Rotatable Fin Bumper Assembly for Dynamic Stiffness Control

Solution Overview

Problem

Vehicle bumpers face a design challenge in achieving the right stiffness for both low-speed damageability and pedestrian impact protection, as existing standards create competing design principles that require different stiffness levels depending on vehicle speed.

Innovation Solution

A bumper reinforcing assembly with rotatable fins that change position based on vehicle speed, providing higher stiffness at low speeds for damage prevention and lower stiffness at higher speeds for energy absorption during pedestrian impacts, utilizing a carrier and fins that are attached to the bumper and fascia, and an actuator system to adjust fin position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the bumper stiffness is increased to prevent damage at low speed, then low-speed damageability is improved, but pedestrian protection at high speed deteriorates due to excessive energy absorption

Engineering Contradiction:

Improvebumper stiffnessVSAvoidpedestrian injury

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The bumper system transitions from a static stiffness structure to a dynamic one by incorporating rotatable fins that can change their orientation based on impact conditions. The fins are connected via rotators that allow them to pivot between different angular positions, enabling the bumper to adapt its stiffness characteristics dynamically rather than being fixed in a single configuration

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the geometric parameter of the fins (specifically their angular orientation relative to the bumper) to alter the overall stiffness of the bumper structure. By adjusting the fin rotation angle, the structural parameters of the bumper are modified, allowing it to provide high stiffness when fins are in one position and low stiffness when rotated to another position, thus addressing different impact scenarios

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If the bumper stiffness is decreased to reduce energy absorption during pedestrian impact, then pedestrian protection is improved, but low-speed damageability deteriorates due to insufficient damage prevention

Engineering Contradiction:

Improvepedestrian injuryVSAvoidbumper stiffness

Core Design Contradiction:

Object-affected harmful factorsVSStrength

Solution Approach 1:

The bumper system transitions from a static stiffness structure to a dynamic one by incorporating rotatable fins that can change their orientation based on impact conditions. The fins are connected via rotators that allow them to pivot between different angular positions, enabling the bumper to adapt its stiffness characteristics dynamically rather than being fixed in a single configuration

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the geometric parameter of the fins (specifically their angular orientation relative to the bumper) to alter the overall stiffness of the bumper structure. By adjusting the fin rotation angle, the structural parameters of the bumper are modified, allowing it to provide high stiffness when fins are in one position and low stiffness when rotated to another position, thus addressing different impact scenarios

Inventive Principle:

Principle #35Parameter changes

3Ease of manufacture

If a fixed stiffness bumper design is used, then manufacturing simplicity is maintained, but adaptability to different impact speeds deteriorates

Engineering Contradiction:

Improvebumper manufacturing simplicityVSAvoidbumper adaptability to different speeds

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The bumper structure is segmented into distinct functional components: the main bumper body and multiple independent fins. Each fin can rotate independently via its own rotator mechanism, allowing the system to segment the stiffness adjustment function across multiple movable elements rather than requiring a completely redesigned monolithic structure

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The fins serve multiple functions: they act as structural reinforcement elements that increase stiffness when in the first angular position, and as energy-absorbing components that reduce stiffness when rotated to the second position. This multi-functionality allows a single component design to address both low-speed damageability and high-speed pedestrian protection requirements

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS9827931B2Bumper reinforcing assembly

Publication Date: 2017.11.28 FORD GLOBAL TECH LLC

AI summary

A vehicle front end includes a bumper and a carrier attached to the bumper. A plurality of fins are movably attached to the carrier and are spaced from each other. The fins taper in a direction transverse to the bumper. The fins may be moved to a deployed position to reinforce the bumper to improve low-speed damageability of the bumper, and may be moved to an inactive position, which may allow a fascia to more easily deform relative to the deployed position to provide energy absorption for pedestrian impacts.