Open-Pore Air Spring Damping for Vehicle NVH Control

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Solution Overview

Problem

Conventional air springs for vehicles require additional components like hydraulic dampers to manage vibrations, which increase weight, generate heat, and have limited functionality at high frequencies, leading to undesirable NVH behavior and increased costs due to complex designs or large volumes.

Innovation Solution

Incorporating an open-pore foam body within the pressure chamber of the air spring, which acts as a micro-restrictor to provide damping without the need for additional space or complex designs, allowing for effective resonance damping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If additional hydraulic dampers are used to dampen vibrations, then damping function is improved, but device complexity and weight increase

Engineering Contradiction:
Improvedamping functionVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines the damping function with the air spring by integrating an open-pore foam body into the pressure chamber. This merging eliminates the need for separate hydraulic dampers, reducing device complexity and weight while maintaining the damping function through the foam's micro-constrictor structure that dissipates vibrational energy.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The air spring is designed to perform multiple functions: it provides suspension support through air pressure and simultaneously achieves vibration damping through the open-pore foam body. This multi-functionality replaces the need for separate damping components, addressing the technical contradiction by making the air spring a universal component that handles both support and damping tasks.

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

2Reliability

If additional hydraulic dampers are used to dampen vibrations, then damping function is improved, but weight increases

Engineering Contradiction:
Improvedamping functionVSAvoidweight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The damping function is merged into the air spring structure itself through the integration of the open-pore foam body within the pressure chamber. This eliminates the need for separate hydraulic damper components, thereby reducing the overall weight of the suspension system while maintaining effective vibration damping through the foam's energy-dissipating microstructure.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If additional hydraulic dampers are used to dampen vibrations, then damping function is improved, but installation space requirements increase

Engineering Contradiction:
Improvedamping functionVSAvoidinstallation space
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent merges the damping function into the existing air spring volume by placing the open-pore foam body inside the pressure chamber. This integration eliminates the need for additional installation space for separate dampers, as the damping component occupies space already allocated for the air spring operation, thereby reducing overall space requirements.

Inventive Principle:
Principle #5Merging (Combining)

4Reliability

If throttle body is used to achieve damping, then damping function is improved, but device complexity and volume increase

Engineering Contradiction:
Improvedamping functionVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs an open-pore foam body as a porous material to achieve damping functionality. The foam's micro-pore structure acts as numerous micro-constrictors that dissipate vibrational energy, providing effective damping without the complexity of a throttle body mechanism. This porous material approach simplifies the device structure while maintaining damping performance.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The invention extracts the essential damping function from complex mechanical mechanisms like throttle bodies and implements it through a passive porous foam structure. This extraction eliminates the need for moving parts, control systems, and complex assembly, resulting in a simpler device that achieves damping through the inherent properties of the open-pore foam material.

Inventive Principle:
Principle #2Taking out (Extraction)

5Reliability

If complex multi-chamber air spring design is used to achieve damping, then damping function is improved, but manufacturing cost increases

Engineering Contradiction:
Improvedamping functionVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent uses an open-pore foam body as a cost-effective alternative to complex multi-chamber air spring designs. The foam material provides damping functionality through its inherent porous structure, eliminating the need for multiple chambers, flaps, or complex internal geometries. This approach significantly reduces manufacturing complexity, assembly effort, and production costs while achieving the desired damping performance.

Inventive Principle:
Principle #31Porous 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 open-pore foam body effectively dampens resonances and vibrations, reducing NVH issues and costs by eliminating the need for external dampers, while maintaining a compact design.

Implementation Method 1

at least one open-pore foam body (14) which is in contact with the pressure chamber A in an air-conducting manner

Methodology Applied
Scientific EffectPorosity: Porosity

Implementation Method 2

the foam pores act as a large number of micro-constrictors that connect the foam bubbles as micro-volumes to ensure damping functionality

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Data Source

PatentEP4488541A1Air spring, in particular for road vehicles and/or for rail vehicles
Publication Date: 2025.01.08 CONTITECH DEUTSCHLAND GMBH
  • EP4488541A1 patent drawingFigure 1~2
  • EP4488541A1 patent drawingFigure 3~4
  • EP4488541A1 patent drawingFigure 5

AI summary

The invention relates to an air spring (1), in particular for road vehicles and/or for rail vehicles, comprising a piston (10), a plate (12), and a bellows (11) arranged between the piston (10) and the plate (12), wherein the piston (10), plate (12), and bellows (11) together form a pressure chamber (A). The air spring (1) is characterized by at least one open-cell foam body (14) which is in contact with the pressure chamber (A) to conduct air.