Veined Drill Blank Rake Geometry for Longer Regrind Life
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The manufacturing of veined drills with superhard materials like PCD or CBN is challenging due to the difficulty and expense of machining these materials, leading to a short lifespan and significant waste, as well as the need for extensive removal of superhard material to achieve desired rake angles, which reduces the number of regrinds possible.
Innovation Solution
A tool blank design with veins of superhard material featuring a nearly constant width and large depth, allowing for a uniform thickness along the cutting edge, and a manufacturing method involving additive manufacturing for the nib pre-blank with vein slots that are filled with superhard material and fused under high pressure and temperature, minimizing the amount of superhard material needed and extending the drill's lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If veins of superhard material are formed in the tool blank using conventional methods, then the cutting edges can be formed in a material better suited for machining specific work piece materials, but a significant amount of superhard material must be removed to create the desired rake angle, rendering the manufacturing process difficult, time-consuming and expensive
Solution Approach 1:
The vein geometry is pre-configured in the tool blank with the correct rake angle inclination already formed. The vein extends from the periphery toward the center with its side surfaces forming the desired rake angle, so that when the cutting edge is formed, the superhard material is already positioned and shaped to minimize removal requirements.
Solution Approach 2:
The vein is designed with non-uniform geometry where the width and depth vary along its extension to achieve the desired rake angle profile. This local variation in vein dimensions allows the cutting edge to have the optimal rake angle at each radial position while minimizing the total volume of superhard material required.
2Shape
If a wide vein is required to manufacture veined drills with high helix angle and conventional twist drill geometry, then the desired rake angle can be achieved, but a significant amount of superhard material must be removed, reducing the number of subsequent regrinds possible
Solution Approach 1:
The vein geometry parameters (width, depth, inclination angle) are specifically optimized to achieve the desired rake angle profile. By carefully controlling these parameters, the design achieves conventional twist drill geometry with high helix angle while minimizing superhard material removal and maximizing the remaining material for future regrinds.
3Shape
If extensive removal of superhard material is performed to achieve desired rake angles, then the conventional twist drill geometry can be obtained, but the manufacturing process becomes more difficult and time-consuming
Solution Approach 1:
The vein is pre-formed in the tool blank with geometry that closely matches the final cutting edge requirements. The vein's side surfaces are configured to form the desired rake angle, and its extension toward the center creates the appropriate profile, significantly reducing the amount of subsequent machining required to achieve conventional twist drill 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
This design and method result in a veined drill with improved geometry and extended lifespan, reducing waste of superhard material and allowing for a higher number of regrinds before the material is depleted, while maintaining the hardness advantage of the superhard material.
Implementation Method 1
filling the vein slot with powder of the superhard material (e.g. PCD), and fusing the superhard material to the tool blank under high pressure and high temperature
Data Source
AI summary
A tool blank is substantially cylindrical and includes a front end, a rear end and a central longitudinal axis extending therebetween. At least one vein of a superhard material is formed in the blank at the front end. The vein has a depth in the axial direction and a bottom surface, a first side surface and a second side surface. Each vein has an extension in an inward direction from the periphery of the blank. For each vein, the first side surface forms an inclination angle with respect to the longitudinal axis that varies with the radial distance to the longitudinal axis of the blank over at least a major part of the extension. The inclination angle corresponds to a desired axial rake angle of a drill to be manufactured from the tool blank. A drill manufactured from such tool blank and a method for manufacturing a drill is provided.