JPH106728A - Suspension device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve sound vibration performance by increasing a lever ratio of a shock absorber and by reducing its own damping force, without arranging a coil spring separately from the shock absorber, and improve comfortableness by lowering the lever ratio of the coil spring so as to reduce a spring constant at a wheel position even if its own spring constant is large. SOLUTION: A cylinder tube 6b of a shock absorber 6 is inserted through a circular hole 4b of an upper link 4, its lower end is positioned lower than the upper link 4, this cylinder tube 6b is connected to a wheel supporting member, and a coil spring 7 is arranged between a lower end of the cylinder tube 6b and below the upper link 4 and on the outer circumference of the cylinder tube 6b. By this, a lever ratio of the shock absorber 6 is set at '1', and the lever ratio of the coil spring 7 is reduced to a value obtained by subtracting a ratio of a distance up to a coil spring connecting point to the upper link length from '1'.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automobile suspension device.

[0002]

2. Description of the Related Art As a conventional suspension device, for example, as described in Japanese Patent Application Laid-Open No. 1-136804, a coil spring and a shock absorber are not arranged coaxially, but they are arranged in a vehicle width direction to mount a wheel. There is a link member that connects a wheel supporting member rotatably supported to a vehicle body, and a link member that is disposed between the vehicle bodies. Such a suspension device has an advantage in that the height of the hood can be reduced, for example, when the shock absorber is employed in a front suspension because the height of the shock absorber is not affected by the coil spring layout. Also, it is difficult as a matter of fact to reduce (lower) the spring constant of the coil spring itself used in such a vehicle suspension device. However, in this suspension device, the coil spring can be placed separately from the shock absorber. Even if the lever ratio of the shock absorber remains large, the lever ratio of the coil spring can be reduced. Therefore, even if the spring constant of the coil spring itself is large (high), the spring constant at the wheel position (wheel end) can be reduced. The ride comfort can be improved by reducing the size. In this case, by increasing the lever ratio of the shock absorber, the damping force of the shock absorber itself may be small. It is also possible to improve the so-called sound vibration performance with respect to the input.

[0003]

However, the conventional suspension apparatus has the following problems. That is, especially when this suspension device is used for a front suspension, the wheels are cut inward with turning, and at the same time, the tie rod member for steering also swings in the longitudinal direction of the vehicle. Despite the small space in the vehicle width direction between the vehicle and the vehicle body side members such as the side members, the coil spring is positioned inward in the vehicle width direction from the relationship of the lever ratio described above. In order to arrange the coil springs side by side in the vehicle width direction, a vehicle body side member such as a side member is moved inward in the vehicle width direction, or the vehicle body side member is partially cut away, and the coil spring is placed there. It is necessary to arrange them, and in any case, the layout is greatly restricted. Furthermore, since the upper end of the coil spring is fixed to the vehicle body, when the wheel bounces, the side surface of the tire approaches the upper end of the coil spring. There is also a problem that it has to be arranged in.

In order to solve these problems, for example, as described in Japanese Utility Model Application Laid-Open No. 62-100205, a coil spring and a shock absorber are arranged coaxially or substantially coaxially, and respectively mounted on the vehicle body side. It is possible to connect. However, in such a case, the coil spring and the shock absorber are disposed between the vehicle body and the link member so that the lever ratio of the coil spring becomes small, based on the actual condition of the spring constant of the coil spring, Therefore, since the lever ratio of the shock absorber also decreases, the damping force of the shock absorber itself increases in order for the shock absorber to exhibit a sufficient damping force at the wheel position (wheel end), or the shock absorber and the vehicle body are increased. It is necessary to harden a so-called upper insulator interposed between the side members. If such measures are taken, there arises a problem that the road surface or road noise where fine irregularities are continuous or the noise and vibration performance at the time of overcoming a protrusion is reduced.

The present invention has been developed to solve these problems. Even if the coil spring having a high spring constant has a high spring constant, the ride comfort can be improved by increasing the lever ratio of the shock absorber even if the lever ratio of the coil spring is small. It is an object of the present invention to provide a suspension device which can improve sound power and can ensure sound and vibration performance without requiring a large damping force for a shock absorber.

[0006]

According to a first aspect of the present invention, there is provided a suspension apparatus comprising: a wheel supporting member for rotatably supporting a wheel; and a wheel supporting member and a vehicle body. A link member to be connected, a shock absorber arranged so that a lower end is located below the link member, and an upper end connected to the link member and a lower end connected to a lower end of the shock absorber. And a coil spring.

[0007] The suspension device according to claim 2 of the present invention is characterized in that the shock absorber is interposed between the wheel support member and the vehicle body.

[0008] In the suspension device according to the first aspect of the present invention, the mass of the vehicle body is reduced by interposing the shock absorber between the wheel supporting member and the vehicle body as in the suspension device according to the second aspect. It is mainly supported by a coil spring interposed between the link member and a shock absorber connected to the wheel support member. On the other hand, when the wheel support member swings up and down,
Since the same or almost the same displacement occurs in the shock absorber, the lever ratio of the substantial shock absorber becomes "1" or a large value equivalent thereto. On the other hand, when the wheel support member swings up and down, the displacement is input to the coil spring from the lower end of the shock absorber, and thus the lever ratio of the coil spring is determined by connecting the coil spring to the link member. Since the distance between the connecting point and the point at which the link member is connected to the vehicle body is the ratio of the distance between the vehicle-body-side connection point and the wheel-support-member-side connection point of the link member, it is always "1". "It becomes a smaller value. Therefore, even if the spring constant of the coil spring itself is high as described above, the spring constant at the wheel position (wheel end) is reduced, and riding comfort can be improved.
Further, since the lever ratio of the shock absorber is large, it is not necessary to increase the damping force of the shock absorber so much, and it is also possible to ensure sound vibration performance.

A suspension device according to a third aspect of the present invention provides a wheel support member for rotatably supporting a wheel, at least two upper and lower link members for connecting the wheel support member and a vehicle body, A shock absorber having a lower end located below the upper link member and connected to the wheel support member; and a coil spring having an upper end connected to the upper link member and a lower end connected to the lower end of the shock absorber. It is characterized by having.

A suspension device according to a fourth aspect of the present invention is a wheel supporting member for rotatably supporting a wheel, and a connecting member rotatably connected to the wheel supporting member about a substantially vertical axis. An upper link member for connecting the connecting member to the vehicle body; a lower link member for connecting the vehicle body to the wheel support member; and a lower end positioned below the upper link member and connected to the connecting member. And a coil spring having an upper end connected to the upper link member and a lower end connected to a lower end of the shock absorber.

[0011] These inventions are embodiments of the suspension device according to claim 1 or 2. Of these, the suspension device according to claim 3 is based on the premise that the wheel support member is connected to the vehicle body by an upper link member, a so-called upper link, and a lower link member, a so-called lower link. The lower end of the shock absorber is positioned below the upper link member with such a suspension device, and a coil spring is disposed between the lower end of the shock absorber and the upper link. The same or substantially the same effects as those of the suspension device according to the first aspect are obtained. On the other hand, in the suspension device according to claim 4, in a suspension device of a similar type,
First, a wheel supporting member is connected to a connecting member so as to be rotatable around an axis in a vehicle vertical direction, and the upper link member is connected to this connecting member. The lower end of the shock absorber is positioned below the upper link member with such a suspension device, and a coil spring is disposed between the lower end of the shock absorber and the upper link. The same or substantially the same effects as those of the suspension device according to the first aspect are obtained. Further, in the present invention, the upper link member is connected to the vehicle body and the connecting member at one point each,
By arranging such that the axis connecting the two connection points and the rotation axis of the connection member have an intersection, only one upper link member can be configured, so that weight and cost are reduced. And the degree of freedom in layout can be improved, and the balance between camber rigidity and lateral rigidity can be suitably maintained.

[0012] The suspension device according to claim 5 of the present invention is characterized in that the shock absorber is disposed inside the coil spring.

In this suspension device, the lever ratio of the coil spring is small and the lever ratio of the shock absorber is small regardless of the relative positional relationship between the coil spring and the shock absorber. The ratio can be set to a large value, and the effect described above can be obtained.
Conversely, by arranging the shock absorber so as to be housed inside the coil spring, the space inside the winding of the coil spring can be effectively used, and the degree of freedom in layout is increased accordingly.

[0014]

As described above, according to the suspension device of the first aspect of the present invention, even if the spring ratio of the coil spring itself is high by reducing the lever ratio of the coil spring itself, the wheel position ( The ride comfort can be improved by reducing the spring constant at the wheel end), and the lever ratio of the shock absorber is increased, without increasing the damping force of the shock absorber so much.
Sound vibration performance can also be ensured.

According to the suspension device of the second aspect of the present invention, the effect of the suspension device of the first aspect is satisfied by satisfying the essential requirements of the suspension device of the first aspect. Can be obtained reliably.

According to the suspension device of the present invention, the lower end of the shock absorber is located below the upper link member, and the coil spring is located between the lower end of the shock absorber and the upper link. Is provided, the same or substantially the same effect as that of the suspension device according to claim 1 or 2 can be obtained.

According to the suspension device of the present invention, the lower end of the shock absorber is located below the upper link member, and the coil spring is located between the lower end of the shock absorber and the upper link. Is provided, the same or substantially the same effect as that of the suspension device according to claim 1 or 2 can be obtained. In addition, the upper link member may be connected to the vehicle body and the connecting member at one point each, and the upper link member may be arranged so that the axis connecting the two connecting points and the rotation axis of the connecting member have an intersection. Since only one upper link member can be used, weight and cost can be reduced, layout flexibility can be improved, and the balance between camber rigidity and lateral rigidity can be appropriately maintained. The effect that can be performed is obtained.

Further, according to the suspension device of the present invention, even if the shock absorber is arranged to be housed inside the coil spring, the lever ratio of the coil spring is small and the lever ratio of the shock absorber is small. Can be set large, whereby the same effects as those of the suspension device according to claims 1 to 4 can be obtained, so that the space inside the winding of the coil spring can be effectively used, and Only the freedom of layout increases.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. Here, among the suspension devices of the present invention that can be deployed on each wheel of a vehicle, a description will be given particularly on behalf of the rear suspension device for the rear left wheel. Of course,
Invert the drawing for that of the rear right wheel, "Right" in the description
Can be considered by replacing "left" with "left" and "left" with "right". In the case of front wheels, connect a conceivable steering device and replace "rear" in the description with "front". Just think about it.

FIGS. 1 to 3 show a first embodiment of the present invention. FIG. 1 is a rear view of a vehicle, FIG.
FIG. 3 shows a plan view. In the figure, a wheel (rear wheel) 1 is rotatably supported by a wheel support member (not shown). The lower end of the wheel support member is rotatably connected to a lower link 2 (lower link member) via a ball joint (not shown), and the rear portion of the wheel support member has an axis substantially corresponding to the vehicle width. Elastic bush 6a forming direction
Through the cylinder tube 6b of the shock absorber 6
Is connected to the lower end. The upper end of the wheel support member has a front portion connected to the front upper link 3 (upper link member) and a rear portion connected to the rear upper link 4 (upper link member). I have. Further, a rear portion at the center of the wheel support member is connected to the lateral link 5.

The lower link 2 is disposed to extend obliquely rearward in the vehicle width direction, and its outer end in the vehicle width direction is rotatably connected to the lower end of the wheel support member via a ball joint (not shown). The end is bifurcated, and each end is vertically swingably connected to a lower position of a suspension member 10 constituting a vehicle body-side member through elastic bushes 2a and 2b. It is formed in a shape. Therefore, the lower link 2 allows the vertical movement of the wheel support member, that is, the bounding and the rebound, but prevents the movement of the wheel support member in the front-rear direction. Incidentally, in the present embodiment, as shown in FIG. 3, the two elastic bushes 2a,
Relative to the lower link second pivot axis by 2b, vertical line passing through the connection point P _LA of the lower link 2 and the wheel support member via a ball joint which is not the shown is connected is a point of intersection to the pivot axis ( Substantially the elastic bush 2
a, actually lower link 2 is substantially corresponding to the middle point of the two connection points that are considered to be connected to the suspension member 10 in 2b) and P _LB, lower link 2 and the wheels via the ball joint A straight line L _L connecting the connection point P _LA to which the support member is connected (that is, a line perpendicular to the swing axis of the lower link 2) LL is considered as a line of action of the lower link 2. The connection point _PLA between the lower link 2 and the wheel supporting member via the ball joint constitutes one point below the (virtual) kingpin axis.

The front upper link 3 is formed of a single I-shaped link extending obliquely rearward in the vehicle width direction, and its outer end in the vehicle width direction is connected to the wheel via an elastic bush (not shown). The support member is vertically swingably connected to a front portion of the upper end portion, and its inner end in the vehicle width direction swings vertically to the upper front position of the suspension member 10 via the elastic bush 3a. It is connected as possible. On the other hand, the rear upper link 4 is constituted by a single I-type link which is disposed so as to extend substantially in the vehicle width direction. Circularly bulging around the center line (the outer shape is smoothly continuous with the inner end and the outer end in the vehicle width direction), and a circular hole 4b through which the shock absorber 6 is inserted is further formed therein. Around the periphery, a support portion 4c for supporting an upper end portion of a coil spring described later is formed. These components will be described in detail later. The rear upper link 4 has an outer end in the vehicle width direction, like the front upper link 3, via an elastic bush (not shown). Of the suspension member 10 is connected to the upper rear portion of the suspension member 10 via an elastic bush 4a so as to be vertically swingable. Have been. In the present embodiment, as shown in FIG. 4, the straight line L _FU connecting the connecting point P _FUA between the connecting point P _FUB and the wheel support member between the suspension member 10 of the front upper link 3 is the front upper link 3 Since the straight line L _RU connecting the connection point P _RUB of the rear upper link 4 with the suspension member 10 and the wheel supporting member P _RUA becomes the line of action of the rear upper link 4, both straight lines L _FU , L The intersection point P _{UA of the RU} is one point above the (virtual) kingpin axis. Therefore, as clearly shown in FIG. 1, a straight line L _K connecting this intersection point P _UA and the connection point P _LA between the lower link 2 and the wheel support member becomes the (virtual) kingpin axis.

The lateral link 5 is formed of an I-shaped link extending substantially in the vehicle width direction, and has an outer end in the vehicle width direction at the center of the wheel support member via an elastic bush (not shown). The rear end of the suspension member 10 is vertically connected to the rear portion of the suspension member 10 via a resilient bush 5a. It is swingably connected.

Reference numeral 21 in the drawing denotes a stabilizer for the rear wheels, and reference numerals 22 and 23 denote mount insulators for connecting the suspension member 10 to the vehicle body, respectively.

On the other hand, the shock absorber 6 has a cylinder tube 6b located below it through the circular hole 4b of the rear upper link 4 and a lower end located outside in the vehicle width direction and rearward in the vehicle front-rear direction. The upper end is disposed slightly obliquely so as to be located inside the vehicle width direction and forward in the vehicle front-rear direction. Therefore, the lower end of the cylinder tube 6 b of the shock absorber 6 is located at least below the front upper link 3 as well as the rear upper link 4. On the other hand, this cylinder tube 6b
The upper end of the piston rod 6c projecting upward from the upper end is connected to a vehicle body side member (not shown) via an upper insulator 11. Incidentally, the reference numeral 24 shown in the figure is:
It is a bump rubber that prevents the so-called excessive sinking of the shock absorber 6. The connection point between the shock absorber 6 and the wheel support member is P _SLA , and the connection point between the shock absorber 6 and the vehicle body-side member is P _SUB .

A coil spring 7 is disposed on the outer periphery of the cylinder tube 6b of the shock absorber 6, and the cylinder tube 6b of the shock absorber 6 is positioned exactly inside the winding of the coil spring 7. In the embodiment, the axis of the coil spring 7 and the sliding axis of the shock absorber 6 match or almost match. And this coil spring 7
Is supported by a support portion 4c formed on the rear upper link 4, and a lower end portion thereof is supported by a support portion 6d attached to a vicinity of a lower end portion of the cylinder tube 6b of the shock absorber 6. . Incidentally, the support portion 4c of the rear upper link 4 is formed as shown in FIG. Here, a concave portion having a semicircular cross section corresponding to the winding radius of the coil spring 7 is formed from the lower surface side of the support portion 4c of the rear upper link 4, and the upper end of the winding wire of the coil spring 7 is fitted into this concave portion. Positioning. Accordingly, in the present embodiment, the coil spring 7 is wound around a straight line L _RU connecting the vehicle body-side connection point P _RUB and the wheel support member-side connection point P _RUA , which constitutes the action line of the rear upper link 4. Are supported so as to contact symmetrically as shown in FIG. Therefore, the coil spring 7 is connected to the action line L of the rear upper link 4.
It is said to be connected on the _RU .

Next, the operation of the suspension device of this embodiment will be described. FIG. 5 is a front view illustrating a skeleton of the suspension device of the present embodiment. In the figure,
The static load of the vehicle body is mainly transmitted from the rear upper link 4 to the coil spring 7, the cylinder tube 6b of the shock absorber 7, the wheel support member, and the wheel (rear wheel) 1 in this order. 7 will be supported.

From this state, assuming that the wheel (rear wheel) 1 and the wheel supporting member are displaced upward (or downward) by the moving amount x with the wheel stroke, the rear wheel is connected to the wheel supporting member. The connection point P _{RUA of the} side upper link 4 (L _RU ) and the connection point P _{LA of the} lower link 2 (L _L ) are also displaced upward (or downward) by the moving amount x, and are also connected to the wheel supporting member. connection point P _SLA of the shock absorber 6 is also displaced upward by the displacement amount x (or downward).
Therefore, the substantial lever ratio of the shock absorber 6 becomes "1".

On the other hand, the action line L of the rear upper link 4
The length of the _{RU in} the vehicle front view is D, and the rear upper link 4 is determined from the vehicle body side connection point _PRUB of the rear upper link 4.
_Assuming that the length to the connection point P _CSU between the coil spring 7 and the axis of the coil spring 7 connected thereto is Ds, the upper end of the coil spring 7 moves upward (or downward) by the amount of displacement (xxDs / D). Displace. On the other hand, the lower end of the coil spring 7 is displaced upward (or downward) by the amount of displacement x in the same manner as the lower end of the cylinder tube 6b of the shock absorber 6. The actual displacement is (xx × (1-Ds / D))
And the lever ratio of the coil spring 7 is (1-Ds /
D). Therefore, assuming that the spring constant of the coil spring 7 itself is k, the spring constant at the wheel position (wheel end) is (k × (1−Ds / D) ² ). Here, since the length Ds is always smaller than the length D, the spring constant (k × (1−Ds / D) ² ) at the wheel end is always smaller than the spring constant k of the coil spring 7 itself. Will be. Usually, the spring constant of the coil spring is restricted by the layout and becomes large when the spring length or the spring diameter is reduced. Therefore, it is difficult to employ a soft coil spring having a small spring constant. Thus, even if a hard coil spring having a large spring constant is used, the spring constant at the wheel end can be made small and soft, so that the riding comfort can be improved.

In this embodiment, since the upper end of the coil spring 7 moves together with the rear upper link 4,
Since the change in the distance between the wheel and the tire in the vehicle width direction is small, and it is not necessary to largely avoid the interference between the wheel and the tire and the coil spring as in the related art, the degree of freedom in layout is increased. In addition, since the upper end of the coil spring 7 is attached to the rear upper ring 4 in accordance with this, it is not necessary to attach a coil spring to the vehicle body and arrange a member for receiving the input as in the conventional case. As a result, there is room in space and the cost is also advantageous.

Further, by arranging the shock absorber so as to be housed inside the winding of the coil spring, the space efficiency is greatly improved as compared with the conventional case where the shock absorber and the coil spring are separately provided. This increases the degree of freedom in layout.

On the other hand, as described above, the shock absorber 6
Lever ratio becomes “1”, and the shock absorber 6
Will be the same as the damping force at the wheel position (wheel end). This reduces the damping force of the shock absorber itself as compared with the case where the lever ratio of the shock absorber is smaller than "1", so that it is not necessary to generate an excessive damping force in the shock absorber. . The upper insulator 1 for connecting the shock absorber and the vehicle body accordingly.
Even if 1 is softened, the damping force of the shock absorber 6 can be effectively transmitted to the wheels, and as a whole, the sound and vibration performance when overcoming a road surface with continuous fine irregularities, road noise, or over a transient projection is improved. I do. Further, in the present embodiment, the elastic force and the damping force of the bump rubber 24 acting when an excessive input is applied to the shock absorber from the wheels are also reduced in the present embodiment because the lever ratio of the shock absorber 6 is large. It works more effectively than in the case, and as a result, the input to the vehicle body can be reduced.

Further, in the present embodiment, the coil spring 7, in a vehicle plan view, because it is attached on the working line L _RU of the rear upper link 4, the elastic force of the coil spring 7 (reaction force) The rear upper link 4 by
_Does not receive a moment to rotate the rotation about the action line _LRU . That is, if the connection point P _CSU between the coil spring 6 and the upper link 4 is shifted from the line of action L _RU of the upper link 4, the displacement of the coil spring 6 caused by the wheel stroke as described above. elastic force of acts as a moment for rotating the rear upper link 4 to the action line L _RU around a real problem attempts to or change the suspension alignment such caster angle and toe angle changes. However, by the concatenation of the coil spring 7 on the acting line L _RU of the rear upper link 4 in the present embodiment, without such moment is generated, suspension alignment does not change by the elastic force of at least a coil spring.

Next, the second embodiment of the suspension device of the present invention will be described.
An embodiment will be described. This embodiment is a suspension device of the present invention that can be deployed on each wheel of a vehicle.
In particular, the description will be given on behalf of the front left wheel front suspension device. Of course, for the front right wheel, the drawing may be reversed and "left" in the description may be replaced with "right" and "right" may be replaced with "left". It may be considered that the description regarding the device is deleted and “before” in the description is replaced with “after”. In the present embodiment, components similar or substantially similar to those of the first embodiment indicate the same and are denoted by the same reference numerals, and detailed description thereof may be omitted.

FIG. 6 is a perspective view showing a schematic configuration of the present embodiment, in which 8 is a wheel (front wheel) not shown.
Is rotatably supported. A cylindrical portion 8a is formed at a center portion for inserting and supporting an axle of a wheel (front wheel), and a lower link 2 is connected to a lower end portion 8b via a ball joint 31. The upper link 4 ′ and the shock absorber 6 are connected to the upper end 1 c via the rotary connecting member 9, and the support 8 protrudes and extends rearward at the center.
The tie rod 12 is connected to d.

The lower link 2 is formed in an A-shape as in the first embodiment, and is disposed so as to extend in the vehicle width direction. The outer end of the lower link 2 is connected to the wheel supporting member 8 via the ball joint 31. The inner end is bifurcated into a lower end 1b of the first member, and each end is connected to a vehicle body-side member such as a suspension member (not shown) via elastic bushes 2a and 2b.

As shown in FIG. 7, the rotation connecting member 9 has a lower end 8b used for connection with the lower link 2.
King axis L _K passing through the center of ball joint 31
The axis of the wheel support member 8 is made to coincide with the extension of the wheel.
A shaft cylinder 9d rotatably supported by bearings 9b and 9c on a stepped support shaft 9a provided at the upper end 8c of the shaft.
As the shaft tube 9d is shown in Figure 8, in its vehicle width direction outer side, 'the upper link 4 that extends in a substantially horizontal direction so as to orthogonal to the line of action L _U' of upper link 4 to be described later Is formed, and a cylindrical support 9f for supporting the shock absorber 6 extending substantially in the front-rear direction is formed on the inner side in the vehicle width direction,
An elastic bush 32 is interposed in the cylindrical support portion 9e, and a collar 33 is fitted in the inner hole. A rotation support shaft 13 made of a bolt member or the like is inserted through the other cylindrical support 9f. The method of mounting the rotation support shaft 13 will be described in detail later.

On the other hand, the upper link 4 'is
Consists of type link, to its vehicle width direction outer end, the upper link 4 as shown in FIG. 3 'are formed through holes 4'd perpendicular to the action line L _U of the through-hole 4' d and the elastic bushing 32 of the rotary connecting member 9 and the inner hole of the collar 33 are aligned so that they are aligned in a straight line, and the upper link 4 ′ is formed of a bolt member from the outside of the outer end in the vehicle width direction. The rotation support shaft 14 is inserted, and a nut member 34 is screwed and fastened to a screw portion corresponding to a protruding tip portion thereof, so that the two are swingably connected only around the rotation support shaft 14 in the vertical direction. The inner end of the upper link 4 'in the vehicle width direction is connected to the elastic bush 4'a similarly to the first embodiment.
Is connected to the vehicle body-side member via the through hole so as to be swingable only in the vertical direction.

As shown in FIG. 8, the upper link 4 'passes through the front side of the rotary connecting member 9 and extends in the vehicle width direction such that the outer end in the vehicle width direction is forward from the inner end. It is disposed diagonally with respect to the front side of the rotary connecting member 9 and moves at the axial center position of the elastic bushes 4'a and 32 at both ends, that is, when a rotational torque is applied to each bush. without rocking center point to the connecting point P _UB and P _UA, arranged as the two connecting points P _UB, the action line L _U connecting the P _UA forms a kingpin axis L _K and intersection point P of the coupling member 5 Have been. Then, the rotation connecting member 9 of the upper link 4 ′
The side connection is arranged to be inserted inside the wheel.

Further, in the present embodiment, as shown in FIG. 8, the central portion of the upper link 4 'passing in front of the rotary connecting member 9 is circularly projected rearward in a plan view of the vehicle. In the center of the part 4'e, a shock absorber 6
A circular hole 4'b through which the cylinder tube 6b is inserted is formed to penetrate therethrough, and a support portion 4'c for supporting the upper end of the coil spring 7 is formed around the circular hole 4'b.

As in the first embodiment, the shock absorber 6 has a cylinder tube 6b located below the shock absorber 6 passing through the circular hole 4'b of the rear upper link 4 ', and a lower end of the shock absorber 6 having an upper link. It is arranged so as to be located lower than 4 '. On the other hand, the upper end of the piston rod 6c of the shock absorber 6 is connected to a vehicle body-side member (not shown) via an upper insulator (not shown). By the way, in FIG. 6, a bump rubber for preventing the so-called excessive sinking of the shock absorber 6 is not provided, but it may be provided.

An A-shaped mounting bracket 15 is mounted on the shock absorber 6 at a position above the upper link 4 'in the center of the cylinder tube 6a. As shown in FIG. 8, the mounting bracket 15 has a cylindrical mounting portion 15a mounted on the outer periphery of the cylinder tube 6b of the shock absorber 6, and a vehicle mounting portion 15a extends outward from the front and rear positions of the cylindrical mounting portion 15a in the vehicle width direction. Arms 15b and 15c which extend in a curved manner, and cylindrical support portions 15d and 15d formed at the tips of the arms 15b and 15c.
The elastic bush 36 is fitted in each of the elastic bushes 15e, and the collar 37 is further fitted in each elastic bush 36.

Then, with the mounting bracket 15 mounted on the center of the cylinder tube 6b of the shock absorber 6, the inner holes of the elastic bush 36 and the collar 37 and the cylindrical support 9f of the rotary connecting member 9 are formed. The two are positioned with the holes aligned with each other, the rotation support shaft 13 composed of a bolt member or the like is inserted into these inner holes, and the nut member 35 is screwed and tightened to the threaded portion of the protruding tip portion, A mounting bracket 15 is mounted on the rotatable connecting member 9 so as to be rotatable only about a substantially longitudinal axis.

A coil spring 7 is disposed on the outer periphery of the cylinder tube 6b of the shock absorber 6, similarly to the first embodiment, and the axis of the coil spring 7 and the sliding axis of the shock absorber 6 are arranged. The cylinder tube 6b of the shock absorber 6 is housed inside the winding of the coil spring 7 so that is substantially or substantially the same. The upper end of the coil spring 7 is supported by a support portion 4'c formed on the upper link 4 ', and the lower end of the coil spring 7 is mounted near the lower end of the cylinder tube 6b of the shock absorber 6. It is supported by the part 6d. Incidentally, in the present embodiment, as shown in FIG. 8, although the axis of the coil spring 7 does not coincide with the line of action L _U of the upper link 4 ', as in the first embodiment, the coil spring 7 it may be connected on the working line L _U of upper link 4 '.

Further, the tie rod 12 is connected to a steering device (not shown). Next, the operation of the suspension device of the above embodiment will be described.

FIG. 9 is a schematic front view of the suspension device of the present embodiment. Here, the static load of the vehicle body is mainly from the upper link 4 ′ to the coil spring 7, the cylinder tube 6 b of the shock absorber 7, the rotary connecting member 15, the wheel supporting member, and the wheels (rear wheels), as in the first embodiment. 1), the static load of the vehicle body is supported by the coil spring 7.

From this state, assuming that the wheel and the wheel supporting member 8 are now displaced upward (or downward) by the moving amount x with the wheel stroke, the upper link 4 'connected to the wheel supporting member, Since the lower link 2 and the cylinder tube 6b of the shock absorber 6 are also displaced upward (or downward) by the same displacement amount x, the substantial lever ratio of the shock absorber 6 becomes "1".

On the other hand, the substantial displacement of the coil spring 7 is determined by the displacement x of the wheel and the wheel supporting member.
'With respect to the length in the vehicle front view of the working line L _U of the upper link 4' the upper link 4 minus the ratio of the length to the connection point of the coil spring 7 from "1" to the body side coupling point value , The lever ratio of the coil spring 7 is smaller than “1”.

Therefore, in the present embodiment, as in the first embodiment, even if a hard coil spring having a large spring constant is used, the spring constant at the wheel end is made small and soft to improve the ride comfort. There is no need to generate excessive damping force on the shock absorber, and even if the upper insulator is softened, the damping force of the shock absorber can be effectively transmitted to the wheels, so that sound vibration performance can be improved, etc. The same effects as those of the first embodiment can be obtained.

As described above, the coil spring 7
Is the action line L of the upper link 4 ′ in a plan view of the vehicle.
_U , the rear upper link 4 due to the elastic force (reaction force) of the coil spring 7 is connected to the action line L.
_There is no moment to rotate around the _RU, and the suspension alignment does not change at least depending on the elastic force of the coil spring.

On the other hand, in the present embodiment, when a lateral force directed inward from the road surface to the front wheels acts on the front wheels during turning of the vehicle, the lateral force is transmitted to the wheel support member 8 as it is.
At this time, since the movement in the vehicle width direction is restricted by the lower link 2 at the lower portion of the wheel supporting member 8, the lateral force transmitted to the wheel supporting member 8 is turned by the rotation connecting member disposed at the upper portion. is transmitted to 9, acts lateral force F _a as shown in FIG. 8 to kingpin axis L _K. The shock absorber 6 hardly generates a drag with respect to the lateral force F _A because the rotation support shaft 13 is oriented substantially in the front-rear direction.

However, in the upper link 4 ',
Working line L_UAbove the lateral force F_ALarge resistance F against_U
Can occur. At this time, the upper link 4 '
Are mounted at one point on the vehicle body side and one point on the rotating connection member 9 side.
I-link and its action line L_UIs Kingpi
Axis L_KAnd the intersection P
Screws of the elastic bushes 4'a and 32 connecting the palinks 4 '
Excluding the slight force due to twisting or twisting, the link axis L_U
Only the compression or pulling axial force acts on the
Pin axis L_KA rotation mode for rotating the rotation connecting member 9 around
Does not occur, and the action line L_UIs in the vehicle width direction
The force F in the front-rear direction due to the inclination _YOnly the rotating chain
Acts on the binding member 9. This front-back force F_YOn the front wheel
Around the longitudinal axis of the rotating connecting member 9 in the same manner as when the longitudinal force is applied.
By a shock absorber 6 rotatably supported on
Can be received. As a result, the upper link 4 'is
The camber stiffness and lateral stiffness are
No degradation occurs at all.

Further, the upper link 4 ′ is connected to the rotation connecting member 9.
Since the cylindrical support portion 9e attached to are disposed perpendicular to the action line L _U, to reduce the displacement amount of the elastic bushing 32 when the axial force acts on the upper link, the balance of the camber stiffness and lateral stiffness Can be maintained more suitably.

When the front wheel 2 is steered, when the wheel support member 8 is rotated by the steering mechanism via the tie rod 12, the support shaft 9a of the rotary connecting member 9 is turned.
Is coincident with the kingpin axis L _K , the shaft cylinder 9 d of the rotation connecting member 9 does not rotate at all, and the input associated with steering does not act on the upper link 4 ′.

As described above, in the first embodiment, the lowering of the camber rigidity and the lateral rigidity are reliably prevented while the upper link 4 'is connected at one point on each of the vehicle body side and the wheel supporting member 8 side. Therefore, the degree of freedom in layout, such as interference between the tire and the wheel and the mounting portion during turning, is increased, and the weight and cost can be reduced.

Further, the upper link 4 ′ is
, The rotation connecting member 9
For example, a mounting plate for mounting the shock absorber 6 to the vehicle body-side member can reduce the strength of the corners of a hood ridge (not shown) and a dash (not shown) constituting an engine room. When adopting as a reinforcing plate to reinforce, even when it becomes necessary to lower the upper end of the shock absorber 6 backward and tilt it obliquely,
It is possible to sufficiently cope with the situation and to increase the degree of freedom in layout.

In the first and second embodiments, the case where the lower link has a substantially A-shape has been described. However, the present invention is not limited to this. The lower die link may be connected via a ball joint, and the other end of the lower link may be supported by a vehicle body-side member. There is an advantage that the kingpin axis can be set at an optimum position regardless of interference with other parts.

[Brief description of the drawings]

FIG. 1 is a rear view showing a first embodiment of a suspension device of the present invention.

FIG. 2 is a left side view of the suspension device of FIG.

FIG. 3 is a plan view of the suspension device of FIG. 1;

FIG. 4 is an explanatory view of a support portion of a coil spring formed on an upper link in the suspension device of FIG. 1;

FIG. 5 is a skeleton diagram of the suspension device of FIG. 1;

FIG. 6 is a perspective view showing a second embodiment of the suspension device of the present invention.

FIG. 7 is a cross-sectional view showing an example of a rotation connecting member applicable to the suspension device of FIG.

FIG. 8 is a plan view showing a connection relationship between a rotation connection member and an upper link in the suspension device of FIG. 6;

FIG. 9 is a schematic front view of the suspension device of FIG. 6;

[Explanation of symbols]

1 is a wheel 2 is a lower link (lower link member) 3 is a front upper link (upper link member) 4 is a rear upper link (upper link member) 4c is a supporting portion 4 'is an upper link (upper link member) 4'c Is a support portion 5 is a lateral link 6 is a shock absorber 6d is a support portion 7 is a coil spring 8 is a wheel support member 9 is a rotation support member 9a is a support shaft 10 is a suspension member (body side member) 11 is an upper insulator 12 is a tie rod 13 rotation support shaft 14 rotation support shaft 15 mounting bracket L _K is the kingpin axis

Continued on the front page (72) Inventor Tamra Kasahara 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd.

Claims (5)

[Claims] 1. A wheel support member for rotatably supporting a wheel, a link member for connecting the wheel support member to a vehicle body, and a shock absorber disposed such that a lower end portion is located below the link member. And a coil spring having an upper end connected to the link member and a lower end connected to a lower end of the shock absorber. 2. The suspension device according to claim 1, wherein the shock absorber is interposed between the wheel supporting member and a vehicle body. 3. A wheel support member for rotatably supporting a wheel, at least two upper and lower link members for connecting the wheel support member and the vehicle body, and a lower end portion located below the upper link member; A suspension device comprising: a shock absorber connected to a wheel support member; and a coil spring connected at an upper end to the upper link member and a lower end connected to a lower end of the shock absorber. 4. A wheel supporting member for rotatably supporting a wheel, a connecting member rotatably connected to the wheel supporting member about a substantially vertical axis, and an upper link connecting the connecting member to a vehicle body. A member, a lower link member connecting the vehicle body and the wheel support member, a lower end portion located below the upper link member and a shock absorber connected to the connecting member, and an upper end portion connected to the upper link member. And a coil spring connected to a lower end of the shock absorber and connected to a lower end of the shock absorber. 5. The suspension device according to claim 1, wherein the shock absorber is disposed inside the coil spring.