Seat Belt Fluid Damper With Variable Duct Overlap Force Modulation
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Solution Overview
Problem
Existing seat belt systems fail to optimally adapt the retaining force to the passenger's weight and impact speed, leading to inadequate deceleration and potential injuries due to insufficient or excessive force application.
Innovation Solution
A fluid damper system with a piston and ducts that automatically adjust damping force based on passenger weight and impact speed by varying the overlap of duct portions and spring element interaction, ensuring a consistent and adaptive retaining force along the seat belt's stroke length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed retaining force is applied by the seat belt system, then the system structure is simple, but the retaining force cannot be adapted to different passenger weights and impact speeds
Solution Approach 1:
The patent implements a dynamic force limiter with a piston that moves within a cylinder, allowing the retaining force to dynamically adapt to different passenger weights and impact speeds. The piston position changes based on the applied force, automatically adjusting the damping characteristics without requiring external sensors or control systems.
Solution Approach 2:
The patent uses a hydraulic damping mechanism where damping fluid flows through variable cross-section ducts in the cylinder wall. The hydraulic system provides smooth force modulation by controlling fluid flow resistance, enabling adaptive retaining force based on passenger mass and impact conditions without complex mechanical linkages.
2Force
If the retaining force is increased to ensure adequate deceleration of heavy passengers, then heavy passengers are adequately decelerated, but light passengers experience excessive force on their shoulder area
Solution Approach 1:
The patent implements variable damping characteristics along the piston stroke, with different cross-sectional areas of ducts at different positions. This creates locally optimized damping properties that automatically provide appropriate force levels for different passenger weights, preventing both insufficient and excessive force application.
Solution Approach 2:
The patent changes the geometric parameters of the ducts (cross-sectional area, shape, distribution) to modify the hydraulic resistance characteristics. This allows the retaining force to be automatically adjusted according to passenger weight and impact speed, ensuring safe deceleration for all passenger types without manual intervention.
3Measurement precision
If additional sensor systems are added to adapt the retaining force to passenger weight, then the adapting precision is improved, but the device complexity and cost increase
Solution Approach 1:
The patent implements a self-regulating force limiter that automatically adapts to passenger weight and impact conditions without external sensors. The system uses the mechanical energy from the passenger's movement to drive the piston and automatically adjust the damping force, eliminating the need for separate detection and control systems.
Solution Approach 2:
The patent replaces electronic sensor and control systems with a purely mechanical-hydraulic solution. The piston-cylinder assembly with variable duct geometry provides automatic adaptation through physical principles, substituting complex electronic measurement and control with simpler mechanical feedback mechanisms.
4Length of moving object
If the piston stroke is made long to provide adequate braking distance, then the deceleration distance is sufficient, but the stroke is not optimally used and load peaks occur causing injuries
Solution Approach 1:
The patent implements dynamic adjustment of damping force throughout the piston stroke, with the hydraulic resistance varying continuously as the piston moves. This creates a smooth deceleration profile that fully utilizes the available stroke length while preventing load peaks, ensuring both adequate braking distance and passenger safety.
Solution Approach 2:
The patent ensures continuous and smooth damping force application throughout the entire piston stroke through carefully designed duct geometries. The hydraulic system maintains continuous fluid flow control, preventing abrupt force changes and ensuring uniform deceleration that maximizes the useful braking distance without creating injurious load peaks.
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 fluid damper system provides a cost-effective, long-lasting solution that ensures smooth deceleration of passengers, adapting the retaining force to match passenger weight and impact speed, thereby minimizing injuries and maintaining optimal load distribution during crashes.
Implementation Method 1
a damping force of the fluid damper which results in the advantages and design options described above
Implementation Method 2
spring element (140)
Data Source
AI summary
A fluid damper for modulating a retaining force of a seat belt is provided. The fluid damper includes an outer cylinder and an inner cylinder. The inner cylinder encloses an inner space. The fluid damper includes a piston shiftable in the inner space. The fluid damper includes a duct. The duct conductively connects a front fluid chamber disposed in front of the piston to a rear fluid chamber disposed behind the piston and/or a reservoir for the damping fluid. The duct includes an outer duct portion and an inner duct portion. The inner cylinder is deflectable from a rest position by a force acting on the piston so that the deflection of the inner cylinder causes an adjustment of an overlap of the outer duct portion and the inner duct portion depending on the magnitude of the force.