Power Tool Torque Dial With Magnetic Sensing Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power tools, such as driver-drills and hammer driver-drills, have a limited torque setting range and require manual adjustment of a change ring, which is cumbersome and often requires grasping a hot part of the tool, making it difficult to set the desired torque accurately.
Innovation Solution
A power tool design featuring a rotatable dial with permanent magnets and a magnetic field sensor that allows for easy adjustment of the torque setting by rotating the dial, enabling precise control of the motor's torque threshold without the need for manual manipulation of a change ring, thereby simplifying the process and improving ergonomics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a change ring is manually rotated to adjust the coil spring length, then the torque can be adjusted, but the torque setting range is narrow and the operation is cumbersome
Solution Approach 1:
The patent replaces the mechanical coil spring adjustment system with an electrical control system. A dial with magnetic field sensors detects rotational position, and a controller electronically adjusts the motor's output torque threshold, eliminating the need for manual spring compression and providing both ease of operation and wide torque setting range.
Solution Approach 2:
The patent changes the physical parameter adjustment method to an electrical parameter control method. Instead of mechanically changing spring length to adjust torque, the system uses a dial to change electrical signals that control the motor's output torque, enabling continuous and wide-range torque adjustment with simple rotation.
2Ease of operation
If the change ring is positioned adjacent to the drill chuck, then the torque can be adjusted, but the user must grasp a hot part with the other hand making adjustment difficult
Solution Approach 1:
The patent relocates the torque adjustment dial from the front end (near the hot drill chuck) to the rear end of the housing, utilizing the unused rear space. This spatial repositioning allows users to adjust torque with one hand while holding the grip with the other, completely avoiding the hot surface problem.
Solution Approach 2:
The patent extracts the torque adjustment function from its traditional location near the drill chuck and places it in a separate, thermally independent location at the rear of the housing. This separation removes the thermal interference that previously made adjustment difficult.
3Reliability
If a mechanical clutch system is used to terminate screwdriving, then the torque limit can be achieved, but the device complexity increases and durability decreases
Solution Approach 1:
The patent replaces the mechanical clutch system with an electrical control system. The controller monitors motor current and compares it to a threshold value, cutting power to the motor when the threshold is exceeded, thereby achieving torque-limited screwdriving without any mechanical clutch components.
Solution Approach 2:
The patent implements a self-regulating system where the controller automatically monitors motor performance and adjusts power delivery based on real-time conditions. The system self-terminates screwdriving when the torque threshold is reached, eliminating the need for separate clutch mechanisms.
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 provides a wider torque setting range with finer adjustments, reduces the effort required to set torque values, and allows for one-handed operation, enhancing user convenience and safety by eliminating the need to handle hot parts during adjustments.
Implementation Method 1
the dial comprises a magnet or magnets. In this case, a magnetic field sensor that detects the magnetic field(s) generated by the magnet(s) is provided
Data Source
AI summary
A power tool, such as a hammer driver-drill (1), includes: a motor (8); a motor housing (7A) that holds the motor (8); a grip housing (7B) connected to the motor housing (7A); a battery mount housing or enlarged-part housing (7C) connected to the grip housing (7B); and a dial (24) that is provided in the enlarged-part housing (7C) such that it is rotatable about a dial shaft (29). A threshold for stopping the motor (8) is settable by rotating the dial (24).