Thread Cutting Drill Tool With Finishing Edges for Smoother Internal Threads
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Solution Overview
Problem
Prior art thread cutting taps often result in insufficient surface finish of internal threads, leading to potential cracks under dynamic forces due to rough surfaces.
Innovation Solution
A thread cutting drill tool with a cutting section featuring axially extending chip flutes, lands, and teeth, where crest cutting edges cut radially inward to form thread grooves, and front and rear finishing edges smooth the thread flanks, improving surface finish by following behind the crest cutting edges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional thread cutting taps with interrupted helical threads are used, then the thread cutting process can be performed, but the surface finish of the thread flanks is rough and insufficient
Solution Approach 1:
The cutting tool is segmented into multiple distinct cutting edges along the helical path, including both crest cutting edges and finishing edges. This segmentation allows different portions of the tool to perform different functions: crest cutting edges for material removal and finishing edges for surface smoothing, thereby resolving the contradiction between cutting capability and surface finish quality
Solution Approach 2:
The finishing edges are positioned to follow behind the crest cutting edges in the cutting sequence. This preliminary action arrangement ensures that the finishing edges smooth the thread flanks immediately after the crest cutting edges have removed material, preventing rough surface formation before the thread is fully cut, thus eliminating the harmful effect of rough surfaces
2Manufacturing precision
If multiple cutting edges are added to smooth thread flanks, then surface finish is improved, but the device complexity increases
Solution Approach 1:
Multiple cutting edges (crest cutting edges and finishing edges) are merged into a single integrated thread cutting tool body, forming a unified helical structure. This merging allows the tool to perform both rough cutting and finishing operations in one pass, improving surface finish without requiring multiple separate tools or complex multi-stage processes
Solution Approach 2:
The thread cutting tool is designed with multi-functionality by incorporating both crest cutting edges for material removal and finishing edges for surface smoothing along the same helical path. This universal design enables the single tool to accomplish multiple functions (cutting and finishing) that would otherwise require separate tools, thereby improving surface finish while maintaining relatively simple device structure
Data Source
AI summary
A thread cutting drill tool for metal cutting includes a cutting section having an axially extending chip flute and land, and a plurality of axially spaced teeth. Each tooth has an axially forward facing front flank and an axially rearward facing rear flank, a radially outward facing crest connecting the front flank and the rear flank, and a cutting edge. The cutting edge includes a set of crest cutting edges, each crest cutting edge being formed by an intersection of the crest of one tooth with the chip flute. The cutting edges include a set of front finishing edges and a set of rear finishing edges. Each front finishing edge is formed by an intersection of the front flank of one tooth with the chip flute. Each rear finishing edge is formed by an intersection of the rear flank of a tooth with the chip flute.