End Mill Arc Cutting Edge Radius for High-Hardness Material Stability
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Solution Overview
Problem
Conventional end mills experience short tool life and instability during high-efficiency machining of high-hardness mold materials due to increased cutting heat, fracture risk, and vibration, especially when machining corners and long overhangs.
Innovation Solution
A cemented carbide end mill with a novel arc-shaped cutting edge design, where the radius of curvature is optimized between 0.3 to 1.5 times the tool radius, featuring a main and sub-bottom edge configuration with a medium-to-low inclination cutting edge, and a sub-peripheral edge positioned perpendicular to the tool axis, enhancing chip removability and edge rigidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional radius end mills are used for high-efficiency roughing of high-hardness mold materials, then chip removal and cutting speed are improved, but tool life is shortened due to increased abrasion and fracture
Solution Approach 1:
The invention applies a specific curved radius configuration where the bottom edge has a radius R1 and the peripheral edge has a radius R2, with R1 being 0.05 to 0.25 times the tool diameter and R2 being 0.005 to 0.02 times the tool diameter. This curved geometry optimizes chip flow and reduces stress concentration, thereby improving both cutting efficiency and tool life when machining high-hardness materials
Solution Approach 2:
The invention changes the geometric parameters of the cutting edges by specifying precise radius values (R1 and R2) relative to the tool diameter. This parameter optimization allows the end mill to achieve better chip thinning, reduced cutting resistance, and improved edge strength, resolving the contradiction between productivity and tool life
2Productivity
If high feed rates are used for high-efficiency machining, then productivity increases, but cutting heat and abrasion increase, shortening tool life
Solution Approach 1:
The curved radius design of the cutting edges facilitates smoother chip flow and reduces chip thickness, which decreases cutting resistance and generates less heat. This allows high feed rates to be maintained without excessive temperature rise, preserving tool life while achieving high productivity
3Adaptability or versatility
If the end mill is used for machining corners and long overhangs, then versatility is improved, but vibration and fracture risk increase
Solution Approach 1:
The curved radius configuration at both the bottom and peripheral edges strengthens the cutting edges by distributing stress more evenly. This enhanced edge strength reduces vibration during corner machining and long overhang operations, maintaining stability while preserving versatility
Data Source
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AI summary
The present invention relates to an end mill, which comprises a bottom edge, which is composed of an arc-shaped cutting edge that is curved when seen from a direction perpendicular to the tool axis and a linear or curved medium-to-low inclination cutting edge, and a peripheral edge, wherein, when seen from a direction parallel to the tool axis, the arc-shaped cutting edge and a rim at the rearward side of the rotation at a flank of the arc-shaped cutting edge are curved with radii of curvatures, and the radius of curvature of the arc-shaped cutting edge is smaller than the radius of curvature of the rim at the rearward side of the rotation at the flank of the arc-shaped cutting edge.