Three-Tooth End Mill Geometry for Burr and Chatter Suppression
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Solution Overview
Problem
Existing end mills face challenges in suppressing burr and delamination, particularly in carbon fiber reinforced materials, due to issues with chip retention and vibration, and previous designs with alternate helical teeth either restrict machining conditions or fail to effectively suppress burr and chatter vibration.
Innovation Solution
An end mill design featuring three types of teeth - right-handed helical, left-handed helical, and curved teeth, with each adjacent pair being different, and a specific arrangement of helix angles and spacing to vary cutting forces and prevent resonance, while the curved teeth help in suppressing burr and chatter vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If herringbone-shaped end mill with alternate helical teeth is used, then burr suppression is improved, but machining conditions are restricted due to chip retention in overlapping portions
Solution Approach 1:
The patent optimizes the overlap regions between right-handed and left-handed helical teeth by controlling helix angles and tooth geometry locally. The overlapping portions are designed with specific helix angle combinations that prevent chip retention while maintaining the burr-suppressing cutting action, thereby improving machining conditions without sacrificing burr suppression performance.
Solution Approach 2:
The patent modifies critical parameters including helix angles (α and β both within 1° to 15°), tooth arrangement patterns, and overlap region geometries to eliminate chip retention issues. By optimizing these parameters, the patent maintains effective burr suppression while expanding usable machining conditions and improving chip evacuation.
2Ease of operation
If peripheral cutting edges cut with obtuse angles, then ease of operation is improved, but burr suppression deteriorates
Solution Approach 1:
The patent creates different cutting angle conditions at different locations on the peripheral cutting edges. By optimizing helix angles and tooth geometries locally, the patent achieves acute cutting angles at the effective cutting portions for burr suppression while maintaining favorable cutting conditions through the overall tooth configuration and arrangement pattern.
Data Source
AI summary
An end mill includes a plurality of peripheral cutting edges that are defined by three types of teeth including a right-handed helical tooth that is twisted rightward, a left-handed helical tooth that is twisted leftward, and a curved tooth which is twisted in a direction reversed right and left on a way thereof and which has a curved shape curved in an arcuate or arched manner in a development view of an outer circumferential surface of the end mill around an axis such that a corresponding one of the peripheral cutting edges is provided on a concave side of the curved shape. Each adjacent pair of the peripheral cutting edges adjacent to each other are defined by the respective teeth that are different in type from each other.