Low-voltage contacting arrangement for a battery, assembly of the low-voltage contacting arrangement, and vehicle having a high-voltage battery

Abstract

The invention relates to a low-voltage contacting arrangement for a battery (1), comprising receiving elements (4) on a surface, the receiving elements being electrically contacted via an enamelled wire (5) welded to them. The low-voltage contacting arrangement according to the invention is characterized in that the receiving elements (4) run at an angle to the surface (9) receiving them, the angle deviating from the perpendicular.

Description

[0001] Low-voltage contact for a battery, assembly of the low-voltage contact and vehicle with a high-voltage battery

[0002] The invention relates to a low-voltage contact for a battery according to the preamble of claim 1. The invention further relates to a method for mounting such a low-voltage contact and to a vehicle with a high-voltage battery which has such a low-voltage contact.

[0003] Batteries such as lithium-ion batteries, which are used to store electrical drive power in vehicles, are well-known from the state of the art. A basic battery module of this type is shown, for example, in the...

[0004] DE 102010035478 Al. This document describes the cell contacting of battery modules for power extraction and charging of individual battery cells. In addition to this so-called high-voltage contacting, where high voltage, according to the definition in ECE 100R, means that voltages of more than 60 V DC prevail, such batteries or battery modules typically also have a low-voltage (LV) contacting at a lower voltage level. This contacting typically serves to acquire measurement data such as individual cell voltages, for control purposes, or similar applications.

[0005] German patent DE 102019000856 describes a well-known and common design for such a low-voltage contact. Typically, varnish-insulated wires are welded to pins or contact forks, creating an electrically conductive connection. The wire for the low-voltage contact is then wrapped around the pins or contact forks and led to a battery management control unit. The design is correspondingly simple, as the raised contact forks and pins allow for exceptionally easy and efficient contact during assembly. However, when used for traction batteries in electric vehicles, these low-voltage contacts can be damaged by intrusions during a crash, for example, if they are bent or the raised wire is torn off by a component damaging the battery.This is particularly critical because information about the battery's condition is crucial in such situations to assess its safety after a crash and to take any necessary countermeasures. If the low-voltage contacts are unavailable at precisely this time, safety-critical disadvantages can arise.

[0006] Further high-voltage contacts or components for them are known from US 2019 / 0189996 Al or DE 102018201155 Al. These patents show terminal elements running obliquely to a surface, which are crimped to cables or, according to the German patent application, also electrically connected in another way.

[0007] For further information on the state of the art, reference can also be made to US 2019 / 0296312 Al and CN 2 17385 761 U.

[0008] The object of the present invention is therefore to provide an improved low-voltage contacting system and a method for its assembly which avoids these disadvantages.

[0009] According to the invention, this problem is solved by a low-voltage contact for a battery with the features of claim 1. Advantageous embodiments and further developments are described in the dependent claims. Furthermore, a method for mounting such a low-voltage contact according to claim 5 solves the problem. Here, too, an advantageous embodiment is described in the dependent claim. Claim 6 also specifies a vehicle with a high-voltage battery equipped with such a low-voltage contact, thus indirectly solving the problem as well.

[0010] The low-voltage contacting system according to the invention comprises – comparable to the prior art – a enamelled wire welded to receiving elements such as contact pins or contact forks. According to the invention, these receiving elements are arranged at an angle to the surface on which they are mounted, deviating from the vertical.

[0011] Furthermore, it is provided that the receiving elements are surrounded on at least two of their sides by protective elements that are firmly connected to the surface or formed integrally with it. These protective elements serve to further reduce damage to the receiving elements for the enamelled wire in the event of intrusion. Ideally, these protective elements are arranged on two opposite sides, and, according to a particularly advantageous embodiment, the upper edge of the receiving element is closer to the surface than the upper edge of the protective elements. This achieves very good protection with minimal additional design effort.

[0012] This angle can be in the range of 10 to 60° to the surface. The mounting elements are therefore no longer arranged perpendicular to the supporting surface, but rather bent towards it. This ensures that the mounting elements themselves require less vertical space, minimizing the risk of damage in the event of an intrusion. Additionally, the angled arrangement to the surface results in the enameled wire running closer to the surface, further minimizing the risk of damage. This allows for a highly effective design that, with minimal additional effort, can significantly improve the construction's crash safety in accordance with current best practices.

[0013] The mounting elements, which are angled to the surface, especially when positioned between two protective elements, significantly complicate assembly. To counteract this problem, the inventive method for mounting the low-voltage contacts can be provided for by wrapping the enameled wire around the mounting elements and welding it to them. Only then are the previously vertical mounting elements bent towards the surface, according to a particularly advantageous embodiment, positioned between the at least two protective elements. This makes the effort required for mounting the low-voltage contacts comparable to that of the prior art, since the initially vertical components can be easily and ideally wrapped with the enameled wire, or the enameled wire can be threaded into them. The connection is then made by welding.Only then are the individual mounting elements bent towards the surface supporting them in order to achieve the low-voltage contact according to the invention. The additional effort during assembly is therefore limited to bending the mounting elements. This small additional effort, however, results in a significantly more reliable design.

[0014] The low-voltage contacting system according to the invention is ideally suited for use in high-voltage batteries that operate under conditions susceptible to mechanical damage. Accordingly, a vehicle can be equipped with a high-voltage battery featuring such a low-voltage contacting system, where the high-voltage battery is designed as a traction battery, i.e., for storing electrical drive power. Since a crash must always be anticipated in vehicle applications, the arrangement of the receiving elements, bent towards the surface, offers a particularly high safety advantage.

[0015] Further advantageous embodiments of a battery with a low-voltage contact according to the invention and of the assembly method according to the invention also result from the exemplary embodiments which are described in more detail below with reference to the figures.

[0016] This shows:

[0017] Fig. 1 shows a section of a battery with a low-voltage contact according to the prior art;

[0018] Fig. 2 shows a section of the representation according to Fig. 1 in an embodiment according to the invention;

[0019] Fig. 3 shows a contact fork of a low-voltage contact according to the invention in a first step of assembly; and

[0020] Fig. 4 shows the assembly according to Fig. 3 after assembly.

[0021] Figure 1 shows a section of a high-voltage battery, designated 1 in its entirety, such as a traction battery used in a vehicle. The section shown includes four individual battery cells 2 and a section of a battery housing, designated 3, which in this case forms the underbody of a vehicle. Within the area of ​​the individual battery cells 2 are several receiving elements 4, designed as contact pins or contact forks projecting perpendicularly from the surface of the individual battery cells. A enamelled wire, designated 5, is wound around these contact elements and welded to them. This enamelled wire 5, of which only a section is shown, is connected to a control unit to transmit measurement data from the individual battery cells 2 to this control unit.This refers to the low-voltage contacting of the individual battery cells 2, which are also connected to each other in parallel via cell connectors designated with 6 with respect to power via a high-voltage contacting, here connected in series in order to extract energy from the battery 1 or to store it.

[0022] In the embodiment shown here, an intrusion 7, depicted as a sphere, damages the battery housing 3, for example, in a vehicle crash. This results in damage to the receiving element 4 shown on the left, indicated by an exploded view symbol 8. In this case, the low-voltage connection may be disrupted because the enameled wire 5 breaks at this point and / or the receiving element 4 is torn off. In this situation, no measured values ​​from the battery 1 are available, meaning that no statement can be made about the status or condition of the battery 1, which is a serious safety disadvantage in the event of a crash.

[0023] Figure 2 shows a section of the structure from Figure 1, modified accordingly. The receiving element 4, with the section of enamelled wire 5 shown here, has been bent relative to the surface of the individual battery cells 2 of battery 1 so that it is positioned at an angle to this surface, thus providing more space between battery 1 and the section of the battery housing labeled 3. The intrusion body 7 now dents the battery housing 3 similarly to the illustration in Figure 1, but sufficient clearance remains to prevent damage to the low-voltage contacts and, in this case, the connection element 4. This simple design modification thus increases safety. During assembly, this can be implemented as shown in Figures 3 and 4.Figure 3 shows a surface designated 9, for example, the surface of the individual battery cells 2 or a circuit board carrying the cell connectors 6, or the like. A contact fork is shown as an example on this surface as a receiving element 4. This fork consists of a base 10 and the actual contact fork 4. The enameled wire 5 is inserted into this contact fork 4 and welded to it to ensure electrical contact. During assembly, the contact fork 4 protrudes perpendicularly from the surface 9, so that no additional effort is required for electrical contact. Only then, as can be seen in Figure 4, is the contact fork 4 bent towards the surface 9 to assume the position also shown in Figure 2.

[0024] In Figures 3 and 4, protective elements 11 are also visible, projecting perpendicularly from the surface 9. They are either connected to the surface 9 or integral with it. They are arranged so that they do not impede the connection between the enameled wire 5 and the contact fork 4 during assembly. However, if the contact fork 4, which is electrically connected to the enameled wire 5, is then bent towards the surface 9, as shown in Figure 4, it comes to rest between these two protective elements 11 and thus receives additional protection in the event of lateral intrusion. Safety can therefore be further increased by bending the contact fork 4 down between the protective elements 11 after it has been electrically connected.

Claims

Patent claims 1. Low-voltage contacting for a battery (1) with receiving elements (4) on a surface which are electrically contacted via a enamelled wire (5) welded to them, characterized in that the receiving elements (4) extend at an angle to the receiving surface (9) which deviates from the perpendicular, wherein the receiving elements (4) are surrounded on at least two of their sides by protective elements (11) which are firmly connected to the surface (9) or are integrally formed with it.

2. Low-voltage contacting according to claim 1, characterized in that the receiving elements (4) are arranged at an angle of 10 to 60° to the surface (9).

3. Low-voltage contacting according to claim 1 or 2, characterized in that the protective elements (11) are arranged on two opposite sides.

4. Low-voltage contacting according to claim 1, 2 or 3, characterized in that an upper edge of the receiving element (4) has less distance from the surface (9) than the upper edge of the protective elements (11).

5. Method for mounting a low-voltage contact according to one of claims 1 to 4, wherein the enamelled wire (5) is wound around or threaded into the receiving elements (4) which are perpendicular to the surface (9), after which the enamelled wire (5) is welded to the receiving elements (4), characterized in that, following the welding, the receiving elements (4) are bent in the direction of the surface (9) between at least two protective elements (11).

6. Vehicle with a high-voltage battery (1) which has a low-voltage contact according to one of claims 1 to 4 and which is intended for storing electrical drive power.

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