Roll stabilizer

Abstract

Roll stabilizer (1) for a rail vehicle, designed for arrangement between a bogie and a car body of the rail vehicle, comprising a torsion bar (2) arranged in an installation position transverse to the longitudinal direction of the vehicle with levers (3, 4) arranged at its two ends in a rotationally fixed manner, a push-pull rod (5, 6) for each lever (3, 4), wherein each lever (3, 4) is pivotally connected to one end of the push-pull rod (5, 6) and the latter is pivotally connected to the car body at its other end, wherein the push-pull rods (5, 6) or the levers (3, 4) or the torsion bar (2) or a connection point between these components have a progressive spring characteristic.

Description

Technical field

[0001] The invention relates to a roll stabilizer for a rail vehicle. State of the art

[0002] In rail vehicles, the car body is typically mounted to the wheel units, such as wheel pairs or wheelsets, or running gear, via one or more spring stages. The centrifugal acceleration (or downhill force in the case of excess cant) that occurs when negotiating curves, acting transversely to the vehicle's direction of travel and thus transversely to its longitudinal axis, causes the car body, due to its relatively high center of gravity, to tilt outwards (or inwards in the case of excess cant) relative to the wheel units. This results in a roll movement around a roll axis parallel to the vehicle's longitudinal axis. To ensure that the vehicle's profile does not exceed the permissible clearance gauge, the maximum permissible roll angle is limited.At the same time, high roll stiffness counteracts excessive wheel unloading in the event of crosswinds, thereby increasing rollover resistance and crosswind stability. A vehicle's roll stiffness can be increased by using stiffer primary and secondary springs. However, this conflicts with the requirements for derailment safety. Stiff spring stages can lead to unacceptably high wheel unloading when slowly negotiating a curved track, posing a derailment risk. Similarly, excessively stiff suspension can significantly impair a vehicle's ride comfort, which is unpleasant for passengers.

[0003] One possible technical solution to these conflicting objectives is the use of roll stabilization devices in the form of so-called roll stabilizers. Their function is to counteract the rolling motion of the car body in order to reduce it, while the up-and-down movements of the car body relative to the wheel assemblies, i.e., the running gear, should not be impeded. Such roll stabilizers are known in various hydraulically or purely mechanically acting designs. A torsion bar (torsion shaft) extending transversely to the longitudinal direction of the vehicle is frequently used, as is known, for example, from WO 2014 009142 A1 or DE 24 21 874 A1. On this torsion bar, levers are mounted on both sides of the longitudinal axis of the vehicle and extend in the longitudinal direction. These levers are in turn connected to links or...The torsion bar is connected by pushrods, which are kinematically parallel to the vehicle's suspension. When the vehicle's suspension compresses, the levers mounted on the torsion bar are set into a rotational movement via the links connected to them. Since both levers rotate through the same angle, the torsion bar remains free of moment. However, if a roll occurs during cornering with different suspension travel on the two sides of the vehicle, this results in different angles of rotation for the levers attached to the torsion bar. The torsion bar is therefore subjected to a torsional moment, which it—depending on its torsional stiffness—compensates for at a specific angle of rotation by a counter-moment resulting from its elastic deformation, thus preventing further roll.In rail vehicles equipped with bogies, the roll stabilization device (roll stabilizer) can be designed for the secondary suspension stage, i.e., acting between a bogie frame and the car body. It can also be used in the primary stage, i.e., acting between the wheelsets and a bogie frame or – in the absence of secondary suspension – a car body. The roll stabilizer is suitable for single-wheel bogies, single-axle bogies (i.e., bogies with only one wheelset), and bogies. Such a roll stabilizer improves the driving dynamics of a rail vehicle; however, its effectiveness is limited, necessitating further adjustment options.In particular, the conflict of objectives between the highest possible derailment safety, for which a softly tuned roll stabilizer is beneficial, and compliance with the loading gauge, which requires a roll stabilizer with the stiffest possible spring characteristic, has not been resolved. Description of the invention

[0004] The invention is therefore based on the objective of providing a roll stabilizer for a rail vehicle which is adjustable over a wide range and which allows the roll of a car body to be optimized with regard to derailment safety and compliance with the clearance profile.

[0005] The problem is solved by a roll stabilizer for a rail vehicle having the features of claim 1 and a rail vehicle according to claim 10. Advantageous embodiments are the subject of dependent claims.

[0006] According to the basic idea of ​​the invention, a roll stabilizer for a rail vehicle is described, which is designed for arrangement between a chassis and a car body of the rail vehicle and which comprises a torsion bar arranged in an installation position transverse to the longitudinal direction of the vehicle with levers arranged at both ends in a rotationally fixed manner, a push-pull rod for each lever, wherein each lever is pivotally connected to one end of the push-pull rod and the other end of the push-pull rod is pivotally connectable to the car body, and wherein the push-pull rods or the levers or the torsion bar or a connection point between these components have a progressive spring characteristic.

[0007] This offers the advantage of being able to implement a roll stabilizer that provides more extensive driving dynamics tuning options than a roll stabilizer from the state of the art.

[0008] According to the invention, a roll stabilizer, which operates on essentially the same principle as a conventional roll stabilizer, is equipped with a progressive spring characteristic curve. This means that after a first, softer section of the spring characteristic curve (force-displacement characteristic or moment-angle-torsion characteristic), a second, stiffer section of the spring characteristic curve comes into effect at greater roll angles. Thus, a softer setting can be achieved at lower lateral accelerations acting on a rail vehicle, while at higher lateral accelerations, compliance with the clearance gauge is ensured.A significant advantage of the presented invention lies in the case of an air-sprung vehicle which, due to a malfunction (burst of an air spring or failure of the compressed air supply), rests on the relatively stiff emergency springs and thus, through the parallel action of the emergency spring and the roll stabilizer, exhibits a significantly increased overall roll stiffness than in regular air-sprung operation. Due to their increased stiffness, the emergency springs permit only small roll angles. In the range of small roll angles, the roll stabilizer disclosed in the invention still exhibits a soft spring characteristic, which has a positive effect on derailment safety when traversing curved track.

[0009] A roll stabilizer according to the invention comprises two push-pull rods, which are pivotally connected at one end to the car body of a rail vehicle and which transmit push-pull forces to a lever each. These levers are arranged at opposite ends of a torsion bar in a rotationally fixed manner. The torsion bar connecting the levers is rotatably mounted on a chassis (generally a bogie, but also a single axle). A progressive spring characteristic is incorporated into this arrangement, which can be integrated either alone or in combination into the push-pull rods, the levers, the torsion bar, or a connection point between these components.

[0010] According to a first preferred embodiment of the invention, the push-pull rods connecting a car body to a lever are equipped with a progressive spring characteristic. In the unloaded state, the push-pull rods have a specific initial length, which changes under tensile or compressive forces according to the spring constant. Such a push-pull rod can be advantageously manufactured by dividing it into a first and a second section and arranging a progressive spring between these sections so that it can act in both the tensile and compressive directions. Coil springs are particularly suitable for this purpose, as they can be wound accordingly to achieve the desired progression. The coil spring can be constructed from two individual springs, each with a progressive characteristic.

[0011] In addition to coil springs, suitable disc springs or elastomers (e.g., rubber cone springs) can also be used. Besides a spring design consisting of two individual springs, a one-piece spring with a point-symmetrical progressive spring characteristic can also be used.

[0012] Another preferred embodiment of the invention provides for equipping the torsion bar with a progressive spring characteristic, in this case a progressive moment-angle-of-twist characteristic. Such a torsion bar is to be made in multiple parts, wherein in a first variant the torsion bar is divided into two sections and an elastic element is inserted between the sections. This elastic element offers less resistance to twisting than the two sections, so that after the deformation path of the elastic element has been exhausted, the spring constant of the two sections acts. The elastic element can be designed, for example, as an elastomer or as a metallic spring, similar to a leaf spring.

[0013] Another preferred embodiment provides for at least one elastic element to be introduced into a connection point between the lever and the torsion bar, in that the connection on the side of the torsion bar is designed as a splined shaft and, as a counterpart to this, on the side of the lever is designed as a splined hub, and the elastic elements are inserted between the teeth.

[0014] Such a connection point can be provided between the torsion bar and one of the levers, or on both levers.

[0015] Another preferred embodiment of a torsion bar with a progressive spring characteristic also employs two sections, with a second section arranged between two first sections. This second section has a softer spring characteristic than the first two sections. When a torque is applied to this torsion bar, the softer second section twists first up to a certain angle of deformation. At this angle, stops engage and prevent further twisting of the second section. Any further deformation (twisting) with increasing torque occurs in the two first sections, which have a stiffer spring characteristic. The overall spring characteristic of such a torsion bar is therefore progressive.

[0016] Another preferred embodiment of the invention provides for at least one of the levers of a roll stabilizer to be designed elastically and with a progressive spring characteristic. For this purpose, the lever is designed elastically, with this elasticity being realized by a progressive spring characteristic, for example by a leaf spring assembly.

[0017] It is advantageous to arrange the roll stabilizer kinematically parallel to the spring assembly. In contrast to kinematically serial arrangements, this creates a far more generally applicable solution, and in particular, existing roll stabilizers can be easily retrofitted with the advantageous property of a progressive spring characteristic by simply replacing individual components such as tension / compression rods or levers.

[0018] Furthermore, the invention comprises a rail vehicle which has a roll stabilizer according to the idea presented here. Brief description of the drawings

[0019] They show, for example: Fig. 1 Roll stabilizer with spring in the tension / push rods. Fig. 2 Push-pull rod with progressive spring. Fig. 3 Roll stabilizer with spring in the torsion bar, first version. Fig. 4 Torsion bar with progressive spring, first version. Fig. 5 Roll stabilizer with spring in the torsion bar, second version. Fig. 6 Torsion bar with progressive spring, second version. Fig. 7 Lever with progressive spring. Implementation of the invention

[0020] Fig. 1 Figure 1 shows an exemplary and schematic representation of a roll stabilizer with springs in the tension / compression rods. A roll stabilizer 1 is depicted, which consists of a first tension / compression rod 5 and a second tension / compression rod 6, which can be pivotally connected to a car body of a rail vehicle by means of a first joint 9 and a second joint 10, respectively. A car body or parts of a running gear are shown in Fig. 1The illustrations are not shown to clarify the invention. Both push-pull rods 5, 6 act on their respective associated levers 3, 4, which in turn are fixedly mounted on a torsion bar 2. The roll stabilizer 1 is designed for attachment to a chassis, for which purpose a first bearing 7 and a second bearing 8 are provided. These bearings allow the torsion bar 2 to rotate freely and are designed for detachable attachment to the chassis. Movement of one of the push-pull rods 5, 6 is thus transmitted synchronously to the other push rod via the levers 3, 4 and the torsion bar 2. However, to allow the car body to roll relative to the chassis, the roll stabilizer 1 is provided with elasticity; that is, the push-pull rods can each assume different positions relative to the chassis, exerting a counterforce proportional to this difference in position.In conventional roll stabilizers, this counterforce is applied by the torsion bar 2, which rotates during the process. According to the present invention, in the illustrated embodiment, the tension-compression rods 5, 6 are spring-loaded and exhibit a progressive spring characteristic.

[0021] Fig. 2 This shows an exemplary and schematic representation of a push-pull rod with a progressive spring. A cross-section through a push-pull rod is shown, as in the embodiment shown in... Fig. 1The push-pull rod is divided into a first section 11 and a second section 12, with the first section 11 comprising a plate 14 at its end facing the second section 12. The second section 12 comprises a sleeve that receives the plate 14 and is designed as a hollow cylinder 13. This arrangement is similar to a conventional pneumatic or hydraulic cylinder; however, two progressive springs 15 are arranged between the plate 14 of the first section 11 and the hollow cylinder 13 of the second section 12. This arrangement ensures that the same spring constant acts in both the tension and compression directions and that a progressive spring characteristic is present. The progressive spring 15 is designed as a helical spring, since the spring characteristic can be precisely determined by the type of coiling and the material used.

[0022] Fig. 3Figure 1 shows an exemplary and schematic representation of a roll stabilizer with a spring in the torsion bar, first embodiment. A further embodiment of a roll stabilizer 1 is shown, which is equivalent to the one in Figure 1. Fig. 1 revealed roll stabilizer, in which the torsion bar 16 is equipped with a progressive torsion spring characteristic.

[0023] Fig. 4 This shows an example and schematic of a torsion bar with a progressive spring, first version. It is the progressive torsion bar 16 from Fig. 3The progressive torsion bar 16 is shown in its individual components and in its assembled state. It is divided into a first section 17 and a second section 18, the opposing ends of sections 17 and 18 being shaped to transmit torque to the other section 17 and 18, i.e., they are designed for positive engagement. This positive engagement includes a clearance about the longitudinal axis of sections 17 and 18, allowing the sections 17 and 18 to rotate relative to each other by a certain angle without moment. An elastic element 19 is inserted into this clearance, which exerts a spring effect corresponding to the spring constant of the elastic element 19, opposing the rotation of sections 17 and 18 relative to each other. Fig. 4A single elastic element 19 is shown, but the design of sections 17 and 18 suggests the use of six elastic elements. The moment-angle characteristic of a progressive torsion bar 16 initially follows the spring constant of the elastic element 19 until, after complete deformation of the elastic element 19, the common rotational spring constant of the first 17 and second sections of the progressive torsion bar 16 comes into effect. Furthermore, in Fig. 4 An assembly diagram of the progressive torsion bar just described is shown.

[0024] Fig. 5 This shows an exemplary and schematic representation of a roll stabilizer with a spring in the torsion bar, second version. A roll stabilizer 1 is shown, which is also based on the principle of the roll stabilizers from the [reference to be added]. Fig. 1 and 3The roll stabilizers shown are constructed using a progressive torsion bar 20, which, however, differs from the one in Fig. 4 The embodiment is revealed. According to this embodiment, a stop is used which, at a certain rotation angle of a first section of the progressive torsion bar 20, blocks further torsion and thus any further torsion takes place in a second section of the torsion bar 20.

[0025] Fig. 6 This shows an example and schematic of a torsion bar with a progressive spring, second version. It is the progressive torsion bar 20 from Fig. 5A detailed illustration shows the progressive torsion bar 20, which consists of a first section 21 with a second section 22 inserted along its length. The second section 22 has a lower torsional spring constant than the entire first section 21. Stops 23 are provided, which are rigidly connected to one of the first sections 21 and engage in corresponding recesses in the second section 21. From a certain angle of rotation of the second section 22, these stops block further rotation of the second section 22, so that further torsion of the progressive torsion bar 20 occurs only in the first section 21.

[0026] Fig. 7Figure 24 shows an exemplary and schematic representation of a lever with a progressive spring. It illustrates an embodiment of the invention in which a lever 24 is equipped with a progressive spring characteristic. A lever, which in conventional roll stabilizers is designed to be as indeformable as possible, is, according to this embodiment, elastically designed with a progressive spring characteristic. The lever 24 consists of an inner spring 25, which is designed at one end for pivotable attachment to a rod 27. This rod 27 connects the lever 24 to a car body and corresponds to the tension-compression rods shown in the preceding embodiments. The rod 27 has no elastic properties, i.e., no significant deformation of the rod 27 occurs under operating forces. The other end of the inner spring 25 is fixedly attached to a base body of the lever 24, which in turn is rotationally fixed to a torsion bar.The forces caused by the rolling movements of the car body and transmitted via the rod 27 deform the inner spring 25, resulting in a linear spring characteristic within a specific angular range of deformation. An outer spring 26 is rigidly connected at one end to the base of the lever 27. It extends in a U-shape around the inner spring 25 and is spaced apart from it when the inner spring 25 is unforced. As the force acting on the inner spring 25 increases, the inner spring 25 and the outer spring 26 come into contact. From this point of deflection onward, the spring constant of the inner spring 25 is the sum of the spring constants of the inner spring 25 and the outer spring 26, thus giving the lever 24 a progressive spring characteristic. This embodiment allows for a particularly adjustable spring characteristic, as additional springs can be used, and the progression can therefore be easily adapted to different requirements. Reference symbol list

[0027] 1 Roll stabilizer 2 Torsion bar 3 First lever 4 Second lever 5 First push-pull rod 6 Second push-pull rod 7 First bearing 8 Second bearing 9 First joint 10 Second joint 11 First section of push-pull rod 12 Second section of push-pull rod 13 Hollow cylinder 14 Plate 15 Progressive spring 16 Progressive torsion bar with elastic element 17 Progressive torsion bar - first section 18 Progressive torsion bar - second section 19 Elastic element 20 Progressive torsion bar with stops 21 Progressive torsion bar with stops - first section 22 Progressive torsion bar with stops - second section 23 Stop 24 Lever with progressive spring characteristic 25 Inner spring 26 Outer spring 27 Rod

Claims

1. Roll stabilizer (1) for a rail vehicle, designed for arrangement between a bogie and a car body of the rail vehicle, comprising a torsion bar (2) arranged in an installation position transverse to the longitudinal direction of the vehicle with levers (3, 4) arranged at its two ends in a rotationally fixed manner, a push-pull rod (5, 6) for each lever (3, 4), wherein each lever (3, 4) is pivotally connected to one end of the push-pull rod (5, 6) and the other end of the latter is pivotally connected to the car body, characterized by the fact that the push-pull rods (5, 6) or the levers (3, 4) or the torsion bar (2) or a connection point between these components have a progressive spring characteristic.

2. Roll stabilizer (1) for a rail vehicle according to claim 1, characterized by the fact thatthe push-pull rods (5, 6) are designed as progressive springs, wherein the push-pull rods (5, 6) are each divided into a first (11) and a second (12) section and wherein at least one progressive spring (15) is arranged between the first (11) and the second (12) section.

3. Roll stabilizer (1) for a rail vehicle according to claim 1, characterized by the fact that the levers (3, 4) are designed as a progressive spring, wherein an inner spring (25) is provided, which is designed as a connection from the torsion bar (2) to a hinged connection with a rod (27) and which comes into contact with an outer spring (26) at a certain deformation, so that from this deformation the sum of the spring constants of the inner (25) and outer (26) springs acts.

4. Roll stabilizer (1) for a rail vehicle according to claim 1, characterized by the fact thata torsion bar (16) is designed as a progressive spring, wherein the torsion bar (16) is divided into a first (17) section and a second (18) section and at least one elastic element is inserted between the sections (17, 18).

5. Roll stabilizer (1) for a rail vehicle according to claim 4, characterized by the fact that the first section (17) of the torsion bar (16) has several recesses and the second section (18) of the torsion bar (16) has several forms which interlock and there are free spaces between the recesses and the forms and elastic elements (19) are inserted into these free spaces.

6. Roll stabilizer (1) for a rail vehicle according to claim 1, characterized by the fact thata torsion bar (20) is designed as a progressive spring, wherein the torsion bar (20) is divided into a first (21) section and a second (22) section, wherein the second section (22) has a lower spring constant than the first (21) section, wherein from a certain torsion angle between the first (21) and the second (22) section stops (23) block the further torsion of the second (22) section and from this section the spring constant of the first section (21) acts.

7. Roll stabilizer (1) for a rail vehicle according to claim 1, characterized by the fact that the connection point between the torsion bar (2) and at least one of the two levers (3, 4) is designed as a progressive spring element, wherein the connections of the torsion bar (2) are designed as a splined shaft, and the connections of the levers have a splined hub profile as a counterpart to this, wherein elastic elements (19) are inserted between these connections.

8. Roll stabilizer (1) for a rail vehicle according to one of claims 1 to 6, characterized by the fact that the spring characteristics of the tension-compression rods (5, 6) or the levers (24) or the torsion bar (16, 20) are symmetrical in tension and compression directions, or in left- and right-hand torsion.

9. Roll stabilizer (1) for a rail vehicle according to claims 1 to 7, wherein the rail vehicle has a spring device between a car body and a chassis, characterized by the fact that the roll stabilizer (1) is arranged kinematically parallel to the spring assembly.

10. Rail vehicle comprising a roll stabilizer according to any one of claims 1 to 8.

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