JPH0490909A - Steering wheel suspension device - Google Patents

Abstract

PURPOSE:To improve freedom for setting positional relation ship between a damper and a lateral link by connecting the lower part of a knuckle to a vehicle body with a lower link, connecting the middle part of the knuckle to the vehicle body with a mid link, and connecting the upper part of the knuckle to the vehicle body by means of the upper link. CONSTITUTION:A mid link 9 connected to height position above the drive shaft 6 of a knuckle 7 and more inside in radial direction than the inside diameter of a tire 2 is extended along nearly width direction of a vehicle body, and the inner end 9b thereof is swingably connected to the bottom side bracket 10a of a main frame 10. An upper link 12 connected to the upper and of an elongation member 7a extended from the upper part of the knuckle 7 is extended backward a little obliquely inward, and the rear end 12b is swingably connected to the upper side bracket 10b of the main frame 10. A lower link 16 connected to the bottom end 7c of the knuckle 7 is connected to the vehicle body so as to be swingable about an axis A the rear side of which is somewhat directed upward against a horizontal line while somewhat inclined in a direction for opening outward.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION Field of Industrial Application The present invention relates to a steering wheel suspension system, and particularly to an improvement of a double wishbone type suspension system.

<Prior art> A double wishbone type suspension system is known as a suspension system that provides a high degree of freedom in setting the suspension geometry and also provides high rigidity, and in recent years, variations with various link configurations have been put into practical use. has been done.

As one of these variations, there is a type in which the connection part of the upper lateral link to the knuckle is provided at a relatively high position on the outside in the radial direction than the inner diameter of the tire (see Japanese Patent Laid-Open No. 59-96008, etc.). . This type of suspension system has the advantage that even if the longitudinal conformance of the connecting portion with the vehicle body on the lower lateral link side is increased, the change in caster angle is relatively small.

<Problems to be Solved by the Invention> On the other hand, the damper in the steering wheel of a double wishbone suspension system cannot be directly connected to the knuckle, so it is generally connected to a lateral link. In order to ensure the bending strength of the lateral link against reaction force and to make the damper stroke as large as possible, it is preferable to provide the connecting portion of the damper as close as possible to the connecting portion of the lateral link with the knuckle.

However, in the suspension system of the type shown in the above publication, the connecting positions of both the upper and lower lateral links and the knuckle are relatively strictly determined by the setting of the virtual kingpin axis, so it is difficult to satisfy this requirement. In order to do this, the upper lateral link connecting portion of the knuckle is extended upwardly so as to avoid the inner surface of the tire. Therefore, in order to avoid interference between the extending portion and the coil spring, it is difficult to move the connecting portion of the damper to the lateral link toward the knuckle. As a result, the so-called damper lever ratio, which represents the relationship between the pivot point between the vehicle body and the knuckle in the lateral link and the connection position of the damper, increases, and the bending stress of the lateral link due to damper reaction force increases, and the damper or vehicle body There was an inconvenience that the cross-sectional area of the side frame was affected because it was moved inward.

The present invention was devised to improve such inconveniences, and its main purpose is to increase the longitudinal compliance of the lower lateral link to the vehicle body.
It is an object of the present invention to provide a wheel suspension device configured to increase the degree of freedom in setting the positional relationship between a tamper and a lateral link while taking advantage of the fact that caster angle changes are relatively small.

[Structure of the Invention] Means for Solving the Problems This object is to connect the lower part of the knuckle that rotatably supports the wheel and the vehicle body with a lower link, and to connect the lower part of the knuckle that rotatably supports the wheel with the vehicle body, and The middle part of the knuckle, which is located at a height inside the tire's inner diameter, and the vehicle body are connected by a mid-link extending generally in the vehicle width direction, and the upper part of the knuckle, which is located at a height outside of the tire's inner diameter, and the vehicle body. This is achieved by providing a steering wheel suspension system that is configured to be connected to the steering wheel suspension system by an upper link that extends generally in the front-rear direction.

In particular, it is preferable to connect the lower end of the damper to the mid-link.

<Function> According to such a configuration, the virtual kingpin axis connects a straight line connecting the connection points of the upper link with the car body and knuckle, a straight line connecting the connection points of the midlink with the car body and knuckle, and the knuckle of the lower link. It is given by a vertical straight line that simultaneously crosses the connecting point. That is, as long as the extending directions of the virtual axes of both the upper and middle links are determined according to the setting of the virtual kingpin axis, the positions of the connection points with respect to these knuckles can be determined relatively freely. Therefore, if the lower end of the damper is connected to the mid-link located above the center of the wheel, it becomes possible to appropriately determine the mounting position of the damper without affecting other components.

In addition, since the portion of the knuckle above the wheel center is supported by the vehicle body in the front-rear direction and left-right direction using separate members, the front-rear component force and the left-right component force applied to the upper part of the knuckle are reduced. They will be supported separately by frames. Therefore, it is possible to relatively easily provide a link connection portion in a highly rigid portion.

<Example> The structure of the present invention will be described in detail below based on a specific example shown in the attached drawings.

1 to 3 show a drive wheel suspension system 1 to which the present invention is applied. A brake rotor 4 and a hub 5 are installed collinearly at the center of a road wheel 3 on which a tire 2 is mounted.

The outer end of a drive shaft 6 is connected to the hub 5 via a hub bearing and a constant velocity joint (not shown). Further, the road wheel 3 is pivotally supported by the knuckle 7 via a hub bearing.

An outer end 9a of a mid-link 9 is connected to the knuckle 7 at a height position above the drive shaft 6 and radially inward than the inner diameter of the tire 2 via a hole joint 8. This mid-link 9 extends generally along the width direction of the vehicle body, and is a closed-section main body extending in the front-rear direction between the wheel house and the engine room of the vehicle body (not shown in the figure). An inner end 9b thereof is swingably connected to a bracket (10a) provided on the lower side of the frame 10.

An extension portion 7a that is curved inwardly and rearwardly extends from the upper part of the knuckle 7 toward a position adjacent to the shoulder portion of the tire 2.

A front end 12a of an upper link 12 is connected to the upper end of this extension 7a via a ball joint 11.

This upper link 12 extends rearward and slightly diagonally inward, and its rear end 12b is connected to the main frame 10.
It is swingably connected to a bracket 10b provided on the upper side.

At a position adjacent to the outer end 9a of the mid-link 9, there is a tamper 13a filled with oil, and a tapered coil spring 13b with a wide upper side! The lower end 13c of the shock absorber 13, which is formed by coaxially combining: is connected. The upper portion 1.3d of this buffer 13 is attached to a side frame 14 connected to the main frame 10.

One end 16a of a lower link 16 is connected to the lower end 7c of the knuckle 7 via a ball joint 15. This lower link 16 has a substantially right triangle shape with one vertex connected to the lower end 7C of the knuckle, and its rear side is slightly upward with respect to the horizontal line (Fig. 2), and its rear side with respect to the center line of the vehicle. It is connected to the vehicle body in such a way that it can swing about an axis A whose sides are inclined slightly outwardly (FIG. 3).

In addition, each of the above upper, middle, and lower links 12, 9,
Rubber bushings having appropriate elasticity are interposed at the 16 connecting portions with the vehicle body. In particular, the lower link 16 is provided with sufficient compliance in the axis A direction (front-rear direction) so that the tire can escape to the rear and absorb the impact when the tire runs over a road protrusion.

At the rear of the axle 6 in the middle part of the knuckle 7, a knuckle arm 7b is integrally provided to protrude rearward (
Figure 2). A tie rod 17 for transmitting the steering force of a steering wheel (not shown) is connected to its free end via a ball joint 18.

In addition, although the above embodiment showed only one side of the wheel,
The other one is bilaterally symmetrical and structurally the same, so its explanation will be omitted.

Next, the operation of this embodiment will be explained.

When the tire 2 moves up and down along the road surface, the upper, mid, and lower links 12, 9, and 1 connected to the knuckle 7
6 swing up and down around the connecting point with the vehicle body, and along with this, the shock absorber 13 performs an expansion and contraction movement, and due to the damping action of the damper 13a and the damping action of the spring 13b, the tire 2 is moved from the tire 2 to the vehicle body. Transmitted vibrations and shocks are effectively absorbed and alleviated.

Now, with conventional high-mount type suspension systems, the upper link, which requires high rigidity in both the front and rear and left and right directions, had to be connected at a relatively distant position from the main frame. Other measures were needed to increase this.

The suspension system 1 of the present invention divides the knuckle 7 into three parts, and provides longitudinal support with an upper link 12 connected to the upper end of the knuckle 7, and provides support in the left-right direction with a middle link 9 connected to the middle part. Therefore, it is possible to achieve a high level of balance between rigidity and compliance.

Moreover, since the mid-link 9 extends above the drive shaft 6 and relatively close to the drive shaft 6, its inner end 9b can be directly connected to the main frame 10.

On the other hand, the virtual kingpin axis in the suspension system 1 of the present invention includes a straight line U connecting the connecting points of the upper link 12 with the vehicle body and the knuckle, and a straight line M connecting the connecting points of the mid-link 9 with the vehicle body and the knuckle. , is given by a vertical straight line that simultaneously crosses the connection point C of the lower link 16 with the knuckle 7 (see FIG. 3). In other words, the extending direction of the virtual axes (straight line U and straight line ~1) of the upper mid links 12 and 9 is determined so that they intersect the virtual king pin axis that has been designed at the same time. The connection point position of both links 12 and 9 with respect to the knuckle 7 is
It only needs to be on this virtual axis.

Therefore, if the lower end 13c of the shock absorber 13 including the damper 13a is connected to the midlink 9 located directly above the axle 6, the midlink 9 can be connected without affecting the setting on the virtual kingpin axis. It is possible to install the shock absorber 13 close to the connection point with the knuckle 7,
Lower end of damper 1 relative to the distance between both supporting points of Mizlink 9
Since the value of the damper lever ratio (ratio of the 3rd dimension to the 5th dimension in Fig. 1), which represents the relationship between the connection positions of the links 3c and 3c, can be reduced, the bending rigidity of the link against the damper reaction force can be substantially increased. can. Moreover, since the shock absorber 13 can be moved toward the outside of the vehicle body, it becomes easy to secure the cross-sectional area of the main frame 10.

In addition, the input to the damper 13a in response to the input from the tire 2 is based on the main frame 1 with the side flares 4 and 14 light.
0 is man-powered. Then, the counter part of the tamper 13a is directly powered from the midlink 9 to the main frame 10.

Therefore, the human force and reaction force of the damper 13a are all converted into internal forces in the main frame 1o, so the number of deformed parts is reduced, and the responsiveness of the damper 13a can be improved.

In the above embodiment, the lower link 16 has a triangular integral structure, but it can also be made up of a plurality of parts. Further, the connection point between the upper link 12 and the knuckle 7 may be located at a position facing the side surface of the tire 2, or the connection point with the vehicle body may be located at the front.

Furthermore, it is not limited to the drive wheels shown in the above embodiments, but especially four wheels.
It can also be suitably applied to a rear wheel suspension system of a wheel-steering vehicle.

[Effects of the Invention] As described above, according to the present invention, even if the longitudinal compliance of the lower link is increased, only a small change in caster is required.
While taking advantage of the high mount type (the second part of the knuckle is located at a relatively high position), it is possible to move the connection position of the damper with the link closer to the connection point of the midlink 9 with the knuckle 7. Therefore, the bending stress of the link due to the damper reaction force is reduced. In addition, as shown in the above embodiments, since the vehicle body side connecting portion of each link can be placed close to the main frame, the attachment is also effective in ensuring rigidity.

In addition, since the portion of the knuckle above the wheel center is supported by the vehicle body in the front-rear direction and left-right direction using separate members, the front-rear component force and the left-right component force applied to the upper part of the knuckle are reduced. Because they are supported separately by frames,
It also has a great effect on achieving a higher level of balance between rigidity and compliance to wheel input.

[Brief explanation of the drawing]

FIG. 1 is a schematic front view showing the configuration of the front wheel suspension system according to the present invention for the left wheel, FIG. 2 is a side view thereof, and FIG. 3 is a diagram with the knuckle and drive shaft omitted. FIG. 1... Suspension system, 2... Tire, 3... Road wheel, 4... Brake disc, 5... Hub, 6...
...Drive shaft, 7...Knuckle, 8...Ball joint, 9...Mizlink, 10...Main frame, 11-...Ball joint, 12...
・Upper link, 13...Buffer, 13a...Tamper 13b...Coil spring, 14...Side frame 15...Ball joint, 16...Lower link, 17...Tie rod, 18 ... hole join)
・Patent applicant: Honda Motor Co., Ltd.
Patent attorney Yo Inujima (1 other person) Figure 2

Claims (2)

[Claims] (1) A knuckle that rotatably supports the wheel, a lower link that connects the lower part of the knuckle and the vehicle body, and an intermediate portion of the knuckle located above the center of the wheel and at a height inside the inner diameter of the tire and the vehicle body. and an upper link that connects the upper part of the knuckle and the vehicle body and extends generally in the longitudinal direction. A steering wheel suspension system comprising: (2) The steering wheel suspension system according to claim 1, wherein the lower end of the damper is connected to the mid link.