Carbide End Mill Phase Offset for Chatter-Free Multi-Mode Cutting

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Solution Overview

Problem

Conventional end mills are not suitable for performing multiple machining operations such as longitudinal-feed cutting, lateral-feed cutting, and oblique cutting efficiently, as they require tool exchange and suffer from issues like chattering vibration, chip removability problems, and reduced service life, especially when used for high-speed cutting with carbide materials.

Innovation Solution

A carbide end mill with equally-separated cutting edges and optimized phase deviation of 1% to 3% is designed, featuring nicked peripheral cutting edges with rounded connections and gash surfaces for improved chip removability and reduced cutting resistance, allowing for high-speed, multi-functional machining without tool exchange.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If an equal separation end mill is used, then manufacturing ease is improved, but chattering vibration occurs due to resonance

Engineering Contradiction:
Improvemanufacturing easeVSAvoidchattering vibration
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies asymmetry by deviating the phases of peripheral cutting edges from equal intervals. Specifically, at least one peripheral cutting edge has a phase that deviates from the reference phase by 1% to 3% of the waveform pitch, creating unequal phase relationships that disrupt resonance patterns and suppress chattering vibration while maintaining manufacturing feasibility.

Inventive Principle:
Principle #4Asymmetry

2Productivity

If the depth of cut is increased for high-efficiency machining, then productivity is improved, but chipping or fracture occurs at nick portions

Engineering Contradiction:
Improvemachining efficiencyVSAvoidchip breaking strength
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The patent changes the geometric parameters of the nicks by rounding the bottom portions with specific radii (0.01D to 0.05D). This parameter modification strengthens the nick portions to prevent chipping and fracture during high-depth cutting operations, while maintaining the chip-breaking functionality and enabling high-efficiency machining.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If phase deviation is increased to suppress chattering vibration, then reliability is improved, but cutting edge strength decreases

Engineering Contradiction:
Improvevibration suppressionVSAvoidcutting edge strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent optimizes the phase deviation parameter within a specific range (1% to 3% of waveform pitch) and combines it with rounded nick bottoms (radius 0.01D to 0.05D). This coordinated parameter change achieves effective vibration suppression while maintaining cutting edge strength by preventing stress concentration at the nick portions.

Inventive Principle:
Principle #35Parameter changes

4Adaptability or versatility

If a single end mill is used for multiple machining operations, then adaptability is improved, but cutting performance deteriorates for specific operations

Engineering Contradiction:
Improvemulti-functional capabilityVSAvoidcutting performance
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent designs a universal end mill with waveform-shaped peripheral cutting edges and rounded nick bottoms that can perform longitudinal-feed cutting, lateral-feed cutting, and oblique cutting effectively. The waveform geometry and rounded nicks provide consistent cutting performance across different machining operations, eliminating the need for tool exchanges while maintaining reliable cutting performance.

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

Data Source

PatentEP2436467B1Carbide end mill
Publication Date: 2022.11.30 MOLDINO TOOL ENG LTD
  • EP2436467B1 patent drawingFigure 1~3
  • EP2436467B1 patent drawingFigure 4~5
  • EP2436467B1 patent drawingFigure 6~7

AI summary

Provided is a long life carbide end mill which can perform stable cutting in high-efficiency machining such as die machining and parts machining, which can be manufactured easily at low cost and can be re-ground, which can disperse cutting resistance sufficiently to thereby suppress chattering vibration, and which enables setting of a permissible rotational speed to a high speed. A cutting method using such an end mill is also provided. When a certain wavy or nicked peripheral cutting edge is considered a reference peripheral cutting edge with reference phases in a pitch of the reference peripheral cutting edge, wherein the distance of each reference phase is an amount corresponding to a value obtained by dividing the pitch of the nicks or waveform of each peripheral cutting edge by the number of the cutting edges; and the phase of at least one of the remaining peripheral cutting edges is deviated in the direction of the tool axis from the corresponding reference phase by an amount corresponding to 5% or less (excluding 0%) of the pitch. The cutting method comprises the step of successively performing at least two types of cutting operations selected from longitudinal-feed cutting, lateral-feed cutting, and oblique cutting.