Drill Bit Helical Thread Profile for Bending Strength
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Solution Overview
Problem
Conventional drill bits are prone to damage from encountering obstructions like nail remnants or metal particles and suffer from bending loads due to their thin, sharp threads, leading to tip breakage and thread wear.
Innovation Solution
A drill bit design featuring a continuous helical thread with a tapered profile, thicker crest, and rounded root to enhance bending strength and resistance to wear, along with a thread pitch of 12-14 tpi and varying thread depth and angle based on tip length, optimizing load dissipation and material removal efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the drill bit uses a thin, sharp thread configuration to grip substrate, then material removal efficiency is improved, but the drill bit becomes highly susceptible to damage from obstructions and bending loads
Solution Approach 1:
The patent changes the geometric parameters of the thread, specifically increasing the thread thickness and modifying the thread profile from a conventional sharp thin thread to a thicker, more robust configuration. This parameter change allows the thread to maintain gripping capability while significantly improving resistance to damage from obstructions like nail remnants and metal particles.
2Productivity
If the drill bit uses a thin, sharp thread configuration, then initial drilling performance is improved, but the drill bit experiences tip breakage, thread wear, and tip bending under bending loads
Solution Approach 1:
The patent modifies the thread geometry parameters including increasing thread thickness and adjusting the thread profile to create a stronger structural configuration that can withstand bending loads without tip breakage, thread wear, or tip bending while maintaining drilling performance.
Solution Approach 2:
The patent applies a coating layer on the thread surface, creating a composite structure that combines the base thread material with a protective coating. This composite approach enhances the overall strength and durability of the thread, allowing it to resist bending loads and wear while maintaining its cutting performance.
3Ease of operation
If the drill bit thread has a thin cross section to allow larger gaps between threads, then substrate gripping is improved, but the thread becomes susceptible to damage and wear
Solution Approach 1:
The patent changes the thread cross-sectional parameters by increasing thread thickness and modifying the thread profile shape. This allows the thread to maintain adequate gaps for substrate gripping while having sufficient thickness to resist damage and wear, resolving the contradiction between gripping effectiveness and thread durability.
Data Source
Figure 1~3
Figure 4(a)~5(e)
AI summary
A drill bit for a boring tool comprises a shank configured for engagement with the boring tool and a working tip having a first end attached to the shank and an opposite second end, and a conical helical thread extending substantially continuously from end to end. The thread root may include a rounded portion while the crest may be flat. The configuration of the helical thread, such as the crest width, thread depth, thread angle, cross sectional area and base width are adjusted as a function of the length of the threaded working tip to maximize bending strength and optimize thread wear and operability.