JP4559047B2 - Vehicle swing arm suspension system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a swing arm type suspension device for a vehicle that is suitable for improving the kinematic performance of a vehicle, improving productivity, further reducing the size of the vehicle, and increasing the degree of freedom in designing a body frame.
[0002]
[Prior art]
2. Description of the Related Art A swing arm type suspension device is known in which an upper portion of a cushion unit that prevents an impact from being transmitted from a rear wheel to a body frame is attached to a rear portion of the body frame. In addition, since there is no description of prior art documents in the original application, it is not described in this application.
[0003]
[Patent Document 1]
[0004]
FIG. 7 is an explanatory diagram of a vehicle equipped with a conventional swing arm type suspension device. A power unit 102 including an engine and a transmission is attached to a lower part of a vehicle body frame 101 of the vehicle 100, and rear portions of the vehicle body frame 101 and the power unit 102. The state which has arrange | positioned the swing arm type suspension apparatus 103 is shown.
The swing arm type suspension device 103 has a swing arm 104 attached to the rear part of the power unit 102 so as to be swingable, a rear wheel 105 is attached to the rear end of the swing arm 104, and one end of the cushion unit 106 is attached to the rear part of the vehicle body frame 101. A first link member 107 attached to the swing arm 104 is connected to the other end of the unit 106, and a second link member 108 attached to the power unit 102 is connected to the first link member 107. In addition, 111 is a head pipe attached to the front end of the vehicle body frame 101, 112 is a front fork attached to the head pipe 111 in a rotatable manner, and 113 is a front wheel.
[0005]
FIG. 8 is a plan view of a conventional vehicle body frame. In the vehicle body frame 101, a head pipe 111 extends a pair of left and right main frames 115, 115 rearward, and a cross beam 116 is provided at each rear end of the main frames 115, 115. A mounting portion 117 for attaching the upper end of the cushion unit 106 (see FIG. 7) is provided on the cross beam 116.
[0006]
[Problems to be solved by the invention]
In the above technique, the position of the cross beam 116 is in a space near the center of the vehicle body, and it is a suitable place for placing equipment such as a battery and various electrical components. It is necessary to disperse and arrange in the place, and the weight is dispersed. Further, if the equipment is dispersed, the work must be performed while moving the equipment when the equipment is assembled to the vehicle 100, and productivity is lowered. Furthermore, the vehicle 100 becomes large and the shape of the body frame 101 is limited.
[0007]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a swing arm type suspension for a vehicle that can improve productivity by concentrating the equipment in the center of the vehicle body, further reduce the size of the vehicle, and increase the degree of freedom in designing the vehicle body frame. To provide an apparatus.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to a first aspect of the present invention, one end of a swing arm is swingably attached to a pivot shaft provided on the vehicle body side, and a wheel is rotatably attached to the other end of the swing arm. The lower end of the cushion unit is attached, and the upper end of the cushion unit is attached to the first link member connected to the swing arm, and the first link member is attached to the second link member connected to the vehicle body at a position below the pivot shaft. In the vehicle swing arm suspension, the first link member is connected to the swing arm via an upper bracket, and the cushion unit is connected to the swing arm via a lower bracket .
[0009]
Conventionally, the upper end of the cushion unit is attached to a vehicle body frame such as a seat frame. On the other hand, in claim 1, the upper end of the cushion unit is attached to the swing arm. As a result, it is not necessary to provide a cross pipe in the body frame or an attachment member for attaching the upper end of the cushion unit, and it becomes possible to concentrate equipment such as electrical components on the body frame, Vehicle productivity can be improved. Further, the centralization of equipment can reduce the size of the vehicle, and the degree of freedom in designing the body frame can be increased.
[0011]
By providing the upper bracket and the lower bracket, it becomes easy to secure the distance between both ends of the cushion unit, and the overall length of the cushion unit can be further increased.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a side view of a vehicle equipped with a swing arm type suspension device (first embodiment) according to the present invention. A motorcycle 10 is provided with a main frame 11 and a front end portion of the main frame 11. A front fork 13 and a front wheel 14 are steerably attached to the head pipe 12, a handle 15 is attached to the upper part of the front fork 13, and a power unit 16 as a vehicle body side consisting of an engine and a transmission is attached to the lower part of the main frame 11. 16 is a vehicle in which the swing arm type suspension device 30 of the present invention is attached to the rear of the vehicle 16, the fuel tank 17 is attached to the upper part of the main frame 11, and seats 18 and 21 are arranged behind the fuel tank 17. In addition, 22 is a cowling, 23 and 24 are seat frames and sub-frames extending obliquely upward and rearward from the rear portion of the main frame 11, and 25 is a rear wheel axle.
[0013]
The swing arm type suspension device 30 is provided with a pivot shaft 31 at the rear part of the power unit 16, a front end of a swing arm 32 is swingably attached to the pivot shaft 31, and a rear wheel 33 as a wheel is attached to the rear end of the swing arm 32. The upper end of the cushion unit 34 that absorbs shock is attached to the vicinity of the pivot shaft 31 of the swing arm 32 so that the shock is not transmitted to the vehicle body via the rear wheel 33 and the swing arm 32, and the lower end of the cushion unit 34 is connected to the power unit 32. It attaches to the lower part of this through a link mechanism (it explains in full detail later).
[0014]
FIG. 2 is a side view showing the main part of the swing arm type suspension device (first embodiment) according to the present invention. The swing arm 32 is provided with an upper bracket 36 for attaching the cushion unit 34 to the upper part. A lower bracket 38 for attaching the link mechanism 37 to the lower part is provided.
[0015]
The cushion unit 34 includes a cylinder part 41, a piston rod 42 attached to a piston (not shown) movably accommodated in the cylinder part 41, a lower end attachment part 43 provided at an end of the piston rod 42, a cylinder part 41 and a suspension spring 44 interposed between each of the lower end attachment portions 43, and an upper end attachment portion 46 provided at the end of the cylinder portion 41 is attached to the upper bracket 36 of the swing arm 32 so as to be swingable. The part 43 is attached to the link mechanism 37.
Reference numeral 47 denotes an upper swing shaft.
[0016]
The link mechanism 37 has a triangular first link 51 attached to the lower bracket 38 of the swing arm 32 so as to be swingable. The link mechanism 37 is attached to the first link 51 so as to be swingable, and provided at the lower part of the power unit 32. The second link 53 is attached to the link attachment portion 52 so as to be swingable. Reference numeral 55 denotes a power unit side swing axis.
[0017]
The first link 51 is connected to the lower bracket 38 of the swing arm 32 by the first shaft 56, is connected to the second link 52 and the second shaft 57, and is respectively connected to the lower end mounting portion 43 and the third shaft 58 of the cushion unit 34. It is connected so that it can swing.
The power unit swing shaft 55 is a shaft positioned below the pivot shaft 31.
[0018]
Next, the operation of the swing arm type suspension device 30 described above will be described.
FIG. 3 is a first action diagram for explaining the action of the swing arm type suspension device (the first embodiment) according to the present invention.
In FIG. 1, for example, when the motorcycle 10 gets over the convex portion of the road surface and the rear wheel 33 moves upward with respect to the vehicle body side (the main frame 11 and the power unit 16), the swing arm 32 is imaginary in FIG. From the position shown by the solid line to the position shown by the solid line, it swings upward as indicated by the arrow {circle around (1)} with the pivot shaft 31 as the center. As a result, the lower end attachment portion 43 attached to the third shaft 58 rises as shown by the arrow (3).
Therefore, the cushion unit 34 generates a damping force while contracting and absorbs an impact.
[0019]
FIG. 4 is a second action diagram for explaining the action of the swing arm type suspension device (the first embodiment) according to the present invention, the amount of movement of the rear wheel axle 25 in the vertical direction of the swing arm 32, and the cushion unit. It is a figure explaining the relationship with 34 stroke amount. In the drawing, large ◎ marks indicate the rear wheel axle 25, and small ◎ marks indicate the upper swing shaft 47 and the third shaft 58.
The position at which the rear wheel axle 25 is indicated by the symbol ◎, that is, the position when the driver gets on the motorcycle and stops (without applying acceleration / deceleration force to the vehicle body) (" This position is also referred to as “a boarding neutral position.” This is also a link when the swing arm 32 and the rear wheel 33 (see FIG. 1) are in the boarding neutral position. A third shaft 58 serving as a connecting shaft between the mechanism 37 (see FIG. 2) and the cushion unit 34 (see FIG. 2) is located at the position indicated by ◎.
[0020]
At this time, the overall length of the cushion unit 34 (the distance between the axial center 47a of the upper swing shaft 47 and the axial center 58a of the third shaft 58; hereinafter the same) is La, and the overall length when the cushion unit 34 is extended to the maximum. When it is Le, the stroke amount of the cushion unit 34 at the boarding neutral position is Sa. (Ie, Sa = Le−La)
[0021]
First, when the swing arm 32 swings (swings downward) from the boarding neutral position to the extension side of the cushion unit 34 (see FIG. 2), the swing arm 32, the upper bracket 36 of the swing arm 32, and the lower end of the cushion unit 34 The mounting portion 43, the third shaft 58, and the rear wheel axle 25 are in the positions indicated by the solid lines, and the amount of movement of the rear wheel axle 25 toward the extension side of the cushion unit 34 (the axis 25a of the rear wheel axle 25) The amount of movement) is Da. At this time, the overall length of the cushion unit 34 is Lb, and the stroke amount is Sb. (Ie, Sb = Le−Lb)
[0022]
Further, when the swing arm 32 swings from the boarding neutral position to the contraction side of the cushion unit 34 (swings upward), the swing arm 32, the upper bracket 36 of the swing arm 32, the lower end mounting portion 43 of the cushion unit 34, the first The three axles 58 and the rear wheel axle 25 are in the positions indicated by the alternate long and short dash lines, and the amount of movement of the rear wheel axle 25 to the contraction side of the cushion unit 43 at this time is the same Da as the amount of movement described above. At this time, the overall length of the cushion unit 34 is Lc, and the stroke amount is Sc. (Ie, Sc = Le−Lc)
[0023]
In the swing arm type suspension device 30 (see FIG. 2) of the present invention, by using the link mechanism 37 (see FIG. 2), (Sc-Sa)> (Sa-Sb).
That is, as the rear wheel axle 25 strokes toward the contraction side of the cushion unit 34, the change in the stroke amount of the cushion unit 34 increases.
Thereby, the moving speed of the piston of the cushion unit 34 increases, and the damping force generated in the cushion unit 34 increases.
[0024]
FIG. 5 is a graph showing the relationship between the displacement amount of the rear wheel axle and the stroke amount of the cushion unit in the swing arm type suspension device (the first embodiment) according to the present invention, and the vertical axis represents the stroke amount of the cushion unit. The horizontal axis represents the amount of vertical displacement of the rear wheel axle. (Refer to FIG. 2 and FIG. 3 for the reference)
When the amount of vertical displacement of the rear wheel axle 25 is in the range from the point A which is the maximum extension position of the cushion unit 34 to the point B which is the riding neutral position, the stroke amount of the cushion unit 34 is the vertical movement of the rear wheel axle 25. As the amount of displacement in the direction increases, it increases almost linearly.
[0025]
Further, in the range from the point B at the riding neutral position to the point C that is the maximum contraction position of the cushion unit 34, the amount of vertical displacement of the rear wheel axle 25 increases. On the other hand, the rate of increase in the stroke amount of the cushion unit 34 gradually increases.
[0026]
Thus, when the rear wheel axle 25 is displaced from the boarding neutral position to the contraction side of the cushion unit 34 by the link mechanism 37, the stroke amount of the cushion unit 34 is gradually increased, that is, the stroke speed of the cushion unit 34 is increased. To increase the damping force generated in the cushion unit 34 near the maximum contracted position of the cushion unit 34 to prevent the cushion unit 34 from bottoming out, and to generate in the cushion unit 34 near the riding neutral position. The damping force can be reduced to improve riding comfort.
[0027]
FIG. 6 is a side view of the main part of the swing arm type suspension device according to the present invention (second embodiment). The same components as those in the first and second embodiments are denoted by the same reference numerals, and detailed description thereof will be given. Omitted.
In the swing arm type suspension device 70, a swing arm 71 is swingably attached to the power unit 16, an upper bracket 72 is attached to an upper portion of the swing arm 71, and a first link 73 is attached to the bracket 72 so as to be swingable. One end of the cushion unit 34 is swingably attached to the end portion of the link 73, and one end of the second link 74 is swingably attached to the intermediate portion of the first link 73, and the lower end of the cushion unit 34 is attached to the lower portion of the swing arm 71. The lower bracket 75 is provided so as to be swingable, and the end of the second link 74 is swingably attached to the power unit 16. Reference numeral 76 denotes a first axis, 77 denotes a second axis, 78 denotes a third axis, and 79 denotes a fourth axis.
[0028]
As described above with reference to FIGS. 1 and 6, according to the present invention, first, one end of the swing arm 71 is swingably attached to the pivot shaft 31 provided in the power unit 16, and the rear wheel is attached to the other end of the swing arm 71. 33 is rotatably attached, the lower end of the cushion unit 34 is attached to such a swing arm 71, the upper end of the cushion unit 34 is attached to a first link 73 connected to the swing arm 71, and the first link 73 is pivoted. It is characterized by being attached to the second link 74 connected to the power unit 16 at a position below the shaft 31.
[0029]
Conventionally, the upper end of the cushion unit is attached to a vehicle body frame such as a seat frame. On the other hand, in claim 1, the upper end of the cushion unit 34 is attached to the first link 73 connected to the swing arm 71, and the first link 73 is connected to the power unit 16 at a position below the pivot shaft 31. It was made to attach to the link 74. As a result, it is not necessary to provide a cross pipe on the vehicle body frame or an attachment member for attaching the upper end of the cushion unit, and electrical components (battery or control unit) are provided inside the main frame 11, the seat frame 23, and the sub frame 24. ), Equipment such as a tool box can be centrally arranged, and it is possible to improve the motion performance of a vehicle of an off-road specification or a race specification and improve the productivity of the motorcycle 10. Further, the centralization of the equipment can reduce the size of the motorcycle 10, and can further increase the degree of freedom in designing the body frames such as the main frame 11, the seat frame 23, and the sub frame 24.
[0030]
Second, the present invention is characterized in that the first link 73 is connected to the swing arm 71 via an upper bracket 72, and the cushion unit 34 is connected to the swing arm 71 via a lower bracket 75.
[0031]
By providing the upper bracket 72 and the lower bracket 75, it is easy to secure the distance between both ends of the cushion unit 34, and the overall length of the cushion unit 34 can be further increased.
[0032]
【The invention's effect】
The present invention exhibits the following effects by the above configuration.
The swing arm type suspension device according to claim 1 has one end of a swing arm attached to a pivot shaft provided on the vehicle body side so as to be swingable, and a wheel is rotatably attached to the other end of the swing arm. The lower end of the unit is attached, and the upper end of the cushion unit is attached to the first link member connected to the swing arm, and the first link member is attached to the second link member connected to the vehicle body at a position below the pivot shaft. Therefore, there is no need to provide a cross pipe on the body frame or an attachment member for attaching the upper end of the cushion unit, and it becomes possible to concentrate electrical equipment and other equipment on the body frame. The vehicle productivity can be improved. Further, the centralization of equipment can reduce the size of the vehicle, and the degree of freedom in designing the body frame can be increased.
[0033]
In addition, the swing arm type suspension system as claimed in claim 1, the swing arm of the first link member via an upper bracket connected, since the connection via the bottom bracket cushion unit to the swing arm, the upper bracket and the lower bracket By providing, it becomes easy to ensure the distance of the both ends of a cushion unit, and the full length of a cushion unit can be enlarged more.
[Brief description of the drawings]
FIG. 1 is a side view of a vehicle provided with a swing arm type suspension device according to the present invention (first embodiment). FIG. 2 is a side view of a swing arm type suspension device according to the present invention (first embodiment). FIG. 3 is a side view showing the main part. FIG. 3 is a first action diagram for explaining the operation of the swing arm type suspension apparatus according to the present invention (first embodiment). FIG. 4 is a swing arm type suspension apparatus according to the present invention. FIG. 5 is a second action diagram for explaining the action of the first embodiment. FIG. 5 shows the displacement amount of the rear wheel axle and the stroke amount of the cushion unit in the swing arm suspension apparatus according to the present invention (first embodiment). FIG. 6 is a side view of a main part of a swing arm suspension device according to the present invention (second embodiment). FIG. 7 is an explanatory diagram of a vehicle equipped with a conventional swing arm suspension device. FIG. 8 is a plan view of a conventional body frame. ]
DESCRIPTION OF SYMBOLS 10 ... Vehicle (motorcycle), 16 ... Vehicle body side (power unit), 31 ... Pivot shaft, 33 ... Wheel (rear wheel), 34 ... Cushion unit, 70 ... Swing arm type suspension device, 71 ... Swing arm, 73 ... No. 1 link member (1st link), 74 ... 2nd link member (2nd link), 72 ... Upper bracket, 75 ... Lower bracket.

Claims (1)

One end of a swing arm is swingably attached to a pivot shaft provided on the vehicle body side, a wheel is rotatably attached to the other end of the swing arm, and the lower end of the cushion unit is attached to such a swing arm. Is attached to a first link member connected to the swing arm, and the first link member is attached to a second link member connected to the vehicle body at a position below the pivot shaft .
The swing arm type suspension device for a vehicle, wherein the first link member is connected to the swing arm via an upper bracket, and the cushion unit is connected to the swing arm via a lower bracket .

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