Triangular Indexable Cutting Insert for Stable Deep Grooving

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Solution Overview

Problem

Existing cutting tools for grooving, parting, and on-edge threading operations lack stability, accuracy, and efficiency, particularly when using polygonal shaped cutting inserts, and struggle with secure indexing and high-depth insertion capabilities.

Innovation Solution

A cutting tool with a triangular-shaped indexable cutting insert featuring three spaced locating surfaces and a central axis, allowing for secure clamping by a wedge mechanism that operates entirely rearward of the central axis, enabling efficient indexing and high stability, and a design where each cutting edge is outside the imaginary triangle defined by the locating surfaces, facilitating deep insertion operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a polygonal shaped cutting insert is used for grooving and parting operations, then the cutting insert can be indexed to multiple positions, but the cutting insert lacks stability and accuracy in positioning

Engineering Contradiction:
Improveindexing capabilityVSAvoidpositioning stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The cutting insert is divided into three distinct cutting portions (first, second, and third cutting portions) with three locating surfaces spaced apart around the central axis. This segmentation allows the insert to be indexed to three different positions while maintaining stable positioning at each index, resolving the contradiction between indexing versatility and positioning stability.

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If the cutting insert is designed with locating surfaces for secure clamping, then positioning accuracy improves, but the device complexity increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidinsert structure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The cutting insert employs an asymmetric triangular configuration with three locating surfaces spaced apart around the central axis, creating an imaginary triangle. This asymmetric design provides precise positioning accuracy through the unique triangular geometry while maintaining relatively simple insert structure, avoiding excessive complexity.

Inventive Principle:
Principle #4Asymmetry

3Productivity

If the cutting insert is designed for deep insertion operations, then productivity increases, but the risk of ejection during cutting increases

Engineering Contradiction:
Improvedeep insertion capabilityVSAvoidejection resistance
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

Each cutting portion is designed with specific local characteristics - the cutting edges extend beyond the imaginary triangle formed by the locating surfaces, allowing deep insertion capability for increased productivity. Simultaneously, the locating surfaces provide localized clamping contact points that anchor the insert securely, preventing ejection during cutting operations.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3377256B1Cutting tool and indexable cutting insert therefore
Publication Date: 2021.02.17 ISCAR LTD
  • EP3377256B1 patent drawingFigure 1~2
  • EP3377256B1 patent drawingFigure 3~4
  • EP3377256B1 patent drawingFigure 5~6

AI summary

A cutting tool having a tool holder, cutting insert and clamping member. The tool holder includes an elongated supporting surface extending in a rearward-to-forward direction. The cutting insert has a central portion and three cutting portions, the central portion having two opposing side surfaces and three spaced apart locating surfaces defining a first imaginary triangle. The cutting insert is indexable about a central axis intersecting the two side surfaces. Each locating surface intersects two of three bisector planes containing the central axis and bisecting respective corners of the first imaginary triangle, and the cutting edge of each cutting portion is located entirely outside of the first imaginary triangle. In each index position the clamping member is located entirely rearward of a first vertical plane containing the central axis and perpendicular to the rearward-to-forward direction, and one of the locating surfaces is in clamping contact with the supporting surface.