WO2018184619A1 - Dual suspension system - Google Patents

Abstract

The invention relates to a suspension system for a vehicle (1), comprising a leaf spring (8) and an air spring (14) having air bellows (11). According to the invention, the suspension system is designed in such a way that the leaf spring (8) and the air spring (14) are mechanically arranged in a row, and the leaf spring (8) is connected to the chassis (5) of the vehicle (1) on one side by means of a joint (12), thus allowing the leaf spring to pivot in the vertical direction.

Description

 Dual suspension

The invention relates to an axle suspension for the wheels of a vehicle according to the preamble of patent claim 1.

BACKGROUND OF THE INVENTION

The wheels of vehicles, such as. As cars or trucks are usually spring mounted relative to the chassis of the vehicle. The suspension includes all components that connect the wheel axles and the chassis elastically with each other. The suspension improves ride comfort by protecting the chassis and thus both the occupants and the load from shocks caused by bumps. At the same time, it ensures as even as possible a ground grip of the wheels and therefore a good one

Driving dynamics of the vehicle.

In the known from the prior art vehicles air springs, coil springs or leaf springs are usually installed in the chassis. In addition, usually also damper installed, which is a shock or

Dampen pivoting movement of the wheels.

In very poor road conditions or slopes with many potholes or bumps get conventional suspensions with air, leaf or coil springs relatively quickly to their load limits. In extreme cases, it may therefore come to break the spring elements, which makes a further journey impossible.

OBJECT OF THE INVENTION

It is therefore an object of the present invention to provide a suspension for a vehicle, especially in adverse road conditions clearly is more robust and still offers good ride comfort. In addition, the suspension should be as fail-safe as possible even with a breakage of the leaf spring or any other component of the suspension or a puncture and thus allow a safe continuation of travel by pressing a button. Therefore, this invention is very advantageous for environmental, economic and safety reasons.

This object is achieved according to the invention by the features specified in claim 1. Further embodiments of the invention will become apparent from the dependent claims.

According to the invention, a suspension for a vehicle is proposed which comprises both a leaf spring and an air spring with an air bellows, wherein the leaf spring and the air spring are arranged mechanically in series. The

Leaf spring is also connected on one side via a hinge to the chassis of the vehicle. As a result, it can be moved vertically in the

 Swing substantially horizontal axis. Such a combined suspension is particularly robust, since the wheel is still sprung by the air spring even with a breakage of the leaf spring. In addition, each wheel can be selectively extended downwards or raised by varying the air pressure of the air suspension. Lifting individual axles reduces wear on the wheels and brake components and minimizes fuel consumption. The air suspension is preferably designed such that a wheel can be lowered by a corresponding adjustment of the air pressure in the air bellows of the associated axle.

According to a preferred embodiment of the invention, the combined suspension is designed so that a spring-loaded wheel can be lowered by increasing the air pressure so far that the leaf spring pivots downward. The suspension according to the invention is preferably attached to an axle of the vehicle. You could optionally but also on another component of the

Chassis or the chassis, such as on a wheel carrier, be attached.

Vehicles in the sense of the invention may be, for example, trucks, semitrailers or even trailers, in particular those with multiple axles.

The suspension according to the invention is preferably used on non-driven.

The leaf spring is preferably arranged in a longitudinal direction of the vehicle. The above-mentioned joint is in this case preferably in front, such. B. at a front end of the leaf spring.

On the opposite side of the joint (ie, eg rear), the leaf spring is preferably mounted on a stop on the chassis. This stop preferably defines an upper position of the leaf suspension. If in this position the pressure prevailing in the air spring pressure increases, the leaf spring can pivot down, whereby the axis attached thereto lowered and the

Vehicle is raised and brought to a desired level. The level can also be regulated.

According to a preferred embodiment of the invention, the leaf spring is releasably fixed in the upper position. For fixing and releasing the leaf spring, for example, a latching mechanism, a mechanical, hydraulic, electromagnetic or other known mechanism may be provided.

The suspension according to the invention preferably also comprises a damper which dampens a shock and pivoting movement of the sprung axle. The damper is preferably arranged between a component of the chassis, such as an axle carrier or wheel carrier, and the chassis.

According to a preferred embodiment of the invention, a suspension provided on a first axis of the vehicle is preferably adjustable independently of other axle suspensions provided on other axles of the vehicle.

The air spring is preferably arranged above the leaf spring.

According to a preferred embodiment of the invention, the air spring is attached at its upper end to the chassis of the vehicle. The lower end of the air spring may, for. B. be attached to the leaf spring, an axle of the vehicle or to another component of the chassis.

The air spring is preferably fixed at the top and bottom by means of a joint. The pivot axes of the joints are preferably aligned in different directions. One of the joints can z. B. a pivoting movement about a horizontal transverse axis and the other joint allow a pivoting movement about a horizontal longitudinal axis. The joints preferably each provide only a single degree of freedom.

The invention also relates to a vehicle (including, for example, a truck) with axle suspension, as described above by way of example.

The axle suspension according to the invention can be used on non-driven axles of vehicles, such. As trucks are used.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described by way of example with reference to the accompanying drawings. Show it: Fig. 1 a and 1 b is a side view of a suspension with a leaf spring and an air spring according to a first embodiment of the invention;

Fig. 2 is a side view of a suspension with a leaf spring and an air spring according to a second embodiment of the invention;

Fig. 3a is a side view of a semi-trailer in the loaded state on all wheels.

Fig. 3b is a side view of a semi-trailer in the partially loaded state with two wheels raised.

3 c is a side view of a semi-trailer in the unloaded state with three wheels raised. Fig.4 cross joints for a pivoting movement.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS Figs. 1a and 1b show an embodiment of a suspension for a vehicle 1, such as a semitrailer or a truck trailer. The suspension comprises in the illustrated embodiment, a leaf spring 8 and an air spring 14 with an air bladder 1 first The leaf spring 8 and the air spring 14 are arranged one above the other in series. Both the leaf spring 8 and the air spring 14 are located above an axis 7, to which a wheel 4a-4d is attached. The leaf spring 8 shown in Fig. 1 b is compared to the leaf spring 8 shown in Fig. 1 on the head to various possible arrangements

demonstrate. The air spring 14 and the Luftbalg 1 1 is attached to the upper end 9 of the chassis 5 of the vehicle. The lower end 10 of the air spring 14 and the bellows 1 1 is attached to the leaf spring 8, but it could be z. B. also be attached to the axis 7.

The leaf spring 8 extends substantially in a longitudinal direction L of the vehicle 1 and is articulated at the front end via a hinge 12 to the chassis 5. The leaf spring 8 can thus pivot about an axis extending in the transverse direction up and down. The leaf spring 8 is further fastened by means of a fastening element 6 on the axis 7.

In the illustrated state of the suspension, the leaf spring 8 is located at its rear end to a provided on the chassis 5 stop 15, which defines an upper position of the leaf spring 8 and the suspension. The weight on the wheel (not shown) is taken up by both the leaf spring 8 and the air suspension 14 in this case. The prevailing in the air spring 14 pressure can be changed to adjust the spring behavior as desired more or less taut or soft.

The leaf spring 8 is preferably fixed at its rear end in the upper position. For this purpose, preferably corresponding means, such as a locking device 16 and a locking device are provided which

preferably can be operated automatically. In the fixed state, the leaf spring 8 can not swing down; it is also held in the upper position by the pressure exerted by the damper 13. In the dissolved state, however, the leaf spring 8 is pivotable downwards by the pressure in the air bladder 1 1 is increased.

To dampen the spring movement of the axle 7 and the attached wheel, the damper 13 is further provided, which is mounted between the chassis 5 and the axle 7. In the embodiment shown in FIG. 2, the leaf spring 8 is arranged below the axis 7. The air spring 14 is located between the chassis 5 and the axis 7. Incidentally, the construction is almost identical to Fig. 1 a and 1 b, so that reference is made to the above description with respect to the other components.

3a shows a schematic representation of a semi-trailer 2 with four axles 7 in a loaded state. All wheels 4a-4d are in their upper position. That is, the leaf spring 8 abuts at its rear end against the provided on the chassis 5 stop 15 and is fixed in this position, as shown in Fig.1 a. In the air spring 14, more or less air pressure may be included as desired to realize either a harder or softer suspension.

In the unloaded state of the vehicle 1, it is usually useful to lift individual axles 7 or wheels 4a-4d from the ground in order to cause less wear or to save fuel. With the aid of the combined suspension of FIGS. 1 a, 1 b or 2, by varying the air pressure, individual wheels 4a-4d or axles 7 of the vehicle 1 can be raised and other wheels 4a-4d lowered.

In order to lower a wheel 4a-4d, the air pressure prevailing in the pneumatic bellows 11 is increased. The air bladder 1 1 then expands, causing the leaf spring 8 to pivot downwardly in the direction of arrow A, thus lowering the associated wheel 4a-4d. To lift a wheel 4a-4d, the air bellows in the 1 1

decreasing prevailing air pressure. The air bladder 1 1 then contracts and causes the leaf spring 8 to pivot upward, lifting the relevant wheel 4a-4d off the ground (if at least one other wheel 4a-4d is lowered).

FIG. 3b shows a schematic representation of the semitrailer 2 of FIG. 3a in a partially loaded state. As can be seen, the two middle wheels 4b, 4c are raised and the two outer wheels 4a and 4d are lowered. FIG. 3 c shows a schematic representation of the semitrailer 2 of FIG. 3 a in an unloaded state. As can be seen, the three front wheels 4a, 4b and 4c are raised and the outer wheel 4d is lowered.

To lower the wheels 4a, 4b, 4c and 4d, the leaf spring 8 is the

associated suspensions released by the locking mechanism 16.

 In addition, the air pressure in the air bellows 1 1 is increased, so that the leaf spring 8 pivots downward and the wheel 4 a, 4 b, 4 c or 4 d extends selectively down. The other wheels, however, remain in the upper position. For this purpose, the locking mechanism remains closed, and the air pressure in the air bladder 1 1 is substantially reduced to ambient pressure or a lower pressure.

After the desired wheels 4a-4d have been lowered, the vehicle 1 is only supported by these wheels 4a-4d or the associated axles 7. The remaining wheels 4a-4d are lifted off the road. In this state, the suspension of the lowered wheels 4a-4d via the air spring 14, partially supported by the damper 13 and the associated leaf spring 8, which is connected at the front end via a hinge 12 to the chassis 5. However, the leaf springs 8 and the damper 13 practice only a small

Counterforce, since the leaf springs 8 are not fixed.

According to the invention, the air springs 14 of the wheels 4a-4d can preferably be controlled independently of each other. It is therefore possible to raise or lower individual wheels. Fig. 4 finally shows a special embodiment of the suspension, in which the air spring 14 is connected at the top and bottom of a respective joint with the adjacent part. One of the joints can z. B. a pivoting movement about a horizontal transverse axis (here the lower joint) and the other joint pivotal about a horizontal longitudinal axis (here the upper joint) allow. The joints preferably each provide only a single

Degree of freedom. On the outside of the joints can each have a plate be provided to easily attach the relevant joint to the adjacent component can.

Claims

claims 1 . Suspension for a vehicle (1), comprising a leaf spring (8) and a  Air spring (14) with an air bellows (1 1),  characterized in that  the leaf spring (8) and the air spring (14) are arranged mechanically in series, and that the leaf spring (8) is connected on one side via a joint (12) to the chassis (5) of the vehicle (1) so that it is in vertical direction (A) is pivotable. 2. Suspension according to claim 1,  characterized in that  it is designed so that a wheel (4a-4d) of the vehicle (1) by  Change in the air bellows (1 1) prevailing air pressure can optionally be lowered, whereby the leaf spring pivots downward, or optionally can be raised, whereby the leaf spring (8) pivots upwards. 3. suspension according to claim 1 or 2,  characterized in that  the leaf spring (8) is arranged in a longitudinal direction (L) of the vehicle (1) and the joint (12) is arranged at the front. 4. Suspension according to one of the preceding claims,  characterized in that  the air spring (14) with its upper end to the chassis (5) of the  Vehicle (1) is attached. 5. Suspension according to one of the preceding claims,  characterized in that  on the chassis (5) a stop (15) is provided, against which the Leaf spring (8) abuts in an upper position. 6. Suspension according to one of the preceding claims,  characterized in that  the leaf spring (8) is releasably fixed in the upper position. 7. Suspension according to claim 6,  characterized in that  a locking mechanism (16) is provided, which fixes the leaf spring (8) in the upper position. 8. Suspension according to one of the preceding claims,  characterized in that  provided on different axes (7) of the vehicle (1) suspensions are independently adjustable. 9. Suspension according to one of the preceding claims,  characterized in that  the air spring (14) is fixed at the top and bottom via a joint on the adjacent component (5, 8). 10. vehicle (1) with a suspension according to one of the preceding  Claims.