Trailer Coupling Cross Member Weight Reduction via Segmented Support Structures
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Solution Overview
Problem
Existing trailer hitches require a solid cross member tube to absorb forces, resulting in a high mass that is not energy efficient, necessitating a design that reduces weight while maintaining stability.
Innovation Solution
The cross member unit is divided into a torsionally rigid support structure and a tension-resistant support structure, with the torsionally rigid structure being tubular and the tension-resistant structure planar, both designed to absorb forces in various directions with optimized geometry to minimize weight and maintain stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a massively constructed crossbeam tube is used to absorb forces, then the stability and strength are improved, but the mass increases significantly
Solution Approach 1:
The crossbeam unit is divided into two distinct support structures: a torsionally stiff support structure (tubular) and a tensilely stiff support structure (planar). Each structure is optimized for specific force directions, allowing weight reduction while maintaining overall strength. The segmentation enables specialized design for different loading conditions rather than using a single massive tube for all forces.
Solution Approach 2:
Different parts of the support structures have different geometries and material properties optimized for their specific functions. The torsionally stiff structure is tubular with wall thickness optimized for torsional loads, while the tensilely stiff structure is planar with varying width to handle tensile forces. This local optimization allows each component to be as light as possible while performing its specific function.
2Use of energy by moving object
If the crossbeam unit mass is reduced for energy-saving reasons, then energy efficiency is improved, but the stability may be compromised
Solution Approach 1:
By segmenting the support functions into two specialized structures, the design achieves weight reduction without sacrificing stability. The torsionally stiff tubular structure maintains rotational stability, while the tensilely stiff planar structure maintains longitudinal stability, together providing comprehensive stability at lower mass.
Solution Approach 2:
The crossbeam unit uses a composite structure combining two different structural forms (tubular and planar) rather than a single homogeneous tube. This composite approach allows optimization for different force types, achieving stability equivalent to a massive tube but with significantly reduced mass and improved energy efficiency.
3Reliability
If a single massive tube is used for the crossbeam, then all forces are absorbed, but the device complexity and material usage increase
Solution Approach 1:
The force absorption function is segmented between two specialized structures: the tubular structure handles torsional and vertical forces, while the planar structure handles tensile forces in the direction of travel. This segmentation reduces material usage and simplifies each component's design compared to a single massive tube handling all forces.
Solution Approach 2:
Each support structure is designed to handle multiple force types within its specialization. The tubular structure absorbs torsional forces, vertical forces, and some tensile forces, while the planar structure absorbs tensile forces and some torsional forces. This multi-functionality within each component reduces the need for additional specialized parts.
Data Source
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AI summary
In order to improve a trailer coupling (20) comprising a cross member unit (44) mountable on a rear area (14) of a body (12) and extending transversely to a longitudinal direction of the vehicle body, in particular of a passenger car, and a bearing unit (40) held by the cross member unit, by means of which a ball neck (22) with a coupling ball (32) is held on the cross member unit, wherein the cross member unit is connected in its two outer, opposing end areas with mounting elements (48a, 48b) with which the cross member unit is fixed to the rear area, in such a way that its mass is lower while maintaining the same stability, it is proposed that the cross member unit has an upper support structure (72) viewed in the vertical direction and a lower support structure (102) arranged lower in the vertical direction than the upper support structure,that the supporting structures are each connected to the mounting elements at their opposing outer end regions and support the bearing unit in a central region (76, 106), that one of the supporting structures is designed as a torsionally stiff supporting structure that at least partially encloses a structural interior, and that the other of the supporting structures is designed as a tensilely stiff supporting structure that is primarily stiff in the direction of travel.