parts. The right crankcase 22R forms a half of the crankcase portion, and the left crankcase 22L is a front crankcase 22L. The portion forms a half of the crankcase portion, and also serves as a transmission case that swells rearward and accommodates a long belt-type continuously variable transmission 31 in the front and rear.

This left crankcase (transmission case) 22L has a front and rear long left open surface covered with a transmission case cover 26, in which a belt type continuously variable transmission 31 is housed, and a rear right open surface is a reducer case 27. The speed reduction mechanism 33 is housed inside.
A rear cushion 12 is interposed between the reduction gear case 27 and the rear portion of the main pipe 4 (see FIG. 1).

Referring to FIG. 5, a belt-type continuously variable transmission 31 has a V-belt 31a hung on a drive pulley supported on a crankshaft (not shown) and a driven pulley 31b supported on an input shaft 33a of a speed reduction mechanism 33. The power is transmitted and transmitted, and by changing the winding diameter of the V-belt 31a, the gear ratio is changed and the continuously variable transmission is performed.
The input shaft 33a is provided with a centrifugal clutch 32 that is connected to the left end of the input shaft 33a according to the number of rotations. The power transmitted to the driven pulley 31b is transmitted to the input shaft 33a when the centrifugal clutch 32 is connected.

The speed reduction mechanism 33 is a gear mechanism in which the gears 34a and 34b are engaged between the input shaft 33a and the intermediate shaft 33b and the gears 34c and 34d are engaged between the intermediate shaft 33b and the rear wheel axle 35. The rotation of the shaft 33a is decelerated and transmitted to the rear wheel axle 35, and the rear wheel 40 is rotated.
The rear wheel axle 35 passes through a bearing hole formed in the side wall of the reduction gear case 27 by a bearing 27b and protrudes to the right.
The right end portion of the rear wheel axle 35 is reduced in diameter and formed with a male screw 35s (see FIG. 10).

  On the other hand, in the rear wheel 41 of the rear wheel 40, an annular wheel rim 44 is integrally formed at the outer end of the spoke part 43 extending radially from the central wheel hub 42. A rear wheel 40 is configured by fitting a tire 45.

  The wheel hub 42 includes a bearing cylindrical portion 42a fitted to the rear wheel axle 35 in the center, a cylindrical brake drum portion 42b that coaxially surrounds the outer periphery of the bearing cylindrical portion 42a, a bearing cylindrical portion 42a, and a brake drum. It consists of a hollow disk-shaped connecting disk portion 42c that connects the portion 42b at one end (the right end in FIG. 5).

Therefore, the wheel hub 42 is formed with an annular recess 42h that is recessed in an annular shape on the inner periphery of the brake drum portion 42b on the outer periphery of the bearing cylindrical portion 42a, and the drum recess 42h has a drum. A brake 50 is configured.
A cast iron liner 46 is lined on the inner peripheral surface of the brake drum portion 42b of the wheel hub 42.

A bush 47 is fitted on the inner peripheral surface of the bearing cylindrical portion 42a of the wheel hub 42.
The bearing cylindrical portion 42a of the rear wheel 41 is fitted through the bush 47 into the rear wheel axle 35 protruding rightward from the side wall of the speed reducer case 27, and protrudes rightward from the bearing cylindrical portion 42a of the rear wheel axle 35. The nut 37 is screwed into the male screw 35s at the right end portion through the washer 36, and the bearing cylindrical portion 42a of the wheel hub 42 is fastened between the inner race of the bearing 27b, and the rear wheel 40 is attached to the rear wheel axle 35. Install in one piece.
Therefore, the rear wheel 40 is cantilevered by the rear wheel axle 35.

  The rear wheel 40 is attached to the rear wheel axle 35 with the opening of the annular recess 42h between the bearing cylindrical portion 42a and the brake drum portion 42b of the wheel hub 42 facing leftward, and protrudes from the reduction gear case 27 into the annular recess 42h. A pair of brake shoes 52, 52 pivotally supported by the pair of anchor pins 51, 51 are provided in the annular recess 42 h along the liner 46 on the inner peripheral surface of the brake drum portion 42 b. Composed.

  As shown in FIG. 2, a throttle body 61 is connected to the intake pipe 60, and the intake pipe 60 extends from the upper part of the cylinder head 24 that is largely inclined forward in front of the internal combustion engine 21 of the power unit 20. Is located above the cylinder block 23, and an air cleaner 63 connected to the throttle body 61 via a connecting pipe 62 is supported above the belt-type continuously variable transmission 31 by a left crankcase (transmission case) 22L. (See FIG. 4).

  On the other hand, referring to FIG. 2, the exhaust pipe 70 extending downward from the lower portion of the cylinder head 24 is bent rightward so as to go around the outside of the right hanger bracket 22b protruding from the lower end of the crankcase 22. A side of the lower end of the crankcase 22 extends rearward and is connected to an exhaust muffler 71 disposed on the right side of the rear wheel 40.

Therefore, as shown in FIG. 5, a power transmission mechanism such as a belt-type continuously variable transmission 31 and a speed reduction mechanism 33 is arranged on the left side with a rear wheel 40 attached to the rear wheel axle 35 and cantilevered. The exhaust muffler 71 is disposed on the right side.
A radiator 65 is disposed on the right side of the right crankcase 22R of the internal combustion engine 21, and a radiator cover 66 covers the outside thereof. The exhaust pipe 70 is located below the radiator 65 and is rearward along the lower end edge of the radiator cover 66. (See FIG. 2).

As shown in FIG. 6, the exhaust muffler 71 disposed on the right side of the rear wheel 40 has an inner case half 73 on which the muffler case 72 is on the rear wheel 40 side (left side) and the side opposite to the rear wheel 40 (right side). And the outer case half 74 forming a shell structure by forming a cavity between them.
The inner case half 73 has a deformed bowl shape in which the inner peripheral wall 73b extends to the right from the outer peripheral edge of the substantially vertical inner wall 73a, and the outer case half 74 has a substantially vertical outer wall. The outer peripheral wall 74b extends to the left from the outer peripheral edge of the 74a and forms a deformed bowl shape that opens to the left. The muffler case 72 is formed by superimposing and welding the opening ends of each other and welding the inner case half 73 and the outer case half 74 together.

The muffler case 72 has a shape that is long in the front-rear direction and flat in the vehicle width direction with a larger vertical width than the width in the vehicle width (left-right width) (see FIG. 9).
Most of the muffler case 72 except for the front part has a cross-sectional shape cut perpendicularly to the front-rear direction (see FIG. 9), which is a vertically long deformed rectangular shape that has a rectangular cylindrical shape extending in the front-rear direction. The front portion extends downwardly from the rectangular tubular portion and tapers forward along the lower edge.
A rear end of the rectangular cylindrical portion is closed by a rear vertical wall.

  2 and 8, the outer wall 74a of the outer case half 74 of the muffler case 72 has a plurality of horizontally elongated recesses 74ad formed in the front-rear direction recessed inward (left side). The lateral recess 74ad enhances the rigidity of the outer case half 74.

  As shown in FIG. 8, the inside of the muffler case 72 is partitioned into three chambers in the front-rear direction by a first separator 75 and a second separator 76 which are substantially vertical partitions, and the central chamber is the first chamber. The first expansion chamber 77, the rear chamber is the second expansion chamber 78, and the front chamber is the third expansion chamber 79.

The first separator 75 and the second separator 76 are provided with peripheral bent pieces 75 a and 76 a welded to the inner surface of the muffler case 72.
The small holes at the positions of the first separator 75 and the second separator 76 of the muffler case 72 are welding holes (see FIG. 7).

As shown in FIGS. 2 and 8, the first separator 75 and the second separator 76 are flat surfaces between the laterally recessed portions 74ad and 74ad which are front and rear of the outer wall 74a of the outer case half 74 of the muffler case 72. Because it is welded, it is easy to weld.
The first expansion chamber 77 and the second expansion chamber 78 constitute a double structure in which an inner wall 80 is provided inside the muffler case 72, and glass wool 88 is partially provided between the muffler case 72 and the inner wall 80. It is sandwiched (see FIG. 5).

As shown in FIG. 8, the catalytic converter 90 is disposed in the third expansion chamber 79 in front of the muffler case 72.
In the catalytic converter 90, a catalyst carrier 91 is surrounded by a cylindrical body 92. A tapered conical tubular upstream connection pipe 93 is welded to the front end opening of the cylindrical body 92, and the cylindrical body 92 has a rear end opening. A tapered conical tubular downstream connection pipe 94 is welded to the rear.

Referring to FIG. 8, the catalytic converter 90 is supported by fitting the rear end portion of the cylindrical body 92 into a circular hole formed in the lower portion of the first separator 75 on the front side, and connected to the front of the cylindrical body 92. An upstream connecting pipe 93 having a conical shape is fitted into the tapered portion at the front end of the muffler case 72, protrudes forward, is supported by welding, and is disposed at the front lower portion inside the muffler case 72.
The catalytic converter 90 is generally in the third expansion chamber 79.

  An exhaust pipe 70 extending from the cylinder head 24 is connected to an upstream connection pipe 93 projecting forward from the muffler case 72, and connected to a downstream connection pipe 94 in the first expansion chamber 77 connected to the rear of the catalytic converter 90. The first communication pipe 81 is connected, and the first communication pipe 81 passes through the second separator 76 on the rear side, curves in the second expansion chamber 78 in a U shape, and passes through the second separator 76 again. The downstream end is opened in the first expansion chamber 77.

A short second communication pipe 82 penetrating the second separator 76 communicates the first expansion chamber 77 and the second expansion chamber 78, and a third communication pipe penetrating the second separator 76 and the first separator 75. 83 communicates the second expansion chamber 78 and the third expansion chamber 79.
A fourth communication pipe 84 that passes through the first separator 75 and the second separator 76 and the tail pipe 84t at the rear end passes through the rear vertical wall of the muffler case 72 communicates the third expansion chamber 79 with the outside. doing.

  Therefore, after the exhaust gas that has passed through the exhaust pipe 70 passes through the catalytic converter 90 in the muffler case 72 of the exhaust muffler 71 and is purified, the exhaust gas passes through the first, second, and third communication pipes 81, 82, and 83. Each time it enters the first, second, and third expansion chambers 77, 78, and 79 sequentially, the expanded pressure wave is dispersed and silenced, and is discharged to the outside through the fourth communication pipe 84.

A long protector support stay 85 protrudes from the front and rear of the outer wall 74a of the outer case half 74 of the exhaust muffler 71, and a protector 86 is fastened to the protector support stay 85 by screws 87, 87 to exhaust the exhaust. The muffler 71 is attached so as to cover the side (see FIGS. 1 to 4).
The protector 86 covers substantially the entire side surface of the exhaust muffler 71 and covers the outer half of the front and rear surfaces and the upper surface, thereby reducing the influence of the heat of the exhaust muffler 71 on the passenger and the cargo bed.

As shown in FIGS. 1 and 4, the protector 86 is provided with longitudinally radiating holes 86 i and 86 j on the front wall and the rear wall, respectively, and both the radiating holes 86 i and 86 j are formed in the upper half of the protector 86. Provided in the department.
Therefore, during traveling, the traveling wind is introduced into the inside of the protector 86 through the heat radiating hole 86i on the front wall, flows along the exhaust muffler 71, and is discharged from the heat radiating hole 86j on the rear wall to improve the cooling performance of the exhaust muffler 71. The heat radiation can be promoted from the heat radiation holes 86i, 86j provided in the upper half of the protector 86 even when the vehicle is stopped where the traveling wind cannot be obtained.
Therefore, even when the protector has a large area, it is possible to efficiently dissipate heat.

  Since the protector 86 covers the side surface of the exhaust muffler 71 having a large vertical width, the protector 86 itself has a wide area side surface, so that an emblem or advertisement is posted by applying a sticker or painting on the side surface of the protector 86. It is also possible to do.

Referring to FIGS. 5, 6, and 7, the inner side wall 73 a of the inner case half 73 facing the rear wheel 41 in the exhaust muffler 71 is recessed rightward in the vehicle width direction at the portion where the rear wheel axle 35 faces. A first rear wheel escape recess 73P (a portion with a thick dotted pattern in FIGS. 6 and 7) is formed, and the second rear is recessed rightward around the first rear wheel escape recess 73P. A concave portion 73Q for wheel escape (a portion with a thin dotted pattern in FIGS. 6 and 7) is formed.
Near the center of the second rear wheel escape recess 73Q recessed inside the inner case half 73 of the exhaust muffler 71, there is a first rear wheel escape recess 73P that is further recessed than the second rear wheel escape recess 73Q. Is formed.

  With respect to the exhaust muffler 71, the axial line (center axis) C of the rear wheel axle 35 is located on the rear side of the first expansion chamber 77 between the first separator 75 and the second separator 76 near the second separator 76. The position is biased (see FIGS. 5 and 7), and the vertical position is biased downward (see FIG. 7).

As shown in FIG. 7, a first rear wheel escape recess 73P is formed in a generally circular shape around the axis C, and the first rear wheel escape recess 73P is first expanded in a side view. The rear lower part of the chamber 77 occupies a large part and partially protrudes to the second expansion chamber 78 behind the chamber 77.
The second rear wheel escape recess 73Q is located behind the first separator 75 on the inner side wall 73a of the inner case half 73 in a side view and from the front to the upper side of the first rear wheel escape recess 73P in the first expansion chamber 77. It wraps around and occupies most of the second expansion chamber 78.

  Therefore, the catalytic converter 90 disposed in the third expansion chamber 79 in the exhaust muffler 71 is positioned in front of the first rear wheel escape recess 73P and further in front of the second rear wheel escape recess 73Q. Has been placed.

The exhaust muffler 71 is supported on the crankcase 22 of the internal combustion engine 21 by a muffler support stay 100 welded to the exhaust muffler 71.
The muffler support stay 100 has a shell structure that is flat in the vehicle width direction, in which a left stay half body 100L and a right stay half body 100R are joined together by forming a cavity therebetween (see FIG. 6).

  As shown in FIGS. 6 and 7, the muffler support stay 100 is divided into two upper and lower forks from the stay central portion 100C so that the upper mounting arm portion 101 and the lower mounting arm portion 102 extend, and the center of the stay is fixed. The upper welding arm portion 103, the lower welding arm portion 104, and the intermediate welding arm portion 105 extend from the portion 100C rearward into three upper and lower forks, and the front upper mounting arm portion 101 and the lower mounting arm portion 102 are extended. On the other hand, the rear upper welding arm portion 103 and the lower welding arm portion 104 are biased to the outer side (right side) in the vehicle width direction, and the stay central portion 100C connecting the two is left in the left and right direction, that is, in the vehicle width direction. Inclined inward.

Mounting holes 101h and 102h are formed in front end portions of the front upper mounting arm portion 101 and the lower mounting arm portion 102.
The rear upper welding arm portion 103 and the lower welding arm portion 104 are elongated rearward, and the respective rear end portions of the welding pieces 103a and 103a and the welding pieces 104a and 104a are opened to the left and right to expand. ing.
The rear intermediate welding arm portion 105 is a welding piece in which a part of the left stay half body 100L extends short rearward, and the upper welding arm portion 103 and the lower welding arm portion 104 are shifted to the right side. I have not moved.

  Referring to FIG. 6, muffler support stay 100 is fitted from the front so that exhaust muffler 71 is sandwiched from above and below by upper and lower upper welding arm portions 103 and lower welding arm portion 104 that are elongated in the rearward direction. The weld pieces 103a, 103a of the upper weld arm 103 and the weld pieces 104a, 104a of the lower weld arm 104 are the inner peripheral wall 73b of the inner case half 73 of the muffler case 72 and the outer peripheral wall 74b of the outer case half 74. Since the weld piece of the intermediate welding arm portion 105 is in contact with the inner side wall 73a of the inner case half body 73 from the inner side (left side), each weld piece is welded to each contact portion of the muffler case 72. A support stay 100 is integrally attached to the front portion of the exhaust muffler 71.

  The muffler support stay 100 has a rear upper welding arm portion 103 and a lower welding arm portion 104 that are biased outward (right side) in the vehicle width direction with respect to the front upper attachment arm portion 101 and the lower attachment arm portion 102. Therefore, the front part of the exhaust muffler 71 welded so as to be sandwiched from above and below by the rear upper welding arm part 103 and the lower welding arm part 104 is the right side of the stay central part 100C inclined in the left-right direction of the muffler support stay 100. (See FIG. 6), and the portion that is biased downward and extends forward and tapering forward is located along the right side of the lower mounting arm 102 on the front side of the muffler support stay 100. (See FIG. 7).

Referring to FIG. 7, welded pieces 104 a and 104 a of lower welding arm portion 104 of muffler support stay 100 are welded to the outer surface of the attachment portion to which bent piece 75 a of first separator 75 of muffler case 72 is welded. .
Therefore, the lower case arm 104 of the muffler support stay 100 is welded to the outer surface of the attachment portion of the muffler case 72 whose rigidity has been increased by the first separator 75, so that the inner case half 73 and the outer case half are further separated. The rigidity of the muffler case 72 formed by combining with 74 is increased, and the exhaust muffler 71 is firmly supported by the crankcase 22 of the internal combustion engine 21.

Further, as shown in FIG. 7, the welded pieces 103 a and 103 a of the upper welding arm 103 of the muffler support stay 100 are arranged in front of the first rear wheel escape recess 73 </ b> P of the muffler case 72. The bent piece 75a is welded to the outer surface of the front part from the first rear wheel escape recess 73P, which is the rear part from the attachment part to be welded.
The intermediate welding arm portion 105 of the muffler support stay 100 is welded to the outer surface of the front portion from the attachment portion where the bent piece 75a of the first separator 75 of the muffler case 72 is welded.

  Accordingly, the lower separator arm 104, the intermediate weld arm portion 105, and the upper weld arm portion 103 of the muffler support stay 100 at the front and rear positions of the first separator 75 in front of the first rear wheel escape recess 73P of the muffler case 72. As a result, the first rear wheel escape recess 73P can be prevented from interfering with the muffler support stay 100 and the degree of freedom of the recess shape can be improved, and the exhaust muffler 71 can be firmly attached to the internal combustion engine 21. The crankcase 22 can be supported.

  As shown in FIG. 2, the muffler support stay 100 which is integrally welded to the front portion of the exhaust muffler 71 in this way has an upper mounting arm portion 101 and a lower mounting arm portion 102 that extend forward, as shown in FIG. Are fixed to the crankcase 22 of the internal combustion engine 21 by mounting bolts 106 and 107 penetrating through the mounting holes 101h and 102h, and an exhaust muffler 71 is attached to the crankcase 22 via the muffler support stay 100, and on the right side of the rear wheel 40. Arranged.

  The exhaust muffler 71 attached in this way has a shape whose vertical width is larger than the width in the vehicle width direction, and completely covers the rear wheel axle 35 in the vehicle side view as shown in FIG. And the upper end edge of the exhaust muffler 71 is disposed below the upper end of the wheel rim 44 of the rear wheel 40.

6 and 7, a first rear wheel escape recess 73P formed in the inner wall 73a on the rear wheel side of the exhaust muffler 71 so as to be recessed on the side opposite to the rear wheel side is provided with a rear wheel axle. An exhaust muffler 71 is disposed so as to be located at a part facing 35.
As shown in FIG. 7, the axis C of the rear wheel axle 35 is located substantially at the center of the first rear wheel escape recess 73P that is recessed in a circular shape.

The exhaust muffler 71 in which the inner wall 73a on the rear wheel side is recessed on the opposite side to the rear wheel side by the first rear wheel escape recess 73P and the second rear wheel escape recess 73Q is the most recessed with reference to FIG. With reference to the axis C of the rear wheel axle 35 that is substantially the center of the first rear wheel escape recess 73P, the rear portion of the front portion in the vehicle width direction is more than the maximum projecting position Pf to the rear wheel side in the vehicle width direction. The maximum projecting position Pr toward the rear wheel is farther from the rear wheel 40.
That is, the space on the rear wheel side (left side) of the exhaust muffler 71 has more room on the rear side than the front side with respect to the axis C.

As shown in FIG. 7, the catalytic converter 90 disposed in the third expansion chamber 79 in front of the muffler case 72 of the exhaust muffler 71 is in front of the first rear wheel escape recess 73P and further to the first rear wheel. It is arranged in front of the second rear wheel escape recess 73Q around the escape recess 73P.
Referring to FIG. 7, assuming a virtual horizontal plane H that includes the axis C of the rear wheel axle 35, the catalytic converter 90 is arranged so as to be biased downward with respect to the virtual horizontal plane H.

Further, as shown in FIG. 7, the catalytic converter 90 is arranged in a posture inclined forward and downward, most of the catalytic converter 90 is below the virtual horizontal plane H, and the upper part of the rear is partially virtual horizontal plane H. Therefore, the catalytic converter 90 is further away from the virtual horizontal plane toward the front side.
A connection bracket 108 is welded to the lower end of the rear portion of the muffler case 72 of the exhaust muffler 71.

As shown in FIG. 2, the rear fender 110 covers substantially the upper half of the tire 45 of the rear wheel 40.
The rear fender 110 has a semi-annular shape with an upper half of an annular shape having a U-shaped cross section that is slightly larger than the outer shape of the tire 45 of the rear wheel 40, and covers the upper and front and rear sides of the rear wheel 40.

Referring to FIG. 4, a mounting bracket 110 a extends from the left front portion of the arc-shaped peripheral wall of the rear fender 110 having a U-shaped cross section to the left.
A mounting bracket 110b protrudes forward from the left rear lower end portion of the arc-shaped peripheral wall of the rear fender 110 having a U-shaped cross section, and a mounting bracket 110c is formed at the right rear lower end portion.

  The left front mounting bracket 110a of the rear fender 110 is attached to a mounting boss 63a of an air cleaner 63 disposed on the left crankcase (transmission case) 22L with mounting bolts 111 (see FIG. 3). The mounting bracket 110b projecting forward from the rear lower end of the left side wall is attached to the support bracket 22Lb projecting further rearward from the rear portion of the left crankcase (transmission case) 22L by mounting bolts 112 (see FIG. 5).

On the other hand, a connecting stay 115 having a front end fixed by a mounting bolt 109 to a connecting bracket 108 welded to the rear lower end of an exhaust muffler case 72 of an exhaust muffler 71 disposed on the right side of the rear wheel 40 protrudes rearward. (See FIG. 2).
A mounting bracket 110c at the rear lower end of the right side wall of the rear fender 110 is attached to a rear end portion of a connecting stay 115 projecting from a connecting bracket 108 at the rear lower end of the muffler case 72 by a mounting bolt 113.

  Accordingly, in the rear fender 110, the left front mounting bracket 110a is attached to the air cleaner 63, the rear left lower mounting bracket 110b is attached to the left crankcase (transmission case) 22L, and the right lower rear mounting bracket. 110 c is attached to the exhaust muffler 71 via the connecting stay 115 and supported by the power unit 20.

Referring to FIGS. 2 to 4, a support bracket 110d is formed to protrude rightward from the upper right front portion of the arc-shaped peripheral wall in the rear fender 110, and the right-side central upper portion rearward from the support bracket 110d of the arc-shaped peripheral wall. A support bracket 110e protrudes in the direction.
Further, a reserve tank support stay 120 is welded and erected on a stay central portion 100C inclined in the left-right direction of the muffler support stay 100 that supports the exhaust muffler 71 (see FIG. 2).

The reserve tank support stay 120 has a lower portion welded to the muffler support stay 100 and protruding upward, a horizontal base 120b stretched on the upper end of the support 120a, and a side base of the horizontal base 120b bent upward. And the mounting bracket portion 120c formed in this manner.
The mounting bracket portion 120c of the reserve tank support stay 120 abuts on the support bracket 110d on the right front upper portion of the arc-shaped peripheral wall of the rear fender 110 from the left side and is fixed by the mounting bolt 121 (see FIG. 2).

The reserve tank 130 is supported by the reserve tank support stay 120 which is welded to the muffler support stay 100 and attached to the rear fender 110 and supported thereby.
As shown in FIG. 2, the reserve tank 130 has a tank upper half 130a having a long rectangular shape in the front and rear, and a rear lower portion of the tank upper half 130a bulges downward to form a tank lower half 130b. A water supply port 130c that is opened and closed by a cap 134 projects upward from the rear part of the tank upper half part 130a.
A scale 131 for checking the amount of water is provided at the rear of the right side wall of the reserve tank 130.

The front part of the tank upper half part 130a rests on the horizontal base 120b of the reserve tank support stay 120, and a pivot support shaft 132 projecting downward from the front bottom wall of the tank upper half part 130a has a horizontal base 120b. The reserve tank 130 is supported so as to be swingable left and right about a pivot support shaft 132 inserted into the bearing portion (see FIG. 2) and oriented in a substantially vertical direction.
A mounting bracket 133 protrudes rearward from the rear wall of the upper tank half 130a of the reserve tank 130, and the rear end of the mounting bracket 133 is attached to the support bracket 110e at the upper right center of the rear fender 110 by mounting bolts 135. Thus, the reserve tank 130 is fixed.

A supply tube 136 is connected to a connection pipe projecting forward from the tank lower half 130 b of the reserve tank 130, and the supply tube 136 is connected to the upper tank of the radiator 65.
An atmosphere release tube 137 is connected to the connection pipe protruding forward from the water supply port 130 c of the reserve tank 130.

The reserve tank 130 is covered with a tank cover 140 from the right side.
The tank cover 140 is attached to the support bracket 110e of the rear fender 110 by being fastened together with the reserve tank 130 by the mounting bolt 135.
The tank cover 140 has a vertically long hole formed in a portion corresponding to the scale portion 131 of the reserve tank 130, and the amount (water level) of the preliminary cooling water in the reserve tank 130 can be inspected from the outside.

As described above, the rear wheel axle 35 that protrudes rightward from the speed reduction mechanism 33 at the rear of the belt-type continuously variable transmission that extends rearward of the power unit 20 that is swingably supported by the vehicle body frame. The scooter-type motorcycle 1 in which the rear wheel 40 is cantilevered and an exhaust muffler 71 having a catalytic converter 90 inside is disposed on the right side of the rear wheel 40, without removing the exhaust muffler 71. Can be replaced.
Hereinafter, the process of removing the rear wheel 40 will be described with reference to FIGS. 5 and 10 to 12.

In order to remove the rear wheel 40, it is first necessary to remove the rear fender 110.
The left front mounting bracket 110a of the rear fender 110 is separated from the muffler case 72 by removing the mounting bolt 111, and the left lower rear mounting bracket 110b of the rear fender 110 is removed from the muffler case 72 by removing the mounting bolt 112. The mounting bracket 110c at the rear lower end of the right side wall of the rear fender 110 is separated from the connecting stay 115 fixed to the exhaust muffler 71 by removing the mounting bolt 113.

Further, the support bracket 110d at the right front portion of the arc-shaped peripheral wall of the rear fender 110 is separated from the mounting bracket portion 120c of the reserve tank support stay 120 by removing the mounting bolt 121, and the support bracket 110e at the upper right center of the rear fender 110 is attached to the mounting bolt 135. Is removed from the mounting bracket 133 of the reserve tank 130.
The rear fender 110 can be removed from the vehicle body by removing the five mounting bolts 111, 112, 113, 121, and 135 described above.

However, the connecting stay 115 attached to the connecting bracket 108 of the exhaust muffler 71 is also obstructed when the rear wheel 40 is replaced.
With the connection stay 115 attached to the rear fender 110, the connection stay 115 can be removed together with the rear fender 110 by removing the attachment bolt 113 and removing the connection stay 115 from the exhaust muffler 71.

Referring to FIG. 4, the reserve tank 130 disposed above the muffler support stay 100 that supports the exhaust muffler 71 can be exposed to the outside by removing the tank cover 140 by removing the mounting bolt 135. .
In this exposed state, the reserve tank 130 whose front is supported by the reserve tank support stay 120 is swung to the right about a pivot support shaft 132 oriented in a substantially vertical direction, so that the muffler support stay 100 is The reserve tank 130 can be tilted parallel to the stay central portion 100C above the stay central portion 100C inclined in the left-right direction (indicated by a two-dot chain line in FIG. 4), and the rear wheel is obliquely upward and rearward of the stay central portion 100C. A space for escape can be formed.
Of course, it is also possible to swing the reserve tank 130 in order to perform the water supply operation to the reserve tank 130 easily.

  Thus, with the rear fender 110 and the connecting stay 115 removed and the reserve tank 130 swung to the right, the rear side of the exhaust muffler 71 on the rear side of the axis C of the rear wheel axle 35 is the vehicle width direction. The rearward wheel 40 is removed rearward of the vehicle body from the rear side where the maximum overhanging position to the rear wheel side is far from the rear wheel 40 (see FIG. 10) and there is a space.

  When removing the rear wheel 40 to the rear of the vehicle body, the first rear wheel escape recess 73P and the second rear wheel escape recess 73Q in the inner wall 73a on the rear wheel side of the exhaust muffler 71 are used. The rear wheel 40 is moved while tilting left and right on a virtual horizontal plane H including the axis C of the rear wheel axle 35 located substantially at the center of the rear wheel escape recess 73P so that the central axis of the rear wheel 40 is always located. The rear wheel 40 is removed to the rear of the vehicle body.

  First, the nut 37 that fastened the rear wheel 40 to the rear wheel axle 35 is loosened and removed together with the washer 36, and the rear wheel 40 is translated to the right in the vehicle width direction, so that the bearing cylinder of the wheel hub 42 of the rear wheel 40 is obtained. The portion 42a is extracted from the rear wheel axle 35 (see FIGS. 5 and 10).

  Referring to FIG. 10, the rear wheel 40 is restricted in parallel movement when the front portion of the tire 45 hits the muffler support stay 100, but when the front portion of the tire 45 hits the muffler support stay 100, the rear wheel 40 is shown in FIG. 10. As shown, the bearing cylindrical portion 42a of the wheel hub 42 reaches the reduced-diameter male screw 35s at the left end portion of the rear wheel axle 35, so that the rear wheel 40 is positioned perpendicular to the axis C of the rear wheel axle 35. It is possible to tilt from side to side.

Therefore, by moving the rear side of the rear wheel 40 to the right from the front side and moving the rear wheel 40 diagonally right and rearward while tilting the rear wheel 40 left and right, the bearing cylindrical portion of the wheel hub 42 from the rear wheel axle 35. 42a can be removed, and when the rear wheel 40 is moved diagonally to the right rear, the stay central portion 100C in which the front portion of the rear wheel 40 is inclined in the left-right direction of the muffler support stay 100 and the brake shoe 52 of the drum brake 50 are formed. It passes through and moves to the position shown by the solid line in FIG.
At this time, the reserve tank 130 swings to the right to form a rear wheel escape space obliquely above the stay central portion 100C, so that the front upper portion of the rear wheel 40 does not interfere with the reserve tank 130. .

  When the wheel rim 44 of the rear wheel 40 moves rearward while turning the rear side of the rear wheel 40 leftward about the position close to the brake shoe 52, as shown by a two-dot chain line in FIG. The front right side of 45 enters the second rear wheel escape recess 73Q in front of the first rear wheel escape recess 73P, and the wheel rim 44 escapes rearward so as to bypass the brake shoe 52.

  Then, the rear wheel 40 is moved rearward substantially in this posture, and when the front left side portion of the tire 45 approaches the rear wheel axle 35, the front right side portion of the tire 45 faces the first rear wheel escape recess 73P. Therefore, the rear wheel 40 can be moved to the right, the rear wheel 40 is moved slightly to the right, and the front right side of the tire 45 is inserted into the first rear wheel escape recess 73P. This is indicated by a solid line in FIG.

Thereafter, the front left side portion of the tire 45 goes around the right end of the rear wheel axle 35 rearward, and the front right side portion of the tire 45 rotates rearward along the curved concave surface of the first rear wheel escape recess 73P. When the rear wheel 40 is moved rearward, as shown by a phantom line in FIG. 12, the front portion of the tire 45 is for the second rear wheel escape behind the rear portion of the brake shoe 52 and the first rear wheel escape recess 73P. It is located between the recess 73Q.
Thereafter, if the rear wheel 40 is moved rearward so that the front right side portion of the tire 45 rotates rearward along the curved concave surface of the second rear wheel escape recess 73Q, the rear wheel 40 is removed from the vehicle body. be able to.

As described above, the scooter type motorcycle 1 can remove the rear wheel 40 from the vehicle body without removing the exhaust muffler 71.
The rear wheel 40 can be attached to the vehicle body by the reverse procedure of the rear wheel removal, and therefore the replacement operation of the rear wheel 40 can be performed efficiently without removing the exhaust muffler 71.

  Since the exhaust device of the scooter type motorcycle 1 according to the present embodiment is configured as described above, the following operational effects can be obtained.

  As shown in FIG. 7, the catalytic converter 90 provided in the exhaust muffler 71 has a first rear wheel escape recess 73 </ b> P formed at a portion of the inner wall 73 a of the exhaust muffler 71 facing the rear wheel axle 35. Is disposed further forward and further forward than the second rear wheel escape recess 73Q around the first rear wheel escape recess 73P. Therefore, the first and second rear parts formed on the inner wall 73a of the exhaust muffler 71 are also provided. The wheel escape recesses 73P and 73Q avoid interference with the catalytic converter 90, and a large degree of freedom of the recess shape is ensured.

Accordingly, the first size and depth required to perform the rear wheel removal / replacement operation without removing the exhaust muffler 71 while suppressing the exhaust muffler 71 from bulging or projecting outward in the vehicle width direction. The second rear wheel escape recesses 73P and 73Q can be easily formed.
By forming the first and second rear wheel escape recesses 73P and 73Q, the exhaust muffler 71 is maintained as shown in FIGS. 10 to 12 while maintaining good appearance and avoiding the enlargement of the vehicle body. The rear wheel 40 can be easily replaced without removing the wheel.

  Further, since the catalytic converter 90 is not disposed on the rear side in the exhaust muffler 71, the width in the vehicle width direction of the exhaust muffler 71 on the rear side can be reduced, and the space for removing the rear wheel 40 is rearward. It is possible to secure a wide area and to easily remove and attach the rear wheel 40 to the rear of the vehicle body.

  As shown in FIG. 10, the exhaust muffler 71 has a front portion with respect to the axis C of the rear wheel axle 35 that is the center of the most recessed first rear wheel escape recess 73 </ b> P on the inner wall 73 a on the rear wheel side. The maximum overhang position Pr of the rear portion in the vehicle width direction toward the rear wheel side is farther from the rear wheel 40 than the maximum overhang position Pf in the vehicle width direction toward the rear wheel.

  In other words, the space on the rear wheel side (left side) of the exhaust muffler 71 has more room on the rear side than the front side with respect to the axis C. Therefore, without removing the exhaust muffler 71, the space on the rear wheel 40 can be increased. The rear wheel 40 can be easily removed by moving backward, and the rear wheel 40 can be easily attached from the rear.

  With reference to FIG. 9, the exhaust muffler 71 is formed so that the vertical width is larger than the width in the vehicle width direction (left-right width), so that the exhaust muffler 71 has an inner capacity on the rear wheel side while ensuring the capacity of the exhaust muffler. By making the wall 73a close to the outer wall and reducing the width in the vehicle width direction so as to be flat in the vehicle width direction, a good appearance can be maintained, and the rear wheel 40 and the exhaust muffler 71 on the side of the rear wheel 40 can be maintained. A space that allows the rear wheel 40 to pass therethrough can be easily secured.

  Further, as shown in FIG. 2, the exhaust muffler 71 is disposed so as to completely cover the rear wheel axle 35 in a side view of the vehicle, and the catalytic converter 90 is located with respect to a virtual horizontal plane H including the axis C of the rear wheel axle 35. Therefore, the exhaust muffler 71 including the heavy catalytic converter 90 can be lowered in the center of gravity, and good steering stability of the scooter type motorcycle 1 can be achieved.

  When removing the rear wheel 40 to the rear of the vehicle body, it is necessary to secure a removal space for the rear wheel 40 in the virtual horizontal plane H including the axis C of the rear wheel axle 35 and in the vicinity thereof. Since the converter 90 is arranged to be biased downward with respect to the virtual horizontal plane H, a space for removing the rear wheel 40 can be easily secured.

  As shown in FIG. 7, the catalytic converter 90 arranged so as to be biased downward with respect to the virtual horizontal plane H including the axis C is inclined so that the front part is farther from the virtual horizontal plane H than the rear part. Therefore, the catalytic converter 90 is farther away from the virtual horizontal plane H toward the front side, and the front part of the rear wheel hardly interferes with the catalytic converter 90 when the rear wheel is removed while being tilted left and right. The rear wheel 40 can be removed and attached more easily.

  As shown in FIG. 2, the exhaust muffler 71 is kept low so that the upper end edge of the exhaust muffler 71 is located below the upper end of the wheel rim 44 of the rear wheel 40. The reserve tank 130 can be arranged in a space-efficient manner at a position overlapping the rear wheel 40 in an easy vehicle side view, and the amount of liquid inside the reserve tank 130 can be easily confirmed from the outside by the scale 131 of the reserve tank 130 And maintainability is improved.

  In addition, since the catalytic converter 90 is provided so as to be biased downward with respect to the virtual horizontal plane H including the axis C, even when the reserve tank 130 is disposed close to the exhaust muffler 71, the reserve tank 130 is not attached to the exhaust muffler 71. It is above and hardly affected by the heat from the catalytic converter 90.

  On the inner wall 73a of the exhaust muffler 71 on the rear wheel 40 side, a second rear wheel escape recess 73Q is formed around the first rear wheel escape recess 73P, and the second rear wheel is recessed inside the exhaust muffler 71. A first rear wheel escape recess 73P is formed in the center of the escape recess 73Q so as to be further recessed than the second rear wheel escape recess 73Q. As shown in FIG. Since it is disposed in front of the rear wheel escape recess 73Q, in addition to the first rear wheel escape recess 73P, the further formed second rear wheel escape recess 73Q avoids interference with the catalytic converter 90, A large degree of freedom in the shape of the recess can be ensured, and the required size and depth of the second rear wheel escape recess 73Q can be easily formed, and the rear wheel 40 can be removed and attached without removing the exhaust muffler 71. The work can be performed more easily, and the second rear wheel escape recess 73Q Further closer to the exhaust muffler 71 to the rear wheel 40 side to miniaturize the vehicle width direction and disposed, it is possible to achieve the improvement of the appearance from the rear, to improve the parked property.

  As shown in FIGS. 5 and 6, the inner wall 73a of the exhaust muffler 71 on the rear wheel 40 side is recessed from the outer periphery to form a second rear wheel escape recess 73Q. Since the center of the escape recess 73Q is further recessed to form the first rear wheel escape recess 73P, the bent portion formed at the outer peripheral edge of the second rear wheel escape recess 73Q and the center first rear wheel escape The rigidity of the inner wall 73a of the exhaust muffler 71 can be increased by the bent portion formed at the boundary between the recess 73P and the second rear wheel escape recess 73Q.

As shown in FIG. 7, since the catalytic converter 90 is supported by the first separator 75 provided in front of the first and second rear wheel escape recesses 73P and 73Q, it interferes with the first rear wheel escape recess 73P. The first separator 75 can be provided without the need, and the first and second rear wheel escape recesses 73P and 73Q can be provided with a greater degree of freedom in the shape of the recesses. The second rear wheel escape recesses 73P and 73Q can be easily formed.
Further, the catalytic converter 90 can be firmly supported by the first separator 75.

  Since the catalytic converter 90 is supported by the first separator 75 at the rear end portion and is disposed in the third expansion chamber 79 in front of the exhaust muffler 71, the second rear wheel as well as the first rear wheel escape recess 73P is disposed. It can be separated forward from the wheel escape recess 73Q, and the degree of freedom of the recess shape of the first and second rear wheel escape recesses 73P and 73Q can be secured more and more.

An exhaust muffler 71 including a muffler case 72 formed by combining an inner case half 73 and an outer case half 74 is supported by a muffler support stay 100 protruding from the internal combustion engine 21, as shown in FIG. In the muffler support stay 100, the lower welding arm portion 104 extending rearward is welded to the outer surface of the attachment portion to which the first separator 75 in the muffler case 72 is attached.
For this reason, the muffler support stay 100 is welded to the outer surface of the attachment portion of the first separator 75 in the muffler case 72 whose rigidity is increased by the first separator 75, so that the inner case half 73 and the outer case half 74 The rigidity of the muffler case 72 formed by combining the two is increased, and the exhaust muffler 71 is firmly supported by the internal combustion engine 21.

  As shown in FIG. 7, the muffler support stay 100 includes a lower welding arm portion 104 welded to an outer surface of an attachment portion to which the first separator 75 of the muffler case 72 is attached, and an attachment to which the first separator 75 is attached. Since the upper welding arm portion 103 welded on the outer surface of the rear portion from the portion and the intermediate welding arm portion 105 welded on the outer surface of the front portion from the attachment portion to which the first separator 75 is attached are provided. The upper, lower, and intermediate welding arms 103, 104, and 105 of the muffler support stay 100 are welded at the position and the front and rear positions thereof, and the exhaust muffler 71 can be firmly supported by the internal combustion engine 21.

  Since the upper welding arm 103 welded to the muffler case 72 behind the first separator 75 is welded forward of the first rear wheel escape recess 73P, the lower, intermediate welding arms 104, 105 are welded. Also, the first rear wheel escape recess 73P is welded in front of the first rear wheel escape recess 73P, and the first rear wheel escape recess 73P avoids interference with the muffler support stay 100 and improves the degree of freedom of the recess shape. With the optimal recess shape, the rear wheel can be removed and replaced without removing the exhaust muffler 71, and the exhaust muffler 71 can be prevented from projecting outward in the vehicle width direction. Can be maintained.

  The upper, lower, and intermediate weld arms 103, 104, and 105 of the muffler support stay 100 are welded to the upper end, the lower end, and the vertical middle of the muffler case 72, respectively, so that the exhaust muffler 71 is further strengthened. It can be supported by the internal combustion engine 21.

The exhaust muffler according to the present invention is suitable for a business scooter type vehicle in which rear wheels are frequently replaced.
In addition, the scooter type vehicle to which the exhaust device according to the present invention is applied is configured to allow the rear wheel to be replaced without removing the exhaust muffler, and can also suppress the exhaust muffler from protruding outward in the vehicle width direction. The parking capacity of vehicles in a small bicycle parking lot is also good.

  As mentioned above, although the exhaust apparatus of the scooter type vehicle of embodiment which concerns on this invention was demonstrated, the aspect of this invention is not limited to the said embodiment, What is implemented in various aspects in the range of the summary of this invention. Is included.

DESCRIPTION OF SYMBOLS 1 ... Scooter type motorcycle, 20 ... Power unit, 21 ... Internal combustion engine, 22 ... Crank case, 23 ... Cylinder block, 24 ... Cylinder head, 27 ... Reduction gear case, 31 ... Belt type continuously variable transmission, 33 ... Reduction mechanism , 35 ... rear axle, 36 ... washer, 37 ... nut, 40 ... rear wheel, 41 ... rear wheel, 42 ... wheel hub, 43 ... spoke part, 44 ... wheel rim, 45 ... tire, 50 ... drum brake, 52 ... Brake shoe, 63 ... Air cleaner,
70 ... Exhaust pipe, 71 ... Exhaust muffler, 72 ... Muffler case, 73 ... Inner case half, 73a ... Inner wall, 73P ... First rear wheel escape recess, 73Q ... Second rear wheel escape recess, 74 ... Outside Half case, 74a ... outer wall, 75 ... first separator, 76 ... second separator, 77 ... first expansion chamber, 78 ... second expansion chamber, 79 ... third expansion chamber, 86 ... protector,
90 ... Catalytic converter, 91 ... Catalyst carrier, 92 ... Cylinder,
100 ... Muffler support stay, 100C ... Stay central portion, 101 ... Upper mounting arm portion, 102 ... Lower mounting arm portion, 103 ... Upper welding arm portion, 104 ... Lower welding arm portion, 105 ... Intermediate welding arm portion,
110 ... rear fender, 120 ... reserve tank support stay, 130 ... reserve tank, 131 ... inspection window.

Claims (14)

Rear wheels on the rear axle (35) provided at the rear of the power transmission mechanism (31, 33) extending rearward from the internal combustion engine (21) of the power unit (20) supported swingably on the body frame (40) is cantilevered,
An exhaust muffler (71) having a catalytic converter (90) inside is disposed on the side opposite to the power transmission mechanism (31, 33) disposed on one side of the rear wheel (40). ,
A scooter-type vehicle exhaust device in which a rear wheel escape recess (73P) is formed in a portion of the inner wall (73a) on the rear wheel (40) side of the exhaust muffler (71) facing the rear wheel axle (35). In
The catalytic converter (90) is disposed in front of the rear wheel escape recess (73P) in the exhaust muffler (71) ,
On the inner wall (73a) on the rear wheel side of the exhaust muffler (71), a second rear wheel escape recess (73Q) is formed around the rear wheel escape recess (73P),
In the center of the second rear wheel escape recess (73Q) that is recessed inside the exhaust muffler (71), the rear wheel escape recess ( 73P) is formed,
The exhaust system for a scooter type vehicle, wherein the catalytic converter (90) is disposed in front of the second rear wheel escape recess (73Q) .   The exhaust muffler (71) has a rear wheel with a maximum protruding position toward the rear wheel (40) in the vehicle width direction on the rear side rather than the front side with respect to the axis (C) of the rear wheel axle (35). 40. The exhaust device for a scooter type vehicle according to claim 1, wherein the exhaust device is far from 40). The exhaust muffler (71) is formed so that the vertical width is larger than the width in the vehicle width direction, and is disposed so as to completely cover the rear wheel axle (35) in a vehicle side view,
3. The catalytic converter (90) is arranged to be biased downward with respect to a virtual horizontal plane (H) including an axis (C) of the rear wheel axle (35). The scooter type vehicle exhaust device described.   The said catalytic converter (90) is arrange | positioned with the attitude | position which inclined frontwardly so that the front part may leave | separate from the said virtual horizontal surface (H) rather than the rear part of the catalytic converter (90). The scooter type vehicle exhaust device described. The exhaust muffler (71) is disposed such that the upper end edge of the exhaust muffler (71) is located below the upper end of the wheel rim (44) of the rear wheel (40),
The reserve tank (130) is disposed at a position above the exhaust muffler (71) and overlapping the rear wheel (40) in a side view of the vehicle. Scooter type vehicle exhaust system.
Rear wheels on the rear axle (35) provided at the rear of the power transmission mechanism (31, 33) extending rearward from the internal combustion engine (21) of the power unit (20) supported swingably on the body frame (40) is cantilevered,
An exhaust muffler (71) having a catalytic converter (90) inside is disposed on the side opposite to the power transmission mechanism (31, 33) disposed on one side of the rear wheel (40). ,
A scooter-type vehicle exhaust device in which a rear wheel escape recess (73P) is formed in a portion of the inner wall (73a) on the rear wheel (40) side of the exhaust muffler (71) facing the rear wheel axle (35). In
The catalytic converter (90) is disposed in front of the rear wheel escape recess (73P) in the exhaust muffler (71) ,
A separator that partitions the inside of the exhaust muffler (71) into a plurality of expansion chambers is provided in front of the recess for escape of the rear wheel (73P),
The exhaust system for a scooter type vehicle , wherein the catalytic converter (90) is supported by the separator (75) . The exhaust muffler (71) has a rear wheel with a maximum protruding position toward the rear wheel (40) in the vehicle width direction on the rear side rather than the front side with respect to the axis (C) of the rear wheel axle (35). 40. The scooter type vehicle exhaust device according to claim 6, which is far from 40).   The exhaust muffler (71) is formed so that the vertical width is larger than the width in the vehicle width direction, and is disposed so as to completely cover the rear wheel axle (35) in a vehicle side view,
  The catalyst converter (90) is disposed to be biased downward with respect to a virtual horizontal plane (H) including an axis (C) of the rear wheel axle (35). The scooter type vehicle exhaust device described.   The said catalytic converter (90) is arrange | positioned with the attitude | position which inclined frontwardly so that the front part may leave | separate from the said virtual horizontal surface (H) rather than the rear part of the catalytic converter (90). The scooter type vehicle exhaust device described.   The exhaust muffler (71) is disposed such that the upper end edge of the exhaust muffler (71) is located below the upper end of the wheel rim (44) of the rear wheel (40),
  The reserve tank (130) is arranged at a position above the exhaust muffler (71) and overlapping the rear wheel (40) in a side view of the vehicle. Scooter type vehicle exhaust system.   On the inner wall (73a) on the rear wheel side of the exhaust muffler (71), a second rear wheel escape recess (73Q) is formed around the rear wheel escape recess (73P),
  In the center of the second rear wheel escape recess (73Q) that is recessed inside the exhaust muffler (71), the rear wheel escape recess ( 73P) is formed,
  The exhaust system for a scooter type vehicle according to any one of claims 6 to 10, wherein the catalytic converter (90) is disposed in front of the second rear wheel escape recess (73Q). . The exhaust muffler (71) is a muffler case (72) formed by combining an inner case half (73) disposed on the inner side which is the rear wheel side in the vehicle width direction and an outer case half (74) disposed on the outer side. ) Is configured,
The exhaust muffler (71) is supported by the internal combustion engine (21) by a muffler support stay (100),
The muffler support stay (100) according to any one of claims 6 to claim 11, characterized in the separator (75) that is welded to the outer surface of the mounting portion to be mounted in the muffler casing (72) Exhaust system for scooter type vehicles. The muffler support stay (100) has a first welding arm portion (104) welded to an outer surface of the attachment portion to which the separator (75) of the muffler case (72) is attached, and the separator (75) is attached. A second welding arm portion (103) welded on the outer surface of the rear portion from the mounting portion to be attached, and a third welding arm portion (105) welded on the outer surface of the front portion from the mounting portion to which the separator (75) is attached. With
The exhaust system for a scooter type vehicle according to claim 12, wherein the second welding arm (103) is welded in front of the rear wheel escape recess (73P). The first, second, and third welding arm portions (104, 103, 105) of the muffler support stay (100) are each dispersed in any one of an upper end portion, a lower end portion, and a vertical middle portion of the muffler case (72). The scooter type vehicle exhaust device according to claim 13 , wherein the scooter type vehicle exhaust device is welded.

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