Carbide End Mill Gash Geometry for Chatter-Stable High-Speed Cutting
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Solution Overview
Problem
Conventional end mills are not suitable for multi-functional machining, such as longitudinal-feed, lateral-feed, and oblique cutting, as they require tool exchange and suffer from chattering vibration, chip removability issues, and short service life, especially when used for high-speed cutting with carbide materials.
Innovation Solution
A carbide end mill with wavy peripheral cutting edges and optimized gash shape, featuring phase deviations and specific gash angles, along with a hard coat, to enhance chip removability, reduce chattering vibration, and extend service life, allowing for high-speed cutting without tool exchange.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wavy or nicked peripheral cutting edges are used to increase depth of cut for high-efficiency machining, then cutting resistance is reduced and chip breaking is improved, but machined surface roughness deteriorates and chattering vibration occurs
Solution Approach 1:
The invention applies different surface quality requirements to different regions of the cutting edge. The active cutting portion maintains high precision for good surface finish, while the wavy/nicked portions are strategically located to handle chip breaking without compromising the primary cutting surface quality.
Solution Approach 2:
The wavy cutting edges or nicked peripheral cutting edges create periodic variations in cutting depth and chip thickness. This periodic action helps break chips into manageable segments, reducing cutting resistance and preventing chip jamming, while the overall surface quality is maintained through controlled waveform parameters.
2Ease of manufacture
If equal separation end mill is used for easy manufacturing, then production cost and time are reduced, but resonance occurs during machining causing chattering vibration
Solution Approach 1:
The invention introduces asymmetric phase deviations in the wavy cutting edges or nick positions along the peripheral cutting edges. This asymmetric distribution disrupts the periodicity of cutting forces, preventing resonance and chattering vibration, while maintaining manufacturing simplicity through controlled deviation patterns.
3Duration of action of stationary object
If phase deviation is increased to suppress chattering vibration, then tool life is extended, but cutting load distribution becomes uneven causing localized wear
Solution Approach 1:
The invention optimizes the phase deviation parameters within specific ranges to achieve the right balance. The phase deviation amount and waveform parameters are carefully controlled to suppress chattering vibration and extend tool life, while preventing excessive localized wear through parameter optimization.
Data Source
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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. The carbide end mill includes gashes having a plurality of gash surfaces such a first gash surface (51) serving as a cutting face of the corresponding end cutting edge, a second gash surface (52) provided on the side toward the rotational center of the tool axis of the end mill, and a third gash surface (53) provided on the peripheral side of the end mill; wherein a first gash angle of 15° to 35° is formed between a crossing portion between the first and second gash surfaces, and a plane perpendicularly intersecting the tool axis, and a second gash angle of 40° to 60° is formed between a crossing portion between the first and third gash surfaces, and the plane perpendicularly intersecting the tool axis. When a certain wavy peripheral cutting edge is considered a reference peripheral cutting edge with reference phases, 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, at least one of the peripheral cutting edges except the reference peripheral edge has no phase deviation from its corresponding reference phase and the phase of at least one of the remaining peripheral cutting edges deviates from its corresponding reference phase.