Drill Flank Clearance Layout for Precise Stable Hole Machining
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Solution Overview
Problem
There is a need for enhanced precision in the drilling process to achieve accurate and stable machining of holes, as existing drills face challenges in reducing cutting resistance, preventing burr formation, and maintaining straight-line stability while controlling movement during the drilling process.
Innovation Solution
The drill design features a body with a cutting edge having three cutting edges and corresponding flank surfaces with distinct clearance angles, where the second clearance angle is smaller than the first and third, facilitating reduced cutting resistance, improved stability, and precise control during drilling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional drill designs with uniform clearance angles are used, then the structure is simple, but cutting resistance is high and machining precision is poor
Solution Approach 1:
The patent applies local quality by assigning different clearance angles to different regions of the drill. Specifically, the first clearance angle (α1) is set to 5-15 degrees, the second clearance angle (α2) is set to 0-5 degrees, and the third clearance angle (α3) is set to 5-20 degrees. This localized differentiation optimizes cutting performance at each region: the larger first and third clearance angles reduce cutting resistance at the entry and exit points, while the smaller second clearance angle provides stability during the main cutting phase, thereby improving overall machining precision.
2Force
If larger clearance angles are used on all flank surfaces, then cutting resistance is reduced, but drill stability and straight-line drilling capability deteriorate
Solution Approach 1:
The patent implements local quality by strategically assigning different clearance angles to different flank surfaces. The second clearance angle (α2 = 0-5 degrees) is deliberately kept small to maintain drill stability and straight-line drilling capability during the primary cutting phase. Meanwhile, the first (α1 = 5-15 degrees) and third (α3 = 5-20 degrees) clearance angles are enlarged to reduce cutting resistance at the entry and exit phases, respectively. This localized optimization resolves the contradiction between reducing cutting resistance and maintaining drill stability.
3Object-generated harmful factors
If conventional single clearance angle design is used, then manufacturing is simple, but burr formation cannot be effectively controlled
Solution Approach 1:
The patent addresses burr formation through local quality by optimizing clearance angles at different locations. The third clearance angle (α3 = 5-20 degrees) is specifically enlarged at the exit region to minimize burr formation as the drill exits the workpiece. The first clearance angle (α1 = 5-15 degrees) is optimized to prevent burr formation at the entry point. This localized differentiation of clearance angles effectively controls burr formation throughout the drilling process without requiring complex overall geometry.
4Manufacturing precision
If the drill design focuses on precision, then machining accuracy improves, but control of drill movement during drilling becomes more difficult
Solution Approach 1:
The patent resolves the contradiction between precision and ease of operation through local quality optimization. The second clearance angle (α2 = 0-5 degrees) is specifically designed to be small to enhance drill stability and ease of movement control during the main cutting phase. Simultaneously, the first (α1 = 5-15 degrees) and third (α3 = 5-20 degrees) clearance angles are optimized to improve hole precision at the entry and exit phases. This localized differentiation allows the drill to be both precise and easy to control.
Data Source
AI summary
A drill has a body extended along a rotation axis from a first end toward a second end. The body has an outer peripheral surface, a cutting edge, a flank surface, and a flute. The cutting edge has a first cutting edge, a second cutting edge extended from the first cutting edge, and a third cutting edge extended from the second cutting edge. The flank surface has a first flank surface which is located along the first cutting edge and has a first clearance angle, a second flank surface which is located along the second cutting edge and has a second clearance angle, and a third flank surface which is located along the third cutting edge and has a third clearance angle. The second clearance angle is smaller than each of the first clearance angle and the third clearance angle.