Axle support structure for the rear axle construction of a vehicle

Abstract

Axle support structure (100; 100*) for the rear axle construction of a vehicle, comprising: two axle supports (20L, 20R) which are fastened to a cross-strut construction, wherein the two axle supports (20L, 20R) each have a flange (25) for a wheel bearing for mounting a wheel, and the two flanges (25) are arranged opposite one another, so that two wheels which form a double wheel can be mounted in a pivoting manner between the axle supports (20L, 20R), wherein the cross-strut construction consists of a cross strut (10) acting as a torsion bar, characterized in that the cross strut (10*) has an open hollow profile (10a*; 10b*; 10c*).

Description

TECHNICAL FIELD

[0001] The invention relates to an axle support structure for the rear axle construction of a vehicle, which is provided with a double wheel. STATE OF THE ART

[0002] From DE 20 2022 101 976 U1, an axle support structure for a vehicle rear axle construction is known, which is provided with a double wheel consisting of two wheels mounted at a short distance, whereby the vehicle can be registered as a three-wheeled vehicle in many countries, for example in Germany for the driving license class A1, so that even young drivers from 16 years of age are allowed to drive this vehicle. The axle support structure there (see also enclosed Fig. 1) is characterized by the fact that the cross strut construction consists of a cross strut 10 acting as a torsion bar, to each of whose ends one of the axle supports 20L or 20R is attached, and that the two axle supports each consist of a set of several flat sheet metal parts, which are folded in sections and / or welded together to form a three-dimensional structure. The cross strut there can, for example, have a T-profile. This construction is very compact, stable and resilient, but nevertheless particularly lightweight because no very massive components, such as cast struts and axle supports, are required. In addition, the cross strut acting as a torsion bar (torsion element), meets high demands in terms of agility and dynamic driving characteristics because the axle supports can be sufficiently pivoted or crossed against each other, but driving stability is maintained.Furthermore, the design is ideal for converting existing four-wheeled vehicles to three-wheeled vehicles, as the wheel arches do not need to be extended toward the center of the vehicle to install this axle support structure; moreover, no measures for stabilizing the vehicle body, such as stiffening beams or the like, are required. TASK AND SOLUTION OF THE INVENTION

[0003] The object of the present invention is to further develop the construction mentioned at the beginning.

[0004] According to the invention, an axle support structure for the rear axle construction of a vehicle with the features of claim 1 is disclosed. The axle support structure comprises: two axle supports which are fastened to a cross-strut construction, wherein the two axle supports each have a flange for a wheel bearing for mounting a wheel, and the two flanges are arranged opposite one another so that two wheels forming a double wheel can be pivotally mounted between the axle supports (longitudinal supports of the structure), wherein the cross-strut construction consists of a cross strut acting as a torsion bar. The invention is characterized in that the cross strut has an open hollow profile, i.e. a profile whose cross section is interrupted at at least one point, thus not completely enclosing the interior of the profile.One can therefore also speak of an essentially tubular cross brace whose profile is open on one side, hereinafter also referred to as a partially open tubular profile.

[0005] This can be, for example, a substantially U-shaped or V-shaped profile or a substantially semi-circular profile or a semi-oval profile.

[0006] The more homogeneous profile shapes preferably have a constant diameter (semi-circular profiles) or at least do not have a greatly changing diameter (semi-oval profiles), which means that there are no locally greatly changing profile shapes with certain discontinuities (e.g. kinks or bends), as is the case with U- and V-profiles. In this respect, the torsion bar function of the semi-circular or semi-oval profiles is similar to that of a round bar or tube. The half-piece tube shape with a one-sided opening saves material without reducing the torsional properties. Secondly, the one-sided opening can be mounted in the installed state of the axle carrier structure in such a way that the profile is aligned with its open side away from the vehicle's floor assembly. The terms "semi-circular" and "round" respectively.The term "semi-oval" profile should not be interpreted narrowly, meaning only exactly half of a circle or oval, but rather express that the profile has an essentially circular or oval contour which does not close completely but is open to one side, as is the case, for example, with a round profile whose circumference covers part of a full circle (<360°); the opening of the profile can be in the range of 45° to 120° and should preferably be between 60° and 90°.

[0007] For certain applications, it may be advantageous for the profile to be asymmetrical, i.e., with a non-symmetrical wall profile. For example, the profile may have a rather steep wall profile on one side (e.g., toward the rear of the vehicle), while on the opposite side, it may have a rather flat wall profile.

[0008] Preferably, the two axle supports (longitudinal members or longitudinal control arms) are provided with slot-shaped receiving openings into which one end of the cross member can be inserted. This creates a positive connection (plug connection) for the potentially high force flow between the cross member and the longitudinal control arms, so that additional welds of the components cannot be overloaded and simpler welds for fixing the components (e.g., by spot welding) are sufficient. In the current technology, however, the components are often "only" welded together, which places particularly high demands on the quality and quantity of the weld seams. This classic production method is often used by vehicle manufacturers or suppliers when axles are to be produced in larger quantities.

[0009] The preferred method for the invention, "plug-in connection with welded fixation," is particularly suitable for small series production: In a first preferred embodiment, the cross strut is designed as an open profile (e.g., a U-profile) or, optionally, as a closed profile with low torsional rigidity. The end sections of the cross strut are each inserted with a positive fit into slot-shaped receiving openings in the trailing arms.

[0010] The plug-in connection allows for precise pre-positioning of the components relative to each other and ensures a force-locking and positive coupling in the force flow even before welding. Final fixation is achieved by simple welding, preferably spot welding or short fillet weld segments, which reduces manufacturing effort and lowers the requirements for weld quality.

[0011] This variant is particularly suitable for small series where flexibility in assembly and low investment costs for complex welding devices are required.

[0012] On the other hand, for large-scale production, the direct welding of an open profile (e.g. U-profile) to the trailing arms is suitable (especially for series production): In an alternative embodiment, the cross strut is designed as a continuous, open-profile torsion element - preferably as a U- or C-shaped sheet metal profile - which rests directly on the longitudinal control arms at both ends and is connected force-fittingly via weld seams without a plug connection.

[0013] The welding is carried out circumferentially or in sections along the contact surfaces, whereby the open cross-sectional shape of the cross strut enables targeted torsional deformation, which influences the elastokinematic behavior of the axle.

[0014] By eliminating plug-in connections, a simpler geometry of the trailing arms is achieved, facilitating automation of the welding process. This design is therefore particularly suitable for large-scale production, as it ensures high process reliability, reproducibility, and structural strength.

[0015] Preferably, the axle support structure is designed such that the two axle supports (longitudinal members or control arms) each consist of a set of several flat sheet metal parts, which are folded in sections and / or welded together to form a three-dimensional structure. This allows the axle support structure to be assembled into a highly resilient construction, similar to a kit consisting of relatively lightweight sheet metal (partially in the manner of a plug-in system - see above).

[0016] The present invention also includes the use of the axle support structure according to the invention for converting a four-wheeled vehicle into a three-wheeled vehicle equipped with a double wheel.

[0017] The invention will be described in more detail below and by means of exemplary embodiments with reference to the enclosed schematic drawings Fig. 2 and Fig. 2a-c, which represent the following ( Fig. 1 shows a prior art axle support structure with cross brace): Fig. 2 shows a section of the area of ​​the axle support structure to which one end of the cross member is attached; and Fig. 2a-c each show in cross section a preferred profile shape of the cross strut according to the invention.

[0018] In Fig. 2 (cf. Fig. 1) shows the area of ​​an axle support structure 100* according to the invention, where one end of the cross member 10* according to the invention is attached to one of the axle supports, here to the left trailing arm 20L'. In contrast to the embodiment of a cross member 10 explicitly disclosed in the prior art (see Fig. 1) with T-profile, the cross brace 10* shown here has a tubular profile that is open or open on one side, which can be seen from the Fig. 2a-c illustrates:

[0019] As the Fig. As shown in Figures 2a-c in more detail, this is a tubular profile that is not completely closed, but whose wall "only" partially encloses the interior of the tube. Preferably, the respective cross brace is installed in the axle support structure 100* so that the open side OS is oriented toward the road surface.

[0020] The Fig. Figure 2a, for example, shows a U-shaped profile 10a*, which elastically absorbs the torsional forces occurring when the trailing arms are interlocked, thus effectively fulfilling the function of a torsion bar or torsion rod, connecting the rather flexurally and torsionally stiff trailing arms to each other in a torsionally soft manner. In general, the torsional stiffness (hardness / softness) of the cross member 10* can be optimally achieved for the desired application by adapting the profile shape, wall thickness, and / or dimensions (especially vertical and horizontal dimensions). The same applies to the choice of material.

[0021] The Fig. Figure 2b, for example, shows a semi-oval profile 10b* whose longitudinal extension runs vertically, i.e., in the main load direction of the axle support structure, allowing profile 10b* to absorb the occurring vertical forces particularly well. The transverse extension of the semi-oval profile 10b* runs horizontally, i.e., in the direction of the lower horizontal forces, and can therefore be dimensioned more slenderly.

[0022] Finally, the Fig. Figure 2c shows an example of an asymmetrical profile 10c*, whose opening OS also points downwards, as with the other profiles. The wall of the profile encloses slightly more than half of the interior space, i.e., the profile extends in the circumferential direction and, relative to a full circle, by approximately 200° of the full circle.

[0023] Based on the state of the art (see Fig. 1) it is clear that the cross member 10* contributes significantly to the agility of the driving dynamics. Preferably, the connection between the axle supports (see 20L and 20R) and the cross member 10* is located approximately one-third of the length of the respective axle support (see also Fig.1). Each axle carrier or trailing arm 20L and 20R has a mount for an axle rubber at one end, via which it is pivotally connected to the vehicle body. At the other end are the flanges for attaching the wheels (double wheel arrangement not shown as it is generally known - see e.g. DE 20 2022 101 976 U1). The axle carriers 20L and 20R are therefore pivotally mounted relative to the body (pivot axis mounting with pivot axis). Since the cross member has a certain degree of flexibility and acts in particular as a torsionally soft torsion bar, the axle carriers 20L and 20R can also be pivoted slightly relative to one another, which significantly improves the dynamic driving characteristics of a vehicle equipped with the axle carrier structure.

[0024] In addition, the above-mentioned advantages also arise from the use of the cross brace according to the invention disclosed here.

[0025] In summary, the invention, based on the basic design of a twist-beam axle, describes a further developed chassis axle with an open or partially open cross-sectional shape of the torsion beam, which enables defined guidance of two individual wheels in a close, central arrangement. Due to their design spacing, these wheels meet the requirements for legal classification as a dual wheel according to the L5e regulation. The invention thus opens up new application possibilities for compact, registration-friendly, and A1-compliant light vehicles in urban areas. The defined torsion also has a very positive impact on handling, particularly with regard to agility. List of reference symbols 10 Cross brace (from the state of the art 20L, 20R axle carrier (trailing arm as in the state of the art) 100* Axle support structure according to the present invention 10* Cross brace with tubular, partially open profile according to the present invention 10a*, 10b* 10c* Examples of preferred profile shapes OS open side of the respective cross brace QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 20 2022 101 976 U1 [0002, 0023]

Claims

[1] Axle carrier structure (100; 100*) for the rear axle construction of a vehicle, comprising: two axle carriers (20L, 20R) which are attached to a cross member structure, wherein the two axle carriers (20L, 20R) each have a flange (25) for a wheel bearing for mounting a wheel, and the two flanges (25) are arranged opposite each other, so that two wheels forming a double wheel can be mounted on pivot bearings between the axle carriers (20L, 20R), wherein the cross member structure consists of a cross member (10) acting as a torsion bar, characterized by , that the cross member (10*) has an open hollow profile (10a*; 10b*; 10c*). [2] Axle carrier structure (100*) according to claim 1, characterized by that the hollow profile is essentially a U-shaped hollow profile (10b*) or a V-shaped hollow profile (10a*). [3] Axle carrier structure (100*) according to claim 1 or 2, characterized by, that the hollow profile is an essentially semi-circular hollow profile or a semi-oval hollow profile (10a*). [4] Axle carrier structure (100*) according to one of the preceding claims, characterized by , that the hollow profile is an asymmetrical hollow profile (10c*). [5] Axle carrier structure (100*) according to one of the preceding claims, characterized by , that in the installed state of the axle carrier structure (100*) the hollow profile (10a*; 10b*; 10c*) is oriented with its open side (OS) away from the floor assembly of the vehicle. [6] Axle carrier structure (100*) according to one of the preceding claims, characterized by , that the two axle carriers (20L, 20R) each consist of a set (200) of several flat sheet metal parts (210 - 270) which are bent section by section and / or welded together to form a three-dimensional structure. [7] Use of the axle carrier structure (100*) according to one of the preceding claims for converting a four-wheeled vehicle into a three-wheeled vehicle equipped with a double wheel.

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