Vehicle with a high-voltage battery system

Abstract

Vehicle with a high-voltage battery system having a battery housing (3), beneath whose housing base (9) an underrun protection plate (13) is arranged, which is spaced from the housing base (9) downwards by a deformation clearance (12) so that, in particular in the event of contact with the ground, an interfering contour on the roadway, such as a bollard or a curb, deforms the underrun protection plate (13) into the deformation clearance (12) with a contact force directed upwards towards the vehicle, wherein at least one spring element (17) is arranged in the deformation clearance (12), which dissipates deformation energy by elastic deformation, wherein the spring element (17) is a hollow profile element with a V-shaped or trapezoidal cross-section, which has at least one profile vertex (19) from which elastically resilient profile flanks (21) protrude on both sides, wherein the flank ends (23) laterally from the profile flanks (21) angled support flanges are characterized in thatthat the flank ends (23) of the hollow profile element are in sliding contact with the associated connection partner, namely the battery housing base (9), so that when the battery housing base (9) touches the ground, a relative movement (R) transverse to the direction of the contact force is possible, that the battery housing base (9) is at least partially double-walled with an upper base plate (4) and a lower cooling plate (6) of a cooling system, that the cooling plate (6) has at least one cooling embossment (8) which projects downwards from a cooling plate base section (10) by an embossing height and delimits a coolant channel (25), and that the cooling embossment (8) formed on the cooling plate (6) protrudes in a nested manner into a cavity (26) delimited between the profile flanks (21) of the hollow profile element.

Description

The invention relates to a vehicle having a high-voltage battery system according to the preamble of claim 1.In an electrically operated two-lane vehicle, the high-voltage battery of vehicle-mounted units can be inserted into a mounting space of the vehicle that is open on the floor side. The high-voltage battery is to be protected as a crash-sensitive component from mechanical damage, inter alia, in the event of a floor landing.Against this background, a vehicle has an underride protection panel below the battery housing base. This is spaced apart from the housing base by a deformation clearance from the vehicle interior. In the case of ground contact, a roadway-side interference contour, for example a bollard or a curbstone, can deform the underride protection panel into the deformation clearance with a contact force directed toward the vehicle. To increase the deformation strength, at least one spring element is arranged in the deformation clearance, which spring element dissipates deformation energy under elastic deformation.In the prior art, the spring element is expensive to produce, for example, made of a foam base material. Its elastic deformation properties cannot be readily configured such that a defined dissipation of deformation energy can take place in the event of a floor being landed.DE 10 2017 103 654 A1 discloses a battery housing of the generic type for a vehicle battery. A surface component is known from DE 10 2019 213 750 B3. DE 10 2018 115 919 A1 discloses a traction battery for a vehicle. An energy storage arrangement is known from DE 10 2019 127 588 B3. From DE 10 2016 125 693 A1, a battery carrier for a vehicle is known. DE 10 2010 024 320 A1 discloses a device for holding a battery in a vehicle body. DE 10 2020 003 193 A1 discloses a motor vehicle bodyshell. U.S. Pat. No. 11,142,058 B2 and U.S. Pat. No. 10,811,649 B2 each disclose vehicles with underrun protection.The object of the invention is to provide a vehicle in which the high-voltage battery can be protected from mechanical damage in the event of a floor contact compared to the prior art with reduced component outlay, reduced installation space requirement and / or reduced production outlay.The object is achieved by the features of claim 1. Preferred developments of the invention are disclosed in the dependent claims.The invention is based on a vehicle having a high-voltage battery system having a battery housing. Below its housing base, an underride protection plate is arranged, which is spaced apart from the housing base by a deformation clearance towards the vehicle interior. In the event of a road surface being seated, a disturbance contour on the road side, for example a bollard or a curbstone, can thereby deform the underride protection panel into the deformation clearance with a seating force directed towards the vehicle. At least one spring element is arranged in the deformation clearance, which can dissipate deformation energy under elastic deformation. According to the invention, the spring element is designed as a hollow profile element which is V-shaped or trapezoidal in cross section. The hollow profile element has at least one profile apex from which elastically resilient profile flanks project on both sides.The profile cross section of the V-shaped or trapezoidal hollow profile element is comparable to the profile cross section of a disk spring, with the difference that the profile cross section of the V-shaped or trapezoidal hollow profile element remains largely constant over its entire component length.In a technical implementation, the hollow profile element can be supported with its profile apex on a connection partner, in particular underrun protection panel, and with its profile flanks on the other connection partner, in particular battery housing base, with a defined prestress.The flank ends are support flanges angled laterally outwards from the profile flanks. A core of the invention consists in the fact that the flank ends of the hollow profile element are supported in sliding contact and with predefined prestress on the associated connection partner, namely the battery housing base. In this way, in the event of a floor landing, a relative movement transversely to the direction of the landing force is made possible between the flank ends of the hollow profile element and the associated connecting partner.In contrast to the flank ends, the profile apex of the hollow profile element is in a firmly bonded or force-fit connection with the other connection partner, in particular underrun protection plate. The fixed connection is preferably realized by welding, adhesive bonding and / or by means of a mechanical auxiliary joining element (for example screws or rivets).In a concrete embodiment, the profile apex of the hollow profile element can be firmly connected to the underrun protection plate, while the profile flanks of the hollow profile element are in sliding contact with the battery housing base. In the event of a floor landing, the profile apex of the hollow profile element therefore acts as a junction point at which a force distribution into the two profile flanks takes place.From a manufacturing standpoint, it is advantageous if the underrun protection plate and the hollow profile element are held in stock as a one-piece structural unit. The underrun protection structural unit can then be fastened to the vehicle underside during the vehicle assembly.The base material of the V-shaped or trapezoidal hollow profile part can preferably be a plastic made of endless fiber-reinforced semi-finished products (e.g. organoplates, laminates made of unidirectional tapes (here preferably made of GF / PP)), alternatively an injection-molded material or a metal sheet (aluminum or steel). By way of example, both the underrun protection plate and the hollow profile element can be manufactured from plastic, in particular fiber composite plastic. In this case, the hollow profile element can be joined to the underride protection panel by ultrasonic welding. With regard to a perfect welded connection, before the welding process is carried out, the hollow profile element and / or the underrun protection plate can be provided with a plastics additional layer at the weld joint in order to provide sufficient welding material for the weld lens between the underrun protection plate and the hollow profile element. For the welding, it is necessary that the plastic base material of the respective spring element is chemically compatible or of the type with the base material in the continuous fiber region of the underride protection panel (e.g. polypropylene with polypropylene).The hollow profile element can be cut from an endless strand, for example, and / or extend over a profile length in the form of a strip and in a straight line. In addition, the hollow profile element can have a constant or varying wall thickness in the longitudinal direction of the profile. In the same way, the hollow profile element can also have a constant or varying wall thickness transversely to the longitudinal direction of the profile. Furthermore, the V-shaped or trapezoidal hollow profile element can be realized in different geometries and / or with different wall thicknesses, curvature angles and radii in order to enable a defined energy absorption. The wall thicknesses can also be variable over the length of the component and range from 0.5 mm to 5 mm.To provide a battery cooling system, a cooling plate can be fastened to the underside of the battery housing base. The cooling plate may have at least one cooling embossment that projects vehicle-unbaked from a cooling plate base portion by an embossment height. The cooling embossment delimits a coolant channel together with the battery housing base. The cooling plate base section, on the other hand, is firmly connected to the battery housing base. In the event of a floor landing, a satisfactory functionality of the hollow profile element is of decisive importance. Against this background, the flank ends of the hollow profile element can be in sliding contact with the respective cooling plate base section. In contrast, it is preferred if the profile flanks of the hollow profile element are spaced apart from the cooling embossment over a clearance, that is to say are free of contact with respect to the cooling embossment.With regard to an arrangement which is reduced in installation space, according to the invention the cooling embossment formed on the cooling plate projects, in a nested manner, into the cavity bounded between the profile flanks of the hollow profile element.An exemplary embodiment of the invention is described below with reference to the attached figures.The following are shown: FIGS. 1 to 10 each show different views, on the basis of which the underrun protection according to the invention is illustrated.FIG. 1 is a side view, partly in elevation, of a two-track vehicle in side view. The vehicle has a mounting space below a vehicle floor 1, in which a high-voltage battery 2 of vehicle-mounted units is installed. A battery housing 3 (FIG. 2 ) of the high-voltage battery 2 is formed with an upper housing cover 5, a laterally encircling housing side wall 7 and a housing base 9. According to FIG. 4, the housing base 9 is embodied in a double-walled manner from an upper base plate 4, on which battery cells 29 (FIG. 3 ) are arranged, and a lower cooling plate 6 of a cooling system described later. Projecting laterally outwards from the housing side wall 7 of the battery housing 3 is a housing flange 11 (FIG. 2 or 3 ), which can be mounted on an underside of a vehicle sill (not shown).The cooling plate 6 of the cooling system is fastened to the underside of the floor plate 4 and, according to FIG. 3 or 4, has a number of cooling embossments 8 which project to the vehicle interior from a cooling plate base section 10 by an embossing height. The cooling embossments 8 together with the base plate 4 delimit coolant channels 25 (FIG. 4 ).Below the housing base 9, there is also provided an underrun protection 13 which, in the event of a base coming down, protects the battery housing 3 from mechanical damage. The underride guard 13 is formed in FIG. 3 or 4 from an underride guard plate 15 and a plurality of spring elements 17. These are designed in the figures as V-shaped hollow profile elements, namely, viewed in cross section, with a profile apex 19 and profile flanks 21 which are raised obliquely outwards on both sides thereof.In the present exemplary embodiment, both the underride protection plate 15 and the spring elements 17 are manufactured, for example, from a fiber composite plastic. The profiled wedge 19 is connected, for example, by welding or bonding, in a fixed connection 20 to the underrun protection plate 15, while the flank ends 23 are supported in sliding contact on the cooling plate 6 with a predefined prestressing force. The flank ends 23 of the spring elements 17 are realized, for example, according to FIG. 4 as support flanges angled laterally from the profile flanks 21.As can be seen from FIG. 3 or 4, two cooling embossments 8 each project into the cavity 26 bounded between the profile flanks 21 of the respective spring element 17. The width b (FIG. 4 ) of the cooling plate base sections 10 is dimensioned such that the flank ends 23 can move freely transversely to the longitudinal extent of the spring elements 17 in a relative movement R without colliding with the cooling embossments 8. In addition, the profiled flanks 21 are spaced apart from the cooling embossments 8 via a clearance f in order to ensure a relative movement R free of disturbing contours.As can be further seen from FIG. 3, gas passages 27 are formed on the housing base 9. In the case of a thermal event in one of the battery cells 29 of the high-voltage battery 2, a gas is discharged from the haemorrhaging battery cell 29 via the associated gas passage 27 as far as into the deformation clearance 12. The gas can be guided via the deformation clearance 12 as far as an emergency degassing opening (not shown) and emerge there to the outside of the vehicle. In order to ensure a disturbance-free gas flow in the deformation clearance 12, the profiled flanks 21 of the spring elements 17 are formed with flow passages 31 (FIG. 4 ).Each of the spring elements 17 is configured in the shape of a strip and elongated in a straight line over a profile length l (FIG. 9 or 10). The spring element 17 can have a constant or a varying wall thickness s in the longitudinal direction of the profile. In addition, the spring element 17 can have a constant wall thickness s or a varying wall thickness transversely to the longitudinal direction of the profile, as is indicated in FIG. 8. According to FIG. 8, the spring element 17 has material thickenings s 2 at the edge transitions between profile apexes 19 and profile flanks 21 and between profile flanks 21 and flank ends 23, while the remaining wall sections have a wall thickness s 1 which is reduced in comparison therewith.In order to ensure a perfect ultrasonic welding process, according to FIG. 6, the spring element 17 and / or the underride protection panel 15 are provided with a plastic additional layer 33 before the welding process is carried out. In this way, sufficient welding material for a weld lens is provided between underrun protection plate 15 and spring element 17.As can be seen from FIG. 7, the profile flanks 21 of the spring element 17 can be realized in any geometrically arbitrary manner. By way of example, in FIG. 7, the left-hand profile flank 21 is indicated in three variants a to c. In variant a, the profile flank 21 is guided in a flat orientation and obliquely outwards in a straight line. In variant b, the profile flank 21 is oriented more steeply and is provided with a bend. In variant c, the profile flank 21 is likewise embodied as steep and with a straight course.List of reference characters1 Vehicle base 2 High-voltage battery 3 Battery housing 4 Base plate 5 Housing cover 6 Cooling plate 7 Housing side wall 9 Housing base 11 Housing flange 12 Deformation clearance 13 Underrun protection 15 Underrun protection plate 17 Spring elements 19 Profile center 20 Fixed connection 21 Profile flanks 23 Flank ends 25 Coolant channel 26 Cavity 27 Gas passage 29 Battery cell 31 Flow passages 33 Plastics additional layer f Clearance s 1, s 2 Wall thickness I Spring element length R Relative movement

Claims

Vehicle having a high-voltage battery system with a battery housing (3), below the housing base (9) of which there is arranged an underrun protection plate (13) which is spaced apart from the housing base (9) in the vehicle's direction by a deformation clearance (12), so that, in particular in the event of a ground landing, a disturbance contour on the road side, for example a bollard or a curbstone, deforms the underrun protection plate (13) into the deformation clearance (12) with a seating force directed in the vehicle's direction, wherein at least one spring element (17) is arranged in the deformation clearance (12), which spring element dissipates deformation energy under elastic deformation, wherein the spring element (17) is a hollow profile element which is V-shaped or trapezoidal in cross section and has at least one profile apex (19) from which elastically resilient profile flanks (21) protrude on both sides, wherein the flank ends (23) are support flanges angled laterally from the profile flanks (21), characterized in that the flank ends (23) of the hollow profile element are in sliding contact with the associated connecting partner, namely the battery housing base (9), so that in the event of a base contact a relative movement (R) transversely to the contact force direction is made possible, in that the battery housing base (9) is at least partially double-walled with an upper base plate (4) and a lower cooling plate (6) of a cooling system, in that the cooling plate (6) has at least one cooling embossment (8) which projects beyond a cooling plate base section (10) in a vehicle-non-vehicle direction and delimits a coolant channel (25), and in that the cooling embossment (8) formed on the cooling plate (6) projects, in a manner nested into a cavity (26) delimited between the profile flanks (21) of the hollow profile element.Vehicle according to claim 1, characterised in that the hollow profile element is supported with its profile apex (19) on one connection partner, namely underrun protection plate (15), and with its profile flanks (21) on the other connection partner, namely battery housing base (9), with defined prestress.Vehicle according to either of Claims 1 and 2, characterized in that the profiled apex (19) of the hollow profiled element is in fixed connection (20) with the other connection partner, in particular underride protection panel (15), for example by welding, adhesive bonding and / or by means of a mechanical auxiliary joining element, and / or in that flow passages (31) are formed in particular in the profiled flanks (21) of the spring element (17).Vehicle according to one of the preceding claims, characterized in that the underride protection panel (15) and the hollow profile element are held in the form of a one-piece structural unit which is fastened to the vehicle underside during vehicle assembly.Vehicle according to one of the preceding claims, characterized in that the underride protection panel (15) and the hollow profile element are manufactured from plastic, in particular fiber composite plastic, and in that the hollow profile element can be bonded to the underride protection panel (15) by ultrasonic welding, and in that, in particular before carrying out the welding process, the hollow profile element and / or the underride protection panel (15) is provided with a plastic additional layer (33) at the welding joint in order to provide welding material between the underride protection panel (15) and the hollow profile element.Vehicle according to one of the preceding claims, characterized in that the hollow profile element is elongate in a straight line in the form of a strip over a profile length (I), and / or in that the hollow profile element has a constant or varying wall thickness (s) in the profile longitudinal direction, and / or in that the hollow profile element has a constant or varying wall thickness (s 1, s 2) transversely with respect to the profile longitudinal direction.Vehicle according to one of claims 2 to 6, characterised in that the flank ends (23) of the hollow profile element are in sliding contact with the respective cooling plate base section (10).Vehicle according to claim 7, characterised in that the profile flanks (21) of the hollow profile element are spaced apart from the cooling embossment (8) via a clearance (f).

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