Underride protection, motor vehicle

Abstract

Underride guard (10) for mounting on a motor vehicle (100) along a third direction (Z) below a traction battery (1), comprising an underride guard base (2), wherein a channel (3) for directing gases (20) from the traction battery (1) along a first direction (X) is arranged between the underride guard base (2) and the traction battery (1), wherein the channel (3) has a plurality of openings (4) which become larger along the first direction (X), characterized in that the channel (3) is expandable along a third direction (Z) which is arranged orthogonally to the first direction (X).

Description

[0001] The present invention relates to an underride guard for mounting on a motor vehicle with a traction battery and to a motor vehicle with a traction battery and an underride guard.

[0002] Modern motor vehicles with electric drive systems, especially electric and hybrid vehicles, have batteries to supply energy, particularly to the electric drive systems. These batteries are also called traction batteries and are equipped with high capacities.

[0003] Traction batteries are typically located relatively low in the vehicle. This improves weight distribution, as the low position results in a very low center of gravity. Therefore, for a low center of gravity, it is advantageous to position the traction battery directly above the vehicle's underride guard.

[0004] Particular attention is paid to measures ensuring a high level of safety in the design surrounding the traction batteries. In the event of a short circuit in the traction battery, for example caused by an accident, a so-called thermal event can occur. This causes the traction battery to heat up, leading to the release of hot and flammable gases from the electrodes.

[0005] To prevent uncontrolled degassing of the traction batteries, degassing channels are known, which are taken into account, for example, in the design of the underride protection.

[0006] From the publication DE 10 2021 127 620 A1 and from the subsequently published publication DE 10 2023 105 980 B3 it is known to arrange a channel for degassing a traction battery of a vehicle between the traction battery and the underride guard and to provide it with openings which vary in size along the longitudinal direction of the vehicle.

[0007] It is an object of the present invention to provide an underride guard and a motor vehicle in which the guidance of the gases in the event of a thermal event is improved compared to the prior art.

[0008] This problem is solved by an underride guard according to claim 1 and a motor vehicle according to claim 9.

[0009] The underride guard according to the invention is designed for mounting on a motor vehicle. The underride guard is attached along a third direction, preferably the vertical direction of the motor vehicle, below the vehicle's traction battery, thus protecting the traction battery from contact with the ground and therefore from damage. The underride guard has a base. A channel for directing gases from the traction battery along a first direction is arranged between the base and the traction battery. The first direction is preferably the longitudinal direction of the motor vehicle. According to the invention, the channel has a plurality of openings that increase in size along the first direction. In other words, openings are arranged along the first direction in ascending order of size.This advantageously allows the gases to be guided through the channel in a degassing jet along the first direction, with larger gas particles traveling a longer distance than smaller particles. This lengthens the path for larger particles, allowing them to cool further before exiting the underride guard. This reduces the risk of the gases igniting upon contact with the ambient air outside the underride guard.

[0010] Preferably, the underride protection floor is formed by the channel itself in the area of ​​the channel. This saves material and therefore weight. Furthermore, it makes it possible to design the underride protection to be flatter, which benefits a lower positioning of the traction battery.

[0011] In particular, it is stipulated that the vehicle has an electric drive motor, i.e., it is a hybrid vehicle or an electric vehicle, and that the traction battery is a battery for supplying the electric drive motor with electrical energy.

[0012] The underride protection floor is preferably made at least partially of metal or plastic.

[0013] Gases within the meaning of the present invention are not merely gases in the physical sense. Gases within the meaning of the present invention also include particles that are expelled from the battery cells in the event of a thermal event. The expelled gaseous, solid, and possibly liquid components of the gases within the meaning of the present invention are carried through the channel in a degassing stream.

[0014] Advantageous embodiments and further developments of the invention can be found in the dependent claims and in the description with reference to the drawings.

[0015] According to a preferred embodiment of the present invention, the channel has a closed back wall that seals off the channel in the opposite direction. This advantageously allows the degassing stream to be directed along the channel from small openings to large openings, rather than exiting the channel at the end with the smallest openings. Large particles in the degassing stream are thus forced over a longer path, during which they can cool down.

[0016] It is preferably provided that the channel is open at a front face opposite the rear wall along the first direction. In other words, the gas flows along the channel from the rear wall to the open front face, passing through the increasingly larger openings. This advantageously ensures very good gas guidance during degassing of the traction battery. In particular, this advantageously allows high overpressures to be reduced quickly and gently through the open front face.

[0017] According to a further preferred embodiment of the present invention, a degassing chamber of the underride guard is arranged between the underride guard floor and the traction battery. The openings connect the interior of the channel to the degassing chamber along a second direction. This second direction is orthogonal to the first and third directions. For degassing, the gas flow is thus directed from the channel into the degassing chamber. Here, the gases cool down further, making ignition of the gases upon contact with ambient air less likely.

[0018] Preferably, the degassing chamber has a degassing opening for venting the gases from the chamber to the outside. This degassing opening is located at the end of the channel facing the rear wall, relative to the first direction of travel. In other words, during degassing, the gas is initially routed through the channel in the first direction. Subsequently, the gas is routed outside the channel in the opposite direction to the first direction until it exits the underride guard through the degassing opening. This further extends the path the gases travel from the traction battery to the degassing opening, allowing them more time to cool down.

[0019] A particularly preferred embodiment of the present invention is one in which, with respect to the first direction, a structure is arranged between the channel and the degassing opening to force a meandering path of the gases towards the degassing opening. This advantageously extends the residence time of the gases in the underride guard, allowing them to cool further before exiting the underride guard.

[0020] According to the invention, the channel is expandable along the third direction, which is orthogonal to the first direction. The third direction is also orthogonal to the second direction. In particular, the third direction is the direction in which or opposite to which the traction battery is mounted on the underride guard. This is, in particular, the upward direction of the vehicle. The expandability of the channel advantageously allows for pressure reduction during degassing. Because the channel is expanded by the gases escaping from the traction battery, other materials of the vehicle are protected. In particular, this prevents the gases from uncontrollably penetrating the underride guard.

[0021] A particularly advantageous embodiment of the present invention is characterized by a two-part channel. This makes it advantageously possible to design the channel so that, if necessary, it can expand to reduce overpressure during degassing. Preferably, both parts of the channel are made from a single sheet of metal.

[0022] According to a further preferred embodiment of the present invention, the channel has inlet openings for introducing gases from the traction battery into the channel. The inlet openings are preferably arranged on the side of the channel facing the traction battery. This advantageously makes it possible to arrange the traction battery directly above the underride guard, thereby achieving a low center of gravity for the vehicle and enabling a space-saving arrangement.

[0023] Another object for solving the aforementioned problem is a motor vehicle comprising a traction battery and an underride guard according to the invention.

[0024] All details, features and advantages disclosed in connection with the underride protection according to the invention also relate to the motor vehicle according to the invention.

[0025] Further details, features, and advantages of the invention will become apparent from the drawings and from the following description of preferred embodiments with reference to the drawings. The drawings merely illustrate exemplary embodiments of the invention, which do not limit the inventive concept. Fig. Figure 1 schematically illustrates an underride guard according to an exemplary embodiment of the present invention for a motor vehicle according to an exemplary embodiment of the present invention. Fig. Figure 2 schematically illustrates a detail of an underride guard according to an exemplary embodiment of the present invention. Fig. Figure 3 schematically illustrates a motor vehicle according to an exemplary embodiment of the present invention.

[0026] Fig. Figure 1 schematically illustrates an underride guard 10 according to an exemplary embodiment of the present invention. The underride guard 10 is designed for mounting on a motor vehicle 100 (see Figure 1). Fig. 3) according to an exemplary embodiment of the present invention. For this purpose, the underride guard 10 is arranged along a third direction Z, which in the illustrated embodiments corresponds to the upward direction of the motor vehicle 100, below a traction battery 1 of the motor vehicle 100. In the illustrated embodiments, the traction battery 1 of the motor vehicle 100 serves to supply electric drive motors (not shown) of the motor vehicle 100. In particular, it is provided that the motor vehicle 100 is an electric vehicle or a hybrid vehicle.

[0027] The underride guard 10 has an underride guard base 2, which closes off the underride guard 10 opposite the third direction Z, i.e., downwards. Between the underride guard base 2 and the traction battery 1, a channel 3 for directing gases 20 from the traction battery 1 along a first direction X is arranged. The first direction X is orthogonal to the third direction Z and, in the illustrated embodiments, is the longitudinal axis of the motor vehicle 100.

[0028] Channel 3 is specifically designed to guide gases 20 that are expelled from the (not shown) battery cells of the traction battery 1 during a thermal event. The gases 20, as defined in the present invention, do not merely comprise gaseous components, but can also include particles or liquid components. Typically, the gases 20 expelled during a thermal event are very hot. Before releasing the gases 20 into the environment of the vehicle 100, it is necessary to cool the gases 20, and in particular their solid components. This is advantageously achieved in the channel 3. Fig. 1 and Fig. 2 shown channel 3 of the underride guard 10.

[0029] Gases 20 from the traction battery 1 enter channel 3 through inlet openings 9. Channel 3 is closed at a rear wall 5. The gases 20 are guided along the first direction X through channel 3 towards an open front. Channel 3 is made of sheet metal and protects the underride protection floor 2 from the hot and abrasive gases 20 by cooling them as they pass through channel 3. Openings 4 are provided on the sides of channel 3, which become progressively larger along the first direction X. This allows larger particles to remain in channel 3 longer and thus have more time to cool before being discharged from channel 3.

[0030] From channel 3, the gases 20 enter a degassing chamber 6, which is located between the traction battery 1 and the underride guard 2. A degassing opening 7 is located in the underride guard 2. The degassing opening 7 is positioned on the side of the rear wall 5 of channel 3, so that the flow of gases 20 from the open front of channel 3 is directed against the first direction X through the degassing chamber 6 to the degassing opening 7. This advantageously extends the path taken by the gases 20 before they are released into the surroundings of the vehicle 100.

[0031] A structure 8 is provided upstream of the degassing opening 7, which forces the gases 20 onto a meandering path. This further promotes the separation of particles from the gases 20 and a further cooling of the gases 20.

[0032] As in the Fig.As can be seen in Figure 2, the channel 3 in the preferred embodiments shown here is designed as a double shell. This advantageously allows the channel 3 to expand in the third direction Z in the event of a thermal event. Thus, more volume is available to the gases 20 exiting the traction battery 1, resulting in lower pressure in the underride guard 10. Reference symbol list 1 traction battery 2 Underride protection floor 3-channel 4 Opening 5 Back panel 6 Degassing room 7 Degassing opening 8 Structure 9 Entrance opening 10 Underride protection 20 Gas 100 motor vehicles X first direction Y second direction Z third direction

Claims

[1] Underride guard (10) for mounting on a motor vehicle (100) along a third direction (Z) below a traction battery (1), comprising an underride guard base (2), wherein a channel (3) for directing gases (20) from the traction battery (1) along a first direction (X) is arranged between the underride guard base (2) and the traction battery (1), wherein the channel (3) has a plurality of openings (4) which increase in size along the first direction (X), characterized by , that the channel (3) is extensible along a third direction (Z) which is arranged orthogonally to the first direction (X). [2] Underride guard (10) according to claim 1, characterized by , that the channel (3) has a closed back wall (5) which closes off the channel (3) in the opposite direction (X). [3] Underride guard (10) according to claim 2, characterized by, that the channel (3) is open at a front side which is opposite the rear wall (5) along the first direction (X). [4] Underride guard (10) according to any of the preceding claims, characterized by , that between the underride protection floor (2) and the traction battery (1) a degassing chamber (6) of the underride protection (10) is arranged, wherein the openings (4) connect an interior of the channel (3) in a second direction (Y) which is arranged orthogonally to the first direction (X). [5] Underride guard (10) according to claim 4, characterized by , that the degassing chamber (6) has a degassing opening (7) for venting the gases (20) from the degassing chamber (6) to the outside, wherein the degassing opening (7) is arranged with respect to the first direction (X) at the end of the channel (3) facing the rear wall (5). [6] Underride guard (10) according to claim 5, characterized by, that, with respect to the first direction (X), a structure (8) is arranged between the channel (3) and the degassing opening (7) to force a meandering path of the gases (20) towards the degassing opening (7). [7] Underride protection (10) according to any of the preceding claims, characterized by , that the channel (3) is constructed in two shells, wherein the two shells of the channel (3) are preferably made of a sheet metal. [8] Underride protection (10) according to any of the preceding claims, characterized by , that the channel (3) has inlet openings (9) for introducing the gases (20) from the traction battery (1) into the channel (3), wherein the inlet openings (9) are preferably arranged on the side of the channel (3) facing the traction battery (1). [9] Motor vehicle (100) comprising a traction battery (1) and an underride guard (10) according to one of the preceding claims.

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