Dental Object Milling Force Simulation for Feed Rate Optimization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current milling processes are inefficient, as they are designed for worst-case scenarios and do not account for dynamic machine behavior or machining forces, leading to low efficiency and tool wear.

Innovation Solution

A machining method that simulates machining forces and adjusts process parameters to maintain optimal force levels, allowing for faster, more robust, and accurate production, while also protecting equipment and enabling the use of smaller, cheaper cutting machines.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If milling templates are designed for worst-case machining scenario, then reliability is improved, but productivity deteriorates

Engineering Contradiction:
Improvemachining reliabilityVSAvoidmachining efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies dynamics by transitioning from static worst-case milling templates to dynamic simulation that accounts for actual machine behavior, control system characteristics, and real-time machining forces. The simulation model adapts to specific machine-tool-workpiece combinations, enabling optimized parameters that maintain reliability while significantly improving productivity.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes parameters by using simulation to determine optimized milling parameters (feed rates, spindle speeds, depths of cut) based on actual machine characteristics rather than conservative worst-case values. This allows pushing parameters closer to their true limits while maintaining reliability, thereby increasing productivity.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If simulation models are used to simulate machining, then manufacturing precision is improved, but device complexity increases

Engineering Contradiction:
Improveworkpiece accuracyVSAvoidsimulation model complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent introduces a simulation model as an intermediary between the machine controller and the milling process. This model acts as a virtual representation that predicts machining forces and outcomes without requiring complex physical modifications to the actual machining system, thereby achieving precision improvements with manageable complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a digital copy (simulation model) of the machining system that replicates its behavior. This virtual copy allows for precise prediction and optimization of machining processes without the complexity of modifying the physical system, enabling accurate manufacturing with controlled model complexity.

Inventive Principle:
Principle #26Copying

3Productivity

If higher feed rates are used to improve productivity, then productivity is improved, but machining forces increase causing tool wear and reduced reliability

Engineering Contradiction:
Improvemachining speedVSAvoidtool life
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent implements feedback by using the simulation model to predict machining forces at different feed rates and using this information to select optimal parameters. The simulation provides feedback on the consequences of parameter choices, enabling selection of feed rates that maximize productivity while keeping forces within acceptable limits to protect tool life and reliability.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4276549A1Chipping method for producing a dental object
Publication Date: 2023.11.15 IVOCLAR VIVADENT AG
  • EP4276549A1 patent drawingFigure 1
  • EP4276549A1 patent drawingFigure 2
  • EP4276549A1 patent drawingFigure 3

AI summary

The present invention relates to a machining process comprising the steps of providing (S101) a data set (101) for the milling process in which at least one process parameter (103) for machining a workpiece (105) is specified; simulating (S102) a machining force on the workpiece (105) based on the data set; and adjusting (S103) the process parameters (103) for machining until a predetermined maximum value for the machining force is reached or a predetermined minimum value is maintained.