Helical Drill Flank Geometry for Higher Cuttings Removal

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing drills for processing mineral materials face inefficiencies in cutting and material removal due to inadequate design of the helix and drill head, leading to suboptimal surface roughness and delivery capacity.

Innovation Solution

The drill features a helix with a conveying flank and a free flank, where the conveying flank has a helical indentation with a deepening that contributes significantly to the delivery capacity, and the free flank is continuously concave in the radial direction, enhancing cutting efficiency and material removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the conveying flank is designed with a helical indentation, then the delivery capacity is significantly improved, but the device complexity increases

Engineering Contradiction:
Improvedelivery capacityVSAvoidhelix structure complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The conveying flank is segmented into different zones: a smooth upper portion and a lower portion with helical indentation. This segmentation allows the upper smooth portion to guide cuttings while the lower indented portion provides enhanced material removal capacity, resolving the contradiction by dividing the function across different structural zones.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The helical indentation is applied locally to specific portions of the conveying flank rather than the entire surface. The indentation depth and distribution are optimized locally to maximize delivery capacity in critical areas while maintaining simpler geometry in other regions, thus improving productivity without proportionally increasing overall complexity.

Inventive Principle:
Principle #3Local quality

2Productivity

If the free flank is made continuously concave in the radial direction, then the cutting efficiency is enhanced, but the manufacturing precision requirements increase

Engineering Contradiction:
Improvecutting efficiencyVSAvoidsurface geometry precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The free flank is designed with a continuously concave curvature in the radial direction, creating a smooth rounded profile rather than sharp edges or flat surfaces. This curved geometry enhances cutting efficiency by improving material engagement while the continuous nature of the curvature provides manufacturability through standard forming processes, balancing productivity gains with reasonable precision requirements.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Productivity

If the indentation covers at least a quarter of the conveyor flank area, then the delivery capacity increases, but the surface area available for cutting reduces

Engineering Contradiction:
Improvedelivery capacityVSAvoidconveyor flank surface area
Core Design Contradiction:
ProductivityVSArea of stationary object

Solution Approach 1:

The helical indentation utilizes the third dimension (depth) by creating a three-dimensional recessed structure rather than simply reducing the two-dimensional surface area. This allows the indentation to occupy volume while the upper surface area remains available for cutting operations, effectively increasing delivery capacity through vertical space utilization without proportionally sacrificing cutting surface area.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP3515640B1Drill bit
Publication Date: 2022.07.20 HILTI AG
  • EP3515640B1 patent drawingFigure 1~4

AI summary

The invention relates to a drill (1) which comprises an insertion end (4), a coil (8) and a drill head (2). A drill axis (6) runs through the insertion end (4), the coil (8) and the drill head (2). The coil (8) has a conveying flank (25) which is inclined with respect to the drill axis (6), faces the drill head (2) and extends helically about the drill axis (6). The conveying flank (25) has a depression that extends helically about the drill axis (6).