Drill Cutting Edge Geometry for Uniform Resistance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional drills face challenges in efficiently and precisely drilling both metals and composite materials like GFRP and CFRP, as existing polygonal drills do not provide optimal cutting conditions, leading to uneven cutting resistance and increased delamination and burr formation.

Innovation Solution

A drill design featuring cutting edges with a line-symmetric and polygonal shape formed by discontinuously connecting linear segments along a parabola or ellipse, which reduces production costs and improves mechanical characteristics, allowing for uniform cutting volumes and reduced abrasion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional polygonal drills are used to drill metals and composite materials, then drilling capability is provided, but cutting resistance becomes uneven and delamination and burr formation increase

Engineering Contradiction:
Improvecutting performance consistencyVSAvoiddelamination and burr formation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies local quality by varying the point angles at different locations along the cutting edge. Specifically, the cutting edge has a first point angle in a first region and a second point angle different from the first in a second region. This allows different segments of the cutting edge to have optimized local geometry for uniform cutting resistance, preventing delamination and burr formation in composite materials while maintaining effectiveness on metals.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If complex polygonal cutting edges are designed to improve cutting uniformity, then cutting performance improves, but manufacturing complexity increases

Engineering Contradiction:
Improvecutting edge geometry precisionVSAvoidcutting edge structure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the cutting edge into multiple regions along its length, with each region having a specific point angle. The cutting edge is segmented into a first region with a first point angle and a second region with a second point angle. This segmentation allows precise control over cutting geometry to achieve uniform cutting resistance while maintaining manufacturability through defined regional characteristics.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2946861B1Drill and method of manufacturing drill
Publication Date: 2020.07.01 SUBARU CORP
  • EP2946861B1 patent drawingFigure 1(a)~1(b)
  • EP2946861B1 patent drawingFigure 2(a)~2(b)
  • EP2946861B1 patent drawingFigure 3(a)~3(b)

AI summary

A drill (1) has at least one cutting edge (2). A projecting shape of a passing area of a ridgeline of the at least one cutting edge (2) when the at least one cutting edge (2) is rotated around a tool axis (Tax) forms a line-symmetric and discontinuous line along a parabola, two parabolas, an ellipse or two ellipses. The projecting shape is drawn on a projection plane parallel to the tool axis (Tax).