Twist Drill Cone Structure for Precise Low-Force Drilling
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Solution Overview
Problem
Conventional twist drills are difficult to position and operate efficiently, requiring high power and resulting in damaged cutting edges due to large reaction forces and low drilling speed.
Innovation Solution
A twist drill design featuring a shank portion with a cone and cylinder portion, equipped with a spiral flute and composite cutting blade groups of increasing diameters, where the cutting tips are distributed on spiral lines, dispersing cutting force and reducing reaction forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional twist drill with two symmetric linear cutting edges is used, then drilling function is provided, but large power is required and reaction forces damage cutting edges
Solution Approach 1:
The single cutting edge is segmented into multiple cutting edges (first cutting edge, second cutting edge, third cutting edge) with different orientations and functions. The first cutting edge performs primary cutting, the second cutting edge performs secondary cutting, and the third cutting edge performs finishing cutting, distributing the cutting load across multiple edges rather than concentrating it on one edge, thereby reducing reaction forces and improving cutting edge durability
Solution Approach 2:
The cutting edges are designed with asymmetric characteristics - the first cutting edge has a specific inclination angle for primary cutting, the second cutting edge has a different orientation for secondary cutting, and the third cutting edge has yet another configuration for finishing. This asymmetric design allows each cutting edge to be optimized for its specific function, improving overall cutting efficiency while distributing mechanical stresses more effectively
2Productivity
If conventional twist drill is used, then drilling operation is performed, but drilling speed and efficiency are low
Solution Approach 1:
The drilling process is segmented into three distinct stages performed by three different cutting edges, allowing each stage to be optimized for its specific function. This segmentation enables more efficient material removal compared to a single cutting edge design, as each cutting edge can be optimized for its particular cutting task, thereby improving overall drilling speed and efficiency
Solution Approach 2:
The first cutting edge performs preliminary cutting to create initial material removal and shape the hole, preparing the workpiece for subsequent cutting stages. This preliminary action reduces the workload for the second and third cutting edges, enabling faster overall drilling progression and improving drilling efficiency
3Measurement precision
If conventional twist drill is used, then cutting is performed, but drill hole positioning is difficult
Solution Approach 1:
The multi-stage cutting process with three distinct cutting edges provides progressive hole formation, where each cutting edge contributes to precise hole positioning through its specific cutting action. The first cutting edge establishes initial hole position, the second refines it, and the third completes the positioning, thereby improving drill hole positioning accuracy while maintaining ease of operation
Data Source
AI summary
The present invention provides a twist drill. A cone portion is provided at a front end of the operating portion, and an exterior surface of the operating portion is provided with a spiral flute for shunting cutting chips. The exterior surface of the cone portion is provided with a plurality of composite cutting blade groups which are sequentially enlarged in diameter from the front end to the rear end of the cone portion. The cone portion is provided with a top blade on the tip. In use, the top blade is used for positioning, and the cutting process is carried out by the top blade and the composite cutting blade groups.