Curved-Tooth End Mill Structure for Chip Flow and Burr Suppression
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Solution Overview
Problem
Herringbone-shaped end mills experience chip clogging due to complex shapes of overlapping peripheral cutting edges, restricting machining conditions and leading to burr formation.
Innovation Solution
The end mill features peripheral cutting edges defined by curved teeth with reversed twist directions and arcuate shapes, where the curved teeth are positioned on the concave side of the end mill's outer surface, ensuring continuous change in cutting force direction and suppressing burr formation by maintaining a smooth curvature and optimal circumferential distances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If herringbone-shaped end mill with two types of peripheral cutting edges opposite in twist direction is used, then anti-vibration performance is improved and burrs are suppressed, but chip retention occurs due to complicated overlapping shapes
Solution Approach 1:
The patent applies curvature by defining peripheral cutting edges with arcuate shapes instead of straight lines. Each curved tooth is formed by an arc consisting of a part of a perfect circle, creating a smooth curved profile that eliminates complicated overlapping regions while maintaining the alternating twist direction configuration for vibration suppression.
Solution Approach 2:
The patent combines multiple design elements into a composite tooth structure: alternating right-handed and left-handed twist directions, arcuate curved profiles, and optimized circumferential distances. This composite approach integrates anti-vibration performance with chip flow efficiency, resolving the contradiction between reliability and chip retention.
2Reliability
If variable-lead end mill with different helix angles is used, then anti-vibration performance is improved, but burrs occur on side surfaces due to obtuse cutting angles
Solution Approach 1:
The patent employs asymmetry through alternating right-handed and left-handed twist directions in adjacent curved teeth. This asymmetric configuration ensures that peripheral cutting edges engage with both upper and lower side surfaces at acute angles, preventing burr formation while maintaining vibration suppression through varied cutting geometries.
3Productivity
If curved teeth with large circumferential distances are used, then chip flow is improved, but tooth strength is reduced
Solution Approach 1:
The patent optimizes the circumferential distances a and b as specific parameters within defined ranges (0.0002-0.1300 times tooth length). This parameter optimization balances chip flow requirements with tooth strength constraints, ensuring that curved teeth maintain adequate structural integrity while providing sufficient space for chip evacuation.
Data Source
AI summary
An end mill includes a plurality of peripheral cutting edges having a cutting diameter that is constant over their entire cutting length. The plurality of peripheral cutting edges, which are adjacent to each other, are defined by curved teeth. Each of the curved teeth is twisted in a twist direction that is changed irreversibly and smoothly from one of rightward and leftward directions to the other of the rightward and leftward directions in the entire cutting length so as to be reversed right and left on its way. Each of the curved teeth 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.