Asymmetric Cutting Insert Design for Edge Strength
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Solution Overview
Problem
Existing hexagonal reversible cutting inserts have a short major cutting edge length and prone to edge corner chipping due to the edge corner protruding in the insert thickness direction, which affects their strength and durability.
Innovation Solution
A cutting insert design featuring a polygonal shape with a recessed portion separating the side surfaces, a longer first cutting edge, and a shorter second cutting edge, where the first cutting edge is inclined to reduce edge corner protrusion and increase strength, and a milling cutter incorporating this insert with a tool body support seat that enhances clamping stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the edge corner is made to protrude in the insert thickness direction to increase sharpness, then the cutting edge sharpness is improved, but the edge corner strength decreases and chipping occurs easily
Solution Approach 1:
The invention transitions from a traditional hexagonal insert shape to an asymmetric polygonal shape with unequal side lengths. By making one side longer than the others and positioning the cutting edge at a specific angular orientation (30°-60° from the normal of the bearing surface), the design achieves enhanced sharpness through geometric configuration rather than relying on edge corner protrusion, thereby maintaining edge strength while improving cutting performance.
Solution Approach 2:
The cutting insert employs an asymmetric polygonal configuration where adjacent sides have different lengths, and the cutting edge is positioned at an asymmetric angle relative to the bearing surface. This asymmetric design allows the cutting edge to be sharply defined through angular geometry without requiring the edge corner to protrude, thus resolving the contradiction between sharpness and strength.
2Length of moving object
If the major cutting edge length is extended by inclining the cutting edge, then the cutting region is expanded, but the edge corner protrusion height increases making it prone to chipping
Solution Approach 1:
The invention applies different geometric characteristics to different regions of the cutting insert. The cutting edge region is designed with a specific angular inclination (30°-60° from the bearing surface normal) to achieve the desired cutting edge length and sharpness, while the overall insert maintains a robust polygonal shape with unequal sides. This localized geometric optimization allows extended cutting edge length without compromising edge corner strength.
3Ease of manufacture
If a traditional hexagonal insert shape is used, then the insert structure is simple and easy to manufacture, but the major cutting edge length is short limiting the cutting region
Solution Approach 1:
The invention replaces the symmetric hexagonal shape with an asymmetric polygonal shape where adjacent sides have different lengths. This asymmetric configuration enables one side to be extended, thereby increasing the major cutting edge length and expanding the cutting region, while still maintaining relative manufacturing simplicity through straightforward geometric forms.
Data Source
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AI summary
A cutting insert includes a first surface and a second surface each of which is polygonal and that face away from each other; a side surface that is continuous with the first surface and a side surface that is continuous with the second surface; a cutting edge formed along each of a ridge where the first surface and the side surface intersect and a ridge where the second surface and the side surface intersect; a bearing surface formed in each of a part the first surface and a part of the second surface adjacent to an insert center, the bearing surfaces disposed parallel to each other; and a recessed portion that separates the side surface that is continuous with the first surface from the side surface that is continuous with the second surface. The cutting edge includes three corner edges, a first cutting edge, and a second cutting edge, the first and second cutting edges being continuous with each other and located between each pair of the corner edges. A length of the first cutting edge is greater than that of the second cutting edge, an end portion of the first cutting edge adjacent to one of the corner edges is at a position higher than the bearing surface, and an end portion of the first cutting edge opposite to the end portion adjacent to the corner edge is at a position lower than the bearing surface. Each of the first surface, the second surface, and a cross section of the recessed portion has such a shape that outlines of the shape before and after rotation of the insert by 120° around the insert center are coincident with each other. The first surface and the second surface have the same shape, and the second cutting edge of the second surface is located at a corner at which the first cutting edge of the first surface is located.