Damper Piston Blowoff Disc Flow Path for Precise Damping

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Solution Overview

Problem

Existing damper designs in automotive suspension systems lack efficient control over fluid flow rate between subchambers, leading to inadequate damping force regulation and assembly complexity due to fixed passage sizes and orientations.

Innovation Solution

A damper assembly with a piston assembly featuring a body and piston rod having axial grooves and notches, allowing fluid to flow between subchambers through passageways, and blowoff discs that flex to adjust fluid flow based on pressure differentials, providing fine control over fluid transfer rates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If fixed-size passages are used in the piston, then the structure is simple, but the damping force cannot be adjusted and fluid flow control is inadequate

Engineering Contradiction:
Improvedamping force adjustmentVSAvoidpassage structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The piston rod includes a groove that forms a passageway with the inner bore, creating a dynamic fluid flow path that can control damping force. The groove geometry allows adjustment of fluid flow characteristics without requiring multiple fixed passages, enabling adaptable damping while maintaining relatively simple structure.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the parameter of fluid flow control by using the groove geometry in the piston rod rather than fixed passages in the piston body. This allows modification of damping characteristics through groove design (depth, width, position) without fundamentally changing the passage structure complexity.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If multiple passages are added to control fluid flow rate, then damping control improves, but assembly complexity increases

Engineering Contradiction:
Improvefluid flow rate controlVSAvoidassembly complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The groove in the piston rod is merged with the inner bore to form an integrated passageway. This combination eliminates the need for separate passages and reduces assembly complexity while providing sufficient fluid flow control capability through the groove geometry.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The groove structure serves multiple functions: it forms the fluid passage, controls damping force, and simplifies assembly by eliminating separate passage components. This multi-functionality addresses both fluid flow control needs and assembly complexity concerns.

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

3Adaptability or versatility

If orientation-dependent passages are used, then manufacturing is simple, but the damper performance varies with orientation

Engineering Contradiction:
Improveorientation independenceVSAvoidpassage manufacturing
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The groove in the piston rod is positioned and oriented to create asymmetric fluid flow characteristics that compensate for orientation variations. The groove geometry is designed to maintain consistent damping performance regardless of the damper's installation orientation, achieving orientation independence while remaining manufacturable.

Inventive Principle:
Principle #4Asymmetry

4Adaptability or versatility

If exponential resistance increase with speed is used, then damping control is achieved, but fine control over fluid transfer rates is lost

Engineering Contradiction:
Improvefluid transfer rate controlVSAvoiddamping force regulation
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The groove in the piston rod creates localized fluid flow control with specific geometric characteristics (depth, width, position) that provide fine control over fluid transfer rates. This local quality modification allows precise damping regulation without relying solely on exponential resistance increase, enabling both control and ease of operation.

Inventive Principle:
Principle #3Local quality

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 precise damping force adjustment and simplified assembly by allowing fluid flow control independent of orientation, enhancing damping performance and reducing component complexity.

Implementation Method 1

blowoff discs that flex to adjust fluid flow based on pressure differentials

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

blowoff discs that flex

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP4293251B1Damper assembly
Publication Date: 2025.10.29 ADVANCED SUSPENSION TECHNOLOGY LLC
  • EP4293251B1 patent drawingFigure 1
  • EP4293251B1 patent drawingFigure 2
  • EP4293251B1 patent drawingFigure 3A

AI summary

A damper assembly includes a pressure tube forming a chamber, a piston assembly disposed in the chamber and dividing the chamber into two subchambers, and a piston rod fixed to the piston assembly. The piston assembly includes a body having an inner bore extending axially through the body. The piston assembly includes a blowoff disc contacting the body at the inner bore and having a throughhole aligned with the inner bore. The piston rod extends through and concentrically contacts the inner bore and the throughhole. The body has a groove extending axially along a length of the inner bore. The groove and the piston rod form a passageway permitting fluid to travel across the body. The blowoff disc has a notch extending from the throughhole and arranged to permit fluid from the passageway to pass across the blowoff disc.