Hollow Sleeve Sensor for Tunnel Boring Machine Load Detection

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Solution Overview

Problem

Existing mining tools for tunnel boring machines face challenges in accurately measuring mechanical loads under harsh conditions, with existing solutions offering limited precision and sensitivity.

Innovation Solution

A high-precision sensor system is integrated into the mining tool, featuring a cutter wheel attachment device with load-sensitive elements and a modular measurement unit in a hollow sleeve design, allowing for precise detection of external cutting forces and force directions, independent of fastening element positions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional sensor arrangements are used in mining tools, then the device complexity is reduced, but the measurement precision and sensitivity are insufficient under harsh conditions

Engineering Contradiction:
Improvedetection accuracy of mechanical loadVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The sensor arrangement is nested within the hollow sleeve structure, which is integrated into the cutting roller mounting device. The load-sensitive elements are positioned within the sleeve's hollow interior, allowing the sensor system to be compactly housed within the existing mechanical structure without adding external complexity.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The hollow sleeve acts as a flexible structural element that can deform under mechanical load, transmitting these deformations to the load-sensitive elements. The sleeve's thin-walled construction allows it to be sufficiently compliant for accurate force measurement while maintaining structural integrity in the harsh mining environment.

Inventive Principle:
Principle #30Flexible shells and thin films

2Measurement precision

If load-sensitive elements are integrated into fastening elements, then the device complexity is reduced, but the measurement precision and sensitivity are compromised

Engineering Contradiction:
Improvesensitivity of force detectionVSAvoidsensor arrangement structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The load-sensitive elements are extracted from the fastening elements and placed within the hollow sleeve structure. This separation allows the fastening elements to perform purely their mechanical fastening function while the sensor arrangement within the sleeve is optimized independently for maximum measurement sensitivity and precision.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The hollow sleeve serves as an intermediary structure between the cutting roller and the load-sensitive elements. It transmits mechanical loads from the cutting roller to the sensors while providing a protected environment for the sensitive measurement components, isolating them from the harsh external conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If thin-walled hollow sleeve is used for sensor mounting, then the sensitivity of measurement is improved, but the structural strength may be reduced

Engineering Contradiction:
Improvemeasurement sensitivityVSAvoidstructural durability under load
Core Design Contradiction:
Measurement precisionVSStrength

Solution Approach 1:

The wall thickness of the hollow sleeve is optimized to a specific range that balances sensitivity and strength requirements. The thin-walled construction provides sufficient compliance for high measurement sensitivity while the material selection and geometric design ensure adequate structural strength to withstand the mechanical loads encountered during mining operations.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The hollow sleeve is constructed from materials that combine high strength-to-weight ratio with appropriate elastic properties. This allows the sleeve to be thin-walled for sensitivity while maintaining the structural integrity needed to withstand harsh mining conditions and repeated mechanical loading cycles.

Inventive Principle:
Principle #40Composite materials

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 provides extremely precise force measurement during drilling operations, with improved sensitivity and reduced hysteresis, enabling accurate detection of mechanical loads and increased durability under harsh conditions.

Implementation Method 1

the elasticity of a thin-walled hollow sleeve body can also be advantageously used to revolutionize the sensitivity of the measurement

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

integrating one or more load-sensitive elements (such as strain gauges) in a hollow sleeve

Methodology Applied
Scientific EffectStrain gauge measurement: Piezoresistive Effect

Data Source

PatentEP3129593B1Precision sensor for determining mechanical constraints on a cutting tool of a tunnel cutting machine
Publication Date: 2019.06.05 HERRENKNECHT AG
  • EP3129593B1 patent drawingFigure 1
  • EP3129593B1 patent drawingFigure 2~4
  • EP3129593B1 patent drawingFigure 5~6

AI summary

A mining tool (100) for a drill head (150) of a tunnel boring machine (180) for mining in rock (102), wherein the mining tool (100) has a roller cutter fastening device (104), mountable on the drill head (150), for accommodating and mounting a rotatable roller cutter (106), the roller cutter (106) for mining in rock (102) is accommodated or in particular can be interchangeably accommodated rotatably in the roller cutter fastening device (104), and a sensor arrangement (112) for detecting a mechanical load of the mining tool (100), in particular of the roller cutter (106), wherein the sensor arrangement (112) is formed at least partially in the roller cutter fastening device (104) and/or on the sleeve (177) mounted on the roller cutter (106) with at least one load-sensitive element (108) mounted thereon.