Trailer hitch arrangement for a motor vehicle

Abstract

Trailer coupling arrangement (1) for a motor vehicle, comprising a transverse tube (2) extending in the transverse direction (Y) of the vehicle, which has a central section (2.1) for at least indirectly connecting a trailer coupling (20) and on both sides of this a side section (2.3) which is connected to a vehicle body-side mounting element (6) via a connecting arrangement (3), wherein each side section (2.3) is arranged at least partially at the level of the mounting element (6) in the transverse direction (Y) and in the vertical direction (Z) of the vehicle and the connecting arrangement (3) is configured to move in the event of an impact on the side section (2.3) to deform in an energy-absorbing manner the pulsating force acting in the longitudinal direction (X) of the vehicle towards the mounting element (6), characterized in that each connecting arrangement (3) has an outer connecting plate (4) and an inner connecting plate (5), each extending between the mounting element (6) and the side section (2.3) and spaced apart from each other in the transverse direction (Y) of the vehicle, wherein the respective connecting plate (4, 5) has three sections (4.1, 5.1; 4.2, 5.2; 4.3, 5.3) which follow one another in the longitudinal direction (X) of the vehicle, each running parallel to the vertical direction (Z) of the vehicle and angled relative to each other, so that they have a different inclination relative to the longitudinal direction (X) of the vehicle, wherein the first section (4.1, 5.1) and the second section (4.2, 5.2) are not parallel to the longitudinal axis (X) of the vehicle but are inclined relative to it, and wherein in a transition area between the second section (4.2,5.2) and a third section (4.3,5.3) each has a through opening (4.4,5.4).

Description

The invention relates to a trailer coupling arrangement for a motor vehicle, comprising the features of the preamble of claim 1, with a transverse tube extending in the transverse direction of the vehicle, which has a central section for at least indirectly connecting a trailer coupling, and on both sides of this a side section which is connected to a vehicle body-side mounting element via a connection arrangement, wherein each side section is arranged at least partially at the level of the mounting element in the transverse direction and in the vertical direction of the vehicle, and the connection arrangement is configured to deform in an energy-absorbing manner when a pulsating force acts on the side section in the longitudinal direction of the vehicle towards the mounting element. DE 10 2012 018 546 A1 describes a trailer coupling arrangement for a motor vehicle with a cross member extending in the transverse direction of the vehicle, which has a central section for at least indirectly connecting a trailer coupling and, on either side of this, a side section which is connected to a mounting element on the vehicle body via a connecting arrangement, wherein each side section is arranged at least partially at the level of the mounting element in the transverse and vertical directions of the vehicle, and wherein the connecting arrangement is designed to deform in an energy-absorbing manner when a fluctuating force acts on the side section in the longitudinal direction of the vehicle towards the mounting element. In particular, the cross member is reinforced by at least one fiber material element comprising a fiber arrangement. DE 10 2011 112 258 A1 discloses a rear assembly for a motor vehicle body with a support and at least one connecting part connected thereto for attachment to a rear supporting structure of the body, wherein the connecting part can be connected to the supporting structure via at least one fastening section and has a deformation structure with a geometric shape designed to absorb mechanical forces. US Patent 2009 / 0072586A1 discloses a one-piece frame subassembly for a motor vehicle with a trailer hitch element. The frame subassembly comprises a pair of objected longitudinal member segments positioned on opposite sides of a vehicle centerline and extending along a generally horizontal plane. The frame subassembly also includes a rear bumper support that is connected to the pair of objected longitudinal member segments and extends transversely between them. The frame subassembly also includes a trailer hitch element that is attached to the rear bumper support adjacent to the vehicle centerline and extends below the generally horizontal plane.Furthermore, the frame subassembly features a pair of outer reinforcements extending below the horizontal plane, each attached to one of the defective longitudinal member segments at two longitudinally defective locations. The outer reinforcements are adjacent to and in front of the rear bumper support and have a longitudinally deformable central section. The outer reinforcements interact with the pair of defective longitudinal member segments to collapse axially in a controlled manner in response to a rear-end collision. DE 10 2012 015 244 A1 describes a support arrangement for a trailer coupling with a load carrier, comprising a cross member and a side carrier connected to the cross member for mounting on the rear of a vehicle body, as well as at least one bracket arranged on the cross member for a trailer coupling or for a coupling component of a load carrier. The support arrangement has at least one load-bearing component with a base body that has a load-bearing wall and a rib structure integrally formed on the load-bearing wall by a primary forming process, in particular by extrusion and / or forging, wherein the load-bearing component forms part of the cross member and extends to the transverse center of the cross member. DE 10 2015 106 489 A1 also discloses a trailer coupling arrangement. This arrangement has a rear frame that is positioned on each side of a vehicle body in a width direction and extends in a length direction along the vehicle body. A trailer coupling is provided, which is connected to the rear frame and has a pair of mounting elements attached to the rear frame. A transverse element connects the mounting elements to each other, with a coupling bracket being attached to the transverse element. A mounting bracket is provided in a rear area of ​​the respective rear frame. The mounting brackets hold the corresponding mounting elements in such a way that they can swing freely in the length direction of the vehicle body. A bumper system according to US 2004 / 0108737A1 comprises a tubular, roll-formed reinforcement beam. A trailer hitch support has an inverted section shaped to fit downward onto the beam. The trailer hitch support also has a laterally extending second section. Attached to the laterally extending second section is a trailer hitch support tube which has a hole for receiving a ball coupling for towing a trailer. An energy absorber is arranged on the beam and includes a rear recess that accommodates the beam, with a central section providing access to the trailer hitch. End sections are also provided, forming steps at the corners of the vehicle. WO 2018 / 162 024 A1 concerns an end section for a trailer coupling for a vehicle. The end section comprises a vehicle connection section that is connected to the vehicle. The end section also comprises a trailer coupling connection section that is connected to a trailer coupling. Furthermore, the end section comprises a first and a second support element that are connected to and extend between the vehicle connection section and the trailer coupling connection section, respectively. The end section also comprises a third support element that is connected to and extends between the first and second support elements, thus forming a box structure. US Patent 5,094,469 A discloses a trailer hitch device for a motor vehicle with a support beam connected to the vehicle's body floor by right and left bumper struts and extending laterally behind the body. A pair of right and left brackets are each connected to the right and left bumpers and are designed as struts extending upward and downward. An upper bumper support is mounted at an upper end of the brackets, and a lower bumper support is mounted at a lower end of the brackets. A rear bumper surface serves to cover the support beam and the upper and lower bumper supports. An interchangeable trailer hitch is located in the center of the support beam and projects rearward through the rear bumper surface between the upper and lower bumper supports.A sleeve is inserted into a hole provided in the rear bumper front face to allow the tow ball to pass through. A tow ball is attached to the tow ball at its outward-extending end. The bumper support has a first groove to accommodate the carrier via an upper and a lower flange. The bracket has a slot for inserting the upper and lower flanges to rigidly support the carrier. The tow ball has a second groove at its front end to ensure a firm fit against the carrier. All rear sections of the vehicle, except for the tow ball, are covered to improve the vehicle's external appearance. Trailer hitches can be used to attach carriers, such as bicycle carriers, to a motor vehicle. They also serve to connect a trailer to a motor vehicle for towing. Various systems are known for this purpose, such as pin couplings, jaw couplings, or fifth wheel couplings. For passenger cars, a ball coupling is generally used, whereby a vehicle-side coupling ball can be connected to a trailer-side towing ball coupling. In addition to rigidly mounted couplings, detachable couplings and swivel couplings are also known on the vehicle side. According to a typical design, the coupling is connected directly or indirectly to a cross tube or cross member running transversely across the vehicle, which is connected to the vehicle body at both ends. A connection of the cross tube to the body is usually preferred.The connection is usually not direct, but rather via a connecting arrangement, which may consist of sheet metal parts, for example. Since the coupling mechanism must transmit a tensile force between the vehicle and the trailer, it is designed to be relatively robust. However, this can be disadvantageous in a rear-end collision, as the force is transmitted either primarily to the trailer hitch and from there to the crossbar, or directly to the latter, with the force flowing in either case continuing through the coupling mechanism to the vehicle body. This creates the risk that the vehicle body will be subjected to brief, strong accelerations, which can lead to whiplash injuries, for example, in the occupants. Furthermore, vehicle components adjacent to the coupling mechanism or the crossbar are exposed to a greater risk of damage. For example, electric and hybrid vehicles often have a battery pack installed in the rear, which could be damaged or torn from the vehicle body in a rear-end collision. Given the current state of the art, the crash behavior of vehicles with trailer hitches in a rear-end collision still offers room for improvement. This applies particularly to the protection of occupants from excessive acceleration forces and the protection of vehicle components located at the rear of the vehicle from damage. The invention is based on the objective of improving the crash behavior of a motor vehicle with a trailer hitch in a rear-end collision. According to the invention, the problem is solved by a trailer coupling arrangement with the features of claim 1, wherein each connection arrangement has an outer connecting plate and an inner connecting plate, each extending between the mounting element and the side section and spaced apart from each other in the transverse direction of the vehicle, wherein each connecting plate has three sections that follow one another in the longitudinal direction of the vehicle, each running parallel to the vertical direction of the vehicle and angled relative to each other so that they have a different inclination with respect to the longitudinal direction of the vehicle, wherein the first section and the second section are not parallel to the longitudinal axis of the vehicle but are inclined with respect to it, and wherein a through-opening is arranged in a transition area between the second section and a third section. The dependent claims relate to advantageous embodiments of the invention. It should be noted that the features and measures listed individually in the following description can be combined in any technically sensible way and demonstrate further embodiments of the invention. The description further characterizes and specifies the invention, particularly in conjunction with the figures. The invention provides a trailer coupling assembly for a motor vehicle. The motor vehicle can be, in particular, a passenger car, but also a light to medium-sized truck, such as a van. The trailer coupling assembly is associated with a trailer coupling and can include the trailer coupling itself. The trailer coupling is designed to couple a trailer to the motor vehicle so that it can be towed, or to attach a carrier element to it. Naturally, a part associated with the motor vehicle interacts with a complementary part associated with the trailer. In this context, the term "trailer coupling" refers in the narrower sense to the part associated with the motor vehicle. The trailer coupling can, for example, be a ball coupling.This can be rigidly mounted with respect to the trailer hitch arrangement, alternatively it can also be removable or adjustable, in particular motor-adjustable. The trailer hitch assembly comprises a cross member extending transversely to the vehicle. This cross member has a central section for the at least indirect attachment of a trailer hitch and, on either side, a lateral section connected to a mounting element on the vehicle body via a connecting arrangement. The cross member is normally made of metal, e.g., steel. It is typically designed as a transverse tube and can be referred to as such in the following. It can have a cross-section that remains constant along its entire length, which, in the case of a transverse tube, can be circular, but may also be, for example, elliptical or rectangular. Aside from a constant cross-section, a cross-section that varies section by section is also conceivable, in which case the transverse tube can be designed as a tailored tube.Preferably, the cross member, i.e., the cross tube, is formed in one piece, which includes the possibility that the cross member consists of a plurality of separately prefabricated and materially bonded (e.g., welded) individual parts. The cross member extends in the transverse direction of the vehicle (Y-direction), i.e., along the vehicle's transverse axis (Y-axis). It can run parallel to the vehicle's transverse direction at least in sections, but also at least in sections at an angle to it. These and further statements regarding the orientation of elements of the trailer hitch assembly naturally refer to the intended installed state in or on the motor vehicle. The cross member has a central section that is provided for at least the indirect connection of the trailer hitch. That is, in the assembled state, the trailer hitch is connected directly or indirectly to this central section. Depending on the design, for example,The central section may also contain an adjustment mechanism for the trailer hitch, including a drive motor. On both sides of the central section, the crossmember has side sections. These side sections can connect directly to the central section, or at least one further section can be interposed. Each side section is connected to a vehicle body-side mounting element via a connection assembly. In the assembled state, the mounting element is located on the side of the vehicle body, where "vehicle body" is used as a general term for those parts of the vehicle that constitute the sprung mass, i.e., the body and chassis. The mounting element is designed to be mounted to the vehicle body, i.e., connected to it. Normally, the mounting element is connected to the body or the body-in-white. The connection can be made, for example, by bolting or riveting. The side section is connected to the mounting element via the connection assembly.The connection arrangement is structurally and with regard to any potential force flow between the side section (of the cross member or cross tube) and the mounting element. To ensure a reliable connection between the vehicle body and the trailer hitch, the aforementioned components are naturally designed so that, during normal operation of the vehicle with a trailer attached, only minimal, elastic deformation of the mounting element, the connection arrangement, and the cross member occurs. Since the trailer hitch assembly is located at the rear of the vehicle, the mounting element is positioned at least partially, and possibly even completely, in front of the associated connection arrangement with respect to the vehicle's longitudinal direction (X-direction), i.e., towards the front of the vehicle.Although a distinction is made here between the mounting element and the connection assembly, it is possible that these two parts of the trailer hitch assembly are manufactured as a single piece. Furthermore, it is particularly possible that they are joined together by a material bond, for example by welding. Each side section is positioned at least partially at the level of the mounting element in both the transverse and vertical directions of the vehicle, and the connecting arrangement is designed to deform in an energy-absorbing manner when a pulsating force acts on the side section in the longitudinal direction of the vehicle towards the mounting element. The side section is positioned at least partially at the level of the mounting element in both the transverse and vertical directions (Z-direction). In other words, the side section is at least partially aligned with the mounting element in the longitudinal direction of the vehicle, i.e., it lies on the same line as the mounting element. This, in turn, typically results in the connecting arrangement being positioned at least partially between the side section and the mounting element in the longitudinal direction of the vehicle. For example, if a force acting forward in the longitudinal direction of the vehicle is applied to the trailer hitch and / or the crossmember in a rear-end collision, the connection assembly is primarily subjected to compressive forces. The connection assembly is designed to deform in an energy-absorbing manner when subjected to a pulsating force acting on the side section in the longitudinal direction of the vehicle towards the mounting element. This pulsating force is a compressive force acting forward on the side section towards the mounting element. Such a force occurs, for example, in a rear-end collision. This force can act directly on the side section or act on other parts of the crossmember or on the trailer hitch and be transmitted within the crossmember to the side section.Since the side section and the mounting element are at least partially aligned along the X-axis, they are normally pushed towards each other by the corresponding force, which in turn is only possible through deformation of the connection assembly. The connection assembly is designed to withstand the corresponding force up to the threshold force and, upon reaching or exceeding the threshold force, yields as intended by deforming in an energy-absorbing manner. The arrangement of the side section relative to the mounting element can also be advantageous during normal operation of the vehicle, as the connection assembly extends along the direction of the expected main tensile load (in the X-direction). The magnitude of the threshold force can be defined – naturally with a certain unavoidable tolerance – by the design of the coupling arrangement. The coupling arrangement is, of course, designed so that it does not undergo (plastic) deformation under relatively low compressive forces, such as those that can occur when reversing with a trailer. Normally, such forces are easily distinguishable from those that can occur in a rear-end collision, which could pose a potential risk of injury to vehicle occupants or damage to certain vehicle components. These risks are mitigated by the fact that the trailer coupling arrangement can absorb energy via at least one or both coupling elements. This reduces the potential deformation of other vehicle components.Furthermore, it has been shown that the maximum acceleration forces acting on the vehicle occupants can be significantly reduced. This considerably lowers the risk of injuries such as whiplash. Although the following discussion focuses on a swell force acting in the longitudinal direction of the vehicle, forces in the transverse direction of the vehicle can also occur in a rear-end collision, particularly when the collision occurs at an angle to the vehicle's longitudinal direction. Even in these cases, the trailer hitch arrangement according to the invention leads to advantageous energy absorption and a reduced risk of injury for the vehicle occupants. Therefore, the term "rear-end collision" also applies to cases where the impact occurs at an angle to the vehicle's longitudinal direction, for example, up to 10° or up to 30°. In principle, it is possible for the crossmember to be entirely straight and parallel to the vehicle's transverse direction, so that the central section and the side sections are at the same height with respect to both the X-axis and the Z-axis. However, it is preferred that the central section be positioned further forward with respect to the vehicle's longitudinal direction than the side sections. That is, with respect to the vehicle's longitudinal direction, the central section is positioned closer to the front of the vehicle than the side sections. This makes it possible to provide sufficient installation space on the central section for the trailer hitch or for a suspension element that supports the trailer hitch. The corresponding installation space is limited to the rear, for example, by a bumper.On the other hand, the side sections are shifted towards the rear in relation to the front, which increases the possible length of the connection arrangement (in the longitudinal direction of the vehicle) and thus the possible deformation length in the event of a rear-end collision. For design reasons, it may also be preferable for the central section to be positioned higher than the side sections relative to the vehicle's height, with at least one suspension element of the trailer coupling extending downwards from the central section. In other words, the central section is positioned above the side sections. The trailer coupling itself, however, can be positioned at the same level as the side sections or even lower, since it is connected to the central section via the at least one suspension element that extends downwards from the central section. Apart from the trailer coupling itself, an adjustment mechanism for the trailer coupling, including a drive motor, can also be suspended from the central section via the at least one suspension element.Even if, in the event of an impact, the force is initially introduced into the trailer coupling and via at least one suspension element into the higher central section, the force can be transferred via the side sections into the connection arrangement due to the interconnected (as described above, normally one-piece) design of the cross member, where it leads to the intended energy absorption. If the central section is shifted forward and / or upward relative to the end sections, the crossmember cannot, of course, be entirely straight, but must exhibit bends and changes in direction. Preferably, the central section and the side sections are connected by intermediate sections that run at an angle of between 20° and 40° to the vehicle's transverse direction. At least the central section, and optionally also the side sections, preferably run at an angle of no more than 30° or no more than 20° to the vehicle's transverse direction, optionally parallel to it. The described embodiment is generally characterized by comparatively small or gentle changes in the direction of the crossmember, which can improve its overall stability and thus the force transmission between the individual parts of the crossmember. According to a preferred embodiment, the mounting element is designed as a mounting flange extending in the transverse and vertical directions of the vehicle. That is, the mounting flange extends along the YZ plane and can, in particular, also run in or parallel to it. It is typically designed as a sheet metal part of sufficient strength, which can be connected, for example, to an opposing flange of a body panel, e.g., by screws or rivets. In this embodiment, the mounting flange is normally prefabricated separately from the connection assembly and subsequently joined to it, possibly by a material bond. The connection to the vehicle body can be supplemented, e.g., by a connecting element extending in the longitudinal direction of the vehicle, which is arranged within a longitudinal member of the body and secured there (e.g., bolted).Such a connecting element can be made of sheet metal and connected to the mounting flange, e.g. by welding. Due to its generally elongated shape, it is sometimes also referred to as a sword. Each connection assembly has two connecting plates extending longitudinally between the mounting element and the side section. The connecting plate is designed as a sheet metal component and can be made of steel, although it can also be made of other metals, such as a suitable aluminum alloy. The connecting plate is normally bonded to the cross member and the mounting flange, for example, by welding. It extends longitudinally between the mounting element and the side section and is thus positioned between them, although this does not preclude it from extending beyond the mounting element and / or the side section. Although the connecting plate extends longitudinally, it does not necessarily have to be completely parallel to the vehicle's longitudinal direction or the X-axis.Since the connecting plate itself is not very compressible, it typically absorbs energy in a rear-end collision primarily through deformation such as bending or buckling. This energy absorption can be supplemented, for example, by deformation of the cross member or cross tube. If the connecting plate runs completely parallel to the vehicle's longitudinal direction, it is difficult to initiate a controlled or predictable deformation of the plate when a force acts in the longitudinal direction. Therefore, it can be provided that at least one connecting plate runs at least partially at an angle to the vehicle's longitudinal direction. A connecting plate, or a section thereof, running at such an angle (i.e., non-parallel) to the vehicle's longitudinal direction is subjected to a force acting in the longitudinal direction, partially perpendicular to the plate's plane, which can initiate bending or buckling of the plate. The magnitude of the aforementioned fluctuating force can be influenced, among other things, by the angle that the connecting plate forms with the x-axis. The fluctuating force is also influenced by the shape of the connecting plate. A planned, at least approximately predictable deformation can be achieved, in particular, by having each connecting plate have a plurality of sections angled relative to one another. The individual sections have different inclinations relative to the longitudinal direction of the vehicle, with at least one section, preferably the third section, also running parallel to the longitudinal direction of the vehicle. Particularly at the transition areas between the sections, greater stresses can arise when the threshold force is reached, which can initiate bending or buckling. Furthermore, a certain temporal sequence of deformation can be established, for example, such that sections with a greater inclination relative to the longitudinal direction of the vehicle deform earlier than sections that run approximately or exactly parallel to the longitudinal direction of the vehicle. Advantageously, at least one connecting plate extends at an angle of less than 30° to the vehicle's vertical direction. The angle can also be less than 20° or less than 10°. This means that the plane of extension of the connecting plate forms the corresponding angle with the Z-axis. According to the invention, the connecting plate extends parallel to the vehicle's vertical direction (Z-direction). Since the connecting plate normally deforms perpendicular to its plane of extension in an accident, e.g., bending or buckling, the deformation in this case occurs at least partially or predominantly in the transverse direction of the vehicle. In other words, during deformation, parts of the connecting plate move laterally and not, or hardly, upwards or downwards.Accordingly, it is unlikely that the cross member connected to the connecting plate will perform a corresponding upward or downward movement, which generally makes crash behavior more difficult to predict. In the embodiment described here, each connecting plate has a recess complementary to the shape of the cross member, as well as claw sections arranged above and below it, between which the cross member is positively engaged in the vertical direction. The corresponding positive engagement, normally together with the aforementioned material connection, ensures that the connection between the connecting plate and the side section does not detach in an accident. To facilitate the planned yielding under the influence of the swelling force, the invention provides that the respective connecting plate has at least one recess that defines a predetermined bending point. Instead of a predetermined bending point, one can generally also speak of a predetermined bending line. The recess is designed as a through-opening within the connecting plate and can additionally be designed as an edge-side cut or notch, or as a groove that can be embossed or pressed into the connecting plate. The predetermined bending point is, of course, a location where the connecting plate is intended to yield early during deformation, whereby a strict distinction is not made between bending and buckling of the plate.It is understood that, particularly depending on the type of impact and the resulting forces on the trailer hitch assembly, it cannot be predicted with certainty whether the connecting plate will actually give way first at the intended bending point. In any case, the recess increases the probability that premature yielding will occur there under the influence of forces. To support the energy-absorbing deformation of the respective connecting plate, it is also preferred that it has a straight, unbranched cross-section in a plane transverse to the longitudinal direction of the vehicle. That is, if one considers the cross-section of the respective connecting plate within the YZ plane, it preferably has a straight profile without any branches. Both a curved or angled shape (e.g., in the manner of an L-profile) and a branching (e.g., in the manner of a T-profile) could stabilize the connecting plate against forces in the longitudinal direction of the vehicle in an undesirable manner. In principle, both a reliable connection during normal vehicle operation and the desired crash behavior can be achieved with only one connecting plate per connection assembly. However, both objectives are generally achieved more reliably if each connection assembly has two connecting plates spaced apart transversely to the vehicle's longitudinal direction. In other words, the two connecting plates of a connection assembly are positioned opposite each other transversely to the vehicle's longitudinal direction. If the respective connecting plate runs at an angle of less than 30° to the vehicle's vertical direction, as described above, the two connecting plates of a connection assembly are spaced apart in the transverse direction of the vehicle, or rather, they are positioned opposite each other in this transverse direction. They can, for example, be identical and arranged parallel to each other, or they can be mirror images of each other with respect to a plane between them.Depending on the impact angle, this ensures that the deformation of the two connecting plates is also approximately mirror-symmetrical to the aforementioned plane. This, in turn, leads to a movement of the crossmember's end section that is at least predominantly in the longitudinal direction of the vehicle, and which is relatively easy to control. The distance between the connecting plates in the transverse direction of the vehicle can be chosen differently. It is advantageous to choose a distance large enough that the two connecting plates do not come into contact with each other, or only minimally, during deformation and can deform, so to speak, freely. For this purpose, the distance between the connecting plates in the transverse direction of the vehicle can be, for example, at least 50% or at least 70% of the distance between the mounting element and the side section in the longitudinal direction of the vehicle. Fig. 1 shows a perspective view of a trailer coupling arrangement according to the prior art. Further advantageous details and effects of the invention are explained in more detail below with reference to an embodiment illustrated in the figures. Fig. 2 shows a perspective view of a trailer hitch arrangement according to the invention in a first embodiment; Fig. 3 shows a first detailed view of the trailer hitch arrangement from Fig. 1 in an undamaged state; Fig. 4A shows a second detailed view of the trailer hitch arrangement from Fig. 1 in an undamaged state; Fig. 4B shows a detailed view of the trailer hitch arrangement after a rear-end collision; Fig. 5 shows a detailed view of a trailer hitch arrangement according to the invention in a second embodiment; and Fig. 6 shows a side view of the trailer hitch arrangement from Fig. 5. In the different figures, identical parts are always provided with the same reference symbols, which is why they are usually only described once. Fig. 1 shows a trailer coupling arrangement 1 according to the prior art, intended for a passenger car. The swiveling trailer coupling 20 and an associated actuator 21 are arranged below a cross member, hereinafter referred to as the cross tube 12, to which they are connected via two suspension elements 22. The straight cross tube 12 runs parallel to the Y-axis and is connected at both ends to a connecting arrangement 13, more precisely to a first sheet metal part 14, which is designed as an L-profile and angled within the YZ plane. It is connected by screws to a second sheet metal part 15, which is also designed as an L-profile. A third sheet metal part 16, which is straight with respect to the YZ plane, is welded to the second sheet metal part 15.All three sheet metal parts 14-16 are welded to a mounting element 6, which can also be referred to as a mounting flange, extending parallel to the YZ plane. This element is in turn connected to a vehicle body 30 (also not shown) by means of screws or rivets (not shown). The connection to the vehicle body 30 is further secured by a blade 7 welded to the mounting flange, which is designed as a sheet metal part and is bolted inside a longitudinal member 31 of the vehicle body 30 (shown in Figs. 5 and 6). Particularly due to the L-profiles angled within the YZ plane, the connection assembly 13 exhibits high stability against forces in the X-direction, which applies to both tensile forces (against the direction of travel or towards the rear of the vehicle) and compressive forces (in the direction of travel or towards the front of the vehicle). Furthermore, the ends of the cross tube 12 are offset inwards relative to the respective mounting flange with respect to the vehicle's transverse direction towards the vehicle's center. If a force acts on the trailer coupling 20 or directly on the cross tube 12 during a rear-end collision, this force is naturally transferred to the connection assembly 13 on both sides. Due to the high stability in the X-direction, the connection assembly 13 absorbs comparatively little energy. On the other hand, the cross tube 12 can, to a certain extent, move forward in the X-direction past the respective mounting flange, potentially...This can lead to bending of the first sheet metal part 14 and / or tearing of the cross tube 2 from the first sheet metal part 14. In any case, it is to be expected that considerable deformation energy and acceleration forces will be transferred to the vehicle body 30, which poses a risk of damage to vehicle components and whiplash injuries to occupants. Figures 2-4B show a trailer coupling arrangement 1 according to a first embodiment of the invention, which partially corresponds to the design shown in Figure 1 and is therefore not explained again. However, there are significant differences. A cross member, hereinafter referred to as the cross tube 2, to which the trailer coupling 20 is connected via the two suspension elements 22, has a central section 2.1 extending parallel to the Y-axis. To this, intermediate sections 2.2 extend downwards and rearwards at an angle of approximately 30° to the Y-axis, and these in turn terminate in side sections 2.3, which again run parallel to the Y-axis. Thus, the central section 2.1, to which the suspension elements 22 are welded, is arranged above the side sections 2.3 with respect to the Z-axis and in front of them with respect to the X-axis, i.e., towards the front of the vehicle. Each side section 2.3 is connected via a connecting arrangement 3 to a mounting element 6, which can also be referred to as a mounting flange in the following. The respective side section 2.3 is arranged at least predominantly at the level of the mounting flange with respect to both the Y-axis and the Z-axis. One could also say that the side section 2.3 lies at least predominantly in line with the mounting flange in the X-direction. Since the central section 2.1 is shifted forward relative to the side sections 2.3, sufficient installation space is available behind the central section 2.1 to accommodate the suspension elements 22 or the trailer coupling 20 attached thereto, for example, in front of a bumper (not shown here). Furthermore, the side sections 2.3 are arranged so far back that the connecting arrangement 3 has a comparatively long length in the direction of the X-axis.Accordingly, the possible deformation length of the connection arrangement 3 is also large, which is advantageous for the crash behavior. The structure of the first embodiment of the connecting arrangement 3 is shown in detail in Fig. 3 and Fig. 4A. The connecting arrangement 3 comprises an outer connecting plate 4 and an inner connecting plate 5. The outer connecting plate 4 has a first section 4.1, a second section 4.2, and a third section 4.3, which follow one another in the X direction. These sections each run parallel to the Z axis and are angled relative to each other, so that they have different inclinations with respect to the X axis. In particular, the first section 4.1 and the second section 4.2 do not run parallel to the X axis, but are inclined with respect to it. The third section 4.3 has a recess that is matched to the cross-section of the transverse tube 2 and is bounded vertically upwards and downwards by two claw sections 4.5. The transverse tube 2, or rather its side section 2.3, is positively engaged between the claw sections 4.5 along the Z-axis. Additionally, the transverse tube 2 is welded to the outer connecting plate 4. Furthermore, the outer connecting plate 4 has a through-opening 4.4 formed at the transition between the second section 4.2 and the third section 4.3. The inner connecting plate 5 also has a first section 5.1, a second section 5.2, and a third section 5.3, which run parallel to the Z-axis and are angled relative to each other, so that they have different inclinations with respect to the X-axis. The respective inclinations with respect to the X-axis of the first sections 4.1, 5.1, and the second sections 4.2, 5.3 are...Sections 2 and 5.3 of the outer connecting plate 4 and the inner connecting plate 5 are at least approximately symmetrical to a plane parallel to the XZ plane located between the two connecting surfaces 4 and 5. In particular, the first section 5.1 and the second section 5.2 do not run parallel to the X-axis, but are inclined relative to it. The third section 5.3 again has claw sections 5.5 between which the transverse tube 2 is positively engaged. A through-opening 5.4 is also formed in the transition area between the second section 5.2 and the third section 5.3. A notch 5.6 is formed on the edge of the second section 5.2. The through-openings 4.4 and 5.4, as well as the notch 5.6, each represent targeted weakenings of the respective connecting plate 4 and 5 and define at least approximately predetermined bending points.-lines where the connecting plate 4, 5 preferentially yields under load. Both connecting plates 4, 5 have a straight, unbranched cross-section within the YZ plane, i.e., perpendicular to the X-axis. In a rear-end collision, where a force directed forward in the X-direction acts on the trailer coupling 20 and / or the cross tube 2, the force flows through the connection arrangement 3 and the mounting flange 6 to the vehicle body 30. Since the respective side section 2.3 is arranged in the X-direction on a line with the mounting flange 6, it is pressed directly towards it, with the two connecting plates 4, 5 of the connection arrangement 3 being interposed along the X-axis and being subjected essentially to a compressive force running parallel to the X-axis. As soon as the corresponding compressive force reaches the magnitude of a predetermined threshold force, the connecting arrangement 3 begins to deform in an energy-absorbing manner. The final state of such deformation is shown in Fig. 4B. The two connecting plates 4, 5 remain connected to the mounting flange and to the side section 2.3 of the transverse tube 2; that is, no connection detaches. However, significant deformation of both connecting plates 4, 5 has occurred. The third sections 4.3, 5.3 have retained approximately their orientation relative to the side section 2.3. In contrast, the first sections 4.1, 5.1 and the second sections 4.2, 5.2 have been clearly bent or kinked. This process is supported by the pairwise angulation of the sections relative to each other and by the fact that the first sections 4.1, 5.1 and the second sections 4.2, 5.2 are each inclined with respect to the X-axis.This results in different lateral force components (in the Y direction), leading to an accordion-like folding of the respective connecting plates 4 and 5. This occurs approximately symmetrically for the outer connecting plate 4 and the inner connecting plate 5, so that the former folds essentially outwards and the latter essentially inwards. The side section 2.3 moves essentially along the X-axis, with movements in the Y or Z direction being comparatively small. The deformation is further supported by the through-openings 4.4 and 5.4, as well as by the notch 5.6. This deformation is associated with energy absorption, which can prevent or at least mitigate damage to other vehicle components belonging to the vehicle body 30. For example, a battery pack mounted in the rear of the vehicle can be protected in this way.Furthermore, due to the yielding of the connection arrangement, acceleration peaks acting on the trailer coupling 20 and the cross tube 2 are only transmitted to the vehicle body 30 to a limited extent. This significantly reduces the risk of whiplash injury to the occupants. While Fig. 4B shows the deformation behavior in a rear-end collision where the force is applied (almost) exactly in the X-direction, the trailer coupling arrangement 1 also offers advantages in an oblique rear-end collision, i.e., when the rear-end collision occurs at an angle to the X-direction, e.g., up to 10° or up to 30°, or possibly even more. In these cases, a significant force component acts on the cross tube 2 in the Y-direction, resulting in force components in the same direction on the two connecting plates 4, 5. In this case, both connecting plates 4, 5 can deform, for example, in an S-shape and approximately parallel to each other, while the side section 2.3 of the cross tube 2 is deflected relative to the mounting flange in both the X-direction and the Y-direction. The second section 4.2, 5.2 of the respective connecting plate 4, 5 can approach the mounting flange or even come into contact with it.In particular, but not exclusively, in such an oblique rear-end collision, the deformation of the connecting plates 4, 5 can be optimized by ensuring that their distance in the Y-direction is sufficiently large so that there is no or no significant contact between them during deformation. This distance can, for example, be at least 50% or at least 70% of the distance between the mounting flange and the side section 2.3 in the X-direction. The second embodiment of the trailer coupling arrangement 1, which is shown in Fig. 5 and Fig. 6, differs from the first embodiment in minor details with regard to the design of the connecting plates 4, 5. In particular, the first connecting plate 4 also has an edge-side notch 4.6, the function of which essentially corresponds to that of the second connecting plate 5. Reference symbol list 1 Trailer coupling assembly 2, 12 Cross tube 2.1 Center section 2.2 Intermediate section 2.3 Side section 3, 13 Connection assembly 4, 5 Connecting plate 4.1, 5.1 First section 4.2, 5.2 Second section 4.3, 5.3 Third section 4.4, 5.4 Through opening 4.5, 5.5 Claw section 4.6, 5.6 Notch 6 Mounting element 7 Sword 14, 15, 16 Sheet metal part 20 Trailer coupling 21 Actuator 22 Suspension element 30 Vehicle body 31 Longitudinal member X X-axis Y Y-axis Z Z-axis

Claims

Trailer coupling arrangement (1) for a motor vehicle, comprising a transverse tube (2) extending in the transverse direction (Y) of the vehicle, which has a central section (2.1) for at least indirectly connecting a trailer coupling (20) and on both sides of this a side section (2.3) which is connected to a vehicle body-side mounting element (6) via a connecting arrangement (3), wherein each side section (2.3) is arranged at least partially at the level of the mounting element (6) in the transverse direction (Y) and in the vertical direction (Z) of the vehicle and the connecting arrangement (3) is configured to move in the event of an impact on the side section (2.3) to deform in an energy-absorbing manner the pulsating force acting in the longitudinal direction (X) of the vehicle towards the mounting element (6), characterized in that each connecting arrangement (3) has an outer connecting plate (4) and an inner connecting plate (5), each extending between the mounting element (6) and the side section (2.3) and spaced apart from each other in the transverse direction (Y) of the vehicle, wherein the respective connecting plate (4, 5) has three sections (4.1, 5.1; 4.2, 5.2; 4.3, 5.3) which follow one another in the longitudinal direction (X) of the vehicle, each running parallel to the vertical direction (Z) of the vehicle and angled relative to each other, so that they have a different inclination relative to the longitudinal direction (X) of the vehicle, wherein the first section (4.1, 5.1) and the second section (4.2, 5.2) are not parallel to the longitudinal axis (X) of the vehicle but are inclined relative to it, and wherein in a transition area between the second section (4.2,5.2) and a third section (4.3,5.3) each has a through opening (4.4,5.4). Trailer coupling arrangement (1) according to claim 1 , characterized in that the central section (2.1) is arranged further forward with respect to the longitudinal direction of the vehicle (X) than the side sections (2.3). Trailer coupling arrangement (1) according to one of the preceding claims, characterized in that the central section (2.1) is arranged higher with respect to the vehicle vertical direction (Z) than the side sections (2.3) and at least one suspension element (22) of the trailer coupling (20) extends downwards from the central section (2.1). Trailer coupling arrangement (1) according to one of the preceding claims, characterized in that the central section (2.1) and the side sections (2.3) are connected by intermediate sections (2.2) which extend at an angle between 20° and 40° relative to the transverse direction (Y) of the vehicle. Trailer coupling arrangement (1) according to one of the preceding claims, characterized in that the respective connecting plate (4, 5) has claw sections (4.5, 5.5) on its respective third section (4.3, 5.3) between which the transverse tube (2) is positively engaged. Trailer coupling arrangement (1) according to one of the preceding claims, characterized in that the distance of the connecting plates (4,5) of each connecting arrangement (3) in the transverse direction of the vehicle (Y) is selected such that the connecting plates (4,5) remain free of contact with each other when they are deformed. Trailer coupling arrangement (1) according to claim 6, characterized in that the distance between the two connecting plates (4, 5) in the transverse direction of the vehicle (Y) is at least 50% or at least 70% of the distance between the mounting element (6) and the side section (2.3) in the longitudinal direction of the vehicle (X). Trailer coupling arrangement (1) according to one of the preceding claims, characterized in that the at least one connecting plate (4, 5) extends at an angle of less than 30° to the vehicle vertical direction (Z). Trailer coupling arrangement (1) according to one of the preceding claims, characterized in that at least one connecting plate (4, 5) has a notch (4.6, 5.6) on its edge in its second section (4.2, 5.2).

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