JP3773685B2 - Stabilizer for air suspension system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a stabilizer for an air suspension device that is suitable for use in large trucks, buses, and the like and has a pair of left and right link arms that extend parallel to each other in the vehicle longitudinal direction so as to connect a vehicle body frame and an axle. .
[0002]
[Prior art]
2. Description of the Related Art Conventionally, axle suspension devices used for large trucks, buses, and the like have been known that use air springs that have improved riding comfort and the like compared to those that use leaf springs. This air spring, when used alone, basically has two points of action and has no width or length. Therefore, unlike a leaf spring, the air spring cannot be connected in the front / rear / left / right direction. Etc. need to be used together. For this purpose, for example, a pair of left and right link arms extending in parallel with each other in the vehicle longitudinal direction to connect the vehicle body frame and the axle, and a similar pair of link arms or a V-shaped rod-shaped link arm on the upper side thereof. There is a parallel link type provided. In the case of providing two pairs of link arms, it is common to provide a lateral rod for connecting the vehicle body frame and the axle .
[0003]
In the suspension device as described above, a stabilizer is often provided separately for suppressing the swing of the left and right wheels, but the weight of this stabilizer is heavy, 20 kg to 30 kg, which has led to an increase in the weight of the vehicle body. .
[0004]
To cope with such an inconvenience, the present the same applicant, in the Pat. Laid Application flat 9-223784, the left and right link arms of the air suspension device, easily bent leaf spring in the lateral direction than the vertical direction formed with Jo members, connected by a torsion bar extending the one ends in the lateral direction, and connecting the other to the axle with one of the other ends and the torsion bar is connected to the vehicle body side, and link arms It proposes to configure suppressing stabilizer sway left and right wheels by the torsion bars.
[0005]
According to this structure, the stabilizer hanger bracket used for supporting the separate stabilizer and the stabilizer on the vehicle body frame is omitted, the vehicle weight is reduced, the number of parts is reduced, and the vehicle cost is reduced.
[0006]
[Problems to be solved by the invention]
At a link arm of the configuration information, the torsion bar side is rigidly connected, such as the anti-torsion bar side is supported via a bushing, of the difference or the support structure of the movable range in the torsion bar side and anti torsion bar side Because there is a difference , it is easier to adjust the spring constant by using a so-called taper leaf with a plate thickness on the anti-torsion bar side thinner than the plate thickness on the torsion bar side, and the maximum generation of the link arm when bending in the left-right direction Stress can be reduced . On the other hand, if the plate thickness on the anti-torsion bar side is made too thin, the strength of that portion will decrease , and conversely, if the plate thickness on the torsion bar side is increased while securing the plate thickness on the anti-torsion bar side , the link arm will device becomes too thick that occur is a problem that the large size and weight reduction.
[0007]
The present invention has been made in view of such problems of the prior art, and its purpose is to maximize the generation of link arms without causing a partial decrease in strength, and without increasing the size and weight. An object of the present invention is to provide a stabilizer for an air suspension device that can reduce stress and improve durability.
[0008]
[Means for Solving the Problems]
The above-described purpose is a pair of left and right link arms 8 that are made of leaf spring-like members that are more flexible in the left-right direction than the up-down direction and extend parallel to each other in the vehicle front-rear direction to connect the vehicle body frames 1, 2 and the axle 7. 9 and a torsion bar 10 extending in the left-right direction by connecting one ends of the link arms, and either one of the other end of the link arms or the torsion bar is a rubber bush or a ball joint. A stabilizer for an air suspension device for suppressing swinging of the left and right wheels T by being coupled to the vehicle body frame side through the rubber bush or a ball joint and the other. but before therebetween together towards the other end of the plate thickness D2 as compared to said one end of the plate thickness D1 is thinner It has a portion of a thinner plate thickness D3 than the thickness of the other end to the other end closer, and provides a stabilizer for an air suspension device, wherein a thickness of each part is changing gradually Is achieved. In particular, the length between both coupling portions of the link arms is taken as L 1, the one end of the plate thickness D1 is 2.75~3.25 × ^{10 -2} × L 1 in the range, the other end The plate thickness D2 on the side is 1 . 5~2.0 × ^{10 -2} × L 1 in the range, the other end of the plate thickness D3 of the thinner portion than the plate thickness 0.85~2.75 × ^{10 -2} × L 1 range, and may If this is set, respectively, also the length between the two coupling portions of the link arms and L1, the distance from the most plate the other end of the coupling portion of the thin portion of the thickness of the link arms and L2 when the, it may have a range of L2 / L1 = 0.25~0.35.
[0009]
Further, the two link arms, that between the plate width with is narrower towards the comparison to the other end of the plate width to plate width of the one end side is changing smoothly, the maximum stress reduction The effect becomes even higher. In that case, the length between coupling portions of the link arms is taken as L 1, the one end of the range plate width W1 is .325-.375 × L 1, the other end of the plate width W2 it is desirable to have become the range of 0.25 to 0.30 × L 1, and has become, respectively, and the range of W1 / W2 = 1.1 to 1.5.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0011]
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 is an axle type suspension device using an air spring. One end of a pair of upper link arms 3 and 4 is pivotally attached to the frames 1 and 2 extending in the front-rear direction on the left and right of the vehicle body via the brackets 5 and 6 and a bush so as to be swingable in the vertical direction. Yes. An axle 7 is connected to the other end of the upper link arms 3 and 4 via a bush .
[0012]
As shown well in FIGS. 2 and 3, lower link arms 8 and 9 are arranged in parallel to the lower portions of the upper link arms 3 and 4, and one end of each of them is a torsion bar 10 extending in the left-right direction. It is rigidly connected together. The other ends of the lower link arms 8 and 9 are pivotally attached to the frames 1 and 2 via brackets 5 and 6 and bushes 11 and 12 so as to be swingable mainly in the vertical direction. In the vicinity of the left and right end portions of the torsion bar 10, the axle 7 is connected to the neck portions 10a and 10b via bushes 13 and 14, respectively. These upper link arms 3 and 4 and lower link arms 8 and 9 constitute a parallel link.
[0014]
Both lower link arms 8,9 only, FIG. 4 exaggerated its thickness and width (a), and FIG. 5 representing movement of FIG. 4 (b), and the lower link arm 8,9 (a), and FIG. 5 (b ), The lower link arms 8 and 9 are made of a leaf spring-like member having relatively high rigidity in the vertical direction and relatively easy to bend in the horizontal direction. Also, the plate thickness D2 on the anti-torsion bar side (the other end side), that is, the frames 1 and 2 side is thinner than the plate thickness D1 on the torsion bar 10 side (one end side) of the lower link arms 8 and 9. In addition, a portion having a thickness D3 that is thinner than the thickness D2 on the frames 1 and 2 side is formed closer to the frames 1 and 2 (the other end side) between them, and the thickness of each portion changes gently. (FIG. 4 ( b )).
[0015]
Here, the length between coupling portions of the link arms 8,9 when the L1, the thickness D1 of the torsion bar 10 side is in the range of 2.75 to 3.25 × ^{10 -2} × L1, frame thickness D2 of 1 side, 1.5 to 2.0 × ^{10 -2} × range of L1, the thickness D3 of the thin section of the most thickness of the frames 1 and 2 close content is 0.85 to 2 range of .75 × ^{10 -2} × L1, the has been respectively. Than the torsion bar 10 side of the plate thickness D1 is 2.75 × ^{10 -2} × L1, than the thickness D2 is 1.5 × ^{10 -2} × L1 of the frame 1 side, the most thickness of the thin parts min than the thickness D3 is 0.85 × ^{10 -2} × L1 of the respective thin can not ensure the strength, the torsion bar 10 side of the plate thickness D1 is larger than 3.25 × ^{10 -2} × L1 not Increase weight if necessary.
[0016]
Further, the length between coupling portions of the link arms 8,9 and L1, the distance from the support portion of the frame 1 side of the thin portion of the most thickness of the link arm 8,9 (part of the thickness D3) the when the L2, and has a range of L2 / L1 = 0.25~0.35. Outside this range, the maximum generated stress increases. Figure 6 is a ^{D1 = 3.07 × 10 -2 × L1} , and ^{D2 = 1.73 × 10 -2 × L1} , L2 / L1, i.e. a plate when a D3 = 1.15 × ^{10 -2} × L1 It is a graph which shows the relationship between the position of the part whose thickness is D3, and the maximum generated stress.
[0017]
As the material of the link arm 8,9 in this arrangement, since the welding the collar and the torsion bars 10 of the probe Tsu shoe, the usual spring steel SUP9,9A, weld cracking occurs, after welding, While using SCM425 put out the same hardness as the spring steel heat treated, for example, the thickness D2 of the frames 1 and 2 side 1.15 × ^{10 -2} × L1, the thickness D1 of the torsion bar 10 side 3. Even if it is gently changed as 07 × 10 ⁻² × L1, the stress of the welded portion on the frames 1 and 2 side becomes larger than 435 (Mpa), so the plate thickness D2 on the frames 1 and 2 side is 1.73 × 10. ⁻² × L or more. It goes without saying that the plate thickness D2 on the frames 1 and 2 side can be made even thinner depending on the material.
[0018]
In such a configuration, as shown in FIGS. 5A and 5B , the lower link arms 8 and 9 are hardly deformed by the vertical input from the wheel T, and the torsion bar 10 is twisted to the left and right. The lower link arms 8, 9 rotate relative to each other to obtain displacement (the vertical spring constant is generated by torsion of the torsion bar 10). Further , the lower link arms 8 and 9 are bent to some extent to absorb the input in the left-right direction (left-right shift between the vehicle body and the axle).
[0019]
Below, the operation | movement point of this embodiment is demonstrated. First, when there is an in-phase up / down input to the left and right wheels T, the air springs 15 and 16 bend up and down. And around the fulcrum of the frame 1 side of the lateral rod 19, the locus of the axle 7 an arc whose radius is the distance between the support points of the lateral rod 19, the left and right displacement between the vehicle body and the axle 7 is generated. On the other hand, since the upper link arms 3 and 4 are supported via bushes at both ends, the upper link arms 3 and 4 follow this shift. Since the lower link arms 8 and 9 are plate spring-like members as described above, the lower link arms 8 and 9 can be easily bent right and left, and the connecting end with the axle 7 can follow this shift. Therefore, the unsprung portion can easily move up and down, and the amount of vibration transmitted to the vehicle body frame can be reduced. In addition, since there is a step in the neck portions 10a and 10b , there is no left-right displacement between the bushes 13 and 14 and the torsion bar 10.
[0020]
Then, when there is a reverse phase input to the left and right wheels T, around the fulcrum of the frame 1 side of the lateral rod 19, the axle 7 is tilted, hand tires increases, other person is lowered. At this time, left and right deflections occur in the lower link arms 8 and 9, and at the same time, the torsion bar 10 is twisted (see FIGS. 5A and 5B). Similarly to the above , the amount of vibration transmitted to the vehicle body frame can be reduced by this left / right deflection. Since the same manner as described above the neck 10a, the 10b there is a step, never left shift occurs between the blanking Tsu shoe 13, 14 and the torsion bar 10.
[0021]
Further, when a lateral acceleration is input to both the left and right wheels T and a roll is generated, the vehicle body frame and the axle 7 are relatively centered around the fulcrum of the lateral rod 19 on the frame 1 side as in the case of the reverse phase input. The lower link arms 8 and 9 are bent in the left and right directions, and at the same time, the torsion bar 10 is twisted, and the roll can be suppressed by the reaction force thereof. Since the lower link arms 8 and 9 are set relatively easily to bend left and right as described above, the reaction force is small and an appropriate roll is transmitted to the driver, so that an appropriate speed at cornering is notified. Can be done. Since the same manner as described above the neck 10a, the 10b there is a step, never left shift occurs between the blanking Tsu shoe 13, 14 and the torsion bar 10.
[0022]
FIGS. 7 (a) and 7 (b), 4 (a) and illustrates a main configuration of the air suspension device for a stabilizer of the driven wheels in the track to a second embodiment of the present invention is applied It is the same figure as 4 (b). In the above configuration, the plate widths (vertical dimensions) of the lower link arms 8 and 9 are constant. However, in this configuration, the plate width W2 on the frames 1 and 2 side is smaller than the plate width W1 on the torsion bar 10 side. The width is narrower and the plate width between them is gently changing. Other configurations are the same as those in the first embodiment.
[0023]
Here, the length between coupling portions of the link arms 8,9 when the L1, the range of the plate width W1 of the torsion bar 10 side 0.325 to 0.375 × L1, frames 1 and 2 the side The plate width W2 is in the range of 0.25 to 0.30 × L1, and W1 / W2 = 1.1 to 1.5. Plate width W1 of the torsion bar 10 side narrower than 0.325 × L1, can not be secured narrow when its strength than the plate width W2 of the frame 1 side is 0.25 to 0.30 × L1, the torsion bar plate width W1 of 10 side is wider and larger and heavier unnecessarily than 3.25 × ^{10 -2} × L1. Further, when W1 / W2 is smaller than 1.1, the stress on the torsion bar 10 side increases abruptly. When W1 / W2 is larger than 1.5, the stress on the frames 1 and 2 side increases abruptly, resulting in the maximum generated stress. Will increase. Figure 8 is a ^{D1 = 3.07 × 10 -2 × L1} , and ^{D2 = 1.73 × 10 -2 × L1} , and ^{D3 = 1.15 × 10 -2 × L1} , and L2 / L1 = 0.3 It is a graph which shows the relationship between W1 / W2 at the time of doing and the maximum generation stress.
[0024]
In each of the above embodiments and rigidly connected integrally to one ends of the lower link arms 8,9 at the torsion bar 10, which in supporting the axle 7, the frame 1 and the other ends of the lower link arms 8,9, 2 was pivoted, as shown in FIG. 9, and pivoted the torsion bar 10 to the frame 1 may be supported axle 7 at the other ends of the lower link arms 8,9. Further, instead of the upper link arm, a V-shaped rod is interposed between the center portion of the axle housing and the frames 1 and 2, and this and the lower link arms 8 and 9 constitute a parallel link. 2, a pair of left and right air springs may be provided.
[0025]
【The invention's effect】
As is clear from the above description, according to the stabilizer for an air suspension device according to the present invention, the plate thickness on the anti-torsion bar side is made thinner than the plate thickness on the torsion bar side in both link arms. A portion thinner than the plate thickness on the anti-torsion bar side is formed near the anti-torsion bar side, and the thickness of each part is changed gently to prevent stress concentration on each part of the link arm, and the maximum generated stress It can reduce and improve durability. In addition, by reducing the plate width on the anti-torsion bar side compared with the plate width on the torsion bar side in both link arms and gently changing the plate width between them, the effect of reducing the maximum generated stress is further enhanced. .
[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 track in a first embodiment to which the present invention is applied.
FIG. 2 is a side view of the suspension device shown in FIG.
FIG. 3 is a bottom view of the main part of the suspension device shown in FIG. 1;
4A is a plan view of only a link arm, and FIG. 4B is a side view thereof.
5A 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. 5B is a bottom view thereof.
FIG. 6 is a graph showing the relationship between the position of the thinnest part of the link arm and the maximum generated stress.
FIG. 7 is a plan view of only a link arm of a suspension device for a driven wheel of a track in a second embodiment to which the present invention is applied, and (b) is a side view thereof.
FIG. 8 is a graph showing the relationship between W1 (plate width on the torsion bar side) / W2 (side plate width opposite to the torsion bar) and maximum generated stress.
FIG. 9 is a view similar to FIG. 3 showing an application example of the present invention.
[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 T Wheel

Claims (5)

A pair of left and right link arms that are parallel to each other in the longitudinal direction of the vehicle and that connect the vehicle body frame and the axle, and are connected to one end of each of the link arms. A torsion bar extending in the left-right direction, and either one of the other ends of the link arms and the torsion bar is coupled to the body frame side via a rubber bush or a ball joint, and the other is a rubber A stabilizer for an air suspension device for suppressing swinging of right and left wheels by being coupled to the axle via a bush or a ball joint ,
The link arms are thinner than the other end of the plate thickness during the other end closer together compared to the thickness of the one end side are thinner is better for the thickness of the other end A stabilizer for an air suspension device, characterized in that the plate has portions and the thickness of each portion changes gently. The length between the both coupling portions of the link arms is taken as L 1, the one end of the plate thickness D1 is 2.75~3.25 × ^{10 -2} × L 1 in the range, of the other end The plate thickness D2 is 1 . 5~2.0 × ^{10 -2} × L 1 in the range, the other end of the plate thickness D3 of the thinner portion than the plate thickness 0.85~2.75 × ^{10 -2} × L 1 range, and The stabilizer for an air suspension device according to claim 1, wherein each of the stabilizers is provided . Wherein the length between the both coupling portions of the link arms and L1, the distance from the most plate the other end of the coupling portion of the thin portion of the thickness of the link arms is taken as L2, L2 / L1 = 0 The stabilizer for an air suspension device according to claim 1, wherein the stabilizer is in a range of .25 to 0.35. Claim 1, wherein the link arms, characterized in that between the plate width with is narrower towards the other end of the plate width in comparison with the plate width of the one end side is changing gradually The stabilizer for an air suspension device according to any one of claims 1 to 3. Wherein a length between coupling portions of the link arms is taken as L 1, the plate width W1 of the one end in the range of 0.325-0.375 × L 1, plate width W2 of the other end side 0 .25~0.30 × L 1 in the range, and has become, respectively, and any of claims 1 to 4, characterized in that has a range of W1 / W2 = 1.1 to 1.5 A stabilizer for an air suspension device according to claim 1.

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