KR20080109965A - Rear suspension system of multi-link type - Google Patents

Abstract

A multi-link rear wheel suspension system is provided to secure the cornering of vehicle performance. The camber angle and toe angle are nearly controlled in 0 and directivity is improved in the driving straight ahead. A multi-link rear wheel suspension system comprises a knuckle(101) supporting wheel, a lower control arm connecting knuckle to the car body, an upper control arm, a trailing arm, an assist link, a camber angle variable bush unit(10) which varies the camber angle of the wheel by taking advantage of the fluid pressure of the working fluid, a toe angle variable bush unit(20) which varies the toe of above wheel by taking advantage of the fluid pressure of the working fluid.

Description

Multi-Link Rear Suspension System {REAR SUSPENSION SYSTEM OF MULTI-LINK TYPE}

1 is a perspective view of a multi-link type rear wheel suspension according to the prior art.

2 is a perspective view of a knuckle applied to a multi-link type rear wheel suspension according to an embodiment of the present invention.

3 is a cross-sectional view taken along the line A-A of FIG. 2, and is a block diagram of a camber angle variable bushing unit according to an embodiment of the present invention.

4 is a cross-sectional view taken along the line B-B of Figure 2, a configuration diagram of a tow angle variable bushing unit according to an embodiment of the present invention.

5 is an operation state diagram of the camber angle variable bushing unit according to an embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

10: camber angle variable bush unit 11: the first outer race

13: the first inner race 15: the first insulator

16: 1st hydraulic chamber 17: 2nd hydraulic chamber

18: first port 19: second port

20: toe angle variable bush unit 21: the second outer race

23: second inner race 25: second insulator

26: third hydraulic chamber 27: fourth hydraulic chamber

28: third port 29: fourth port

The present invention relates to a multi-link type rear wheel suspension device, and more particularly, to a multi-link type rear wheel suspension device for actively controlling a camber angle and a toe angle according to a vehicle speed and a steering angle of a vehicle.

Suspension in a vehicle exists between a vehicle body and a wheel, and is a device that connects these two rigid bodies by using one or more links. It is supported by springs and hydraulic shock absorbers in the vertical direction, and in other directions. By properly matching the high rigidity and flexibility, it performs a function to mechanically match the relative movement between the vehicle body and the wheel.

The suspension system effectively blocks irregular input of the road surface generated while driving the vehicle, providing a comfortable ride to the occupant, and provides driving convenience by appropriately controlling the shaking of the vehicle body caused by the driver's driving behavior and the curvature of the road surface. In the case of driving on irregular roads, the vertical load on the tire ground surface should be maintained at an appropriate level to satisfy the basic conditions of ensuring the maneuverability and stability of the vehicle during turning and braking.

In order to satisfy these conditions, the wheel's posture by the suspension geometry is very important. The wheel's posture changes greatly according to the relative movement with the body, and the overall performance of the vehicle is changed according to the changing wheel posture. It will be greatly influenced.

Recently, a multi-link type rear suspension system has been developed that can effectively accommodate shocks and vibrations input from the road surface using at least three links and vibrations of the vehicle body with ideal kinematic movements. It is applied to a mass production vehicle.

As illustrated in FIG. 1, the multi-link type rear wheel suspension includes a knuckle 101 rotatably supporting a wheel (not shown), and a rear lower side of the knuckle 101 disposed in the vehicle width direction. A lower control arm 103 for connecting the vehicle to the vehicle body, an upper control arm 105 arranged in the vehicle width direction to connect an upper side of the knuckle 101 to the vehicle body, and a front side of the lower control arm 103. An assist link 107 disposed in the vehicle width direction to connect the front side portion of the knuckle 101 to the vehicle body, and a trailing arm arranged in the longitudinal direction of the vehicle body to connect the front side portion of the knuckle 101 to the vehicle body; 109.

Of course, the suspension device is disposed in the vertical direction and the coil spring (not shown) and shock absorber 111 to perform a buffering action is disposed.

Here, the lower control arm 103 and the assist link 107 are respectively connected to the knuckle 101 via a bush 113.

The multi-link type rear suspension with such a configuration has less turning radius when the vehicle is turning, so that the slip angle of the rear wheel becomes larger than the slip angle of the front wheel. In order to prevent understeer, which is a phenomenon in which the slip angle of the front wheel becomes larger than the slip angle of the rear wheel, it is applied to various means in the design to give stability to the vehicle.

Among them, as an example, the lower control arm 103 is raised while pushing the lower part of the wheel by the motion trajectory during the bump, so that the camber angle of the wheel is inclined toward the negative side, and the assist link ( 107) has a method of increasing the lateral force by increasing the toe change as a toe-in, or increasing the lateral force by changing the toe change in the lateral force as a toe in.

However, since they all fall straight due to the change in toe in during bump, the change in toe in during bump and lateral force is generally considered in consideration of straightness, steering stability and ride comfort. Is compromised so that it does not occur small, and there is a limit to maximizing each performance.

Therefore, the conventional multi-link type rear wheel suspension uses the AGCS (Active Geometry Control Suspension) in order to solve the design constraint, which is the top and bottom of the wheel (wheel) when the motor (actuator) is mounted straight By changing the toe caused by exercise to zero and actively controlling it with toe in during turning, performance that is difficult to achieve in general suspension systems is obtained, but the price is high and the weight of the motor There is a problem that there is a big limit such as the reduction of fuel economy and the possibility of failure.

Accordingly, the present invention has been created to solve the above problems, and an object of the present invention is to operate the knuckle and the lower control arm and the knuckle and the assist link at each connection of the hydraulic supply system according to the driving state of the vehicle. By controlling the camber angle variable bushing unit and the tow angle variable bushing unit operated by fluid, respectively, the camber angle and the toe angle of the rear wheel are actively controlled to secure the turning performance of the vehicle, and to adjust the camber angle and the toe angle when driving straight. It is to provide a multi-link type rear wheel suspension which improves straightness by controlling close to zero.

Multi-link type rear wheel suspension according to the present invention for achieving this object, a knuckle for rotatably supporting the wheel, a lower control arm and upper control arm, trailing arm, and assist connecting the knuckle to the vehicle body A rear link suspension of a vehicle multi-link type including a link, comprising: a camber angle variable bushing unit configured to be connected to the lower control arm and the knuckle to vary the camber angle of the wheel by using hydraulic pressure of a working fluid; And a tow angle variable bushing unit configured to be connected to the assist link and the knuckle to vary the tow of the wheel by using hydraulic pressure of a working fluid.

The camber angle variable bushing unit, The camber angle variable bushing unit, the first outer race which is integrally fixed to the connecting portion of the knuckle to which the lower control arm is connected; A second inner race in which the lower control arm is fastened in the first outer race; It is vulcanized and bonded between the outer race and the inner race, and forms a semi-circular first hydraulic chamber on the outside in the vehicle width direction with respect to the inner race therein, and has a semicircle shape in the vehicle width direction with respect to the inner race. A first insulator forming a second hydraulic chamber of the first insulator; And first and second ports connected to the first and second hydraulic chambers, respectively, to supply and discharge the working fluid.

The toe angle variable bushing unit may include: a second outer race fixed integrally with a connection portion between the assist arm and the knuckle; A second inner race inside the outer race, to which the assist arm is fastened; It is vulcanized and bonded between the outer race and the inner race, and forms a semi-circular third hydraulic chamber on the outer side in the vehicle width direction with respect to the inner race therein, and has a semicircle shape in the vehicle width direction around the inner race. A second insulator forming a fourth hydraulic chamber of the fuel cell; And third and fourth ports connected to the third and fourth hydraulic chambers, respectively, to supply and discharge the working fluid.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail as follows.

FIG. 2 is a perspective view of a knuckle applied to a multi-link type rear wheel suspension according to an embodiment of the present invention, and FIG. 3 is a cross-sectional view taken along the line AA of FIG. 2 and shows a camber angle variable bush unit according to an embodiment of the present invention. 4 is a cross-sectional view taken along line BB of FIG. 2, and is a block diagram of a tow angle variable bushing unit according to an exemplary embodiment of the present invention.

First, the configuration of the multi-link type rear wheel suspension to which the present invention is applied will be described with reference to FIG.

That is, the basic configuration of the multi-link type rear wheel suspension according to the embodiment of the present invention, as shown in Figure 1, is disposed in the vehicle width direction and the knuckle 101 for rotatably supporting the wheel (not shown) A lower control arm 103 connecting the rear lower side of the knuckle 101 with the vehicle body, an upper control arm 105 arranged in the vehicle width direction and connecting the upper one side of the knuckle 101 with the vehicle body; An assist link 107 disposed at the front side of the lower control arm 103 to connect the front side of the knuckle 101 with the vehicle body, and the front side portion of the knuckle 101 disposed at the vehicle body lengthwise direction. It comprises a trailing arm 109 for connecting to the vehicle body.

Of course, the suspension device is disposed in the vertical direction and the coil spring (not shown) and shock absorber 111 to perform a buffering action is disposed.

In the multi-link type rear wheel suspension having such a configuration, as shown in Fig. 2, in this embodiment, the knuckle 101, the lower control arm 103, the knuckle 101, and the assist link 107 Each of the connecting portions are respectively configured to the camber angle variable bush unit 10 for varying the camber angle of the wheel by using the hydraulic pressure of the working fluid and the tow angle variable bush unit 20 for varying the tow of the wheel.

First, as shown in FIG. 3, the camber angle variable bushing unit 10 includes a first outer race 11, a first inner race 13, a first insulator 15, and first and second parts. It consists of ports 18 and 19.

That is, the first outer race 11 is integrally fixed to the connection portion of the knuckle 101 to which the lower control arm 103 is connected.

The first inner race 13 is formed inside the first outer race 11.

The first inner race 13 is fastened through the lower control arm 103 and the assembly bolt.

The first insulator 15 is interposed between the first outer race 11 and the first inner race 13.

The first insulator 15 is vulcanized and bonded between the first outer race 11 and the first inner race 13, and has a semicircle on the outside in the vehicle width direction with respect to the first inner race 11. A first hydraulic chamber 16 having a shape is formed, and a semicircular second hydraulic chamber 17 is formed inside the first inner race 13 in the vehicle width direction.

Here, the first and second hydraulic chambers 16 and 17 are formed with the first and second ports 18 and 19 for supplying and discharging a working fluid, respectively.

As shown in FIG. 4, the tow angle variable bush unit 20 includes a second outer race 21, a second inner race 23, a second insulator 25, and third and fourth ports. It consists of (28) (29).

The second outer race 21 is integrally fixed to the connection portion of the knuckle 101 to which the assist arm 107 is connected.

A second inner race 23 is formed inside the second outer race 21.

The second inner race 23 is fastened to the assist arm 107 through the assembly bolt.

A second insulator 25 is interposed between the second outer race 21 and the second inner race 23.

The second insulator 25 is vulcanized and bonded between the second outer race 21 and the second inner race 23, and has a semicircle on the outside in the vehicle width direction with respect to the second inner race 23. A third hydraulic chamber 26 having a shape is formed, and a semicircular fourth hydraulic chamber 27 is formed inside the second inner race 23 in the vehicle width direction.

Here, the third and fourth hydraulic chambers 26 and 27 are formed with third and fourth ports 28 and 29 for supplying and discharging working fluid, respectively.

The camber angle variable bushing unit 10 and the tow angle variable bushing unit 20 configured as described above have the first, second, third, and fourth ports 18, 19, 28, and 29 respectively provided with a hydraulic supply system ( 40), the hydraulic pressure supply system 40 has a general configuration for supplying and blocking the hydraulic pressure supplied from the hydraulic pump in accordance with the control signal of the controller 50 through the solenoid valve.

Here, the controller 50 outputs a control signal to the hydraulic pressure supply system 40 according to the speed and the steering angle of the vehicle, and the hydraulic pressure is supplied to the first, second, third, and fourth ports according to the signal. It is supplied to and discharged from the first, second, third and fourth hydraulic chambers 16, 17, 26 and 27 through 18, 19, 28 and 29.

Therefore, the operation of the multi-link type rear wheel suspension configured as described above will be described below.

First, when the vehicle turns to the right, as shown in FIG. 5 (S1), the camber angle variable bushing unit 10 of the right suspension is controlled by the controller 50 according to the speed and the steering angle. The hydraulic pressure is supplied to the second hydraulic chamber 17 of the camber angle variable bushing unit 10 by the hydraulic pressure supply system 40 via a signal, and the volume thereof increases, and the hydraulic pressure is applied to the first hydraulic chamber 16. As it is released, its volume is reduced.

Then, the first inner race 13 is moved outward in the vehicle width direction by the second hydraulic chamber 17 having increased volume, and at the same time, the lower control arm 103 is also moved in the same direction (-) The angle will increase.

On the other hand, the camber angle variable bushing unit 10 of the left suspension is, as shown in (S2) of Figure 5, as opposed to the right suspension, the first hydraulic chamber (10) of the camber angle variable bushing unit 10 ( Hydraulic pressure is supplied to 16 to increase the volume, and the volume is reduced while the hydraulic pressure is discharged from the second hydraulic chamber 17.

Then, the first inner race 13 is moved inward of the vehicle width direction by the first hydraulic chamber 16 having increased volume, and at the same time, the lower control arm 103 is also moved in the same direction while having a positive camber. The angle will increase.

In addition, the tow angle variable bush unit 20 operates opposite to that of the camber angle variable bush unit 10. Therefore, when the vehicle is turned to the right, the tow angle variable bush unit 20 of the right suspension device , Toe-in is increased by being deformed into the shape as shown in FIG. 5 (S2).

On the other hand, the tow angle variable bushing unit 20 of the left suspension is deformed into a shape as shown in FIG. 5 (S1), thereby increasing the toe-out.

Accordingly, when turning the right side of the vehicle, the right wheel of the vehicle is increased by the camber angle variable bushing unit 10 and the tow angle variable bushing unit (-) and the toe-in increases. The positive camber angle increases and the toe-out increases, and when the vehicle is turning to the left side, the reverse operation is performed while the lateral force is increased as much as possible, thereby preventing oversteering or understeering, thereby enabling safer turning.

In addition, when the vehicle travels straight, the camber angle and toe angle are controlled to be close to zero through the camber angle variable bush unit 10 and the tow angle variable bush unit 20 to improve the straightness.

As described above, according to the multi-link type rear wheel suspension according to the present invention, the knuckle and the lower control arm, and the camber angle variable bush unit controlled by the working fluid according to the driving state of the vehicle at each connection portion of the knuckle and the assist link; By actively controlling the camber angle and toe angle of the rear wheel by applying the variable toe angle bushing unit, there is an effect of improving overturning or understeer to improve the turning performance of the vehicle.

In addition, when going straight, the camber angle and the tow angle are controlled to be close to zero, thereby improving the straightness.

Claims (3)

In a vehicle multi-link type rear wheel suspension including a knuckle for rotatably supporting a wheel, a lower control arm and an upper control arm for connecting the knuckle to a vehicle body, a trailing arm, and an assist link, A camber angle variable bush unit configured to connect the lower control arm and the knuckle to vary the camber angle of the wheel by using hydraulic pressure of a working fluid; And And a toe angle variable bushing unit configured to be connected to the assist link and the knuckle to vary the toe of the wheel by using hydraulic pressure of a working fluid. The method of claim 1, The camber angle variable bush unit, A first outer race fixed integrally with a connection portion of the knuckle to which the lower control arm is connected; A second inner race in which the lower control arm is fastened in the first outer race; It is vulcanized and bonded between the outer race and the inner race, and forms a semicircular first hydraulic chamber on the outside in the vehicle width direction with respect to the inner race therein, and a semicircle on the inner side in the vehicle width direction around the inner race. A first insulator forming a second hydraulic chamber of a shape; And Multi-link type rear wheel suspension system, characterized in that the first and second ports connected to the first and second hydraulic chamber, respectively, for supplying and discharging the working fluid. The method of claim 1, The tow angle variable bush unit, A second outer race fixed integrally with a connection portion of the assist arm and the knuckle; A second inner race inside the outer race, to which the assist arm is fastened; It is vulcanized and bonded between the outer race and the inner race, and forms a semi-circular third hydraulic chamber on the outer side in the vehicle width direction with respect to the inner race therein, and has a semicircle shape in the vehicle width direction around the inner race. A second insulator forming a fourth hydraulic chamber of the fuel cell; And And a third and fourth ports connected to the third and fourth hydraulic chambers respectively to supply and discharge the working fluid.

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