Multi-Thread Fastener Structure for Chip Removal and Quick Screwing
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Solution Overview
Problem
Conventional screws face challenges with increased drilling resistance due to entanglement with uncut fibers and debris accumulation, leading to decreased drilling speed and potential workpiece cracking.
Innovation Solution
A fastener design featuring a shank unit with a drilling portion and a thread unit comprising a first thread on the shank portion and second and third threads on the drilling portion, where the third thread is connected to the first thread, allowing for efficient chip removal and reduced drilling resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional single-threaded screws are used, then the structure is simple, but drilling resistance increases and drilling speed decreases due to debris accumulation
Solution Approach 1:
The screw thread is segmented into multiple independent thread paths (first thread, second thread, third thread) with different spiral arrangements. Each thread independently cuts and removes chips, preventing debris accumulation and reducing drilling resistance, thereby maintaining high drilling speed without excessive complexity
Solution Approach 2:
The invention introduces multiple thread paths winding in different directions and angles around the shank, adding dimensional complexity to the thread structure. This multi-dimensional approach creates multiple chip ejection paths and reduces interference between threads, improving chip removal efficiency while keeping the overall structure manageable
2Strength
If threads are closely arranged to increase engagement, then fastening strength improves, but chip removal becomes difficult and workpiece cracking occurs
Solution Approach 1:
The thread structure is divided into multiple separate thread paths that do not interfere with each other. The different spiral arrangements create spaced chip ejection channels, allowing chips to be effectively removed without compromising thread engagement density, thus preventing workpiece cracking while maintaining fastening strength
Solution Approach 2:
Different thread paths have different local characteristics (spiral directions, pitch, depth) optimized for specific functions: some threads are optimized for cutting and engagement, while others are optimized for chip ejection. This local differentiation allows simultaneous achievement of strong fastening and effective chip removal
3Productivity
If thread spiral angle is increased to improve cutting ability, then drilling speed increases, but drilling resistance also increases due to entanglement
Solution Approach 1:
Multiple thread paths with different spiral angles are implemented, allowing each thread to operate at its optimal cutting angle. The segmentation prevents fiber entanglement by distributing cutting forces across multiple independent paths, maintaining high drilling speed while reducing overall drilling resistance
Solution Approach 2:
The thread paths employ asymmetric spiral arrangements with different angles and directions. This asymmetry optimizes the cutting action of each thread while creating natural chip ejection paths, reducing the force required for drilling while maintaining high drilling speed
Data Source
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AI summary
A fastener (3) includes a head (31), a shank unit (32) having a shank portion (322) and a drilling portion (321) with a tip (T), and a thread unit (33). The thread unit (33) includes a first thread (331) spirally disposed on the shank portion (322) and includes a second thread (332) and a third thread (333) spiraling on the drilling portion (321) respectively. The third thread (333) is located between the first thread (331) and the second thread (332) . A first end (3331) of the third thread (333) is connected to the first thread (331) . A second end (3332) of the third thread (333) can be connected to the tip (T). The second thread (332) and the third thread (333) cooperate to increase the cutting ability and efficiency, thereby reducing drilling resistance and attaining a quick screwing effect. The third thread (333) connected to the first thread (331) facilitates the removal of chips caused by cutting a workpiece (5), thereby preventing the workpiece (5) from cracking and attaining an anti-loosening effect.