Extruded Vehicle Subframe Nodes for Weight and Cost Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The automotive industry faces challenges in creating a subframe that is lightweight, cost-efficient, and meets strict safety requirements, particularly in the context of emerging electric and hybrid vehicles, where traditional casting methods for nodes are seen as necessary for rigidity but are heavy and costly.
Innovation Solution
The subframe is designed using extruded profiles for longitudinal and transverse members and nodes, with integrated features like pole absorbing members and triggers for enhanced safety and crash performance, allowing for a lightweight, cost-effective, and rigid structure that can handle vehicle crashes effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If casting is used for nodes to achieve rigidity, then structural strength is improved, but weight and manufacturing cost increase
Solution Approach 1:
The patent applies parameter changes by transitioning from casting to extrusion process, and from isotropic to anisotropic material orientation. The extruded nodes are designed with grain flow direction optimized for load-bearing paths, achieving comparable or superior strength-to-weight ratio compared to traditional casting methods
2Strength
If casting is used for nodes to achieve rigidity, then structural strength is improved, but manufacturing cost increases
Solution Approach 1:
The patent changes the manufacturing process parameter from casting to extrusion. Extrusion is a more cost-effective process for high-volume production, with lower tooling costs and faster cycle times compared to casting, while still achieving the required structural strength through optimized profile design
Solution Approach 2:
The extrusion process serves multiple functions: it creates the node geometry, optimizes material grain structure for strength, and enables integration with other extruded subframe members. This multi-functionality reduces the need for separate manufacturing operations and assembly steps, lowering overall manufacturing cost
3Weight of moving object
If extruded profiles are used for all members including nodes, then weight and cost are reduced, but achieving rigid connections becomes difficult
Solution Approach 1:
The patent applies local quality by designing the extruded nodes with enhanced cross-sectional geometry at connection points. The nodes feature reinforced walls and optimized thickness distributions specifically at joint locations to maintain rigidity, while other portions of the structure use standard thinner walls for weight reduction
Solution Approach 2:
The patent utilizes the extrusion direction as an additional design dimension, orienting the grain flow and wall thickness variations along the extrusion length to optimize connection rigidity. The nodes are designed with varying cross-sections along the extrusion direction, creating three-dimensional complexity from a one-dimensional process
Data Source
Figure 1
Figure 2
Figure 3a~3c
AI summary
The present disclosure regards a subframe (1) for a vehicle, which comprises a first (21) and second (22) longitudinal member, wherein the longitudinal members (21, 22) extend in a longitudinal direction (x) and are relatively offset in a transverse direction (y) of the subframe (1), a transverse front member (3) connectable to the first and second longitudinal member (21, 22) at a front section of the subframe (1), a transverse rear member (4) connectable to the first and second longitudinal member (21, 22) at a rear section of the subframe (1). The transverse front member (3) and transverse rear member (4) are relatively offset in a longitudinal direction (x) of the subframe (1), wherein the respective first and second longitudinal member (21, 22) and the respective transverse front and rear member (3, 4) are extruded profiles, and whereby the extrusion of each respective longitudinal member (21, 22) extends substantially in the longitudinal direction (x) and the extrusion of each respective transverse front and rear member (3, 4) extends substantially in the transverse direction (y). The subframe (1) further comprises a first (51) and a second (52) node connectable to the transverse rear member (4) at opposite transverse end sections thereof, wherein the first and second nodes (51, 52) are extruded profiles. Moreover, the present disclosure regards a method and a vehicle (100).