Veined Drill Blank Geometry for Low-Waste Regrindable Cutting Edges

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Solution Overview

Problem

Existing veined drills with superhard material cutting edges are difficult and expensive to manufacture due to extensive removal of superhard material, leading to a limited number of regrinds and significant waste.

Innovation Solution

A tool blank design with veins of superhard material having a varying inclination angle and constant width, allowing for a nearly constant rake angle, reducing the amount of superhard material needed and enabling more regrinds while minimizing waste.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If a wide vein and extensive removal of superhard material is used to create high helix angle veined drills with conventional twist drill geometry, then the desired drill geometry is achieved, but the manufacturing process becomes difficult, time-consuming, and expensive with significant waste of superhard material

Engineering Contradiction:
Improvedrill geometryVSAvoidsuperhard material waste
Core Design Contradiction:
ShapeVSLoss of substance

Solution Approach 1:

The invention changes the geometric parameters of the vein by forming it with a varying inclination angle that corresponds to the desired rake angle distribution. This parameter change allows the vein to provide the correct geometry with minimal material removal, resolving the contradiction between achieving proper drill geometry and minimizing superhard material waste.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The vein is pre-formed in the tool blank with the correct varying inclination angle and constant width before any cutting edge formation. This preliminary action ensures that when flutes and cutting edges are subsequently formed, minimal superhard material needs to be removed, significantly reducing manufacturing complexity and material waste.

Inventive Principle:
Principle #10Preliminary action

2Shape

If extensive removal of superhard material is performed to create the desired rake angle, then conventional twist drill geometry with high helix angle is achieved, but the number of subsequent regrinds is reduced

Engineering Contradiction:
Improverake angle geometryVSAvoiddrill lifespan
Core Design Contradiction:
ShapeVSDuration of action of moving object

Solution Approach 1:

The vein is designed with a varying inclination angle that corresponds to the desired rake angle distribution, allowing the full depth of the vein to be utilized for cutting edge formation. This parameter optimization maximizes the usable superhard material, enabling more regrinds and extending drill lifespan.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The vein extends deeper into the tool blank than conventional designs, providing excess superhard material reserve that can be utilized through multiple regrinds. This excessive action in the axial direction ensures the drill can be reground multiple times before the superhard material is depleted.

Inventive Principle:
Principle #16Partial or excessive action

3Loss of substance

If a constant width vein with varying inclination angle is used, then the amount of superhard material removal is minimized and manufacturing is simplified, but the complexity of vein geometry increases

Engineering Contradiction:
Improvesuperhard material removalVSAvoidvein geometry
Core Design Contradiction:
Loss of substanceVSDevice complexity

Solution Approach 1:

The vein geometry is defined by varying only one parameter (inclination angle) while keeping another parameter (width) constant. This selective parameter variation simplifies the manufacturing process and material utilization while achieving the desired functional outcome, balancing geometry complexity with manufacturing efficiency.

Inventive Principle:
Principle #35Parameter changes

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

The design extends the lifespan of veined drills by allowing more regrinds and reducing superhard material waste, while simplifying the manufacturing process through additive manufacturing of complex geometries.

Implementation Method 1

The first side surface of the vein forms an inclination angle with respect to the longitudinal axis that varies with the radial distance to the longitudinal axis of the tool blank over at least a major part of the extension of the vein, such that the inclination angle substantially corresponds to a desired axial rake angle of a drill to be manufactured from the tool blank.

Methodology Applied
Scientific EffectGeometry: Geometry

Data Source

PatentEP3569351B1Veined tool blank
Publication Date: 2025.07.09 SANDVIK COROMANT
  • EP3569351B1 patent drawingFigure 1~2B
  • EP3569351B1 patent drawingFigure 3A~3B
  • EP3569351B1 patent drawingFigure 3C~3F

AI summary

The invention relates to a tool blank (1) for a drill, the tool blank being substantially cylindrical and having a front end (2), a rear end (3) and a central longitudinal axis (L) extending therebetween. The tool blank comprises at least one vein (4) of a superhard material formed at the front end, wherein the vein has a depth (D) in the axial direction and comprises a bottom surface (12), a first side surface (13) and a second side surface (14). Each vein has an extension in an inward direction from the periphery of the tool blank. For each vein, the first side surface forms an inclination angle (α) with respect to the longitudinal axis that varies with the radial distance to the longitudinal axis of the tool blank over at least a major part of the extension of the vein. The inclination angle substantially corresponds to a desired axial rake angle of a drill (5) to be manufactured from the tool blank. The invention also relates to a drill manufactured from such tool blank, and a method for manufacturing a drill.