Automatic central buffer coupling with spring means

Abstract

The present invention relates to an automatic center buffer coupler (1) for a rail vehicle. The center buffer coupler (1) comprises a housing (2) for accommodating a hook disc (3) with a pivot axis (5) for pivoting the hook disc (3) at least between a coupled position and a decoupled position, and an actuator (8) with an actuating device (10) for pivoting the hook disc (3) into a decoupled position. The actuating device (10) comprises a spindle drive unit (11) driven by an electric motor (9). The spindle drive unit (11) is self-locking and arranged in the housing (2) such that it is axially movable opposite to the actuating direction (A), with at least one spring element (17) being provided which counteracts axial movement of the spindle drive unit (11).

Description

[0001] The present invention relates to an automatic center buffer coupler for a rail vehicle, comprising a housing for accommodating a hook disc with a pivot axis for pivoting the hook disc at least between a coupled position and a decoupled position, and an actuator with an actuating device for pivoting the hook disc into a decoupled position. The actuating device includes a spindle drive unit driven by an electric motor. The invention also relates to a freight rail vehicle equipped with such an automatic center buffer coupler.

[0002] The invention's field of application extends to railway vehicle technology. For coupling individual cars or train sections, the central buffer couplers of interest here are increasingly used; these couplers, arranged along the longitudinal axis of the car, represent a combination of buffer and coupling. Specifically, the present invention relates to a technical improvement of such a central buffer coupler of the Scharfenberg type, which is specially equipped with an electromechanical or electrohydraulic actuator as a means of automatic operation. The use of such electromechanical assemblies in railway vehicle technology results from the trend toward increasing electrification and digitalization. State of the art

[0003] German patent DE 10 2021 133 227 A1 describes an automatic train coupler for freight wagons of a rail vehicle. The train coupler consists of a coupler head comprising a coupler head housing and a coupling lock with a locking mechanism. The coupling lock consists of a coupling eye and a frog that is rotatable about a main axis. The frog has a jaw for receiving a coupling eye of a corresponding coupler head. An electrically, hydraulically, or pneumatically actuated uncoupling device is also provided, which can rotate the coupling lock from the coupled position to the uncoupled position. The uncoupling device can be located either entirely within the coupler head housing or within the coupler head housing and an attached coupling rod.

[0004] German patent application DE 10 2021 111 206 A1 describes an automatic train coupling with a coupling lock and a uncoupling device. The uncoupling device is designed as an electro-hydraulic unit and is arranged either within the coupling head housing or within the housing and an adjacent coupling rod. This design eliminates the need for additional protective devices and minimizes the installation space required for the uncoupling device. The uncoupling device comprises an electric motor, a pump, and at least one cylinder / piston unit connected to the frog. The electro-hydraulic drive unit can be coupled to either an external or an internal operating medium source. A locking mechanism can hold the frog in the uncoupled position, preventing rotation, while the uncoupling device blocks the frog from rotating from the uncoupled to the coupled position.

[0005] Recently, center buffer couplers of the type of interest here have been further developed for use in freight wagons, with the intention of using electrical energy for actuation. Therefore, unlike in passenger transport, the opening of the center buffer coupler should not be hydraulically operated. For this purpose, the electromechanical actuator of interest here is suitable, which uses a threaded drive to convert the rotary drive energy generated by an electric motor into a linear positioning motion.

[0006] A crucial factor is the so-called coupling prevention position, also known as buffer position or "prevent coupling." This is a position of the frog in the coupling designed to prevent unintentional re-engagement of both couplings. Due to the parallelogram of forces, only one of the two couplings needs to be in this position to block unintentional re-engagement. However, if the other coupling is in a different position than the coupling prevention position, the coupling eye experiences a high impact load on the coupling in the prevention position. This can lead to increased wear or even damage, resulting in a shortened service life and ultimately the failure of the center buffer coupling and, more importantly, the actuator.

[0007] The object of the present invention is to further improve an automatic central buffer coupling with actuator for releasing the mechanically coupled position, which reliably withstands high loads. Disclosure of the invention

[0008] The problem is solved starting from an automatic center buffer coupler according to the preamble of claim 1 in conjunction with its characterizing features. The following dependent claims specify advantageous embodiments of the invention. Claim 12 relates to a rail vehicle for freight transport which includes an automatic center buffer coupler according to the invention.

[0009] The invention includes the technical teaching that the spindle drive unit is designed to be self-locking and is arranged in the housing in such a way that it is axially movable against the direction of actuation, wherein at least one spring means is provided which counteracts an axial movement of the spindle drive unit.

[0010] The axial mobility of the spindle drive unit, combined with the spring element advantageously designed as a steel spring, compensates for hard impacts on the actuator to such an extent that the stresses encountered in freight transport applications, in particular, can be adequately absorbed. This means that these impact loads cannot lead to excessive wear or actuator failure. In this way, impact loads on the actuator are reduced in a simple manner. This results in a longer actuator lifespan and reduced wear on the components involved.

[0011] Advantageously, the spring element is arranged between the spindle drive unit and the actuator housing. Specifically, the spring element is positioned at one axial end of the spindle drive unit. This allows the spring element to be easily accommodated within the actuator housing. Furthermore, the design effort required to support the spindle drive unit against the spring element can be minimized.

[0012] Preferably, the spring element, which is made of steel, comprises at least one disc spring. Using disc springs allows for a wide range of spring force-to-displacement characteristics. Furthermore, a disc spring exhibits high load-bearing capacity with a small displacement. A disc spring also makes it possible to minimize the space required for the spring. Thus, a disc spring can absorb the high loads occurring during such an impact on the coupling eye in a space-saving manner.

[0013] According to a further improvement of the invention, it is proposed that the spring element be designed as a disc spring assembly. In such a disc spring assembly, several individual disc springs are connected in series. Such a disc spring assembly offers the possibility of variably designing the spring travel and spring force. Despite this, such a disc spring assembly can also be arranged in a space-saving manner.

[0014] In an alternative embodiment, the spring element is designed as an elastomer spring. Unlike a steel spring, such an elastomer spring is made of an elastomer material. This elastomer material prevents the spring element from breaking. As a result, the elastomer spring achieves a high level of safety and reliability. Furthermore, such an elastomer spring provides damping, thus better decoupling the housing of the center buffer coupling from the spindle drive unit.

[0015] In a further advantageous embodiment, the elastomer spring is preferably designed as a rubber-metal component. Compared to an elastomer spring without metal, the combination with metal results in improved force transmission and distribution within the elastomer material. This improved transmission and distribution reduces force peaks in the transmission area, thus further enhancing the durability of the elastomer spring. The more uniform force distribution within the elastomer material allows for more efficient use of the material, enabling a more compact design compared to an elastomer spring without metal.

[0016] According to a preferred embodiment of the invention, the spring element is arranged at the end of the spindle drive unit facing away from the hook disc, and the spring element is designed as a compression spring. By arranging the spring element at one end of the spindle drive unit, the spindle drive unit can remain essentially unchanged in order to introduce the axial force into the spring element. A spring element arranged in this way can thus be more easily integrated into an existing concept of a center buffer coupling.

[0017] To provide a smaller and therefore more compact electric motor, the electric motor is preferably coupled to the spindle drive unit via a spur gear transmission. This creates a gear reduction between the spindle drive unit and the electric motor, thus reducing the torque that the electric motor has to generate. As a result, the electric motor can be made smaller.

[0018] Preferably, the spindle drive unit is designed with a trapezoidal thread. In a trapezoidal thread, the threads form the shape of an equilateral trapezoid. The threads are therefore thicker than those with a triangular profile. Such threads are suitable for transmitting large axial forces before shearing failure. A spindle drive unit of this type can thus generate a high force for decoupling the center buffer coupling. Furthermore, such a spindle drive unit can prevent damage caused by shock loads.

[0019] In an alternative embodiment, the spindle drive unit is designed as a ball screw drive. By using a ball screw drive, as opposed to a spindle drive unit without balls, friction within the spindle drive unit can be significantly reduced. This allows for a lower-power electric motor, which can therefore be smaller and thus lighter. However, this requires a motor brake that prevents coupling without motor input, and also in a normally closed configuration (i.e., it closes when no current is applied, thus maintaining torque and consequently force). Detailed description based on drawing

[0020] Further measures improving the invention are described in more detail below, together with a description of the preferred embodiments, with reference to the figures. The figures show: Fig. 1 a side view of an opened housing of the center buffer coupling with internal hook disc and an electromechanical actuator, Fig. 2 an enlarged view of the electromechanical actuator according to Figure 1 in a first embodiment, and Fig. 3 an enlarged view of the electromechanical actuator in a second embodiment.

[0021] According to Fig. 1An automatic center buffer coupler 1 of Scharfenberg design essentially comprises a hook disc 3 housed in a casing 2, for switching between a coupled and a decoupled position. The hook disc 3 is mounted via a main bolt 4 as a pivot axis 5. A coupling eye 6 serves as an actuating plunger, which is also articulated to the hook disc 3 via a coupling eye bolt 7, with an axial distance to the main bolt 4. The hook disc 3 also interacts with an electromechanical actuator 8 for releasing the coupler in automatic operation.

[0022] The electromechanical actuator 8 essentially comprises an electric motor 9 and an actuating device 10, wherein the actuating device 10 includes a spindle drive unit 11 driven by the electric motor 9. In the illustrated embodiment, the spindle drive unit 11 is self-locking. To generate a transmission, a spur gear 13 is provided between the electric motor 9 and a spindle 12 of the spindle drive unit 11. The drive rotary motion of the electric motor 9 displaces a spindle nut 14 arranged on the spindle 12 in the axial direction, so that a pressure tube 15 arranged on the spindle nut 14 performs a linear movement. The pressure tube 15 rests at its end against a roller bearing 16 formed by the hook disc 3 for support opposite the hook disc 3. To pivot the hook disc 3 into a decoupled position, the pressure tube 15 acts on the hook disc 3 in an actuating direction A.

[0023] In a coupling obstruction position of the hook disc 3 (not shown here), it is possible that a coupling eye 6 of a center buffer coupler 1 of another wagon may strike the hook disc 3. To prevent damage to the actuator 8, a spring element 17 is provided, which counteracts axial movement of the spindle drive unit 11. In the illustrated embodiment, the spring element 17 is arranged between the spindle drive unit 11 and an actuator housing 19 of the electromechanical actuator 8. The spindle drive unit 11 can thus perform a resilient axial movement, so that a force opposite to the direction of actuation A does not lead to damage to the actuator 8.

[0024] An enlarged view of the electromechanical actuator 8 with the spring element 17 after Figure 1 in a first embodiment, is in Figure 2shown. In this figure, the spring element 17 is shown enlarged. The spring element 17, designed as a disc spring, is arranged at an axial end of the spindle drive unit 11 in the illustrated embodiment. A second embodiment of the actuator 8 is shown in Figure 3 As shown in the figure, an elastomer spring is used for the spring element 17 instead of a disc spring 17. The elastomer spring 17 is designed as a rubber-metal component, which is arranged at one axial end of the spindle 12, between the actuator housing 19 and the spindle 12.

[0025] In embodiments not shown, the spring element 17 can also be designed, for example, as a tension spring. Likewise, the spring element 17 can be arranged laterally to the spindle drive unit 11 instead of at an axial end. REFERENCE MARK LIST

[0026] 1 Center buffer coupling 2 Housing 3 Hook washer 4 Main bolt 5 Swivel shaft 6 Coupling eye 7 Coupling eye bolt 8 Actuator 9 Electric motor 10 Actuating device 11 Spindle drive unit 12 Spindle 13 Spur gear 14 Spindle nut 15 Pressure tube 16 Roller bearing 17 Spring element 19 Actuator housing A Actuating direction

Claims

1. Automatic intermediate buffer coupler (1) of a rail vehicle, comprising a housing (2) for accommodating a hook disc (3) with a pivot axis (5) for pivoting the hook disc (3) at least between a coupled position and a decoupled position, and an actuator (8) with an actuating device (10) for pivoting the hook disc (3) into a decoupled position, wherein the actuating device (10) comprises a spindle drive unit (11) driven by an electric motor (9), characterized by the fact that the spindle drive unit (11) is designed to be self-locking and is arranged in the housing (2) in such a way that it is axially movable against the direction of actuation (A), wherein at least one spring means (17) is provided which counteracts an axial movement of the spindle drive unit (11).

2. Automatic center buffer coupling (1) according to claim 1, characterized by the fact that the spring element (17) is designed as a steel spring.

3. Automatic center buffer coupling (1) according to claim 2, characterized by the fact that the spring element (17) consisting of steel comprises at least one disc spring.

4. Automatic center buffer coupling (1) according to claim 3, characterized by the fact that the spring element (17) is designed as a disc spring assembly.

5. Automatic center buffer coupling (1) according to claim 1, characterized by the fact that the spring element (17) is designed as an elastomer spring.

6. Automatic center buffer coupling (1) according to claim 5, characterized by the fact that The elastomer spring is designed as a rubber-metal part.

7. Automatic center buffer coupling (1) according to one of the preceding claims, characterized by the fact that the spring means (17) is arranged at the end of the spindle drive unit (11) facing away from the hook disc (3), wherein the spring means (17) is designed as a compression spring.

8. Automatic center buffer coupling (1) according to one of the preceding claims, characterized by the fact thatthe electric motor (9) is coupled to the spindle drive unit (11) via a spur gear transmission (13).

9. Automatic center buffer coupling (1) according to one of the preceding claims, characterized by the fact that the spindle drive unit (11) is designed with a trapezoidal thread.

10. Automatic center buffer coupling (1) according to one of the preceding claims, characterized by the fact that the spindle drive unit (11) is designed as a ball screw drive.

11. Automatic center buffer coupling (1) according to one of the preceding claims, characterized by the fact that which is constructed according to the Scharfenberg method.

12. Rail vehicle for freight transport, comprising an automatic central buffer coupler (1) according to one of the preceding claims.

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