Spring-Assisted Stiffener Beam for Pedestrian Protection and Ground Clearance

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Solution Overview

Problem

Light duty trucks and SUVs with high bumper heights pose a risk of pedestrian leg injury during impacts, as the lower leg can bend and slide under the bumper, necessitating a solution for pedestrian leg impact energy management while maintaining ground clearance.

Innovation Solution

A front-end stiffener system with a hinge bracket, support bracket, and spring mechanism that deploys and undeploys the stiffener beam based on speed and terrain, using a locking mechanism to maintain the beam in a deployed position at higher speeds and retract it for ground clearance during off-road or low-speed operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If a high bumper height is used to provide ground clearance for off-road capabilities, then ground clearance is improved, but pedestrian leg impact protection deteriorates

Engineering Contradiction:

Improvebumper heightVSAvoidpedestrian leg injury risk

Core Design Contradiction:

Length of moving objectVSObject-affected harmful factors

Solution Approach 1:

The stiffener beam is designed to be movable between a deployed position (for pedestrian protection) and a retracted position (for ground clearance). The system dynamically adjusts the bumper assembly's configuration based on operating conditions, allowing the stiffener beam to rotate about a pivot point between brackets, thereby resolving the contradiction between high bumper height and pedestrian protection

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the spatial parameter of the stiffener beam by deploying it below the bumper during pedestrian impact scenarios and retracting it during off-road operations. This parameter change allows the same structure to serve dual purposes: providing pedestrian protection when deployed and maintaining ground clearance when retracted

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If a deployable stiffener beam is added to manage pedestrian impact energy, then pedestrian protection is improved, but device complexity increases

Engineering Contradiction:

Improvepedestrian leg impact energyVSAvoidfront-end stiffener mechanism

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The spring mechanism automatically deploys or retracts the stiffener beam based on vehicle speed without requiring active control systems. At low speeds (off-road conditions), the spring allows the beam to be raised; at higher speeds (road conditions), the spring maintains the beam in the deployed position, eliminating the need for complex electronic controls or actuators

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The spring acts as an intermediary mechanism between the stiffener beam and the vehicle's active control systems. Instead of directly controlling the beam's position through complex actuators, the spring provides a passive mechanical means to maintain the beam in appropriate positions based on speed-dependent locking mechanism activation

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If a locking mechanism is implemented to maintain the stiffener beam in deployed position at higher speeds, then pedestrian protection reliability is improved, but manufacturing complexity increases

Engineering Contradiction:

Improvestiffener beam position maintenanceVSAvoidlocking mechanism assembly

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The locking mechanism replaces complex electronic control systems with a simpler speed-dependent mechanical system. The mechanism uses speed-sensitive components to automatically lock the stiffener beam in the deployed position at higher speeds, eliminating the need for electronic sensors, controllers, and actuators while maintaining reliability

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 system effectively manages pedestrian leg impact energy while minimizing damage from obstacles and reducing manufacturing complexity, enhancing reliability and durability by automatically adjusting the stiffener beam's position based on speed and terrain.

Implementation Method 1

A spring (40) engages the support bracket (24) and the hinge bracket (14) biasing the stiffener beam (36) in a deployed position

Methodology Applied

Scientific EffectSpring: Spring

Implementation Method 2

The spring (40) may allow the hinge bracket (14) to pivot relative to the support bracket (24) such that the stiffener beam (36) may be moved from the deployed position to the undeployed position when the stiffener beam (36) contacts ground obstacles

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS9821754B2Spring assist lock and release lower leg front-end stiffener

Publication Date: 2017.11.21 FORD GLOBAL TECH LLC

AI summary

A vehicle front-end stiffener includes a hinge bracket pivotally coupled to a support bracket. The hinge bracket supports a stiffener beam. A spring engages the support bracket and the hinge bracket biasing the stiffener beam in a deployed position. A moving element in a locking mechanism can retractably interlock the hinge bracket when a vehicle exceeds a threshold speed to maintain the stiffener beam in the deployed position.