Trailer for a motor vehicle

Abstract

Trailer for a motor vehicle, with a frame (12) for transporting payloads, a shaft rotatably mounted on the frame (12), wherein the shaft is connected to a wheel (18) that can be supported on a base, an electrical machine (22) coupled to the shaft for generating electrical energy from the rotation of the shaft, a battery (24) that can be charged by the electric machine (22) and a charging station (26) that is electrically connected to the battery (24) for charging an electrically powered motor vehicle, wherein the charging station (26) has a charging plug (28) electrically connected via a charging cable (30) for insertion into a charging socket of the electrically powered motor vehicle, wherein a cable length of the charging cable (30) is greater than a longitudinal extent of the frame (12).

Description

[0001] The invention relates to a trailer for a motor vehicle, with the help of which the motor vehicle used as a towing vehicle can transport an additional payload.

[0002] From US 2007 / 051542 A1, a trailer for a motor vehicle is known in which an electric machine designed as an emergency power generator for electrical consumers can be driven as a generator by a shaft rigidly connected to wheels while driving, in order to charge a battery of the emergency power generator.

[0003] From DE 10 2017 121 794 A1, a trailer that can be mechanically and electrically coupled to a motor vehicle is known, comprising a rechargeable battery and an electric machine that can be operated in generator mode and is connected to the battery, which can recuperate braking energy during deceleration in order to power the motor vehicle with the recuperated electrical energy.

[0004] From DE 10 2018 129 905 A1 a transport vehicle for transporting stationary charging stations on a trailer is known, which can be electrically powered from the residual charge state of the transported charging stations.

[0005] There is a constant need to improve the usability of purely electric vehicles.

[0006] The purpose of the invention is to demonstrate measures that enable good usability of electric motor vehicles.

[0007] The problem is solved according to the invention by a pendant having the features of claim 1. Preferred embodiments of the invention are specified in the dependent claims and the following description, each of which can individually or in combination represent an aspect of the invention.

[0008] One aspect concerns a trailer for a motor vehicle, comprising a frame for transporting payloads, a shaft rotatably mounted on the frame, the shaft being connected to a wheel supported on a ground, an electric machine coupled to the shaft for generating electrical energy from the rotation of the shaft, a battery rechargeable by the electric machine, and a charging station electrically connected to the battery for charging an electrically powered motor vehicle, the charging station having a charging plug electrically connected via a charging cable for insertion into a charging socket of the electrically powered motor vehicle, wherein the length of the charging cable is greater than the longitudinal extent of the frame.

[0009] When the trailer is coupled to a motor vehicle used as a towing vehicle, particularly a passenger car, the electric machine can generate electrical energy while the motor vehicle is in motion. Operating in generator mode, the electric machine can convert mechanical energy from the rotation of the wheel and the axle attached to the wheel into electrical energy and store it in the rechargeable battery. The charging station can then use the electrical energy stored in the rechargeable battery to charge an electrically powered motor vehicle, particularly a purely electric vehicle.

[0010] This system utilizes the understanding that an electric vehicle whose battery discharges to the point of stalling typically requires towing to a stationary charging station to recharge and resume use. However, the integrated charging station in the trailer eliminates the need to transport the stranded electric vehicle to a charging station. Instead, the mobile charging station, brought to the stranded vehicle, is transported directly to the stranded electric vehicle. This allows the electric vehicle to be recharged on-site without the need for a cumbersome, expensive, and time-consuming towing. This significantly reduces the impact on the electric vehicle's usability when it breaks down due to a discharged battery.

[0011] Even with limited coverage and / or availability of stationary charging stations, and / or an inaccurate assessment of the electric vehicle's energy consumption and the associated electric range, the vehicle's usability can be maintained and / or any impairment of usability can be reduced. Furthermore, it is possible that the electrical energy stored in the battery will increase during the journey to the stranded electric vehicle, thus ensuring a sufficiently high charge level for charging the vehicle.Furthermore, the battery of the electric vehicle, which is discharged after charging, can be at least partially recharged upon returning to a starting point. This reduces the amount of external energy required to charge the trailer's battery for the charging station, assuming any external energy is needed at all. The charging station, connected to the battery that can be charged while driving, allows for quick and cost-effective charging of a stranded electric vehicle without the need for towing, thus enabling the usability of electric vehicles even in regions with a limited availability of stationary charging stations.

[0012] The charging station has a charging plug, electrically connected via a charging cable, for insertion into a charging socket of the electric vehicle. The cable length of the charging cable is greater than the longitudinal extent of the frame, in particular greater than two or four times the longitudinal extent of the frame. The cable length can thus be dimensioned such that a stranded electric vehicle can still be charged by the charging station even when the trailer, coupled to the towing vehicle, is positioned in front of and / or behind the stranded electric vehicle in the direction of travel. This allows for easy charging even in situations where the stranded electric vehicle is difficult to access.Difficult parking maneuvers to position the charging station attached to the trailer as close as possible to a charging point of the stranded electric vehicle can be avoided.

[0013] The frame can, in particular, have a rectangular support frame to which a drawbar, preferably designed as a V-shaped drawbar, is connected, allowing the trailer to be coupled to the motor vehicle used as the towing vehicle. Preferably, in addition to the installation space provided for the electric motor, the battery, and the charging station, a further storage area remains on the frame to allow for the transport of additional payloads. Particularly preferably, the electric motor, the battery, and the charging station are arranged substantially centrally to a rotational axis of the shaft, so that a tilting moment acting on the rotational axis of the shaft, caused by the weight of the electric motor, the battery, and the charging station, can be minimized.For example, it is possible to have two wheels located on opposite sides of the frame, connected to each other via a common shaft, so that the shaft can form a rotor of the electric machine or be coupled to a rotor shaft of the electric machine, particularly one arranged parallel to the axle. Alternatively, the wheels can be rotatably mounted on a fixed axle and / or axle stub of the frame, with the electric machine of at least one wheel designed as a wheel hub drive driven by the axle of the respective wheel in generator mode. Preferably, each wheel has its own electric machine designed as a wheel hub drive, which is connected to the battery, in particular via electrical cables.The electric motor can also be operated in motor mode, allowing the trailer's wheels to be driven by the electric motor powered by the battery. This makes it possible, for example, to move the trailer when uncoupled from the towing vehicle using a specially designed control unit, particularly for parking. The battery is electrically connected to a charging socket for recharging it via a stationary power grid. This allows the battery to be charged not only while driving, but also when the trailer is not in use and awaiting its next deployment.

[0014] The charging station can be specifically designed for charging electrically powered vehicles, such as hybrid and pure electric vehicles. For this purpose, the charging station can provide a correspondingly high charging current and / or a correspondingly high charging voltage. The charging station mounted on the frame can therefore meet all requirements and standards that also apply to stationary charging stations referred to as "electric vehicle charging stations." The charging station preferably features a fast-charging mode, in which charging takes place with a charging power of 20–180 kW and / or up to a charge level of approximately 80% of the maximum charging capacity of the vehicle battery being charged, so that the electric vehicle can be sufficiently charged within approximately 30 minutes to travel a considerable distance under its own power.

[0015] In particular, at least one solar cell electrically connected to the battery is provided for generating electrical energy from sunlight. This allows the battery to be additionally charged by sunlight. This utilizes the fact that the mobile charging station, transported by trailer, is not located in a shaded building, but rather, at least on its way to a stranded electric vehicle, is outside of buildings and therefore more easily and intensely exposed to sunlight. Furthermore, it is possible to park the trailer outdoors when it is not needed and charge the battery using the solar cell via sunlight, without requiring any electrical energy from the power grid.

[0016] Preferably, a surface of the charging station and / or the battery and / or the electric motor and / or a storage container connected to the frame is at least partially, and in particular largely, covered by the at least one solar cell. These trailer components can have an outward-facing surface to which the solar cell can be attached. This makes it possible to utilize the comparatively large surface areas of these components for the solar cells while still leaving usable space on the frame. The at least one solar cell can be attached to a surface facing upwards in the direction of gravity, for example, a lid of the storage container. Additionally or alternatively, it is possible to equip surfaces facing essentially horizontally with the at least one solar cell.It can be taken into account that the superstructures are preferably provided in the area of ​​the axle and the wheels of the trailer and are thus far enough away from the vehicle used as a towing vehicle that shading of a solar cell pointing in the direction of travel by the vehicle used as a towing vehicle is unlikely.

[0017] In particular, the charging station features a cooling module for cooling the battery and / or the charging station itself, especially the charging cable, with the cooling module being electrically connected to the battery. Unnecessary heating of the charging station and / or the charging cable, particularly in fast-charging mode, can be avoided by the cooling module's cooling capacity, thus enabling charging with low ohmic resistance. The cooling module may include an electrically driven pump for circulating a cooling fluid and / or an electrically driven cooling compressor, which can be powered by the battery. Without external electrical energy from a stationary power grid, a high charging capacity can be achieved to recharge the vehicle battery of a stranded electric vehicle.

[0018] Preferably, the frame has a trailer hitch for coupling to the vehicle intended as the towing vehicle, wherein the trailer hitch has a trailer connector electrically connected to the battery for exchanging electrical energy between the trailer battery and a vehicle battery of the vehicle intended as the towing vehicle. This makes it possible, when the trailer battery is fully charged, to store electrical energy generated by the electric motor in the vehicle battery of the towing vehicle and to recharge the vehicle battery of the towing vehicle while driving.This eliminates the need for the electric motor to switch between no-load operation and generator operation while driving, thus preventing seemingly inexplicable changes in traction for the driver of the towing vehicle due to the resulting changes in the applied drag torque, which could be perceived as a reduction in driving comfort. Furthermore, it is generally possible to use the towing vehicle's battery, connected via the trailer plug, for charging using the charging station.

[0019] Preferably, at least one electrically connected power outlet for the detachable connection of electrical devices is provided with the battery. This power outlet can be designed for connecting electrical appliances that would otherwise be connected to a standard household outlet intended for outdoor use and connected to a fixed power grid. This allows the trailer to carry payloads that can be electrically powered and / or electrically charged. For example, an electrically operated cool box and / or lights can be connected via the power outlet, enabling the trailer to be used, in particular, as a mobile power source for camping applications.

[0020] In particular, a two-wheel carrier is attached to the frame, especially via a detachable trailer hitch connection, with the power outlet designed to charge an electrically powered two-wheeler mounted on the carrier. The two-wheel carrier can be detachably connected to the frame, allowing it to be attached when needed and avoiding the additional weight of the carrier otherwise. The two-wheel carrier can be designed for attachment to a trailer hitch. Since the trailer itself is intended to be coupled to the towing vehicle's trailer hitch, the frame can incorporate the geometry of an additional trailer hitch at a suitable location to actually attach the two-wheel carrier, which is actually designed for attachment to the trailer hitch of a passenger vehicle, to the trailer frame.This allows the use of an already established and standardized fastening system for a detachable two-wheel carrier. The two-wheeler carried in the carrier can be, in particular, an e-bike, a pedelec, an e-scooter, or similar. The electrically powered two-wheeler can have a rechargeable battery that can be charged from the trailer's battery and / or from the electric motor, especially while driving. For this purpose, the electrically powered two-wheeler can be plugged into the charging socket.

[0021] Preferably, a replaceable battery module that can be charged by the electric motor is provided, particularly for electrically powered two-wheelers and / or electrically powered passenger vehicles. Specifically, a charging cradle electrically connected to the battery and / or the electric motor is provided, into which the at least one battery module can be inserted for charging. This allows the electrically powered two-wheeler and / or vehicle to be recharged by replacing at least one battery module. The discharged battery module can be recharged by the battery and / or the electric motor, particularly while driving, and thus prepared for further replacement.

[0022] The frame is particularly preferably designed for a single-axle trailer. The frame can be designed to have only one pivot point for the wheels. This simplifies charging the battery using the electric motor. In particular, this allows the frame, and therefore the trailer, to be designed to be especially small and space-saving. Preferably, a support wheel, which can be moved and / or folded out in the direction of gravity, is provided on the frame. Positioned at a distance in the direction of travel from the wheel pivot point, this support wheel can help distribute the weight of the trailer when uncoupled, preventing the drawbar or a trailer coupling connected to the drawbar from striking the ground.

[0023] The invention is explained below by way of example with reference to the accompanying drawings and preferred embodiments, wherein the features shown below can represent an aspect of the invention, either individually or in combination. The drawings show: Fig. 1: A schematic side view of a first embodiment of a trailer, Fig. 2: a schematic side view of a second embodiment of a trailer and Fig. 3: a schematic perspective view of a third embodiment of a trailer.

[0024] The in Fig. The single-axle trailer 10, as depicted in Figure 1, can be coupled to a motor vehicle, in particular a passenger car, serving as a towing vehicle. For this purpose, the trailer 10 has a frame 12 designed for transporting payloads, with a trailer coupling 14 that projects in the direction of travel 16 to be coupled to the motor vehicle. In addition to the mechanical coupling, an electrical connection can also be made via the trailer coupling 14, for example, to operate the trailer's rear lights. The single-axle trailer 10 has a pair of wheels 18 spaced laterally apart from each other, which can roll passively on a surface 20 when the trailer 10 is pulled by the towing vehicle. Each wheel 18 is attached to a rotating shaft, whereby, in particular, a single common shaft may be provided for both wheels 18.The at least one shaft is rotatably mounted on the frame 12 and can interact on the side facing away from the wheel 18 between the two wheels 18 with an electric machine 22, for example, designed in the form of a wheel hub drive. For this purpose, the shaft can form a rotor shaft of the electric machine 22 or be coupled to a rotor shaft of the electric machine 22. In generator mode, the electric machine 22 can generate electrical energy from the passively rotating wheels 18 and the shaft rotating with the wheels. This energy can be stored in a battery 24 attached to the frame 12. The battery 24 can be connected via the trailer hitch 14 to a vehicle battery of the vehicle serving as the towing vehicle.In particular, if the vehicle serving as the towing vehicle is designed as an electrically powered vehicle, the electric range can be increased by the battery 24 of the trailer 10, so that the trailer can serve as a so-called "range extender" for the towing vehicle. Preferably, the electric motor 22 and the battery 24 are mounted substantially centrally to the axis of rotation of the wheels 18 and the axle with the frame 12.

[0025] Additionally, the trailer 10 has a charging station 26 designed for charging electrically powered motor vehicles, in particular hybrid vehicles and / or purely electric vehicles, which can essentially correspond to a stationary charging station. The charging station 26 can, in particular, have several charging plugs 28 conforming to different standards, which are preferably each electrically connected via a charging cable 30. The charging station 26 is connected to the battery 24 of the trailer 10, so that the electrical power for charging an electrically powered motor vehicle, in particular an electric vehicle that has broken down due to a discharged vehicle battery, can be supplied from the battery 24. It is also possible, in principle, to use the vehicle battery of the towing vehicle connected via the trailer coupling 14 for this purpose.The charging cable 30 is chosen to be sufficiently long to allow charging of the stranded electric vehicle in various conceivable parking positions of the trailer 10 attached to the tractor unit, for example, when the vehicle combination consisting of the trailer and tractor unit is parked behind the stranded electric vehicle. Preferably, the charging station 26, including its associated support systems, such as a cooling module for cooling the charging station 26 and / or the charging cable 30 and / or the charging plug 28, is mounted to the frame 12 essentially centrally to the axis of rotation of the wheels 18 and the axle. The charging station 26 can be positioned above the electric motor and / or the battery 24. The support systems of the charging station 26 can also be electrically powered by the battery 24.

[0026] A height-adjustable support wheel 32 can be attached to the frame 12. Preferably, the support wheel 32 can be adjusted in height by means of an electric actuator, the electric actuator being electrically connected to and driven by the battery 24. In particular, the electric motor 22 can also be operated in motor mode, so that the trailer 10 can be moved purely electrically using the electrical energy stored in the battery 24, for example, to park the trailer 10 when uncoupled from the towing vehicle and / or to move it to a stranded electric vehicle.

[0027] As in Fig. As shown in Figure 2, it is possible to detachably connect at least one two-wheel carrier 34 to the frame 12 in front of and / or behind the battery 24, in particular via a standardized trailer hitch connection 36. In the illustrated embodiment, the battery 24 is provided in a storage container 38. The storage container 38 also provides additional storage space that can be used to transport smaller items. The storage container 38 is, for example, located below the charging station 26 and is accessible via a lid that can be opened upwards to the side next to the charging station 26 and / or laterally at the transversely facing end faces. Alternatively, it is possible to position the battery 24 and the charging station 26 transversely centered in the middle of the frame 12 and to provide a storage container 38 to the right and / or left of the battery 24 and the charging station 26, respectively, in the transverse direction.

[0028] As in Fig. As shown in Figure 3, a power outlet 40, particularly one designed in the manner of a household outlet suitable for outdoor use, can be connected to the battery 24, and electrical devices can be operated via this outlet. Preferably, electrically powered two-wheelers mounted in the two-wheel carrier 34 can be connected to the power outlet 40 for charging. For this purpose, the at least one power outlet 40 can be provided in a side wall of the storage container 38 facing the two-wheel carrier 34.

[0029] Using the storage container 38 as an example, it is shown that an outward-facing surface can be equipped with a solar cell 42. The solar cell 42 is electrically connected to the battery 24 and can charge the battery 24 using sunlight. The solar cell 42 can also be mounted on suitable surfaces of the storage container 38. Fig.The charging station 26 (not shown) and, if applicable, the battery 24 and / or the electric machine 22 may be provided. Horizontal and / or vertical surfaces of the trailer 10 can be used for the solar cell 42.

Claims

[1] Trailer for a motor vehicle, with a frame (12) for transporting payloads, a shaft rotatably mounted on the frame (12), wherein the shaft is connected to a wheel (18) that can be supported on a base, an electrical machine (22) coupled to the shaft for generating electrical energy from the rotation of the shaft, a battery (24) that can be charged by the electric machine (22) and a charging station (26) that is electrically connected to the battery (24) for charging an electrically powered motor vehicle, wherein the charging station (26) has a charging plug (28) electrically connected via a charging cable (30) for insertion into a charging socket of the electrically powered motor vehicle, wherein a cable length of the charging cable (30) is greater than a longitudinal extent of the frame (12). [2] Pendant according to claim 1 characterized by, that at least one solar cell (42) electrically connected to the battery (24) is provided for generating electrical energy from sunlight. [3] Trailer according to claim 2 characterized by , that a surface of the charging station (26) and / or the battery (24) and / or the electric machine (22) and / or a storage container (38) connected to the frame (12) is at least partially, in particular to a large extent, covered by the at least one solar cell (42). [4] Pendant according to any one of claims 1 to 3 characterized by , that the cable length of the charging cable (30) is greater than two or four times the longitudinal extent of the frame (12). [5] Pendant according to any one of claims 1 to 4 characterized by , that the charging station (26) has a cooling module for cooling the battery (24) and / or the charging station (26), in particular a charging cable (30) of the charging station (26), wherein the cooling module is electrically connected to the battery (24). [6] Pendant according to any one of claims 1 to 5 characterized by , that the frame (12) has a trailer coupling (14) for coupling to the motor vehicle intended as a towing vehicle, wherein the trailer coupling (14) has a trailer plug electrically connected to the battery (24) for exchanging electrical energy between the battery (24) and a motor vehicle battery of the motor vehicle intended as a towing vehicle. [7] Pendant according to any one of claims 1 to 6 characterized by , that at least one electrically connected power outlet (40) is provided with the battery (24) for the detachable connection of electrical consumers. [8] Trailer according to claim 7 characterized by , that a two-wheel carrier (34) is attached to the frame (12), in particular via a detachable trailer coupling connection (36), wherein the supply socket (40) is designed to charge an electrically driven two-wheeler taken up by the two-wheel carrier (34). [9] Pendant according to any one of claims 1 to 8 characterized by , that a replaceable battery module rechargeable by the electric machine (22) is provided, in particular for electrically powered two-wheelers and / or electrically powered passenger vehicles. [10] Pendant according to any one of claims 1 to 9 characterized by , that the frame (12) is designed for a trailer (10) designed as a single axle.

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