Vehicle Step Arrangement With Dual Pivot Steps for BEV Access

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Solution Overview

Problem

Battery electric vehicles (BEVs) face challenges in providing ergonomic step access while maintaining crash protection and battery space, as traditional step designs either compromise battery volume or ergonomics, and foldable steps penalize crash protection.

Innovation Solution

A step arrangement with a frame, an upper step, and a lower step connected by pivotable linking elements that switch between a folded and unfolded position, allowing the upper step to pivot around one axis and the lower step to move in an arc, providing two stepping planes without increasing vertical space, thus enhancing ergonomics and crash protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If traditional cut-out steps are provided in battery packs, then step access is enabled, but battery volume is reduced and driving range is shortened

Engineering Contradiction:
Improvestep accessVSAvoidbattery volume
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The step arrangement is divided into separate components (frame, upper step, lower step) that are positioned outside the battery packs rather than cutting into them. This segmentation allows the steps to be provided without reducing battery volume, as the steps are formed by separate structural elements rather than cut-outs in the battery housing.

Inventive Principle:
Principle #1Segmentation

2Volume of moving object

If foldable steps are provided to save space, then battery volume is maintained, but crash protection capability is reduced

Engineering Contradiction:
Improvebattery volumeVSAvoidcrash protection
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

Instead of making the steps foldable to save space (which compromises crash protection), the invention inverts the approach by using a compact fixed structure that achieves space efficiency through its geometric configuration rather than through folding mechanisms. The upper step is positioned above and behind the lower step, creating a compact footprint without requiring movement or folding capabilities.

Inventive Principle:
Principle #13The other way round (Inversion)

3Reliability

If only one step is provided to maintain crash protection, then crash protection is improved, but ergonomic accessibility is reduced

Engineering Contradiction:
Improvecrash protectionVSAvoidergonomic accessibility
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The invention transitions from a single-step configuration to a two-step configuration by utilizing vertical and spatial arrangement in another dimension. The upper step is positioned above and behind the lower step, creating a stepped configuration that provides ergonomic accessibility for users of different heights while maintaining a compact overall structure that does not compromise crash protection.

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

4Ease of operation

If two foldable steps are provided for ergonomic access, then accessibility is improved, but vertical space increases and crash protection is penalized

Engineering Contradiction:
ImproveaccessibilityVSAvoidvertical space
Core Design Contradiction:
Ease of operationVSLength of stationary object

Solution Approach 1:

The invention employs a dynamic spatial arrangement where the upper step is positioned above and behind the lower step, allowing the structure to provide two stepping planes while maintaining a compact vertical profile. This dynamic configuration enables ergonomic access without significantly increasing the overall vertical space requirement, as the steps are arranged to overlap in the vertical dimension rather than extending linearly.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4378760A1A step arrangement for a vehicle
Publication Date: 2024.06.05 VOLVO TRUCK CORP
  • EP4378760A1 patent drawingFigure 1
  • EP4378760A1 patent drawingFigure 2~3
  • EP4378760A1 patent drawingFigure 4~5

AI summary

A step arrangement (10) comprises a frame (12), an upper step (16), a lower step (24) and a linking element (26). The upper step is, relative to the connected frame, pivotable around a first geometrical axis (X) to allow the upper step to be moved from a folded position in a storage state of the step arrangement to an unfolded position, the lower step following the movement of the upper step. The linking element, interconnecting the upper and lower steps, is, relative to the upper step, pivotable around a second geometrical axis (Y1, Y2) which extends in a direction which is substantially perpendicular to the direction of extension of the first geometrical axis, in order to allow the lower step to be moved along an arc of a geometrical circle so that the lower step becomes spaced apart from the upper step in a completely unfolded position of the lower step in an in-use state of the step arrangement.