JPS5940645B2 - Suspension system for large vehicles - Google Patents

Description

Detailed Description of the Invention The present invention provides a suspension system for supporting each axle with a balance beam in a large vehicle having three adjacent axles, one of which serves as a single-wheel steering axis. It is related to.

For large vehicles with a large gross vehicle weight, such as truck cranes, the number of axles is increased to reduce the axle load, and two front axles are used.
There are one to three axles, three rear axles, etc.

In general, all rear axles are double-wheeled, but
Due to restrictions on the minimum turning radius, the steering axis is often set to either the front or the rear.

In such a case, it is desirable that the axle load ratio of each axle is basically 1:1:0.5, corresponding to the number of wheels.

However, when driving on a general road, for example when passing over a bridge, the axle load ratio of each axle may be limited to i:i:,t due to the strength of the bridge.

In addition, the permissible weight limit for bridge traffic based on laws and regulations is calculated based on the relationship between each axle load and the distance between the axles, so if the last axle is a steering axle, the axle load ratio is 1:1:1.1. There are some circumstances in which it is advantageous to set the value to 1.2 because the total vehicle weight can be increased.

SUMMARY OF THE INVENTION Therefore, the present invention aims to provide a suspension system for a large vehicle that can arbitrarily change the axle load ratio of the steering axle in two series according to such driving conditions.

Embodiments of the present invention will be described below with reference to the drawings.

The present invention can be applied to large-sized vehicles in general, including large-sized construction vehicles such as truck cranes, including trailer-type vehicles.

In Figures 1 and 2, 1 is the vehicle body, 2 is the vehicle frame, and 3
, 4 are front axles, and the front axles 3 and 4 serve as steering axles, and are equipped with single-wheel tires 5 and 6.

7, 8.9 are the rear axles, of which the frontmost and center wheels 7
, 8 are non-steering axles and are equipped with double-wheel tires 10, 11, and the rearmost axle 9 is a steering axle and is equipped with single-wheel tires 12.

In this embodiment, the present invention is applied as a suspension system for the rear axles 7, 8, and 9.

13.13, 14.14 and 15.15 are a pair of left and right bogie booms, and each beam forms a balance beam at the bottom of the car body, and each axle is connected by this balance beam. , 8.9 is supported.

The front beam 13 and the rear beam 15 are attached to the lower surface of the vehicle body frame 2 via a bracket 16 and a horizontal pin 17 at their respective intermediate portions, and are attached to the lower surface of the vehicle body frame 2 via a bracket 16 and a horizontal pin 17, respectively.
It is designed to be able to rotate using the fulcrum as a fulcrum.

The front end of the front beam 13 is pivoted to the front axle 7, the rear end of the rear beam 15 is pivoted to the rear axle 9, and the intermediate part of the center beam 14 is pivoted to the center axle 8 via a bracket 18 and a horizontal pin 19, respectively. It is connected.

Furthermore, in order to connect the beams 13, 14 and 15, the front beam 13 and the central beam 14 are pivotally connected via an articulating link 20 and horizontal pins 21, 21, as shown in FIG. The central beam 14 and the rear beam 15 are the sixth
As shown in the figure, they are pivotally connected via a horizontal pin 22.

In this way, a basic axle support mechanism using a balance beam is constructed.

In such a configuration, each beam 1 is
The distances from the swing fulcrums to the points of action on both sides at Nos. 3, 14, and 15, that is, the arm lengths P, Q, R, S, T, and U, are set under the following conditions.

P:Q=i R: S = (1-i) / i T: U=to/(1-i) far.

With this setting, when the unit axle load of the front axle 7 is 1, the load acting on the connecting link 20 will be i.

Then, the load acting on the connection point between the central beam 14 and the rear beam 15 is i (1-i )/-1-i.

Therefore, the axle load of the central axle 8 is i+(1-i)=1 becomes.

In addition, the above-mentioned arm ratio of the rear beam 15 T :U=ni/1-i) Therefore, the load acting on the rear axle 9 is: (:r-1), ni/(ti)-ni becomes.

In this case, the axle load ratio of each axle 7, 8, and 9 is 1:1:.

The value of k is the tire 10 mounted on each axle 7, 8.9.
, 11.12 are of the same size (same load capacity),
And each axis? , 8.9 are also the same, set it as 0.5 corresponding to the number of tires.

A basic axle load ratio of 1:1:0.5 is thus obtained.

In addition, if the size of the tire 12 of the rear axle 9 or the strength of the axle 9 is different from the tire size or axle strength of the other dual-wheel axles 7, 8, the above-mentioned conditions will be applied depending on the load capacity of the tire. It is only necessary to determine a value, and in practice, this value may be set in the range of 0.4 to 0.7, with 0.5 as the basic value.

In this way, by setting the arm ratio of each beam 13, 14, 15 under specific conditions, the axle load ratio of each axle 7, 8, 9 when each axle is supported by a balance beam can be adjusted to l. :1:
It can be easily and accurately set to a basic value of 0.4 to 0.7.

Note that the arm ratio setting described above can be applied even when the distance between adjacent axles is different.

Further, a specific numerical value of the arm ratio i of the front beam 13 can be arbitrarily selected.

By selecting this i value, the mounting position of the front and rear beams 13.15 to the vehicle body frame 2, that is, the bracket 16
Since the position of 16 degrees can be selected, consideration can be given to the position of this bracket so that it does not interfere with other equipment.

Further, the detailed structure of each part of the above-mentioned balance beam is as follows.

First, at the connecting portion between the front and rear beams 13, 15 and the beam mounting brackets T-16, 16, the axial clearance between the beam 13, 15 and the bracket 16 is set to zero, as shown in FIG.

That is, the beam 13.15 is attached to the bracket 16 in such a manner that it cannot be moved in the axle direction.

On the other hand, to connect each beam 13, 14, 15 to the axle 7, 8.9, as shown in FIG.
, 15 are fitted onto the spherical bearing 23 and the horizontal pin 19 through a cylindrical shaft 7 as a sliding bearing
, 8.9 is connected to the bracket 18.

In this way, the beams 13, 14.degree. 15 and the axles 7, 8, 9 are connected to each other so that they can freely rotate back and forth, left and right, diagonally, and slide in the axle direction.

However, when the left and right corresponding beams are in the same plane, that is, when the left and right tires are at the same height level, the beams 13, 14, 15 as shown in FIG.
and the axially inner portion of the bracket 18 are in contact with each other, so that the lateral component of the tire reaction force from the road surface is transmitted from this portion.

As above, the axles 7, 8, 9 are connected to the beam 13°14.1
5, so that the axle can be moved in the axial direction and the rocking displacement of the tires can be easily tolerated when the corresponding tires on both sides swing asymmetrically up and down. This is what I did.

On the other hand, as shown in FIG. 3, each axle on the lower surface of the vehicle body frame 2? , 8.9, there are stoppers 25, 25 on the parts facing each other.
, 25 are provided, and the axle 7,
The amount of swinging displacement of the upper blades 8 and 9 is limited.

However, the stoppers 25 are provided with a sufficiently large distance from the axles 7 to 9 so that the amount of upward displacement of the axles 7 to 9 can be as large as possible when traveling on rough terrain.

Also, the front and rear beams 13.15 on the lower surface of the same frame.
A stopper 26.degree. 26 is provided at a portion facing the axles 7 to 9 to limit the amount of downward rocking displacement to a relatively small amount.

By these stoppers 25... and 26, 26,
By regulating the amount of vertical rocking displacement of the axles 7 to 9 to an extent that does not cause strain on each part of the balance beam, and by suppressing the amount of downward displacement of the axles 7 to 9 to a small value, it is possible to avoid abnormally low road surfaces. Axles 7 to 9 are the key to preventing tires from falling down.
By allowing as large an amount of upward displacement as possible, the stability of running on rough terrain can be improved.

In Figures 3 and 4, 27... is a radius rod, one end of which is attached to a bracket 28... provided on the lower surface of the vehicle body frame 2.
Bracket 29 with the other end provided on the top surface of the vehicle bodies 7 to 9...
A cushioning material 3 such as rubber is attached to the outer periphery of each of the
0 is attached via a spherical bearing 31 and a horizontal pin 32.

The radius rods 27 share with each of the beams 13 to 15 the road surface reaction force in the longitudinal force direction that is exerted by the driving force or braking force of the vehicle.

Therefore, in this device, in addition to the basic axle support mechanism using the above-mentioned balance beam, a pair of left and right double-acting hydraulic cylinders 33 are provided between the rear beam 15 and the vehicle body frame 2.
．． 33, and by switching between activation and deactivation of this cylinder 33.33, the axle load ratio of the rear axle 9 is changed to the basic values 0.4 to 0.7 and 1 to 1.2. It is configured so that it can be used.

In detail, brackets 1-34 are attached to the hydraulic cylinders 33 and 33, respectively, with their respective rond sides located behind the swinging fulcrum of the rear beam 15, and their head sides mounted on the vehicle body frame 2.
．． 35 and pins 36 and 37, and are pivotally connected thereto via a spherical bearing (not shown).

The hydraulic circuit of this hydraulic cylinder 33, 33 is shown in FIG.

In the figure, 38 is a hydraulic pump, and its discharge port is connected to the hydraulic cylinder 3 via a first switching valve 39 and a check valve 40.
3. Connected to the push side (head side) of 33.

41 is an accumulator in which gas pressure is accumulated, and is connected to the push side of the cylinders 33, 33, and this accumulator 41
gas pressure is applied to the pushing side of the cylinder 33.33.

42 is an unload valve, and the cylinder pressure is determined by the set pressure of this valve 42.

Reference numeral 43 denotes an IJ-F valve, whose opening pressure is set to N higher than that of the unload valve 42 to prevent an excessive increase in cylinder pressure when the upward displacement of the rear axle 9 is extremely large. To prevent.

Reference numeral 44 denotes a second switching valve, and a conduit 4 for communicating the pushing side and pulling side of the cylinder 33 through the switching valve 44.
5.

In such a configuration, for example, when a construction vehicle is traveling at a work site, the first. The second two-way switching valves 39 and 44 are each set to the left position in the figure.

In this way, all the pressure oil from the pump 38 is unloaded, and the pushing side and opening side of both cylinders 33, 33 are brought into electrical continuity.

Therefore, the cylinder 33°33 becomes inactive.

That is, at this time the cylinders 33.33 do not participate in the support of the rear axle 9, and the axle 9 is supported only by the above-mentioned balancing beam.

Therefore, the axle load ratio of each axle 7 to 9 is the basic value of 1:1:
It is maintained at 0.4-0.7.

On the other hand, when driving on general roads with the work attachment removed and without large rolling, the axle load ratio should be set to 1:1:1 to 1 to increase the allowable gross vehicle weight for bridge traffic as much as possible, as described above. Since it is advantageous to set the ratio to .2, the axle load ratio of the rear axle 9 is changed to the appropriate value.

In this case, the first and second switching valves 39 and 44 are set to the right position in the figure.

In this way, pressure oil from the pump 38 is supplied to both cylinders 33, which actuate the rear axle 9.
together with the balance beam.

The axle load borne by this hydraulic cylinder 33.33 is the difference between the overall axle load of the rear axle 9 corresponding to the desired axle load ratio and the axle load borne when supported only by the balance beam, and the load borne by this cylinder is The axle load may be converted into cylinder thrust, and the set pressure of the unload valve 42 may be selected based on it.

Incidentally, the accumulator 41 exerts a buffering effect against the expansion and contraction of the cylinder 33.33 due to the vertical swinging of the rear axle 9, and allows the cylinder 33.33 to stably perform the axle support function.

In this way, when using this device, the axle load ratio of each axle 7 to 9 can be set to 0.4 to 0.7 or 1 depending on the vehicle running conditions.
:1:1 to 1.2 can be arbitrarily changed.

Moreover, since the axle load ratio is changed by switching the cylinder 33.33 between the operating and non-operating states, the change operation is easy, and the hydraulic cylinder 33.33 is not disabled due to a failure of the hydraulic circuit, etc. Even if such an unexpected situation were to occur, there would be no safety problem because the balance beam would mechanically support the structure.

By the way, in the case of the hydraulic circuit shown in FIG. 10, pressure is applied to the pushing side of the hydraulic cylinders 33.33, but in the hydraulic circuit shown in FIG.
This applies pressure to the pull side.

The other configurations are the same as in the case of FIG.

According to this circuit configuration, the value of the axle load ratio of 1:1:k (0.4 to 0.7) when supported only by the balance beam is the same as that of the cylinder 33°33, contrary to the case shown in Fig. It can be made smaller by actuation.

In addition, in the above embodiment, the front beam 13 and the center beam 14
Although these are pivotally connected via the connecting link 20, a connecting link 46 may also be interposed between the center beam 14 and the rear beam 15 as shown in FIG.

However, in such a case, it is necessary to provide a lower radius rod 47 as a member that shares the road surface reaction force in the longitudinal direction due to the driving force and the braking force.

The radius rods 47 are provided on both left and right sides, with one end pivotally connected to the mounting pin 19 of the central beam 14 and the other end pivotally connected to the mounting pin 17 of the rear beam 15.

Furthermore, in the above embodiment, a case has been described in which the rearmost axle 9 is a single-wheel steering axle, but even when the frontmost axle 7 is used as a steering axle, the same effect can be obtained by adopting the same configuration as described above. Effects can be obtained.

As described above, the present invention has three adjacent axles,
Among large vehicles, the front or rearmost axle is a single-wheel steering axle, and the others are double-wheel non-steering axles.
Each axle is supported by a balance beam consisting of three pairs of beams,
In addition, a fluid pressure cylinder is interposed between the beam supporting the steering axle and the vehicle body, and by switching this cylinder between an operating state and a non-operating state, the axle load ratio of the steering axle can be adjusted at will. It is designed so that it can be changed to .

According to the present invention, for example, in a construction vehicle such as a truck crane, the axle load ratio can be changed to a value that is advantageous depending on the difference in driving conditions between on-site movement and general road driving, which provides practical benefits. is extremely large.

Furthermore, the axle load ratio can be easily changed by simply switching between cylinder activation and deactivation.

In addition, since mechanical support using a balance beam and support using a fluid pressure cylinder are used together, even if the support function of the cylinder is lost, the axle support will not be affected, ensuring safety. can be secured.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is a side view of the entire vehicle, Fig. 2 is a plan view of the same, Fig. 3 is an enlarged side view of the main parts with the vehicle body and tires omitted, and Fig. 4 is the same. A bottom view, FIG. 5 is an enlarged sectional view taken along line ■-■ in FIG. 3, FIG. 6 is an enlarged sectional view taken along line L-VI in FIG. 3, and FIG. 7 is an enlarged sectional view taken along line ■-■ in FIG. Figure 8 is an enlarged sectional view taken along the same line ■-■, Figure 9 is an enlarged sectional view taken along the same line ■-■, Figure 10 is a hydraulic circuit diagram of the hydraulic cylinder, and Figure 11 is different from Figure 10. A hydraulic circuit diagram with a circuit configuration, FIG. 12 is a diagram corresponding to FIG. 3 showing another example of the configuration of the balance beam. 1... Vehicle body, 2... Vehicle body frame, 7
, 8... Double-wheel non-steering axle, 9...
Single-wheel steering axle, 10.11...Double-wheel tire, 12...Single-wheel tire, 13...Front beam, 14... Central beam, 15...
- Rear beam, 16...Bracket for mounting beam on vehicle body frame, 18...Bracket for connecting beam to axle, 33...Hydraulic cylinder, 38.
...Hydraulic pump, 39...Switching valve, 41
...Accumulator, 45...Cylinder push/pull communication conduit.

Claims (1)

[Scope of Claims] 1. A large vehicle having three phase-adjacent axles, of which the frontmost or rearmost axle is a single-wheel steering axle, and the others are double-wheel non-steering axles. A balanced beam consisting of three bogie beams, one pair each on the left and right at the front, center, and rear, is provided at the bottom of the car body, and the parallel beams are parallel beams. The front and rear beams are attached to the underside of the vehicle body frame, the center beam is attached to the underside of the central axle, and the middle part of each is rotatably attached around a horizontal axis via a bracket, and one end of the front and rear beams is attached to the bottom of the vehicle body frame. is pivotally connected to the central beam and the other end is pivotally connected to the front and rear axles, and a fluid pressure cylinder is interposed between the beam supporting the steering axle, the vehicle body, and the frame, and the cylinder is in an operating state. A suspension system for a large vehicle, characterized in that the suspension system for a large vehicle is configured to be able to change the axle load ratio of the steering axle by switching between a state and a non-operating state. 2. For large vehicles that have three axles adjacent to each other, the frontmost or rearmost axle is a single-wheel steering axle, and the others are double-wheel non-steering axles. It has a balance beam consisting of a pair of front, middle and rear three bogie beams, the front and rear beams of the balance beams are on the lower surface of the body frame, the center beam is on the lower surface of the central axle, and the middle part of each is mounted rotatably around a horizontal axis via a bracket, one end of the front and rear beams is pivotally connected to the central beam, the other end is pivotally connected to the front and rear axles, and the above-mentioned steering axle is connected to the center beam. A double-acting hydraulic cylinder is interposed between the supporting beam and the vehicle body frame,
Connect the cylinder to a pump via a switching valve, and connect an accumulator to the push side of the cylinder.
Moreover, a conduit is provided that allows communication between the push side and the pull side of the cylinder, and the axle load ratio of the steering axle is changed by switching the cylinder between an operating state and a non-operating state using the switching valve. A suspension system for a large vehicle, characterized in that the suspension system has a structure that allows the suspension to be suspended.