Single-Lip Drill Guide Elements for Deep Hole Centering

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Solution Overview

Problem

Conventional single-lip drills require two work steps to achieve precise deep holes with a small center course, as they cannot produce holes with a center course significantly smaller than the drill diameter in a single step, leading to increased manufacturing time and costs.

Innovation Solution

The single-lip drill design features guide elements arranged over a predeterminable angular range greater than 245°, providing improved guidance and allowing for full drilling in a single step with a significantly smaller center course, achieved by positioning guide elements with a smaller radial distance from the tool center axis in specific angular ranges and a tapered drill head to prevent jamming.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional single-lip drills are used, then drilling can be performed, but the center course deviation is large and requires two work steps (pre-drilling and subsequent drilling)

Engineering Contradiction:
Improvecenter courseVSAvoidnumber of work steps
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The guide elements are segmented into multiple sections arranged at different angular positions around the drill head circumference, with each segment providing guidance in a specific direction. This segmentation allows the drill to maintain better center alignment throughout the drilling process, achieving small center course deviation in a single work step.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different angular segments of the drill head are equipped with guide elements having specific radial distances tailored to local guidance needs. The guide elements are strategically positioned at different radial distances from the tool center axis in different angular ranges, providing optimized local guidance quality that prevents center course deviation while enabling full drilling in one step.

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If guide elements are arranged over a large angular range (>245°), then guidance is improved and center course is reduced, but the risk of drill jamming increases

Engineering Contradiction:
Improvecenter courseVSAvoiddrill jamming prevention
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The guide elements are arranged asymmetrically around the drill head, with different radial distances in different angular ranges. Specifically, guide elements in certain angular segments are positioned at smaller radial distances from the tool center axis, creating an asymmetric configuration that provides excellent guidance (>245° angular coverage) while maintaining sufficient clearance to prevent jamming in the bore.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The radial distance parameter of the guide elements is varied according to their angular position. By changing the radial distance parameter in different angular ranges, the drill achieves optimal guidance coverage while avoiding the jamming risk that would result from uniform, large radial distances across all angular positions.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the entire circular cross-section is machined by solid drilling, then a single work step is used, but the center course deviation is large

Engineering Contradiction:
Improvenumber of work stepsVSAvoidcenter course
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The guide elements are pre-positioned on the drill head at specific angular ranges and radial distances before the drilling operation begins. This preliminary arrangement of guide elements ensures that the drill maintains proper center alignment throughout the full drilling process, enabling single-step drilling with small center course deviation without requiring preliminary centering operations.

Inventive Principle:
Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This design enables the production of bores with a center course 50% smaller than conventional drills, allowing for precise deep-hole drilling in a single work step, reducing manufacturing time and costs while maintaining optimal chip removal and preventing drill jamming.

Implementation Method 1

Starting from the clamping end, coolant is supplied under pressure through this channel, which emerges at the drill head and, in addition to cooling the cutting edge and the guide elements, has the particular task of removing the chips produced during drilling

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 2

The single-lip drill penetrates the workpiece, the material of the workpiece being chipped off at the cutting edge arranged on the drill head and separated from the workpiece in the form of chips

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP2635394B1Gun drill
Publication Date: 2019.05.15 BOTEK PRAEZISIONSBOHRTECHNIK GMBH
  • EP2635394B1 patent drawingFigure 1a~1b
  • EP2635394B1 patent drawingFigure 2a~2b
  • EP2635394B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a single-lip drill (10) having at least one cutting edge (160) for solid drilling, comprising a drill head (13) arranged on a shaft (12), a chip removal channel (151) extending substantially along the axis of the drill head (13) and of the shaft (12) and arranged in both the drill head (13) and the shaft (12), and a plurality of guiding elements (170, 171, 172, 173) arranged on the circumference of the drill head (13), wherein said single-lip drill is characterized in that at least one guiding element (170) is arranged at least partially in an angle range of greater than or equal to 245°, measured from the cutting edge (160) arranged at 0° in a direction opposite the rotational direction of the single-lip drill.