Electric Vehicle Battery Chassis Side Impact Protection

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Solution Overview

Problem

Existing body structures for electrically powered passenger vehicles do not effectively protect the traction battery from damage during collisions, particularly side impacts, and are complex in terms of production technology.

Innovation Solution

The traction battery is arranged in a space-saving manner within a vehicle shell originally designed for combustion engines, with a self-supporting battery compartment created by attaching open-bottom shells to the center tunnel and connecting them via intermediate plates to the side members, forming a deformation space that absorbs impact energy and protects the battery from side crashes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of stationary object

If the traction battery is positioned in the center tunnel below the seats, then the battery space is maximized and structurally favorable positioning is achieved, but the structure cannot sufficiently dissipate impact energy in side impacts

Engineering Contradiction:
Improvebattery compartment volumeVSAvoidside impact damage to battery
Core Design Contradiction:
Volume of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The battery compartment is segmented into a main compartment in the center tunnel and additional lateral compartments formed by attaching shells to the side members, allowing the structure to absorb impact energy in stages while protecting the battery

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Deformation free spaces are introduced as intermediary zones between the battery compartment and the body side members, allowing impact energy to be absorbed by deformation of these spaces rather than being transmitted to the battery

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If a cross member with battery flap is used to form the battery compartment, then the structure is very stiff, but impact energy dissipation capability is limited

Engineering Contradiction:
Improvebattery compartment stiffnessVSAvoidimpact energy dissipation
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

The structure employs local quality variation by making the battery compartment stiff in normal operation areas while creating localized deformation free spaces that can absorb impact energy, achieving both strength and energy dissipation

Inventive Principle:
Principle #3Local quality

3Volume of stationary object

If the battery compartment is expanded laterally by attaching shells to side members, then additional battery space is created, but the structure becomes more complex

Engineering Contradiction:
Improvebattery compartment volumeVSAvoidbody structure complexity
Core Design Contradiction:
Volume of stationary objectVSDevice complexity

Solution Approach 1:

The intermediate plates serving to connect the shells to the side members also function as structural reinforcement elements and potential mounting surfaces for other components, reducing the need for additional separate parts

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

This solution provides enhanced protection for the traction battery during collisions by creating additional deformation space, allowing the body to absorb impact energy without damaging the battery cells, while also simplifying production by using compatible components with conventional internal combustion engine vehicles.

Implementation Method 1

In the event of a side collision, the body side member on the sill is first deformed into the deformation space without damaging the battery cells

Methodology Applied
Scientific EffectImpact energy absorption: Deformation

Data Source

PatentEP2766247B1Chassis for an electric powered car
Publication Date: 2018.08.08 VOLKSWAGEN AG
  • EP2766247B1 patent drawingFigure 1
  • EP2766247B1 patent drawingFigure 2
  • EP2766247B1 patent drawingFigure 3

AI summary

The invention relates to an assembly structure for an electrically driven passenger vehicle comprising a traction battery arranged on the undercarriage below the seats. The battery compartment runs transversely between lateral longitudinal beams so as to a adjoin a central tunnel. The aim of the invention is to produce a traction battery which is particularly protected against side impact forces and which can be accommodated inexpensively. This is achieved in that shells (8) which are open towards the bottom are placed on the central tunnel (3), said shells transitioning into the undercarriage (2b) at the front and at the rear and being connected to the longitudinal beams (5) via lateral intermediate sheets (2c). A self-supporting battery box (13, 14) which is reinforced with supports (13b) that are circumferential in the shape of a frame can be inserted into the main battery compartment which is open towards the bottom and which runs through the central tunnel and into the battery sub-compartment produced by the shell (8) in the transverse vehicle direction (y). A free deformation space (21) can be provided between the lateral wall of the battery sub-compartment and the vehicle body longitudinal beam (5) in order to protect the battery (12a, 12b, 12c) from a side crash.