Nonagon Cutting Insert with Asymmetric Edges for Variable Force
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing indexable cutting inserts have limited cutting edges, leading to higher costs per edge and inadequate variable cutting force during machining operations.
Innovation Solution
A double-sided, nonagon cutting insert with 18 cutting edges and a non-symmetric profile, featuring identical side surfaces, corner radii, and a specific edge geometry that tapers to provide variable cutting force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a conventional polygonal insert shape (square, triangular, rhombus) is used, then the insert structure is simple and easy to manufacture, but the number of cutting edges is limited (4, 3, or 2 edges per side)
Solution Approach 1:
The insert is divided into multiple identical side surfaces (five side surfaces per face) that can be independently indexed. Each side surface contains a cutting edge, allowing the insert to be segmented into 18 usable cutting edges total (9 per face × 2 faces). This segmentation enables progressive use of cutting edges without replacing the entire insert.
Solution Approach 2:
The insert design adds a rotational dimension to the conventional polygonal shape. By creating a nonagon (9-sided) geometry with identical side surfaces arranged around a central axis, the insert enables rotational indexing to access multiple cutting edges. The double-sided design further multiplies the cutting edges by allowing flipping between faces.
2Force
If a symmetric cutting edge profile is used, then the insert structure is simple to manufacture, but the cutting force is constant during fine finishing operations
Solution Approach 1:
The cutting edge profile is designed with asymmetric geometry relative to the insert centerline. Each cutting edge includes a relief surface that is angled differently from the cutting surface, creating an asymmetric profile. This asymmetry allows the cutting force to vary during the cutting stroke, providing better control for fine finishing operations while maintaining reasonable manufacturability through standard grinding or CBN dressing processes.
Data Source
AI summary
A double-sided, nonagon cutting insert includes a top surface, a bottom surface identical to the top surface, nine side surfaces that are identical to each other, a cutting edge formed at an intersection between each of the nine side surfaces and the top and bottom surfaces for a total of eighteen cutting edges, and nine corner radiuses identical to each other, each corner radius extending between the top and bottom surfaces and each of the nine side surfaces. Each cutting edge has a non-symmetric profile with respect to a central, longitudinal axis. The non-symmetrical profile of the cutting edge has the technical advantage of providing a variable cutting force, particularly during fine finishing cutting operations.