High-Feed Milling Insert Geometry for Chip-Wedging Relief

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Solution Overview

Problem

Existing cutting inserts for high-feed milling face challenges in ramping operations, including pocketing, due to chip wedging issues between the workpiece and the milling tool's peripheral relief surface, leading to inefficiencies and increased risk of tool damage.

Innovation Solution

A cutting insert design with specific geometric features, including obtuse-angled main and ramping cutting edges, sloping corner cutting edges, and chip breakers, which facilitate smooth chip movement and reduce the risk of chip wedging by ensuring chips move radially outward, away from the active cutting edges, thereby improving the cutting process and chip evacuation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional cutting insert designs are used for high-feed milling, then the tool can perform basic cutting operations, but chip wedging occurs between the workpiece and peripheral relief surface during ramping operations

Engineering Contradiction:
Improvechip evacuationVSAvoidchip wedging
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The cutting edges are designed to extend at obtuse angles (95°-160°, preferably 100°-125°, more preferably 112°±5°) relative to the peripheral relief surface, creating a three-dimensional chip evacuation path that directs chips away from the harmful wedging zone between the workpiece and relief surface

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

Different portions of the cutting insert have specialized functions: main cutting edges for material removal, ramping cutting edges for controlled chip formation at obtuse angles, and corner cutting edges for finishing. Each region is optimized to prevent chip wedging in its specific operational zone

Inventive Principle:
Principle #3Local quality

2Productivity

If aggressive cutting parameters are used for high-feed milling, then productivity increases, but chip evacuation becomes difficult and tool damage risk increases

Engineering Contradiction:
Improvecutting speedVSAvoidtool damage risk
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The ramping cutting edges are positioned and angled to perform preliminary chip formation and directional control before the main cutting edges engage, pre-positioning chips for smooth evacuation and preventing wedging that could lead to tool damage

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The cutting insert is divided into multiple specialized cutting edges (main, ramping, corner, secondary) that perform sequential and coordinated functions, allowing aggressive feed rates while maintaining reliable chip evacuation through distributed cutting action

Inventive Principle:
Principle #1Segmentation

3Productivity

If the cutting edges are positioned to maximize material removal, then productivity improves, but chip wedging between workpiece and peripheral relief surface occurs

Engineering Contradiction:
Improvematerial removal rateVSAvoidchip wedging
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The cutting edges are asymmetrically positioned and angled relative to the peripheral relief surface, with obtuse angles (95°-160°) that create an inherent chip evacuation pathway, breaking the symmetry that would otherwise cause chips to wedge against the relief surface

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP3964314A1Cutting insert and high feed milling tool
Publication Date: 2022.03.09 SANDVIK COROMANT
  • EP3964314A1 patent drawingFigure 1a~1c
  • EP3964314A1 patent drawingFigure 1d
  • EP3964314A1 patent drawingFigure 1e~1g

AI summary

A cutting insert for use in high-feed milling, which has 180° rotational symmetry about a centre axis (C) and comprises: - first and second major faces (2, 3); - a median plane (MP) extending between said major faces perpendicularly to the centre axis; - a first main cutting edge (31) and an associated first ramping cutting edge (51); and - a second main cutting edge and an associated second ramping cutting edge. Each main cutting edge has a first end (31a) facing the associated ramping cutting edge and an opposite second end (31b). Each ramping cutting edge has a first end (51a) facing the associated main cutting edge and an opposite second end (51b). Said cutting edges slope such that their second ends are located closer to the median plane (MP) than their first ends, and the second ends of the main cutting edges are located closer to the median plane than the second ends of the ramping cutting edges.