Turnout Switch Rail Monitoring for Creep and Closing Force

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Solution Overview

Problem

Existing technologies fail to simultaneously and effectively monitor the crawling quantity and close-attaching force of turnout tongue rails and external locking apparatuses in real time, requiring complex mounting and lacking long-term stability due to environmental disturbances.

Innovation Solution

A sensing unit is mounted on the external locking apparatus, utilizing magnetic field inductive sensors and optical fiber pin type sensors to monitor crawling quantity and close-attaching force without altering the ballast bed or rail, ensuring simple installation and high stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If existing detection devices are mounted beside the rail, then the close-attaching force can be detected, but the device structure becomes complex and mounting becomes tedious

Engineering Contradiction:
Improveclose-attaching force detectionVSAvoiddevice structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines multiple sensing functions (crawling quantity detection and close-attaching force detection) into a single integrated sensing unit that is mounted on the external locking apparatus. This merging of functions eliminates the need for separate detection devices beside the rail, thereby simplifying the overall device structure while maintaining detection capabilities.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sensing unit mounted on the external locking apparatus serves multiple functions: it detects both the crawling quantity of the tongue rail and the close-attaching force between the tongue rail and stock rail. This multi-functional design reduces the number of separate devices needed and simplifies mounting procedures.

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

2Measurement precision

If detection devices are mounted beside the rail, then monitoring can be performed, but the mounting process becomes tedious and time-consuming

Engineering Contradiction:
Improvecrawling quantity and close-attaching force monitoringVSAvoidmounting process
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

By combining multiple sensing functions into one integrated unit that mounts on the existing external locking apparatus, the patent eliminates the need for separate mounting procedures for multiple devices. This single mounting process replaces what would otherwise be multiple separate installations beside the rail.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The sensing unit utilizes the existing external locking apparatus as its mounting base, leveraging already-installed infrastructure. This approach eliminates the need for additional mounting structures or modifications to the ballast bed and rail, thereby simplifying the manufacturing and installation process.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If existing sensors are used in outdoor environment, then detection can be performed, but long-term stability is compromised due to environmental disturbances

Engineering Contradiction:
Improvedetection accuracyVSAvoidlong-term stability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent introduces an optical fiber pin type sensor as an intermediary detection mechanism that is immune to electromagnetic interference and environmental disturbances. This intermediary sensing approach transfers the detection function to a medium (optical fiber) that maintains signal integrity in harsh outdoor conditions, thereby ensuring long-term stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces traditional electrical or mechanical sensors with optical fiber-based sensing technology. This substitution eliminates susceptibility to electromagnetic interference, corrosion, and other environmental factors that affect conventional sensors, thereby improving long-term reliability in outdoor railway environments.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Measurement precision

If punching ballast bed and rail is required for mounting, then sensors can be installed, but the mounting complexity increases significantly

Engineering Contradiction:
Improvesensor installation capabilityVSAvoidmounting structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The sensing unit utilizes the existing external locking apparatus as its mounting base, leveraging already-installed infrastructure. This approach eliminates the need for additional mounting structures or modifications to the ballast bed and rail, thereby simplifying the manufacturing and installation process.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The external locking apparatus serves dual purposes: it functions as both the mechanical locking device for the turnout and as the mounting platform for the sensing unit. This universal use of existing infrastructure eliminates the need for separate mounting structures and avoids punching or modifying the ballast bed and rail.

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

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

Enables simultaneous monitoring of crawling quantity and close-attaching force with high accuracy and reliability, achieving ±0.1 mm precision and real-time data transmission, supporting online remote monitoring and reducing maintenance complexity.

Implementation Method 1

A sensing unit is mounted on the external locking apparatus, utilizing magnetic field inductive sensors

Methodology Applied
Scientific EffectMagnetic field induction: Electromagnetic Induction

Implementation Method 2

optical fiber pin type sensors to monitor crawling quantity and close-attaching force

Methodology Applied
Scientific EffectOptical fiber sensing: Optical Fibre

Data Source

PatentEP4455618B1Method and system for monitoring creep and closing force of switch rail and external locking device of turnout
Publication Date: 2026.04.01 CRSC RESEARCH & DESIGN INSTITUTE GROUP CO LTD
  • EP4455618B1 patent drawingFigure 1~3
  • EP4455618B1 patent drawingFigure 4a~4b
  • EP4455618B1 patent drawingFigure 4c~5

AI summary

The present invention belongs to the technical field of rail traffic and discloses a method and system for monitoring crawling and a close-attaching force of a turnout tongue rail and an external locking apparatus. The method includes: in a case that a tongue rail connecting iron and a connecting iron base are relatively displaced, converting, by a magnetic field inductive sensor, the number of acquired magnetic grids passing through a magnetic grid ruler and a magnetic pickup sequence into a magnetic signal; in a case that a latch hook assembly pushes the connecting iron base, converting, by an optical fiber pin type sensor, a force applied to the optical fiber pin type sensor into an optical fiber signal; processing the magnetic signal to acquire crawling quantities of the tongue rail and the external locking apparatus; and processing the optical fiber signal to acquire a turnout close-attaching force. According to the present invention, a sensing unit is mounted on the external locking apparatus, and it is unnecessary to punch a ballast bed and a rail to mount other instruments and sensing devices. The method is simple and convenient in mounting and simple in construction. According to the present invention, the crawling quantity and the close-attaching force of the tongue rail and the external locking apparatus can be monitored at the same time.