Radius End Mill Wiper Geometry for Glossy Milled Surfaces

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Solution Overview

Problem

Radius end mills often leave cutting marks on surfaces, necessitating labor-intensive polishing processes to achieve glossy finishes, which reduces productivity.

Innovation Solution

Incorporating corner radius wiper faces and end wiper faces with specific widths and configurations along the cutting edges to minimize surface roughness and eliminate visible cutting marks, thereby reducing the need for extensive polishing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a radius end mill with corner radius cutting edge is used for final finishing, then the tool can mill curved surfaces and inclined surfaces, but cutting marks appear on the cut surface

Engineering Contradiction:
Improveability to mill curved surfaces and inclined surfacesVSAvoidsurface finish quality
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The cutting edge is segmented into two distinct functional zones: a corner radius cutting edge for material removal and a wiper face for surface finishing. This segmentation allows each zone to perform its specific function optimally, with the wiper face specifically designed to eliminate cutting marks while the corner radius cutting edge maintains versatility for curved and inclined surfaces.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different portions of the tool have different properties: the corner radius cutting edge has a specific radius for versatile cutting, while the wiper face has a specific width (0.01-0.06 times the tool diameter) and angle (5-15 degrees) optimized for surface finishing. This local differentiation of properties enables the tool to simultaneously achieve versatility and high surface finish quality.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If polishing process is applied after cutting to remove cutting marks, then glossy surfaces are obtained, but labor time and cost increase

Engineering Contradiction:
Improvesurface glossinessVSAvoidlabor time for polishing
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The wiper face performs the surface finishing action during the cutting process itself, before the workpiece leaves the tool. This preliminary action of surface smoothing eliminates the need for subsequent polishing operations, thereby maintaining high surface glossiness while significantly improving productivity by removing the additional labor step.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The cutting tool serves dual functions: it both removes material and finishes the surface. The wiper face automatically smooths the cut surface as the tool passes, making the tool self-sufficient for both cutting and finishing operations without requiring separate polishing equipment or operations.

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If the wiper face width is increased to improve surface finish, then cutting marks are reduced, but chip evacuation and tool performance deteriorate

Engineering Contradiction:
Improvesurface roughnessVSAvoidchip evacuation difficulty
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The wiper face width is precisely controlled within the range of 0.01 to 0.06 times the tool diameter, and the wiper face angle is set between 5 to 15 degrees. These optimized parameter values provide the minimum necessary width to effectively smooth cutting marks while maintaining sufficient clearance for proper chip evacuation and preventing tool performance deterioration.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3808481A1Radius end mill
Publication Date: 2021.04.21 UNION TOOL CO
  • EP3808481A1 patent drawingFigure 1
  • EP3808481A1 patent drawingFigure 2
  • EP3808481A1 patent drawingFigure 3

AI summary

An object of the present invention is to provide a radius end mill with which cutting marks are not apparent following a cutting process, with which glossy milled surfaces are obtained, and with which the amount of labor involved in a polishing process can be reduced. A radius end mill comprises an end cutting edge (1), a corner radius cutting edge (2) that is formed contiguous with a peripheral side of the end cutting edge (1), and a peripheral cutting edge (3) that is formed contiguous with the corner radius cutting edge (2). A corner radius wiper face (5) is provided running along the corner radius cutting edge (2) so as to be contiguous therewith. The corner radius wiper face (5) wipes a cut surface cut by said corner radius cutting edge (2).