Tunnel Boring Cutting Wheel Wear Detection by Embedded Conductors

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Solution Overview

Problem

Existing cutting wheels for tunnel boring machines lack a reliable and easily adaptable tool condition monitoring system that can be retrofitted into existing designs, leading to inefficient wear monitoring and replacement of mining tools.

Innovation Solution

A tool condition monitoring device with electrically conductive current conductor elements embedded in carrier parts, allowing for spatial separation and easy integration with mining tools, which monitor wear by detecting interruptions in electrical current flow, enabling adaptive wear monitoring and easy retrofitting.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If current conductor elements are integrated into the excavation tools themselves, then wear detection is achieved, but the complexity of retrofitting to existing designs increases significantly

Engineering Contradiction:
Improvewear detection reliabilityVSAvoidretrofitting ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The monitoring system is segmented into separate functional modules: carrier parts mounted on the cutting wheel frame, excavation tools with integrated abrasion probes, and current conductor elements embedded in the carrier parts. This segmentation allows the monitoring device to be retrofitted without modifying existing excavation tools, as the tools only need to accommodate abrasion probes while the electronic monitoring infrastructure is provided by separately installable carrier parts.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Carrier parts serve as intermediary components that bridge the cutting wheel frame structure and the excavation tools. These carrier parts contain the current conductor elements and provide mounting positions for abrasion probes, enabling wear monitoring functionality to be added to existing tools through simple mechanical coupling rather than direct integration into the tool design.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If multiple current conductor elements of different lengths are embedded in excavation tools, then wear measurement precision is improved, but device complexity increases

Engineering Contradiction:
Improvewear measurement precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The current conductor elements are extracted from the excavation tools and placed in separate carrier parts mounted on the frame structure. This extraction simplifies the excavation tools while maintaining measurement precision, as the conductor elements remain positioned to detect wear through their electrical connection to the abrasion probes on the tools.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The carrier parts serve multiple functions: they house current conductor elements for electrical connection, provide structural support for mounting excavation tools, and incorporate abrasion probes for wear detection. This multi-functionality reduces overall device complexity by consolidating multiple components into single integrated carrier assemblies.

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

The solution effectively reduces tool wear monitoring complexity, allows for easy adaptation to various installation situations, and facilitates straightforward retrofitting without modifying existing structures, ensuring timely replacement of worn tools.

Implementation Method 1

the degree of abrasion of protruding abrasion probes can be detected via a resistance measurement

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Data Source

PatentEP4288637B1Cutting wheel for a tunnel boring machine
Publication Date: 2024.10.23 HERRENKNECHT AG
  • EP4288637B1 patent drawingFigure 1
  • EP4288637B1 patent drawingFigure 2
  • EP4288637B1 patent drawingFigure 3

AI summary

The invention relates to a cutting wheel (103) for a tunnel boring machine, in which cutting wheel, for the purpose of monitoring the condition of at least one mining tool (112, 115, 118) during removal of a geological structure present, during tunneling, at the cutting wheel (103) in a tunneling direction, a tool condition monitoring device is provided, which device has at least one support part (121, 124, 127) which is installed separately and at a distance from the or a relevant mining tool (112, 115, 118). In the relevant support part (121, 124, 127), a current-conductor element is embedded, which is interrupted in terms of its ability to carry current after a wear limit which is characteristic of the condition of the relevant mining tool (112, 115, 118) has been reached. In this way, the condition of mining tools (112, 115, 118) can be reliably determined during a relatively simple maintenance operation or retrofitting with a support part (121, 124, 127).