Variable-Width Nicked Indexable Insert for Stable Low-Force Cutting

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Solution Overview

Problem

Existing vertical indexable inserts with nicks face challenges in providing reliable surface relief, leading to potential contact with the workpiece and limited machining conditions due to constant nick width and restricted radial rake, which affects cutting force and tool strength.

Innovation Solution

A vertical indexable insert with nicks featuring a side surface as a rake face, upper surface as a flank face, and nicks that divide the cutting edge, with each nick's width increasing towards the end, allowing for proper surface relief and reduced cutting force, and preferably manufactured by press forming to enhance strength and machining flexibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the nick width is kept constant, then the manufacturing is simplified, but the surface relief is insufficient and the nick contacts the workpiece

Engineering Contradiction:
Improvenick manufacturing simplicityVSAvoidsurface relief reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The nick width varies along its length, being smaller at the entrance and larger at the end. This local variation in geometry provides sufficient surface relief at the critical end region while maintaining manufacturability through standard press forming processes.

Inventive Principle:
Principle #3Local quality

2Reliability

If the radial rake is increased to provide surface relief, then the nick relief is improved, but the tool strength decreases

Engineering Contradiction:
Improvenick surface reliefVSAvoidinsert strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

Surface relief is achieved locally through the varying nick geometry rather than through overall radial rake changes. The nick width increases toward the end, providing localized relief where needed while preserving the overall structural integrity and strength of the insert.

Inventive Principle:
Principle #3Local quality

3Reliability

If the nick extends to the end of the flank face, then the surface relief is maximized, but the insert strength is compromised

Engineering Contradiction:
Improvesurface reliefVSAvoidinsert strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The nick geometry is optimized with varying width along its length, concentrating the relief function at the end region where the wider portion provides sufficient clearance. This allows effective surface relief without requiring the nick to extend fully to the flank face end, thereby preserving insert strength.

Inventive Principle:
Principle #3Local quality

4Productivity

If the feed is increased to improve productivity, then the machining efficiency increases, but the nick surface contacts the workpiece causing insufficient relief

Engineering Contradiction:
Improvemachining feed rateVSAvoidsurface relief sufficiency
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The varying nick width, particularly the increased width at the end region, provides sufficient surface relief even at higher feed rates. This geometric variation ensures that the nick surface maintains adequate clearance from the workpiece across a broader range of machining conditions.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP2106870B2Indexable insert with nick
Publication Date: 2023.03.22 SUMITOMO ELECTRIC HARDMETAL CORP
  • EP2106870B2 patent drawingFigure 1~2
  • EP2106870B2 patent drawingFigure 3~4
  • EP2106870B2 patent drawingFigure 5~6

AI summary

An indexable insert (10) with nicks (8) for a rotary tool includes plurality of nicks (8) are provided in an upper surface (1) serving as a flank face. The nicks (8) have their ends in the upper surface (1). The nicks (8) divide a ridge line (5) serving as a main cutting edge in a longitudinal direction. Each nick (8) has a width (W) gradually increasing toward the end.