Electromagnetic Fastener Driver With Pulse-Shaped Coil Current
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing setting tools for driving fastening elements into substrates lack efficiency and setting quality, particularly in ensuring effective transfer of fastening elements with optimal energy delivery and control.
Innovation Solution
A setting tool with a holder, a drive-in element, and a drive that includes an electrical capacitor and a squirrel-cage rotor with an excitation coil, where the current intensity through the coil has a specific time profile and density to generate a magnetic field accelerating the drive-in element, optimizing the transfer of fastening elements into substrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional drive system is used, then the device complexity is reduced, but the productivity and setting quality deteriorate
Solution Approach 1:
The patent replaces conventional mechanical drive systems with an electromagnetic drive system comprising a capacitor, excitation coil, and squirrel-cage rotor. This substitution enables precise control of the drive-in element through electromagnetic fields, significantly improving setting efficiency and quality while accepting increased device complexity as a trade-off for superior performance
2Speed
If the current rise time is too short, then the power delivery is faster, but the setting quality deteriorates due to insufficient energy transfer
Solution Approach 1:
The patent optimizes the current rise time parameter to a specific range (0.020-0.275 ms) to balance fast power delivery with sufficient energy transfer. This parameter optimization ensures that the electromagnetic pulse delivers energy efficiently while maintaining control over the drive-in element's motion, achieving both speed and setting quality
3Force
If the current intensity is increased, then the driving force is improved, but the energy loss and thermal effects worsen
Solution Approach 1:
The patent employs periodic pulsed current delivery through the excitation coil, where current flows in controlled bursts rather than continuously. This periodic action generates the necessary Lorentz force for driving the fastening element while minimizing thermal accumulation and energy loss, as the system has time to dissipate heat between pulses
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The tool ensures high efficiency and good setting quality by precisely controlling the energy transfer, allowing for efficient driving of fastening elements into substrates with adjustable parameters for optimal performance.
Implementation Method 1
an excitation coil, which during discharge of the capacitor is flowed through by current and generates a magnetic field that accelerates the drive-in element toward the fastening element
Implementation Method 2
generates a magnetic field that accelerates the drive-in element toward the fastening element
Data Source
AI summary
A tool comprising a drive-in element, transferring a fastening element into a substrate along setting axis by a setting energy Ekin, a drive for driving the drive-in element along the setting axis, the drive comprising a capacitor, a rotor, and a coil, wherein current flows through the coil generating a magnetic field accelerating the drive-in element toward the fastening element, wherein a current intensity Acoil of current flowing through the excitation coil while discharging the capacitor has a time profile with a rising edge, a maximum current intensity Amax and a falling edge, Acoil rising during current rise time Δtrise from 0.1 to 0.8 times Amax and during impact time Δtimpact is more than 0.5 times the Amax, wherein Δtrise is at least 0.020 ms and at most 0.275 ms and/or the impact time Δtimpact is at least 0.15 ms and at most 2.0 ms.