Active Headrest Mechanism for Rear-End Collision Protection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing active headrest mechanisms for preventing neck injuries in rear-end collisions have complex structures, leading to increased costs and issues with instability and noise during normal driving, which affects user convenience and the perceived quality of the vehicle seat.

Innovation Solution

An active headrest with a simplified structure featuring a guide bar integrated with a stay rod, sliders, a moving bar, a front cover, and a latch unit, which allows for forward and upward movement of the headrest during collisions while being securely attached to the seat to prevent shake and adjust inclination for comfort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a complex active headrest mechanism is installed to quickly support the head in rear-end collisions, then neck injury prevention is improved, but device complexity and cost increase

Engineering Contradiction:
Improveneck injury preventionVSAvoidheadrest mechanism structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the guide bar and stay rod into a single integrated component. The guide bar serves dual functions: guiding the sliders during normal operation and acting as the stay rod for structural support. This merging reduces the number of parts and simplifies the overall mechanism while maintaining the active headrest's injury prevention capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The guide bar is designed to perform multiple functions: it guides slider movement during normal operation, provides structural support as a stay rod, and enables the pivoting motion of the moving bar. This multi-functionality reduces the need for separate components, simplifying the mechanism while ensuring reliable head support in collisions.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If the headrest is designed to move quickly in collisions, then neck injury prevention is improved, but shake and noise occur during ordinary driving

Engineering Contradiction:
Improvehead support responsivenessVSAvoidshake and noise
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The headrest mechanism transitions between two dynamic states: during normal operation, the latch unit keeps the headrest in a stable fixed position, preventing shake and noise. Upon collision detection, the latch unit releases, allowing the springs to rapidly move the headrest forward and upward to support the head. This dynamic switching resolves the contradiction between stability and responsiveness.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The springs are pre-compressed during normal operation, storing elastic potential energy. When a collision occurs, this stored energy is rapidly converted to kinetic energy, causing the headrest to move quickly to support the head. The preliminary compression of springs enables fast response without requiring complex actuators, while the latch unit ensures this energy remains stored until needed.

Inventive Principle:
Principle #10Preliminary action

3Device complexity

If the headrest structure is simplified, then device complexity is reduced, but the ability to provide both safety function and convenience adjustments is worsened

Engineering Contradiction:
Improveheadrest mechanism structureVSAvoidadjustment functionality
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The headrest is divided into functionally independent segments: the main body containing the active safety mechanism (springs, sliders, guide bar), the movable front cover for inclination adjustment, and the latch unit for state control. This segmentation allows the simplified safety mechanism to coexist with adjustment features, as each segment can be optimized for its specific function without interfering with others.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The front cover is designed to be movable relative to the main body, allowing users to adjust the inclination angle for comfort during normal operation. This dynamic adjustment capability is independent of the active safety mechanism, which remains in the simplified structure. The latch unit controls when the movable parts are locked or free to move, enabling both safety and comfort functions.

Inventive Principle:
Principle #15Dynamics

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 prevents neck injuries during rear-end collisions by ensuring the headrest is securely positioned and adjustable for comfort, reducing noise and vibration, and enhancing the overall quality of the vehicle seat and car experience.

Implementation Method 1

a driving spring (15) which provides an elastic force for pushing the sliders (3) upwardly

Methodology Applied
Scientific EffectElastic force: Elasticity

Data Source

PatentEP2361801B1Active headrest
Publication Date: 2012.11.14 DYMOS
  • EP2361801B1 patent drawingFigure 1
  • EP2361801B1 patent drawingFigure 2
  • EP2361801B1 patent drawingFigure 3~4

AI summary

An active headrest has a simple structure so that injuries of the neck and a portion near the neck of a passenger can be effectively prevented in the event of a rear-end collision and forward and rearward inclinations of the active headrest can be adjusted in an ordinary driving state to improve user's convenience and shake of the active headrest with respect to a vehicle seat in an ordinary state can be prevented to suppress noise and vibration and the quality of the vehicle seat and the car can be improved.