Grooving Cutting Insert Geometry for Short-Chip Partial Cuts

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Solution Overview

Problem

Existing cutting inserts are not well-suited for partial cuts, leading to undesirable chip formation and potential damage due to long chip formation, which affects process reliability and tool/workpiece safety.

Innovation Solution

A cutting insert with a rectilinear main cutting edge and a chamfer divided into three sections, where the chamfer is oriented at a negative rake angle relative to the xy plane, and a chip trough with specific wall geometry that stabilizes the cutting edges and influences chip formation, allowing for improved chip control and breakage during both full and partial cuts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the cutting insert is designed for full cuts with a specific chip-forming geometry, then chip formation is optimized for full cuts, but chip formation deteriorates during partial cuts resulting in long chips

Engineering Contradiction:
Improvechip formation qualityVSAvoidsuitability for different cut types
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The chamfer is divided into three distinct sub-areas (first, second, and third sub-areas) that are arranged in a common chamfer plane. Each sub-area serves a specific function in chip formation during partial cuts, allowing the cutting insert to handle different cutting scenarios effectively.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the cutting insert have specialized geometries tailored to their specific functions. The chip trough includes a wall with five wall regions having different profiles, and the chamfer has three sub-areas with distinct orientations and positions, optimizing chip control for both full and partial cuts in their respective zones.

Inventive Principle:
Principle #3Local quality

2Productivity

If the main cutting edge is designed for full width contact, then full cut performance is optimized, but partial cut chip control deteriorates

Engineering Contradiction:
Improvefull cut machining efficiencyVSAvoidprocess reliability during partial cuts
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The chamfer is segmented into three sub-areas that work together to control chip formation during partial cuts. The first sub-area is arranged adjacent to a first end of the main cutting edge, the second sub-area extends along at least a large part of the main cutting edge, and the third sub-area is arranged adjacent to a second end of the main cutting edge.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The solution moves from a two-dimensional chip control approach to a three-dimensional approach by introducing a chamfer plane that is inclined relative to the cutting area plane. This adds a vertical dimension to chip control, allowing chips to be guided and broken more effectively during partial cuts.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Ease of manufacture

If the chip trough geometry is simplified, then manufacturing is easier, but chip breaking control deteriorates

Engineering Contradiction:
Improvechip trough fabrication simplicityVSAvoidchip breaking control
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The wall of the chip trough is divided into five wall regions that adjoin one another in ascending order. The profile line of the wall is segmented into five sub-sections corresponding to these wall regions, with specific concave and rectilinear/convex characteristics in different sections, enabling precise chip control.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The chip trough geometry employs asymmetric design elements, particularly in the wall profile where the first, third, and fifth sub-sections are concave while the second and fourth sub-sections are rectilinear or convex. This asymmetric configuration optimizes chip flow and breaking control.

Inventive Principle:
Principle #4Asymmetry

Data Source

PatentEP4010137B1Cutting insert and tool having such a cutting insert
Publication Date: 2024.03.20 HARTMETALL WERKZEUGFAB PAUL HORN
  • EP4010137B1 patent drawingFigure 1~2
  • EP4010137B1 patent drawingFigure 3~4
  • EP4010137B1 patent drawingFigure 5~7

AI summary

A cutting insert (10) for a tool (16) for machining. The cutting insert (10) is suitable in particular for grooving tools for grooving. The cutting insert (10) has, in its lip region (12), a chip breaker geometry, which allows machining of full cuts and machining of partial cuts and machining of webs. In particular on account of the shaping of a chip pocket (26) provided in the lip region (12) and on account of the presence of a negative chamfer (28), very short chips can be created in all three machining variants, with the result that there is high process reliability and long service lives are made possible.