JP4499640B2 - Low floor type motorcycle - Google Patents

Description

  The present invention relates to a low floor type motorcycle in which an exhaust pipe is extended from each cylinder of an engine, and these exhaust pipes are gathered at a gathering portion.

2. Description of the Related Art Conventionally, there is known a low-floor type motorcycle in which exhaust pipes are extended from each cylinder of an engine and these exhaust pipes are gathered at a collecting portion (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-99980 (FIG. 2)

  FIG. 2 of Patent Document 1 is a plan view of a motorcycle having a low floor type floor. The motorcycle 1 includes a horizontally opposed internal combustion engine 3 (hereinafter referred to as an engine 3). The left and right cylinders 4l and 4r are arranged in front of the left and right floors 2l and 2r, and the exhaust pipe 32r extends rearward from the cylinder 4r and the exhaust pipe 32l extends rearward from the cylinder 4l. The pipe 32l is configured to extend to the exhaust pipe 32r side and gather in the exhaust pipe 32r.

  However, since the exhaust pipe 32l extends rearward and then extends toward the exhaust pipe 32r so as to be gathered in the exhaust pipe 32r, for example, the rear fork 14 that swings up and down with the exhaust pipe 32l (hereinafter referred to as the exhaust pipe 32l). It is necessary to secure a sufficient space behind the engine 3 such as a sufficient clearance between the rear swing arm 14 and the rear swing arm 14.

  Further, since the exhaust pipes 32l and 32r are extended to the rear of the engine 3, the position of the gathering portion where the exhaust pipe 32l and the exhaust pipe 32r gather is limited to the rear of the engine 3. For this reason, the length of each exhaust pipe from each cylinder of the engine 3 to the collecting portion must be secured to a certain value or more, and when one is extended to the other side as in the prior art, There may be a limitation in adjusting the power performance between the cylinders, such as a difference in the length of the pipes.

  There is no need to provide a space for arranging an exhaust pipe behind the engine, and it is preferable to have a low floor type motorcycle that can flexibly adjust the power performance between the cylinders.

  It is an object of the present invention to provide a low-floor type motorcycle that does not require a space for disposing an exhaust pipe behind the engine and can flexibly adjust power performance between the cylinders. .

The invention according to claim 1 includes a step floor on which the occupant puts his / her foot on the left and right sides of the body frame, a cover member that covers the body frame between the step floors, and an engine below the cover member. In a low-floor type motorcycle in which exhaust pipes are extended from each cylinder and these exhaust pipes are combined to form one exhaust pipe at the gathering portion, the opening area is adjusted in the vicinity of the rear of the gathering portion according to the operating conditions. An exhaust valve is provided, and a plurality of exhaust pipes are bundled and extended along the lower part of the left and right sides of the step floor . The collecting part and the exhaust valve are arranged below the step floor, and each cylinder is separated from the cylinder part. The exhaust pipe is extended downward and the exhaust pipe connected to the cylinder closest to one side among the cylinders in the vehicle side view is more forward of the vehicle than the exhaust pipe connected to the cylinder far from one side. After that, each exhaust pipe is extended upward, and the exhaust pipe connected to the cylinder close to one side is extended above the exhaust pipe connected to the cylinder far from one side. After that, in the vehicle plan view, the exhaust pipe connected to the cylinder close to one side is extended to the outside in the vehicle width direction than the exhaust pipe connected to the cylinder far from one side. The vehicle body frame behind the engine is provided with a pivot shaft that supports the rear swing arm so that the rear swing arm can swing, and the longitudinal direction between the rear swing arm and the vehicle body frame is the height of the vehicle behind the pivot shaft. A rear cushion unit is provided to direct the direction .

In the invention according to claim 2 , the engine is a water-cooled engine, and the cooling water piping provided in the engine is on the other side opposite to the one side where the exhaust pipe is disposed below the step floor. It is characterized by arranging.

The invention according to claim 3 is characterized in that a cooling water pump is built in the engine, and this cooling water pump is arranged on the opposite side of the exhaust pipe with respect to the vehicle center line in plan view.

In the invention according to claim 1, since the plurality of exhaust pipes are bundled, the exhaust pipes can be concentrated and arranged on one of the left and right sides of the vehicle body frame. Since the exhaust pipe can be concentrated on the left and right sides of the vehicle body frame, the space around the engine can be saved.
Moreover, since the exhaust pipe is disposed below the step floor, the appearance of the motorcycle can be improved.

  In this way, the exhaust pipe can be concentrated on the left or right side of the body frame, so that the exhaust pipe space behind the engine can be used effectively without passing the exhaust pipe behind the engine. It becomes. Since the exhaust pipe space behind the engine can be used effectively, for example, the degree of freedom in vehicle design such as the arrangement of the rear swing arm can be increased.

Also, the set section, that is disposed below the step floor.
In a low-floor type motorcycle, the space below the step floor has a triangular cross-section formed by the side of the engine and the surface that secures the bank angle. Can be arranged. Since the degree of freedom of arrangement of the collecting portion increases, for example, the length of each exhaust pipe from each cylinder to the collecting portion can be freely set. If the length of the exhaust pipe to the collecting portion can be set freely, the power performance between the cylinders can be easily adjusted and the degree of design freedom can be increased.
Further, a collecting portion for collecting the exhaust pipes is arranged below the step floor, and an exhaust valve that constitutes a part of a control mechanism that adjusts the opening area according to the operating condition is provided in the vicinity of the collecting portion. By adjusting the position back and forth, the exhaust valve can be disposed in the vicinity of the collecting portion without increasing the width of the vehicle.

In the invention according to claim 2 , the exhaust pipe of the engine is arranged below the step floor on one side of the left and right, and the cooling water pipe provided in the engine is arranged below the step floor on the other side .
Since the cooling water pipe and the exhaust pipe are arranged below the left and right step floors, the exhaust pipe having a relatively high temperature is separated from the cooling water pipe, so that the cooling efficiency can be improved.

In the invention which concerns on Claim 3 , the cooling water pump of an engine is arrange | positioned on the opposite side to an exhaust pipe by planar view.
Since the cooling water pump and the exhaust pipe are arranged below the left and right step floors, the exhaust pipe can be sufficiently separated from the cooling water pump.

  When the cooling water pump is disposed below the same step floor with the cooling water pump, the length of the cooling water piping extending from the cooling water pump can be shortened, and the weight of the vehicle can be reduced.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. “Front”, “rear”, “left”, “right”, “upper”, and “lower” indicate directions viewed from the driver. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a right side sectional view of a low-floor type motorcycle according to the present invention. The motorcycle 10 includes a body frame 11, a head pipe 13 provided at the front end of the vehicle 12, and a body pipe 11. Upper members 16 and 16 (only reference numeral 16 on the front side) provided above the engine 14 and extending rearward from the head pipe 13 and seat rails 18 and 18 extending rearward and obliquely upward from the upper members 16 and 16 ( Only the front side reference numeral 18 is shown), the support frames 19 and 19 (only the front side reference numeral 19 are shown) for supporting these seat rails 18 and 18 from below, and the upper members 16 and 16 are branched. Same as down members 17 and 17 (only reference numeral 17 on the front side is shown) provided on the side of the cylinder block 23 of the engine 14 and extending downward. (Only the near side of the code 25.) From the top of the upper members 16 and 16 step floors 25, 25 extend rearwardly (only the front side reference numeral 26.) Floor brackets 26, 26 for placing a as a vehicle constructed out.

  A pivot shaft 28 is attached to the upper members 16, 16, a rear swing arm 31 is attached so as to be swingable up and down around the pivot shaft 28, and a rear cushion unit 32 is attached between the rear swing arm 31 and the vehicle body frame 11. .

  In the motorcycle 10, a front fork 35 is attached to the head pipe 13 so as to be steerable, a front wheel 36 is rotatably attached to the lower end of the front fork 35, a steering handle 37 is attached to the upper portion of the front fork 35, and the upper member 16 The engine 14 is disposed in a space between the rear member 17 and the down member 17, and a rear wheel 39 is rotatably attached to the rear end of the rear swing arm 31, and the engine 14 and the rear wheel 39 are driven to drive the rear wheel 39. The vehicle has a power transmission mechanism 42 including a drive shaft 41 interposed therebetween.

  That is, the motorcycle 10 includes a vehicle body frame 11, a rear swing arm 31 that is swingably attached to the vehicle body frame 11 via a pivot shaft 28, an engine 14 that is fixed to the vehicle body frame 11, and a drive shaft 41 from the engine 14. And a power transmission mechanism 42 that transmits a driving force to the rear wheel 39 via the rear wheel 39.

The main body of the engine 14 includes a crankcase 43 and a cylinder block 23 attached to the crankcase 43 so as to be tilted forward. The engine 14 is a water-cooled in-line three-cylinder engine, and includes a radiator portion 44 below the cylinder block 23 and behind the front wheel 36.
The cylinder block 23 includes a cylinder portion 45 having a cylindrical inner surface. The number of cylinder portions 45 is three.

The air cleaner unit 46 constituting a part of the intake system will be described.
The air cleaner unit 46 includes an air intake duct 47 provided in front of the head pipe 13, a first chamber 48 provided below the air intake duct 47, and a connection duct 50 disposed behind the first chamber 48. And a second chamber 49 provided. First, the air taken in by the air intake duct 47 is cleaned by an element (not shown) provided in the first chamber 48, then passed through the connection duct 50 and put into the second chamber 49, and finally, the second Cleaned air from the second chamber 49 is supplied to the engine 14.

  Thus, by arranging the air cleaner unit 46 in front of and behind the head pipe 13, a sufficient capacity can be secured and it can be arranged in the vicinity of the engine 14.

  Explaining the exhaust system, a first exhaust pipe 51, a second exhaust pipe 52, and a third exhaust pipe 53 are connected to a cylinder block 23 provided in the in-line three-cylinder engine 14, and these first to third exhaust pipes 51 to 53 are connected. The first to third exhaust pipes 51 to 53 are gathered by the gathering part 54 provided behind the exhaust pipes 51 to 53, and the silencer 55 is connected to the rear of the gathering part 54.

  The cover member 61 is a member that covers a part of the vehicle 12 and also serves as a cowl member. The cover member 61 includes a front cover member 62 that covers the front portion of the vehicle body frame 11 such as the head pipe 13, an intermediate cover member 63 that is provided behind the front cover member 62, and a rear portion of the intermediate cover member 63. And a rear cover member 64 covering the rear of the vehicle 12.

  Here, the intermediate cover member 63 is a member that includes a foot passage space 65 that allows an occupant to pass his / her foot when moving up and down and includes the engine 14 below. Therefore, the engine 14 is provided below the foot passage space 65 through which the occupant passes his / her foot when moving up and down.

  Step floors 25 and 25 (only the reference numeral 25 on the near side is shown) are members attached to floor brackets 26 and 26 that are a part of the body frame 11, and are footrests on which the occupants place their feet during traveling.

That is, the plurality of exhaust pipes 51 to 53 are bundled and arranged below the step floor 25, and the gathering portion 54 that bundles the exhaust pipes 51 to 53 is arranged below the step floor 25. To do.
An exhaust valve 67 capable of restricting the flow rate of exhaust gas is provided in the vicinity of the collecting portion 54. The exhaust valve 67 is one of the constituent members of the exhaust gas control device 70.

  The exhaust gas control device 70 includes an exhaust valve 67 that adjusts an opening area according to an operation state, operating wires 71 and 72 that open and close the exhaust valve 67, a servo motor 73 that drives these operating wires 71 and 72, The control unit 74 is configured to adjust the flow rate of the exhaust gas by controlling the servo motor 73. Details of the exhaust valve 67 will be described later.

  76 is a link mechanism interposed between the rear cushion unit 32 and the rear swing arm 31, 77 is a fuel tank, 78 is a fuel pump, 79 is a reservoir tank of the rear cushion unit 32, 81 is a front brake unit, and 82 is a universal joint. 83 is an occupant seat, 86 is a main stand, and 87 is a helmet stored in a storage space.

  FIG. 2 is a right side view for explaining the arrangement of elements around the engine of the low floor type motorcycle according to the present invention. The exhaust pipes 51 to 53 are bundled on the right side of the engine 14 and below the step floor 25. A collecting portion 54 is disposed, an exhaust valve 67 is disposed behind the collecting portion 54, and a silencer 55 is disposed behind the exhaust valve 67. The silencer 55 hangs the stay member 111 from the support frame 19 and is attached to the stay member 111 so as to be integrated with the vehicle body frame 11.

  The support frame 19 is provided with operating wires 71 and 72 from the exhaust valve 67, and a servo motor 73 and a controller 74 for driving the operating wires 71 and 72 are attached to the rear portion 19b.

FIG. 3 is a bottom view for explaining the arrangement of elements around the engine of the low-floor type motorcycle according to the present invention. A radiator portion 44 is arranged in front of the engine 14, and the space between the radiator portion 44 and the engine 14 is shown. The cooling water pipe 112 is connected. Reference numeral 113 denotes an output shaft of the engine 14, and 114 denotes a spring interposed between the main stand 86 and the vehicle body frame 11.
The power transmission mechanism is omitted.

  The bundled exhaust pipes 51 to 53 are disposed below the right step floor 25 and the collecting portion 54 is disposed below the right step floor 25, so that a sufficient space 115 is secured behind the engine 14. Can do. Therefore, conventionally, the interference between the exhaust pipes 51 to 53 and the rear swing arm 31 (see FIG. 1), which has been required when the exhaust pipes 51 to 53 are extended to the rear of the engine 14, is not considered. The exhaust pipe space behind the engine 14 can be utilized.

That is, the engine 14 is a water-cooled engine, and the bundled exhaust pipes 51 to 53 are disposed below the right step floor 25, and the cooling water pipe 112 provided in the engine 14 is disposed below the left step floor 25. It arrange | positions at the feature.
The bundled exhaust pipes 51 to 53 may be disposed below the left step floor 25 and the cooling water pipe 112 may be disposed below the right step floor 25.

That is, the exhaust pipes 51 to 53 of the engine 14 are arranged to be bundled below one of the left and right sides of the step floor 25, and the cooling water pipe 112 provided in the engine 14 is arranged below the other step floor 25.
Since it is necessary to avoid the temperature of the cooling water from rising, it is necessary to separate the exhaust pipes 51 to 53 from the cooling water pipe 112.
In the present invention, since the cooling water pipe 112 and the exhaust pipes 51 to 53 are arranged below the left and right step floors 26 and 26, the cooling water pipe 112 becomes the relatively high temperature exhaust pipes 51 to 53, Cooling efficiency can be increased.

A cooling water pump 116 is built in the engine 14, and the cooling water pump 116 is provided on the opposite side of the exhaust pipes 51 to 53 with respect to the vehicle center line 119 in a plan view.
Since it is necessary to avoid the temperature of the cooling water from rising, it is necessary to separate the exhaust pipes 51 to 53 from the cooling water pump 116.
In the present invention, since the cooling water pump 116 and the exhaust pipes 51 to 53 are arranged below the left and right step floors 25 and 25, the exhaust pipes 51 to 53 can be sufficiently separated from the cooling water pump 115.

  When the cooling water pipe 116 is arranged below the same step floor 25 in the cooling water pump 116, the length of the cooling water pipe 112 extending from the cooling water pump 116 can be shortened, and the weight of the vehicle can be reduced. .

  FIG. 4 is a left side view for explaining the arrangement of elements around the engine of the low-floor type motorcycle according to the present invention. The cooling water pump 116 is provided on the side surface of the crankcase 43 of the engine 14. The cooling water pipe 112 is extended forward and connected to the radiator section 44.

  FIG. 5 is a front view for explaining the element arrangement around the engine of the low-floor type motorcycle according to the present invention. The floor brackets 26 and 26 are front subpipes extending from the upper members 16 and 16 to the left and right and obliquely downward. 121, 121, main pipes 122, 122 extending obliquely downward and rearward from the front sub-pipes 121, 121, and a rear portion connecting the rear end portions of the main pipes 122, 122 and the rear portions of the upper members 16, 16 It consists of sub pipes 123 and 123. Then, the floors 124 and 124 are covered with the main pipes 122 and 122 to form step floors 25 and 25.

  The engine 14 is an in-line three-cylinder engine in which a cylinder portion tilts forward as shown in FIG. The engine 14 includes forwardly inclined cylinder portions 45 (... indicates a plurality. The same applies hereinafter), and an exhaust pipe is provided downward from each of the cylinder portions 45. After extending 51 to 53, these exhaust pipes 51 to 53 are bundled and extended to the right side of the engine 14.

Since the engine 14 includes the cylinder portions 45... And the exhaust pipes 51 to 53 are extended downward from the cylinder portions 45... For each cylinder, the center of gravity of the vehicle 12 can be lowered. .
Since the center of gravity of the vehicle 12 can be lowered, maneuverability can be improved.
Further, since the engine 14 bundles the exhaust pipes 51 to 53 and extends to the left or right side of the engine 14, the exhaust pipes 51 to 53 can be easily arranged on the side of the engine 14.

Returning to FIG. 1, the engine 14 includes the cylinder portion 45 that is inclined forward, so that the engine 14 can be disposed low. Since the engine 14 can be disposed low, the intermediate cover member 63 that is one of the cover members 61 can be disposed low, and a wide leg space 65 positioned above the intermediate cover member 63 is ensured. be able to.
In the present embodiment, the exhaust pipes 51 to 53 are bundled and extended to the right side of the engine 14. However, the exhaust pipes 51 to 53 may be bundled and extended to the left side of the engine 14.

  FIG. 6 is a perspective view for explaining the arrangement of elements around the engine of the low floor type motorcycle according to the present invention. A floor bracket 26 for attaching a step floor 25 (see FIG. 1) is extended to the right side of the vehicle 12, and this floor is shown. The exhaust pipes 51 to 53 and the collecting portion 54 are disposed below the bracket 26, and an exhaust valve 67 that adjusts the opening area according to the operating condition is provided in the vicinity of the collecting portion 54.

FIG. 7 is a cross-sectional view taken along line 7-7 in FIG.
The exhaust valve 67 includes a valve 131 that changes the flow rate of the exhaust gas in the collecting portion 54, a valve rod 132 that serves as an exhaust valve shaft to which the valve 131 is attached, a pulley 133 that rotates the valve rod 132, and the pulley 133. And an L-shaped stopper piece 134 that is attached to the valve stem 132, a stopper receiver 135 that restricts the opening / closing angle of the valve 131 by applying the stopper piece 134, the pulley 133, and the stopper piece. 134 and the case 136 for storing the stopper receiver 135, the lid 138 having the mounting portion 137 described above for covering the case 136, and the valve 136 is biased in the opening direction between the case 136 and the pulley 133. From a torsion spring 139 and a nut 142 fixed to be screwed into a male thread portion 141 formed at one end of the valve stem 132 That.

  In the figure, 144 is a bolt for fixing the valve 131 to the valve stem 132 via the seat plate 145, 146 is a bolt for fixing the case 136 to the stay 147 via the stopper receiver 135, and 148 is the case 136 via the stopper receiver 135. A bolt 149 for fixing the one end of the torsion spring 139 to the stay 147 and a stepped bolt 149 for directly fixing the lid 138 covering the case 136 to the stay.

  FIG. 8 is a plan view (partially cross-sectional view) of an exhaust valve provided in a low-floor type motorcycle according to the present invention. The exhaust valve 67 is inserted into the through holes 152 and 152 of the valve mounting portion 151 in addition to the valve rod 132. The end 132b is inserted, the valve 131 is attached to the other end 132b of the valve stem 132 with bolts 153 and 153 via the seat plate 153a, and the case bearing portion 155 of the case 136 is inserted from the end 132a of the valve stem 132 to mount the valve. By fixing the case 136 to the stay 147 (see FIG. 7) of the portion 151, the valve rod 132 can be rotatably supported by the bearing portion 156 and the case bearing portion 155.

  Returning to FIG. 1, an exhaust gas control device 70 having the exhaust valve 67 having such a configuration as an operating part is attached to the vehicle body frame 11, the servo motor 73 is moved based on a command from the control part 74, and the servo motor 73 is operated. The opening area of the exhaust valve 67 is adjusted via the wires 71 and 72.

Returning to FIG. 3, since the exhaust valve 67 is provided in the vicinity of the collecting portion 54, the exhaust valve 67 is provided in the vicinity of the collecting portion 54 without increasing the width of the vehicle 12 by adjusting the position of the collecting portion 54 back and forth. Can be arranged.
Note that the exhaust valve 67 may be omitted.

  FIG. 9 is a side view for explaining the power transmission mechanism provided in the low floor type motorcycle according to the present invention. The power transmission mechanism 42 is provided at the rear end portion of the rear swing arm 31 and on the outer side of the rear swing arm 31. The drive shaft 41 is extended from the output shaft 113 (see FIG. 4) of the engine 14 and the power of the drive shaft 41 is transmitted to the rear wheel 39. The drive shaft 41 is arranged around the shaft 39J of the rear wheel 39. A drive case 170 is provided that incorporates a transmission device that converts the direction of the drive force to be transmitted to the rear wheel 39.

The rear swing arm 31 is a curved frame that is convex upward.
Since the rear swing arm 31 is curved, the appearance of the rear swing arm 31 can be improved.

  A pivot shaft 28 is disposed above the drive shaft 41, and a rear swing arm 31 having a convex shape is extended rearward from the pivot shaft 28. A lower end of the rear cushion unit 32 is connected to the rear swing arm 31 via a link mechanism 76. The upper end of the rear cushion unit 32 was fixed to the body frame 11 side.

  That is, the power transmission mechanism 42 includes a drive case 170 that is provided at the rear end portion of the rear swing arm 31 and incorporates a transmission device that converts the direction of the drive force of the drive shaft 41 and transmits it to the rear wheel 39. The drive shaft 41 is disposed below the rear swing arm 31 and below the pivot shaft 28. Details of the transmission device will be described later.

10 is a cross-sectional view taken along line 10-10 of FIG. 9, and shows a cross section of the rear swing arm 31. FIG.
Since the cross-sectional shape of the rear swing arm 31 is not a rectangular cross-section that normally uses much, but a sun-shaped cross-section, the section modulus can be increased. Since the section modulus is increased, the bending rigidity of the rear swing arm 31 can be improved.
Note that the cross-sectional shape may not be a sun-shaped cross section. For example, an eye-shaped cross section may be used.

  FIG. 11 is a perspective view for explaining the power transmission mechanism provided in the low floor type motorcycle according to the present invention. The rear case 39 has a shaft 39J and a drive case 170 around the shaft 39J. The rear end 31b of the rear swing arm 31 is connected, the rear brake unit 157 is fixed in the axial direction, and a wheel speed sensor 158 for, for example, an ABS (Antilock Breaking System) is attached to a part of the rear brake unit 157. . Reference numeral 159 denotes a brake pipe.

FIG. 12 is a cross-sectional view illustrating a power transmission mechanism provided in a low floor type motorcycle according to the present invention.
(A) is an embodiment, and the power transmission mechanism 42 is composed of a drive shaft 170 and a drive case 170 that incorporates a transmission device 154 that converts the direction of the drive force of the drive shaft 41 and transmits the direction to the rear wheel 39. Here, the transmission device 154 includes a pair of final gear sets 161 that change the direction of the driving force, and the damper device 162 is interposed between the final gear set 161 and the shaft 39J of the rear wheel 39 to reduce a shock caused by torque fluctuation. A damper member 166 is provided.

  A detailed configuration will be described. The final gear set 161 includes a first final gear 163 and a second final gear 164. The first final gear 163 is attached to the rear end portion 41b of the drive shaft 41, and the first final gear 163 is attached. The second final gear 164 is meshed with the center of the rear wheel shaft 39J, and the second final gear 164 is rotatably arranged.

  The damper device 162 includes a damper member 166 and a damper holder 167. A damper member 166 is disposed on the rear surface 164b of the second final gear 164, and the damper member 166 is a disc-shaped damper holder 167 fixed to the shaft 39J of the rear wheel 39. And the damper member 166 is sandwiched between the rear surface 164b of the second final gear 164 and the surface 167a of the damper holder 167, so that the drive force of the drive shaft 41 is reduced while reducing the shock caused by torque fluctuation of the drive shaft 41. 39 is transmitted to the shaft 39J.

  The drive case 170 that covers the power transmission mechanism 42 covers the damper device 162 and the transmission device 154, and includes a damper case 174 and a differential case 173. Then, a drive chamber 171 that houses the damper device 162 and the transmission device 154 is formed inside the cases 173 and 174. The drive chamber 171 is filled with oil.

Reference numeral 172 denotes a shaft case, which is a member provided in front of the differential case 173 and covering the drive shaft 41.
176a to 176d are bearings, 177 is a rear disc brake plate, and 178 is a wheel of the rear wheel 39.

That is, a drive case 170 containing a transmission device 154 that converts the direction of the drive force of the drive shaft 41 and transmits it to the rear wheel 39 at the rear end 31b of the rear swing arm 31 is provided.
A damper device 162 is provided in the drive case 170 to reduce the impact applied to the rear wheel 39, and a damper member 166 is provided on the damper device 162 coaxially with the shaft 39J of the rear wheel 39.

(B) is a comparative example, and it demonstrates centering on a point greatly different from (a).
A drive case 170B that covers the transmission device 154B is provided at a substantially central portion of the shaft 39Jb of the rear wheel 39B, and a damper case 174B that covers the damper device 162B, and the drive shaft 41B in the axial direction of the rear wheel 39B of the damper case 174B. A lid member 181 that covers the damper case 174B provided on the side, and a differential case 173B that covers the transmission device 154 from the outside of the lid member 181.

The drive case 170B is composed of a damper case 174B, a lid member 181 and a differential case 173B. A damper chamber 182 containing a damper device 162B is formed inside the damper case 174B, and a transmission device 154B is built inside the differential case 173B. A differential chamber 183 is formed. The damper chamber 182 and the differential chamber 183 are each filled with oil.
Thus, the damper chamber 182 is provided on the wheel 178B side of the rear wheel 39B, and the differential chamber 183 is provided separately from the damper chamber 182.

The length of the shaft 39J of the rear wheel 39 is compared between (a) and (b).
In (a), since the drive chamber 171 including the transmission device 154 and the damper device 162 is provided inside the drive case 170, the length can be reduced by a length W as compared with the length of the shaft in (b).

  Since the transmission device 154 and the damper device 162 are built in the drive case 170, the transmission device 154 and the damper device 162 can be combined into one room. For example, it is not necessary to provide a partition wall that partitions between the transmission device 154 and the damper device 162.

When the damper member 162 is provided with the damper member 166 coaxially with the shaft 39J of the rear wheel 39, the length of the shaft 39J of the rear wheel 39 is eliminated if a partition wall for partitioning the transmission device 154 and the damper device 162 is not necessary. Can be shortened. If the length of the shaft 39J of the rear wheel 39 can be shortened, the width of the vehicle 12 can be suppressed.
In addition, the shaft case 172 can be made smaller than when the damper member 166 is provided on the shaft case 172 that covers the drive shaft 41.

Next, the operation of the low floor type motorcycle described above will be described.
Returning to FIG. 3, since the plurality of exhaust pipes 51 to 53 are bundled, the exhaust pipes 51 to 53 can be concentrated on the left and right sides of the vehicle body frame 11 without being dispersed. Since the exhaust pipes 51 to 53 can be concentrated on the left and right sides of the vehicle body frame 11, the space around the engine 14 can be saved.
Further, since the exhaust pipes 51 to 53 are disposed below the step floor 25, the appearance of a low floor type motorcycle can be enhanced.

  Thus, since the exhaust pipes 51 to 53 are bundled and arranged below the step floor 25, the exhaust pipes 51 to 53 can be concentrated on the left and right sides of the vehicle body frame 11 without being dispersed. Since the exhaust pipes 51 to 53 can be arranged concentrated on one side of the vehicle body frame 11, the exhaust pipe space behind the engine 14 (the space where the exhaust pipe is arranged) without passing the exhaust pipe behind the engine 14. 115) can be effectively utilized. Since the exhaust pipe space behind the engine 14 can be used effectively, for example, the degree of freedom in vehicle design such as the arrangement of the rear swing arm 31 (reference numeral 31 in FIG. 1) can be increased.

The gathering portion 54 is disposed below the step floor 25.
In the low floor type motorcycle 10, the step floors 25, 25 have a triangular space formed by a side surface of the engine 14 and a surface for securing a bank angle below the step floors 25, 25. The gathering portion 54 can be freely arranged below. Since the freedom degree of arrangement | positioning of the gathering part 54 goes up, the length of each exhaust pipe 51-53 from each cylinder to the gathering part 54 can be set freely, for example. If the exhaust pipe length to the collecting portion 54 can be set freely, the power performance between the cylinders can be easily adjusted and the degree of freedom in design can be increased.

  The present invention is suitable for motorcycles.

1 is a right side cross-sectional view of a low floor type motorcycle according to the present invention. FIG. 3 is a right side view for explaining the element arrangement around the engine of the low floor type motorcycle according to the present invention. FIG. 6 is a bottom view for explaining the element arrangement around the engine of the low floor type motorcycle according to the present invention. FIG. 3 is a left side view for explaining the element arrangement around the engine of the low floor type motorcycle according to the present invention. FIG. 2 is a front view for explaining the element arrangement around the engine of the low floor type motorcycle according to the present invention. FIG. 2 is a perspective view for explaining an element arrangement around the engine of the low floor type motorcycle according to the present invention. FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. 6. 1 is a plan view (partially sectional view) of an exhaust valve provided in a low floor type motorcycle according to the present invention. It is a side view explaining the power transmission mechanism with which the low floor type motorcycle according to the present invention is provided. FIG. 10 is a sectional view taken along line 10-10 in FIG. 9; It is a perspective view explaining the power transmission mechanism with which the low floor type motorcycle according to the present invention is provided. It is sectional drawing explaining the power transmission mechanism with which the low floor type motorcycle which concerns on this invention is equipped.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Motorcycle, 11 ... Body frame, 14 ... Engine, 25 ... Step floor, 45 ... Cylinder part, 51 ... 1st exhaust pipe, 52 ... 2nd exhaust pipe, 53 ... 3rd exhaust pipe, 54 ... Collecting part, 67 ... Exhaust valve, 61 ... Cover member, 112 ... Cooling water piping, 116 ... Cooling water pump, 119 ... Vehicle center line.

Claims (3)

Comprising a step floor (25) the occupant put feet on the left and right of the vehicle body frame (11), comprising a cover member (61) covering said body frame (11) during the step floor (25), the cover member ( an engine (14) below the 61), extends an exhaust pipe from each cylinder of the engine (14) (51, 52, 53), a set portion of these exhaust pipe (51, 52, 53) (54) In a low-floor type motorcycle that is combined to form one exhaust pipe ,
An exhaust valve (67) that adjusts the opening area according to the operating condition is provided in the vicinity of the rear of the collecting portion (54),
The plurality of exhaust pipes (51, 52, 53) are bundled and extended along the lower side of the left and right sides of the step floor (25) ,
The gathering part (54) and the exhaust valve (67) are arranged below the step floor (25) ,
An exhaust pipe (51, 52, 53) extends downward from the cylinder portion (45) for each cylinder and is connected to a cylinder close to the one side of the cylinders in a side view of the vehicle ( 53) extending forward of the vehicle from the exhaust pipe (51) connected to the cylinder far from the one side,
Thereafter, the exhaust pipes (51, 52, 53) are extended upward, and the exhaust pipe (53) connected to the cylinder close to the one side is connected to a cylinder far from the one side. Extending to the upper side of the exhaust pipe (51), then extending to the rear of the vehicle,
An exhaust pipe (53) connected to a cylinder close to the one side in a plan view of the vehicle is extended outward in the vehicle width direction from an exhaust pipe (51) connected to a cylinder far from the one side;
A pivot shaft (28) for swingably supporting the rear swing arm (31) is provided on the vehicle body frame (11) behind the engine (14). A low floor type characterized in that a rear cushion unit (32) is provided between the swing arm (31) and the vehicle body frame (11) so that the longitudinal direction is directed to the height direction of the vehicle . Motorcycle. The engine (14) is a water-cooled engine,
A cooling water pipe (112) provided in the engine (14) is provided below the step floor (25) on the other side opposite to one side where the exhaust pipes (51, 52, 53) are arranged. claim 1 Symbol placement of the low floor type motorcycle characterized by arrangement. A built-in cooling water pump (116) wherein the engine (14), the cooling water pump (116), the exhaust pipe to the vehicle center line in plan view of the vehicle lateral side opposite to the (51, 52, 53) claim 1 or claim 2 Symbol placement of the low floor type motorcycle characterized by arrangement.

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