Cutting Insert Chip Breaker Structure for Broad Chip Fragmentation

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Solution Overview

Problem

Existing cutting inserts with chip breakers made from difficult-to-machine materials like CBN or PCD struggle to effectively fragmentize broad chips and maintain durability, especially as the depth of cut increases, leading to reduced chip control and wear issues.

Innovation Solution

A cutting insert design featuring a sintered compact with a polygonal upper surface, a downward inclined surface, an upward inclined surface, a jutting portion, and a stepped surface that distributes chip contact and load, along with a wiper cutting edge to efficiently fragmentize chips and enhance durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a simple protruding portion chip breaker is used, then the structure is simple and manufacturing is easy, but the jutting portion readily becomes worn when chips become broad due to increased depth of cut

Engineering Contradiction:
Improveease of manufactureVSAvoiddurability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The chip breaker is segmented into multiple functional surfaces: a downward inclined surface for initial chip contact and curving, an upward inclined surface for supporting broad chips, and a jutting portion for focused chip curving. This segmentation allows each surface to handle specific chip conditions, distributing the wear load and improving durability while maintaining manufacturability through standard laser processing techniques.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a simple single-level protruding portion to a multi-level three-dimensional structure with stepped surfaces at different heights. The downward inclined surface, upward inclined surface, and jutting portion create multiple zones along the depth dimension, enabling progressive chip control that accommodates varying chip widths without increasing lateral complexity.

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

2Reliability

If a chip breaker with large contact area is used, then durability is improved, but the area of contact with the protruding portion remains small when chips become broad, causing the distal end to readily become worn

Engineering Contradiction:
ImprovedurabilityVSAvoidchip fragmentization efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

Different surfaces of the chip breaker are assigned different functional qualities: the downward inclined surface provides a sloped contact zone for initial chip deflection and curving, the jutting portion concentrates force on a narrow region for effective rain gutter formation, and the upward inclined surface provides a broader support area for stable chip holding. This local differentiation optimizes both chip fragmentization and wear distribution.

Inventive Principle:
Principle #3Local quality

3Productivity

If the distal end of the protruding portion is used to bend chips, then chip curving is effective for thin chips, but the effects are diminished when chips become broader and contact surrounding portions

Engineering Contradiction:
Improvechip curving effectivenessVSAvoidchip breaker structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The chip breaker structure dynamically adapts to varying chip widths through its multi-surface geometry. For narrow chips, the jutting portion and downward inclined surface provide concentrated curving action. For broad chips, the upward inclined surface engages to provide distributed support and stability. This dynamic adaptation occurs passively through the geometric arrangement, avoiding complex active control mechanisms.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4342607A1Cutting insert
Publication Date: 2024.03.27 TUNGALOY CORP
  • EP4342607A1 patent drawingFigure 1
  • EP4342607A1 patent drawingFigure 2
  • EP4342607A1 patent drawingFigure 3

AI summary

To provide a cutting insert that readily fragmentizes chips, and that has excellent durability. At least a cutting part of a cutting insert (1) is formed of a sintered compact (10). The sintered compact includes a chip breaker (14) that is a recessed portion in which a partial region of a cutting part upper surface (13) is depressed downward. The chip breaker includes a downward inclined surface(41), an upward inclined surface(42), a jutting portion (40) that juts out along a first axial line (X1) that passes through a distant end of a cutting edge, and a stepped surface (43) that adjoins the jutting portion in a Y axis direction orthogonal to the first axial line. An upper end (40U) of the jutting portion is formed at a height (H3) of an upper stage. The stepped surface is formed at a height (H2) of an intermediate stage at a part (40L) closest to the first axial line.