JPH01208290A - Two-front wheels suspension device and steering device for saddle type vehicle - Google Patents

Abstract

PURPOSE:To reduce steering force by steering a front wheel via the first and second steering axis having a handle bar on the upper end and rotatably supported in a nearly vertical direction to the suitable part of a frame. CONSTITUTION:The vertical motion of a front wheel 15 or 16 at the time of traveling is conducted in the condition where the motion is regulated by the vertical motion of the tip part of an upper and lower pair of swing arms 10, 11 and 12, 13 composing parallel links. The front wheel 15 or 16 makes the vertical motion in the nearly vertical direction in the fore and aft direction of a body (on the vertical plane in parallel to the body center plane N). The shock at that time is buffered by the elastic action of a suspension unit 21 or 22. Moreover the shock applied to the wheel 15 or 16 from the road surface when traveling or the vibration of the wheel 15 or 16 is absorbed with a second steering axis 6, and less applied to the handle bar 5 at the upper end of a first steering axis 2. Consequently steering force is reduced.

Description

Detailed Description of the Invention (Field of Industrial Application) This invention relates to an independent front two-wheel suspension and steering system for a riding type vehicle having two front wheels and two or two rear wheels suitable for traveling on rough terrain. This is about the device.

(Prior Art) As an independent front two-wheel suspension system for this type of riding vehicle, a double wishbone system or a strut system is generally adopted (for example,
No. 28989). In both of these systems, the base end pivots of both swing arms that support the front wheels via knuckle arms are arranged in the longitudinal direction of the vehicle body, and when the front wheels move up and down, the tip of each swing arm (the front wheel support part) ) swings vertically on a vertical plane perpendicular to the center plane of the vehicle body.

In addition, as a front two-wheel steering system for a riding type vehicle equipped with a front two-wheel suspension system as described above, the lower end of a steering shaft having a handlebar and knuckle arms on both sides are generally directly connected by a link mechanism. A sliding wheel structure is adopted in which the front two wheels are steered by rotating J'' in the direction of travel of the vehicle.

(Problems to be Solved by the Invention) According to the conventional suspension system described above, when the front wheels move up and down, the front wheels on both sides move up and down on a vertical plane perpendicular to the center plane of the car body, using the center of the car body as a fulcrum. Because the front wheels move in this direction, the tread and camber change each time the front wheels move up and down.

In addition, with the conventional steering system described above, when the front wheels move up and down, the impact from the road is directly transmitted to the handlebar at the upper end of the steering shaft via the knuckle arm and link mechanism, so the driver himself or herself has to control the handlebar. He is steering the vehicle while holding on to it and blocking the reaction force.

This invention was made in view of the above points, and the tread and camber do not change even when the front wheels move up and down, and the impact from the road surface on the front wheels is less likely to act on the handlebars, reducing steering force. The present invention aims to provide a front two-wheel suspension and steering device for a riding type vehicle used for traveling on rough terrain.

(Means for Solving the Problems) The gist of the present invention for achieving the above-mentioned object is to provide a pair of upper and lower swing arm bases on both sides of the lower center of the front end of the frame by means of pivots perpendicular to the center plane of the vehicle body. The ends thereof are pivoted so as to be able to freely swing in the vertical direction, and between the ends of the upper and lower swing arms on both sides, a knuckle arm with a front wheel rotatably supported is supported so as to be freely pivotable horizontally, and is mounted at a suitable position on the frame. The front two wheels are steered via a first steering shaft and a second steering shaft, each of which is rotatably supported in a substantially vertical direction and has a handlebar at its upper end.

(Function) According to the front two-wheel suspension and steering device of the present invention, 4+ii
When the seven wheels move up and down, the front wheel support position at the tip of the swing arm moves up and down along the longitudinal direction of the vehicle body (a vertical plane parallel to the center plane of the vehicle body), and the front wheel is regulated by the vertical movement of the tip of the swing arm. Therefore, the tread and camber do not change and remain almost constant. Further, most of the impact from the road surface on the front wheels and the vibrations of the front wheels are absorbed by the second steering shaft, and are unlikely to directly act on the handlebar at the upper end of the first steering shaft.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a partially omitted front view of the riding type vehicle, FIG. 2 is a partial top view of FIG. 1, and FIG. 3 is a view taken along the line ■-■ in FIG. 1.

As shown in FIG. 3 of these drawings, a frame l of the riding type vehicle X extends forward from the center of the front part of the vehicle It extends downward in a letter shape. As shown in FIGS. 1 and 3, a head vibrator 3 is fixed approximately vertically to the upper rear side of the frame 01j.
The first steering shaft 2 passes through the bearing 4 and is rotatably supported on the bearing 4. A handlebar 5 is attached to the upper end of the first steering shaft 2 so as to be rotatable therewith.

A middle vibe 7 is vertically fixed to the lower front end of the frame 1, and a second steering wheel 6 is rotatably supported by a bearing 8 passing through the middle vibe 7.

On both sides of the lower front end of the frame 1, as shown in FIGS. 1 and 2, there are upper and lower pairs of swing arms 10, 11 and 12, 13, which are shaped like an upward cursor, and which are attached to the vehicle body at their base ends, respectively. Pivot axes 10a, 11a and 1 perpendicular to central plane N
2a and 13a, and extends rearward so as to be swingable in the vertical direction.

As shown in FIG. 1, front wheels 15 and 16 are rotatably supported by knuckle arms 17 and 18, respectively.
Each knuckle arm 17 and 18 is pivotally mounted between the tip portions of the swing arms to, it and 12.13 via king pins 19 and 20 so as to be horizontally pivotable. Each of the knuckle arms 17 and 18 has a horizontal portion 1 whose lower end side extends in the direction of the vehicle body center plane N.
7a and 18a.

Further, suspension units 21 and 22 such as shock absorbers are stretched between intermediate portions of the upper swing arms 1° and 12 on both sides and near the bent portion of the frame 1.

As shown in FIGS. 1 and 2, an offset lever 31 is fixedly installed at the lower end of the first steering shaft 2 so as to protrude to the right side of the vehicle center plane N, and at the upper end of the second steering shaft 6. The offset lever 3 protrudes to the left of the vehicle center plane N.
2 is fixedly installed, and between the tips of both offset levers 31 and 32, a first tie rod 33 connects the rod ends 33 at both ends.
a, 33b.

Furthermore, an offset lever 34 is fixedly installed at the lower end of the second steering shaft 6 so as to protrude to both sides of the vehicle body center plane N, and both ends of the offset lever 34 and the horizontal part 1 of the knuckle arm 1 are connected to each other.
The rod ends 35a, 3 at both ends are connected between the tips of the rods 7a and 18a by second tie rods 35 and 36, respectively.
5b and are connected via 36a and 36b.

By the way, in this example, as is clear from FIG.
The tip side of the second tie rod 36 with respect to the knuckle arm 18 and the pivot points A, B, and C of the pair of upper and lower swing arms 12 and 13 are located on the same straight line P when viewed from the side,
Also, the pair of swing arms 12, 1 are connected to the proximal side pivot point of the second tie rod 36 and the lower front end of the frame l.
3, each pivot point E, F is on the same straight line Q parallel to the straight line P.
The second tie rod 36 and the swing arms 12, 13 located above are parallel to each other when viewed from the side, and form so-called parallel links. For this reason,
Even if the front wheel 16 moves up and down during driving, the middle part of the knuckle arm 18 will not be pushed or pulled by the second tie rod 36 due to the up and down movement, and therefore the knuckle arm 18 (front wheel 16) will not be pushed or pulled by the second tie rod 36. The direction of does not change. However, the present invention is not limited to this configuration, and the pair of swing arms 12 and 1 are connected to the proximal pivot point of the tie rod 36 and the lower front end of the frame l.
If the pivot points E and F of 3 are arranged on the same straight line Q, for example, it is possible to change the length of the second tie rod 36 or make the tie rod 36 somewhat inclined with respect to the swing arm 12.13. be. Although the above description relates to the right front wheel 16, the same applies to the left front wheel 15. In addition, in this embodiment, swing arms 10.
The tips of swing arms 11 and 12.13 (supporting parts for the front two wheels) are extended to the rear of the vehicle body to provide a mounting space for an engine, etc., immediately behind the front two wheels 15 and 16. It is also possible to extend the tip end (support part of the front two wheels) of .13 toward the front of the vehicle body. Although not shown, the riding type vehicle X has a frame extending rearward from the first steering shaft 2 in FIG. 2, and two rear wheels are attached to the rear end of the extended frame. or - wheels are provided, and a seat is provided on the frame at a position approximately midway between the front wheels 15 and 16 and the rear wheel;
It has a well-known structure in which the engine, electrical components, etc. are mounted on the rear of parts 5 and 16.

Further, in FIG. 1, 15c and 16c are tires of the front wheels 15 and 16, 15d and 16d are wheels, 15e and 16e are brake discs, and 15f and 16r are calipers.

Next, the operation mode of the suspension system and the steering system for the two front wheels will be explained in the above-described embodiment.

In FIG. 2, when the driver rotates the handlebar 5 in the direction in which the driver intends to proceed (for example, to the right), the first steering shaft 2 rotates clockwise, and the offset lever 31 is rotated together with the first steering shaft 2. Rotate clockwise. at the same time,
Pulled rearward by the first tie rod 33, the offset lever 32 at the upper end of the second steering shaft 6 rotates counterclockwise together with the second steering shaft 6. At the same time, the offset lever 34 at the lower end of the second steering sleeve 6 rotates counterclockwise together with the second steering sleeve 6. As the offset lever 34 rotates, the second tie rod 35 on the left side is pushed backward, and the second tie rod 36 on the right side is pushed backward as shown in FIG.
is pulled forward, the knuckle arms 17 and 18 on both sides rotate clockwise around pivot points B and C with the swing arms 10, 11 and 12, 13, and the front wheel 1
5 and 16 simultaneously turn to the right. In addition, in the opposite direction (
When the handlebar 5 is rotated to the left (left side), the front wheels 15 and 16 turn to the left in the same manner as described in item 1.

Further, the vertical movement of the surface 15 or 16 during running is caused by a pair of upper and lower swing arms 10.1 forming a parallel link.
1 and 12.13, the front wheels 15 or 16i11 move up and down approximately vertically in the longitudinal direction of the vehicle body (on a vertical plane parallel to the vehicle center plane N). The impact when the front wheels 15 or 16 move up and down is buffered by the expansion and contraction action of the suspension unit 21 or 22.

Furthermore, shocks from the road surface that act on the front wheels 5 or 16 and vibrations of the front wheels 15 or 16 during driving are absorbed by the second steering shaft 6 and act on the handlebar 5 at the upper end of the first steering shaft 2. Less is.

(Effects of the Invention) The front wheel steering device for a two-wheeled vehicle of the present invention configured as described above provides the following effects.

(1) The base ends of the pair of upper and lower swing arms are pivoted so that they can freely swing in the vertical direction using pivots perpendicular to the center plane of the vehicle body, so when the front wheels move up and down, the front wheel support position of the tip of the swing arms is fixed to the vehicle body. The front wheels move up and down along the longitudinal direction (vertical plane parallel to the center plane of the vehicle body), and the front wheels follow the vertical movement of the tip of the swing arm, so the tread and camber do not change and remain almost constant.

(2) The front two wheels are steered via a first steering shaft and a second steering shaft each having a handlebar at the upper end, which are rotatably supported in a substantially vertical direction at appropriate positions on the frame. Each member of the system, such as tie rods and offset levers, can be formed into a simple shape such as a straight rod or a plate, making manufacturing easier. In addition, since the steering system is supported by the frame at two locations, the first steering shaft and the second steering shaft,
Structurally, it has higher strength.

(3) With the configuration described in (2) above, most of the reaction force from the road that acts on the front wheels and vibrations of the single wheel during driving are absorbed by the second steering shaft, and are less likely to act on the handlebars. Become.

(4) If the frame pivot point of the swing arm is provided in front of the front two wheels as in the above embodiment, a space can be secured to mount an ennon etc. immediately after the front two wheels, increasing the degree of freedom in design.

[Brief explanation of the drawing]

FIG. 1 is a partially omitted side view of a riding type vehicle showing an embodiment of the present invention, FIG. 2 is a partial top view of FIG. 1, and FIG.
The figure is a view taken along the line lll-1 in FIG. 1. l... Frame, 2... First steering shaft, 5... Handlebar, 6... Second steering shaft, 10, 11, 12.13.
・Swing arm, 15.16...Front wheel, 17.18
...Knuckle arm, 31, 32.34...Offset lever, 33,35.36...Tie rod. Figure 1 Figure 2

Claims (1)

[Claims] The base ends of a pair of upper and lower swing arms are pivoted to both sides of the lower center of the front end of the frame by pivots perpendicular to the center plane of the vehicle body, allowing them to swing freely in the vertical direction, and the front wheels are rotated between the tips of the upper and lower swing arms on both sides. A first steering shaft and a second steering shaft each having a handlebar at an upper end, each supporting a movably pivotally supported knuckle arm so as to be horizontally rotatable, and each having a handle bar at an upper end, each of which is rotatably supported in a substantially vertical direction at an appropriate position on the frame. A front two-wheel suspension and steering device for a riding type vehicle, in which the front two wheels are steered through the vehicle.