Power Tool Inadvertent Rotation Detection via Holding Force
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Solution Overview
Problem
Existing power tools lack accuracy in detecting and preventing inadvertent rotation due to excessive reaction torque, which can lead to uncontrollable situations during operations like hammer drilling.
Innovation Solution
A hand-held power tool equipped with a first sensor for kinetic movement state detection and a second sensor for output torque measurement, along with a controller that calculates holding force and controls torque transmission using an electromagnetic clutch to prevent inadvertent rotation by interrupting torque transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If torque transmission interruption is used to prevent inadvertent rotation, then safety is improved, but detection accuracy remains insufficient
Solution Approach 1:
The patent combines multiple sensors (acceleration sensor, angular velocity sensor, torque sensor) to detect different aspects of tool rotation and integrates their signals through a controller. This merging of multiple detection methods enables accurate calculation of holding force by combining kinetic movement data with torque data, resolving the contradiction between safety intervention and detection accuracy.
Solution Approach 2:
The system continuously monitors tool rotation through sensors and provides feedback to the controller, which calculates holding force in real-time. When the holding force falls below a threshold indicating inadvertent rotation, the controller interrupts torque transmission. This closed-loop feedback mechanism ensures both accurate detection and timely safety intervention.
2Measurement precision
If multiple sensors are used to improve detection accuracy, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The controller serves multiple functions: it processes signals from multiple sensors, calculates holding force by integrating acceleration and torque data, determines when inadvertent rotation occurs, and controls torque transmission interruption. This multi-functionality reduces the need for separate dedicated components for each function, managing system complexity while maintaining high detection accuracy.
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 accurately detects and prevents inadvertent rotation by integrating angular acceleration and output torque data to determine holding force, enabling precise control of torque transmission and preventing tool body rotation.
Implementation Method 1
controlling driving of the power tool preferably includes aspects of stopping driving of the motor, applying a brake, and the like
Data Source
AI summary
A power tool enabled to detect an inadvertent rotation at higher accuracy includes a first sensor that detects a first driving information corresponding to a kinetic movement state of the tool body when the tool body is rotated around a longitudinal axis of the tool bit in the event of a working operation of the power tool, a second sensor that detects a second driving information corresponding to an output torque of the tool bit driven by the motor, and a controller connected to the first sensor and the second sensor for controlling the power tool. The controller is configured to calculate holding information corresponding to a holding force of a user to hold the tool body based on the first driving information and the second driving information and control the driving of the power tool based on the holding information.