Projecting add-on part with integrated vibration damper

Abstract

The invention relates to a projecting add-on part (1). The projecting add-on part (1) has a projecting element (2), which has a fixed end and a free end, and a securing unit (3) for securing the fixed end of the projecting element (2) to a base (4), and the projecting element (2) has a vibration element (5), which can be made to vibrate relative to the base (4) by the action of an external force, said vibration element having known vibrational properties. The projecting add-on part (1) additionally comprises a functional component (6), which is designed to perform a specified function of the projecting add-on part (1), said functional component having a damping mass. The projecting element (2) also comprises a mechanical securing interface (8), having a specified elasticity and damping property, between the functional component (6) and the vibration element (5). The vibrational properties of the vibration element (5), the damping mass of the functional component (6) and the elasticity and damping property of the mechanical securing interface (8) are coordinated with one another in such a way that the resonance frequency of the projecting element (2) or of the vibration element (5) is damped. The invention further relates to a rail vehicle (90) having the projecting add-on part (1) according to the invention and to a method for producing a projecting add-on part (1).

Description

[0001] Description

[0002] Cantilevered attachment with integrated vibration damper

[0003] The invention relates to a cantilevered attachment. Furthermore, the invention relates to a rail vehicle with such a cantilevered attachment. Furthermore, the invention relates to a method for producing an attachment.

[0004] Rail vehicles must be fitted with track clearance devices, often referred to as rail cleaners, in front of the first wheelset in the direction of travel to reduce the risk of derailment caused by obstacles on the rails. The track clearance devices must be fitted in front of the wheels and be a defined distance from the top of the rail. The height of the lower end of the track clearance device above the top of the rail must be at least 30 mm (under all conditions) and at most 130 mm (under all conditions). Track clearance devices are required to remove objects from tracks that are to be used. One type of track clearance device is a structure that projects downwards from the bogie frame. Rail vehicle track clearance devices, which are designed as cantilevered add-on components, are repeatedly subject to fatigue strength damage due to resonance vibrations.

[0005] This problem also occurs with other cantilevered attachments.

[0006] Attempts have been made so far to shift the natural frequency of an attachment into a frequency range in which little excitation is to be expected during operation.

[0007] However, such an approach is associated with certain difficulties, as excitations during operation may occur at frequencies different from those measured before the component was used. Furthermore, for design reasons, the natural frequency of some designs cannot be shifted to a frequency range with low excitation.

[0008] Alternatively, attempts were made to make the attachment solid in order to keep the load in the event of resonance at a level that the component could tolerate. This has the disadvantage of increasing the mass of the attachments. This circumstance can lead to technical disadvantages and problems with vehicle registration, particularly with attachments to the bogie.

[0009] Attachments can be equipped with dampers. A damper reduces the vibration amplitude at the resonant frequency and thus the load. However, the damper has additional mass and requires additional installation space.

[0010] The task is therefore to develop a cantilevered attachment which at least partially overcomes the aforementioned disadvantages.

[0011] This object is achieved by a cantilevered attachment according to patent claim 1, a rail vehicle with such a cantilevered attachment according to patent claim 12 and a method for producing a cantilevered attachment according to patent claim 13.

[0012] The cantilevered attachment according to the invention, preferably a track clearer, comprises a cantilevered element with a fixed end and a free end. A cantilevered element is understood to be an object that protrudes significantly from a base body. The cantilevered attachment preferably comprises an attachment of a rail vehicle, particularly preferably an attachment on a bogie of a rail vehicle.

[0013] The cantilevered attachment further comprises a fastening unit for fastening the cantilevered element by its fixed end to a base. The base comprises the aforementioned base body, preferably a bogie frame, to which the attachment is mounted. The cantilevered element has a vibration element which can be set into vibrational movement relative to the base by the application of external force and which has known vibration properties. The vibration properties can be determined experimentally in advance or calculated on the basis of the dimensions and knowledge of the material used for the vibration element. The vibration element forms a vibration body caused by the cantilever, which can be set into vibrations, in particular bending vibrations, by external influences.Such a vibration element preferably comprises , in particular when the projecting attachment comprises a track clearer , a shaft of the projecting attachment which , due to its more or less elongated shape , is prone to vibrations caused by external influences .

[0014] Furthermore, the cantilevered element comprises a functional component designed to perform a predetermined function of the cantilevered attachment. The functional component also comprises a damping mass, which is preferably integrated into the functional component and thus preferably does not change the dimensions and geometry of the functional component.

[0015] Part of the cantilevered element is also a mechanical fastening interface with a predetermined elasticity and damping property between the functional component and the vibration element.

[0016] The vibration properties of the vibration element, the damping mass of the functional component, and the elasticity and damping properties of the mechanical mounting interface are advantageously coordinated in such a way that a resonance frequency of the cantilevered element is damped. The "resonance frequency" refers to the resonance frequency that would occur if the mechanical mounting interface were not designed to be elastic. Vibration absorbers (also known as dampers or pendulum absorbers) are special types of vibration dampers.

[0017] Vibration dampers are not attached between two objects, but rather to one. The connection to the object is designed to be so soft thanks to the elastic mounting interface mentioned above that the mass of the damper follows the object's movements with a certain delay. The natural frequency of the damper is tuned to the object's resonance frequency, which is to be eliminated. The phase shift cancels out the two vibrations. When the object vibrates, the connection is stretched and compressed, converting the vibration energy into heat.

[0018] The absorber mass or damping mass, together with its own absorber spring, in this case the elastic mounting interface, forms a mass-spring system whose natural frequency is set to the vibration frequency to be eliminated (in this case the vibration element). At this frequency, the absorber can perform large deflections - the forces at the spring attachment point (= attachment point with the structure to be stabilized) are therefore also large. At this frequency, the vibration absorber extracts vibration energy from the structure for its own vibrational movements, which is then ultimately converted into heat through friction. An elastic element can be used as the absorber spring, which is arranged between the cantilevered element and the functional component.

[0019] The use of a damper reduces the risk of fatigue strength damage occurring on a cantilevered attachment. Because the damper is designed as an integral damper, the mass and installation space of the cantilevered attachment are utilized, thus avoiding the need for additional mass or additional installation space. An integral damper is understood to be a damper whose damper mass does not represent the additional mass of a functional element, but is formed by the mass of a component of the functional element that is required to perform the function of the functional element.

[0020] The rail vehicle according to the invention has a car body and a plurality of bogies according to the invention, which are rotatably connected to the car body. Furthermore, the rail vehicle according to the invention comprises at least one cantilevered attachment according to the invention, preferably a track clearer, on the car body or one of the bogies. The rail vehicle according to the invention shares the advantages of the cantilevered attachment according to the invention.

[0021] In the method according to the invention for producing a cantilevered attachment, preferably a cantilevered attachment of a rail vehicle, particularly preferably a cantilevered attachment of a bogie of a rail vehicle, a cantilevered element with a fixed end and a free end is produced. The cantilevered element is produced with an oscillation element which, by the application of external force, can be set into an oscillating movement relative to the base and which has predetermined oscillation properties.

[0022] Furthermore, the cantilevered element is manufactured with a functional component which is designed to perform a predetermined function of the cantilevered attachment and comprises a damping mass.

[0023] In addition, a mechanical fastening interface with a predetermined elasticity and damping property is added to the cantilevered element between the vibration element of the functional component, which serves as a damper mass, and the functional component, or also between the functional component and a damper mass arranged on the functional component. The elasticity and damping property of the mechanical fastening interface depends on the vibration properties of the vibration element and its mass, the position of the damper mass, the position of the functional component and the masses of the damper mass and the functional component, or is coordinated with these, in such a way that a superposition of the vibration of the damper mass and the vibration of the vibration element contributes to a reduction in the vibration amplitude of the vibration element.

[0024] Finally, the cantilevered element is fixed with its fixed end to a base, preferably a bogie frame, by a fixing unit.

[0025] In the method, the vibration properties of the vibration element, the damping mass of the functional component, and the elasticity and damping properties of the mechanical fastening interface are coordinated in such a way that a resonance frequency of the cantilevered element is damped. The method according to the invention shares the advantages of the cantilevered attachment according to the invention.

[0026] The dependent claims and the following description each contain particularly advantageous embodiments and developments of the invention. In particular, the claims of one claim category can also be developed analogously to the dependent claims of another claim category and their description sections. Furthermore, within the scope of the invention, the various features of different embodiments and claims can also be combined to form new embodiments.

[0027] In a preferred embodiment of the cantilevered attachment, the vibration element comprises the fixed end of the cantilevered element and the functional component comprises the free end of the cantilevered element. Advantageously, the damping effect is particularly pronounced due to the arrangement at the free end of the cantilevered element and the associated leverage. The vibration element is preferably designed as a shaft. A shaft is to be understood as an elongated element fastened on one side. In particular, such a shaft preferably comprises a fastening option for a clearing blade of a track clearer. Advantageously, a vibration of the shaft caused by external influences on the shaft can be dampened by the damper arranged on the shaft, preferably a clearing blade.

[0028] In a variant of the cantilevered attachment according to the invention, the damping mass of the functional component as well as the elasticity and damping properties of the mechanical fastening interface are matched to the vibration properties of the vibration element in such a way that a damping of a resonance frequency of the cantilevered element is achieved. Advantageously, the amplitude of a resonance frequency of the vibration element or of the cantilevered element is reduced.

[0029] Preferably, the elasticity and damping properties of the mechanical fastening interface are configured such that broadband cancellation is achieved, wherein a changing resonance frequency of the cantilevered element due to a predetermined maximum change in the mass of the cantilevered element is sufficiently canceled. Advantageously, a vibration amplitude can be reduced even if the resonance frequency changes slightly.

[0030] In a variant of the cantilevered attachment according to the invention, the functional component has at least one mounting point for mounting an additional compensating mass for adjusting the frequency range in which the functional component effectively cancels the resonance frequency. If necessary, an additional mass can advantageously be attached to the integrated damper in order to change the frequency range to be canceled.

[0031] In a preferred embodiment of the cantilevered attachment according to the invention, the functional component is arranged at an end of the cantilevered element opposite the fastening unit. Advantageously, the damper integrated into the functional component has a particularly strong effect because it is arranged at the free end of the cantilevered element, and thus the damper force, with the lever arm of the cantilevered attachment, effectively reduces the load caused by bending moments at the interface between the cantilevered attachment and the base, preferably a bogie.

[0032] In a variant of the cantilevered attachment according to the invention, the vibration element has mechanical stops in the region of the mechanical fastening interface to limit relative movement of the functional component relative to the vibration element. Advantageously, the possible deflections of the vibration element relative to the functional component are limited to prevent damage in the region of the fastening interface.

[0033] The cantilevered element is particularly preferably designed as a component of a web clearer. Small, permanent loads from operation, which could contribute to vibrations in the vibration element and possibly also trigger vibrations in the resonance range of the vibration element, can advantageously be cushioned by the damping mass designed as an integral damper. If vibrations of the vibration element are generated in the resonance range of the vibration element by clearing impacts acting on a web clearer, these are also cushioned or dampened by the damping mass designed as an integral damper.

[0034] If the cantilevered element is designed as a track clearer, the track clearer preferably comprises a clearing plate as a functional component. This clearing plate can advantageously be used as an integral damper without additional mass being required for such a damper. In one embodiment of the cantilevered attachment, the base comprises a bogie frame of a bogie, preferably of a rail vehicle. Advantageously, the cantilevered element, i.e. preferably the shaft of a track clearer, can be fastened to the bogie frame, while the functional element is arranged at the end of the cantilevered element opposite the bogie frame, thus enabling particularly effective damping of resonant vibrations.

[0035] The invention is explained in more detail below with reference to the accompanying figures using exemplary embodiments. They show:

[0036] FIG 1 is a schematic representation of a bogie with a bogie frame and a plurality of track clearers,

[0037] FIG 2 a perspective view of a track clearer,

[0038] FIG 3 a schematic sectional view of a track clearer,

[0039] FIG 4 is a schematic representation of a track clearer according to an embodiment of the invention,

[0040] FIG 5 is a schematic representation of a mechanical fastening interface of a track clearer according to an embodiment of the invention,

[0041] FIG 6 is a schematic representation of elastic connecting elements for a mechanical fastening interface of a track clearer according to an embodiment of the invention,

[0042] FIG. 7 shows a schematic representation of an alternative embodiment of a mechanical fastening interface of a track clearer according to an embodiment of the invention, FIG. 8 shows a flow chart illustrating a method for producing a cantilevered attachment according to an embodiment of the invention,

[0043] FIG 9 is a schematic representation of a rail vehicle according to an embodiment of the invention.

[0044] FIG. 1 shows a schematic representation of a bogie 10 with a bogie frame 10a and a plurality of track clearers 1. The track clearers 1 are each arranged at the four corner regions of the bogie frame 10a and extend vertically downwards from the bogie frame 10a. At the lower end of the track clearers 1, a type of scoop plate or a clearing shovel 6 is mounted as a functional component, with which objects lying on a rail are cleared away during travel.

[0045] FIG. 2 shows a perspective view of a track clearer 1. This track clearer 1 comprises a fastening unit 3 designed as a fastening bracket, which comprises a square, flat fastening plate. From the center of the fastening bracket 3 extends a shaft 5 which runs vertically in the direction of the ground and has a curve 5a in its end section facing the ground. At the end of this curve, a mounting plate 8a is fastened, to which a clearing blade 6 is fastened.

[0046] The fastening bracket 3 can be fastened to a bogie frame 10a (see FIG 1) using four screws 3a arranged at its corners.

[0047] FIG. 3 shows a schematic sectional view of a conventional track clearer 1a. The conventional track clearer 1a is fastened to a bogie frame 10a by means of a fastening bracket 3. The track clearer 1a has a shaft 5, at the lower end of which a clearing blade 6 is mounted. FIG. 4 shows a schematic representation of a track clearer 1 according to an exemplary embodiment of the invention. The track clearer 1 shown in FIG. 4 differs from the conventional track clearer 1a illustrated in FIG. 3 in that a mechanical fastening interface 8 is arranged between the shaft 5 and the clearing blade 6, which has elasticity and damping properties. As a result of this partial decoupling of the clearing blade 6 from the shaft 5 of the track clearer 1, the clearing blade 6 becomes a vibration damper.Instead of a fixed connection with a direct screw connection, the clearing blade 6 is connected via elastic elements. Because the integral damper thus generated is arranged at the bottom of the track clearer 1, the damper forces can effectively dampen the resonance of the track clearer 1. The elastic elements of the mechanical fastening interface 8 are provided with screws and include rubber elements to create the elasticity of the connection.

[0048] FIG 5 shows a schematic representation of a mechanical fastening interface 8 of a track clearer according to an embodiment of the invention. The fastening interface 8 comprises several rubber elements 7a which are arranged between two damper flanges 7b and the clearing blade 6. The rubber elements 7a are firmly connected to the damper flanges 7b and the clearing blade 6. A screw 7c clamps the damper flanges 7b to one another via a sleeve 7g and connects the clearing blade 6 to the shaft 5 of the track clearer 1. The screw 7c is locked by a nut 7h. The length of the sleeve 7g can be used to adjust the preload of the rubber elements 7a and thus to influence the properties of the fastening interface 8, with which the clearing blade 6, which performs a damper function, is connected to the shaft 5 of the track clearer 1.The sleeve 7g can also serve as a mechanical stop for the clearing blade 6 in order to limit the relative movement of the clearing blade 6 to the shaft 5 of the path clearer 1. FIG. 6 shows a schematic representation of a fastening interface 8 with elastic connecting elements 7a for a path clearer 1 according to an exemplary embodiment of the invention. The elastic connecting elements 7a are arranged with screws 7c around a clearing blade 6 to be fixed. A damper flange 7b and an elastic connecting element 7a are arranged between the screw 7c and the clearing blade 6. An elastic connecting element 7a and a shaft 5 are also arranged between the clearing blade 6 and a shaft 5 of the path clearer 1.

[0049] FIG. 7 shows a schematic representation of an alternative fastening interface 8 with a rubber element 7a for mechanically fastening a track clearer 1 according to an exemplary embodiment of the invention. The rubber element 7a is located between a damper flange 7b, which is shown in FIG. 7 on the upper side of the rubber element 7a, and a metal frame which is part of a clearing blade 6. Below the clearing blade 6 there is another rubber element and another damper flange, which in FIG. 7 are largely concealed by the clearing blade 6 and the metal frame, respectively.

[0050] FIG 8 shows a flow chart 800 which illustrates a method for producing a path clearer according to an embodiment of the invention.

[0051] In step 8.1, a track clearer 1 with a cantilevered element 2 is first manufactured.

[0052] In step 8.II, the projecting element 2 is provided with a vibration element 5 which can be set into a vibration movement relative to a base 4 by the application of external force and which has predetermined vibration properties.

[0053] Furthermore, the cantilever element 2 is

[0054] 8 . III is designed with a functional component 6 which is designed to perform a predetermined function of the projecting attachment part 1, for example a clearing blade, and has a relieving mass.

[0055] In step 8.IV, a mechanical fastening interface 8 with a predetermined elasticity and damping property is formed between the functional component 6, for example a clearing blade, and the vibration element 5.

[0056] Finally, in step 8.V, the cantilevered element 2 is fastened to a base 4 by a fastening bracket 3.

[0057] The vibration properties of the vibration element 5, the damping mass of the functional component 6 as well as the elasticity and damping properties of the mechanical fastening interface 8 are coordinated with one another in such a way that a damping of a resonance frequency of the cantilevered element 2 or of the vibration element 5 is achieved.

[0058] FIG 9 shows a schematic representation of a rail vehicle 90 according to an embodiment of the invention.

[0059] The rail vehicle 90 comprises two bogies 10 with track sweepers 1 according to an embodiment of the invention.

[0060] Finally, it is pointed out once again that the methods and devices described above are merely preferred embodiments of the invention and that the invention can be varied by a person skilled in the art without departing from the scope of the invention, insofar as it is defined by the claims. For the sake of completeness, it is also pointed out that the use of the indefinite articles "a" or "an" does not exclude the possibility that the features in question may be present in multiple copies. Likewise, the term "unit" does not exclude the possibility that this may consist of several components, which may also be spatially distributed. Regardless of the grammatical gender of a particular term, persons with male, female or other gender identity are included.

Claims

Patent claims 1. Cantilevered attachment (1) comprising: - a cantilevered element (2) with a fixed end and a free end, - a fastening unit (3) for fastening the cantilevered element (2) with its fixed end to a base (4), the cantilevered element (2) comprising: - a vibration element (5) which, by external force, is set into a vibration movement relative to the base (4) is movable, with known vibration properties, - a functional component (6) which is designed to perform a predetermined function of the projecting attachment (1), comprising a damping mass, - a mechanical fastening interface (8) with a predetermined elasticity and damping property between the functional component (6) and the vibration element (5), wherein the vibration properties of the vibration element (5), the damping mass of the functional component (6) and the elasticity and damping properties of the mechanical fastening interface (8) are matched to one another in such a way that a damping of a resonance frequency of the cantilevered element (2) is achieved.

2. Cantilevered attachment according to claim 1, wherein the vibration element (5) comprises the fixed end of the cantilevered element (2) and the functional component (6) comprises the free end of the cantilevered element (2).

3. Projecting attachment according to claim 1 or 2, wherein the vibration element (5) is formed with a shaft.

4. Projecting attachment according to one of the preceding claims, wherein the damping mass of the functional component (6) as well as the elasticity and damping properties of the mechanical fastening interface (8) are adapted to the vibration properties of the vibration element (5) in such a way that a cancellation of a resonance frequency of the cantilevered element (2) is achieved.

5. Cantilevered attachment according to one of the preceding claims, wherein the elasticity and damping properties of the mechanical fastening interface (8) are designed such that broadband cancellation is achieved, wherein a resonant frequency of the cantilevered element (2) changing due to a predetermined maximum change in the mass of the cantilevered element (2) is sufficiently canceled.

6. Cantilevered attachment according to one of the preceding claims, wherein the functional component (6) has at least one mounting point for mounting an additional compensating mass for adjusting the frequency range in which cancellation of the resonance frequency by the functional component (6) becomes effective.

7. Projecting attachment according to one of the preceding claims, wherein the functional component (6) is arranged at an end of the projecting element (2) opposite the fastening unit (3).

8. Projecting attachment according to one of the preceding claims, wherein the vibration element (5) in the region of the mechanical fastening interface (8) has mechanical stops for limiting a relative movement of the functional component (6) relative to the vibration element (5).

9. Cantilevered attachment according to one of the preceding claims, wherein the cantilevered element (2) is designed as a component of a track clearer (1).

10. Cantilevered attachment according to claim 9, wherein the track clearer (1) comprises a clearing plate as a functional component (6).

11. Cantilevered attachment according to one of the preceding claims, wherein the base (4) comprises a bogie frame (10a) of a bogie (10).

12. Rail vehicle (90) comprising: - a car body, - a plurality of bogies (10), - at least one projecting attachment (1) according to one of the preceding claims on the car body or one of the bogies (10).

13. A method for producing a cantilevered attachment (1), comprising the steps: - producing a cantilevered element (2) with a fixed end and a free end, - Forming the cantilevered element (2) with - a vibration element (5) which can be set into a vibration movement relative to the base (4) by external force, with known vibration properties, - a functional component (6) which is designed to perform a predetermined function of the projecting attachment (1) is formed, comprising a repayment mass, - a mechanical fastening interface (8) with a predetermined elasticity and damping property between the functional component (6) and the vibration element (5), - Fastening the cantilevered element (2) with its fixed end to a base (4) by means of a fastening unit (3), wherein the vibration properties of the vibration element (5), the damping mass of the functional component (6) and the elasticity and damping properties of the mechanical fastening interface (8) are coordinated with one another in such a way that a cancellation of a resonance frequency of the cantilevered element (2) is achieved.

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