Measuring unit for a vehicle combination as well as vehicle combinations with this measuring unit

Abstract

Measuring unit for a vehicle combination (1) consisting of a towing vehicle (2) and a transport device (3), wherein the transport device (3) can be positively connected to a trailer coupling device (4) of the towing vehicle (1) by attaching a drawbar (5) of the transport device (4) to a coupling head (7) of the trailer coupling device (4), and wherein the transport device (3) has a breakaway device (6) that can be attached to a fastening device (8) of the transport device (3) and to a fastening device (9) of the towing vehicle (2), characterized in that the measuring unit determines the impedance at at least one measuring point (11, 12) electrically connected to the fastening device (9) of the towing vehicle (2) for the breakaway device (6) and / or to the fastening device (8) of the transport device (3) for the breakaway device (6).

Description

[0001] The invention relates to a measuring unit for a vehicle combination according to the preamble of claim 1.

[0002] Vehicles often come equipped with a tow hitch or trailer coupling as optional equipment or as a retrofitted accessory. This allows for the attachment of transport devices such as cargo carriers, car trailers, bicycle carriers, boat trailers, horse trailers, or caravans. The resulting vehicle combination, consisting of the towing vehicle and the attached transport device, can be used for a variety of purposes, depending on the specific transport device.

[0003] When attaching the transport device to the towing vehicle, it must be ensured that the attachment process has been carried out correctly. This includes a secure connection of the drawbar of the transport device to the towing device or coupling of the towing vehicle and the attachment of a breakaway device in the form of a safety cable or breakaway cable, preferably to a designated eyelet on the towing vehicle.

[0004] During the journey of the vehicle combination consisting of the towing vehicle and transport device, it can happen that the transport device detaches from the towing vehicle, especially if it was not correctly attached to the towing vehicle's trailer hitch or coupling. In this case, the parking brake of the transport device should be applied using a correctly attached breakaway cable.

[0005] From DE 10 2022 104 351 A1, a method for determining the presence of a trailer connection between the towing vehicle and the trailer is known. This method uses measurements of the impedance, resistance, conductivity, or other electrical properties between contacts of the vehicle connector between the towing vehicle and the trailer to verify whether a trailer is connected to the towing vehicle.

[0006] Furthermore, WO 2004 / 078519 A1 discloses a detection device for distinguishing between the coupled and uncoupled states of a tractor and a trailer. A test signal is generated by means of a signal generator, and the change in impedance that occurs between a trailer connected to the tractor and a trailer disconnected from the tractor is detected by means of a monitoring device.

[0007] The invention is based on the objective of providing a measuring unit for a vehicle combination according to the preamble of claim 1, which enables a reliable determination of the functional state of the vehicle combination in a simple manner.

[0008] This problem is solved according to the invention by a measuring unit for a vehicle combination with the features listed in claim 1.

[0009] Advantageous further developments of the measuring unit according to the invention for a vehicle combination are part of the further patent claims.

[0010] The measuring unit according to the invention for a vehicle combination consisting of a towing vehicle and a transport device determines the impedance at at least one measuring point electrically connected to the fastening device of the towing vehicle for the breakaway device or to the fastening device of the transport device for the breakaway device.

[0011] The at least one measuring point can therefore be formed directly on the fastening device for the breakaway device provided on the towing vehicle, for example on an eyelet of the towing vehicle's trailer hitch for attaching the breakaway device, or the at least one measuring point can be formed on a body part of the towing vehicle connected to the fastening device for the breakaway device provided on the towing vehicle, or the at least one measuring point can be formed directly on the fastening device for the breakaway device provided on the transport device, or the at least one measuring point can be formed on a component of the transport device connected to the fastening device for the breakaway device provided on the transport device.

[0012] With correct connection of the transport device to the trailer hitch by attaching a drawbar of the transport device to a coupling head of the towing vehicle's trailer hitch, and with correct connection of the breakaway device to the mounting device on the towing vehicle (e.g., to the body of the towing vehicle or to an eyelet in the towing vehicle's trailer hitch), at least one measuring point is electrically connected to the towing vehicle's trailer hitch and to the breakaway device. Since, in this case, the at least one measuring point lies in a closed circuit formed by the trailer hitch with its coupling head, the drawbar of the transport device, and the breakaway device, the low-resistance connection at the respective measuring point results in a low impedance, typically in the kiloohm range.

[0013] If the transport device is not correctly connected to the towing vehicle's coupling device and / or if the breakaway device is not correctly, faultily, or is missing, the circuit formed by the coupling device's coupling head, the transport device's drawbar, and the breakaway device is not closed. At least one measuring point is therefore located in an open circuit, resulting in a high impedance, typically in the megaohm range, due to the high-resistance connection at that measuring point.

[0014] Thus, according to the invention, by determining the impedance at the at least one measuring point in the circuit formed by the trailer hitch with the coupling head, the drawbar of the transport device, and the breakaway device, and in particular by an evaluation circuit of the measuring unit, it is possible to distinguish whether the breakaway device is correctly attached to the towing vehicle or not. In particular, depending on this, a corresponding status message can also be issued to the driver of the towing vehicle, especially in the case that the breakaway device is not attached to the towing vehicle or is not correctly attached. This status message can be issued, for example, visually, audibly, or haptically, for example, by means of a signal tone, a status indicator, or a warning message, such as a warning that the breakaway device is not attached to the towing vehicle or is not correctly attached.

[0015] In a further preferred embodiment of the invention, the impedance at the at least one measuring point is determined by the measuring unit relative to a reference potential, i.e., in particular relative to the vehicle mass of the towing vehicle.

[0016] The measuring unit can be located either in the towing vehicle or in the transport device of the vehicle combination consisting of a towing vehicle and a transport device. If the measuring unit is located in the transport device, it transmits a corresponding status message about the condition of the breakaway device connection to the towing vehicle in a suitable manner, in particular as an electrical signal, an optical signal, or an acoustic signal.

[0017] The activation of the measuring unit for determining the impedance at the at least one measuring point can be carried out in different ways. For example, the measuring device can be activated to start the impedance measurement by a data signal generated during electrical contact when a transport device is connected to the trailer hitch of the towing vehicle and the drawbar of the transport device is connected to the coupling head of the towing vehicle via the socket of the towing vehicle's trailer hitch. Additionally or alternatively, the connection of a transport device to the trailer hitch of the towing vehicle can be detected by an optical unit of the vehicle combination, in particular camera-based by evaluating the data from a camera, and the measuring unit for determining the impedance at the at least one measuring point can be activated accordingly.Additionally or alternatively, the connection of a transport device to the trailer coupling of the towing vehicle can also be activated by operating a control element of the towing vehicle, in particular by operating a switch or a control lever or a button by a user of the towing vehicle.

[0018] In a further preferred embodiment of the invention, the measuring unit determines reference values ​​for the impedance at the at least one measuring point for different transport devices connected to the towing vehicle by performing frequency-dependent measurement series. In these measurement series, the impedance resulting from the application of alternating current at the at least one measuring point is determined for different transport devices, both for a transport device correctly connected to the towing vehicle and for a transport device incorrectly connected to the towing vehicle. The corresponding measured values ​​from the measurement series can then be stored in the towing vehicle and used as reference values ​​when connecting a corresponding transport device.

[0019] Preferably, the measuring unit determines the impedance at two measuring points, one of which is conductively connected to the towing vehicle's mounting device for the breakaway device, and the other of which is electrically connected to the towing vehicle's trailer hitch. The two measuring points can also be isolated from the towing vehicle's reference potential, i.e., in particular, from the towing vehicle's chassis ground. In the event of an incorrect connection of the transport device to the towing vehicle's trailer hitch and / or an incorrect or missing connection of the breakaway device to the towing vehicle, the two measuring points are galvanically isolated, resulting in a high impedance between them, typically in the megaohm range.If the transport device is correctly connected to the towing vehicle's hitch and the breakaway device is correctly attached to the towing vehicle, the two measuring points are galvanically connected, resulting in a low impedance between them, typically in the kiloohm range. By evaluating the impedance between these two measuring points, it can be determined whether the breakaway device is correctly attached to the towing vehicle or not.

[0020] In a further preferred embodiment of the invention, the measuring unit includes an evaluation unit for evaluating the measurement results of the impedance measurement and thus for differentiating between cases where the transport device is correctly connected to the trailer hitch of the towing vehicle and / or the breakaway device is correctly connected to the towing vehicle, or where the transport device is incorrectly connected to the trailer hitch of the towing vehicle and / or the breakaway device is incorrectly or missingly connected to the towing vehicle. This evaluation unit of the measuring unit is preferably designed as a control unit of the towing vehicle.

[0021] A breakaway cable, a breakaway line or a breakaway chain can be provided as a breakaway safety device to be installed between the transport device and the trailer coupling of the towing vehicle in the vehicle combination.

[0022] The transport device to be coupled to the trailer hitch of the towing vehicle in a vehicle combination can in particular be a bicycle carrier, a vehicle trailer, a horse trailer, a boat trailer or a caravan.

[0023] In a vehicle combination consisting of a towing vehicle and a transport device, the measuring unit according to the invention can advantageously and reliably detect the correct connection of the breakaway cable of the transport device to the towing vehicle, which is necessary for the safe operation of the vehicle combination. Furthermore, the detachment of a transport device coupled to the towing vehicle can also be detected at an early stage, even while the vehicle combination is in motion.

[0024] An embodiment of the invention is described below. The following is shown: Fig. 1 a schematic representation of a vehicle combination consisting of a towing vehicle and trailer; Fig. 2 a detailed representation of the connection between a towing vehicle and a coupled trailer; Fig. 3 a schematic representation of an electrical circuit in a connection between a towing vehicle and a coupled trailer and Fig. 4 A schematic representation of an electrical circuit when the connection between a towing vehicle and a coupled trailer is disconnected.

[0025] The exemplary embodiments described below are preferred embodiments of the invention. In these exemplary embodiments, the described components each represent individual features of the invention, which are to be considered independently of one another and which further develop the invention independently. Therefore, the disclosure is intended to include combinations of features of the embodiments other than those shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described. Thus, the invention also includes combinations of features of the described embodiments. The invention therefore also includes realizations that each exhibit a combination of features from several of the described embodiments, provided that the embodiments have not been described as mutually exclusive.

[0026] In the figures, functionally identical elements are each provided with the same reference symbols.

[0027] In one of the Fig. In the schematically depicted vehicle combination 1, consisting of a towing vehicle 2 and a transport device 3 coupled to the towing vehicle 2, this transport device 3 is, for example, designed as a vehicle trailer. This vehicle trailer 3 is connected to the trailer hitch 4 of the towing vehicle 2 by means of the drawbar 5.

[0028] As in the Fig. As can be seen in Figure 2, the drawbar 5 of the vehicle trailer 3 is attached to the coupling head 7 of the trailer hitch 4 of the towing vehicle 2. Furthermore, a breakaway device 6 of the vehicle trailer 3, attached to a fastening device 8 on the vehicle trailer 3 and designed, for example, as a breakaway cable, is provided, which is also to be attached to a fastening device 9 of the trailer hitch 4 of the towing vehicle 2, designed, for example, as a fastening eye.

[0029] At the start of the journey of vehicle combination 1, consisting of towing vehicle 2 and trailer 3, and also during the journey of vehicle combination 1, the correct connection of the breakaway cable 6 of trailer 3 to the towing vehicle 2 is checked. This check of the correct connection of the breakaway cable 6 of trailer 3 to the towing vehicle 2 is carried out during the journey of vehicle combination 1, either continuously or at specific intervals.

[0030] For this purpose, a measuring unit, arranged, for example, in the towing vehicle 2 of the vehicle combination 1, is provided with an evaluation unit, designed, for example, as a control unit of the towing vehicle 2 of the vehicle combination 1. The measuring unit determines the frequency-dependent impedance at, for example, two measuring points 11, 12.

[0031] According to the Fig. 3 and the Fig. Figure 4 shows that the first measuring point 11 is provided on the fastening device 9 of the breakaway cable 6 on the trailer coupling 4 of the towing vehicle 2 of the vehicle combination 1 and the second measuring point 12 is provided on a component of the trailer coupling 4 of the towing vehicle 2 of the vehicle combination 1 connected to the coupling head 7 of the trailer coupling 4 of the towing vehicle 2 of the vehicle combination 1.

[0032] First, measurement series are performed for the frequency-dependent impedance between the two measuring points 11, 12 at different excitation frequencies for different vehicle trailers as transport device 3. The resulting measured values ​​are then determined and stored for both correctly connected vehicle trailers as transport device 3 and for incorrectly connected vehicle trailers as transport device 3. For example, these measured values ​​of the frequency-dependent impedance between the two measuring points 11, 12, obtained from the measurement series, are stored in the measuring unit and, in particular, in the evaluation unit, which is designed as the control unit of the towing vehicle 2 of the vehicle combination 1.

[0033] In accordance with the Fig. When the trailer 3, as shown in Figure 3, is correctly attached to the coupling device 4 of the towing vehicle 2 of the vehicle combination 1, and thus the drawbar 5 of the trailer 3 is correctly coupled to the coupling head 7 of the coupling device 4, and the breakaway cable 6 is correctly attached to the fastening device 9, a closed circuit 10 is formed, thus establishing a galvanic connection between the two measuring points 11 and 12. This results in a low-resistance, frequency-dependent impedance between the two measuring points 11 and 12, for example, a frequency-dependent impedance in the kiloohm range.

[0034] In accordance with the Fig.If the vehicle trailer 3 shown in Figure 4 is not, or not correctly, attached to the trailer hitch 4 of the towing vehicle 2, and thus if the drawbar 5 of the vehicle trailer 3 is not correctly coupled to the coupling head 7 of the trailer hitch 4, or if the breakaway cable 6 is not correctly attached to the mounting device 9, an interruption 13 is created in the circuit 10, thereby establishing galvanic isolation between the two measuring points 11 and 12. This results in a high-impedance, frequency-dependent impedance between the two measuring points 11 and 12, for example, a frequency-dependent impedance in the megaohm range.

[0035] By comparing the frequency-dependent impedance measurements obtained and stored from measurement series with the currently measured frequency-dependent impedance measurements, an incorrect, faulty, or missing connection of the trailer 3 to the trailer hitch 4 of the towing vehicle 2 can be detected. In particular, if an incorrect, faulty, or missing connection of the trailer 3 to the trailer hitch 4 of the towing vehicle 2 is detected, the driver of the towing vehicle 2 can be warned. For example, the driver of the towing vehicle 2 can be warned by means of acoustic, visual, and / or haptic warning signals. Reference symbol list 1 vehicle combination 2 Towing vehicle 3 trailers 4 Towing hitch 5 drawbar 6 Breakaway cables as breakaway protection 7 Coupling head 8. Attaching the breakaway cable to the trailer 9. Attaching the breakaway cable to the towing vehicle 10 circuits 11 first measuring point 12 second measuring point 13. Circuit breaker QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2022 104 351 A1

[0005] WO 2004 / 078519 A1

[0006]

Claims

[1] Measuring unit for a vehicle combination (1) consisting of a towing vehicle (2) and a transport device (3), wherein the transport device (3) can be positively connected to a trailer coupling device (4) of the towing vehicle (1) by attaching a drawbar (5) of the transport device (4) to a coupling head (7) of the trailer coupling device (4), and wherein the transport device (3) has a breakaway device (6) that can be attached to a fastening device (8) of the transport device (3) and to a fastening device (9) of the towing vehicle (2), characterized by , that the measuring unit determines the impedance at at least one measuring point (11, 12) electrically connected to the fastening device (9) of the towing vehicle (2) for the breakaway device (6) and / or to the fastening device (8) of the transport device (3) for the breakaway device (6). [2] Measuring unit according to claim 1, characterized by, that the measuring unit determines the impedance at at least one measuring point (11, 12) in a circuit (10) formed from the trailer device (4) with the coupling head (7), from the drawbar (5) of the transport device (3) and from the breakaway device (6). [3] Measuring unit according to claim 1 or 2, characterized by , that the measuring unit determines the impedance at the at least one measuring point (11, 12) relative to the reference potential. [4] Measuring unit according to any one of claims 1 to 3, characterized by , that the measuring unit is provided in the transport device (3), wherein the measuring unit transmits a status message to the towing vehicle (2) electrically, optically or acoustically via a connection of the breakaway device (6). [5] Measuring unit according to any one of claims 1 to 4, characterized by, that the measuring unit for determining the impedance at the at least one measuring point (11, 12) can be activated by electrical contacting the transport device (3) with the towing vehicle (2) when the transport device (3) is connected to the trailer coupling (4) of the towing vehicle (2) and / or can be activated by an optical unit of the vehicle combination (1) for detecting a connection of a transport device (3) to the trailer coupling (4) of the towing vehicle (2), and / or can be activated by actuating a control element of the towing vehicle (2). [6] Measuring unit according to any one of claims 1 to 5, characterized by , that the measuring unit performs frequency-dependent measurement series for different transport devices (3) connected to the towing vehicle (2) to determine reference values ​​for the impedance at the at least one measuring point (11, 12). [7] Measuring unit according to any one of claims 1 to 6, characterized by, that the measuring unit determines the impedance between two measuring points (11, 12), one of which is electrically connected to the fastening device (9) of the towing vehicle (2) for the breakaway device (6) and one of which is electrically connected to the trailer device (4) of the towing vehicle (2). [8] Measuring unit according to any one of claims 1 to 7, characterized by , that the measuring unit has an evaluation unit designed as a control unit of the towing vehicle (2). [9] Vehicle combination (1) with a measuring unit according to one of claims 1 to 8, characterized by , that the breakaway device (6) is designed as a breakaway rope or breakaway cord or breakaway chain. [10] Vehicle combination (1) with a measuring unit according to one of claims 1 to 9, with a towing vehicle (2) and with a transport device (3) designed as a bicycle carrier or as a vehicle trailer or as a horse trailer or as a boat trailer or as a caravan..

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