Rail vehicle with pneumatic suspension

Abstract

The invention relates to a rail vehicle (1) with a pneumatic suspension, comprising a car body (2) and at least one chassis (3) which is rotatably supported relative to the car body (2), wherein at least one pneumatic spring (4) is arranged between the car body (2) and the chassis (3), and each pneumatic spring (4) is paired with an auxiliary air tank (5), the volume of which is connected to the volume of the pneumatic spring (4). The auxiliary air tank (5) is arranged above the pneumatic spring (4) and extends in a recess (6) in the car body (2).

Description

[0001] Description

[0002] Rail vehicle with air suspension

[0003] Technical area

[0004] The invention relates to a rail vehicle with air suspension, in particular a passenger rail vehicle.

[0005] State of the art

[0006] Passenger rail vehicles are often equipped with air suspension, as this not only offers better ride comfort compared to conventional steel suspension but also the option of level control. Air suspension comprises the actual air spring made of elastic material, which is arranged between a running gear and a car body and is filled with compressed gas. The air suspension also includes corresponding piping for supplying and discharging the compressed gas as well as a compressed gas source, usually an air compressor or a connection to a compressed air system for operating a brake. If the air suspension has level control, corresponding control valves and measuring devices are provided to determine the current deflection of the car body relative to the running gear.A significant improvement in suspension comfort can be achieved by increasing the volume of compressed gas enclosed in the air spring, as this makes it possible to achieve a softer spring characteristic for this air spring. However, the dimensions of an air spring, which is usually designed as a cylindrical, ring-shaped or torus-shaped rubber bellows, are determined by the conditions in the area between a car body and a chassis and cannot be significantly increased. For this reason, a so-called additional air volume can be provided, the volume of which is coupled to the volume of the air spring, so that a flow of compressed gas can occur between these volumes. This measure makes it possible to achieve a spring characteristic even with air springs of conventional dimensions that would otherwise only be possible with larger air springs.The additional air volumes are designed as compressed gas tanks and are located as close as possible to the air spring to avoid excessive frictional obstruction of the flow between the volumes. The tank for the additional air volume can be located on the chassis itself, which is usually impossible due to the limited space available there, or this tank can be attached to the car body, which, however, requires longer piping with flexible sections. The latter design, however, is detrimental to the suspension properties and increases maintenance costs.

[0007] Description of the invention

[0008] The invention is therefore based on the object of specifying a rail vehicle with an air suspension in which an additional air tank is coupled to an air spring, wherein the installation space required for this is minimized.

[0009] The object is achieved by a rail vehicle with air suspension having the features of claim 1. Advantageous embodiments are the subject of subordinate claims. According to the basic idea of ​​the invention, a rail vehicle with air suspension is described, which comprises a car body and at least one chassis mounted so as to be rotatable relative to the car body, wherein at least one air spring is arranged between the car body and the chassis and wherein each air spring is assigned an additional air tank, the volume of which is connected to the volume of the air spring, and wherein the additional air tank is arranged above the air spring and extends in a recess in the car body.

[0010] This has the advantage of being able to reduce the installation space required for an additional air tank and of being able to use previously unused installation space for it.

[0011] According to the invention, an air suspension system is provided on a rail vehicle, comprising an air spring and an additional air tank coupled to this air spring. The volume enclosed in the air spring is coupled to the volume of the additional air tank, so that gas exchange can take place between these volumes. By dimensioning the additional air tank, the spring characteristic of the air spring can be changed, whereby, in particular, a softer spring characteristic is possible compared to the spring characteristic of the air spring without a coupled additional air tank.

[0012] The invention provides for the additional air tank to be arranged above its associated air spring so that it extends into a recess in the car body. In principle, it is also possible to design the car body in such a way that it has airtight sections that can be used as additional air tanks. However, this is disadvantageous because the entire car body would then be subject to different approval regulations and tests for these pressure tanks. The inventive design of the additional air tank as a separate, autonomous component that can be subjected to the corresponding tests on its own eliminates the need for these complex tests of the entire car body. Likewise, the repair or replacement of an additional air tank is made considerably easier.

[0013] The typical design of a rail vehicle usually includes a reinforced cross member in its undercarriage at the location of the bogie connection, the so-called main cross member. This main cross member transmits, among other things, the weight of the car body and the load to the bogie. Consequently, this cross member is designed with significantly greater strength than other parts of the car body, as it can also include, for example, lifting points for the vehicle.

[0014] In steel rail vehicles, this main cross member is made of several steel components that are welded together. These components can be made of sheet metal of varying thickness or strength, and cast parts can also be welded into this composite component.

[0015] Modern simulation methods make it possible to leave certain areas of a main cross member free and to compensate for the resulting reduction in strength by appropriate reinforcements outside these areas. An additional air tank can then be arranged in these free areas (recesses). By providing these recesses directly above the air springs, the gas flow path between an air spring and its assigned additional air tank is optimally short and the flow resistance along this path is thus minimized. This results in better coupling of the volume of the additional air tank and consequently improved suspension properties compared to additional air tanks connected via pipes.

[0016] Due to the usually complex shape of the recesses into which the auxiliary air tanks are inserted in practical designs, the auxiliary air tanks must be designed with an equally complex shape so that the available volume in the recesses can be used as fully as possible. This requires complex production of the auxiliary air tanks, which is only inadequately possible by joining individual components that have to be welded together. It is therefore advantageous to produce an auxiliary air tank from light metal using a casting process, as this eliminates any risk of leaks at welds and even allows complex geometries to be produced. Furthermore, this also makes it possible to locally reinforce the strength of the auxiliary air tank at points of high load.This is necessary because the force is transmitted between the air spring and the main cross member via the auxiliary air tank, which is thus subjected to the weight of the rail vehicle. Consequently, significantly greater strength is required in this force path than in areas that only serve to maintain pressure.

[0017] In a further development of the invention, it is advantageous to design the auxiliary air tank with a hollow shape whose volume is connected to the volume of the air spring. In this way, the volume available for the suspension can be further increased. In particular, this additional volume can be arranged at locations outside the main cross member. By producing the auxiliary air tank as a cast part, even complex geometries with corresponding cavities can be produced, whereby these cavities are connected to the volume of the air spring by corresponding internal gas ducts.

[0018] It is particularly advantageous to design the hollow shape so that it extends in a ring around the air spring. To make optimal use of the available installation space, the shape can also extend essentially cuboidally toward the center of the vehicle.

[0019] The present invention also increases the operational safety of a rail vehicle, since the risk of leakage is reduced by eliminating the need for a large number of compressed air screw connections and flexible lines.

[0020] Brief description of the drawings

[0021] Examples include:

[0022] Fig. l Rail vehicle with air suspension. Fig. 2 Air suspension and main cross member. Fig. 3 Additional air tank.

[0023] Embodiment of the invention Fig. 1 shows, by way of example and schematically, a section through a rail vehicle with air suspension. It is a highly abstract representation of a rail vehicle 1 in a longitudinal section, wherein the underframe of the car body 2 of the rail vehicle 1 is visible. A chassis 3 is arranged beneath the underframe 2 and is rotatably connected to the car body 2. An air spring 4, which is designed as a rubber bellows, is provided as the suspension between the chassis 3 and the car body 2. An additional air tank 5 is connected to the air spring 4 so that their two volumes are connected to one another and a gas exchange can take place between the volume of the air spring 4 and the additional air tank 5. This additional air tank 5 is arranged above the air spring 4, as seen from the chassis 3, and extends into a recess 6 in the car body 2 of the rail vehicle 1.

[0024] Fig. 2 shows an example and schematically an air suspension and a main cross member. A practical embodiment of a rail vehicle according to the invention with an air suspension is shown, wherein only a part of the car body of the rail vehicle 1 is shown to simplify the illustration. This part is designed as a main cross member 8 and represents part of an underframe which has increased strength compared to other parts of an underframe. As a result, weight forces and dynamic loads can be transmitted point-like between a car body and a chassis. In the exemplary embodiment shown, the main cross member 8 is made from a plurality of steel components which are welded to one another. This so-called differential construction allows the mechanical properties of a main cross member 8 to be dimensioned in such a way that a recess 6, i.e.to provide a cavity and at the same time maintain the overall strength compared to a main cross member without a recess 6. To do this, for example, additional parts must be welded in or steel of higher strength or greater thickness must be used. Fig. 2 shows the installation situation in an exploded view, with the air springs 4 and associated compressed air piping 7 being shown outside of their final installation position so that the interaction between the recesses 6 and the additional air tanks 5 can be seen. These additional air tanks 5 are shaped such that they optimally fill the space of the recesses 6. Since the recesses 6 cannot generally be designed as a simple basic geometric shape, as this would make it difficult to maintain the strength of a main cross member, it is advantageous to adapt the shape of an additional air tank 5 to a possible shape of a recess 6.This can be achieved, in particular, by manufacturing the auxiliary air tank 5 from light metal using a casting process, which, for more complex shapes, is advantageous compared to manufacturing from welded molded or sheet metal parts. To increase the volume enclosed in the auxiliary air tank 5 for compressed gas, a hollow formation 9 is provided, which is connected to the remaining internal volume. This hollow formation 9 extends toward the center of the vehicle, since the installation space located there can thus be utilized.

[0025] Fig. 3 shows, by way of example and in schematic form, a section through an additional air tank. The exemplary embodiment from Fig. 2 is shown, the section being made transversely to the vehicle's longitudinal axis and parallel to the central axis of the main cross member 8. This illustration shows that the additional air tank 5 is designed as a complex cast part whose internal volume has a main part 10 and a further volume 11 coupled thereto. The shape of the main part 10 of the volume is adapted to the recess 6 in the main cross member 8, since this recess 6 cannot generally be produced in any desired shape and therefore determines the shape of the additional air tank 5 and thus of the main part 10 of the volume. The further volume is arranged in a recess 9 in the cast part, which extends along the outer contour of the additional air tank 5.It is arranged in a ring shape around the air spring 4, with a section of this additional volume 11 extending in the direction of the vehicle's transverse axis. For this purpose, the formation 9 is enlarged towards the center of the vehicle, since more installation space is available in this direction. The casting itself is arranged between the air spring 4 and the main cross member 8 and therefore transmits the weight of the rail vehicle to the air spring. It is therefore necessary to design the casting, i.e. the additional air tank 5, with sufficient strength and at the same time to provide the largest possible internal volume. In particular in the space directly between the air spring 4 and the main cross member 8, the weight of the rail vehicle is transmitted to the air spring 4, and accordingly the casting is designed with thick walls at this point.For connecting the additional volume 11, openings are provided in the inner walls of the cast part, so that gas exchange between the air spring 4, the main part 10, and the annularly arranged additional volume 11 can take place as undisturbed as possible. List of designations.

[0026] 1 rail vehicle

[0027] 2 Car body 3 Chassis

[0028] 4 air spring

[0029] 5 Additional air tank

[0030] 6 Recess

[0031] 7 Compressed air piping 8 Main cross member

[0032] 9 Hollow formation

[0033] 10 Main part

[0034] 11 Additional volume

Claims

Patent claims 1. Rail vehicle (1) with an air suspension, comprising a car body (2) and at least one bogie (3) rotatably mounted relative to the car body (2), wherein at least one air spring (4) is arranged between the car body (2) and the bogie (3), characterized in that each air spring (4) is associated with an additional air tank (5) whose volume is connected to the volume of the air spring (4), wherein the additional air tank (5) is arranged above the air spring (4) and extends in a recess (6) in the car body (2).

2. Rail vehicle (1) with an air suspension according to claim 1, characterized in that the recess (6) is formed in a main crossbeam (8) of the car body (2).

3. Rail vehicle (1) with an air suspension according to claim 2, characterized in that the main crossbeam (8) is made of a plurality of steel components which are welded together.

4. Rail vehicle (1) with an air suspension according to one of claims 1 to 3, characterized in that the at least one additional air tank (5) is made of light metal by means of a casting process. Rail vehicle (1) with an air suspension according to claim 4, characterized in that the additional air tank (5) comprises a hollow form (9) whose volume corresponds to the volume of the air spring (4) is connected. Rail vehicle (1) with an air suspension according to claim 4, characterized in that the hollow form (9) extends in a ring shape around the air spring (4) and in a substantially cuboid shape towards the center of the vehicle.

Images