Shock Absorber Damping Valve With Variable Leaf Valve Bias

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Solution Overview

Problem

Conventional shock absorbers face limitations in adjusting damping force at low piston speeds, resulting in reduced riding comfort and a narrow damping force adjustment range, as they rely on fixed orifices which restrict the ability to decrease damping force effectively.

Innovation Solution

A damping valve with a leaf valve and variable biasing system, featuring gaps between the leaf valves and valve seats, allows for adjustable damping force by varying the biasing force and flow path area, enabling reduced damping force at low speeds and expanded adjustment range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the opening area of the fixed orifice is increased to decrease damping force at low piston speeds, then the damping force can be reliably decreased, but the damping force adjustment width is remarkably reduced

Engineering Contradiction:

Improvedamping forceVSAvoiddamping force adjustment width

Core Design Contradiction:

ForceVSAdaptability or versatility

Solution Approach 1:

The damping valve separates the flow control function into two distinct paths: a fixed orifice for high-speed flow control and a leaf valve with adjustable opening area for low-speed flow control. This segmentation allows each component to optimize its function without compromising the overall damping force adjustment range, resolving the contradiction between decreasing low-speed damping force and maintaining adjustment width.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The leaf valve introduces a dynamic, adjustable flow path that can vary its opening area according to piston speed and pressure differential. Unlike the fixed orifice, the leaf valve's opening area can be dynamically controlled through the biasing part, enabling continuous adjustment of damping force across the full speed range while preserving the complete adjustment width.

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If the disc valve is not provided with an orifice to increase damping force adjustment width, then the damping force adjustment width increases, but the damping force may increase too much at low speeds which may worsen the riding comfort

Engineering Contradiction:

Improvedamping force adjustment widthVSAvoiddamping force

Core Design Contradiction:

Adaptability or versatilityVSForce

Solution Approach 1:

The damping valve segments the flow control function into two distinct paths: a fixed orifice for high-speed flow control and a leaf valve with adjustable opening area for low-speed flow control. This segmentation allows each component to optimize its function without compromising the overall damping force adjustment range, resolving the contradiction between decreasing low-speed damping force and maintaining adjustment width.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The leaf valve's opening area is made variable through the biasing part, allowing the flow resistance parameter to be dynamically adjusted. This enables the system to maintain low damping force at low piston speeds by increasing the leaf valve opening area, while preserving the full damping force adjustment width through coordinated control of both the fixed orifice and variable leaf valve.

Inventive Principle:

Principle #35Parameter changes

3Device complexity

If a fixed orifice is used to control damping force, then the structure is simple, but the damping force cannot be effectively decreased at low piston speeds

Engineering Contradiction:

Improvevalve structureVSAvoiddamping force

Core Design Contradiction:

Device complexityVSForce

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The leaf valve acts as an intermediary component between the fixed orifice and the piston, providing an additional controllable flow path. This intermediary element enables effective damping force reduction at low piston speeds by offering an alternative flow route with adjustable resistance, complementing the fixed orifice's high-speed control function.

Inventive Principle:

Principle #24Intermediary (Mediator)

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 solution effectively decreases damping force at low piston speeds and expands the damping force adjustment range, improving riding comfort and mitigating sudden changes in damping characteristics, thus enhancing vehicle stability and comfort.

Implementation Method 1

a biasing part configured to exert a variable biasing force on the leaf valve toward the valve disc

Methodology Applied

Scientific EffectElastic force: Elasticity

Implementation Method 2

a solenoid pressure control valve that controls the pressure within the back pressure chamber

Methodology Applied

Scientific EffectHydraulic pressure control: Hydraulic Press

Implementation Method 3

The disc valve opens/closes the passage by separating from or sitting on the valve seat

Methodology Applied

Scientific EffectValve closure: Valve

Implementation Method 4

the shock absorber mainly exerts the damping force with the fixed orifice

Methodology Applied

Scientific EffectDamping: Damping

Data Source

PatentUS11614140B2Damping valve and shock absorber

Publication Date: 2023.03.28 KYB CORP

AI summary

A damping valve includes a valve disc including a passage and a valve seat configured to surround an outlet end of the passage, a leaf valve configured to separate from/sit on the valve seat to open/close the passage, and a biasing part configured to exert a variable biasing force on the leaf valve toward the valve disc, and a gap is provided between the leaf valve and the valve seat.