JPH03276805A - Multi-link type suspension for vehicle - Google Patents

Abstract

PURPOSE:To reduce the hood height while securing the sufficient bound and rebound strokes of wheels by combining a knuckle, an upper control arm, a lower control arm, a vertical link and a horizontal link into a specific structure. CONSTITUTION:The tip of a tie rod 18 is pivotally fitted to the knuckle arm 10a of a knuckle 10 rotatably supporting a wheel 14 via a bearing 12 with a ball joint 16. The inner end of an upper arm 20 is pivotally supported on a vehicle body 28 with a joint 24. The inner end of a lower arm 22 is pivotally supported on the vehicle body 28 with a joint 30, and the outer end is pivotally fitted to the lower end of the knuckle 10 with a ball joint 34. The upper end of a vertical link 36 is pivotally fitted to the outer end of the upper arm 20 with a ball joint 38, and the lower end is pivotally fitted to the middle section of the lower arm 22 with a joint 40. The outer end of a horizontal link 42 is pivotally fitted to the upper end of the knuckle 10 with a joint 44, and the inner end is pivotally fitted to the middle section of a vertical link 36 with a joint 46.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a suspension for a vehicle such as an automobile, and more particularly to a multi-link type suspension that is improved from a double wishbone type suspension.

[Prior Art] As is well known, the conventional double wishbone type suspension has a knuckle that rotatably supports the wheel, an inner end that is pivoted to the vehicle body, and an outer end that is pivoted to the knuckle. The lower control arm has an upper control arm that is pivoted to the vehicle body at an inner end, and a lower control arm that is pivoted to a knuckle at an outer end.

In order to separate the element for setting the kingpin axis and the element for setting the camber angle in such a double wishbone type suspension, for example, Japanese Patent Application Laid-Open No. 63-5730
As described in Publication No. 7, there is a knuckle that rotatably supports the wheel, an upper control arm that is pivotally supported on the vehicle body at the inner end, and a knuckle that is pivotally supported on the vehicle body at the inner end and the outer end of the knuckle. a lower control arm pivotally connected to the lower end;
a vertical link having an upper end pivoted to the outer end of the upper control arm, a lower end pivoted to the outer end of the lower control arm, and an intermediate part pivoted to the upper end of the knuckle;
An improved double wishbone suspension has already been proposed in which the kingpin axis is defined by a pivot point between the knuckle and the control arm and a pivot point between the knuckle and the vertical link. .

[Problems to be Solved by the Invention] However, in the double wishbone type suspension described in the above-mentioned Japanese Patent Application Laid-Open No. 63-57307, the amount of vertical displacement of the knuckle due to the bounce and rebound of the wheel. Since the amount of vertical displacement of the outer end of the upper control arm and the amount of vertical displacement of the outer end of the upper control arm are substantially the same, the height of the hood of the vehicle body cannot be reduced.

In view of the above-mentioned problems with the suspension described in Japanese Patent Application Laid-open No. 63-57307, the present invention has been developed to reduce the height of the hood while ensuring sufficient bounce and rebound stroke of the wheels. The aim is to provide a multi-link suspension system with improved performance.

[Means for Solving the Problems] According to the present invention, the above objects include: a knuckle that rotatably supports a wheel; an upper control arm that is pivotally supported on the vehicle body at the inner end; a lower control arm which is pivotally supported on the vehicle body and whose outer end is pivotally connected to the knuckle, whose upper end is pivotally connected to the outer end of the upper control arm and whose lower end is pivotally connected to the intermediate portion of the lower control arm. This is achieved by a multi-link suspension for a vehicle having a vertical link and a horizontal link pivotally connected to the vertical link at an inner end and to the knuckle at an outer end.

[Operation of the Invention] According to the present invention, the effective length of the lower control arm is D, and the distance from the pivot point between the lower control arm and the vertical link to the inner end of the lower control arm is d.
Assuming that the outer end of the lower control arm is displaced upward by a distance #A+ due to the bounce of the wheel, the pivot point between the lower control arm and the vertical link is vertically displaced by a distance B, then B+ - (d /D) AI. Since the amount of upward displacement of the outer end of the upper control arm is substantially the same as the amount of upward displacement of the vertical link, (d/D)A.

becomes. Therefore, the vertical stroke of the outer end of the upper control arm is reduced according to the arm ratio d/D.
It becomes possible to reduce the height of the hood of the vehicle body while ensuring sufficient vertical stroke of the wheels.

The invention will now be described in detail by way of example embodiments with reference to the accompanying drawings.

[Example] Fig. 1 is a front view of one embodiment of the multi-link suspension according to the present invention as seen from the front side of the vehicle, and Fig. 2 is a skeleton diagram showing the operation of the embodiment shown in Fig. 1. FIG.

In these figures, reference numeral 10 indicates a knuckle that rotatably supports the wheel 14 via a bearing 12, and a knuckle arm 10a integrally provided with the knuckle is connected to the tip of a tie rod 18 by a ball joint 16. is pivoted. Further, in the figure, 20 and 22 indicate an upper control arm and a lower control arm, respectively. The upper control arm 2o extends obliquely toward the rear of the vehicle when viewed from the inner end toward the outer end, and is pivotable around an axis 26 by a bush-type joint 24 at the inner end. is pivotally supported on the vehicle body 28. The lower control arm 22 is pivotally supported on the vehicle body 28 at the inner end by a bush-type joint 3o so as to be pivotable around an axis 32, and at the outer end is pivotally connected to the lower end of the knuckle 10 by a ball joint 34. .

A vertical link 3 is attached to the outer end of the upper control arm 20.
The upper end of the vertical link 6 is pivotally connected by a ball joint 38, and the lower end of the vertical link is pivotally connected by a bush type joint 40 to the middle portion of the lower control arm 22, that is, between its inner and outer ends. The outer end of a horizontal link 42 forming an A-type arm is pivotally connected to the upper end of the knuckle 10 by a ball joint 44, and the inner end of the horizontal link is connected to the middle part of the vertical link 36, that is, its upper end, by a bush type joint 46. It is pivoted between the lower end. Further, the lower end of the shock absorber 5o is pivotally connected to the intermediate portion of the vertical link 36 by a bush type joint 48, and the upper end of the shock absorber 5o is pivotally connected to the vehicle body 28 by an upper support 52.

A suspension spring 58 is elastically mounted between spring seats 54 and 56 provided on the upper support 52 and the shock absorber 50, respectively.

FIG. 4 is a perspective view of another embodiment of the multi-link suspension according to the present invention, seen diagonally from the front of the vehicle, and FIG. 5 is a front view showing the operation of the embodiment shown in FIG. 4 as a skeleton diagram. It is a diagram. In these figures, parts corresponding to those shown in Figs. 1 and 2 are designated with the same reference numerals and symbols as those shown in Figs. 1 and 2. There is.

In this embodiment, the lower control arm is pivotally supported to the vehicle body at the inner end by a bush-type joint 30a around an axis 32, and at the outer end is connected to the lower end of the knuckle 10 by a ball joint 34a. The front lower arm 22a is pivotally connected to the vehicle body by a bush type joint 30b at the inner end so as to be pivotable around an axis 32, and the knuckle 1 is supported by a ball joint 34b at the outer end.
The rear lower arm 22b is pivotally attached to the lower end of the rear lower arm 22b. The joint 40 is provided at a pivot point between the vertical link 36 and the front lower arm 22a.

The axis 60 of the front lower arm 22a, that is, the straight line connecting the centers of the joints at both ends of the front lower arm, and the axis 62 of the rear lower arm 22b, that is, the straight line connecting the centers of the joints at both ends of the rear lower arm, intersect each other at an intersection 64. , a kingpin axis 66 is defined by this intersection 64 and the center of the joint 38. In particular, in the illustrated embodiment, when the wheel 14 is in its substantially neutral position, i.e., when the wheel is neither bouncing nor rebounding and is substantially unsteered, the ball joint The center of 44 is positioned on the kingpin shaft 66. Although the center of the ball joint 44 does not have to be on the kingpin shaft 66, the center of the ball joint 44 does not need to be on the kingpin axis 66, but the ball joint 4
Preferably, a straight line passing through the center of the joint 46 and perpendicular to the axis of the joint 46 intersects the kingpin axis 66.

As shown in FIG. 2, in the embodiment shown in FIG. As shown in FIG. 5, for the embodiment shown in FIG. 4, the effective length of the front lower arm 22a, that is, the distance between the centers of the joints 30a and 34a at both ends thereof, is d. is D, and the distance between the centers of joints 30g and 40 is d. Due to the bounce of the wheel 14, the joints 34 and 4
4 are displaced upward by distances A and A2, respectively, since the joints 34 and 44 move together with the knuckle 10, A, middle A2.

Also, the joints 34 and 40 are connected to the common arm 22 or 2.
Since it is provided on the joint 2a, if the upward displacement amount of the joint 40 is B, then B+ - (d/D)A+. Further, if the upward displacement amounts of the joints 46 and 38 are B2 and B3, respectively, since these joints are provided on the vertical link 36, they are B2, B3, and B depth. Therefore, (d/D)A+ in B3, and the vertical stroke of the outer end of the upper control arm 2o is reduced according to the arm ratio d/D, so that the hood of the vehicle body 28 can be adjusted without sacrificing the vertical stroke of the wheel. The height can be reduced.

Furthermore, in a range where the wheel bounce and rebound stroke are relatively small, the amount of lateral displacement of the outer end of the upper control arm 20 is also small, so from the above relationship A = = A2 92 = i = 83, Arm 22 (22a) and horizontal link 4
2 moves as if it were a parallel link.

Therefore, it is possible to reduce camber angle changes and torso/toad changes, thereby improving the straight-line running performance of the vehicle. Further, in this case, since the length of the horizontal link 42 may be short, it is possible to improve straight running performance with good space efficiency.

Also, when the vehicle is turning, when the wheel nozzle (land stroke) is relatively large, the upper control arm 2
Since the amount of lateral displacement of the outer end of 0 is also large, the camber angle becomes negative, and the change in the camber angle relative to the ground during turning becomes small. Therefore, the turning performance of the vehicle can be improved with a short upper control arm that is space efficient.

Furthermore, as shown in FIG. 3 corresponding to the embodiment shown in FIG. Moreover, since the extending direction of the horizontal link can be set relatively freely, the height H of the roll center Oc of the vehicle can be set relatively freely.

In particular, in the embodiment shown in FIGS. 4 and 5, the kingpin shaft 66 can be set regardless of the length of the lower arms 22a and 22b, so the kingpin shaft 66 can be set regardless of the arm ratio d/D. can be set. Therefore, the fifth
As shown in the figure, regardless of the arm ratio d/D, the kingpin offset R, can be set, and the horizontal distance L between the center of the wheel and the kingpin axis (driving force of the wheel during acceleration/deceleration accompanied by turning) The rotational moment generated around the kingpin axis by the braking force can be set (substantially proportional to the arm length), thereby reducing changes in steering torque and flutter, and reducing steering torque when turning The stability of the steering wheel during acceleration and deceleration can be improved.

Although the present invention has been described in detail with respect to specific embodiments above, the present invention is not limited to these embodiments, and various other embodiments are possible within the scope of the present invention. This will be obvious to those skilled in the art.

[Effects of the Invention] As is clear from the above description, according to the present invention, the effective length of the lever and lower control arm is set to D, and the inner end of the lower control arm is extended from the pivot point between the lower control arm and the vertical link. If the distance to the pivot point is d, the vertical stroke of the outer end of the upper control arm can be reduced in accordance with the arm ratio d/D. The height can be reduced.

In addition, in a range where the vertical stroke of the wheel is relatively small, the lower control arm and horizontal link move as if they were parallel links, which reduces camber angle changes and tread changes and improves the straight-line running performance of the vehicle. In addition, when the bounding stroke of the wheel is relatively large, such as when the vehicle is turning, the camber angle becomes negative and the change in the camber angle relative to the ground when turning becomes small, so it is recommended to use a short upper control arm that is space efficient. It is possible to improve the turning performance of the vehicle.

Furthermore, the instantaneous center of the knuckle is determined by the extending direction of the lower control arm and the horizontal link, and since the extending direction of the horizontal link can be set relatively freely, the height of the roll center of the vehicle can be set relatively freely. be able to.

[Brief explanation of the drawing]

FIG. 1 is a front view of one embodiment of the multi-link suspension according to the present invention as seen from the front side of the vehicle; FIG. 2 is a front view showing the operation of the embodiment shown in FIG. 1 as a skeleton diagram; FIG. 3 is an explanatory diagram showing that the embodiment shown in FIG. 1 has a high degree of freedom in setting the roll center height;
The figure is a perspective view of another embodiment of the multi-link suspension according to the present invention, seen diagonally from the front of the vehicle, and FIG. 5 is a front view showing the operation of the embodiment shown in FIG. 4 as a skeleton diagram. be. DESCRIPTION OF SYMBOLS 10... Knuckle, 12... Bearing, 14... Wheel, 16... Ball joint, 18... Tie rod, 20... Upper control arm, 22... Lower control arm, 24...・Joint, 28・
...Vehicle body. 30...Joint, 34...Ball joint,
36... Vertical link, 38... Ball joint,
40... joint, 42... horizontal link, 44...
...Ball joint, 46.48...Ball joint, 50...Shock absorber, 52...Upper support. 54.56...Spring seat, 58...Suspension spring, 66...King pin shaft support
Applicant Toyota Motor Corporation Representative
Person Patent Attorney Masaki Akashi Ward 1/28 10..Knuckle 14..Wheel 20..Upper control arm 22..Lower control arm 28..Vehicle body 36..Vertical link 42..Horizontal link 10..Knuckle 14.・Wheel 20th control arm 22・・0a control arm 36・・Vertical link 42・・Horizontal link Figure 6

Claims (1)

[Claims] a knuckle rotatably supporting a wheel; an upper control arm pivotally supported on the vehicle body at an inner end; a lower control arm pivotally supported on the vehicle body at an inner end and pivotally attached to the knuckle at an outer end; a vertical link having an upper end pivotally connected to the outer end of the upper control arm and a lower end pivotally connecting to the intermediate portion of the lower control arm; an inner end pivotally connected to the vertical link and an outer end thereof supporting the knuckle; A multi-link suspension for a vehicle having a horizontal link pivotally connected to a horizontal link.