Electric Fastener Driver Control for High Striking Frequency
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Solution Overview
Problem
Conventional electric nail guns have a maximum striking frequency inferior to pneumatic nail guns, leading to a suboptimal user experience.
Innovation Solution
A fastener driver incorporating a battery pack, striking assembly, drive assembly, electric motor, and control circuit, with a controller that controls the electric motor to achieve a striking frequency greater than 6 fasteners/second, utilizing field weakening control and precise shutdown mechanisms to optimize striking performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If an electric motor is used to drive the striking member, then the device can operate electrically without pneumatic systems, but the striking frequency is limited and inferior to pneumatic nail guns
Solution Approach 1:
The patent implements dynamic control of the electric motor through field weakening control methodology, allowing the motor to operate beyond its base speed and achieve higher rotational speeds. The controller dynamically adjusts motor parameters to optimize striking frequency, enabling the electric nail gun to reach frequencies greater than 6 fasteners/second, thereby resolving the contradiction between electrical operation and high productivity.
2Productivity
If the electric motor operates at high rotational speed to increase striking frequency, then productivity improves, but control precision for shutdown positioning becomes more difficult
Solution Approach 1:
The patent employs feedback control mechanisms where the controller monitors motor rotation and implements precise shutdown control based on rotation count, rotational speed, or operating time parameters. This feedback system ensures that even at high speeds exceeding 6 fasteners/second, the striking assembly stops substantially at the top dead point, maintaining positioning accuracy while achieving high productivity.
Solution Approach 2:
The controller is configured to anticipate the shutdown point by monitoring motor parameters such as rotation count and rotational speed, allowing the motor to be stopped in advance at the precise top dead point position. This preliminary control action ensures accurate positioning is achieved before the striking cycle completes, resolving the contradiction between high speed operation and positioning precision.
3Productivity
If the conduction angle of stator windings is increased to improve motor performance, then striking frequency increases, but motor control complexity increases
Solution Approach 1:
The patent utilizes parameter changes in the motor control system, specifically adjusting the conduction angle of stator windings to be greater than 120° and less than 180° to optimize motor performance and achieve higher striking frequencies. The controller implements field weakening control by dynamically adjusting electrical parameters, enabling the system to reach frequencies greater than 6 fasteners/second while managing control complexity through systematic parameter optimization.
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 solution enhances the striking frequency to exceed 6 fasteners/second, providing improved user experience and efficiency.
Implementation Method 1
an electric motor configured to drive the drive wheel to rotate
Implementation Method 2
the controller is configured to adjust a conduction angle of stator windings during operation of the electric motor to be greater than 120° and less than 180°
Data Source
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AI summary
Provided is a fastener driver. The fastener driver includes a battery pack; a striking assembly including a striking member configured to strike a fastener; a drive assembly including at least a drive wheel configured to drive the striking member to move along a central axis of the striking member; an electric motor configured to drive the drive wheel to rotate; and a control circuit configured to control the electric motor to operate, start, or stop. A striking frequency of the striking member is greater than 6 fasteners/second.