Impact Wrench Controller Adjusts Rotary Impact Frequency for Anchor Expansion
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Solution Overview
Problem
The existing methods for setting expansion anchors rely on torque wrenches, which lack visibility into proper expansion, leading to insufficient or excessive expansion, affecting load-bearing capacity and anchor fatigue, as users cannot visually confirm the expansion anchor's proper setting.
Innovation Solution
An impact wrench with a reading device for entering the type or torque of expansion anchor, a percussion mechanism for repetitive rotary impacts, and a controller that adjusts the repetition rate based on the anchor type or torque, along with a sensor to detect the pull rod speed and deactivate the mechanism when the speed falls below a threshold, ensuring proper expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a torque wrench is used to set the expansion anchor, then the tightening torque can be controlled, but the user cannot visually confirm proper expansion leading to insufficient or excessive expansion
Solution Approach 1:
The system incorporates a sensor that detects the rotation angle of the pull rod and provides feedback to the control unit. The control unit monitors the expansion process in real-time and compares the detected rotation angle against predetermined threshold values to determine when proper expansion has been achieved, providing closed-loop feedback control for reliable expansion confirmation
Solution Approach 2:
The patent replaces the purely mechanical torque wrench system with an electromechanical system that includes electronic sensors, a control unit, and a display device. This substitution enables digital measurement and visualization of the expansion process, allowing users to visually confirm proper expansion through the display device while maintaining precise torque control
2Strength
If excessive tightening torque is applied, then the expansion anchor may be over-expanded, but this causes fatigue and reduces load-bearing capacity
Solution Approach 1:
The sensor continuously monitors the rotation angle of the pull rod during the tightening process and provides real-time feedback to the control unit. When the rotation angle reaches the predetermined threshold indicating proper expansion, the control unit automatically stops the tightening process, preventing excessive torque application and anchor fatigue while ensuring adequate load-bearing capacity
Solution Approach 2:
The system uses a predetermined rotation angle threshold that corresponds to the optimal expansion point. By stopping the tightening process at this partial completion point (rather than continuing until mechanical resistance increases), the system achieves sufficient expansion for load-bearing capacity while avoiding the excessive action that would cause anchor fatigue
3Reliability
If insufficient tightening torque is applied, then the expansion anchor may not be properly expanded, but this also reduces load-bearing capacity
Solution Approach 1:
The sensor and control unit provide real-time monitoring and feedback during the tightening process. The display device shows the current rotation angle, allowing users to visually confirm that the expansion has reached the predetermined threshold for proper setting, ensuring adequate load-bearing capacity is achieved
4Ease of operation
If a traditional torque wrench is used, then the operation is simple, but there is no visual confirmation or automation of the expansion process
Solution Approach 1:
The system incorporates automatic control features where the control unit monitors the sensor data and automatically determines when proper expansion has been achieved. The display device automatically shows the expansion status, and the system can automatically stop the tightening process when the threshold is reached, reducing the need for manual judgment while maintaining ease of operation
Solution Approach 2:
The impact wrench is designed to perform multiple functions: it provides the mechanical tightening action, incorporates sensor detection, processes data through the control unit, displays expansion status, and automatically controls the tightening process. This multi-functionality integrates both ease of operation and automation, allowing the single device to handle both simple operation and sophisticated expansion control
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 ensures accurate expansion of the anchor by controlling the rotary impacts' frequency and torque, preventing under or over-expansion, thus enhancing the load-bearing capacity and reducing anchor fatigue.
Implementation Method 1
A percussion mechanism (21) of the impact wrench (20) is used to generate repetitive rotary impacts
Implementation Method 2
A sensor is used to detect a speed of the pull rod (2)
Data Source
Figure 1~2
Figure 3
AI summary
The method involves adjusting a repetition rate (Nsoll) of rotary percussions depending on starting torques predetermined for expansion of an expansion sleeve of an expansion anchor. Exertions of the rotary percussions on a draw bar of the expansion anchor are adjusted (107) by an impact screwdriver when detected center speed of the draw bar exceeds a threshold value. A repetition rate is adjusted responding to an input of a type of the expansion anchor or starting torques by the screwdriver. Duration for setting the expansion anchor is detected by the screwdriver. The impact screwdriver has a reading unit for a radio frequency identification chip. The type of the expansion anchor is indicated by LEDs. An independent claim is also included for an impact screwdriver for setting an expansion anchor.