Underbody system with detachable protective element and means of transport

The underbody system with a detachable skid-like protective element addresses the issue of battery damage and high repair costs by providing predictable force absorption and easy replacement, enhancing vehicle safety and efficiency.

WO2025168420A1PCT designated stage Publication Date: 2025-08-14VOLKSWAGEN AG
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Patent Information

Application Number
PCT/EP2025/052303
Authority / Receiving Office
WO · WO
Patent Type
Applications
Current Assignee / Owner
Priority Date
2024-02-09
Filing Date
2025-01-30
Publication Date
2025-08-14

AI Technical Summary

Technical Problem

Existing underbody systems for vehicles, particularly those with integrated traction batteries, face issues such as increased risk of battery damage due to grounding, varying force application points, and high repair costs from frequent impacts, which are not adequately addressed by prior solutions like underrun guards and energy absorption structures.

Method used

An underbody system with a detachable skid-like protective element that protrudes from the underside, providing a defined contact area and force transmission, integrated with a frame for load conduction, and allowing easy replacement, thus reducing wear and tear and simplifying repairs.

Benefits of technology

The system effectively protects the functional units, such as traction batteries, by absorbing impact forces predictably, reducing repair costs, and maintaining vehicle comfort and efficiency by minimizing ground clearance.

✦ Generated by Eureka AI based on patent content.

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Abstract

The invention relates to an underbody system (2) for a means of transport (1), comprising: an underbody structure (10) having a functional unit (11) for a driving function of the means of transport (1) and having a cover element (12) which forms an underside (10.1) of the underbody structure (10) in order to protect the functional unit (11); and a runner-like protective element (20) which is fastened to the underbody structure (10). The invention also relates to a means of transport (1).
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Description

[0001] Description

[0002] Underbody system with removable protective element and means of transport

[0003] The invention relates to an underbody system for a means of transport and to a means of transport, in particular in the form of a vehicle.

[0004] It is known from the prior art to integrate traction batteries for vehicles into an underbody system so that the traction batteries extend below the vehicle interior. However, in certain driving situations the vehicle may bottom out. For example, when driving over a curb or parking garage ramp the vehicle may compress depending on the speed and bottom out. To reduce the Cd value without any loss of comfort it is also advisable to reduce the distance between the road surface and the vehicle, i.e. the ground clearance, so that bottoming out becomes more likely in other driving situations too. Due to the design described, if the vehicle bottomed out without further measures then the traction battery would come into contact with the ground and thus possibly impair high-voltage safety or require repair of the traction battery.

[0005] Various measures to protect the battery are known from the prior art. For example, document DE 102017 103654 A1 discloses the placement of a force transfer element behind an underrun guard. However, due to the lateral force transfer and the necessary curvature, the design requires additional installation space. Furthermore, depending on the surface, the vehicle can touch down at any point on the underrun guard, so the force application point varies greatly depending on the situation.

[0006] From document DE 102020 003 193 A1, it is also known to provide a cover with an energy absorption structure. However, the energy absorption structure does not allow, or only allows to a limited extent, the force transmission within the underbody.

[0007] With all known solutions, wear caused by frequent or heavy impacts can result in increased repair costs. With DE 102017 103654 A1, the underride guard would also be damaged and would require replacement, or at least dismantled to remove the force-dissipating element. With DE 102020 003 193 A1, damage to the energy absorption structure would require replacement of the entire cover.

[0008] It is an object of the present invention to at least partially remedy the above-mentioned disadvantages known from the prior art. In particular, it is an object of the present invention to enable improved power transmission when a means of transport is grounded and to reduce and / or simplify repair costs resulting from the grounding.

[0009] The above object is achieved by an underbody system having the features of claim 1, as well as a means of transport having the features of claim 10. Further features and details of the invention emerge from the respective subclaims, the description, and the drawings. Features and details described in connection with the underbody system according to the invention naturally also apply in connection with the means of transport according to the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is always made to each other.

[0010] According to a first aspect of the invention, an underbody system for a means of transport is provided. The underbody system has an underbody structure with a functional unit for a driving function of the means of transport and a cover element which forms an underside of the underbody structure to protect the functional unit. The underbody system further comprises a skid-like protective element which is detachably fastened to the underbody structure via at least one fastening interface. Furthermore, the protective element extends along a direction of travel of the means of transport, in particular on the underside, to protect the functional unit when the underbody system comes into contact with a ground surface, in particular in a situational manner. The protective element protrudes from the underside to define a contact area for contact with the ground surface.

[0011] The means of transport is preferably a motor vehicle, in particular an electric vehicle. However, it is also conceivable that the means of transport is another means of transport for, in particular, the independent transport of persons and / or a load. For example, the means of transport can be an electric scooter, in particular an e-scooter.

[0012] The underbody structure can comprise body parts of the means of transport. The functional unit preferably extends beneath a passenger area and / or an interior of the means of transport. The underside of the underbody structure forms, in particular, the underside of the means of transport. The functional unit can support and / or provide the driving function of the means of transport. For example, the functional unit can comprise a battery, a control unit, and / or a drive train of the means of transport. The cover element can form an underrun protection of the underbody system for protection against environmental influences, such as rain or moisture. Furthermore, the cover element can be part of the functional unit.

[0013] The protective element is designed in particular as an additional component which is arranged on the underbody structure. The skid-like design of the protective element can preferably comprise an elongated extension of the protective element along the direction of travel. The protective element can be designed to be narrow. In particular, a width of the protective element extending in a transverse direction of the means of transport, i.e. in particular a transverse direction of the vehicle, can be smaller, preferably significantly smaller, than a length of the protective element extending along the direction of travel. The protective element can protrude from the underside in that the protective element is fastened to the underside and / or projects beyond the underside in the direction of the ground, e.g. by a projection of the protective element.Preferably, the contact area can be located at a smaller distance from the ground than the underside, in particular the entire underside, and / or the subfloor structure. For contact with the ground, the protective element preferably has a contact surface that forms the contact area.

[0014] It can be provided that cables, e.g., in the form of electrical cables for a vehicle's electrical system, in the form of brake lines, and / or in the form of cooling hoses, are arranged between the functional unit and the protective element. The cables can be protected by the protective element.

[0015] The fastening interface for detachable fastening to the underbody structure can be designed for positive and / or force-fitting fastening of the protective element to the underbody structure. For example, the fastening interface can comprise an opening in the protective element, through which the protective element is screwed to the underbody structure. The protective element preferably has a plurality of fastening interfaces, in particular along the direction of travel. The underbody structure, in particular the cover element, can have a structural part, for example in the form of a structural sheet, to which the protective element is detachably fastened.

[0016] Situational contact with the ground can be understood, in particular, as the temporary contact of the underbody system with the ground. Contact can be caused, for example, by the vehicle driving over a speed bump or an edge, such as an incline or curb. Contact can result in the introduction of a force into the underbody system.

[0017] Within the scope of the invention, it has therefore been recognized that the skid-like design of the protective element, in which the protective element protrudes from the underside of the underbody structure, can form a sacrificial element which wears out upon contact, particularly upon repeated contact, and can then be replaced. Due to the detachable fastening of the protective element, the protective element can be easily replaced in a workshop, e.g. without dismantling other parts. The protective element thus forms a cost-effective replacement element which, due to the definition of the contact area, preferably only touches the ground upon contact. At the same time, the contact area enables contact to occur in a reproducible and / or predictable manner and the protective element can transmit the force accordingly into the underbody structure.This can simplify structural protection measures within the underbody system and / or the vehicle. Furthermore, the protective element makes it possible to reduce the ground clearance of the vehicle, thereby improving the vehicle's wind resistance and / or increasing the payload and / or comfort of the chassis setup. Furthermore, as an additional component, the protective element enables special equipment variants for the vehicle, e.g., for rough terrain.

[0018] Within the scope of the invention, it is further conceivable for the functional unit to be a traction battery for providing electrical energy for driving the means of transport. The drive can, for example, comprise an electric motor for driving the means of transport, in particular in the form of a vehicle drive. The traction battery can preferably be a high-voltage battery for operating the drive. By protecting the traction battery with the protective element, the overall safety of the means of transport can be improved. In particular, the risk of the means of transport touching down can be accepted despite the presence of the traction battery in the underbody structure, for example by further reducing the ground clearance of the means of transport. The cover element can, in particular, be a battery cover for the traction battery.The cover element and the functional unit can form a battery device to which the protective element is directly or indirectly attached. This simplifies the installation of the traction battery and / or completes the attachment of the traction battery to the body of the vehicle, without requiring any additional cladding measures beyond the protective element. By reducing wind resistance with reduced ground clearance, a longer range can be achieved, for example, with the same battery capacity.

[0019] Furthermore, in an underbody system according to the invention, it can advantageously be provided that the underbody structure comprises a frame for supporting the functional unit on a body of the means of transport, in particular wherein the protective element at least partially or completely forms a load conducting path for conducting a touchdown force, in particular during touchdown, via the frame to the body. The frame can form a structural component which absorbs the loads of the protective element during touchdown. For this purpose, the frame can be directly or indirectly connected to the body. The protective element can be directly or indirectly connected to the frame. The functional unit can be integrated into the frame and / or fastened to the frame. The load conducting path can comprise a plurality of components or sections of components via which the touchdown force can be conducted to the body.The load guidance path allows the load to be guided past functional elements, such as the traction battery cells, during impact, to prevent damage to the functional elements. In particular, the impact force is guided in a reproducible and / or predictable manner, allowing structural protection measures within the underbody system and / or the means of transport to be adapted accordingly.

[0020] Furthermore, in an underbody system according to the invention, it is conceivable for the frame to be made of metal and / or the protective element to be made of plastic. The frame can, for example, comprise aluminum, in particular be designed as an aluminum die-cast part. The protective element can preferably be made of a polyamide and / or a polypropylene, such as PA6 or PP. It is conceivable for the protective element to be made of a recycled material. Advantageously, the protective element can be designed as an injection-molded plastic part. This allows the protective element and / or the frame to be lightweight and cost-effective to manufacture. The division of the frame as a metal component and the protective element as a plastic component enables a functional division in which the plastic enables damping for impact, in particular through deformation, and the metal provides advantageous structural strength.Additionally or alternatively, the protective element may comprise a metal, for example in the form of an aluminum alloy.

[0021] Furthermore, in an underbody system according to the invention, it can advantageously be provided that the frame forms a support structure for the functional unit, wherein the protective element extends along a longitudinal member of the support structure. The frame can thus in particular be integrated into the functional unit and / or be part of the functional unit. Preferably, the frame is a battery frame for accommodating battery cells of the traction battery. The frame can, for example, have a rectangular shape. The longitudinal member can be an inner longitudinal member that extends within the rectangular shape to stiffen the frame, and / or an outer longitudinal member that defines one long side of the rectangular shape. Preferably, the frame has several, in particular two, inner and / or outer longitudinal members. This makes it possible to achieve a high level of component integration and thus a compact design in the underbody system.

[0022] In an underbody system according to the invention, it can preferably be provided that the frame has at least one tower-like support element, via which the load conduction path is guided through the functional unit. In particular, the support element can thus be part of the load conduction path. The tower-like support element can, for example, be an integral part of the longitudinal member. Furthermore, the tower-like support element can extend from the cover element or the underside of the underbody structure to an upper side of the functional unit. The support element can be fastened to and / or supported on the body at the upper side of the functional unit. Due to the tower-like support element, the load can be guided in a straight line through the functional unit upon placement, so that a compact geometry for the load conduction path is achieved and bending stresses on components can be reduced and / or avoided.

[0023] It is further conceivable in an underbody system according to the invention for the protective element to have a fastening side oriented towards the underbody structure and a contact side for contact with the ground, in particular wherein a rib structure is formed on the contact side. The fastening side can preferably be flat and / or smooth in order to form a flat contact surface for contact with the underbody structure. The contact side can be oriented opposite to the fastening side, ie in particular towards the ground during operation of the means of transport. The rib structure can have one or more ribs. The ribs can preferably extend along the direction of travel, in particular in order to keep wind resistance low.The rib structure can form a sacrificial structure, via the geometry of which material can be removed in a targeted manner during contact in order to reduce or avoid an impulse and / or a load on the functional unit. Load control for contact can be carried out depending on a rib height, a number of ribs and / or a rib width of the rib structure. The rib structure can be designed for a defined contact during predetermined driving maneuvers. It is further conceivable in an underbody system according to the invention that a degassing channel for degassing the functional unit is provided, which extends between the cover element and the protective element, in particular wherein a fastening means for fastening the protective element to the underbody structure extends into the degassing channel.Particularly if the functional unit is a traction battery, the functional unit can outgas due to aging and / or wear. The escaping gas can be discharged to the outside via the degassing channel. By extending the fastening means into the degassing channel, a compact, multifunctional design can be achieved. The degassing channel preferably extends parallel to the protective element along the direction of travel, in particular over the entire length of the protective element.

[0024] Within the scope of the invention, it is further conceivable for a plurality of skid-like protective elements to be detachably fastened to the underbody structure and to extend parallel to one another along the direction of travel of the means of transport. The underbody system preferably has two skid-like protective elements. The protective elements can advantageously be of identical construction. Each of the protective elements is preferably assigned to a longitudinal member of the support structure and / or fastened to at least one support element. The parallel arrangement makes it possible to share the load when the underbody system is placed straight on the ground. Furthermore, the distance to an outer edge of the underbody structure, e.g. to a side of the vehicle, can be reduced on both sides by using a plurality of protective elements.This allows the protective elements to be designed to be flat and / or to protrude only slightly from the underside and at the same time to define the contact area even if the underbody system is placed at an angle to one of the protective elements.

[0025] According to a further aspect of the invention, a means of transport is provided. The means of transport has an underbody system according to the invention.

[0026] Thus, a means of transport according to the invention offers the same advantages as those already described in detail with reference to an underbody system according to the invention. Preferably, the means of transport is an electric vehicle with a traction battery, which forms a functional unit of the underbody system.

[0027] Further advantages, features, and details of the invention will become apparent from the following description, which describes embodiments of the invention in detail with reference to the drawings. The features mentioned in the claims and in the description may be essential to the invention individually or in any combination. They show schematically:

[0028] Figure 1 shows an underbody system according to the invention in a plan view of an underside of an underbody structure of the underbody system,

[0029] Figure 2 the subfloor system in a cross-section,

[0030] Figure 3 shows a detailed view of a further cross-section of the underbody system with a fastening interface of a protective element of the underbody system,

[0031] Figure 4 shows a means of transport according to the invention with the underbody system.

[0032] In the following description of some embodiments of the invention, the same reference numerals are used for the same technical features even in different embodiments.

[0033] Figure 1 shows an underbody system 2 according to the invention for a means of transport 1 in a plan view of a bottom side 10.1 of an underbody structure 10 of the underbody system 2 in a first exemplary embodiment. The means of transport 1 is shown with the underbody system 2 in Figure 4. The means of transport 1 is preferably an electric vehicle with a drive 3 in the form of an electric motor.

[0034] The underbody system 2 comprises the underbody structure 10 with a functional unit 11 for a driving function of the means of transport 1. As shown in Figure 4, the functional unit 11 is a traction battery which, according to Figure 2, has several battery cells 11.1 for providing electrical energy for the drive 3 of the means of transport 1. Furthermore, the underbody structure 10 comprises a cover element 12, which forms the underside 10.1 of the underbody structure 10 to protect the functional unit 11. In the present exemplary embodiment, the cover element 12 is a battery cover, which forms part of a housing of the functional unit 11.

[0035] Furthermore, the underbody system 2 has a plurality of, here two, skid-like protective elements 20, which are fastened to the underbody structure 10, in particular via a structural part 17 for underrun protection, and extend parallel to one another along a direction of travel 200 of the means of transport 1. The protective elements 20 are arranged on the cover element 12 on the underside 10.1 of the underbody structure 10 to protect the functional unit 11 in the event of the underbody system 2 coming into contact with a subsurface 5, e.g., in the form of a roadway or an obstacle on the roadway. As shown in Figure 4, the contact can be caused, for example, by an edge, such as a curb and / or the obstacle, of the subsurface 5.

[0036] As shown in Figures 2 and 3, the protective elements 20 each protrude from the underside 10.1 to define a contact area 20.1 for contacting the substrate 5. As a result, the protective elements 20 are at the smallest distance from the substrate 5 relative to the underside 10.1, so that only the protective elements 20 contact the substrate 5, or at least one of the protective elements 20 contacts the substrate 5 before the underside 10.1 when contacting the substrate 5. To minimize the repair costs resulting from contacting the protective elements 20 with the substrate 5, the replaceable protective elements 20 can comprise a plastic and / or a metal, in particular can be made of plastic or metal.

[0037] The protective elements 20 are each detachably attached to the underbody structure 10 via at least one fastening interface 21. Thus, the protective elements 20 can form sacrificial elements and / or replacement elements that wear out upon installation and can subsequently be replaced. Damage to surrounding parts can be prevented by the protective elements 20 due to their protruding, skid-like design.

[0038] The underbody structure 10 further comprises a frame 13 for supporting the functional unit 11 on a body 4 of the means of transport 1. The frame 13 comprises a metal and forms a support structure for the functional unit 11, which has several, here at least two, longitudinal members 13.1. Each of the protective elements 20 extends along one of the longitudinal members 13.1 of the support structure. This allows for advantageous load distribution and the most direct possible support of the protective elements 20.

[0039] In particular, a load conduction path 30 for conducting a contact force via the frame 13 to the body 4 is formed at least partially through each of the protective elements 20. As shown in Figure 2, at least one tower-like support element 16 is formed on each of the longitudinal members 13.1, which is designed integrally with the frame 13. The load conduction path 30 is guided through the functional unit 11 via the support element 16. This allows the load from the contact force to be guided past the battery cells 11.1, in particular without the battery cells 11.1 being subjected to stress.

[0040] As shown in further detail in Figure 3, each of the protective elements 20 has a fastening side 22 oriented toward the underbody structure 10. Furthermore, each of the protective elements 20 has a contact side 23 for contact with the ground 5. A rib structure 24 with a plurality of ribs extending along the direction of travel 200 is formed on the contact side 23. The rib structure 24 can be used to adjust the load and / or damping upon contact, in particular by configuring the height, width, and / or number of ribs.

[0041] Furthermore, the underbody system 2 has at least one degassing channel 14 for degassing the functional unit 11. Battery gases, which can arise, for example, during aging of the traction battery, can be discharged from the battery cells 11.1 to the outside via the degassing channel 14. The degassing channel 14 extends, as shown in Figure 3, between the cover element 12 and each of the protective elements 20. A fastening means 15, which is passed through the fastening interface 21 for fastening the respective protective element 20, further extends on the underbody structure 10 into the degassing channel 14. However, it is also conceivable for the underbody system 2 to be designed without a degassing channel 14.

[0042] The above explanation of the embodiments describes the present invention exclusively by way of examples. Of course, individual features of the embodiments can be freely combined with one another, provided they are technically feasible, without departing from the scope of the present invention.

[0043] List of reference symbols

[0044] Means of transport Underbody system Drive Body Subsoil

[0045] Underbody structure Underside Functional unit Battery cell Cover element Frame

[0046] Longitudinal member Degassing duct Fastening element Support element Structural part

[0047] Protective element Contact area Fastening interface Fastening side Contact side Rib structure

[0048] Load routing path

[0049] Direction of travel

Claims

Patent claims 1. An underbody system (2) for a means of transport (1), comprising an underbody structure (10) with a functional unit (11) for a driving function of the means of transport (1), and a cover element (12) which forms an underside (10.1) of the underbody structure (10) to protect the functional unit (11), and a skid-like protective element (20) which is detachably fastened to the underbody structure (10) via at least one fastening interface (21) and extends along a direction of travel (200) of the means of transport (1) to protect the functional unit (11) when the underbody system (2) is placed on a ground (5) in a given situation, wherein the protective element (20) protrudes from the underside (10.1) to define a placement area (20.1) for placement on the ground (5).

2. Underbody system (2) according to claim 1, characterized in that the functional unit (11) is a traction battery for providing electrical energy for a drive (3) of the means of transport (1).

3. Underbody system (2) according to claim 1 or 2, characterized in that the underbody structure (10) comprises a frame (13) for supporting the functional unit (11) on a body (4) of the means of transport (1), wherein the protective element (20) at least partially forms a load conducting path (30) for conducting a contact force via the frame (13) to the body (4).

4. Underbody system (2) according to one of the preceding claims, characterized in that the frame (13) comprises a metal and the protective element (20) comprises a plastic.

5. Underbody system (2) according to one of the preceding claims, characterized in that the frame (13) forms a support structure of the functional unit (11), wherein the protective element (20) extends along a longitudinal member (13.1) of the support structure.

6. Underbody system (2) according to one of the preceding claims, characterized in that the frame (13) has at least one tower-like support element (16) via which the load conducting path (30) is guided through the functional unit (11).

7. Underbody system (2) according to one of the preceding claims, characterized in that the protective element (20) has a fastening side (22) which is oriented towards the underbody structure (10) and a mounting side (23) for mounting on the substrate (5), wherein a rib structure (24) is formed on the mounting side (23).

8. Underbody system (2) according to one of the preceding claims, characterized in that a degassing channel (14) for degassing the functional unit (11) is provided, which extends between the cover element (12) and the protective element (20), wherein a fastening means (15) for fastening the protective element (20) to the underbody structure (10) extends into the degassing channel (14).

9. Underbody system (2) according to one of the preceding claims, characterized in that several skid-like protective elements (20) are detachably fastened to the underbody structure (10) and extend parallel to one another along the direction of travel (200) of the means of transport (1).

10. Means of transport (1) comprising an underbody system (2) according to one of the preceding claims.

Citation Information

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