Battery terminal for two-wheelers with electric drive unit

Abstract

Battery terminal for two-wheelers with electric drive unit, comprising a housing (31) with a plug connection (35) for connecting a drive battery (20), a plug connection (36) for the electric drive unit (10) and plug connections (37a, 37b, 37c) for small electrical consumers (50), a voltage converter (40) arranged on or in the housing (31) for reducing the voltage of the drive battery (20) to the supply voltage of the small consumers (50).

Description

[0001] The invention relates to a battery terminal for two-wheelers with electric drive units, in particular e-bikes, pedelecs, electric bicycles, electric motorcycles, and scooters. The invention further relates to the arrangement of the electrical components of such a two-wheeler.

[0002] The electrical energy for the drive unit comes from a relatively large drive battery with a relatively high voltage, for example, 36 V or 48 V; comparatively high currents flow. In addition, smaller consumers such as headlights, taillights, handlebar remote controls with displays, or even charging devices for mobile devices must also be supplied with power from the drive battery. These small consumers are usually operated at a lower voltage, usually 12 V. Therefore, the small consumers cannot be connected directly to the high-voltage drive battery; a voltage converter must be inserted to reduce the voltage of the drive battery to the supply voltage of the small consumers.

[0003] Very often, the voltage converter is installed in the drive unit, i.e., in the immediate vicinity of the electric motor. In this case, the resulting architecture is such that the drive unit acts as a kind of distribution hub to which all electrical consumers, both the electric motor and small consumers, are connected. If the drive unit is a relatively large and heavy component and the number of small consumers is small, this architecture represents a proven and effective solution, especially for e-bikes with mid-mounted motors. The vast majority of pedelecs are therefore built this way.

[0004] However, the trend is toward two-wheelers, especially e-bikes, with increasingly smaller drive units and an ever-increasing number of additional electrical devices, including multifunctional electronic gearshifts, heated grips, electric locks, and control units with large screens. If the front or rear wheel is powered by a hub motor, it is not possible at all to connect the small devices to the drive unit for power supply.

[0005] As an alternative to locating the voltage converter in the drive unit, there have long been architectures in which the voltage converter is located in the drive battery, together with the battery management system (BMS). This has the advantage that the drive unit (DU), including the electronic motor control unit, can be made smaller and more compact, because it no longer needs to include the interfaces and connectors for the small consumers.

[0006] If the voltage converter is located in the drive battery, the individual small consumers can no longer be plugged directly into the drive battery. Instead, the distribution function is relocated to a wiring harness. This architecture is particularly common in high-powered two-wheelers and e-motorcycles.

[0007] A DC-DC converter naturally generates a relatively high level of heat loss. This makes it problematic to install voltage converters, especially for higher power outputs, in the drive battery. The battery cells are sensitive to higher temperatures, which inevitably occur under heavy loads from the electric drive unit and / or high charging currents when charging the battery. A further disadvantage of locating the voltage converter in the drive battery is that the necessary wiring harness in a modular product like a pedelec leads to unmanageable variability due to different frame sizes, equipment variants, etc.

[0008] From DE 20 2019 104 797 U1 an energy supply system based on an accumulator battery with integrated charger for an electrically powered bicycle is known.

[0009] From DE 10 2018 210 149 A1 an electric bicycle component is known which is provided with a wireless communication unit.

[0010] From DE 10 2021 123 822 A1 a driver posture changing device having an electric actuator is known.

[0011] An e-bike with an integrated air supply system is known from WO 2021 / 041 081 A1.

[0012] The technical problem is to optimize the architecture of the electrical components of a two-wheeler with an electric drive unit in such a way that, on the one hand, it supports a larger number of small consumers, but on the other hand, it can be designed in a simple modular way while at the same time keeping the drive unit as compact as possible and its overall weight as low as possible.

[0013] The problem is solved by a battery terminal according to the first patent claim.

[0014] The battery terminal according to the invention has a housing with a plug connection for connecting a traction battery, a plug connection for the electric drive unit, and a number of additional plug connections for the small electrical consumers. The voltage converter for reducing the voltage of the traction battery to the supply voltage of the small consumers is located on or in the housing of the battery terminal. The voltage converter is therefore located neither in the drive unit nor in the traction battery, but rather where the discharge plug is normally located.

[0015] A first advantage of the battery terminal according to the invention is that neither the electric drive unit nor the drive battery is exposed to the waste heat from the voltage converter. A second advantage is that the battery terminal, which is physically separated from the drive battery, also accommodates a larger number of connections or plug-in connectors for a variety of small consumers. This eliminates the need for a complex wiring harness with numerous branches and is replaced by simple, thin connecting cables that lead directly from the small consumers to the battery terminal.

[0016] The inventive approach of not using up the limited space for the drive unit or drive battery for the voltage converter, but rather locating the voltage converter in a location where there is sufficient space, namely between the drive unit and the drive battery, results in particularly good space economy and simplifies the design of the two-wheeler. The waste heat from the voltage converter is also not disruptive at this location and can be easily dissipated into the environment.

[0017] The battery terminal with integrated voltage converter can, in principle, be installed anywhere on the two-wheeler. However, a preferred design is one in which the housing has a front side, on which the plug connection for the drive battery is located, and a rear side, on which the plug connection for the drive unit and the plug connections for the small consumers are located. The plug connection for the drive battery can either be a purely electrical connection or simultaneously be designed as a mechanical connection between the housing of the battery terminal and the drive battery or its housing. It is essential that the battery terminal is a separate module from the drive battery.

[0018] The voltage converter arranged on or preferably in the housing advantageously has a heat sink to dissipate the waste heat. Depending on the size and power of the voltage converter, it may be sufficient for the waste heat from the heat sink to be dissipated to the outside through the housing wall. In a particularly advantageous embodiment, however, the heat sink of the voltage converter protrudes from an opening in the housing, allowing even larger amounts of heat to be effectively dissipated.

[0019] Since, as explained, the drive battery should be subjected to as little additional heat as possible, the opening for the heat sink is conveniently located on the rear of the housing, i.e., on the side facing away from the drive battery. The rear of the housing can essentially be formed by a frame that surrounds the opening for the heat sink. This ensures optimal cooling of the voltage converter; the outward-projecting heat sink is not obstructive at this point and is optimally positioned in the airflow. The plug connections for the electric drive unit and / or the small electrical consumers are conveniently located on this frame, allowing the heat sink protruding from the center to optimally utilize the available length.

[0020] The drive batteries for electric two-wheelers typically have an elongated shape and a cross-sectional profile that matches the frame profile. Therefore, the housing of the battery terminal is preferably adapted to the cross-sectional shape of the drive battery, so that the battery terminal appears as a single unit when the drive battery is connected.

[0021] The relatively heavy and usually elongated drive battery is often mounted on a mounting rail, which can be attached to the frame of the bicycle, for example, with screws. The battery terminal is also advantageously mounted on this mounting rail or a suitably designed extension. This eliminates the need for additional mounting hardware for attachment to the frame of the bicycle.

[0022] The battery terminal housing can be designed to form a positive connection with the front of the drive battery. This makes the battery terminal act like an extension of the drive battery, integrating seamlessly into the design of the two-wheeler. Furthermore, the battery terminal is also part of the drive battery's mounting mechanism.

[0023] The described technical problem is also solved by an arrangement according to patent claim 11. The arrangement according to the invention comprises all electrical components of the two-wheeler, i.e. electric drive unit, drive battery, small consumers and battery terminal arranged between drive battery and drive unit, on or in which the voltage converter for reducing the voltage of the drive battery to the supply voltage of the small consumers is arranged.

[0024] An embodiment of the invention is explained below with reference to the accompanying drawings. They show: Fig. 1 an arrangement of the electrical components of a two-wheeler, in a schematic diagram; Fig. 2a a battery terminal with voltage converter according to the arrangement of Fig. 1, in a perspective view obliquely from the front; Fig. 2b the back of the battery terminal of Fig. 2a, perspective.

[0025] In the principle diagram of Fig. Figure 1 shows a schematic illustration of the electrical components of a Pedelec (Pedal Electric Cycle). The arrangement comprises a drive unit 10 consisting of a DC motor and the associated power electronics. A drive battery 20 supplies the drive unit 10 with energy. The drive unit 10 comprises a number of rechargeable battery cells and an electronic battery management system (BMS), which are housed together in a compact housing. The drive battery 20 is arranged at some distance from the drive unit 10 on the frame of the Pedelec. The drive unit 10 is designed, for example, as a mid-engine and sits directly on the crank of the bicycle as part of the bottom bracket, whereas the drive battery is detachably attached, for example, to the down tube of the frame.

[0026] A battery terminal 30 is arranged between the drive unit 10 and the drive battery 20. A voltage converter 40 is integrated into the battery terminal 30.

[0027] Several small consumers 50, here for example a headlight 51, a taillight 52, a remote control 53 for controlling and monitoring the drive unit 10 and another electronic circuit 54, are electrically connected directly to the battery terminal 30.

[0028] The traction battery 20, for example, has a nominal voltage of 48 V. The voltage converter 40 is used to reduce the voltage to the supply voltage of the small consumers 50, which is usually 12 V.

[0029] Constructive details of the battery terminal 30 are shown in the Fig. 2a and Fig. 2b.

[0030] The battery terminal 30 has a two-part housing 31 consisting of a tub-like lower part 32 and a screwed-on upper part in the form of a frame 33. The frame 33 essentially forms the rear of the housing 31 and frames a large square opening 34. The voltage converter 40 (not visible here) is located inside the housing 31. Fig. 2a only the heat sink 41 of the voltage converter 40 can be seen, which protrudes from the opening 34 in the frame 33 so that it has contact with the surrounding air.

[0031] On the back of the housing 31, in the lower part 32, there is a plug connection 35, via which the electrical contact with the electronics of the drive battery 20 (cf. Fig. 1) and the housing of the drive battery 20 is mechanically connectable to the battery terminal 30. On the back of the housing 31 ( Fig. 2a) there is also a plug connection 36, via which the drive unit 10 (cf. Fig. 1) is electrically connected to the drive battery 20. Additional plug connections 37a, 37b, 37c serve for the electrical connection of the small consumers 50 (cf. Fig. 1). A connector plug 38 is connected to a charging socket (not shown) for charging the drive battery 20. The plug connection 36, the additional plug connections 37a, 37b, 37c, and the connector plug 38 are arranged on the frame 33 at the edge of the housing 31, so that they surround the centrally arranged heat sink 41.

[0032] The battery terminal 30 is located on the underside of a support rail 60, which can be screwed to the frame of the bicycle. Dovetail-shaped fixing elements 61a, 61b are formed on this support rail 60, onto which the drive battery 20 (not shown) can be slid.

[0033] The contour of the housing 31 of the battery terminal 30 is adapted to the cross-sectional shape of the drive battery 20. Connected to the housing 31 are a receptacle 70 for the drive battery and a locking device 71 with a key 72. Reference symbol 10 Drive unit 20 traction battery 30 Battery terminal 31 housings 32 Lower part (housing) 33 Frame (housing) 34 Opening 35 Plug connection (traction battery) 36 Plug connection (drive unit) 37a, 37b, 37c Plug-in connections (small consumers) 38 connectors 40 voltage converters 41 heat sinks 50 small consumers 51 headlights 52 taillight 53 Remote control 54 electronic circuit 60 mounting rail 61a, 61b Fixing elements 70 recording (drive battery) 71 Locking device 72 keys

Claims

[1] Battery terminal for two-wheelers with electric drive unit, comprising a housing (31) with a plug connection (35) for connecting a drive battery (20), a plug connection (36) for the electric drive unit (10) and plug connections (37a, 37b, 37c) for small electrical consumers (50), a voltage converter (40) arranged on or in the housing (31) for reducing the voltage of the drive battery (20) to the supply voltage of the small consumers (50). [2] Battery terminal according to claim 1, wherein the housing (31) has a front side on which the plug connection (35) for the drive battery (20) is arranged, and a rear side on which the plug connection (36) for the drive unit (10) and the plug connections (37a, 37b, 37c) for the small consumers (50) are arranged. [3] Battery terminal according to one of the preceding claims, wherein the voltage converter (40) has a heat sink (41) for dissipating the waste heat. [4] Battery terminal according to claim 3, wherein the heat sink (41) projects into the open through an opening (34) of the housing (31). [5] Battery terminal according to claim 4, wherein the opening (34) for the heat sink (41) is arranged on the rear side of the housing (31). [6] Battery terminal according to claim 5, wherein the rear side of the housing (31) is substantially formed by a frame (33) which surrounds the opening (34) for the heat sink (41). [7] Battery terminal according to claim 6, wherein the plug connections (36, 37a, 37b, 37c) are arranged on the frame (33) around the heat sink (41). [8] Battery terminal according to one of the preceding claims, wherein the contour of the housing (31) is adapted to the cross-sectional shape of the drive battery (20). [9] Battery terminal according to one of the preceding claims, wherein the housing (31) sits on a support rail (60) which can be fastened to the frame of the two-wheeler, and the support rail has fixing elements (61a, 61b) for the releasable fastening of the drive battery (20). [10] Battery terminal according to one of the preceding claims, wherein the housing (31) is designed for a positive connection with the drive battery (20). [11] Arrangement of electrical components of a two-wheeler with electric drive unit (10), drive battery (20), small consumers (50) and a battery terminal (30) arranged between drive battery and drive unit with integrated voltage converter (40) according to one of the preceding claims.

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