Cutting Insert Nose Geometry for Low-Resistance Fine Machining

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing cutting tools and methods face challenges in maintaining low cutting resistance and surface roughness during machining processes, particularly due to heat generation and broad contact areas between the cutting tool and the workpiece.

Innovation Solution

A cutting tool design featuring a first curved part with a smaller second curved part and a connecting part positioned at the front end perpendicular to the cutting direction, combined with a posture changing device and control system to manage the cutting tool's posture, ensuring the connecting part remains contiguous with the machined surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a wiper blade or wiper insert is used to improve surface finish, then surface roughness is improved, but the contact area between cutting tool and workpiece increases causing heat generation and high cutting resistance

Engineering Contradiction:

Improvesurface roughnessVSAvoidcutting resistance

Core Design Contradiction:

Manufacturing precisionVSForce

Solution Approach 1:

The nose part is divided into two distinct curved parts: a first curved part (R1) for primary material removal and a second curved part (R2) with smaller radius for surface finishing. This segmentation allows each part to perform its specific function optimally - the first curved part handles bulk cutting with minimal resistance, while the second curved part provides the necessary contact for surface finishing without excessive heat generation.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the cutting tool nose are given different curvatures tailored to their specific functions. The first curved part has a larger radius suitable for cutting, while the second curved part has a smaller radius specifically for achieving fine surface finish. This local differentiation of geometric properties allows simultaneous optimization of cutting performance and surface quality.

Inventive Principle:

Principle #3Local quality

2Force

If an ISO standard insert is used with work inside the contact part of the nose part to reduce cutting resistance and heat generation, then cutting resistance and heat are reduced, but surface roughness deteriorates

Engineering Contradiction:

Improvecutting resistanceVSAvoidsurface roughness

Core Design Contradiction:

ForceVSManufacturing precision

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Inventive Principle:

Principle #3Local quality

3Ease of operation

If the nose part is made longer to make the line connecting centers of curvature parallel with the cross-cutting edge as disclosed in PTL 1, then the cutting angle is optimized, but it becomes difficult to form such a nose part at an ISO standard insert

Engineering Contradiction:

Improvecutting angle optimizationVSAvoidnose part formation difficulty

Core Design Contradiction:

Ease of operationVSEase of manufacture

Solution Approach 1:

The invention specifies precise parameter relationships between the two curved parts - the radius ratio (R2 < R1), the connection geometry, and the angular relationship between the line connecting centers of curvature and the cross-cutting edge. By defining these parameters within specific ranges, the invention achieves optimal cutting angles while maintaining compatibility with standard insert dimensions and manufacturability.

Inventive Principle:

Principle #35Parameter changes

4Force

If the cutting tool is positioned to maintain the same cutting angle at all times as disclosed in PTL 2, then cutting resistance is kept from increasing, but surface roughness may deteriorate

Engineering Contradiction:

Improvecutting resistanceVSAvoidsurface roughness

Core Design Contradiction:

ForceVSManufacturing precision

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS20250303473A1Machining method, machine tool, cutting tool, and cutting insert

Publication Date: 2025.10.02 MAKINO MILLING MASCH CO LTD

AI summary

A machining method for cutting process by making a workpiece (W) and a cutting tool (11) move relatively, characterized by using a cutting tool (11) comprising a cutting insert (28) having a first curved part (40a), a second curved part (40c) formed continuing from the first curved part (40a) and with a curvature smaller than the first curved part (40a), and a connecting part (40b) connecting the first curved part (40a) and the second curved part (40c) and by cutting while positioning the connecting part (40b) at the front end in the cut direction perpendicular to the direction of relative movement at the time of cutting.