Rail Vehicle Friction Control via Temperature Regulation

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Solution Overview

Problem

Existing anti-skid and anti-skid devices in rail vehicles fail to fully transmit desired drive and braking forces due to low frictional connections, leading to wheel skidding or sliding, increased wear, and damage to the drive system, especially under conditions like moisture on the rail.

Innovation Solution

A method and control device that regulate driving and braking forces by controlling the frictional connection between the wheel and rail by adjusting the temperature of the friction partners, determining the necessary friction power based on temperature variables and speed values to optimize the frictional connection and prevent damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing anti-skid and anti-skid devices are used to control wheel slip and slide, then wheel skidding and sliding are prevented, but the desired drive and braking forces cannot be fully transmitted due to low frictional connection

Engineering Contradiction:
Improvewheel skid and slide preventionVSAvoiddrive and braking force transmission
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The invention changes the physical parameter of temperature of the friction partners (wheel and rail) to improve the frictional connection. By controlling the temperature through friction power input, the system optimizes the friction coefficient between wheel and rail, enabling full transmission of desired drive and braking forces while maintaining reliable slip prevention.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system applies friction power in controlled periodic cycles to gradually increase the temperature of the friction partners. This periodic heating action allows the frictional connection to be optimized over time without causing excessive temperature rise, balancing force transmission improvement with thermal management.

Inventive Principle:
Principle #19Periodic action

2Force

If friction power is increased to improve frictional connection, then drive and braking force transmission is improved, but temperature of friction partners increases which may cause material damage

Engineering Contradiction:
Improvefrictional connectionVSAvoidfriction partner temperature
Core Design Contradiction:
ForceVSTemperature

Solution Approach 1:

The system incorporates feedback control by monitoring the temperature of the friction partners and adjusting the friction power input accordingly. When the temperature approaches material boundary limits, the system reduces or stops friction power application, preventing thermal damage while maintaining optimal frictional connection during safe temperature ranges.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system applies friction power in gradual, controlled increments rather than sudden large increases, allowing the friction partners to adapt thermally. This progressive heating approach cushions against thermal shock and prevents excessive temperature rise that could cause material damage, while still improving the frictional connection.

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

3Force

If temperature of friction partners is increased to optimize friction potential, then frictional connection is improved, but wear and damage to wheel and rail increases

Engineering Contradiction:
Improvefriction potentialVSAvoidwear and damage
Core Design Contradiction:
ForceVSObject-generated harmful factors

Solution Approach 1:

The system continuously monitors temperature and provides feedback control to prevent excessive heating. By maintaining temperature within optimal but safe ranges, the system maximizes friction potential while avoiding the thermal conditions that lead to increased wear and material damage to the wheel and rail.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system optimizes the temperature parameter within a controlled range that maximizes friction potential without reaching thresholds that cause material degradation. By precisely controlling temperature as a physical parameter, the system achieves improved frictional connection while preventing wear and damage.

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

This approach enhances the frictional connection between the wheel and rail, allowing for improved transmission of drive and braking forces, reducing wear and damage, and ensuring safe operation by maintaining the material boundaries of the wheel and rail.

Implementation Method 1

the frictional connection between wheel and rail represents a measure of the available braking or driving force

Methodology Applied
Scientific EffectFriction: Friction

Implementation Method 2

a friction power is set in such a way that a predetermined temperature value of the friction partners is reached to influence the frictional connection

Methodology Applied
Scientific EffectFrictional heating: Viscous Heating

Data Source

PatentEP2231448B1Method for a regulating device for controlling the driving and braking force of a vehicle, and a vehicle having said regulating device
Publication Date: 2014.06.25 KNORR BREMSE SYST FUR SCHIENENFAHRZEUGE GMBH
  • EP2231448B1 patent drawingFigure 1
  • EP2231448B1 patent drawingFigure 2
  • EP2231448B1 patent drawingFigure 3

AI summary

The invention relates to a method for controlling the driving and braking force of a vehicle, particularly of a rail vehicle, having at least two friction elements, particularly a wheel (2) and a running surface (4), wherein a value corresponding to the driving or braking force FSoIl is determined from at least one predetermined or determined temperature value dTempSoll and a determined speed value for regulating or controlling the driving or braking force, and a regulating device (16) for controlling the driving and braking force, and to a vehicle having at least one such regulating device.