Unequal Helix-Angle End Mill Vibration Control
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Solution Overview
Problem
Conventional unequal helix-angle end mills suffer from uneven strength along the axial direction of their cutting blades, leading to potential breakage during axial roughing feed or deep sawing, which compromises their durability and cutting efficiency.
Innovation Solution
The end mill features peripheral blades with a constant width along the axial direction, ensuring uniform strength and rigidity, achieved by maintaining the width of the edge flap at 0.16 to 0.25 times the outer diameter, and extending the length of each blade to 2.5 to 5 times the diameter, with a rear face comprising three ground faces for enhanced rigidity and strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the helix-angle of peripheral blades is made unequal to prevent resonance vibration, then the anti-vibration performance is improved, but the strength and rigidity of cutting blades become weak due to narrowed edge flap width
Solution Approach 1:
The patent applies asymmetry by setting different helix angles for different peripheral blades (first peripheral blade: 30°, second peripheral blade: 45°) to prevent resonance vibration. This asymmetric configuration ensures that blades engage the workpiece at different intervals, disrupting periodic vibration patterns and improving anti-vibration performance while maintaining varying edge flap widths.
Solution Approach 2:
The patent applies local quality by optimizing the edge flap width of each peripheral blade individually based on its specific helix angle and position. The first peripheral blade has edge flap width B1 = 0.15D to 0.20D, while the second peripheral blade has edge flap width B2 = 0.20D to 0.25D. This localized optimization ensures each blade has sufficient strength for its specific cutting conditions while maintaining the unequal helix angle configuration for vibration control.
2Reliability
If the edge flap width is reduced to achieve unequal helix-angle configuration, then the vibration control is improved, but the durability decreases due to potential breakage in axial roughing feed
Solution Approach 1:
The patent uses asymmetric helix angle configuration (30° and 45°) to control vibrations during milling operations. This asymmetric design prevents resonance by ensuring peripheral blades engage the workpiece at different time intervals, thereby reducing periodic vibrations that could lead to blade breakage and improving overall durability.
Solution Approach 2:
The patent applies local quality by assigning different edge flap width ranges to different peripheral blades based on their helix angles. The first peripheral blade with 30° helix angle has edge flap width B1 = 0.15D to 0.20D, while the second peripheral blade with 45° helix angle has edge flap width B2 = 0.20D to 0.25D. This localized optimization ensures each blade has appropriate strength for its specific cutting conditions, preventing premature failure and enhancing durability.
3Manufacturing precision
If the peripheral blades are designed with varying helix-angles to prevent resonance, then the surface quality is enhanced, but the cutting efficiency decreases due to weaker blade structure
Solution Approach 1:
The patent employs asymmetric helix angle design with the first peripheral blade at 30° and the second peripheral blade at 45°. This asymmetry prevents resonance vibration during milling, leading to improved surface quality by eliminating periodic vibrations that cause surface irregularities, while the optimized edge flap widths maintain sufficient cutting efficiency.
Solution Approach 2:
The patent applies local quality by optimizing each peripheral blade's edge flap width according to its helix angle. The first peripheral blade (30°) has edge flap width B1 = 0.15D to 0.20D, and the second peripheral blade (45°) has edge flap width B2 = 0.20D to 0.25D. This localized optimization ensures each blade has adequate strength and rigidity for efficient cutting while the unequal helix angles prevent resonance, thereby maintaining high surface quality and cutting efficiency simultaneously.
Data Source
AI summary
An unequal helix-angle end mill includes a cutting part and a handle part. The cutting part is provided with a plurality of flutes, each spirally extending from the bottom end to the handle part. The face of each flute facing the cutting rotation direction is a rake face, wherein the rake face and an outer peripheral face of the cutting part are intersected to form an outer peripheral blade, and the helix-angle of at least one of the peripheral blades is different from those of the other peripheral blades. A face joined with the peripheral blade among the outer peripheral face of the cutting part is a rear face. The width B of the edge flap of each peripheral blade is equal on a plane orthogonal to a rotating axis of the end mill. The unequal helix-angle end mill has high strength, and enhances the cutting depth and durability.