Non-Circular Cutting Insert for Chip Control in Wheel Reprofiling

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Solution Overview

Problem

Existing cutting inserts for re-profiling railway vehicle wheels lack a design that effectively manages cutting forces and chip removal while maintaining circularity and indexability, particularly in non-circular peripheral edges.

Innovation Solution

A non-circular indexable cutting insert with a continuous peripheral side surface featuring upper and lower cutting edges exhibiting N-fold rotational symmetry, where the upper peripheral edge is non-circular and the upper cutting edges are non-linear, allowing for tilting to maintain a constant radius of curvature for efficient engagement with the workpiece, and a double-sided design for improved chip breakage and removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a circular cutting insert with non-circular peripheral edge is used, then chip removal efficiency is improved, but cutting forces increase

Engineering Contradiction:
Improvechip removal efficiencyVSAvoidcutting forces
Core Design Contradiction:
ProductivityVSForce

Solution Approach 1:

The cutting insert employs a non-circular peripheral edge with asymmetric geometry that varies around the circumference. This asymmetric design optimizes chip flow paths and cutting force distribution, allowing efficient chip removal while managing cutting forces through strategic placement of cutting edges at different radial positions

Inventive Principle:
Principle #4Asymmetry

2Productivity

If the upper peripheral edge is made non-circular, then chip breakage and removal are improved, but the radius of curvature varies causing engagement issues with the workpiece

Engineering Contradiction:
Improvechip breakage and removalVSAvoidradius of curvature consistency
Core Design Contradiction:
ProductivityVSShape

Solution Approach 1:

The cutting insert is designed to be tiltable about a central axis, transforming a static geometric constraint into a dynamic adjustment capability. By tilting the insert, the operator can select different cutting edges that present a constant effective radius of curvature to the workpiece, while the non-circular geometry continues to provide superior chip breaking and removal performance

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Multiple cutting edges are pre-positioned at different angular locations around the non-circular peripheral edge, each optimized for specific cutting conditions. This preliminary arrangement allows the operator to pre-select the appropriate cutting edge by tilting the insert before engagement, ensuring optimal radius of curvature for the specific workpiece and cutting parameters

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If a single-sided cutting insert design is used, then manufacturing is simpler, but chip removal efficiency is reduced

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidchip removal efficiency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

The cutting insert is divided into functionally distinct surfaces: an upper peripheral edge for primary cutting and chip breaking, and a lower peripheral edge for secondary cutting and chip removal. This segmentation allows each surface to be optimized for its specific function, with the lower edge providing additional chip management capability that enhances overall productivity

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3411172B1Circular cutting insert having non-circular peripheral edge
Publication Date: 2024.04.24 ISCAR LTD
  • EP3411172B1 patent drawingFigure 1A~1B
  • EP3411172B1 patent drawingFigure 1C~1D
  • EP3411172B1 patent drawingFigure 1E~1F

AI summary

A cutting tool has an insert holder with an indexable cutting insert (20, 120) removably secured therein. The cutting insert has upper and lower end surfaces (22, 24) with a peripheral side surface (26) and a through bore (40) extending therebetween, and a plurality of upper cutting edges (36) formed on an upper peripheral edge (28). The peripheral side surface (26) includes a non-circular upper relief surface (32) adjacent the upper peripheral edge (28) and a circular upper abutment surface (34a) spaced apart from the upper peripheral edge (28). Each upper cutting edge (36) exhibits mirror symmetry about a bisector plane, and is non-linear in a side view. The through bore (40) has an inner undercut formed by upper and lower bore surfaces located on opposite sides of a median plane, and a clamping member makes contact with one of the upper and lower bore surfaces at an inner contact zone located between the median plane and a seat surface of the insert holder.