Rail Brake Leak Detection via Pressure Gradient Monitoring

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Solution Overview

Problem

Existing electro-pneumatic brake systems in rail vehicles fail to reliably detect leaks in brake pressure lines due to the standard pressure booster's ability to compensate for pressure losses, making it difficult to identify brake pressure loss and its impact on coupled brake cylinders.

Innovation Solution

A method that utilizes regular brake tests to detect leaks by monitoring the main air reservoir line pressure, applying the brake actuator, and checking for deviations in pressure values or gradients, generating an error message if predetermined limits are exceeded, without separate pressure sensors in each brake pressure line.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a standard pressure booster (EDU) is used to feed compressed air into brake pressure lines during leaks, then the brake pressure loss is compensated, but the ability to detect the leak is reduced

Engineering Contradiction:
Improvebrake pressure maintenanceVSAvoidleak detection capability
Core Design Contradiction:
ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent introduces an intermediary evaluation device that monitors the control signals sent to the pressure booster. By analyzing these control signals, the system can detect when the pressure booster is actively compensating for leaks, thereby identifying leak locations without compromising the pressure maintenance function. This intermediary monitoring approach resolves the contradiction by adding detection capability while preserving the compensatory function.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system implements feedback by continuously monitoring the control signals from the pressure booster and using this information to identify leak conditions. The evaluation device receives feedback about pressure booster activity and uses this to detect leaks, allowing the system to maintain reliable brake pressure while simultaneously detecting leaks through the feedback loop.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If pressure sensors are installed in each brake pressure line to detect leaks, then leak detection precision is improved, but device complexity and cost increase

Engineering Contradiction:
Improveleak detection precisionVSAvoidnumber of pressure sensors
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent makes the existing pressure booster serve multiple functions: it continues to maintain brake pressure by compensating for leaks while simultaneously providing detection information through its control signals. The evaluation device processes these control signals to identify leak locations. This multi-functionality approach achieves precise leak detection without adding separate pressure sensors to each brake pressure line, thereby reducing system complexity.

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

Solution Approach 2:

The pressure booster's control signals, which are already present for pressure maintenance, are repurposed to provide leak detection information. The system uses its own operational data (the control signals sent to the pressure booster) to detect leaks, eliminating the need for additional dedicated detection sensors and reducing overall device complexity.

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 method allows for reliable detection of leaks in brake pressure lines during routine brake tests, ensuring the integrity of the brake system without the need for additional pressure sensors, thus enhancing safety and efficiency.

Implementation Method 1

a compressed air source supplying the main air tank line with compressed air

Methodology Applied
Scientific EffectCompressed air: Compression

Implementation Method 2

the pressure gradient of the main air reservoir line pressure in the period between the beginning and the end of the application of the at least one brake actuator exceeds a predetermined pressure gradient

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP2870039B1Method for detecting leaks in a brake pressure line, under braking pressure, of a rail vehicle
Publication Date: 2016.09.21 KNORR BREMSE SYST FUR SCHIENENFAHRZEUGE GMBH
  • EP2870039B1 patent drawingFigure 1

AI summary

The invention relates to a method for detecting leaks in at least one brake pressure line (26, 28), under braking pressure (C), of a compressed air brake device (1) of a rail vehicle comprising an indirect electro-pneumatic brake, wherein the indirect electro-pneumatic brake has a master air vessel line (HB) to hold a master air vessel line pressure, and a compressed air source (7) supplying the master air vessel line (HB) with compressed air and is controlled by the master air line pressure in a master air line (HL), wherein the at least one brake pressure line (26, 28) under braking pressure (C) extends between a valve device (12), which controls the braking pressure (C) in dependence upon the master air line pressure in the master air line (HL), and at least one brake actuator (3), and wherein the method comprises a braking test carried out when the rail vehicle is stationary, having at least the following steps: a) checking whether, in the event of replenishment of compressed air from the compressed air source (7) into the master air vessel line (HB) being cut off, the master air vessel line pressure exceeds a preset limit value; and if so, b) controlling the master air line pressure in the master air line (HL) to apply the at least one brake actuator (3). According to the invention, within the framework of the braking test, the following further steps are carried out: c) monitoring the master air vessel line pressure to see whether c1) the value of the master air vessel line pressure arising after application of the at least one brake actuator (3) deviates by more than a preset difference from a preset plausible value for the master air vessel line pressure, and/or c2) in the period between the beginning and the end of the application of the at least one brake actuator (3), the pressure gradient of the master air vessel line pressure exceeds a preset pressure gradient; and d) if c1) and/or c2) applies, generating an error message that there is a leak in the at least one brake pressure line (26, 28).