BATTERY ARRANGEMENT FOR AN ELECTRIC VEHICLE

Abstract

A battery arrangement for an electric vehicle including a battery housing and a plurality of battery cells. The battery cells are arranged in the battery housing. A protective plate is arranged on a side of the battery and faces toward a roadway. A deformation detection device includes at least one deformation sensor arranged at the protective plate. The protective plate is constructed of multiple layers and includes at least one first layer and one second layer separate from the first layer. The deformation detection device includes a first deformation sensor and a second deformation sensor. The first deformation sensor is arranged at the first layer of the multi-layer protective plate and the second deformation sensor is arranged at the second layer of the multi-layer protective plate.

Claims

1. A battery arrangement for an electric vehicle, said battery arrangement comprising: a battery assembly comprising a battery housing and a plurality of battery cells arranged in the battery housing, a multi-layer protective plate arranged on a side of the battery assembly that faces toward a roadway, the multi-layer protective plate having multiple layers and comprising at least one first layer and one second layer that is separate from the first layer, and a deformation detection device comprising at least one deformation sensor arranged at the protective plate, wherein the deformation detection device comprises a first deformation sensor and a second deformation sensor, wherein the first deformation sensor is arranged at the first layer of the multi-layer protective plate and the second deformation sensor is arranged at the second layer of the multi-layer protective plate.

2. The battery arrangement as claimed in claim 1, wherein the first deformation sensor and/or the second deformation sensor are divided into different segments.

3. The battery arrangement as claimed in claim 1, wherein the deformation sensors are implemented as strain gauges, as resistance sensors, as piezoelectric strain gauges or as Bragg sensors.

4. The battery arrangement as claimed in claim 1, wherein the first deformation sensor is arranged at a side of the first layer that faces toward the second layer, and the second deformation sensor is arranged at a side of the second layer that faces toward the first layer.

5. The battery arrangement as claimed in claim 1, wherein the first deformation sensor is embedded in the first layer and/or the second deformation sensor is embedded in the second layer.

6. The battery arrangement as claimed in claim 1, wherein the protective plate is spaced apart from the battery housing.

7. The battery arrangement as claimed in claim 1, wherein a third layer is arranged between the first layer and the second layer, and wherein the third layer is composed of a deformable material.

8. The battery arrangement as claimed in claim 7, wherein the third layer is made of a structural foam.

9. The battery arrangement as claimed in claim 1, wherein the first layer and the second layer are composed of a fiber-reinforced plastic.

10. The battery arrangement as claimed in claim 1, wherein the deformation detection device comprises an evaluation unit that is operatively connected to the at least one deformation sensor.

11. An electric vehicle comprising the battery arrangement as claimed in claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] An exemplary embodiment of the invention is explained in more detail with reference to the drawings.

[0020] FIG. 1 shows a schematically illustrated electric vehicle, and

[0021] FIG. 2 shows an embodiment of a battery arrangement.

DETAILED DESCRIPTION OF THE INVENTION

[0022] FIG. 1 shows a schematic illustration of an electric vehicle 10 that comprises a battery 12 and a drive unit 14. The battery 12 serves to store electrical energy and to supply the drive unit 14 with electrical energy when the electric vehicle 10 is in driving operation.

[0023] The battery 12 comprises a battery housing 16, and is arranged at the underbody 18 of the electric vehicle 10. A multiplicity of battery cells 20 are arranged in the battery housing 16, and are separated from the external environment in a fluid-tight manner by the battery housing 16, and thereby protected from environmental influences by the battery housing 16. A protective plate 30 is arranged underneath the battery 12, i.e. between the battery 12 and a roadway 22. The protective plate 30 is fastened to a vehicle bodywork, and entirely covers the battery 12 as far as the roadway 22 is concerned.

[0024] The purpose of the protective plate 30 is that when the electric vehicle 10 is in driving operation, an object lying on the roadway that is projected upward strikes the protective plate 30. The battery 12, and the battery housing 16, are thereby protected by the protective plate 30 against objects that are projected upward, whereby the risk of damage to the battery 12 is reduced.

[0025] In spite of the protective plate 30, the battery 12, and in particular the battery cells 20, can be damaged by objects that are driven over or that are lying on the roadway 22 and are projected upward, in that the protective plate 30 deforms heavily or is penetrated.

[0026] The driver of the electric vehicle 10 must be informed as quickly as possible if the battery cells 20 are damaged, and/or corresponding measures must be introduced in order in particular to prevent a fire in the battery 12 or even in the entire electric vehicle 10.

[0027] Possible damage to the battery 12 is acquired by a deformation detection device 31. FIG. 2 shows such a deformation detection device 31 that is arranged at the protective plate 30. The protective plate 30 is made of multiple layers, and comprises three layers 32, 34, 36. When the protective plate 30 is assembled, the first layer 32 is arranged closest to the battery. The protective plate 30 is fastened to a bodywork of the electric vehicle 10 by the first layer 32, namely by way of the side segments. The second layer 36 is arranged at a side of the protective plate 30 that faces toward the roadway 22. The second layer 36 is thus the layer that deforms first upon the impact of an object. The third layer 34 is arranged between the first layer 32 and the second layer 36, and entirely fills the space between the two layers 32, 36. The first and second layers 32, 36 are made of a fiber-reinforced plastic, and thereby have a relatively high strength. The third layer 34 is made of a structural foam, wherein the original material of the structural foam is filled into the space between the two layers 32, 36, and then foamed.

[0028] The deformation detection device 31 comprises two deformation sensors 40, 42 and an evaluation unit 50. The evaluation unit 50 is connected in terms of signals to the deformation sensors 40, 42, wherein the evaluation unit 50 receives the signals of the deformation sensors 40, 42, evaluates them and introduces appropriate measures such as, for example, switching the battery 12 off or transmitting a message to the driver regarding the damage to the battery 12. A first deformation sensor 40 is arranged at the first layer 32, wherein the first deformation sensor 40 is arranged at a side of the first layer 32 that faces toward the second layer 36, i.e. between the first and the third layer 32, 34, whereby the first deformation sensor 40 is protected from environmental influences. A second 35 deformation sensor 42 is arranged at a side of the second layer 36 that faces toward the first layer 32, i.e. between the second layer 36 and the third layer 34. Both deformation sensors 40, 42 extend over the full surface of the protective plate 30, wherein the deformation sensors 40, 42 are divided into a multiplicity of segments, whereby the deformation can be localized.

[0029] When there is an impact of an object on the protective plate 30, a deformation of the protective plate 30 caused thereby is acquired by the deformation sensors 40, 42. Depending on the force of the impact of the object, either only the second layer 36 and, possibly, the third layer 34 are deformed, or all the layers 32, 34, 36. The impact of the object here can be slight enough that only the second layer 36 is deformed, and only the second deformation sensor 42 acquires a deformation. In spite of the deformation of the protective plate 30, immediate measures do not have to be taken, since damage to the battery 12 or to the battery housing 16 is not to be expected. In the event of the impact of an object with a great force, all the layers 32, 34, 36 deform, whereby, with knowledge of the stiffnesses of the individual layers 32, 34, 36 and the ascertained deformation of the individual layers 32, 36, the stress acting on the battery 12 can be estimated. On this basis it is possible to estimate whether a critical stress is present at the battery 12, and whether appropriate measures have to be introduced.

[0030] The availability of the electric vehicle 10 can be significantly increased by such a design of the deformation detection device 31, since the electric vehicle 10 can continue to be used for the usual driving operation with slight damage to the protective plate 30, and only in the case of critical damage to the protective plate 30 and the battery 12 must it be switched off or immediately brought to the workshop.

[0031] Constructive embodiments other than the embodiments described are also possible and fall within the protective scope of the main claim.