Rotary Cutting Tool End Geometry for Steep-Angle Ramping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional solid end mills face performance difficulties, especially when ramping at steep angles, due to structural strength concerns and inefficient chip formation and evacuation, making large ramping angles impractical.
Innovation Solution
A rotary cutting tool with an end face configuration featuring two distinct cutting edge portions: a first end face cutting edge for moderate ramp angles and a second end face cutting edge for large ramp angles, each with specific radial and axial rake angles, enabling the tool to maintain structural stability and manage chip formation effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the ramping angle is increased to improve productivity, then the productivity increases, but the risk of end mill failure increases due to structural strength concerns
Solution Approach 1:
The end face cutting edge is divided into two distinct portions: a first end face cutting edge portion for moderate ramp angles and a second end face cutting edge portion for large ramp angles. This segmentation allows each portion to be optimized for its specific function, enabling the tool to handle high ramp angles without failure.
Solution Approach 2:
Different radial and axial rake angles are applied to different portions of the end face cutting edge. The second end face cutting edge portion has a second radial angle of +11 to +15 degrees and a second axial rake angle of -1 to -15 degrees, specifically optimized for large ramp angles, while the first portion has different angles optimized for moderate ramp angles.
2Object-generated harmful factors
If the number of flutes is increased to improve chip evacuation, then chip evacuation improves, but the structural strength of the end mill decreases
Solution Approach 1:
The patent applies a highly positive second radial angle (+11 to +15 degrees) and negative second axial rake angle (-1 to -15 degrees) to the second end face cutting edge portion. This creates sufficiently wide and deep gashes for effective chip evacuation without requiring an excessive number of flutes, thereby maintaining structural strength.
3Adaptability or versatility
If the radial angle is increased to improve ramping capability, then the ramping angle capability improves, but the chip formation and evacuation becomes more difficult
Solution Approach 1:
The patent applies different radial angles to different portions of the end face cutting edge. The second end face cutting edge portion has a highly positive second radial angle of +11 to +15 degrees optimized for large ramp angles, while the first end face cutting edge portion has a first radial angle of -2 to +2 degrees for moderate ramp angles. This local differentiation allows high ramping capability without compromising chip evacuation.
Data Source
AI summary
A rotary cutting tool includes a shank portion, a cutting portion, and a cutting tip. The cutting portion includes a plurality of blades and a plurality of flutes. Each blade includes a leading face, a trailing face, and a land surface extending between the leading face and the trailing face. The cutting end includes an end cutting edge having a first end face cutting edge portion formed with a positive, neutral or negative radial angle, a positive dish angle and a negative axial rake angle, and second end face cutting edge portion formed with a highly positive radial angle, a positive dish angle and a negative axial rake angle. The highly positive radial angle of the second end face cutting edge portion enables the rotary cutting tool to perform a ramp operation at very large ramp angles of between about 15-45 degrees.