Cutting Insert Depressed Portions Chip Control
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Solution Overview
Problem
Cutting edge replaceable drills generate long, spirally extending chips when processing materials with high ductility like stainless steel and mild steel, leading to entanglement issues, productivity loss, and safety concerns due to the speed difference between the radial inner and outer cutting edges.
Innovation Solution
A cutting insert with depressed portions and groove portions on its end surfaces, where the depressed portions have increasing depth and length, and the groove portions have smaller rake angles, are designed to manage chip discharge effectively by creating varying rake angles and chip breaker surfaces, allowing for better chip control and reduction of long chip generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If cutting edges are arranged radially with speed difference between inner and outer portions, then cutting efficiency is improved, but long spirally extending chips are generated causing entanglement and productivity loss
Solution Approach 1:
The invention applies different rake angles to different radial positions of the cutting edge. The outer circumferential portion has a larger rake angle while the inner circumferential portion has a smaller rake angle, optimizing chip control at each location to prevent long chip formation while maintaining cutting efficiency
Solution Approach 2:
The invention changes the rake angle parameter along the radial direction of the cutting edge. By varying the rake angle from inner to outer circumferential portions, the chip flow characteristics are controlled to prevent spiraling and entanglement while maintaining effective cutting
2Object-generated harmful factors
If larger rake angle is applied to peripheral edge to curl chips, then chip extension is suppressed, but cutting resistance increases rapidly
Solution Approach 1:
The invention applies a larger rake angle specifically to the outer circumferential portion where chip curling is needed, while maintaining a smaller rake angle at the inner circumferential portion to avoid excessive cutting resistance, thus locally optimizing both chip control and cutting force
3Object-generated harmful factors
If smaller rake angle is applied to center edge to avoid clogging, then chip discharge is improved, but chip curling is insufficient
Solution Approach 1:
The invention applies a smaller rake angle to the inner circumferential portion to prevent chip clogging and improve discharge, while applying a larger rake angle to the outer circumferential portion to ensure adequate chip curling, thus locally optimizing both chip discharge and curling
Data Source
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AI summary
The present invention provides a cutting insert used in a cutting edge replaceable rotary cutting tool. The cutting insert includes a first cutting edge formed on an intersecting ridge portion between a first end surface of two opposite end surfaces and a circumferential side surface, and a first depressed portion formed along a part of the first cutting edge. The first depressed portion is provided to form a larger rake angle at the first cutting edge than that at a part not having the first recess portion of the first cutting edge.