Vehicle Suspension Side Rails Impact Absorption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional suspension members face challenges in efficiently absorbing impact loads from the vehicle body front side, leading to reduced energy absorption by longitudinal members during frontal impacts, which can result in damage or breakage of front coupler portions.
Innovation Solution
A suspension member design featuring a rear cross member with open cross-sectional shape, front cross member with closed cross-sectional shape, and side rails with higher ductility, where side rails are positioned to overlap and absorb impact loads before they reach the front body mounts, with ribs and recessed bead portions for enhanced joint strength and deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If front coupler portions are formed by die casting, then manufacturing efficiency is improved, but the susceptibility to breakage by impact load increases
Solution Approach 1:
The patent changes the material parameter by using a different material for the side rails compared to the front body mounts. The side rails are made from material with higher ductility (different material properties) than the die-cast front body mounts, allowing them to absorb impact loads through deformation without breaking, while maintaining manufacturing efficiency through extrusion processes.
Solution Approach 2:
The suspension member employs a composite structure where components made by different manufacturing processes (die casting for front body mounts, extrusion for side rails) are assembled together. This composite approach allows each component to have optimized properties for its specific function - the die-cast mounts provide structural support while the extruded side rails provide impact absorption through their higher ductility.
2Loss of energy
If side rails with higher ductility are used, then energy absorption capability is improved, but structural complexity increases
Solution Approach 1:
The patent segments the suspension member into functionally distinct components: front body mounts for structural support and side rails for impact absorption. By dividing the structure into separate components with specialized functions, the design achieves high energy absorption capability through the ductile side rails without requiring the entire structure to be complex, as each segment is optimized for its specific role.
Solution Approach 2:
The patent applies local quality by giving different material properties to different parts of the suspension member. The side rails specifically have higher ductility localized to the regions that will experience impact loads, while other components maintain their original properties. This localized optimization achieves improved energy absorption without unnecessarily increasing the complexity of the entire structure.
3Loss of energy
If side rails overlap front body mounts, then impact load absorption is improved, but manufacturing complexity increases
Solution Approach 1:
The patent merges the front body mounts and side rails into an integrated assembly where the side rails overlap and are joined to the front body mounts. This merging creates a unified load path that improves impact load absorption, as the overlapping configuration allows forces to be distributed across both components. The assembly is then manufactured as an integrated unit, reducing overall assembly complexity despite the overlapping geometry.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design effectively absorbs impact loads, reduces the likelihood of front body mount damage, improves joint strength, and enhances energy absorption characteristics during frontal impacts.
Implementation Method 1
the side rails are each formed in a closed cross-sectional shape having a higher ductility than that of the front body mounts and the secondary side rails. Consequently, when a load is input from the vehicle body front side to the suspension member such as when the vehicle is involved in a frontal impact, the load is efficiently absorbed by the side rails.
Data Source
AI summary
A suspension member that includes: a rear cross member having a pair of secondary side rails; a front cross member; a right and left pair of front body mounts; and a right and left pair of side rails that are each formed in a closed cross-sectional shape having a higher ductility than a ductility of the front body mounts and the secondary side rails, extend in the extension direction of the secondary side rails, and are covered from vehicle body upper side by and joined to the front body mounts in a state in which vehicle body rear side sections of the side rails are covered from their vehicle body upper side by and joined to the secondary side rails and vehicle body front side sections of the side rails overlap front end portions of the front body mounts as seen in a plan view.