Spiral Step Twist Drill Bit With Segmented Cutting Edges
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Solution Overview
Problem
Conventional step twist drill bits with parallel steps suffer from machining overlap, reduced cutting efficiency, and chip retention, leading to decreased drilling precision and increased power consumption.
Innovation Solution
A spiral step twist drill bit with a spiral flute and cutting groove that divides the cutting edge into segments, featuring a varying pitch and spiral chip removal groove for enhanced chip discharge, reducing machining overlap and improving cutting speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If parallel steps are used on the drill bit, then positioning during layered drilling is facilitated, but machining overlap occurs and cutting efficiency is reduced
Solution Approach 1:
The patent applies spiral curvature to the step surfaces, transforming the conventional parallel straight steps into spiral-shaped steps that follow the drill bit's rotation. This curved design eliminates machining overlap by ensuring each step engages the workpiece at a different angular position during rotation, thereby maintaining cutting efficiency while preserving positioning capability.
2Ease of manufacture
If step surfaces are made perpendicular to the drill bit axis, then manufacturing is simplified, but cutting chips are retained at the step surfaces
Solution Approach 1:
The step surfaces are designed with spiral curvature instead of being perpendicular to the drill bit axis. This curved configuration creates a downward slope along the spiral path that naturally guides cutting chips away from the step surfaces and toward the chip discharge direction, eliminating chip retention while maintaining manufacturability through standard spiral fluting processes.
3Device complexity
If conventional straight cutting edges are used, then the structure is simple, but machining overlap occurs and drilling precision is reduced
Solution Approach 1:
The cutting edges are transformed from straight lines to spiral curves that follow the drill bit's helical path. This curvature ensures that different portions of the cutting edge engage the workpiece sequentially during rotation rather than simultaneously, eliminating machining overlap and improving drilling precision while adding only minimal structural complexity.
4Device complexity
If parallel steps are used, then the design is straightforward, but power consumption increases due to overlapping processing
Solution Approach 1:
The spiral-shaped steps distribute the cutting action along the rotational path, preventing overlapping engagement of multiple step portions simultaneously. This reduces the total cutting resistance and heat generation, thereby lowering power consumption while maintaining design simplicity through the natural spiral geometry of the drill bit.
Data Source
AI summary
A spiral step twist drill bit, including a shank and a cutting portion. The cutting portion is provided with a spiral flute and a body clearance. A tip of the cutting portion is provided with a chisel edge and a cutting edge. A flank face is connected to the cutting edge, and is provided with a spiral cutting groove. A spiral direction of the spiral cutting groove is the same as that of the spiral flute. A slope of the spiral cutting groove is the same as that of the flank face. The spiral cutting groove is configured to divide the cutting edge into multiple segments to form multiple first edges and second edges.