Rail Vehicle with Pneumatic Suspension

Abstract

A rail vehicle with a pneumatic suspension includes a car body and at least one chassis that is rotatably supported relative to the car body, wherein at least one pneumatic spring is arranged between the car body and the chassis, and each pneumatic spring is paired with an auxiliary air tank that has a volume that is connected to the volume of the pneumatic spring, where the auxiliary air tank is arranged above the pneumatic spring and extends in a recess in the car body.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This is a U.S. national stage of application No. PCT / EP2023 / 063900 filed 24 May 2023. Priority is claimed on Austrian Application No. A50374 / 2022 filed 25 May 2022, the content of which is incorporated herein by reference in its entirety.BACKGROUND OF THE INVENTION1. Field of the Invention

[0002] The invention relates to a rail vehicle with pneumatic suspension, in particular a passenger rail vehicle.2. Description of the Related Art

[0003] Passenger rail vehicles are frequently equipped with pneumatic suspension because this offers better ride comfort compared to conventional steel suspension, as well as the option of level control. Pneumatic suspension comprises the actual pneumatic spring made of elastic material, which is arranged between a chassis and a car body and which is filled with compressed gas. Furthermore, pneumatic suspension comprises corresponding piping for supplying and discharging the compressed gas and a compressed-gas source, usually a compressed-air compressor or a connection to a compressed-air system provided to operate a brake. If the pneumatic suspension has level control, then corresponding control valves and measuring facilities are provided for determining the current deflection of the car body relative to the chassis. A substantial improvement to suspension comfort can be achieved by increasing the volume of compressed gas enclosed in the pneumatic spring because this allows a softer spring characteristic. However, the dimensions of a pneumatic spring, which is usually formed as cylindrical, ring-shaped or toroidal rubber bellows, are determined by the conditions in the region between a car body and a chassis and cannot be substantially enlarged. Therefore, an “auxiliary air volume” can be provided, the volume of which is coupled to the volume of the pneumatic spring so that a compressed-gas flow can take place between these volumes. This measure makes it possible, even with pneumatic springs, to achieve a spring characteristic that would otherwise only be possible with larger pneumatic springs. The auxiliary air volumes are structured in the form of compressed air tanks and are arranged as closely as possible to the pneumatic spring so that the flow between the volumes is not excessively impeded by friction. Herein, the tank for the auxiliary air volume can be arranged on the chassis itself, which is usually impossible due to the limited space available there. Alternatively, this tank can be attached to the car body, although this requires longer piping with flexible sections. However, the latter embodiment is disadvantageous for the suspension properties and increases the maintenance effort.SUMMARY OF THE INVENTION

[0004] It view of the foregoing, it is therefore an object of the invention to provide a rail vehicle with pneumatic suspension in which an auxiliary air tank is coupled to a pneumatic spring, where the installation space required for this is minimized.

[0005] This and other objects and advantages are achieved in accordance with the invention by a rail vehicle with pneumatic suspension, comprising a car body and at least one chassis mounted such that it can rotate relative to the car body, where at least one pneumatic spring is arranged between the car body and the chassis, where each pneumatic spring is paired with an auxiliary air tank, the volume of which is connected to the volume of the pneumatic spring, and where the auxiliary air tank is arranged above the pneumatic spring and extends in a recess in the car body.

[0006] This has the advantage of enabling the installation space required for an auxiliary air tank to be reduced and enabling previously unused installation space to be used for this purpose.

[0007] In accordance with the invention, a pneumatic suspension comprising a pneumatic spring and an auxiliary air tank coupled to this pneumatic spring is provided on a rail vehicle. Herein, the volume enclosed in the pneumatic spring is coupled to the volume of the auxiliary air tank so that gas exchange can take place between volumes. The dimensioning of the auxiliary air tank enables the spring characteristic to be changed, where in particular a softer spring characteristic is possible compared to the spring characteristic of the pneumatic spring without a coupled auxiliary air tank.

[0008] The invention provides for the auxiliary air tank to be arranged above the pneumatic spring paired therewith so that it extends into a recess of the car body. It is in principle also possible for the car body to be structured such that it is provided with air-tight sections that can be used as an auxiliary air tank. However, this is disadvantageous because the entire car body would then be subject to other approval regulations and tests for these pressure tanks. The embodiment in accordance with the invention of the auxiliary air tank as an independent separate component, which can be subjected to the corresponding tests on its own, eliminates the need for such time-consuming tests on the entire car body. This also makes it much easier to repair or replace an auxiliary air tank.

[0009] The typical structure of a rail vehicle usually provides a reinforced cross member in its underframe, the “main cross member”, at the position where the chassis is connected. This main cross member is inter alia used to transmit the weight force of the car body and the load to a chassis. As a result, this arm is formed as much stronger than other parts of the car body because it can, for example, also comprise lifting points for the vehicle.

[0010] In the case of steel rail vehicles, this main cross member is produced from a plurality of steel components that are welded together. Herein, these components can be formed as sheets of different thicknesses or strengths and cast parts can also be welded into this composite component.

[0011] Modern simulation methods enable certain regions of a main cross member to be left free and the resulting reduction in strength to be compensated by corresponding reinforcements outside these free regions. An auxiliary air tank can be arranged in these free regions (recesses). Providing these recesses directly above the pneumatic springs also ensures an optimally short path for the gas flow between a pneumatic spring and the auxiliary air tank with which it is paired, thus minimizing flow resistance along this path. This achieves better coupling of the volume of the auxiliary air tank and consequently improved suspension properties compared to auxiliary air tanks connected by pipes.

[0012] Due to the usually complex shape of the recesses into which the auxiliary air tanks are introduced, the auxiliary air tanks should be formed with an equally complex shape so that the available volume in the recesses can be utilized as fully as possible. This requires a complex manufacturing process for the auxiliary air tanks, but this is only insufficiently enabled by connecting individual components that have to be welded together. Therefore, it is advantageous to manufacture an auxiliary air tank from light metal via a casting process because this eliminates any risk of leaks at welding points and also allows complicated geometries. Furthermore, this also enables local reinforcement of the strength of the auxiliary air tank at points of high stress. This is necessary because the force is transmitted between the pneumatic spring and the main cross member via the auxiliary air tank, which is thus loaded with the weight force of the rail vehicle. Consequently, a substantially higher strength is required in this force path than at points that only serve to maintain pressure.

[0013] In a further embodiment of the invention, it is advantageous for the auxiliary air tank to be formed with a hollow shape, the volume of which is connected to the volume of the pneumatic spring. This enables the volume available for the suspension to be further enlarged. In particular, this further volume can be arranged at points outside the main cross member. By manufacturing the auxiliary air tank as a cast part, it is also possible to manufacture complicated geometries with corresponding cavities, where these cavities are connected to the volume of the pneumatic spring by corresponding internal gas guides.

[0014] It is particularly advantageous for the hollow shape to be formed such that it extends annularly around the pneumatic spring. In order to make optimum use of the available installation space, the shape can additionally also extend in a substantially cuboid shape in the direction of the center of the car.

[0015] The present invention also increases the operational safety of a rail vehicle because the risk of leaks is reduced due to the elimination of a large number of compressed-air fittings and flexible lines.

[0016] Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In the drawings, by way of example:

[0018] FIG. 1 shows a rail vehicle with pneumatic suspension in accordance with the invention;

[0019] FIG. 2 shows a pneumatic suspension and main cross member in accordance with the invention; and

[0020] FIG. 3 shows an auxiliary air tank in accordance with the invention.DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0021] FIG. 1 shows an exemplary and schematic view of a section through a rail vehicle with pneumatic suspension. This shows a highly abstracted representation of a rail vehicle in a longitudinal section, where the underframe of the car body 2 of the rail vehicle 1 is visible. A chassis 3 that is connected to the car body 2 in a rotatable manner is arranged underneath the underframe 2. A pneumatic spring 4 in the form of rubber bellows is provided between the chassis 3 and the car body 2. An auxiliary air tank 5 is connected to the pneumatic spring 4 so that their two volumes are connected to one another and gas can be exchanged between the volume of the pneumatic spring 4 and the auxiliary air tank 5. This auxiliary air tank 5 is arranged above the pneumatic spring 4, when viewed from the chassis 3, and extends into a recess 6 in the car body 2 of the rail vehicle 1.

[0022] FIG. 2 is an exemplary and schematic view of a pneumatic suspension and a main cross member. This is a practice-oriented embodiment of a rail vehicle in accordance with the invention with pneumatic suspension, wherein only part of the car body of the rail vehicle 1 is depicted to simplify the representation. This part is formed as a main cross member 8 and represents a part of an underframe that has increased strength compared to other parts of an underframe. This enables weight forces and dynamic loads to be transmitted at points between a car body and a chassis. In the exemplary illustrated embodiment, the main cross member 8 is produced from a plurality of steel components that are welded together. This “differential configuration” allows the mechanical properties of a main cross member 8 to be dimensioned such that a recess 6, i.e., a cavity, is also provided, while maintaining the overall strength compared to a main cross member without a recess 6. For this purpose, it is, for example, possible to weld in additional parts or to use steel of higher strength or greater thickness. FIG. 2 shows the installation conditions in an exploded view, where the pneumatic springs 4 and associated compressed-air piping 7 are shown outside their final installation position so that the interaction between the recesses 6 and the auxiliary air tanks 5 can be seen. These auxiliary air tanks 5 are shaped such a that they optimally fill the space in the recesses 6. Since the recesses 6 generally cannot be designed as a simple geometric basic shape, since otherwise it would be difficult to maintain the strength of a main cross member, it is advantageous to adapt the shape of an auxiliary air tank 5 to a possible shape of a recess 6. This can in particular be accomplished by manufacturing the auxiliary air tank 5 from light metal via a casting process, which is advantageous for more complex shapes compared to manufacturing from molded parts or sheet metal parts welded together. In order to increase the volume for compressed gas enclosed in the auxiliary air tank 5, a hollow shape 9 is provided that is connected to the remaining internal volume. This hollow shape 9 extends in the direction of the center of the car since the installation space located there can be used.

[0023] FIG. 3 shows an exemplary and schematic section through an auxiliary air tank. This depicts the exemplary embodiment from FIG. 2, where the section is transverse to the longitudinal axis of the vehicle and parallel to the central axis of the main cross member 8. In this representation, it can be seen that the auxiliary air tank 5 is formed as a complex cast part, the internal volume of which 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 because this recess 6 cannot generally be shaped at will and therefore determines the shape of the auxiliary air tank 5 and thus of the main part 10 of the volume. The further volume is arranged in a shape 9 in the cast part, which extends along the outer contour of the auxiliary air tank 5. It is arranged in an annular shape around the pneumatic spring 4, where a section of this further volume 11 extends in the direction of the transverse axis of the vehicle. For this purpose, the shape 9 is enlarged in the direction of the center of the car, because more installation space is available in this direction. The cast part itself is arranged between the pneumatic spring 4 and the main cross member 8 and therefor transmits the weight force of the rail vehicle to the pneumatic spring. It is therefore necessary to form the cast part, i.e., the auxiliary air tank 5, with sufficient strength and at the same time provide the greatest possible internal volume. In particular, in the space directly between the pneumatic spring 4, and the main cross member 8 transmits the weight force of the rail vehicle to the pneumatic spring 4 and so the cast part is formed as thick-walled at this point. For coupling the further volume 11, openings are provided in inner walls of the cast part so that gas can be exchanged between the pneumatic spring 4, the main part 10 and the annularly arranged further volume 11 with as little disruption as possible.

[0024] Thus, while there have been shown, described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements that perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and / or elements shown and / or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.

Claims

1. -6. (canceled)7. A rail vehicle with pneumatic suspension, comprising:a car body;at least one chassis rotatable mounted relative to the car body; andat least one pneumatic spring arranged between the car body and the at least one chassis;wherein each pneumatic spring is paired with an auxiliary air tank having a volume which is connected to a volume of the pneumatic spring; andwherein the auxiliary air tank is arranged above the pneumatic spring and extends in a recess in the car body.

8. The rail vehicle with pneumatic suspension as claimed in claim 7, wherein the recess is formed in a main cross member of the car body.

9. The rail vehicle with pneumatic suspension as claimed in claim 8, wherein the main cross member is produced from a plurality of steel components which are welded together.

10. The rail vehicle with pneumatic suspension as claimed in claim 7, wherein the at least one auxiliary air tank is made of light metal via a casting process.

11. The rail vehicle with pneumatic suspension as claimed in claim 8, wherein the at least one auxiliary air tank is made of light metal via a casting process.

12. The rail vehicle with pneumatic suspension as claimed in claim 9, wherein the at least one auxiliary air tank is made of light metal via a casting process.

13. The rail vehicle with pneumatic suspension as claimed in claim 10, wherein the auxiliary air tank comprises a hollow shape having the volume which is connected to the volume of the pneumatic spring.

14. The rail vehicle with pneumatic suspension as claimed in claim 13, wherein the hollow shape extends annularly around the pneumatic spring and in a substantially cuboid shape in a direction of a center of the car body.

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