Motor vehicle having a drive battery and an underbody panel

Abstract

According to the invention, a motor vehicle has an electric drive, a drive battery which is mounted on an underside of the body of the motor vehicle, and an underbody panel which is fastened at least to the drive battery, in particular from below. The underbody panel is fastened to the drive battery by means of a coupling device. The coupling device has a vehicle-side coupling element and an underbody-panel-side coupling element. The vehicle-side coupling element of the coupling device is fastened to the drive battery, in particular to an underside of the drive battery or of a housing of the drive battery. The vehicle-side coupling element is designed for interlocking engagement with an underbody-panel-side coupling element.

Description

[0001] Motor vehicle with a traction battery and underbody paneling

[0002] The invention relates to a motor vehicle with an electric drive, a drive battery which is mounted in the area of ​​an underside of a body of the motor vehicle, and an underbody panel which is attached from below at least to the drive battery.

[0003] It is common practice to install underbody paneling on motor vehicles, particularly passenger vehicles. Underbody paneling is a flat component that is attached to the underside of the vehicle using bolts or screws. It protects the underbody from dirt and damage and improves the vehicle's aerodynamics.

[0004] Furthermore, a motor vehicle with an electric drive has a drive battery which is mounted under a passenger compartment from below the motor vehicle and extends in an area from a left sill to a right sill as well as a front and a rear section.

[0005] The object of the present invention is to provide a motor vehicle with an electric drive, a drive battery and an underbody panel mounted on the drive battery from below, wherein the ground clearance of the motor vehicle is restricted as little as possible by the attachment of the underbody panel to the drive battery.

[0006] This problem is solved by a motor vehicle that incorporates the combination of features of claim 1. Advantageous further developments are described in the dependent claims.

[0007] According to the invention, a motor vehicle has an electric drive, a drive battery (for the electric drive), which is mounted, for example, from below on the underside of the vehicle body, and an underbody panel, which is attached, in particular, from below, at least to the drive battery. The underbody panel is attached to the drive battery by means of a coupling device. The coupling device has a vehicle-side coupling element and an underbody panel-side coupling element. The vehicle-side coupling element of the coupling device is attached to the drive battery, in particular to an underside of the drive battery or a housing of the drive battery. The vehicle-side coupling element is designed for positive engagement with an underbody panel-side coupling element.

[0008] The positive-locking engagement between the coupling elements enables a space-saving yet reliable connection of the underbody panel to the drive battery. The underbody panel's coupling element, which is positively coupled to the vehicle-side coupling element, in turn positively locks the underbody panel into the drive battery.

[0009] The coupling device according to the invention is in particular not a force-fit connection. For example, it is not a screw connection or

[0010] Bolted connection. The coupling device according to the invention is, for example, also not a riveted connection. In particular, the coupling device according to the invention is also not a material-bonded connection.

[0011] The positive engagement of the coupling element on the underbody panel side is preferably achieved by means of an undercut, i.e. an undercut connection.

[0012] Preferably, the vehicle-side coupling element of the coupling device is bonded to the traction battery, in particular by adhesive bonding. The vehicle-side coupling element can also be welded to the traction battery. However, the adhesive bond is advantageous because, in the event of a damaged or defective coupling element, it can be replaced more easily without affecting or damaging the traction battery or its housing.

[0013] Preferably, the coupling element on the underbody panel side is designed to be movable.

[0014] This allows the underbody paneling to be attached without having to move the underbody paneling itself.

[0015] The coupling element on the underbody panel side can be a component completely separate from the underbody panel, i.e., the coupling element on the underbody panel side is not connected to the underbody panel.

[0016] Alternatively, the coupling element on the underbody panel side can be movably mounted on the underbody panel, i.e., the coupling element on the underbody panel side can be movably connected to the underbody panel.

[0017] This has the advantage during the installation of the underbody paneling that the coupling element is already attached to the underbody paneling.

[0018] According to a preferred embodiment, the movable coupling element on the underbody panel side is designed to be displaceable or slidable parallel to the extent of the underbody panel in order to engage with the coupling element on the vehicle side. For example, the coupling element on the underbody panel side is movable in a plane parallel to an xy-plane and / or parallel to the underside of the drive battery and / or parallel to an extent of the underbody panel.

[0019] This allows for good compensation of dimensional tolerances in the underbody paneling. Furthermore, a particularly space-saving coupling device is enabled in the vehicle's vertical direction. Preferably, the movable coupling element on the underbody paneling side is rotatably designed to engage with the vehicle-side coupling element parallel to the extension of the underbody paneling.

[0020] The coupling device is therefore preferably designed in the manner of a so-called bayonet connection. In particular, the coupling device can have a locking mechanism perpendicular to the direction of movement of the coupling element on the underbody panel side.

[0021] This protects the coupling device against unwanted decoupling, i.e., unwanted movement, of the coupling element on the underbody panel side in the opening direction of the coupling.

[0022] The vehicle-side coupling element can in particular have concentrically arranged undercuts, which are formed in particular by means of a rotary movement to engage with in particular concentrically arranged wings or projections of the underbody panel-side coupling element.

[0023] The vehicle-side coupling element can have a large number of wings, for example three, four, five, six.

[0024] According to a preferred embodiment of the present invention, the traction battery is coated with a corrosion protection layer that overlaps with the vehicle-side coupling element.

[0025] The corrosion protection layer can consist of sprayed-on polyvinyl chloride (PVC).

[0026] The underbody paneling can be connected to the drive battery via a variety of coupling devices.

[0027] The underbody paneling can consist of several underbody paneling parts, each of which is connected to the drive battery via the coupling device according to the invention. Advantageously, the vehicle-side coupling element is made of a preferably heat-resistant plastic, in particular polybutylene terephthalate, and / or a fiber-reinforced plastic. Furthermore, the underbody panel-side coupling element is made of plastic, in particular polybutylene terephthalate and / or a fiber-reinforced plastic.

[0028] Plastic has the advantage of being lightweight and inexpensive. Furthermore, if the coupling device strikes a surface or an object on the surface during vehicle operation, plastic is advantageous because it may break or be destroyed before the forces are transmitted to the traction battery housing and damaged. A heat-resistant plastic for the vehicle-side coupling element is particularly advantageous with regard to a coating process using an oven to create the corrosion protection layer. This allows the vehicle-side coupling element to pass through the oven together with the battery housing. Polybutylene terephthalate is particularly suitable as a heat-resistant plastic.

[0029] According to a preferred embodiment of the invention, the underbody panel can additionally be frictionally connected at a point projecting over the traction battery to a vehicle body and / or to a projection located on or attached to a lateral edge of the traction battery. Likewise, the vehicle-side coupling element can additionally be frictionally connected at a point projecting over the traction battery to a vehicle body and / or to a projection located on or attached to a lateral edge of the traction battery.

[0030] The projection can be any type of mounting tab suitable for a screw connection or bolt connection.

[0031] The aforementioned characteristics can be combined in any way possible and where appropriate. A brief description of the figures follows.

[0032] Fig. 1 is a schematic, perspective exploded view of a coupling device for attaching an underbody panel to a drive battery according to a first embodiment of the present invention.

[0033] Fig. 2 is a schematic top view from below of an underbody panel according to the first embodiment of the present invention.

[0034] Fig. 3 is a schematic sectional view of the coupling device according to the first embodiment of the present invention.

[0035] Fig. 4 is a schematic perspective view of a vehicle-side coupling element of the coupling device according to the first embodiment of the present invention.

[0036] Fig. 5 is a schematic perspective view of an underbody panel-side coupling element of the coupling device according to the first embodiment of the present invention.

[0037] Fig. 6 is a schematic top view from below of an underbody panel according to the second embodiment of the present invention.

[0038] Fig. 7 is a schematic sectional view of the coupling device according to the second embodiment of the present invention.

[0039] Fig. 8 is a schematic sectional view of an additional fastening of an underbody panel or an underbody panel coupling element according to the embodiments of the present invention.

[0040] Exemplary embodiments of the present invention are explained below with reference to Figures 1 to 8. According to a first embodiment of the present invention, a motor vehicle, in particular a passenger car, with an electric drive has a drive battery 1 for the electric drive, which is mounted, for example, from below, on an underside or an underbody assembly of a body of the motor vehicle under a passenger compartment, and an underbody panel 3, which is attached to the drive battery 1 from below. As shown in Fig. 1, the underbody panel 3 is attached to the drive battery 1 by means of a coupling device. The coupling device consists of a vehicle-side coupling element 5 and an underbody panel-side coupling element 7. In Fig. 1, only a small section, namely a coupling section, of the underbody panel is visible.

[0041] The vehicle-side coupling element 5 is bonded over its entire surface to the underside of the traction battery 1 or to a traction battery housing of the traction battery 1. The underbody panel 1 has a through-hole 31. Around the through-hole 31, the underbody panel 1 is provided with a recess 33 similar to an embossing. In the area of ​​the recess 33, the underbody panel 3 rests against the traction battery 1 in the assembled state. The recess 33 is provided at one point with an aerodynamically effective chamfer 35, which improves the aerodynamics of the underbody panel 3 in the area of ​​the coupling device. The chamfer 35 is located behind the coupling device in the direction of travel.

[0042] Fig. 2 shows the entire underbody panel 3 from below. As can be seen, the underbody panel 3 consists of three underbody panel elements 301, 302, 303, which are mounted adjacent to each other on the underbody of the vehicle and the traction battery 1. The traction battery 1, located above the underbody panel 3, is indicated by a dashed line. In total, twelve coupling elements 7 on the underbody panel side can be seen in Fig. 2, all of which are located in the area of ​​the traction battery 1; that is, the underbody panel is attached to the traction battery 1 by a total of twelve coupling devices. The underbody panel 3 protects the traction battery 1 from below against mechanical damage and corrosion. In addition, the underbody panel 3 improves the aerodynamics of the vehicle. The underbody panel 3, or rather,The three underbody paneling elements 301, 302, 303 are preferably a plastic injection molded part / plastic injection molded parts.

[0043] The coupling device is particularly well illustrated in the schematic sectional view of Fig. 3. At least one substantially flat underside of the traction battery 1 is shown at the top of Fig. 3. The vehicle-side coupling element 5 is glued to this underside with a flat base 55 or a flat base plate 55. Furthermore, the underside of the traction battery 1 is coated with a PVC layer 9 (polyvinyl chloride layer) that overlaps the base plate 55 of the vehicle-side coupling element 5. The PVC layer 9 was applied only after the vehicle-side coupling element 5 had been attached. The PVC layer 9 serves as corrosion protection for the underside of the traction battery 1, whose housing is made of steel. The overlapping PVC layer 9 prevents corrosion between the traction battery 1 and the base plate 55. A rear side of the recess 33 (a projection when viewed from the rear) of the underbody panel 3 rests against the traction battery 1.

[0044] The vehicle-side coupling element 5 has a base plate 55, which can also be referred to as a base plate, from which a projection with wings 53 extends. The wings 53, together with the base plate 55, form an undercut 51. The underbody panel-side coupling element 7 essentially consists of an annular plate 75 with wings 71 arranged in the area of ​​an annular hole 79, which engage with the undercuts 51 of the vehicle-side coupling element 5. An outer edge of the annular plate 75 of the underbody panel-side coupling element 7 engages with an edge of the passage opening 31 of the underbody panel 3. Thus, the underbody panel 3 is clamped in the area of ​​the passage opening 31 between the plate 75 of the underbody panel-side coupling element 7 and the traction battery housing of the traction battery 1, which is coated with the PVC layer 9, and is therefore positively connected.The coupling element 7 on the underbody panel side is in turn positively connected to the coupling element 5 on the vehicle side. The coupling device according to the first embodiment is explained in more detail below with reference to Figures 4 and 5.

[0045] As can be seen in Fig. 4, the vehicle-side coupling element 5 has four evenly spaced wings 53, which form four undercuts 51 with the base 55. The four wings 53 are formed on an annular cylinder element 59 and each project radially outwards from the annular cylinder element 59. Furthermore, the vehicle-side coupling element 5 has a projection 57 in its center. The projection 57 serves to attach a masking element (not shown), which, during the application of the PVC layer 9, is intended to prevent the components of the vehicle-side coupling element 7, which mechanically couple with the underbody panel-side coupling element 7, from being coated with the PVC layer 9. The projection 57 no longer serves a function after the PVC layer 9 has been applied and the masking element removed.

[0046] The sprayed-on PVC layer 9 is cured in an oven at approximately 160°C, or at least within a temperature range of 140°C to 180°C or above 100°C. Therefore, both the vehicle-side coupling element 5 and the bonding of the coupling element 5 to the drive battery 1 must be appropriately heat-resistant. A suitable heat-resistant plastic with sufficient strength and rigidity is, for example, polybutylene terephthalate.

[0047] As shown in Fig. 5, the underbody panel coupling element 7 has four evenly spaced wings 71 on the inner circumference of the annular hole 79, projecting radially inwards. At one end of each wing 71 is a stop 73, which serves both as a stop to prevent the underbody panel coupling element 7 from over-rotating and to provide mechanical stability to the respective wing 71. The direction of rotation for opening and locking the underbody panel coupling element 7 is indicated by an arrow and the terms "OPEN" and "CLOSE". When installing the underbody panel 3, it is positioned on the underside of the vehicle's traction battery 1. The underbody panel coupling element 7 is then positioned on the vehicle-side coupling element 5.The underbody panel-side coupling element 7 is then rotated with the vehicle-side coupling element 5 until the stops 73 of the underbody panel-side coupling element 7 fully engage, so that the wings 71 of the underbody panel-side coupling element 7 engage with the undercuts 51 of the vehicle-side coupling element 5. Grooves 77 on an outer side of the annular plate 75 are provided for engagement with a suitable assembly tool to rotate and establish the positive locking of the underbody panel-side coupling element 7. The underbody panel-side coupling element 7 can also be rotated by hand without a tool. Detent projections or locking lugs may be provided on the wings 71 of the underbody panel-side coupling element 7 and on the wings 53 of the vehicle-side coupling element 5.Interlocking recesses are provided, serving as an anti-rotation device after the underbody panel coupling element 7 has been installed. After the underbody panel coupling element 7 has been installed, the outer edge of the plate 75 overlaps with the edge of the through-hole 33 of the underbody panel 3, so that the underbody panel 3 is positively locked between the plate 75 and the drive battery 1.

[0048] Overall, the coupling device of the first embodiment functions similarly to a so-called bayonet connection.

[0049] As can be seen from the figures, the coupling device according to the first embodiment has a low height in the Z-direction, i.e., in the vehicle's vertical direction. The overall height of the attachment of the underbody panel 3 to the traction battery 1, for example, is approximately 5 mm – including and especially in the area of ​​the coupling device. Thus, the underbody panel 3 has a minimal impact on the vehicle's ground clearance. Furthermore, this coupling device allows for large tolerances in the attachment of the underbody panel 3 in an xy plane of the vehicle. The coupling device is also essentially flush with the underbody panel 3. This coupling device also eliminates the need to provide the traction battery 1 or the traction battery housing with a hole for a screw or bolt connection, thereby weakening it or increasing the potential for leaks in the traction battery housing.

[0050] The underbody panel 3 serves to protect the PVC layer 9 on the traction battery 1. Without the underbody panel 3, this PVC layer 9 could easily be damaged from below during the vehicle's operation, leaving the underside of the traction battery housing unprotected against corrosion.

[0051] According to a second embodiment of the present invention, shown in Figures 6 and 7, in contrast to the first embodiment described above, a coupling device is designed alternatively such that an underbody panel-side coupling element 7' is linearly displaceable relative to a vehicle-side coupling element 5' when an underbody panel 3' is mounted on a drive battery 1', thereby creating a corresponding undercut, positive-locking engagement between the coupling elements 5' and 7'.

[0052] According to the second embodiment, the coupling element 7' on the underbody panel side is a coupling strip that extends over the entire width of the underbody panel 3' and engages with a straight edge 33' of the underbody panel 3' over its entire width. Preferably, the coupling strip 7' is arranged between two underbody panel elements 30T and 302', so that the positively fitted coupling strip 7' positively engages both underbody panel elements 301' and 302' with the drive battery 1'.

[0053] The vehicle-side coupling element 5' has a flat base plate 55', which is bonded to the underside of the drive battery 1', and a mushroom-shaped, circular head 59' on a corresponding stem that projects downwards from the base plate 55'. The coupling strip 7' has several coupling openings 79', of which only two coupling openings 79' are shown by way of example in Fig. 6. Each coupling opening 79' is designed in the form of an elongated hole 79', which has a circular diameter widening at one end. The circular cylindrical stem of the mushroom-shaped head 59' has a slightly smaller diameter than the width of the elongated hole 79'. The mushroom-shaped head 59' has a slightly smaller diameter than the diameter of the circular diameter widening. As shown in Fig. 7, when the coupling strip 7' is mounted, the mushroom-shaped head 59' engages with the coupling strip 7' and the underbody panel 3' is thereby held in a form-fitting manner.The mushroom-shaped head 59' is flush with both the coupling strip 7' and the underbody paneling 3'.

[0054] During assembly of the coupling strip 7', the mushroom-shaped heads 59' of the vehicle-side coupling element 5' initially align with the circular diameter expansions of the corresponding elongated holes 79'. The coupling strip 7' is then brought into contact with the base plate 55', allowing it to be moved along the elongated holes while engaging the mushroom-shaped heads 59'. The coupling strip 7' is then moved linearly in the xy plane of the vehicle, resulting in a positive engagement between the mushroom-shaped heads 59' and the coupling strip 7'.

[0055] The coupling strip 7' is preferably made of metal or plastic, with metal, for example aluminium, being preferred due to its corrosion resistance and higher stiffness.

[0056] In principle, according to the embodiments described above, the underbody panel can also be additionally connected laterally to the traction battery, i.e., to the vehicle body or to a lateral projection of the traction battery housing, by means of a screw or bolt connection, either to the left, right, in front of, or behind the traction battery. Figure 8 shows a sectional view of a lateral section of such a traction battery 1, T. As can be seen, the underbody panel 3, 3' projects laterally beyond the traction battery 1, 1'. A mounting tab 13, 13' or the like is attached laterally to the traction battery housing, to which the underbody panel 3, 3' is fastened by means of a screw connection 15, 15'. At this position laterally to the traction battery housing, there is sufficient space in the vertical direction of the vehicle for the screw connection 15, 15' without weakening the traction battery housing itself.The lateral screw connection 15, 15' can thereby additionally secure the underbody panel 3, 3'.

[0057] Likewise, according to the second embodiment, the coupling strip 7' can be additionally secured laterally with the screw connection 15', thereby preventing an unwanted linear displacement of the coupling strip 7' in a decoupling direction.

Claims

Patent claims 1. Motor vehicle with electric drive and a traction battery (1 ; 1 ') and an underbody panel (3; 3'), wherein the underbody panel (3; 3') is attached to the traction battery (1; T) by means of a coupling device, wherein a vehicle-side coupling element (5; 5') of the coupling device is attached to the traction battery (1; T), which is designed to engage positively with an underbody panel-side coupling element (7; 7').

2. Motor vehicle according to claim 1, wherein the coupling element (7; 7') on the underbody panel side is movably designed, and wherein in particular the coupling element (7; 7') on the underbody panel side is movable in a plane parallel to an xy-plane and / or parallel to the underside of the traction battery (1;T) and / or parallel to an extension of the underbody panel (3; 3').

3. Motor vehicle according to claim 2, wherein the coupling element on the underbody panel side is movably mounted to the underbody panel.

4. Motor vehicle according to claim 2 or 3, wherein the movable underbody panel-side coupling element (7') is designed to be displaceable parallel to the extension of the underbody panel (3') for engagement with the vehicle-side coupling element (5').

5. Motor vehicle according to claim 2 or 3, wherein the movable underbody panel-side coupling element (7) is rotatably designed to engage with the vehicle-side coupling element (5) parallel to the extension of the underbody panel (3).

6. Motor vehicle according to claim 5, wherein the vehicle-side coupling element (5) has in particular concentrically arranged undercuts (51) which are designed to engage with in particular concentrically arranged wings (71) of the underbody panel-side coupling element (7).

7. Motor vehicle according to one of claims 1 to 6, wherein the traction battery (9) is coated with a corrosion protection layer (9), in particular polyvinyl chloride, which overlaps with the vehicle-side coupling element (5).

8. Motor vehicle according to one of claims 1 to 7, wherein the vehicle-side coupling element (5; 5') and / or the underbody panel-side coupling element (7; 7') are made of plastic, in particular of polybutylene terephthalate and / or a fiber-reinforced plastic.

9. Motor vehicle according to one of claims 1 to 8, wherein the vehicle-side coupling element (5; 5') is materially bonded to the traction battery (1 ; 1'), in particular by bonding.

10. Motor vehicle according to one of claims 1 to 9, wherein the underbody paneling (3, 3') and / or the coupling element (7') on the underbody paneling side is additionally connected to a body of the motor vehicle by means of a force-fit area projecting over the traction battery (1; T) and / or is connected to a projection (13) present or attached to a lateral edge of the traction battery (1; T).

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