PULL AND SHOCK DEVICE FOR A DRIVE COUPLING AND DRIVE COUPLING

Description

[0001] The present invention relates to a pulling and buffing device for a train coupling, in particular a central buffer coupling, and to a train coupling with such a pulling and buffing device.

[0002] Traction and shock devices of this type are used in couplings to cushion tensile and compressive shocks. They feature a spring assembly that transmits tensile and compressive forces between opposing first and second connections of the traction and shock device. For example, DE 20 2004 014 532 U1 discloses a spring assembly box with a spring assembly that is pivotally connected on one side to a coupling arm and on the other side to an assembly box that is screwed to a stop plate of the vehicle. Compressive forces are transmitted to the compression stops on the vehicle via a tension push-fit, a spring, a rear plate, and a housing, and tensile forces are transmitted to the draw stops via a pivot pin, the housing, the rear plate, the spring, and the tension push-fit. Thus, the single spring transmits both tensile and compressive forces.

[0003] A disadvantage of a draw and buffing device of the type shown, with one or more springs subjected to full tensile and compressive force in both axial directions, is the load change with a zero crossing in the spring, which has an adverse effect on the train dynamics. Furthermore, the spring travel cannot be changed without altering the spring characteristics, which complicates the installation of such spring assembly boxes in various train couplings, since additional spacers must be provided in the comparatively large installation space to transfer the compressive forces into the wagon structure. This involves additional effort and weight for the draw and buffing device.

[0004] A generic tensile and shock device is disclosed, for example, in US 3,031,089 A. This device comprises a spring assembly with a hydraulic displacement damper and at least one compression spring, wherein, according to a first embodiment, the hydraulic damper absorbs compression shocks and the compression spring cushions tensile shocks. According to an alternative embodiment, a second compression spring is provided in the force flow parallel to the hydraulic damper and parallel to the first compression spring, which cushions both compression and tensile shocks. According to a third embodiment, two compression springs are arranged parallel to each other in the force flow, which cushion tensile shocks, combined with a hydraulic damper that cushions compression shocks. The hydraulic damper includes an internal return spring that returns a piston rod of the damper to its original position after a compression shock. The hydraulic damper cushions only compression shocks.

[0005] A disadvantage of the tension and shock device according to US 3,031,089 A is that it requires considerable axial installation space and that pressure surges are essentially only damped by the hydraulic damper, because the compression spring, which may be arranged in parallel, has a comparatively small spring stroke. Since the damping effect of the hydraulic damper is dependent on mass and speed, there is hardly any damping at low speeds in the first and third embodiments. Under quasi-static loads, the tension and shock device will always cushion the full stroke in the compression direction, which is associated with corresponding mechanical stresses. Furthermore, during load changes, there are hard metallic stops, which lead to noise and wear. Additionally, various stop surfaces arranged one behind the other at intervals must be aligned with each other to ensure proper function.The installation of the draw and buffer mechanism is therefore complex. A failure of the hydraulic damper quickly leads to a complete failure of the draw and buffer mechanism.

[0006] Furthermore, EP 2305531 A1 also discloses a device for damping compressive forces with a combination of a spring assembly connected in series and a hydraulic damping device. US 5908123 discloses a buffer with a spring and damping device connected in series.

[0007] It is also known to combine springs with friction dampers in train couplings, as disclosed, for example, in WO 2007 / 103087 A1.

[0008] US 3 556 311 A discloses the combination of rubber buffers with an air damper.

[0009] US 3 854 596 A discloses the combination of a hydraulic damper and elastomer buffers.

[0010] DE 20 2004 014 532 U1 discloses a spring assembly box with a spring assembly which is connected on the one hand by a pivot to a coupling arm and on the other hand to an assembly box which is screwed to a stop plate of the vehicle, wherein compressive forces are transmitted to the pressure stops of the vehicle via a pull-push piece, a spring, a rear plate and a housing and tensile forces are transmitted to pull stops via a pivot bolt, the housing, the rear plate, the spring and the pull-push piece.

[0011] WO 2013 / 040119 A1 discloses the combination of an elastomeric component with friction damping for a tension and compression device of a coupling. Here, too, a pressure plate is provided at each end of a stack of elastomeric elements, so that compressive forces are transmitted across the entire elastomeric stack in both the tensile and compressive directions. The spring travel is therefore identical in both axial directions, and the tension and compression device must be adapted accordingly with spacers or the like when installed in different environments.

[0012] EP 1 225 114 B1 discloses a draw and compression device for a center buffer coupling, in which a coupling arm or coupling shaft is supported by a joint on a pivot pin, wherein, under tensile load, the coupling shaft transmits the tensile force via the pivot pin, an upper chord, a lower chord, an end plate, a tension-side play spring, a stop plate, and a spring system to a pressure plate which is supported against vehicle-side draw stops. During compression load, the coupling shaft transmits the compressive force without play via a joint play spring to the pivot pin, which is supported against the pressure plate, wherein the pressure plate compresses the spring system and transmits the compressive forces via the stop plate against the vehicle-side compression stops.

[0013] WO 2016 / 026708 A1 discloses a pulling and bumping device for a train coupling with a reversible and an irreversible energy absorption device. The irreversible energy absorption device is connected in series with the reversible energy absorption device, wherein the irreversible energy absorption device is irreversibly deformed or destroyed if a predefined maximum pulling / bumping force is exceeded.

[0014] EP 1 732 798 B1 discloses a high-performance long-stroke friction coupling traction device arrangement for absorbing both trailing and traction loads that are applied to a central sleeper element of a railway vehicle during the assembly of a train and the rail operation of the train assembly, with a friction coupling mechanism having different pairs of plate elements and a wedge element to absorb heat energy generated during the closing of the friction coupling traction device arrangement.

[0015] US 3 150 782 A discloses a tensile and shock device for a towing coupling in which a hydraulic damper is connected in parallel to a plurality of compression springs in order to cushion tensile and shock forces simultaneously with the compression springs and the damper.

[0016] US 3 368 698 A discloses a pull and slam device for a towing coupling, in which a hydraulic damper is arranged parallel to a plurality of compression springs in the force flow, further comprising an additional return spring that acts on the damper housing to return the pull and slam device to its initial position.

[0017] US 3,447,693 A discloses a generic towing and impact device for a towing coupling with the features summarized in the preamble of claim 1. A hydraulic damper is arranged within a friction damping device parallel to a plurality of compression springs. A compression spring is arranged between a cup-shaped ram and the bottom of the housing forming the damping chamber to push the ram into its fully extended position.

[0018] In known embodiments, compression springs and dampers are connected in parallel to achieve a sufficiently large equivalent spring constant. The equivalent spring constant is the spring constant of the entire spring assembly, including the compression springs and the damper. Springs connected in series with the damper also compress simultaneously with the damper.

[0019] A disadvantage of the known designs is that, in practice, the damper's sealing system typically determines the service life of the tension and compression mechanism, as it is usually the first component to fail. Furthermore, the metal compression springs used are relatively stiff but are subject to settling, which leads to a change in the spring constant over time.

[0020] The present invention is based on the objective of providing a pulling and pushing device for a train coupling, in particular a central buffer coupling, which is characterized by a particularly long service life, whose spring constant remains as unchanged as possible over the service life and which can be manufactured cost-effectively, as well as being easy to use in different installation spaces even without additional spacers.

[0021] The problem according to the invention is solved by a pulling and buffer device for a train coupling, in particular a center buffer coupling, with the features of claim 1. The dependent claims describe advantageous and particularly expedient embodiments of the invention.

[0022] A draw and buffer device according to the invention for a train coupling, suitable for mechanically coupling two cars of a rail vehicle, particularly for a center buffer coupling, but also usable in a side buffer, for example as a long spring assembly in a side buffer, is characterized by a small housing, low weight and easy adaptability to various installation spaces without the need for comparatively heavy spacers. Preferably, for example, the housing described below and optionally other components of the draw and buffer device can be manufactured from sheet metal parts, which can be produced, for example, by stamping or flame cutting.By combining a hydraulic and / or pneumatic damper with a compression spring, preferably a polymer spring, the damper's sealing system is protected. This is because the vast majority of strokes occurring in practice are absorbed by the maintenance-free compression spring, particularly the polymer spring. Simultaneously, the oscillation behavior of the traction element is reduced by the smaller strokes of the compression spring and the force jump to the damper preload force at larger strokes.

[0023] In detail, a draw and buffing device according to the invention for a draw coupling, in particular a central buffer coupling, has a first connection for a coupling shaft and a second connection which is designed for fastening the draw and buffing device to a vehicle structure, for example to a vehicle frame or car body of a rail vehicle.

[0024] The tension and compression device according to the invention further comprises a spring assembly that transmits tensile and compressive forces between the first connection and the second connection. The spring assembly includes at least one compression spring, in particular exactly one compression spring, and at least one hydraulic and / or pneumatic damper, in particular exactly one hydraulic and / or pneumatic damper. The compression spring and the damper are arranged in series with each other in the force flow from the first connection to the second connection, so that compressive forces are transmitted from the compression spring to the damper.

[0025] According to the invention, the spring constant of the compression spring is smaller than the spring constant of the damper. The spring constant, also called spring stiffness, spring rate, spring constant, or simply constant, indicates the ratio of the force acting on a spring to the resulting deflection of the spring, i.e., in this case, the compression. By selecting different spring constants for the compression spring and the damper according to the invention, the damper is only effective at comparatively larger tensile and shock forces transmitted by the tension and shock device, whereas the compression spring is additionally effective if it is not already fully compressed at the higher forces, or only compresses at correspondingly smaller transmitted forces.

[0026] A minimum force is preferred for the initial compression of the damper; that is, a force at which the damper's compression begins, greater than a compressive force at which the compression spring is compressed by at least 50 percent, in particular at least 70 percent or at least 90 percent of its travel, or even greater than a compressive force at which the compression spring is compressed by 100 percent of its travel, i.e., is already fully compressed. This limits the damper's response or compression to the cases where the comparatively large force occurs, thus minimizing wear on the damper.

[0027] Preferably, the compression spring is made of plastic, in particular of a polymer. Such a plastic spring has a favorable spring characteristic and is subject to virtually no settling behavior.

[0028] According to one embodiment of the present invention, the damper or compression spring is pressurized via a first end-mounted pressure plate that is axially displaceable. Such a first pressure plate is held, for example, by a linear guide in a housing, as will be described below. The first pressure plate can further form one half of a stabilizing joint that causes the coupling shaft to return to its center position.

[0029] In the area of ​​the second connection, a second pressure plate can be provided against which the spring or damper is supported with its other axial end. The second connection is formed, for example, by a bracket in which the second pressure plate is arranged to be displaceable in the axial direction of the tension and compression device and, in particular, to be rotatable about a vertical axis of rotation. This makes the tension and compression device according to the invention particularly slim and cost-effective to manufacture.

[0030] The second console can, for example, form a linear guide for the second pressure plate, ensuring that the second pressure plate is guided axially.

[0031] The tension and impact device preferably comprises a housing that forms the first connection, particularly in the form of a receptacle for a coupling shaft bolt, and that forms the second connection, particularly in the form of a bracket, wherein the housing encloses the compression spring and the damper on at least two sides. For example, the housing has an upper chord and a lower chord arranged on both sides of the damper and the compression spring. The upper chord and the lower chord can be connected to each other, for example, by vertical components, particularly sheet metal components, and can also be manufactured as sheet metal components. It is particularly preferred if the housing is assembled entirely from sheet metal parts, particularly sheet metal plates, which enables cost-effective manufacturing and easy adaptation to different installation spaces.The sheet metal components can be manufactured, for example, by stamping or flame cutting, which is particularly cost-effective.

[0032] Particularly preferably, the first pressure plate has a free, at least substantially flat contact surface pointing towards the first connection, allowing free contact with a corresponding contact surface of the coupling shaft. This creates a stabilizing joint between the two contact surfaces. Because two at least substantially flat contact surfaces of the first pressure plate and the coupling shaft bear against each other in the pressure direction, advantageously pre-tensioned by the spring mechanism, the two at least substantially flat contact surfaces tilt relative to each other when the coupling shaft is deflected from its central position. This results in a restoring torque that returns the coupling shaft to its central position, i.e., to the fully axially aligned position.The preferably pressurized, yet free contact of the two at least essentially flat surfaces and the possibility of tilting the two at least essentially flat surfaces relative to each other thus represents a central return integrated into the pulling and pushing device.

[0033] The first pressure plate preferably has, in the axial direction towards the first connection, in addition to the illustrated, at least substantially flat contact surface, an end-face stop surface for at least one vehicle stop of a vehicle equipped with the coupling shaft. For example, the side with the contact surface and the stop surface is stepped, for example with a central projecting area that forms the flat contact surface, and with an outer area that surrounds the central area on both sides or completely, forming the at least one end-face stop surface.

[0034] The first connection is preferably formed, as described, by a receptacle for a coupling shaft pin, which is, for example, mounted in the housing in a fixed position and rotatably. The fixed arrangement does not preclude a small axial play, for example, a maximum of 1 cm in each axial direction, and in particular a maximum of 5 mm, 3 mm, 2 mm, or less. Alternatively, the coupling shaft pin can be displaceable within the housing, with the displacement preferably being limited in both axial directions. The displacement in the axial direction is then generally greater than half the diameter or the diameter of the coupling shaft pin.

[0035] A coupling according to the invention, in particular a central buffer coupling, has a coupling shaft which forms at least a substantially flat contact surface at its free end and which is pivotable about a vertical axis, as well as a pulling and pushing device according to the invention of the type shown, wherein the contact surface of the first pressure plate, in particular by the spring device, is subjected to a pressure force in the second axial direction, rests freely against the contact surface of the coupling shaft.

[0036] Thus, the coupling shaft can transmit the pressure forces, which are transmitted from one vehicle to another via the towing coupling, to the other vehicle via the first and second pressure plates and the intermediate spring assembly with compression spring and damper, which in particular alone form the spring assembly.

[0037] The invention will be described below by way of example with reference to embodiments and the figures.

[0038] They show: Figure 1: A three-dimensional representation of a draw and buffer device in a train coupling; Figure 2: The draw and buffer device from the Figure 1 with other components of the installation environment; Figure 3 the draw and buffer device from the Figure 1 in a horizontal top view; Figure 4 the draw and push mechanism from the Figure 3 with other components of the installation environment; Figure 5 the draw and buffer device from the Figure 1 in a vertical sectional view; Figure 6 a further embodiment of a pulling and pushing device according to the invention; Figure 7 the pulling and pushing device from the Figure 6 in a vertical sectional view; Figure 8 the draw and push device from the Figure 6 in a horizontal top view.

[0039] In the Figures 1 to 5Figure 1 shows an embodiment of a pulling and pushing device according to the invention, and further components of a pulling coupling according to the invention are shown in dashed lines. The pulling coupling has a coupling shaft 3 which is pivotally mounted in a housing 12 of the pulling and pushing device by means of a coupling shaft pin 14, so that it can pivot about a vertical axis 15. The housing 12 thus forms a first connection 1 for the coupling shaft 3 or its coupling shaft pin 14 with a receptacle 13, whereby tensile forces and compressive forces can be transmitted in opposite axial directions via the first connection 1.

[0040] The second connection 2 of the draw and buffer device, by which the draw and buffer device is attached to a vehicle structure, is formed by a bracket 9, which can be attached, for example, to a vehicle body or vehicle frame, in particular by bolting. The bracket 9 is part of the housing 12.

[0041] The draw and buffer device is arranged in a vehicle interface 16, for example UIC-530 vehicle interface, which is shown by a double dot dash line.

[0042] Vehicle stops 17 are provided in the area of ​​the first connection 1, which can transmit compressive forces to the draw and buffer device, as will be explained below. The tensile forces in the area of ​​the first connection 1, on the other hand, are transmitted via the coupling shaft bolt 14.

[0043] In the area of ​​the second connection 2, compressive and tensile forces are transmitted via a second pressure plate 8, which is pivotally mounted in the bracket 9, i.e., pivotable about a vertically oriented axis of rotation 10, with limited displacement in both axial directions. Alternatively, the second pressure plate 8 could also be rigidly connected to the bracket 20 or be formed by it, for example, as will be shown below with reference to a further embodiment and the Figures 6 to 8 is depicted.

[0044] In the housing 12, a first pressure plate 7 is mounted so as to be reciprocally displaceable in both axial directions. The first pressure plate 7 has a contact surface 7.1 facing the coupling shaft 3, which is at least substantially flat. The coupling shaft 3 rests against this contact surface with an end contact surface 3.1, which is at least substantially flat. Because the two contact surfaces 3.1 and 7.1, which are at least substantially flat, rest freely against each other and are pre-tensioned against each other by a spring device 4 arranged between the first pressure plate 7 and the second pressure plate 8, they can tilt relative to each other when the coupling shaft 3 is pivoted about the vertical axis 15 from its central position shown, thereby exerting a restoring force on the coupling shaft 3.

[0045] At the same time, it is avoided that lateral forces are transferred to the spring device 4.

[0046] The housing 12 is formed by a sheet metal structure and has an upper chord 18 and a lower chord 19, which are arranged parallel to each other and rigidly connected to each other by two vertical sheet metal plates 20. The sheet metal plate 20 located at the end of the upper chord 18 and the lower chord 19, together with a rear section of the upper chord 18 and the lower chord 19, forms the bracket 9.

[0047] The first pressure plate 7 is held in a linear guide 11 in the housing 12. For example, the linear guide 11 is formed by the upper belt 18 and the lower belt 19.

[0048] In the illustrated embodiment, the second pressure plate 8 is also guided in a linear guide 11 in the housing 12, namely in the area of ​​the console 9.

[0049] The spring assembly 4 is formed by a compression spring 5 and a hydraulic and / or pneumatic damper 6, wherein the compression spring 5 and the damper 6 are arranged in series in the direction of force flow from the first connection 1 to the second connection 2 and from the first pressure plate 7 to the second pressure plate 8, respectively. The compression spring 5 bears directly against an end face of the damper 6. The spring constants of the compression spring 5 and the damper 6 are such that when the first pressure plate 7 and the second pressure plate 8 are compressed, the compression spring 5 compresses first over a predetermined distance, for example, at least 50, 70, or 90 percent of its spring travel, before the damper 6 begins to compress.

[0050] In the Figure 2 Side stops 21 for the application of the compressive force are shown. The housing 12 is supported against these.

[0051] Because the housing 12 guides the two pressure plates 7, 8, fully accommodates the spring assembly 4, and forms the first connection 1 and the second connection 2, an extremely compact design is achieved. The design of the housing 12 allows for easy adaptation to different installation lengths.

[0052] In the exemplary embodiment according to the Figures 6 to 8An intermediate plate 22 is provided in the axial direction between the compression spring 5 and the damper 6. The intermediate plate 22 is fixedly mounted in the housing 12 in both axial directions, but preferably rotatable about a vertical axis of rotation to prevent lateral force from being introduced into the compression spring 5. The second pressure plate 8 is displaceable relative to the housing 12 and is formed by the bracket 9, but can also be pivotally connected to it. When the damper 6 compresses, the housing 12 moves, which is advantageously otherwise mounted according to the exemplary embodiment shown in the Figures 1 to 5 The assembly is designed, for example, from an upper chord 18, a lower chord 19, and at least two sheet metal plates 20, facing the console 9. In this embodiment, the coupling shaft bolt 14 can also be fixedly mounted in the housing 12 except for axial play.

[0053] In the design according to the Figures 6 to 8When tensile forces are transmitted by the tension and compression device, the damper 6 is not subjected to a compressive force, but only the compression spring 5. This allows the damper load to be further reduced.

[0054] When the coupling device is subjected to compression, the coupling shaft 3 presses the first pressure plate 7 against the console 9 via the compression spring 5, the intermediate plate 22, and the damper 6, so that compressive forces can be transmitted via the compression spring 5 and the damper 6. Under tensile stress, the coupling shaft 3 pulls the housing 12, and thus the intermediate plate 22, against the compressive force of the compression spring 5 and the first pressure plate 7 against the vehicle stops 13 via the coupling shaft bolt 14, so that the tensile force is absorbed. Simultaneously, the tensile force is transmitted to the console 9 via the damper 6 and / or, if applicable, a tie rod and the second pressure plate 8.

[0055] The damper 6 is also connected in series with the compression spring 5 and only responds to comparatively larger pressure shocks.

[0056] In both embodiments, the compression spring 5 can be designed, for example, as a polymer spring, and the damper 6 can be designed as a gas-hydraulic or fluid-elastomeric damper. If the damper preload is significantly higher than the spring preload, normal traction loads in both the tensile and compressive directions are absorbed by the spring 5, while the damper 6 only acts in the compressive direction for higher clutch shocks and during strong traction changes. This two-stage preload reduces load change reactions during driving. Reference symbol list

[0057] 1. First connection 2. Second connection 3. Coupling shaft 3.1. Contact surface 4. Spring assembly 5. Compression spring 6. Damper 7. First pressure plate 7.1. Contact surface 8. Second pressure plate 9. Console 10. Rotary axis 11. Linear guide 12. Housing 13. Mount 14. Coupling shaft bolt 15. Vertical axis 16. Vehicle interface 17. Vehicle stop 18. Upper chord 19. Lower chord 20. Sheet metal plate 21. Side stop 22. Intermediate plate

Claims

1. Coupler and drawgear device for a train coupling, in particular a centre buffer coupling, with a first connection (1) for a coupling shaft (3) and a second connection (2) designed to attach the traction and impact device to a vehicle structure; with a spring device (4) that transmits tensile forces and compressive forces between the first connection (1) and the second connection (2); wherein the spring device (4) comprises a compression spring (5) and a hydraulic and / or pneumatic damper (6); and the compression spring (5) and the damper (6) are arranged in series with each other in the force flow from the first connection (1) to the second connection (2), so that compressive forces are transmitted from the compression spring (5) to the damper (6); characterised in that a spring constant of the compression spring (5) is smaller than a spring constant of the damper (6), wherein a minimum force for initial deflection of the damper (6) is greater than a compressive force with which the compression spring (5) is deflected by at least 50 per cent, preferably at least 70 per cent or 90 per cent, of its spring travel.

2. Coupler and drawgear device according to claim 1, characterised in that a minimum force for initial deflection of the damper (6) is greater than a compressive force with which the compression spring (5) is deflected by 100 per cent of its spring travel.

3. Coupler and drawgear device according to one of claims 1 to 2, characterised in that the compression spring (5) is made of plastic, in particular of a polymer.

4. Coupler and drawgear device according to one of claims 1 to 3, characterised in that the damper (6) or the compression spring (5) is subjected to pressure via a first pressure plate (7) at the end that can be displaced in the axial direction.

5. Coupler and drawgear device according to claim 4, characterised in that a second pressure plate (8) is provided in the area of the second connection (2), on which the spring (5) or the damper (6) is supported with its other axial end.

6. Coupler and drawgear device according to claim 5, characterised in that the second connection (2) is formed by a bracket (9) in which the second pressure plate (8) is arranged so that it can be displaced in the axial direction and, in particular, rotated about a vertical axis of rotation (10).

7. Coupler and drawgear device according to claim 6, characterised in that the bracket (9) forms a linear guide (11) for the second pressure plate (8).

8. Pull and push device according to one of claims 1 to 7, characterised in that the pull and push device comprises a housing (12) which forms the first connection (1), in particular in the form of a receptacle (13) for a coupling shaft bolt (14), and which forms the second connection (2), in particular in the form of the bracket (9), wherein the housing (12) encloses the pressure spring (5) and the damper (6) on at least two sides.

9. Coupler and drawgear device according to claim 8, characterised in that the housing (12) is assembled from sheet metal parts, in particular sheet metal plates.

10. Coupler and drawgear device according to one of claims 4 to 9, characterised in that the first pressure plate (7) has a free, at least substantially flat contact surface (7.1) facing in the direction of the first connection (1) for free contact with a corresponding contact surface (3.1) of the coupling shaft (3).

11. Train coupling, in particular a centre buffer coupling, with a coupling shaft (3) which has an at least substantially flat contact surface (3.1) at its free end and which can be pivoted about a vertical axis (15), and with at least one coupler and drawgear device according to one of claims 1 to 10, wherein the contact surface (7.1) of the first pressure plate (7) is freely supported on the contact surface (3.1) of the coupling shaft (3) by the spring device (4) with a pressure force.