JP2647096B2 - Steering wheel suspension - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a steering system in which the upper and lower positions of a hub carrier and a vehicle body are connected by a pair of lateral links arranged in the front-rear direction. The present invention relates to a wheel suspension device.

<Conventional technology> As a steering wheel suspension device capable of reducing steering space as much as possible upon steering while satisfying steering characteristics and running stability, for example, Japanese Patent Publication No. 52-9889. A structure has been proposed in which the upper and lower positions of a hub carrier that supports wheels are connected to a vehicle body via a pair of lateral link arms, respectively, as disclosed in Japanese Patent Application Laid-Open Publication No. H11-163,036. A wheel steered by the link mechanism having such a structure turns around an instantaneous rotation center given by a point of intersection of a straight line connecting the vehicle body of the lateral link arm arranged in front and rear and the pivot point of the hub carrier.

On the other hand, as a geometric configuration of a suspension for mitigating a so-called nose dive phenomenon in which the front side of the vehicle body sinks during sudden braking or the like, a bump side (a contraction side of the suspension) is used.
There is known an anti-dive geometry in which the caster angle of the front wheel is increased.

<Problems to be solved by the invention> However, since the wheels relatively move up and down due to the roll of the vehicle body, in the case of a bridge device in which the caster angle is changed according to the up and down movement of the wheels, It is conceivable that the steering holding force sometimes changes.

In view of such circumstances, a main object of the present invention is to provide a steering wheel suspension device capable of realizing an anti-die geometry without affecting a steering force at the time of turning.

<Means for Solving the Problems> According to the present invention, one end of each of the hub carriers rotatably supporting a wheel is pivotally connected to the upper and lower positions of the hub carrier, and the other end is provided on the vehicle body side. A pair of upper and lower lateral links pivotally attached to each other in the front-rear direction to support the hub carrier so as to be able to move up and down. The steering system is characterized in that the directional link is such that, when the rear-side one is placed in a horizontal state, the front-side one is inclined upward from a pivot point with the vehicle body. This is achieved by providing a wheel suspension.

<Operation> In this way, the projected length of the lateral link on the horizontal plane becomes shorter on the front side than on the rear side as the wheel bumps. Therefore, the trajectory of the pivotal connection between the upper and lower links and the hub carrier as viewed from the side of the vehicle body is pulled by the front link, and is displaced forward as the bump is made.
As a result, the center of contact with the tire moves forward on the bump side without changing the caster angle.

Embodiments Hereinafter, the present invention will be described in detail with reference to the accompanying drawings with reference to specific embodiments.

1 and 2 show a steering wheel suspension according to the invention. The wheel 1 is rotatably supported by a bearing 3 which is integrally and laterally protruded from a hub carrier 2. From the lower part of the hub carrier 2, the knuckle arm 4
Are integrally extended rearward, and a tie rod 5 for transmitting a steering force is pivotally attached to a free end thereof.

One end 6a, 7a of the upper link arm 6, 7 is pivotally connected via a ball joint to the front and rear position of the upper portion of the hub carrier 2, and the other end 6b, 7b of the upper link arm 6, 7 Each is connected to a vehicle body (not shown) via a ball joint. Further, one end 8a of the lower link arm 8.9 is pivotally connected to the lower front and rear position of the hub carrier 2 via a similar ball joint, and the other end 8b of the lower link arm 8.9 is connected to the lower link arm 8.9.
9b, the front end 8b is through the damper and the rear end
9b are respectively connected to the vehicle body via bushes.
The other ends 8b and 9b can be connected to the vehicle body via ball joints in the same manner as the one ends 8a and 9a. However, since the lower link arms 8 and 9 have relatively small lateral angular displacement with respect to the vehicle body, Lower link arm 8 for turning
9) The angular displacement of 9 can be sufficiently tolerated by bending of a rubber bush or the like.

The rear lower link arm 9 of the lower link arms 8 and 9 extends substantially linearly substantially along the vehicle width direction, and the front lower link arm 8 is provided on the vehicle body so as to also act as a radius rod. It extends diagonally forward. A lower end of a shock absorber 10 composed of a compression coil spring and an oil damper is connected to an intermediate portion of the rear lower link arm 9, and a stabilizer 11 is provided near the shock absorber connection portion of the rear lower link arm 9. Are connected. Although the upper end of the above-described shock absorber 10 is coupled to a vehicle body (not shown), so as not to interfere with the shock absorber 10,
The upper link arms 6, 7 extend obliquely in the front-rear direction with respect to the vehicle width direction.

In this embodiment, the driving wheels of the front wheel driving wheels are shown in FIG.

In this way, the wheel 1 is supported so as to be able to move up and down,
Moreover, the change of the camber angle, the toe angle, and the like can be freely set by appropriately selecting the length of the link, the position of the pivot point, and the like. In addition, a turning force is transmitted to the hub carrier 2 by applying a traction force in the left-right direction to the tie rod 5, and in this case, the wheel 1 is turned around a virtual kingpin axis described below.

Focusing on the upper link arms 6 and 7, as shown in FIG.
Is given as a locus 13 drawn by the intersection of the extension lines connecting the pivot points at both ends of both upper link arms 6 and 7. Focusing on the lower link arms 8.9, as shown in FIG. 4, the instantaneous center of rotation 14 at the lower end portion of the hub carrier 2 is also an extension line connecting the pivot points at both ends of both lower link arms 8.9. Given as a locus 15 of the intersection of Therefore, the rotation center axis of the hub carrier 2, that is, the virtual kingpin axis is
It is given by a line connecting these instantaneous rotation centers 12 and 14.

Now, the longer the wheelbase, the higher the anti-dive rate. That is, it is known that the nose of the vehicle is unlikely to sink. Therefore, an anti-dive effect can be obtained by moving the ground contact point of the wheel forward on the bump side.
Therefore, in the present invention, the apparent dimensions of the front upper and lower link arms 6.8 at the time of bumping are made shorter than those of the rear upper and lower link arms 7.9. ing.

As shown in FIG. 5, a straight line l1 connecting both ends 7a and 7b of the rear upper link arm 7 in a natural state extends substantially in the horizontal direction, whereas the front upper link arm 6
A straight line l2 connecting both ends 6a and 6b has an inclination angle that becomes higher as it goes from the pivot point to the hub carrier 2 side. A straight line l3 connecting both ends 8a and 8b of the front lower link arm 8 extends substantially in the horizontal direction, while a straight line l4 connecting both ends 9a and 9b of the rear lower link arm 9 has a pivot with the vehicle body. The inclination angle is set to be lower as going from the landing point to the hub carrier 2 side. The vertical angle between the pair of the upper and lower link arms 6, 7, 8, and 9 has a relationship determined by being connected to the hub carrier 2, and needless to say, the lower link arm 9 on the rear side. When the straight line l4 is placed in the horizontal state in the middle of the bump, the straight line l3 of the front lower link arm 8 has an inclination angle that becomes higher as it goes from the pivot point with the vehicle body to the hub carrier 2 side. In this way, as shown by l1 'to l4' in FIG. 5, the length of the upper and lower link arms 6, 7, 8, 9 projected on the horizontal plane when bumped from the natural state is as follows: The front link arms 6.8 are made shorter than the rear link arms 7.9.

On the other hand, one end 6a, 7a, 8a, 9a of the upper and lower link arms 6, 7, 8, 9 is connected to the hub carrier 2 which is a rigid body, and the longitudinal distance is mechanically determined. . Therefore, both upper and lower link arms 6.7
The virtual kingpin axis connecting the instantaneous rotational centers 12 and 14 at the upper and lower ends of the hub carrier 2 given at the intersection of 8.9 is pulled by the front link arms 6.8 on the bump side, and moves substantially parallel to the front. Becomes As a result, the wheel 1 is displaced forward together with the hub carrier 2, the wheel contact point at the time of bumping moves forward, and the anti-dive rate increases.

<Effect of the Invention> As described above, according to the present invention, it is possible to realize the anti-dive geometry of the suspension without changing the caster angle, and to achieve the anti-dive performance without affecting the steering holding force during turning. And there is a great effect in improving the characteristics of the steering wheel suspension device.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a steered wheel to which a suspension device according to the present invention is applied. FIG. 2 is a plan view of the suspension device of FIG. FIG. 3 is a skeleton diagram showing the geometric relationship of the upper link. FIG. 4 is a skeleton diagram showing the geometric relationship of the lower link. FIG. 5 is a skeleton diagram showing a change in apparent length accompanying rotation of each of the front and rear upper and lower link arms. DESCRIPTION OF SYMBOLS 1 ... Wheel 2 ... Hub carrier 3 ... Bearing 4 ... Knuckle arm 5 ... Tie rod, 6-9 ... Link arm 6a-9a ... One end, 6b-9b ... The other end 10 ... Buffer Apparatus, 11 Stabilizer 13.15 Track, 12.14 Instantaneous center of rotation

Claims (1)

(57) [Claims] 1. A pair of upper and lower lateral links each having one end pivotally attached to a vertical position of a hub carrier rotatably supporting a wheel and the other end pivotally attached to a vehicle body, respectively, in the front-rear direction. A steering wheel suspension device which supports the hub carrier so as to be vertically movable by being juxtaposed, wherein a relationship between the pair of upper and lower lateral links is located at a rear side, respectively. A steering wheel suspension device, wherein when it is placed, the front wheel is inclined upward from a pivot point with the vehicle body.