JP2708075B2 - Steering wheel suspension - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an upper link arm and a lower link extending laterally between a vertical position of a hub carrier that rotatably supports wheels and a vehicle body. The present invention relates to a steering wheel suspension device connected by an arm. <Conventional technology> The caster angle of the front wheels is increased on the bump side (shrinkage side of the suspension) as a geometric configuration of the suspension to reduce the so-called nose dive phenomenon in which the front side of the vehicle body sinks during sudden braking etc. Anti-dive geometries are known. In order to realize such a dynamic change in wheel alignment by a double wishbone type suspension device in which a vertical link arm connects a vertical position of a hub carrier and a vehicle body, an upper link arm and a lower link arm are used. The extension line of the rotating shaft on the vehicle body side intersects behind the front wheel axle and above the tire contact point, that is, to give the vehicle body rotating shaft of the upper link arm a forward-inclined inclination, or Generally, a configuration is adopted in which the vehicle body-side rotation axis of the arm is parallel to the vehicle body center line, and an extension of the vehicle body-side rotation axis of the left and right upper arms crosses the front axle. <Problems to be Solved by the Invention> According to these, the front and rear positions of the pivot point of the upper link arm of the vehicle body need to be provided with a deviation in the height direction or the width direction, and a dead space exists in the engine room. And the shape of the upper link arm mounting portion of the frame becomes complicated, making it difficult to secure rigidity. In view of such disadvantages of the related art, a main object of the present invention is to provide a steering wheel suspension device capable of realizing an anti-dive geometry while simplifying a vehicle body structure of a pivot portion of an upper link arm. Is to do. <Means for Solving the Problems> According to the present invention, there is provided an upper link extending in a lateral direction between a vertical position of a hub carrier rotatably supporting a wheel and a vehicle body. A steering wheel suspension device connected by an arm and a lower link arm,
The upper link arms are composed of a pair of front and rear juxtaposed, the pivot heights of the pair of upper link arms with respect to the vehicle body are substantially equal to each other, and the pivot height of the upper link arms with respect to the hub carrier is lower than the rear side. The steering wheel suspension is characterized in that the front side is lowered. <Operation> With this configuration, a difference in the projected length of the upper link arms on the horizontal plane occurs as the wheels move up and down. Especially on the bump side, since the rear link arm tends to be shorter, the trajectory seen from the side of the vehicle body at the upper link arm pivot point of the hub carrier moves rearward as it bumps. Becomes Therefore, the caster angle at the time of bump can be increased. 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 front 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. A knuckle arm 4 is integrally extended rearward from a lower portion of the hub carrier 2, and a tie rod 5 for transmitting a steering force is pivotally attached to its free end. One end 6a, 7a of an upper link arm 6, 7 is pivotally connected via a ball joint to the front and rear position of the upper part of the hub carrier 2, and the other end 6b, 7b of the upper link arm 6, 7 is the same. (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 rear 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 as in the case of the one ends 8a and 9a, but since the lower left and right angular displacements of the lower link arms 8 and 9 with respect to the vehicle body are relatively small, The angular displacement of the lower link arms 8 and 9 accompanying the steering can be sufficiently tolerated even by bending of the 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. The upper end of the shock absorber 10 is connected to a vehicle body (not shown).
And extend obliquely in the front-rear direction with respect to the vehicle width direction so as not to interfere with the vehicle. In this embodiment, the driving wheels of a front-wheel drive vehicle are used.
A part indicated by reference numeral D in the figure is a drive shaft. In this manner, the axle 1 is supported 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 or the position of the pivot point. In addition, tie rod 5
The right and left traction force is applied to the hub carrier 2
In this case, the wheel 1 is steered about 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 two instantaneous rotation centers 12 and 14. As is well known, an anti-dive effect can be obtained by increasing the caster angle of the front wheel on the bump side. Therefore, in the present invention, as shown in FIG. 5, the height positions of the other ends 6b, 7b, which are the vehicle body-side pivot points of the front and rear upper link arms 6, 7, are set to be substantially equal to each other. The height position of one end 6a, 7a, which is the side pivot point, is
It is set so that the front side 6a is lower than that of. FIG. 6 schematically shows the relationship between the upper link arms 6 and 7, and the upper link arms 6 and 7.
Rotates about the other end 6b, 7b as the center axis 16, and with this rotation, the one end 6a, 7a also moves in the vehicle width direction.
Here, since both ends 6a and 7a have a vertical difference, that is, a rotational phase difference with respect to the rotation center 16, the arm length 1 of the front upper link arm 6 projected on the horizontal plane and the arm of the rear upper link arm 7 The dimension difference δl from the length l2 increases (δl ') as it rotates upward. On the other hand, both ends 6a and 7a are connected to the upper end of the hub carrier 2 which is a rigid body, so that the longitudinal gap is mechanically determined. Therefore, the locus of the upper end of the hub carrier 2 given by the intersection of the upper link arms 6 and 7 is pulled by the rear link arm 7 as it rotates upward, and moves rearward on the bump side. This means that the vertical angle of the hub carrier 2 increases as bumping occurs, that is, the caster angle increases. In order to obtain an anti-dive geometry, it is common to appropriately set the position of the vehicle body-side pivot point of the upper link arm, but this tends to complicate the frame shape. According to the present invention, as described above, it is not necessary to provide a deviation in the height direction or the width direction at the front and rear positions of the pivot point of the upper link arm of the vehicle body, so that the frame design can be simplified. <Effects of the Invention> As described above, according to the present invention, it is possible to realize an effective anti-dive geometry without complicating the frame structure, increase the toe-camber rigidity, and increase the steering wheel suspension device. There is a great effect in improving the characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a steering 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 side view of a main part of the suspension device of FIG. FIG. 6 is an explanatory diagram showing a change in apparent length accompanying rotation of the front and rear upper 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 ... Other end 10 ... Shock absorber, 11 ... Stabilizer 13.15 ... Trajectory, 12.14 ... instantaneous rotation center 16 ... center

Continuation of front page    (56) References JP-A-59-223507 (JP, A)                 JP-A-58-67508 (JP, A)                 JP-A-61-171604 (JP, A)                 JP-A-60-64006 (JP, A)                 JP-A-60-92907 (JP, A)                 JP-A-61-263809 (JP, A)                 Japanese Patent Publication No. 52-9889 (JP, B2)

Claims (1)

(57) [Claims] A steering wheel suspension device comprising an upper link arm and a lower link arm extending in a lateral direction, respectively, connecting a vertical position of a hub carrier that rotatably supports wheels and a vehicle body, wherein the upper link The pair of arms are arranged side by side in front and rear, the pivotal height of the pair of upper link arms with respect to the vehicle body is substantially equal to each other, and the pivotal height with respect to the hub carrier is higher than that of the rear side. A steering wheel suspension device characterized in that the side is lowered.