Chassis axle with torsionally flexible connecting beam

Abstract

Chassis axle (FA) for wheel guidance on a vehicle, with two longitudinal control arms (LL, LL') which are articulated on both sides to a vehicle body, and with a torsion beam (TT) connecting the longitudinal control arms (LL, LL'), characterized in that the torsion beam (TT) has a profile (P, P*) with a partially open cross-section and is manufactured from sheet steel by means of at least one of the following processing methods: laser cutting, sheet metal forming, welding or bending.

Description

TECHNICAL FIELD

[0001] The invention relates to a chassis axle with a torsionally flexible connecting beam, which is particularly suitable as a rear axle construction of a vehicle equipped with two centrally arranged, closely spaced, single wheels. The invention thus serves for wheel guidance on vehicles, in particular of category L5e, in which a single wheel on each side of the vehicle is arranged centrally. The close wheel-side positioning fulfills the legal requirements for classification as a "dual wheel" within the meaning of EU type approval.

[0002] The axle construction is based on the principle of a twist-beam axle, but with a torsionally flexible connecting beam used as a cross brace between the trailing arms. The axle construction has been redesigned in such a way that it implements a legally approved dual-wheel design with only two individual wheels and meets all requirements of vehicle class L5e, in particular the track width specifications and drivability with a class A1 driving license from the age of 16. STATE OF THE ART

[0003] From DE 20 2022 101 976 U1, an axle support structure or chassis axle with a torsionally flexible connecting beam 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, which acts as a torsionally flexible connecting beam and to whose two 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 therein 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. Furthermore, no measures to stabilize the vehicle body, such as stiffening supports or the like, are required. Accordingly, DE 20 2022 101 976 U1 discloses a chassis axle that serves to guide the wheels on a vehicle and has two trailing arms that are hinged to a vehicle body on both sides, and a torsion beam connecting the trailing arms. OBJECT OF THE INVENTION

[0004] The object of the present invention is to further develop the construction mentioned at the beginning.

[0005] In particular, the invention is intended to provide a torsionally flexible, rigid and space-optimized chassis axle which has at least one of the following properties: ◯ The chassis axle should be based on the twist beam axle principle; ◯ The chassis axis should use an alternative, open or partially open cross-sectional shape of the connecting beam (e.g. U-, omega or barrel profile); ◯ The chassis axle should only carry two individual wheels, which are positioned centrally on the axle but separately on the right and left; ◯ The individual wheels should be arranged in such a way that they are considered as “dual wheels” according to EU regulations. ◯ The design should remain within the track width specifications for L5e vehicles (compliance with the maximum distance between the two wheels required by the vehicle registration law so that they are considered a dual wheel) and allow the vehicle to be operated with an A1 driving license from the age of 16. SOLUTION OF THE INVENTION

[0006] The problem is solved by a chassis axle for wheel guidance on a vehicle with the features of claim 1.

[0007] According to the invention, a chassis axle of the type mentioned at the outset is further developed so that it is characterized in that the torsion beam has a profile with a partially open cross-section (open hollow profile) and that the torsion beam is manufactured from sheet steel by means of laser cutting, sheet metal forming, welding or bending.

[0008] Furthermore, the use of the chassis axle according to the invention for converting a four-wheeled vehicle into a three-wheeled vehicle equipped with a double wheel is also disclosed and claimed here.

[0009] Preferred embodiments result from the subclaims: The profile of the torsion beam preferably has a U-shaped, barrel-shaped or omega-shaped cross-section.

[0010] The torsion beam can be designed in one piece or in several pieces as a folded sheet metal part with a barrel-shaped cross-section.

[0011] In particular, the torsion beam can consist of two laser-cut half-shells that are welded to form a partially open profile.

[0012] The torsion beam can also be designed to have a maximum defined torsional flexibility and at the same time a high, minimum defined bending stiffness.

[0013] The geometry of the trailing arms and the torsion beam are preferably adapted in such a way that a single wheel is guided on each side of the vehicle in the installed state, with a central orientation, whereby the distance between the two wheels is adjusted so that the two individual wheels are considered as a double wheel in the legal sense in accordance with the specifications of vehicle class L5e.

[0014] Preferably, the chassis axle is designed for vehicles according to class L5e according to Regulation (EU) No 168 / 2013, which makes a vehicle equipped with it drivable with a driving license class A1. PRESENTATION OF THE INVENTION

[0015] The invention is described in more detail below and by means of exemplary embodiments with reference to the accompanying schematic drawings, which show the following: Fig. 1a, b show as a first embodiment (in transverse view and top view respectively) a chassis axle with a torsion beam (torsionally flexible cross strut) which has a barrel-shaped cross-sectional profile; Fig. 2a, b show, as a second embodiment (in transverse view and view from below respectively), a chassis axle with a torsion beam having an omega-shaped cross-sectional profile; Fig. 3 shows the chassis axis to Fig. 2a,b in a 3D view from above; and Fig. 4 shows the chassis axis Fig. 2a,b and Fig. 3 in a 3D view from below.

[0016] Based on the Fig. 1a, b, a first chassis axle FA according to the invention is described, which has a torsion beam TT that connects both longitudinal beams LL, LL'. In this respect, this construction corresponds to that of a twist beam axle. The special feature here is that a torsionally flexible connecting beam TT, which has an open hollow profile P, is used as the cross strut. Fig. 1a, b is a barrel-shaped profile P, whereby the connecting beam TT is installed in the chassis axis FA in such a way that the open side of the profile P is aligned towards the road surface.

[0017] When the trailing arms are twisted, the torsional forces that occur are absorbed by the connecting beam TT in a spring-elastic manner, thus effectively realizing the function of a torsion or torsion bar, which connects the rather flexurally and torsionally stiff trailing arms to one another in a torsionally soft manner.

[0018] In general, the torsional stiffness (hardness / softness) of the TT torsion beam can be optimally achieved for the desired application by adapting its profile shape, wall thickness, and / or dimensions (such as dimensions in vertical and horizontal directions); the same applies to the choice of material.

[0019] The Fig. Figure 2a shows a transverse view of the longitudinal member LL and a torsion beam TT attached to it with a profile P* in the shape of the Greek letter Ω (Omega), i.e. with an omega-shaped profile. Fig. Figure 2b shows a view of the chassis axis FA from below, where it can be seen that the profile P* opens downwards, ie towards the road surface.

[0020] Finally, the Fig. 3 and Fig. 4 the chassis axle FA in 3D view from above and below. Here, too, the cross strut (torsion beam) TT, which contributes significantly to the agility of the driving dynamics, is located at about a quarter of the length of the respective trailing arm (as is also the case Fig. 2a / b can be seen).

[0021] Each trailing arm LL and LL' has a mount AG' at one end for an axle rubber, via which it is pivotally connected to the vehicle body. At the other end are the flanges FL' for attaching the wheels (double wheel arrangement not shown, as this is generally known - see e.g. DE 20 2022 101 976 U1). The trailing arms LL and LL' are therefore pivotally mounted relative to the body (pivot axis mounting with pivot axis). Since the cross strut TT has a certain degree of flexibility and acts in particular as a torsionally soft torsion bar, the trailing arms LL and LL' can also be pivoted slightly relative to each other, which significantly improves the dynamic driving characteristics of a vehicle equipped with the chassis axle FA.

[0022] The flange FL'Flansch provided on each trailing arm LL is used to attach a single wheel. The two flanges are arranged opposite each other so that two single wheels, forming a double wheel, can be pivotally mounted between the longitudinal members LL and LL' (the wheels are not shown). At the other end of the respective trailing arm LL or LL* there is a mount AG' or bushing for an axle rubber. Any shock absorbers present are also not shown. This allows the longitudinal members LL and LL' to be pivoted with spring damping by means of the pivot axis bearing on the respective mount AG'.

[0023] As can be seen from all figures and the above description, the FA chassis axle according to the invention is ideally suited for converting four-wheeled vehicles into three-wheeled vehicles of class L5e.

[0024] The basic construction of the chassis axle FA consists of: ◯ two longitudinal control arms LL and LL', which are hinged on both sides to a vehicle body; and ◯ a torsion beam TT connecting the trailing arms. According to the invention, the torsion beam TT has at least two of the following features: ◯ the TT torsion beam is made of sheet steel to form a single-piece or multi-piece profile element, whereby the sheet steel has been processed by bending, welding, laser cutting, pressing or deep drawing; ◯ the torsion beam TT has a substantially open or partially open cross-section, in particular a U-shaped, barrel-shaped or omega-shaped profile; ◯ the torsion beam is designed in terms of profile shape, wall thickness and choice of material in such a way that it offers a defined torsional flexibility while at the same time maintaining high flexural rigidity; ◯ the axle construction is designed in such a way that a single wheel is guided on each side of the vehicle, with these wheels being arranged centrally on both sides of the vehicle (ie the distance between them is within the vehicle width), and their mutual distance being selected in such a way that they are considered to be a double wheel for vehicle registration purposes; ◯ the axle width, wheel position and design are designed so that the construction meets the requirements of class L5e according to EU Regulation 168 / 2013, in particular the following criteria: - Track width of 460 mm with double wheel design, - permissible vehicle weight, - Ability to drive with a class A1 driving license from the age of 16.

[0025] In addition to the advantages of the invention already mentioned, the following points should be mentioned: ◯ Novel profile design of the torsion beam: In contrast to known solutions, especially solutions with box profiles, an open or curved profile is used here, which is significantly lighter, more torsionally flexible and more material-efficient. ◯ Defined torsional flexibility combined with high flexural rigidity: This results in both the toe-in and toe-out changing intentionally and specifically, which contributes to very good steering behavior, good load change reactions and high driving stability and safety. ◯ The axle carries two individual wheels, thus saving weight and costs, while still meeting the requirements of a legal double wheel. ◯ (Old) conventional axles with single outer wheels do not offer the possibility of implementing a central dual-wheel design with only two wheels. Likewise, there is no reference to the A1 driver's license or L5e-specific requirements. ◯ Flexibility in manufacturing: The chassis axle presented here can be manufactured using different processes (e.g. laser cutting, bending, welding) without losing functionality or classifiability.

[0026] 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 FA chassis axle (here design for rear axle) LL, LL' trailing arm (axle carrier) TT connecting beam (cross brace), torsionally flexible P, P* Hollow profile, barrel or omega-shaped FL' Flange for attaching a single wheel AG' mount for axle rubber 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 [0003, 0021]

Claims

[1] Chassis axle (FA) for wheel guidance on a vehicle, with two longitudinal control arms (LL, LL') which are articulated on both sides to a vehicle body, and with a torsion beam (TT) connecting the longitudinal control arms (LL, LL'), characterized by , that the torsion beam (TT) has a profile (P, P*) with a partially open cross-section and is made of sheet steel by means of at least one of the following processes: laser cutting, sheet metal forming, welding or bending. [2] Chassis axle (FA) according to claim 1, characterized by , that the profile (P, P*) has a U-shaped, barrel-shaped or omega-shaped cross-section. [3] Chassis axle (FA) according to claim 1 or 2, characterized by that the torsion beam (TT) is formed at least in one piece as an angled sheet metal part with a barrel-shaped cross-section (P). [4] Chassis axle (FA) according to any of the preceding claims, characterized by, that the torsion beam (TT) consists of several parts made up of two laser-cut half-shells which are welded together to form a partially open profile. [5] Chassis axle (FA) according to any of the preceding claims, characterized by , that the torsional beam (TT) is designed to have a maximally defined torsional flexibility and simultaneously a high, minimally defined bending stiffness. [6] Chassis axle (FA) according to any of the preceding claims, characterized by , that the geometry of the longitudinal control arms (LL, LL') and the torsion beam (TT) is adapted such that a single wheel is guided in the installed state per side of the vehicle, with a central orientation, whereby the distance between the two wheels is set in such a way that the two single wheels are considered a double wheel in the legal sense in accordance with the requirements of vehicle class L5e. [7] Chassis axle (FA) according to any of the preceding claims, characterized by, that the chassis axle (FA) is designed for vehicles of class L5e according to Regulation (EU) No 168 / 2013 and therefore a vehicle equipped with it can be driven with driving licence class A1. [8] Use of the chassis axle (FA) according to any of the preceding claims for converting a four-wheeled vehicle into a three-wheeled vehicle equipped with a double wheel.

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