Cutting Insert Inclined Contact Surface Against Machining Shift

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Solution Overview

Problem

Cutting inserts with circular-arc-shaped cutting edges often experience unstable fixation and shifting during machining, leading to potential fracture and reduced machining accuracy, as existing solutions either compromise the thickness around the cutting edge or require additional configurations to prevent rotation.

Innovation Solution

The cutting insert features an inclined contact surface on its second end surface and a corresponding inclined holding surface in the insert seat, which suppresses shifting forces during cutting, preventing abnormal damage and improving machining accuracy without reducing the cutting edge thickness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If flat portions are provided on the peripheral side surface to suppress shifting, then shifting is suppressed, but the cutting edge thickness is reduced and fracture resistance deteriorates

Engineering Contradiction:
Improvefixation stabilityVSAvoidcutting edge fracture resistance
Core Design Contradiction:
Stability of the object's compositionVSStrength

Solution Approach 1:

The invention transitions from suppressing shifting in the radial direction (peripheral side surface contact) to suppressing shifting in the axial direction (end surface contact). By providing contact surface portions on the end surface that contact the tool body, the solution moves to a different dimensional approach for achieving fixation stability without compromising cutting edge integrity.

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

2Stability of the object's composition

If contact surface portions are added to suppress shifting, then fixation stability improves, but the device complexity increases

Engineering Contradiction:
Improvefixation stabilityVSAvoidinsert structure complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The end surface of the cutting insert serves multiple functions: it provides the contact surface portions for fixation stability while also maintaining the structural integrity and thickness of the cutting edges. This multi-functional design achieves suppression of shifting without requiring additional separate components or complex structures.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP3117941B1Cutting insert and cutting tool
Publication Date: 2023.05.10 TUNGALOY CORP
  • EP3117941B1 patent drawingFigure 1
  • EP3117941B1 patent drawingFigure 2
  • EP3117941B1 patent drawingFigure 3

AI summary

A cutting insert capable of suppressing shifting of the cutting insert during cutting is provided. A cutting insert having first and second end surfaces and a peripheral side surface comprises: a cutting edge which includes at least one circular-arc-shaped cutting edge; and a contact surface portion formed in the second end surface. When a reference axis A is defined as a line passing through the center of the first end surface and being perpendicular to the first end surface, and when a virtual circle is defined so that the virtual circle includes, as its arc, a first circular-arc-shaped cutting edge in a plan view, the center E of the virtual circle is apart from the reference axis A. When a first reference plane B is defined as a plane including the reference axis A and extending through the center of the virtual circle; a second reference plane C is defined as a plane extending perpendicularly to the reference axis A; and a virtual plane D is defined as a plane orthogonal to both the first reference plane B and the second reference plane C and extending so as to intersect with the first circular-arc-shaped cutting edge and traverse the contact surface portion, the contact surface portion has, in the virtual plane D, an inclined portion which gradually becomes more distant from the second reference plane C heading from one end to the other.