Structural Battery Pack Reducing Sill Height
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Solution Overview
Problem
Current electric vehicle battery packs compromise cabin ergonomics and aerodynamic efficiency due to high sill height and the need for external side-spanning structures, which occupy valuable space and increase energy consumption.
Innovation Solution
A structural battery pack design where the battery casing forms the vehicle body's bottom and incorporates a deformable section that absorbs side impact energy, eliminating the need for external side-spanning members and allowing a lower sill height, with the battery pack integrated between longitudinal members of a pre-assembled frame structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external side-spanning structures are used to protect the battery pack, then crash safety is improved, but vehicle width and aerodynamic drag increase
Solution Approach 1:
The battery pack casing is merged with the vehicle's side impact protection structure. The casing includes deformable sections that directly absorb side impact energy, eliminating the need for separate external side-spanning members. This integration maintains crash safety while reducing vehicle width and aerodynamic drag.
Solution Approach 2:
The battery pack casing serves multiple functions: it encloses and protects the battery cells, provides structural support, and acts as the side impact absorption structure. This multi-functionality eliminates the need for separate protective structures, reducing overall vehicle dimensions and aerodynamic resistance.
2Reliability
If heavy side-spanning members are used over the battery pack, then side impact protection is improved, but vehicle weight increases
Solution Approach 1:
The side impact protection function is merged into the battery pack casing itself. The casing includes deformable sections designed to absorb side impact energy, eliminating the need for separate heavy side-spanning members and reducing overall vehicle weight.
Solution Approach 2:
The battery pack casing is designed with deformable sections that convert the harmful side impact force into beneficial energy absorption through controlled deformation. This approach provides effective protection without requiring heavy rigid structures.
3Reliability
If the battery pack is designed as a standalone unit with safety cage, then cell protection is improved, but volumetric efficiency decreases
Solution Approach 1:
The safety cage function is merged into the battery pack casing structure. The casing itself is designed with deformable sections that provide side impact protection, eliminating the need for a separate external safety cage and improving volumetric efficiency.
Solution Approach 2:
The battery pack casing serves as both the enclosure for battery cells and the safety protection structure. This multi-functionality eliminates the need for separate safety cage structures, maximizing the use of available space for battery cells.
4Strength
If high sill height is used to accommodate battery pack, then structural integrity is improved, but cabin ergonomics and roofline height increase
Solution Approach 1:
The side impact protection function is merged into the battery pack casing, allowing the sill height to be reduced to near the bottom plane. The deformable sections of the casing provide the necessary structural integrity and crash protection at the lower height.
Solution Approach 2:
The sill height parameter is changed from a high position to near the bottom plane. The battery pack casing is designed with deformable sections that maintain structural integrity and crash protection at this reduced height, improving cabin ergonomics and allowing for a lower roofline.
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 design enhances volumetric efficiency, reduces aerodynamic drag, and improves cabin ergonomics by allowing a lower roofline and minimizing the size of side-spanning structures, thereby increasing the vehicle's range and reducing energy consumption.
Implementation Method 1
a deformable section extending outwardly from the side wall to a position near the adjacent longitudinal member
Data Source
AI summary
An electric vehicle includes: a frame with two spaced-apart longitudinal members having an upper transversely oriented wall member that is situated a vertical distance Hu from a bottom plane and a lower transversely oriented wall member that is situated near the bottom plane, and a battery pack with an array of battery cells defining an array top surface, an array bottom surface and an array side surface. A casing top plate contacts the array top surface, a casing bottom plate contacting the array bottom surface and a casing side wall, connected to the top and bottom plates and contacting the array side surface. The casing top plate is situated a vertical distance Hct from the bottom plane that substantially corresponds with the distance Hu. The battery pack includes a longitudinal impact absorption structure.