Milling Insert Clamping Structure to Prevent Detachment

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Solution Overview

Problem

Conventional milling tools face issues with insufficient clamping force, leading to displacement and potential detachment of cutting inserts during cutting, affecting accuracy and stability.

Innovation Solution

The milling tool design includes a recessed insert attachment portion with specific angled surfaces and a fly-off prevention surface, along with a screw system that enhances clamping force, ensuring secure attachment and reducing the risk of insert detachment, while also incorporating an oil hole for cooling the cutting edge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a conventional bolt and locking piece system is used to attach the cutting insert, then the structure is simple, but the clamping force is insufficient leading to insert displacement and potential detachment

Engineering Contradiction:
Improveclamping forceVSAvoidattachment structure complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The attachment structure is segmented into multiple functional surfaces: a first seat surface for basic support, a second seat surface with a flat portion for enhanced clamping, and a fly-off prevention surface for additional security. This segmentation allows each surface to contribute specifically to the overall clamping force and insert retention.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a simple single-plane attachment to a multi-dimensional attachment system with surfaces oriented at different angles and positions. The first seat surface, second seat surface with flat portion, and fly-off prevention surface create a three-dimensional clamping configuration that significantly enhances insert retention.

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

2Reliability

If the cutting insert is securely clamped with enhanced structures, then insert retention is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveinsert retentionVSAvoidmanufacturing ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Multiple attachment functions are merged into a single integrated body structure. The first seat surface, second seat surface with flat portion, and fly-off prevention surface are all formed as part of the same body, eliminating the need for separate components and simplifying the manufacturing process while maintaining high insert retention.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The body structure serves multiple functions simultaneously: it provides support surfaces for the insert, generates clamping force through its geometric configuration, and prevents insert fly-off. This multi-functionality reduces the need for additional specialized components.

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

3Ease of operation

If the screw hole is oriented perpendicular to the seat surface, then the screw installation is simple, but the clamping force distribution is suboptimal

Engineering Contradiction:
Improvescrew installation easeVSAvoidclamping force distribution
Core Design Contradiction:
Ease of operationVSForce

Solution Approach 1:

The screw hole is positioned asymmetrically with respect to the seat surfaces, specifically on the flat portion of the second seat surface. This asymmetric positioning allows the screw to engage optimally with the multi-dimensional attachment structure, improving clamping force distribution while maintaining reasonable installation ease.

Inventive Principle:
Principle #4Asymmetry

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The improved clamping force and design features enhance machining accuracy and prevent insert fly-away, maintaining stability and efficiency during cutting operations.

Implementation Method 1

a screw (3) attaching the cutting insert (2) to the body (1)

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 2

incorporating an oil hole for cooling the cutting edge

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3603862B1Milling tool
Publication Date: 2024.01.24 SUMITOMO ELECTRIC HARDMETAL CORP
  • EP3603862B1 patent drawingFigure 1~2
  • EP3603862B1 patent drawingFigure 3~4
  • EP3603862B1 patent drawingFigure 5~6

AI summary

A milling tool includes: a body having an outer circumferential surface formed around a central axis; a cutting insert having a rake surface, a flank surface, and a cutting edge formed by a ridgeline of the rake surface and the flank surface; and a screw attaching the cutting insert to the body. The outer circumferential surface has an insert attachment portion to which the cutting insert is attached. The insert attachment portion is defined by a first seat surface continuing to the outer circumferential surface and a second seat surface continuing to the first seat surface and having a flat portion provided with a screw hole in which the screw is inserted. The cutting edge is formed of a sintered material containing at least one of cubic boron nitride and polycrystalline diamond. In a cross section perpendicular to the central axis, a first angle formed by a first direction in which the screw hole extends and a second direction perpendicular to the flat portion of the second seat surface and oriented inward of the body is an acute angle.