Milling Feed Rate Control via Deflection Estimation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Components often deflect during milling operations due to cutting forces, making it difficult to maintain accuracy in component dimensions, as measuring deflections is challenging and existing technologies do not effectively address this issue.

Innovation Solution

A system that adjusts the feed rate of a milling tool based on estimated deflection by determining the force applied and using compliance tensor data to compare against deflection criteria, thereby reducing the force and deflection, ensuring accurate milling operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a high feed rate is used during milling operations, then productivity is improved, but manufacturing precision deteriorates due to increased cutting forces causing component deflection

Engineering Contradiction:
Improvefeed rateVSAvoidcomponent dimension accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The system dynamically adjusts the feed rate during milling operations based on real-time monitoring of component deflection. The feed rate is not fixed but varies continuously to maintain deflection within acceptable limits while maximizing material removal rate, resolving the contradiction between productivity and precision

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system implements a closed-loop feedback mechanism where component deflection is measured during milling, compared against target deflection criteria, and used to automatically adjust the feed rate. This feedback control enables the system to maintain manufacturing precision while optimizing productivity through adaptive feed rate modification

Inventive Principle:
Principle #23Feedback

2Manufacturing precision

If a low feed rate is used during milling operations, then manufacturing precision is improved by reducing cutting forces and component deflection, but productivity deteriorates

Engineering Contradiction:
Improvecomponent dimension accuracyVSAvoidmilling operation speed
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The system changes the feed rate parameter dynamically based on the actual component deflection state. By adjusting this critical parameter in real-time, the system achieves high precision when needed (low feed rate) and high productivity when possible (high feed rate), eliminating the need to choose between the two extremes

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If the feed rate is adjusted frequently to maintain precision, then manufacturing precision is improved, but device complexity increases due to additional control systems

Engineering Contradiction:
Improvecomponent dimension accuracyVSAvoidcontrol system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The system uses the milling machine's own measurement capabilities and control systems to automatically monitor and adjust feed rate without requiring external complex equipment. The existing machine tools and controllers are utilized to their full capability, achieving precision through self-service rather than adding external complexity

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3447592B1Milling machine feed rate control
Publication Date: 2020.10.21 RTX CORP
  • EP3447592B1 patent drawingFigure 1
  • EP3447592B1 patent drawingFigure 2
  • EP3447592B1 patent drawingFigure 3

AI summary

An estimated force applied by a milling tool at a surface point of a component is determined during milling operations of the component. An estimated deflection of the component associated with the estimated force is determined using the estimated force and a compliance tensor of the component corresponding to the surface point of the component. The estimated deflection of the component is compared to one or more deflection criteria. A feed rate of the milling tool is adjusted during the milling operations of the component based on results of the comparing.