EV Rocker Reinforcement Assembly for Side-Impact Battery Protection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing rocker assemblies in electric vehicles face challenges in efficiently assembling closed cross-section reinforcements due to accessibility issues of assembly tools and geometrical tolerances, leading to suboptimal mechanical cooperation and increased penetration during side impacts, which can damage the battery pack.

Innovation Solution

A rocker assembly design with a closed section reinforcement that is assembled in transition zones between rocker components' flanges and horizontal walls, using angles between 90° and 180°, allowing for continuous or semi-continuous assembly along the length, and employing filler wire welding or adhesive bonding to secure the reinforcement to the rocker components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a closed cross section reinforcement is used to maximize space occupation and mechanical resistance, then the strengthening effect is improved, but the accessibility of assembly tools and geometrical tolerances worsen

Engineering Contradiction:
Improvemechanical resistanceVSAvoidassembly accessibility
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The reinforcement is divided into multiple segments or sections along its length, with assembly features distributed at intervals rather than requiring continuous access. This segmentation allows assembly tools to reach attachment points while maintaining the overall closed cross-section structure for maximum strength.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Assembly fixtures or jigs are introduced as intermediary tools that can reach into the confined space to position and attach the reinforcement to the rocker components. These intermediaries bridge the gap between the limited tool accessibility and the requirement for precise assembly of the closed-section reinforcement.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If the reinforcement is attached only at front and rear extremities for assembly ease, then the assembly process is simplified, but the mechanical cooperation and impact resistance worsen

Engineering Contradiction:
Improveassembly simplicityVSAvoidimpact resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The attachment system is segmented into multiple discrete attachment points distributed along the length of the reinforcement, rather than continuous attachment. This provides sufficient mechanical cooperation for impact resistance while maintaining assembly simplicity at each discrete location.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The reinforcement structure combines the closed cross-section material with strategically placed attachment features that integrate multiple functions: structural strength from the closed section and mechanical cooperation from distributed attachment points, achieving both reliability and manufacturing ease.

Inventive Principle:
Principle #40Composite materials

3Strength

If the reinforcement occupies the biggest possible space within the hollow volume, then the stiffness performance is improved, but the assembly tool accessibility worsens

Engineering Contradiction:
Improvest stiffness performanceVSAvoidassembly tool accessibility
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

Assembly access is provided through dimensions or directions not previously considered - such as through the flange openings or through strategically positioned gaps in the rocker assembly - allowing tools to reach the reinforcement attachment points without compromising the maximum space occupation of the closed-section reinforcement.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 ensures optimal mechanical resistance, maximizes space utilization, and maintains assembly flexibility, reducing penetration during side impacts and protecting the battery pack while allowing production of both reinforced and non-reinforced vehicles on the same line.

Implementation Method 1

employing filler wire welding or adhesive bonding to secure the reinforcement to the rocker components

Methodology Applied
Scientific EffectWelding: Welding

Implementation Method 2

employing filler wire welding or adhesive bonding to secure the reinforcement to the rocker components

Methodology Applied
Scientific EffectAdhesive bonding: Adhesive

Data Source

PatentEP4153467B1Rocker reinforcement for an electric vehicle
Publication Date: 2025.11.05 ARCELORMITTAL SA
  • EP4153467B1 patent drawingFigure 1
  • EP4153467B1 patent drawingFigure 2
  • EP4153467B1 patent drawingFigure 3

AI summary

Reinforced rocker assembly having a closed section reinforcement located in the hollow volume formed between the rocker components, wherein the reinforcement is assembled to a rocker component in the transition zones between an upper horizontal wall and an upper flange of said rocker component and in the transition zones between a lower horizontal wall and a lower flange of said rocker component and wherein in said transition zones, the angles α and β formed between the flange and the branch of the reinforcement extending outwards of the rocker component are comprised between 90° and 180°.