JPH10324127A - Vehicular suspension device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the position of a beam parallel to a car body frame to improve the durability of an air spring by mounting the beam to an axle case through a mounting-assembly body having caster plate. SOLUTION: An axle case 13 is connected to a car body frame 2 at an angle θof intersection, which corresponds to the tilt angle of a propeller shaft. The mounting of a beam 24 to the axle case 13 is performed through a mounting- assembly body 25 surrounding the periphery of the axle case 13. Since a caster plate 90 having an inclined plane inclined at the tilt angle which corresponds to an angle θ of intersection, is interposed between the axle case 13 out of mounting-assembly body 25, and the beam 24, the beam 24 is mounted to the axle case 13 in a position parallel to the car body frame 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle suspension device.

[0002]

2. Description of the Related Art Conventionally, as a large vehicle, a front axle 3 is provided in front of a body frame 2 and a rear axle 2 is provided as shown in FIG.
There is a rear two-axle vehicle 1 having a rear axle 4. After that 2
In the axle vehicle 1, the rear axle 4 is composed of a front drive axle 5 and a rear driven axle 6, and a so-called rear two-axis one-axis drive (6 ×) for driving two wheels out of six wheels including the front wheels. It is common to simplify the power transmission system for the vehicle of 2).
The total weight WG of the vehicle 1 and the load is distributed to a front tire 7 (supporting the load WF) provided on the front axle 3 and rear tires 8 and 9 (supporting the load WR) provided on the rear axle 4. It is supported on the road surface. Of the total load WR, the drive axle 5 is the WRF and the driven axle 6 is the WRR (usually, WRR = WR
F), which provides a vehicle that can reduce the axle load that one axle bears and that can withstand a larger load as a whole.

In such a rear two-axle vehicle 1, the suspension device for the rear axle 4 is provided between the body frame 2 and an axle case that rotatably supports the respective axles 5, 6.
It is configured by interposing a leaf spring (leaf spring), an air spring, or a combination of an air spring and a leaf spring. In either configuration, when the natural frequency of the spring and the frequency of the vehicle body frame 2 match, the vibration of the spring is in a resonance state, and the convergence of the vibration is poor. for that reason,
A shock absorber is arranged between the body frame 2 and the axle case to absorb vibration.

FIG. 4 shows an example of an air suspension device in which a drive axle 5 and a driven axle 6 are both supported using an air spring 21 as a suspension device for the rear axle 4. The air spring 21 is advantageous in that the weight can be sufficiently reduced even in consideration of various tanks and piping systems for supplying air, as compared with the leaf spring. In this air suspension device, the vehicle body frame 2 can be flexibly supported by the wheels, but on the other hand, the spring constant of the air spring 21 is small, so that a small change in force causes a large change in vertical displacement. That is, rolling occurs.
Therefore, in general, in a rear two-axle vehicle suspension device using an air spring, the rigidity of a stabilizer for keeping the body frame 2 inclined horizontally is set higher than that of a suspension using another type of spring. .

In FIG. 4, the vehicle body frame 2 includes side members 20 extending in the front-rear direction of the vehicle on both sides in the vehicle width direction, and a cross member extending in the vehicle width direction at a center position of the rear axle 4, as indicated by imaginary lines. And a member 29. At a center position of the rear axle 4, a torque rod bracket 22 is fixed to an outer surface of the side member 20 via a mounting plate 23. The torque rod bracket 22 hangs down below a level connecting the axis centers of the drive axle 5 and the driven axle 6. Beams 24 that extend horizontally in the front-rear direction of the vehicle are attached to lower portions of both ends of an axle case 13 that rotatably supports the drive axle 5 and an axle case 14 that rotatably supports the driven axle 6, by a mounting assembly 25. ing. An air spring 21 is interposed between the front and rear ends of each beam 24 and the body frame 2. A total of eight air springs 21 are used for the rear axle 4, and the load acting on the rear axle 4 from the body frame 2 is dispersed and supported by the eight air springs 21, so that the load on each air spring 21 is reduced. ing. The load supported by the air spring 21 is transmitted from the axle case 13 or 14 to the tires 8 and 9 and is supported on the road surface. Since the air spring 21 has a small spring constant, supporting the air spring 21 only
The body frame 2 easily vibrates and, when it comes into a resonance state, damping of the vibration continues for a long time. In order to prevent this, a shock absorber 26 is provided between each beam 24 and the vehicle body frame 2 to reduce the vibration of the vehicle body frame 2.

On each side in the vehicle width direction, a torque rod 17 is provided between the torque rod bracket 22 and the beams 24 attached to the axle case 13 and the axle case 14, respectively. Each end of the torque rod 17 is connected to a lower end of the torque rod bracket 22 and a lower portion of the beam 24 by a pivot portion having a vehicle transverse axis (the pivot portion 2 for one torque rod 17).
7 only). Torque rod 1
7 is capable of transmitting a force in the axial direction of the rod, so that a force in the vehicle longitudinal direction acting between the vehicle body frame 2 and the wheel side, such as a driving force during acceleration and a braking force during deceleration, is transmitted. However, when the vehicle travels on an uneven road surface, the wheels, that is, the tires, the axle cases 13, 14 and the beams 24
Is not restricted from being displaced in the vertical direction with respect to the body frame 2. Therefore, the suspension device operates in response to this displacement, and the suspension device functions to reduce the impact transmitted from the road surface to the vehicle body frame 2 as it is.

At the center position of the rear axle 4, a cross member 29 is stretched between the left and right side members 20 and 20 and is integrally fixed with, for example, rivets or bolts. A front V-rod 32 is disposed between the axle case 13 and an intersection 30 where both ends of the cross member 29 intersect the vehicle body frame 2, and a rear V-rod 33 is provided between the intersection 30 and the axle case 14. Is arranged. The front V-rod 32 is provided with a housing cover 31 containing a differential device for the intersection 30 and the drive axle 5.
Are arranged so as to extend toward the rear of the vehicle. That is, the associated end 34 of the front V-rod 32 is connected to the front mounting bracket 35 mounted on the bulging upper part of the housing cover 31 integrally formed with the axle case 13 of the drive axle 5. In addition, V
Each branch end 36 of the rod 32 is connected to an intersection bracket 37 attached to the body frame 2 and the cross member 29 at the intersection 30.

The rear V-rod 33 is connected to the intersection 30 intersecting the vehicle body frame 2 and the axle case 14 of the driven axle 6.
It is arranged in a state of branching toward the front of the vehicle between the rear mounting bracket 38 mounted on the vehicle. That is, the associated end 39 of the rear V-rod 33 is pivotally attached to the rear mounting bracket 38 mounted on the upper surface of the axle case 14 of the driven axle 6, and each branch end 40 of the rear V-rod 33 intersects. At a portion 30, it is connected to a cross bracket 41 attached to the body frame 2 and the cross member 29. Cross bracket 41
Are symmetrically arranged with the cross bracket 37 for the front V rod 32, and are connected back to back with the cross member 29 interposed therebetween.

The front V rod 32 and the rear V rod 33 are connected to the tires 8 and 9 and the axle cases 13 and 14 in the same manner as the torque rod 17 so that the suspension functions when the vehicle runs on an uneven road surface. Rear axle 4 including
Must be allowed to displace vertically with respect to the body frame 2. Therefore, in the front V rod 32 and the rear V rod 33, the associated end 34 is connected to the front mounting bracket 35 so as to be rotatable around an axis parallel to the drive axle 5, and the associated end 39 is connected to the rear mounting bracket 35. 38 is connected so as to be rotatable around an axis parallel to the driven axle 6. Similarly, the branch end 36 of the front V-rod 32 is rotatably connected to the cross bracket 37, and the branch end 40 of the rear V-rod 33 is rotatably connected to the cross bracket 41. The meeting ends 34 and 39 and the branch ends 36 and 40 are connected to the brackets 35, 38, 37 and 4 respectively.
1 so that the front V rod 3
When attaching the 2 and the rear V-rod 33 to each bracket, the posture of the rod can be adjusted. The meeting ends 34 and 39 and the branch ends 36 and 40 are provided with friction bushes that can be rotated by friction sliding so as not to inadvertently move with respect to the brackets 35, 38, 37 and 41. Is equipped.

The front V-rod 32 and the rear V-rod 33 are used by the torque rod 1 for the longitudinal force acting between the body frame 2 and the axle cases 13 and 14.
It has the function of transmitting in the same manner as 7. Further, the front V-rod 32 and the rear V-rod 33 can transmit a lateral force between the axle cases 13 and 14 and the body frame 2 because of the V-shaped structure.

Between the lower portions of the beams 24 attached to both sides of the axle case 13 of the drive axle 5, a stabilizer provided on the drive axle side, that is, a first stabilizer 42 is provided.
Has been passed over. As for the first stabilizer 42, only the first arm portion 44 extending forward of the vehicle is shown. The distal end of the first arm portion 44 is pivotally attached by a lower pivot 49 to a first rod 47 which is rotatably attached to the vehicle body frame 2 via a bracket 46 by an upper pivot 48 and hangs down. Is being worn. Similarly, the second stabilizer 52 extends between the lower portions of the beams 24 of the driven axle 6. The second stabilizer 52 includes a second torsion bar portion 53 and a second arm portion 5.
4 and is rotatably supported by a support portion 55 provided below each beam 24. The distal end of the second arm portion 54 is pivotally attached by a lower pivot 59 to a second rod 57 which is rotatably attached to the vehicle body frame 2 via a bracket 56 by an upper pivot 58 and hangs down. Is being worn. When the vehicle rolls and a relative displacement occurs in the vertical direction between the body frame 2 and the axle cases 13 and 14 on one side in the vehicle width direction, the first stabilizer 42 and the second stabilizer 52
A torsional force is generated in accordance with the displacement, which affects the height between the body frame 2 and the axle cases 13 and 14 on the other side in the vehicle width direction, thereby preventing the vehicle from rolling.

FIG. 5 shows an example in which an air spring 21 is provided between each end of the beam 24 attached to the axle case 13 and the vehicle body frame 2 as a suspension device. To the drive axle 5 of the rear axle 4, a propeller shaft extending rearward of the vehicle so as to transmit the driving force of an engine provided at the front of the vehicle is drivingly connected to a differential device (contained in a housing cover 31). ,
The driving force of the engine is transmitted to a driving axle 5 via a differential device. The engine is installed on the upper surface of the vehicle body frame 2, and in order to optimally transmit power to the differential device, the propeller shaft is arranged to be inclined obliquely downward and extend rearward. Therefore, the input axis from the propeller shaft to the differential device has an intersection angle θ with respect to the drive axle 5 (in FIG. 5, the position of the drive axle 5 is shown as the inclination angle of the axle case 13 with respect to the vertical axis). Must be attached. In order to make the axle case 13 and the beam 24 have the posture of the intersection angle θ with respect to the body frame 2, it is possible to set the lengths of the torque rod 17, the V rods 32, 33, and (see FIG. 4). is there.

[0013]

In the vehicle suspension device shown in FIG. 5, the beam 24 is attached to the axle case 13 by the attachment assembly 25 at an angle of intersection θ in a direction extending in the longitudinal direction of the vehicle. The air spring 21 as a spring means for the suspension is
4 are provided between the respective end portions and the body frame 2.
When the beam 24 is attached to the axle case 13 at an angle of intersection θ, the following problem occurs in the air spring 21. That is, the air spring 21
Has a diaphragm, 63 and a piston 62 that reciprocates relatively in the diaphragm 63. The piston 62, which is a support member of the air spring 21, is not aligned with the diaphragm 63 by an amount corresponding to the intersection angle θ. In this state, when the piston 62 repeats the relative reciprocation within the diaphragm 63 as a function of the air spring 21, the diaphragm 63 rubs against the piston 62, and the durability of the diaphragm 63 is greatly reduced.

In FIG. 5, a torque rod bracket 2 fixed to the vehicle body frame 2 via a mounting plate 23 is shown.
2 is suspended below the level of the drive axle 5, and a torque rod 17 is provided between the torque rod bracket 22 and the beam 24 via a pivot 27. The torque rod 17 transmits the axial force of the rod acting between the vehicle body frame 2 and the wheel side, such as the driving force during acceleration and the braking force during deceleration, that is, the force in the vehicle longitudinal direction. When the vehicle runs on uneven road surfaces, the tires, axle cases 13, 14 and beams 24
Is not restricted from being displaced in the vertical direction with respect to the body frame 2. A first stabilizer 42 extends between the lower portions of the beams 24 attached to both sides of the axle case 13 of the drive axle 5. The front end of the first arm portion 44 of the first stabilizer 42 extending forward of the vehicle is rotatably attached to the vehicle body frame 2 via a bracket 46 by an upper pivot 48 so as to hang down.
Are pivoted by the lower pivot 49. The first stabilizer 42 has a first torsion bar portion 43 extending between first arm portions 44, 44 provided on both sides in the vehicle width direction.
4 is supported by a support portion 45. When the vehicle rolls and a relative displacement occurs between the body frame 2 and the axle case 13 on one side in the vehicle width direction, the first stabilizer 42 generates a torsional force according to the displacement. This affects the height between the vehicle body frame 2 and the axle case 13 on the other side in the vehicle width direction, thereby preventing the vehicle from rolling.

[0015]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problem, that is, a caster plate having an angle corresponding to the intersection angle θ is interposed between an axle case and a beam. By attaching the beam to the axle case so that the beam is horizontal, the durability of the diaphragm of the air spring as described above is prevented, and the air spring is protected.

The present invention has been made in order to solve the above-mentioned object.
It is configured as follows. That is, the present invention provides a vehicle body frame supporting an engine, a differential device to which a propeller shaft to which the driving force of the engine is transmitted is connected, a driving axle to which the driving force of the engine is transmitted via the differential device, In a vehicle provided with an axle case that supports the differential device and rotatably supports the drive axle, and a suspension device provided between the body frame and the axle case, the suspension device includes the axle case. A beam attached to the beam via a mounting assembly, and an air spring disposed between the beam and the vehicle body frame, wherein the mounting assembly includes the beam between the axle case and the beam. Incline at an inclination angle corresponding to the intersection angle of the propeller shaft It relates to a vehicle suspension system, characterized in that it has a caster plate having.

Since the vehicle suspension device according to the present invention is configured as described above, it operates as follows. That is, according to the vehicle suspension system of the present invention, when the beam is mounted on the axle case via the mounting assembly, the elements of the mounting assembly interposed between the axle case and the beam are connected to the intersection angle of the propeller shaft. Since the caster plate has a slope inclined at an inclination angle corresponding to the above, the beam is attached to the axle case without being inclined even though the axle case is inclined with respect to the vehicle body frame. Therefore,
The misalignment between the center line of the piston of the air spring provided between the beam and the body frame and the center line of the diaphragm is reduced, and the air spring is not used in an abnormal posture.

In this vehicle suspension device, the beam is made of an aluminum alloy. Since the Young's modulus of aluminum alloys is generally lower than that of cast iron, the beam is susceptible to bending deformation. In some air springs, the misalignment between the axis of the piston and the axis of the diaphragm is further increased by this bending deformation. If the degree of misalignment of the two air springs is reduced by attaching the beam to the axle case without tilting, the prevention of damage to the air spring due to friction between the piston and the diaphragm will be effective. .

Further, in this vehicle suspension device, the caster plate is formed of an iron plate or a forged product. The aluminum and the iron-based metal constituting the mounting assembly form a local battery according to the ionization tendency using rainwater that has entered between them as an electrolyte. Therefore, especially aluminum can cause electrolytic corrosion and the beam can be damaged. Iron-based metals include iron plates,
There is a forged product or a cast product, but it is known that electrolytic corrosion is likely to occur when the carbon content is high. Therefore, it is preferable that the caster plate be formed of an iron plate or a forged product having a low carbon content.

In this vehicle suspension device, the mounting assembly includes a top plate member that covers a top surface of the axle case, a front holding member that is disposed along a front side surface of the axle case, and a rear side surface of the axle case. It consists of a rear holding member arranged along. That is, in addition to the caster plate on the bottom side, each side surface around the axle case is covered with a top plate member, and front and rear holding members,
The beam is easily attached to the axle case. For example, a bolt insertion hole is formed in each member surrounding the axle case, and the beam can be attached to the axle case by a mounting bolt passing through the bolt insertion hole.

Further, in this vehicle suspension device, the caster plate, the top plate member, the front holding member and the rear holding member are integrated with the axle case by welding. If the members constituting the mounting assembly are separated from each other and the mounting assembly is also fixed to the axle case when the beam is mounted on the axle case with mounting bolts, the axle case of the mounting assembly will be over time. Is loosened,
As a result, the attachment of the beam to the axle case may be loosened. However, if the members constituting the attachment assembly are integrated with the axle case by welding,
Such loosening does not occur, and the attachment of the beam to the axle case is ensured for a long period of time.

In this vehicle suspension device, the beam extends from the lower part of the axle case in the front-rear direction of the vehicle, and air springs are arranged between both ends of the beam and the body frame. Even in such an arrangement of the beam and the air spring, since the beam is mounted on the axle case by the mounting assembly including the caster plate, friction between the diaphragm constituting the air spring and the piston is reduced, and The durability of the air spring can be improved.

Further, in this vehicle suspension device, another suspension device provided between the vehicle body frame and another axle case rotatably supporting a driven axle provided corresponding to the drive axle. Incorporates a caster plate equivalent to the caster plate in the mounting assembly. In other words, the connection between the axle case supporting the driven axle and the beam attached to the axle case also uses the mounting assembly incorporating the caster plate, so that the parts can be shared and the vehicle manufacturing cost can be improved. This will contribute to reduction.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a vehicle air suspension device according to the present invention will be described with reference to the accompanying drawings. FIG. 1 is a side view of a drive axle side of a vehicle to which a vehicle air suspension device according to the present invention is applied. The vehicle air suspension device shown in FIG.
Compared with the air suspension device for a vehicle shown in FIG. 5, the basic structure is the same except for the connection structure between the axle case and the beam. Therefore, the same components as those shown in FIG. 5 are denoted by the same reference numerals, and the description thereof will not be repeated.

The vehicle air suspension device according to the present invention is applicable to vehicles of the rear two-axis one-axis drive (6 × 2) type and other types of shaft drive (for example, 6 × 4) type vehicle. is there. In the embodiment shown in FIG.
The upper surface 76 of the beam 24 is flattened, and the beam 24 is attached to the axle case 13 with the caster plate 90 interposed therebetween so that the upper surface 76 of the beam 24 is horizontal, that is, parallel to the vehicle body frame 2. Become. Therefore, the air spring 21 provided between the end of the beam 24 and the vehicle body frame 2 can prevent the diaphragm 63 from being displaced from the center of the piston 62 and the diaphragm 63.
The diaphragm 63 is rubbed by the
Is not deteriorated.

FIG. 2 is an enlarged sectional view showing an example of a mounting structure of the axle case 13 and the beam 24 in the vehicle suspension device shown in FIG. As shown in FIG. 2, not only the caster plate 90 but also the front holding member 94,
The rear holding member 95 and the top plate member 97 surround and are integrated by welding to form the mounting assembly 25.
Each of the front holding member 94 and the rear holding member 95 has a bolt hole 96 through which the mounting bolt 100 is inserted. The bolt holes 93 formed in the caster plate 90, the bolt holes 98 formed in the top plate member 97, and the bolt holes 9 formed in the beam 24 correspond to the bolt holes 96 formed in the front holding member 94 and the rear holding member 95, respectively.
9 are aligned respectively, and the aligned bolt holes 93, 96, 9
The beam 24 is attached to the axle case 13 in which the attachment assembly 25 is integrated by tightening the nut 101 to the attachment bolt 100 inserted through 8.

The caster plate 90 has an upper surface formed as an inclined surface 92 inclined between the axle case 13 and the beam 24 at an inclination angle θ corresponding to the intersection angle of the propeller shaft. Therefore, the beam 24 can be attached to the axle case connected to the vehicle body frame 2 at a position inclined at the intersection angle θ so as to take a position parallel to the vehicle body frame 2.

When the beam 24 is considered as a symmetrical object mounted on the axle case 13, the Young's modulus of the beam 24 is about one third of that of the iron system. If the mounting assembly 25 has a separate structure in which the caster plate 90, the front holding member 94, the rear holding member 95, and the top plate member 97 are not integrated, the beam 24 is mounted on the axle case 13 by tightening the mounting bolts 100 and simultaneously. The assembly 25 is integrated by tightening. However, if only the fastening force is used for integration, the mounting assembly 25 is likely to loosen due to long-term running of the vehicle. In this embodiment, the beam 24
Before the axle case 13 is mounted on the axle case 13, the axle case 13 and the mounting assembly 25 are previously integrated by welding.
5 is tightened, there is no looseness between the members constituting the mounting assembly 25, and the mounting bolt 100
All the tightening force on the axle case 13 of the beam 24
The beam 24 can be used to mount the beam 24 to the axle case 13 in a favorable state reliably over a long period of time.

As the material of the caster plate 90, an iron-based material in terms of strength, that is, an iron plate, a forged product or a cast product can be considered. However, if the beam 24 is formed of an aluminum alloy, an electro-chemical reaction between the caster plate 90 and the iron-based metal in a state where water such as rainwater adheres to the contact surface with the axle case 13, that is, ,
A local battery may be generated and aluminum may melt out due to electrolytic corrosion. Therefore, the caster plate 9
0 is formed by an iron plate or a forged product which has a low carbon content and has a relatively low electrolytic corrosion action even in an iron-based material in order to prevent electrolytic corrosion.

[0030]

Since the present invention is configured as described above, it has the following effects. That is, according to the vehicle suspension device of the present invention, the beam is mounted on the axle case via the mounting assembly, and the elements of the mounting assembly interposed between the axle case and the beam are connected to the propeller shaft. The caster plate has a slope inclined at the angle of inclination corresponding to the intersection angle, so the beam is still in spite of the fact that the axle case is inclined at the intersection angle with respect to the body frame to cope with the inclination of the propeller shaft. It is attached to the axle case with a posture that does not lean with respect to the body frame. Therefore, the friction between the piston and the diaphragm of the air spring provided between the beam and the vehicle body frame is reduced, and the durability of the air spring is improved.

[Brief description of the drawings]

FIG. 1 is a side view of a drive axle side of a rear two-axle vehicle to which a vehicle air suspension device according to the present invention is applied.

FIG. 2 is an enlarged sectional view showing an example of a mounting structure of an axle case and a beam in the vehicle suspension device shown in FIG.

FIG. 3 is an explanatory diagram showing an overall outline of a conventional rear two-axle vehicle.

FIG. 4 is a perspective view showing an example of a rear axle structure using an air spring in a rear two-axle vehicle suspension device.

FIG. 5 is a side view of a vehicle equipped with a conventional vehicle air suspension device on a drive axle side.

[Explanation of symbols]

 Reference Signs List 1 rear two-axle vehicle 2 body frame 4 rear axle 5 drive axle 6 driven axle 13 axle case (drive axle side) 14 axle case (driven axle side) 21 air spring 24 beam 25 mounting assembly 62 piston (second support member) 63 Diaphragm 90 Caster plate 92 Slope 94 Front holding member 95 Rear holding member 97 Top plate member θ Intersection angle

Claims (7)

[Claims] 1. A vehicle body frame supporting an engine, a differential device to which a propeller shaft to which a driving force of the engine is transmitted is drivingly connected, a driving axle to which a driving force of the engine is transmitted via the differential device, In a vehicle provided with an axle case supporting a differential device and rotatably supporting the drive axle, and a suspension device provided between the body frame and the axle case, the suspension device is provided on the axle case. A beam mounted via a mounting assembly; and an air spring disposed between the beam and the body frame, the mounting assembly including the propeller between the axle case and the beam. Has a slope that slopes at an angle corresponding to the shaft intersection angle A suspension device for a vehicle, comprising: 2. The vehicle suspension device according to claim 1, wherein the beam is made of an aluminum alloy. 3. The vehicle suspension device according to claim 2, wherein the caster plate is formed of an iron plate or a forged product. 4. The mounting assembly is provided with a top plate member covering a top surface of the axle case, a front holding member disposed along a front side surface of the axle case, and a front side holding member disposed along a rear side surface of the axle case. The vehicle suspension device according to any one of claims 1 to 3, further comprising a rear holding member. 5. The caster plate, the top plate member,
The vehicle suspension device according to claim 4, wherein the front holding member and the rear holding member are integrated with the axle case by welding. 6. The beam extends from a lower part of the axle case in a front-rear direction of the vehicle, and the air spring is disposed between both ends of the beam and the body frame. The vehicle suspension device according to any one of claims 1 to 5. 7. A suspension device provided between the vehicle body frame and another axle case rotatably supporting a driven axle provided corresponding to the drive axle, wherein the suspension assembly includes: The vehicle suspension device according to any one of claims 1 to 6, wherein a caster plate equivalent to the caster plate is incorporated.