Drill Chip Flute Depth Gradient for Jamming Reduction

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Solution Overview

Problem

Drills with straight cutting edges experience chip jamming due to shallow chip flutes, leading to vibrations and potential breakage, while drills with curved cutting edges have disadvantages such as grinding issues and reduced sharpness.

Innovation Solution

A drill design featuring straight cutting edges combined with deeper chip flutes that are concavely vaulted, with a radius of curvature smallest near the cutting edge and increasing towards the rear, and a planar chip surface that connects to the flute, reducing chip jamming and improving hole quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If straight cutting edges are used with shallow chip flutes, then the cutting edge sharpness and ease of manufacture are improved, but chip jamming occurs leading to vibrations and potential breakage

Engineering Contradiction:

Improvecutting edge manufacturingVSAvoiddrill reliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The chip flute depth is varied locally along its length, being deepest near the cutting edge and gradually shallower towards the rear, allowing optimal chip evacuation at the critical cutting zone while maintaining structural integrity elsewhere

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The invention transitions from a two-dimensional shallow flute design to a three-dimensional progressively deepening flute structure, creating additional vertical space for chip accommodation where it is most needed near the cutting edge

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If curved cutting edges are used with deeper chip flutes, then chip jamming is reduced, but grinding issues and reduced sharpness occur

Engineering Contradiction:

Improvechip release reliabilityVSAvoidcutting edge sharpness

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The cutting edge geometry is segmented into two distinct types: straight cutting edges for precision and curved cutting edges only where deeper flutes are needed, allowing each zone to be optimized independently for its specific function

Inventive Principle:

Principle #1Segmentation

3Reliability

If uniform deep chip flutes are used, then chip jamming is reduced, but the overall drill design complexity and manufacturing difficulty increase

Engineering Contradiction:

Improvechip evacuation reliabilityVSAvoidflute design complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The flute depth transitions dynamically from deep to shallow along its length, creating a gradient structure that adapts to the varying chip evacuation needs at different positions along the drill

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS7252465B2Drill for chip removing machining

Publication Date: 2007.08.07 SANDVIK INTELLECTUAL PROPERTY AB

AI summary

A drill for chip removing machining, including a front tip including at least one cutting edge and a chip flute. The chip flute is countersunk in an envelope surface of a body of the drill and extends rearwardly from the cutting edge. The chip flute is generally defined by a cross-section-wise concavely vaulted surface located between first and second longitudinal borders, the first longitudinal border extending from an area of a peripheral end of the cutting edge. The chip flute is deeper in an area of the first longitudinal border than in an area of the second longitudinal border such that a curve defining the cross-sectional shape of the flute surface has a radius of curvature that is smallest in the vicinity of the first longitudinal border and that increases towards the second longitudinal border. The flute surface transforms into a planar chip surface, which in turn transforms into the cutting edge.