Asymmetric Honing on Cutting Inserts for Edge Strength and Finish

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Solution Overview

Problem

Increasing the width of the honing surface at both ends of a cutting edge to strengthen the cutting edge can lead to increased cutting resistance and degrade the quality of the finished surface of a processed workpiece, particularly when cutting is initiated from one end side that protrudes more outward than the other.

Innovation Solution

The cutting insert is designed with a honing surface that gradually increases in width from one end to the other, featuring a distance from the central axis that inclines towards the fourth side surface, and a coating film thickness that varies accordingly, ensuring stability and reducing cutting resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the width of the honing surface is increased at both end parts of the cutting edge to strengthen the cutting edge, then the fracture resistance of the cutting edge is improved, but the cutting resistance increases and the quality of the finished surface degrades

Engineering Contradiction:
Improvefracture resistance of cutting edgeVSAvoidcutting resistance and surface quality
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The honing surface width is made non-uniform along the cutting edge, with a wider honing surface at the position where cutting is initiated (protruding end) and a narrower honing surface at the other end. This local differentiation allows the cutting edge to have enhanced fracture resistance where needed while maintaining low cutting resistance and high surface quality at the finishing end.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The cutting edge is designed with asymmetric honing surface distribution, where the honing surface width varies along the length of the cutting edge. This asymmetric design matches the asymmetric cutting action where one end protrudes and initiates cutting, allowing optimized performance for both cutting initiation and finishing operations.

Inventive Principle:
Principle #4Asymmetry

2Strength

If a large honing surface is provided to strengthen the cutting edge, then the cutting edge strength is improved, but the cutting resistance increases

Engineering Contradiction:
Improvecutting edge strengthVSAvoidcutting resistance
Core Design Contradiction:
StrengthVSForce

Solution Approach 1:

Instead of providing a uniformly large honing surface along the entire cutting edge, the invention applies a larger honing surface width specifically at the position where cutting is initiated (the protruding end), and a smaller honing surface width at the other end. This localized approach provides necessary strength where cutting forces are highest during initiation, while reducing cutting resistance during the finishing phase.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3450064B1Cutting insert
Publication Date: 2025.10.01 TUNGALOY CORP
  • EP3450064B1 patent drawingFigure 1
  • EP3450064B1 patent drawingFigure 2
  • EP3450064B1 patent drawingFigure 3

AI summary

Provided is a cutting tool (1) that simultaneously improves both fracture resistance and wear resistance. The cutting tool according to the present invention has an end surface (10), a peripheral side surface (12) intersecting with the end surface, and a cutting edge (20) in an intersecting ridge part along the end surface and the peripheral side surface, and when first and second points A and B are defined on the cutting edge, the first point A protrudes further toward an outer side of the cutting tool than the second point B. The cutting edge has a honing surface (21). The honing surface has a portion, the width of which gradually increases from the first point A toward the second point B.