Rail Vehicle Air Spring Flow Limiting by Speed

Solution Overview

Problem

Existing air suspension systems in rail vehicles experience unnecessary pressurization and venting at high speeds due to dynamic centrifugal forces, leading to inefficient air flow management.

Innovation Solution

Limiting the volume flow in compressed air lines based on the speed of the rail vehicle, with stricter limitations at high speeds to prevent unnecessary pressurization and venting, using existing valve technology and control units that adapt air flow dynamically.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the air spring valve continuously adjusts air pressure to compensate for dynamic car body level changes, then driving comfort is improved, but unnecessary pressurization and venting occur at high speeds leading to energy waste

Engineering Contradiction:

Improvedriving comfortVSAvoidenergy waste from unnecessary pressurization and venting

Core Design Contradiction:

Ease of operationVSLoss of energy

Solution Approach 1:

The system dynamically adjusts the air flow limitation based on the vehicle's operating speed. At high speeds, the compressed air line is severely limited to prevent unnecessary venting, while at low speeds the limitation is reduced to allow comfortable level compensation. This dynamic adaptation resolves the contradiction by making the control characteristic speed-dependent.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The control parameter (air flow limitation) is changed based on the vehicle speed parameter. The system transitions from a fixed control mode to a variable control mode where the degree of air flow limitation is adjusted according to the measured speed, thereby preventing energy waste at high speeds while maintaining comfort at low speeds.

Inventive Principle:

Principle #35Parameter changes

2Loss of energy

If the compressed air line is severely limited at high speeds to prevent unnecessary venting, then energy waste is reduced, but the response time of the air suspension system increases

Engineering Contradiction:

Improveenergy waste reductionVSAvoidresponse time

Core Design Contradiction:

Loss of energyVSLoss of time

Solution Approach 1:

The system dynamically adjusts the air flow limitation based on the vehicle's operating speed. At high speeds, the compressed air line is severely limited to prevent unnecessary venting, while at low speeds the limitation is reduced to allow comfortable level compensation. This dynamic adaptation resolves the contradiction by making the control characteristic speed-dependent.

Inventive Principle:

Principle #15Dynamics

3Stability of the object's composition

If level control is continuously active during driving, then car body level stability is improved, but unnecessary air spring adjustments occur leading to reduced system efficiency

Engineering Contradiction:

Improvecar body level stabilityVSAvoidsystem efficiency

Core Design Contradiction:

Stability of the object's compositionVSProductivity

Solution Approach 1:

The system dynamically adjusts the air flow limitation based on the vehicle's operating speed. At high speeds, the compressed air line is severely limited to prevent unnecessary venting, while at low speeds the limitation is reduced to allow comfortable level compensation. This dynamic adaptation resolves the contradiction by making the control characteristic speed-dependent.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system periodically activates level control based on driving conditions. At high speeds, level control is essentially disabled through severe air flow limitation, while at low speeds it is activated. This periodic activation pattern improves system efficiency by avoiding unnecessary adjustments during high-speed operation.

Inventive Principle:

Principle #19Periodic action

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

Reduces unnecessary air flow adjustments during high-speed travel, maintaining driving comfort by minimizing unnecessary air spring pressurization and venting, and eliminating level control while driving.

Implementation Method 1

The air spring (2) consists of two parts and is fastened to a bogie... The air spring (2) is set up for cushioning and damping the car body on the bogie

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

a compressed air supply (4) which is pneumatically connected to the air spring (2) via an air spring valve (6) for venting or for filling the air spring (2) with compressed air

Methodology Applied

Scientific EffectPneumatic pressure: Pressure Increase

Implementation Method 3

means for limiting the volume flow in at least one of the compressed air lines (3) as a function of the speed of the rail vehicle

Methodology Applied

Scientific EffectVolume flow limitation:

Data Source

PatentEP2114744B1Regulation of an air spring

Publication Date: 2012.08.01 SIEMENS AG

AI summary

In order to disclose a device (1) having a pneumatic spring (2) for supporting a load on a bogie of a rail vehicle having a compressed air supply (4) which is pneumatically connected to the air spring (2) via an air spring valve (6) in order to vent and to fill the air spring (2) with compressed air, and having a control unit which is designed to adjust the air volume and/or the air pressure in the air spring (2) - a compressed air line (3) making available the pneumatic connection between the compressed air supply (4), air spring (2), air spring valve (6) and control unit - in which unnecessary filling and venting of the air spring (2) is prevented, means are proposed for limiting the volume flow (7) into the compressed air line (3) as a function of the speed of the rail vehicle.