Impact Tool Control Mode for Adjustable Impact Transition Torque
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing impact tools transition from rotary mode to impact mode at a fixed, predetermined torque threshold, which can lead to inadvertent damage to fasteners or workpieces during certain operations.
Innovation Solution
Implementing a controller that allows the impact tool to transition from rotary mode to impact mode at a user-selectable, higher torque threshold by controlling power delivery to the motor, using a series of intermediate power limits and time intervals to manage inertia and prevent premature transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the impact mechanism transitions from rotary mode to impact mode at the normal transition torque, then the tool can deliver high torque quickly, but this may cause inadvertent damage to fasteners or workpieces
Solution Approach 1:
The controller dynamically adjusts the power delivery parameters (current, voltage, duty cycle) to the motor based on the selected operating mode. In control mode, the controller modifies these parameters to delay the transition torque threshold, thereby changing the operational characteristics of the impact mechanism to prevent damage while still allowing high torque delivery when needed.
Solution Approach 2:
The system transitions from a static, fixed transition torque mechanism to a dynamic, controllable transition torque system. The controller continuously monitors operating conditions and dynamically adjusts the power delivery to the motor, enabling the transition torque to vary based on the selected mode (normal vs. control mode), thus adapting to different operational requirements.
2Object-affected harmful factors
If the controller limits power delivery to delay transition to impact mode, then damage to fasteners is reduced, but the tool response time and productivity decrease
Solution Approach 1:
The controller dynamically adjusts power delivery parameters based on the selected operating mode. In control mode, it temporarily limits power to delay transition and prevent damage, but can quickly switch to normal mode for rapid torque delivery when appropriate, thus dynamically optimizing both protection and response time based on real-time operational needs.
Solution Approach 2:
The controller implements periodic monitoring of operating parameters (current, speed, torque) and periodically adjusts power delivery limits. This allows the system to maintain protective control when needed while enabling rapid transitions to full power when the operational context changes, creating a rhythmic pattern of control that balances protection and productivity.
3Ease of operation
If the impact mechanism uses a higher transition torque threshold, then control over the tool operation is improved, but the mechanical design complexity increases
Solution Approach 1:
The patent replaces a purely mechanical torque-threshold transition system with an electronically controlled system. Instead of relying on mechanical characteristics of the impact mechanism components alone to determine transition torque, the system uses a controller that electronically manages power delivery to the motor, thereby achieving higher and adjustable transition torque thresholds through electronic control rather than mechanical design modifications.
Solution Approach 2:
The controller changes the electrical parameters (current, voltage, duty cycle) delivered to the motor to achieve the desired higher transition torque threshold. By manipulating these electrical parameters, the system achieves improved operational control and delayed impact mode transition without requiring complex mechanical modifications to the impact mechanism itself.
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
Enables controlled operation at higher torques, reducing the risk of damage to fasteners or workpieces and providing users with greater control over tool operation.
Implementation Method 1
an anvil coupled to the output shaft, and a spring that biases the hammer toward the spindle
Implementation Method 2
A controller is configured to control power being delivered to the motor
Data Source
AI summary
An impact tool includes a controller configured to control power being delivered to the and operable in one of: (a) a normal mode where the controller allows power to be delivered to the motor so that the impact mechanism transitions from operation in the rotary mode to operation in the impacting mode when an output torque exceeds a normal transition torque; and (b) a control mode where the controller controls power being delivered to the motor so that the impact mechanism transitions from operation in the rotary mode to operation in the impacting mode when an output torque exceeds a control transition torque that is greater than the normal transition torque.