Hydraulic Damper with Nested Piston Assembly for Progressive Damping

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Solution Overview

Problem

Existing hydraulic dampers for motor vehicles lack a simple and cost-efficient solution to progressively increase damping force dependent on piston rod displacement while limiting excessive damping forces within tunable thresholds, especially in existing damper constructions.

Innovation Solution

A hydraulic damper design featuring a main piston assembly with a narrowed section and an additional piston assembly, including a compression valve assembly with deflective discs, a rebound valve assembly with deflective discs, and a sealing ring assembly, which generates additional damping force based on piston position and velocity, with a conical section inclination and radial recesses for tuning, and a sealing ring supported by a spring for smooth engagement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If an additional piston assembly is introduced into the narrowed section to generate additional damping force, then the damping force control capability is improved, but the device complexity increases

Engineering Contradiction:
Improvedamping force control capabilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The additional piston assembly is nested within the narrowed section of the main tube, with the sealing ring assembly positioned between the compression and rebound valve assemblies. This nested configuration allows the hydraulic stop arrangement to be integrated into the existing damper structure without requiring separate external components, thereby improving damping control capability while minimizing the increase in device complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The additional piston assembly serves multiple functions: it generates additional damping force during compression and rebound strokes, provides progressive engagement based on piston rod displacement, and enables velocity-dependent damping control. By consolidating these functions into a single integrated assembly rather than multiple separate mechanisms, the patent achieves enhanced adaptability while controlling device complexity.

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

2Reliability

If the hydraulic stop arrangement is designed to provide progressive increase of damping force dependent on piston rod displacement, then the damping performance is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improvedamping performanceVSAvoidmanufacturing complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The conical section of the narrowed section is designed with a specific inclination angle that can be adjusted to tune the progressive engagement characteristics of the hydraulic stop arrangement. By changing this geometric parameter, the damping force progression can be optimized for different performance requirements without fundamentally altering the manufacturing process or structure, thus improving damping performance while maintaining ease of manufacture.

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If the sealing ring assembly is designed with displaceable sealing ring for smooth engagement, then the engagement smoothness is improved, but the device complexity increases

Engineering Contradiction:
Improveengagement smoothnessVSAvoiddevice complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The sealing ring is designed to be displaceable rather than fixed, allowing it to move dynamically in response to pressure changes and piston position. This dynamic capability enables smooth engagement of the hydraulic stop arrangement by accommodating variations in operating conditions, while the simplicity of the displaceable design (relying on natural pressure-driven movement rather than active control mechanisms) keeps the increase in device complexity minimal.

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

Enables a wide range of tunable damping force gains during both compression and rebound strokes, ensuring smooth engagement and durability, while maintaining a simple and cost-effective construction suitable for existing damper applications.

Implementation Method 1

a compression valve assembly comprising at least one deflective disc; a rebound valve assembly comprising at least one deflective disc

Methodology Applied
Scientific EffectDeflection:

Implementation Method 2

a sealing ring assembly disposed between the compression valve assembly and the rebound valve assembly

Methodology Applied
Scientific EffectSealing:

Implementation Method 3

at least one end of the tube is provided with a narrowed section having a smaller diameter than a diameter of the main section of the tube and the damper is further provided with at least one additional piston assembly, displaceable along with the main piston assembly and adapted to be slidably introduced into the narrowed section of the tube to generate additional damping force

Methodology Applied
Scientific EffectHydraulic damping: Hydraulic Press

Implementation Method 4

a sealing ring supported by a spring for smooth engagement

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3366945B1Hydraulic damper with a hydraulic stop arrangement
Publication Date: 2020.04.08 BEIJING WEST IND CO LTD
  • EP3366945B1 patent drawingFigure 1
  • EP3366945B1 patent drawingFigure 2
  • EP3366945B1 patent drawingFigure 3~4

AI summary

A hydraulic damper (1) is disclosed having the main damper tube (3) with a narrowed section (34) and including at least one additional piston assembly (8) adapted to be received in the narrowed section (34) to generate additional damping force. The piston assembly (8) comprises a compression valve assembly (82) and a rebound valve assembly (83) each comprising at least one deflective disc (823, 824). A sealing ring assembly (84) is disposed between the compression and rebound valve assembles and comprises a first annular member (841) having a plurality of channels (8411) covered by the deflective disc of the compression valve assembly; a second annular member (842) having a plurality of channels (8421), covered by the deflective disc of the rebound valve assembly; an axial projection (847) between the annular members radially internal to the axial channels; and a sealing ring (843a) displaceable axially between the annular members and radially over the axial projection and adapted to cooperate with the narrowed section (34) of the tube (3).