JPH03182818A - Rear suspension device - Google Patents

Abstract

PURPOSE:To restrain harshness vibration and prevent toe-out change of a rear wheel by connecting a front link to a vehicle body so that it may oscillate in the front and rear direction of the body, and connecting a rear link to the vehicle body so that it may move at multiple points in the front and rear direction of the vehicle body. CONSTITUTION:In a rear suspension device, a rear wheel 23 is supported against a body by at least two links of a front link 20 and a rear link 22. The front link 20 is connected to a suspension member 21 of a vehicle body side so that it may oscillate in the front and rear direction of the vehicle body, so that the first connecting point 20a is set. Also, the rear link 22 is connected to the suspension member 21 at least at two points in the approximately front and rear direction A of the body, so that the second and third connecting points 22a and 22b are set. The second and third connecting points 22a and 22b are constructed so that they may move in the front and rear direction A of the body. When braking is applied to the vehicle, the wheel supporting point of the front link 20 is made to locate deeply inside the body than the link 22.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rear suspension device for a vehicle, specifically,
Relating to rear suspension devices such as parallel link, multi-link or double wishbone suspension.

(Prior Art) In recent years, demands on vehicles have become more sophisticated, such as improving ride comfort by suppressing harshness vibrations when driving over small protrusions on the road surface,
There is a need to improve steering stability by optimizing the toe angle change during braking.

Suspension devices play a major role in improving ride comfort and handling. For example, in the parallel link type suspension device shown in Figure 7.8, the front link 10 extending in the width direction of the vehicle is The rear wheel 13 is supported on a vehicle body side member such as a suspension member 14 by a plurality of links such as a rear link 11 extending in the width direction and a radius rod 12 extending in the longitudinal direction of the vehicle body,
A front link bushing 15, a rear link bushing 1
6 and a radius Rondo plush 17.

By setting the rigidity of each bushing 15, 16, 17 to be low, the harshness vibration can be suppressed and the riding comfort can be improved.

(Problem to be solved by the invention) However, in this conventional rear suspension device, the front link 10 and the rear link 11
Since the front link bushing 15 and the rear link bushing 16 are provided between the front link bushing 15 and the suspension member 14, for example, the link bushing 15.1(j
If the toe angle of the rear wheel 13 is lowered, the ride comfort can be improved, but there is a problem that the toe angle of the rear wheel 13 changes in one direction during braking, impairing the steering stability. Ta.

That is, in FIG. 7, when braking, a rearward braking force is applied to the rear wheels 13, but the center of the wheel grounding point (D) where the braking force acts is outside the wheel support point (B) of the radius rod 12 in the vehicle width direction. , a moment in the I-out direction acts on the rear wheel 13 and the axle that supports it, a tensile force acts on the front link 10, and a compressive force acts on the rear link 11. A force acts, therefore, the wheel support point (C) of the rear link 11 is moved to the front link 10.
As a result of entering the inside of the vehicle body from the wheel support point (A>),
The 1-angle of the rear wheels 13 increases in the 1-out direction (2) the turning characteristics of the vehicle increase in the direction in which the oversteer tendency increases;
In addition to the changes, there are issues that need to be improved in terms of maneuverability.

On the other hand, if the rigidity of the wheels 15 and 16 is increased, the rear wheel 130) l---out can be reduced, but in that case, the above-mentioned barge vibration can be suppressed. A problem arises in that riding comfort cannot be improved.

(Object of the Invention) The present invention was made in view of the above problems, and provides a rear suspension device that effectively suppresses versive and ness vibrations and does not cause toe-out changes in the rear wheels during braking. is intended to provide.

(Means for Solving the Problems) In order to achieve the object described in item L, the present invention provides a Ricoh suspension system in which a rear wheel is supported on the vehicle body side by at least two front and rear links. The rear link and the vehicle body side are connected at least two points in the longitudinal direction of the vehicle body, and the two connection points are connected to the vehicle body side so as to be swingable in the longitudinal direction of the vehicle body. It is characterized by being configured to be movable approximately in the front-back direction.

(Function) In the present invention, the front link is attached to be swingable about the vehicle body, whereas the rear link is attached to be movable substantially forward and rearward of the vehicle body.

Therefore, during braking, the wheel support point of the front link (corresponding to A in the conventional example) is further inside the vehicle body than the wheel support point of the rear link (corresponding to C in the conventional example), so the toe angle of the rear wheel is zero. Alternatively, the turning characteristics change to the toe-in direction, and the turning characteristics tend to exhibit neural steering or understeer.

As a result, it is possible to suppress harshness vibrations, avoid toe-out changes in the rear wheels during braking, and improve steering stability.

<Example) Hereinafter, the present invention will be explained based on the drawings.

1 to 5 are diagrams showing one embodiment of the rear suspension device according to the present invention, in which the rear wheels are supported on the vehicle body side by at least two front and rear links (or rondos), a parallel link, multi-link, or double suspension system. This is an example of application to a rear suspension device such as a shock-bone suspension.

First, the configuration will be explained. As shown in FIG. 1, the conceptual configuration diagram of the rear suspension device of this embodiment connects a front link 20 and a suspension member 21 on the vehicle body side so that they can swing in the longitudinal direction of the vehicle body (hereinafter, this The connection point is referred to as a first connection point 20a), and the rear link 2
2 and the suspension member 21 at at least two points, a second connection point 22a and a third connection point 22b) in the approximately longitudinal direction of the vehicle body (the direction indicated by arrow A in the figure),
Moreover, the two connecting points 22a and 22b are configured to be movable approximately in the longitudinal direction of the vehicle body. In addition, 20b in the figure is the wheel support point of the front link 20 (hereinafter referred to as the first wheel support point),
22c is a wheel support point of the rear link 22 (hereinafter referred to as a second wheel support point), 11 is a longitudinal centerline of the vehicle body, and 23 is a rear wheel.

FIG. 2 is a diagram specifically showing the configuration of the left half of FIG. 1, and the same members are given the same numbers.

In FIG. 2, 24 is an axle on which the wheel 23 is mounted, and the axle 24 is supported by each wheel support point 20b, 22c of the front link 20 and the rear link 22. On the other hand, the front link 20 and the rear link 22 are connected to a first connection point 20a, a second connection point 22a, and a third connection point, respectively.
It is connected to, for example, the gussets 21a and 21b of the suspension member 21 via the connection point 22b, and link bushes containing an elastic material such as rubber are interposed at these connection points.

Here, the front and back rigidity of the link bushings used for the front link 20 is high, and the front and rear rigidity of the link bushings used at the two connection points of the rear link 22 (second connection point 22a and third connection point 22b) is Set the rigidity low.

Figures 3 to 5 show these two connection points (second connection point 22a
FIG. 4 is a diagram showing three examples of link bushings preferably used for the third connection point 22b).

The link bush shown in FIG. 3 has a structure in which an elastic body 32 such as rubber is sandwiched between an inner cylinder 30 and an outer cylinder 31.
．． 31 is coupled to the rear link 22 and the other to the suspension member 21, and the rigidity of the elastic body 32 is set to be suitably low, so that the direction) allows for movement.

FIG. 4 shows an improved example of the link bushing shown in FIG. 3, in which a No. 1 elastic body 42 is sandwiched between the inner cylinder 40 and the outer cylinder 41, and stoppers 43 and 44 are fixed to both ends of the inner cylinder 40. A second elastic body 45, 46 is provided between these stoppers 43, 44 and the outer cylinder 41.

By setting the rigidity of the first elastic body 42 to be high and setting the rigidity of the second elastic bodies 45, 46 to be much lower, the wheel lateral force input in the direction crossing the axis 13 of the link bushing can be reduced. , the high rigidity of the first elastic body 42 allows the bridge to be stopped, while the low rigidity of the second elastic bodies 45 and 46 prevents the back and forth movement force of the rear link 22 that is manually applied in parallel to the axis E3. It can be stopped. That is,
The rigidity in the axial direction and the rigidity in the direction perpendicular to the axis of the link bushing can be set independently, and the lateral rigidity can be increased while allowing the rear link 22 to smoothly move backward.

Fig. 5 shows an example in which the link bushing shown in Fig. 4 is further improved. ), a pair of first elastic bodies 53,54 are disposed facing each other in the axial direction (direction indicated by arrow C in the figure) in contact with the stopper 51,52, Elastic body 53
．． A second cylindrical member 55 and a third cylindrical member (corresponding to the outer cylinder in FIG. 3.4) are located between 54 and in the direction away from the outer peripheral surface of the first cylindrical member 50 (direction indicated by arrow B in the figure). 5
6 are arranged in sequence, the first cylindrical member 50 and the second cylindrical member 55
A friction reducing member 57 is interposed between the second cylindrical member 55 and the third cylindrical member 56, and a second elastic body 58 is interposed between the second cylindrical member 55 and the third cylindrical member 56.
It is composed by intervening.

Note that the second elastic body 58 may be press-fitted into the gap between the third cylindrical member 56 and the second cylindrical member 55, or may be bonded to both members. Further, both ends of the second cylindrical member 55 are bent along the end surface of the second elastic body 58, and the friction reducing member 57 is also bent in the same manner, so that the bent portion and the first elastic body 53,54 are bent. Between plate metal fittings 59.6
0 are interposed therebetween, so that the plate metal fittings 59 and 60 can slide on the outer circumferential surface of the first cylindrical member 50.

In the configuration shown in FIG. 5, when a load (lateral force of the wheel) in a direction approximately perpendicular to the axis β4 is applied between the first cylindrical member 50 and the third cylindrical member 56, both members 50, 56 Since the relative displacement of the second elastic body 58 occurs in a direction that changes the wall thickness of the second elastic body 58, the rigidity against the lateral force of the wheel is mainly due to the second elastic body 5.
given by the stiffness of 8. On the other hand, the first cylindrical member 50
When a load (rearward moving force of the rear link 22) in a direction parallel to the axis 14 is applied between the third cylindrical member 56 and the third cylindrical member 56, the relative displacement of both members 50, 56 is approximately parallel to the axis 14. This relative displacement occurs in parallel with the friction reducing member 57.
As a result of the second cylindrical member 55, second elastic body 58, and third cylindrical member 56 moving together in the axial direction, the rigidity against the rearward movement of the rear link 22 is 0. This is mainly given by the rigidity of the pair of first elastic bodies 53,54.

That is, as in FIG. 4, the axial rigidity and the axially perpendicular rigidity of the link bushing can be set independently, allowing the rear link 22 to smoothly move backward while ensuring appropriate lateral rigidity. In addition, since the sliding bush structure uses the friction reducing member 57, the friction in the axial direction and torsional direction is extremely small, and the riding comfort is greatly improved.

Next, the effect will be explained. In the diagram for explaining the action during braking in FIG. 6, when the wheel 23 moves backward due to the braking torque, the front link 20 swings around the first connection point 20a, but the rear link 22 swings around the second connection point 22a and the rear link 22. 3. Move toward the rear of the vehicle while sliding the connecting point 22b. This is the two connection points 22a and 22b of the rear link 22.
This is because the link bush provided in the link bush has the configuration shown in any one of FIGS. 3 to 5, and the rigidity of the link bush in the axial direction is set to be low.

1. Therefore, during braking, the entire rear link 22 slides toward the rear of the vehicle body, which prevents the second wheel support point 22c from entering the inside of the vehicle body, while the first wheel support point 20b is connected to the front link 20. The first wheel support point 20b and the second wheel support point 20b and the second
Depending on the behavior of the wheel support point 22c, the toe angle of the wheel 23 can be increased to zero or to the I/-in direction.

As described above, in this embodiment, the front link 20 is swingably attached to the first connection point 20a on the vehicle body side, while the rear link 22 is attached to the second connection point 20a on the vehicle body side.
A and the third connection point 22b are movable points and are movable in the approximately longitudinal direction of the vehicle body. Therefore, during braking, the wheel support point of the front link 20 (the first wheel support point 20b
) on the rear link 22 at the wheel support point (second wheel support point 22
In other words, it is possible to prevent the rear link 22 from going around to the inside of the vehicle body, and it is possible to change the 1-angle of the rear wheel 23 to zero or toe-in direction. can. Therefore, it is possible to achieve both of the following two characteristics of turning characteristics: (1) Improving steering stability by increasing the neutral steering or understeer tendency, and (2) Improving ride comfort by suppressing harshness vibrations.

(Effects) According to the present invention, the front link and the vehicle body side are connected to be swingable in the longitudinal direction of the vehicle body, and the rear link and the vehicle body side are connected at at least two points approximately in the longitudinal direction of the vehicle body. Since the two connecting points are configured to be movable approximately in the longitudinal direction of the vehicle body, it is possible to effectively suppress harshness vibration and prevent the rear link from turning inward to the vehicle body during braking. Therefore, it is possible to provide a rear suspension device that does not cause any change in rear wheels.

[Brief explanation of drawings]

1 to 6 are diagrams showing an embodiment of a rear suspension device according to the present invention, and FIG. 1 is a conceptual configuration diagram thereof;
Figure 2 is a specific configuration diagram corresponding to the main parts of Figure 1, and Figure 3
The figure is a sectional view of one example of the link bushing, FIG. 4 is a sectional view of three other examples of the link bushing, FIG. 5 is a sectional view of yet another example of the link bushing, and the sixth The figure is an explanatory diagram of the action during braking.
7.8 are diagrams showing a conventional rear suspension device, FIG. 7 is a conceptual plan layout thereof, and FIG. 8 is a conceptual elevational layout thereof. 20...Front link, 20a...First connection point, 21...Suspension member 22...
...Rear side link, 22a...Second connection point, 22b...Third connection point.

Claims (1)

[Claims] In a rear suspension device that supports a rear wheel on the vehicle body side by at least two front and rear links, the front link and the vehicle body side are connected so as to be swingable in the longitudinal direction of the vehicle body, and the rear link and the vehicle body side are connected so as to be swingable in the longitudinal direction of the vehicle body. A rear suspension device, characterized in that the rear suspension is connected at at least two points in a substantially longitudinal direction of a vehicle body, and the two connecting points are configured to be movable substantially in a longitudinal direction of a vehicle body.