Cryogenic Tool Cooling Feedback Control for Dullness Detection

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Solution Overview

Problem

Current machining systems lack the ability to monitor the efficiency of cryogenic cooling of cutting tools and detect when tools have dulled, leading to inefficient use of cryogenic coolants and suboptimal workpiece quality.

Innovation Solution

A feedback-controlled cryogenic machining system that includes a pressurized cryogenic fluid source, flow regulator, sensors, and a machining control unit to analyze and adjust the cryogenic fluid flow and temperature in real-time, providing quantitative data on tool and coolant state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If cryogenic coolant is used to cool the cutting tool, then tool longevity is increased, but there is no way to monitor cooling efficiency or tool condition

Engineering Contradiction:
Improvetool longevityVSAvoidcooling efficiency monitoring
Core Design Contradiction:
Duration of action of stationary objectVSLoss of information

Solution Approach 1:

The patent implements feedback control by using sensors to monitor tool temperature and coolant conditions, then adjusting coolant flow rates accordingly. Temperature sensors detect tool temperature, and this information feeds back to the control system which modulates the coolant flow to maintain optimal cooling efficiency and extend tool life.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces qualitative, trial-and-error assessment methods with quantitative sensor-based monitoring systems. Optical sensors and temperature sensors provide objective measurements of tool condition and cooling efficiency, eliminating the need for manual inspection and enabling precise control of the cooling process.

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

2Loss of energy

If cutting tool is used until it no longer works, then no tool replacement cost is incurred, but work piece quality deteriorates due to tool dulling

Engineering Contradiction:
Improvetool replacement costVSAvoidwork piece quality
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

The system continuously monitors tool condition through temperature sensors and other detection devices. When the tool approaches its effective life limit, the feedback signal triggers an alert or automatic tool replacement, ensuring workpiece quality is maintained while avoiding premature tool changes that would waste tool life and increase costs.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent enables preliminary detection of tool deterioration through sensor monitoring before the tool actually fails. This allows operators to plan tool replacement in advance, maintaining optimal tool condition for quality production while maximizing tool utilization to reduce replacement frequency and cost.

Inventive Principle:
Principle #10Preliminary action

3Temperature

If cryogenic coolant flow is increased to improve cooling, then cooling efficiency increases, but coolant consumption and cost increase

Engineering Contradiction:
Improvecooling efficiencyVSAvoidcoolant consumption
Core Design Contradiction:
TemperatureVSLoss of substance

Solution Approach 1:

The patent employs dynamic adjustment of coolant flow rates based on real-time tool temperature and machining conditions. The system modulates flow rates rather than maintaining constant high flow, optimizing cooling efficiency while minimizing coolant consumption. Flow rates are adjusted dynamically to match actual cooling needs throughout the machining process.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes coolant flow rate parameters in response to sensor feedback about tool temperature and machining conditions. By varying flow rate parameters dynamically rather than using fixed high rates, the system achieves effective cooling while reducing overall coolant consumption and associated costs.

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 system extends cutting tool life, improves workpiece metallurgy and surface finish, and optimizes coolant usage by providing real-time data for efficient coolant management and tool replacement.

Implementation Method 1

Some cryogenic machining systems run a coolant through the cutting tool

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

These methods utilize cryogenic coolants, such as liquid nitrogen or carbon dioxide, to cool the tool

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 3

EP 2 353 779 A1 discloses a cutting tool holder arrangement

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Data Source

PatentEP3311953B1Feedback-controlled system for cryogenically cooling machining tools
Publication Date: 2022.03.02 RTX CORP
  • EP3311953B1 patent drawingFigure 1
  • EP3311953B1 patent drawingFigure 2

AI summary

Disclosed is an improved method (26) for cryogenically cooling machining tools (20) where a feedback-controlled system (10) uses temperature, pressure, flow and/or infrared sensors (16) to regulate flow of a cryogenic coolant and functioning of a cutting tool (20).