End Mill Gash Geometry for Chip Flow and Tip Rigidity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing end mills face challenges in maintaining rigidity at the distal end portion while ensuring effective chip dischargeability through gashes, as conventional designs may lead to clogging and reduced rigidity due to planar gash surfaces and inadequate chip capacities.
Innovation Solution
The end mill features a configuration with distal and rear side depressed faces forming overlapping curved surfaces, where the rear side faces have a smaller acute angle with the rotation axis, enhancing rigidity and guiding chips efficiently to the discharge flutes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If gashes are formed with planar surfaces to ensure chip capacity, then chip dischargeability is improved, but rigidity at the distal end portion decreases
Solution Approach 1:
The gash surface is divided into two distinct regions with different properties: a distal end side depressed face with a larger acute angle (30°-60°) for effective chip discharge, and a rear side depressed face with a smaller acute angle (10°-30°) for maintaining rigidity. This local differentiation allows each region to optimize its function while balancing the overall performance.
Solution Approach 2:
The invention transitions from conventional planar gash surfaces to three-dimensional depressed faces with varying angles. By introducing angular dimensionality and creating overlapping curved surfaces, the design achieves both adequate chip capacity and enhanced rigidity at the distal end portion.
2Productivity
If gashes are formed with larger volumes to increase chip capacity, then chip dischargeability is improved, but the boundary line becomes convex reducing rigidity
Solution Approach 1:
Instead of making the boundary line convex to increase chip capacity (conventional approach), the invention inverts the approach by making the boundary line depressed. This depression maintains rigidity while the overlapping curved surfaces of the two-tier gashes provide adequate chip dischargeability through their angular design.
3Productivity
If the acute angle with the rotation axis is increased to improve chip flow, then chip dischargeability is improved, but rigidity at the distal end portion decreases
Solution Approach 1:
Different acute angles are applied to different regions of the gash: the distal end side depressed face uses a larger acute angle (30°-60°) to promote chip flow and discharge, while the rear side depressed face uses a smaller acute angle (10°-30°) to maintain structural rigidity. This local differentiation resolves the contradiction between chip flow and rigidity.
Data Source
AI summary
An end mill includes: at a distal end portion side in a rotation axis direction of a tool body, a plurality of cutting edges continuous from a center side to an outer peripheral side in a radial direction and adjacently arranged in a rotation direction of the tool body; gashes formed on front sides in a rotation direction of the respective cutting edges; and chip discharge flutes continuous with the gashes. The gashes are composed of distal end side depressed faces formed along a distal end side axis making an acute angle with the rotation axis and rear side depressed faces formed along a rear side axis making a smaller acute angle with the rotation axis than the distal end side axis. The distal end side depressed faces and the rear side depressed faces are formed to have shapes overlapping with one another.