Conical Centering Section for Stable Metal Drilling
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Solution Overview
Problem
Conventional metal drilling tools experience oscillating movements and vibrations during machining, leading to reduced tool life, poor hole quality, and increased stress on guide surfaces, especially when drilling in metallic workpieces.
Innovation Solution
A metal drilling tool with a centering section replacing the chisel edge, featuring at least three cutting edges arranged on conical surfaces, providing improved self-centering and stability, minimizing vibrations, and enhancing guide surface durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a chisel edge is used for self-centering, then the tool can center itself on flat surfaces, but oscillating movements and vibrations occur during machining
Solution Approach 1:
The chisel edge is divided into multiple discrete cutting edges (at least three) arranged on conical surfaces, with each edge providing independent cutting action. This segmentation eliminates the oscillating movements inherent in a single chisel edge while maintaining self-centering capability through the geometric arrangement of the divided edges.
Solution Approach 2:
The cutting edges are arranged on conical surfaces (first and second conical surfaces with different angles) rather than a single plane or line. This dimensional arrangement on multiple conical surfaces provides stable geometric engagement with the workpiece, preventing vibrations while enabling self-centering through the three-dimensional configuration.
2Stability of the object's composition
If three main cutting edges with cross-cutting segments are used, then pendulum movements are suppressed, but relatively high contact forces must be applied
Solution Approach 1:
The conical angles of the cutting edges are optimized to balance stability and force requirements. By carefully selecting the first and second conical angles, the tool achieves reliable guidance through geometric stability while minimizing the contact forces required during machining operations.
3Measurement precision
If the centering section has an acute second cone angle for better centering, then tool centering in the workpiece is improved, but the centering section becomes more susceptible to chipping
Solution Approach 1:
The centering section is formed from materials with enhanced toughness and wear resistance, such as coated carbides or composite materials, which allow the use of acute conical angles for precise centering while preventing chipping through superior material properties that combine hardness with fracture resistance.
Data Source
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AI summary
The invention relates to a metal drilling tool (1) comprising: a middle axis (M), a front side (7) and an opposite end (E), with at least two cutting edges (3/1,3/2) arranged in the region of the front side (7), a first free surface (5/1,5/2) being associated with each of same. According to the invention, the at least two cutting edges (3/1,3/2) lie on an imaginary first conical surface arranged concentrically in relation to the middle axis (M), with a first conical angle (α) that opens up towards the opposite end (E) and reaches a maximum of 180°. The invention is characterised by a centring section (19) with at least three edges (21/1,21/2,21/3), at least three side surfaces (17/1,17/2,17/3) and an imaginary base surface, where at least two of the edges (21/1,21/2,21/3,21/4) lie on an imaginary second conical surface which is arranged concentrically in relation to the middle axis (M) and has a second conical angle (ß) that opens up towards the opposite end (E), where the second conical angle (ß) is smaller than the first conical angle (α), such that the imaginary second conical surface, seen from the opposite end (E), projects opposite the front surface (7).