Cutting Insert Protrusion for Radial Force Absorption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In high speed and high ramp machining, radially outward forces cause cutting inserts in milling cutters to be pushed out of their pockets, leading to clamping screw breakage and separation, which can result in damaged workpieces and milling cutters, especially when machining precision parts like aircraft components.
Innovation Solution
A cutting insert design with a protrusion portion on its bottom surface that is received by a recess in the milling cutter's insert pocket, allowing the insert to be stably mounted and absorbing radial forces without requiring strict tolerance maintenance, featuring a shape that contacts the side wall of the recess at higher speeds to support the insert.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the cutting insert is mounted with strict tolerance maintenance and high precision contact surfaces, then the retention reliability is improved, but the manufacturing complexity and cost increase
Solution Approach 1:
The cutting insert is divided into distinct functional elements: a mounting hole for clamping, peripheral surfaces for lateral support, and a protrusion portion for radial force absorption. This segmentation allows each element to perform its specific function with relaxed tolerance requirements compared to a fully contact-dependent design.
Solution Approach 2:
The protrusion portion acts as an intermediary element between the cutting insert and the insert pocket. It selectively contacts the insert pocket under high radial load conditions to absorb forces, while the clamping screw and support surfaces provide retention under normal conditions. This intermediary structure enables the system to handle both precision retention and high-force absorption without requiring strict tolerance maintenance across all contact surfaces.
2Stability of the object's composition
If the cutting insert uses multiple contact surfaces (rail bottom surface, peripheral surface, and insert bottom surface), then the retention stability is improved, but the manufacturing precision requirements increase
Solution Approach 1:
Different regions of the cutting insert have different functional qualities: the peripheral surfaces provide lateral support and positioning, the mounting hole area provides clamping retention, and the protrusion portion provides radial force absorption. This local differentiation of functions allows each region to be manufactured with appropriate precision levels for its specific role, rather than requiring all surfaces to meet high precision standards.
Solution Approach 2:
The protrusion portion is designed to selectively contact the insert pocket based on the magnitude of radial forces. Under normal operating conditions, the protrusion remains disengaged and the insert is retained by the clamping screw and support surfaces. When radial forces exceed a threshold, the protrusion engages to absorb the excessive forces. This dynamic engagement mechanism provides retention stability across varying load conditions without requiring all contact surfaces to maintain high precision under all conditions.
3Strength
If the cutting insert is firmly retained using traditional clamping methods, then the retention strength is improved, but the susceptibility to clamping screw breakage under high radial force increases
Solution Approach 1:
The protrusion portion is pre-positioned on the cutting insert to engage with the insert pocket under high radial load conditions before the clamping screw can be subjected to excessive forces. This preliminary engagement mechanism absorbs the initial shock and sustained radial forces, preventing them from being transmitted to the clamping screw and causing breakage.
Solution Approach 2:
The radial forces that would otherwise be harmful to the clamping screw are converted into a beneficial loading mechanism for the protrusion portion. When radial forces act on the cutting insert, they cause the protrusion to engage with the insert pocket, transforming the potentially damaging force into a stabilizing contact that protects the clamping screw from excessive loading and breakage.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design ensures the cutting insert remains securely attached during high speed and high ramp machining, preventing clamping screw breakage and allowing precise machining of workpieces while simplifying the manufacturing process by reducing precision requirements.
Implementation Method 1
a radially outward force is applied to a cutting insert, which is mounted in a milling cutter, due to a centrifugal force and a radially outward cutting force
Data Source
Figure 1~2
Figure 3~5
Figure 6~7
AI summary
A cutting insert mountable in an insert pocket of a milling cutter and capable of effectively absorbing a radially outward force during high speed machining and high ramp machining. The cutting insert has a top surface, a bottom surface, peripheral surfaces extending between the top surface and the bottom surface, a mounting hole extending through the top surface and the bottom surface, a protrusion portion protruding from the bottom surface, and a pair of lower inclined surfaces at the bottom surface. The lower inclined surface faces to the protrusion portion and is inclined outwardly upwardly. The protrusion portion extends across the mounting hole and has a lateral surface facing radially outwardly of the milling cutter. The lateral surface selectively contacts or does not contact the insert pocket depending on a revolution speed of the milling cutter.