Adjustable Clutch Mechanism for Impact Tool Torque Control
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Solution Overview
Problem
Conventional pneumatic impact wrenches lack a flexible torque adjustment mechanism that allows for precise control of torque output, leading to inefficiencies in tightening or loosening fasteners, especially when high reaction torques are encountered.
Innovation Solution
The impact tool incorporates a clutch mechanism with adjustable torque settings, enabled by a spring-loaded washer and ball system, which diverts torque from the output shaft to an impact mechanism when a predetermined torque threshold is exceeded, allowing for incremental torque adjustments and mode selection between driver and drill modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional pneumatic impact wrenches are used, then the tool can provide striking rotational force, but the torque output cannot be precisely controlled
Solution Approach 1:
The clutch mechanism transitions from a static fixed-torque design to a dynamic adjustable-torque system. The spring-loaded clutch allows the torque threshold to be adjusted by changing spring preload, enabling the system to adapt to different torque requirements while maintaining precise control through the incremental engagement of multiple clutch plates.
Solution Approach 2:
The invention changes the torque parameter from a fixed value to an adjustable range. By modifying the spring preload force and the number of clutch plates engaged, the output torque can be precisely controlled within a specific range, directly addressing the need for torque control precision while maintaining operational flexibility.
2Force
If high reaction torques are encountered, then fastener tightening or loosening can be achieved, but damage may occur from excessive torque
Solution Approach 1:
The clutch mechanism provides inherent feedback control by engaging and disengaging based on the reaction torque encountered. When the reaction torque exceeds the spring preload threshold, the clutch plates incrementally engage to reduce output torque, automatically preventing damage without requiring external sensing or control systems.
Solution Approach 2:
The spring-loaded clutch mechanism provides beforehand cushioning by being pre-configured with a specific preload force that acts as a torque threshold. This pre-set mechanism cushions against excessive reaction torques before they can cause damage, and the incremental engagement of multiple clutch plates provides progressive torque reduction.
3Adaptability or versatility
If a valve meters air entering the air motor for torque control, then torque output can be adjusted, but the adjustment range is limited
Solution Approach 1:
The clutch mechanism is segmented into multiple independent clutch plates that can engage incrementally. This segmentation allows for discrete torque levels within a broad range, providing versatile torque adjustment without requiring a complex continuously variable valve mechanism. Each clutch plate represents a discrete torque threshold level.
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
This solution enables precise control over torque output, preventing damage from high reaction torques and allowing users to adjust torque settings as needed, enhancing the tool's efficiency and versatility in various applications.
Implementation Method 1
a spring-loaded washer and ball system, which diverts torque from the output shaft to an impact mechanism when a predetermined torque threshold is exceeded
Data Source
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AI summary
An impact tool includes a housing, a motor supported in the housing, an output shaft rotatably supported in the housing about a central axis, an impact mechanism coupled between the motor and the output shaft and operable to impart a striking rotational force to the output shaft, and a clutch mechanism coupled between the impact mechanism and the output shaft. The clutch mechanism is operable in a first mode, in which torque from the motor is transferred to the output shaft through the impact mechanism, and a second mode, in which torque from the motor is diverted from the output shaft toward a portion of the impact mechanism.