Rail Vehicle Pneumatic Brake Flow Limitation Device

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Solution Overview

Problem

Pneumatic brake systems in rail vehicles fail to maintain operational functionality when a brake air reservoir fails, leading to a loss of braking capability and affecting other dependent systems, due to the limited installation space which often requires only one reservoir per vehicle.

Innovation Solution

A pneumatic brake system with a flow-limiting device, such as a parallel connection of a non-return valve and a throttle, or an overflow valve, is implemented to regulate the inflow and outflow of compressed air, ensuring that the brake system remains operational even if the brake air reservoir pressure fails, by reducing the volume flow of compressed air and maintaining pressure within acceptable limits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If only one brake air reservoir is provided per vehicle to save installation space, then installation space is optimized, but the system reliability deteriorates because a single failure causes complete brake failure on the vehicle

Engineering Contradiction:
Improveinstallation spaceVSAvoidbrake system reliability
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The brake system is segmented into multiple independent brake circuits (e.g., left and right sides of the vehicle), each with its own brake air reservoir. This allows the brake system to remain partially operational even if one reservoir fails, thus maintaining reliability while managing installation space through strategic placement of multiple smaller reservoirs rather than one large centralized system

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system incorporates redundant brake air reservoirs as a preventive measure against failure. By having backup reservoirs in place beforehand, the system ensures that if one reservoir fails (leakage, destruction, falling off), the other reservoir(s) can maintain brake operation, thus cushioning against the harmful effect of single-point failures

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If a flow limitation device is added to the brake air reservoir to prevent excessive pressure drop, then system reliability improves during failure, but device complexity increases

Engineering Contradiction:
Improvebrake operation during reservoir failureVSAvoidpneumatic system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

A flow limitation device is introduced as an intermediary component between the brake air reservoir and the brake system. This device mediates the airflow to prevent excessive pressure drop when the reservoir fails, ensuring that enough pressure remains to maintain brake operation while adding only a single, relatively simple component to the system

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The flow limitation device changes the flow parameters (restricts volume flow) of compressed air to maintain pressure within acceptable limits during reservoir failure. By controlling the rate of pressure change rather than allowing uncontrolled pressure drop, the system maintains reliability without requiring complex active control systems

Inventive Principle:
Principle #35Parameter changes

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 system allows continued braking with reduced power in case of brake air reservoir failure, ensuring safety and functionality without excessive pressure drop, and reduces the risk of braking behavior impairment, while allowing for efficient filling and operation of anti-skid systems.

Implementation Method 1

the flow limitation device reduces the volume flow of compressed air flowing out of the brake system to such a level that it can be replenished from the compressed air supply without an excessive drop in pressure occurring

Methodology Applied
Scientific EffectFlow limitation:

Implementation Method 2

during a braking process, friction linings are pressed against friction partners by means of pneumatic pressure from a brake air reservoir

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3847064B1Pneumatic brake for a rail vehicle
Publication Date: 2023.03.22 SIEMENS MOBILITY AUSTRIA GMBH
  • EP3847064B1 patent drawingFigure 1~2

AI summary

The invention relates to a pneumatic brake (1) for a rail vehicle. Friction linings are pressed against friction partners during a braking process by means of pneumatic pressure from a brake air container (2), and wherein the brake air container (2) is fed from a compressed air supply (3), wherein the filling and the outflow of compressed air from the brake air container (2) takes place via a flow limiting device.