Dual-Nose Turning Insert for Internal Chip Evacuation
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Solution Overview
Problem
Existing turning tools for internal metal cutting face challenges with poor chip breaking and evacuation, especially at cutting depths equal to or less than the nose radius, leading to increased wear and reduced efficiency, requiring separate tools for roughing and finishing operations.
Innovation Solution
A turning tool with a dual nose cutting edge configuration, featuring acute and obtuse angles for improved chip evacuation and reduced wear, allowing for both roughing and finishing with a single tool, and enabling machining of internal surfaces with constant diameters and 90° corners.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single turning tool is used for both roughing and finishing operations, then cost efficiency is improved and time is saved, but the tool must accommodate multiple cutting configurations which increases design complexity
Solution Approach 1:
The turning insert is segmented into two distinct nose cutting edges (first and second nose cutting edges) with different geometries. Each nose cutting edge is optimized for specific operations: one for roughing with higher entering angles and another for finishing with lower entering angles. This segmentation allows a single tool to perform multiple operations without requiring tool changes, thereby improving productivity while managing complexity through modular insert design.
Solution Approach 2:
The turning insert is designed as a universal component that can perform both roughing and finishing operations. The insert includes multiple cutting edges (first and second nose cutting edges, forward and rearward cutting edges) that can be selectively used depending on the operation required. This multi-functionality eliminates the need for separate tools for roughing and finishing, reducing tooling costs and cycle times while maintaining operational versatility.
2Object-generated harmful factors
If the entering angle is increased to improve chip evacuation, then chip flow is improved, but insert wear increases at shallow cutting depths
Solution Approach 1:
Different regions of the turning insert are given different geometric qualities optimized for specific functions. The first nose cutting edge has a geometry suited for roughing operations with higher entering angles to promote chip evacuation, while the second nose cutting edge has a geometry optimized for finishing operations with lower entering angles to reduce insert wear. This local differentiation of geometric properties allows each cutting edge to perform optimally in its designated operation, balancing chip evacuation and wear resistance.
Solution Approach 2:
The patent applies opposite entering angles for different cutting edges to address the contradiction. The first nose cutting edge uses a higher entering angle configuration to improve chip evacuation during roughing, while the second nose cutting edge uses a lower entering angle to reduce wear during finishing. By inverting the angle configuration between the two nose cutting edges, the tool optimizes performance for each specific operation rather than compromising both.
3Manufacturing precision
If cutting depth is reduced to achieve constant diameter surface, then surface quality is improved, but chip breaking becomes poor and evacuation is hindered
Solution Approach 1:
The turning insert employs different nose cutting edge geometries at different locations to address the contradiction between surface quality and chip breaking. When machining at shallow cutting depths to achieve constant diameter surfaces, the optimized nose geometry ensures proper chip flow and breaking characteristics are maintained despite the reduced depth of cut. The specific nose radius and entering angle configurations are tailored to prevent chip entanglement and ensure effective evacuation even in light cutting conditions.
Data Source
AI summary
A turning tool for internal turning of a metal work piece having a rear end, an opposite forward end and a longitudinal center axis extending therebetween. The first nose cutting edge includes a first radially distal point having an associated first rake face and separates and connects a first forward cutting edge and a first rearward cutting edge. A second nose cutting edge of the turning tool includes a second radially distal point having an associated second rake face and separates and connects a second forward cutting edge and a second rearward cutting edge. The second radially distal point is positioned ahead of the first radially distal point. The first forward cutting edge forms an acute first entering angle, the second forward cutting edge forms an obtuse second back clearance angle, and the second rearward cutting edge forms an acute second entering angle.