Frequency Dependent Valve Spring Buffer for Pressure Drop

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Solution Overview

Problem

Existing frequency-dependent hydraulic shock absorbers and dampers experience sharp pressure drops during stroke due to the opposition from the valve assembly, leading to undesirable damping characteristics when subjected to varying frequencies.

Innovation Solution

Incorporating a spring element that opposes the change in volume of the pressure chamber faster than the valve assembly, which helps return the pressure chamber to its resting volume quickly, thereby controlling the preload force without adding to the valve assembly's preload, and utilizing a flow restrictor and check valve to manage fluid flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the valve assembly opposes change in volume of the pressure chamber to control preload force, then the valve assembly maintains frequency-dependent damping characteristics, but sharp pressure drops occur during the damper's stroke

Engineering Contradiction:
Improvedamping characteristicsVSAvoidpressure drop
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

A spring element is introduced as an intermediary component between the piston and the valve assembly. This spring element absorbs and smooths out the pressure fluctuations that would otherwise cause sharp pressure drops, while still allowing the valve assembly to maintain its frequency-dependent preload force control. The spring acts as a buffer that mediates between the pressure chamber volume changes and the valve assembly response.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If the valve assembly alone opposes pressure chamber volume change, then frequency-dependent valve control is achieved, but the reaction force causes sharp pressure changes

Engineering Contradiction:
Improvefrequency-dependent controlVSAvoidpressure stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The invention merges two opposing mechanisms into a unified system: the spring element provides a stabilizing force that opposes volume changes, while the valve assembly provides frequency-dependent control. By combining these two elements working in parallel, the system achieves both pressure stability and adaptive frequency-dependent damping characteristics.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The spring element serves as a mediator that smooths out the interaction between the pressure chamber and valve assembly. It transforms the sharp, abrupt pressure changes into more gradual transitions, allowing the valve assembly to maintain its frequency-dependent control without causing instability in the overall system.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stress or pressure

If the spring element opposes pressure chamber volume change faster than the valve assembly, then pressure changes are smoothed out, but the system complexity increases

Engineering Contradiction:
Improvepressure stabilityVSAvoidvalve system complexity
Core Design Contradiction:
Stress or pressureVSDevice complexity

Solution Approach 1:

The invention uses the existing hydraulic fluid system to transmit forces between the spring element, pressure chamber, and valve assembly. By leveraging hydraulic pressure transmission, the system achieves coordinated operation of multiple components without requiring complex mechanical linkages or additional control systems, thus minimizing the increase in overall system complexity.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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

This solution provides improved frequency-dependent performance by smoothing out pressure changes and enhancing damping characteristics, reducing sharp pressure drops and optimizing fluid flow management.

Implementation Method 1

a spring element (370) that helps the valve assembly (100) oppose change in volume of the pressure chamber (300)

Methodology Applied
Scientific EffectSpring: Spring

Implementation Method 2

utilizing a flow restrictor and check valve to manage fluid flow

Methodology Applied
Scientific EffectFlow restrictor:

Implementation Method 3

utilizing a flow restrictor and check valve to manage fluid flow

Methodology Applied
Scientific EffectValve: Valve

Data Source

PatentEP3397874B1Improvement to frequency dependent valves
Publication Date: 2020.03.11 YAN SHI
  • EP3397874B1 patent drawingFigure 1~2
  • EP3397874B1 patent drawingFigure 3~4
  • EP3397874B1 patent drawingFigure 5

AI summary

A valve (1) comprises: a pressure chamber (300); a valve assembly (100) controlling a passage of fluid (150), the valve assembly (100) being configured in such a way that its preload force is controlled by the pressure chamber (300); a spring element (370) that helps the valve assembly (100) oppose change in volume of the pressure chamber (300), its preload force also controlled by the pressure chamber (300); characterized in that: for a given change in volume of the pressure chamber (300), reaction force from the spring element (370) changes faster than reaction force of the valve assembly (100).