Preassembled Rear Module Load Path Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle rear structures face challenges in crash safety, lightweight construction, logistics, and assembly efficiency, with secondary load paths introducing unwanted steps and potential destruction of screw connections during rear-end collisions, and requiring complex body shell variants.
Innovation Solution
A preassembled rear end module with support structures forming primary and secondary load paths, connected to the vehicle body for direct force transmission, featuring die-cast or welded components and adaptable design for various equipment variants, including a trough-like floor structure for additional units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If screw connections are used to connect the rear axle support to the body, then the rear axle support can be reliably installed on the body with tolerance compensation, but the screw connections may be destroyed during rear-end collisions and reliable force transmission is not ensured
Solution Approach 1:
The support structure is divided into a first support structure (rear axle support) and a second support structure (load path element), where each serves a distinct function: one for component mounting and the other for force transmission. This segmentation allows the load path element to directly transmit collision forces to the body without relying on screw connections, while the rear axle support can use screw connections for reliable installation with tolerance compensation.
Solution Approach 2:
The second support structure acts as an intermediary element between the first support structure and the body. It receives collision forces from the first support structure and transmits them directly to the body, bypassing the screw connections that would otherwise be the only load path. This intermediary structure ensures reliable force transmission during collisions while allowing the screw connections to fulfill their installation function.
2Reliability
If a secondary load path is formed with auxiliary side members on the body shell, then crash safety is improved, but the structure requires controlled body parts and modified production in body shell construction
Solution Approach 1:
The support system is segmented into a first support structure (rear axle support) and a second support structure (load path element forming secondary load path). This segmentation allows the secondary load path to be implemented as a separate, modular component rather than requiring modifications to the body shell itself, thus maintaining crash safety while avoiding increased body shell construction complexity.
Solution Approach 2:
The second support structure serves as an intermediary that creates the secondary load path without requiring modifications to the body shell. It connects to the body at specific attachment points and provides the necessary load path for crash safety, eliminating the need for controlled body parts and modified production sequences in body shell construction.
3Productivity
If the rear end module is preassembled as a subassembly, then assembly effort and logistics are reduced, but the structure must accommodate various equipment variants
Solution Approach 1:
The second support structure is designed with universal attachment points and a modular configuration that can accommodate different equipment variants. It can be adapted to various body types and equipment configurations without requiring completely different designs, thus enabling preassembly as a subassembly while maintaining versatility for different vehicle variants.
Solution Approach 2:
The support structures are designed with adjustable and configurable features that allow them to be adapted to different equipment variants. The modular design enables reconfiguration for different vehicle types (front-wheel drive, rear-wheel drive, all-wheel drive) and equipment options, while still allowing preassembly as a subassembly to reduce assembly effort and logistics complexity.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a motor vehicle comprising a body (2), which body has at least two rear longitudinal members each forming a primary load path for collision forces, wherein the motor vehicle (1) has a rear-end module (20) that can be pre-assembled as a sub-assembly, which rear-end module can be connected to the body (2) as part of the vehicle assembly after the completion of the body-in-white and has at least a supporting structure (21a, 21b) for fastening chassis components of a rear wheel suspension and a support structure (22a, 22b) extending from the supporting structure (21a, 21b) toward the motor-vehicle rear for absorbing collision forces, wherein the supporting structure (21a, 21b) and the support structure (22a, 22b) form at least one second load path for collision forces.