JPH03114906A - Suspension device of automobile - Google Patents

Abstract

PURPOSE:To improve damping function of horizontal vibration for a suspension device of a trailing link installing car, by forming a bush on the car body mounting side of the trailing link, out of liquid sealed bush for which plural liquid chambers are communicated with each other so as to generate different damping forces to horizontal input. CONSTITUTION:A bush 4 with which a trailing link 3 is mounted on a car body 5 is formed as a liquid sealed bush for which plural liquid chambers 9, 10 are communicated with each other by a communicating route 11, whose front end diameter da is defined larger than the rear end diameter db, and is formed into an orifice with its middle part as a gradual taper, so as to generate different damping forces in horizontal direction. In this structure, horizontal vibration can be effectively damped.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a suspension device for a vehicle, and more particularly to a bushing provided at a mounting end of a trailing link to a vehicle body.

(Prior art) For example, in Japanese Patent Application Laid-Open No. 58-170609, liquid chambers are provided in rubber fitted between an inner cylinder and an outer cylinder, and which face each other with the inner cylinder in between. A bushing is disclosed in which fluid chambers are communicated through a straight orifice and oil is sealed within the fluid chambers.

(Problem to be Solved by the Invention) If the above-mentioned bushing is used at the end of the car body attachment of the trailing link of a vehicle, when the car runs over a protrusion such as a stone on the road surface, the trailing link along with the wheels will be removed. As the link vibrates back and forth, the oil in both liquid chambers within the bushing is pushed by the vibration force and flows back and forth within the orifice, and the fluid resistance of the oil at this time dampens the back and forth vibration of the trailing link. . Since the orifice is in the shape of a straight tube with a uniform cross-sectional area, the respective damping forces against input in the longitudinal direction of the trailing link are equal.

However, in order to make it easier for the wheels to ride over the protrusion, it is better to have a small damping force for the rearward input of the trailing link. It is necessary to increase the damping force to quickly damp the longitudinal vibration of the trailing link.

The present invention has been made in view of the above points.
The purpose is to provide a suspension system for a vehicle in which the bushings at the end of the trailing link that are attached to the vehicle body are configured to generate different damping forces in response to input from the trailing link in the longitudinal direction. .

(Means for Solving the Problems) As shown in FIGS. 1 to 4 of the embodiment drawings, the present invention is arranged along the longitudinal direction of a vehicle, and the wheels 1 are vertically swingable with respect to the vehicle body 5. In the suspension system for a vehicle, the bushings 4, 12, 14 at the vehicle body attachment end of the trailing link 3 are connected to a communication path between a plurality of fluid chambers 9, 10 arranged in the front and rear. 11,13
．． The fluid-filled bushings 4, 12.14 are connected at 17, and the communication passages 11, 13.17 are set so as to generate different damping forces respectively in response to input from the trailing link 3 in the longitudinal direction.

(Function) When the car rides on a bump on the road, the trailing link 3 vibrates in the longitudinal direction, but the bushings 4°12, 14. Therefore, a large damping force acts on the forward input of the trailing link 3, and a small damping force acts on the rearward input.

(Example) Embodiments of the present invention will be described based on the drawings.

FIG. 1 is a side view of a strut-type rear suspension in which the present invention is applied, and FIG. 2 is a sectional view of a bushing showing a first embodiment of the present invention. 1 is a rear wheel, 2 is a coil spring, and a shock absorber 13 is a trailing link, which is connected to a vehicle body 5 via a bush 4 at a front end 3a and to an axle at a rear end 3b.

The outer cylinder 6 of the bush 4 is connected to the front end 3a of the trailing link 3 by welding, and the inner cylinder 7 is connected to the vehicle body 5.

Further, a rubber 8 is fitted between the outer cylinder 6 and the inner cylinder 7, and liquid chambers 9 and 10 are formed before and after this rubber 8. Further, the rubber 8 has an orifice 11. which communicates both liquid chambers 9.10.
The orifice 11.11 has a large diameter da at the front end, a small diameter db at the rear end, and has a gentle taper in the middle.

Therefore, when the rear axle 1 rides on a protrusion while driving, the trailing link 3 is displaced rearward with respect to the vehicle body 5, and the outer cylinder 6 of the bushing 4 also moves rearward, and the front fluid chamber 9 is pinched, causing the oil inside to become trapped. passes through the orifice 11.11 and moves to the liquid chamber 10 on the rear side. In this way, oil flows through the tapered orifice 11.11 from the large diameter da side to the small diameter db.
When the fluid flows to the side, the fluid resistance is not so large in terms of hydraulics, so the backward displacement of the trailing link 3 is carried out without much resistance, and therefore the rear wheel l rides on the protrusion relatively easily.

After the rear wheel 1 rides on the vehicle, the trailing link 3 is displaced forward with respect to the vehicle body 5, and the oil flows from the small diameter db side to the large diameter da side of the orifice 11.11, contrary to the above, so in this case This causes a hydraulic separation phenomenon in the fluid, increasing the fluid resistance of the oil. In other words, a large damping force acts on vibrations in the longitudinal direction of the trailing link 3, and the vibrations are suppressed at an early stage.

FIG. 3 is a sectional view showing a second embodiment of the present invention. This embodiment is different from the bushing 4 of the first embodiment shown in FIG.
．． The only difference is that 10 orifices are provided outside the outer cylinder 6. That is, in the bushing 12 of this embodiment, the large diameter da side pipe 13a of the orifice 13 is connected to the outer cylinder 6 on the liquid chamber 9 side on the front side, and the small diameter db side pipe 13b is connected to the outer cylinder 6 of the liquid chamber 10 on the rear side. A tapered pipe 13c is formed in the middle of the orifice 13. Therefore, in this case as well, as in the first embodiment, the small diameter db of the orifice 13 is
When oil flows from the side to the large diameter da side, large fluid resistance acts and vibrations are damped.

FIG. 4 is a sectional view showing a third embodiment of the present invention.

In the bushing 14 of this embodiment, an orifice 15 with a relatively small diameter that communicates both the liquid chambers 9 and 10 is formed in the rubber 8a, and the outer cylinder 6 on the liquid chamber 9 side and the outer cylinder 6 on the liquid chamber 10 side are connected. A straight pipe 17 having a check valve 16 in the middle is connected therebetween. Therefore, when the trailing link 3 is displaced rearward, the oil in the liquid chamber 9 does not pass through the small diameter orifice 15, but instead enters the liquid chamber 10 through the large diameter check valve 16 (through the pipe 17). In this case, the fluid resistance is small, so the damping force against the longitudinal vibration of the trailing link 3 is small.Afterwards, when the trailing link 3 is displaced forward, the oil in the liquid chamber 10 flows through the pipe 17. Even if the oil tries to flow into the liquid chamber 9, the check valve 16 is closed and the oil cannot flow into the liquid chamber 9. Therefore, the oil flows into the liquid chamber 9 through the small diameter orifice 15, and at this time, the oil is subjected to a large fluid resistance due to the orifice 15. This generates a large damping force of 4° against the vibration of the trailing link 3.

(Effects of the Invention) The present invention is a suspension system for a vehicle equipped with a trailing link, in which bushings at the end of the trailing link that are attached to the vehicle body generate different damping forces in response to input in the longitudinal direction of the trailing link. Because it is,
For example, when a wheel runs onto a protrusion on the road, that is, when a rearward input is applied to the trailing link, the damping force against vibration by the bushing is small, making it easier to run over, and then when a forward input is applied to the trailing link. This generates a large damping force and can effectively suppress the vibration of the trailing link.

[Brief explanation of drawings]

1 and 2 illustrate a first embodiment of the present invention, in which FIG. 1 is a side view of a suspension device for a vehicle, and FIG. 2 is a sectional view of a bushing. FIG. 3 is a sectional view of a bushing showing a second embodiment of the present invention. Fig. 4 shows the third embodiment of the present invention.Push wheels 3.Trailing link 4.12.14.Buttons 5.Vehicle body 9,10.Liquid chamber 11.13.17.Communication path Figure Q0-

Claims (1)

[Claims] In a vehicle suspension device equipped with a trailing link that is disposed along the longitudinal direction of the vehicle and supports a wheel in a vertically swingable manner with respect to the vehicle body, the bushing at the vehicle body attachment end of the trailing link is moved back and forth. A fluid-filled bush in which a plurality of arranged liquid chambers are connected through a communication path,
A suspension device for a vehicle, wherein the communication path is configured to generate different damping forces in response to an input in the longitudinal direction of the trailing link.