DE2806247C2 - Air suspension system for cabs of commercial vehicles - Google Patents

Description

a) the spring supports (3) are designed as double springs known per se, each of which from the suspension spring (4) and one acting in the opposite direction, also as Air spring designed stabilizing spring (5) consist,

b) the two double springs, each assigned to one of the four sides of the driver's cab (2) (3) boiled pneumatically in a manner known per se connected with each other,

c) the connection of the two double springs (3), the first two opposite each other Pages of the driver's cab (2) are assigned, takes place in a manner known per se only between their suspension springs (4) and

d) the connection of the two double springs (3), each of which is opposite to the other two The sides of the cab (2) are assigned only between their stabilizing springs (S).

2. Air spring system according to claim 1, characterized in that with respect to the vehicle longitudinal direction parallel sides of the cab (2), the suspension springs (4) with one another in a known manner are connected.

3. Air spring system according to claim 1, characterized characterized in that with respect to the sides of the driver's cab (2) parallel to the transverse direction of the vehicle the suspension springs (4) are connected to one another in a known manner.

4. Air spring system according to one of the preceding claims, characterized in that at least with respect to two of the opposite sides of the cab (2) between their connected suspension springs (4) or stabilizing springs (5) of the double springs (3) have a throttle point (Throttle element 9 or 11) is provided.

5. Air spring system according to claim 4, characterized in that the cross section of the throttle point is changeable.

6. Air spring system according to claim 5, characterized in that the cross section of the throttle point depending on the unevenness of the road and / or depending on the vehicle speed is controlled.

7. Air spring system according to claim 6, characterized in that the cross section of the throttle point is small at high driving speed.

8. Air spring system according to claim 6, characterized characterized in that the cross section of the throttle point is large when the road surface is uneven.

9. Air spring system according to one of the preceding claims, characterized in that the Pressure in the air suspension system in relation to the suspension springs (4) and / or the stabilization springs (5) in

is known to be changeable,

10. Air suspension system according to one of the preceding Claims, characterized in that at least the connection between two double springs 3 is assigned an additional volume (12).

11. Air spring system according to claim 10, characterized characterized in that the additional volume (12) is assigned to the connection between the suspension springs (4) is.

12. Air suspension system according to one of the preceding Claims, characterized in that the suspension spring (4) and stabilizing spring (5) are coaxial are combined in the spring support (3).

13. Air spring system according to one of the preceding claims, characterized in that the Double springs (spring supports 3) with two supports that can move against each other in the direction of the spring as well as with a closed spring volume and with two different sizes, opposite one another pressurized, facing away from each other and variable in size depending on the spring travel effective spring surfaces are provided, two rolling bellows are provided, their from each other remote spring surfaces are supported on firmly interconnected spring pistons and the partial volumes assigned to the two rolling bellows with a view to the spring support (3) separated from each other on a substantially independent of the spring travel independent maintenance of their volume size are.

14. Air spring system according to one of the preceding claims, characterized in that in known manner in addition to the spring support (3) this associated separate damper elements, in particular hydraulic shock absorbers (6) are provided.

15. Air spring system according to one of the preceding claims, characterized in that at least the suspension springs (4) e ^: -ne level-adjusting compressed air supply (level control valves 15, 15 ') is assigned.

The invention relates to an air suspension system for cabs of commercial vehicles, the stabilization devices and the four corner points of the driver has four spring supports associated with the house, which comprise suspension springs designed as air springs, of which at least the suspension springs assigned to one of the four sides of the driver's cab are pneumatic are connected to each other.

An air suspension system for cabs with the above features is already known (DE-OS 48 749)

With this air suspension system, the suspension springs supplied with compressed air are those at the front corner points of the cab are provided, pneumatically controlled via separate level control valves, while the suspension springs located at the rear corner points are pneumatically connected to each other and via a common level control valve can be controlled.

*> 5 Da level control valves with a time delay work, the suspension springs can roll and pitch movements of the cab with this air suspension system not prevent. Therefore, in order to

To dampen these conditions, every suspension spring is inserted between the frame of the vehicle structure and the driver's cab Assigned telescopic shock absorbers. So that nodding movements can be suppressed even better, is additionally still an arrangement of front and rear control arms is provided, which is from the front, pivot points located on the driver's cab in the direction of the rear pivot points located on the frame at an angle extend downwards.

The level control valves here still fulfill the task of a: Stabilization device, as they Load-dependent adjustment of the cab to a constant height via the suspension springs allow against the chassis frame.

The adaptability of such an air suspension system to a given road condition is This is relatively narrow and with its usual interpretation for European road conditions Air suspension system without profound changes for sand tracks or similar rough roads that cause great distortion of the frame, not suitable.

The invention is therefore based on the object of providing an air spring system of the type described at the beginning create that is not subject to restrictions with regard to its use and in which the Only support the driver's cab and stabilize it against rolling and pitching movements is accomplished by its spring supports.

This object is achieved according to the invention in a generic air spring system by the combination solved the following features:

a) the spring supports are designed as known double springs, each from the Suspension spring and one acting in the opposite direction, also designed as an air spring Stabilizing spring exist,

b) the two double springs assigned to one of the four sides of the cab are in pneumatically connected to one another in a manner known per se,

c) the connection of the two Doppelfcdern, the two first opposite ropes of the Are assigned to the driver's cab, takes place in a known manner only between their suspension springs and

d) the connection of the two double springs, each opposite to the other two Sides of the cab are assigned only between their stabilizing springs.

The use of a suspension spring and a stabilizing spring acting in the opposite direction to this existing double springs as well as the mutual connection of the suspension springs and the Stabilizing springs cause force to be applied to the cab in the event of rolling or pitching movements due to the mutual support against such forces directed and thus such cab movements oppressive opposing forces. Each with the same feather as the opposite Stabilizing springs with feedback on the driver's cab side have an automatically stabilizing effect on the driver's cab. Here the air suspension system presents itself as one fictitious pneumatic suspension. spring support points in the pivot point benches of the driver's cab licscn.

The cab support is maintained even if, for. B. caused by uneven road surface connections occur. The spring assembly ensures that the same support forces are given at all four corner points of the driver's cab. Due to their length compensation, the double springs enable a corresponding adaptation to frame twisting.
In commercial vehicles for the sprung arrangement of the

to use an air suspension system on the vehicle frame in the driver's cab, which consists of a suspension spring and a Stabilizing spring formed double spring arrangement comprises is known per se (US-PS 38 41 694). Included includes this air spring system only such a double spring arrangement, which is only used to the three Points to support the resiliently resiliently suspended driver's cab on its rear side on a springy central position. It is also known the structure of two-axle motor vehicles with respect to the vehicle axles by means of an air suspension system to reduce roll and pitch movements, the per vehicle wheel comprises a double spring, wherein; on the one hand the double springs of the wheels of each Fahrzcug; eke about theirs first spring chambers and on the other hand the double springs of the front and rear axles via their second spring chambers are connected (US-PS 29 88 372).

The combined single springs of the double springs are, however, in their mode of operation designed exclusively as suspension springs, so that a stabilization of the vehicle body in the sense of Invention did not take place.

In an embodiment of the invention, it proves to be particularly advantageous if for vehicles that in particular

J5 are specially designed for road use, with regard to the sides of the vehicle that are parallel to the longitudinal direction of the vehicle Cab, the suspension springs are connected in a known manner, while with respect to the V ° rbunien the stabilizing springs under each other on the sides of the cab that are parallel to the vehicle transverse direction are. This leads to a particularly good elimination of pitching vibrations, both when braking as aucii when starting up. Likewise, nodding jolts, for example in the case of semi-trailers, can also be good be intercepted. Furthermore, this configuration also proves to be with regard to wind pressure forces expedient. The reverse type of connection of the double springs can be useful in vehicles, which are primarily or exclusively intended for off-road use and where it is for use on particularly high roll stabilization is important. Both application situations can thereby be achieved in a simple manner It must be taken into account that the network can be switched over, i.e. the two possibilities mentioned above can be switched optionally.

Furthermore, there is the possibility of influencing the spring behavior in a simple manner take that between at least two of the opposite sides of the cab their connected suspension springs or stabilizing springs of the Doppelfede.n a throttle point is provided will. Depending on the setting of the throttle, the network is released more or less, with the effect that at strong throttling a quasi-real four-lane distance

hj support arises as it is for pure road operation with regard to the best possible feedback and detection of German · ι F-ahr / cuguewegjngen by the driver is desired.

With a view to maintaining the functional capability of the air delivery system regardless of the charge state of the driver's cab at the door the support of the driver's cab / regular, small spring deflections it proves to be advantageous to assign a level-matching compressed air supply to at least the suspension springs. The control of this compressed air supply can take place in the known ways, be it load-dependent, mechanically or manually, so that, in particular in connection with throttling, the greatest possible degree of adaptation are given to all circumstances. In a further embodiment of the invention can at least the connection between two double springs can be assigned an additional volume in order to achieve good spring comfort to be able to guarantee even with small double springs.

The suspension springs and the stabilizing springs are preferably coaxial with one another in the spring support summarized. In addition to the spring support, separate damping elements assigned to it can also be used, in particular hydraulic shock absorbers may be provided. It turns out to be in particular It is expedient to use compact double springs of the type described in DE-OS 27 50 666 are.

An embodiment of the invention is described below with reference to a schematic drawing explains, which shows the air suspension system in the arrangement between the vehicle frame and driver's cab, wherein the vehicle frame, which is denoted by 1, is shown in volume, while the driver's cab, with 2 referred to, is indicated by dash-dotted lines.

A four-point support is provided between the vehicle frame 1 and the cab 2, the Corner points of the support are formed by spring support 3, each of which is a suspension spring 4 and a Stabilizing spring 5 include. Suspension spring 4 and stabilizing spring 5 are illustrated in FIG Solution summarized coaxially in a spring support 3, which centrally has a shock absorber 6 contains. Between the suspension spring 4 and the stabilizing spring 5, both of which are designed as air springs, there is a Separating element 7, which can be designed as a rigid wall or as a membrane. The carrying and Stabilizing springs 4 and 5, the differently sized, oppositely pressurized, facing away from each other and have effective spring surfaces that are variable in size as a function of the spring travel each has a rolling bellows, and there are two, facing away from each other spring surfaces of the springs interconnected spring piston supported, this spring piston in the indicated embodiment can for example be connected via the jacket tube of the shock absorber 6. The through the Both rolling bellows limited spring volumes are essentially independent of the spring travel designed according to their volume size.

In the illustrated embodiment, the spring supports are in relation to the longitudinal direction of the vehicle 3, assigned to the longitudinal sides of the vehicle, the suspension springs 4 each via a connecting line 8 connected to one another, in the illustrated embodiment in each of these connecting lines 8, essentially bisecting this, a throttle element 9 is provided. The throttle element 5 is controllable, and can, for example, manually or in Depending on the current road conditions, with the widest possible opening of the Throttle element 9 is provided for those cases where large frame twists as a result of uneven road surfaces appear.

In pairs, .inch

ι the front and rear springs 3 connected to one another, with a connecting line here 10 / between the stabilizing springs 5 and also here in the connecting line 10 a throttle element 11 can be arranged in each case.

ι In the connecting line 8 / wipe each Interconnected suspension springs 4 are provided additional volumes 12, here in the form of Intermediate container ι or the like are indicated. Of course, it is also possible to do this

ι additional volumes 12 for example by corresponding To realize cross section of the connecting line 8.

Given the support of the driver's cab 2 with respect to the vehicle frame 1, imaginary swivel axes arise for the 'movement of the Fiiiueii'iaii!> CS 2 in relation to uciTi rahrzeugrahmen 1, which lie in the planes of the center of gravity of the driver's cab 2 and which intersect at point M with 13 and 14 are designated, with 13 the longitudinal or roll axis

> of the driver's cab is marked.

In order to take account of changes in the load on the driver's cab 2, in the exemplary embodiment of further level control valves 15; 15 'b / w. 16; 16 'proceed with regard to the pitch and ι Rolling movements as independent as possible detection of the level in the imaginary pivot axes 13 or 14 are arranged. The level lock valves 15 and 15 ' are the connecting lines 8 between the suspension springs 4 and the level control valves 16 and 16 'the

> Connecting lines 10 between the stabilization springs 5 assigned. The respective connection to the line 8 or 10 is shown schematically in the area of here respectively provided throttle elements 9 and 11 are indicated. The fact that the level control valves 15;

) 15 '; 16; 16 'lie in said pivot axes 13 and 14, the respective corresponding pairs of valves not addressed by pitching or rolling movements. As far as mixed movements occur, the Level control valves 15; 15 '; 16; 16 'in the area of the lowest relative height offset and they will especially do not respond if they work with a corresponding amount of time sluggishness.

Also indicated in the drawing is a circuit arrangement with valves 17 and 17 'above which independently of one another the working pressure in the suspension springs 4 and the stabilization springs 5 controlled can be, so that by appropriate relative change in the pressures in the suspension springs 4 and Stabilization springs 5 the overall spring behavior with regard to a softer or harder suspension can be adjusted. The higher the pressures are set, the harder the suspension works and the more The rolling and pitching movements of the driver's cab 2 are less, so that a relatively immediate Connection to the vehicle frame 1 and thus a direct feeling for the vehicle movements results. It can of course be used for the suspension springs 4 or stabilization springs 5 connected to one another a separate pressure setting can also be made in each case.

! is an air spring system of the type according to the invention intended for tilting cabs, it may be useful to switch off the

. <iiveaurcgiilicriing or a blocking at least those springs to be provided in the area of which the respective Tilt axis lies. A mechanical blocking can also be provided here if necessary are to control the Fedei'volumina from each other. This control can, if necessary, as a function from the tilt angle.

In the solution according to the invention, the solubilization springs 5 preferably have a significantly smaller one Volume than the suspension springs 4. Furthermore, the stabilizing springs 5 and suspension springs 4 expediently opposite progressive r. Identifier. In this case, the suspension springs 4 are preferably in the compression direction and the stabilizing springs 5 progressively in the rebound direction. This results in a stabilization on one Milk layer that counteracts pitching and rolling movements. One spring system (e.g. Stabilizing springs 5) are each given opposing forces that counteract the movements that the other spring system (e.g. Suspension springs 4) can counteract this. Even with relative

". hard design of the spring support 3, as it is in the With regard to the desired direct frame contact is partially desired, be unilateral or Mutual impacts are absorbed relatively softly, since all spring supports 3

in each case can be addressed practically at the same time. The air suspension system can also be used by appropriately strengthening the progressivity in the end positions include the end position limits. This can preferably be achieved by appropriate design of the Spring surfaces.

1 sheet of drawings

Claims (1)

Patent claims: 1. Air suspension system for cabs of commercial vehicles, the stabilization devices as well has four spring supports assigned to the vipx corner points of the driver's cab, which act as air springs comprise trained suspension springs, of which at least one of the four sides of the cab associated suspension springs are pneumatically connected to each other, characterized by the Combination of the following features: