JPH03227708A - Suspension device for vehicle - Google Patents

Abstract

PURPOSE:To improve the head turning ability and stability by supporting a wheel supporting member by a rear side arm extending along the car width, and a front side arm extending along the length of a car body, and providing the front side arm with a damping means to generate a damping force to a displacement along the car width. CONSTITUTION:A rear side arm 3 is disposed extending along the car width at a position at a rear part of a car body to a wheel center l1 of a rear wheel 2 between a wheel supporting member 1 for axially supporting the rear wheel 2 and a body side cross member 4. A front side arm 11 consisting of a link member 12 extending diagonally directing out at a rear part of the car body to a body center line l2 and a second link member 13 extending along the length of the car body is disposed at a front part of the car body to the rear side arm 3. For both link members 12, 13, the first link member 12 is inserted into a sleeve 21 fixed at the front end of the second link member 13 through a rubber 23, they are connected with each other through a support shaft 22, and a front part of the second link member 13 is supported at the car body through a damper 31.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a suspension system for a vehicle, and in particular, the present invention relates to a suspension system for a vehicle, and in particular, the rear wheel is fixed to the vehicle body so that the rear wheel changes in the toe-in direction due to a lateral force acting on the rear wheel when turning. This relates to the improvement of suspension systems.

(Prior Art) As a suspension device for a vehicle, a so-called visor-jaw axle type device disclosed, for example, in Japanese Patent Publication No. 60-42041 has been known. Basically, in this type of vehicle, the wheel support member is supported to the vehicle body by at least two front and rear arms, and of the two front and rear arms, the rear arm extends approximately in the width direction of the vehicle. It consists of one link member, and the front arm extends diagonally outward toward the rear of the vehicle with respect to the centerline of the vehicle.

It consists of one link member and a second link member extending substantially in the longitudinal direction of the vehicle body. One end of the first link member is rotatably connected to the vehicle body by a rubber bushing around a substantially vertical rotation axis, and the front end of the second link member is connected to the other end of the vehicle body by a rubber bushing. The two link members are connected to each other so as to be rotatable around the two link members, and an elastic member is provided between the two link members to allow relative rotation of the two members within a predetermined range. When a braking force is applied to the grounding point of the wheel, the rearward reaction force acting on the rotation axis of the connection part of both link members of the front arm causes the first link member to move around the rotation axis of the connection part with the φ body. The front end of the second link member rotates toward the center line of the vehicle body, and the front end of the second link member is displaced inward of the vehicle body, thereby changing the rear wheel in the toe-in direction.

(Problem to be Solved by the Invention) The above-mentioned visor-shoulder axle type suspension device was developed to change the rear wheel in the toe-in direction during braking, but when turning, the rear wheel, which is the outer turning wheel, is changed in the toe-in direction. It is also possible to change it to . In other words, if the link members constituting the rear arm are arranged to extend approximately in the vehicle width direction behind the wheel center of the corresponding wheel, inward lateral force (cornering force) is applied to the wheel center of the rear wheel when turning. When this occurs, an inward reaction force acts on the rotation axis of the connecting portion of both link members of the front arm, and as a result, the first link member rotates around the fii1 rotation axis of the connecting portion with the t-body. The second
The front end of the link member is displaced inward into the body, and the rear wheel changes in the toe-in direction.

By the way, the purpose of changing the rear wheels, especially the rear wheels that are the outer wheels of the turn, toward toe-in during a turn is to strengthen the tendency of understeering and improve stability.
Immediately after turning, the tendency to understeering becomes stronger.
The heavy vehicle does not turn as quickly as the driver would like, resulting in poor maneuverability.

The present invention has been made in view of the above, and its purpose is to maintain the rear wheels in a straight-line state (zero toe angle state) immediately after turning, in the above-mentioned visor-shoulder axle type suspension device. The object of the present invention is to provide a suspension device for a vehicle that can achieve a high level of controllability and stability during turns by then changing the rear wheels toward toe-in and increasing the understeering tendency.

(Means for Solving the Problems) In order to achieve the above [1], the solution means of the present invention is a medium-thickness suspension device in which the wheel support member is supported by at least two front and rear arms against the vehicle body. Of the two front and rear arms, the rear arm consists of one link member extending substantially in the vehicle width direction, and the front arm consists of a first link member extending diagonally outward from the rear of the vehicle with respect to the vehicle center line. and a second link member extending substantially in the longitudinal direction of the vehicle body, one end of the first link member being rotatably connected to the vehicle body by a rubber bushing about a substantially vertical axis of rotation. The front end of the second link member is connected to the other end so as to be rotatable about another rotation axis, and there is a space between the two link members that allows relative rotation between the two within a predetermined range. It is assumed that an elastic member is provided.

In such a suspension device, the link member constituting the rear arm is disposed further rearward of the vehicle body than the wheel center of the corresponding wheel, and the link member constituting the rear arm is arranged at the rear of the vehicle body than the wheel center of the corresponding wheel. The structure includes a damping means that generates a damping force.

(Function) With the above configuration, in the present invention, when an inward lateral force acts on the wheel center of the rear wheel during a turn, an inward reaction force acts on the rotation axis of the connecting portion of both link members of the front arm. As a result, the first link member rotates toward the center line of the t-body around the rotation axis of the connecting portion with the vehicle body, and the front end of the second link member is displaced inward into the vehicle body. In this case, immediately after the start of a turn when the lateral force and reaction force act rapidly, the damping means generates a damping force due to the displacement of the front end of the second link member in the vehicle width direction and resists the displacement.
Toe-in changes of the rear wheels are suppressed.

After that (in other words, after the lateral force, etc. starts to act substantially constant), the damping means expands and contracts without producing any damping force, allowing the front end of the second link member to be displaced inward of the vehicle body. The wheels change in the toe-in direction.

(Implemented fljJ) Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a so-called visor-shoulder axle type suspension device for a vehicle according to an embodiment of the present invention, in which 1 is a wheel support member that rotatably supports a rear wheel (wheel) 2, and 3 is the wheel support member 1. and the cross member 4 on the vehicle body side, the rear arm is made of one link member extending substantially in the vehicle width direction at a position rearward of the vehicle body relative to the wheel center 91 of the rear wheel 2, One end (outer end) of the arm 3 is connected to the wheel support member 1 via a rubber bush 5 and a support shaft 6.
The other end (inner end) is rotatably connected to a cross member 4 on the vehicle body side via a rubber bush 7 and a support shaft 8, respectively. Although not shown, each of the rubber bushes 5.7 includes an outer cylinder fixed to the arm 3, an inner cylinder arranged concentrically within the outer cylinder, and into which the support shaft 6 or 8 is inserted. It consists of rubber that is filled and fixed between the outer cylinder and the inner cylinder.

Reference numeral 11 denotes a front arm of the rear arm 3 disposed in front of the vehicle body, and the arm 11 is connected to the vehicle body center line 9.
2, and a second link member 13 that extends substantially in the longitudinal direction of the vehicle body, that is, substantially parallel to the insect center line Q2. One end of the first link member 12 is rotatably connected to a bracket 14 attached to the vehicle body via a rubber bush 15 and a support shaft 16. The rubber bushings 15, like the rubber bushings 5.7 at both ends of the rear arm 3, are filled with rubber between the outer cylinder and the inner side. Further, the first link member 12 is not only rotatable about the support shaft 16 with respect to the vehicle body, but also rotates on the rubber bush 15 within the elastic range of the rubber bush 15 (specifically, rubber that is an elastic member). It is provided so as to be rotatable around a substantially vertical rotation axis P.

A front end of the second link member 13 is connected to the other end of the first link member 12 . Both link members 1
2.13, as shown in detail in FIGS. 2 and 3, a sleeve 21 is fixed to the front end of the second link member 13, and the first link member 12 is disposed within the sleeve 21.
is inserted. The first link member 12 is connected to the sleeve 21 via a support shaft 22 extending in a substantially vertical direction, and is rotatably connected to the second link member 13 about the support shaft 22. There is. As can be seen, there is a rubber 2 as an elastic member between the sleeve 21 and the first link 12.
Recesses 24 and 24 are formed in the rubber 23 at both front and rear side positions sandwiching the link member 12 at one end of the sleeve 21.
The support shaft 22 is provided at the end opposite to the side where the recesses 24 and 24 are formed, so that the rubber 23 is
The first link member 12 and the sleeve 21 through the second link member 13 due to elastic deformation at the clearance 24°24, etc.
Relative rotation around the support shaft 22 is allowed within a predetermined range. Incidentally, relative rotation between the first link member 12 and the second link member 13 is not allowed much in the vertical direction where the rubber 23 has no clearance.

Furthermore, a strut 26 is arranged to extend in the vertical direction, and the upper end of the strut 26 is connected to the vehicle body, and the lower end is connected to the wheel support member 1.

The wheel support member 1 consists of the above-mentioned two front and rear arms 11.3.
It is connected and supported to the vehicle body by struts 16 and the like.

Further, 31 is a damper as damping means disposed at the front end of the second link member 13 and extending in the vehicle width direction at right angles to the link member 13. The damper 31 is composed of a shock absorber, and one end thereof ( The outer end) is connected to the link member 13, and the other end (inner end) is connected to the vehicle body, so that displacement of the front end of the link member 13 in the vehicle width direction generates a damping force.

Next, to explain the operation of the above embodiment, when an inward lateral force F acts on the wheel center Ql of the rear wheel 2 when the vehicle is turning, both link members 12 and 13 of the front arm 11 When the inward reaction force R acts on the support shaft 22 of the connecting portion, the first link member 12 moves around the center line of the heavy body around the rotation axis P thereon due to elastic deformation of the rubber bushing 15 at the connecting portion with the vehicle body. It rotates toward Q2, and the front end of the second link member 13 moves inward into the vehicle body.

In this case, when the front end of the second link member 13 starts to be displaced inward from the vehicle body, that is, immediately after the start of a turn when the lateral force F and the reaction force R rapidly increase, the damper 31 moves the front end of the link member 13 The displacement of the link member 13 generates a damping force to resist the displacement, thereby suppressing the displacement of the front end of the link member 13 inward of the vehicle body.

After that (after the lateral force F and the reaction force R come to act substantially constant), the damper 31 begins to contract without producing any damping force, and the front end of the link member [3] is displaced inward within the insect body. This is permitted, and the rear wheels 2 change in the toe-in direction (inward in the direction of travel).

In this way, in the case of this embodiment, the toe-in change of the rear wheel 2, which is the outer wheel of the turn, is suppressed immediately after the start of a turn, and then the rear wheel 2 causes a toe-in change, which improves turning performance and stability when turning. It is possible to achieve both at a high level. Fourth
The figure shows the toe-in change characteristics of the rear wheels during a turn.In the case of the conventional example shown by the broken line B in the figure, the toe-in change occurs immediately after the turn in response to the generation of lateral force.
In the case of this embodiment shown by the solid line A, the toe-in change occurs after the generation of the lateral force.

(Effects of the Invention) As described above, according to the vehicle suspension device of the present invention, in the so-called visor-a-axle type, the toe-in change of the wheel is suppressed by the damping force of the damping means immediately after turning, and then the Since a toe-in change occurs, it is possible to achieve both turning performance and stability at a high level when turning.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a plan view showing the overall structure of the suspension device, FIG. 2 is a cross-sectional view showing the connection structure between the link members of the front arm, and FIG. FIG. 4, which is a sectional view taken along the line ■-■ in the figure, is a characteristic diagram showing the toe-in change characteristics of the rear wheels during turning. 1... Wheel support member 2... Rear wheel (wheel) 3... Rear arm 11... Front arm 12... First link member 13... Second link member 15 ... Rubber bush 22 ... Support shaft (rotating shaft of second link member) 23 ...
- Rubber (elastic member) 1... Wheel support member 2... Rear wheel (wheel) 3... Rear arm 11... Front arm 12... First link member 13... Second link member 15...Rubber bushing 22...Support shaft (rotating shaft of second link member) 23...
・Rubber (elastic member) P...The rotating shaft box diagram of the first link member is shown in Fig. 4.

Claims (1)

[Claims] (1) The wheel support member is supported with respect to the vehicle body by at least two front and rear arms, and of the two front and rear arms, the rear arm is composed of one link member extending substantially in the vehicle width direction, The front arm includes a first link member extending obliquely outward toward the rear of the vehicle with respect to the centerline of the vehicle;
and a second link member extending substantially in the longitudinal direction of the vehicle body,
One end of the first link member is connected to the vehicle body by a rubber bush so as to be rotatable about a substantially vertical axis of rotation, and the front end of the second link member is connected to the other end so as to be rotatable about a substantially vertical axis of rotation. A suspension device for a vehicle, which is rotatably connected around an axis and is provided with an elastic member between the two link members that allows relative rotation between the two within a predetermined range,
The link member constituting the rear arm is arranged at the rear of the vehicle body than the wheel center of the corresponding wheel, and includes damping means that generates a damping force against displacement of the front end of the second link member in the vehicle width direction. A suspension device for a vehicle characterized by comprising: