Damper Valve Leaf Bending Restriction for High Speed Damping

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Solution Overview

Problem

Conventional damper valve structures fail to provide sufficient damping force at high piston speeds, leading to inadequate vibration suppression and compromised vehicle comfort.

Innovation Solution

A valve structure for a damper that includes a piston, a piston nut, a laminated leaf valve, a valve restraining member, and a coil spring, where the leaf valve is biased to close the port and the valve restraining member restricts its bending, ensuring increased damping force at high piston speeds by maintaining contact with the valve restraining member, thereby enhancing damping coefficient.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the inner periphery of the leaf valve is not supported fixedly and simply pushed downward in the axial direction, then the device complexity is reduced, but the damping force becomes insufficient at high piston speeds

Engineering Contradiction:
Improvevalve structure complexityVSAvoiddamping force
Core Design Contradiction:
Device complexityVSForce

Solution Approach 1:

The valve structure is segmented into multiple functional components: the leaf valve body, the valve restraining member with bending restriction function, and the upright member with positioning function. This segmentation allows each component to perform its specific function independently, achieving both structural simplicity and sufficient damping force through coordinated action of the segmented elements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The valve restraining member acts as an intermediary element between the leaf valve and the piston rod. It mediates the interaction by providing bending restriction while allowing axial movement, thus enabling the leaf valve to generate sufficient damping force without requiring complex fixed support structures.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If the flow passage area is increased to suppress excessive damping force at medium speeds, then the vehicle comfort is improved, but the damping force becomes insufficient at high piston speeds

Engineering Contradiction:
Improvevehicle comfortVSAvoiddamping force
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The valve structure employs dynamic characteristics where the leaf valve bends elastically in response to varying piston speeds. At medium speeds, the increased flow area provides comfort, while at high speeds, the elastic bending of the leaf valve dynamically increases the damping force. This dynamic response is achieved through the flexible leaf valve design that adapts to different operating conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The effective flow passage area and damping characteristics are changed by varying the bending degree of the leaf valve. As piston speed increases, the leaf valve bends more, changing the flow characteristics and increasing damping force. This parameter change allows the system to provide appropriate damping force across different speed ranges without complex control mechanisms.

Inventive Principle:
Principle #35Parameter changes

3Force

If the leaf valve is allowed to bend freely, then the damping coefficient increases at medium speeds, but the damping coefficient does not increase at high piston speeds

Engineering Contradiction:
Improvedamping forceVSAvoidpiston speed range
Core Design Contradiction:
ForceVSSpeed

Solution Approach 1:

The valve restraining member provides beforehand cushioning by restricting the bending of the leaf valve outer periphery. This pre-established constraint ensures that even at high piston speeds where excessive bending would occur, the damping force continues to increase proportionally with speed. The restriction acts as a preventive measure that maintains proper damping characteristics across the entire speed range.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The valve structure combines materials and components with different mechanical properties: the flexible leaf valve material that allows controlled bending, and the rigid valve restraining member that provides bending restriction. This composite approach creates a system where the softer leaf valve provides damping while the harder restraining member maintains structural integrity and proper damping characteristics at high speeds.

Inventive Principle:
Principle #40Composite materials

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 ensures sufficient damping force is maintained at high piston speeds, preventing vibration and improving vehicle comfort by adjusting the damping characteristic to increase damping force proportionally with piston speed, while preventing excessive damping force at very high speeds.

Implementation Method 1

A lower surface of the leaf valve 3L is biased by a spring 3S via a main valve 3M

Methodology Applied
Scientific EffectElastic force: Elasticity

Implementation Method 2

the pressure of working fluid passing through a port 3Po increases such that the leaf valve 3L is pushed down together with the main valve 3M in an axial direction relative to the piston 3P against the biasing force of the spring 3S

Methodology Applied
Scientific EffectFluid pressure: Pressure Increase

Implementation Method 3

the outer peripheral side of the leaf valve 3L bends using a site that contacts the main valve 3M laminated onto the leaf valve 3L as a fulcrum

Methodology Applied
Scientific EffectLever mechanism: Lever

Data Source

PatentEP1892436B1Valve structure for damper
Publication Date: 2010.06.09 KYB CORP
  • EP1892436B1 patent drawingFigure 1
  • EP1892436B1 patent drawingFigure 2
  • EP1892436B1 patent drawingFigure 3

AI summary

A valve structure for a damper has a partition member (1) formed with a port, an upright member (4) that stands upright from an axial center portion of the partition member (1), a ring-shaped leaf valve (10), an inner peripheral side of which is penetrated by the upright member (4), and which is laminated onto the partition member (1) so as to close the port, a ring-shaped valve restraining member (11) which is laminated onto the leaf valve (10) to restrict a bending amount of the leaf valve (10), and an elastic body (15) which biases the leaf valve (10) in a direction for closing the port via the valve restraining member (11). In this valve structure, the elastic body (15) biases the leaf valve (10) in such a manner that compression of the elastic body (15) does not begin until at least an outer periphery of the leaf valve (10) bends into contact with the valve restraining member (11).