JPS63112207A - Suspension device for automobile - Google Patents

Abstract

PURPOSE:To fully prevent the production of vibration of a trailing arm on which a brake reaction force is exerted, by a method wherein a pair of front and rear suspension dampers is spanned between a spring upper weight and a spring lower weight containing a trailing arm with a rotation center, serving as a boundary, therebetween. CONSTITUTION:A suspension S has a trailing arm 3 and a plurality of lateral links 4-6. The front end of the trailing arm 3 is coupled to a cross member 2, and a rear end part is fixed to a carrier 8 supporting a hub 7 to which rear wheels 1 are mounted. In this constitution, two suspension dampers 10 and 11, extended in a vertical direction, are spanned in parallel between a carrier 8, being a part of a spring lower weight, and a car body 9 being a spring upper weight. Vertical vibration of the trailing arm 3 and the carrier 8 caused by a brake reaction force during working of a brake 17 is effectively adsorbed by means of the two dampers 10 and 11.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a suspension device for an automobile.

(Prior Art) As a type of suspension that supports wheels in a vertically movable manner with respect to a vehicle body, there is a type of suspension equipped with a trailing arm, as shown in Japanese Patent Laid-Open No. 60-92106. As is known, this trailing arm extends in the front-rear direction, and its front end is connected to the vehicle body so as to be able to swing freely about an axis that extends in the width direction of the vehicle. Depending on the direction of the moving axis, they are divided into so-called full trailing arms and semi-trailing arms.

(Problem to be Solved by the Invention) As mentioned above, in a suspension equipped with a trailing arm, the brake reaction force during deceleration acts on the trailing arm as torque fluctuation, causing the trailing arm to vibrate. become more susceptible to

Therefore, by offsetting the connection position of the suspension damper installed between the unsprung weight and the unsprung weight including the trailing arm with respect to the unsprung weight before or after the axis of rotation of the axle, it is possible to reduce the torque. Even though attempts have been made to absorb as much as possible the vibrations of the trailing arm caused by fluctuations using suspension dampers, the reality is that it is not always possible to obtain a fully satisfactory result. In particular, the damping force characteristics of a suspension damper must be set to ensure a certain degree of ride comfort, so it is necessary to set the damping force characteristics to ensure a certain level of riding comfort. to do so,
This will inevitably lead to limitations.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an automobile suspension system that can sufficiently reduce vibrations of a trailing arm that receives brake reaction force.

(Means and operations for solving the problem of m points) In order to achieve the above-mentioned object, the present invention has the following configuration. That is, in an automobile suspension system in which a wheel is supported vertically relative to the vehicle body via a trailing arm that receives a brake reaction force, there is a gap between the sprung weight and the unsprung weight including the trailing arm. ,
The structure is such that a pair of suspension dampers are installed in front and behind the center of rotation of the wheel.

In this way, in the present invention, since a pair of front and rear suspension dampers are provided across the center of rotation of the wheel, vibrations of the trailing arm caused by the brake reaction force during deceleration can be suppressed by using both suspension dampers. Can be absorbed effectively. In particular, since a pair of suspension dampers is provided at the front and rear, it is possible to divide the functions between each other, for example, with the rear side for ensuring ride comfort and the front side for reducing vibrations, and the damping force characteristics can be optimally set according to the function. It becomes possible.

(Example) Examples of the present invention will be described below based on the attached drawings.

In FIG. 1, reference numeral 1 denotes a left rear wheel, and this rear wheel 1 is supported via a suspension mechanism S to a cross member 2 integrated with a vehicle body so as to be vertically movable.

The suspension S includes one trailing arm 3 and three lateral links 4.5.6. The trailing arm 3 extends in the front-rear direction, and its front end portion is connected to the cross member 2 so as to be rotatable about an axis extending in the vehicle width direction. Also, trailing arm 3
The rear end portion of the rear end portion is fixed to a carrier 8 that rotatably supports a hub 7 to which the rear wheel 1 is attached.

Of the three wooden lateral links 4,5,6, two are used as a pair of front and rear lower arms 4, 5 for toe control, and the remaining one is an upper arm 6 for camber control.
It is said that In other words, the front and rear lower arms 4.5 are
They are arranged front and rear with respect to each other while the rear wheel 1 is rotating, and their outer ends are rotatably connected to the carrier 8, and their inner ends are rotatably connected to the cross member 2. Also,
The upper arm 6 is also rotatably connected to the carrier 8 at its outer end and to the cross member 2 at its inner end.

The above-mentioned three lateral links 4, 5, 6 can be set appropriately by appropriately setting the vertical and longitudinal inclination angles, lengths, mounting positions on the carrier 8, and lateral rigidity at the mounting positions. It becomes possible to control toe changes and camber angle changes of the rear wheel 1 in a desirable manner when the rear wheel 1 bumps, rebounds, and when lateral force or longitudinal force is applied to the rear wheel 1. The trailing arm 3 has low rigidity in the lateral direction so as not to restrict posture control of the three lateral links 4, 5, 6.

Two suspension dampers 10 and 11 extending in the vertical direction are installed in parallel with each other between the carrier 8, which forms part of the unsprung mass i, and the vehicle body 9, which represents the spring E weight. Of the two suspension dampers 10, 11, one is a large main damper IO, and the other is a small sub-damper 11. As is known, this main damper 10 includes a cylinder 10a and a cylinder! The piston rod 10b extends upward from inside Oa. The lower end of the cylinder 10a is rotatably connected to the carrier 8 at a position further rearward than when the rear wheel l is rotating. Further, the upper end portion of the piston rod 10b is connected to the vehicle body 9. The lower spring seat 12 and the piston rod 10 are fixed to the cylinder 10a.
A coil spring 14 is installed between the spring seat 13 and the upper spring seat 13 fixed to b.

In the embodiment, the main damper 10 is of a variable damping force type, and the actuator therefor is indicated by reference numeral 16. The damping force is set so that it satisfies the riding comfort when it is set to "soft", and when it is set to "hard".
At least the setting is suitable for controlling pitching.

On the other hand, the sub-damper 11 also includes a cylinder lla and a piston rod llb extending upward from the cylinder lla. The lower end of this cylinder lla is connected to the carrier 8
On the other hand, the piston rod Ilb is rotatably connected to the front of the rear wheel Ib during rotation, and the upper end of the piston rod Ilb is connected to the vehicle body 9. The sub-damper 11 has a fixed damping force, and is suitable for reducing vibrations of the trailing arm 3 due to brake reaction force. In addition, the code|symbol 11c is a protection cylinder.

The brake 17 for controlling the rear wheel l is a disc brake in the embodiment. That is, a brake disc 18 is integrated into the hub 7, while a caliper 19 holding a friction pad is attached to the carrier 8. In the embodiment, since the rear wheel 1 (hub 7) is used as a rear wheel drive shaft, an axle shaft for transmitting driving force is connected to the rear wheel 1 (hub 7), but the illustration thereof is omitted.

In the above configuration, when decelerating, that is, when brake 1
7, a brake reaction force acts on the trailing arm 3. In other words, the rear wheel 1 that is about to be rotated forward
Therefore, a reaction force acts on the carrier 8, that is, the rear end portion of the trailing arm 3, in a direction corresponding to the backward rotation of the rear wheel l. Then, due to this brake reaction force, the trailing arm 3 and the carrier 8 integrated with the rear end thereof tend to be violently vibrated in the vertical direction. However, this vibration is effectively absorbed by both dampers 1O111, which are placed on both sides of the rear wheel 1 while the rear wheel 1 is rotating. In particular, since the sub-damper 11 is set to be suitable for controlling the trailing arm and its vibrations, it reduces the vibration of the trailing arm 3 while ensuring the ride comfort provided by the main damper 10. can do.

In the above embodiments, a full trailing arm type was described, but it can be similarly applied to a semi-trailing arm type.

(Effects of the Invention) As is clear from the above description, the present invention can sufficiently suppress the vibration of the trailing arm that receives brake reaction force during deceleration.

In addition, the functions of the two front and rear suspension dampers can be distributed such that one is used to ensure ride comfort and the other is used to control vibration of the trailing arm, ensuring ride comfort and preventing vibration of the trailing arm. It becomes possible to optimally set and at a high level.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing one embodiment of the present invention. Figure 2 is a left side view of the main part of Figure 1. FIG. 3 is a plan view of the main part of FIG. 1. FIG. 4 is a front view of the main part of FIG. 1 showing the arrangement of lateral links. Cross: Center of rotation S: Suspension mechanism 1: Rear wheel 2 Cross member 3: Trailing arm 4.5.6: Lateral link 7: Hub 8: Carrier 9: Vehicle body 10, ll: Suspension damper 17: Brake Fig. 2 3rd figure 4th figure

Claims (1)

[Claims] (1) In an automobile suspension system in which a wheel is supported vertically relative to the vehicle body via a trailing arm that receives a brake reaction force, the difference between the sprung weight and the unsprung weight including the trailing arm A suspension device for an automobile, characterized in that a pair of suspension dampers are installed in front and behind the center of rotation of a wheel.