Torque Wrench Strain Gauge Layout for Variable Force Locations
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional torque wrenches suffer from inaccurate torque measurements due to the variable location of force application on the handle, which affects the strain gauge readings, making it difficult to ensure precise tightening of fasteners.
Innovation Solution
A torque wrench design incorporating two strain gauges positioned symmetrically on the deflection member, aligned with equivalent distancing ratios, allows for accurate torque measurement regardless of the force application location on the handle.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single strain gauge is used in conventional torque wrenches, then the device structure is simple, but the measurement accuracy deteriorates when the force application location varies on the handle
Solution Approach 1:
The deflection member is segmented into multiple regions with strain gauges positioned at different locations. The first strain gauge is positioned between the drive head and the first loading point, while the second strain gauge is positioned between the first and second loading points. This segmentation allows independent measurement of strain at different locations, enabling accurate torque measurement regardless of where force is applied on the handle.
Solution Approach 2:
Multiple strain gauge measurements are merged through processing circuitry that combines the output signals from both strain gauges. The processing circuitry integrates the strain measurements from different locations to calculate the total torque applied, merging the partial measurements into a complete and accurate torque reading that compensates for variable force application positions.
2Ease of operation
If the force application location on the handle is fixed, then the torque measurement is accurate, but the ease of operation deteriorates as the user cannot apply force at different positions
Solution Approach 1:
The torque wrench is designed with universal measurement capability that works regardless of where the user applies force on the handle. The multiple strain gauges and processing circuitry create a system that can accurately measure torque whether the force is applied at the first loading point, second loading point, or anywhere in between, making the device universally applicable for different user preferences and force application locations.
Solution Approach 2:
The system dynamically adapts to the user's force application location. The processing circuitry processes signals from both strain gauges in real-time and calculates torque based on the actual strain distribution caused by the user's specific force application point. This dynamic processing allows accurate measurement regardless of the static position where the user chooses to apply force.
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 torque wrench provides precise torque measurements even when the force is applied at different positions, ensuring consistent accuracy and enabling correct fastener tightening.
Implementation Method 1
a strain gauge assembly coupled to the deflection member. The strain gauge assembly may be configured to measure strain on the deflection member as an indication of a torque being applied to the fastener by the torque wrench
Data Source
AI summary
An example torque wrench is provided. The example torque wrench may include a drive head configured to engage with a tool for rotating a fastener. The drive head may have a drive axis about which the drive head rotates when rotating the fastener. The torque wrench may also include a deflection member coupled to the drive head and an outer body coupled to the deflection member at a first loading point and a second loading point. The torque wrench may also include a first strain gauge coupled to the deflection member between the drive head and the first loading point, and a second strain gauge coupled to the deflection member between the first loading point and the second loading point.