Inclined-Flute Solid End Mill for Stable Rake Angles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The manufacturing and cutting performance of existing tulip or onion end mills for dovetail slots are hindered by difficulties in achieving consistent radial rake angles due to differences in diameter between the lobe, neck, and shoulder cutting edge portions, leading to inadequate tool life and chip evacuation.
Innovation Solution
A solid end mill with peripheral cutting edges that extend at a linear and constant axial inclination angle between 5° and 15°, facilitating uniform positive radial rake angles along the entire cutting edge, which simplifies grinding and enhances tool life and cutting performance by reducing strain and vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If straight and non-inclined flutes are provided on the end mill, then the grinding of desired radial rake angle is more easily achieved along the peripheral cutting edges, but the cutting performance, tool life and chip evacuation become rather poor
Solution Approach 1:
The patent applies parameter changes by introducing a specific axial inclination angle range (5° to 15°) for the peripheral cutting edges. This parameter modification allows the cutting edges to achieve both manufacturability through grinding and improved cutting performance. The axial inclination creates a more favorable rake angle configuration that reduces cutting forces and improves chip evacuation while maintaining grindability.
Solution Approach 2:
The patent introduces dynamics by transitioning from straight, non-inclined flutes to flutes with axial inclination. This dynamic geometric configuration allows the cutting edges to engage the workpiece more effectively, reducing vibrations and improving cutting action while still allowing for controlled grinding operations to establish the desired rake angles.
2Productivity
If a flute helix is provided on the solid end mill, then cutting performance and chip evacuation are improved, but the manufacturing/grinding operation becomes complicated and large variations on radial rake angles occur between different cutting edge portions
Solution Approach 1:
The patent controls the axial inclination parameter within a specific range (5° to 15°) to achieve an optimal balance. This parameter control allows the flutes to provide improved chip evacuation and cutting performance while maintaining consistency in radial rake angles across different cutting edge portions during grinding operations.
Solution Approach 2:
The patent applies local quality by ensuring that each peripheral cutting edge portion (lobe, neck, and shoulder portions) maintains appropriate radial rake angles through the controlled axial inclination. This localized geometric configuration ensures consistent cutting performance across all portions of the peripheral cutting edges while allowing the overall flute structure to provide effective chip evacuation.
3Manufacturing precision
If the radial rake angle varies significantly between lobe, neck, and shoulder cutting edge portions, then the grinding operation becomes difficult, but maintaining consistent rake angles with straight flutes results in poor cutting performance
Solution Approach 1:
The patent resolves this contradiction by introducing a controlled axial inclination parameter (5° to 15°) that modifies the geometry of peripheral cutting edges. This parameter change allows the grinding operation to establish consistent radial rake angles across all cutting edge portions while simultaneously improving cutting performance through the inclined configuration that reduces cutting forces and enhances chip flow.
Data Source
Figure 1~3
Figure 4~6
Figure 7~8
AI summary
The present invention relates to solid end mill (1) being rotatable around a central rotational axis (R), wherein the solid end mill has a cutting portion (2) and a shank portion (3). The cutting portion (2) includes a plurality flutes (4) with peripheral cutting edges (5) formed between associated rake surfaces (6) and clearance surfaces (7). The peripheral cutting edge (5), in a view perpendicular to the central rotational axis and toward the rake surface (6), is forming a convexly curved lobe cutting edge portion (8) disposed along an axial front part of the cutting portion (2), a neck cutting edge portion (9) connected to the convexly curved lobe cutting edge portion (8), wherein the neck cutting edge portion (9) is disposed along an axial intermediate part of the cutting portion (2), and a shoulder cutting edge portion (10) connected to the neck cutting edge portion (9), wherein the shoulder cutting edge portion is disposed along an axial rear part of the cutting portion (2). The peripheral cutting edge (5), in a view perpendicular to the central rotational axis (R) and toward the clearance surface (7), extends at a linear and constant axial inclination angle θ within the range 5° ≤ θ ≤ 15° in relation to the central rotational axis (R), wherein the rake surface (6), as seen in cross-sections perpendicular to the central rotational axis (R), is forming positive radial rake angles αL,N,S along the entire extension of the peripheral cutting edge (5).