Lathe Feed Control for Chip Segmentation and Surface Roughness

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Solution Overview

Problem

Existing automatic lathe cutting processes face challenges in optimizing processing time and surface roughness due to issues with chip breaking, where long chips can wrap around the workpiece or cause scratches, and current control methods either deteriorate surface roughness or increase processing time.

Innovation Solution

A process control device and method for cutting chip segmentation that applies different control algorithms to instantaneous acceleration and deceleration phases, using a pre-control algorithm converted into a sine waveform to rapidly increase feed in the acceleration section and smoothly reduce feed in the deceleration section, thereby optimizing processing time and roughness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If chips are segmented through instantaneous direction changes, then chip segmentation is achieved, but surface roughness deteriorates

Engineering Contradiction:
Improvechip segmentation efficiencyVSAvoidsurface roughness
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent changes the parameter of feed motion from instantaneous direction changes to continuous speed variations. By controlling the feed speed to vary continuously (acceleration and deceleration phases) rather than changing direction abruptly, the system achieves chip segmentation while maintaining surface roughness quality.

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If speed is reduced through speed changes to segment chips, then surface roughness is improved, but processing time increases

Engineering Contradiction:
Improvesurface roughnessVSAvoidprocessing time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent applies periodic acceleration and deceleration actions to the feed motion. By rhythmically varying the feed speed with controlled acceleration and deceleration phases, the system segments chips effectively while minimizing the time penalty, as the speed variations are applied in periodic cycles rather than continuous slowdowns.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically changes the feed speed parameter during processing, applying acceleration to reduce processing time and deceleration to segment chips and maintain surface quality. This dynamic parameter adjustment resolves the trade-off between processing time and surface roughness.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If a tool rest is used for chip segmentation by rapid forward and backward switching, then chips are segmented, but tool rest vibration increases and equipment durability decreases

Engineering Contradiction:
Improvechip segmentationVSAvoidequipment durability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent replaces the mechanical tool rest oscillation system with a control algorithm applied to the feed motion. Instead of mechanically vibrating the tool rest to segment chips, the system uses programmed acceleration and deceleration of the feed, eliminating mechanical vibrations and their harmful effects on equipment durability.

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

Data Source

PatentEP4566753A1Process control device for processed chip segmentation and control method thereof
Publication Date: 2025.06.11 HANWHA PRECISION MACHINERY CO LTD
  • EP4566753A1 patent drawingFigure 1
  • EP4566753A1 patent drawingFigure 2
  • EP4566753A1 patent drawingFigure 3

AI summary

A process control device for processed chip segmentation, according to an embodiment of the present invention, discriminates an acceleration section in a pre-control algorithm transformed into a sine-wave form through the speed of a tool, and rapidly increases feed in the acceleration section in a linear form and smoothly decreases the feed in a deceleration section in a sine-wave form, thereby separating and dualizing the sections for acceleration and deceleration for chip segmentation, so that different control algorithms can be applied thereto. In addition, the process control device for processed chip segmentation can be variously implemented according to embodiments.