Diamond-Insert Drilling Tool for Hard Material Hole Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Drilling through sintered cemented carbide and ceramics is challenging due to the high hardness of these materials, as conventional drilling tools lack strength and stability, and existing methods like eroding are inefficient, with diamond-coated milling tools having short service life and being cost-intensive.
Innovation Solution
A drilling tool with a specially adapted cutting edge geometry, featuring CVD thick film diamond cutting inserts and a concave cutting edge design that starts machining from the outside to the inside, reducing pressure on the drill center and utilizing the wear resistance of diamond for efficient machining of hard materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional drilling tools are used on sintered cemented carbide, then the tool structure is simple and easy to manufacture, but the tool lacks strength and stability and cannot effectively machine the hard material
Solution Approach 1:
The patent uses CVD thick film diamond coating on the cutting insert, creating a composite material structure where the diamond layer provides extreme hardness and wear resistance while the substrate provides structural support. This composite approach enables the tool to machine sintered cemented carbide effectively by combining the properties of two different materials to overcome the strength limitation of conventional single-material tools.
2Reliability
If conventional drilling tools are used on sintered cemented carbide, then the tool structure is simple, but the cutting edges lack stability and precision under high pressure
Solution Approach 1:
The patent applies local quality by concentrating the advanced CVD diamond coating and specialized geometry only at the cutting edge region where it is most needed, while the rest of the tool holder maintains a simpler structure. This localized enhancement provides cutting edge stability and precision under high pressure without requiring the entire tool structure to be complex.
Solution Approach 2:
The patent employs a concave cutting edge geometry with specific curvature radii (R1, R2, R3) that distribute stress more evenly across the cutting edge. This curved geometry enhances cutting edge stability by reducing stress concentration points, allowing the tool to maintain precision under the high pressures required for machining sintered cemented carbide.
3Temperature
If conventional drilling methods are used, then the process is simple, but extreme heat development occurs during machining of sintered cemented carbide
Solution Approach 1:
The patent replaces conventional mechanical drilling with a specialized CVD diamond-coated insert that utilizes the extreme hardness and thermal conductivity of diamond. This substitution allows for more efficient cutting action that generates less heat, while the diamond coating's thermal properties help dissipate the heat that is generated, maintaining machining efficiency without extreme temperature buildup.
4Stress or pressure
If conventional drilling starts from the center, then the drilling process is straightforward, but too much pressure builds up in the center of the drill
Solution Approach 1:
The patent inverts the conventional drilling approach by using a concave cutting edge geometry that engages the workpiece from the outer diameter and progresses inward, rather than starting from the center. This inverted approach distributes the cutting pressure away from the center, reducing stress concentration at the drill center while maintaining operational simplicity through the specialized insert geometry.
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 tool achieves high stability, axial accuracy, and roundness in drilling, extending the service life of cutting edges and reducing costs by effectively machining hard materials with minimal stress and pressure on the drill center.
Implementation Method 1
utilizing the wear resistance of diamond for efficient machining of hard materials
Data Source
AI summary
A drilling tool comprising a tool holder that extends along a central axis and comprises a first cutting insert receptacle having a first abutment surface oriented parallel to the central axis. The drilling tool further comprises a first cutting insert that is fixed in the first cutting insert receptacle and abuts with one of its sides against the first abutment surface, wherein an axial portion of the first cutting insert projects axially beyond an end face end of the tool holder, and wherein the first cutting insert comprises in the axial portion a first main cutting edge that is inclined with respect to a first imaginary plane, which is oriented orthogonally to the central axis and arranged at the end face end of the tool holder, so that a radially outer end of the first main cutting edge is spaced a larger distance from the first imaginary plane than a radially inner end of the first main cutting edge and the first main cutting edge does not intersect the first imaginary plane, and wherein the first main cutting edge touches or intersects a second imaginary plane that is spanned by the central axis and oriented orthogonally to the first abutment surface.