Multi-Edge End Mill Flute Geometry for Chip Clog Prevention
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Solution Overview
Problem
End mills with multiple breaker flutes experience reduced chip separation efficiency when the number of cutting edges increases, leading to chip clogging and shortened cutting length due to smaller chip discharging flute capacity.
Innovation Solution
The end mill features two concave curved surfaces on the chip discharging flute, with a protrusion between them, allowing effective chip separation even with a small flute capacity, preventing chip clogging and extending cutting length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the number of end cutting edges is increased to three or more, then the cutting capacity is improved, but the chip discharging flute capacity becomes small which reduces chip separation effects
Solution Approach 1:
The invention applies local quality by creating a protrusion with specific geometric features (two concave curved surfaces) at a particular location within the chip discharging flute. This localized structural modification enhances chip breaking capability at the critical region where chips accumulate, without altering the overall flute capacity or number of cutting edges. The protrusion's height (0.1 to 0.4 times the flute depth) and concave surfaces provide targeted chip separation functionality while maintaining the multi-edge configuration for high cutting capacity.
2Productivity
If the cutting amount is increased to improve productivity, then more material is removed, but chips climb over the breaker flutes causing chip clogging
Solution Approach 1:
The invention employs curvature by designing the protrusion with two concave curved surfaces instead of flat or sharp edges. These curved surfaces guide chips smoothly through the flute, preventing them from climbing over the breaker structure. The concave curvature creates a natural chip flow path that accommodates thick chips generated during high cutting amount operations, thereby preventing chip clogging while maintaining high productivity.
3Reliability
If breaker flutes are provided to improve chip separation, then chip breaking is enhanced, but the flute capacity becomes insufficient for high cutting amounts
Solution Approach 1:
The invention applies partial action by implementing a protrusion with moderate height (0.1 to 0.4 times the flute depth) rather than a full-depth breaker structure. This partial protrusion provides sufficient chip breaking capability for high cutting amounts without excessively reducing the available flute capacity. The concave curved surfaces further enhance chip separation efficiency, achieving effective chip breaking with minimal impact on flute volume.
Data Source
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AI summary
To provide an end mill having good chip discharging performance even under a machining condition where chips are discharged in large amount. An end mill (10) includes an end mill body (1) including a rotation center axis (O) , three or more end cutting edges (2) on a side of a front end side of the end mill body (1), peripheral cutting edges (5) at a rear side of the respective end cutting edges (2), chip discharging flutes (7) between corresponding two of the peripheral cutting edges (5), and heels (3) located at respective opposite sides of the peripheral cutting edges (5) to interpose a corresponding one of the chip discharging flutes (7) therebetween. A shape of each of the chip discharging flutes (7) between corresponding two of the peripheral cutting edges (5) in a cross section perpendicular to the rotation center axis (O) includes a first concave curve (12) on a side of a corresponding one of the peripheral cutting edges (5), a second concave curve (13) on a side of a corresponding one of the heels (3), and a protrusion (14) located between the two concave curves (12, 13), the protrusion (14) includes both sides lines of concave curves, and a ratio (h/H) of a distance (h) from a circle (c) including a maximum diameter capable of being drawn in the end mill body (1) centered on the rotation center axis (O) to a top (P) of the protrusion (14) to a distance H from the circle (c) to the peripheral cutting edge (5) is 0.1 to 0.4 times.