Rotary Cutting Insert Wiper Edge Geometry for Fine Surface Finish
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cutting tools struggle to achieve surface roughness of 5 µm or smaller, especially when machining hard steel materials, due to issues with step difference and surface finish in both tool feed and radius directions.
Innovation Solution
A cutting insert with an arc-shaped wiper edge, where the angle between tangent lines of the wiper edge is within 0.010° ≤ θ ≤ 3.0°, is used in an indexable rotary cutting tool. This design reduces surface roughness and step differences, improving the flatness of the machined surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a linear wiper edge is used, then the structure is simple and easy to manufacture, but the surface roughness cannot be reduced to 5 µm or smaller
Solution Approach 1:
The patent applies curvature to the wiper edge by forming it with a specific radius of curvature (R1) to create an arc-shaped profile. This curved geometry allows the wiper edge to smoothly follow the contour of the workpiece surface, reducing surface roughness to 5 µm or smaller while maintaining manufacturability through standard forming processes.
Solution Approach 2:
The patent optimizes specific geometric parameters of the wiper edge, including the radius of curvature (R1) and the angle (θ) between tangent lines, to achieve the desired surface finish. By carefully controlling these parameters within specific ranges, the invention achieves high precision surface roughness without excessive complexity.
2Manufacturing precision
If an arc-shaped wiper edge with large radius is used to reduce surface roughness, then surface finish improves, but step difference in radial direction increases
Solution Approach 1:
The patent carefully optimizes the radius of curvature (R1) of the wiper edge within a specific range to balance two competing requirements: achieving sufficient surface roughness reduction while minimizing step difference in the radial direction. This parameter optimization allows the arc-shaped wiper edge to perform well in both aspects.
Solution Approach 2:
The patent applies different geometric characteristics to different portions of the cutting edge. The wiper edge portion has a specific arc shape with radius R1 optimized for surface finish, while other portions of the cutting insert have geometries optimized for their specific functions, creating a locally optimized tool design that addresses multiple requirements simultaneously.
3Productivity
If a positive rake angle is used to improve cutting performance on aluminum, then cutting performance on aluminum improves, but chipping occurs when cutting hard steel
Solution Approach 1:
The patent applies different rake angle characteristics to different portions of the cutting insert. The main cutting edges may have rake angles optimized for hard steel machining with chip resistance, while the wiper edge portion has a positive rake angle configuration optimized for surface finish on softer materials like aluminum, allowing the single insert to handle multiple material types effectively.
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
A cutting insert (1) includes a rake face (2), a seating surface (3) facing the rake face (2), a flank face (4) configured to connect the rake face (2) and the seating surface (3), and a cutting edge (5) formed in an intersecting ridgeline between the rake face (2) and the flank face (4). The cutting edge (5) includes a linear main cutting edge (5b), a corner edge (5a), and a wiper edge (5c) in this order. A recess portion (6) is provided in an end portion of the main cutting edge (5b) on a side opposite to an end portion connected to the corner edge (5a). The wiper edge (5c) is formed in an arc shape, and is connected to the corner edge (5a) by a tangent line. When viewed from a side facing the rake face (2), and when an extension line of the main cutting edge (5b) is defined as L1, a tangent line of the wiper edge (5c) which is perpendicular to the extension line L1 of the main cutting edge (5b) is defined as L2, and a tangent line of the wiper edge (5c) which passes through an end point P of the wiper edge (5c) on a corner edge (5a) side is defined as L3, an angle θ formed by the tangent line L2 and the tangent line L3 is within a range of 0.010° ≤ θ ≤ 3.0°.