End Mill Rake Surface Curvature for Chip Discharge
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing end mills, such as those described in JP 2005-125465 A and JP 5-37411 Y, face issues with unstable chip discharge direction and entanglement of chips with the tool, leading to inefficient cutting machining due to chips not being easily curled and discharged.
Innovation Solution
The end mill design features a recess on the end cutting edge and a curved rake surface with a wall section acting as a breaker, which divides and directs chips for stable discharge, preventing entanglement and ensuring smooth cutting machining by bending chips towards a designated direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a nick (recess) is formed in the end cutting edge, then chip curling is improved at the nick location, but chip discharge direction becomes unstable and outer peripheral chips get entangled with the end mill
Solution Approach 1:
The invention divides the rake surface into multiple functional zones: a first rake surface portion for receiving chips from the end cutting edge, a second rake surface portion for receiving chips from the peripheral cutting edge, and a curved rake surface portion connecting them. This segmentation allows different chip regions to be directed along controlled paths, preventing entanglement while maintaining stable discharge direction.
Solution Approach 2:
The invention introduces a curved rake surface portion with a predetermined curvature radius that connects the first and second rake surface portions. This curved surface acts as a breaker that guides outer peripheral chips along a controlled arc path, ensuring they are directed toward the chip discharge groove without entangling with the end mill, while maintaining stable chip discharge direction.
2Ease of operation
If chips are not easily curled, then chip discharge may be straightforward, but chips get entangled with the end mill and hinder cutting machining
Solution Approach 1:
The invention segments the chip flow path into distinct zones with different surface characteristics. The curved rake surface portion specifically addresses outer peripheral chips by providing a controlled curvature that promotes curling and directs these chips away from the end mill body, preventing entanglement while maintaining smooth discharge.
Solution Approach 2:
The curved rake surface portion with predetermined curvature radius serves as a breaker that actively curls outer peripheral chips and directs them along a controlled arc toward the chip discharge groove. This curvature ensures chips are properly formed and directed without entangling with the end mill, solving the entanglement problem while maintaining ease of discharge.
3Ease of manufacture
If the rake surface is flat, then manufacturing is simple, but chips from different locations follow unpredictable paths
Solution Approach 1:
The invention divides the rake surface into multiple portions with different geometric characteristics. The curved rake surface portion has a specifically designed curvature radius that controls chip flow from the peripheral cutting edge, while the first and second rake surface portions handle chips from different cutting edges. This segmentation provides precise chip discharge control while remaining manufacturable.
Solution Approach 2:
The curved rake surface portion with predetermined curvature radius provides precise control over outer peripheral chip trajectories. By designing the curvature radius appropriately, the invention ensures chips are directed along predictable paths toward the chip discharge groove, achieving manufacturing precision in chip discharge control while maintaining ease of manufacture through a relatively simple curved surface geometry.
Data Source
Figure 1(a)~1(b)
Figure 2(a)~2(c)
Figure 3(a)~3(c)
AI summary
The invention provides an end mill having an improved chip discharging performance and capable of carrying out excellent cutting machining. The end mill includes an end cutting edge (2) provided on a front end of a tool body (1) which rotates around a central axis, a peripheral cutting edge (4) provided on an outer periphery of the tool body (1), a rake surface of the end cutting edge (2) and the peripheral cutting edge (4), and at least one recess (6), which locally breaks the continuity of the end cutting edge (2) is provided, wherein a wall section (8) which extends toward the rear of the outer peripheral side is provided at least in that area of the rake surface(3) which is closer to the outer peripheral side than the recess (6) .