JPWO2018025652A1 - Exhaust structure of saddle-ride type vehicle - Google Patents

Abstract

Provided is an exhaust structure for a saddle-ride type vehicle that can easily activate a catalyst while securing a bank angle of the vehicle. The motorcycle includes a fuel tank 56 disposed below the floor step 63, and a power unit 14 that is disposed behind the floor step 63 and the fuel tank 56 and is swingably supported by the vehicle body frame 11 via a link member 38. And an exhaust pipe 51 connected to the power unit 14 and a catalytic converter 54 provided in the exhaust pipe 51. The catalytic converter 54 is arranged with its longitudinal direction directed in the vehicle width direction, and the catalytic converter 54 The catalytic converter 54 is disposed behind the fuel tank 56 so that the whole overlaps with the fuel tank 56 when viewed from the front of the vehicle.

Description

  The present invention relates to an exhaust structure for a saddle-ride type vehicle.

  Conventionally, in a lower link type scooter type vehicle in which a lower part of a power unit is swingably supported by a body frame via a link, an exhaust structure including a catalyst in the middle of an exhaust pipe connected to the power unit is disclosed (for example, , See Patent Document 1).

JP 2013-36422 A

In the prior art, the exhaust pipe extends in the front-rear direction on one side in the vehicle width direction, and a catalyst having a large outer diameter is provided in the middle of the exhaust pipe. It becomes difficult to secure. Therefore, in order to increase the bank angle of the vehicle, it is conceivable to dispose the catalyst so as to extend in the vehicle width direction in the vicinity of the connection portion between the power unit and the exhaust pipe. There is a problem that it becomes difficult to activate.
An object of the present invention is to provide an exhaust structure for a saddle-ride type vehicle that can easily activate a catalyst while ensuring a bank angle of the vehicle.

This specification includes all the contents of Japanese Patent Application No. 2006-154861 filed on Aug. 5, 2016.
In order to solve the above-described problem, the present invention (first feature) includes a vehicle body frame (11), a seat (17) supported by the vehicle body frame (11), and a front side of the seat (17). A footrest (63) provided at a lower portion of the vehicle body frame (11), a fuel tank (56) disposed below the footrest (63), the footrest (63) and the fuel tank ( 56) and a power unit (14) disposed behind the body frame (11) via a link member (38) so as to be swingable, and an exhaust pipe (51) connected to the power unit (14). And a silencer (52) connected to the exhaust pipe (51), and a catalytic converter (54) provided in the exhaust pipe (51), wherein the catalytic converter ( 4), the catalytic converter (54) is arranged such that the longitudinal direction thereof is arranged in the vehicle width direction and the whole of the catalytic converter (54) overlaps the fuel tank (56) in a front view of the vehicle. It is arranged behind the fuel tank (56).

The second feature is that the link member (38) is disposed above the cylinder part (44) of the engine (41) constituting the power unit (14), and the catalytic converter (54) It is good also as a structure arrange | positioned in front of the crankcase (43) of the said engine (41) while arrange | positioning under (44).
The third feature is that an under cover (64, 124) is disposed below the fuel tank (56) and between each of the fuel tank (56) and the catalytic converter (54), and the under cover is further provided. (64, 124) may be arranged in front of the catalytic converter (54).

A fourth feature is that an oxygen sensor (108) is arranged in the middle of the exhaust pipe (51), and the oxygen sensor (108) is arranged with its longitudinal direction directed in the vehicle width direction, and in bottom view. Further, it may be configured to be disposed above the catalytic converter (54) so as to overlap at least a part of the catalytic converter (54).
A fifth feature is that the exhaust pipe (51) is fastened to the power unit (14) by a fastening member (91) and the fastening member (91) is turned to the under cover (64, 124). Cutouts (64k, 124k) are formed, and the cutouts (64k, 124k) are formed so as to overlap the fastening member (91) and not the catalytic converter (54) in bottom view. It is good also as a structure.

  According to the first feature of the present invention, since the catalytic converter does not protrude outward in the vehicle width direction from the fuel tank, the bank angle of the vehicle can be easily secured. Further, since the fuel tank is positioned in front of the catalytic converter, it is possible to make it difficult for the catalytic converter to hit the traveling wind and to easily activate the catalytic converter.

According to the second feature, since the catalytic converter is disposed in the space in front of the crankcase below the cylinder portion, the space can be used effectively and interference with other members can be prevented.
According to the third feature, the catalytic converter can be protected from external factors by the under cover, and at the same time, the appearance can be improved by covering the front of the catalytic converter.

According to the fourth feature, the oxygen sensor can be protected from below by the catalytic converter.
According to the fifth feature, by providing the notch, it is easy to protect the catalytic converter by bringing the under cover closer to the catalytic converter, and it is possible to easily attach and detach the exhaust apparatus when performing maintenance or replacement of the exhaust apparatus. Thus, workability can be improved.

FIG. 1 is a right side view (first embodiment) of a motorcycle including an exhaust structure according to the present invention. FIG. 2 is a bottom view showing the motorcycle. FIG. 3 is a perspective view showing the exhaust pipe, the catalytic converter, and the surroundings thereof. FIG. 4 is an enlarged view of a main part of FIG. FIG. 5 is a right side view showing the power unit, fuel tank, and surroundings of the motorcycle. FIG. 6 is an enlarged view of a main part of FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. FIG. 8 is a right side view of a main part of a motorcycle having an exhaust structure according to the present invention (second embodiment). FIG. 9 is a bottom view showing the catalytic converter, the under cover, and the periphery thereof.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the description, descriptions of directions such as front and rear, right and left and up and down are the same as directions relative to the vehicle body unless otherwise specified. Further, in each figure, the symbol FR indicates the front of the vehicle body, the symbol UP indicates the upper side of the vehicle body, and the symbol LH indicates the left side of the vehicle body.
<First Embodiment>
FIG. 1 is a right side view of a motorcycle 10 having an exhaust structure according to the present invention (first embodiment).
The motorcycle 10 includes a front wheel 13 supported by a front end of a vehicle body frame 11 via a front fork 12 and a rear wheel 16 supported by a lower portion of the vehicle body frame 11 via a power unit 14 so as to swing up and down. And a seat 17 on which the driver is seated.
The vehicle body frame 11 includes a front frame 21 disposed on the front side, a rear frame 22 attached to a rear end portion of the front frame 21, and a seat frame 23 attached to an upper portion of the rear frame 22.
The seat frame 23 supports the seat 17 at an upper portion thereof.

The front frame 21 includes a head pipe 25 that rotatably supports the front fork 12, a down frame 26 that extends downward and obliquely rearward from the head pipe 25, and a pair of left and right lower frames 27 that extend rearward from the down frame 26. .
The rear frame 22 is fixed to a pair of left and right rear pipes 31, a front cross pipe 32 and a rear cross pipe 33 provided on the left and right rear pipes 31 so as to extend in the vehicle width direction, and front ends of the left and right rear pipes 31, respectively. Support frame 34.
The support frame 34 is a member to which the rear end portions of the left and right lower frames 27 of the front frame 21 are connected.

The front fork 12 has a bar handle 36 attached to the upper end portion, and the front wheel 13 is supported on the lower end portion via an axle 37.
The power unit 14 includes an engine 41 that is swingably supported on the rear frame 22 via a link member 38, and a continuously variable transmission 42 that is provided integrally with the engine 41 so as to extend rearward.
The engine 41 includes a crankcase 43 and a cylinder portion 44 that extends forward and forward from the crankcase 43. The cylinder portion 44 includes a cylinder head 46, and an exhaust device 47 is connected to the lower portion of the cylinder head 46. The exhaust device 47 includes an exhaust pipe 51 connected to the cylinder head 46, a catalytic converter 54 provided in the middle of the exhaust pipe 51, and a silencer 52 connected to the rear end portion of the exhaust pipe 51. .
The catalytic converter 54 is provided in the middle of the exhaust pipe 51 so as to extend in the vehicle width direction, and purifies the exhaust with the catalyst. A fuel tank 56 (see FIG. 5) is attached to the left and right lower frames 27 in front of the exhaust pipe 51.
In the continuously variable transmission 42, the rear wheel 16 is supported at the rear end portion thereof via an axle 57.

A part of the vehicle body frame 11 described above is covered with a vehicle body cover 60. The vehicle body cover 60 includes a front cover 61, a front inner cover 62, a floor step 63, an under cover 64, and a rear cover 66.
The front cover 61 covers the upper part of the front fork 12 and the front of the head pipe 25. The front inner cover 62 is attached to the rear part of the front cover 61 and covers the upper part of the front fork 12, the head pipe 25, and the upper part of the down frame 26 from the rear.
The front cover 61 and the front inner cover 62 constitute a front case 68 in which a battery, a fuse box, and the like are accommodated.

The floor step 63 is attached to the upper part of the left and right lower frames 27, covers the lower part of the down frame 26 from the rear, and functions as a footrest part for the driver. The under cover 64 is attached to the left and right lower frames 27 and covers the front portion (portion where the catalytic converter 54 is located) of the exhaust pipe 51 from the front and the bottom, and covers the fuel tank 56 from the bottom. The rear cover 66 is attached to the rear frame 22 and covers the power unit 14 and the rear wheel 16 from above.
The front wheel 13 is covered with a front fender 71 from above. The rear wheel 16 is covered with a rear fender 72 from above.
A main stand 74 is disposed below the crankcase 43. The silencer 52 is covered with a heat shield plate 76 at the upper side and the upper side.

FIG. 2 is a bottom view showing the motorcycle 10.
The left and right lower frames 27, 27 of the front frame 21 extend from the down frame 26 to the left and right sides, are curved backward, and further extend in the front-rear direction.
The left and right lower frames 27, 27 are integrally connected at their rear portions with a cross member 81, and an under cover 64 is attached to the left and right lower frames 27, 27 so as to straddle the cross member 81 in the front-rear direction.
The exhaust pipe 51 extends from the cylinder portion 44 in the vehicle width direction (specifically, to the right) and further extends rearward and is connected to the silencer 52. A portion of the exhaust pipe 51 extending in the vehicle width direction is covered with a rear end portion 64 a of the under cover 64 at the front and lower sides thereof. A catalytic converter 54 is provided at a portion of the exhaust pipe 51 that extends in the vehicle width direction. A rear end portion 64 a of the under cover 64 is disposed in front of and below the catalytic converter 54.

A main stand 74 is fixed to the lower surface of the crankcase 43 of the engine 41 via a lower plate 93. Further, a rear wheel 16 is disposed behind the engine 41. A continuously variable transmission 42 is disposed on one side (specifically, the left side) of the rear wheel 16, and a silencer 52 is disposed on the other side (specifically, the right side) of the rear wheel 16.
The fuel tank 56 includes a tank main body (a portion indicated by a broken line) 56h that stores fuel, and a flange 56f (see FIG. 5) that protrudes from the tank main body 56h to both sides. The flange 56f is fixed to the left and right lower frames 27, 27, and the tank body 56h is disposed between the left and right lower frames 27, 27.

FIG. 3 is a perspective view showing the exhaust pipe 51, the catalytic converter 54, and the periphery thereof, as viewed from obliquely below the left side of the vehicle body.
The cylinder portion 44 of the engine 41 includes a cylinder block 83 provided so as to protrude forward from the crankcase 43, and a cylinder head 46 attached to the front end portion of the cylinder block 83 via a head gasket (not shown). Prepare.
The exhaust pipe 51 includes a front exhaust pipe 85 connected to the lower surface of the cylinder head 46 and a rear exhaust pipe 86 connected to the rear end portion of the catalytic converter 54.

The front exhaust pipe 85 includes an upstream pipe 87 and a downstream pipe 88. The upstream pipe 87 extends downward from the cylinder head 46 and is curved to extend sideward (specifically, the right side). The downstream pipe 88 extends from the end of the catalytic converter 54 connected to the end of the upstream pipe 87 to the side (specifically, the right side) and is curved and extends rearward.
As described above, the catalytic converter 54 is provided between the upstream pipe 87 and the downstream pipe 88, that is, in the middle of the front exhaust pipe 85. The catalytic converter 54 is disposed so that both ends thereof are connected to the upstream pipe 87 and the downstream pipe 88 and extend in the vehicle width direction.

  The upstream pipe 87 includes a flange 87a fastened to connect to the cylinder head 46 at the upstream end, and the diameter gradually increases from the flange 87a toward the downstream. The downstream pipe 88 gradually decreases in diameter as it goes downstream, and the downstream end is connected to the rear exhaust pipe 86. That is, the end portions of the upstream pipe 87 and the downstream pipe 88 connected to the catalytic converter 54 have the largest diameter, and have an outer diameter substantially the same as the outer diameter of the catalytic converter 54. The flange 87a is applied to the mounting surface of the cylinder head 46 and a pair of stud bolts (not shown) protruding from the mounting surface of the cylinder head 46 are penetrated, and a nut 91 is screwed to the tip of each stud bolt. . As a result, the exhaust device 47 is fastened to the cylinder head 46.

A lower plate 93 is attached to the lower part of the crankcase 43, and a main stand 74 (see FIG. 2) is attached to the lower plate 93.
The cross member 81 of the front frame 21 is integrally formed with left and right side walls 81a and 81a extending downward from the left and right lower frames 27 and a bottom wall 81b connecting the left and right side walls 81a and 81a.
The rear end portion 64a of the under cover 64 extends in the front-rear direction inside the cross member 81, and further extends from the front of the front exhaust pipe 85 to the lower side. The rear end portion 64a is formed with a notch 64k through which a tool 97 for turning one nut 91 is passed so as to extend in the front-rear direction and to be opened at the rear.

By the notch 64k, the rear end portion 64a is divided into a left end portion 64m located below the upstream pipe 87 and a right end portion 64n located below the catalytic converter 54. The right end portion 64n protrudes rearward from the left end portion 64m and covers the catalytic converter 54 from the front and the bottom.
The notch 64k may be an air passage that discharges air around the catalytic converter 54 having a high temperature together with the traveling wind or supplies the traveling wind to the catalytic converter 54. Therefore, the catalytic converter 54 can be appropriately cooled. Furthermore, the notch 64k may also serve as a drainage portion that prevents rainwater from accumulating at the rear end portion 64a.
By forming the rear end portion 64a of the under cover 64 in this way, the catalytic converter 54 can be covered from the front and the lower side, and the catalytic converter 54 can be protected. Further, the catalytic converter 54 is hardly exposed to the outside by the rear end portion 64a of the under cover 64, and the appearance can be improved.

FIG. 4 is an enlarged view of a main part of FIG.
The catalytic converter 54 is composed of a cylindrical carrier carrying a catalyst and an outer cylinder 54A into which the carrier is inserted. The outer cylinder 54A is connected to an upstream pipe 87 (see FIG. 3) and a downstream pipe 88. Yes. The carrier has innumerable pores and gaps through which exhaust passes, and a catalyst substance made of metal or the like is carried on the inner surfaces of the pores and gaps.
The radiator 101 is directly attached to the side wall of the crankcase 43 of the engine 41, or the radiator 101 is attached via an intermediate member, and the outer surface of the radiator 101 is covered with the radiator cover 103. A rear exhaust pipe 86 is arranged below the radiator 101 and the radiator cover 103 so as to extend in the front-rear direction.

  The radiator 101 is provided with an upper tank and a lower tank capable of storing cooling water at an upper part and a lower part thereof, and the upper tank and the lower tank are connected by a radiator core. The radiator core includes a plurality of cooling water flow pipes through which cooling water can flow between the upper tank and the lower tank, and cooling fins provided across adjacent cooling water flow pipes, and cooling through the cooling water flow pipes The cooling water is cooled by dissipating heat from the water through the cooling fins.

The upper tank of the radiator 101 communicates with a water jacket formed in the cylinder block 83 via a cooling water pipe. A thermostat (not shown) is connected to the lower tank of the radiator 101 via a first radiator hose 104. The thermostat is connected to a water jacket and a water pump in the cylinder head 46 via piping (not shown).
The thermostat switches the cooling water flow path between a flow path for flowing cooling water in the radiator 101 and a flow path for not flowing cooling water in the radiator 101 according to the cooling water temperature.
A water pump is connected to the lower part of the cylinder block 83 via a second radiator hose 106.

  A cross member 81 of the front frame 21, a lower end portion 31 a of the rear pipe 31 of the rear frame 22, and a rear end portion 64 a of the under cover 64 are disposed in front of the catalytic converter 54 in a side view. In addition, a crankcase 43 and a lower plate 93 of the engine 41 are disposed behind the catalytic converter 54 in a side view. Further, the cylinder portion 44 (specifically, the cylinder head 46), the first radiator hose 104, and the second radiator hose 106 are disposed above the catalytic converter 54 in a side view. Further, a rear end portion 64a of the under cover 64 is disposed below the catalytic converter 54 in a side view. Thus, since the front, back, upper, and lower sides of the catalytic converter 54 are covered, the catalytic converter 54 can be effectively protected.

A space 95 that can be formed in front of the crankcase 43 and below the cylinder portion 44 is a space formed behind the cross member 81 of the front frame 21, the lower end portion 31 a of the rear frame 22, and the rear end portion 64 a of the under cover 64. It is. By arranging the catalytic converter 54 so as to extend in the vehicle width direction, the space 95 can be effectively utilized.
As described above, by disposing the catalytic converter 54 below the cylinder portion 44 and in front of the crankcase 43 and the lower plate 93, the space surrounded by the cylinder portion 44 and the crankcase 43 and the lower plate 93 direction. 95 can be used effectively.

FIG. 5 is a right side view showing the power unit 14, the fuel tank 56 and their surroundings of the motorcycle 10, and the front frame 21 (see FIG. 1) is omitted.
The lower end 54b of the catalytic converter 54 is at the same height as the lower end 56b of the lower surface 56a of the fuel tank 56 or above the lower end 56b in an empty state where no occupant is in the vehicle and in a state where the driver is in the vehicle. Is arranged. Reference numeral 107 denotes a horizontal line extending from the lower end 56 b of the fuel tank 56.
By setting the height of the catalytic converter 54 in this way, the ground height of the catalytic converter 54 can be increased, and the catalytic converter 54 can be protected from protrusions and flying stones from the ground.

One end 104a of the first radiator hose 104 is connected to the lower tank of the radiator 101, and the other end 104b is connected to a thermostat. The thermostat is connected to the water pump and communicates with the water pump of the cylinder head 46.
The second radiator hose 106 has one end 106 a connected to the water pump and the other end 106 b communicating with the water jacket of the cylinder block 83. The water jacket of the cylinder block 83 and the water jacket of the cylinder head 46 communicate with each other.

Next, the flow of the cooling water around the radiator 101 described above will be described.
During normal operation after the engine 41 is warmed up, the cooling water discharged from the water pump flows into the water jacket of the cylinder block 83 through the second radiator hose 106, and further into the water jacket in the cylinder head 46. Flow into. Then, it further flows into the upper tank of the radiator and flows from the upper tank through the radiator core into the lower tank. When the cooling water flows through the radiator core, heat of the cooling water is released to the outside, and the cooling water temperature decreases.
Further, the cooling water passes from the lower tank through the first radiator hose 104 into the thermostat as indicated by an arrow. In this case, since the thermostat is switched to the flow path to the water pump, the cooling water flows from the thermostat to the water pump and repeats the above circulation.

  Further, during the warm-up operation immediately after the engine 41 is started, the cooling water discharged from the water pump flows into the water jacket of the cylinder block 83 through the second radiator hose 106 as indicated by an arrow. Further, the cooling water flows into a water jacket in the cylinder head 46. Then, by switching the flow path by the thermostat, the cooling water flows from the water jacket in the cylinder head 46 through a pipe (not shown) to the thermostat, and further from the thermostat to the water pump to repeat the above circulation. Therefore, the cooling water does not flow into the radiator 101 and is not cooled. Therefore, the coolant temperature is likely to rise, and warm-up is promoted.

As shown in FIGS. 4 and 5, the link member 38 is disposed above the cylinder portion 44 of the engine 41 constituting the power unit 14. The catalytic converter 54 is disposed below the cylinder portion 44 and is disposed in front of the crankcase 43 of the engine 41.
According to this configuration, since the catalytic converter 54 is disposed in the space 95 in front of the crankcase 43 below the cylinder portion 44, the space 95 can be used effectively and interference with other members can be prevented. Further, by disposing the catalytic converter 54 in the space 95 so as to extend in the vehicle width direction, the space 95 can be used more effectively, and the catalytic converter 54 can be compactly disposed in the space 95.

FIG. 6 is an enlarged view of a main part of FIG.
Pull a vehicle front-rear center line (that is, a center line passing through the center of the width in the vehicle width direction of the front wheel 13 (see FIG. 2) and the rear wheel 16) 110 that extends back and forth through the center of the motorcycle 10 in the vehicle width direction. The connection portion 46A of the cylinder head 46 with the exhaust pipe 51 is mostly disposed on one side (specifically, on the left side) of the vehicle body longitudinal center line 110. Further, the catalytic converter 54 is disposed on the other side (specifically, on the right side) of the vehicle body longitudinal center line 110. Further, the end 54 c of the catalytic converter 54 on the outer side in the vehicle width direction is located on the inner side in the vehicle width direction than the one side surface 56 c of the tank body 56 h of the fuel tank 56.
Thus, by disposing the catalytic converter 54 between the vehicle body longitudinal centerline 110 and the one side surface 56c of the fuel tank 56, the amount of protrusion of the front exhaust pipe 85 in the vehicle width direction side is reduced. And the bank angle of the vehicle can be secured. Further, the catalytic converter 54 can be compactly disposed in the space 95, and further, a portion of the space 95 where the catalytic converter 54 is not disposed can be utilized as a space for disposing other components.

A rear end portion 64a of the under cover 64, specifically, a right end portion 64n of the rear end portion 64a covers the entire catalytic converter 54 from below in a bottom view. Therefore, the catalytic converter 54 can be protected more reliably.
The notch 64k formed in the rear end portion 64a of the under cover 64 is formed at a position overlapping with one nut 91 of the pair of nuts 91, 91 in a bottom view. Accordingly, when the exhaust device 47 is attached to and detached from the engine 41, when the one nut 91 is rotated by the tool 97, the tool 97 can be hung on the nut 91 through the notch 64k, thereby improving workability. it can.

Further, the clearance in the front-rear direction between the crankcase 43 and the rear surface 64b (see FIG. 5) of the rear end portion 64a of the under cover 64 in the space 95 is larger than the outer diameter of the catalytic converter 54. Therefore, as long as the catalytic converter 54 does not interfere with the crankcase 43 and the under cover 64, the outer diameter of the catalytic converter 54 can be increased, and the purification performance of the catalytic converter 54 can be enhanced by increasing the amount of catalyst.
Further, the cross sectional shape of the catalytic converter 54 is an ellipse or an ellipse whose major axis is horizontal or substantially horizontal, so that the volume of the catalytic converter 54 is the same as that of the catalytic converter 54 whose circular cross section is circular, and the minimum ground clearance of the catalytic converter 54 is increased. Can be high. Thereby, the catalytic converter 54 can be more advantageously protected from protrusions, stepping stones, and the like from the ground.

As shown in FIGS. 5 and 6, an under cover 64 is disposed below the fuel tank 56 and between each of the fuel tank 56 and the catalytic converter 54. Further, the under cover 64 has a rear end 64a at the rear end 64a. It is arranged in front of and below the converter 54.
According to this configuration, the catalytic converter 54 can be protected from external factors by the under cover 64, and at the same time, the appearance can be improved by covering the front of the catalytic converter 54. Further, the under cover 64 makes it difficult for the traveling wind to hit the catalytic converter 54, and activation of the catalyst in the catalytic converter 54 can be promoted.

7 is a cross-sectional view taken along line VII-VII in FIG.
The left and right lower frames 27, 27 of the front frame 21 include a frame groove 27a formed on the upper surface so as to extend in the front-rear direction, and an outer flange portion 27b extending outward in the vehicle width direction from the upper edge of the outer surface.
The rear frame 22 includes a rear pipe 31 inclined downward and a support frame 34 attached to the upper portion of the rear pipe 31. The rear pipe 31 is a round pipe, and the support frame 34 is a member having a cross-sectional channel shape including a bottom wall and a pair of side walls raised from both edges of the bottom wall. The rear ends of the left and right lower frames 27, 27 are fastened to the left and right support frames 34, 34 with bolts and nuts, respectively.

The under cover 64 includes a center cover part 64c having a cup-shaped cross section provided at the center part, and mounting flange parts 64d and 64d extending from the upper part of the center cover part 64c to both sides.
The center cover portion 64c includes a bottom wall 64e forming a bottom portion and a pair of left and right side walls 64f and 64f raised from both ends of the bottom wall 64e. The mounting flange portion 64d includes an inner flat portion 64g extending outward in the vehicle width direction from the upper edge of the side wall 64f, a lower protruding portion 64h protruding downward from the outer edge of the inner flat portion 64g, and an upper edge of the outer surface of the lower protruding portion 64h. Is formed integrally with an outer flat portion 64j extending outward in the vehicle width direction.

The under cover 64 is attached in a state in which the downward projecting portions 64 h and 64 h of the left and right attachment flange portions 64 d and 64 d are inserted into the frame grooves 27 a of the lower frame 27 of the front frame 21. The bottom wall 64 e of the under cover 64 is located above the cross member 81 of the front frame 21.
A floor step 63 is supported on the mounting flange portions 64 d and 64 d of the under cover 64. Specifically, the floor step 63 is integrally formed with a plurality of columnar portions 63a projecting downward on the lower surface thereof, and the lower ends of the columnar portions 63a are mounting flange portions 64d and 64d of the under cover 64 (specifically, the outer flat portion 64j). , 64j). Then, screws that penetrate the outer flange portions 27b and 27b and the outer flat portions 64j and 64j of the front frame 21 are screwed into the columnar portion 63a from below. That is, the floor step 63 is supported on the front frame 21 via the under cover 64.

When a vehicle body vertical center line (center line extending in the vertical direction through the vehicle longitudinal center line 110 (see FIG. 6)) 111 extending in the vertical direction through the vehicle width direction center of the vehicle body is drawn, the catalytic converter 54 is It is arranged on one side (specifically, on the right side) of the vehicle body vertical center line 111. The catalytic converter 54 is disposed horizontally or substantially horizontally. Thereby, the minimum ground clearance of the catalytic converter 54 can be increased.
The upstream pipe 87 of the front exhaust pipe 85 is attached with an oxygen sensor (O ₂ sensor) 108 that detects the oxygen concentration in the exhaust so as to extend in the vehicle width direction on the outer peripheral surface of the front exhaust pipe 85 on the side where the catalytic converter 54 is located. It has been. In this way, the oxygen sensor 108 is covered from below by the upstream pipe 87 and the catalytic converter 54 extending from the lower surface of the cylinder head 46 so as to bend downward and to the right, so that the oxygen sensor 108 is protected from stepping stones and the like. Can do.
The catalytic converter 54 is entirely disposed inside the contours of the front frame 21, the fuel tank 56, and the under cover 64 in a front view. As a result, the catalytic converter 54 can be protected from external factors from the front of the vehicle (for example, an object that is rolling on the ground, an object that protrudes from the ground, or an object that is scattered from the front of the vehicle).

As shown in FIGS. 1, 5, and 7, the motorcycle 10 as a saddle-ride type vehicle includes a body frame 11, a seat 17 supported by the body frame 11, and the body frame 11 in front of the seat 17. And a floor step 63 as a footrest provided in the lower part.
The motorcycle 10 is disposed below the floor step 63, and is disposed behind the floor step 63 and the fuel tank 56 so as to be swingably supported by the vehicle body frame 11 via a link member 38. Power unit 14. The motorcycle 10 further includes an exhaust pipe 51 connected to the power unit 14, a silencer 52 connected to the exhaust pipe 51, and a catalytic converter 54 provided in the exhaust pipe 51.
The catalytic converter 54 is disposed behind the fuel tank 56 so that the longitudinal direction of the catalytic converter 54 is oriented in the vehicle width direction and the entire catalytic converter 54 overlaps the fuel tank 56 when viewed from the front of the vehicle. The

  According to this configuration, since the catalytic converter 54 does not protrude outward in the vehicle width direction from the fuel tank 56, the bank angle of the motorcycle 10 can be easily secured. Further, since the fuel tank 56 is located in front of the catalytic converter 54, it is possible to make it difficult for the traveling air to hit the catalytic converter 54 and to make the catalytic converter 54 easy to activate. Furthermore, by disposing the entire catalytic converter 54 behind the fuel tank 56, the catalytic converter 54 is not exposed from the fuel tank 56, so that the catalytic converter 54 can be protected from external factors by the fuel tank 56.

6 and 7, the oxygen sensor 108 is arranged in the middle of the exhaust pipe 51, specifically, the upstream pipe 87 attached to the cylinder head 46, and the longitudinal direction of the oxygen sensor 108 is the vehicle width. Arranged in the direction. Further, it is disposed above the catalytic converter 54 so as to overlap the upstream pipe 87 and at least a part of the catalytic converter 54 in a bottom view.
According to this configuration, the oxygen sensor 108 can be protected by being covered with the catalytic converter 54 and the upstream pipe 87 from below.

Second Embodiment
FIG. 8 is a right side view of a main part of a motorcycle 120 having an exhaust structure according to the present invention (second embodiment). The same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
An under cover 124 is disposed in front of the catalytic converter 54 so as to cover the lower side of the fuel tank 56 (see FIG. 5).
The under cover 124 differs from the under cover 64 (see FIGS. 4 and 5) of the first embodiment only in the rear end portion 124a.
That is, the rear end portion 124a of the under cover 124 is disposed in front of the catalytic converter 54 and covers a part of the front side of the catalytic converter 54 from below. The catalytic converter 54 is located above the lower end 124b of the rear end portion 124a. Thus, by providing the rear end portion 124a of the under cover 124, the catalytic converter 54 can be protected from the front and the lower side by the rear end portion 124a of the under cover 124.

FIG. 9 is a bottom view showing the catalytic converter 54, the under cover 124, and the periphery thereof.
The rear end portion 124a of the under cover 124 covers the front portion of the catalytic converter 54 from below. A notch 124k is formed at the center in the vehicle width direction of the rear end portion 124a so as to overlap with one of the pair of nuts 91, 91 in a bottom view.
The notch 124k is a part through which the tool 97 used when turning the nut 91 is passed, and is formed so as to open to the rear of the vehicle.
Further, the notch 124k does not overlap with the catalytic converter 54 in a bottom view, and the notch 124k is offset in the vehicle width direction (specifically, the left direction) with respect to the catalytic converter 54. Therefore, it is possible to prevent a stepping stone or the like from hitting the catalytic converter 54 through the notch 124k from the front of the vehicle.

Thus, the front exhaust pipe 85 is fastened to the cylinder head 46 of the engine 41 by the nut 91 as a fastening member, and the notch 124k through which the tool 97 for turning the nut 91 is passed is formed in the under cover 124. The notch 124k is formed so as to overlap the nut 91 and not to overlap the catalytic converter 54 when viewed from the bottom.
By providing the notch 124k, when the maintenance or replacement of the exhaust device 47 (see FIG. 1) is performed while the under cover 124 is brought close to the catalytic converter 54, the under cover 124 or the like can be removed without removing the under cover 124 or the like. It can be easily attached and detached. Thereby, workability | operativity can be improved, making it easy to protect the catalytic converter 54. FIG.

The above-described embodiment is merely an aspect of the present invention, and can be arbitrarily modified and applied without departing from the gist of the present invention.
For example, in the above embodiment, as shown in FIG. 6, the catalytic converter 54 is arranged so as to extend in the vehicle width direction. However, if the catalytic converter 54 is arranged in the space 95, the catalytic converter 54 is arranged in the vehicle width direction. It may be tilted against. Further, as shown in FIG. 7, the catalytic converter 54 is arranged horizontally or substantially horizontally. However, when the entire catalytic converter 54 overlaps the fuel tank 56 in the front view of the vehicle, the catalytic converter 54 is set horizontally. Can be tilted greatly.
The present invention is not limited to the case where the present invention is applied to the motorcycles 10 and 120 which are saddle riding type vehicles, but can be applied to saddle riding type vehicles other than the motorcycles 10 and 120. The saddle-ride type vehicle includes all vehicles that ride on the vehicle body, and includes not only motorcycles (including bicycles with motors) but also three-wheeled vehicles and four-wheeled vehicles classified as ATVs (rough terrain vehicles). It is a vehicle including.

10,120 Motorcycles (saddle-ride type vehicles)
DESCRIPTION OF SYMBOLS 11 Body frame 14 Power unit 17 Seat 38 Link member 41 Engine 43 Crankcase 51 Exhaust pipe 52 Silencer 54 Catalytic converter 56 Fuel tank 63 Floor step (footrest part)
64,124 Under cover 64k, 124k Notch 108 Oxygen sensor 110 Front and rear centerline of vehicle body (vehicle centerline)
111 Body vertical center line (vehicle center line)

Claims (5)

A body frame (11), a seat (17) supported by the body frame (11), a footrest portion (63) provided in front of the seat (17) and below the body frame (11), A fuel tank (56) disposed below the footrest (63) and a link member (56) disposed behind the footrest (63) and the fuel tank (56) to the vehicle body frame (11). 38), a power unit (14) supported so as to be swingable, an exhaust pipe (51) connected to the power unit (14), and a silencer (52) connected to the exhaust pipe (51). And an exhaust structure of a saddle-ride type vehicle comprising a catalytic converter (54) provided in the exhaust pipe (51),
The catalytic converter (54) is arranged such that its longitudinal direction is directed in the vehicle width direction, and the catalytic converter (54) is overlapped with the fuel tank (56) when viewed from the front of the vehicle. An exhaust structure for a saddle-ride type vehicle, wherein (54) is arranged behind the fuel tank (56).   The link member (38) is disposed above the cylinder portion (44) of the engine (41) constituting the power unit (14), and the catalytic converter (54) is disposed below the cylinder portion (44). The exhaust structure for a saddle-ride type vehicle according to claim 1, wherein the exhaust structure is disposed in front of a crankcase (43) of the engine (41).   An under cover (64, 124) is disposed below the fuel tank (56) and between each of the fuel tank (56) and the catalytic converter (54). Further, the under cover (64, 124) The exhaust structure of a saddle-ride type vehicle according to claim 1 or 2, wherein the exhaust structure is disposed in front of the catalytic converter (54).   An oxygen sensor (108) is disposed in the middle of the exhaust pipe (51), and the oxygen sensor (108) is disposed such that its longitudinal direction is in the vehicle width direction, and when viewed from the bottom, the catalytic converter (54). The exhaust structure of the saddle-ride type vehicle according to any one of claims 1 to 3, wherein the exhaust structure is disposed above the catalytic converter (54) so as to overlap at least a part of the exhaust structure.   The exhaust pipe (51) is fastened to the power unit (14) by a fastening member (91), and a notch (64k) through which a tool (97) for turning the fastening member (91) passes is passed through the under cover (64, 124). 124k), and the cutout (64k, 124k) is formed so as to overlap the fastening member (91) and not the catalytic converter (54) when viewed from the bottom. Item 5. Exhaust structure for saddle riding type vehicle according to Item 3 or 4.

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