Cutting Insert Edge Geometry for Reduced Resistance

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Solution Overview

Problem

Conventional cutting inserts experience increased cutting resistance due to negative axial rake angles near the upper end of major cutting edges, which can lead to inefficiencies in machining processes.

Innovation Solution

A cutting insert design featuring a major cutting edge, a flat cutting edge, and a minor cutting edge with specific inclination angles and peripheral cutting edge angles, where the minor cutting edge has a larger peripheral cutting edge angle than the major cutting edge, reducing cutting resistance and enhancing chip discharge performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a conventional cutting insert design is used, then the structure is simple, but cutting resistance increases due to negative axial rake angle regions

Engineering Contradiction:
Improvecutting insert structureVSAvoidcutting resistance
Core Design Contradiction:
Device complexityVSForce

Solution Approach 1:

The cutting edge is segmented into multiple sections with different functions: a major cutting edge section, a flat cutting edge section, and a minor cutting edge section. Each section has optimized geometry to perform specific cutting tasks, eliminating the negative axial rake angle problem while maintaining overall structural simplicity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different sections of the cutting edge are given different local geometries and rake angles optimized for their specific functions. The major cutting edge has one set of angles, the flat section has another, and the minor section has yet another, allowing each local region to operate under optimal conditions without causing negative rake angles elsewhere

Inventive Principle:
Principle #3Local quality

2Productivity

If the minor cutting edge has a larger peripheral cutting edge angle, then chip discharge performance improves, but the cutting edge geometry becomes more complex

Engineering Contradiction:
Improvechip discharge performanceVSAvoidcutting edge geometry
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The cutting edge is divided into distinct segments including a minor cutting edge section with specifically optimized peripheral angle. This segmentation allows the minor section to have a larger peripheral cutting edge angle for improved chip discharge, while other sections maintain their own optimized geometries, managing overall complexity through functional division

Inventive Principle:
Principle #1Segmentation

3Force

If the cutting edge has multiple sections with different angles, then cutting resistance is reduced, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvecutting resistanceVSAvoidinclination angle precision
Core Design Contradiction:
ForceVSManufacturing precision

Solution Approach 1:

Each section of the cutting edge (major, flat, and minor) is given specific local quality parameters including optimized inclination angles and peripheral angles. The major cutting edge has inclination angle θ2, the flat section has θ1 where θ1>θ2, and the minor section has θ3 where θ3<θ1. This localized optimization reduces cutting resistance in each region while the patent provides specific angular relationship guidelines to manage manufacturing precision requirements

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2495060B1Cutting insert and cutting tool, and cut workpiece manufacturing method using same
Publication Date: 2018.02.07 KYOCERA CORP
  • EP2495060B1 patent drawingFigure 1
  • EP2495060B1 patent drawingFigure 2
  • EP2495060B1 patent drawingFigure 3

AI summary

A cutting insert according to an embodiment of the present invention includes an upper surface; a lower surface; a side surface; and a cutting edge which is located in an intersection region of the upper surface and the side surface, and includes a major cutting edge, a flat cutting edge, and a minor cutting edge located between the major cutting edge and the flat cutting edge. The cutting edge reaches a top portion thereof while being inclined upward from the flat cutting edge to the major cutting edge with respect to a reference plane perpendicular to a central axis of the cutting insert in a side view. The cutting edge is thereafter inclined downward with respect to the reference plane. A peripheral cutting edge angle of the minor cutting edge is larger than a peripheral cutting edge angle of the major cutting edge. A cutting tool including the cutting insert; and a method of manufacturing a machined product using the cutting tool are provided.