Impact Wrench Reverse-Speed Control for Stuck Fastener Removal
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Solution Overview
Problem
Impact wrenches struggle to loosen rusted or deformed fasteners due to their inability to adjust torque and speed effectively in reverse rotation mode, leading to inefficient disassembly.
Innovation Solution
An impact tool with a controller that adjusts the motor's speed and torque based on load parameters, switching between normal and extreme speed modes to accommodate tightened or loosened states, using a detection mechanism to determine the fastener's state and adjust the duty cycle accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a relatively large duty cycle is set for reverse rotation mode, then the motor starts at full speed, but the impact tool cannot remove rusted or deformed fasteners
Solution Approach 1:
The patent applies dynamics by making the motor speed adjustable during operation. The controller dynamically changes the motor speed from a first speed to a second speed (higher than the first) based on real-time detection of fastener state through load parameters, enabling the system to adapt to varying resistance conditions during fastener removal
Solution Approach 2:
The patent changes the motor operating parameters (speed and duty cycle) based on detected load conditions. When the fastener is detected to be in a tightened state through load parameter analysis, the controller adjusts the duty cycle and increases motor speed to provide higher torque for breaking rusted or deformed fastener connections
2Productivity
If the motor rotates at higher speed, then the disassembly efficiency improves, but the torque output may be insufficient for tightened fasteners
Solution Approach 1:
The system dynamically adjusts motor speed based on real-time feedback from load parameter detection. The controller monitors load parameters to determine fastener state, then dynamically switches between first speed (for initial engagement) and second speed (for breaking tightened connections), optimizing both torque delivery and disassembly efficiency
Solution Approach 2:
The patent implements feedback control by detecting load parameters (such as current, voltage, or mechanical load) during motor operation and using this information to determine fastener state. This feedback loop enables the controller to adjust motor speed and torque output appropriately, ensuring sufficient force is applied to tightened fasteners while maintaining high productivity
Data Source
AI summary
An impact tool includes a controller for controlling a motor. The controller is configured to, when the direction of rotation of the motor is set to the reverse rotation direction, a drive shaft rotates at a first speed, and after an impact mechanism applies an impact force to an output shaft for a preset time, determine that a fastener is in a tightened state according to a load parameter of the output shaft and control the drive shaft to rotate at a second speed, where the second speed is greater than the first speed.