JPH1159154A - Air suspension device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with a stabilizer hanger bracket, so as to reduce vehicle weight and costs, by forming a pair of right and left link arms for regulating the relative movement of a vehicle body and an axle, by a plate spring member capable of being easily made flex in the lateral direction in comparison with the vertical direction. SOLUTION: When the same phase is input to both wheels T, air springs 15, 16 are vertically made flex. Since an axle 7 describes an arc by taking the distance between supporting points of a lateral rod 19 as the radius, the lateral deviation between a vehicle body and the axle 7 is generated. However, since upper link arms 3, 4 are supported on both ends through bushes and since right and left lower link arms 8, 9 are formed of plate spring members capable of being easily made flex in the lateral direction in comparison with the vertical direction, the vehicle body and axle can follow the deviation. When the opposite phases are input to both wheels T, lateral flexure is generated on the lower link arms 8, 9, torsion is generated on a torsion bar 10, and vibration is restrained from being transmitted to the vehicle body frame side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a pair of left and right link arm air springs extending parallel to each other in the front-rear direction of a vehicle for connecting a vehicle body frame and an axle, which are suitable for use in a large truck, a bus or the like. The present invention relates to an air suspension device.

[0002]

2. Description of the Related Art Conventionally, there has been known an axle suspension device used for a large truck, a bus, or the like, which uses an air spring whose riding comfort is improved as compared with a device using a leaf spring. ing. This air spring, when used alone, basically acts at two points and has no width or length, so unlike a leaf spring, it cannot be connected back and forth, left and right by itself, and is a well-known connecting rod. Must be used together. For example, a pair of left and right link arms extending parallel to each other in the vehicle front-rear direction to connect the body frame and the axle, and a similar pair of link arms or a V-shaped link arm above the link arms are provided. There is a parallel link type provided. In the case where two pairs of link arms are provided, it is common to also provide a lateral rod.

[0003]

In the above-mentioned suspension device, a stabilizer for suppressing the swing of the left and right wheels is often provided separately. However, the weight of the stabilizer is as heavy as 20 to 30 kg. , Causing the weight of the vehicle body to increase.

On the other hand, in a suspension device provided with the above-mentioned two pairs of link arms at the time of reverse phase input displacement or roll of the left and right wheels, a suspension provided with a V-shaped rod-shaped link arm around a fulcrum of a lateral link. In the device, since a relative rotational movement occurs between the vehicle body frame and the axle about the center fulcrum of the V-shaped rod, the two are relatively displaced in the left-right direction. It is desirable that the stabilizer can absorb this, but usually the stabilizer does not have a low spring constant enough to absorb such a lateral shift. Therefore, a slightly longer stabilizer hanger bracket is interposed to support the stabilizer on the vehicle body frame, and a bush is provided between the vehicle body frame and the bracket and between the stabilizer and the bracket. It was tilted to absorb the left-right deviation. This stabilizer hanger bracket is also heavy, and the vehicle body tends to be heavier in addition to the stabilizer.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and a main object of the present invention is to reduce the weight of a vehicle with a simple structure without impairing the functions. It is an object of the present invention to provide an air suspension device for a vehicle that can perform the above.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided, in accordance with the present invention, a pair of left and right sides which extend parallel to each other in a vehicle longitudinal direction so as to support a vehicle body with an air spring and connect a vehicle body frame and an axle. An air suspension device having a link arm, wherein the two link arms are made of a plate-like spring member that is more likely to flex in the left-right direction than in the up-down direction, and one end of each of the two link arms is extended by a torsion bar extending in the left-right direction. Connected, one end of each of the other ends and the rod are supported on the vehicle body side, and the other is supported on the axle, and the other ends of the link arms and the torsion bar are connected via a rubber bush or a ball joint. A stabilizer that is attached and suppresses swinging of the left and right wheels by the two link arms and the torsion bar. It is achieved by providing an air suspension device according to claim.

[0007]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIGS. 1 to 3 show a schematic configuration of an air suspension device for a driven wheel of a truck in a first embodiment to which the present invention is applied. This suspension device
This is an axle suspension device using an air spring. One end of a pair of upper link arms 3 and 4 is supported by frames 1 and 2 extending in the front-rear direction on the left and right sides of the vehicle body via brackets 5 and 6 and a bush so as to be swingable mainly in a vertical direction. . The other ends of the upper link arms 3, 4 are supported on the axle 7 via bushes so as to be able to swing mainly in the vertical direction.

As shown in FIGS. 2 and 3, lower link arms 8 and 9 are arranged in parallel with the lower portions of the upper link arms 3 and 4, and one end thereof extends in the left-right direction. The bar 10 is integrally rigidly connected. The other ends of the lower link arms 8 and 9 are respectively connected to the brackets 5 and 6 and the bushes 11 and 12 on the frames 1 and 2.
The main body is supported so as to be able to swing mainly in the vertical direction. Near the left and right ends of the torsion bar 10 are necks 10a, 10
At b, it is supported on the axle 7 via the bushes 13 and 14. The upper link arms 3 and 4 and the lower link arms 8 and 9 form a parallel link.

On the other hand, air springs 15, 16 are interposed between the frames 1, 2 and the axle 7. Further, shock absorbers 17 and 18 having one end connected to the vehicle body side and the other end connected to the axle 7 side are provided in a gap surrounded by the frames 1 and 2 and the wheels T. Further, one end of the lateral rod 19 is connected to the axle housing 7 and the other end is connected to either the frame 1 or the frame 2.

As shown in FIGS. 4 (a) and 4 (b), the lower link arms 8, 9 have relatively high rigidity in the vertical direction and are relatively flexible in the horizontal direction. (Spring constant in left and right directions (for two sheets) /
Vertical spring constant ≒ 0.3-1). Therefore, the lower link arms 8 and 9 hardly deform in response to a vertical input from the wheel T, and the lower link arms 8 and 9 rotate due to the torsion of the torsion bar 10 to obtain a displacement (the vertical spring constant is torsion). This is caused by the twist of the bar 10). In addition, a leftward or rightward input (lateral shift between the vehicle body and the axle) is bent to some extent and absorbed.

The operation of this embodiment will be described below. First, when there is an in-phase input to both wheels of the wheel T, the air springs 15 and 16 bend up and down. The axle 7 is centered on the fulcrum of the lateral rod 19 on the frame 1 side.
Draws an arc with the distance between the support points of the lateral rod 19 as a radius, so that a lateral shift occurs between the vehicle body and the axle.
On the other hand, since the upper link arms 3 and 4 are supported at both ends via bushes, they follow this shift. Further, since the lower link arms 8 and 9 form the plate-like spring members as described above, they can easily bend right and left (for example, a spring constant of 15 kgf / mm), and can follow this shift. Therefore, the unsprung portion is likely to vibrate, and the vibration is not transmitted to the vehicle body frame side, which can be reduced.
Since the necks 10a and 10b are stepped, there is no left and right displacement between the bushes 13 and 14 and the torsion bar 10.

Next, when there is an opposite phase input to both wheels T, the axle 7 rotates around the fulcrum of the lateral rod 19 on the frame 1 side, and one tire rises and the other falls. . At this time, the lower link arms 8 and 9 bend right and left, and at the same time, the torsion bar 10 is twisted (see FIGS. 4A and 4B). As described above, the vibration is not transmitted to the vehicle body frame due to the left-right bending, and the vibration can be reduced. In addition, the neck 10 is similar to the above.
Since a and 10b are stepped, the bushes 13 and 14
There is no left and right displacement between the torsion bar 10 and the torsion bar 10.

Further, when a lateral acceleration is applied to both wheels of the wheel T, that is, when a roll occurs, the vehicle body frame and the axle 7 are connected to each other around the fulcrum of the lateral rod 19 on the frame 1 side as in the case of the reverse phase input. It rotates relatively, and the lower link arms 8 and 9 bend right and left, and at the same time, the torsion bar 10 is twisted and the roll can be suppressed by their reaction force. Since the lower link arms 8 and 9 are relatively easily bent to the left and right as described above, the reaction force is small, and an appropriate roll is transmitted to the driver. Is available. In addition, the neck 10 is similar to the above.
Since a and 10b are stepped, the bushes 13 and 14
There is no left and right displacement between the torsion bar 10 and the torsion bar 10.

In the above embodiment, the lower link arms 8, 9
Are rigidly connected together by a torsion bar 10 and are supported by an axle 7 and the other ends of the lower link arms 8 and 9 are supported by frames 1 and 2, as shown in FIG. The torsion bar 10 may be supported by the frames 1 and 2, and the other ends of the lower link arms 8 and 9 may be supported by the axle 7. Further, a so-called tapered leaf whose thickness gradually decreases from one end where the torsion bar is connected to the other end may be used as the lower link arm. According to this, the spring constant can be easily adjusted, and the stress between the lower link arms 8 and 9 and the torsion bar 10 can be suppressed to a low level when bending right and left.

FIGS. 6 and 7 show a schematic configuration of a truck drive wheel suspension device according to a second embodiment to which the present invention is applied, and the same parts as those in the first embodiment are the same. And a detailed description thereof will be omitted.

In this embodiment, the center of the axle housing 21 and the frame 1,
2, a V-shaped rod 22 is interposed therebetween, and the lower link arms 8 and 9 constitute a parallel link. A pair of left and right air springs 23 to 26 are provided between the axle housing 21 and the frames 1 and 2. Other structures of the suspension device are the same as those of the first embodiment.

[0018]

As is apparent from the above description, according to the air suspension device of the present invention, the pair of left and right link arms for restricting the relative movement between the vehicle body and the axle are bent more in the left-right direction than in the vertical direction. One end is connected to each other by a torsion bar extending in the left-right direction via a bush or a universal joint, and one of the other end and the torsion bar is supported on the vehicle body side and the other is formed. A stabilizer that supports the axle and suppresses the swinging of the left and right wheels with both link arms and torsion bars, omitting the separate stabilizer and the stabilizer hanger bracket used to support the stabilizer on the body frame The vehicle weight is reduced, the number of parts is reduced, and the vehicle cost is reduced.

[Brief description of the drawings]

FIG. 1 is a plan view showing a schematic configuration of a suspension device for a driven wheel of a truck according to a first embodiment to which the present invention is applied.

FIG. 2 is a side view of FIG. 1;

FIG. 3 is a bottom view of a main part of FIG. 1;

4A is a side view of a lower link arm for explaining the operation of the air suspension device according to the present invention, and FIG. 4B is a bottom view thereof.

FIG. 5 is a view similar to FIG. 3, showing an application example of the first embodiment;

FIG. 6 is a plan view showing a schematic configuration of an air suspension device for driving wheels of a truck according to a second embodiment to which the present invention is applied.

FIG. 7 is a side view of FIG. 6;

[Explanation of symbols]

 1, 2 Body frame 3, 4 Upper link arm 5, 6 Bracket 7 Axle 8, 9 Lower link arm 10 Torsion bar 10a, 10b Neck 11, 12, Bush 13, 14, Bush 15, 16, Air spring 17, 18, Shock absorber 19 Lateral Rod 21 Axle housing 22 V-shaped rod 23-26 Air spring T Wheel

Claims (4)

[Claims] 1. An air suspension device having a pair of left and right link arms extending parallel to each other in the vehicle front-rear direction to support a vehicle body with an air spring and to connect a vehicle body frame and an axle. Is formed of a plate-like spring member that is more flexible in the left-right direction than in the up-down direction. One end of each of the link arms is connected to each other by a torsion bar extending in the left-right direction, and one of the other end and the rod is connected to the vehicle body. And the other end of the both link arms and the torsion bar are attached via a rubber bush or a ball joint. An air suspension device comprising a stabilizer that suppresses shaking. 2. A ratio of a spring constant in the left-right direction of the plate-shaped spring member to a spring constant in the up-down direction is defined as: left-right spring constant (for two sheets) / up-down spring constant ≒ 0.
3. The air suspension device according to claim 2, wherein the number is 3 to 1. 3. 3. The air suspension device according to claim 1, wherein a parallel link is formed by providing a link arm parallel to the upper or lower one of the link arms. 4. The air suspension device according to claim 1, wherein a parallel link is formed by providing a V-shaped rod on one of the upper and lower sides of each of the link arms.