Rail Air Spring Stiffness Control via Segmented Chambers

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Solution Overview

Problem

Existing air spring systems for rail vehicles lack the ability to dynamically adjust spring stiffness and characteristics in response to changing load conditions and route profiles, limiting comfort and safety, especially at high speeds.

Innovation Solution

The air spring system incorporates multiple individual volumes within the air spring cover that can be connected or isolated via actively controlled valves, allowing for adjustable spring stiffness by altering the air volume distribution, which can be controlled wirelessly and powered by accumulators, enabling real-time adaptation of spring characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If an additional volume is formed in the air spring cover to change the spring characteristic, then comfort is improved through softer suspension, but the device complexity increases due to additional components and wiring

Engineering Contradiction:
ImprovecomfortVSAvoiddevice complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The air spring cover is divided into multiple sealed chambers (first additional volume, second additional volume, third additional volume) that can be independently connected or isolated from the working chamber using valves. This segmentation allows selective activation of different spring characteristics without requiring complete redesign of the air spring system.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system transitions from a static additional volume to a dynamic configuration where valves (first valve, second valve, third valve) enable real-time switching between different chamber connections. This allows the spring characteristic to be dynamically adjusted based on operating conditions such as load, speed, and route profile.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If multiple individual volumes are connected via actively controlled valves to adjust spring stiffness, then adaptability is improved for different load and route conditions, but the device complexity increases due to additional valves and control systems

Engineering Contradiction:
ImproveadaptabilityVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The air spring system incorporates multiple valves that can be actively controlled to connect or isolate different additional volumes from the working chamber. This enables dynamic adjustment of spring stiffness to match varying operational requirements such as different loads, speeds, and route profiles.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

By controlling the connection state of different additional volumes (first, second, third) to the working chamber, the system changes the effective air volume and thus the spring characteristic parameter. This allows continuous adaptation of suspension properties without mechanical modification of the air spring structure.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If complex wiring and cable routing are used to power controlled valves, then functionality is improved for dynamic adjustment, but the ease of manufacture and installation deteriorates

Engineering Contradiction:
ImprovefunctionalityVSAvoidease of manufacture
Core Design Contradiction:
Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The air spring system incorporates accumulators that automatically supply compressed air to the valves for their actuation. This self-service mechanism eliminates the need for external power sources, complex electrical wiring, and cable routing through the air spring assembly, significantly simplifying manufacturing and installation while maintaining full dynamic adjustment functionality.

Inventive Principle:
Principle #25Self-service

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

This solution enhances comfort and safety by allowing dynamic adjustment of spring stiffness based on load and route conditions, improving driving safety and maintaining high-speed operation while reducing the need for complex wiring and cable routing.

Implementation Method 1

an air spring bellows arranged between the air spring cover and the wheel rim

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

a working or pressure chamber forming a spring volume, which is delimited by an air spring cover on the body, a wheel rim on the running gear

Methodology Applied
Scientific EffectGas compression: Compression

Data Source

PatentEP3672858B1Air suspension system for a rail vehicle
Publication Date: 2022.07.06 CONTITECH LUFTEDERSYSTEME GMBH
  • EP3672858B1 patent drawingFigure 1
  • EP3672858B1 patent drawingFigure 2

AI summary

An air suspension system in a rail vehicle, arranged as a secondary suspension system between a waggon body and a chassis or undercarriage, with a working or pressure space which forms a suspension volume and is bounded by a body-side air suspension cover, a chassis-side rim and an air suspension bellows arranged between the air suspension cover and the rim, wherein an additional volume which is connectable so as to interact with the working or pressure space is formed in the air suspension cover, wherein the additional volume in the air suspension cover is formed from a plurality of individual volumes which are connectable to one another and/or to the working or pressure space via valves or are closable in relation to one another and/or with respect to the working or pressure space.