Cutting Insert with Variable Rake Face for Gear Tooth Chatter Reduction
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Solution Overview
Problem
Conventional cutting inserts used for tooth cutting, particularly for involute gears, suffer from poor cutting performance and high cutting resistance due to negative axial rake angles, leading to chattering vibrations and reduced tool lifetime.
Innovation Solution
A cutting insert with a rake face inclined inwardly from the upper to the lower face, featuring a concave curved shape forming part of a conical side face, and a cutting edge in a substantially involute curved line shape, allowing for adjustable radial and axial rake angles to improve cutting performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the side face of the insert body is formed with a large inclination angle, then the cutting performance at high positions is improved, but the radial rake angle becomes excessively negative at low positions, deteriorating cutting performance
Solution Approach 1:
The patent applies local quality by dividing the rake face into multiple zones with different inclination angles. The front end portion (for low positions) has a smaller inclination angle to maintain appropriate radial rake angle, while the rear end portion (for high positions) has a larger inclination angle to improve cutting performance. This zone-based differentiation resolves the contradiction by optimizing each local region for its specific functional requirements.
Solution Approach 2:
The patent implements dynamics by making the inclination angle variable along the cutting edge rather than constant. The inclination angle changes progressively from the front end to the rear end of the rake face, allowing the radial rake angle to be dynamically adjusted according to the cutting position. This dynamic variation enables the cutting insert to maintain optimal performance across different cutting depths and positions.
2Device complexity
If a constant inclination angle is used for the rake face, then the structure is simple, but the cutting performance varies significantly between different positions of the gear tooth
Solution Approach 1:
The patent applies local quality by dividing the rake face into multiple zones with different inclination angles. The front end portion (for low positions) has a smaller inclination angle to maintain appropriate radial rake angle, while the rear end portion (for high positions) has a larger inclination angle to improve cutting performance. This zone-based differentiation resolves the contradiction by optimizing each local region for its specific functional requirements.
Solution Approach 2:
The patent implements dynamics by making the inclination angle variable along the cutting edge rather than constant. The inclination angle changes progressively from the front end to the rear end of the rake face, allowing the radial rake angle to be dynamically adjusted according to the cutting position. This dynamic variation enables the cutting insert to maintain optimal performance across different cutting depths and positions.
Data Source
AI summary
A cutting insert is removably mountable on an insert seat formed in a peripheral of a tool body rotated around an axis O and of substantial disc shape. The cutting insert includes a substantially planar insert body of a substantially square shape in plan view, a flank at an upper face of the body, a rake face at a side of the body intersecting with the flank, and a cutting edge at an intersection ridge between the rake face and the flank. The cutting edge is a substantial involute in side view of the body, the rake face is inclined to an inside of the body from an upper toward a lower face, and at least a front end arranged in a peripheral of the tool body is concave constituting a part of a substantially conical side face.