JP3618380B2 - Rear wheel suspension system for saddle riding type vehicles - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a rear wheel suspension device for a saddle-ride type vehicle.
[0002]
[Prior art]
A straddle-type vehicle is a small vehicle suitable for rough terrain traveling, for example, supported by a steerable front wheel and a pair of left and right rear wheels, and a rider straddling a straddle-type driving seat disposed at the upper part of a vehicle body frame. Thus, the front wheels are steered by the steering handle, and the engine mounted on the body frame is driven to travel.
[0003]
This straddle-type vehicle is provided with a suspension device for reducing the impact from the road surface, improving the ride comfort, ensuring the ground contact of the tire during cornering, and holding the wheels in the correct direction.
[0004]
Among them, as a rear wheel suspension device, there is a type that employs a rigid axle type in which an axle shaft is integrated by a differential housing.
[0005]
The rigid axle type rear-wheel suspension system supports the vehicle weight by a link, and can move up and down with the attachment portion of the link to the vehicle body as a fulcrum. The basic arrangement of the links is a four-link type in which an upper link and a lower link are provided on the left and right sides, and the differential housing is supported by a total of four links.
[0006]
The driving force from the engine is transmitted differentially by the propeller shaft via the universal joint, and drives the axle shaft.
[0007]
[Problems to be solved by the invention]
However, in the four-link type rigid axle type rear wheel suspension device, there are four vehicle body side attachment portions of the link, and the structure of the vehicle body attachment portion becomes complicated.
[0008]
Further, the position change on the input side of the differential is large, and it is necessary to provide universal joints at both ends of the propeller shaft.
[0009]
Furthermore, when the length of the propeller shaft is set to be short, the angle change of the universal joint becomes large, so that an expensive constant velocity joint is required.
[0010]
The present invention has been made in consideration of the above-described circumstances, and an object of the present invention is to provide a rear wheel suspension device for a straddle-type vehicle that has a simple structure, is not costly, and can obtain good performance.
[0011]
[Means for Solving the Problems]
In order to solve the above-described problems, a rear wheel suspension device of a saddle-ride type vehicle according to the present invention has an engine mounted on a lower center portion of a vehicle body frame and an engine on the front side of the engine. The exhaust pipe and muffler that constitute the exhaust system of the engine are connected, and the exhaust pipe and muffler are arranged above the differential housing that holds the axle shaft and the rear link while the exhaust pipe and muffler are arranged in the same shape in side view. In a rear-wheel suspension system for a saddle-ride type vehicle in which an absorber is attached to the front side of the vehicle with the upper part inclined forward and wide low-pressure tires are attached to the front and rear wheels, the upper link and The front ends of the lower links are juxtaposed in the width direction of the car body, and the single pivot shaft On the other hand, the upper link is extended obliquely upward from the pivot portion, and the rear end portion is pivotally attached to a mounting bracket provided on the differential housing, and the lower link is inclined downward from the pivot portion. The rear link is pivotally attached to a mounting bracket provided on the differential housing, and the upper link and the lower link are symmetrically arranged in a plan view with respect to the center line of the pivot portion. The rear shock absorber is arranged so as to form an isosceles triangle and isosceles triangles that are vertically symmetrical with respect to a line connecting the pivot shaft and the axle shaft in a side view. Is mounted on the vehicle with the lower axle shaft side widened against the upper body frame side It is, moreover lower end of the rear shock absorber is obtained by pivotally at the top of the mounting bracket for mounting the lower link A above the line connecting the said pivot shaft and the axle shaft.
[0012]
[Action]
In the present invention having the above-described configuration, the rear wheel suspension device is configured by the upper link and the lower link having the same shape, the differential housing that holds the axle shaft, and the rear shock absorber, and the pivot portion provided in the vehicle body frame The upper link and the front link of the lower link are juxtaposed in the width direction of the vehicle body, and are attached by a single pivot shaft, while the upper link extends obliquely upward from the pivot portion, The rear end is pivotally attached to the mounting bracket provided on the differential housing, the lower link is extended obliquely downward from the pivot portion, and the rear end is attached to the mounting bracket provided on the differential housing. On the other hand, the upper link and the lower An isosceles triangle that is symmetrical in plan view with respect to a line connecting the pivot shaft and the axle shaft so as to form an isosceles triangle that is bilaterally symmetric in plan view with the center line of the pivot portion as an axis. Since the mounting parts on the vehicle body side of each link are reduced, the structure is simplified and the assembly is easy, the cost is not reduced, and the isosceles triangle shape of each link is in the vertical direction. And good running performance can be obtained because the lateral movement is sufficiently restricted.
[0013]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0014]
FIG. 1 is a left side view showing an example of a saddle riding type vehicle to which the present invention is applied.
[0015]
As shown in FIG. 1, the saddle riding type vehicle 1 has a body frame 2 made of, for example, a steel pipe. The vehicle body frame 2 is configured by connecting a pair of left and right side frames 3 including an upper pipe 3a as an upper member and a lower pipe 3b as a lower member to each other.
[0016]
The upper part of the vehicle body frame 2 is covered with an integral or separate vehicle body cover 4, and a front fender 5 </ b> F and a rear fender 5 </ b> R are formed at the front part and rear part, respectively. An upper front side of the vehicle body cover 4 is a tank cover 4a that covers a fuel tank (not shown), and a saddle riding type operation seat 6 is provided behind the tank cover 4a. An engine 7 is mounted at the center lower portion of the body frame 2, and an exhaust pipe 8a and a muffler 8b constituting an engine exhaust system are connected to the front side thereof. Reference numeral 9 denotes a steering wheel.
[0017]
Front wheels 10 with wide low-pressure tires are arranged on the front left and right of the body frame 2, and these front wheels 10 are supported on the body frame 2 by a front wheel suspension device 12 including a front shock absorber 11 and the like so as to be swingable in the vertical direction. The The front wheel 10 is steered left and right by a steering handle 9 via a steering mechanism (not shown).
[0018]
On the other hand, rear wheels 13 with wide low-pressure tires are disposed on the left and right of the body frame 2, and these rear wheels 13 are supported on the body frame 2 by a rear wheel suspension device 14 so as to be swingable in the vertical direction. The power of the engine 7 is transmitted to the rear wheel 13 through a propeller shaft and a differential, which will be described later.
[0019]
2 is a plan view of the rear wheel suspension device 14, FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2, and FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG.
[0020]
As shown in FIGS. 1 to 4, the rear wheel suspension device 14 includes a pair of left and right upper links 15, a pair of left and right lower links 16, a propeller shaft 17 and a differential 18, and connects the left and right rear wheels 13. This is a 4-link type rigid axle type composed of a differential housing 20 for holding the axle shaft 19 and a rear shock absorber 21. The upper link 15 and the lower link 16 have the same shape.
[0021]
A pair of pivot portions 22 are arranged at the center lower portion of the vehicle body frame 2 so as to be symmetrical with respect to the vehicle body center line 23 in plan view. A front end portion 15F of the upper link 15 and a front end portion 16F of the lower link 16 are juxtaposed in the width direction of the vehicle body, and are pivotally attached to the pivot portion 22 by a single pivot shaft 24. An axis line 25 connecting the left and right pivot shafts 24 is disposed so as to pass through the rotation shaft center 27 of the universal joint 26 that connects the engine 7 and the propeller shaft 17. Further, as shown in FIG. 5, the front end portions 15F and 16F of each link are pivotally attached to the pivot portion 22 via a ring bush 28 made of an elastic body such as rubber.
[0022]
As shown in FIG. 3, the lower link 16 extends obliquely downward from the pivot portion 22, and the rear end portion 16 </ b> R is pivotally attached to a lower link mounting bracket 29 provided in the differential housing 20. Further, as shown in FIG. 4, the upper link 15 extends obliquely upward from the pivot portion 22, and the rear end portion 15 </ b> R is pivotally attached to an upper link mounting bracket 30 provided in the differential housing 20. As shown in FIG. 2, the upper link 15 and the lower link 16 are arranged so as to be bilaterally symmetric in plan view about the center line 31 of the pivot portion 22, and form an isosceles triangle 32. As shown in FIG. 3, the isosceles triangle 34 is formed so as to be vertically symmetric with respect to a line 33 connecting the pivot shaft 24 and the axle shaft 19 when viewed from the side.
[0023]
As shown in FIG. 3, a rear shock absorber mounting portion 36 is integrally formed on the upper portion of the lower link mounting bracket 29, and the lower end portion of the rear shock absorber 21 is pivotally attached to the mounting portion 36. The upper end of the rear shock absorber 21 is pivotally attached to a rear shock absorber mounting bracket 37 provided on the vehicle body frame 2 as shown in FIG.
[0024]
Next, the operation of this embodiment will be described.
[0025]
The front end portion 15F of the upper link 15 and the front end portion 16F of the lower link 16 are arranged side by side in the width direction of the vehicle body on the pivot portion 22 and are pivotally attached by a single pivot shaft 24. The car body side mounting part is reduced to two places.
[0026]
Further, by using the upper link 15 and the lower link 16 having the same shape, the cost is reduced, and assembly and component management are facilitated. Specifically, it is possible to prevent erroneous link assembly and shipping.
[0027]
Further, by using the upper link 15 and the lower link 16 having the same shape, the links 15 and 16 can be arranged to form isosceles triangles 32 and 34 in a plan view and a side view. Further, by arranging the links 15 and 16 in an isosceles triangle shape in a plan view and a side view, the vertical movement such as driving force and braking force is an isosceles triangle shape in a plan view, and the rear wheel 13 is turned during turning. The lateral movement according to the isosceles triangle shape in a side view can be sufficiently regulated, and a traveling performance close to that of an independent suspension type rear wheel suspension device can be obtained.
[0028]
Furthermore, the axial line 25 connecting the left and right pivot shafts 24 is disposed so as to pass through the rotation shaft center 27 of the universal joint 26 that connects the engine 7 and the propeller shaft 17, thereby changing the position of the differential 18 on the input side. As a result, the universal joint on the differential 18 side becomes unnecessary.
[0029]
When the vehicle 1 travels on rough terrain and the left and right rear wheels 13 have different heights, the rear wheels 13 follow the road surface by deforming the ring bushes 28 of the link front end portions 15F and 16F. Is possible, and stable running is possible.
[0030]
【The invention's effect】
As described above, according to the rear wheel suspension device of the saddle-ride type vehicle according to the present invention, the upper link and the lower link having the same shape, the differential housing that holds the axle shaft, and the rear shock absorber are configured. In the rear-wheel suspension device, the front links of the upper link and the lower link are juxtaposed in the width direction of the vehicle body at the pivot portion provided in the vehicle body frame, and the upper link is pivotally attached by a single pivot shaft. Is extended obliquely upward from the pivot portion, the rear end thereof is pivotally attached to a mounting bracket provided on the differential housing, and the lower link is extended obliquely downward from the pivot portion, The rear end is pivotally attached to the mounting bracket provided on the differential housing. On the other hand, the upper link and the lower link are formed so as to form an isosceles triangle symmetrical in a plan view with the center line of the pivot portion as an axis, and with a line connecting the pivot shaft and the axle shaft as an axis. Since it is arranged so as to form an isosceles triangle that is symmetrical in the vertical direction when viewed from the side, the vehicle body side mounting portion of each link is reduced, the structure is simplified and the assembly is facilitated, so there is no cost. Since the isosceles triangle shape sufficiently restricts the movement in the vertical and horizontal directions, good running performance can be obtained.
[Brief description of the drawings]
FIG. 1 is a left side view of a saddle riding type vehicle showing an embodiment of a rear wheel suspension device of the saddle riding type vehicle according to the present invention.
FIG. 2 is a plan view of a rear wheel suspension device.
3 is a cross-sectional view taken along line III-III in FIG.
4 is a cross-sectional view taken along the line IV-IV in FIG.
5 is a cross-sectional view taken along line VV in FIG.
[Explanation of symbols]
1 straddle-type vehicle 2 body frame 7 engine 10 front wheel 13 rear wheel 14 rear wheel suspension device 15 upper link 15F upper link front end 15R upper link rear end 16 lower link 16F lower link front end 16R lower link rear End portion 19 Axle shaft 20 Differential housing 21 Rear shock absorber 22 Pivot portion 24 Pivot shaft 29 Lower link mounting bracket 30 Upper link mounting bracket 31 Centerline of pivot portion 32 Isosceles triangle in plan view 33 Line connecting pivot shaft and axle shaft 34 Isosceles triangle in side view

Claims (1)

The engine is mounted at the center lower part of the body frame, and the exhaust pipe and muffler that constitute the exhaust system of the engine are connected to the front side of the engine, and the exhaust pipe and muffler have the same shape of the upper link and lower link in side view. The rear suspension of a straddle-type vehicle is arranged above the differential housing that holds the axle shaft , and the rear shock absorber is attached to the front side of the vehicle with the upper part tilted forward and wide low-pressure tires are attached to the front and rear wheels. In the device
The front links of the upper link and the lower link are arranged side by side in the width direction of the vehicle body on the pivot portion provided on the vehicle body frame, and the upper link is inclined from the pivot portion while being pivotally attached by a single pivot shaft. Extending upward, the rear end thereof is pivotally attached to a mounting bracket provided on the differential housing, the lower link is extended obliquely downward from the pivot portion, and the rear end thereof is extended to the differential. While pivotally attached to a mounting bracket provided in the housing, the upper link and the lower link form an isosceles triangle symmetrical in a plan view with respect to the center line of the pivot portion, and the pivot Form an isosceles triangle that is vertically symmetric in side view with respect to the line connecting the shaft and the axle shaft Arrangement, and further in plan view, the rear shock absorber is attached to the vehicle in a state where the lower portion of the axle shaft side is widened with respect to the body frame of the upper, yet lower end of the rear shock absorber, the pivot shaft and the axle shaft A rear-wheel suspension device for a saddle-ride type vehicle, wherein the rear-wheel suspension device is mounted on an upper portion of a mounting bracket to which the lower link is attached above a line connecting the two .

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