Engine Hood Guide Mechanism for Pedestrian Protection
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Solution Overview
Problem
Current pedestrian protection devices for vehicles are inadequate in reducing the impact of secondary collisions at the rear end portion of the engine room, as they often rely on improperly positioned engine hoods that do not effectively absorb the impact or cover critical areas like the cowl box.
Innovation Solution
A pedestrian protection device featuring an engine-hood guide mechanism that pivots the engine hood upward and rearward to cover the cowl box when a collision is detected, and lowers it when the load exceeds a specified threshold, utilizing a move mechanism with an actuator and a weak portion for buckling deformation to absorb kinetic energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the engine hood is lifted upwardly using actuators as in conventional hood devices, then the hood can be positioned to cover the engine room, but the cowl box cannot be properly covered and the specified stroke for impact absorption cannot be ensured
Solution Approach 1:
The engine hood is guided to move not only upwardly but also rearwardly along a predetermined trajectory defined by the engine-hood guide mechanism. This two-dimensional movement allows the hood to cover both the engine room and the cowl box area, while maintaining the specified stroke distance from the vehicle body for effective impact absorption.
Solution Approach 2:
The engine-hood guide mechanism acts as an intermediary device that guides the engine hood along a predetermined trajectory. This guide mechanism includes upward guides and rearward guides that work together to position the engine hood correctly, ensuring it covers the cowl box while maintaining the specified stroke for impact absorption.
2Area of stationary object
If the engine hood is positioned at a high level to cover the cowl box, then the protection area is extended rearward, but the specified stroke for impact absorption cannot be maintained
Solution Approach 1:
The engine hood is designed to be dynamically positionable along a predetermined trajectory rather than being fixed at a single high position. The engine-hood guide mechanism enables the hood to move upwardly and rearwardly while maintaining the specified stroke distance from the vehicle body, ensuring both extended protection area and effective impact absorption capability.
3Volume of moving object
If a bumping member projects rearwardly inside the hood to cover the cowl box, then the cowl box is covered, but the impact is absorbed only through deformation of the bumping member rather than utilizing the crash stroke
Solution Approach 1:
The engine hood is pre-positioned along a predetermined trajectory using the engine-hood guide mechanism before collision occurs. This preliminary positioning ensures the hood covers the cowl box area and maintains the specified stroke distance from the vehicle body, preparing the system to absorb impact energy through the controlled crash stroke rather than relying solely on bumping member deformation.
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
Effectively reduces the impact of secondary collisions by creating a specified stroke between the engine hood and the vehicle body, ensuring proper absorption and protection even when the protection area is positioned rearward, while preventing collisions with the windshield and wiper devices.
Implementation Method 1
a move mechanism which moves the engine hood rearwardly as the engine hood rises
Data Source
AI summary
A pedestrian protection device for a vehicle is provided at a vehicle-body front portion which comprises an engine room, a cowl box provided at an upper portion of a dash panel and extending in a vehicle width direction, and an engine hood pivotally supported at the vehicle body via a first hinge provided at a rear end portion so as to cover over the engine room. An engine-hood guide mechanism guides the engine hood upwardly and rearwardly so as to cover at least part of the cowl box when a collision of a pedestrian against a front bumper face is detected or predicted, and lowers the engine hood downwardly when a load acting on the engine hood exceeds a specified load.