JP2008247352A - Rear structure of motorcycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for restraining failures such as brake noise by reducing a change in the position relationship between a disc plate and a caliper. <P>SOLUTION: This motorcycle 10 comprises a rear swing arm 37 swingably supporting a rear wheel 39 at a rear part of a vehicle body frame 11, and a rear cushion unit 62 absorbing a force applied to the rear swing arm 37. Arm members 30 comprising upper arms 33L, 33R and lower arms 34L, 34R are swingably provided between the vehicle body frame 11 and the rear swing arm 37, and the rear swing arm 37 is formed into a backward-opened approximately U-shape when seeing the vehicle from above. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rear structure of a motorcycle including a rear swing arm that supports a rear wheel in a swingable manner at a rear portion of a vehicle body.

There is known a rear structure of a motorcycle including a rear swing arm that swingably supports a rear wheel at a rear portion of a vehicle body, and a rear cushion unit that absorbs a force applied to the rear swing arm (for example, Patent Documents). 1).
JP 2002-87364 A (FIG. 6)

In FIG. 6 of Patent Document 1, a rear arm 14 is swingably provided on a vehicle body. The rear arm 14 is provided with a rear wheel 15 rotatably provided via an axle 46 and a rear wheel for braking the rear wheel 15. And a brake device 50.
The rear brake device 50 includes a disk plate 51 attached to the rear wheel 15 and a caliper 54 attached to the rear arm 14 and sandwiching the disk plate 51.

By the way, in the technique of Patent Document 1, when the rear wheel 15 receives force from the road surface and the inclination of the rear arm 14 changes, the angle formed between the caliper 54 and the vertical line changes. When the rear wheel 15 is braked before and after the angle changes, the direction of the force received by the rear arm 14 changes. The rear arm 14 receives a force from the caliper 54 in addition to the force received from the road surface, and the rear arm 14 undergoes deformation such as fine torsion. As a result, the positional relationship between the disk plate 51 and the caliper 54 changes, and there is a possibility that problems such as brake noise will occur.
If the positional relationship between the disk plate and the caliper is difficult to change, it is possible to suppress problems such as brake noise.

  An object of the present invention is to provide a technique for reducing a change in the positional relationship between a disk plate and a caliper and suppressing problems such as brake noise.

According to a first aspect of the present invention, there is provided a rear part of a motorcycle including a rear swing arm that swingably supports a rear wheel behind a vehicle body frame or an engine, and a rear cushion unit that absorbs a force applied to the rear swing arm. In the structure, between the body frame or the engine and the swing arm, an arm member composed of an upper arm and a lower arm is swingably provided up and down,
The rear swing arm is formed in a substantially U shape that opens rearward when the vehicle is viewed from above.

  In the invention according to claim 2, the drive mechanism for driving the rear wheel includes a drive shaft that transmits the driving force of the engine, and a reduction gear unit that transmits the driving force of the drive shaft to the rear wheel. When viewed from the side, the case body that covers the reduction gear unit is fastened to the rear swing arm via a fastening member that is provided at an edge of the case body and extends in the vehicle width direction.

  According to a third aspect of the present invention, the rear part of the rear swing arm is provided with an upper arm and a lower arm that are spaced apart and formed vertically, and a speed reducer unit is disposed between the upper arm and the lower arm. The upper arm and the lower arm are connected by the case body.

In the invention according to claim 1, between the body frame or engine and the rear swing arm, an arm member composed of an upper arm and a lower arm is swingably provided up and down.
When the swing arm is connected to the conventional pivot shaft, the trajectory of the rear wheel axle is a trajectory that swings up and down about the pivot shaft.

  On the other hand, the trajectory of the rear wheel axle according to the present invention is a trajectory that moves substantially parallel to the road surface because the arm member is interposed. That is, the change in the posture of the rear swing arm can be reduced. In addition, the posture change of the brake caliper attached to the rear swing arm can be suppressed. If the brake caliper posture change can be suppressed, the direction of the force applied to the rear swing arm is less likely to change when the brake is applied, so the deformation of the rear swing arm is suppressed compared to the case where the direction of the force changes. Can do.

In addition, since the rear swing arm is formed in a substantially U shape, the force can be received with a good left-right balance, and the deformation of the rear swing arm can be reduced.
Since the deformation of the rear swing arm can be reduced, the positional relationship between the disk plate and the brake caliper is difficult to change.
Since the positional relationship between the disk plate and the brake caliper becomes difficult to change, problems such as brake noise can be suppressed.

  In the invention according to claim 2, since the edge of the case body covering the reduction gear unit is fastened to the rear swing arm via the fastening member, the force applied to the case body can be supported by the rear swing arm. Since the force applied to the case body is reduced, the rigidity of the case body can be reduced. If the rigidity of the case body can be reduced, the case body can be thinned, and thus the reduction gear unit can be reduced in weight.

In the invention according to claim 3, since the speed reducer unit is disposed between the upper arm and the lower arm, it is not necessary to project the speed reducer unit outward from the rear swing arm.
That is, when the vehicle is viewed from above, the speed reducer unit can be disposed so as to overlap the rear swing arm, so that an increase in the vehicle width can be suppressed. Therefore, the vehicle can be made compact.

The best mode for carrying out the present invention will be described below with reference to the accompanying drawings. In the figure, “front”, “rear”, “left”, “right”, “upper”, and “lower” respectively indicate directions viewed from the occupant. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a left side view of a motorcycle according to the present invention, and FIG. 2 is a front view of the motorcycle according to the present invention. Hereinafter, description will be given with reference to FIGS. 1 and 2.

  The front portion 10F of the motorcycle 10 extends so as to be able to swing up and down via a main frame 11a as a component of the body frame 11 and the front upper swing shafts 12L and 12R forward from the upper portion of the main frame 11a. Upper arms 13L and 13R to be extended, and lower arms 15L extending forward and downward through lower front pivot shafts 14L and 14R (only the reference numeral 14L on the front side is shown) from the lower portion of the main frame 11a. 15R, a hub steer mechanism 20 that is provided at the tip of these lower arms 15L and 15R and supports the front wheel 16 so as to be steerable, knuckle arms 21L and 21R that are provided above the hub steer mechanism 20 and support the front wheel 16 so as to be steerable, and these The knuckle arms 21L and 21R are attached to the upper ends of the knuckle arms 21L and 21R so that the knuckle arms 21L and 21R can be expanded and contracted up and down The handle link 22 that is connected, the steering handle 23 that is attached to the upper end portion 22t of the handle link 22 and steered by the occupant, and the front portion that is provided between the upper arms 13L and 13R and the main frame 11a and absorbs the force received by the front wheels 16 And a cushion mechanism 25.

  In other words, the lower ends of the knuckle arms 21L and 21R are supported by the lower arms 15L and 15R, and the upper ends of the knuckle arms 21L and 21R are supported by the upper arms 13L and 13R.

  The steering handle 23 is a member that extends from the engine 26 in front of a handle support frame 27, attaches a head pipe 28 to the front end of the handle support frame 27, and is rotatably provided on the head pipe 28. . The knuckle arms 21L and 21R and the steering handle 23 are connected to each other by a handle link 22 so that the knuckle arms 21L and 21R can be expanded and contracted to absorb the vertical movement of the knuckle arms 21L and 21R.

  By providing the handle link 22, the force applied to the knuckle arms 21 </ b> L and 21 </ b> R is not directly transmitted to the steering handle 23, so that the handle support frame 27 can be reduced in weight.

  A vertical portion of the rear portion 10R of the motorcycle 10 is swingably extended from the main frame 11a through upper and lower pivot shafts 31L, 31R, 32L, and 32R (only the reference numbers 31L and 32L are shown on the front side). Arm members 33L, 33R, 34L, and 34R (only front side symbols 33L and 34L are shown), and rear support shafts 35, 36L, and 36R (from the rear ends of the upper and lower arm members 33L, 33R, 34L, and 34R) The rear swing arm 37 extends so as to be able to swing rearward through the rear swing arm 37, and is attached to the rear end portion of the rear swing arm 37 via the rear wheel axle 38. And a rear cushion mechanism 41 provided between the rear swing arm 37 and the main frame 11a for absorbing the force applied to the rear wheel 39. Upper arm members 33L, 33R (only the front side reference 33L is shown) are members extending from the upper part of the rear end of the main frame 11a, and lower arm members 34L, 34R (only the front side reference 34L are shown). .) Is a member extending from the lower part of the rear end of the main frame 11a.

An engine 26 as a drive source is suspended from the main frame 11a, and a drive shaft 42 for driving the rear wheel 39 extends from the rear end of the engine 26 to the rear.
The details of the hub steering mechanism 20 and the front cushion mechanism 25 will be described later.

The engine 26 includes an air cleaner 44 as a component of the intake system and an exhaust pipe 45 through which the exhaust gas of the engine 26 passes as a component of the exhaust system.
Further, front disk brakes 47L and 47R (only the reference numeral 47L on the front side is shown) are attached to the front wheel 16. The front disc brakes 47L and 47R are attached to the front wheel brake discs 48L and 48R attached to the front wheel 16 and the knuckle arms 21L and 21R, and the front wheel disc calipers 49L and 49R that sandwich the front wheel brake discs 48L and 48R at the time of braking. Only 49L is shown.)

  A rear disc brake 51 is attached to the rear wheel 39. The rear disk brake 51 includes a rear wheel brake disk 52 attached to the rear wheel 39 and a rear wheel disk caliper 53 attached to the rear swing arm 37 and sandwiching the rear wheel brake disk 52 during braking.

  Between the engine 26 and the front wheel 16, two upper and lower radiators 55T and 55B that are disposed above and below and cool the engine 26 are provided. The upper radiator 55T is disposed between the upper arms 13L and 13R and the lower arms 15L and 15R, and the lower radiator 55B is disposed below the lower arms 15L and 15R.

  In front of the upper and lower radiators 55T and 55B, there are provided upper and lower ducts 56T, 56T, 56B and 56B for guiding the sucked air to the radiators 55T and 55B, respectively. The upper and lower radiators 55T, 55B and the upper and lower ducts 56T, 56T, 56B, 56B are respectively attached to the lower arms 15L, 15R.

That is, since the body frame 11 and the front wheel 16 are connected by the four arms of the upper arms 13L and 13R and the lower arms 15L and 15R, a space can be secured in front of the engine 26. If space can be secured, the degree of freedom of component placement can be secured. For example, the upper and lower radiators 55T and 55B can be arranged in this space, and a sufficient cooling capacity can be obtained.
In the figure, 57 is a front cowl, 58 is a fuel tank, and 59 is a seat.

  In this embodiment, the engine 26 is a V-type engine, but may be an in-line engine in which cylinders are arranged in series. The engine is arranged in a so-called horizontal arrangement in which the crankshaft is arranged in the width direction of the vehicle. However, a so-called vertical arrangement in which the crankshaft is arranged in the longitudinal direction of the vehicle may be used. Further, the engine is not limited to the water cooling type and may be an air cooling type. In other words, the engine type and the arrangement thereof can be arbitrarily set without being limited to the embodiment.

  The front cushion mechanism 25 is provided with a front cushion unit 61 that absorbs force, and an exhaust pipe 45 through which the exhaust gas of the engine 26 passes is disposed outside the front cushion unit 61.

  Since the exhaust pipe 45 through which the exhaust gas of the engine 26 passes is arranged outside or in front of the front cushion unit 61, the expensive front cushion unit 61 can be protected by the exhaust pipe 45. Become.

FIG. 3 is a plan view of the rear part of the motorcycle according to the present invention, and FIG. 4 is a perspective view of the rear part of the motorcycle according to the present invention. Hereinafter, description will be made with reference to FIGS. 3 and 4.
At the rear of the motorcycle, an arm member 30 comprising upper arms 33L, 33R and lower arms 34L, 34R is provided, and a rear swing arm 37 is provided at the rear end of the arm member 30, and the upper arms 33L, 33R and lower arms are provided. A rear cushion unit 62 that absorbs the force applied to the rear swing arm 37 is provided between 34L and 34R.

The upper arms 33L and 33R are composed of a left arm 33L and a right arm 33R arranged on the left and right of the vehicle when the vehicle is viewed from above, and the left arm 33L and the right arm 33R are substantially V-shaped.
Since the upper arm 33 is formed so that the left arm 33L and the right arm 33R are substantially V-shaped, the degree of freedom in setting the width of the seat 59 can be increased.

  When the vehicle is viewed from above, the lower arms 34L and 34R are substantially X-shaped between the left lower arm 34L, the right lower arm 34R, and the left lower arm 34L and the right lower arm 34R. It consists of the cross part 63 formed and connected so that it may exhibit.

  Since the lower arm 34 includes the left lower arm 34L, the right lower arm 34R, and the cross portion 63 that connects and reinforces the left and right lower arms 34L and 34R, a predetermined rigidity can be easily ensured.

  The rear swing arm 37 is formed in a substantially U shape that opens rearward when the vehicle is viewed from above. For this reason, the force can be received with a good left / right balance, and the deformation of the rear swing arm 37 can be reduced.

  That is, the rear cushion structure of the motorcycle 10 extends rearwardly from the vehicle body frame 11 so as to be swingable and supports the rear wheel 39, and is connected to the rear swing arm 37 and is received by the rear wheel 39. A rear rod 66 serving as a rod member 65 that transmits force to the rear cushion unit 62, a rear link 67 that changes the direction of the force applied to the rear rod 66, and a rear link 67 that is connected to the rear link 67 and horizontally in the vehicle width direction. And a rear cushion unit 62 that absorbs the force received by the rear wheel 39 provided.

The upper end portion 65t of the rod member 65 is connected to a connection point 69 of the upper arms 33L and 33R formed in a substantially V shape.
Specifically, a stay 68 is provided at a coupling point 69 located at the center in the width direction of the vehicle, and an upper end portion 65 t of the rod member 65 is connected to the stay 68.
For this reason, the force transmitted by the rear wheel 39 to the receiving rear swing arm 37 can be received evenly at the center of the vehicle.

FIG. 5 is a view taken in the direction of arrow 5 in FIG. 3. The drive mechanism 71 that drives the rear wheel 39 includes a drive shaft 42 and a speed reducer unit 72 connected to the drive shaft 42.
A rear portion 37r of the rear swing arm 37 is provided with an upper arm 74 and a lower arm 75 that are formed to be spaced apart from each other. A reduction gear unit 72 is disposed between the upper arm 74 and the lower arm 75. A case body 76 covering the reduction gear unit 72 connects the upper arm 74 and the lower arm 75.

When the vehicle is viewed from the right side, the case body 76 that covers the speed reducer unit 72 is provided on the edge 76f of the case body 76 and extends in the vehicle width direction. It is fastened to the rear swing arm 37 through the following.
In the figure, 81 is a constant velocity joint.

Since the edge portion 76f of the case body 76 covering the reduction gear unit 72 is fastened to the rear swing arm 37 via the fastening members 78..., The force applied to the case body 76 can be supported by the rear swing arm 37. it can. Since the force applied to the case body 76 is reduced, the rigidity of the case body 76 can be kept low.
If the rigidity of the case body 76 can be kept low, the thickness of the case body 76 can be reduced, so that the reduction gear unit 72 can be reduced in weight.

Returning to FIG. 3, since the speed reducer unit 72 is disposed between the upper arm 74 and the lower arm 75, it is not necessary to project the speed reducer unit 72 outward of the rear swing arm 37.
When the vehicle is viewed from above, the speed reducer unit 72 can be disposed so as to overlap the rear swing arm 37, so that an increase in the vehicle width can be suppressed. Therefore, the vehicle can be made compact.

The operation of the rear structure of the motorcycle described above will be described next.
FIG. 6 is an explanatory diagram of the operation of the rear part of the motorcycle according to the embodiment.
In (a), it is a state when the rear wheel 39 is not receiving force from the road surface.
In (b), when the rear wheel 39 receives a force from the road surface, an upward force is applied to the rear swing arm 37, the upper arm member 33 swings about the upper pivot shaft 31, and the lower The lower arm member 34 swings around the pivot shaft 32. At this time, a force in the direction of arrow s is applied to the rear rod 66.

In (c), the rear wheel 39 receives a larger force than in (b), and the rear rod 66 is further pulled upward.
In the figure, when the angles formed by the rear wheel disk caliper 53 with respect to the vertical line VL are θa, θb, and θc, the relationship of θa≈θb≈θc can be obtained by interposing the arm member 30 regardless of the magnitude of the force. maintain. That is, the posture change of the rear wheel disc brake caliper 53 attached to the rear swing arm 37 can be suppressed.

  FIG. 7 is a configuration diagram and an operation diagram of the rear cushion mechanism of the motorcycle according to the present invention, and FIGS. 7A to 7C correspond to FIGS. 6A to 6C, respectively. For example, FIG. 7A corresponds to FIG.

  In (a), the rear cushion mechanism 41 includes a rear cushion bracket 64 and a support shaft 60 extending from the vehicle body frame side, a substantially L-shaped rear link 67 provided swingably on the support shaft 60, and a rear portion. A rear cushion unit 62 provided between the intermediate portion 67m of the link 67 and the rear cushion bracket 64 is provided.

One end 62 a of the rear cushion unit 62 is attached to the intermediate portion 67 m of the rear link 67, the other end 62 b of the rear cushion unit 62 is attached to the rear cushion bracket 64, and the other end 67 b constituting the root of the rear link 67 is attached to the support shaft 60. The rear rod 66 is attached to one end 67 a constituting the tip of the rear link 67.
In the drawing, no force is applied to the rear rod 66.

  In (b), when the rear wheel 39 receives a force, a force in the direction of the arrow s is applied to the rear rod 66, and a force for contracting the rear cushion unit 62 in the direction of the arrow t is applied via the rear link 67. .

In (c), a larger force is applied to the rear rod 66 than in (b), and a force to contract the rear cushion unit 62 in the direction of the arrow t is applied.
When the force is no longer applied, the rear cushion unit 62 applies a force in the direction opposite to the arrow t to the rear link 67 and tries to return to the position (a).

FIG. 8 is an explanatory diagram of the operation of the rear part of the motorcycle according to the comparative example. The rear swing arm 37B is provided so as to be able to swing rearward from the vehicle body frame via a pivot shaft 79B.
(A)-(c) respond | corresponds to Fig.6 (a)-(c).

  (A) shows the state when the rear wheel 39 is not receiving force from the road surface, (b) shows the state where the rear wheel 39 is receiving force from the road surface, and (c) shows the state when the rear wheel 39 is (b ) Indicates the state when receiving a greater force.

In the figure, when the angles formed by the rear wheel disk caliper 53 with respect to the vertical line VL are respectively βa, βb, and βc, the trajectory of the rear wheel axle is a trajectory centered on the pivot shaft 79B.
As the force increases, the angle increases, and βa <βb <βc. In other words, when the force is applied, the rear swing arm 37B swings, and the posture of the rear wheel disc caliper 53B attached to the rear swing arm 37B changes.
If the posture of the rear wheel disc caliper 53B changes, the direction of the force applied to the rear swing arm 37B changes when the brake is applied. Therefore, compared to the case where the direction of the force does not change, the rear swing arm 37B Deformation is likely to occur.

Returning to FIG. 6, between the vehicle body frame 11 and the rear swing arm 37, an arm member 30 composed of upper and lower arms 33L, 33R and lower arms 34L, 34R is swingably provided.
The trajectory of the rear wheel axle 38 according to the present invention is a trajectory that moves substantially parallel to the road surface G because the arm member 30 is interposed. That is, the change in the posture of the rear swing arm 37 can be reduced. Further, the posture change of the brake caliper 53 attached to the rear swing arm 37 can be suppressed. If the change in the posture of the brake caliper 53 is suppressed, the direction of the force applied to the rear swing arm 37 is difficult to change when the brake is applied. Therefore, the deformation of the rear swing arm 37 is less than when the direction of the force is changed. Can be suppressed.

  In addition, since the rear swing arm 37 is formed in a substantially U shape as shown in FIG. 3, the force can be received with a good left-right balance, and the deformation of the rear swing arm 37 can be reduced.

Since the deformation of the rear swing arm 37 can be reduced, the positional relationship between the rear wheel brake disk 52 and the brake caliper 53 as a disk plate is difficult to change.
Since the positional relationship between the rear wheel brake disk 52 and the brake caliper 53 is difficult to change, problems such as brake squealing can be suppressed.

  FIG. 9 is a diagram for explaining that the position of the rear cushion unit can be changed. The rear cushion unit 62 is disposed between the upper arms 33L and 33R and the lower arms 34L and 34R, and the upper and lower pivot shafts 31 are arranged. , 32 are arranged in front of each other.

  Between the body frame 11C and the rear swing arm 37, there is an arm member 30 composed of upper arms 33L, 33R (only the reference numeral 33L in the figure is shown) and lower arms 34L, 34R (only the reference numeral 34L in the figure is shown). The rear cushion unit 62 is swingably provided, and is disposed between the upper arms 33L and 33R and the lower arms 34L and 34R. Therefore, the rear cushion unit 62 can be disposed behind the upper and lower pivot shafts 31 and 32. By shortening the lengths of the upper arms 33L and 33R and the lower arms 34L and 34R, the upper and lower pivot shafts 31, 32 can be placed in front of.

Moreover, the position of the rear cushion unit 62 can be changed by changing the length of the rear rod 66.
That is, by changing the lengths of the upper arms 33L and 33R, the lower arms 34L and 34R, and the rod member 65, the arrangement position of the rear cushion unit 62 can be freely set, and the rear cushion unit 62 is arranged at an optimal position. Is possible.

  Further, since the upper end portion 66t of the rear rod 66 is connected to the upper arms 33L and 33R, a sufficiently long cushion stroke can be secured by providing the rear cushion unit 62 at the lower portion of the vehicle body frame 11. .

FIG. 10 is a diagram of another embodiment of FIG. 4, and the point that differs greatly from FIG. 4 is that a rear link and a rod member are provided on the left and right sides and connected to the rear cushion unit.
The rod member 65 includes a left rod member 65L and a right rod member 65R. The rear link 67 includes a left rear link 67L and a right rear link 67R. The left rod member 65L passes through the left rear link 67L. The right rod member 65R is connected to the other end 62b of the rear cushion unit 62 via the right rear link 67L.

The rod member 65 includes a left rod member 65L and a right rod member 65R. The left rod member 65L is connected to the other end 62b of the rear cushion unit 62 via a left rear link 67L, and the right rod member 65 is A right rear link 67 is connected to one end 62 a of the rear cushion unit 62.
That is, the rear cushion unit 62 is provided to be extendable and contractable by the left rear link 67L and the right rear link 67R.

  The forces transmitted to the arm portions 33L and 33R are received by the left and right rod members 65L and 69R, and the forces received by the left and right rod members 65L and 69R are received by the one end 62a and the other end 62b of the rear cushion unit 62. The force applied to 39 can be absorbed in a balanced manner on the left and right.

FIG. 11 is another embodiment of FIG. 1. The difference from FIG. 1 is that the main frame is omitted, and the upper arms 13L, 13R, the lower arm and the upper and lower arm members 33L, 33R, 34L, 34R are directly mounted on the engine 26. It is in the point.
By providing the engine 26 with the function of the main frame 11a, the weight of the vehicle can be reduced.

  Although the present invention is applied to a four-wheeled vehicle in the embodiment, it can also be applied to a three-wheeled vehicle and can be applied to a general saddle-ride type vehicle.

  The present invention is suitable for the rear structure of a motorcycle.

1 is a left side view of a motorcycle according to the present invention. 1 is a front view of a motorcycle according to the present invention. 1 is a plan view of a rear part of a motorcycle according to the present invention. 1 is a perspective view of a rear part of a motorcycle according to the present invention. FIG. 5 is a view taken in the direction of arrow 5 in FIG. 3. FIG. 6 is an operation explanatory diagram of a motorcycle rear portion according to the embodiment. FIG. 6 is a configuration diagram and an operation diagram of a rear cushion mechanism of a motorcycle according to the present invention. It is an operation explanatory view of the motorcycle rear part concerning a comparative example. It is a figure explaining that the position of a rear cushion unit can be changed. It is another Example figure of FIG. It is another Example figure of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Motorcycle, 11 ... Body frame, 26 ... Engine, 30 ... Arm member, 33L, 33R ... Upper arm, 34L, 34R ... Lower arm, 37 ... Rear swing arm, 39 ... Rear wheel, 42 ... Drive shaft, 62 ... Rear cushion unit, 71 ... drive mechanism, 72 ... reduction gear unit, 74 ... upper arm, 75 ... lower arm, 76 ... case body, 76f ... edge of case body, 78 ... fastening member.

Claims (3)

In a rear structure of a motorcycle comprising a rear swing arm that swingably supports a rear wheel behind a vehicle body frame or an engine, and a rear cushion unit that absorbs a force applied to the rear swing arm.
Between the vehicle body frame or the engine and the rear swing arm, an arm member composed of an upper arm and a lower arm is swingably provided up and down,
The rear swing arm is formed in a substantially U-shape that opens rearward when the vehicle is viewed from above, and is a rear structure of the motorcycle. The drive mechanism for driving the rear wheel includes a drive shaft that transmits the driving force of the engine, and a reduction gear unit that transmits the driving force of the drive shaft to the rear wheel,
When the vehicle is viewed from the side, a case body that covers the reduction gear unit is fastened to the rear swing arm via a fastening member that is provided at an edge of the case body and extends in the vehicle width direction. The rear structure of the motorcycle according to claim 1.   The rear part of the rear swing arm is provided with an upper arm and a lower arm that are separated and formed vertically, and the speed reducer unit is disposed between the upper arm and the lower arm, The rear structure of the motorcycle according to claim 2, wherein the upper arm and the lower arm are connected to each other.

Images